WorldWideScience

Sample records for n-substituted aryl compounds

  1. Palladium-Catalyzed Carbonylation of Aryl Bromides with N-Substituted Cyanamides

    DEFF Research Database (Denmark)

    Lian, Zhong; Friis, Stig D.

    2014-01-01

    The palladium(0)-catalyzed three-component coupling reaction of aryl bromides, carbon monoxide, and N-alkyl cyan­amides has been developed employing a two-chamber system with ex situ generation of carbon monoxide from a silacarboxylic acid. The reactions proceeded well and were complete with a reaction time of only five hours leading to the corresponding N-alkyl cyanamides in good yields. The methodology was further extended to 13C isotope labeling of the carbonyl group through the use of a 13CO produced from the corresponding 13C-labeled version of the sila­carboxylic acid.

  2. N-substituted derivatives of 5-(4-chlorophenyl)-1,3,4-oxadiazol-2-yl-2-sulfanyl acetamide as valuable bioactive compounds

    International Nuclear Information System (INIS)

    In the described research work, a new series of N-substituted derivatives of 5-(4-chlorophenyl)-1,3,4-Oxadiazol-2-yl-2-sulfanyl acetamide has been synthesized. The synthesis was carried out by converting 4-chlorobenzoic acid (1) into ethyl 4-chlorobenzoate (2), 4-chlorobenzohydrazide (3) and then 5-(4-chlorophenyl)-1,3,4-Oxadiazol-2-thiol (4) respectively. The target molecules 6a-o were synthesized by reacting compound 4 with different N-alkyl/aryl substituted 2-bromoacetamide (5a-o) in equimolar ratios of using DMF and sodium hydride (NaH). The structure of all the synthesized compounds was confirmed by spectral data like EI-MS, IR and 1H-NMR. The compounds were also analysed for antimicrobial and hemolytic activity and most of them were found active against the selected microbial species at variable extent relative to reference standards. But 6f and 6o were the active against the selected panel of microbes and former was most potent one. This series revealed less toxicity and may consider for further biological screening and application trial except 6g and 6j, exhibiting high cytotoxicity. (author)

  3. Historical and modern epidemiological studies on populations exposed to N-substituted aryl compounds.

    OpenAIRE

    Cartwright, R A

    1983-01-01

    The historical exposures to aromatic amines of various occupational groups are briefly reviewed. Modern studies indicate that other occupational groups might have risks worth investigating; these include machinists and workers in the chemical industry. Details of a recent investigation into the exposure of dye workers are given which indicate a lowered risk in recent years since the introduction of safety measures. Nonoccupational exposures to the aromatic amines are also discussed. They incl...

  4. Evaluation of N-substitution in 6,7-benzomorphan compounds.

    Science.gov (United States)

    Pasquinucci, Lorella; Prezzavento, Orazio; Marrazzo, Agostino; Amata, Emanuele; Ronsisvalle, Simone; Georgoussi, Zafiroula; Fourla, Danai-Dionysia; Scoto, Giovanna M; Parenti, Carmela; Aricò, Giuseppina; Ronsisvalle, Giuseppe

    2010-07-15

    6,7-benzomorphan derivatives, exhibiting different mu, delta, and kappa receptor selectivity profiles depending on the N-substituent, represent a useful skeleton for the synthesis of new and better analgesic agents. In this work, an aromatic ring and/or alkyl residues have been used with an N-propanamide or N-acetamide spacer for the synthesis of a new series of 5,9-dimethyl-2'-hydroxy-6,7-benzomorphan derivatives (12-22). Data obtained by competition binding assays showed that the mu opioid receptor seems to prefer an interaction with the 6,7-benzomorphan ligands having an N-substituent with a propanamide spacer and less hindered amide. Highly stringent features are required for delta receptor interaction, while an N-acetamide spacer and/or bulkier amide could preferentially lead to kappa receptor selectivity. In the propanamide series, compound 12 (named LP1) displayed high mu affinity (Ki=0.83 nM), good delta affinity (Ki=29 nM) and low affinity for the kappa receptor (Ki=110 nM), with a selectivity ratio delta/mu and kappa/mu of 35.1 and 132.5, respectively. Further, in the adenylyl cyclase assay, LP1 displayed a mu/delta agonist profile, with IC50 values of 4.8 and 12 nM at the mu and delta receptors, respectively. The antinociceptive potency of LP1 in the tail-flick test after sc administration in rat was comparable with the potency of morphine (ED50=2.03 and 2.7 mg/kg, respectively), and was totally reversed by naloxone. LP1, possessing a mu/delta agonist profile, could represent a lead in further developing benzomorphan-based ligands with potent in vivo analgesic activity and a reduced tendency to induce side effects. PMID:20599386

  5. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Science.gov (United States)

    2010-07-01

    ...Salt of a substituted sulfonated aryl azo compound (generic). 721.9597 Section...Salt of a substituted sulfonated aryl azo compound (generic). (a) Chemical substance...salt of a substituted sulfonated aryl azo compound (PMN P-00-0094) is subject...

  6. Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

    Directory of Open Access Journals (Sweden)

    Burkhard Koenig

    2011-01-01

    Full Text Available N-Arylated aliphatic and aromatic amines are important substituents in many biologically active compounds. In the last few years, transition-metal-mediated N-aryl bond formation has become a standard procedure for the introduction of amines into aromatic systems. While N-arylation of simple aromatic halides by simple amines works with many of the described methods in high yield, the reactions may require detailed optimization if applied to the synthesis of complex molecules with additional functional groups, such as natural products or drugs. We discuss and compare in this review the three main N-arylation methods in their application to the synthesis of biologically active compounds: Palladium-catalysed Buchwald–Hartwig-type reactions, copper-mediated Ullmann-type and Chan–Lam-type N-arylation reactions. The discussed examples show that palladium-catalysed reactions are favoured for large-scale applications and tolerate sterically demanding substituents on the coupling partners better than Chan–Lam reactions. Chan–Lam N-arylations are particularly mild and do not require additional ligands, which facilitates the work-up. However, reaction times can be very long. Ullmann- and Buchwald–Hartwig-type methods have been used in intramolecular reactions, giving access to complex ring structures. All three N-arylation methods have specific advantages and disadvantages that should be considered when selecting the reaction conditions for a desired C–N bond formation in the course of a total synthesis or drug synthesis.

  7. Preparing poly(aryl ethers) using alkaline earth metal carbonates, organic acid salts, and optionally copper compounds, as catalysts

    International Nuclear Information System (INIS)

    This patent describes an improved process for preparing poly(aryl ethers) and poly(aryl ether ketones) by the reaction of a mixture of at least one bisphenol and at least one dihalobenzenoid compound, and/or a halophenol. The improvement comprises providing to the reaction, a base which is a combination of an alkaline earth metal carbonate and/or bicarbonate and a potassium, rubidium, or cesium salt of an organic acid or combination of organic salts thereof

  8. Synthesis of positron labeled photoactive compounds: {sup 18}F labeled aryl azides for positron labeling of biochemical molecules

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Kazunari; Hashimoto, Naota; Miyake, Yoshihiro [Institute for Biofunctional Research, Osaka (Japan)

    1995-10-20

    The authors have prepared various [{sup 18}F] fluorine labeled aryl azides as a novel photoactive compounds suitable for positron labeling of biochemical molecules. The introduction of fluorine substituents to aryl azides can be expected to have dramatic effects on their nature and reactivity toward photolysis. Positron labeled reagents for labeling proteins or peptides have recently attracted considerable attention due to their wide applicability in biochemistry and positron emission tomography (PET). Various labeled azide compounds are often used in biochemistry for radiolabeling biological molecules by photolysis, but there have been no reports on the preparation or use of fluorine-18 labeled azides. The authors now report a novel synthesis of {sup 18}F-labeled aryl azides which will have wide application in the biochemistry and nuclear medicine as a means for {sup 18}F-fluorine labeling for proteins, peptides, and nucleic acids. 2 tabs.

  9. Rhodium-Catalyzed C-H Alkylation of Indolines with Allylic Alcohols: Direct Access to ?-Aryl Carbonyl Compounds.

    Science.gov (United States)

    Han, Sang Hoon; Choi, Miji; Jeong, Taejoo; Sharma, Satyasheel; Mishra, Neeraj Kumar; Park, Jihye; Oh, Joa Sub; Kim, Woo Jung; Lee, Jong Suk; Kim, In Su

    2015-11-01

    The rhodium(III)-catalyzed site-selective C-H alkylation of various N-heterocycles, such as indolines, carbazoles, and pyrroles with readily available allylic alcohols is described. This protocol allows the generation of a heterocyclic scaffold containing a ?-aryl carbonyl moiety, which is known to be a crucial structural unit of biologically active compounds. PMID:26440560

  10. Photophysical investigations on some synthesized electron donor aryl-bridged compounds

    International Nuclear Information System (INIS)

    The measurements of electronic absorption, steady-state fluorescence emission and time resolved transient spectra are made for two novel synthesized aryl-bridged compounds: 2,6-bis(4,5-dihydro-7,8-dimethoxy)-isoquinolino benzene(DIB) and 2,6-bis(4,5-dihydro-7,8-dimethoxy)-isoquinolino pyridine(DIP) at the ambient temperature in presence of the well-known electron acceptor 9-fluorenone (9FL). The energy positions of the absorption bands of both DIB and DIP are found to be similar to those of the corresponding bands of naphthalene and isoquinoline. Solvent effect shows that the two closely lying bands (260 and around 310 nm) of both DIB and DIP are of ??* type. Steady-state polarization experiments demonstrate that these two close-lying bands are responsible for two different type of transitions, 260 nm is responsible for 1La1A and 310 nm is due to 1Lb1A. This polarization study also shows that 1La and 1Lb bands are largely overlapping. Large bimolecular fluorescence quenching rates (kq?1011 M-1 s-1) observed from both intensity reduction and fluorescence lifetime quenching of the acceptor 9-fluorenone(9FL) in presence of the aryl-bridged donors indicate that the electron transfer (ET) radius is slightly greater than the hydrodynamic radius. The possibility of occurrence of some other fast non-radiative process along with photoinduced electron transfer whose possibility was tested by cyclic voltammetry measurements and presence was confirmed by laser flash photolysis study has been discussed. Transient absorption spectral measurements reveal that in the excited singlet (S1) of 9FL photoinduced ET reaction is present but in its triplet (T1) only energy transfer process is operative. Laser flash photolysis experiments provide the direct evidence for ion recombination mechanisms for production of monomeric triplets of both 9FL and the donors DIB and DIP

  11. Photophysical investigations on some synthesized electron donor aryl-bridged compounds

    Energy Technology Data Exchange (ETDEWEB)

    Misra, T.; Maiti, M.; Saini, R.D.; Panda, S.K.; Ganguly, T

    2003-01-15

    The measurements of electronic absorption, steady-state fluorescence emission and time resolved transient spectra are made for two novel synthesized aryl-bridged compounds: 2,6-bis(4,5-dihydro-7,8-dimethoxy)-isoquinolino benzene(DIB) and 2,6-bis(4,5-dihydro-7,8-dimethoxy)-isoquinolino pyridine(DIP) at the ambient temperature in presence of the well-known electron acceptor 9-fluorenone (9FL). The energy positions of the absorption bands of both DIB and DIP are found to be similar to those of the corresponding bands of naphthalene and isoquinoline. Solvent effect shows that the two closely lying bands (260 and around 310 nm) of both DIB and DIP are of {pi}{pi}* type. Steady-state polarization experiments demonstrate that these two close-lying bands are responsible for two different type of transitions, 260 nm is responsible for {sup 1}L{sub a}<-{sup 1}A and 310 nm is due to {sup 1}L{sub b}<-{sup 1}A. This polarization study also shows that {sup 1}L{sub a} and {sup 1}L{sub b} bands are largely overlapping. Large bimolecular fluorescence quenching rates (k{sub q}{approx}10{sup 11} M{sup -1} s{sup -1}) observed from both intensity reduction and fluorescence lifetime quenching of the acceptor 9-fluorenone(9FL) in presence of the aryl-bridged donors indicate that the electron transfer (ET) radius is slightly greater than the hydrodynamic radius. The possibility of occurrence of some other fast non-radiative process along with photoinduced electron transfer whose possibility was tested by cyclic voltammetry measurements and presence was confirmed by laser flash photolysis study has been discussed. Transient absorption spectral measurements reveal that in the excited singlet (S{sub 1}) of 9FL photoinduced ET reaction is present but in its triplet (T{sub 1}) only energy transfer process is operative. Laser flash photolysis experiments provide the direct evidence for ion recombination mechanisms for production of monomeric triplets of both 9FL and the donors DIB and DIP.

  12. Synthesis and luminescent properties of 4?-phenyl-2,2?:6?,2?-terpyridyl compounds bearing different aryl substituents

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yujian; Guo, Jun [Department of Applied Chemistry, College of Sciences, Nanjing Tech University, Nanjing 210009 (China); Liu, Rui, E-mail: rui.liu@njtech.edu.cn [Department of Applied Chemistry, College of Sciences, Nanjing Tech University, Nanjing 210009 (China); Wang, Qiang; Jin, Xiaodong; Ma, Liangwei; Lv, Wangjie [Department of Applied Chemistry, College of Sciences, Nanjing Tech University, Nanjing 210009 (China); Liu, Shishen; Yuan, Shidong [Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Zhu, Hongjun, E-mail: zhuhj@njtech.edu.cn [Department of Applied Chemistry, College of Sciences, Nanjing Tech University, Nanjing 210009 (China)

    2015-01-15

    A series of new 4?-phenyl-2,2?:6?,2?-terpyridine compounds bearing different aryl substituents (Ar=phenyl (1a), 2,4-difluorophenyl (1b), 4-(trifluoromethyl) phenyl (1c), 4-methoxyphenyl (1d), 9-hexyl-9H-carbazolyl (1e), 9,9-dihexyl-9H-fluorenyl (1f), 4-(diphenylamino)phenyl (1g)) were synthesized and characterized. The influence of the aryl substituents on the luminescence of these compounds is systematically investigated by spectroscopic methods and simulated by density functional theory (DFT) calculations. All compounds exhibit structured absorption bands in the UV region; and broad, structureless charge-transfer bands/shoulders for 1d–1g, which systematically red-shifts when electron-donating substituents are introduced to the phenyl rings, but blue-shifts when electron-withdrawing substituents are attached on the phenyl rings. All compounds are emissive in solution at room temperature (? (table) =358–489 nm, ?{sub F}=0.16–0.92, ?{sub F}=0.77–2.24 ns), which can be attributed to {sup 1}?, ?*/{sup 1}ICT (intramolecular charge transfer) state. Their fluorescent quantum yields increases when the electron-donating aryl substituents attached on the phenyl rings. DFT calculations on 1a–1g were also performed to gain insight into the nature of the ground electronic state. As the representative of compounds with electron-donating substituents, 1f exhibited high fluorescent quantum yields (?{sub f}?0.90 in solvents) while the compounds with electron-withdrawing substituents showed relative low fluorescent quantum yields. Their photophysical properties have been investigated with the aim to provide a basis for elucidating the structure-property correlations and developing new blue light-emitting materials. - Highlights: • A series of 4?-phenyl-2,2?:6?,2?-terpyridine derivatives terminally capped with different aryl substituents. • Photophysical properties of these D-?-A or A-?-A type compounds were systematically investigated via spectroscopic, theoretical and electrochemical methods. • The relatively high fluorescence quantum yields make these compounds as potential candidates of blue light-emitting materials.

  13. Study using 1 H and 13 V NMR of 3-aryl-s-triazole benzoate azole type compounds and intermediaries

    International Nuclear Information System (INIS)

    Approximately 62% of the compounds used for medical purposes are heterocyclic, and are distributed as follows: 95% containing hydrogen, 28% containing sulfur and 18% containing oxygen in the structural composition. Some triazole-s-triazole type hetero aromatic systems and intermediaries, such as 1-aryl hydrazides exhibited bactericide, anti inflammatory and fungi stat activities. All the triazoles are are obtained synthetically, and are not found in the Nature. The proton and carbon-13 spectra of the non usual I, II and III compounds that we obtained are discussed in this work

  14. Synthesis, central nervous system activity and structure-activity relationship of N-substituted derivatives of 1-arylimidazolidyn-2-ylideneurea and products of their cyclization.

    Science.gov (United States)

    Szaco?, El?bieta; Rz?dkowska, Marzena; Kaczor, Agnieszka A; K?dzierska, Ewa; Mazur, Antonina; Fidecka, Sylwia; Matosiuk, Dariusz

    2015-10-01

    A series of 20?N-substituted derivatives of 1-arylimidazolidyn-2-ylideneurea and products of their cyclization was designed as compounds having double antinociceptive and serotoninergic activity. Ethyl {[(1-arylimidazolidin-2-ylidene)carbamoyl]amino}acetates were prepared from 1-aryl-4,5-dihydro-1H-imidazol-2-amines and ethyl isocyanatoacetate, and then converted with ammonia solution to 2-{[(1-phenylimidazolidin-2-ylidene)carbamoyl]amino}acetamides. Both series of N-substituted derivatives of 1-arylimidazolidyn-2-ylideneureas were subjected to cyclization to respective imidazo[1,2-a][1,3,5]triazines. Chain and cyclic compounds bearing ester moiety affected spontaneous locomotor activity, body temperature of mice as well as showed antinociceptive and serotoninergic activity. Interestingly, their antinociceptive activity was not reversed by naloxone, thus it is not mediated through the opioid system. Chain and cyclic compounds bearing amide moiety were devoid of central nervous system (CNS) activity which may be attributed to unfavorably low lipophilicity (connected with too high polar surface area and too small molecular volume) and poor blood-brain barrier permeation properties. PMID:25669349

  15. Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

    Directory of Open Access Journals (Sweden)

    Siphamandla Sithebe

    2014-05-01

    Full Text Available There has been a significant interest in organoboron compounds such as arylboronic acids, arylboronate esters and potassium aryltrifluoroborate salts because they are versatile coupling partners in metal-catalysed cross-coupling reactions. On the other hand, their nitrogen analogues, namely, 1,3,2-benzodiazaborole-type compounds have been studied extensively for their intriguing absorption and fluorescence characteristics. Here we describe the first palladium-catalysed Suzuki–Miyaura cross-coupling reaction of easily accessible and ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole derivatives with various aryl bromides. Aryl bromides bearing electron-withdrawing, electron-neutral and electron-donating substituents are reacted under the catalytic system furnishing unsymmetrical biaryl products in isolated yields of up to 96% in only 10 minutes.

  16. New efficient preparation of arylzinc compounds from aryl halides using cobalt catalysis and sacrificial anode process

    Science.gov (United States)

    Gosmini; Rollin; Nedelec; Perichon

    2000-09-22

    Electroreduction of aryl-chlorides or -bromides in an electrochemical cell fitted with a sacrificial zinc anode and in the presence of cobalt halide associated with pyridine as ligand in DMF or acetonitrile as solvent affords the corresponding organozinc species in good yields. PMID:10987936

  17. Solid-Phase Synthesis of N-Substituted Pyrrolidinone Tethered N-substituted Piperidines via Ugi Reaction

    OpenAIRE

    Liu, Zhang; Nefzi, Adel

    2010-01-01

    Starting with resin-bound glutamic acid, an efficient synthesis of N-substituted pyrrolidinones is described utilizing the Ugi four-component reaction (U-4CR). The same methodology is employed to produce N-substituted pyrrolidinone tethered N-substituted piperidines.

  18. Structural and Spectroscopic Properties of Aryl Substituted Aminoboranes as Model Compounds and Synthons for B-C-N- Materials and New Fluorescent Systems

    OpenAIRE

    SACHDEV, Hermann; ZAHN, Nina; HUCH, Volker

    2009-01-01

    Abstract Abstract: The compounds tetraphenylaminoborane (1) and carbazonyldiphenylborane (2) can serve as examples for isolated BN- bonds substituted by aryl ligands enabling ???interactions. Such systems can serve as building blocks for new fluorescent polymers and are also suitable precursors for B-C-N materials. The compounds were characterized by multinuclear NMR-spectroscopy and single crystal X-ray diffractometry. Both compounds (1) and (2) are principal structures for th...

  19. Novel Fluorinated Phosphorus–Sulfur Heteroatom Compounds: Synthesis and Characterization of Ferrocenyl- and Aryl-Phosphonofluorodithioic Salts, Adducts, and Esters

    Directory of Open Access Journals (Sweden)

    Guoxiong Hua

    2015-07-01

    Full Text Available A series of novel ferrocenyl- and aryl-phosphonofluorodithioic salts, adducts, and esters has been prepared. The reaction of 2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide {[FcP(?-SS]2, FcLR} with dry KF or tetrabutylammonium fluoride (TBAF led to the corresponding potassium and tetrabutylammonium salts of ferrocenyldithiofluorophosphinic acids. Treating potassium ferrocenyldithiofluorophosphinic acid with an equimolar amount of tetraphenylphosphonium chloride readily yielded the corresponding organic adducts, and with mono- and di-halogenated alkanes generated a series of the corresponding esters of ferrocenylphosphonofluoridodithioates. Similarly, using 1,3-epithionaphtho[1,8-cd][1,2,6] oxadiphosphinine 1,3-disulfide or Belleau’s Reagent in place of FcLR resulted in the corresponding novel salts, adducts, and ester derivatives. All new compounds have been characterized by means of multi-NMR (1H, 13C, 31P, 19F spectroscopy and accurate mass measurement in conjunction with single crystal X-ray crystallography of four structures.

  20. Novel Fluorinated Phosphorus-Sulfur Heteroatom Compounds: Synthesis and Characterization of Ferrocenyl- and Aryl-Phosphonofluorodithioic Salts, Adducts, and Esters.

    Science.gov (United States)

    Hua, Guoxiong; Du, Junyi; Surgenor, Brian A; Slawin, Alexandra M Z; Woollins, J Derek

    2015-01-01

    A series of novel ferrocenyl- and aryl-phosphonofluorodithioic salts, adducts, and esters has been prepared. The reaction of 2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide {[FcP(?-S)S]2, FcLR} with dry KF or tetrabutylammonium fluoride (TBAF) led to the corresponding potassium and tetrabutylammonium salts of ferrocenyldithiofluorophosphinic acids. Treating potassium ferrocenyldithiofluorophosphinic acid with an equimolar amount of tetraphenylphosphonium chloride readily yielded the corresponding organic adducts, and with mono- and di-halogenated alkanes generated a series of the corresponding esters of ferrocenylphosphonofluoridodithioates. Similarly, using 1,3-epithionaphtho[1,8-cd][1,2,6] oxadiphosphinine 1,3-disulfide or Belleau's Reagent in place of FcLR resulted in the corresponding novel salts, adducts, and ester derivatives. All new compounds have been characterized by means of multi-NMR (1H, 13C, 31P, 19F) spectroscopy and accurate mass measurement in conjunction with single crystal X-ray crystallography of four structures. PMID:26151115

  1. Mechanism of tritium-atom-promoted isotope exchange in the benzene ring: application to tritium labeling of biologically important aryl compounds

    International Nuclear Information System (INIS)

    Reaction of thermal tritium atoms, generated by microwave activation of T2 gas, with benzene and biphenyl was studied at approx. -50 and -1960C. The saturation reactions (i.e., benzene ? cyclohexane-t6) predominated over isotope exchange (i.e. benzene ? benzene-t) at-1960C. However, significant exchange labeling occurred at approx. -500C, with a concomitant reduction in the yields of saturated products. This reversal in labeled product yields at the different temperatures is due, in part, to the faster rate of H expulsion from the intermediate cyclohexadienyl radical at -500C and to the increased mobility of the warmer matrix that retards multiple T. reactions with the same aryl molecule by covering up singly tritiated intermediates. The less volatile aryl compound, biphenyl, was labeled in a diffusionally active matrix of either benzene or cyclohexane, whereas it could not be labeled otherwise

  2. Lewis acid free high speed synthesis of nimesulide-based novel N-substituted cyclic imides

    Energy Technology Data Exchange (ETDEWEB)

    Kankanala, Kavitha; Mukkanti, Khagga [JNT University Hyderabad, Kukatpally (India); Pal, Sarbani, E-mail: sarbani277@yahoo.co [MNR Degree and PG College, Kukatpally, Hyderabad (India). Dept. of Chemistry; Reddy, Vangala Ranga [Dr. Reddy' s Laboratories Ltd. Integrated Product Development, Bachupally, Hyderabad (India)

    2010-07-01

    The first synthesis of nimesulide-based novel cyclic imides has been accomplished via the reaction of an amine prepared from nimesulide with appropriate anhydrides in the presence of sodium acetate. Using this process a variety of N-substituted cyclic imides was prepared in good yields in glacial acetic acid. Some of the compounds synthesized showed anti-inflammatory activities when tested in vivo. (author)

  3. Lewis acid free high speed synthesis of nimesulide-based novel N-substituted cyclic imides

    International Nuclear Information System (INIS)

    The first synthesis of nimesulide-based novel cyclic imides has been accomplished via the reaction of an amine prepared from nimesulide with appropriate anhydrides in the presence of sodium acetate. Using this process a variety of N-substituted cyclic imides was prepared in good yields in glacial acetic acid. Some of the compounds synthesized showed anti-inflammatory activities when tested in vivo. (author)

  4. Quantitative High-Throughput Screening and Confirmation Studies for Identification of Compounds that Activate the Aryl Hydrocarbon Receptor Pathway (SETAC)

    Science.gov (United States)

    The aryl hydrocarbon receptor (AhR) is a transcription factor that mediates adaptive responses to known environmental pollutants, such as aromatic hydrocarbons, through regulation of Phase I and II xenobiotic metabolizing enzymes as well as important growth and differentiation pa...

  5. Palladium-Catalyzed Carbonylation of Aryl Bromides with N-Substituted Cyanamides

    DEFF Research Database (Denmark)

    Lian, Zhong; Friis, Stig D.; Lindhardt, Anders T.; Skrydstrup, Troels

    2014-01-01

    reaction time of only five hours leading to the corresponding N-alkyl cyanamides in good yields. The methodology was further extended to 13C isotope labeling of the carbonyl group through the use of a 13CO produced from the corresponding 13C-labeled version of the sila­carboxylic acid....

  6. Prostaglandin hydroperoxidase-catalyzed activation of certain N-substituted aryl renal and bladder carcinogens

    OpenAIRE

    Zenser, T. V.; Cohen, S.M.; Mattammal, M. B.; Wise, R. W.; Rapp, N. S.; Davis, B B

    1983-01-01

    Certain carcinogens are thought to induce renal and bladder cancer following metabolic activation. We propose a model system for this activation and provide supporting experimental evidence. This model proposes that renal and bladder carcinogens' entry into the urinary tract is facilitated, that carcinogens are activated by the prostaglandin hydroperoxidase activity of prostaglandin endoperoxide synthetase (PES), and that activation results in covalent binding to nucleic acids which can initi...

  7. Synthesis of N-substituted N-nitrosohydroxylamines as inhibitors of mushroom tyrosinase.

    Science.gov (United States)

    Shiino, M; Watanabe, Y; Umezawa, K

    2001-05-01

    A series of N-substituted N-nitrosohydroxylamines including six new compounds were synthesized and examined for inhibition of mushroom tyrosinase. Corresponding hydroxylamines were reacted with n-butyl nitrite to give substituted nitrosohydroxylamines as their ammonium salt. The N-substituted hydroxylamines were prepared from the primary amines via the oxaziridine, or from the carbonyl compounds via the oxime. Most of the nitrosohydroxylamines tested inhibited mushroom tyrosinase. Among them, N-cyclopentyl-N-nitrosohydroxylamine exhibited the most potent activity (IC(50)=0.6 microM), as powerful as that of tropolone, one of the most powerful inhibitors. As removal of nitroso or hydroxyl moiety, the enzyme inhibitory activity was completely diminished. Both N-nitroso group and N-hydroxy group were suggested to be essential for the activity, probably by interacting with the copper ion at the active site of the enzyme. Lineweaver-Burk plotting showed that cupferron was a competitive inhibitor but that N-cyclopentyl-N-nitrosohydroxylamine was not. PMID:11377181

  8. N-substituted bis-C-alkyloxadiazolones as dual effectors: efficient intermediates to amidoximes or amidines and prodrug candidates of potent antimalarials.

    Science.gov (United States)

    Degardin, Mélissa; Wein, Sharon; Durand, Thierry; Escale, Roger; Vial, Henry; Vo-Hoang, Yen

    2009-09-01

    A convenient route to N-substituted bis-C-alkylamidines possessing antiplasmodial activity and their oxadiazolone and amidoxime prodrug candidates, is described. These three families of compounds were available after a key N-alkylation step of the parent oxadiazolone 1a. Testing of the three compound classes in vitro and in vivo is also presented. PMID:19643611

  9. Synthesis and antitumor activity of novel N-substituted carbazole imidazolium salt derivatives

    Science.gov (United States)

    Liu, Lan-Xiang; Wang, Xue-Quan; Zhou, Bei; Yang, Li-Juan; Li, Yan; Zhang, Hong-Bin; Yang, Xiao-Dong

    2015-01-01

    A series of novel N-substituted carbazole imidazolium salt derivatives has been prepared and investigated for their cytotoxic activity against five human tumor cell lines by MTS assay. The results indicated that the existence of 5,6-dimethyl-benzimidazole ring, substitution of the imidazolyl-3-position with a 2-bromobenzyl or naphthylacyl group, as well as alkyl chain length between carbazole and imidazole ring were important for the antitumor activity. Compound 61, bearing a 2-bromobenzyl substituent at position-3 of the 5,6-dimethyl-benzimidazole, showed powerful inhibitory activities and was more selective to HL-60, SMMC-7721, MCF-7 and SW480 cell lines with IC50 values 0.51–2.48??M. Mechanism of action studies revealed that this new compound could remarkably induce cell cycle arrest and apoptosis in SMMC-7721 cells. This work provides alternative novel way for future drug development based on carbazole and imidazolium salt scaffolds. PMID:26287982

  10. Synthesis of N-substituted acyclic ?-amino acids and their investigation as GABA uptake inhibitors.

    Science.gov (United States)

    Sitka, Ingolf; Allmendinger, Lars; Fülep, Günther; Höfner, Georg; Wanner, Klaus T

    2013-07-01

    In this publication, we describe the synthesis of new inhibitors for the GABA transporter subtypes GAT1 and especially GAT3. We started with 3-aminopropanoic acid possessing a distinct preference for GAT3 in comparison to GAT1 and furthermore its homolog 3-aminobutanoic acid. A series of respective N-substituted amino acids was synthesized by selective N-monoalkylation of these parent structures with 6 different arylalkyl alcohols via a Mitsunobu-type reaction. The resulting compounds were investigated for their inhibitory potency GABA transporter subtypes. Among all tested compounds the 4,4-diphenylbut-3-enyl substituted 3-aminobutanoic acid (rac)-6b showed highest potency with a pIC50 value of 5.34 at GAT1. Unfortunately, the expected GAT3 potency for 2-[tris(4-methoxyphenyl)methoxy]ethyl substituted derivatives was not as high as observed for the respective nipecotic acid derivatives. PMID:23770450

  11. Activity of Antifungal Organobismuth(III Compounds Derived from Alkyl Aryl Ketones against S. cerevisiae: Comparison with a Heterocyclic Bismuth Scaffold Consisting of a Diphenyl Sulfone

    Directory of Open Access Journals (Sweden)

    Toshihiro Murafuji

    2014-07-01

    Full Text Available A series of hypervalent organobismuth(III compounds derived from alkyl aryl ketones [XBi(5-R'C6H3-2-COR(Ar] was synthesized to investigate the effect of the compounds’ structural features on their antifungal activity against the yeast Saccharomyces cerevisiae. In contrast to bismuth heterocycles [XBi(5-RC6H3-2-SO2C6H4-1'-] derived from diphenyl sulfones, a systematic quantitative structure-activity relationship study was possible. The activity depended on the Ar group and increased for heavier X atoms, whereas lengthening the alkyl chain (R or introducing a substituent (R' reduced the activity. IBi(C6H4-2-COCH3(4-FC6H4 was the most active. Its activity was superior to that of the related acyclic analogues ClBi[C6H4-2-CH2N(CH32](Ar and ClBi(C6H4-2-SO2 tert-Bu(Ar and also comparable to that of heterocyclic ClBi(C6H4-2-SO2C6H4-1'-, which was the most active compound in our previous studies. Density function theory calculations suggested that hypervalent bismuthanes undergo nucleophilic addition with a biomolecule at the bismuth atom to give an intermediate ate complex. For higher antifungal activity, adjusting the lipophilicity-hydrophilicity balance, modeling the three-dimensional molecular structure around the bismuth atom, and stabilizing the ate complex appear to be more important than tuning the Lewis acidity at the bismuth atom.

  12. Lipase-Catalyzed Kinetic Resolution of Novel Antifungal N-Substituted Benzimidazole Derivatives.

    Science.gov (United States)

    Łukowska-Chojnacka, Edyta; Staniszewska, Monika; Bondaryk, Małgorzata; Maurin, Jan K; Bretner, Maria

    2016-04-01

    A series of new N-substituted benzimidazole derivatives was synthesized and their antifungal activity against Candida albicans was evaluated. The chemical step included synthesis of appropriate ketones containing benzimidazole ring, reduction of ketones to the racemic alcohols, and acetylation of alcohols to the esters. All benzimidazole derivatives were obtained with satisfactory yields and in relatively short times. All synthesized compounds exhibit significant antifungal activity against Candida albicans 900028 ATCC (% cell inhibition at 0.25 μg concentration > 98%). Additionally, racemic mixtures of alcohols were separated by lipase-catalyzed kinetic resolution. In the enzymatic step a transesterification reaction was applied and the influence of a lipase type and solvent on the enantioselectivity of the reaction was studied. The most selective enzymes were Novozyme SP 435 and lipase Amano AK from Pseudomonas fluorescens (E > 100). Chirality 28:347-354, 2016. © 2016 Wiley Periodicals, Inc. PMID:26922853

  13. MICROWAVE ASSISTED SYNTHESIS OF FLUORO, CHLORO, 2-N (SUBSTITUTED SCHIFF’S BASES AMINO BENZOTHIAZOLES FOR THEIR ANTIMICROBIAL AND ANTITUBERCULAR ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Dr. S. M. Hipparagi

    2010-05-01

    Full Text Available The present research work is aimed to synthesize a series of various substituted benzothiazole derivatives containing 7-chloro-6-fluoro-N(substituted hydrozones- benzothiazole.Structures of compounds have been established by means of IR, 1H-NMR and elemental analysis. All the compounds were evaluated foe antibacterial, antifungal and antitubercular activities. Most of the compounds have shown significant antibacterial, antifungal and antitubercular activity when compared with the standard drug.

  14. N-substituted 2-isonicotinoylhydrazinecarboxamides--new antimycobacterial active molecules.

    Science.gov (United States)

    Rychtar?íková, Zuzana; Krátký, Martin; Gazvoda, Martin; Komlóová, Markéta; Polanc, Slovenko; Ko?evar, Marijan; Stola?íková, Ji?ina; Vinšová, Jarmila

    2014-01-01

    This report presents a new modification of the isoniazid (INH) structure linked with different anilines via a carbonyl group obtained by two synthetic procedures and with N-substituted 5-(pyridine-4-yl)-1,3,4-oxadiazole-2-amines prepared by their cyclisation. All synthesised derivatives were characterised by IR, NMR, MS and elemental analyses and were evaluated in vitro for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv, Mycobacterium avium 330/88, Mycobacterium kansasii 235/80 and one clinical isolated strain of M. kansasii 6509/96. 2-Isonicotinoyl-N-(4-octylphenyl)hydrazinecarboxamide displayed an in vitro efficacy comparable to that of INH for M. tuberculosis with minimum inhibitory concentrations (MICs) of 1-2 ?M. Among the halogenated derivatives, the best anti-tuberculosis activity was found for 2-isonicotinoyl-N-(2,4,6-trichlorophenyl)hydrazinecarboxamide (MIC=4 ?M). In silico modelling on the enoyl-acyl carrier protein reductase InhA confirmed that longer alkyl substituents are advantageous for the interactions and affinity to InhA. Most of the hydrazinecarboxamides, especially those derived from 4-alkylanilines, exhibited significant activity against INH-resistant nontuberculous mycobacteria. PMID:24686575

  15. N-Substituted 2-Isonicotinoylhydrazinecarboxamides — New Antimycobacterial Active Molecules

    Directory of Open Access Journals (Sweden)

    Zuzana Rychtar?íková

    2014-03-01

    Full Text Available This report presents a new modification of the isoniazid (INH structure linked with different anilines via a carbonyl group obtained by two synthetic procedures and with N-substituted 5-(pyridine-4-yl-1,3,4-oxadiazole-2-amines prepared by their cyclisation. All synthesised derivatives were characterised by IR, NMR, MS and elemental analyses and were evaluated in vitro for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv, Mycobacterium avium 330/88, Mycobacterium kansasii 235/80 and one clinical isolated strain of M. kansasii 6509/96. 2-Isonicotinoyl-N-(4-octylphenylhydrazinecarboxamide displayed an in vitro efficacy comparable to that of INH for M. tuberculosis with minimum inhibitory concentrations (MICs of 1–2 ?M. Among the halogenated derivatives, the best anti-tuberculosis activity was found for 2-isonicotinoyl-N-(2,4,6-trichlorophenylhydrazinecarboxamide (MIC = 4 ?M. In silico modelling on the enoyl-acyl carrier protein reductase InhA confirmed that longer alkyl substituents are advantageous for the interactions and affinity to InhA. Most of the hydrazinecarboxamides, especially those derived from 4-alkylanilines, exhibited significant activity against INH-resistant nontuberculous mycobacteria.

  16. 40 CFR 721.225 - 2-Chloro-N-methyl-N-substituted acetamide (generic name).

    Science.gov (United States)

    2010-07-01

    ... acetamide (generic name). 721.225 Section 721.225 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.225 2-Chloro-N-methyl-N-substituted acetamide (generic name). (a...-methyl-N-substituted acetamide (PMN P-84-393) is subject to reporting under this section for...

  17. Modern Arylation Methods

    CERN Document Server

    Ackermann, Lutz

    2009-01-01

    Today, arylation methods are belonging to the most important reaction types in organic synthesis. Lutz Ackermann, a young and ambitious professor has gathered a number of top international authors to present the first comprehensive book on the topic. Starting from a historical review, the book covers hot topics like Palladium-catalyzed arylation of N-H and alpha-C-H-acidic Bonds, Copper-catalyzed arylation of N-H and O-H Bonds, direct arylation reactions, carbanion aromatic synthesis, arylation reactions of alkenes, alkynes and much more. This compact source of high quality information is indi

  18. Transition Metal Catalyzed Synthesis of Aryl Sulfides

    Directory of Open Access Journals (Sweden)

    Chad C. Eichman

    2011-01-01

    Full Text Available The presence of aryl sulfides in biologically active compounds has resulted in the development of new methods to form carbon-sulfur bonds. The synthesis of aryl sulfides via metal catalysis has significantly increased in recent years. Historically, thiolates and sulfides have been thought to plague catalyst activity in the presence of transition metals. Indeed, strong coordination of thiolates and thioethers to transition metals can often hinder catalytic activity; however, various catalysts are able to withstand catalyst deactivation and form aryl carbon-sulfur bonds in high-yielding transformations. This review discusses the metal-catalyzed arylation of thiols and the use of disulfides as metal-thiolate precursors for the formation of C-S bonds.

  19. Novel N-substituted aminobenzamide scaffold derivatives targeting the dipeptidyl peptidase-IV enzyme

    Directory of Open Access Journals (Sweden)

    Al-Balas QA

    2014-01-01

    Full Text Available Qosay A Al-Balas,1 Munia F Sowaileh,1 Mohammad A Hassan,1 Amjad M Qandil,1,2 Karem H Alzoubi,3 Nizar M Mhaidat,3 Ammar M Almaaytah,4 Omar F Khabour51Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan; 2Pharmaceutical Sciences Department, College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; 3Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan; 4Department of Pharmaceutical Technology, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan; 5Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, JordanBackground: The dipeptidyl peptidase-IV (DPP-IV enzyme is considered a pivotal target for controlling normal blood sugar levels in the body. Incretins secreted in response to ingestion of meals enhance insulin release to the blood, and DPP-IV inactivates these incretins within a short period and stops their action. Inhibition of this enzyme escalates the action of incretins and induces more insulin to achieve better glucose control in diabetic patients. Thus, inhibition of this enzyme will lead to better control of blood sugar levels.Methods: In this study, computer-aided drug design was used to help establish a novel N-substituted aminobenzamide scaffold as a potential inhibitor of DPP-IV. CDOCKER software available from Discovery Studio 3.5 was used to evaluate a series of designed compounds and assess their mode of binding to the active site of the DPP-IV enzyme. The designed compounds were synthesized and tested against a DPP-IV enzyme kit provided by Enzo Life Sciences. The synthesized compounds were characterized using proton and carbon nuclear magnetic resonance, mass spectrometry, infrared spectroscopy, and determination of melting point.Results: Sixty-nine novel compounds having an N-aminobenzamide scaffold were prepared, with full characterization. Ten of these compounds showed more in vitro activity against DPP-IV than the reference compounds, with the most active compounds scoring 38% activity at 100 µM concentration.Conclusion: The N-aminobenzamide scaffold was shown in this study to be a valid scaffold for inhibiting the DPP-IV enzyme. Continuing work could unravel more active compounds possessing the same scaffold.Keywords: diabetes mellitus, dipeptidyl peptidase-IV, aminobenzamide derivatives, hypoglycemic activity, CDOCKER software

  20. Structural Requirements of N-Substituted Spiropiperidine Analogues as Agonists of Nociceptin/Orphanin FQ Receptor

    Directory of Open Access Journals (Sweden)

    Ling Yang

    2011-12-01

    Full Text Available The nociceptin/orphanin FQ (NOP receptor is involved in a wide range of biological functions, including pain, anxiety, depression and drug abuse. Especially, its agonists have great potential to be developed into anxiolytics. In this work, both the ligand- and receptor-based three-dimensional quantitative structure–activity relationship (3D-QSAR studies were carried out using comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA techniques on 103 N-substituted spiropiperidine analogues as NOP agonists. The resultant optimal ligand-based CoMSIA model exhibited Q2 of 0.501, R2ncv of 0.912 and its predictive ability was validated by using an independent test set of 26 compounds which gave R2pred value of 0.818. In addition, docking analysis and molecular dynamics simulation (MD were also applied to elucidate the probable binding modes of these agonists. Interpretation of the 3D contour maps, in the context of the topology of the active site of NOP, provided insight into the NOP-agonist interactions. The information obtained from this work can be used to accurately predict the binding affinity of related agonists and also facilitate the future rational design of novel agonists with improved activity.

  1. Novel multicomponent synthesis of 2,9-dihydro-9-methyl-2-oxo-4-aryl- 1-pyrido[2,3-]indole-3-carbonitrile compounds

    Indian Academy of Sciences (India)

    Saman Damavandi; Reza Sandaroos

    2013-01-01

    Novel multicomponent approach for the synthesis of 2,9-dihydro-2-oxo-4-aryl-1-pyrido[2,3-]indole-3-carbonitrile derivatives via one-pot cyclocondensation reaction of substituted (triethoxymethyl) arene, 1-methyl-1-indol-2-ol and cyanoacetamide in the presence of silica supported ionic liquid [pmim]HSO4SiO2 (silica-supported 1-methyl-3-(triethoxysilylpropyl)imidazolium hydrogensulphate) has been reported.

  2. Concise synthesis of dihydrochalcones via palladium-catalyzed coupling of aryl halides and 1-aryl-2-propen-1-ols.

    Science.gov (United States)

    Briot, Anne; Baehr, Corinne; Brouillard, Raymond; Wagner, Alain; Mioskowski, Charles

    2004-02-20

    An expedient route to substituted dihydrochalcones is reported. The key step is a palladium-assisted arylation of 1-aryl-2-propen-1-ols. This two-step/one-purification process allows the synthesis of a wide range of compounds with original substitution patterns, including polyphenolic derivatives. PMID:14961696

  3. Solvent free preparation of N-substituted maleanilic acid

    Directory of Open Access Journals (Sweden)

    H. Saedi

    2013-04-01

    Full Text Available Six N-maleanilic acids namely N-(4-carboxymaleanilic acid (CAMAA, N-(4-bromomaleanilic acid (BMAA, N-(4-hydroxymaleanilic acid (HMAA, N-(3-hydroxymaleanilic acid (mHMAA, N-(4-chloromaleanilic acid (CMAA and N-(4-methylmaleanilic acid (MMAA were prepared by solvent free reaction between maleic anhydride and a 4-carboxy, 4-bromo, 4-hydroxy, 3-hydroxy, 4-chloro and 4-methyl aniline derivatives in good to excellent yield. FT-IR, 1H-NMR and 13C-NMR spectra revealed the confirmation of these compounds in good agreement.DOI: http://dx.doi.org/10.4314/bcse.v27i1.15

  4. Synthesis of nanodispersible 6-aryl-2,4-diamino-1,3,5-triazine and its derivatives

    International Nuclear Information System (INIS)

    A series of novel branched derivatives of 6-aryl-2,4-diamino-1,3,5-triazine from corresponding aryl nitriles and dicyanodiamide was synthesized. These compounds show a nanodispersibility and good thermal stability.

  5. Structure-activity relationships for novel drug precursor N-substituted-6-acylbenzothiazolon derivatives: A theoretical approach

    Science.gov (United States)

    S?d?r, Yadigar Gülseven; S?d?r, ?sa

    2013-08-01

    In this study, the twelve new modeled N-substituted-6-acylbenzothiazolon derivatives having analgesic analog structure have been investigated by quantum chemical methods using a lot of electronic parameters and structure-activity properties; such as molecular polarizability (?), dipole moment (?), EHOMO, ELUMO, q-, qH+, molecular volume (Vm), ionization potential (IP), electron affinity (EA), electronegativity (?), molecular hardness (?), molecular softness (S), electrophilic index (?), heat of formation (HOF), molar refractivity (MR), octanol-water partition coefficient (log P), thermochemical properties (entropy (S), capacity of heat (Cv)); as to investigate activity relationships with molecular structure. The correlations of log P with Vm, MR, ?, EA, EHOMO - ELUMO (?E), HOF in aqueous phase, ?, ?, S, ? parameters, respectively are obtained, while the linear relation of log P with IP, Cv, HOF in gas phase are not observed. The log P parameter is obtained to be depending on different properties of compounds due to their complexity.

  6. Synthesis and Screening of Some New N-Substituted Derivatives of N-(4-Methylpyridin-2-ylbenzenesulfonamides as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Aziz-ur-Rehman

    2014-03-01

    Full Text Available The two step synthesis of a series of N-substituted derivatives of N-(4-Methylpyridin-2-ylbenzenesulfonamide with potential antibacterial activity, has been reported. First step includes the synthesis of N-(4-Methylpyridin-2-ylbenzenesulfonamide (3 by reaction of 2-Amino-4-methylpyridine (1 and Benzenesulfonyl chloride (2 in a slightly basic aqueous medium. The molecule 3 was converted to N-Alkyl/aralkyl-N-(4-methylpyridin-2-ylbenzenesulfonamide derivatives, 5a-f, on treatment with alkyl/aralkyl halides, 4a-f, using lithium hydride as activator in N,N-dimethylformamide. The synthesized molecules were well corroborated by 1H-NMR, IR and EI-MS spectral data and evaluated for antibacterial activity against four gram-negative and two gram-positive bacteria. The evaluation results rendered these compounds as moderately good inhibitors and may be employed as therapeutic agent for certain inflammatory ailments.

  7. Vibrational and electronic spectra of N-aryl ring substituted (Z)-N-(4-amino-5-(4-chlorophenyl)-3-phenylthiazol-2(3H)-ylidene)benzamide compounds

    Science.gov (United States)

    Rao, Y. B. Shankar; Mohan, S. Ram; Veeraiah, V.

    2015-04-01

    In the present paper the vibrational, electronic and nonlinear optical properties of three N-aryl ring substituted (Z)-N-(4-amino-5-(4-chlorophenyl)-3-phenylthiazol-2(3H)-ylidene)benzamide compounds have been investigated by UV-vis, FT-IR and FT-Raman spectroscopic measurements. The electrochemical properties of the compounds were measured by cyclic voltammetry. Density functional theory calculations with B3LYP/6-31 + G(d,p) basis set was used to determine the ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies, infrared intensities and Raman activities of title compounds. Potential energy distributions (PEDs) and normal modes, for the spectral data computed at B3LYP/6-31 + G(d,p) level, have also been obtained from force-field calculations. A comparison of the theoretical spectra and experimental FT-IR and FT-Raman spectra of the title molecule has been made and full vibrational assignments of the observed spectra have been proposed. The substituent effect on the electronic properties of the title compounds were investigated by time-dependent density functional theory calculations.

  8. Study of germathiazolidines and germylated dithiocetals derived from N-substituted cysteamine and methylcysteamine: synthesis and radioprotective activity

    International Nuclear Information System (INIS)

    Synthesis and pharmacological studies (toxicity, radioprotective activity) of new N-substituted germathiazolidines and germylated dithioacetals prepared from N-substituted cysteamine and methylcysteamine by an acetyl group or a partial amino acid are described. A notable decrease in the toxicity and a rather important increase in the radioprotective activity of these new organometallic molecules compared to N-substituted cysteamine and methylcysteamine have been observed

  9. 40 CFR 721.275 - Halogenated-N-(2-propenyl)-N-(substituted phenyl) acetamide.

    Science.gov (United States)

    2010-07-01

    ...-(substituted phenyl) acetamide. 721.275 Section 721.275 Protection of Environment ENVIRONMENTAL PROTECTION...) acetamide. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated-N-(2-propenyl)-N-(substituted phenyl) acetamide (P-83-1085) is...

  10. ON THE ANTIOXIDANT EFFECTIVENESS OF N,N´–SUBSTITUTED P-PHENYLENEDIAMINES

    OpenAIRE

    Vladimír Lukeš; Erik Klein; Zuzana Cibulková

    2004-01-01

    The ground-state geometry of six N,N’-substituted p-phenylenediamines (PPDs): N-phenyl-N’-dimethyl-butyl-p-phenylenediamine (6PPD), N-phenyl-N’-isopropyl-p-phenylenediamine (IPPD), N-phenyl-N’-(?-methylbenzyl)-p-phenylenediamine (SPPD), N-(2-methoxybenzyl)-N’-phenyl-p-phenylenediamine (MBPPD), N-benzyl-N’-phenyl-p-phenylenediamine (MBPPDH), N-(1-methyl-1-phenylethyl)-N’-phenyl-p-phenylene-diamine (CPPD) molecules, their radical structures and the energy characterisation of these molecules and...

  11. Synthesis and characterization of thermoresponsive polymers, hydrogels and microgels, based on poly(N-substituted acrylamides)

    OpenAIRE

    Panayiotou, Marilia

    2004-01-01

    Stimuli-responsive polymers have the unique property of undergoing a reversible phase transition. This property has attracted much interest for their application in the field of medicine and biotechnology, such as drug delivery systems. Linear polymers of the poly(N-substituted acrylamides) family and their three-dimensional macroscopic (hydrogels) or microscopic (microgels) networks demonstrate such a phase transition behavior. In particular, polymers of this family have the ability to respo...

  12. The Genetic Basis for Evolved Tolerance to Dioxin-Like Compounds in Wild Atlantic Killifish: More Than the Aryl Hydrocarbon Receptor

    Science.gov (United States)

    Populations of Atlantic killifish (Fundulus heteroclitus) resident to some US urban estuaries have independently evolved extreme and inherited tolerance to toxic dioxin-like compounds (DLCs). To further understand the genetic basis for this trait, we densely genotyped families o...

  13. An Expeditious Synthesis of N-substituted Pyrroles via Microwave-Induced Iodine-Catalyzed Reactions under Solventless Conditions

    Directory of Open Access Journals (Sweden)

    Debasish Bandyopadhyay

    2010-04-01

    Full Text Available An expeditious synthesis of N-substituted pyrroles has been developed by reacting 2,5-dimethoxy tetrahydrofuran and several amines using a microwave-induced molecular iodine-catalyzed reaction under solventless conditions.

  14. Inorganic base-catalyzed formation of antivirally active N-substituted benzamides from ?-amido sulfones and N-nucleophile

    Directory of Open Access Journals (Sweden)

    Wang Zhenchao

    2011-05-01

    Full Text Available Abstract Background Heteronucleophiles as well as carbanionic reagents can be used to react with ?-amido sulfones, thus giving the opportunity to prepare a large array of amino derivatives. Since, novel 1,3,4-oxadiazole-2-thiol derivatives can serve as potent nucleophiles, we employed 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the nucleophilic source of nitrogen in the reaction with ?-amido sulfones. Results A series of N-substituted benzamides bearing 1,3,4-oxadiazol unit were prepared for the first time by the reaction of in situ generated protected imine from ?-amido sulfones with 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophile. Some of the synthesized products displayed favourable antiviral activity against cucumber mosaic virus (CMV in preliminary antiviral activity tests. The title compounds 5c, 5o and 5r revealed curative activity of 42.2%, 48.7% and 40.5%, respectively against CMV (inhibitory rate compared to the commercial standard Ningnanmycin (53.4% at 500 ?g/mL. Conclusion A practical synthetic route to N-benzoyl-?-amido sulfones by the reaction of 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophiles with in situ generated protected imine from N-benzoyl-?-amido sulfones is presented. The reaction catalyzed by an inorganic base has considerable significance to exploit the potential of ?-amido sulfones in organic synthesis.

  15. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    International Nuclear Information System (INIS)

    N, N',N, N'-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO4)4) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed in refluxing H2O. The catalyst was recovered and reused at least four times, maintaining its efficiency. (author)

  16. Synthesis and Photophysical Properties of 2-Aryl-6,8-bis(arylethenyl-4-methoxyquinolines

    Directory of Open Access Journals (Sweden)

    Tebogo Ankie Khoza

    2012-11-01

    Full Text Available Iodine-methanol mediated oxidative-aromatization of 2-aryl-6,8-dibromo-2,3-dihydroquinolin-4(1H-ones afforded the corresponding 2-aryl-6,8-dibromo-4-methoxy-quinolines in high yield and purity. The isomeric 1-(2-amino-3,5-dibromophenyl-3-aryl-2-propen-1-ones reacted with iodine in methanol afford in a single pot operation the corresponding 2-aryl-6,8-dibromo-4-methoxyquinoline (major and 2-aryl-6,8-dibromoquinolin-4(1H-one (minor products that were separated in sequence by column chromatography on silica gel. Suzuki-Miyaura cross-coupling of the 6,8-dibromo-4-methoxyquinoline derivatives with excess arylvinylboronic acids afforded the corresponding 2-aryl-6,8-bis(2-arylethenyl-4-methoxyquinolines. The absorption and fluorescence properties of these compounds were also determined.

  17. Synthesis of N-substituted 6-trifluoromethyl-1,3-oxazinanes

    Scientific Electronic Library Online (English)

    Nilo, Zanatta; Adriana M. C., Squizani; Leonardo, Fantinel; Fabiane M., Nachtigall; Deise M., Borchhardt; Helio G., Bonacorso; Marcos A. P., Martins.

    2005-12-01

    Full Text Available Este trabalho apresenta a síntese de duas novas séries de 6-trifluormetil-1,3-oxazinanas N-substituídas e 6-trifluormetil-1,3-oxazinan-2-onas N-substituídas, a partir da ciclização de 4-ilamino-1,1,1-trifluor-butan-2-óis com formaldeído e trifosgênio, respectivamente. Os 4-ilamino-1,1,1-trifluor-but [...] an-2-óis foram obtidos através da reação de redução dos precursores 4-ilamino-1,1,1-trifluor-but-3-en-2-onas, utilizando hidrogênio e 10% Pd/C, com bons rendimentos. Abstract in english This work reports the synthesis of two new series of N-substituted 6-trifluoromethyl-1,3-oxazinanes and N-substituted 6-trifluoromethyl-1,3-oxazinan-2-ones from the cyclization of 4-ylamino-1,1,1-trifluoro-butan-2-ols with formaldehyde and triphosgene, respectively. The 4-ylamino-1,1,1-trifluoro-but [...] an-2-ols were obtained in good yields from the reduction of the parent 4-ylamino-1,1,1-trifluoro-but-3-en-2-ones with hydrogen and 10% Pd/C.

  18. Copper Mediated Fluorination of Aryl Iodides

    OpenAIRE

    Fier, Patrick S.; Hartwig, John. F.

    2012-01-01

    The synthesis of aryl fluorides has been a topic of considerable interest because of the importance of aryl fluorides in pharmaceuticals, agrochemicals and materials. The stability, reactivity and biological properties of aryl fluorides can be distinct from those of the corresponding arenes. Methods for the synthesis of aryl fluorides, however, are limited. We report the conversion of a diverse set of aryl iodides to the corresponding aryl fluorides. This reaction occurs with a cationic coppe...

  19. Experimental and theoretical study of [N-substituted] p-aminoazobenzene derivatives as corrosion inhibitors for mild steel in sulfuric acid solution

    Science.gov (United States)

    Shihab, Mehdi Salih; Al-Doori, Hanan Hussien

    2014-11-01

    [N-substituted] p-aminoazobenzene derivatives (1), (2), (3), (4) and (5) were prepared and investigated as corrosion inhibitors for mild steel in 1 M H2SO4 solution by weight loss measurements. It has been observed that the corrosion rate decreases, inhibition efficiencies increase and surface coverage degree increases with increasing inhibitor concentration. Inhibition efficiencies for prepared compounds were ordered: (1) > (2) > (5) > (4) > (3) with the highest inhibiting efficiency of 63% for 10-3 M. The values of ?Gadso are showing physisorption effect for all prepared compounds. Semiempirical molecular orbital calculations for (1), (2), (3), (4) and (5) could be used as a useful tool to obtain information for explaining the nature of interaction between the metal surface and the organic molecule as a corrosion inhibitor.

  20. Synthesis of non-purine analogs of 6-aryl-9-benzylpurines, and their antimycobacterial activities. Compounds modified in the imidazole ring.

    Science.gov (United States)

    Khoje, Abhijit Datta; Kulendrn, Aisvareya; Charnock, Colin; Wan, Baojie; Franzblau, Scott; Gundersen, Lise-Lotte

    2010-10-15

    Purine analogs modified in the five-membered ring have been synthesized and examined for antibacterial activity against Mycobacterium tuberculosis H(37)Rv in vitro employing the microplate alamar blue assay (MABA). The 9-deaza analogs were only found to be weak inhibitors, but the 8-aza-, 7-deaza- and 8-aza-7-deazapurine analogs studied displayed excellent antimycobacterial activities, some even substantially better than the parent purine. In the 7-deazapurine series, MIC values between 0.08 and 0.35 ?M, values comparable or better than the reference drugs used in the study (MIC rifampicin 0.09 ?M, MIC isoniazid 0.28 ?M and MIC PA-824 0.44 ?M). The five most active compounds were also examined against a panel of drug-resistant Mtb strain, and they all retained their activity. The compounds examined were significantly less active against M. tuberculosis in a state of non-replicating persistence (NRP). MIC in the low-oxygen-recovery assay (LORA) ? 60 ?M. The 7-deazapurines were somewhat more toxic towards mammalian cells, but still the selectivity indexes were excellent. The non-purine analogs exhibit a selective antimycobacterial activity. They were essentially inactive against Staphylococcus aureus and Escherichia coli. PMID:20833056

  1. Efficient synthesis of ?-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp2–H bond arylations

    Directory of Open Access Journals (Sweden)

    Fatiha Abdelmalek

    2015-10-01

    Full Text Available We report herein a two or three step synthesis of fluorinated ?-conjugated oligomers through iterative C–H bond arylations. Palladium-catalyzed desulfitative arylation of heteroarenes allowed in a first step the synthesis of fluoroaryl-heteroarene units in high yields. Then, the next steps involve direct arylation with aryl bromides catalyzed by PdCl(C3H5(dppb to afford triad or tetrad heteroaromatic compounds via regioselective activation of C(sp2–H bonds.

  2. Direct N9-arylation of purines with aryl halides

    DEFF Research Database (Denmark)

    Larsen, Anders Foller; Ulven, Trond

    2014-01-01

    An efficient method for N-arylation of purines is reported. The N-arylation is catalysed by Cu(i) and 4,7-bis(2-hydroxyethylamino)-1,10-phenanthroline (BHPhen) in aqueous DMF or ethanol. The reaction generally proceeds with high selectivity for the N(9)-position.

  3. Synthesis of 3-fluoro-3-aryl oxindoles: Direct enantioselective α arylation of amides

    KAUST Repository

    Wu, Linglin

    2012-02-06

    Modus operandi: Catalytic access to the title compounds through a new asymmetric α-arylation protocol is reported (see scheme). These products are formed in good yields and excellent enantioselectivities by using a new and easily synthesized chiral N-heterocyclic carbene (NHC) ligand. Advanced DFT calculations reveal the properties of the NHC ligand and the mode of operation of the catalyst. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Electrochemical synthesis and characterization of N-substituted polypyrrole derivatives on nickel

    International Nuclear Information System (INIS)

    1-Dodecylpyrrole (PyCH3) and 12-(pyrrol-1-yl)dodecane-1-thiol (PySH) films have been successfully electrochemically polymerised on a nickel electrode from acetonitrile solutions containing the monomer and the lithium perchlorate as supporting electrolyte. The electrochemical study of the polymer growth has been carried out by cyclic voltammetry (CV) detecting the nickel dissolution during electropolymerisation. Several surface spectroscopic and microscopic techniques have been used to characterize the surface in term of chemical composition and polymer topography. The presence of unbound and unoxidised thiol groups at the PPySH surface has been evidenced together with a very strong adhesion to the nickel substrate. Furthermore, N-substituted pyrrole derivatives exhibited some corrosion protection properties in neutral NaCl medium

  5. Synthesis and characterization of methacrylamidopropyltrimethylammonium chloride and N-substituted acrylamide ionomers

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available Quaternary ammonium ionomers of Methacrylamidopropyltrimethyl ammonium chloride with N-substituted acrylamides were prepared at 55±1°C using azobiscyanovaleric acid (ACVA initiator. The monomers and ionomers were characterized by 1H- and 13C-NMR spectroscopy and the copolymer composition was calculated from elemental analysis data. The reduced viscosity of ionomers in methanol behaves as non-polyelectrolytes at lower mole percentage and as polyelectrolyte at higher mole percentage. The molecular weights of ionomers were found to be high and the polydispersity index values indicate termination mainly by disproportionation. The glass transition temperature (Tg of ionomers were greater than those of the corresponding homopolymers, attributed to a reduction in segmental mobility. The initial decomposition temperature (IDT showed that the stability of ionomers increases with increasing mole percentage of ionic content.

  6. Synthesis and receptor binding of N-substituted tropane derivatives. High-affinity ligands for the cocaine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Milius, R.A.; Saha, J.K.; Madras, B.K.; Neumeyer, J.L. (Research Biochemicals Inc., Natick, MA (USA))

    1991-05-01

    The synthesis and pharmacological characterization of a series of N-substituted 3-(4-fluorophenyl)tropane derivatives is reported. The compounds displayed binding characteristics that paralleled those of cocaine, and several had substantially higher affinity at cocaine recognition sites. Conjugate addition of 4-fluorophenyl magnesium bromide to anhydroecgonine methyl ester gave 2 beta-(carbomethoxy)-3 beta-(4-fluorophenyl)tropane (4a, designated CFT, also known as WIN 35,428) after flash chromatography. N demethylation of 4a was effected by Zn/HOAc reduction of the corresponding 2,2,2-trichloroethyl carbamate to give 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)nortropane (5), which was alkylated with allyl bromide to afford the N-allyl analogue, 6. The N-propyl analogue, 7, was prepared by catalytic reduction (Pd/C) of 6. The most potent analogue, 4a, was tritiated at a specific activity of 81.3 Ci/mmol. ({sup 3}H)4a bound rapidly and reversibly to caudate putamen membranes; the two-component binding curve typical of cocaine analogues was observed. Equilibrium was achieved within 2 h and was stable for at least 4 h. High- and low-affinity Kd values observed for ({sup 3}H)4a (4.7 and 60 nM, respectively) were more than 4 times lower than those for ({sup 3}H)cocaine, and the density of binding sites (Bmax = 50 pmol/g, high, and 290 pmol/g, low) for the two drugs were comparable. Nonspecific binding of ({sup 3}H)4a was 5-10% of total binding.

  7. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Ghodsinia, Sara S.E.; Akhlaghinia, Batool; Eshghi, Hossein, E-mail: akhlaghinia@um.ac.ir [Ferdowsi University of Mashhad (Iran, Islamic Republic of). Faculty of Sciences. Department of Chemistry; Safaei, Elham [Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of). Department of Chemistry

    2013-06-15

    N, N',N{sup ,} N{sup '}-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO{sub 4}){sub 4}) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed in refluxing H{sub 2}O. The catalyst was recovered and reused at least four times, maintaining its efficiency. (author)

  8. Aryl diazonium salts new coupling agents and surface science

    CERN Document Server

    Chehimi, Mohamed Mehdi

    2012-01-01

    Diazonium compounds are employed as a new class of coupling agents to link polymers, biomacromolecules, and other species (e. g. metallic nanoparticles) to the surface of materials. The resulting high performance materials show improved chemical and physical properties and find widespread applications. The advantage of aryl diazonium salts compared to other surface modifiers lies in their ease of preparation, rapid (electro)reduction, large choice of reactive functional groups, and strong aryl-surface covalent bonding.This unique book summarizes the current knowledge of the surface and

  9. Aryl substitution of pentacenes

    Directory of Open Access Journals (Sweden)

    Andreas R. Waterloo

    2014-07-01

    Full Text Available A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films, thermoanalytical methods (DSC and TGA, cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives. X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices.

  10. New 1-Aryl-3-Substituted Propanol Derivatives as Antimalarial Agents

    Directory of Open Access Journals (Sweden)

    Antonio Monge

    2009-10-01

    Full Text Available This paper describes the synthesis and in vitro antimalarial activity against a P. falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of the tested compounds showed an IC50 lower than 1 ?M. These compounds were also tested for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic option for the treatment of malaria.

  11. ON THE ANTIOXIDANT EFFECTIVENESS OF N,N´–SUBSTITUTED P-PHENYLENEDIAMINES

    Directory of Open Access Journals (Sweden)

    Vladimír Lukeš

    2004-10-01

    Full Text Available The ground-state geometry of six N,N’-substituted p-phenylenediamines (PPDs: N-phenyl-N’-dimethyl-butyl-p-phenylenediamine (6PPD, N-phenyl-N’-isopropyl-p-phenylenediamine (IPPD, N-phenyl-N’-(?-methylbenzyl-p-phenylenediamine (SPPD, N-(2-methoxybenzyl-N’-phenyl-p-phenylenediamine (MBPPD, N-benzyl-N’-phenyl-p-phenylenediamine (MBPPDH, N-(1-methyl-1-phenylethyl-N’-phenyl-p-phenylene-diamine (CPPD molecules, their radical structures and the energy characterisation of these molecules and radicals were theoretically investigated using PM3 method. Our calculations reveal the most probable radical formation in the order SPPD > MBPPD > MBPPDH > 6PPD > IPPD > CPPD. The theoretical values have been compared with the values obtained by the analysis of structural units contributions based on the results of non-isothermal DSC measurements. The results show that the most likely process is homolytic cleavage of C–H bond at the carbon atom in the neighbourhood of the amino nitrogen atom and the sterical arrangement is related to the antioxidant effectiveness of the antioxidants under study. The suggested models can be used for the interpretation and prediction of experimental data what is important from the technological point of view.

  12. N-substituted aminomethanephosphonic and aminomethane-P-methylphosphinic acids as inhibitors of ureases.

    Science.gov (United States)

    Berlicki, Lukasz; Bochno, Marta; Grabowiecka, Agnieszka; Bia?as, Arkadiusz; Kosikowska, Paulina; Kafarski, Pawe?

    2012-05-01

    Small unextended molecules based on the diamidophosphate structure with a covalent carbon-to-phosphorus bond to improve hydrolytic stability were developed as a novel group of inhibitors to control microbial urea decomposition. Applying a structure-based inhibitor design approach using available crystal structures of bacterial urease, N-substituted derivatives of aminomethylphosphonic and P-methyl-aminomethylphosphinic acids were designed and synthesized. In inhibition studies using urease from Bacillus pasteurii and Canavalia ensiformis, the N,N-dimethyl derivatives of both lead structures were most effective with dissociation constants in the low micromolar range (Ki=13±0.8 and 0.62±0.09 ?M, respectively). Whole-cell studies on a ureolytic strain of Proteus mirabilis showed the high efficiency of N,N-dimethyl and N-methyl derivatives of aminomethane-P-methylphosphinic acids for urease inhibition in pathogenic bacteria. The high hydrolytic stability of selected inhibitors was confirmed over a period of 30 days using NMR technique. PMID:21559954

  13. The photoredox catalyzed Meerwein arylation

    OpenAIRE

    Hari, Durga Prasada Rao

    2015-01-01

    A fundamental challenge in the field of catalysis is the development of sustainable and efficient methods for the activation of molecules. One approach for the activation of organic molecules that has recently received much attention is photoredox catalysis with visible light. On the other hand, the application of aryl radicals in organic synthesis is challenging, but very useful. This thesis describes the generation of aryl radicals and their application in organic synthesis, such as the dir...

  14. Antibacterial and Enzyme Inhibition Studies of N'-Substituted Benzylidene-2-(2, 4-Dimethylphenoxy Acetatohydrazides

    Directory of Open Access Journals (Sweden)

    1S. Nadeem

    2014-09-01

    Full Text Available The molecules bearing azomethine group are known to possess biological activities. In the present work, the synthesis of N'-Substitutedbenzylidene-2-(2, 4-dimethylphenoxy acetatohydrazide (5a-d has been elaborated using 2,4-Dimethylphenol (1 as precursor. The molecule, 1, was converted to ethyl 2-(2,4-dimethylphenoxyacetate (2 on refluxing with ethyl 2-bromoacetate in ethanol in the presence of KOH. Ethyl ester, 2, was refluxed with hydrated hydrazine (80% in ethanol to yield 2-(2,4-dimethylphenoxy acetohydrazide (3. The target molecules, 5a-d, were synthesized by stirring 3 with phenyl/aryl carboxaldehyde (4a-d in methanol in the presence of glacial acetic acid. The synthesized molecules were characterized by spectral data and evaluated for antibacterial and anti-enzymatic activities.

  15. Chemometric approach in studying of the retention behavior and lipophilicity of potentially biologically active N-substituted-2-phenylacetamide derivatives

    Scientific Electronic Library Online (English)

    Gyöngyi Gy., Vastag; Suzana Lj., Apostolov; Borko M., Matijevi& #263; ; Aleksandar D., Marinkovi& #263; .

    2014-11-01

    Full Text Available A atividade biológica potencial de moléculas depende largamente da sua lipofilicidade. A lipofilicidade de derivados de 2-fenilacetamida N-substituída foi investigada experimentalmente, aplicando cromatografia em camada delgada em fase inversa (RP-TLC em RP 18 F254s) na presença de etanol e de dioxa [...] no, e usando pacotes de software. A fim de estabelecer a dependência entre a lipofilicidade obtida de diferentes formas foram usados análise de regressão linear e métodos multivariados. Agrupamentos aproximadamente semelhantes dos parâmetros lipofílicos e dos compostos testados foram registados no caso de ambos os métodos quimiométricos usados. Todos os resultados obtidos confirmam o fato de que as análises de regressão linear e multivariada aplicadas oferecem oportunidades para comparar os dados sobre a retenção cromatográfica e parâmetros lipofílicos dos derivados de fenilacetamida investigados. Os resultados sugerem que a lipofilicidade das moléculas estudadas depende largamente da natureza dos substituintes ligados ao átomo de nitrogênio e, por outro lado, que as constantes retenção cromatográfica, R M0, determinada pelo método de RP-TLC, são semelhantes à medida padrão de lipofilicidade, log P, o que torna este método adequado para a previsão de lipofilicidade. Abstract in english The potential biological activity of a molecule largely depends on its lipophilicity. The lipophilicity of derivatives of N-substituted-2-phenylacetamide was investigated experimentally, by applying thin-layer chromatography on reversed phase (RP-TLC on RP 18 F254s) in the presence of ethanol and di [...] oxane and by using relevant software packages. In order to establish dependence between lipophilicity obtained in different ways, linear regression analysis and multivariate methods were used. Approximately similar groupings of lipophilic parameters and tested compounds were registered in case of both chemometric methods. The obtained results confirm the fact that the applied linear regression analysis and multivariate analysis provide opportunities for comparing chromatographic retention data and lipophilic parameters of the investigated phenylacetamide derivatives. Results suggest that the lipophilicity of investigated molecules largely depends on the nature of the substituents linked to nitrogen atom and on the other hand that the chromatographic retention constants, R M0, determined by RP-TLC method, are similar to the standard measure of lipophilicity, log P, which makes this method appropriate for predicting lipophilicity.

  16. Smiles Rearrangement Based Practical One-pot Synthesis of N-Alkyl/aryl-6-aminoquinolines from 6-Hydroxylquinoline

    International Nuclear Information System (INIS)

    The C-N coupling protocol reported herein represents a convenient and practical synthesis of N-alkyl/aryl-6-aminoquinolines in a three-step one-pot manner by simple addition of 6-hydroxyquinoline and N-alkyl/aryl-2-chloroacetamides with Cs2CO3 or K2CO3 in DMF at 150 .deg. C via Smiles rearrangement. An electron donating substituent on the nitrogen counterpart would accelerate the rearrangement process to achieve various anilines in good yields. We currently engaged in making a chemical library including multifarious N-substituted-6-aminoquinolines, to be used in the screening for specific AChEI activity. Furthermore, this work extends the scope of preparing different heterocyclic synthons in drug design for various biological activities. Aminoquinolines and their derivatives are important chemical entities that are widely used as pro-drugs and drugs due to their antimicrobial, cytotoxic and anti-malarial activities etc

  17. Synthesis, Antibacterial and Antifungal Activity of 4-Substituted-5-Aryl-1,2,4-Triazoles

    Directory of Open Access Journals (Sweden)

    Aleksandra Buzarovska

    2001-09-01

    Full Text Available A few 4-allyl/amino-5-aryl-1,2,4-triazoles were synthesized and tested for antibacterial and antifungal effects against Escherichia coli, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Aspergillus niger and Candida albicans. 4-Allyl-5-aryl-1,2,4-triazoles were obtained by the oxidative cyclization of the appropriate 1-substituted-4-allylthiosemicarbazides and 4-amino-5-aryl-1,2,4-triazoles were obtained by cyclization of the potassium salts of appropriately substituted dithiocarbazinic acids with hydrazine hydrate. The new synthesized compounds were characterized using IR, 1H- NMR, 13C-NMR and UV spectral data together with elemental analysis.

  18. SYNTHESIS AND ANTIMICROBIAL EVALUATION OF 2-(4-FLUORO BENZYLTHIO-N-(SUBSTITUTED PHENYLPYRIMIDINE-4-AMINES

    Directory of Open Access Journals (Sweden)

    N.M. Goudgaon*, Y. Rohini Reddy and B.U. Sheshikant

    2013-11-01

    Full Text Available Reaction of 4-fluorobenzylchloride with 2-thiouracil (1 gave 2-(4-fluorobenzylthiopyrimidin-4(3H-one (2, which on chlorination with POCl3 furnished 4-chloro-2-(4-fluorobenzylthio-4-chloropyrimidine (3. This intermediate when treated with various substituted anilines gave desired targeted compounds 4(a-k in 50-90% yield. Structural assignments of the synthesized compounds were based on their IR, 1H NMR, Mass and analytical data. The antimicrobial evaluation of newly synthesized compounds was carried out by cup-plate method. The investigation of antimicrobial screening reveals that the compounds 4b, 4g, 4c and 4f showed good activity against bacterial strain B. subtilis. Compounds 4a, 4e, 4b, 4c, 4f, 4g and 4h were active against bacterial strain P. aeruginosa. Compounds 4a and 4c were active against fungul strain A. niger. Compounds 4e, 4b and 4j showed good activity against fungal strain A. flavus. All the synthesized compounds showed excellent antifungal activity against T.viridae. Remaining compounds exhibited moderate to poor activity against bacterial and fungal strains when compared to standard drugs Gentamycin and Fluconazole respectively. So, further we have carried out the antifungal screening of all the synthesized compounds at different concentrations against T. viridae to determine their IC50 values. Compounds 4e, 4b, 4g, 4i, 4d, 4f and 4j have shown better IC50 values.

  19. Palladium-catalyzed aminosulfonylation of aryl halides.

    OpenAIRE

    B. Van Nguyen; Emmett, EJ; Willis, MC

    2010-01-01

    The palladium-catalyzed three-component coupling of aryl iodides, sulfur dioxide, and hydrazines to deliver aryl N-aminosulfonamides is described. The colorless crystalline solid DABCO·(SO(2))(2) was used as a convenient source of sulfur dioxide. The reaction tolerates significant variation of both the aryl iodide and hydrazine coupling partners.

  20. Aryl bromides as inexpensive starting materials in the catalytic enantioselective arylation of aryl aldehydes: the additive TMEDA enhances the enantioselectivity.

    Science.gov (United States)

    Yang, Yong-Xin; Liu, Yue; Zhang, Lei; Jia, Yan-E; Wang, Pei; Zhuo, Fang-Fang; An, Xian-Tao; Da, Chao-Shan

    2014-11-01

    We used aryl bromides as inexpensive starting materials to enantioselectively arylate aldehydes in one pot. Aryl bromides readily transfer aryls to aryllithiums with n-butyllithium, successively to triarylaluminums with aluminum chloride, and then to aryltitaniums with titanium isopropoxide. Finally aryltitaniums arylate aldehydes catalyzed by (S)-H8-BINOL-Ti(Oi-Pr)2 in excellent yields and enantioselectivities. The additive TMEDA evidently suppresses the racemic background reaction promoted by LiCl generated from salt metathesis. This procedure represents a cost-effective and operationally convenient method for enantioenriched diarylmethanols. PMID:25279967

  1. Anti-Candida activity and cytotoxicity of a large library of new N-substituted-1,3-thiazolidin-4-one derivatives.

    Science.gov (United States)

    De Monte, Celeste; Carradori, Simone; Bizzarri, Bruna; Bolasco, Adriana; Caprara, Federica; Mollica, Adriano; Rivanera, Daniela; Mari, Emanuela; Zicari, Alessandra; Akdemir, Atilla; Secci, Daniela

    2016-01-01

    On the basis of the recent findings about the biological properties of thiazolidinones and taking into account the encouraging results about the antifungal activity of some (thiazol-2-yl)hydrazines, new N-substituted heterocyclic derivatives were designed combining the thiazolidinone nucleus with the hydrazonic portion. In details, 1,3-thiazolidin-4-ones bearing (cyclo)aliphatic or (hetero)aromatic moieties linked to the N1-hydrazine at C2 were synthesized and classified into three series according to the aromatic or bicyclic rings connected to the lactam nitrogen of the thiazolidinone. These molecules were assayed for their anti-Candida effects in reference to the biological activity of the conventional topic (clotrimazole, miconazole, tioconazole) and systemic drugs (fluconazole, ketoconazole, amphotericin B). Finally, we investigated the selectivity against fungal cells by testing the compounds endowed with the best MICs on Hep2 cells in order to assess their cell toxicity (CC50) and we noticed that two derivatives were less cytotoxic than the reference drug clotrimazole. Moreover, a preliminary molecular modelling approach has been performed against lanosterol 14-? demethylase (CYP51A1) to rationalize the activity of the tested compounds and to specify the target protein or enzyme. PMID:26562544

  2. Solvent-Free Synthesis, DNA-Topoisomerase II Activity and Molecular Docking Study of New Asymmetrically N,N'-Substituted Ureas

    Directory of Open Access Journals (Sweden)

    Aurea Echevarria

    2012-11-01

    Full Text Available A new series of asymmetrically N,N'-substituted ureas 20–25 was prepared using solvent free conditions, which is an eco-friendly methodology, starting with Schiff bases derived from cinnamaldehyde and p-substituted anilines, which are subsequently submitted to reduction reactions that afford the corresponding asymmetric secondary amines. All of the intermediates were prepared using solvent free reactions, which were compared to traditional methodologies. All of the reactions required a remarkably short amount of time and provided good yields when solvent free conditions were employed compared to other methodologies. The DNA-topoisomerase II-α (topo II-α activity was evaluated in relaxation assays, which showed that all of the compounds inhibited the enzyme activity at 10 μM, except for urea 24. Furthermore, a molecular docking study indicated that the compounds 20–25 binding to the topo II-α are able to interact with the same binding site as the anticancer drug etoposide, suggesting that the ureas could inhibit the enzyme by the same mechanism of action observed for etoposide, which prevents re-ligation of the DNA strands.

  3. Synthesis and characterisation of new 4-oxo-N-(substituted-thiazol-2-yl)-4H-chromene-2-carboxamides as potential adenosine receptor ligands

    Science.gov (United States)

    Cagide, Fernando; Borges, Fernanda; Gomes, Ligia R.; Low, John Nicolson

    2015-06-01

    Chromones are 4H-benzopyran-4-one heterocycles that have been thoroughly studied due to their interesting biological activities. Thiazole based compounds have been used in therapeutics as antimicrobial, antiviral and as antifungal agents for a long time but, in the past decades, they have been identified as potent and selective ligands for adenosine receptor. In continuation of our project related to the syntheses of pharmacologically important heterocycles, a new series of chromone-thiazole hybrids have been designed as potential ligands for human adenosine receptors. In this context, new 4-oxo-N-(substituted-thiazol-2-yl)-4H-chromene-2-carboxamides were synthesized from chromone-2-carboxylic acid by two different amidation methods. The development of dissimilar synthetic approaches provided the possibility of working with diverse reaction conditions, namely with conventional heating and/or microwave irradiation. The structure of the compounds has been established on the basis of NMR and MS spectroscopy and X-ray crystallography. Relevant data related to the molecular geometry and conformation of the chromone-thiazole hybrids has been acquired which can be of the utmost importance to understand ligand-receptor binding.

  4. Palladium-Catalyzed Thiocarbonylation of Aryl, Vinyl, and Benzyl Bromides

    DEFF Research Database (Denmark)

    Burhardt, Mia; Ahlburg, Andreas

    2014-01-01

    A catalytic protocol for synthesis of thioesters from aryl, vinyl, and benzyl bromides as well as benzyl chlorides was developed using only stoichiometric amounts of carbon monoxide, produced from a solid CO precursor inside a two-chamber system. As a catalytic system, the combination of bis(benzonitrile) palladium(II) chloride and Xantphos furnished the highest yields of the desired compounds, along with the weak base, NaOAc, in anisole at 120 °C. The choice of catalytic system as well as solvent turned out to be important in order to ensure a high chemoselectivity in the reaction. Both electron-rich and electron-deficient aryl bromides worked well in this reaction. Addition of 1 equiv of sodium iodide to the reaction improved the chemoselectivity with the electron-deficient aryl bromides. The thiol scope included both aryl and alkyl thiols, including 2-mercaptobenzophenones, whereby a thiocarbonylation followed by a subsequent McMurry coupling yielded differently substituted benzothiophenes. It was demonstrated that the methodology could be applied for (13)C introduction into the thiophene ring.

  5. Palladium-catalyzed thiocarbonylation of aryl, vinyl, and benzyl bromides.

    Science.gov (United States)

    Burhardt, Mia N; Ahlburg, Andreas; Skrydstrup, Troels

    2014-12-19

    A catalytic protocol for synthesis of thioesters from aryl, vinyl, and benzyl bromides as well as benzyl chlorides was developed using only stoichiometric amounts of carbon monoxide, produced from a solid CO precursor inside a two-chamber system. As a catalytic system, the combination of bis(benzonitrile) palladium(II) chloride and Xantphos furnished the highest yields of the desired compounds, along with the weak base, NaOAc, in anisole at 120 °C. The choice of catalytic system as well as solvent turned out to be important in order to ensure a high chemoselectivity in the reaction. Both electron-rich and electron-deficient aryl bromides worked well in this reaction. Addition of 1 equiv of sodium iodide to the reaction improved the chemoselectivity with the electron-deficient aryl bromides. The thiol scope included both aryl and alkyl thiols, including 2-mercaptobenzophenones, whereby a thiocarbonylation followed by a subsequent McMurry coupling yielded differently substituted benzothiophenes. It was demonstrated that the methodology could be applied for (13)C introduction into the thiophene ring. PMID:24919457

  6. Potency and species specificity of aryl hydrocarbon receptor ligands

    OpenAIRE

    Wall, Richard John

    2012-01-01

    The aryl hydrocarbon receptor (AhR) binds a wide range of structurally diverse compounds such as halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls which are abundant in the environment. Activation of AhR leads to the regulation of a battery of xenobiotic enzymes including cytochrome P4501A1 (CYP1A1). The purely chlorinated compounds feature in the World Health Organisation’s (WHO) evaluation of dioxin-like compounds derived from a meta-analysis of previous potency data (toxic equival...

  7. Comparative study of spectroscopic properties of the low-lying electronic states of 2,4-pentadien-1-iminium cation and its N-substituted analogues

    Indian Academy of Sciences (India)

    Anjan Chattopadhyay

    2012-09-01

    Semiempirical and ab initio-based CI methods have been employed to study the low-lying electronic states of 2,4-pentadien-1-iminium cation and its N-substituted analogues with electron-donating (methyl, isopropyl) and electron-withdrawing (fluoromethyl) groups on nitrogen. Variations of the dihedral angles (Γ3, Γ4) of the ground state have given the global minima and global maxima at (180°, 180°) and (90°, 0°) conformations, respectively, with some exceptions in the case of fluoromethyl compound. Increase in the +I effect on nitrogen shifts the TICT conical intersection point away from the 90° (Γ3 dihedral angle) value, when the Γ4 value is kept fixed at 180°. Transition moment values of the allowed S0(1A -like) → S1 (2B-like) transitions are expectedly higher than the forbidden S0(1A -like) → S2(2A -like) transitions by almost 5.6 D. Radiative lifetime values of the first excited states are calculated to be around 215 ps for all the four compounds. At (180°, 180°) conformation the vertical excitation energy (VEE) between the S0 and S1 states of the 2,4-pentadieniminium cation is found to be 3.3 eV, which corresponds to the absorption wavelength value of roughly 375 nm. The VEE value increases with substituents having +I effect on nitrogen, while for the fluoromethyl compound it is calculated to be around 2.85 eV. The energy gap between the first two excited singlet states is found to have the least value in the isopropyl-substituted compound, where the S2 state contains a huge contribution from the HOMO2→LUMO2 configuration.

  8. Toxicity Studies on Novel N-Substituted Bicyclo-Heptan-2-Amines at NMDA Receptors

    Directory of Open Access Journals (Sweden)

    Michelle Farbaniec

    2013-04-01

    Full Text Available Several novel norcamphor derivatives were designed and synthesized as uncompetitive NMDA receptor antagonists at the phencyclidine (PCP binding site. Such compounds have potential as ligands for understanding and possibly the treatment of several neurodegenerative disorders and other glutamate-dependent disorders. We examined the toxic effects of the compounds as compared with memantine, an NMDA receptor antagonist that is FDA approved for treatment of Alzheimer’s disease, by testing these compounds on two cell lines: MDCK (to mimic blood brain barrier and N2a (a neuronal cell line. The compounds showed toxicity profiles similar to those of memantine i.e., dose dependence above 100 ?M and IC50 values above 150 ?M for each cell line. It is known that the serum level of memantine under therapeutic conditions in patients is about 1 µM, indicting these compounds could have acceptable therapeutic indexes. 2-Phenyl-N-(2-(piperidin-1-yl ethylbicyclo[2.2.1]heptan-2-amine (5a was found to possess acceptable toxicity profiles in both cell lines. Interestingly, this was the compound identified as a good lead in our previous studies based on binding and anticonvulsant (MES activity studies. It has thus emerged as an excellent lead compound for further studies.

  9. Reductive cleavage of N-substituted aromatic amides as tert-butyl acylcarbamates

    OpenAIRE

    Ragnarsson, Ulf; Grehn, Leif; Maia, Hernâni L. S.; Monteiro, Luís S.

    2002-01-01

    Synthetic and spectroscopic details related to a set of heteroaromatic N-benzyl carboxamides and especially the corresponding tert-butyl acylcarbamates are reported. These compounds were required to study the postulated effect of various heterocycles (pyridine and pyrazine with and without condensed benzene rings) on the cleavage of acyl-N bonds by reduction. All compounds were initially characterized by cyclic voltammetry which indicated various degrees of facilitated reduction, reflecting a...

  10. Substituent effect on the photolability of 4-aryl-1,4-dihydropyridines.

    Science.gov (United States)

    García, Cristóbal; Cabezas, Karina; Nonell, Santi; Núñez-Vergara, Luis J; Morales, Javier; Günther, Germán; Pizarro, Nancy

    2013-10-01

    The electronic nature of substituents attached to the 4-aryl moiety of 1,4-dihydropyridines strongly affect the photophysical and photochemical behavior of these family of compounds. The presence of an electron-donor substituent on the 4-aryl moiety (or the absence of electron-withdrawing ones), modifies the luminescence lifetimes (? changing more than two orders of magnitude as the polarity is increased. Studies in micellar media allow us to conclude that 4-aryl-1,4-dihydropyridines are located near to the interface, however the surface charge of micelles has no effect on the photodegradation rate constant or the photoproducts profile. The main conclusion of this work is that the photolability of 4-aryl-1,4-dihydropyridines can be significantly reduced by the incorporation of antioxidant moieties. This article is protected by copyright. All rights reserved. PMID:24112052

  11. Three New Sesquiterpene Aryl Esters from the Mycelium of Armillaria mellea

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2015-05-01

    Full Text Available Three new sesquiterpene aryl esters and eight known compounds were isolated from the EtOH extract of the mycelium of Armillaria mellea. The structures of new compounds were established by analysis of their spectroscopic data. Some of the isolates showed cytotoxicity to a variety of cancer cell lines, including MCF-7, H460, HT-29, and CEM.

  12. Convenient preparation of deuterium-labeled analogs of peptides containing N-substituted glycines for a stable isotope dilution LC-MS quantitative analysis.

    Science.gov (United States)

    B?chor, Remigiusz; D?bowski, Dawid; ??gowska, Anna; Stefanowicz, Piotr; Rolka, Krzysztof; Szewczuk, Zbigniew

    2015-11-01

    N-substituted glycines constitute mimics of natural amino acids that are of great interest in the peptide-based drug development. Peptoids-oligo(N-substituted glycines) have been recently demonstrated to be highly active peptidomimetics in biological systems, resistant to proteolytic degradation. We developed a method of the deuterium labeling of peptidomimetics containing N-substituted glycine residues via H/D exchange of their ?-carbon hydrogen atoms. The labeling was shown to be easy, inexpensive, and without the use of derivatization reagents or the need for a further purification. The deuterons introduced at the ?-carbon atoms do not undergo a back exchange under acidic conditions during liquid chromatography mass spectrometry (LC-MS) analysis. The LC-MS analysis of a mixture of isotopologues revealed a co-elution of deuterated and nondeuterated forms of the peptidomimetics, which may be useful in the quantitative isotope dilution analysis of peptoids and other derivatives of N-substituted glycines. PMID:26415697

  13. Room-temperature chromium(II)-catalyzed direct arylation of pyridines, aryl oxazolines, and imines using arylmagnesium reagents.

    Science.gov (United States)

    Kuzmina, Olesya M; Knochel, Paul

    2014-10-01

    We report a CrCl2-catalyzed oxidative arylation of various pyridines, aryl oxazolines, and aryl imines using aromatic Grignard reagents in the presence of 2,3-dichlorobutane (DCB). Most of the reactions proceed rapidly at 25 °C and do not require any additional ligand. Benzo[h]quinoline, 2-arylpyridine, aryl oxazoline, and imines were successfully arylated in good yields under these conditions. A TMS-substituent was used to prevent double arylation. After oxidative cross-coupling the TMS-group was further converted to a second ortho-aryl substituent. Remarkably, inexpensive aryl N-butylimine derivatives are excellent substrates for this oxidative arylation. PMID:25230000

  14. Optimized Anti-pathogenic Agents Based on Core/Shell Nanostructures and 2-((4-Ethylphenoxyethyl-N-(substituted-phenylcarbamothioyl-benzamides

    Directory of Open Access Journals (Sweden)

    Mariana Carmen Chifiriuc

    2012-10-01

    Full Text Available The purpose of this study was to design a new nanosystem for catheter surface functionalization with an improved resistance to Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853 colonization and subsequent biofilm development. New 2-((4 ethylphenoxymethyl-N-(substituted-phenylcarbamothioyl-benzamides were synthesized and used for coating a core/shell nanostructure. Their chemical structures were elucidated by NMR, IR and elemental analysis, being in agreement with the proposed ones. Fe3O4/C12 of up to 5 nm size had been synthesized with lauric acid as a coating agent and characterized by XRD, FT-IR, TGA, TEM and biological assays. The catheter pieces were coated with the fabricated nanofluid in magnetic field. The microbial adherence ability was investigated in 6 multiwell plates by using culture based methods and Scanning Electron Microscopy (SEM. The nanoparticles coated with the obtained compounds 1a–c inhibited the adherence and biofilm development ability of the S. aureus and P. aeruginosa tested strains on the catheter functionalized surface, as shown by the reduction of viable cell counts and SEM examination of the biofilm architecture. Using the novel core/shell/adsorption-shell to inhibit the microbial adherence could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with improved anti-biofilm properties.

  15. Synthesis and evaluation of dual antiplatelet activity of bispidine derivatives of N-substituted pyroglutamic acids.

    Science.gov (United States)

    Misra, Ankita; Anil Kumar, K S; Jain, Manish; Bajaj, Kirti; Shandilya, Shyamali; Srivastava, Smriti; Shukla, Pankaj; Barthwal, Manoj K; Dikshit, Madhu; Dikshit, Dinesh K

    2016-03-01

    N-aralkylpyroglutamides of substituted bispidine were prepared and evaluated for their ability to inhibit collagen induced platelet aggregation, both in vivo and in vitro. Some compounds showed high anti-platelet efficacy (in vitro) of which six inhibited both collagen as well as U46619 induced platelet aggregation with concentration dependent anti-platelet efficacy through dual mechanism. In particular, the compound 4j offered significant protection against collagen epinephrine induced pulmonary thromboembolism as well as ferric chloride induced arterial thrombosis, without affecting bleeding tendency in mice. Therefore, the present study suggests that the compound 4j displays a remarkable antithrombotic efficacy much better than aspirin and clopidogrel. PMID:26807542

  16. Dinitroso and polynitroso compounds

    OpenAIRE

    Gowenlock, Brian G.; Richter-Addo*, George B.

    2005-01-01

    The growing interest in the chemistry of C-nitroso compounds (RN=O; R = alkyl or aryl group) is due in part to the recognition of their participation in various metabolic processes of nitrogen-containing compounds. C-Nitroso compounds have a rich organic chemistry in their own right, displaying interesting intra- and intermolecular dimerization processes and addition reactions with unsaturated compounds. In addition, they have a fascinating coordination chemistry. While most of the attention ...

  17. Rh(I)-Catalyzed Direct Arylation of Pyridines and Quinolines

    Energy Technology Data Exchange (ETDEWEB)

    Berman, Ashley; Lewis, Jared; Bergman, Robert; Ellman, Jonathan

    2008-07-29

    The pyridine and quinoline nuclei are privileged scaffolds that occupy a central role in many medicinally relevant compounds. Consequently, methods for their expeditious functionalization are of immediate interest. However, despite the immense importance of transition-metal catalyzed cross-coupling for the functionalization of aromatic scaffolds, general solutions for coupling 2-pyridyl organometallics with aryl halides have only recently been presented. Direct arylation at the ortho position of pyridine would constitute an even more efficient approach because it eliminates the need for the stoichiometric preparation and isolation of 2-pyridyl organometallics. Progress towards this goal has been achieved by activation of the pyridine nucleus for arylation via conversion to the corresponding pyridine N-oxide or N-iminopyridinium ylide. However, this approach necessitates two additional steps: activation of the pyridine or quinoline starting material, and then unmasking the arylated product. The use of pyridines directly would clearly represent the ideal situation both in terms of cost and simplicity. We now wish to document our efforts in this vein, culminating in an operationally simple Rh(I)-catalyzed direct arylation of pyridines and quinolines. We recently developed an electron-rich Rh(I) system for catalytic alkylation at the ortho position of pyridines and quinolines with alkenes. Therefore, we initially focused our attention on the use of similarly electron-rich Rh(I) catalysts for the proposed direct arylation. After screening an array of electron-rich phosphine ligands and Rh(I) salts, only marginal yields (<20%) of the desired product were obtained. Much more efficient was an electron-poor Rh(I) system with [RhCl(CO){sub 2}]{sub 2} as precatalyst (Table 1). For the direct arylation of picoline with 3,5-dimethyl-bromobenzene, addition of P(OiPr){sub 3} afforded a promising 40% yield of the cross coupled product 1a (entry 1). The exclusion of phosphite additive proved even more effective, with the yield of 1a improving to 61% (entry 2). Further enhancement in yield was not observed upon the inclusion of other additives such as MgO (entry 3), various organic bases (entries 4, 5), or a protic acid source (entry 6). Absolute concentration proved very important, with the best results being obtained at relatively high concentrations of the aryl bromide (compare entries 7 and 8). A marginal improvement was observed upon running the reaction with 6 equivalents of 2-methyl pyridine (entry 9). The reaction temperature could also be increased to 175 or 190 C while maintaining reaction yield, to enable the reaction time to be reduced to 24 h (entries 10 and 11). In summary, we have developed a Rh(I)-catalyzed strategy for the direct arylation of pyridines and quinolines. The heterocycle is used without the need for prefunctionalization, and all reaction components are inexpensive and readily available. The strategy represents an expeditious route to an important class of bis(hetero)aryls and should be of broad utility.

  18. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    Scientific Electronic Library Online (English)

    Sara S. E., Ghodsinia; Batool, Akhlaghinia; Elham, Safaei; Hossein, Eshghi.

    2013-06-01

    Full Text Available N,N',N'',N'''-Tetrametil tetra(2,3-piridil)porfirazinato metil sulfato de cobre(II) ([Cu(2,3-tmtppa)](MeSO4)4) catalisou com sucesso a conversão direta de nitrilas a amidas N-substituídas. A síntese seletiva do tipo one pot de amidas N-substituídas a partir de nitrilas e aminas primárias foi realiza [...] da em refluxo de água. O catalisador foi recuperado e reusado no mínimo 4 vezes, mantendo a sua eficiência. Abstract in english N,N',N'',N'''-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO4)4) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed [...] in refluxing H2O. The catalyst was recovered and reused at least four times, maintaining its efficiency.

  19. Application of double-hybrid density functionals to charge transfer in N-substituted pentacenequinones

    Science.gov (United States)

    Sancho-García, J. C.

    2012-05-01

    A set of N-heteroquinones, deriving from oligoacenes, have been recently proposed as n-type organic semiconductors with high electron mobilities in thin-film transistors. Generally speaking, this class of compounds self-assembles in neighboring ?-stacks linked by weak hydrogen bonds. We aim at theoretically characterizing here the sequential charge transport (hopping) process expected to take place across these arrays of molecules. To do so, we need to accurately address the preferred packing of these materials simultaneously to single-molecule properties related to charge-transfer events, carefully employing dispersion-corrected density functional theory methods to accurately extract the key molecular parameters governing this phenomenon at the nanoscale. This study confirms the great deal of interest around these compounds, since controlled functionalization of model molecules (i.e., pentacene) allows to efficiently tune the corresponding charge mobilities, and the capacity of modern quantum-chemical methods to predict it after rationalizing the underlying structure-property relationships.

  20. Synthesis of N-substituted phthalimidoalkyl 1,2,3-triazoles via click chemistry

    Directory of Open Access Journals (Sweden)

    Moara T. da Silva

    2012-06-01

    Full Text Available In the present work, we have developed a facile procedure for synthesis of new N-phthalimidoalkyl 1H-1,2,3-Triazoles (1-4(a-h using DMF, 10 mol% CuI, Et3N and ultrasound energy at room temperature. This protocol furnished 28 new compounds in 20 to 30 min of reaction and moderate-to-excellent yields (64-94%.

  1. Silver-Mediated Oxidative Trifluoromethylation of Phenols: Direct Synthesis of Aryl Trifluoromethyl Ethers.

    Science.gov (United States)

    Liu, Jian-Bo; Chen, Chao; Chu, Lingling; Chen, Zeng-Hao; Xu, Xiu-Hua; Qing, Feng-Ling

    2015-09-28

    Aryl trifluoromethyl ethers (ArOCF3 ) are prevalent in pharmaceuticals, agrochemicals, and materials. However, methods for the general and efficient synthesis of these compounds are extremely underdeveloped and limited. Herein, we describe a highly efficient and general procedure for the direct O-trifluoromethylation of unprotected phenols through a silver-mediated cross-coupling reaction using CF3 SiMe3 as the CF3 source and exogenous oxidants. This novel oxidative trifluoromethylation provides access to a wide range of aryl trifluoromethyl ethers from simple phenols. The mild process was also applied to the late-stage trifluoromethylation of a medicinally relevant compound. PMID:26268604

  2. Involvenflavones A-F, six new flavonoids with 3'-aryl substituent from Selaginella involven.

    Science.gov (United States)

    Long, Hong-Ping; Zou, Hui; Li, Fu-Shuang; Li, Jing; Luo, Ping; Zou, Zhen-Xing; Hu, Chang-Ping; Xu, Kang-Ping; Tan, Gui-Shan

    2015-09-01

    Six new flavonoids, involvenflavones A-F (1-6), were isolated from Selaginella involven. Their structures were elucidated based on UV, IR, 1D and 2D NMR as well as HR-ESI-MS techniques. All compounds belong to apigenin derivatives with 3'-aryl substituent. This is the first report of the apigenin derivatives with 3'-aryl substituent from nature resources. These compounds also exhibited a potent effect against the injury of human umbilical vein endothelial cell (HUVECs) induced by high concentrations of glucose in vitro. PMID:26226107

  3. Synthesis, characterization and antibacterial activity of halogenated aryl sulfonamides derived from 2-amino-4-chloroanisole

    International Nuclear Information System (INIS)

    In the current work, a number of new N-(5-chloro-2-methoxyphenyl)aryl sulfonamides (3a-e) and N-ethyl/benzyl-N-(5-chloro-2-methoxyphenyl)aryl sulfonamides (6a-e and 7a-e) were synthesized and evaluated for their biological activities. The synthesis was carried out by coupling 2-amino-4-chloroanisole (1) with different aryl sulfonyl chlorides, 2a-e, under dynamic pH control in aqueous medium to form aryl sulfonamides, 3a-e. Further, N-ethyl/benzyl-N-(5-chloro-2-methoxyphenyl)aryl sulfonamides (6a-e and 7a-e) were synthesized by stirring 3a-e with the electrophiles, 4 and 5, in the presence of sodium hydride and N,N-dimethylformamide. The structures of the synthesized compounds were characterized from their spectral data. In addition, the in vitro antibacterial activity of all the target compounds was investigated against Gram-negative and Gram-positive bacteria using ciprofloxacin as a reference drug. Many of these compounds exhibited moderate to good activity and subtle structural changes in the substituents altered the inhibitory properties significantly. (author)

  4. Compound

    Science.gov (United States)

    Suzumura, Akitoshi; Watanabe, Masaki; Nagasako, Naoyuki; Asahi, Ryoji

    2014-06-01

    Recently, Cu-based chalcogenides such as Cu3SbSe4, Cu2Se, and Cu2SnSe3 have attracted much attention because of their high thermoelectric performance and their common feature of very low thermal conductivity. However, for practical use, materials without toxic elements such as selenium are preferable. In this paper, we report Se-free Cu3SbS4 thermoelectric material and improvement of its figure of merit ( ZT) by chemical substitutions. Substitutions of 3 at.% Ag for Cu and 2 at.% Ge for Sb lead to significant reductions in the thermal conductivity by 37% and 22%, respectively. These substitutions do not sacrifice the power factor, thus resulting in enhancement of the ZT value. The sensitivity of the thermal conductivity to chemical substitutions in these compounds is discussed in terms of the calculated phonon dispersion and previously proposed models for Cu-based chalcogenides. To improve the power factor, we optimize the hole carrier concentration by substitution of Ge for Sb, achieving a power factor of 16 ?W/cm K2 at 573 K, which is better than the best reported for Se-based Cu3SbSe4 compounds.

  5. Effects of pesticide compounds (chlorothalonil and mancozeb) and benzo[a]pyrene mixture on aryl hydrocarbon receptor, p53 and ubiquitin gene expression levels in haemocytes of soft-shell clams (Mya arenaria).

    Science.gov (United States)

    Pariseau, Julie; McKenna, Patricia; Aboelkhair, Mohammed; Saint-Louis, Richard; Pelletier, Emilien; Davidson, T Jeffrey; Tremblay, Réjean; Berthe, Franck C J; Siah, Ahmed

    2011-11-01

    The aim of this study is to investigate the effects of the pesticides/polycyclic aromatic hydrocarbon mixture on aryl hydrocarbon receptor (AhR), p53 and ubiquitin mRNA level in haemocytes of Mya arenaria exposed to a mixture of chlorothalonil, mancozeb and benzo[a]pyrene (BaP) for 48 and 72 h. AhR, p53 and ubiquitin gene expression levels were quantified using quantitative Real-time PCR. For robust and accurate quantification of transcripts, suitable housekeeping genes were selected from four sets of ribosomal and elongation factors transcripts previously sequenced from Mya arenaria using geNorm open source software. Quantitative Real-time PCR data exhibited a significantly high expression of AhR after 72 h of exposure (P ? 0.05). p53 gene expression seems to be up-regulated by the mixture after 48 h, however not significantly; but the level of p53 mRNA is down-regulated by the xenobiotics between 48 and 72 h after exposure. This study postulates that AhR mRNA levels could be used as an indicator of the exposure of clams' haemocytes to a mixture of xenobiotics such as chlorothalonil, mancozeb and BaP. However, further studies have to be pursued in order to unravel the molecular mechanisms involved in the p53 signaling pathway. PMID:21688059

  6. Synthesis, antimicrobial, and anti-inflammatory activity, of novel S-substituted and N-substituted 5-(1-adamantyl-1,2,4-triazole-3-thiols

    Directory of Open Access Journals (Sweden)

    Al-Abdullah ES

    2014-05-01

    Full Text Available Ebtehal S Al-Abdullah,1 Hanadi H Asiri,1 Siham Lahsasni,2 Elsayed E Habib,3 Tarek M Ibrahim,4 Ali A El-Emam1 1Department of Pharmaceutical Chemistry, College of Pharmacy, 2Department of Chemistry, College of Sciences, King Saud University, Riyadh, 3Department of Pharmaceutics and Pharmaceutical Technology, College of Pharmacy, Taibah University, Medinah, Saudi Arabia; 4Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Mansoura, Mansoura, Egypt Abstract: The reaction of 5-(1-adamantyl-4-phenyl-1,2,4-triazoline-3-thione (compound 5 with formaldehyde and 1-substituted piperazines yielded the corresponding N-Mannich bases 6a–f. The reaction of 5-(1-adamantyl-4-methyl-1,2,4-triazoline-3-thione 8 with various 2-aminoethyl chloride yielded separable mixtures of the S-(2-aminoethyl 9a–d and the N-(2-aminoethyl 10a–d derivatives. The reaction of compound 5 with 1-bromo-2-methoxyethane, various aryl methyl halides, and ethyl bromoacetate solely yielded the S-substituted products 11, 12a–d, and 13. The new compounds were tested for activity against a panel of Gram-positive and Gram-negative bacteria and the pathogenic fungus Candida albicans. Compounds 6b, 6c, 6d, 6e, 6f, 10b, 10c, 10d, 12c, 12d, 12e, 13, and 14 displayed potent antibacterial activity. Meanwhile, compounds 13 and 14 produced good dose-dependent anti-inflammatory activity against carrageenan-induced paw edema in rats. Keywords: adamantane derivatives, 1,2,4-triazoles, N-Mannich bases, antimicrobial activity, anti-inflammatory activity

  7. Synthesis and antitubercular evaluation of aryl substituted 2-oxazolines from L-amino acids

    Directory of Open Access Journals (Sweden)

    Leidiane Araújo de Souza

    2014-07-01

    Full Text Available This paper describes the synthesis and the in vitro antibacterial activity of a series of twelve substituted aryl-2-oxazolines against Mycobacterium tuberculosis. Seven compounds showed activity and two compounds exhibited a minimal inhibitory concentration (MIC of 25 ?g/mL were not cytotoxic for the host cells in cell viability assay. These results could be a good starting point for the development of new antitubercular lead series based on this family of compounds.

  8. Electrospun N-Substituted Polyurethane Membranes with Self-Healing Ability for Self-Cleaning and Oil/Water Separation.

    Science.gov (United States)

    Fang, Wenyuan; Liu, Libin; Li, Ting; Dang, Zhao; Qiao, Congde; Xu, Jinku; Wang, Yanyan

    2016-01-01

    Membranes with special functionalities, such as self-cleaning, especially those for oil/water separation, have attracted much attention due to their wide applications. However, they are difficult to recycle and reuse after being damaged. Herein, we put forward a new N-substituted polyurethane membrane concept with self-healing ability to address this challenge. The membrane obtained by electrospinning has a self-cleaning surface with an excellent self-healing ability. Importantly, by tuning the membrane composition, the membrane exhibits different wettability for effective separation of oil/water mixtures and water-in-oil emulsions, whilst still displaying a self-healing ability and durability against damage. To the best of our knowledge, this is the first report to demonstrate a self-healing membrane for oil/water separation, which provides the fundamental research for the development of advanced oil/water separation materials. PMID:26603820

  9. N-SUBSTITUTION AND á1-ADRENERGIC RECEPTOR AFFINITY OF LAUDANOSINE ANALOGUES

    Directory of Open Access Journals (Sweden)

    PATRICIO ITURRIAGA-VÁSQUEZ

    2006-09-01

    Full Text Available Benzyltetrahydroisoquinoline (BTHIQ molecules are able to adopt widely differing conformations that depend on the presence or absence of N-substituents. To assess the possible role of BTHIQ conformation on the affinity of these compounds for a 1-adrenergic receptors, of interest for the management of hypertension, the racemic N-unsubstituted BTHIQ norlaudanosine and a series of N-alkylated derivatives were assessed for binding to rat brain cortical sites labelled with the radioligand [³H]prazosin. The a 1-adrenergic affinity in this series increased with the bulk of the substituent on the nitrogen atom, from the N-ethyl to the N-propyl analogue. Comparison of these results with published data for related BTHIQs and for the rigid mimics of the fully extended and semi-folded conformations of laudanosine, tetrahydropalmatine and glaucine, suggested that the a 1-adrenergic receptor binding site is able to accommodate either conformation. The presence of a bulky substituent on the nitrogen atom seems to favor receptor binding independently of the favored conformation, and that the orientation in which BTHIQs are bound probably differs depending on the presence or absence of a hydroxyl group at a key position

  10. Naphthalene bisimides asymmetrically and symmetrically N-substituted with triarylamine--comparison of spectroscopic, electrochemical, electronic and self-assembly properties.

    Science.gov (United States)

    Rybakiewicz, Renata; Zapala, Joanna; Djurado, David; Nowakowski, Robert; Toman, Petr; Pfleger, Jiri; Verilhac, Jean-Marie; Zagorska, Malgorzata; Pron, Adam

    2013-02-01

    Two semiconducting naphthalene bisimides were comparatively studied: NBI-(TAA)(2), symmetrically N-substituted with triaryl amine and asymmetric NBI-TAA-Oc with triaryl amine and octyl N-substituents. Both compounds show very similar spectroscopic and redox properties but differ in their supramolecular organization. As evidenced by STM, in monolayers on HOPG they form ordered 2D structures, however of different packing patterns. NBI-(TAA)(2) does not form ordered 3D structures, yielding amorphous thin films whereas films of NBI-TAA-Oc are highly crystalline. DFT calculations predict the ionization potential (IP) of 5.22 eV and 5.18 eV for NBI-TAA-Oc and NBI-(TAA)(2), respectively, as well as the electron affinity values (EA) of -3.25 eV and -3.22 eV. These results are consistent with the cyclic voltammetry data which yield similar values of IP (5.20 eV and 5.19 eV) and somehow different values of EA (-3.80 eV and -3.83 eV). As judged from these data, both semiconductors should exhibit ambipolar behavior. Indeed, NBI-TAA-Oc is ambipolar, showing hole and electron mobilities of 4.5 × 10(-5) cm(2)/(V s) and of 2.6 × 10(-4) cm(2)/(V s), respectively, in the field effect transistor configuration. NBI-(TAA)(2) is not ambipolar and yields field effect only in the p-channel configuration. This different behavior is rationalized on the basis of structural factors. PMID:23243662

  11. Living Polymerization of N -Substituted β-Alanine N -Carboxyanhydrides: Kinetic Investigations and Preparation of an Amphiphilic Block Copoly-β-Peptoid

    KAUST Repository

    Grossmann, Arlett

    2012-07-03

    Poly(α-peptoid)s (N-substituted polyglycines) are interesting peptidomimetic biomaterials that have been discussed for many applications. Poly(β-peptoid)s (N-substituted poly-β-alanines), although equally intriguing, have received much less attention. Here we present results that suggest that while N-substituted β-alanine N-carboxyanhydrides can undergo a living nucleophilic ring-opening polymerization, the solubility of poly(β-peptoid)s can be very poor, which contributes to the limited accessibility using other synthetic approaches. The living character of the polymerization was utilized for the preparation of the first polymerized amphiphilic block copoly-β-peptoid. Our results may open a new route towards highly defined functional poly(β-peptoid)s which could represent biomaterials. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Synthesis of N-substituted Cyclic Hydrocarbons, such as Pyrimidine, in The Ionosphere of Titan

    Science.gov (United States)

    Bera, P. P.; Peverati, R.; Head-Gordon, M.; Lee, T. J.

    2014-12-01

    The instruments on board the CASSINI spacecraft observed large carbonaceous molecules in the upper atmosphere of Titan. How these large polyatomic molecules are synthesized in such exotic conditions is, thus far, unknown. Molecular ions, including positive and negative ions, are in relative abundance in the ionosphere of Titan. Hence, barrierless ion-molecule interactions may play a major role in guiding molecules towards each other and initiating reactions. We study these condensation pathways to determine whether they are a viable means of forming large pure hydrocarbon molecules, and nitrogen-containing carbonaceous chains, stacks, and even cyclic compounds. By employing accurate quantum chemical methods we have investigated the processes of growth, structures, nature of bonding, mechanisms, and spectroscopic properties of the ensuing ionic products after pairing small carbon, hydrogen, and nitrogen-containing molecules with major ions observed in the upper atmosphere of Titan, e.g. C2H5+ and HCNH+. We have also studied the ion-neutral association pathways involving pure-carbon molecules e.g. acetylene, ethylene and other hydrocarbons, and their dissociation fragments in a plasma discharge. We have investigated how nitrogen atoms are incorporated into the carbon ring during growth. Specifically, we explored the mechanisms by which the synthesis of pyrimidine will be feasible in the atmosphere of Titan in conjunction with ion-mobility experiments. We have used accurate ab initio coupled cluster theory, Møller-Plesset perturbation theory, density functional theory, and coupled cluster theory quantum chemical methods together with large correlation consistent basis sets in these investigations. We found that a series of hydrocarbons with a specific stoichiometric composition prefers cyclic molecule formation rather than chains. Some of the association products we investigated have large oscillator strengths for charge-transfer type electronic excitations in the near infrared and visible regions of the electromagnetic spectrum. Our quantum chemistry computations complement well the results from the molecular/ion plasma experiments performed by the Laboratory Astrochemistry groups at Ames.

  13. Formation Routes For Pure and N-substituted Cyclic Hydrocarbon Molecules in The Ionosphere of Titan

    Science.gov (United States)

    Bera, P. P.; Peverati, R.; Head-Gordon, M.; Lee, T. J.

    2013-12-01

    Titan's upper atmosphere contains large carbonaceous molecules as has been observed by the instruments on board the CASSINI spacecraft. How these large polyatomic molecules are synthesized in such exotic conditions is, thus far, unknown. Molecular ions are in relative abundance in the ionosphere of Titan. Hence, barrierless ion-molecule interactions may play a major role in guiding molecules towards each other and initiating reactions. We study these cold condensation pathways to determine whether they are a viable means of forming large pure hydrocarbon molecules, and nitrogen-containing carbonaceous chains, stacks, and even cyclic compounds. By employing accurate quantum chemical methods we have investigated the processes of growth, structures, nature of bonding, mechanisms, and spectroscopic properties of the ensuing ionic products after pairing small carbon, hydrogen, and nitrogen-containing molecules with major ions observed in the upper atmosphere of Titan, e.g. C2H5+ and HCNH+. We have also studied the ion-neutral association pathways involving pure-carbon molecules e.g. acetylene, ethylene and other hydrocarbons, and their dissociation fragments in a plasma discharge. Additionally, we have investigated how nitrogen atoms are incorporated into the carbon ring during growth. We have used accurate ab initio coupled cluster theory, Møller-Plesset perturbation theory and density functional theory quantum chemical methods together with large correlation consistent basis sets in these investigations. We also employed time-dependent density functional theory and equations-of-motion coupled cluster theory to compute electronic excitation energies and oscillator strengths of the products of the ion-molecule reactions. We obtained accurate vibrational frequencies under the harmonic approximation and vibrational intensities using the double harmonic approximation for fundamental molecular vibrations. We identified three types of bonding motifs with strong, moderate, and weak binding energies among the carbonaceous complexes. Both linear and cyclic isomers identified on the potential energy surface of these molecular complexes are expected to form rather easily due to electrostatic interactions. We uncovered that a series of hydrocarbons with a specific stoichiometric composition prefers cyclic molecule formation rather than chains. Some of the association products we investigated have large oscillator strengths for charge-transfer type electronic excitations in the near infrared and visible regions of the electromagnetic spectrum. Our quantum chemistry computations complement well the results from the molecular/ion plasma experiments performed by the Laboratory Astrochemistry groups at Ames. P. P. Bera, Martin Head-Gordon, and Timothy J. Lee Astron & Astrophys. 535, A74, (2011) P. P. Bera, M. Head-Gordon, and T. J. Lee, 15, 2012-2023,Phys. Chem. Chem. Phys. (2013) P. P. Bera, Roberto Peverati, M. Head-Gordon, and Timothy J. Lee, To be submitted (2013)

  14. N-Aryl-benzimidazolones as novel small molecule HSP90 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Bruncko, Milan; Tahir, Stephen K.; Song, Xiaohong; Chen, Jun; Ding, Hong; Huth, Jeffrey R.; Jin, Sha; Judge, Russell A.; Madar, David J.; Park, Chang H.; Park, Cheol-Min; Petros, Andrew M.; Tse, Christin; Rosenberg, Saul H.; Elmore, Steven W. (Abbott)

    2012-03-16

    We describe the development of a novel series of N-aryl-benzimidazolone HSP90 inhibitors (9) targeting the N-terminal ATP-ase site. SAR development was influenced by structure-based design based around X-ray structures of ligand bound HSP90 complexes. Lead compounds exhibited high binding affinities, ATP-ase inhibition and cellular client protein degradation.

  15. Testing for partial agonism of the aryl hydrocarbon receptor

    OpenAIRE

    Wall, Richard J

    2008-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent of a group of persistent organic pollutants (POPs). The aryl hydrocarbon receptor (AhR) has a high affinity for these dioxin-like compounds with activation increasing transcription of CYP1A1. The aim of this paper was to measure the agonistic and potential antagonistic effects of four of the most prevalent and potent dioxin-like agonists: 3-Methylcholanthrene (3-MC), 2,3,7,8-Tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-Pentachlorodibe...

  16. Synthesis and antifungal activity of novel (1-aryl-2-heterocyclyl)ethylideneaminooxymethyl-substituted dioxolanes

    International Nuclear Information System (INIS)

    A novel series of (1-aryl-2-heterocyclyl)ethylideneaminooxymethyl -substituted dioxolanes IIIa-n were synthesized by condensation of substituted 1,3-dioxolan-4-ylmethyl p-toluenesulfonates 4 with 1-(hydroxyimino)-1-aryl-2-heterocyclylethanes 5. Compounds IIIa-n were found to have effective in vitro antifungal activity when evaluated against the pathogenic fungi Candida albicans, Aspergillus flavus and Fusarium solani with MIC (minimum inhibitory concentration) values of 10 ?g-ml-1 for IIIa-I and 5 ?g-ml-1 for IIIm,n. (authors). 24 refs., 4 figs., 5 tabs

  17. Discovery of novel N-aryl piperazine CXCR4 antagonists.

    Science.gov (United States)

    Zhao, Huanyu; Prosser, Anthony R; Liotta, Dennis C; Wilson, Lawrence J

    2015-11-01

    A novel series of CXCR4 antagonists with substituted piperazines as benzimidazole replacements is described. These compounds showed micromolar to nanomolar potency in CXCR4-mediated functional and HIV assays, namely inhibition of X4 HIV-1(IIIB) virus in MAGI-CCR5/CXCR4 cells and inhibition of SDF-1 induced calcium release in Chem-1 cells. Preliminary SAR investigations led to the identification of a series of N-aryl piperazines as the most potent compounds. Results show SAR that indicates type and position of the aromatic ring, as well as type of linker and stereochemistry are significant for activity. Profiling of several lead compounds showed that one (49b) reduced susceptibility towards CYP450 and hERG, and the best overall profile when considering both SDF-1 and HIV potencies (6-20 nM). PMID:25935642

  18. Novel aryl carbamate derivatives of metronidazole as potential antiamoebic agents.

    Science.gov (United States)

    Hayat, Faisal; Wahedi, Hussain Mustatab; Park, Seonghyeok; Tariq, Saba; Azam, Amir; Shin, Dongyun

    2016-01-01

    A series of novel aryl carbamate derivatives of metronidazole (MNZ) were designed, synthesized, and screened for antiamoebic activity. As compared to MNZ, most of the derivatives exhibited moderate to excellent activity against the HM1:IMSS strain of Entamoeba histolytica. Compounds 7, 14, 16, 19, and 21 exhibited the most promising antiamoebic activity with IC50 values of 0.24, 0.08, 0.26, 0.26, and 0.15 ?M, respectively, compared to that of MNZ (1.78 ?M). Moreover, from the toxicological studies of these compounds on human melanocytes, the melan-a cell line revealed that the potent compounds are nontoxic at concentrations ranging from 2.5 to 50 ?M. PMID:26597858

  19. Synthesis and biological evaluation of novel dioxa-bicycle C-aryl glucosides as SGLT2 inhibitors.

    Science.gov (United States)

    Yan, Qi; Ding, Ning; Li, Yingxia

    2016-02-01

    A series of novel C-aryl glucosides containing dioxa-bicycle were synthesized and evaluated for inhibition activity against hSGLT2. Among the compounds tested, compound 6a showed moderate SGLT2 inhibition activities at 700 nM. The results could benefit the discovery of new SGLT2 inhibitors. PMID:26735747

  20. Anaerobic Aryl Reductive Dehalogenation of Halobenzoates by Cell Extracts of "Desulfomonile tiedjei".

    Science.gov (United States)

    Deweerd, K A; Suflita, J M

    1990-10-01

    We studied the transformation of halogenated benzoates by cell extracts of a dehalogenating anaerobe, "Desulfomonile tiedjei." We found that cell extracts possessed aryl reductive dehalogenation activity. The activity was heat labile and dependent on the addition of reduced methyl viologen, but not on that of reduced NAD, NADP, flavin mononucleotide, flavin adenine dinucleotide, desulfoviridin, cytochrome c(3), or benzyl viologen. Dehalogenation activity in extracts was stimulated by formate, CO, or H(2), but not by pyruvate plus coenzyme A or by dithionite. The pH and temperature optima for aryl dehalogenation were 8.2 and 35 degrees C, respectively. The rate of dehalogenation was proportional to the amount of protein in the assay mixture. The substrate specificity of aryl dehalogenation activity for various aromatic compounds in "D. tiedjei" cell extracts was identical to that of whole cells, except differences were observed in the relative rates of halobenzoate transformation. Dehalogenation was 10-fold greater in "D. tiedjei" extracts prepared from cells cultured in the presence of 3-chlorobenzoate, suggesting that the activity was inducible. Aryl reductive dehalogenation in extracts was inhibited by sulfite, sulfide, and thiosulfate, but not sulfate. Experiments with combinations of substrates suggested that cell extracts dehalogenated 3-iodobenzoate more readily than either 3,5-dichlorobenzoate or 3-chlorobenzoate. Dehalogenation activity was found to be membrane associated. This is the first report characterizing aryl dehalogenation activity in cell extracts of an obligate anaerobe. PMID:16348308

  1. Anaerobic aryl reductive dehalogenation of halobenzoates by cell extracts of Desulfomonile tiedjei

    Energy Technology Data Exchange (ETDEWEB)

    DeWeerd, K.A.; Suflita, J.M. (Univ. of Oklahoma, Norman (USA))

    1990-10-01

    The authors studied the transformation of halogenated benzoates by cell extracts of a dehalogenating anaerobe, Desulfomonile tiedjei. The authors found that cell extracts possessed aryl reductive dehalogenation activity. The activity was heat labile and dependent on the addition of reduced methyl viologen, but not on that of reduced NAD, NADP, flavin mononucleotide, flavin adenine dinucleotide, desulfoviridin, cytochrome c{sub 3}, or benzyl viologen. Dehalogenation activity in extracts was stimulated by formate, CO, or H{sub 2}, but not by pyruvate plus coenzyme A or by dithionite. The pH and temperature optima for aryl dehalogenation were 8.2 and 35{degree}C, respectively. The rate of dehalogenation was proportional to the amount of protein in the assay mixture. The substrate specificity of aryl dehalogenation activity for various aromatic compounds in D. tiedjei cell extracts was identical to that of whole cells, except differences were observed in the relative rates of halobenzoate transformation. Dehalogenation was 10-fold greater in D. tiedjei extracts prepared from cells cultured in the presence of 3-chlorobenzoate, suggesting that the activity was inducible. Aryl reductive dehalogenation in extracts was inhibited by sulfite, sulfide, and thiosulfate, but not sulfate. Experiments with combinations of substrates suggested that cell extracts dehalogenated 3-iodobenzoate more readily than either 3,5-dichlorobenzoate or 3-chlorobenzoate. Dehalogenation activity was found to be membrane associated. This is the first report characterizing aryl dehalogenation activity in cell extracts of an obligate anaerobe.

  2. Electrochemical and Physical properties of N-substituted arylmethylene pyrrole polymers and N-alkylmethine pyrrole copolymers

    International Nuclear Information System (INIS)

    Highlights: •N-Arylmethylene and methine pyrroles were electropolymerised into polymers and copolymers. •N-arylmethylene pyrrole monomers readily formed stable homopyrrole polymer films. •N-alkylmethine pyrrole monomers only formed stable copolymers films with pyrrole. •N-(1,2-dicarboxyethyl)-1H-pyrrole films readily complexed Cu+ or Cd2+ ions under a applied–ve field. -- Abstract: The electrochemical behaviour of N-arylmethylene and N-alkylmethine pyrrole monomers were investigated in their ability to be electropolymerised into polymer and co-polymer films with pyrrole using the techniques of cyclic voltammetry and scanning electron microscopy (SEM). N-substituted arylmethylene pyrrole monomers readily formed homopolymers by the oxidative electropolymerisation of pyrrole monomers by potentiostatic cycling in acetonitrile containing tetrabutylammonium perchlorate. The polymer films formed were brown in appearance and redox active, with the exception of the 1-((4-chlorophenyl)methyl)-1H-pyrrole (1d) which formed a pale yellow film lacking redox activity. The thickness of films produced calculated on the charge consumed followed the order 1e + and Cd2+ ions at a concentration of 1 × 10?4 M under an applied–ve field and to release the metal ion on stepping the potential to zero

  3. Synthesis and antileishmanial activity of new 1-Aryl-1H-Pyrazole-4- carboximidamides derivatives

    International Nuclear Information System (INIS)

    Chemotherapy for leishmaniasis, diseases caused by protozoa of the genus Leishmania, remains inefficient in several treatments. So there is a need to search for new drugs. In this work, we have synthesized 1-aryl-1H-pyrazole-4-carboximidamides derivatives and evaluated antileishmanial activities in vitro, as well as cytotoxic effects. Structure-activity relationship (SAR) studies were carried out with all the compounds of the series. Compound 2 showed an activity profile that can be improved through medicinal chemistry strategies. (author)

  4. Synthesis and antileishmanial activity of new 1-Aryl-1H-Pyrazole-4- carboximidamides derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Mauricio S. dos; Gomes, Adriana O.; Bernardino, Alice M.R.; Souza, Marcos C. de, E-mail: alicerolim@globo.co [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-Graduacao em Quimica Organica; Khan, Misbahul A. [The Islamia University of Bahawalpur (Pakistan). Chemistry Dept.; Brito, Monique A. de [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Fac. de Farmacia. Lab. de Quimica Medicinal Computacional; Castro, Helena C.; Abreu, Paula A. [Universidade Federal Fluminense (LABioMol/GCM/UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Antibioticos, Bioquimica e Modelagem Molecular; Rodrigues, Carlos R. [Universidade Federal do Rio de Janeiro (ModMol/UFRJ), RJ (Brazil). Fac. de Farmacia. Lab. de Modelagem Molecular e QSAR; Leo, Rosa M.M. de; Leon, Leonor L.; Canto-Cavalheiro, Marilene M. [Fundacao Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto Oswaldo Cruz. Lab. de Bioquimica de Tripanosomatideos

    2011-07-01

    Chemotherapy for leishmaniasis, diseases caused by protozoa of the genus Leishmania, remains inefficient in several treatments. So there is a need to search for new drugs. In this work, we have synthesized 1-aryl-1H-pyrazole-4-carboximidamides derivatives and evaluated antileishmanial activities in vitro, as well as cytotoxic effects. Structure-activity relationship (SAR) studies were carried out with all the compounds of the series. Compound 2 showed an activity profile that can be improved through medicinal chemistry strategies. (author)

  5. Palladium-catalysed ortho arylation of acetanilides

    Indian Academy of Sciences (India)

    Guo-zhen zhang; Cheng-Qun Chen; Xin-Hua Feng; Guo-Sheng Huang

    2010-03-01

    The palladium-catalysed direct arylation of acetanilides by using C-H activation methodology has been demonstrated. Several acetanilides were coupled with aryl iodides in the presence of 10 mol% of Pd(OAc)2, 1.0 equiv of Cu(OTf)2, and 0.6 equiv of Ag2O to afford the corresponding products in moderate to excellent yields. The results showed that the amount of Ag2O was important for this protocol.

  6. Role of the aryl hydrocarbon receptor in cell cycle regulation

    International Nuclear Information System (INIS)

    One of the most puzzling aspects of the biological impact of polycyclic aromatic hydrocarbon compounds is that they elicit an apparently unrelated variety of toxic, teratogenic, and carcinogenic responses in exposed animals and in humans. At the cellular level, these environmental toxicants affect cell cycle regulatory mechanisms and signal transduction pathways in ways that are equally diverse and often contradictory. For example, depending on the particular cell lines studied, exposure to these compounds may lead to cell proliferation, to terminal differentiation, or to apoptosis. These effects are mediated by the aryl hydrocarbon receptor, a ligand-activated transcription factor well known for its regulatory activity on the expression of several phase I detoxification cytochrome P450 genes. Research into the molecular mechanisms of aryl hydrocarbon receptor function has uncovered a novel role for this protein during cell cycle progression. The activated receptor acts as an environmental sensor and cell cycle checkpoint that commits cells exposed to adverse environmental stimuli to arrest before the onset of DNA replication

  7. Novel Synthesis and Anti-HIV-1 Activity of 2-Arylthio-6-benzyl-2,3-dihydro-1H-pyrimidin-4-ones (Aryl S-DABOs)

    DEFF Research Database (Denmark)

    Aly, Youssef L.; Pedersen, Erik Bjerreg.; La Colla, Paolo; Loddo, Roberta

    2007-01-01

    The synthesis and the anti-HIV-1 activity of a series of 2-arylthio-6-benzyl-2,3-dihydro-1H-pyrimidin-4-ones (aryl S-DABOs) are reported. These compounds were synthesized via a coupling reaction of the corresponding 6-benzyl-2-thiouracils with aryl iodides in the presence of neocuproine hydrate...

  8. Photocatalytic Arylation of Alkenes, Alkynes and Enones with Diazonium Salts

    OpenAIRE

    Schroll, Peter; Hari, Durga Prasad; König, Burkhard

    2012-01-01

    Teaching old dogs new tricks: Visible light photoredox catalysis improves the classic Meerwein arylation protocol significantly and allows the light-controlled arylation of alkenes, alkynes and enones by diazonium salts.

  9. Smiles Rearrangement Based Practical One-pot Synthesis of N-Alkyl/aryl-6-aminoquinolines from 6-Hydroxylquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yongsheng; Vijaykumar, B. V. D.; Jang, Kiwan; Choi, Kyungmin; Shin, Dongsoo [Changwon National Univ., Changwon (Korea, Republic of); Zuo, Hua [Southwest Univ., Chongqing (Korea, Republic of); Yoon, Yongjin [Gyeongsang National Univ., Chinju (Korea, Republic of)

    2013-12-15

    The C-N coupling protocol reported herein represents a convenient and practical synthesis of N-alkyl/aryl-6-aminoquinolines in a three-step one-pot manner by simple addition of 6-hydroxyquinoline and N-alkyl/aryl-2-chloroacetamides with Cs{sub 2}CO{sub 3} or K{sub 2}CO{sub 3} in DMF at 150 .deg. C via Smiles rearrangement. An electron donating substituent on the nitrogen counterpart would accelerate the rearrangement process to achieve various anilines in good yields. We currently engaged in making a chemical library including multifarious N-substituted-6-aminoquinolines, to be used in the screening for specific AChEI activity. Furthermore, this work extends the scope of preparing different heterocyclic synthons in drug design for various biological activities. Aminoquinolines and their derivatives are important chemical entities that are widely used as pro-drugs and drugs due to their antimicrobial, cytotoxic and anti-malarial activities etc.

  10. An efficient and convenient synthesis of N-substituted amides under heterogeneous condition using Al(HSO4)3 via Ritter reaction

    Indian Academy of Sciences (India)

    Elnaz Karimian; Batool Akhlaghinia; Sara S E Ghodsinia

    2016-03-01

    An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. Thecatalyst which is an air-stable, cost-effective solid acid could be readily recycled by filtration and reused four times without any significant loss of its activity.

  11. Palladium-catalyzed ?-selective arylation of zincated Boc-allylamines.

    Science.gov (United States)

    Millet, Anthony; Baudoin, Olivier

    2014-08-01

    The regio- and diastereoselective arylation of Boc-protected allylamines was performed via a one-pot lithiation/transmetalation to zinc/cross-coupling sequence, through an appropriate choice of a phosphine ligand. A variety of ?-arylated products were obtained in moderate to good yield, and the products could be directly transformed into valuable ?-arylamines and ?-aryl aldehydes. PMID:25054519

  12. C-Aryl glucoside SGLT2 inhibitors containing a biphenyl motif as potential anti-diabetic agents.

    Science.gov (United States)

    Ding, Yuyang; Mao, Liufeng; Xu, Dengfeng; Xie, Hui; Yang, Ling; Xu, Hongjiang; Geng, Wenjun; Gao, Yong; Xia, Chunguang; Zhang, Xiquan; Meng, Qingyi; Wu, Donghai; Zhao, Junling; Hu, Wenhui

    2015-07-15

    A series of highly active C-aryl glucoside SGLT2 inhibitors containing a biphenyl motif were designed and synthesized for biological evaluation. Among the compounds tested, compound 16l demonstrated high inhibitory activity against SGLT2 (IC50=1.9 nM) with an excellent pharmacokinetic profile. Further study indicated that the in vivo efficacy of compound 16l was comparable to that of dapagliflozin, suggesting that further development would be worthwhile. PMID:26026363

  13. Nickel-catalyzed three-component domino reactions of aryl Grignard reagents, alkynes, and aryl halides producing tetrasubstituted alkenes.

    Science.gov (United States)

    Xue, Fei; Zhao, Jin; Hor, T S Andy; Hayashi, Tamio

    2015-03-11

    Three-component reaction of aryl Grignard reagents, alkynes, and aryl halides in the presence of 1 mol % of NiCl2 proceeded sequentially through carbomagnesiation of the alkyne followed by cross-coupling of the resulting alkenyl Grignard reagent with aryl halide to give tetrasubstituted alkenes in high yields. PMID:25714497

  14. Pseudoephedrine-Directed Asymmetric ?-Arylation of ?-Amino Acid Derivatives.

    Science.gov (United States)

    Atkinson, Rachel C; Fernández-Nieto, Fernando; Mas Roselló, Josep; Clayden, Jonathan

    2015-07-27

    Available ?-amino acids undergo arylation at their ??position in an enantioselective manner on treatment with base of N'-aryl urea derivatives ligated to pseudoephedrine as a chiral auxiliary. In?situ silylation and enolization induces diastereoselective migration of the N'-aryl group to the ??position of the amino acid, followed by ring closure to a hydantoin with concomitant explulsion of the recyclable auxiliary. The hydrolysis of the hydantoin products provides derivatives of quaternary amino acids. The arylation avoids the use of heavy-metal additives, and is successful with a range of amino acids and with aryl rings of varying electronic character. PMID:26083236

  15. Synthesis and antibacterial activity of some novel 2-Aroylimino-3-aryl-thiazolidin-4-ones

    Scientific Electronic Library Online (English)

    Aamer, Saeed; Naeem, Abbas; Ulrich, Flörke.

    Full Text Available Este trabalho relata uma síntese eficiente e regio-seletiva de algumas 2-aroylimino-3-aryl-thiazolidin-4-ones (2a-j) envolvendo a ciclização de 1-aroyl-3-aryl tio-uréias em meio básico com cloreto de cloroacetila em dioxana. As estruturas foram confirmadas por dados espectroscópicos, análises elemen [...] tares e, em um caso (2j), por dados de difração de raios X tipo cristal único. Os compostos foram testados in vitro quanto à sua atividade antimicrobiana em relação a bactérias Gram positivas e Gram negativas. Os resultados revelaram uma atividade promissora desses compostos em relação aos microorganismos testados, comparando-se e, em alguns casos, até superando a atividade das drogas existentes. Abstract in english An efficient, regioselective synthesis of some 2-aroylimino-3-aryl-thiazolidin-4-ones (2a-j) involving base-catalyzed cyclization of 1-aroyl-3-aryl thioureas with chloroacetyl chloride in dioxane is reported. The structures were confirmed by spectroscopic data, elemental analyses and in one case (2j [...] ) by single crystal X-ray diffraction data. Compounds (2a-j) were assayed in vitro for their antimicrobial activity against Gram positive and Gram negative bacteria and were found to exhibit promising activity towards the tested microorganisms, comparable to and in some cases better than those of the standard drugs.

  16. Synthesis of novel substituted N-aryl benzamides as hA3G stabilizers and their inhibitory activities against hepatitis C virus replication

    Directory of Open Access Journals (Sweden)

    Yanping Li

    2013-09-01

    Full Text Available A series of novel amino-substituted N-aryl benzamide analogs were synthesized and evaluated for their ability to inhibit hepatitis C virus (HCV replication in acutely infected Huh7.5 cells. Most of the substituted N-aryl benzamide compounds showed convincing anti-HCV activities. Compounds 1f, 1g and 4c exhibited potent anti-replicative activity at low micromolar levels (IC50=1.0–2.0 ?M with selective indices (SI greater than 40. Mechanistic analysis indicated that the active compounds increased intracellular hA3G protein levels and inhibited HCV replication in a dose-dependent manner. The results demonstrate that this series of substituted N-aryl benzamide compounds warrant further investigation as inhibitors of HCV replication.

  17. One-pot synthesis of N-aryl 1,4-dihydropyridine derivatives and their biological activities

    Indian Academy of Sciences (India)

    Isaivani Dhinakaran; Vediappen Padmini; Nattamai Bhuvanesh

    2015-12-01

    Highly efficient, one pot synthesis of N-aryl, 1,4-dihydopyridines was carried out by four component reaction. Synthesized 1,4-dihydropyridines were screened for their cytotoxicity against A549 cell line. All the synthesized compounds exhibited better DPPH radical scavenging activity.

  18. Preparation of Peptide p-Nitroanilides using an Aryl Hydrazine Solid Support

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Y; Welsh, K; Mitchell, A R; Camarero, J A

    2004-08-05

    Peptide p-nitroanilides are useful compounds for studying protease activity, however the poor nucleophilicity of p-nitroaniline makes their preparation difficult. We describe a new efficient approach for the Fmoc-based synthesis of peptide p-nitroanilides using an aryl hydrazine resin. Mild oxidation of the peptide hydrazide resin yields a highly reactive acyl diazene, which efficiently reacts with weak nucleophiles. We have prepared several peptide p-nitroanilides, including substrates for the Lethal Factor protease from B. anthracis.

  19. 3-methylcholanthrene induces differential recruitment of aryl hydrocarbon receptor to human promoters

    DEFF Research Database (Denmark)

    Pansoy, Andrea; Ahmed, Shaimaa; Valen, Eivind; Sandelin, Albin; Matthews, Jason

    2010-01-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated protein that mediates the toxic actions of polycyclic aromatic and halogenated compounds. Identifying genes directly regulated by AHR is important in understanding the pathways regulated by this receptor. Here we used chromatin immunoprecipitation and promoter focused microarrays (ChIP-chip) to detect AHR bound genomic regions after 3-methylcholanthrene (3MC) treatment of T-47D human breast cancer cells. We identified 241 AHR-3MC bound re...

  20. Discovery of an ?-Amino C–H Arylation Reaction Using the Strategy of Accelerated Serendipity

    OpenAIRE

    McNally, Andrew; Prier, Christopher K.; MacMillan, David W. C.

    2011-01-01

    Serendipity has long been a welcome yet elusive phenomenon in the advancement of chemistry. We sought to exploit serendipity as a means of rapidly identifying unanticipated chemical transformations. By using a high-throughput, automated workflow and evaluating a large number of random reactions, we have discovered a photoredox-catalyzed C–H arylation reaction for the construction of benzylic amines, an important structural motif within pharmaceutical compounds that is not readily accessed via...

  1. Aryl carbinols as nerve agent probes. Influence of the conjugation on the sensing properties

    OpenAIRE

    Royo Calvo, Santiago; Gotor Candel, Raul Jesús; COSTERO NIETO, ANA MARIA; PARRA ALVAREZ, MARGARITA; GIL GRAU, SALVADOR; Martínez Mañez, Ramón; Sancenón Galarza, Félix

    2012-01-01

    Two new aryl carbinols (1 and 3) have been synthesised and characterised and their ability as OFF-ON probes for the chromogenic detection of the nerve agent simulant in acetonitrile has been tested. In addition compound 2 has been also studied. The carbinols suffered a phosphorylation reaction followed by an elimination process giving rise to the corresponding carbocations. This transformation of the carbinol into the carbocation is responsible for a significant color change. © The Royal Soci...

  2. QSAR Studies on N-aryl Derivative Activity Towards Alzheimer’s Disease

    OpenAIRE

    Kamalakaran Anand Solomon; Veluchamy Abirami; Srinivasan Sundararajan

    2009-01-01

    A Quantitative Structure Activity Relationship (QSAR) study has been an attempted on a series of 88 N-aryl derivatives which display varied inhibitory activity towards both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), targets in Alzheimer’s drug discovery. QSAR models were derived for 53 and 61 compounds for each target, respectively, with the aid of genetic function approximation (GFA) technique using topological, molecular shape, electronic and structural descriptors. The p...

  3. Novel Synthesis and Anti-HIV-1 Activity of 2-Arylthio-6-benzyl-2,3-dihydro-1H-pyrimidin-4-ones (Aryl S-DABOs)

    DEFF Research Database (Denmark)

    Aly, Youssef L.; Pedersen, Erik Bjerreg.; La Colla, Paolo; Loddo, Roberta

    2007-01-01

    The synthesis and the anti-HIV-1 activity of a series of 2-arylthio-6-benzyl-2,3-dihydro-1H-pyrimidin-4-ones (aryl S-DABOs) are reported. These compounds were synthesized via a coupling reaction of the corresponding 6-benzyl-2-thiouracils with aryl iodides in the presence of neocuproine hydrate, copper(I) iodide, and sodium tert-butoxide. Target compounds showed moderate activity against HIV-1.

  4. Aryl Polyphosphonates: Useful Halogen-Free Flame Retardants for Polymers

    Directory of Open Access Journals (Sweden)

    Li Chen

    2010-10-01

    Full Text Available Aryl polyphosphonates (ArPPN have been demonstrated to function in wide applications as flame retardants for different polymer materials, including thermosets, polycarbonate, polyesters and polyamides, particularly due to their satisfactory thermal stability compared to aliphatic flame retardants, and to their desirable flow behavior observed during the processing of polymeric materials. This paper provides a brief overview of the main developments in ArPPN and their derivatives for flame-retarding polymeric materials, primarily based on the authors’ research work and the literature published over the last two decades. The synthetic chemistry of these compounds is discussed along with their thermal stabilities and flame-retardant properties. The possible mechanisms of ArPPN and their derivatives containing hetero elements, which exhibit a synergistic effect with phosphorus, are also discussed.

  5. Development of N-substituted quinolinimides, as potential PET tracers for the visualisation of δ-opioid receptors

    International Nuclear Information System (INIS)

    In order to develop radiotracers for in vivo studies of δ-opioid receptors by Positron Emission Tomography (PET) or Single Photon Emission computed Tomography (SPECT), we undertook the synthesis of halogenated analogues (chlorinated and brominated) of compound 12. These analogues were prepared by a convergent synthesis and from these novel structures a halogen exchange reaction has been performed to complete this series. These molecules were tested to determine their in vitro affinity and selectivity toward δ opioid receptors. The compounds 12 and 15 were labelled with carbon-11. The radiosynthesis of compound 12, in weak radioactivity chemistry, was performed first by the Stille reaction and second by a new methodology based on the transfer reaction of [11C]-methyl group. This new methodology used a mono-organotin compound prepared by addition of [11C]-iodomethane onto Lappert's stannylene. The compound [11C]-12 was obtained with 60 and 10% radiochemical yield respectively. In order to produce higher radioactivity quantities, the Stille reaction was automated. The compounds [11C]-12 and [11C]-15 were obtained in 40 minutes with a specific radioactivity ranging from 322 to 747 mCi/μmol. (author)

  6. 3-Alkyl-3-(alkylamino)indolin-2-ones via Base-Mediated C-Arylation of 2-Nitrobenzenesulfonamides.

    Science.gov (United States)

    Giménez-Navarro, Vanesa; Volná, Tereza; Krch?ák, Viktor

    2015-08-10

    Resin-bound intermediates prepared from polymer-supported amino acid esters, 2-nitrobenezenesulfonyl chlorides, and alcohols were used to synthesize 3-alkyl-3-(alkylamino) indolin-2-ones. The key step of the reaction sequence was the formation of a quaternary carbon via the base-mediated C-arylation of 2-nitrobenzenesulfonamides. The cleavage of the acyclic precursors from the resin and subsequent reduction of the nitro group by Zn in acetic acid triggered the spontaneous cyclization of the arylated compounds to indolinones. The synthesis was carried out using simple commercially available building blocks under mild conditions and provided the 3,3-disubstituted indolinone derivatives with good overall yields however, the arylation reaction resulted in the epimerization of the quaternary carbon. PMID:26181142

  7. N-Substituted 5-Amino-6-methylpyrazine-2,3-dicarbonitriles: Microwave-Assisted Synthesis and Biological Properties

    Directory of Open Access Journals (Sweden)

    Ondrej Jandourek

    2014-01-01

    Full Text Available In this work a series of 15 N-benzylamine substituted 5-amino-6-methyl-pyrazine-2,3-dicarbonitriles was prepared by the aminodehalogenation reactions using microwave assisted synthesis with experimentally set and proven conditions. This approach for the aminodehalogenation reaction was chosen due to its higher yields and shorter reaction times. The products of this reaction were characterized by IR, NMR and other analytical data. The compounds were evaluated for their antibacterial, antifungal and herbicidal activity. Compounds 3 (R = 3,4-Cl, 9 (R = 2-Cl and 11 (R = 4-CF3 showed good antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL. It was found that the lipophilicity is important for antimycobacterial activity and the best substitution on the benzyl moiety of the compounds is a halogen or trifluoromethyl group according to Craig’s plot. The activities against bacteria or fungi were insignificant. The presented compounds also inhibited photosynthetic electron transport in spinach chloroplasts and the IC50 values of the active compounds varied in the range from 16.4 to 487.0 µmol/L. The most active substances were 2 (R = 3-CF3, 3 (R = 3,4-Cl and 11 (R = 4-CF3. A linear dependence between lipophilicity and herbicidal activity was observed.

  8. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD+-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  9. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Tomofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135 (Japan); Ichinose, Hirofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Wariishi, Hiroyuki, E-mail: hirowari@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Innovation Center for Medical Redox Navigation, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

    2010-04-09

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  10. Synthesis of 2,3-Dioxo-5-(substitutedarylpyrroles and Their 2-Oxo-5-aryl-3-hydrazone Pyrrolidine Derivatives

    Directory of Open Access Journals (Sweden)

    A. S. Hamzah

    2009-01-01

    Full Text Available Some novel2,3-dioxo-5-(substitutedarylpyrroles have been synthesized. Among these, pyrrolidine compound 1b was converted to 2,3-dioxo-5-aryl pyrrolidine 2b. Finally a set of hydrazone derivatives was obtained from the reaction of 2b with various hydrazine salts. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR and 1H-NMR spectra.

  11. C(aryl-O Bond Formation from Aryl Methanesulfonates via Consecutive Deprotection and SNAr Reactions with Aryl Halides in an Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Yang Chen

    2007-04-01

    Full Text Available An efficient K3PO4-mediated synthesis of unsymmetrical diaryl ethers using the ionic liquid [Bmim]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate as solvent has been developed. The procedure involves consecutive deprotection of aryl methane-sulfonates and a nucleophilic aromatic substitution (SNAr with activated aryl halides.

  12. Copper-catalysed N-arylation of arylsulfonamides with aryl bromides and aryl iodides using KF/Al2O3

    Indian Academy of Sciences (India)

    Rahman Hosseinzadeh; Mahmood Tajbakhsh; Maryam Mohadjerani; Mohammad Alikarami

    2010-03-01

    An efficient synthesis of -arylsulfonamides with a variety of aryl bromides, aryl iodides and heteroaryl bromides using KF/Al2O3 as a suitable base, CuI as an inexpensive catalyst and ,'-dimethylethylenediamine (,'-DMEDA) as an effective ligand is described.

  13. C(aryl)-O Bond Formation from Aryl Methanesulfonates via Consecutive Deprotection and SNAr Reactions with Aryl Halides in an Ionic Liquid

    OpenAIRE

    Yang Chen; Hui Xu

    2007-01-01

    An efficient K3PO4-mediated synthesis of unsymmetrical diaryl ethers using the ionic liquid [Bmim]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) as solvent has been developed. The procedure involves consecutive deprotection of aryl methane-sulfonates and a nucleophilic aromatic substitution (SNAr) with activated aryl halides.

  14. Theoretical study on the electronic structures and phosphorescent properties of a series of iridium(III) complexes with the different positional N-substitution in the pyridyl moiety

    Energy Technology Data Exchange (ETDEWEB)

    Han, Deming; Hao, Fengqi [School of Life Science and Technology, Changchun University of Science and Technology, Changchun 130022 (China); Tian, Jian [Clean Energy Technology Laboratory, Changchun University of Science and Technology, Changchun 130022 (China); Pang, Chunying; Li, Jingmei [School of Life Science and Technology, Changchun University of Science and Technology, Changchun 130022 (China); Zhao, Lihui, E-mail: zhaolihui@yahoo.com [School of Life Science and Technology, Changchun University of Science and Technology, Changchun 130022 (China); Zhang, Gang [State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023 (China)

    2015-03-15

    The geometry structures, electronic structures, absorption and phosphorescent properties of a series of iridium(III) complexes with the different N-substitution cyclometalating ligand and the same benzyldiphenylphosphine auxiliary ligand have been theoretically investigated by using the density functional theory method. The lowest energy absorption wavelengths are located at 378 nm for A, 430 nm for B, 411 nm for C, 436 nm for D, and 394 nm for E. The introduction of N atom substitution at 1-, 2-, 3-, and 4-positions on the pyridyl moiety of complex A leads to an obvious redshifted absorption. The lowest energy emissions for complexes A–E are localized at 450, 409, 438, 483, and 429 nm, respectively, simulated in CH{sub 2}Cl{sub 2} medium at M052X level. Ionization potential and electron affinity have been calculated to evaluate the injection abilities of holes and electrons into these complexes. For complex C, the calculated results showed that it can possibly possess the larger radiative decay rate (k{sub r}) value than those of other four complexes. It is anticipated that the theoretical studies can provide valuable information for designing new phosphorescent metal complexes of organic light-emitting diodes. - Highlights: • Five Ir(III) complexes have been theoretically investigated. • The effect of N-substitution cyclometalating ligand has been studied. • The complex C possibly possesses the largest radiative decay rate value.

  15. Synthesis and fluorescence properties of N-substituted 1-cyanobenz[f]isoindole chitosan polymers and nanoparticles for live cell imaging.

    Science.gov (United States)

    Gonil, Pattarapond; Sajomsang, Warayuth; Ruktanonchai, Uracha Rungsardthong; Na Ubol, Preeyawis; Treetong, Alongkot; Opanasopit, Praneet; Puttipipatkhachorn, Satit

    2014-08-11

    Highly fluorescent N-substituted 1-cyanobenz[f]isoindole chitosans (CBI-CSs) with various degrees of N-substitution (DS) were synthesized by reacting chitosan (CS) with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide under mild acidic conditions. Introduction of 1-cyanobenz[f]isoindole moieties into the CS backbone resulted in lowering of polymer thermal stability and crystallinity. The fluorescence quantum yield (?f) of CBI-CS was found to be DS- and molecular-weight-dependent, with ?f decreasing as DS and molecular weight were increased. At similar DS values, CBI-CS exhibited 26 times higher ?f in comparison with fluorescein isothiocyanate-substituted chitosan (FITC-CS). CBI-CS/TPP nanoparticles were fabricated using an ionotropic gelation method in which pentasodium triphosphate (TPP) acted as a cross-linking agent. CS and CBI-CS exhibited low cytotoxicity to normal skin fibroblast cells over a concentration range of 0.1-1000 ?g/mL, while an increased cytotoxicity level was evident in CBI-CS/TPP nanoparticles at concentrations greater than 100 ?g/mL. In contrast with CBI-CS polymers, the CBI-CS/TPP nanoparticles exhibited lower fluorescence; however, confocal microscopy results showed that living normal skin fibroblast cells became fluorescent on nanoparticle uptake. These results suggest that CBI-CS and fabricated nanoparticles thereof may be promising fluorescence probes for live cell imaging. PMID:24956200

  16. Theoretical study on the electronic structures and phosphorescent properties of a series of iridium(III) complexes with the different positional N-substitution in the pyridyl moiety

    International Nuclear Information System (INIS)

    The geometry structures, electronic structures, absorption and phosphorescent properties of a series of iridium(III) complexes with the different N-substitution cyclometalating ligand and the same benzyldiphenylphosphine auxiliary ligand have been theoretically investigated by using the density functional theory method. The lowest energy absorption wavelengths are located at 378 nm for A, 430 nm for B, 411 nm for C, 436 nm for D, and 394 nm for E. The introduction of N atom substitution at 1-, 2-, 3-, and 4-positions on the pyridyl moiety of complex A leads to an obvious redshifted absorption. The lowest energy emissions for complexes A–E are localized at 450, 409, 438, 483, and 429 nm, respectively, simulated in CH2Cl2 medium at M052X level. Ionization potential and electron affinity have been calculated to evaluate the injection abilities of holes and electrons into these complexes. For complex C, the calculated results showed that it can possibly possess the larger radiative decay rate (kr) value than those of other four complexes. It is anticipated that the theoretical studies can provide valuable information for designing new phosphorescent metal complexes of organic light-emitting diodes. - Highlights: • Five Ir(III) complexes have been theoretically investigated. • The effect of N-substitution cyclometalating ligand has been studied. • The complex C possibly possesses the largest radiative decay rate value

  17. Synthesis of aryl b-N-acetylglucosamine desmodified at C-6 as potential antimicrobial agents

    International Nuclear Information System (INIS)

    We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of Nacetylglucosamine in fungi and bacteria. None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), filamentous fungus (Aspergillus niger) and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis), at the concentration of 1 mg/mL in agar diffusion assay. (author)

  18. Synthesis of 3-aryl-5-decapentyl-1,2,4-oxadiazoles possessing antiinflammatory and antitumor properties.

    Science.gov (United States)

    Bezerra, Natércia M Miranda; De Oliveira, Shalom P; Srivastava, Rajendra M; Da Silva, Joel R

    2005-01-01

    A simple, convenient and straightforward synthesis of 3-aryl-1,2,4-oxadiazoles 4a-f from arylamidoximes 1a-f and palmitic acid 2 is described. Compounds 4a-f are non-lethal in mice at four times the therapeutic dose (i.p., LD50>1 g kg(-1) of the animals' body weight). These heterocycles have been found to possess antiinflammatory property similar to aspirin and ibuprofen. Three compounds, viz., 4a, d, e have also been evaluated for antitumor activity, where 4d exhibited an excellent activity comparable to lapachol. PMID:16242685

  19. Novel 3-aryl indoles as progesterone receptor antagonists for uterine fibroids.

    Science.gov (United States)

    Richardson, Timothy I; Clarke, Christian A; Yu, Kuo-Long; Yee, Ying K; Bleisch, Thomas J; Lopez, Jose E; Jones, Scott A; Hughes, Norman E; Muehl, Brian S; Lugar, Charles W; Moore, Terry L; Shetler, Pamela K; Zink, Richard W; Osborne, John J; Montrose-Rafizadeh, Chahrzad; Patel, Nita; Geiser, Andrew G; Galvin, Rachelle J Sells; Dodge, Jeffrey A

    2011-02-10

    We report the synthesis and characterization of novel 3-aryl indoles as potent and efficacious progesterone receptor (PR) antagonists with potential for the treatment of uterine fibroids. These compounds demonstrated excellent selectivity over other steroid nuclear hormone receptors such as the mineralocorticoid receptor (MR). They were prepared from 2-bromo-6-nitro indole in four to six steps using a Suzuki cross-coupling as the key step. Compound 8f was orally active in the complement 3 model of progesterone antagonism in the rat uterus and demonstrated partial antagonism in the McPhail model of progesterone activity. PMID:24900294

  20. Infrared study of lignin: Reexamination of aryl-alkyl ether C-O stretching peak assignments

    International Nuclear Information System (INIS)

    Infrared (IR) C-O ether stretching peak assignments of beta- O-4 interunit bonds and methoxyl groups have been assigned by isotope labeling. The Caryl-O peak for both types of ethers was typically found at 1262-1224 cm-1, but syringyl and 3,5-dimethoxyl derivatives gave Caryl-O peaks of 1328-1295 cm-1 and 1254-1204 cm-1. The Caryl-O peak for all ethers was found at 1047-1004 cm-1. These assignments are similar to values reported in general IR tables for aryl-alkyl ethers, except for the unusually high Caryl-O stretch for syringyl and 3,5- dimethoxyl compounds. IR shift tables also often list a peak at 1176 cm-1 associated with the Caryl-O bond of aryl-alkyl ethers. It is doubtful the peaks observed in this region are due to the Caryl-O bond

  1. Silver-Mediated Fluorination of Functionalized Aryl Stannanes

    OpenAIRE

    Ritter, Tobias; Furuya, Takeru; Strom, Alexandra E.

    2009-01-01

    We report a regiospecific silver-mediated fluorination of aryl stannanes. The presented reaction can afford complex fluoroarenes from readily available phenols in three steps. The operational simplicity and the broad substrate scope of the fluorination should render this reaction a useful tool for the synthesis of milligram to gram quantities of functionalized aryl fluorides. Silver-mediated oxidative transformations of aryl nucleophiles that proceed via bimetallic redox processes are a new a...

  2. Synthesis and Fungicidal Activity of Novel Chloro-Containing 1-Aryl-3-oxypyrazoles with an Oximino Ester or Oximino Amide Moiety

    Directory of Open Access Journals (Sweden)

    Yuanyuan Liu

    2014-06-01

    Full Text Available Six novel chloro-containing 1-aryl-3-oxypyrazoles TMa–TMf with an oximino ester or an oximino amide moiety were prepared by the reaction of 1-aryl-1H-pyrazol-3-ols with benzyl bromide. Their structures were characterized by 1H-NMR, 13C-NMR, IR, MS, and elemental analysis. A preliminary in vitro bioassay indicated that compounds TMa, TMe and TMf displayed excellent fungicidal activity against Rhizoctonia solani and could be used as potential lead compounds for further development of novel fungicides.

  3. N-Heterocyclic carbene–palladium catalysts for the direct arylation of pyrrole derivatives with aryl chlorides

    Directory of Open Access Journals (Sweden)

    Ismail Özdemir

    2013-02-01

    Full Text Available New Pd–NHC complexes have been synthesized and employed for palladium-catalyzed direct arylation of pyrrole derivatives by using electron-deficient aryl chlorides as coupling partners. The desired coupling products were obtained in moderate to good yields by using 1 mol % of these air-stable palladium complexes. This is an advantage compared to the procedures employing air-sensitive phosphines, which have been previously shown to promote the coupling of aryl chlorides with heteroarenes.

  4. Evidence for in Situ Catalyst Modification during the Pd-Catalyzed Conversion of Aryl Triflates to Aryl Fluorides

    OpenAIRE

    Maimone, Thomas J.; Milner, Phillip J.; Kinzel, Tom; Zhang, Yong; Michael K. Takase; Buchwald, Stephen L.

    2011-01-01

    A mechanistic investigation of the Pd-catalyzed conversion of aryl triflates to fluorides is presented. Studies reveal that C—F reductive elimination from an LPd(II)(aryl) fluoride complex (L = t-BuBrettPhos (2), RockPhos (3)) does not occur when the aryl group is electron rich. Evidence is presented that a modified phosphine, generated in-situ, serves as the actual supporting ligand during catalysis with such substrates. A preliminary study of the reactivity of an LPd(II)(aryl) fluoride comp...

  5. Synthesis, characterisation of few N-substituted 1,8-naphthalimide derivatives and their copper(II) complexes

    Indian Academy of Sciences (India)

    Nilotpal Barooah; Chandan Tamuly; Jubaraj B Baruah

    2005-03-01

    A few 1,8-naphthalimide derivatives with phenyl (1), benzyl (2), 3,4-dimethoxyphenyl ethyl (3), 4-pyridyl (4), 2-hydroxy ethyl (5), 4-pyridylmethyl (6) groups attached to the nitrogen atom are synthesized and characterized. Cyclic voltammograms of all these compounds show one-electron reversible redox cycle (-1.24 V to -1.18 V) due to formation of anion radicals. However, in the case of (5), quenching of this redox process occurs when polyhydroxy-aromatic compounds such as 1,3-dihydroxy benzene and 1,3,5-trihydroxybenzene are added. Copper complexes, namely bis-{N-(4-pyridylmethyl)1,8-naphthalimide}copper (II) perchlorate (8), bis-{N-(4-pyridylmethyl)1,8-naphthalimide}copper (II) perchlorate (9) and bis-{N-(4-pyridylmethyl)phthalimide} copper (II) perchlorate (10) are synthesized and characterised. The complexes (8) and (9) show reversible redox couple of the ligand without any significant interaction with the redox active copper (II) centre.

  6. Palladium-Catalyzed, tert-Butyllithium-Mediated Dimerization of Aryl Halides and Its Application in the Atropselective Total Synthesis of Mastigophorene?A.

    Science.gov (United States)

    Buter, Jeffrey; Heijnen, Dorus; Vila, Carlos; Hornillos, Valentín; Otten, Edwin; Giannerini, Massimo; Minnaard, Adriaan J; Feringa, Ben L

    2016-03-01

    A palladium-catalyzed direct synthesis of symmetric biaryl compounds from aryl halides in the presence of tBuLi is described. In?situ lithium-halogen exchange generates the corresponding aryl lithium reagent, which undergoes a homocoupling reaction with a second molecule of the aryl halide in the presence of the palladium catalyst (1?mol?%). The reaction takes place at room temperature, is fast (1?h), and affords the corresponding biaryl compounds in good to excellent yields. The application of the method is demonstrated in an efficient asymmetric total synthesis of mastigophorene?A. The chiral biaryl axis is constructed with an atropselectivity of 9:1 owing to catalyst-induced remote point-to-axial chirality transfer. PMID:26878822

  7. SYNTHESIS OF NOVEL N-SUBSTITUTED 2-(1H-BENZOTRIAZOL-1-YL - ACETOHYDRAZIDE DERIVATIVES AS ANTIMICROBIAL AGENTS

    Directory of Open Access Journals (Sweden)

    Jimit S. Patel

    2012-06-01

    Full Text Available As a part of research project on the synthesis of number of substituted benzotriazole derivatives with electron donating as well as electron withdrawing groups was done and evaluated them for antibacterial and antifungal activity. First of all benzotriazole was prepared using o-phenylene diamine and sodium nitrite in acidic conditions. Now benzotriazole was reacted with ethyl chloroacetate to form benzotriazole ethyl acetate which was then reacted with hydrazine hydrate to produce benzotriazole acetohydrazide. Finally it was reacted with different sulfonyl chlorides and benzoyl chlorides to give various derivatives. The purity of all compounds have been checked by the TLC monitoring and the confirmation of the structure is checked by different spectral analysis like UV, IR, Mass and NMR and evaluated as antibacterial agent by using sulfacetamide as standard drug and for antifungal activity by using clotrimazole as standard drug.

  8. Mechanism-based inactivation of benzo[a]pyrene hydroxylase by aryl acetylenes and aryl olefins

    International Nuclear Information System (INIS)

    A series of aryl acetylenes and aryl olefins have been examined as substrates and inhibitors of cytochrome P-450 dependent monooxgenases in liver microsomes from 5,6-benzoflavone or phenobarbital pretreated rats. 1-Ethynylpyrene, 3-ethynylperylene, 2-ethynylfluorene, methyl 1-pyrenyl acetylene, cis- and trans-1-(2-bromovinyl)pyrene, and 1-allylpyrene serve as mechanism-based irreversible inactivators (suicide inhibitors) of benzo[a]pyrene hydroxylase, while 1-vinylpyrene and phenyl 1-pyrenyl acetylene do not cause a detectable suicide inhibition of benzo[a]pyrene hydroxylase. The mechanism-based loss of benzo[a]pyrene hydroxylase caused by the aryl acetylenes is not accompanied by a corresponding loss of the P-450 content of the microsomes (suicide destruction). The suicide inhibition by these aryl acetylenes therefore does not involve covalent binding to the heme moiety of the monooxygenase. Nevertheless, in the presence of NADPH, 3H-labeled 1-ethynylpyrene becomes covalently attached to the cytochrome P-450 protein; the measured stoichiometry of binding is one 1-ethynylpyrene per P-450 heme unit. The authors conclude that the inhibition of benzo[a]pyrene hydroxylase produced by 1-ethynylpyrene may be related to the mechanism of suicide inhibition of P-450 activity by chloramphenicol rather than the mechanism of suicide destruction of P-450 previously described for acetylene and propyne

  9. Selective copper catalysed aromatic N-arylation in water

    DEFF Research Database (Denmark)

    Engel-Andreasen, Jens; Shimpukade, Bharat; Ulven, Trond.

    2013-01-01

    4,7-Dipyrrolidinyl-1,10-phenanthroline (DPPhen) was identified as an efficient ligand for copper catalyzed selective arom. N-arylation in water. N-Arylation of indoles, imidazoles and purines proceeds with moderate to excellent yields and complete selectivity over aliph. amines. Aq. medium and th...

  10. Aryl (meth)acrylates and polymers based on them

    International Nuclear Information System (INIS)

    Data on the synthesis, polymerisation and copolymerisation of aryl (meth)acrylates are generalised and systematised. Chemical and photochemical properties of the polymers and copolymers are considered. Basic directions of practical application of poly[aryl (meth)acrylates] and copolymers are demonstrated. The bibliography includes 449 references.

  11. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates.

    Science.gov (United States)

    Ackerman, Laura K G; Lovell, Matthew M; Weix, Daniel J

    2015-08-27

    The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts--multimetallic catalysis--can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts--(bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium--enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this reaction will simplify the synthesis of pharmaceuticals, many of which are currently made with pre-formed organometallic reagents, and lead to the discovery of new multimetallic reactions. PMID:26280337

  12. Synthesis, Half-Wave Potentials and Antiproliferative Activity of 1-Aryl-substituted Aminoisoquinolinequinones

    Directory of Open Access Journals (Sweden)

    Juana Andrea Ibacache

    2014-01-01

    Full Text Available The synthesis of a variety of 1-aryl-7-phenylaminoisoquinolinequinones from 1,4-benzoquinone and arylaldehydes via the respective 1-arylisoquinolinequinones is reported. The cyclic voltammograms of the new compounds exhibit two one-electron reduction waves to the corresponding radical-anion and dianion and two quasi-reversible oxidation peaks. The half-wave potential values (EI½ of the members of the series have proven sensitive to the electron-donor effect of the aryl group (phenyl, 2-thienyl, 2-furyl at the 1-position as well as to the phenylamino groups (anilino, p-anisidino at the 7-position. The antiproliferative activity of the new compounds was evaluated in vitro using the MTT colorimetric method against one normal cell line (MRC-5 lung fibroblasts and two human cancer cell lines: AGS human gastric adenocarcinoma and HL-60 human promyelocytic leukemia cells in 72-h drug exposure assays. Among the series, compounds 5a, 5b, 5g, 5h, 6a and 6d exhibited interesting antiproliferative activities against human gastric adenocarcinoma. The 1-arylisoquinolinequinone 6a was found to be the most promising active compound against the tested cancer cell lines in terms of IC50 values (1.19; 1.24 µM and selectivity index (IS: 3.08; 2.96, respect to the anti-cancer agent etoposide used as reference (IS: 0.57; 0.14.

  13. Design, synthesis and evaluation of N-substituted saccharin derivatives as selective inhibitors of tumor-associated carbonic anhydrase XII.

    Science.gov (United States)

    D'Ascenzio, Melissa; Carradori, Simone; De Monte, Celeste; Secci, Daniela; Ceruso, Mariangela; Supuran, Claudiu T

    2014-03-15

    A series of N-alkylated saccharin derivatives were synthesized and tested for the inhibition of four different isoforms of human carbonic anhydrase (CA, EC 4. 2.1.1): the transmembrane tumor-associated CA IX and XII, and the cytosolic CA I and II. Most of the reported derivatives inhibited CA XII in the nanomolar/low micromolar range, hCA IX with KIs ranging between 11 and 390 nM, whereas they were inactive against both CA I (KIs >50 ?M) and II (K(I)s ranging between 39.1 nM and 50 ?M). Since CA I and II are off-targets of antitumor carbonic anhydrase inhibitors (CAIs), the obtained results represent an encouraging achievement for the development of new anticancer candidates without the common side effects of non-selective CAIs. Moreover, the lack of an explicit zinc binding function on these inhibitors opens the way towards the exploration of novel mechanisms of inhibition that could explain the high selectivity of these compounds for the inhibition of the transmembrane, tumor-associated isoforms over the cytosolic ones. PMID:24560739

  14. C- versus O-Arylation of an Enol-Lactone Using Potassium tert-butoxide

    Directory of Open Access Journals (Sweden)

    El Moktar Essassi

    2003-05-01

    Full Text Available Abstract: The use of potassium tert-butoxide as the base in arylation reactions of an enollactone with a series of benzyl halides was explored. Our work demonstrates that the ratio of C-arylation to O-arylation varies with the substitution pattern of the aryl halide.

  15. Synthesis and Antiviral Bioactivities of 2-Aryl- or 2-Methyl-3-(substituted- Benzalamino-4(3H-quinazolinone Derivatives

    Directory of Open Access Journals (Sweden)

    Zhuo Chen

    2007-12-01

    Full Text Available A simple and general method has been developed for the synthesis of various4(3H-quinazolinone derivatives by the treatment of the appropriate 3-amino-2-aryl-4(3H-quinazolinone with a substituted benzaldehyde in ethanol. The structures of the compoundswere characterized by elemental analysis, IR, 1H-NMR and 13C-NMR spectra. The title 2-aryl- or 2-methyl-3-(substituted-benzalamino-4(3H-quinazolinone compounds III-1~III-31 were found to possess moderate to good antiviral activity. Semi-quantitative PCR andReal Time PCR assays were used to ascertain the target of action of compound III-31against TMV. The studies suggest that III-31 possesses antiviral activity due to inductionof up-regulation of PR-1a and PR-5, thereby inhibiting virus proliferation and movementby enhancement of the activity of some defensive enzyme.

  16. Stabilization of CoI by ZnII in pure acetonitrile and its reaction with aryl halides.

    Science.gov (United States)

    Seka, Sylvaine; Buriez, Olivier; Périchon, Jacques

    2003-08-01

    The study of the electrochemical behavior of cobalt(II) bromide (CoBr(2)) in pure acetonitrile allowed us to demonstrate that Co(2+) is the catalyst precursor involved in the electrochemical and chemical conversions of arylhalides, ArX, to arylzinc compounds in that solvent. The reduction of Co(2+) leads to the Co(+) species, which disproportionates too rapidly to react further with aryl halides. However, the presence of zinc(II) bromide allows us to stabilize the electrogenerated cobalt(I) and to observe it on the timescale of slow cyclic voltammetry. Under such conditions, the Co(I) species has time to react with aryl halides and produce [Co(III)ArX](+) complexes that are reduced into [Co(II)ArX] by a single electron uptake at the same potential at which Co(2+) is reduced. Rate constants for the oxidative addition of ArX to Co(I) have been determined for various aryl halides and compared to the values obtained in an acetonitrile (ACN)/pyridine (9:1, v/v) mixture. It is shown that Co(I) is stabilized more by ZnBr(2) than by pyridine. A transmetallation reaction between [Co(II)ArX] and ZnBr(2) has also been observed. We finally propose a mechanism for the cobalt-catalyzed electrochemical conversion of aryl bromides into organozinc species in pure acetonitrile. PMID:12898686

  17. Synthesis and antimicrobial activities of new oxime carbamates of 3-aryl-2-thioquinazolin-4(3H)-one

    Indian Academy of Sciences (India)

    Suresh S Patil; Swati D Jadhav; M B Deshmukh

    2012-09-01

    S-alkylation of 3-aryl-2-thioquinazolin-4(3H)-one (1) with chloroacetone gave 2-(propanonyl thio)-3-arylquinazol-4(3H)ones (2). Further, the treatment of compound (2) with hydroxylamine hydrochloride gave the corresponding oximes (3) which on reaction with phenyl isocyanate in THF yielded corresponding oxime carbamates 4. The synthesized compounds have been confirmed using IR and 1H NMR, mass spectral data together with elemental analysis. All newly synthesized compounds have been tested for their antibacterial and antifungal activities.

  18. Consecutive Three-Component Synthesis of 3-(HeteroAryl-1H-pyrazoles with Propynal Diethylacetal as a Three-Carbon Building Block

    Directory of Open Access Journals (Sweden)

    Thomas J. J. Müller

    2011-11-01

    Full Text Available A novel consecutive three-component synthesis of 3-(heteroaryl-1H-pyrazoles via room temperature Sonogashira arylation of propynal diethylacetal used as a propargyl aldehyde synthetic equivalent has been disclosed. The final acetal cleavage-cyclocondensation with hydrazine hydrochloride at 80 °C rapidly furnishes the title compounds in a one-pot fashion.

  19. A new one-pot synthesis of 1,2,4-oxadiazoles from aryl nitriles, hydroxylamine and crotonoyl chloride

    Indian Academy of Sciences (India)

    Masoumeh Zakeri; Majid M Heravi; Ebrahim Abouzari-Lotf

    2013-07-01

    The reaction of aryl nitriles with hydroxylamine using acetic acid as a catalyst followed by subsequent addition of crotonoyl chloride to the intermediate amidoxime represents a straightforward one-pot access to new 1,2,4-oxadiazole synthesis under mild conditions. The course of the reaction was found to be high yielding and all new compounds were well characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS) and elemental analysis.

  20. Synthesis of Novel 1-[(2,6-Dichloro-4-trifluoromethyl)phenyl]-3-aryl-1H-pyrazole-4-carbaldehydes

    OpenAIRE

    Anjiang Zhang; Lisheng Ding; Changhua Ge; Huanan Hu

    2010-01-01

    A series of novel 1-[(2,6-dichloro-4-trifluoromethyl)phenyl]-3-aryl-1H-pyrazole-4-carbaldehydes 6a-i were synthesized using the Vilsmeier-Haack reagent. The structures of all the title compounds have been confirmed by elemental analysis, 1H-NMR and 13C-NMR and in addition, the structure of intermediate 5b was investigated by X-ray crystallography.

  1. Glucosides with cyclic diarylpolynoid as novel C-aryl glucoside SGLT2 inhibitors.

    Science.gov (United States)

    Kang, Suk Youn; Kim, Min Ju; Lee, Jun Sung; Lee, Jinhwa

    2011-06-15

    Novel C-aryl glucoside SGLT2 inhibitors containing cyclic diarylpolynoid motif were designed and synthesized for biological evaluation. Alkylzinc bromides have been efficiently prepared by the direct insertion of zinc metal into alkyl bromides. The organozinc reagents underwent smooth Pd-catalyzed cross-coupling reactions. Subsequent ring closing metathesis using 2nd generation Grubbs catalyst successfully generated novel class of ansa-compounds. These glucosides with cyclic diarylpolynoids demonstrated moderate in vitro inhibitory activity against SGLT2 in this series to date (IC(50)=59.5-103 nM). PMID:21592794

  2. Boronated porphyrin compounds

    Science.gov (United States)

    Kahl, Stephen B. (Portola Valley, CA); Koo, Myoung-Seo (San Francisco, CA)

    1992-01-01

    A compound is described having the structure ##STR1## where R preferably is ##STR2## and most preferably R.sup.3 is a closo-carborane and R.sup.2 is --H, an alkyl or aryl having 1 to about 7 carbon atoms, This invention was made with Government support under NIH Grant No. CA-37961 awarded by the Department of Health and Human Services and under the Associated Universities Inc. Contract No. De-AC02-76CH00016 with the U.S. Department of Energy. The Government has rights in this invention.

  3. Multicomponent, solvent-free synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[]-xanthen-11-one derivatives catalysed by cyanuric chloride

    Indian Academy of Sciences (India)

    Zhan-Hui Zhang; Peng Zhang; Shu-Hong Yang; Hong-Juan Wang; Jia Deng

    2010-05-01

    An efficient and direct protocol for the preparation of 12-aryl-8,9,10,12-tetrahydro-benzo[] xanthen-11-one derivatives employing a three-component one-pot reaction of aryl aldehydes, 2-naphthol and cyclic 1,3-dicarbonyl compounds in the presence of a catalytic amount of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine, TCT) under solvent-free conditions is described. The desired products are obtained in high yields with short reaction times.

  4. Synthesis and Biological Evaluation of 3-Aryl-quinoxaline-2-carbonitrile 1,4-Di-N-oxide Derivatives as Hypoxic Selective Anti-tumor Agents

    OpenAIRE

    Yongzhou Hu; Rong Sheng; Xiaowen Liu; Shihao Shangguan; Qing Xia; Yunzhen Hu

    2012-01-01

    A series of 3-aryl-2-quinoxaline-carbonitrile 1,4-di-N-oxide derivatives were designed, synthesized and evaluated for hypoxic and normoxic cytotoxic activity against human SMMC-7721, K562, KB, A549 and PC-3 cell lines. Many of these new compounds displayed more potent hypoxic cytotoxic activity compared with TX-402 and TPZ in the tumor cells based evaluation, which confirmed our hypothesis that the replacement of the 3-amine with the substituted aryl ring of TX-402 increa...

  5. Cloning, expression and characterization of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium strain BKM-F-1767

    Directory of Open Access Journals (Sweden)

    Yang Dong-Dong

    2012-06-01

    Full Text Available Abstract Background The white-rot fungus Phanerochaete chrysosporium is among the small group of fungi that can degrade lignin to carbon dioxide while leaving the crystalline cellulose untouched. The efficient lignin oxidation system of this fungus requires cyclic redox reactions involving the reduction of aryl-aldehydes to the corresponding alcohols by aryl-alcohol dehydrogenase. However, the biochemical properties of this enzyme have not been extensively studied. These are of most interest for the design of metabolic engineering/synthetic biology strategies in the field of biotechnological applications of this enzyme. Results We report here the cloning of an aryl-alcohol dehydrogenase cDNA from the white-rot fungus Phanerochaete chrysosporium, its expression in Escherichia coli and the biochemical characterization of the encoded GST and His6 tagged protein. The purified recombinant enzyme showed optimal activity at 37°C and at pH 6.4 for the reduction of aryl- and linear aldehydes with NADPH as coenzyme. NADH could also be the electron donor, while having a higher Km (220 ?M compared to that of NADPH (39 ?M. The purified recombinant enzyme was found to be active in the reduction of more than 20 different aryl- and linear aldehydes showing highest specificity for mono- and dimethoxylated Benzaldehyde at positions 3, 4, 3,4 and 3,5. The enzyme was also capable of oxidizing aryl-alcohols with NADP?+?at 30°C and an optimum pH of 10.3 but with 15 to 100-fold lower catalytic efficiency than for the reduction reaction. Conclusions In this work, we have characterized the biochemical properties of an aryl-alcohol dehydrogenase from the white-rot fungus Phanerochaete chrysosporium. We show that this enzyme functions in the reductive sense under physiological conditions and that it displays relatively large substrate specificity with highest activity towards the natural compound Veratraldehyde.

  6. Palladium-Catalyzed alpha-Arylation of Tetramic Acids

    DEFF Research Database (Denmark)

    Storgaard, Morten; Dorwald, F. Z.; Peschke, B.; Tanner, David Ackland

    2009-01-01

    A mild, racemization-free, palladium-Catalyzed alpha-arylation of tetramic acids (2,4-pyrrolidinediones) has been developed. Various amino acid-derived tetramic acids were cleanly arylated by treatment with 2 mol % of Pd(OAc)(2), 4 mol % of a sterically demanding biaryl phosphine, 2.3 equiv of K2CO3 or K3PO4, and aryl chlorides, bromides, or triflates in THF. With conventional heating, conversions >95% could be attained after 1 h at 80 degrees C, whereas microwave-induced heating led to much sho...

  7. Compounds of thiourea and its complexes with metal salts

    International Nuclear Information System (INIS)

    A review of literature on thiourea compounds is given. Three types of the compounds are described: clathrates, ion complexes and coordination compounds. The main attention is paid to thiourea complexes of transition metals. The structure of the complexes is considered, using X-ray structural analysis and other physicochemical methods. Stability and lability of thiourea coordination compounds and its N- and N, N'-substituted derivatives are characterized, as well as peculiarities of the given ligands in substitution reactions. Acid-basic, redox and thermal properties of thioamide complexes are discussed

  8. The discovery of new potent non-peptide Angiotensin II AT1 receptor blockers: A concise synthesis, molecular docking studies and biological evaluation of N-substituted 5-butylimidazole derivatives.

    Czech Academy of Sciences Publication Activity Database

    Agelis, G.; Resvani, A.; Durdagi, S.; Spyridaki, K.; T?mová, Tereza; Slaninová, Ji?ina; Giannopoulos, P.; Vlahakos, D.; Liapakis, G.; Mavromoustakos, T.; Matsoukas, J.

    2012-01-01

    Ro?. 55, Sep (2012), s. 358-374. ISSN 0223-5234 Institutional research plan: CEZ:AV0Z40550506 Keywords : synthesis * angiotensin II receptor blockers * N-substituted 5-butylimidazole derivatives * antihypertensive activity * molecular docking Subject RIV: CC - Organic Chemistry Impact factor: 3.499, year: 2012

  9. The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

    Directory of Open Access Journals (Sweden)

    Volodymyr V. Tkachenko

    2014-12-01

    Full Text Available The switchable three-component reactions of 5-amino-3-methylisoxazole, salicylaldehyde and N-aryl-3-oxobutanamides under different conditions were studied and discussed. The unexpected influence of the aryl substituent in N-aryl-3-oxobutanamides on the behavior of the reaction was discovered. The key influence of ultrasonication and Lewis acid catalysts led to an established protocol to selectively obtain two or three types of heterocyclic scaffolds depending on the substituent in the N-aryl moiety.

  10. A novel dihydropyridine with 3-aryl meta-hydroxyl substitution blocks L-type calcium channels in rat cardiomyocytes

    International Nuclear Information System (INIS)

    Rationale: Dihydropyridines are widely used for the treatment of several cardiac diseases due to their blocking activity on L-type Ca2+ channels and their renowned antioxidant properties. Methods: We synthesized six novel dihydropyridine molecules and performed docking studies on the binding site of the L-type Ca2+ channel. We used biochemical techniques on isolated adult rat cardiomyocytes to assess the efficacy of these molecules on their Ca2+ channel-blocking activity and antioxidant properties. The Ca2+ channel-blocking activity was evaluated by confocal microscopy on fluo-3AM loaded cardiomyocytes, as well as using patch clamp experiments. Antioxidant properties were evaluated by flow cytometry using the ROS sensitive dye 1,2,3 DHR. Results: Our docking studies show that a novel compound with 3-OH substitution inserts into the active binding site of the L-type Ca2+ channel previously described for nitrendipine. In biochemical assays, the novel meta-OH group in the aryl in C4 showed a high blocking effect on L-type Ca2+ channel as opposed to para-substituted compounds. In the tests we performed, none of the molecules showed antioxidant properties. Conclusions: Only substitutions in C2, C3 and C5 of the aryl ring render dihydropyridine compounds with the capacity of blocking LTCC. Based on our docking studies, we postulate that the antioxidant activity requires a larger group than the meta-OH substitution in C2, C3 or C5 of the dihydropyridine ring. - Highlights: • Dihydropyridine (DHP) molecules are widely used in cardiovascular disease. • DHPs block Ca2+ entry through LTCC—some DHPs have antioxidant activity as well. • We synthesized 6 new DHPs and tested their Ca2+ blocking and antioxidant activities. • 3-Aryl meta-hydroxyl substitution strongly increases their Ca2+ blocking activity. • 3-Aryl meta-hydroxyl substitution did not affect the antioxidant properties

  11. Docking of oxalyl aryl amino benzoic acid derivatives into PTP1B.

    Science.gov (United States)

    Verma, Neelam; Mittal, Minakshi; Verma, Raman Kumar

    2008-01-01

    Protein Tyrosine Phosphatases (PTPs) that function as negative regulators of the insulin signaling cascade have been identified as novel targets for the therapeutic enhancement of insulin action in insulin resistant disease states. Reducing Protein Tyrosine Phosphatase1B (PTP1B) abundance not only enhances insulin sensitivity and improves glucose metabolism but also protects against obesity induced by high fat feeding. PTP1B inhibitors such as Formylchromone derivatives, 1, 2-Naphthoquinone derivatives and Oxalyl aryl amino benzoic derivatives may eventually find an important clinical role as insulin sensitizers in the management of Type-II Diabetes and metabolic syndrome. We have carried out docking of modified oxalyl aryl amino benzoic acid derivatives into three dimensional structure of PTP1B using BioMed CAChe 6.1. These compounds exhibit good selectivity for PTP1B over most of phosphatases in selectivity panel such as SHP-2, LAR, CD45 and TCPTP found in literature. This series of compounds identified the amino acid residues such as Gly220 and Arg221 are important for achieving specificity via H-bonding interactions. Lipophilic side chain of methionine in modified oxalyl aryl amino benzoic acid derivative [1b (a2, b2, c1, d)] lies in closer vicinity of hydrophobic region of protein consisted of Meth258 and Phe52 in comparison to active ligand. Docking Score in [1b (a2, b2, c1, d)] is -131.740Kcal/mol much better than active ligand score -98.584Kcal/mol. This information can be exploited to design PTP1B specific inhibitors. PMID:19238234

  12. Selective copper catalysed aromatic N-arylation in water

    DEFF Research Database (Denmark)

    Engel-Andreasen, Jens; Shimpukade, Bharat; Ulven, Trond.

    2013-01-01

    4,7-Dipyrrolidinyl-1,10-phenanthroline (DPPhen) was identified as an efficient ligand for copper catalyzed selective arom. N-arylation in water. N-Arylation of indoles, imidazoles and purines proceeds with moderate to excellent yields and complete selectivity over aliph. amines. Aq. medium and the possibility for low metal and ligand loadings give the process a benign environmental profile. [on SciFinder(R)

  13. 2-Anilino-4-aryl-1,3-thiazole inhibitors of valosin-containing protein (VCP or p97).

    Science.gov (United States)

    Bursavich, Matthew G; Parker, Daniel P; Willardsen, J Adam; Gao, Zhong-Hua; Davis, Thaylon; Ostanin, Kirill; Robinson, Rosann; Peterson, Ashley; Cimbora, Daniel M; Zhu, Ju-Fen; Richards, Burt

    2010-03-01

    Valosin-containing protein (VCP; also known as p97) is a member of the AAA ATPase family with a central role in the ubiquitin-degradation of misfolded proteins. VCP also exhibits antiapoptotic function and metastasis via activation of nuclear factor kappa-B signaling pathway. We have discovered that 2-anilino-4-aryl-1,3-thiazoles are potent drug-like inhibitors of this enzyme. The identified compounds show low nanomolar VCP potency, demonstrate SAR trends, and show activity in a mechanism based cellular assay. This series of compounds represents the first steps towards a novel, small molecule VCP inhibitor as a cancer therapeutic. PMID:20137940

  14. Selective antagonists at group I metabotropic glutamate receptors: synthesis and molecular pharmacology of 4-aryl-3-isoxazolol amino acids

    DEFF Research Database (Denmark)

    Kromann, Hasse; Sløk, Frank A; Stensbøl, Tine B; Bräuner-Osborne, Hans; Madsen, Ulf; Krogsgaard-Larsen, Povl

    2002-01-01

    Homologation of (S)-glutamic acid (Glu, 1) and Glu analogues has previously provided ligands with activity at metabotropic Glu receptors (mGluRs). The homologue of ibotenic acid (7), 2-amino-3-(3-hydroxy-5-isoxazolyl)propionic acid (HIBO, 8), and the 4-phenyl derivative of 8, compound 9a, are both antagonists at group I mGluRs. Here we report the synthesis and molecular pharmacology of HIBO analogues 9b-h containing different 4-aryl substituents. All of these compounds possess antagonist activit...

  15. C-aryl glucosides substituted at the 4'-position as potent and selective renal sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes.

    Science.gov (United States)

    Xu, Baihua; Feng, Yan; Cheng, Huawei; Song, Yanli; Lv, Binhua; Wu, Yuelin; Wang, Congna; Li, Shengbin; Xu, Min; Du, Jiyan; Peng, Kun; Dong, Jiajia; Zhang, Wenbin; Zhang, Ting; Zhu, Liangcheng; Ding, Haifeng; Sheng, Zelin; Welihinda, Ajith; Roberge, Jacques Y; Seed, Brian; Chen, Yuanwei

    2011-08-01

    A series of C-aryl glucosides with various substituents at the 4'-position of the distal aryl ring have been synthesized and evaluated for inhibition of hSGLT1 and hSGLT2. Introduction of alkyl or alkoxy substituents at the 4'-position was found to improve SGLT2 potency, whereas introduction of a hydrophilic group at this position was deleterious. Compounds with alkoxy-, cycloalkoxy- or cycloalkenyloxy-ethoxy scaffolds exhibited good inhibitory activity and high selectivity toward SGLT2. Selected compounds were investigated for in vivo efficacy. PMID:21737266

  16. High-resolution laser spectroscopy and magnetic effect of the B ˜ 2 E ' ? X ˜ 2 A 2 ' transition of the 15N substituted nitrate radical

    Science.gov (United States)

    Tada, Kohei; Teramoto, Kanon; Ishiwata, Takashi; Hirota, Eizi; Kasahara, Shunji

    2015-03-01

    Rotationally resolved high-resolution fluorescence excitation spectra of the 0-0 band of the B ˜ 2 E ' ? X ˜ 2 A 2 ' transition of the 15N substituted nitrate radical were observed for the first time, by crossing a jet-cooled molecular beam and a single-mode dye laser beam at right angles. Several thousand rotational lines were detected in the 15 080-15 103 cm-1 region. We observed the Zeeman splitting of intense lines up to 360 G in order to obtain secure rotational assignment. Two, nine, and seven rotational line pairs with 0.0248 cm-1 spacing were assigned to the transitions from the X ˜ 2 A 2 ' (?? = 0, k? = 0, N? = 1, J? = 0.5 and 1.5) to the 2 E3 / 2 ' (J' = 1.5), 2 E1 / 2 ' (J' = 0.5), and 2 E1 / 2 ' (J' = 1.5) levels, respectively, based on the ground state combination differences and the Zeeman splitting patterns. The observed spectrum was complicated due to the vibronic coupling between the bright B ˜ 2 E ' (? = 0) state and surrounding dark vibronic states. Some series of rotational lines other than those from the X ˜ 2 A 2 ' (J = 0.5 and 1.5) levels were also assigned by the ground state combination differences and the observed Zeeman splitting. The rotational branch structures were identified, and the molecular constants of the B ˜ 2 E1 / 2 ' (? = 0) state were estimated by a deperturbed analysis to be T0 = 15 098.20(4) cm-1, B = 0.4282(7) cm-1, and DJ = 4 × 10-4 cm-1. In the observed region, both the 2 E1 / 2 ' and 2 E3 / 2 ' spin-orbit components were identified, and the spin-orbit interaction constant of the B ˜ 2 E ' (? = 0) state was estimated to be -12 cm-1 as the lower limit.

  17. The use of AgNO3/BF3.Et2O and HNO3/Al(H2PO43 systems in the synthesis of aryl thiosulfonates

    Directory of Open Access Journals (Sweden)

    Edson Anjos Santos

    2012-06-01

    Full Text Available The thiosulfonates are a class of compounds of great industrial importance. It is worth noting that the aryl thiosulfonates present several biological activities. The synthesis of these compounds is known in the literature although; only a few make use of thiols as the sole starting material. This work shows the use of two reaction systems employed for the synthesis of nitrophenols, AgNO3/BF3.EtO2 (I and HNO3/Al(H2PO43 (II, as an alternative to the preparation of aryl thiosulfonates. The use of system I led to higher yields (72-76% then system II (56-61%. These methodologies have not been reported before for the synthesis of these compounds and the products were obtained with good purity.

  18. Synthesis of aryl-1H-1,2,3-triazoles via 1,3-dipolar cycloaddition

    Directory of Open Access Journals (Sweden)

    Wagner O. Valença

    2012-06-01

    Full Text Available A series of Aryl-1H-1,2,3-triazoles were prepared from the reaction between aril-azide (1 with 1.5 equiv. of terminal alkynes (2a-o. The reactions carried out at room temperature and in the presence of CuI (10 mol% in acetonitrile. The compounds (3a-o were obtained in moderate-to-good yields (50-94%. In general, not was observed significant inductive effect on the reactivity of the alkynes (2a-f. The alcohol alkynes (2i-k showed moderate yields 50-72%. On the other hand, the reaction with alkyl alkynes (2m,n furnished the compounds (3m and (3n in excellent yields of 89% and 90%, respectively.

  19. Discovery and evaluation of potent P1 aryl heterocycle-based thrombin inhibitors.

    Science.gov (United States)

    Young, Mary Beth; Barrow, James C; Glass, Kristen L; Lundell, George F; Newton, Christina L; Pellicore, Janetta M; Rittle, Kenneth E; Selnick, Harold G; Stauffer, Kenneth J; Vacca, Joseph P; Williams, Peter D; Bohn, Dennis; Clayton, Franklin C; Cook, Jacquelynn J; Krueger, Julie A; Kuo, Lawrence C; Lewis, S Dale; Lucas, Bobby J; McMasters, Daniel R; Miller-Stein, Cynthia; Pietrak, Beth L; Wallace, Audrey A; White, Rebecca B; Wong, Bradley; Yan, Youwei; Nantermet, Philippe G

    2004-06-01

    In an effort to discover potent, clinically useful thrombin inhibitors, a rapid analogue synthetic approach was used to explore the P(1) region. Various benzylamines were coupled to a pyridine/pyrazinone P(2)-P(3) template. One compound with an o-thiadiazole benzylic substitution was found to have a thrombin K(i) of 0.84 nM. A study of ortho-substituted five-membered-ring heterocycles was undertaken and subsequently demonstrated that the o-triazole and tetrazole rings were optimal. Combination of these potent P(1) aryl heterocycles with a variety of P(2)-P(3) groups produced a compound with an extraordinary thrombin inhibitory activity of 1.4 pM. It is hoped that this potency enhancement in P(1) will allow for more diversification in the P(2)-P(3) region to ultimately address additional pharmacological concerns. PMID:15163182

  20. Discovery of potent cytotoxic ortho-aryl chalcones as new scaffold targeting tubulin and mitosis with affinity-based fluorescence.

    Science.gov (United States)

    Zhu, Cuige; Zuo, Yinglin; Wang, Ruimin; Liang, Baoxia; Yue, Xin; Wen, Gesi; Shang, Nana; Huang, Lei; Chen, Yu; Du, Jun; Bu, Xianzhang

    2014-08-14

    A series of new ortho-aryl chalcones have been designed and synthesized. Many of these compounds were found to exhibit significant antiproliferation activity toward a panel of cancer cell lines. Selected compounds show potent cytotoxicity against several drug resistant cell lines including paclitaxel (Taxol) resistant human ovarian carcinoma cells, vincristine resistant human ileocecum carcinoma cells, and doxorubicin resistant human breast carcinoma cells. Further investigation revealed that active analogues could inhibit the microtubule polymerization by binding to colchicine site and thus induce multipolar mitosis, G2/M phase arrest, and apoptosis of cancer cells. Furthermore, affinity-based fluorescence enhancement was observed during the binding of active compounds with tubulin, which greatly facilitated the determination of tubulin binding site of the compounds. Finally, selected compound 26 was found to exhibit obvious in vivo antitumor activity in A549 tumor xenografts model. Our systematic studies implied a new scaffold targeting tubulin and mitosis for novel antitumor drug discovery. PMID:25061803

  1. Reductive carbonylation of aryl halides employing a two-chamber reactor : a protocol for the synthesis of aryl aldehydes including 13C- and D-isotope labeling

    DEFF Research Database (Denmark)

    Korsager, Signe; Taaning, Rolf H

    2013-01-01

    A protocol has been developed for conducting the palladium-catalyzed reductive carbonylation of aryl iodides and bromides using 9-methylfluorene-9-carbonyl chloride (COgen) as a source of externally delivered carbon monoxide in a sealed two-chamber system (COware), and potassium formate as the in situ hydride source. The method is tolerant to a wide number of functional groups positioned on the aromatic ring, and it can be exploited for the isotope labeling of the aldehyde group. Hence, reductive carbonylations run with (13)COgen provide a facile access to (13)C-labeled aromatic aldehydes, whereas with DCO2K, the aldehyde is specifically labeled with deuterium. Two examples of double isotopic labeling are also demonstrated. Finally, the method was applied to the specific carbon-13 labeling of the ?-amyloid binding compound, florbetaben.

  2. Toxicity of teriflunomide in aryl hydrocarbon receptor deficient mice.

    Science.gov (United States)

    Redaelli, Chiara; Gaffarogullari, Ece Cazibe; Brune, Maik; Pilz, Caroline; Becker, Simon; Sonner, Jana; Jäschke, Andres; Gröne, Hermann-Josef; Wick, Wolfgang; Platten, Michael; Lanz, Tobias Volker

    2015-12-01

    The intracellular transcription factor aryl hydrocarbon receptor (AHR) is bound and activated by xenobiotics, thereby promoting their catabolism by inducing expression of cytochrome P450 oxidase (CYP) genes through binding xenobiotic response elements (XRE) in their promoter region. In addition, it is involved in several cellular pathways like cell proliferation, differentiation, regeneration, tumor invasiveness and immune responses. Several pharmaceutical compounds like benzimidazoles activate the AHR and induce their own metabolic degradation. Using newly generated XRE-reporter mice, which allow in vivo bioluminescence imaging of AHR activation, we show here that the AHR is activated in vivo by teriflunomide (TER), which has recently been approved for the treatment of multiple sclerosis. While we did not find any evidence that the AHR mediates the immunomodulatory effects of TER, AHR activation led to metabolism and detoxification of teriflunomide, most likely via CYP. Mice deficient for the AHR show higher blood levels of teriflunomide, suffer from enhanced thrombo- and leukopenia and elevated liver enzymes as well as from severe gastrointestinal ulcers and bleeding which are lethal after 8-11 days of treatment. Leukopenia, acute liver damage and diarrhea have also been described as common side effects in human trials with TER. These data suggest that the AHR is relevant for detoxification not only of environmental toxins but also of drugs in clinical use, with potential implications for the application of AHR-modifying therapies in conjunction to TER in humans. The XRE-reporter mouse is a useful novel tool for monitoring AHR activation using in vivo imaging. PMID:26341389

  3. Synthesis, structure elucidation, DNA-PK and PI3K and anti-cancer activity of 8- and 6-aryl-substituted-1-3-benzoxazines.

    Science.gov (United States)

    Morrison, Rick; Al-Rawi, Jasim M A; Jennings, Ian G; Thompson, Philip E; Angove, Michael J

    2016-03-01

    The synthesis of 6-aryl, 8- aryl, and 8-aryl-6-chloro-2-morpholino-1,3-benzoxazines with potent activity against PI3K and DNA-PK is described. Synthesis of thirty one analogues was facilitated by an improved synthesis of 3-bromo-2-hydroxybenzoic acid 13 by de-sulphonation of 3-bromo-2-hydroxy-5-sulfobenzoic acid 12 en route to 2-methylthio-substituted-benzoxazine intermediates 17-19. From this series, compound 20k (LTURM34) (dibenzo[b,d]thiophen-4-yl) (IC50 = 0.034 ?M) was identified as a specific DNA-PK inhibitor, 170 fold more selective for DNA-PK activity compared to PI3K activity. Other compounds of the series show markedly altered selectivity for various PI3K isoforms including compound 20i (8-(naphthalen-1-yl) a potent and quite selective PI3K? inhibitor (IC50 = 0.64 ?M). Finally, nine compounds were evaluated and showed antiproliferative activity against an NCI panel of cancer cell lines. Compound 20i (8-(naphthalen-1-yl) showed strong anti-proliferative activity against A498 renal cancer cells that warrants further investigation. PMID:26854431

  4. Kinetics and Mechanism of Pyridinolyses of Aryl Methyl and Aryl Propyl Chlorothiophosphates in Acetonitrile

    International Nuclear Information System (INIS)

    The nucleophilic substitution reactions of Y-aryl methyl (8) and Y-aryl propyl (10) chlorothiophosphates with X-pyridines are studied kinetically in acetonitrile at 35.0 .deg. C. The Hammett and Bronsted plots with X in the nucleophiles for both substrates exhibit biphasic concave upwards with a break region between X = 3-Me and H. The obtained values of the cross-interaction constants (?XY) are negative with 8 while positive with 10 despite the same free energy correlations with X for both substrates. A stepwise mechanism with a rate-limiting bond formation is proposed with 8, whereas a stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed with 10 based on the sign of ?XY, negative and positive with 8 and 10, respectively. A frontside nucleophilic attack is proposed with strongly basic pyridines based on the considerably great magnitudes of ?X and ?X values while a backside attack is proposed with weakly basic pyridines based on the relatively small magnitudes of ?X and ?X for both substrates

  5. Synthesis and Antifungal Evaluation of 1-Aryl-2-dimethyl-aminomethyl-2-propen-1-one Hydrochlorides

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Topaloglu

    2011-06-01

    Full Text Available The development of resistance to current antifungal therapeutics drives the search for new effective agents. The fact that several acetophenone-derived Mannich bases had shown remarkable antifungal activities in our previous studies led us to design and synthesize some acetophenone-derived Mannich bases, 1-8 and 2-acetylthiophene-derived Mannich base 9, 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochloride, to evaluate their antifungal activities. The designed chemical structures have ?,?-unsaturated ketone moieties, which are responsible for the bioactivities of the Mannich bases. The aryl part was C6H5 (1; 4-CH3C6H4 (2; 4-CH3OC6H4 (3; 4-ClC6H4 (4; 4-FC6H4 (5; 4-BrC6H4 (6; 4-HOC6H4 (7; 4-NO2C6H4 (8; and C4H3S(2-yl (9. In this study the designed compounds were synthesized by the conventional heating method and also by the microwave irradiation method to compare these methods in terms of reaction times and yields to find an optimum synthetic method, which can be applied for the synthesis of Mannich bases in further studies. Since there are limited number of studies reporting the synthesis of Mannich bases by microwave irradiation, this study may also contribute to the general literature on Mannich bases. Compound 7 was reported for the first time. Antifungal activities of all compounds and synthesis of the compounds by microwave irradiation were also reported for the first time by this study. Fungi (15 species were used for antifungal activity test. Amphotericin B was tested as an antifungal reference compound. In conclusion, compounds 1-6, and 9, which had more potent (2–16 times antifungal activity than the reference compound amphotericin B against some fungi, can be model compounds for further studies to develop new antifungal agents. In addition, microwave irradiation can be considered to reduce reaction period, while the conventional method can still be considered to obtain compounds with higher reaction yields in the synthesis of new Mannich bases.

  6. Tuning Aryl?CH···O Intermolecular Interactions on Pt(111)

    DEFF Research Database (Denmark)

    Demers-Carpentier, Vincent; Laliberte, Marc-Andre?

    2011-01-01

    Scanning tunneling microscopy (STM) data are reported for the room-temperature adsorption of 2,2,2-trifluoroacetophenone (TFAP), 2,2,2-trifluorovinylbenzene (TFVB), octafluoroacetophenone (OFAP), and methyl benzoate (MB) on Pt(111). The objective of the study is to establish the role of aryl?CH···O bonding in forming self-assembled low-nuclearity structures at room temperature and to compare aryl?CH···O bonding by ester and ketone carbonyl functions. The STM images clearly evidence the formation of homochiral dimers and trimers of TFAP, and density functional theory (DFT) calculations reveal aryl?CH···O bonding as the driving force for dimer formation. In contrast to TFAP, chemisorbed TFVB and OFAP do not form such self-assembled structures as they lack carbonyl and aryl?CH groups, respectively. The self-assembly of MB on Pt(111) differs from that of TFAP, in that it can form structures stabilized by one, as distinct from two, aryl?CH···O bonds. The results are discussed with respect to the enantioselective hydrogenation of ?-ketoesters on cinchona modified Pt catalysts.

  7. Rational design, green synthesis, and initial evaluation of a series of full-color tunable fluorescent dyes enabled by the copper-catalyzed N-arylation of 6-phenyl pyridazinones and their application in cell imaging.

    Science.gov (United States)

    Liang, Lei; Wang, Wei; Wu, Jun; Xu, Fengrong; Niu, Yan; Xu, Bo; Xu, Ping

    2013-10-01

    There is widespread interest in the application, optimization, and evolution of the transition-metal-catalyzed arylation of N-heteroarenes to discover full-color tunable fluorescent core frameworks. Inspired by the versatile roles of pyridazinone in organic synthesis and medicinal chemistry, herein, we report a simple and efficient copper-catalyzed cross-coupling reaction for the N-functionalization of pyridazinones in neat water. To achieve the efficient conversion of pyridazinones and organic halides in aqueous phase, a series of copper-salen complexes composed of different Schiff base ligands were investigated by rational design. A final choice of fine-tuned hydrophilicity balanced with lipophilicity among the candidates was confirmed, which affords excellent activity towards the reaction of a wide range of pyridazinones and organic halides. More importantly, the products as N-substituted pyridazinones were synthesized rationally by this methodology as full-color tunable fluorescent agents (426-612?nm). The N2 position of pyridazinones was modified by different aryl group such as benzothiazole, N,N-dimethylaniline, 3-quinoline, 4-isoquinoline and 2-thiophene, resulting in a series of full-color tunable fluorescent reagents. Meanwhile, the effects of electron-donating and electron-withdrawing groups of the 6-substituted phenyl ring have also been investigated to optimize the fluorescent properties. These fluorescent core frameworks were studied in several cell lines as fluorescent dyes. Different colors from blue to red were observed by using fluorescence microscopy and confocal microscopy. PMID:24038329

  8. Ligand-controlled ?- and ?-arylation of acyclic N-Boc amines.

    Science.gov (United States)

    Millet, Anthony; Dailler, David; Larini, Paolo; Baudoin, Olivier

    2014-03-01

    The palladium-catalyzed ligand-controlled arylation of ?-zincated acyclic amines, obtained by directed ?-lithiation and transmetalation, is described. Whereas PtBu3 gave rise to ?-arylated Boc-protected amines, more flexible N-phenylazole-based phosphine ligands induced major ?-arylation through migrative cross-coupling. PMID:24504659

  9. Photoreactive molecular layers containing aryl ester units: Preparation, UV patterning and post-exposure modification

    Energy Technology Data Exchange (ETDEWEB)

    Hoefler, Thomas [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Track, Anna M. [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Pacher, Peter [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Shen, Quan [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Flesch, Heinz-Georg [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Hlawacek, Gregor [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Koller, Georg; Ramsey, Michael G. [Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Schennach, Robert; Resel, Roland [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Teichert, Christian [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Kern, Wolfgang [Institute of Chemistry of Polymers, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Trimmel, Gregor [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Griesser, Thomas, E-mail: thomas.griesser@unileoben.ac.at [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Institute of Chemistry of Polymers, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria)

    2010-01-15

    The photolithographic modification of thin functional silane layers provides a versatile and powerful means of fabricating functionalized patterned surfaces which can be applied for tuning inorganic surface properties and for modern immobilisation techniques. In this contribution we present the synthesis of a new functional trichloro organosilane bearing photoreactive aryl ester groups and its application in thin silane layers on silicon oxide surfaces. Whereas the trichlorosilyl group acts as anchoring unit to the inorganic surface, the aryl ester group undergoes the photo-Fries rearrangement to yield hydroxyketones upon irradiation with UV-light of 254 nm which leads to a change in chemical reactivity of the surface. By a subsequent reaction with perfluorobutyryl chloride, the photogenerated hydroxy groups yield the corresponding perfluorinated ester compound, which allows further tuning of surface properties. The layer formation as well as the photoreaction and post-modification reaction was monitored by FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the obtained thin layers was determined by X-ray reflectivity (XRR). Photopatterned surfaces were produced using a contact mask during illumination followed by the post-modification reaction. Friction force microscopy (FFM) revealed the contrast between modified and unmodified regions of the patterned samples.

  10. Crystal structure analysis of a bacterial aryl acylamidase belonging to the amidase signature enzyme family.

    Science.gov (United States)

    Lee, Saeyoung; Park, Eun-Hye; Ko, Hyeok-Jin; Bang, Won Gi; Kim, Hye-Yeon; Kim, Kyoung Heon; Choi, In-Geol

    2015-11-13

    The atomic structure of a bacterial aryl acylamidase (EC 3.5.1.13; AAA) is reported and structural features are investigated to better understand the catalytic profile of this enzyme. Structures of AAA were determined in its native form and in complex with the analgesic acetanilide, p-acetaminophenol, at 1.70 Å and 1.73 Å resolutions, respectively. The overall structural fold of AAA was identified as an ?/? fold class, exhibiting an open twisted ?-sheet core surrounded by ?-helices. The asymmetric unit contains one AAA molecule and the monomeric form is functionally active. The core structure enclosing the signature sequence region, including the canonical Ser-cisSer-Lys catalytic triad, is conserved in all members of the Amidase Signature enzyme family. The structure of AAA in a complex with its ligand reveals a unique organization in the substrate-binding pocket. The binding pocket consists of two loops (loop1 and loop2) in the amidase signature sequence and one helix (?10) in the non-amidase signature sequence. We identified two residues (Tyr(136) and Thr(330)) that interact with the ligand via water molecules, and a hydrogen-bonding network that explains the catalytic affinity over various aryl acyl compounds. The optimum activity of AAA at pH > 10 suggests that the reaction mechanism employs Lys(84) as the catalytic base to polarize the Ser(187) nucleophile in the catalytic triad. PMID:26454172

  11. Synthesis and biological studies of some new n-substituted derivatives of n-(1,3-benzodioxol-5-yl)-4-methylbenzenesulfonamide

    International Nuclear Information System (INIS)

    Sulfonamides are biologically active compounds with broad spectrum of activities. In the presented research, a small collection of Nalkyl/aralkyl substituted sulfonamides have been synthesized and investigated for inhibition of different bacterial strains. The 1,3 Benzodioxol 5amine (1) was treated with tosyl chloride (2) in water under mild basic conditions to yield the molecule, N(1,3Benzodioxol5yl) 4methylbenzenesulfonamide (3). The target compounds, 5a-i, were obtained by stirring 3 with different electrophiles, 4a-i, in the presence of N,N dimethylformamide and sodium hydride. The structures of the synthesized compounds were established by spectroscopic techniques like IR, 1HNMR and EIMS. These compounds were assayed for their antimicrobial activities via screening against Gram-positive and Gram-negative bacteria. The most of the compounds showed moderate activity against P. aeruginosa relative to reference standard drug, ciprofloxacin. (author)

  12. Design and synthesis of novel 3,5-bis-N-(aryl/heteroaryl) carbamoyl-4-aryl-1,4-dihydropyridines as small molecule BACE-1 inhibitors.

    Science.gov (United States)

    Razzaghi-Asl, Nima; Firuzi, Omidreza; Hemmateenejad, Bahram; Javidnia, Katayoun; Edraki, Najmeh; Miri, Ramin

    2013-11-15

    Alzheimer disease (AD) is a neuronal dementia for which no treatment has been consolidated yet. Major pathologic hallmark of AD is the aggregated extracellular amyloid-? plaques in the brains of disease sufferers. A?-peptide is a major component of amyloid plaques and is produced from amyloid precursor protein (APP) via the proteolysis action. An aspartyl protease known as ?-site amyloid precursor protein cleaving enzyme (BACE-1) is responsible for this proteolytic action. Distinctive role of BACE-1 in AD pathogenesis has made it a validated target to develop anti-Alzheimer agents. Our structure-based virtual screening method led to the synthesis of novel 3,5-bis-N-(aryl/heteroaryl) carbamoyl-4-aryl-1,4-dihydropyridine BACE-1 inhibitors (6a-6p; in vitro hits). Molecular docking and DFT-based ab initio studies using B3LYP functional in association with triple-? basis set (TZV) proposed binding mode and binding energies of ligands in the active site of the receptor. In vitro BACE-1 inhibitory activities were determined by enzymatic fluorescence resonance energy transfer (FRET) assay. Most of the synthesized dihydropyridine scaffolds were active against BACE-1 while 6d, 6k, 6n and 6a were found to be the most potent molecules with IC50 values of 4.21, 4.27, 4.66 and 6.78 ?M, respectively. Superior BACE-1 inhibitory activities were observed for dihydropyridine derivatives containing fused/nonfused thiazole containing groups, possibly attributing to the additional interactions with S2-S3 subpocket residues. Relatively reliable correlation between calculated binding energies and experimental BACE-1 inhibitory activities was achieved (R(2)=0.51). Moreover, compounds 6d, 6k, 6n and 6a exhibited relatively no calcium channel blocking activity with regard to nifedipine suggesting them as appropriate candidates for further modification(s) to BACE-1 inhibitory scaffolds. PMID:24113238

  13. Ethyl 3-(2,4-dioxocyclohexyl)propanoate as a novel precursor for N-substituted 4,4a,5,6-tetrahydroquinoline-2,7(1H,3H)-diones and their corresponding 3,4-dihydro-7-hydroxyquinolin-2(1H)-ones and 7-hydroxyquinolin-2(1H)-ones synthesis.

    Science.gov (United States)

    Thakur, Vandna; Sharma, Dharminder; Das, Pralay

    2016-02-01

    Ethyl 3-(2,4-dioxocyclohexyl)propanoate has been explored as a precursor for the synthesis of N-substituted 4,4a,5,6-tetrahydroquinoline-2,7(1H,3H)-diones following conventional protecvtion, selective amidation, and deprotective-cyclization approaches. Moreover, a facile process for the selective dehydrogenative aromatization of these diones was developed to afford the corresponding N-substituted 3,4-dihydro-7-hydroxyquinolin-2(1H)-ones and N-substituted 7-hydroxyquinolin-2(1H)-ones under mild conditions. PMID:26537729

  14. Studies on Inclusion Complexes of 1-Nicotinoyl-4-Aryl-3-Methyl 3a, 4-Dihydropyrazolo [3, 4c] pyrazoles with ?-Cyclodextrin

    OpenAIRE

    Sunakar Panda; Singh, D L; S.K.Nayak

    2013-01-01

    Some 1-Nicotinoyl-4-aryl-3-methyl 3a, 4-dihydropyrazole [3, 4c] pyrazoles were synthesised and their inclusion complexes were prepared with ?-cyclodextrin. The compounds and their inclusion complexes were characterised by the study of their physical and spectral properties. The determination of stability constant of inclusion complexes and other thermodynamic parameters such as change in free energy, change in enthalpy and change in entropy, suggested the inclusion complex formation to be the...

  15. Effects of currently used pesticides and their mixtures on the function of thyroid hormone and aryl hydrocarbon receptor in cell culture

    DEFF Research Database (Denmark)

    Ghisari, Mandana; Long, Manhai; Tabbo, Agnese; Bonefeld-Jørgensen, Eva Cecilie

    2015-01-01

    Evidence suggest that exposure to pesticides can interfere with the endocrine system by multiple mechanisms. The endocrine disrupting potential of currently used pesticides in Denmark was analyzed as single compounds and in an equimolar mixture of 5 selected pesticides. The pesticides were previously analyzed for effects on the function of estrogen and androgen receptors, the aromatase enzyme and steroidogenesis in vitro. In this study, the effect on thyroid hormone (TH) function and aryl hydroc...

  16. Base-Promoted Domino Reaction of 5-Substituted 2-Nitrosophenols with Bromomethyl Aryl Ketones: A Transition-Metal-Free Approach to 2-Aroylbenzoxazoles.

    Science.gov (United States)

    Aljaar, Nayyef; Malakar, Chandi C; Conrad, Jürgen; Beifuss, Uwe

    2015-11-01

    The reaction of 5-substituted 2-nitrosophenols with bromomethyl aryl ketones and related compounds employing K2CO3 as a base in refluxing THF and DMF at 80 °C, respectively, delivers 2-aroylbenzoxazoles in a single step with yields up to 85%. The new method involves an intermolecular nucleophilic substitution followed by intramolecular 1,2-addition and elimination. It allows an efficient and practical access to 2-aroylbenzoxazoles under transition-metal-free conditions. PMID:26399156

  17. Pd-catalyzed cross-coupling of aryllithium reagents with 2-alkoxy-substituted aryl chlorides: mild and efficient synthesis of 3,3'-diaryl BINOLs.

    Science.gov (United States)

    Castelló, Luis M; Hornillos, Valentín; Vila, Carlos; Giannerini, Massimo; Fañanás-Mastral, Martín; Feringa, Ben L

    2015-01-01

    Palladium-catalyzed cross-coupling of aryllithium reagents with 2-alkoxy-substituted aryl chlorides is described. The reactions proceed under mild conditions with short reaction times and provide a wide range of 2-alkoxy-substituted biaryls. This new methodology is applied to the efficient preparation of 3,3'-diaryl BINOLs and represents the first synthesis of this important class of chiral compounds from the corresponding 3,3'-dichloro BINOLs. PMID:25514438

  18. Ultrasound promoted and SiO2/CCl3COOH mediated synthesis of 2-aryl-1-arylmethyl-1-benzimidazole derivatives in aqueous media: An eco-friendly approach

    Indian Academy of Sciences (India)

    Brajesh Kumar; Kumari Smita; Brajendra Kumar; Luis Cumbal

    2014-11-01

    Ultrasonic irradiation is an efficient and innocuous technique of reagent activation for synthesizing organic compounds. First one-pot synthesis of 2-aryl-1-arylmethyl-1H- benzimidazole derivatives from o- phenylenediamine and an aromatic aldehyde in the presence of silica gel supported trichloroacetic acid (SiTCA) was carried out with excellent yields at 50°C by sonication. This method provided several advantages such as green solvent, inexpensive catalyst, simple experimental methodology, shorter reaction time and higher yield.

  19. Double N-arylation reaction of polyhalogenated 4,4’-bipyridines. Expedious synthesis of functionalized 2,7-diazacarbazoles

    Directory of Open Access Journals (Sweden)

    Mohamed Abboud

    2012-02-01

    Full Text Available Unusual 2,7-diazacarbazoles were prepared in one step from readily available tetra-halogenated 4,4’-bipyridines by using a double N-arylation reaction in the presence of the Pd–XPhos catalyst system. Moderate to good yields were obtained in this site-selective Buchwald–Hartwig double amination. The functionalization of these tricyclic derivatives was performed by using Pd-catalyzed cross-coupling reactions such as the Stille and Suzuki couplings. Two compounds were analyzed by X-ray diffraction and show ?–? stacking involving the diazacarbazole moieties and the phenyl rings of functionalized groups.

  20. Synthesis and Antimicrobial Activity of N-Substituted-?-amino Acid Derivatives Containing 2-Hydroxyphenyl, Benzo[b]phenoxazine and Quinoxaline Moieties

    Directory of Open Access Journals (Sweden)

    Kristina Mickevi?ien?

    2015-02-01

    Full Text Available 3-[(2-Hydroxyphenylamino]butanoic and 3-[(2-hydroxy-5-methyl(chlorophenylamino]butanoic acids were converted to a series of derivatives containing hydrazide, pyrrole and chloroquinoxaline moieties. The corresponding benzo[b]phenoxazine derivatives were synthesized by the reaction of the obtained compounds with 2,3-dichloro-1,4-naphthoquinone. Five of the synthesized compounds exhibited good antimicrobial activity against Staphylococcus aureus and Mycobacterium luteum, whereas three compounds showed significant antifungal activity against Candida tenuis and Aspergillus niger.

  1. Synthesis, Characterization and Biological Screening of Various O-phenyl-N-aryl Carbamates

    International Nuclear Information System (INIS)

    A series of O-phenyl-N-aryl carbamates (3a-i) were synthesized by the reaction of phenyl chloroformate (1) with different aromatic amines (2a-i). The compounds were characterized by IR and 1H-NMR and screened against acetylcholinesterase, butrylcholinesterase and lipoxygenase enzymes. The results revealed that O-phenyl-N-phenyl carbamate (3a) and O-phenyl-N-(3-hydroxyphenyl) carbamate (3e) were active against acetylcholinesterase while O-phenyl-N-benzyl carbamate (3b), O-phenyl-N-(4-hydroxyphenyl) carbamate (3f) and O-phenyl-N-(3-methoxyphenyl) carbamate (3h) exhibited potential inhibitory activity against 5-lipoxygenase. All these carbamates were also assayed for their antimicrobial and hemolytic activities. O-phenyl-N-(2-hydroxyphenyl) carbamate (3d), O-phenyl-N-(4-hydroxyphenyl) carbamate (3f) and O-phenyl-N-(3-methoxyphenyl) carbamate (3h) showed good antimicrobial and hemolytic activity among all the carbamates. (author)

  2. Influence of conjugation axis on the optical and electronic properties of aryl-substituted benzobisoxazoles.

    Science.gov (United States)

    Tlach, Brian C; Tomlinson, Aimée L; Ryno, Alden G; Knoble, Dawn D; Drochner, Dana L; Krager, Kyle J; Jeffries-EL, Malika

    2013-07-01

    Six different 2,6-diethyl-4,8-diarylbenzo[1,2-d:4,5-d']bis(oxazoles) and four different 2,4,6,8-tetraarylbenzobisoxazoles were synthesized in two steps: a Lewis acid catalyzed orthoester cyclization followed by a Suzuki or Stille cross-coupling with various arenes. The influence of aryl group substitution and/or conjugation axis variation on the optical and electronic properties of these benzobis(oxazole) (BBO) compounds was evaluated. Structural modifications could be used to alter the HOMO, LUMO, and band gap over a range of 1.0, 0.5, and 0.5 eV, respectively. However, depending on the location and identity of the substituent, the HOMO level can be altered without significantly impacting the LUMO level. This is supported by the calculated frontier molecular orbitals. Our results indicate that the FMOs and band gaps of benzobisoxazoles can be readily modified either jointly or individually. PMID:23796165

  3. Activity of 2-aryl-2-(3-indolyl)acetohydroxamates against drug-resistant cancer cells.

    Science.gov (United States)

    Aksenov, Alexander V; Smirnov, Alexander N; Magedov, Igor V; Reisenauer, Mary R; Aksenov, Nicolai A; Aksenova, Inna V; Pendleton, Alexander L; Nguyen, Gina; Johnston, Robert K; Rubin, Michael; De Carvalho, Annelise; Kiss, Robert; Mathieu, Véronique; Lefranc, Florence; Correa, Jaime; Cavazos, David A; Brenner, Andrew J; Bryan, Brad A; Rogelj, Snezna; Kornienko, Alexander; Frolova, Liliya V

    2015-03-12

    Many types of tumor, including glioma, melanoma, non-small cell lung, esophageal, and head and neck cancer, among others, are intrinsically resistant to apoptosis induction and poorly responsive to current therapies with proapoptotic agents. In addition, tumors often develop multidrug resistance based on the cellular efflux of chemotherapeutic agents. Thus, novel anticancer agents capable of overcoming these intrinsic or developed tumor resistance mechanisms are urgently needed. We describe a series of 2-aryl-2-(3-indolyl)acetohydroxamic acids that are active against apoptosis- and multidrug-resistant cancer cells as well as glioblastoma neurosphere stemlike cell cultures derived from patients. Thus, the described compounds serve as a novel chemical scaffold for the development of potentially highly effective clinical cancer drugs. PMID:25671501

  4. Mannosylated N-aryl substituted 3-hydroxypyridine-4-ones: synthesis, hemagglutination inhibitory properties, and molecular modeling.

    Science.gov (United States)

    Car, Zeljka; Hrenar, Tomica; Petrovi? Perokovi?, Vesna; Ribi?, Rosana; Seni?ar, Mateja; Tomi?, Sr?anka

    2014-10-01

    Structural alterations of the aglycon portions of ?-mannosides influence their inhibitory potency toward type 1-fimbriated Escherichia coli. The aim of our work was to prepare and explore inhibitory properties of novel mannosylated N-aryl-substituted 3-hydroxypyridine-4-ones because they possess needed structural characteristics as possible FimH antagonists. Hemagglutination inhibitory tests showed that the examined 3-hydroxypyridine-4-one ?-mannosides exhibited better inhibitory activity than methyl ?-d-mannopyranoside used as a reference compound. Molecular modeling studies revealed the specific interactions responsible for the observed binding activities toward the mannose-specific FimH lectin. The activity depends on the substituent in p-position on the aglycon aromatic ring. PMID:24674669

  5. Enantiomeric separations of ?-aryl ketones with cyclofructan chiral stationary phases via high performance liquid chromatography and supercritical fluid chromatography.

    Science.gov (United States)

    Breitbach, Anthony S; Lim, Yeeun; Xu, Qing-Long; Kürti, László; Armstrong, Daniel W; Breitbach, Zachary S

    2016-01-01

    Normal phase chiral HPLC and SFC methods are presented for the enantiomeric separation of 21 ?-aryl ketones with a unique class of chiral stationary phases (CSPs) based on cyclofructans (CFs). Separations were achieved for all but 2 analytes, with 17 compounds attaining baseline separation having resolution values up to 4.0. Most separations obtained in HPLC could be transferred to SFC, but the HPLC resolutions were generally better due to greater enantiomeric selectivity values. A structure-separation relationship (SSR) was developed to identify important structural features for separation of this class of compounds using CF-based CSPs. Preliminary studies are also presented that demonstrate the utility of the CF CSPs to investigate the base-induced enantiomerization of ?-aryl ketones. It was demonstrated that even small amounts of base (0.01%v/v) in the mobile phase results in rapid, on-column, enantiomerization. Lastly, CSPs composed of superficially porous particles were used to achieve comparable separations of this class of chiral compounds, but at a fraction of the analysis time compared to CSPs composed of fully porous particles. PMID:26687164

  6. An Efficient Three Component One-Pot Synthesis of 5-Amino-7-aryl-7,8-dihydro-[1,2,4] triazolo[4,3-a]-pyrimidine-6-carbonitriles

    Directory of Open Access Journals (Sweden)

    Sun Wan-Fu

    2012-02-01

    Full Text Available A series of novel 5-amino-7-aryl-7,8-dihydro-[1,2,4] triazolo[4,3-a]-pyrimidine-6-carbonitriles were synthesized by a one-pot reaction of 3-amino-1,2,4-triazole, malononitrile and aryl aldehydes in the presence of 20 mol% NaOH in ethanol under heating or ultrasonic irradiation. The structures of the target compounds were confirmed by inspection of their 1H- NMR, 13C-NMR, IR and MS spectra. The advantages of this method are short reaction times, good yields, high selectivity and operational simplicity.

  7. Characterization of Natural Aryl Hydrocarbon Receptor Agonists from Cassia Seed and Rosemary

    Directory of Open Access Journals (Sweden)

    Yoshiaki Amakura

    2014-04-01

    Full Text Available Many recent studies have suggested that activation of the aryl hydrocarbon receptor (AhR reduces immune responses, thus suppressing allergies and autoimmune diseases. In our continuing study on natural AhR agonists in foods, we examined the influence of 37 health food materials on the AhR using a reporter gene assay, and found that aqueous ethanol extracts of cassia seed and rosemary had particularly high AhR activity. To characterize the AhR-activating substances in these samples, the chemical constituents of the respective extracts were identified. From an active ethyl acetate fraction of the cassia seed extract, eight aromatic compounds were isolated. Among these compounds, aurantio-obtusin, an anthraquinone, elicited marked AhR activation. Chromatographic separation of an active ethyl acetate fraction of the rosemary extract gave nine compounds. Among these compounds, cirsimaritin induced AhR activity at 10–102 ?M, and nepitrin and homoplantagenin, which are flavone glucosides, showed marked AhR activation at 10–103 ?M.

  8. Aryl azoles with neuroprotective activity--parallel synthesis and attempts at target identification.

    Science.gov (United States)

    Cocconcelli, Giuseppe; Diodato, Enrica; Caricasole, Andrea; Gaviraghi, Giovanni; Genesio, Eva; Ghiron, Chiara; Magnoni, Letizia; Pecchioli, Elena; Plazzi, Pier Vincenzo; Terstappen, Georg C

    2008-02-15

    A parallel synthesis of aryl azoles with neuroprotective activity is described. All compounds obtained were evaluated in an in vitro assay using a NMDA toxicity paradigm showing a neuroprotective activity between 15% and 40%. The potential biological target of the active compounds was investigated by extensive literature searches based around similar scaffolds with reported neuroprotective activity. The most interesting molecules active in the NMDA toxicity assay (3a and 2g) showed moderate but significant activity in the inhibition of the Site 2 Sodium Channel binding assay at 10 microM. To confirm our hypothesis compounds 3a, c, f and 2g were tested in the Veratridine assay which is one of the excitotoxicity assays of relevance to NaV channels. The compounds tested showed an activity between 40% and 70%. The identification of neuroprotective small molecules and the identification of NaV channels as the potential site of action were the most important goals of this work. PMID:18024137

  9. Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups

    Directory of Open Access Journals (Sweden)

    Julien Rolland

    2009-10-01

    Full Text Available A continuous flow system for the synthesis of enantioenriched diarylmethanols from aldehydes is described. The system uses an amino alcohol-functionalized polystyrene resin as the catalyst, and the arylating agent is conveniently prepared by transmetallation of triarylboroxins with diethylzinc.

  10. The synthesis, X-ray crystal structure and optical properties of novel 5-aryl-3-ferrocenyl-1-pyridazinyl-pyrazoline derivatives.

    Science.gov (United States)

    Gong, Zhong-Liang; Xie, Yong-Sheng; Zhao, Bao-Xiang; Lv, Hong-Shui; Liu, Wei-Yong; Zheng, Liang-Wen; Lian, Song

    2011-01-01

    A series of novel 5-aryl-3-ferrocenyl-1-pyridazinyl pyrazoline derivatives was synthesized by the reaction of ferrocenyl chalcone and 3-chloro-6-hydrazinylpyridazine in 10-65% yields. The compounds were characterized using IR, (1)H NMR, HRMS spectroscopic techniques and representative compounds 3c and 4c were assigned based on the X-ray crystallographic structure. The absorption and fluorescence characteristics of the compounds were investigated in chloroform, tetrahydrofuran and acetonitrile, respectively. The results showed that the absorption maxima of the compounds varied from 323 to 327 nm depending on the groups bonded to benzene and pyridazine ring. The maximum emission spectra of compounds in CHCl(3) were dependent on groups in pyridazine ring in which a strong donating-electron group such as propoxyl group on pyridazine ring in N-1 position of pyrazoline made the emission wavelength of 4a-4e small red shifte than that of compounds 3a-3e with chlorine group. The intensity of absorption and fluorescence was also correlated with substituent on aryl ring in C-5 position of pyrazoline. In addition, the absorption spectra of these compounds changed very little, but the fluorescence spectra had much change with increasing solvent polarity. PMID:20890645

  11. On the mechanism of the palladium-catalyzed ?-arylation of ester enolates.

    Science.gov (United States)

    Larini, Paolo; Kefalidis, Christos E; Jazzar, Rodolphe; Renaudat, Alice; Clot, Eric; Baudoin, Olivier

    2012-02-13

    The palladium-catalyzed ?-arylation of ester enolates with aryl bromides was studied both experimentally and computationally. First, the effect of the ligand on the selectivity of the ?/?-arylation reactions of ortho- and meta-fluorobromobenzene was described. Selective ?-arylation was observed for the reaction of o-fluorobromobenzene with a range of biarylphosphine ligands, whereas ?-arylation was predominantly observed with m-fluorobromobenzene for all ligands except DavePhos, which gave an approximate 1:1 mixture of ?-/?-arylated products. Next, the effect of the substitution pattern of the aryl bromide reactant was studied with DavePhos as the ligand. We showed that electronic factors played a major role in the ?/?-arylation selectivity, with electron-withdrawing substituents favoring ?-arylation. Kinetic and deuterium-labeling experiments suggested that the rate-limiting step of ?-arylation with DavePhos as the ligand was the palladium-enolate-to-homoenolate isomerization, which occurs by a ??H-elimination, olefin-rotation, and olefin-insertion sequence. A dimeric oxidative-addition complex, which was shown to be catalytically competent, was isolated and structurally characterized. A common mechanism for ?- and ?-arylation was described by DFT calculations. With DavePhos as the ligand, the pathway leading to ?-arylation was kinetically favored over the pathway leading to ?-arylation, with the palladium-enolate-to-homoenolate isomerization being the rate-limiting step of the ?-arylation pathway and the transition state for olefin insertion its highest point. The nature of the rate-limiting step changed with PCy(3) and PtBu(3) ligands, and with the latter, ?-arylation became kinetically favored. The trend in selectivity observed experimentally with differently substituted aryl bromides agreed well with that observed from the calculations. The presence of electron-withdrawing groups on these bromides mainly affected the ?-arylation pathway by disfavoring C-C reductive elimination. The higher activity of the ligands of the biaryldialkylphosphine ligands compared to their corresponding trialkylphosphines could be attributed to stabilizing interactions between the biaryl backbone of the ligands and the metal center, thereby preventing deactivation of the ?-arylation pathway. PMID:22241631

  12. A novel dihydropyridine with 3-aryl meta-hydroxyl substitution blocks L-type calcium channels in rat cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Galvis-Pareja, David [Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Zapata-Torres, Gerald [Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago (Chile); Hidalgo, Jorge [Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago (Chile); Ayala, Pedro [Centro Estudios Moleculares de la Célula (CEMC), Facultad de Ciencias Químicas y Farmacéuticas and Facultad Medicina, Universidad de Chile, Santiago (Chile); and others

    2014-08-15

    Rationale: Dihydropyridines are widely used for the treatment of several cardiac diseases due to their blocking activity on L-type Ca{sup 2+} channels and their renowned antioxidant properties. Methods: We synthesized six novel dihydropyridine molecules and performed docking studies on the binding site of the L-type Ca{sup 2+} channel. We used biochemical techniques on isolated adult rat cardiomyocytes to assess the efficacy of these molecules on their Ca{sup 2+} channel-blocking activity and antioxidant properties. The Ca{sup 2+} channel-blocking activity was evaluated by confocal microscopy on fluo-3AM loaded cardiomyocytes, as well as using patch clamp experiments. Antioxidant properties were evaluated by flow cytometry using the ROS sensitive dye 1,2,3 DHR. Results: Our docking studies show that a novel compound with 3-OH substitution inserts into the active binding site of the L-type Ca{sup 2+} channel previously described for nitrendipine. In biochemical assays, the novel meta-OH group in the aryl in C4 showed a high blocking effect on L-type Ca{sup 2+} channel as opposed to para-substituted compounds. In the tests we performed, none of the molecules showed antioxidant properties. Conclusions: Only substitutions in C2, C3 and C5 of the aryl ring render dihydropyridine compounds with the capacity of blocking LTCC. Based on our docking studies, we postulate that the antioxidant activity requires a larger group than the meta-OH substitution in C2, C3 or C5 of the dihydropyridine ring. - Highlights: • Dihydropyridine (DHP) molecules are widely used in cardiovascular disease. • DHPs block Ca{sup 2+} entry through LTCC—some DHPs have antioxidant activity as well. • We synthesized 6 new DHPs and tested their Ca{sup 2+} blocking and antioxidant activities. • 3-Aryl meta-hydroxyl substitution strongly increases their Ca{sup 2+} blocking activity. • 3-Aryl meta-hydroxyl substitution did not affect the antioxidant properties.

  13. Synthesis, Characterization and Antibacterial Activity of New 1,2- and 1,4-Bis(N' -Substituted Thioureido)benzene Derivatives

    Scientific Electronic Library Online (English)

    Aamer, Saeed; Naeem, Abbas; Zaman, Ashraf; Michael, Bolte.

    2013-08-01

    Full Text Available Synthesis of two series of 1,2- and 1,4-bis(thioureido)benzene derivatives was accomplished by the treatment of corresponding alkanoyl/aroyl chlorides with potassium thiocyanate in dry acetone to afford the respective isothiocyanates as intermediates. The latter were treated in situ with 1,2- and 1, [...] 4-diaminobenzene, respectively, to afford the title compounds in high yields. A total of sixteen new compounds are reported herein. The structures of the products were confirmed by spectroscopic techniques (IR, ¹H and 13C NMR, mass spectrometry), elemental analysis and in case of 1d, by X-ray diffraction technique. All the synthesized compounds were also subjected to antibacterial bioevaluation against ten different Gram-positive and Gram-negative bacterial strains using levofloxacin as the standard drug and were shown to possess promising activities.

  14. Synthesis of N-Substituted Derivatives of N-(4-(N- (5-Chloro-2 methoxyphenyl)sulfamoyl)phenyl)acetamide with potential antiurease activity

    International Nuclear Information System (INIS)

    In this study, a new series of N-alkyl/arakyl derivatives of N-(4-(N-(5-chloro-2-methoxyphenyl)sulfamoyl)phenyl)acetamide (5a-k) was synthesized and screened for enzyme inhibition activity. Target compounds, N-alkyl/arakyl sulfamoylacetamides (5a-k) were synthesized by stirring N-(4-(N-(5-chloro-2-methoxyphenyl)sulfamoyl)phenyl)acetamide (3) with different electrophiles (4a-k) in the presence of sodium hydride (NaH) and N, N-dimethylformamide (DMF). The structures of all the synthesized compounds have been deduced from their spectral (1H-NMR, IR, EI-MS) data. All the new compounds displayed antiurease activity to varying degree. (author)

  15. Insight into technetium amidoxime complex: oxo technetium(V) complex of N-substituted benzamidoxime as new basic structure for molecular imaging.

    Science.gov (United States)

    Thipyapong, Khajadpai; Uehara, Tomoya; Tooyama, Yuji; Braband, Henrik; Alberto, Roger; Arano, Yasushi

    2011-02-01

    In search of benzamidoxime (BHam) derivatives that provide a single (99m)Tc-labeled compound of high in vivo stability, we synthesized three N-alkyl compounds of benzamidoxime (BHam) ligand. They provided a single (99m)Tc-labeled compound by ligand exchange reaction of (99m)Tc-glucoheptonate in high radiochemical yields (over 95% at MBHam concentration of 1 × 10(-5) M). (99m)Tc-N-methyl benzamidoxime ((99m)Tc-MBHam) showed higher stability than the parental (99m)Tc-BHam. The complex of this compound with (99g)TcO(3+) ion was prepared, isolated, and characterized by FT-IR and NMR spectra as well as X-ray diffraction. (99g)Tc-MBHam crystallized in an orthorhombic space group Pna2(1) with a = 13.4823(5), b = 15.5410(7), c = 7.7907(3) Å, V = 1632.39(11) Å(3), and Z = 4. The (99g)Tc complex possessed square base pyramid coordination geometry. The equatorial plane was formed by two-amine nitrogen and two-oxime oxygen atoms in trans position, while the oxo core of the technetium(V) occupied the apical position. The (99g)Tc-MBHam proved to be identical with the (99m)Tc-MBHam prepared at the no-carrier-added level by comparison of their HPLC profiles. PMID:21226472

  16. Apparent correlation between structure and carcinogenicity of phenylenediamines and related compounds.

    OpenAIRE

    Milman, H A; Peterson, C

    1984-01-01

    The carcinogenicity of 23 phenylenediamines and related compounds was reviewed. An extensive analysis of the methods used indicated that the bioassays were conducted well. The data suggest that the carcinogenicity of 4-substituted 1,3-phenylenediamines is reduced substantially or eliminated completely by oxidation of one or both amine groups or by N-substitution. Oxidation of a methyl substituent on nitroaniline to a carboxyl group eliminated all carcinogenic activity. It required dichlorinat...

  17. Functionalization of poly(aryl ether ether ketone)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fei; Roovers, J. [Institute for Environmental Chemistry, Ontario (Canada)

    1993-12-31

    Bromomethyl and dibromomethyl substituted poly(aryl ether ether ketone) have been prepared from methyl poly(aryl ether ether ketone) by bromination with bromine. These brominated polymers are intermediates that can be further functionalized by: hydrolysis, oxidation, substitution etc. A series of new functionalized PEEK polymers has been prepared. The functional group includes -CH{sub 2}OH, -CH{sub 2}OCH{sub 3}, -CHO, -COOH, -COOCH{sub 3}, -CH{sub 2}CN, -CH{sub 2}COOH, -CH{sub 2}OCOCH{sub 3}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 2}Br{sup {minus}}, -CH{sub 2}N(CH{sub 2}CH{sub 3}){sub 2}, -CH{sub 2}N{sup +}H(CH{sub 2}CH{sub 3}){sub 3}Br{sup {minus}}.

  18. Aryl-BIAN-ligated silver(i) trifluoromethoxide complex.

    Science.gov (United States)

    Chen, Shouxiong; Huang, Yangjie; Fang, Xin; Li, Haohong; Zhang, Zhongxing; Hor, T S Andy; Weng, Zhiqiang

    2015-12-01

    A reaction of acetonitrile-solvated AgOCF3 with 1 equiv. of Aryl-BIAN ligand in THF at room-temperature afforded the silver(i) complex (Aryl-BIAN)AgOCF3 (1) in 75% yield. The crystal structure of this silver(i) trifluoromethoxide was determined by single-crystal X-ray crystallography. The molecular structure of 1 shows the metal centre bound to one molecule of BIAN, one trifluoromethoxide and one THF solvate, resulting in a distorted tetrahedral silver. Density functional theory (DFT) calculations and the natural bond orbital (NBO) analysis were conducted to give insights into the electronic structure of 1 and the bonding characters of the OCF3 group. The reactivity of 1 towards trifluoromethoxylation of organic halides was also examined; a reaction with benzyl bromides gave the desired products of benzyl trifluoromethyl ethers in good to excellent yields. PMID:26144841

  19. Preparation and characterization of aryl-substituted polysilsesquioxanes

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, D.A.; Loy, D.A.; Baugher, B.M.; Wheeler, D.R.; Assink, R.A.; Alam, T.M.; Saunders, R.

    1998-09-01

    Polymerizations of aryltrialkoxysilanes generally afford soluble oligomeric or polymeric aryl-substituted silsesquioxanes. This is in spite of being based on trifunctional precursors capable of forming highly crosslinked and insoluble network polymers. In this study, soluble phenyl, benzyl, and phenethyl-substituted silsesquioxane oligomers and polymers were prepared by hydrolyzing their respective triethoxysilyl precursor with water or aqueous acid. Additional samples of the polymers were prepared by heating the materials at 100 C or 200 C under vacuum in order to drive the condensation chemistry. One sample of polybenzylsilsesquioxane was heated at 200 C with catalytic NaOH. The resulting materials were characterized using solution {sup 1}H, {sup 13}C, and {sup 29}Si NMR spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Of particular interest was the effect of the aryl substituent, and processing conditions on the molecular weight and glass transition temperatures of the polysilsesquioxanes.

  20. 2-Aryl substituted pyridine C-region analogues of 2-(3-fluoro-4-methylsulfonylaminophenyl)propanamides as highly potent TRPV1 antagonists.

    Science.gov (United States)

    Ryu, HyungChul; Seo, Sejin; Kim, Myeong Seop; Kim, Mi-Yeon; Kim, Ho Shin; Ann, Jihyae; Tran, Phuong-Thao; Hoang, Van-Hai; Byun, Jieun; Cui, Minghua; Son, Karam; Sharma, Pankaz Kumar; Choi, Sun; Blumberg, Peter M; Frank-Foltyn, Robert; Bahrenberg, Gregor; Koegel, Babette-Yvonne; Christoph, Thomas; Frormann, Sven; Lee, Jeewoo

    2014-08-15

    A series of 2-aryl pyridine C-region derivatives of 2-(3-fluoro-4-methylsulfonylaminophenyl)propanamides were investigated as hTRPV1 antagonists. Multiple compounds showed highly potent TRPV1 antagonism toward capsaicin comparable to previous lead 7. Among them, compound 9 demonstrated anti-allodynia in a mouse neuropathic pain model and blocked capsaicin-induced hypothermia in a dose-dependent manner. Docking analysis of 9 with our hTRPV1 homology model provided insight into its specific binding mode. PMID:25011915

  1. Synthesis of multi-functional materials through self-assembly of N-alkyl phenothiazine linked poly(aryl ether) dendrons.

    Science.gov (United States)

    Vidhya Lakshmi, Neelakandan; Madhu Babu, Thunga; Prasad, Edamana

    2016-01-11

    Multi-functional self-assembled systems are developed from first and second generation poly aryl ether dendrons, which are covalently attached to N-alkyl phenothiazine unit through an acylhydrazone linkage. For the first time, dendron based systems have been utilized for efficient oil spill recovery. Furthermore, the hydrophobic nature of the compound has been exploited to make self-cleaning surfaces with anti-wetting properties. More importantly, the visco-elastic property of the gel enables us to develop a gel based ink from the compound, which can be read under UV-light. PMID:26553102

  2. A quantitative structure-activity relationship study of novel inhibitors of cyclooxygenase-2: The 5-aryl-2,2-dialkyl-4-phenyl-3(2 Hfuranone derivatives

    Directory of Open Access Journals (Sweden)

    Singh P

    2007-01-01

    Full Text Available The cyclooxygenase-2 enzyme inhibition activity of 5-aryl-2,2-dialkyl-4-phenyl-3(2 H furanone derivatives is quantitatively analyzed through Fujita-Ban and Hansch type of approaches. The analyses have helped to ascertain the role of different substituents in explaining the observed inhibitory activity of these congeners. From both approaches it is revealed that more hydrophobic susbtituents at 4- R1, a non-hydrogen bond acceptor substitutent, preferably a -F substituent, at 3- R1 in 4-phenyl ring of 3(2 H furanone scaffold improve inhibitory action of a compound. The substituents exhibiting collective molecular bulk smaller than spirocyclopentyl at X and Y positions are preferred as these geminal positions seems to be involved in steric interation. Similarly, 4-aminosulfonyl in 5-aryl ring of 3(2 H furanone moiety emerged as a better choice than 4-methylsulfonyl substitution.

  3. Carbamoylation of aryl halides by molybdenum or tungsten carbonyl amine complexes.

    Science.gov (United States)

    Ren, Wei; Yamane, Motoki

    2010-05-01

    When aryl halide is treated with molybdenum carbonyl amine complex in the presence of base, carbamoylation proceeds to give amide in good yield. The proposed mechanism involves oxidative addition of aryl halide to molybdenum(0) complex, migratory insertion to carbon monoxide giving acyl(amino)molybdenum(II) or aryl(carbamoyl)molybdenum(II) intermediate, and reductive elimination of the amide. This method is simple and provides an alternative method to the conventional palladium-catalyzed amide formation using gaseous carbon monoxide. PMID:20349980

  4. Transition metal-catalyzed arylation of unactivated C(sp3)-H bonds.

    Science.gov (United States)

    Baudoin, Olivier

    2011-10-01

    Transition-metal-catalyzed C-H bond arylation has recently emerged as a powerful tool for the functionalization of organic molecules that may complement or even replace traditional catalytic cross-couplings. While many efforts have focused on the arylation of arenes and heteroarenes in the past two decades, less studies have been devoted to the arylation of nonacidic C-H bonds of alkyl groups. This tutorial review highlights recent work in this active area. PMID:21505712

  5. Oxidative addition of aryl chlorides to monoligated palladium(0): A DFT-SCRF study

    DEFF Research Database (Denmark)

    Ahlquist, Mårten Sten Gösta; Norrby, Per-Ola

    2007-01-01

    Oxidative addition of aryl chlorides to palladium has been investigated by hybrid density functional theory methods (B3LYP), including a continuum model describing the solvent implicitly. A series of para-substituted aryl chlorides were studied to see the influence of electronic effects on the reaction. It was found that the experimentally observed higher reactivity of the more electron deficient aryl chlorides is due to their ability to accept back-donation from Pd-0 and form reasonably strong ...

  6. Divergent Reaction Pathways for Phenol Arylation by Arynes: Synthesis of Helicenes and 2-Arylphenols

    OpenAIRE

    Truong, Thanh; Daugulis, Olafs

    2012-01-01

    Two reactions of phenols with arynes have been developed. If LiTMP base is employed, arynes generated from aryl chlorides react with phenols to form helicenes. o-Arylation of phenols can be achieved by employing tBuONa base in the presence of AgOAc. Direct arylation of binol was achieved leading to the shortest pathway to o,o’-diarylbinols.

  7. NRF2 Modulates Aryl Hydrocarbon Receptor Signaling: Influence on Adipogenesis? †

    OpenAIRE

    Shin, Soona; Wakabayashi, Nobunao; Misra, Vikas; Biswal, Shyam; Lee, Gum Hwa; Agoston, Elin S.; YAMAMOTO, Masayuki; Kensler, Thomas W

    2007-01-01

    The NF-E2 p45-related factor 2 (NRF2) and the aryl hydrocarbon receptor (AHR) are transcription factors controlling pathways modulating xenobiotic metabolism. AHR has recently been shown to affect Nrf2 expression. Conversely, this study demonstrates that NRF2 regulates expression of Ahr and subsequently modulates several downstream events of the AHR signaling cascade, including (i) transcriptional control of the xenobiotic metabolism genes Cyp1a1 and Cyp1b1 and (ii) inhibition of adipogenesis...

  8. A three-component synthesis of aryl(heteroaryl)acylamides.

    Science.gov (United States)

    Loska, Rafa?; Bukowska, Patrycja

    2015-09-23

    A three-component reaction of azole or azine N-oxides, 1,1-difluorostyrenes and amines gives amides of ?-aryl-?-heteroarylacetic or propionic acids. The key step is 1,3-dipolar cycloaddition between N-oxide and difluorostyrene leading to the acyl fluoride intermediate, which has been identified and characterized by NMR spectroscopy. The whole process is an example of selective functionalization of C-H bonds in both 5- and 6-membered heterocyclic systems. PMID:26288176

  9. Persistent Binding of Ligands to the Aryl Hydrocarbon Receptor

    OpenAIRE

    Bohonowych, Jessica E.; Denison, Michael S

    2007-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxic effects of halogenated aromatic hydrocarbons (HAHs), polycyclic aromatic hydrocarbons (PAHs), and other structurally diverse ligands. While HAHs are several orders of magnitude more potent in producing AhR-dependent biochemical effects than PAHs or other AhR agonists, only the HAHs have been observed to produce AhR-dependent toxicity in vivo. Here we have characterized...

  10. Photoredox Activation for the Direct ?-Arylation of Ketones and Aldehydes

    OpenAIRE

    Pirnot, Michael T.; Rankic, Danica A.; Martin, David B. C.; MacMillan, David W. C.

    2013-01-01

    The direct ?-activation of saturated aldehydes and ketones has long been an elusive transformation. We found that photoredox catalysis in combination with organocatalysis can lead to the transient generation of 5?-electron ?-enaminyl radicals from ketones and aldehydes that rapidly couple with cyano-substituted aryl rings at the carbonyl ?-position. This mode of activation is suitable for a broad range of carbonyl ?-functionalization reactions and is amenable to enantioselective catalysis.

  11. Copper Mediated Difluoromethylation of Aryl and Vinyl Iodides

    OpenAIRE

    Fier, Patrick S.; Hartwig, John. F.

    2012-01-01

    Selectively fluorinated molecules are important as materials, pharmaceuticals, and agrochemicals, but their synthesis by simple, mild, laboratory methods is challenging. We report a straightforward method for the cross-coupling of a difluoromethyl group with readily available reagents to form difluoromethylarenes. The reaction of electron-neutral, electron-rich, and sterically hindered aryl and vinyl iodides with the combination of CuI, CsF and TMSCF2H leads to the formation of difluoromethyl...

  12. Ginsenosides Are Novel Naturally-Occurring Aryl Hydrocarbon Receptor Ligands

    OpenAIRE

    Hu, Qin; He, Guochun; Zhao, Jing; Soshilov, Anatoly; Denison, Michael S; Zhang, Aiqian; Yin, Huijun; Fraccalvieri, Domenico; BONATI, LAURA; Xie, Qunhui; Bin ZHAO

    2013-01-01

    The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that mediates many of the biological and toxicological actions of structurally diverse chemicals. In this study, we examined the ability of a series of ginsenosides extracted from ginseng, a traditional Chinese medicine, to bind to and activate/inhibit the AHR and AHR signal transduction. Utilizing a combination of ligand and DNA binding assays, molecular docking and reporter gene analysis, we demonstrated the abil...

  13. Aryl Polyphosphonates: Useful Halogen-Free Flame Retardants for Polymers

    OpenAIRE

    Li Chen; Yu-Zhong Wang

    2010-01-01

    Aryl polyphosphonates (ArPPN) have been demonstrated to function in wide applications as flame retardants for different polymer materials, including thermosets, polycarbonate, polyesters and polyamides, particularly due to their satisfactory thermal stability compared to aliphatic flame retardants, and to their desirable flow behavior observed during the processing of polymeric materials. This paper provides a brief overview of the main developments in ArPPN and their derivatives for flame-re...

  14. Asymmetric ?-arylation of ?-amino acids via rearrangement of urea derivatives

    OpenAIRE

    Atkinson, Rachel Clare

    2015-01-01

    Quaternary amino acids are biologically important and useful building blocks for both natural product and pharmaceutical targets. They can be made from their naturally occurring proteinogenic tertiary counterparts through methods such as alkylation. However, ?-arylation of amino acids is challenging with only a small number of methods available, which are far from general and access only a limited substrate scope.The N to C rearrangement chemistry established in the Clayden group allowed us t...

  15. Bioelectrochemical investigations of aryl-alcohol oxidase from Pleurotus eryngii

    OpenAIRE

    Munteanu, Florentina-Daniela; Ferreira, Patrícia; Ruiz-Duenas, Francisco J.; Martínez, Angel T.; Paulo, Artur Cavaco

    2008-01-01

    Aryl-alcohol oxidase (AAO) electrochemistry studies, using graphite-modified electrodes, are presented for the first time herein. The increase in current upon injection of the analyzed substrate was shown to be approximated by Michaelis–Menten type dependence. The calculated kinetic constants were used to characterize the native (non-mutated) recombinant AAO expressed in Escherichia coli, as well as the native enzyme and the F501Y and F501A variants expressed in Emericella nidulans. Results f...

  16. Synthesis of 3-Aryl Coumarin Derivatives Using Ultrasound

    OpenAIRE

    Kandasamy Logeeswari; Shubashini Krishnan Sripathi

    2013-01-01

    Coumarins occupy an important place in the realm of natural products and synthetic organic chemistry. A fast and highly efficient green method for synthesizing 3-aryl coumarin derivatives from salicylaldehyde and phenyl acetyl chloride in the presence of tetrahydrofuran and K2CO3 using ultrasound irradiation is reported. Ultrasound assisted reactions have resulted in better yields and faster reaction time of the desired products than when prepared under conventional conditions. The resulting...

  17. Group 9 Metal Complexes of meso-Aryl-Substituted Rubyrin.

    Science.gov (United States)

    Soya, Takanori; Osuka, Atsuhiro

    2015-07-20

    Invited for the cover of this issue are Takanori Soya and Atsuhiro Osuka at Kyoto University. The image depicts Group 9 metal (Co, Rh, and Ir) complexes of meso-aryl-substituted rubyrin and a meteorite approaching to the atmosphere. A large amount of Iridium is often contained in meteorites. Read the full text of the article at 10.1002/chem.201501080. PMID:26042817

  18. Synthesis and in vitro antibacterial activity of N-methylnitrone and nitrovinyl derivatives of some N-substituted 2-chloroindol-3-carboxaldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Gatti, R.; Cavrini, V.; Roveri, P.; Bianucci, F.; Legnani, P.

    1981-02-01

    N-methylnitrones and nitrovinyl derivatives from 1-substituted-2-chloroindol-3-carboxaldehydes were synthesized and evaluated for their in vitro antibacterial activity. Some nitrovinyl derivatives displayed good in vitro activity against Gram-positive bacteria; the compound (II e), 1-(o-chlorobenzyl)-2-chloro-3-(2-nitroethenyl)indole, was more active than nitrofurantoin against Staphylococcus aureus and Streptococcus pyogenes. Some structure-activity relationships are discussed.

  19. N-Substituted Quinolinonyl Diketo Acid Derivatives as HIV Integrase Strand Transfer Inhibitors and Their Activity against RNase H Function of Reverse Transcriptase.

    Science.gov (United States)

    Pescatori, Luca; Métifiot, Mathieu; Chung, Suhman; Masoaka, Takashi; Cuzzucoli Crucitti, Giuliana; Messore, Antonella; Pupo, Giovanni; Madia, Valentina Noemi; Saccoliti, Francesco; Scipione, Luigi; Tortorella, Silvano; Di Leva, Francesco Saverio; Cosconati, Sandro; Marinelli, Luciana; Novellino, Ettore; Le Grice, Stuart F J; Pommier, Yves; Marchand, Christophe; Costi, Roberta; Di Santo, Roberto

    2015-06-11

    Bifunctional quinolinonyl DKA derivatives were first described as nonselective inhibitors of 3'-processing (3'-P) and strand transfer (ST) functions of HIV-1 integrase (IN), while 7-aminosubstituted quinolinonyl derivatives were proven IN strand transfer inhibitors (INSTIs) that also displayed activity against ribonuclease H (RNase H). In this study, we describe the design, synthesis, and biological evaluation of new quinolinonyl diketo acid (DKA) derivatives characterized by variously substituted alkylating groups on the nitrogen atom of the quinolinone ring. Removal of the second DKA branch of bifunctional DKAs, and the amino group in position 7 of quinolinone ring combined with a fine-tuning of the substituents on the benzyl group in position 1 of the quinolinone, increased selectivity for IN ST activity. In vitro, the most potent compound was 11j (IC50 = 10 nM), while the most active compounds against HIV infected cells were ester derivatives 10j and 10l. In general, the activity against RNase H was negligible, with only a few compounds active at concentrations higher than 10 ?M. The binding mode of the most potent IN inhibitor 11j within the IN catalytic core domain (CCD) is described as well as its binding mode within the RNase H catalytic site to rationalize its selectivity. PMID:25961960

  20. Synthesis of Novel Aryl(heteroarylsulfonyl Ureas of Possible Biological Interest

    Directory of Open Access Journals (Sweden)

    Maria Gdaniec

    2010-02-01

    Full Text Available The course of reaction of aryl and heteroaryl sulfonamides with diphenylcarbonate (DPC and 4-dimethylaminopyridine (DMAP was found to depend on the pKa of the sulfonamide used. Aryl sulfonamides with pKa ~ 10 gave 4-dimethylamino-pyridinium arylsulfonyl-carbamoylides, while the more acidic heteroaryl sulfonamides (pKa ~ 8 furnished 4-dimethylaminopyridinium heteroarylsulfonyl carbamates. Both the carbamoylides and carbamate salts reacted with aliphatic and aromatic amines with the formation of appropriate aryl(heteroarylsulfonyl ureas, and therefore, can be regarded as safe and stable substitutes of the hazardous and difficult to handle aryl(heteroarylsulfonyl isocyanates.

  1. Microwave Assisted Solvent Free Synthesis of Azomethines from Aryl Aldehydes on Melamin Formaldehyde as Solid Support

    OpenAIRE

    Ramin Rezaei; Mohammadi, Mohammad K; Tahereh Ranjbar

    2011-01-01

    Various aryl aldehydes underwent prompt one pot conversion into the corresponding azomethines in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation.

  2. Synthesis and characterization of 5-heteroarylsulfanyl-4-aryl-1,2,3-selena/thiadiazoles

    Indian Academy of Sciences (India)

    Ramaiyan Manikannan; Masilamani Shanmugaraja; Seetharaman Manojveer; Shanmugam Muthusubramanian

    2012-03-01

    Synthesis and spectral characterization of 2-methyl-5-[(4-aryl-1,2,3-selenadiazol-5-yl)sulfanyl]-1,3,4-thiadiazoles, 5-[4-aryl-1,2,3-selenadiazol-5-yl]sulfanyl-1-phenyl-1-1,2,3,4-tetraazoles, 4-aryl-5-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanyl]-1,2,3-thiadiazole and 5-[4-aryl-1,2,3-thiadiazol-5-yl]sulfanyl-1-phenyl-1-1,2,3,4-tetraazole have been reported.

  3. Discovery of 5-aryl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones as positive allosteric modulators of metabotropic glutamate subtype-2 (mGlu2) receptors with efficacy in a preclinical model of psychosis.

    Science.gov (United States)

    Layton, Mark E; Reif, Alexander J; Hartingh, Timothy J; Rodzinak, Kevin; Dudkin, Vadim; Wang, Cheng; Arrington, Ken; Kelly, Michael J; Garbaccio, Robert M; O'Brien, Julie A; Magliaro, Brian C; Uslaner, Jason M; Huszar, Sarah L; Fillgrove, Kerry L; Tang, Cuyue; Kuo, Yuhsin; Jacobson, Marlene A

    2016-02-15

    Optimization of a benzimidazolone template for potency and physical properties revealed 5-aryl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones as a key template on which to develop a new series of mGlu2 positive allosteric modulators (PAMs). Systematic investigation of aryl-SAR led to the identification of compound 27 as a potent and highly selective mGlu2 PAM with sufficient pharmacokinetics to advance to preclinical models of psychosis. Gratifyingly, compound 27 showed full efficacy in the PCP- and MK-801-induced hyperlocomotion assay in rats at CSF concentrations consistent with mGlu2 PAM potency. PMID:26810316

  4. Theoretical investigations on Rh(III)-catalyzed cross-dehydrogenative aryl-aryl coupling via C-H bond activation.

    Science.gov (United States)

    Zhao, Dan; Li, Xiaoxi; Han, Keli; Li, Xingwei; Wang, Yong

    2015-03-26

    The reaction mechanism of Rh(III)-catalyzed cross-dehydrogenative aryl-aryl coupling between benzamides and haloarenes was investigated through detailed density functional theoretical (DFT) studies in terms of regioselectivity and deuterium kinetic isotope effects (KIEs). Three possible routes including one PivO(-)-assisted reaction route and two non-PivO(-)-assisted reaction routes have been studied. The calculated results refute the proposed mechanism (without PivO(-)-assisted process) in the experimental paper and demonstrate that the PivO(-)-assisted reaction mechanism is the most favored. Meanwhile, the calculation revealed that the PivO(-) anion plays a crucial role as a proton acceptor in the C-H bond activation, especially when the second C-H activation of haloarenearene proceeds via a S(E)3 mechanism. The S(E)3 mechanism is presented for the Rh(III)-catalyzed aryl-aryl reaction for the first time. Our mechanism is evaluated by the calculations of the para-/meta-regioselectivity and KIEs. And it is found that the second activation process is the rate-determining step of the whole catalytic cycle. All these calculated properties agree well with the experiment and Glorius's proposal that the Rh(III)-catalyzed cross-dehydrogenative C-C coupling reaction proceeds by dual C-H activations. Our theoretical studies suggest that the Rh(III) complex catalyst strongly affects the mechanisms of the second C-H activation step and thus this work might provide insight into the design of new catalytic systems. PMID:25693049

  5. Potential of aryl-urea-benzofuranylthiazoles hybrids as multitasking agents in Alzheimer's disease.

    Science.gov (United States)

    Kurt, Belma Zengin; Gazioglu, Isil; Basile, Livia; Sonmez, Fatih; Ginex, Tiziana; Kucukislamoglu, Mustafa; Guccione, Salvatore

    2015-09-18

    New benzofuranylthiazole derivatives containing the aryl-urea moiety were synthesized and evaluated in vitro as dual acetylcholinesterase (AChE)-butyrylcholinesterase (BuChE) inhibitors. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. The result showed that all the synthesized compounds exhibited inhibitory activity on both AChE and BuChE with 1-(4-(5-bromobenzofuran-2-yl)thiazol-2-yl)-3-(2-fluorophenyl)urea (e25, IC50 value of 3.85 ?M) and 1-(4-iodophenyl)-3-(4-(5-nitrobenzofuran-2-yl)thiazol-2-yl)urea (e38, IC50 value of 2.03 ?M) as the strongest inhibitors against AChE and BuChE, respectively. Compound e38 was 8.5-fold more potent than galanthamine. The selectivity index of e25 and e38 was 2.40 and 0.37 against AChE and BuChE, respectively. Compound e2, e4 and e11 (IC50 = 0.2, 0.5 and 1.13 ?M, respectively) showed a better ABTS cation radical scavenging ability than the standard quercetin (IC50 = 1.18 ?M). Best poses of compounds e38 on BuChE and e25 on AChE indicate that the thiazole ring and the amidic moiety are important sites of interaction with both ChEs. In addition, the benzofuran ring and phenyl ring are anchored to the side chains of both enzymes by ?-?(pi-pi) interactions. PMID:26244990

  6. Synthesis and antibacterial activity of 2-(2,4-dinitrophenyl-3,5-diphenyl (substituted-6-aryl-3,3a,5,6-tetrahydro-2H-pyrazolo[3,4-d] thiazoles

    Directory of Open Access Journals (Sweden)

    Sahu S

    2006-01-01

    Full Text Available Condensation of substituted benzaldehydes with primary aryl amines gave a series of Schiff bases(1a 1 -e 1 ,a 2 ,b 2 ,d 2 ,b 3 -e 3 which, on reaction with thioglycolic acid, resulted in the formation of the corresponding 4-thiazolidinones(2a 1 -e 1 ,a 2 ,b 2 ,d 2 ,b 3 -e 3 . These compounds, on condensation with substituted benzaldehydes in anhydrous sodium acetate, furnished 2-phenyl(substituted-3-aryl-5-benzilidine(substituted-thiazolidine-4-ones(3a 1 -e 1 ,a 2 ,b 2 ,d 2 , b 3 -e 3 . The latter, on heating with 2,4-dinitrophenyl hydrazine in anhydrous sodium acetate, gave the title compounds(4a 1 -e 1 ,a 2 ,b 2 ,d 2 ,b 3 -e 3 . The structures have been established on the basis of elemental analysis and spectral data. The title compounds have been screened in vitro for their possible antibacterial activity

  7. Synthesis of 2-aryl-1,2,4-oxadiazolo-benzimidazoles: Tubulin polymerization inhibitors and apoptosis inducing agents.

    Science.gov (United States)

    Kamal, Ahmed; Reddy, T Srinivasa; Vishnuvardhan, M V P S; Nimbarte, Vijaykumar D; Subba Rao, A V; Srinivasulu, Vunnam; Shankaraiah, Nagula

    2015-08-01

    A new series of 2-aryl 1,2,4-oxadiazolo-benzimidazole conjugates have been synthesized and evaluated for their antiproliferative activity in the sixty cancer cell line panel of the National Cancer Institute (NCI). Compounds 5l (NSC: 761109/1) and 5x (NSC: 761814/1) exhibited remarkable cytotoxic activity against most of the cancer cell lines in the one dose assay and were further screened at five dose concentrations (0.01, 0.1, 1, 10 and 100 ?M) which showed GI50 values in the range of 0.79-28.2 ?M. Flow cytometric data of these compounds showed increased cells in G2/M phase, which is suggestive of G2/M cell cycle arrest. Further, compounds 5l and 5x showed inhibition of tubulin polymerization and disruption of the formation of microtubules. These compounds induce apoptosis by DNA fragmentation and chromatin condensation as well as by mitochondrial membrane depolarization. In addition, structure activity relationship studies within the series are also discussed. Molecular docking studies of compounds 5l and 5x into the colchicine-binding site of the tubulin, revealed the possible mode of interaction by these compounds. PMID:26169762

  8. Synthesis and antileishmanial activity of new 1-aryl-1H-pyrazole-4-carboximidamides derivatives

    Scientific Electronic Library Online (English)

    Maurício S. dos, Santos; Adriana O, Gomes; Alice M. R, Bernardino; Marcos C. de, Souza; Misbahul A, Khan; Monique A. de, Brito; Helena C, Castro; Paula A, Abreu; Carlos R, Rodrigues; Rosa M. M. de, Léo; Leonor L, Leon; Marilene M, Canto-Cavalheiro.

    2011-02-01

    Full Text Available A quimioterapia para as leishmanioses, doenças causadas por protozoários do gênero Leishmania, ainda permanece ineficiente em diversos tratamentos. Portanto, existe a necessidade de pesquisa por novos fármacos. Nesse trabalho, foram sintetizados derivados 1-aril-1H-pirazol-4-carboximidamidas, avalia [...] das as atividades leishmanicida e os efeitos citotóxicos in vitro, e realizado um estudo de relação estrutura-atividade (REA) com a série de compostos. O composto 2 apresentou um perfil de atividade que pode ser melhorado através de estratégias de modificação molecular da química medicinal. Abstract in english Chemotherapy for leishmaniasis, diseases caused by protozoa of the genus Leishmania, remains inefficient in several treatments. So there is a need to search for new drugs. In this work, we have synthesized 1-aryl-1H-pyrazole-4-carboximidamides derivatives and evaluated antileishmanial activities in [...] vitro, as well as cytotoxic effects. Structure-activity relationship (SAR) studies were carried out with all the compounds of the series. Compound 2 showed an activity profile that can be improved through medicinal chemistry strategies.

  9. Microwave Assisted Condensation Reactions of 2-Aryl Hydrazonopropanals with Nucleophilic Reagents and Dimethyl Acetylenedicarboxylate

    Directory of Open Access Journals (Sweden)

    Rita M. Borik

    2007-08-01

    Full Text Available The reaction of methyl ketones 1a-g with dimethylformamide dimethylacetal (DMFDMA afforded the enaminones 2a-g, which were coupled with diazotized aromatic amines 3a,b to give the corresponding aryl hydrazones 6a-h. Condensation of compounds 6a-h with some aromatic heterocyclic amines afforded iminoarylhydrazones 9a-m. Enaminoazo compounds 12a,b could be obtained from condensation of 6c with secondary amines. The reaction of 6e,h with benzotriazolylacetone yielded 14a,b. Also, the reaction of 6a,b,d-f,h with glycine and hippuric acid in acetic anhydride afforded pyridazinone derivatives 17a-f. Synthesis of pyridazine carboxylic acid derivatives 22a,b from the reaction of 6b,e with dimethyl acetylenedicarboxylate (DMAD in the presence of triphenylphosphine at room temperature is also reported. Most of these reactions were conducted under irradiation in a microwave oven in the absence of solvent in an attempt to improve the product yields and to reduce the reaction times.

  10. New Synthesis and Antiparasitic Activity of Model 5-Aryl-1-methyl-4-nitroimidazoles

    Directory of Open Access Journals (Sweden)

    Mustafa M. El-Abadelah

    2009-07-01

    Full Text Available A number of 5-aryl-1-methyl-4-nitroimidazoles 5a-f have been synthesized in good yields by the Suzuki coupling reaction between 5-chloro-1-methyl-4-nitroimidazole (3 and arylboronic acids 4a-f, aided by dichlorobis-(triphenylphosphinepalladium(II, K2CO3, and tetrabutylammonium bromide in water at 70-80 °C. Compounds 5a-f were characterized by elemental analysis, NMR and MS spectral data. On the basis of in vitro screening data, 5-(3-chlorophenyl-1-methyl-4-nitro-1H-imidazole (5fexhibited potent lethal activity against Entamoeba histolytica and Giardia intestinalis with IC50 = 1.47 µM/mL, a value lower by a factor of two than that of the standard drug, metronidazole. The boosted activity of 5f was not accompanied by any increased cytotoxicity.The rest of the series also exhibited potent antiparasitic activity with IC50 valuesin the 1.72-4.43 µM/mL range. The cytotoxicity of the derivatives 5c and 5e was increased compared to the precursor compound, metronidazole, although they remain non-cytotoxic at concentrations much higher than the antiparasitic concentration of the two derivatives.

  11. Synthesis of 1-Aryl-3-phenethylamino-1-propanone Hydrochlorides as Possible Potent Cytotoxic Agents

    Directory of Open Access Journals (Sweden)

    Cavit Kazaz

    2007-12-01

    Full Text Available 1-Aryl-3-phenethylamino-1-propanone hydrochlorides 1-10, which are potentialpotent cytotoxic agents, were synthesized via Mannich reactions using paraformaldehyde,phenethylamine hydrochloride as the amine component and acetophenone, 4’-methyl-, 4’-methoxy-, 4’-chloro-, 4’-fluoro-, 4’-bromo-, 2’,4’-dichloro-, 4’-nitro-, 4’-hydroxyacetophenone or 2-acetylthiophene as the ketone component. Yields were in the87-98 % range. Of the compounds synthesized, compounds 2, 6-8 and 10 were new. Theoptimum reaction conditions were investigated by changing the mol ratios of the reactants,the solvents and the acidity levels using 1 and 10 as representative targets. It was observedthat the best mol ratio of the ketone, paraformaldehyde and phenethylamine hydrochloridewas 1:1.2:1 (compared with a 2:2.1 ratio, and the most suitable reaction medium wasethanol containing concentrated hydrochloric acid (compared with only ethanol or nosolvent. This study may serve as a guide for the conditions of the reactions to synthesizecompounds having similar chemical structures.

  12. Solvation of dichlorocarbene: complexation with aryl ethers.

    Science.gov (United States)

    Moss, Robert A; Wang, Lei; Odorisio, Christina M; Zhang, Min; Krogh-Jespersen, Karsten

    2010-01-14

    Dichlorocarbene (CCl(2)), generated by laser flash photolysis of dichlorodiazirine, formed pi- and O-ylidic complexes with aromatic ethers such as anisole, 1,3-dimethoxybenzene, 1,3,5-trimethoxybenzene, dibenzofuran, and dibenzo-18-crown-6 and with the aromatic ester phenyl acetate. These complexes were visualized by UV-vis spectroscopy, and they retarded the addition of CCl(2) to tetramethylethylene by factors of 18-152. Computational studies based on density functional theory provided structures and energetics for the transient species and rationalized their absorption spectra. Complexes were not observed between CCl(2) and simple, nonaromatic ethers such as THF, dioxane, or 18-crown-6, nor did these ethers much affect the addition rate of CCl(2) to tetramethylethylene. Computations also suggested that pi-complexes of CCl(2) and, e.g., mesitylene and durene, were energetically reasonable transients. Although these species were not detected spectroscopically, the aromatic compounds did slow the addition of CCl(2) to tetramethylethylene by factors of 15 and 31, respectively. PMID:19877654

  13. In vitro evaluation of anti-pathogenic surface coating nanofluid, obtained by combining Fe3O4/C12 nanostructures and 2-((4-ethylphenoxy)methyl)- N-(substituted-phenylcarbamothioyl)-benzamides

    Science.gov (United States)

    Anghel, Ion; Limban, Carmen; Grumezescu, Alexandru Mihai; Anghel, Alina Georgiana; Bleotu, Coralia; Chifiriuc, Mariana Carmen

    2012-09-01

    In this paper, we report the design of a new nanofluid for anti-pathogenic surface coating. For this purpose, new 2-((4-ethylphenoxy)methyl)- N-(substituted-phenylcarbamothioyl)-benzamides were synthesized and used as an adsorption shell for Fe3O4/C12 core/shell nanosized material. The functionalized specimens were tested by in vitro assays for their anti-biofilm properties and biocompatibility. The optimized catheter sections showed an improved resistance to Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853 in vitro biofilm development, as demonstrated by the viable cell counts of biofilm-embedded bacterial cells and by scanning electron microscopy examination of the colonized surfaces. The nanofluid proved to be not cytotoxic and did not influence the eukaryotic cell cycle. These results could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with improved anti-biofilm properties.

  14. Gold-catalyzed domino aminocyclization/1,3-sulfonyl migration of N-substituted N-sulfonyl-aminobut-3-yn-2-ols to 1-substituted 3-sulfonyl-1H-pyrroles.

    Science.gov (United States)

    Teo, Wan Teng; Rao, Weidong; Koh, Ming Joo; Chan, Philip Wai Hong

    2013-08-01

    A method to prepare 1-substituted 3-sulfonyl-1H-pyrroles efficiently that relies on the gold(I)-catalyzed cycloisomerization of N-substituted N-sulfonyl-aminobut-3-yn-2-ols is described. The method was shown to be applicable to a broad range of 1,7-enyne alcohols containing electron-withdrawing, electron-donating, and sterically demanding substrate combinations. The mechanism is suggested to involve activation of the propargylic alcohol by the Au(I) catalyst, which causes the intramolecular nucleophilic addition of the sulfonamide unit to the alkyne moiety. The resulting nitrogen-containing heterocyclic intermediate undergoes dehydration and deaurative 1,3-sulfonyl migration, a process that remains rare in gold catalysis, to give the aromatic nitrogen-containing product. PMID:23883133

  15. MORPHOLOGICAL ALTERATIONS OF STAPHYLOCOCCUS AUREUS CAUSED BY ARYL ALIPHATIC AMINOALCOHOL DERIVATIVE

    Directory of Open Access Journals (Sweden)

    Dronova M.

    2015-05-01

    Full Text Available Increasing of antimicrobial resistance has created a critical need of the novel antimicrobial agents. One of the promising chemical classes for its development are aryl aliphatic aminoalcohols. New compounds of this class were synthesized at the Institute of organic chemistry (Kiev, Ukraine, by Y. Korotkiy. After the screening studies compound KVM-194 was selected as the potent antistaphylococcal agent. The aim of the study was to examine ultrastructural changes in the bacterial cells under the influence of the compound KVM-194. Materials and methods. Staphylococcus aureus ATCC 25923 was used in all experiments. The minimum inhibitory concentration was determined by serial macrodilution method in Mueller-Hinton broth. Bacteria were exposed to the 0,5 MIC and 5 MICs of the KVM- 194 for 1 h and 24 h. Ultrastructure of intact and treated Staphylococcus aureus cells was examined by transmission electron microscopy after contrasting by osmium tetraoxide and lead citrate. Results and Discussion. The compound KVM-194 possesses a distinct antibacterial activity against Staphylococcus aureus, the minimum inhibitory concentration is 1.25 ?g/ml. We found that exposure to KVM-194 at a subinhibitory concentration resulted in alterations of the cell morphology even after 1 h of treatment. The roughness of the cell surface and emerging of the intracellular particles of different electron density were observed. Increase of the incubation time to 24 h led to detachment of membrane from cytoplasm, multimembrane structures within cells emergence and formation of nonpolar septum. 1 h exposition to suprainhibitory concentration of KVM-194 resulted in nucleoid fragmentation, septum abnormalities and necrosis of some cells. We found that increasing of the incubation period to 24 h led to exacerbation of alterations: cell wall rupture, leakage of cytoplasm and a large number of lysed cells were registered. Conclusion. Observed alterations, suggest the possible mechanism of action of KVM-194, due to its influence on the cell membrane and intracellular processes.

  16. Base-Mediated Intermolecular sp2 C-H Bond Arylation via Benzyne Intermediates

    OpenAIRE

    Truong, Thanh; Daugulis, Olafs

    2011-01-01

    A transition-metal-free method for arylation of heterocycle and arene carbon-hydrogen bonds by aryl chlorides and fluorides has been developed. The reactions proceed via aryne intermediates and are highly regioselective with respect to the C-H bond coupling component.

  17. Visible-light-mediated chan-lam coupling reactions of aryl boronic acids and aniline derivatives.

    Science.gov (United States)

    Yoo, Woo-Jin; Tsukamoto, Tatsuhiro; Kobayashi, Sh?

    2015-05-26

    The copper(II)-catalyzed aerobic oxidative coupling reaction between aryl boronic acids and aniline derivatives was found to be improved significantly under visible-light-mediated photoredox catalysis. The substrate scope of this oxidative Chan-Lam reaction was thus expanded to include electron-deficient aryl boronic acids as viable starting materials. PMID:25873290

  18. New chemical cross-coupling between aryl halides and allylic acetates using a cobalt catalyst.

    Science.gov (United States)

    Gomes, Paulo; Gosmini, Corinne; Périchon, Jacques

    2003-04-01

    [reaction: see text] The cobalt-catalyzed coupling reaction of aromatic halides and allylic acetates proceeds readily under mild conditions in the presence of the appropriate reducing agent to produce allylaromatic derivatives either in pure acetonitrile (aryl bromides) or in an acetonitrile/pyridine mixture (aryl chlorides). PMID:12659569

  19. Cobalt-catalyzed preparation of arylindium reagents from aryl and heteroaryl bromides.

    Science.gov (United States)

    Adak, Laksmikanta; Yoshikai, Naohiko

    2011-09-16

    A cobalt-bathophenanthroline catalyst has been developed for the direct preparation of a variety of arylindium reagents from the corresponding aryl and heteroaryl bromides in the presence of indium metal and lithium chloride. The thus-formed arylindium reagents undergo efficient palladium-catalyzed cross-coupling reactions with aryl iodides, tolerating various functional groups including hydroxy and free amino groups. PMID:21838263

  20. Efficient synthesis of 5-substituted 2-aryl-6-cyanoindolizines via nucleophilic substitution reactions

    OpenAIRE

    Vasilevich Natalya I; Babaev Eugene V; Ivushkina Anna S

    2005-01-01

    Abstract 2-Aryl-6-cyano-7-methyl-5-indolizinones were successfully converted into 2-aryl-5-chloro-6-cyano-7-methylindolizines. The obtained 5-chloroindolizines readily underwent nucleophilic substitution at position 5 leading in high yields to novel 5-functionalised indolizines.

  1. Aryl ethynyl anthraquinones: a useful platform for targeting telomeric G-quadruplex structures.

    Science.gov (United States)

    Percivalle, Claudia; Sissi, Claudia; Greco, Maria Laura; Musetti, Caterina; Mariani, Angelica; Artese, Anna; Costa, Giosuè; Perrore, Maria Lucia; Alcaro, Stefano; Freccero, Mauro

    2014-06-14

    Aryl ethynyl anthraquinones have been synthesized by Sonogashira cross-coupling and evaluated as telomeric G-quadruplex ligands, by the FRET melting assay, circular dichroism, the DNA synthesis arrest assay and molecular docking. Both the binding properties and G-quadruplex vs. duplex selectivity are controlled by the structures of the aryl ethynyl moieties. PMID:24789544

  2. A convenient method for the synthesis of radioactively labelled aryl glycosides

    International Nuclear Information System (INIS)

    Fluoride-directed methylation of the aryl hydroxyl of hydroxyphenyl glycosides with radioactive methyl iodide allows the incorporation of labels under mild conditions that preserve the glycosidic link. The effectiveness of this approach has been demonstrated by the synthesis of two 14C-labelled aryl ?-glycosides. (Author)

  3. Chemo-, regio-, and stereoselective Heck-Matsuda arylation of allylic alcohols under mild conditions.

    Science.gov (United States)

    Chaudhari, Tohasib Yusub; Hossian, Asik; Manna, Manash Kumar; Jana, Ranjan

    2015-05-01

    Heck arylation with allylic alcohol is extremely challenging due to chemo-, regio-, and stereoselective scrambling. Here we report a mild protocol for the alcohol selective β- and α-arylation of allylic and cinnamyl alcohols respectively with aryldiazonium salts. The steric and electronic parameters of the alkene play a prominent role in the regioselectivity. PMID:25814005

  4. MICROWAVE ASSISTED SYNTHESIS OF 6-BENZOYL-5-METHYL-2-[(Z)-1-ARYL METHYLIDENE]-2,3-DIHYDROFURO [3’,2’ :4,5] BENZO[b] FURAN-3-ONES AND THEIR ANTIBACTERIAL ACTIVITY Mikrowellen unterstützte Synthese von 6-Benzoyl-5-METHYL-2-[(Z)-1-ARYL Methyliden] -2,3-DIHYDROFURO [3", 2": 4,5] benzo [b] furan-3-one und Ihre antibakterielle Aktivität

    OpenAIRE

    Ashok D, Sudershan K and Khalilullah M

    2011-01-01

    A series of 6-Benzoyl-5-methyl-2-[(Z)-1-arylmethylidene]-2,3-dihydrofuro[3’,2’:4,5] benzo[b]furan-3-ones have been prepared by an efficient oxidation of (E)-1-(2-Benzoyl- 6-hydroxy-3-methyl benzo[b] furan-5-yl)-3-aryl-2-propen-1-ones with cupric bromide or mercuric acetate under microwave irradiation. The structures of newly synthesized compounds have been established on the basis of elemental analysis, IR, 1H-NMR,13 C-NMR and mass spectral data. All the compounds were screened for their anti...

  5. A New Method for Production of Chiral 2-Aryl-2-fluoropropanoic Acids Using an Effective Kinetic Resolution of Racemic 2-Aryl-2-fluoropropanoic Acids

    Directory of Open Access Journals (Sweden)

    Atsushi Tengeiji

    2012-06-01

    Full Text Available We report a new method for the preparation of chiral 2-aryl-2-fluoropropanoic acids, including 2-fluoroibuprofen, a fluorinated analogue of non-steroidal anti-inflammatory drugs (NSAIDs, by the kinetic resolution of racemic 2-aryl-2-fluoropropanoic acids using enantioselective esterification. By applying pivalic anhydride (Piv2O as a coupling agent, bis(?-naphthylmethanol [(?-Np2CHOH] as an achiral alcohol, and (+-benzotetramisole (BTM as a chiral acyl-transfer catalyst, a series of racemic 2-aryl-2-fluoropropanoic acids were kinetically separated to afford the optically active carboxylic acids and the corresponding esters with good to high enantiomeric excesses. This technology can provide a convenient approach to furnish the chiral ?-fluorinated drugs containing quaternary carbons at the ?-positions in the 2-aryl-2-fluoropropanoic acid structure.

  6. Molecular and crystal structures of some novel derivatives of 3-aryl-7-arylidene-3,3a,4,5,6,7-hexahydroindazoles

    International Nuclear Information System (INIS)

    The stereochemical aspects of the interaction of 2,6-bis(arylidene)-cyclohexanone and 2,6-bis(arylidene)-3-methylcyclohexanone with arylhydrazine (aryl is phenyl or 4-nitrophenyl) and methylhydrazine are investigated using X-ray diffraction analysis. The molecular structure of the 3-aryl-7-arylidene-3,3a,4,5,6,7-hexahydroindazoles synthesized is determined by X-ray diffraction analysis for the first time. It is established that the stereochemistry of the products of the interaction between the cyclohexanone derivatives and arylhydrazines depends on the electronic nature of the substituent in the aryl group. Two regioisomeric products with different positions of the methyl group in the cyclohexane ring with respect to the arylidene fragment are synthesized by the reaction of 2,6-bis(4-methoxybenzylidene)-3-methylcyclohexanone with methylhydrazine. The influence of the substituents at the nitrogen atom of the pyrazoline ring on the intramolecular electronic interactions and the geometry of the heterocycle in the compounds under investigation is discussed

  7. Molecular and crystal structures of some novel derivatives of 3-aryl-7-arylidene-3,3 a,4,5,6,7-hexahydroindazoles

    Science.gov (United States)

    Abakumov, V. V.; Shishkina, S. V.; Zubatyuk, R. I.; Gella, I. M.; Pivnenko, N. S.; Kutulya, L. A.; Shishkin, O. V.

    2007-03-01

    The stereochemical aspects of the interaction of 2,6-bis(arylidene)-cyclohexanone and 2,6-bis(arylidene)-3-methylcyclohexanone with arylhydrazine (aryl is phenyl or 4-nitrophenyl) and methylhydrazine are investigated using X-ray diffraction analysis. The molecular structure of the 3-aryl-7-arylidene-3,3 a,4,5,6,7-hexahydroindazoles synthesized is determined by X-ray diffraction analysis for the first time. It is established that the stereochemistry of the products of the interaction between the cyclohexanone derivatives and arylhydrazines depends on the electronic nature of the substituent in the aryl group. Two regioisomeric products with different positions of the methyl group in the cyclohexane ring with respect to the arylidene fragment are synthesized by the reaction of 2,6-bis(4-methoxybenzylidene)-3-methylcyclohexanone with methylhydrazine. The influence of the substituents at the nitrogen atom of the pyrazoline ring on the intramolecular electronic interactions and the geometry of the heterocycle in the compounds under investigation is discussed.

  8. Triazole-assisted ruthenium-catalyzed C-H arylation of aromatic amides.

    Science.gov (United States)

    Al Mamari, Hamad H; Diers, Emelyne; Ackermann, Lutz

    2014-07-28

    Site-selective ruthenium(II)-catalyzed direct arylation of amides was achieved through C?H cleavages with modular auxiliaries, derived from easily accessible 1,2,3-triazoles. The triazolyldimethylmethyl (TAM) bidentate directing group was prepared in a highly modular fashion through copper(I)-catalyzed 1,3-dipolar cycloaddition and allowed for ruthenium-catalyzed C?H arylations on arenes and heteroarenes, as well as alkenes, by using easy-to-handle aryl bromides as the arylating reagents. The triazole-assisted C?H activation strategy was found to be widely applicable, to occur under mild reaction conditions, and the catalytic system was tolerant of important electrophilic functionalities. Notably, the flexible triazole-based auxiliary proved to be a more potent directing group for the optimized ruthenium(II)-catalyzed direct arylations, compared with pyridyl-substituted amides or substrates derived from 8-aminoquinoline. PMID:24957002

  9. Cyprodinil as an activator of aryl hydrocarbon receptor

    International Nuclear Information System (INIS)

    Highlights: ? Cyprodinil activated the aryl hydrocarbon receptor (AHR). ? Cyprodinil induced nuclear translocation of the AHR, and the expression of CYP1A1. ? Cyprodinil enhanced dexamethasone-induced gene expression. ? Cyprodinil phosphorylated ERK, indicating its deregulation of ERK activity. -- Abstract: Cyprodinil is a pyrimidinamine fungicide, used worldwide by agriculture. It is used to protect fruit plants and vegetables from a wide range of pathogens. Benzo[a]pyrene (BaP) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are toxic environmental pollutants and are prototypes of aryl hydrocarbon receptor (AHR) ligands. Although the structure of cyprodinil distinctly differs from those of BaP and TCDD, our results show that cyprodinil induced nuclear translocation of the AHR, and induced the transcriptional activity of aryl hydrocarbon response element (AHRE). Cyprodinil induced the expression of cytochrome P450 (CYP) 1A1, a well-known AHR-targeted gene, in ovarian granulosa cells, HO23, and hepatoma cells, Hepa-1c1c7. Its induction did not appear in AHR signal-deficient cells, and was blocked by the AHR antagonist, CH-223191. Cyprodinil decreased AHR expression in HO23 cells, resulting in CYP1A1 expression decreasing after it peaked at 9 h of treatment in HO23 cells. Dexamethasone is a synthetic agonist of glucocorticoids. Cyprodinil enhanced dexamethasone-induced gene expression, and conversely, its induction of CYP1A1 expression was decreased by dexamethasone in HO23 cells, indicating its induction of crosstalk between the AHR and glucocorticoid receptor and its role as a potential endocrine disrupter. In addition to BaP, TCDD, and an AHR agonist, ?-NF, cyprodinil also phosphorylated extracellular signal-regulated kinase (ERK) in HO23 and Hepa-1c1c7 cells, indicating its deregulation of ERK activity. In summary, our results demonstrate that cyprodinil, similar to BaP, acts as an AHR activator, a potential endocrine disrupter, and an ERK disrupter

  10. Design, Synthesis and in vivo Evaluation of Novel C-Aryl Glucosides as Potent Sodium-Dependent Glucose Cotransporters Inhibitors for the Treatment of Diabetes.

    Science.gov (United States)

    Li, Zheng; Wang, Xuekun; Xu, Xue; Qiu, Qianqian; Jiao, Lei; Huang, Wenlong; Qian, Hai

    2015-10-01

    A series of novel C-aryl glucosides with substituents at the 3'-position or cyclization at 3', 4'-positions of the distal aryl ring were designed and synthesized, which might decrease the oxidative metabolism of dapagliflozin. Preliminary evaluation for hypoglycemic effect and the risk of hypoglycemia were carried out both in normal and in streptozotocin-induced diabetic mice. Among the synthesized compounds, compound 19a exerted potency-similarity with dapagliflozin and triggered the hypoglycemic effect in a dose-dependent manner. Besides, compound 19a, even at the high dose of 10 mg/kg, revealed a low risk of hypoglycemia. In further studies, 19a exhibited sustained antihyperglycemic effect without particular side-effects in 30-day chronic diabetic mice studies. Moreover, histological changes in the pancreas of diabetic mice indicated 19a might protect pancreatic ?-cell from apoptosis by reducing the damage of glucotoxicity. All of these results demonstrated that compound 19a, with excellent in vivo pharmacological activity and safety profile, was considered to be a promising drug candidate for the treatment of diabetes mellitus. PMID:25732240

  11. Highly dispersed pd catalyst locked in knitting aryl network polymers for Suzuki-Miyaura coupling reactions of aryl chlorides in aqueous media.

    Science.gov (United States)

    Li, Buyi; Guan, Zhenhong; Wang, Wei; Yang, Xinjia; Hu, Jianglin; Tan, Bien; Li, Tao

    2012-07-01

    Highly dispersed palladium chloride catalysts locked in triphenylphosphine-functionalized knitting aryl network polymers (KAPs) are developed and exhibit excellent activity under mild conditions in the Suzuki-Miyaura cross-coupling reactions of aryl chlorides in aqueous media. This work highlights that the microporous polymers not only play the role of support materials, but also protect the Pd species from aggregation and precipitation, hence, positively effect the catalysis activity. PMID:22674537

  12. Systematic investigations on the reduction of 4-aryl-4-oxoesters to 1-aryl-1,4-butanediols with methanolic sodium borohydride

    Directory of Open Access Journals (Sweden)

    Subrata Kumar Chaudhuri

    2010-09-01

    Full Text Available 4-Aryl-4-oxoesters undergo facile reduction of both the keto and the ester groups with methanolic NaBH4 at room temperature to yield the corresponding 1-aryl-1,4-butanediols whereas 4-alkyl-4-oxoesters furnish the corresponding 1,4-butanolides via selective reduction of the keto moiety. Results of a detailed and systematic investigation of the reaction are described.

  13. Catalytic arylation methods from the academic lab to industrial processes

    CERN Document Server

    Burke, Anthony J

    2014-01-01

    A current view of the challenging field of catalytic arylation reactions. Clearly structured, the chapters in this one-stop resource are arranged according to the reaction type, and focus on novel, efficient and sustainable processes, rather than the well-known and established cross-coupling methods.The entire contents are written by two authors with academic and industrial expertise to ensure consistent coverage of the latest developments in the field, as well as industrial applications, such as C-H activation, iron and gold-catalyzed coupling reactions, cycloadditions or novel methodologies

  14. Role of the Aryl Hydrocarbon Receptor in Colon Neoplasia

    International Nuclear Information System (INIS)

    For both men and women, colorectal cancer (CRC) is the second leading cause of cancer death in the United States, primarily as a consequence of limited therapies for metastatic disease. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor with diverse functions in detoxification of xenobiotics, inflammatory responses, and tissue homeostasis. Emerging evidence indicates that AhR also plays an important role in regulating intestinal cell proliferation and tumorigenesis. Here, we review both the pro- and anti-carcinogenic properties of AhR signaling and its potential role as a therapeutic target in CRC

  15. Role of the Aryl Hydrocarbon Receptor in Colon Neoplasia.

    Science.gov (United States)

    Xie, Guofeng; Raufman, Jean-Pierre

    2015-01-01

    For both men and women, colorectal cancer (CRC) is the second leading cause of cancer death in the United States, primarily as a consequence of limited therapies for metastatic disease. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor with diverse functions in detoxification of xenobiotics, inflammatory responses, and tissue homeostasis. Emerging evidence indicates that AhR also plays an important role in regulating intestinal cell proliferation and tumorigenesis. Here, we review both the pro- and anti-carcinogenic properties of AhR signaling and its potential role as a therapeutic target in CRC. PMID:26264025

  16. Role of the Aryl Hydrocarbon Receptor in Colon Neoplasia

    Directory of Open Access Journals (Sweden)

    Guofeng Xie

    2015-07-01

    Full Text Available For both men and women, colorectal cancer (CRC is the second leading cause of cancer death in the United States, primarily as a consequence of limited therapies for metastatic disease. The aryl hydrocarbon receptor (AhR is a ligand-dependent transcription factor with diverse functions in detoxification of xenobiotics, inflammatory responses, and tissue homeostasis. Emerging evidence indicates that AhR also plays an important role in regulating intestinal cell proliferation and tumorigenesis. Here, we review both the pro- and anti-carcinogenic properties of AhR signaling and its potential role as a therapeutic target in CRC.

  17. Functionalization of Rhenium Aryl Bonds by O-Atom Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, Steven M. [Scripps Research Inst., Jupiter, FL (United States); Cheng, Mu-Jeng [California Inst. of Technology (CalTech), Pasadena, CA (United States); Nielsen, Robert J. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Gunnoe, T. Brent [Univ. of Virginia, Charlottesville, VA (United States); Goddard, William A. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Periana, Roy A. [Scripps Research Inst., Jupiter, FL (United States)

    2011-03-29

    Aryltrioxorhenium (ArReO3) has been demonstrated to show rapid oxy-functionalization upon reaction with O-atom donors, YO, to selectively generate the corresponding phenols in near quantitative yields. 18O-Labeling experiments show that the oxygen in the products is exclusively from YO. DFT studies reveal a 10.7 kcal/mol barrier (Ar = Ph) for oxy-functionalization with H2O2 via a Baeyer-Villiger type mechanism involving nucleophilic attack of the aryl group on an electrophilic oxygen of YO coordinated to rhenium.

  18. Radiation Parameters of Some Potential Bioactive Compounds.

    Science.gov (United States)

    Gedik, Zeynep; Tugrak, Mehtap; Dastan, Aysenur; Gul, Halise Inci; Yilmaz, Demet

    2015-06-01

    In this study, we aimed to determine the radiation parameters of some potential bioactive compounds. 1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method. Aryl part was changed as phenyl (C6H5), 4-methylphenyl (4-CH3C6H4), 4-fluorophenyl ( 4-FC6H4), 4-nitrophenyl (4-NO2C6H4), 4-chlorophenyl (4-ClC6H4), 4-bromophenyl (4-BrC6H4), and 2-thienyl (C4H3S-2-yl). Mass attenuation coefficient (μm), effective atomic number (Z(eff)) and effective electron density (N(el)) of compounds were determined experimentally and theoretically for at 8.040, 8.910, 13.40, 14.96, 17.48, 19.61, 22.16, 24.94, 32.19, 36.38, 44.48, 50.38 and 59.54 keV photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. Radiation parameters of these compounds which can be anti-cancer drug candidate were given in the tables. The results show that phenyl ring behave like thiophene ring in terms of radiation absorption. It is thought that the results of study may drive allow the development of drug candidate new compounds in medical oncology. PMID:26601355

  19. Solid-phase synthesis of 2-aryl-3-alkylamino-1H-indoles from 2-nitro-N-(2-oxo-2-arylethyl)benzenesulfonamides via base-mediated C-arylation.

    Science.gov (United States)

    Schütznerová, Eva; Krch?ák, Viktor

    2015-02-01

    Polymer-supported 2-nitro-N-(2-oxo-2-arylethyl)benzenesulfonamides, prepared from resin-bound amines by sulfonylation with 2-nitrobenzenesulfonyl chlorides followed by alkylation with ?-bromoacetophenones, represent advanced intermediates for the synthesis of different nitrogenous heterocycles. We report their application for the synthesis of 2-aryl-3-alkylamino-1H-indoles via base-mediated C-arylation reactions followed by the reduction of the C-arylated intermediates. Linear precursors for C-arylation were prepared on solid-phase support from simple, commercially available building blocks. The effects of different substituents on the amino and aryl groups were addressed. PMID:25547263

  20. Preparation and assessment of [99mTc]technetium aquacarbonyl complexes with 1,2-diaminoethane-N-substituted ligands for tumor detection

    International Nuclear Information System (INIS)

    Over least 15 years the complex [[99mTc](H20)3(CO)3]+ has been used as an intermediary to obtain technetium radiopharmaceuticals for applications in cardiology, neurology and oncology. Two important characteristics of this molecule are: the facility for obtaining that compound from aqueous solutions and the easiness of substituting H2O molecules by atoms of other ligand molecules. In this project we prepared new complexes [[99mTc](CMNS001-3)(H2O)(CO)3]+, where (CMNS001) = N-[(4-methoxy) benzyl]-1,2-diaminoethane, (CMNS003) = N,N'-bis-[(4-methoxy)benzyl]-1,2-diaminoethane, and assessed the uptake of these complexes in murine melanoma cancer cell B16F10 and breast cells MCF-7 and MDA-MD-231, and compared with [[99m](MIBI)6]+ uptake. In vitro uptake for both new technetium complex reached values close to 5%, for all cell lines, whereas the [[99mTc](MIBI)6]+ uptake was close to 1 %. The assessment of subcellular distribution showed high accumulation of the new complex in the membrane fraction, for MDAMB-231, while for B16F10 accumulation occurred both in membrane and cytoplasm; the concentration of [[99mTc](MIBI)6]+ was mainly in the cytoplasm portion. Biodistribution study in mice allowed to observe the capture of up to 1.6% of the administered dose per gram of tumor tissue for the complex [[99mTc](CMNS001)(H2O)(CO)3]+, whereas other organs such as heart, lung and muscle, showed uptake of about 5.6%, 6.4% and 2%, respectively. The complexes in this work showed a high rate of uptake in vitro, but was not reproduced in vivo model, which can be related to low concentration of the complexes inside the cells and reduced vascularity of tumor tissue, with lower intake of complex through the blood system. (author)

  1. Synthesis of Pure and N-substituted Cyclic Hydrocarbons (e.g. Pyrimidine) via Gas-Phase Ion-Molecule Reactions

    Science.gov (United States)

    Bera, Partha P.; Peverati, Roberto; Head-Gordon, Martin; Lee, Timothy J.

    2015-08-01

    Large polyatomic carbonaceous molecules, known as polycyclic aromatic hydrocarbons, are known to exist in the outflows of carbon stars. How these large polyatomic molecules are synthesized in such exotic conditions is, thus far, unknown. Molecular ions, including positive and negative ions, are in relative abundance in the high radiation fields present under such conditions. Hence, barrierless ion-molecule interactions may play a major role in guiding molecules towards each other and initiating reactions. We study these condensation pathways to determine whether they are a viable means of forming large pure hydrocarbon molecules, and nitrogen-containing carbonaceous chains, stacks, and even cyclic compounds. By employing accurate quantum chemical methods we have investigated the processes of growth, structures, nature of bonding, mechanisms, and spectroscopic properties of the ensuing ionic products after pairing small carbon, hydrogen, and nitrogen-containing molecules. We have also studied the ion-neutral association pathways involving pure-carbon molecules e.g. acetylene, ethylene and other hydrocarbons, and their dissociation fragments in a plasma discharge as well as how nitrogen atoms are incorporated into the carbon ring during growth. Specifically, we explored the mechanisms by which the synthesis of pyrimidine will be feasible in the gas phase in conjunction with ion-mobility experiments. We have used accurate ab initio coupled cluster theory, Møller-Plesset and Z-averaged perturbation theories, density functional theory, and coupled cluster theory quantum chemical methods together with large correlation consistent basis sets in these investigations. We found that a series of hydrocarbons with a specific stoichiometric composition prefers cyclic molecule formation rather than chains. Some of the association products we investigated have large oscillator strengths for charge-transfer type electronic excitations in the near infrared and visible regions of the electromagnetic spectrum.P. P. Bera, Roberto Peverati, M. Head-Gordon, and Timothy J. Lee, Phys. Chem. Chem. Phys. 17, 1859-1869 (2015)

  2. Evaluation of sensitizers found in wastewater from paper recycling areas, and their activation of the aryl hydrocarbon receptor in vitro.

    Science.gov (United States)

    Terasaki, Masanori; Yasuda, Michiko; Shimoi, Kayoko; Jozuka, Kazuhiko; Makino, Masakazu; Shiraishi, Fujio; Nakajima, Daisuke

    2014-09-15

    The in vitro potential of sensitizers and related compounds (SRCs) originating from impurities in waste paper in activating the human aryl hydrocarbon receptor (AhR) ? was assessed using yeast reporter gene as well as cytochrome P450 (CYP)1A1 and ethoxyresorufin O-deethylase (EROD) assays. In the yeast assay, eight compounds exhibited agonist activity, and their activity relative to ?-naphthoflavone (BNF) ranged from 1.4 × 10(-4) to 8.3 × 10(-2), with the highest activity observed for benzyl 2-naphthyl ether (BNE). In the EROD assay, six compounds caused a more significant induction of CYP1A-dependent activity than did the vehicle control at 50 ?M (pflorisil cartridge. In gas chromatography-mass spectrometry (GC-MS) analysis, SRCs were detected in the first fraction, at a total concentration of 5.5 ?g/L. This fraction also activated AhR, and its activity, expressed as a BNF equivalent value, was 0.42 nM in the yeast assay. The contribution ratio of active compounds accounted for up to 34% and 4.4% observed activity of the fraction and total samples, respectively. To our knowledge, this is the first study to show that paper industry-related compounds, namely aromatic sensitizers, activate AhR by using a yeast assay and HepG2 cells. PMID:24950494

  3. Synthesis of fluorinated carbazoles via C-H arylation catalyzed by Pd/Cu bimetal system and their antibacterial activities.

    Science.gov (United States)

    Kong, Xianqiang; Zhang, Huizi; Cao, Changsheng; Zhou, Shengliang; Pang, Guangsheng; Shi, Yanhui

    2016-03-15

    An effective intramolecular C-H arylation reaction catalyzed by a bimetallic catalytic system Pd(OAc)2/CuI for the synthesis of fluorine-substituted carbazoles from corresponding N-phenyl-2-haloaniline derivatives under ligand free conditions is demonstrated. The established method is effective for both N-phenyl-2-bromoaniline and N-phenyl-2-chloroaniline, and requires the low loading of Pd(OAc)2 (0.5mol%). A series of new fluorinated carbazoles were synthesized in excellent yields using the protocol (>83%, 19 examples) and were fully characterized by (1)H, (13)C and (19)F NMR spectral data, HRMS and elemental analysis. All compounds were evaluated for their antibacterial activities against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and methicillin-resistant S. aureus with resistance to gentamicin) by serial dilution technique. All tested compounds showed antibacterial activity against three test strains (S. aureus, B. subtilis and MRSA), and most of these compounds displayed pronounced antimicrobial activities against these three strains with low MIC values ranging from 0.39 to 6.25μg/mL. Among them, compounds 7 and 14 exhibited potent inhibitory activity better than reference drugs meropenem and streptomycin. Three compounds (2, 4 and 5) showed antibacterial activity against E. coli. with MIC values from 12.5 to 25μg/mL. PMID:26879853

  4. Synthesis of some novel thiourea derivatives obtained from 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3H-1,2,4-triazole-3-thiones and evaluation as antiviral/anti-HIV and anti-tuberculosis agents.

    Science.gov (United States)

    Küçükgüzel, Ilkay; Tatar, Esra; Küçükgüzel, S Güniz; Rollas, Sevim; De Clercq, Erik

    2008-02-01

    As a continuation of our previous efforts on N-alkyl/aryl-N'-[4-(4-alkyl/aryl-2,4-dihydro-3H-1,2,4-triazole-3-thione-5-yl)phenyl]thioureas 1-19 and N-alkyl/aryl-N'-[4-(3-aralkylthio-4-alkyl/aryl-4H-1,2,4-triazole-5-yl)phenyl]thioureas 20-22, a series of novel 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3H-1,2,4-triazole-3-thiones 23-26 and several related thioureas, N-alkyl/aryl-N'-{4-[(4-alkyl/aryl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methoxy]phenyl}thioureas 27-42 were synthesized for evaluation of their antiviral potency. Structures of the synthesized compounds were confirmed by the use of (1)H NMR, (13)C NMR and HR-MS data. All compounds 1-42 were evaluated in vitro against HIV-1 (IIIB) and HIV-2 (ROD) strains in MT-4 cells, as well as other selected viruses such as HSV-1, HSV-2, Coxsackie virus B4, Sindbis virus and Varicella-zoster virus using HeLa, Vero, HEL and E6SM cell cultures, and anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv. Compounds 4 and 5 showed weak activity against HSV-1, HSV-2 and TK(-) HSV, whereas eight compounds showed marginal activity against Coxsackie virus B4. The most active derivative in this series was compound 38 which showed moderate protection against Coxsackie virus B4 with an MIC value of 16 microg/ml and a selectivity index of 5. This compound was also active against thymidine kinase positive Varicella-zoster virus (TK(+) VZV, OKA strain) with an EC(50) value of 9.9 microg/ml. Compound 38 was the most active compound with 79% inhibition against M. tuberculosis H37Rv. PMID:17583388

  5. Synthesis and solid state structures of Chalcogenide compounds of Imidazolin-2-ylidene-1,1-Diphenyl-phosphinamine

    Indian Academy of Sciences (India)

    Naktode Kishor; Suman Das; Abhinanda Kundu; Hari Pada Nayek; Tarun K Panda

    2016-03-01

    We report the synthesis and solid state structures of 1,3-di-aryl-imidazolin-2-ylidine-1,1-diphenylphosphinamine [(aryl=mesityl (1a) and aryl=2,6-diisopripyl (1b)] and their chalcogenide compounds 3-di-aryl-imidazolin-2-ylidine-P, P-diphenylphosphinicamide (2a,b), 1,3-di-aryl-imidazolin-2-ylidine-P,P diphenyl-phosphinothioicamide (3a,b) and 1,3-diaryl-imidazolin-2-ylidine-P,P -diphenyl-phosphinoselenoicamide (4a,b).The compounds 1a,b were prepared in good yield by the reaction of 1,3-di-aryl-imidazolin-2-imine and chlorodiphenylphosphine in the presence of triethylamine in toluene. The reactions of 1a,b with elemental sulphur and selenium afforded the corresponding chalcogenide compounds 3a,b and 4a,b respectively.The corresponding oxo- derivative (2a,b) was obtained by reacting compound 1a,b with 30% aqueous hydrogen peroxide in THF. The molecular structures of 1a, 2a, 3a and 4a,b have been established by single crystal X-ray diffraction analyses. The molecular structures reveal that even C1–N1–P1 angle (124.62o) in compound 1a is less obtuse compared to the corresponding C1–N1–Si1 angles (157.8o) observed in related N-silylated 2-iminoimidazolines and trimethylsilyl iminophosphoranes. C1–N1–P1 angles are further widened in compounds 2a, 3a, and 4a,b due to the attachment of chalcogen atoms onto phosphorus atom.

  6. 1-Aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamide: an effective scaffold for the design of either CB1 or CB2 receptor ligands.

    Science.gov (United States)

    Piscitelli, Francesco; Ligresti, Alessia; La Regina, Giuseppe; Gatti, Valerio; Brizzi, Antonella; Pasquini, Serena; Allarà, Marco; Carai, Mauro Antonio Maria; Novellino, Ettore; Colombo, Giancarlo; Di Marzo, Vincenzo; Corelli, Federico; Silvestri, Romano

    2011-11-01

    New 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamides were synthesized as cannabinoid (CB) receptor ligands. Compound 11 (CB(1)K(i) = 2.3 nM, CB(1) SI = 163.6) showed CB(1) receptor affinity and selectivity superior to Rimonabant and AM251. Acute administration of 2mg/kg 11 reduced sucrose, but not regular food, intake in rats. On the other hand, compound 23 (CB(2)K(i) = 0.51 nM, CB(2) SI = 30.0) showed significant affinity and selectivity for the CB(2) receptor. The results presented here show that the 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamide may serve as an effective scaffold for the design of either CB(1) or CB(2) receptor ligands. PMID:21996466

  7. Catalytic Enantioselective Synthesis of N,C(?),C(?)-Trisubstituted ?-Amino Acid Derivatives Using 1H-Imidazol-4(5H)-ones as Key Templates.

    Science.gov (United States)

    Etxabe, Julen; Izquierdo, Joseba; Landa, Aitor; Oiarbide, Mikel; Palomo, Claudio

    2015-06-01

    1H-Imidazol-4(5H)-ones are introduced as novel nucleophilic ?-amino acid equivalents in asymmetric synthesis. These compounds not only allow highly efficient construction of tetrasubstituted stereogenic centers, but unlike hitherto known templates, provide direct access to N-substituted (alkyl, allyl, aryl) ?-amino acid derivatives. PMID:25907987

  8. Silicon dioxide surfaces with aryl interaction sites for chromatographic applications

    International Nuclear Information System (INIS)

    The paper presents the results of a study on aryl phases aimed at the increase of the separation selectivity of substances containing ? electrons, and improving the reproducibility of retention data. The above phases contain not only a carbon chain of a different length, linking them to the support, but also one or two aromatic rings. The suitability of the newly obtained packings for the purposes of high-performance liquid chromatography was verified on the basis of a description of surface topography before and after the modification process. Various physicochemical methods were employed to determine the effectiveness of chemical modification, i.e., elemental analysis, infrared spectroscopy, and nuclear magnetic resonance. The aryl packings obtained were used for the separation of polynuclear aromatic hydrocarbons and budesonide epimers, tested under hydroorganic conditions (water/ethanol, water/methanol, water/acetonitrile). The application of a methanol/water mobile phase and a new-generation naphthylpropyl stationary phase for the separation of the 22R and 22S diastereoisomers of budesonide allowed the obtention of reproducible results and make qualitative and quantitative determinations of particular enantiomers

  9. Synthesis and Biological Activity of 3-(2-Furanyl-6-Aryl-1,2,4-Triazolo[3,4-b]-1,3,4 –Thiadiazoles

    Directory of Open Access Journals (Sweden)

    Zi-Yi Zhang

    2002-08-01

    Full Text Available 3-(2-Furanyl-4-amino-5-mercapto-1,2,4-triazole (1 was prepared from 2-furoic acid through a multi-step reaction sequence. Compound 1 reacted with aromatic acids in the presence of phosphorus oxychloride to give 3-(2-furanyl-6-aryl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles (2. The structures of all the newly synthesized compounds have been confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and mass spectra. The bioassay indicated most of the title compounds possess significant growth promoting effects on mung bean radicles.

  10. Naturally occurring marine brominated indoles are aryl hydrocarbon receptor ligands/agonists.

    Science.gov (United States)

    DeGroot, Danica E; Franks, Diana G; Higa, Tatsuo; Tanaka, Junichi; Hahn, Mark E; Denison, Michael S

    2015-06-15

    The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates the toxic and biological effects of structurally diverse chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). As part of a larger effort to identify the full spectrum of chemicals that can bind to and activate the AhR, we have examined the ability of several naturally occurring marine-derived brominated indoles and brominated (methylthio)indoles (collectively referred to as brominated indoles) to bind to the AhR and stimulate AhR-dependent gene expression. Incubation of mouse, rat, and guinea pig recombinant cell lines containing a stably transfected AhR-responsive luciferase reporter gene with eight brominated indoles revealed that all compounds stimulated luciferase reporter gene activity, although some species-specific differences were observed. All compounds induced significantly more luciferase activity when incubated with cells for 4 h as compared to 24 h, demonstrating that these compounds are transient activators of the AhR signaling pathway. Three of the brominated indoles induced CYP1A1 mRNA in human HepG2 cells in vitro and Cyp1a mRNA in zebrafish embryos in vivo. The identification of the brominated indoles as direct ligands and activators/agonists of the AhR was confirmed by their ability to compete with [(3)H]TCDD for binding to the AhR and to stimulate AhR transformation and DNA binding in vitro. Taken together, these results indicate that marine-derived brominated indoles are members of a new class of naturally occurring AhR agonists. PMID:26001051

  11. Mechanistic Study of the Acid Degradation of Lignin Model Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sturgeon, M.; Kim, S.; Chmely, S. C.; Foust, T. D.; Beckham, G. T.

    2012-01-01

    Lignin is a major constituent of biomass, which remains underutilized in selective biomass conversion strategies to renewable fuels and chemicals. Here we are interested in understanding the mechanisms related to the acid deconstruction of lignin with a combined theoretical and experimental approach. Two model dimers with a b-O-4 aryl ether linkage (2-phenoxy-1-phenethanol and 2-phenoxy-1-phenyl-1,3 propanediol) and model dimmers with an a-O-4 aryl ether linkage were synthesized and deconstructed in H2SO4. The major products of the acidolysis of the b-O-4 compounds consisted of phenol and two aldehydes, phenylacetaldehyde and benzaldehyde. Quantum mechanical calculations were employed to elucidate possible deconstruction mechanisms with transition state theory. To confirm proposed mechanisms several possible intermediates were studied under similar acidolysis conditions. Although the resonance time for cleavage was on the order several hours, we have shown that the cleavage of the aryl ether linkage affords phenol and aldehydes. We would next like to utilize our mechanism of aryl ether cleavage in actual lignin.

  12. Synthesis of quinoxaline derivatives via condensation of aryl-1,2-diamines with 1,2-diketones using (NH4)6 Mo7 O24 . 4 H2 O as an efficient, mild and reusable catalyst

    International Nuclear Information System (INIS)

    Ammonium heptamolybdate tetrahydrate [(NH4)6Mo7O24.4H2O] efficiently catalyzes the condensation of aryl-1,2-diamines with l,2-diketones in EtOH/H2O as a green media at room temperature to afford quinoxaline derivatives as biologically interesting compounds. Ease of recycling of the catalyst is one of the most advantages of the proposed method

  13. Modification of PEEK model compounds and PEEK film by energetic heavy ion and ultraviolet irradiations

    Science.gov (United States)

    Ferain, E.; Legras, R.

    1993-10-01

    To prepare nuclear track membranes from poly(aryl ether ether ketone) (PEEK) film, we first determined the modifications induced by heavy ion and UV irradiations in this polymer and two of its model compounds, paraphenoxy benzophenone (PPB) and diphenoxy benzophenone (DPB). This article displays the first results obtained by SEC, HPLC, DSC, FTIR, UV and 13C NMR.

  14. Synthesis, characterization and antibacterial activity of some 5-aryl-1, 3-Diphenyl 1-4, 5-dihydro-1H-Pyrazoles

    International Nuclear Information System (INIS)

    The condensation of acetophenone (I) with arylaldehyde (II) was investigated and the resulting chalcones 2-Arylidene 1-Acetophenone (III) were reacted with phenyl hydrazine and acetic acid to produce substituted 5-aryl-1, 3-diphenyl-4, 5-dihydro-1H-Pyrazoles (IV). The structures of all products were studied by H-NMR, IR, thermal and elemental analysis. Thermo-gravimetric (TG) and differential thermal analysis (DTA) was applied to investigate the thermal behavior and structure of the synthesized compounds. 2-Pyrazolines (IV) exhibited moderate activity against Streptococcus faecalis ATCC 19433, Klebsiella pneumoniae ATCC 13883, Proteus vulgaris ATCC 25922, Shigella sonnei ATCC 25931 and Peseudom oaeruginosa ATCC 27853. (author)

  15. Principal component analysis for verifying 1H NMR spectral assignments. The case of 3-aryl (1,2,4)-oxadiazole-5-carbohydrazide benzylidene

    International Nuclear Information System (INIS)

    The 1H NMR data set of a series of 3-aryl (1,2,4)-oxadiazole-5-carbohydrazide benzylidene derivatives synthesized in our group was analyzed using the chemometric technique of principal component analysis (PCA). Using the original 1H NMR data PCA allowed identifying some misassignments of the proton aromatic chemical shifts. As a consequence of this multivariate analysis, nuclear Overhauser difference experiments were performed to investigate the ambiguity of other assignments of the ortho and meta aromatic hydrogens for the compound with the bromine substituent. The effect of the 1,2,4-oxadiazole group as an electron acceptor, mainly for the hydrogens 12,13, has been highlighted. (author)

  16. A study of substituent effects on the NH bond in alkyl and aryl 4,6-disubstituted-3-cyano-2-pyridones

    Directory of Open Access Journals (Sweden)

    MILICA MISIC–VUKOVIC

    2007-12-01

    Full Text Available Substituent effects on the IR stretching frequencies and 1H-NMR chemical shifts of the pyridone NH group in 4- and 6-disubstituted alkyl and aryl 3-cyano-2-pyridones were investigated. The bands most sensitive to substituent effects from the broad and multiple IR NH band for each compound were selected by a computer calculation. The selected values of the IR frequencies and the determined 1H-NMR chemical shifts were subjected to LFER analysis, by correlations with the Hamett ?m/p and Swain–Lupton F and R substituent constants.

  17. Brønsted acid catalyzed, conjugate addition of ?-dicarbonyls to in situ generated ortho-quinone methides--enantioselective synthesis of 4-aryl-4H-chromenes.

    Science.gov (United States)

    El-Sepelgy, Osama; Haseloff, Stefan; Alamsetti, Santosh Kumar; Schneider, Christoph

    2014-07-21

    We describe herein a catalytic, enantioselective process for the synthesis of 4H-chromenes which are important structural elements of many natural products and biologically active compounds. A sequence comprising a conjugate addition of ?-diketones to in situ generated ortho-quinone methides followed by a cyclodehydration reaction furnished 4-aryl-4H-chromenes in generally excellent yields and high optical purity. A BINOL-based chiral phosphoric acid was employed as a Brønsted acid catalyst which converted ortho-hydroxy benzhydryl alcohols into hydrogen-bonded ortho-quinone methides and effected the carbon-carbon bond-forming event with high enantioselectivity. PMID:24938645

  18. Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

    Directory of Open Access Journals (Sweden)

    Paul Knochel

    2011-09-01

    Full Text Available In this review we summarize the most important procedures for the preparation of functionalized organzinc and organomagnesium reagents. In addition, new methods for the preparation of polyfunctional aryl- and heteroaryl zinc- and magnesium compounds, as well as new Pd-catalyzed cross-coupling reactions, are reported herein. Experimental details are given for the most important reactions in the Supporting Information of this article.

  19. Symmetric diarylsulfoxides as asymmetric sulfinylating reagents for dialkylmagnesium compounds.

    Science.gov (United States)

    Ruppenthal, Simon; Brückner, Reinhard

    2015-01-16

    At ?78 °C, primary dialkylmagnesium compounds reacted with diarylsulfoxides when 1.5 equiv of the dilithium salt of (S)-BINOL was added as a promotor. Alkyl aryl sulfoxides resulted in up to quantitative yield and with up to 97% ee. This demonstrates the feasibility of asymmetric sulfinylations by achiral sulfinylating agents (from the perspective of Alkyl2Mg) as well as the feasibility of asymmetric sulfoxide–magnesium exchanges (from the perspective of Ar2SO). PMID:25553340

  20. Effective attenuation of atrazine-induced histopathological changes in testicular tissue by antioxidant N-phenyl-4-aryl-polyhydroquinolines.

    Science.gov (United States)

    Chandak, Navneet; Bhardwaj, Jitender K; Zheleva-Dimitrova, Dimitrina; Kitanov, Gerassim; Sharma, Rajnesh K; Sharma, Pawan K; Saso, Luciano

    2015-10-01

    Some of the environmental toxicants acting as endocrine disruptors have been associated with health hazards in human and wildlife by modulating hormonal actions. Atrazine, a strong endocrine disruptor, induces detrimental effects on gonads in male and female, and causes impairment of fertility and developmental problems as well as sex alterations. Atrazine decreases the activities of antioxidant enzymes and thus responsible for oxidative stress. Natural antioxidants have shown ability to reduce/slow down the apoptotic effect of atrazine on testicular tissue. In the present study, some N-phenyl-4-aryl-polyhydroquinolines bearing phenolic or/and alkoxy group(s) (6a-6g) were synthesized and evaluated for antioxidant activity in four different assays. Three best compounds (6e-6g) were studied for their ameliorative effect on testicular tissue supplemented with atrazine in vitro. PMID:25265324

  1. Electronic effects on keto-enol tautomerism of p-substituted aryl-1,3-diketone malonates

    Science.gov (United States)

    Jiménez-Cruz, Federico; Ríos-Olivares, Hector; García-Gutiérrez, José Luis; Mar, Lubanski Fragoza

    2015-12-01

    Electronic effects on keto-enol tautomerism of 1-(p-substituted aryl)-1,3-diketone malonates 1-10 were determined and established by NMR-Hammett linear free energy relationships. In addition, tautomeric equilibrium constants were determined for the title compounds by 1H NMR in DMSO-d6, showing an increasing to diketo tautomer with the increasing in the temperature. In this context, the enol form becomes less stable with increasing temperature suggesting that the intramolecular hydrogen bonding of the cis enol-keto form are increasingly broken at higher temperatures. In general, the enolic form (rather than the keto) is the most stable conformation due to its six member cyclic structure fulfilled by an internal O-H … O hydrogen bond.

  2. Palladium-catalyzed arylation of 2H-chromene: a new entry to pyrano[2,3-c]carbazoles.

    Science.gov (United States)

    Ranjith Reddy, K; Siva Reddy, A; Dhaked, Devendra K; Rasheed, S K; Pathania, Anup Singh; Shankar, Ravi; Malik, Fayaz; Das, Parthasarathi

    2015-09-21

    Pyrano[2,3-c]carbazoles which are biologically valuable and synthetically challenging frameworks are synthesized in high yields over five steps from commercially available resorcinol. Palladium-catalyzed arylation remains a key step in this novel strategy. The versatility of this protocol has been demonstrated by the synthesis of naturally occurring alkaloid clauraila C and 7-methoxyglycomaurin. The anti-proliferative activity of these designed compounds (5a, 5f, and 5l) has been evaluated in a cancer cell line (MOLT-4). The molecular docking study revealed that this pyrano[2,3-c]carbazole class of molecules selectively occupies the colchicine binding site of the tubulin-polymer. PMID:26235231

  3. In Vitro Nematicidal Activity of Aryl Hydrazones and Comparative GC-MS Metabolomics Analysis.

    Science.gov (United States)

    Eloh, Kodjo; Demurtas, Monica; Deplano, Alessandro; Ngoutane Mfopa, Alvine; Murgia, Antonio; Maxia, Andrea; Onnis, Valentina; Caboni, Pierluigi

    2015-11-18

    A series of aryl hydrazones were synthesized and in vitro assayed for their activity on the root-knot nematode Meloidogyne incognita. The phenylhydrazones of thiophene-2-carboxyaldehyde 5, 3-methyl-2-thiophenecarboxyaldehyde, 6, and salicylaldehyde, 2, were the most potent with EC50/48h values of 16.6 ± 2.2, 23.2 ± 2.7, and 24.3 ± 1.4 mg/L, respectively. A GC-MS metabolomics analysis, after in vitro nematode treatment with hydrazone 6 at 100 mg/L for 12 h, revealed elevated levels of fatty acids such as lauric acid, stearic acid, 2-octenoic acid, and palmitic acid. Whereas control samples showed the highest levels of monoacylglycerols such as monostearin and 2-monostearin, surprisingly, 2 h after treatment with hydrazone 6, nematodes excreted 3 times the levels of ammonia eliminated in the same conditions by controls. Thus, phenylhydrazones may represent a good scaffold in the discovery and synthesis of new nematicidal compounds, and a metabolomics approach may be helpful in understanding their mechanisms of toxicity and mode of action. PMID:26528945

  4. Structural investigation of HIV-1 nonnucleoside reverse transcriptase inhibitors: 2-Aryl-substituted benzimidazoles

    Science.gov (United States)

    Zió?kowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

    2009-11-01

    Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) is one of the most destructive epidemics in history. Inhibitors of HIV enzymes are the main targets to develop drugs against that disease. Nonnucleoside reverse transcriptase inhibitors of HIV-1 (NNRTIs) are potentially effective and nontoxic. Structural studies provide information necessary to design more active compounds. The crystal structures of four NNRTI derivatives of 2-aryl-substituted N-benzyl-benzimidazole are presented here. Analysis of the geometrical parameters shows that the structures of the investigated inhibitors are rigid. The important geometrical parameter is the dihedral angle between the planes of the ?-electron systems of the benzymidazole and benzyl moieties. The values of these dihedral angles are in a narrow range for all investigated inhibitors. There is no significant difference between the structure of the free inhibitor and the inhibitor in the complex with RT HIV-1. X-ray structures of the investigated inhibitors are a good basis for modeling enzyme-inhibitor interactions in rational drug design.

  5. Enzymatic aryl-O-methyl-14C labeling of model lignin monomers

    International Nuclear Information System (INIS)

    Aryl-O-methyl ethers are abundant in aerobic and anaerobic environments. In particular, lignin is composed of units of this type. Lignin monomers specifically radiolabeled in methoxy, side chain, and ring carbons have been synthesized by chemical procedures and are important in studies of lignin synthesis and degradation, humus formation, and microbial O-demethylation. In this paper attention is drawn to an enzymatic procedure for preparing O-methyl-14C-labeled aromatic lignin monomers which has not previously been exploited in microbial ecology and physiology studies and which has several advantages compared with chemical synthesis procedures. O-[methyl-14C]vanillic and O-[methyl-14C]ferulic acids were prepared with S-[methyl-14C]adenosyl-L-methionine as the methyl donor, using commercially obtained porcine liver catechol-O-methyltransferase (EC 2.1.1.6). The specific activity of the methylated products was the same as that of the methyl donor, a maximum of about 58 ?Ci/?mol, and the yields were 42% (vanillate) and 35% (ferulate). Thus lignin monomers are readily prepared as O-methylated products of the catechol-O-methyltransferase reaction and, with this enzyme method of preparation, would be more widely available than labeled compounds which require chemical synthesis

  6. Effects of perfluoroalkyl acids on the function of the thyroid hormone and the aryl hydrocarbon receptor

    DEFF Research Database (Denmark)

    Long, Manhai; Ghisari, Mandana

    2013-01-01

    Perfluoroalkyl acids (PFAAs) are perfluorinated compounds that widely exist in the environment and can elicit adverse effects including endocrine disruption in humans and animals. This study investigated the effect of seven PFAAs on the thyroid hormone (TH) system assessing the proliferation of the 3,3',5-triiodo-L-thryonine (T3)-dependent rat pituitary GH3 cells using the T-screen assay and the effect on the aryl hydrocarbon receptor (AhR) transactivation in the AhR-luciferase reporter gene bioassay. A dose-dependent impact on GH3 cells was observed in the range 1?×?10(-9)-1?×?10(-4) M: seven PFAAs (perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA)) inhibited the GH3 cell growth, and four PFAAs (PFOS, PFHxS, PFNA, and PFUnA) antagonized the T3-induced GH3 cell proliferation. At the highest test concentration, PFHxS showed a further increase of the T3-induced GH3 growth. Among the seven tested PFAAs, only PFDoA and PFDA elicited an activating effect on the AhR. In conclusion, PFAAs possess in vitro endocrine-disrupting potential by interfering with TH and AhR functions, which need to be taken into consideration when assessing the impact on human health.

  7. Synthesis of -aryl--lactones and relationship: Structure – antifeedant and antifungal activity

    Indian Academy of Sciences (India)

    Andrzej Skrobiszewski; Witold Gładkowski; Paulina Walczak; Anna Gliszczyńska; Gabriela Maciejewska; Tomasz Klejdysz; Jan Nawrot; Czesław Wawrzeńczyk

    2015-04-01

    Eighteen racemic -aryl--lactones derived from simple aromatic aldehydes have been obtained in the chemical synthesis. Iodolactones (5c and 6c) were synthesized from ()-4-(benzo[][1′,3′]-dioxol-5′-yl)- but-3-en-2-one (1). Reductive dehalogenation of iodolactones 5a–c and 6a–c afforded -ethyl--lactones (7a–c, 8a–c) whereas the unsaturated lactones (9a–c, 10a–c) were obtained by dehydrohalogenation of iodolactones. All synthesized lactones were fully characterized by spectroscopic data (NMR, IR, HRMS) and subjected to the tests on the antifeedant activity towards Tribolium confusum, Trogoderma granarium and Sitophilus granaries as well to the tests on the antifungal activity towards four Fusarium species. The biological tests allowed to find some relationships between the structure and biological activity of the compounds studied. -Ethyl--lactones 7a–c, 8a–c and unsaturated lactones 9a–c, 10a-c were usually stronger antifeedants than their parent iodolactones 5a–c and 6a–c. trans-Iodolactones 6a–c were more active than cis isomers 5a-c both in antifeedant and antifungal assays. The structure of aromatic substituent was the key factor in antifungal activity. The lactones with benzo [][1,3]dioxole ring (5c, 6c, 7c, 8c, 9c) were the most active whereas those with unsubstituted benzene ring exhibited almost no activity.

  8. Polymorphism of the aryl-hydrocarbon receptor gene in intron 10 of human cancers

    Scientific Electronic Library Online (English)

    M., Rocas; E., Jakubauskiene; A., Kanopka.

    2011-11-01

    Full Text Available Polychlorinated dibenzo-p-dioxins (PCDDs) and related halogenated aromatic hydrocarbons (e.g., PCDFs), often called "dioxins", are ubiquitously present environmental contaminants. Some of them, notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are among the most toxic synthetic compounds known. Th [...] e biological effects of dioxins are mediated via the aryl hydrocarbon receptor (AhR). Mutations in the AhR transactivation domain are linked to sensitivity to the acute lethality of TCDD. We present here a study of AhR gene polymorphism in normal and cancer human tissues affecting pre-mRNA splicing in the AhR gene-coding transactivation domain region (exon 10, intron 10, exon 11 region), previously shown to be associated with AhR dysfunction. We tested 126 pairs of normal and cancer tissue samples from liver, lung, stomach, kidney, mucous, breast, and pancreas of 49 males and 77 females (45-70 years of age). We used in vitro splicing assay, RT-PCR and sequencing methods. Our results showed that in an in vitro system it is possible to reconstitute cellular pre-mRNA splicing events. Tested cancer tissues did not contain mutations in the AhR transactivation domain region when the DNA sequences were compared with those from normal tissues. There were also no differences in AhR mRNA splice variants between normal and malignant breast tissues and no polymorphisms in the studied regions or cDNA.

  9. Polymorphism of the aryl-hydrocarbon receptor gene in intron 10 of human cancers

    Directory of Open Access Journals (Sweden)

    M. Rocas

    2011-11-01

    Full Text Available Polychlorinated dibenzo-p-dioxins (PCDDs and related halogenated aromatic hydrocarbons (e.g., PCDFs, often called "dioxins", are ubiquitously present environmental contaminants. Some of them, notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, are among the most toxic synthetic compounds known. The biological effects of dioxins are mediated via the aryl hydrocarbon receptor (AhR. Mutations in the AhR transactivation domain are linked to sensitivity to the acute lethality of TCDD. We present here a study of AhR gene polymorphism in normal and cancer human tissues affecting pre-mRNA splicing in the AhR gene-coding transactivation domain region (exon 10, intron 10, exon 11 region, previously shown to be associated with AhR dysfunction. We tested 126 pairs of normal and cancer tissue samples from liver, lung, stomach, kidney, mucous, breast, and pancreas of 49 males and 77 females (45-70 years of age. We used in vitro splicing assay, RT-PCR and sequencing methods. Our results showed that in an in vitro system it is possible to reconstitute cellular pre-mRNA splicing events. Tested cancer tissues did not contain mutations in the AhR transactivation domain region when the DNA sequences were compared with those from normal tissues. There were also no differences in AhR mRNA splice variants between normal and malignant breast tissues and no polymorphisms in the studied regions or cDNA.

  10. Interaction of fish aryl hydrocarbon receptor paralogs (AHR1 and AHR2) with the retinoblastoma protein

    Energy Technology Data Exchange (ETDEWEB)

    Merson, Rebeka R., E-mail: rmerson@ric.edu [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Biology Department, Rhode Island College, 500 Mt. Pleasant Ave., Providence, RI 02908 (United States); Karchner, Sibel I.; Hahn, Mark E. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2009-08-13

    The aryl hydrocarbon receptor (AHR) mediates the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. In some mammalian cell lines, TCDD induces G1 cell cycle arrest, which depends on an interaction between the AHR and the retinoblastoma tumor suppressor (RB). Mammals possess one AHR, whereas fishes possess two or more AHR paralogs that differ in the domains important for AHR-RB interactions in mammals. To test the hypothesis that fish AHR paralogs differ in their ability to interact with RB, we cloned RB cDNA from Atlantic killifish, Fundulus heteroclitus, and studied the interactions of killifish RB protein with killifish AHR1 and AHR2. In coimmunoprecipitation experiments, in vitro-expressed killifish RB coprecipitated with both AHR1 and AHR2. Consistent with these results, both killifish AHR1 and AHR2 interacted with RB in mammalian two-hybrid assays. These results suggest that both fish AHR1 and AHR2 paralogs may have the potential to influence cell proliferation through interactions with RB.

  11. Synthesis, biological activity evaluation and molecular docking studies of novel coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes.

    Science.gov (United States)

    Vaarla, Krishnaiah; Kesharwani, Rajesh Kumar; Santosh, Karnewar; Vedula, Rajeswar Rao; Kotamraju, Srigiridhar; Toopurani, Murali Krishna

    2015-12-15

    A novel series of coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes (4a-o) were synthesized via an efficient, one-pot multicomponent approach involving 3-(2-bromoacetyl)coumarins (1a-g), thiosemicarbazide (2) and substituted acetophenones (3a-c) utilizing Vilsmeier-Haack reaction condition with good yields. The title compounds structure was elucidated by spectroscopic data (IR, NMR and Mass) and elemental analysis. All the synthesized compounds were screened for their in vitro cytotoxic activity against MCF-7, DU-145 and HeLa cell lines and studied detailed about molecular interaction of probable target protein human microsomal cytochrome CYP450 2A6 using docking simulation. These coumarin derivatives were exhibiting moderate to appreciable cytotoxic activities. The compounds 4m and 4n exhibited significant cytotoxic activity with IC50 values having 5.75 and 6.25?M against HeLa cell line. Similarly compound 4n also exhibiting good anti cancer property and antibacterial activity against DU-145 cell line and Gram negative bacterial strains. PMID:26542964

  12. Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

    KAUST Repository

    Huang, Ronglu

    2015-03-17

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated. Efficiency drive: A series of copper(I) fluoroalkoxide complexes bearing N,N ligands have been prepared and structurally characterized. These well-defined complexes serve as efficient reagents for the fluoroalkoxylation of aryl and heteroaryl bromides to produce a wide range of trifluoroethyl, pentafluoropropyl, and tetrafluoropropyl (hetero)aryl ethers in good to excellent yields.

  13. Reactivity of Aryl Halides for Reductive Dehalogenation in (Seawater Using Polymer-Supported Terpyridine Palladium Catalyst

    Directory of Open Access Journals (Sweden)

    Toshimasa Suzuka

    2015-05-01

    Full Text Available A polymer-supported terpyridine palladium complex was prepared. The complex was found to promote hydrodechlorination of aryl chlorides with potassium formate in seawater. Generally, reductive cleavage of aryl chlorides using transition metal catalysts is more difficult than that of aryl bromides and iodides (reactivity: I > Br > Cl; however, the results obtained did not follow the general trend. Therefore, we investigated the reaction inhibition agents and found a method to remove these inhibitors. The polymeric catalysts showed high catalytic activity and high reusability for transfer reduction in seawater.

  14. Enantioselective cross-coupling of meso-epoxides with aryl halides.

    Science.gov (United States)

    Zhao, Yang; Weix, Daniel J

    2015-03-11

    The first enantioselective cross-electrophile coupling of aryl bromides with meso-epoxides to form trans-?-arylcycloalkanols is presented. The reaction is catalyzed by a combination of (bpy)NiCl2 and a chiral titanocene under reducing conditions. Yields range from 57 to 99% with 78-95% enantiomeric excess. The 30 examples include a variety of functional groups (ether, ester, ketone, nitrile, ketal, trifluoromethyl, sulfonamide, sulfonate ester), both aryl and vinyl halides, and five- to seven-membered rings. The intermediacy of a carbon radical is strongly suggested by the conversion of cyclooctene monoxide to an aryl [3.3.0]bicyclooctanol. PMID:25716775

  15. Novel fluorescent 1,8-naphthalimide derivatives containing thiophene and pyrazole moieties: Synthesis by direct C-H arylation and evaluation of photophysical and electrochemical properties

    Science.gov (United States)

    Jin, Zhengneng; Wu, Jiashou; Wang, Chuanfeng; Dai, Guoliang; Liu, Shiyong; Lu, Jianmei; Jiang, Huajiang

    2014-01-01

    A series of novel 1,8-naphthalimide derivatives containing thiophene and pyrazole moities were synthesized by direct Pd-catalyzed C-H arylation and then characterized by 1H NMR, 13C NMR, MALDI-HRMS, and elementary analysis. The photophysical and electrochemical properties of the derivatives were also investigated. All compounds have green emission both in diluted CH2Cl2 solution and solid film. The cyclic voltammetry (CV) measurements showed that the target compounds had a lowest unoccupied molecular orbital (LUMO) range from -3.49 eV to -3.29 eV and a highest occupied molecular orbital (HOMO) range from -6.04 eV to -5.81 eV. Quantum chemical calculations were performed to obtain the optimized ground-state geometry as well as the spatial distributions of the HOMO, LUMO levels of the compounds.

  16. Intercalated organic-inorganic perovskites stabilized by fluoroaryl-aryl interactions.

    Science.gov (United States)

    Mitzi, David B; Medeiros, David R; Malenfant, Patrick R L

    2002-04-22

    Crystals of several new hybrid tin(II) iodide-based perovskites, involving 2,3,4,5,6- pentafluorophenethylammonium or phenethylammonium cation bilayers and intercalated aryl or perfluoroaryl molecules, were grown by slow evaporation of a methanol solution containing the hybrid perovskite and the intercalating species. The (C(6)F(5)C(2)H(4)NH(3))(2)SnI(4).(C(6)H(6)) structure was solved at -75 degrees C in a monoclinic C2/c subcell [a = 41.089(12) A, b = 6.134(2) A, c = 12.245(3) A, beta = 94.021(5) degrees, Z = 4] and consists of sheets of corner-sharing distorted SnI(6) octahedra separated by bilayers of pentafluorophenethylammonium cations. The intercalated benzene molecules form a single well-ordered layer interposed between adjacent fluoroaryl cation layers. The corresponding hybrid with an unfluorinated organic cation and fluorinated intercalating molecule, (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4).(C(6)F(6)), is isostructural [a = 40.685(4) A, b = 6.0804(6) A, c = 12.163(1) A, beta = 93.136(2) degrees, Z = 4]. For each intercalated system, close C...C contacts (3.44-3.50 A) between the aromatic cation and the intercalated molecule are indicative of a significant face-to-face interaction, similar to that found in the complex C(6)H(6).C(6)F(6). Crystal growth runs with the organic cation and prospective intercalating molecule either both fluorinated or both unfluorinated did not yield stable intercalated compounds, demonstrating the significance of fluoroaryl-aryl interactions in the current intercalated structures. Thermal analysis of (C(6)F(5)C(2)H(4)NH(3))(2)SnI(4).(C(6)H(6)) and (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4).(C(6)F(6)) crystals yields, in addition to the characteristic transitions of the parent perovskite, endothermic transitions [12.6(5) and 32.1(8) kJ/mol, respectively] with an onset at 145 degrees C and a weight loss corresponding to the complete loss of the intercalated molecule. The relatively high deintercalation temperature (well above the boiling point of benzene and hexafluorobenzene) demonstrates the usefulness of the hybrid perovskites in providing a stable framework for the examination of the fluoroaryl-aryl interaction, as well as the potential importance of this interaction in tailoring new hybrid perovskites. UV-vis absorption measurements on (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4).(C(6)F(6)) thin films indicate a small reversible wavelength shift to higher energy for the tin(II) iodide framework exciton peak (with respect to that of the parent perovskite spectrum), from 608(2) nm [2.04 eV] to 595(2) nm [2.08 eV], and a corresponding shift in the band edge position. This spectral shift can most reasonably be attributed to subtle structural changes induced in the tin(II) iodide sheets by the intercalated hexafluorobenzene molecules. PMID:11952366

  17. Selective transformations of substituted aryl compounds to fluorenes and phosphoramidates : synthetic and spectroscopic studies

    OpenAIRE

    Haggam, Reda

    2010-01-01

    Because of their diverse biological properties and their high potential for the development of new drugs the synthesis of fluorenes and related systems such as benzo[b]fluorenes is of great interest in the fields of organic and medicinal chemistry. The most relevant benzo[b]fluorenes include the naturally occurring kinamycins. Recently, two fluorene derivatives have been isolated from the sweat of hippopotamus (Hippopotamus amphibius). The biological function of the two dyes named hipposudori...

  18. Synthesis of Aza-Aromatic Compounds by Photocyclodehydrogenation Reaction of N-Aryl Imines.

    Czech Academy of Sciences Publication Activity Database

    Kos, Martin

    Prague : Institute of Chemical Process Fundamental of the CAS, v. v. i, 2015 - (Bendová, M.; Wagner, Z.), s. 32 ISBN 978-80-86186-70-2. [Bažant Postgraduate Conference 2015. Prague (CZ)] Institutional support: RVO:67985858 Keywords : photocyclodehydrogenation reaction * acid * polxyaromatic molecules Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Aryl hydrocarbon mono-oxygenase activity in human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, G.D.; Schuresko, D.D.

    1981-06-01

    Aryl hydrocarbon mono-oxygenase (AHM), an enzyme of key importance in metabolism of xenobiotic chemicals such as polynuclear aromatic hydrocarbons (PNA), is present in human lymphocytes. Studies investing the relation of activity of AHM in human lymphocytes to parameters such as disease state, PNA exposure, in vitro mitogen stimulation, etc. have been summarized in this report. Some studies have demonstrated increased AHM activity in lymphocytes from cigarette smokers (compared to nonsmokers), and in lung cancer patients when compared to appropriate control groups. These observations are confused by extreme variability in human lymphocyte AHM activities, such variability arising from factors such as genetic variation in AHM activity, variation in in vitro culture conditions which affect AHM activity, and the problematical relationship of common AHM assays to actual PNA metabolism taking place in lymphocytes. If some of the foregoing problems can be adequately addressed, lymphocyte AHM activity could hold the promise of being a useful biomarker system for human PNA exposure.

  20. Fluorescence characteristics of aryl boronic acid derivate (PBA)

    Science.gov (United States)

    Patil, S. S.; Muddapur, G. V.; Patil, N. R.; Melavanki, R. M.; Kusanur, R. A.

    2015-03-01

    The absorption and fluorescence spectra of newly synthesized aryl boronic acid derivative namely Phenyl boronic acid (PBA) have been recorded in various solvents of different polarities. The ground state dipole moment of PBA was obtained from quantum chemical calculations. Solvatochromic correlations were used to estimate the ground state (μg) and excited state (μe) dipole moments. The excited state dipole moments are observed to be greater than the ground state dipole moments. Further, the ground and excited state dipole moments are not parallel but subtend by an angle of 70°. The changes in dipole moment (Δμ) were calculated both from solvatochromic shift method and microscopic solvent polarity parameter (ETN), and the values are compared. Solvent effects on the absorption and fluorescence spectra were quantified using Reichardt's and bulk solvent polarity parameters were complemented by the results of the Kamlet-Taft treatment.

  1. Screening of indigenous plants from Japan for modulating effects on transformation of the aryl hydrocarbon receptor.

    Science.gov (United States)

    Nishiumi, Shin; Hosokawa, Keizo; Mukai, Rie; Fukuda, Itsuko; Hishida, Atsuyuki; Iida, Osamu; Yoshida, Ken-ichi; Ashida, Hitoshi

    2006-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor with which halogenated and polycyclic aromatic hydrocarbons such as dioxins and benzo[a]pyrene interact as ligands. Since such compounds cause various toxicological effects, including cancer, through the transformation of AhR, it is important to determine influence of modulating factors. It has been reported that certain plant components such as flavonoids and indoles can affect AhR transformation. In this study, to obtain clues to novel ligands of AhR, 191 species of indigenous plants were collected in Japan, and their 50% methanolic extracts (total 368 plant parts) were tested for modulating effects on AhR transformation in a cell-free system using a rat hepatic cytosolic fraction. Among tested extracts at a concentration of 1 mg dry weight of plant/mL, 174 of 368 extracts suppressed 1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AhR transformation to 50% or less, while 9 extracts per se induced AhR transformation equivalent to more than 20% of that induced by 1 nM TCDD. Mallotus japonicus (Thunb.) Muell. (leaf) and Trichosanthes rostrata Kitamura (fruit and fruit skin) strongly suppressed 1 nM TCDD-induced AhR transformation, while Phellodendron amurense Ruprecht (seed) per se strongly induced AhR transformation. These results suggest that a large variety of plants in Japan contain various compounds modulating, mainly suppressing, AhR transformation. PMID:16839212

  2. Reduction of sulphur from polysulphidic model compounds by the hyperthermophilic archaebacterium pyrococcus furiosus

    Energy Technology Data Exchange (ETDEWEB)

    Tilstra, L.; Eng, G.; Olson, G.J.; Wang, F.W. (National Institute of Standards and Technology, Gaithersburg, MD (USA). Polymer Science Division)

    1992-07-01

    Several polysulphidic model compounds were studied for their reducibility by a hyperthermophilic archaebacterium, {ital Pyrococcus furiosus}. Model compounds that may represent forms of organic sulphur in coal were selected for study including model compounds with bulky alkyl and aryl groups surrounding the sulphur atoms and polymeric polysulphides. {ital P. furiosus} reduced these organic polysulphides to hydrogen sulphide with varying efficiency. The use of complex model compounds may be more realistic than simple model compounds for evaluating the potential for microbial removal of organic sulphur from coal. 17 refs., 1 fig., 3 tabs.

  3. Phosphine-free palladium-catalyzed direct bisarylation of pyrroles with aryl iodides on water.

    Science.gov (United States)

    Cho, Beom Shin; Bae, Hyun Jung; Chung, Young Keun

    2015-05-15

    The Pd-catalyzed bisarylation of pyrroles with aryl iodides on water is described. The reaction proceeds under mild reaction conditions, i.e., relatively low temperature (40 °C) and phosphine-free. PMID:25919427

  4. Pd(II)-Catalyzed para-Selective C–H Arylation of mono-Substituted Arenes

    OpenAIRE

    Wang, Xisheng; Leow, Dasheng; Yu, Jin-Quan

    2011-01-01

    Pd-catalyzed para-selective C–H arylation of mono-substituted arenes including toluene is developed for the first time using F+ as a bystanding oxidant. This finding provides a new retrosynthetic disconnection for biaryl synthesis.

  5. Influence of Functionality on Direct Arylation of Model Systems as a Route Toward Fluorinated Copolymers via Direct Arylation Polymerization (DArP)

    DEFF Research Database (Denmark)

    Livi, Francesco; Gobalasingham, Nemal S.

    2015-01-01

    A screening of direct arylation conditions on amodel small molecule system is carried out to develop suitableconditions for the direct arylation polymerization (DArP) of fluorinatedcopolymers, which are incompatible with conditionspreviously utilized successfully for nonfluorinated systems. Themodel system features a coupling between a 2-substituted thiopheneand a pentafluorobenzene, where one of the partnerswas brominated. A substantial difference in reactivity isobserved, demonstrating that the optimal functionalization fordirect arylation between a thiophene-based donor and a highlyfluorinated acceptor is a halogenated thiophene and anunfunctionalized fluorinated unit, which is opposite of typicalcross coupling reactions, where the acceptor is typicallyhalogenated. The best conditions are applied to the copolymerizationof 1,2,4,5-tetrafluorobenzene and 2,2’-(2,5-bis((2-hexyldecyl)oxy)21,4-phenylene)dithiophene. Polymers arefree of ?-defects and significant homocoupling. This work furtherunderscores the attractive simplicity, relevance, and easeof DArP while reconfirming its broad compatibility withincreasingly popular fluorinated copolymers.

  6. Synthesis and preliminary evaluation of antinociceptive activity of novel isoxazolyl-aryl-hydrazones

    International Nuclear Information System (INIS)

    New 2-isoxazoline aldehydes were synthesized, in good yields, from cycloadduct of the 1,3-dipolar cycloaddition reaction between endocyclic enecarbamate and carboethoxyformonitrile oxide (CEFNO). Condensation of these 2-isoxazoline aldehydes with several phenyl-hydrazines produced new isoxazolyl-aryl-hydrazones, which showed low toxicity and excellent antinociceptive activity, when compared to dipyrone. The antinociceptive activity of isoxazolyl-aryl-hydrazones was performed using the acetic acid-induced mice abdominal constrictions test. (author)

  7. Unprecedentedly mild direct Pd-catalyzed arylation of oxazolo[4,5-b]pyridine

    DEFF Research Database (Denmark)

    Zhuravlev, Fedor

    2006-01-01

    Pd-catalyzed C-2 arylation of oxazolo[4,5-b]pyridine proceeds efficiently at 30 degrees C and tolerates a variety of aryl halides, including derivatized amino acids for which no racemization was observed during the reaction. Experimental evidence for facile deprotonation of oxazolo[4,5-b]pyridine under the reaction conditions is presented and the nature of the anionic intermediates is computationally examined. (c) 2006 Elsevier Ltd. All rights reserved.

  8. Direct ?-Functionalization of Cyclic Ketones with Aryl Ketones via the Merger of Photoredox and Organocatalysis

    OpenAIRE

    Petronijevi?, Filip R.; Nappi, Manuel; MacMillan, David W. C.

    2013-01-01

    The direct ?-coupling of cyclic ketones with aryl ketones has been achieved via the synergistic combination of photoredox catalysis and organocatalysis. Diaryl oxymethyl or aryl–alkyl oxymethyl radicals, transiently generated via single-electron reduction of ketone precursors, readily merge with ?-enaminyl radical species – generated by photon-induced enamine oxidation – to produce ?-hydroxyketone adducts. Experimental evidence indicates that two discrete reaction pathways can be operable in ...

  9. Application of Visible-to-UV Photon Upconversion to Photoredox Catalysis: The Activation of Aryl Bromides.

    Science.gov (United States)

    Majek, Michal; Faltermeier, Uwe; Dick, Bernhard; Pérez-Ruiz, Raúl; Jacobi von Wangelin, Axel

    2015-10-26

    The activation of aryl-Br bonds was achieved by sequential combination of a triplet-triplet annihilation process of the organic dyes, butane-2,3-dione and 2,5-diphenyloxazole, with a single-electron-transfer activation of aryl bromides. The photophysical and chemical steps were studied by time-resolved transient fluorescence and absorption spectroscopy with a pulsed laser, quenching experiments, and DFT calculations. PMID:26368791

  10. Combination of Microwave Reactions with Fluorous Separations in the Palladium-Catalyzed Synthesis of Aryl Sulfides

    OpenAIRE

    Zhang, Wei; Lu, Yimin; Chen, Christine Hiu-Tung

    2003-01-01

    Coupling of microwave reactions with fluorous separations can dramatically increase the efficiency of high-speed synthesis. Described in this paper is a fluorous synthesis of aryl sulfides by palladium-catalyzed cross-coupling of aryl perfluoroalkylsulfonates (C8F17O2SOAr) with thiols (RSH) under microwave irradiation. Fluorous solid-phase extractions (F-SPE) are employed for the purification of reaction mixtures. No fluorous solvents are involved in reaction and separation processes. The flu...

  11. An air-stable copper reagent for nucleophilic trifluoromethylthiolation of aryl halides

    KAUST Repository

    Weng, Zhiqiang

    2012-12-12

    A series of copper(I) trifluoromethyl thiolate complexes have been synthesized from the reaction of CuF2 with Me3SiCF 3 and S8 (see scheme; Cu red, F green, N blue, S yellow). These air-stable complexes serve as reagents for the efficient conversion of a wide range of aryl halides into the corresponding aryl trifluoromethyl thioethers in excellent yields. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Ligand-Enabled Reactivity and Selectivity in a Synthetically Versatile Aryl C–H Olefination*

    OpenAIRE

    Wang, Dong-Hui; Engle, Keary M.; Shi, Bing-Feng; Yu, Jin-Quan

    2009-01-01

    The Mizoroki–Heck reaction, which couples aryl halides with olefins, has been widely used to stitch together the carbogenic cores of numerous complex organic molecules. Given that the position-selective introduction of a halide onto an arene is not always straightforward, direct olefination of aryl C–H bonds would obviate the inefficiencies associated with generating halide precursors or their equivalents; however, methods for carrying out such a reaction have suffered from narrow substrate s...

  13. Synthesis of 5,5-Disubstituted Butenolides Based on a Pd-Catalyzed ©-Arylation Strategy

    OpenAIRE

    Hyde, Alan M.; Buchwald, Stephen L.

    2009-01-01

    Methods for the construction of quaternary carbon centers are of great interest to synthetic chemists due to their presence in natural products. Development of the Pd-catalyzed arylation of butenolides with high selectivity for the ?-position allows for a facile construction of quaternary centers. The preparation of a wide variety of ?-aryl butenolides containing a number of functional groups is outlined. An application of this chemistry for a one-pot synthesis of a tricyclic tetrahydroisoqui...

  14. Synthesis, Density Functional Theory (DFT), Urease Inhibition and Antimicrobial Activities of 5-Aryl Thiophenes Bearing Sulphonylacetamide Moieties.

    Science.gov (United States)

    Noreen, Mnaza; Rasool, Nasir; Gull, Yasmeen; Zubair, Muhammad; Mahmood, Tariq; Ayub, Khurshid; Nasim, Faiz-Ul-Hassan; Yaqoob, Asma; Zia-Ul-Haq, Muhammad; de Feo, Vincenzo

    2015-01-01

    A variety of novel 5-aryl thiophenes 4a-g containing sulphonylacetamide (sulfacetamide) groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs) analysis of all compounds 4a-g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP) mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response) were simulated at the B3LYP/6-31G (d, p) level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4g N-((5-(4-chlorophenyl)thiophen-2-yl)sulfonyl) acetamide showed excellent urease inhibition with percentage inhibition activity ~46.23 ± 0.11 at 15 µg/mL with IC50 17.1 µg/mL. Moreover, some other compounds 4a-f also exhibited very good inhibition against urease enzyme. PMID:26556326

  15. Synthesis, Density Functional Theory (DFT, Urease Inhibition and Antimicrobial Activities of 5-Aryl Thiophenes Bearing Sulphonylacetamide Moieties

    Directory of Open Access Journals (Sweden)

    Mnaza Noreen

    2015-11-01

    Full Text Available A variety of novel 5-aryl thiophenes 4a–g containing sulphonylacetamide (sulfacetamide groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT studies were performed using the B3LYP/6-31G (d, p basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs analysis of all compounds 4a–g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response were simulated at the B3LYP/6-31G (d, p level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4g N-((5-(4-chlorophenylthiophen-2-ylsulfonyl acetamide showed excellent urease inhibition with percentage inhibition activity ~46.23 ± 0.11 at 15 µg/mL with IC50 17.1 µg/mL. Moreover, some other compounds 4a–f also exhibited very good inhibition against urease enzyme.

  16. ULTRASOUND ASSISTED EFFICIENT AND GREENER ONE POT SYNTHESIS OF ARYL-14-H-DIBENZO [a,j]XANTHENE DERIVATIVES Ultraschall unterstützt effizientere und umweltfreundlichere ONE Eintopfsynthese ARYL-14-H-dibenzo [a, j] Xanthenderivate

    Directory of Open Access Journals (Sweden)

    Saurabh Puri, Balbir Kaur, Anupama Parmar and Harish Kumar

    2011-07-01

    Full Text Available Aryl-14-H-dibenzo[a,j]xanthenes have been synthesized in high yields from the condensation of aryl aldehydes and 2-napthol in presence of copper perchlorate hexahydrate as catalyst at room temperature gives aryl-14-H-dibenzo[a,j]xanthenes with excellent yields under ultrasound irradiation (35 kHz. This method has the advantages of high yield, simple methodology, greener and one pot procedure.

  17. ULTRASOUND ASSISTED EFFICIENT AND GREENER ONE POT SYNTHESIS OF ARYL-14-H-DIBENZO [a,j]XANTHENE DERIVATIVES Ultraschall unterstützt effizientere und umweltfreundlichere ONE Eintopfsynthese ARYL-14-H-dibenzo [a, j] Xanthenderivate

    OpenAIRE

    Saurabh Puri, Balbir Kaur, Anupama Parmar and Harish Kumar

    2011-01-01

    Aryl-14-H-dibenzo[a,j]xanthenes have been synthesized in high yields from the condensation of aryl aldehydes and 2-napthol in presence of copper perchlorate hexahydrate as catalyst at room temperature gives aryl-14-H-dibenzo[a,j]xanthenes with excellent yields under ultrasound irradiation (35 kHz). This method has the advantages of high yield, simple methodology, greener and one pot procedure.

  18. Selective C-Arylation of 2,5-Dibromo-3-hexylthiophene via Suzuki Cross Coupling Reaction and Their Pharmacological Aspects

    Directory of Open Access Journals (Sweden)

    Hafiz Mansoor Ikram

    2015-03-01

    Full Text Available The present study reports the synthesis of various new derivatives based on 5-aryl-2-bromo-3-hexylthiophene with moderate-to-good yields via a palladium-catalyzed Suzuki cross-coupling reaction. This coupling method involved the reaction of 2,5-dibromo-3-hexylthiophene with several arylboronic acids in order to synthesize corresponding thiophene derivatives under controlled and optimal reaction conditions. The different substituents (CH3, OCH3, Cl, F etc. present on arylboronic acids are found to have significant electronic effects on the overall properties of new products. The synthesized thiophene molecules were studied for their haemolytic, biofilm inhibition and anti-thrombolytic activities, and almost all products showed potentially good properties. The compound 2-bromo-5-(3-chloro-4-fluorophenyl-3-hexylthiophenein particular exhibited the highest values for haemolytic and bio-film inhibition activities among all newly synthesized derivatives. In addition, the compound 2-bromo-3-hexyl-5-(4-iodophenylthiophene also showed high anti-thrombolytic activity, suggesting the potential medicinal applications of these newly synthesized compounds.

  19. Palladium-Catalyzed Carbonylative alpha-Arylation of 2-Oxindoles with (Hetero)aryl Bromides : Efficient and Complementary Approach to 3-Acyl-2-oxindoles

    DEFF Research Database (Denmark)

    Lian, Zhong; Friis, Stig D.

    2014-01-01

    An efficient Pd-catalyzed carbonylative alpha-arylation of 2-oxindoles with aryl and heteroaryl bromides for the one-step synthesis of 3-acyl-2-oxindoles has been developed. This reaction proceeds efficiently under mild conditions and is complementary to the more common oxindole forming reactions. The transformation only requires a mild base and provides good to excellent yields even with heteroaromatic substrates. Employing a near stoichiometric amount of (13)COgen, the methodology was easily extended to [C-13] acyl labeling. The general applicability of the reaction conditions was demonstrated in the synthesis of a structure related to the pharmaceutically active 3-acyl-2-oxindoles, tenidap.

  20. Synthesis and NMR Studies of (E)-1-Aryl-3-(2-pyrrolyl)-2-propenones and (E)-3-Aryl-1-(2-pyrrolyl)-2-propenones

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Insook; Jeoung, Eun Ji; Lee, Chang Kiu [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2013-03-15

    Series of (E)-1-aryl-3-(2-pyrrolyl)-2-propenones, that were aldol condensation products between pyrrole-2-carbaldehyde and m- and p-substituted acetophenones, were prepared and their {sup 1}H and {sup 13}C NMR spectra were examined to obtain the information on the conformation of the enone system. Similar studies were carried out with (E)-3-aryl-1-(2-pyrrolyl)-2-propenones that were prepared from 2-acetylpyrrole and m- and p-substituted benzaldehydes. The substituent chemical shifts were studied by applying the Hammett relationship.

  1. Synthesis of aryl b-N-acetylglucosamine desmodified at C-6 as potential antimicrobial agents; Sintese de b-N-acetilglicosaminideos de arila modificados em C-6 como potenciais agentes antimicrobianos

    Energy Technology Data Exchange (ETDEWEB)

    Manfrini, Rozangela Magalhaes; Souza Filho, Jose Dias de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas; Figueireido, Rute Cunha; D' Angelis, Allison Fabiano; Prado, Maria Auxiliadora Fontes; Nunan, Elziria de Aguiar; Martins, Gabriela Aires; Alves, Ricardo Jose [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos]. E-mail: ricardodylan@farmacia.ufmg.br

    2008-07-01

    We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of Nacetylglucosamine in fungi and bacteria. None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), filamentous fungus (Aspergillus niger) and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis), at the concentration of 1 mg/mL in agar diffusion assay. (author)

  2. Síntese de beta-N-acetilglicosaminídeos de arila modificados em C-6 como potenciais agentes antimicrobianos / Synthesis of aryl beta-N-acetylglucosaminedes modified at C-6 as potential antimicrovial agents

    Scientific Electronic Library Online (English)

    Rozângela Magalhães, Manfrini; José Dias de, Souza Filho; Rute Cunha, Figueiredo; Allison Fabiano, D' Angelis; Maria Auxiliadora Fontes, Prado; Elzíria de Aguiar, Nunan; Gabriela Aires, Martins; Ricardo José, Alves.

    Full Text Available [...] Abstract in english We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of N-acetylglucosamine in fungi and bacteria. [...] None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), filamentous fungus (Aspergillus niger) and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis), at the concentration of 1 mg/mL in agar diffusion assay.

  3. Síntese de beta-N-acetilglicosaminídeos de arila modificados em C-6 como potenciais agentes antimicrobianos Synthesis of aryl beta-N-acetylglucosaminedes modified at C-6 as potential antimicrovial agents

    Directory of Open Access Journals (Sweden)

    Rozângela Magalhães Manfrini

    2008-01-01

    Full Text Available We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of N-acetylglucosamine in fungi and bacteria. None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, filamentous fungus (Aspergillus niger and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis, at the concentration of 1 mg/mL in agar diffusion assay.

  4. Synthesis and in vitro antimicrobial evaluation of 5-amino-7-aryl-6-cyano-4H- pyrano[3,2,b]pyrrole derivatives catalyzed by reusable ZrOCl2•8H2O

    Directory of Open Access Journals (Sweden)

    A. Mohammed Hussain

    2014-01-01

    Full Text Available An efficient synthesis of a new series of 5-amino-7-aryl-6-cyano-4H-pyrano[3,2-b]pyrrole derivatives from the reaction of 3-hydroxypyrrole, malononitrile, and various aromatic aldehydes using ZrOCl2·8H2O, an environmentally friendly catalyst under a thermal solvent-free green procedure is described. This simple protocol offer advantages such as shorter reaction times, simple work-up and excellent yield. The catalyst ZrOCl2·8H2O can be reused. The reusability of the catalyst has been studied for the synthesis of 5-amino-7-aryl-6-cyano-4H-pyrano[3,2-b]pyrrole. All the compounds were screened for their antibacterial and antifungal activity. DOI:http://dx.doi.org/10.4314/bcse.v28i1.11

  5. Copper oxide nanoparticle-catalyzed coupling of diaryl diselenide with aryl halides under ligand-free conditions.

    Science.gov (United States)

    Reddy, Vutukuri Prakash; Kumar, Akkilagunta Vijay; Swapna, Kokkirala; Rao, Kakulapati Rama

    2009-02-19

    A new, efficient and ligand-free cross-coupling reaction of aryl halides and diaryl diselenides using a catalytic amount of nanocrystalline CuO as a recyclable catalyst with KOH as the base in DMSO at 110 degrees C is reported. This protocol has been utilized for the synthesis of a variety of aryl selenides in excellent yields from the readily available aryl halides and diaryl diselenides. PMID:19182886

  6. Directing/Protecting-Group-Free Synthesis of Tetraaryl-Substituted Pyrazoles through Four Direct Arylations on an Unsubstituted Pyrazole Scaffold.

    Science.gov (United States)

    Fuse, Shinichiro; Morita, Taiki; Johmoto, Kohei; Uekusa, Hidehiro; Tanaka, Hiroshi

    2015-10-01

    A directing/protecting-group-free synthesis of 1,3,4,5-tetraaryl-substituted pyrazoles was achieved through four transition metal-catalyzed direct arylations. Various pyrazoles with four different aryl rings were obtained using readily available reagents from an unsubstituted pyrazole. Two aryl-substituted pyrazoles showed intense violet fluorescence, high quantum yields (?f =0.68, 0.64), and large Stokes shifts (19000, 15200?cm(-1) ). PMID:26330168

  7. A general strategy for organocatalytic activation of C-H bonds via photoredox catalysis: direct arylation of benzylic ethers.

    Science.gov (United States)

    Qvortrup, Katrine; Rankic, Danica A; MacMillan, David W C

    2014-01-15

    Direct C-H functionalization and arylation of benzyl ethers has been accomplished via photoredox organocatalysis. The productive merger of a thiol catalyst and a commercially available iridium photoredox catalyst in the presence of household light directly affords benzylic arylation products in good to excellent yield. The utility of this methodology is further demonstrated in direct arylation of 2,5-dihydrofuran to form a single regioisomer. PMID:24341523

  8. Merging Photoredox and Nickel Catalysis: The Direct Synthesis of Ketones by the Decarboxylative Arylation of ?-Oxo Acids.

    Science.gov (United States)

    Chu, Lingling; Lipshultz, Jeffrey M; MacMillan, David W C

    2015-06-26

    The direct decarboxylative arylation of ?-oxo acids has been achieved by synergistic visible-light-mediated photoredox and nickel catalysis. This method offers rapid entry to aryl and alkyl ketone architectures from simple ?-oxo acid precursors via an acyl radical intermediate. Significant substrate scope is observed with respect to both the oxo acid and arene coupling partners. This mild decarboxylative arylation can also be utilized to efficiently access medicinal agents, as demonstrated by the rapid synthesis of fenofibrate. PMID:26014029

  9. Synthesis of novel 1,2-benzothiazine 1,1-dioxide-3-ethanone oxime N-aryl acetamide ether derivatives as potent anti-inflammatory agents and inhibitors of monocyte-to-macrophage transformation.

    Science.gov (United States)

    Gannarapu, Malla Reddy; Vasamsetti, Sathish Babu; Punna, Nagender; Royya, Naresh Kumar; Pamulaparthy, Shanthan Rao; Nanubolu, Jagadeesh Babu; Kotamraju, Srigiridhar; Banda, Narsaiah

    2014-03-21

    A series of novel 1,2-benzothiazine 1,1-dioxide-3-ethanone oxime N-aryl acetamide ether derivatives 7a-h and 9a-h were synthesized starting from sodium salt of saccharin 1 in series of steps. Final compounds 7a-h and 9a-h were evaluated for the anti-inflammatory activity and their ability to inhibit monocyte-to-macrophage transformation. Compounds 7e, 9b, 9e and 9h showed impressive anti-inflammatory activities (TNF-?, IL-8 and MCP-1) at micro molar concentration which was found to be better than positive control i.e., piroxicam. Compound 9e marginally and compound 9h significantly inhibited PMA-induced MMP-9 gelatinase activity. Also compounds 9e and 9h greatly inhibited the PMA-induced monocyte-to-macrophage transformation, a pre-requisite step in the formation of atheroma. PMID:24531227

  10. Toxicological implications of polymorphisms in receptors for xenobiotic chemicals: The case of the aryl hydrocarbon receptor

    International Nuclear Information System (INIS)

    Mechanistic toxicology has predominantly been focused on adverse effects that are caused by reactive metabolites or by reactive oxygen species. However, many important xenobiotics exert their toxicity, not by generating reactive products, but rather by altering expression of specific genes. In particular, some environmental contaminants target nuclear receptors that function as regulators of transcription. For example, binding of xenobiotic chemicals to steroid receptors is a principle mechanism of endocrine disruption. The aryl hydrocarbon receptor (AHR) mediates toxicity of dioxin-like compounds. In mice, a polymorphism in the AHR ligand-binding domain reduces binding affinity by about 10-fold in the DBA/2 strain compared with the C57BL/6 strain; consequently, dose-response curves for numerous biochemical and toxic effects are shifted about one log to the right in DBA/2 mice. In the Han/Wistar (Kuopio) (H/W) rat strain, a polymorphism causes a deletion of 38 or 43 amino acids from the AHR transactivation domain. This deletion is associated with a greater than 1000-fold resistance to lethality from 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Genes in the conventional AH gene battery (e.g. CYP1A1, CYP1A2, CYP1B1, ALDH3A1, NQO1 and UGT1A1) remain responsive to TCDD in H/W rats despite the large deletion. However, the deletion may selectively alter the receptor's ability to dysregulate specific genes that are key to dioxin toxicity. We are identifying these genes using an expression array approach in dioxin-sensitive vs. dioxin-resistant rat strains and lines. Polymorphisms exist in the human AH receptor, but thus far they have not been shown to have any substantial effect on human responses to AHR-ligands

  11. Synthesis and aryl hydrocarbon receptor binding properties of radiolabeled polychlorinated dibenzofuran congeners

    International Nuclear Information System (INIS)

    Microchlorination of 1,4,9[3H]dibenzofuran gave several polychlorinated dibenzofuran (PCDF) products and 2,3,7,8-[3H]tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-[3H]pentachlorodibenzofuran (PeCDF), and 1,2,3,6,7,8-/1,2,3,4,7,8-hexachlorodibenzofuran (HCDF) of high specific activity (57, 34, and 32.5 Ci/mmol, respectively) were purified by preparative high-pressure liquid chromatography. These compounds were investigated as radioligands for the rat liver cytosolic aryl hydrocarbon (Ah) receptor protein. Like 2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin (TCDD), the radiolabeled PCDF congeners exhibited saturable binding with the receptor protein and sucrose density gradient analysis of the radiolabeled ligand-receptor complexes gave specific binding peaks with comparable sedimentation profiles. The rank order of radioligand binding affinities (Kd values) was 2,3,7,8-TCDD greater than 2,3,7,8-TCDF greater than 1,2,3,6,7,8-HCDF greater than 1,2,3,7,8-PeCDF and the maximum difference in Kd values for the four radioligands was less than 13-fold (0.44-5.9 nM). The interactions of the PCDF radioligands with the cytosolic receptor all exhibited saturable binding curves and linear Scatchard plots and the slopes of their Hill plots were in the range 1.0-1.1, thus indicating that cooperativity was not a factor in these binding interactions. The relative stabilities and dissociation kinetics of the radioligand-receptor complexes were highly dependent on the structure of the radioligand. The dissociation curves of the 2,3,7,8-[3H]TCDD and PCDF receptor complexes were biphasic and this suggests that there may be a temporal shift in ligand binding affinities. However, the rates of dissociation did not correlate with the rank order of ligand binding affinities

  12. Harman induces CYP1A1 enzyme through an aryl hydrocarbon receptor mechanism

    International Nuclear Information System (INIS)

    Harman is a common compound in several foods, plants and beverages. Numerous studies have demonstrated its mutagenic, co-mutagenic and carcinogenic effects; however, the exact mechanism has not been fully identified. Aryl hydrocarbon receptor (AhR) is a transcription factor regulating the expression of the carcinogen-activating enzyme; cytochrome P450 1A1 (CYP1A1). In the present study, we examined the ability of harman to induce AhR-mediated signal transduction in human and rat hepatoma cells; HepG2 and H4IIE cells. Our results showed that harman significantly induced CYP1A1 mRNA in a time- and concentration-dependent manner. Similarly, harman significantly induced CYP1A1 at protein and activity levels in a concentration-dependent manner. Moreover, the AhR antagonist, resveratrol, inhibited the increase in CYP1A1 activity by harman. The RNA polymerase inhibitor, actinomycin D, completely abolished the CYP1A1 mRNA induction by harman, indicating a transcriptional activation. The role of AhR in CYP1A1 induction by harman was confirmed by using siRNA specific for human AhR. The ability of harman to induce CYP1A1 was strongly correlated with its ability to stimulate AhR-dependent luciferase activity and electrophoretic mobility shift assay. At post-transcriptional and post-translational levels, harman did not affect the stability of CYP1A1 at the mRNA and the protein levels, excluding other mechanisms participating in the obtained effects. We concluded that harman can directly induce CYP1A1 gene expression in an AhR-dependent manner and may represent a novel mechanism by which harman promotes mutagenicity, co-mutagenicity and carcinogenicity.

  13. What Are the Potential Sites of Protein Arylation by N-Acetyl-p-benzoquinone Imine (NAPQI)?

    Science.gov (United States)

    Leeming, Michael G; Gamon, Luke F; Wille, Uta; Donald, William A; O'Hair, Richard A J

    2015-11-16

    Acetaminophen (paracetamol, APAP) is a safe and widely used analgesic medication when taken at therapeutic doses. However, APAP can cause potentially fatal hepatotoxicity when taken in overdose or in patients with metabolic irregularities. The production of the electrophilic and putatively toxic compound N-acetyl-p-benzoquinone imine (NAPQI), which cannot be efficiently detoxicated at high doses, is implicated in APAP toxicity. Numerous studies have identified that excess NAPQI can form covalent linkages to the thiol side chains of cysteine residues in proteins; however, the reactivity of NAPQI toward other amino acid side chains is largely unexplored. Here, we report a survey of the reactivity of NAPQI toward 11 N-acetyl amino acid methyl esters and four peptides. (1)H NMR analysis reveals that NAPQI forms covalent bonds to the side-chain functional groups of cysteine, methionine, tyrosine, and tryptophan residues. Analogous reaction products were observed when NAPQI was reacted with synthetic model peptides GAIL-X-GAILR for X = Cys, Met, Tyr, and Trp. Tandem mass spectrometry peptide sequencing showed that the NAPQI modification sites are located on the "X" residue in each case. However, when APAP and the GAIL-X-GAILR peptide were incubated with rat liver microsomes that contain many metabolic enzymes, NAPQI formed by oxidative metabolism reacted with GAIL-C-GAILR exclusively. For the peptides where X = Met, Tyr, and Trp, competing reactions between NAPQI and alternative nucleophiles precluded arylation of the target peptide by NAPQI. Although Cys residues are favorably targeted under these conditions, these data suggest that NAPQI can, in principle, also damage proteins at Met, Tyr, and Trp residues. PMID:26523953

  14. Association between polymorphisms in the aryl hydrocarbon receptor repressor gene and disseminated testicular germ cell cancer

    DEFF Research Database (Denmark)

    Brokken, Leon J S; Lundberg-Giwercman, Yvonne

    2013-01-01

    In the Western world, testicular germ cell cancer (TGCC) is the most common malignancy of young men. The malignant transformation of germ cells is thought to be caused by developmental and hormonal disturbances, probably related to environmental and lifestyle factors because of rapidly increasing incidence of TGCC in some countries. Additionally, there is a strong genetic component that affects susceptibility. However, genetic polymorphisms that have been identified so far only partially explain the risk of TGCC. Many of the persistent environmental pollutants act through the aryl hydrocarbon receptor (AHR). AHR signaling pathway is known to interfere with reproductive hormone signaling, which is supposed to play a role in the pathogenesis and invasive progression of TGCC. The aim of the present study was to identify whether AHR-related polymorphisms were associated with risk as well as histological and clinical features of TGCC in 367 patients and 537 controls. Haplotype-tagging single-nucleotide polymorphisms (SNPs) were genotyped in genes encoding AHR and AHR repressor (AHRR). Binary logistic regression was used to calculate the risk of TGCC, non-seminoma versus seminoma, and metastasis versus localized disease. Four SNPs in AHRR demonstrated a significant allele association with risk to develop metastases (rs2466287: OR = 0.43, 95% CI 0.21-0.90; rs2672725: OR = 0.49, 95% CI: 0.25-0.94; rs6879758: OR = 0.27, 95% CI: 0.08-0.92; rs6896163: OR = 0.34, 95% CI: 0.12-0.98). This finding supports the hypothesis that compounds acting through AHR may play a role in the invasive progression of TGCC, either directly or through modification of reproductive hormone action.

  15. Evodiamine as a novel antagonist of aryl hydrocarbon receptor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hui [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Department of Laboratory Medicine, The Affiliated Tenth People' s Hospital, Tongji University, Shanghai 200072 (China); Tu, Yongjiu; Zhang, Chun; Fan, Xia; Wang, Xi [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Wang, Zhanli [College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014 (China); Liang, Huaping, E-mail: huaping_liang@yahoo.com.cn [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China)

    2010-11-05

    Research highlights: {yields} Evodiamine interacted with the AhR. {yields} Evodiamine inhibited the specific binding of [{sup 3}H]-TCDD to the AhR. {yields} Evodiamine acts as an antagonist of the AhR. -- Abstract: Evodiamine, the major bioactive alkaloid isolated from Wu-Chu-Yu, has been shown to interact with a wide variety of proteins and modify their expression and activities. In this study, we investigated the interaction between evodiamine and the aryl hydrocarbon receptor (AhR). Molecular modeling results revealed that evodiamine directly interacted with the AhR. Cytosolic receptor binding assay also provided the evidence that evodiamine could interact with the AhR with the K{sub i} value of 28.4 {+-} 4.9 nM. In addition, we observed that evodiamine suppressed the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced nuclear translocation of the AhR and the expression of CYP1A1 dose-dependently. These results suggested that evodiamine was able to bind to the AhR as ligand and exhibit antagonistic effects.

  16. In vitro cytotoxicity and apoptotic inducing activity of the synthesized 4-aryl-4H-chromenes derivatives against human cancer cell lines

    Directory of Open Access Journals (Sweden)

    Mohagheghi MA

    2009-09-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: 4-Aryl-4H-chromenes are novel anticancer agents which induce apoptosis in cancer cells. These compounds were found to induce apoptosis by targeting the tubulin/microtubule system in cell proliferation process. The aim of this study was to report cyototoxic and apoptosis inducing activities of a new series of synthesized 4-aryl-4H-chromenes compounds."n"n Methods: The in vitro cytotoxic activity of the synthesized 4-aryl-4H-chromenes was investigated against a paned of human cancer cell lines including MCF-7 (breast carcinoma, A549 (lung carcinoma, HEPG-2 (liver carcinoma, SW-480 (colon adenocarcinoma, U87-MG (glioblastoma, 1321N1 (astrocytoma, and DAOY (medulloblastoma. The percentage of growth inhibitory activity was evaluated using MTT colorimetric assay versus controls not treated with test derivatives. The data for etoposide, a well known anticancer drug, was included for comparison. For each compound, the 50% inhibitory concentration (IC50 were determined. Apoptosis inducing activity were assessed by DAPI staining."n"n Results: Preliminary screening showed that those chromenes analogs bearing phenyl-isoxazole-3-yl substitution or the derivatives containing methoxyphenyl in chromene ring exhibited cytotoxic and apoptotic inducing activity comparable with or even superior than the reference drug, etoposide. The compounds without this type of substitution have lower activity. "n"nConclusions: Replacement of 3, 4, 5-trimethoxyphenyl group with thiazol ring in the synthesized derivatives reduced the cytotoxic activity. However, the derivatives with phenyl-isoxazole analogue showed potent cytotoxic and apoptotic inducing activity.

  17. Synthesis and antibacterial activity of tert-butyl [1-benzyl-2[(4-aryl-2-thiazolyl)hydrazono]ethyl]carbamate derivatives.

    Science.gov (United States)

    Turan-Zitouni, Gülhan; Fehrentz, Jean-Alain; Chevallet, Pierre; Martinez, Jean; Kaplancikli, Zafer Asim; Ozdemir, Ahmet; Arslanyolu, Muhittin; Yildiz, Mehmet Taha

    2007-06-01

    The increasing clinical importance of drug-resistant fungal and bacterial pathogens has lent additional urgency to microbiological research and new antibacterial compound development. For this purpose, new tert-butyl[1-benzyl-2[(4-aryl-2-thiazolyl)hydrazono]ethyl]carbamate derivatives were synthesized and evaluated for antibacterial activity. The reaction of Boc-L-phenylalaninal with thiosemicarbazide gave the thiosemicarbazone which furnished the title compounds by reaction with phenacyl bromides. The newly synthesized compounds were screened for antibacterial activity and toxicity. While microdilution broth susceptibility assay was used for the antibacterial activity evaluation of the compounds against the strains E. coli (NRRL B-3704), M. luteus (NRRL B-4375), B. cereus (NRRL B-3711), P. aeruginosa (NRRL B-23), and S. fecalis (NRRL B-14617), the Artemia salina 96-well assay was used to determine cytotoxicities of the compounds. Observations obtained from the bioassays showed that some of the compounds are highly active against E. coli, M. luteus, and B. cereus when compared with the control agent and showed low toxicity. PMID:17562564

  18. Aryl sulfate formation in sea urchins (Strongylocentrotus droebachiensis) ingesting marine algae (Fucus distichus) containing 2,6-dimethylnapthalene

    International Nuclear Information System (INIS)

    The metabolism of tritiated 2,6-dimethylnapthalene (2,6-DMN) was studied in sea urchins (Strongylocentrotus droebachiensis) feeding on marine algae (Fucus distichus). The Fucus accumulated this hydrocarbon from sea water without converting it to metabolites. Most of the tritium accumulated by the sea urchins (e.g., 70.8% after 3 days) from feeding on 2,6-DMN-exposed Fucus was present in the exoskeleton (shell and spines). Moreover, after 3 days feeding, about 90% of the tritium in the total metabolite fraction of the gonads and digestive tract of the sea urchin was present as sulfate derivatives. These metabolites were identified through hydrolysis with aryl sulfatase, followed by thin-layer chromatography of the products. After 14 days of feeding, the tritium associated with the sulfate derivatives decreased in the gonads and digestive tract to 61 and 65%, respectively, of the total metabolite fraction. Hydroxy compounds from sulfatase hydrolysis were chromatographed using multiple elutions with toluene. The hydroxy isomers were separated and the R/sub f/ values were compared to those of pure reference compounds. The data indicated that 80% of the 2,6-dimethylnaphtyl sulfate contained the sulfate on the 1 and/or 3 position of the aromatic ring. Moreover, 6-methyl-2-naphthalenemethanol was not detected, which implies that sea urchins, unlike fish, metabolize alkyl-substituted aromatic hydrocarbons primarily through aromatic ring oxidations

  19. Expedient synthesis of C-aryl carbohydrates by consecutive biocatalytic benzoin and aldol reactions.

    Science.gov (United States)

    Hernández, Karel; Parella, Teodor; Joglar, Jesús; Bujons, Jordi; Pohl, Martina; Clapés, Pere

    2015-02-16

    The introduction of aromatic residues connected by a C-C bond into the non-reducing end of carbohydrates is highly significant for the development of innovative structures with improved binding affinity and selectivity (e.g., C-aril-sLex). In this work, an expedient asymmetric "de novo" synthetic route to new aryl carbohydrate derivatives based on two sequential stereoselectively biocatalytic carboligation reactions is presented. First, the benzoin reaction of aromatic aldehydes to dimethoxyacetaldehyde is conducted, catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I. Then, the ?-hydroxyketones formed are reduced by using NaBH4 yielding the anti diol. After acetal hydrolysis, the aldol addition of dihydroxyacetone, hydroxyacetone, or glycolaldehyde catalyzed by the stereocomplementary D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase is performed. Both aldolases accept unphosphorylated donor substrates, avoiding the need of handling the phosphate group that the dihydroxyacetone phosphate-dependent aldolases require. In this way, 6-C-aryl-L-sorbose, 6-C-aryl-L-fructose, 6-C-aryl-L-tagatose, and 5-C-aryl-L-xylose derivatives are prepared by using this methodology. PMID:25640727

  20. Enhanced interfacial properties of carbon fiber composites via aryl diazonium reaction “on water”

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuwei [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Meng, Linghui [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Fan, Liquan [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Ma, Lichun; Qi, Meiwei; Yu, Jiali [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Huang, Yudong, E-mail: ydhuang.hit1@yahoo.com.cn [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China)

    2014-10-15

    Highlights: • Carbon fibers are grafted with phenyl amine group via aryl diazonium reaction. • Interfacial shear strength of the carbon fibers increases by 73%. • Tensile strength of the carbon fibers does not decrease distinctly. • Using water as the reaction medium can avoid pollution from organic solvents. • Grafting via aryl diazonium reaction in one step can improve modification efficiency. - Abstract: Polyacrylonitrile-based carbon fibers were functionalized with phenyl amine group via aryl diazonium reaction “on water” to improve their interfacial bonding with resin matrix. Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were employed to characterize ordered degree, functional groups, chemical states and morphology of carbon fiber surface, respectively. The results showed that phenyl amine groups were grafted on the fiber surface successfully. Mechanical property test results indicated that the aryl diazonium reaction in this paper could improve the interfacial shear strength by 73%, while the tensile strength was down very slightly. Hence aryl diazonium reaction “on water” could be a facile green platform to functionalize carbon fibers for many interesting applications.

  1. Enhanced interfacial properties of carbon fiber composites via aryl diazonium reaction “on water”

    International Nuclear Information System (INIS)

    Highlights: • Carbon fibers are grafted with phenyl amine group via aryl diazonium reaction. • Interfacial shear strength of the carbon fibers increases by 73%. • Tensile strength of the carbon fibers does not decrease distinctly. • Using water as the reaction medium can avoid pollution from organic solvents. • Grafting via aryl diazonium reaction in one step can improve modification efficiency. - Abstract: Polyacrylonitrile-based carbon fibers were functionalized with phenyl amine group via aryl diazonium reaction “on water” to improve their interfacial bonding with resin matrix. Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were employed to characterize ordered degree, functional groups, chemical states and morphology of carbon fiber surface, respectively. The results showed that phenyl amine groups were grafted on the fiber surface successfully. Mechanical property test results indicated that the aryl diazonium reaction in this paper could improve the interfacial shear strength by 73%, while the tensile strength was down very slightly. Hence aryl diazonium reaction “on water” could be a facile green platform to functionalize carbon fibers for many interesting applications

  2. Computational Study on the Acid Catalyzed Reactions of Fluorine-Containing 2,4-Dialkoxy-3,4-dihydro-2H-pyrans with Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Norio Ota

    2012-02-01

    Full Text Available The reaction of 2,4-diethoxy-6-trifluoromethyl-3,4-dihydro-2H-pyran (1 with aromatic compounds in refluxing acetonitrile in the presence of p-toluenesulfonic acid gave the mixture of 4-aryl-2-trifluoromethyl-4H-pyrans (3 and 6-aryl-1,1,1-trifluorohexa-3,5-dien-2-ones (4. In contrast, the same reaction carried out in trifluoroacetic acid at ambient temperature afforded 4-aryl-2-ethoxy-6-trifluoromethyl-3,4-dihydro-2H-pyrans (2 selectively. These two types of reactions giving quite different products under each condition were studied on the basis of DFT calculations. Moreover, the proposed mechanism for the reaction of 5-trifluoroacetyl-6-trifluoromethyl-3,4-dihydro-2H-pyran (5 with aromatic compounds affording butadiene derivatives (6 exclusively was also discussed based on the calculations and comparison with the reactivity of pyrylium intermediate (7.

  3. Catalytic enantioselective arylations: boron to zinc exchange as a powerful tool for the generation of transferable aryl groups

    Scientific Electronic Library Online (English)

    Márcio W., Paixão; Antonio L., Braga; Diogo S., Lüdtke.

    Full Text Available A transmetalação entre boro e zinco apresenta uma grande importância para diversas aplicações em síntese orgânica, uma vez que permite a formação de novas ligações carbono-carbono entre reagentes organometálicos e espécies eletrofílicas. A arilação direta de aldeídos e, mais raramente de cetonas, de [...] maneira catalítica e enantiosseletiva, empregando catalisadores quirais, têm sido descrita recentemente. Os diaril metanóis opticamente enriquecidos, obtidos nessas reações são precursores valiosos para a síntese de moléculas bioativas. O presente trabalho apresenta uma revisão sobre essa crescente área de atuação e destaca alguns dos desafios que ainda permanecem. Abstract in english The transmetalation between boron and zinc is of great importance for application in organic synthesis, since it allows the formation of new carbon-carbon bonds between organometallic units and electrophiles. The direct arylation of aldehydes or more scarcely ketones, in a catalytic, enantioselectiv [...] e manner using chiral catalysts has been described recently. The enantiomerically enriched diarylmethanols obtained in these reactions are valuable precursors for important bioactive molecules. This review provides a synopsis of this ever-growing field and highlights some of the challenges that still remain.

  4. Synthesis and evaluation of 2-(5-(aryl)-1,3,4-oxadiazol-2-ylthio)-N-(3-(trifluoromethyl)phenyl)acetamides and N-(4-chloro-3-fluorophenyl)-2-(5-(aryl)-1,3,4-oxadiazol-2-ylthio)acetamides as antimicrobial agents

    Indian Academy of Sciences (India)

    Kalpesh Parikh; Deepkumar Joshi

    2014-05-01

    A series of 2-mercapto-5-phenyl-1,3,4-oxadiazole derivatives have been condensed with different phenyl acetamide derivatives possessing fluorine atom at meta position; resulting in the formation of 2-(5-aryl- 1,3,4-oxadiazol-2-ylthio)-N-(3-(trifluoromethyl)phenyl)acetamide (5a-j) and N-(4-chloro-3-fluorophenyl)-2-(5-aryl-1,3,4-oxadiazol-2-ylthio)acetamide (5k-t) derivatives. The antimicrobial properties of the synthesized entities (5a-t) measured as their MIC (Minimum Inhibitory Concentration) values were evaluated by using the broth dilution method against Gram-positive bacteria (S. aureus and E. faecalis), Gram-negative bacteria (E. coli and P. aeruginosa) and fungi (C. albicans and A. niger). The results of antimicrobial activities (in g/ml) revealed the fact that the compounds 5a and g bearing a maximum number of fluorine atoms showed the highest potency among the synthesized compounds against the broad panel of bacterial and fungal strains. The presence of fluorine atom at the meta position in the phenyl ring of final derivatives (5a-t) brought about an enhancement of their antimicrobial properties to a notable extent.

  5. Intramolecular Acylation of Aryl- and Aroyl-Aliphatic Acids by the Action of Pyrophosphoryl Chloride and Phosphorus Oxychloride

    Directory of Open Access Journals (Sweden)

    Saleh Rayyan

    2001-03-01

    Full Text Available Both pyrophosphoryl chloride and phosphorus oxychloride react with aryl aliphatic acids to form mixed anhydrides which undergo intramolecular acylation to afford cyclic ketones without the addition of a Friedel-Crafts catalyst. Aryl and aroylbenzoic acids could be cyclized to the corresponding anthrones and anthraquinones respectively.

  6. A solution to the 2-pyridyl organometallic cross-coupling problem: regioselective catalytic direct arylation of pyridine N-oxides.

    OpenAIRE

    Campeau, LC; Rousseaux, S.; Fagnou, K

    2005-01-01

    Direct arylation reactions of pyridine N-oxides occur in excellent yield with complete selectivity for the 2-position with a wide range of aryl bromides. This reactivity permits the use of inexpensive, commercially available, and bench-stable pyridine N-oxides as replacements for problematic 2-metallapyridines in palladium-catalyzed cross-coupling reactions.

  7. A Copper-Catalyzed Formal [3 + 2]-Cycloaddition for the Synthesis of All Different Aryl-Substituted Furans and Thiophenes.

    Science.gov (United States)

    Ishikawa, Shingo; Noda, Yushi; Wada, Masaru; Nishikata, Takashi

    2015-08-01

    A highly efficient formal [3 + 2]-cycloaddition was established using a copper catalyst. The resulting dihydrofurans were subjected to oxidation followed by arylations to produce tetraarylfurans. In addition, the dihydrofuran can be converted to diaryldihydrothiophene by using Lawesson's reagent. This protocol will facilitate the synthesis of all different aryl-substituted furans and thiophenes. PMID:26158487

  8. A Convenient Palladium-Catalyzed Carbonylative Suzuki Coupling of Aryl Halides with Formic Acid as the Carbon Monoxide Source.

    Science.gov (United States)

    Qi, Xinxin; Jiang, Li-Bing; Li, Hao-Peng; Wu, Xiao-Feng

    2015-12-01

    A practical palladium-catalyzed carbonylative Suzuki coupling of aryl halides under carbon monoxide gas-free conditions has been developed. Here, formic acid was utilized as the carbon monoxide source for the first time with acetic anhydride as the additive. A variety of diarylketones were produced in moderate to excellent yields from the corresponding aryl halides and arylboronic acids. PMID:26486227

  9. Dithiocarbamate promoted practical synthesis of N-Aryl-2-aminobenzazoles: Synthesis of novel Aurora-A kinase inhibitor

    Indian Academy of Sciences (India)

    Naresh Kumar Katari; M Venkatanarayana; Kummari Srinivas

    2015-03-01

    Various N-aryl-2-aminobenzoxazoles and N-aryl-2-aminobenzothiazoles were synthesized from o-aminophenol and o-aminothiophenol, respectively, mediated by dithiocarbamate in one step. The salient features of this method include mild reaction condition, high yield and large scale synthesis. Application of this methodology has been demonstrated by synthesizing potent Aurora kinase-A inhibitors.

  10. Aryl(sulfonyl)amino group: a convenient and stable yet activated modification of amino group for its intramolecular displacement.

    Science.gov (United States)

    Kato, Yuzo; Yen, Dinh Hoang; Fukudome, Yasuhiro; Hata, Takeshi; Urabe, Hirokazu

    2010-09-17

    Aryl(sulfonyl)amino groups, readily derived from sulfonyl- or arylamines by standard methods as well as the recently introduced methods of sulfonylation and arylation, proved to be good leaving groups in intramolecular substitution reactions by various nitrogen, oxygen, and carbon nucleophiles. PMID:20734982

  11. Sulfonylation of quinoline N-oxides with aryl sulfonyl chlorides via copper-catalyzed C-H bonds activation.

    Science.gov (United States)

    Wu, Zhiyong; Song, Hongyu; Cui, Xiuling; Pi, Chao; Du, Weiwei; Wu, Yangjie

    2013-03-15

    An efficient and concise one-pot protocol to synthesize sulfonylated quinoline N-oxides via copper-catalyzed C-H bond activation has been developed. Commercially available and less expensive aryl sulfonyl chlorides were used as the sulfonylation reagents. Various 2-aryl sulfonyl quinolines were obtained in up to 91% yields in chemo- and regioselective manners. PMID:23461790

  12. Copper-Catalyzed N-Arylation of Amides Using (S-N-Methylpyrrolidine-2-carboxylate as the Ligand

    Directory of Open Access Journals (Sweden)

    Dong-Sheng Ma

    2010-03-01

    Full Text Available (S-N-methylpyrrolidine-2-carboxylate, a derivative of natural L-proline, was found to be an efficient ligand for the copper-catalyzed Goldberg-type N-arylation of amides with aryl halides under mild conditions. A variety of N-arylamides were synthesized in good to high yields.

  13. Homocoupling of aryl halides in flow: Space integration of lithiation and FeCl3 promoted homocoupling

    Directory of Open Access Journals (Sweden)

    Aiichiro Nagaki

    2011-08-01

    Full Text Available The use of FeCl3 resulted in a fast homocoupling of aryllithiums, and this enabled its integration with the halogen–lithium exchange reaction of aryl halides in a flow microreactor. This system allows the homocoupling of two aryl halides bearing electrophilic functional groups, such as CN and NO2, in under a minute.

  14. Regioselective Multi-component Synthesis of 7-Aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-diones Catalyzed by n-Propylsulfonated ?-Al2O3

    International Nuclear Information System (INIS)

    We have developed a straightforward method for the synthesis of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b] quinazoline-5,6-dione derivatives by nano n-propylsulfonated ?-Al2O3 catalyzed three-component reaction of aldehyde, 2-hydroxy-1,4-naphthoquinone and 3-amino-1,2,4-triazole. A series of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-dione derivatives have been synthesized in excellent yield (85-96%). The catalyst can be recycled up to six cycles without much decrease in catalytic activity. Environment friendly catalyst, high regioselectivity and good yield are the advantages of the method. To the best of our knowledge this is the first report on synthesis of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-dione derivatives. We are evaluating anticancer activity of 4, which will be published elsewhere. Naphthoquinones constitute a major class of naturally occurring compounds, and interests in their chemistry continues unabated because of their wide range of biological and therapeutic properties such as antioxidant, antifungal, anti-inflammatory, antiallergic, antiviral, and anticancer activity

  15. Regioselective Multi-component Synthesis of 7-Aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-diones Catalyzed by n-Propylsulfonated ?-Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weilin; Tian, Shuanbao; Wu, Liqiang [Xinxiang Medical Univ., Xinxiang (China)

    2013-09-15

    We have developed a straightforward method for the synthesis of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b] quinazoline-5,6-dione derivatives by nano n-propylsulfonated ?-Al{sub 2}O{sub 3} catalyzed three-component reaction of aldehyde, 2-hydroxy-1,4-naphthoquinone and 3-amino-1,2,4-triazole. A series of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-dione derivatives have been synthesized in excellent yield (85-96%). The catalyst can be recycled up to six cycles without much decrease in catalytic activity. Environment friendly catalyst, high regioselectivity and good yield are the advantages of the method. To the best of our knowledge this is the first report on synthesis of 7-aryl-benzo[h][1,2,4]-triazolo[5,1-b]quinazoline-5,6-dione derivatives. We are evaluating anticancer activity of 4, which will be published elsewhere. Naphthoquinones constitute a major class of naturally occurring compounds, and interests in their chemistry continues unabated because of their wide range of biological and therapeutic properties such as antioxidant, antifungal, anti-inflammatory, antiallergic, antiviral, and anticancer activity.

  16. Intramolecular Direct Arylation of 3-Halo-2-pyrones and 2-Coumarins.

    Science.gov (United States)

    Nolan, Marie-T; Pardo, Leticia M; Prendergast, Aisling M; McGlacken, Gerard P

    2015-11-01

    Direct arylation represents a favorable alternative to traditional cross-coupling and has found widespread use with simple aryls and robust heterocycles. Herein a direct arylation protocol has been optimized and applied to 2-pyrones, which are delicate and privileged biological motifs. Regioselective halogenation at the 3-position allows intramolecular coupling by activation of a pyrone C-Br or C-Cl bond and a phenoxy C-H bond. Importantly, electron-poor phenoxy substrates also worked well. The methodology was extended to 2-coumarins and applied to the synthesis of flemichapparin C and a novel analogue. Deuterium isotope effects, typical of a concerted metalation-deprotonation (CMD) mechanism, were observed in the case of a bromopyrone, but a highly unusual, inverse kinetic isotope effect was evident using a chlorocoumarin, implying that a different mechanism is operating. PMID:26491882

  17. Highly Efficient Synthesis of 2-Aryl-3-methoxyacrylates via Suzuki-Miyaura Coupling Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Ho; Lee, Chun Ho; Song, Young Seob; Park, No Kyun; Kim, Bum Tae; Heo, Jung Nyoung [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2006-02-15

    We have developed a highly efficient and convergent synthesis of 2-aryl-3-methoxyacrylates via the Suzuki-Miyaura coupling reaction of ?-iodo-?-methoxy-acrylate with arylboronic acids. The biological activities of 2-aryl-3-methoxyacrylate derivatives will be reported in due course. The Suzuki-Miyaura coupling reaction provides a convenient access to the carbon-carbon bond formation with high efficiency. Recently, a number of 2-aryl-3-methoxy-acrylates served as a key scaffold for the development of biologically active pharmaceuticals and agrochemicals. Especially, the discovery of the naturally-occurring fungicides, such as strobilurin A and oudemansin A, possessing a ?-methoxyacrylate moiety was immediately seized great attention by industrial research groups to open a new era of the strobilurin family including azoxy-strobin and picoxystrobin.

  18. N-aryl pyrrolo-tetrathiafulvalene based ligands: synthesis and metal coordination.

    Science.gov (United States)

    Balandier, Jean-Yves; Chas, Marcos; Dron, Paul I; Goeb, Sébastien; Canevet, David; Belyasmine, Ahmed; Allain, Magali; Sallé, Marc

    2010-03-01

    A straightforward general synthetic access to N-aryl-1,3-dithiolo[4,5-c]pyrrole-2-thione derivatives 6 from acetylenedicarbaldehyde monoacetal is depicted. In addition to their potentiality as precursors to dithioalkyl-pyrrole derivatives, thiones 6 are key building blocks to N-aryl monopyrrolo-tetrathiafulvalene (MPTTF) derivatives 10. X-ray structures of four of these thiones intermediates, reminiscent of the corresponding MPTTF derivatives, are provided. When the aryl group is a binding pyridyl unit, the MPTTF derivative 10a can coordinate M(II) salts (M = Pt, Pd). The first examples of metal-directed orthogonal MPTTF-based dimers 11-14, obtained through coordination of 10a to cis-blocked square planar Pt or Pd complexes are described. Studies on the parameters influencing the dimer construction are presented, as well as first recognition properties of the resulting electron-rich clip for C(60). PMID:20143799

  19. Aromatic stacking interactions govern catalysis in aryl-alcohol oxidase.

    Science.gov (United States)

    Ferreira, Patricia; Hernández-Ortega, Aitor; Lucas, Fátima; Carro, Juan; Herguedas, Beatriz; Borrelli, Kenneth W; Guallar, Victor; Martínez, Angel T; Medina, Milagros

    2015-08-01

    Aryl-alcohol oxidase (AAO, EC 1.1.3.7) generates H2 O2 for lignin degradation at the expense of benzylic and other ? system-containing primary alcohols, which are oxidized to the corresponding aldehydes. Ligand diffusion studies on Pleurotus eryngii AAO showed a T-shaped stacking interaction between the Tyr92 side chain and the alcohol substrate at the catalytically competent position for concerted hydride and proton transfers. Bi-substrate kinetics analysis revealed that reactions with 3-chloro- or 3-fluorobenzyl alcohols (halogen substituents) proceed via a ping-pong mechanism. However, mono- and dimethoxylated substituents (in 4-methoxybenzyl and 3,4-dimethoxybenzyl alcohols) altered the mechanism and a ternary complex was formed. Electron-withdrawing substituents resulted in lower quantum mechanics stacking energies between aldehyde and the tyrosine side chain, contributing to product release, in agreement with the ping-pong mechanism observed in 3-chloro- and 3-fluorobenzyl alcohol kinetics analysis. In contrast, the higher stacking energies when electron donor substituents are present result in reaction of O2 with the flavin through a ternary complex, in agreement with the kinetics of methoxylated alcohols. The contribution of Tyr92 to the AAO reaction mechanism was investigated by calculation of stacking interaction energies and site-directed mutagenesis. Replacement of Tyr92 by phenylalanine does not alter the AAO kinetic constants (on 4-methoxybenzyl alcohol), most probably because the stacking interaction is still possible. However, introduction of a tryptophan residue at this position strongly reduced the affinity for the substrate (i.e. the pre-steady state Kd and steady-state Km increase by 150-fold and 75-fold, respectively), and therefore the steady-state catalytic efficiency, suggesting that proper stacking is impossible with this bulky residue. The above results confirm the role of Tyr92 in substrate binding, thus governing the kinetic mechanism in AAO. PMID:25639975

  20. Effect of dioxins on regulation of tyrosine hydroxylase gene expression by aryl hydrocarbon receptor: a neurotoxicology study

    Directory of Open Access Journals (Sweden)

    Akahoshi Eiichi

    2009-06-01

    Full Text Available Abstract Background Dioxins and related compounds are suspected of causing neurological disruption. Epidemiological studies indicated that exposure to these compounds caused neurodevelopmental disturbances such as learning disability and attention deficit hyperactivity disorder, which are thought to be closely related to dopaminergic dysfunction. Although the molecular mechanism of their actions has not been fully investigated, a major participant in the process is aryl hydrocarbon receptor (AhR. This study focused on the effect of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD exposure on the regulation of TH, a rate-limiting enzyme of dopamine synthesis, gene expression by AhR. Methods N2a-R? cells were established by transfecting murine neuroblastoma Neuro2a with the rat AhR cDNA. TH expression induced by TCDD was assessed by RT-PCR and Western blotting. Participation of AhR in TCDD-induced TH gene expression was confirmed by suppressing AhR expression using the siRNA method. Catecholamines including dopamine were measured by high-performance liquid chromatography. A reporter gene assay was used to identify regulatory motifs in the promoter region of TH gene. Binding of AhR with the regulatory motif was confirmed by an electrophoretic mobility shift assay (EMSA. Results Induction of TH by TCDD through AhR activation was detected at mRNA and protein levels. Induced TH protein was functional and its expression increased dopamine synthesis. The reporter gene assay and EMSA indicated that AhR directly regulated TH gene expression. Regulatory sequence called aryl hydrocarbon receptor responsive element III (AHRE-III was identified upstream of the TH gene from -285 bp to -167 bp. Under TCDD exposure, an AhR complex was bound to AHRE-III as well as the xenobiotic response element (XRE, though AHRE-III was not identical to XRE, the conventional AhR-binding motif. Conclusion Our results suggest TCDD directly regulate the dopamine system by TH gene transactivation via an AhR-AHRE-III-mediated pathway. The AhR- mediated pathway could have a particular AhR-mediated genomic control pathway transmitting the effects of TCDD action to target cells in the development of dopaminergic disabilities.

  1. A Metal-Free Synthesis of N-Aryl Carbamates under Ambient Conditions.

    Science.gov (United States)

    Guo, Wusheng; Gónzalez-Fabra, Joan; Bandeira, Nuno A G; Bo, Carles; Kleij, Arjan W

    2015-09-28

    The first chemo- and site-selective process for the formation of N-aryl-carbamates from cyclic organic carbonates and aromatic amines is reported. The reactions proceed smoothly under extremely mild reaction conditions using TBD (triazabicyclodecene) as an effective and cheap organocatalyst, thus providing a sustainable and new methodology for the formation of a wide variety of useful N-aryl carbamate synthons in good to excellent yields. Computational investigations have been performed and show the underlying reason for the observed unique reactivity as related to an effective proton-relay mechanism mediated by the bicyclic guanidine base. PMID:26385130

  2. General Approach for Monolayer Formation of Covalently Attached Aryl Groups Through Electrografting of Arylhydrazines

    DEFF Research Database (Denmark)

    Malmos, Kristoffer; Iruthayaraj, Joseph

    2009-01-01

    An electrochemical approach is presented for carrying out controlled modification of carbon and metal surfaces with aryl groups through mild anodic oxidation of arylhydrazines. Electrochemical, PM-IRRAS, and ellipsometrical measurements reveal that monolayers are formed, the thickness of which is essentially independent of the substituent, pH, and grafting time and potential. This feature makes the approach very tolerant toward variations in the experimental conditions. Hence, this method should be considered as a strong option if the aim is to form thin, well-defined, and covalently assembled aryl layers on surfaces.

  3. Asymmetric synthesis of quaternary aryl amino acid derivatives via a three-component aryne coupling reaction

    Directory of Open Access Journals (Sweden)

    Elizabeth P. Jones

    2011-11-01

    Full Text Available A method was developed for the synthesis of ?-alkyl, ?-aryl-bislactim ethers in good to excellent yields and high diastereoselectivities, consisting of a facile one-pot procedure in which the aryl group is introduced by means of a nucleophilic addition to benzyne and the alkyl group by alkylation of a resultant benzylic anion. Hydrolysis of the sterically less hindered adducts gave the corresponding quaternary amino acids with no racemization, whereas hydrolytic ring opening gave the corresponding valine dipeptides from bulkier bislactims.

  4. Nature of phenolic compounds in coffee melanoidins.

    Science.gov (United States)

    Coelho, Carina; Ribeiro, Miguel; Cruz, Ana C S; Domingues, M Rosário M; Coimbra, Manuel A; Bunzel, Mirko; Nunes, Fernando M

    2014-08-01

    Phenolic compounds are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different melanoidin populations being observed. The incorporation of phenolic compounds into coffee melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compounds can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages. PMID:24998624

  5. Palladium-Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite.

    Science.gov (United States)

    Shavnya, Andre; Hesp, Kevin D; Mascitti, Vincent; Smith, Aaron C

    2015-11-01

    A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis. PMID:26383866

  6. On the search for potential antimycobacterial drugs: synthesis of naphthoquinoidal, phenazinic and 1,2,3-triazolic compounds and evaluation against mycobacterium tuberculosis

    Scientific Electronic Library Online (English)

    Guilherme A. M., Jardim; Eduardo H. G., Cruz; Wagner O., Valença; Jarbas M., Resende; Bernardo L., Rodrigues; Daniela F., Ramos; Ronaldo N., Oliveira; Pedro E. A., Silva; Eufrânio N. da, Silva Júnior.

    2015-05-01

    Full Text Available Fifteen naphthoquinones, sixteen phenazines and fifteen aryl triazoles were synthesized and evaluated against Mycobacterium tuberculosis. Twenty five substances are reported here for the first time and, among all of the compounds evaluated, six presented MIC (minimal inhibitory concentration) values [...

  7. A 13C and 1H NMR spectroscopic investigation of the structure of the iminium ion with a dipolar form in metal complexes of 2-N-substituted N-confused porphyrins.

    Science.gov (United States)

    Chang, Wen-Pin; Lin, Wen-Chain; Chen, Jyh-Horung; Wang, Shin-Shin; Tung, Jo-Yu

    2012-11-21

    The crystal structures of chloro(2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N?N??) zinc(II) [Zn(2-NCH2COOC2H5NCTPP)Cl; 4], (2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N?N??) palladium(II) [Pd(2-NCH2COOC2H5NCTPP); 5], bromo(2-aza-2-ethoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N?N??) manganese(III) [Mn(2-NCH2COOC2H5NCTPP)Br; 6], [2-aza-(3?-phenoxypropyl)-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N?N??] nickel(II) [Ni(2-NCH2CH2CH2OC6H5NCTPP); 7] and chloro(2-aza-2-methoxycarbonylmethyl-5,10,15,20-tetraphenyl-21-carbaporphyrinato-N,N?N??) zinc(II) [Zn(2-NCH2COOCH3NCTPP)Cl; 8] have been established. The g value of 9.54, which was measured from the parallel polarization of the X-band EPR spectra in CHCl3 at 4 K, is consistent with the high spin mononuclear manganese(III) centre (S = 2) in 6. The magnitude of the axial (D) zero-field splitting (ZFS) for the mononuclear Mn(III) centre in 6 was determined approximately to be 1.63 cm(?1) by paramagnetic susceptibility measurements. The NMR spectroscopic investigation of the iminium ion with a dipolar canonical contribution to the metal complexes 5–7, Pd(2-NCH2C6H5NCTPP) (10) and Ni(2-NCH2C6H5NCTPP) (11) in CDCl3 is reported. A resonance between the dipolar canonical form II and covalent canonical form I exists for complexes 5–7, 10 and 11 in CDCl3. To develop the correlations between ?13C [C(3)], ?1H [H(3)] and the canonical form II in 5–7, 10 and 11, this work thoroughly examines the 13C and 1H NMR of N+=CH(Ar) fragment on seven metal complexes of 2-N substituted N-confused porphyrin. According to these results, the 13C [C(3)] and 1H [H(3)] chemical shifts of the N+=CH(Ar) fragment at 20 °C in CDCl3 are separately located at 152.6 ± 0.5 and 8.30 ± 0.15 ppm respectively for the iminium ion. This exists as a dipolar canonical form II for complexes 5–7, 10 and 11, and the N–CH(Ar) group appears at 121.1 ± 0.1 ppm and 6.35 ± 0.01 ppm, which is in a covalent canonical form I contribution to complexes 4 and 8. X-Ray diffraction data indicate that N(2)–C(3) = 1.315 ± 0.011 Å for the dipolar contribution of 5–7, 10–13, while N(2)–C(3) = 1.331 ± 0.008 Å for the covalent contribution of 4 and 8. PMID:23010770

  8. Allium Discoloration: Color Compounds Formed during Pinking of Onion and Leek.

    Science.gov (United States)

    Kubec, Roman; Urajová, Petra; Lacina, Ond?ej; Hajšlová, Jana; Kuzma, Marek; Zápal, Jakub

    2015-11-25

    Structures and formation pathways of compounds responsible for pink discoloration of onion and leek were studied. A procedure was developed for the isolation and purification of the color compounds from various model systems and their identification by HPLC-DAD-MS/MS. In total, structures of 15 major color compounds were tentatively determined. It was found that the pigment is a complex mixture of highly conjugated species composed of two N-substituted 3,4-dimethylpyrrole-derived rings linked by either a methine or a propenylidine bridge. These two-ring units are further modified by various C1- and C3-side chains. Experiments with isotope-labeled thiosulfinates revealed that the methine bridge and C1-side chains originate from the methyl group of methiin, whereas the C3 units are derived from the propenyl group of isoalliin. PMID:26548475

  9. O-methylation of natural phenolic compounds based on green chemistry using dimethyl carbonate

    Science.gov (United States)

    Prakoso, N. I.; Pangestu, P. H.; Wahyuningsih, T. D.

    2016-02-01

    The alkyl aryl ether compounds, of which methyl eugenol and veratraldehyde are the simplest intermediates can be synthesized by reacting eugenol and vanillin with the green reagent dimethyl carbonate (DMC). The reaction was carried out under mild of temperature and pressure. Excellent yields and selective products were obtained (95-96%) after a few hours. In the end of the reaction, the catalysts (base and Phase Transfer Catalyst) can be recovered and regenerated.

  10. Synthesis and in Vitro Antimicrobial Evaluation of New N-Heterocyclic Diquaternary Pyridinium Compounds

    OpenAIRE

    Bianca Furdui; Georgiana Parfene; Ioana Otilia Ghinea; Rodica Mihaela Dinica; Gabriela Bahrim; Martine Demeunynck

    2014-01-01

    A series of bis-pyridinium quaternary ammonium salts (bis-PyQAs) with different aryl and heteroaryl moieties were synthesized and their antimicrobial activity investigated. The inhibition effect of the compounds was evaluated against bacteria, molds and yeasts; the activities were expressed as the minimum inhibitory concentrations (MIC). The relationships between the structure descriptors (logP, polarizability, polar surface area (2D), van der Waals area (3D)) and the biological activity of t...

  11. Brønsted Acidic Ionic Liquid Accelerated Halogenation of Organic Compounds with N-Halosuccinimides (NXS)

    OpenAIRE

    Vraži?, Dejan; Jereb, Marjan; Laali, Kenneth; Stavber, Stojan

    2012-01-01

    The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into ?-halo and ?,?-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures o...

  12. Brønsted Acidic Ionic Liquid Accelerated Halogenation of Organic Compounds with N-Halosuccinimides (NXS)

    OpenAIRE

    Stojan Stavber; Laali, Kenneth K; Dejan Vraži?; Marjan Jereb

    2012-01-01

    The Brønsted-acidic ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into ?-halo and ?,?-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenat...

  13. Inhibition of mucin glycosylation by aryl-N-acetyl-alpha-galactosaminides in human colon cancer cells

    International Nuclear Information System (INIS)

    Specific inhibitors of the glycosylation of O-glycosidically linked glycoproteins have not previously been described. When tested for their effects on mucin glycosylation in a mucin-producing colon cancer cell line, LS174T, benzyl-, phenyl-, and p-nitrophenyl-N-acetyl-alpha-galactosaminide inhibited the formation of fully glycosylated mucin in a dose-dependent manner. Free aryl-oligosaccharides were found in the medium of treated cells labeled with [3H]glucosamine, [3H]galactose, [3H]fucose, [3H]mannosamine, or phenyl-alpha-[6-3H] N-acetylgalactosamine. UDP-Gal:GalNAc-beta 1,3-galactosyltransferase was inhibited by aryl-N-acetyl-alpha-galactosaminides but not by a number of other aryl-glycosides. Treatment with these inhibitors also causes reversible morphologic changes including formation of intercellular cysts. Aryl-N-acetyl-alpha-galactosaminides can be useful for the structural and functional studies of mucin macromolecules and other O-linked glycoproteins

  14. Smoke carcinogens cause bone loss through the aryl hydrocarbon receptor and induction of CYP1 enzymes

    Science.gov (United States)

    Smoking is a major risk factor for osteoporosis and fracture. Here, we show that smoke toxins and environmental chemicals such as benzo[a]pyrene (BaP), 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD), and 3-methyl cholanthrene, which are well known aryl hydrocarbon receptor (AHR) agonists, induce osteocla...

  15. Switching the regioselectivity of direct C-H arylation of 1,3-dimethyluracil.

    Czech Academy of Sciences Publication Activity Database

    ?er?ová, Miroslava; Pohl, Radek; Hocek, Michal

    -, ?. 22 (2009), s. 3698-3701. ISSN 1434-193X R&D Projects: GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z40550506 Keywords : pyrimidines * C-H arylation * palladium Subject RIV: CC - Organic Chemistry Impact factor: 3.096, year: 2009

  16. Palladium-catalyzed carbonylative sonogashira coupling of aryl bromides using near stoichiometric carbon monoxide

    DEFF Research Database (Denmark)

    Neumann, Karoline T.; Laursen, Simon R.

    2014-01-01

    A general procedure for the palladium-catalyzed carbonylative Sonogashira coupling of aryl bromides is reported, using near stoichiometric amounts of carbon monoxide. The method allows a broad substrate scope in moderate to excellent yields. The formed alkynone motive serves as a platform for synthesis of various heterocyclic structures, including pyrimidines. Furthermore, the presented strategy allows effective 13C labeling.

  17. Magnetic silica supported palladium catalyst: synthesis of allyl aryl ethers in water

    Science.gov (United States)

    A simple and benign procedure for the synthesis of aryl allyl ethers has been developed using phenols, allyl acetates and magnetically recyclable silica supported palladium catalyst in water; performance of reaction in air and easy separation of the catalyst using an external mag...

  18. Magnetic Silica Supported Copper: A Modular Approach to Aqueous Ullmann-type Amination of Aryl Halides

    Science.gov (United States)

    One-pot synthesis of magnetic silica supported copper catalyst has been described via in situ generated magnetic silica (Fe3O4@SiO2); the catalyst can be used for the efficacious amination of aryl halides in aqueous medium under microwave irradiation.

  19. Continuous flow photolysis of aryl azides: Preparation of 3H-azepinones

    Directory of Open Access Journals (Sweden)

    Farhan R. Bou-Hamdan

    2011-08-01

    Full Text Available Photolysis of aryl azides to give nitrenes, and their subsequent rearrangement in the presence of water to give 3H-azepinones, is performed in continuous flow in a photoreactor constructed of fluorinated ethylene polymer (FEP tubing. Fine tuning of the reaction conditions using the flow reactor allowed minimization of secondary photochemical reactions.

  20. Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings

    OpenAIRE

    Shinichiro Fuse; Nobutake Tanabe; Akio Tannna; Yohei Konishi; Takashi Takahashi

    2013-01-01

    Sterically crowded diimine ligands with five aryl rings were prepared in one step in good yields using a micro-flow technique. X-ray crystallographic analysis revealed the detailed structure of the bulky ligands. The nickel complexes prepared from the ligands exerted high polymerization activity in the ethylene homopolymerization and copolymerization of ethylene with polar monomers.

  1. Access to aryl mellitic acid esters through a surprising oxidative esterification reaction.

    Science.gov (United States)

    Geraskina, Margarita R; Juetten, Mark J; Winter, Arthur H

    2014-06-01

    A serendipitously discovered oxidative esterification reaction of cyclohexane hexacarboxylic acid with phosphorus pentachloride and phenols provides one-pot access to previously unknown aryl mellitic acid esters. The reaction features a solvent-free digestion and chromatography-free purifications and demonstrates the possibility of cyclohexane-to-benzene conversions under relatively mild, metal-free conditions. PMID:24815576

  2. Pd(0)-catalyzed intramolecular ?-arylation of sulfones: domino reactions in the synthesis of functionalized tetrahydroisoquinolines.

    Science.gov (United States)

    Solé, Daniel; Pérez-Janer, Ferran; Mancuso, Raffaella

    2015-03-16

    A new strategy for the synthesis of tetrahydroisoquinolines based on the Pd(0)-catalyzed intramolecular ?-arylation of sulfones is reported. The combination of this Pd-catalyzed reaction with intermolecular Michael and aza-Michael reactions allows the development of two- and three-step domino processes to synthesize diversely functionalized scaffolds from readily available starting materials. PMID:25677083

  3. Synthesis of enaminones and their difluoroboron complexes through domino aryl migration†

    Science.gov (United States)

    Yang, Zheng; Jiang, Bo; Hao, Wen-Juan; Zhou, Peng; Tu, Shu-Jiang; Li, Guigen

    2015-01-01

    A new domino strategy for selective synthesis of enaminones and their difluoroboron complexes through aryl migration has been developed. The reaction features low-cost and readily accessible starting materials, reliable scalability, and bond-forming efficiency as well as simple one-pot operation, which makes this strategy highly viable for future applications. PMID:25475958

  4. Organocatalytic enantioselective formal arylation of azlactones using quinones as the aromatic partner.

    Science.gov (United States)

    Li, Guofeng; Sun, Wangsheng; Li, Jingyi; Jia, Fengjing; Hong, Liang; Wang, Rui

    2015-06-30

    A new method for the catalytic enantioselective formal arylation of azlactones using quinones as the aromatic partner was developed for the first time. Under mild conditions, the domino Michael/aromatization/cyclization reaction worked well to afford the corresponding products in moderate to high yields with excellent enantioselectivities, some of which have promising cytotoxicity against cancer cells and antibacterial activities. PMID:26083993

  5. Synthesis of enaminones and their difluoroboron complexes through domino aryl migration.

    Science.gov (United States)

    Yang, Zheng; Jiang, Bo; Hao, Wen-Juan; Zhou, Peng; Tu, Shu-Jiang; Li, Guigen

    2015-01-25

    A new domino strategy for selective synthesis of enaminones and their difluoroboron complexes through aryl migration has been developed. The reaction features low-cost and readily accessible starting materials, reliable scalability, and bond-forming efficiency as well as simple one-pot operation, which makes this strategy highly viable for future applications. PMID:25475958

  6. Reductive carbonylation of aryl halides employing a two-chamber reactor

    DEFF Research Database (Denmark)

    Korsager, Signe; Taaning, Rolf H; Lindhardt, Anders T; Skrydstrup, Troels

    2013-01-01

    A protocol has been developed for conducting the palladium-catalyzed reductive carbonylation of aryl iodides and bromides using 9-methylfluorene-9-carbonyl chloride (COgen) as a source of externally delivered carbon monoxide in a sealed two-chamber system (COware), and potassium formate as the in...

  7. Telescoped approach to aryl hydroxymethylation in the synthesis of a key pharmaceutical intermediate.

    Science.gov (United States)

    Slattery, Catherine N; Deasy, Rebecca E; Maguire, Anita R; Kopach, Michael E; Singh, Utpal K; Argentine, Mark D; Trankle, William G; Scherer, Roger Brian; Moynihan, Humphrey

    2013-06-21

    An efficient synthetic approach leading to introduction of the hydroxymethyl group to an aryl moiety via combination of the Bouveault formylation and hydride reduction has been optimized using a rational, mechanistic-based approach. This approach enabled telescoping of the two steps into a single efficient process, readily amenable to scaleup. PMID:23718859

  8. Novel synthesis of primary arylamides from aryl methyl ketone oxidations using iodine in aqueous ammonia

    Scientific Electronic Library Online (English)

    Norma A., Angeles; Felipe, Villavicencio; Carlos, Guadarrama; David, Corona; Erick, Cuevas-Yañez.

    Full Text Available Arilamidas primárias foram obtidas em bons rendimentos quando diversas arilmetilcetonas foram tratadas com iodo em amônia aquosa a temperatura ambiente. [...] Abstract in english Primary arylamides were obtained when several aryl methyl ketones were treated with iodine in aqueous ammonia at room temperature in goods yields. [...

  9. Diastereo- and enantioselective intramolecular C(sp3)-H arylation for the synthesis of fused cyclopentanes.

    Science.gov (United States)

    Martin, Nicolas; Pierre, Cathleen; Davi, Michaël; Jazzar, Rodolphe; Baudoin, Olivier

    2012-04-10

    All C-H bonds are not equal: The intramolecular arylation of unactivated C(sp(3))-H bonds in the presence of a chiral Pd/binepine catalyst allows the synthesis of fused cyclopentanes efficiently and in an diastereo- and enantioselective manner (see scheme). PMID:22407525

  10. La2O3 Catalyzed C–C Coupling of Aryl Iodides and Boronic Acids

    OpenAIRE

    Payal Malik; Debashis Chakraborty

    2012-01-01

    An efficient La2O3-catalyzed new route for the carbon-carbon bond formation in particular, symmetrical and unsymmetrical biphenyls has been developed, which proceeds through carbon-carbon coupling reaction of aryl iodides with boronic acids. The reaction provided the desired products in moderate-to-good yields with a wide range of functional group tolerance.

  11. Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings

    Directory of Open Access Journals (Sweden)

    Shinichiro Fuse

    2013-11-01

    Full Text Available Sterically crowded diimine ligands with five aryl rings were prepared in one step in good yields using a micro-flow technique. X-ray crystallographic analysis revealed the detailed structure of the bulky ligands. The nickel complexes prepared from the ligands exerted high polymerization activity in the ethylene homopolymerization and copolymerization of ethylene with polar monomers.

  12. New class of 8-aryl-7-deazaguanine cell permeable fluorescent probes.

    Science.gov (United States)

    Dhimitruka, Ilirian; Eubank, Timothy D; Gross, Amy C; Khramtsov, Valery V

    2015-10-15

    A one step synthesis of fluorescent 8-aryl-(7-deazaguanines) has been accomplished. Probes exhibit blue to green high quantum yield fluorescence in a variety of organic and aqueous solutions, high extinction coefficients, and large Stokes shifts often above 100nm. The probes are highly cell permeable, and exhibit stable bright fluorescence once intracellular; therefore are suited to the design of biosensors. PMID:26320620

  13. Brominated Thiophenes as Precursors in the Preparation of Brominated and Arylated Anthraquinones

    Directory of Open Access Journals (Sweden)

    Thies Thiemann

    2009-03-01

    Full Text Available Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended ?-systems with interspersed anthraquinone units.

  14. Stereoselective Synthesis of 2-Deoxy-?-glycosides Using Anomeric O-Alkylation/Arylation

    OpenAIRE

    Morris, William J.; Shair, Matthew David

    2009-01-01

    Anomeric O-alkylation/arylation is applied to the synthesis of 2-deoxy-?-glycosides. Treatment of lactols with NaH in dioxane followed by the addition of electrophiles leads to the formation of 2-deoxy-?-glycosides in high yield and high selectivity. The high ?-selectivity observed here demonstrates a powerful stereoelectronic effect for the stereoselective formation of acetals under kinetic control.

  15. Metal-Free Approach for the Synthesis of N-Aryl Sulfoximines via Aryne Intermediate.

    Science.gov (United States)

    Aithagani, Sravan Kumar; Dara, Saidulu; Munagala, Gurunadham; Aruri, Hariprasad; Yadav, Mahipal; Sharma, Shweta; Vishwakarma, Ram A; Singh, Parvinder Pal

    2015-11-20

    A metal-free and operationally simple N-arylation of NH-sulfoximines with aryne precursors is reported. Transition metal-free reaction conditions and shorter reaction times are the highlights of the present method. The mild optimized condition was also found to be suitable with enantiopure substrates. PMID:26562479

  16. Synthesis of 4-aryl-4,5-dihydro-1-indeno[1,2-]pyrimidines by Biginelli condensation and their antibacterial activities

    Indian Academy of Sciences (India)

    Ramandeep Kaur; Monika Bansal; Balbir Kaur; Tulika Mishra; Aruna Bhatia

    2011-07-01

    A simple and efficient method has been developed for the synthesis of series of 4-aryl-1,3,4,5-tetrahydro-2-indeno[1,2-]pyrimidine-2-thiones through Biginelli’s one-pot multicomponent condensation reaction via microwave irradiations. Then, these thiones were converted to their S-alkylated/aralkylated derivatives. The prepared heterocyclic products were structurally confirmed by analytical and spectral data and evaluated for their antibacterial activities. The results showed that this skeletal framework exhibited marked potency as antibacterial agents. The compound 2-(Ethylthio)-4-(4-Hydroxy-3-methoxyphenyl)-4,5-dihydro-1-indeno[1,2-]pyrimidines 4b have shown antibacterial activity towards all the seven clinical isolates used.

  17. The slow dissociation rate of K-1602 contributes to the enhanced inhibitory activity of this novel alkyl-aryl-bearing fluoroketolide.

    Science.gov (United States)

    Krokidis, Marios; Bougas, Anthony; Stavropoulou, Maria; Kalpaxis, Dimitrios; Dinos, George P

    2016-04-01

    Ketolides belong to the latest generation of macrolides and are not only effective against macrolide susceptible bacterial strains but also against some macrolide resistant strains. Here we present data providing insights into the mechanism of action of K-1602, a novel alkyl-aryl-bearing fluoroketolide. According to our data, the K-1602 interacts with the ribosome as a one-step slow binding inhibitor, displaying an association rate constant equal to 0.28?×?10(4?)M(-1) s(-1) and a dissociation rate constant equal to 0.0025?min(-1). Both constants contribute to produce an overall inhibition constant Ki equal to 1.49?×?10(-8?)M, which correlates very well with the superior activity of this compound when compared with many other ketolides or fluoroketolides. PMID:25807301

  18. ANTIMICROBIAL ACTIVITY OF DIFFERENT THIOSEMICARBAZONE COMPOUNDS AGAINST MICROBIAL PATHOGENS

    Directory of Open Access Journals (Sweden)

    Negi Parul

    2012-05-01

    Full Text Available Thiosemicarbazone belongs to a large group of thiourea derivatives, whose biological activities are a function of parent aldehyde or ketone moiety. They have been evaluated over the last 50 year as antiviral, antibacterial, antifungal, antimalarial, anticancer, leprosy, rheumatism, trypanosomiasis and coccidiodis. Thiosemicarbazones were prepared by simple process in which N4-thiosemicarbazone moiety was replaced by aliphatic, arylic and cyclic amines. Present study reported the anti-microbial activity of different thiosemicarbazone compounds against certain bacterial and fungal pathogens viz. Bacillus cereus, Staphylococcus epidermis, Moraxella cattarhalis, Staph. Saprophyticus, Candida albicans and Aspergillus flavans.

  19. A Convenient N-Arylation Route for Electron-Deficient Pyridines: The Case of ?-Extended Electrochromic Phosphaviologens.

    Science.gov (United States)

    Reus, Christian; Stolar, Monika; Vanderkley, Jeffrey; Nebauer, Johannes; Baumgartner, Thomas

    2015-09-16

    A simple and representative procedure for the synthesis of N,N'-diarylated phosphaviologens directly from both electron-rich and electron-poor diaryliodonium salts and 2,7-diazadibenzophosphole oxide is reported. The latter are electron-deficient congeners of the widely utilized N,N'-disubstituted 4,4'-bipyridinium cations, also known as viologens, that proved to be inaccessible by the classical two-step route. The single-step preparation method for phosphaviologens described herein could be extended to genuine viologens but reached its limit when sterically demanding diaryliodonium salts were used. The studied phosphaviologens feature a significantly lowered reduction threshold as compared to all other (phospha)viologens known to date due to the combination of an extended ?-system with an electron deficient phosphole core. In addition, a considerably smaller HOMO-LUMO gap was observed due to efficient ?-delocalization across the phosphaviologen core, as well as the N-aryl substituents, which was corroborated by quantum chemical calculations. Detailed characterizations of the singly reduced radical species by EPR spectroscopy and DFT calculations verified delocalization of the radical over the extended ?-system. Finally, to gain deeper insight into the suitability of the new compounds as electroactive and electrochromic materials, multicolored proof-of-concept electrochomic devices were manufactured. PMID:26325450

  20. Synthesis and Antifungal Activity of Some New Guanidines

    Directory of Open Access Journals (Sweden)

    Puran Chandra Joshi

    1979-10-01

    Full Text Available The synthesis of some N-subsituted -N'-aryl-N"-ethyl/benzyl guanidines (II and (III and their precurser thiocarbamides (I has been carried out. All these compounds have been screened in vitro for their antifungal activity against Helminthosporium oryzae, Drechlere papendor fii and Alternaria alternata. In general, N-substituted-N'aryl-N"benzyl guanidines except N-(p-pyrolidinopropoxyphenyl-N'-p-tolyl-N"-benzyl guanidine possess high antifungal activity against all the test fungi at concentration 2% and comparatively less at 0.2% None of these compounds exhibit fungicidal activity at lower concentrations (0.02 and 0.002%.

  1. Synthesis and serotonin transporter activity of 1,3-bis(aryl)-2-nitro-1-propenes as a new class of anticancer agents

    DEFF Research Database (Denmark)

    McNamara, Yvonne M.; Cloonan, Suzanne M.

    2011-01-01

    Structural derivatives of 4-MTA, an illegal amphetamine analogue have been previously shown to have anticancer effects in vitro. In this study we report the synthesis of a series of novel 1,3-bis(aryl)-2-nitro-1-propene derivatives related in structure to 4-MTA. A number of these compounds containing a classic nitrostyrene structure are shown to have antiproliferative activities in vitro in a range of malignant cell lines, particularly against Burkitt’s lymphoma derived cell lines, whilst having no effect on ‘normal’ peripheral blood mononuclear cells. Such effects appear to be independent of the serotonin transporter, a high affinity target for amphetamines and independent of protein tyrosine phosphatases and tubulin dynamics both of which have been previously associated with nitrostyrene-induced cell death. We demonstrate that a number of these compounds induce caspase activation, PARP cleavage, chromatin condensation and membrane blebbing in a Burkitt’s lymphoma derived cell line, consistent with these compounds inducing apoptosis in vitro. Although no specific target has yet been identified for the action of these compounds, the cell death elicited is potent, selective and worthy of further investigation.

  2. 1-Aryl-3-(1H-imidazol-1-yl)propan-1-ol esters: synthesis, anti-Candida potential and molecular modeling studies

    Science.gov (United States)

    2013-01-01

    Background An increased incidence of fungal infections, both invasive and superficial, has been witnessed over the last two decades. Candida species seem to be the main etiology of nosocomial fungal infections worldwide with Candida albicans, which is commensal in healthy individuals, accounting for the majority of invasive Candida infections with about 30-40% of mortality. Results New aromatic and heterocyclic esters 5a-k of 1-aryl-3-(1H-imidazol-1-yl)propan-1-ols 4a-d were successfully synthesized and evaluated for their anti-Candida potential. Compound 5a emerged as the most active congener among the newly synthesized compounds 5a-k with MIC value of 0.0833 ?mol/mL as compared with fluconazole (MIC value >1.6325 ?mol/mL). Additionally, molecular modeling studies were conducted on a set of anti-Candida albicans compounds. Conclusion The newly synthesized esters 5a-k showed more potent anti-Candida activities than fluconazole. Compounds 7 and 8 revealed significant anti-Candida albicans activity and were able to effectively satisfy the proposed pharmacophore geometry, using the energy accessible conformers (Econf?

  3. Pd(OAc)2/DPPF-catalysed microwave-assisted cyanide-free synthesis of aryl nitriles

    Indian Academy of Sciences (India)

    Dinesh N Sawant; Bhalchandra M Bhanage

    2014-03-01

    This study reports microwave-assisted cyanide-free synthesis of aryl nitriles from aryl halides using palladium acetate/1,1-bis(diphenylphosphino)ferrocene as a new catalyst system. Reported protocol is a rapid, cyanide-free, single step reaction, wherein formamide acts as a solvent as well as a source of cyanide. The use of microwave increases the rate of reaction substantially and it was observed that aryl nitriles can be synthesised in 50 min of microwave irradiation compared to conventional thermal heating protocol which requires 48 h.

  4. 2,2- and 2,6-Diarylpiperidines by aryl migration within lithiated urea derivatives of tetrahydropyridines.

    Science.gov (United States)

    Tait, Michael B; Butterworth, Sam; Clayden, Jonathan

    2015-03-01

    2-Aryltetrahydropyridines formed by anionic cyclization or ring-closing metathesis were converted to their N'-aryl urea derivatives. Depending on the position of the unsaturation within the tetrahydropyridine ring, metalation by deprotonative lithiation or carbolithiation led to migration of the N'-aryl substituent to the 2- or 6-position via intramolecular nucleophilic attack of a benzylic organolithium on the aryl ring. The products are a range of 2,2-, 2,2,3-, and 2,6-polysubstituted piperidine derivatives. Related chemistry was observed in pyrroline homologues. PMID:25692395

  5. Efficient synthesis of new 1-[Alkyl(aryl)]-5-(3,3,3-trihalo-2-oxopropylidene)pyrrolidin-2-ones

    Scientific Electronic Library Online (English)

    Alex F. C., Flores; Darlene C., Flores; Graciela, Oliveira; Lucas, Pizzuti; Rubia M. S. da, Silva; Marcos A. P., Martins; Helio G., Bonacorso.

    Full Text Available Este trabalho mostra a síntese, em bons rendimentos (57-95%), de duas séries de 1-alquil(aril)amino-2-oxo-5-(2-oxo-3,3,3-trialopropiliden)-pirrolidinas 5 e 6, a partir dos intermediários 4-[alquil(aril)amino]-6-oxo-7,7,7-trialo-4-hepteno-atos de metila 3 e 4 obtidos por substituição da metoxila-beta [...] nos precursores 4-metoxi-6-oxo-7,7,7-trialo-4-heptenoatos de metila 1 e 2, pela série de aminas primárias RNH2, onde R = PhCH2, PhCH2CH2, Ph, 4-MeC6H4, 4-MeOC6H4, 4-ClC6H4, 4-BrC6H4, 2-piridnil, 5-metil-3-isoxazolil, 4-NH2C6H4. A estrutura molecular dos produtos inéditos foi atribuída a partir dos dados de RMN ¹H, 13C e espectrometria de massas. A configuração geométrica dos compostos 3d e 5b foi confirmada pelos dados de difração de raios-X em monocristal. Abstract in english Reactions of methyl 4-methoxy-6-oxo-7,7,7-trihalo-4-heptenoates 1 and 2 with primary amines RNH2, where R = PhCH2, PhCH2CH2, Ph, 4-MeC6H4, 4-MeOC6H4, 4-ClC6H4, 4-BrC6H4, 2-pyridyl, 5-methyl-3-isoxazolyl, 4-NH2C6H4 affording methyl 4-[alkyl(aryl)amino]-6-oxo-7,7,7-trihalo-4-heptenoates 3, 4, in good [...] yields (57-95%), which suffer quantitative intramolecular cyclocondensation to produce 1-alkyl(aryl)-5-(2-oxo-3,3,3-trihalopropylidene)pyrrolidin-2-ones 5, 6, are reported. The structures of the isolated new products were assigned by means of ¹H,13C NMR measurements and mass spectrometry. The Z and E configuration of compounds 3d and 5b respectively were established from X-ray crystallography.

  6. Intermediates in the intermolecular, asymmetric Heck arylation of dihydrofurans

    OpenAIRE

    Hii, KK; Claridge, TDW; Brown, JM

    1997-01-01

    Double isomerization results in a Pd alkyl compound with unexpected structure, which is stable until -40, from the reaction of the Pd complex shown on the right with 2,3-dihydrofuran. The course of the asymmetric Heck reaction was followed by NMR spectroscopy. P(a)P(b) = (S)-BINAP.

  7. Polymer compound

    OpenAIRE

    Lange, RFM (Ronald); Meijer, EW

    1995-01-01

    A Polymer compound comprising a polymer (a) that contains cyclic imidesgroups and a polymer (b) that contains monomer groups with a 2,4-diamino-1,3,5-triazine side group. According to the formula (see formula) whereby themole percentage ratio of the cyclic imides groups in the polymer compoundwith respect to the mole percentage of the monomer units with 2,4-diamino-1,3,5-triazine side group in the polymer compound is 0.1-10.0. Preferablypolymer (a) and/or polymer (b) contain styrene and/or al...

  8. Multipurpose Compound

    Science.gov (United States)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  9. Secondary effects of catalytic diesel particulate filters: reduced aryl hydrocarbon receptor-mediated activity of the exhaust.

    Science.gov (United States)

    Wenger, Daniela; Gerecke, Andreas C; Heeb, Norbert V; Zennegg, Markus; Kohler, Martin; Naegeli, Hanspeter; Zenobi, Renato

    2008-04-15

    Diesel exhaust contains numerous toxic substances that show different modes of action such as triggering aryl hydrocarbon receptor (AhR)-mediated pathways. We investigated AhR-mediated activity of exhaust generated by a heavy-duty diesel engine operated with or without iron- or copper/iron-catalyzed diesel particulate filters (DPFs). AhR agonists were quantified using the DR-CALUX reporter gene assay (exposure of cells for 24 h). We found 54-60 ng 2,3,7,8-tetrachlorodibenzo-p-dioxin CALUX equivalents (TCDD-CEQs) per m3 of exhaust in unfiltered samples and 6-16 ng TCDD-CEQ m3 in DPF-treated samples. DPF applications decreased TCDD-CEQ concentrations by almost 90%. Concentrations of known AhR agonists were determined with GC/HRMS and converted to TCDD-CEQ concentrations using compound-specific relative potency values. The analyzed nine polycyclic aromatic hydrocarbons (PAHs) and the 172,3,7,8-chlorinated dibenzodioxins/furans (23,7,8-PCDD/Fs) contributed only marginally (0.6-1.6%) to the total agonist concentration. However, both DPFs also decreased concentrations of individual PAHs by 7(0-80%. Variation of the assay exposure time (8, 24, 48,72, and 96 h) revealed that AhR-mediated activity decreased over time and reached a plateau after 72 h, which was most likely due to biotransformation of AhR agonists by the exposed H4IIE cells. At the plateau, we measured 1-2 ng TCDD-CEQ m(-3) in both an unfiltered and a filtered exhaust sample. Our findings show that DPFs are a promising technology to detoxify diesel exhaust regarding compounds with AhR-mediated activity. PMID:18497156

  10. Cooperative effect of silver in copper-catalyzed trifluoromethylation of aryl iodides using Me3SiCF3

    KAUST Repository

    Weng, Zhiqiang

    2011-06-13

    An effective model of cooperative effect of silver for the coppercatalyzed trifluoromethylation of activated and unactivated aryl iodides to trifluoromethylated arenes using Me3SiCF3 was achieved with a broad substrate scope. © 2011 American Chemical Society.

  11. Selective synthesis of either isoindole- or isoindoline-1-carboxylic acid esters by Pd(0)-catalyzed enolate arylation.

    Science.gov (United States)

    Solé, Daniel; Serrano, Olga

    2010-09-17

    Two efficient palladium-catalyzed intramolecular ?-arylation reactions of ?-amino acid esters have been developed that allow either 1-isoindolecarboxylic acid esters or the corresponding isoindolines to be selectively synthesized simply by a slight change of reaction conditions. PMID:20738127

  12. Radical based strategy toward the synthesis of 2,3-dihydrofurans from aryl ketones and aromatic olefins.

    Science.gov (United States)

    Naveen, Togati; Kancherla, Rajesh; Maiti, Debabrata

    2014-10-17

    A copper-mediated annulation of aryl ketones with a wide range of aromatic olefins has been developed. This strategy allowed convenient access to 2,3-dihydrofuran derivatives. The versatility of the protocol is shown by synthesizing ?-methyl dihydrofurans, which serve as an intermediate for the synthesis of vitamin B1. In addition, the applicability of the protocol in conjugated systems is demonstrated. A radical pathway was presumed and supported for annulation of aryl ketones with olefins. PMID:25275799

  13. Tandem copper (Cu) catalysed N-arylation-vinylogous nitroaldol condensation of 3,5-disubstituted 4-nitropyrazoles.

    Science.gov (United States)

    Obulesu, Owk; Nanubolu, Jagadeesh Babu; Suresh, Surisetti

    2015-08-14

    A tandem process involving copper catalysed N-arylation and vinylogous nitroaldol condensation is described. The reaction of 3,5-dialkyl substituted 4-nitropyrazoles and ortho-halo substituted (hetero)aryl aldehydes or ketones furnished 3-nitropyrazolo[1,5-a]quinoline and heteroaryl-fused 3-nitropyrazolo[1,5-a]pyridine derivatives in moderate to high yields. PMID:26135392

  14. Phosphane-free Suzuki-Miyaura coupling of aryl imidazolesulfonates with arylboronic acids and potassium aryltrifluoroborates under aqueous conditions

    OpenAIRE

    Cívicos García, José Francisco; Gholinejad, Mohammad; Alonso Velasco, Diego Antonio; Nájera Domingo, Carmen

    2011-01-01

    Aryl imidazole-1-sulfonates are efficiently cross-coupled with arylboronic acids and potassium aryltrifluoroborates using only 0.5 mol % of oxime palladacycles 1 under aqueous conditions at 110 °C. Under these simple phosphane-free reaction conditions a wide array of biaryl derivatives has been prepared in high yields. This methodology allows in situ phenol sulfonation and one-pot Suzuki arylation as well as the employment of microwave irradiation conditions.

  15. Enantioselective 1,2-Difunctionalization of Dienes Enabled by Chiral Palladium Complex-Catalyzed Cascade Arylation/Allylic Alkylation Reaction.

    Science.gov (United States)

    Wu, Xiang; Lin, Hua-Chen; Li, Ming-Li; Li, Lu-Lu; Han, Zhi-Yong; Gong, Liu-Zhu

    2015-10-28

    A Pd-catalyzed highly enantioselective three-component coupling of 1,3-dienes with aryl iodines and sodium dialkyl malonates has been successfully established by using a H8-BINOL-based phosphoramidite ligand. This reaction proceeded via a Pd-catalyzed cascade arylation and asymmetric allylic alkylation reaction, providing an efficient strategy for the enantioselective 1,2-difunctionalization of 1,3-dienes. PMID:26437362

  16. Metal-free arylation of pyrimidines through a photochemical process.

    Science.gov (United States)

    Ruch, Jonas; Aubin, Ariane; Erbland, Guillaume; Fortunato, Audrey; Goddard, Jean-Philippe

    2016-01-28

    Pyrimidinyl and pyrazinyl radicals were generated under moderate energetic irradiation conditions (UVA), and proved to be prompt to undergo C-C bond formation processes. Hetero-biaryl derivatives were obtained in good to high yields with highly interesting functional group selectivities. Bis hetero-biaryls were also easily accessible leading to original compounds, ready for further transformations. Experiments supporting radical processes have been reported. PMID:26728790

  17. Rh(I)-Catalyzed Arylation of Heterocycles via C-H Bond Activation: Expanded Scope Through Mechanistic Insight

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Jared; Berman, Ashley; Bergman, Robert; Ellman, Jonathan

    2007-07-18

    A practical, functional group tolerant method for the Rh-catalyzed direct arylation of a variety of pharmaceutically important azoles with aryl bromides is described. Many of the successful azole and aryl bromide coupling partners are not compatible with methods for the direct arylation of heterocycles using Pd(0) or Cu(I) catalysts. The readily prepared, low molecular weight ligand, Z-1-tert-butyl-2,3,6,7-tetrahydrophosphepine, which coordinates to Rh in a bidentate P-olefin fashion to provide a highly active yet thermally stable arylation catalyst, is essential to the success of this method. By using the tetrafluoroborate salt of the corresponding phosphonium, the reactions can be assembled outside of a glove box without purification of reagents or solvent. The reactions are also conducted in THF or dioxane, which greatly simplifies product isolation relative to most other methods for direct arylation of azoles employing high-boiling amide solvents. The reactions are performed with heating in a microwave reactor to obtain excellent product yields in two hours.

  18. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  19. Simple preparation of new N-aryl-N-(3-indolmethyl acetamides and their spectroscopic analysis

    Directory of Open Access Journals (Sweden)

    José A. Henao

    2009-12-01

    Full Text Available To prepare new indolic molecules and characterize them by spectroscopic methods. Materials and methods: All reagentswere purchased from Aldrich, commercial grade. The purity of the products and the composition of the reaction mixtures were monitoredby thin layer chromatography over Silufol UV254 0.25 mm-thick chromatoplates. Product isolation and purification were performed bycolumn chromatography (SiO2, using ethyl acetate-petroleum ether mixtures as eluents. Results. The synthesis of new N-aryl-N-(3-indolmethyl acetamides based on first step iminization reaction of indol-3-carbaldehyde is accomplished. The structures of the C-3substituted indoles were confirmed by 1H-NMR and 13C-NMR studies supported by inverse-detected 2D NMR experiments and alsothrough monocrystal X-ray diffraction. Conclusions. An efficient, economic, and fast synthetic route was designed to the construction ofthe N-aryl-N-(3-indolmethyl acetamides, structural analogues of some alkaloids.

  20. Aryl-derivatized, water-soluble functionalized carbon nanotubes for biomedical applications

    International Nuclear Information System (INIS)

    The functionalization of very-thin multi-walled carbon nanotubes (VT-MWNTs) with an aniline derivative, via the protocol of in situ generated aryl diazonium salts results, upon acidic deprotection of the terminal BOC group, on the formation of the water-soluble positively charged ammonium functionalized VT-MWNTs-NH3+ material. The new materials have been structurally and morphologically characterized by infra-red (ATR-IR) spectroscopy and transmission electron microscopy (TEM). The quantitative calculation of the grafted aryl units onto the skeleton of VT-MWNTs has been estimated by thermogravimetric analysis (TGA), while the quantitative Kaiser test showed the amine group loaded onto VT-MWNTs-NH3+ material. The aqueous solubility of this material has allowed the performance of some initial toxicological in vitro investigations

  1. 3D shapes of aryl(dihydro)naphthothiophenes: a comprehensive and structural study.

    Science.gov (United States)

    Boufroura, H; Souibgui, A; Gaucher, A; Marrot, J; Pieters, G; Aloui, F; Ben Hassine, B; Clavier, G; Prim, D

    2015-11-28

    Convenient access to new aryl(dihydro)naphthothiophenes is described using a common β-chloroacrolein derivative. Our strategy is based on the construction of a condensed thiophene ring prior to a Suzuki-Miyaura coupling and allowed installing various substituents at the molecular platform. The overall shapes of these architectures were confirmed by X-ray analyses and were in good agreement with theoretical calculations. It has been established that the relative orientation between all fragments that composed molecules within this series is strongly related to both steric and electronic factors. Contribution of these key parameters revealed to be crucial to rationalize attempts to prepare fluorenone and fluorene derivatives from aryl(dihydro)naphthothiophene platforms. PMID:26365700

  2. Visible Light Mediated Reductive Cleavage of C-O Bonds Accessing ?-Substituted Aryl Ketones.

    Science.gov (United States)

    Speckmeier, Elisabeth; Padié, Clément; Zeitler, Kirsten

    2015-10-01

    C-O ?-bonds in multifaceted benzoin derivatives can be effectively cleaved as acetates using catalytic amounts of [Ru(bpy)3]Cl2 as photoredox catalyst in combination with Hantzsch ester and triethylamine as a sacrificial electron donor. This mild and operationally simple method is applicable to a great variety of substrates. Homo- and cross-benzoins, which are easily accessed by NHC (N-heterocyclic carbene) catalysis, with both electron-withdrawing and electron-donating substituents, including aryl halogenides, can be employed. The deoxygenated counterparts are isolated in good to excellent yields. These broadly accessible, ?-substituted (nonsymmetric) aryl ketones are versatilely applicable for further transformations as illustrated by the syntheses of 2-arylbenzofurans. PMID:26372674

  3. Accelerated Submonomer Solid-Phase Synthesis of Peptoids Incorporating Multiple Substituted N-Aryl Glycine Monomers.

    Science.gov (United States)

    Proulx, Caroline; Yoo, Stan; Connolly, Michael D; Zuckermann, Ronald N

    2015-11-01

    N-Aryl glycines are a chemically diverse class of peptoid monomers that have strong structure-inducing propensities. Yet their use has been limited due to the sluggish reactivity of the weakly nucleophilic aniline submonomers. Here, we report up to a 76-fold rate acceleration of the displacement reaction using aniline submonomers in solid-phase peptoid synthesis. This is achieved by adding halophilic silver salts to the displacement reaction, facilitating bromide abstraction and AgBr precipitation. Mechanistic insight derived from analysis of a series of 15 substituted anilines reveals that the silver-mediated reaction proceeds through a transition state that has considerably less positive charge buildup on the incoming nucleophile and an enhanced leaving group. This straightforward enhancement to the submonomer method enables the rapid room temperature synthesis of a wide variety of N-aryl glycine-rich peptoid oligomers, possessing both electron-withdrawing and -donating substituents, in good yields. PMID:26280152

  4. Antioxidant and DNA damage inhibition activities of 4-Aryl-N-(4-arylthiazol-2-yl)-5,6-dihydro-4H-1,3,4-oxadiazine-2-carboxamides

    Indian Academy of Sciences (India)

    K Shubakara; K B Umesha; N Srikantamurthy; J Chethan

    2014-11-01

    A series of 4-aryl--(4-pheny-thiazol-2-yl)-5,6-dihydro-4-1,3,4-oxadiazine-2-carboxamides were synthesized by condensing 4-aryl-5,6-dihydro-4-1,3,4-oxadiazine-2-carboxylic acid with 2-amino-4-aryl-thiazole derivatives. The newly synthesized molecules were characterized by spectral analysis and subjected to antioxidant and DNA damage inhibition studies.

  5. A General Strategy for the Organocatalytic Activation of C–H Bonds via Photoredox Catalysis: The Direct Arylation of Benzylic Ethers

    Science.gov (United States)

    Qvortrup, Katrine; Rankic, Danica A.

    2014-01-01

    The direct C–H functionalization and arylation of benzyl ethers has been accomplished via photoredox organocatalysis. The productive merger of a thiol catalyst and a commercially available iridium photoredox catalyst in the presence of household light directly affords benzylic arylation products in good to excellent yield. The utility of this methodology was further demonstrated in the direct arylation of 2,5-dihydrofuran to form a single regioisomer. PMID:24341523

  6. A General Strategy for the Organocatalytic Activation of C–H Bonds via Photoredox Catalysis: The Direct Arylation of Benzylic Ethers

    OpenAIRE

    Qvortrup, Katrine; Rankic, Danica A.; MacMillan, David W. C.

    2013-01-01

    The direct C–H functionalization and arylation of benzyl ethers has been accomplished via photoredox organocatalysis. The productive merger of a thiol catalyst and a commercially available iridium photoredox catalyst in the presence of household light directly affords benzylic arylation products in good to excellent yield. The utility of this methodology was further demonstrated in the direct arylation of 2,5-dihydrofuran to form a single regioisomer.

  7. Synthesis of tricyclic nitrogen heterocycles by a sequence of palladium-catalyzed N-H and C(sp3)-H arylations.

    Science.gov (United States)

    Guyonnet, Mathieu; Baudoin, Olivier

    2012-01-01

    A range of tricyclic nitrogen heterocycles were synthesized in a straightforward and efficient manner via a sequence involving palladium-catalyzed N-arylation and C(sp(3))-H arylation as the key steps. Whereas the C(sp(3))-H arylation furnished fused 6,5,6-membered ring systems efficiently, the formation of the more strained 6,5,5-membered systems proved to be more challenging and required a subtle adjustment of the reaction conditions. PMID:22176522

  8. General Approach for Monolayer Formation of Covalently Attached Aryl Groups Through Electrografting of Arylhydrazines

    DEFF Research Database (Denmark)

    Malmos, Kristoffer; Pedersen, Steen U.; Daasbjerg, Kim; Iruthayaraj, Joseph

    2009-01-01

    An electrochemical approach is presented for carrying out controlled modification of carbon and metal surfaces with aryl groups through mild anodic oxidation of arylhydrazines. Electrochemical, PM-IRRAS, and ellipsometrical measurements reveal that monolayers are formed, the thickness of which is essentially independent of the substituent, pH, and grafting time and potential. This feature makes the approach very tolerant toward variations in the experimental conditions. Hence, this method should...

  9. The role of endogenous aryl hydrocarbon receptor signaling in cardiovascular physiology

    OpenAIRE

    Zhang, Nan

    2011-01-01

    The aryl hydrocarbon receptor (AHR) is an orphan nuclear receptor with a primary function of mediating xenobiotic metabolism through transcriptional activation of Phase I and Phase II drug-metabolizing enzymes. Although no high-affinity physiological activators of AHR have been discovered, the endogenous signaling of the AHR pathway is believed to play an important role in the development and function of the cardiovascular system, based on the observations on ahr gene-deficient mice. The AHR ...

  10. Microwave-Assisted Synthesis of Some 3,5-Arylated 2-Pyrazolines

    OpenAIRE

    Hassan Ghasemnejad; Davood Azarifar

    2003-01-01

    Condensation of 2-acetylnaphthalene with benzaldehydes under microwave irradiation affords chalcones which undergo facile and clean cyclizations with hydrazines RNHNH2 (R= H, Ph, Ac) to afford 3,5-arylated 2-pyrazolines in quantitative yields, also under microwave irradiation and in the presence of dry AcOH as cyclizing agent. The results obtained indicate that, unlike classical heating, microwave irradiation results in higher yields, shorter reaction times (2-12 min.) and cleaner reactions.

  11. Microwave-Assisted Synthesis of Some 3,5-Arylated 2-Pyrazolines

    Directory of Open Access Journals (Sweden)

    Hassan Ghasemnejad

    2003-07-01

    Full Text Available Condensation of 2-acetylnaphthalene with benzaldehydes under microwave irradiation affords chalcones which undergo facile and clean cyclizations with hydrazines RNHNH2 (R= H, Ph, Ac to afford 3,5-arylated 2-pyrazolines in quantitative yields, also under microwave irradiation and in the presence of dry AcOH as cyclizing agent. The results obtained indicate that, unlike classical heating, microwave irradiation results in higher yields, shorter reaction times (2-12 min. and cleaner reactions.

  12. Demethylation of the aryl hydrocarbon receptor repressor as a biomarker for nascent smokers

    OpenAIRE

    PHILIBERT, ROBERT A.; Beach, Steven R. H.; Brody, Gene H

    2012-01-01

    Epigenetic modifications to peripheral white blood cell DNA occur in response to a wide variety of exposures. In prior work, we and others have shown that broad changes in DNA methylation, particularly at the aryl hydrocarbon receptor repressor (AHRR) locus, occur in samples from subjects with long histories of smoking. However, given the large number of epigenetic changes that occur in response to prolonged smoking, the primacy of the response at AHRR and the sensitivity of these changes to ...

  13. Corrigendum to Solvent-dependent oxidative coupling of 1-aryl-1,3-dicarbonyls and styrene

    OpenAIRE

    Casey, Brian M; Eakin, Cynthia A.; Jiao, Jingliang; Sadasivam, Dhandapani V.; Flowers, Robert A.

    2010-01-01

    This report describes the scope and mechanism of the solvent-dependent, chemoselective oxidative coupling of 1-aryl-1,3-dicarbonyls with styrene using Ce(IV) reagents. Dihydrofuran derivatives are obtained when reactions are performed in methanol whereas nitrate esters can be selectively synthesized in acetonitrile and methylene chloride. Mechanistic studies are consistent with the rate of solvent-assisted deprotonation of a radical cation intermediate playing an integral role in the selectiv...

  14. Solvent-dependent oxidative coupling of 1-aryl-1,3-dicarbonyls and styrene

    OpenAIRE

    Casey, Brian M; Eakin, Cynthia A.; Jiao, Jingliang; Sadasivam, Dhandapani V.; Flowers, Robert A.

    2009-01-01

    This report describes the scope and mechanism of the solvent-dependent, chemoselective oxidative coupling of 1-aryl-1,3-dicarbonyls with styrene using Ce(IV) reagents. Dihydrofuran derivatives are obtained when reactions are performed in methanol whereas ?-tetralones can be selectively synthesized in acetonitrile and methylene chloride. Mechanistic studies are consistent with the rate of solvent-assisted deprotonation of a radical cation intermediate playing an integral role in the selective ...

  15. Synthesis and Antifungal Evaluation of 1-Aryl-2-dimethyl-aminomethyl-2-propen-1-one Hydrochlorides

    OpenAIRE

    Mehmet Emin Topaloglu; Medine Gulluce; Oztekin Algul; Ebru Mete; Halise Inci Gul; Cavit Kazaz; Sinan Bilginer

    2011-01-01

    The development of resistance to current antifungal therapeutics drives the search for new effective agents. The fact that several acetophenone-derived Mannich bases had shown remarkable antifungal activities in our previous studies led us to design and synthesize some acetophenone-derived Mannich bases, 1-8 and 2-acetylthiophene-derived Mannich base 9, 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochloride, to evaluate their antifungal activities. The designed chemical structures have ?,?...

  16. Carbonylative Suzuki Couplings of Aryl Bromides with Boronic Acid Derivatives under Base-Free Conditions

    DEFF Research Database (Denmark)

    Bjerglund, Klaus Meier; Skrydstrup, Troels

    2014-01-01

    The carbonylative Suzuki-Miyaura reaction between aryl bromides and arylboronic acid equivalents is herein reported, using base-free conditions and a limited excess of carbon monoxide generated ex situ from stable CO. precursors. Under these conditions, unsymmetrical biaryl ketones were obtained in modest to excellent yields. This method was adapted to the synthesis of the triglyceride and cholesterol regulator drug, fenofibrate, and its C-13-labeled derivative in good yields from the appropriate CO-precursor.

  17. Synthesis and thermal degradation characterization of novel poly(phosphazene-aryl amides)

    OpenAIRE

    Z. P. Zhao; Guo, Q.; Li, X.; Sun, J.L.; Z. J. Nie

    2012-01-01

    New fully aromatic poly(phosphazene-aryl amides) were prepared by polycondensation reaction of our synthesized aromatic diamine: 1,1,3,5-tetraphenoxy-4,6-bis(4-aminophenoxy)oligocyclotriphosphazene (monomer 1) with terephthaloyl dichloride. Their chemical structure and composition were characterized by elemental analysis, 1H and 31P NMR (Nuclear Magnetic Resonance), and FT-IR (Fourier transform infrared) spectroscopy, whereas their thermal degradation properties were determined by DSC (Differ...

  18. Merging photoredox with nickel catalysis: Coupling of ?-carboxyl sp3-carbons with aryl halides

    OpenAIRE

    Zuo, Zhiwei; Ahneman, Derek T.; Chu, Lingling; Terrett, Jack A.; Doyle, Abigail G.; MacMillan, David W. C.

    2014-01-01

    Over the past 40 years, transition metal catalysis has enabled bond formation between aryl and olefinic (sp2) carbons in a selective and predictable manner with high functional group tolerance. Couplings involving alkyl (sp3) carbons have proven more challenging. Here, we demonstrate that the synergistic combination of photoredox catalysis and nickel catalysis provides an alternative cross-coupling paradigm, in which simple and readily available organic molecules can be systematically used as...

  19. Room-Temperature Decarboxylative Couplings of ?-Oxocarboxylates with Aryl Halides by Merging Photoredox with Palladium Catalysis.

    Science.gov (United States)

    Cheng, Wan-Min; Shang, Rui; Yu, Hai-Zhu; Fu, Yao

    2015-09-14

    Enabled by merging iridium photoredox catalysis and palladium catalysis, ?-oxocarboxylate salts can be decarboxylatively coupled with aryl halides to generate aromatic ketones and amides at room temperature. DFT calculations suggest that this reaction proceeds through a Pd(0) -Pd(II) -Pd(III) pathway, in which the Pd(III) intermediate is responsible for reoxidizing Ir(II) to complete the Ir(III) -*Ir(III) -Ir(II) photoredox cycle. PMID:26230749

  20. Space radiation effects on poly(aryl-ether-ketone) thin films and composites

    Science.gov (United States)

    Funk, Joan G.; Sykes, George F., Jr.

    1988-01-01

    The purpose of this study was to assess the space durability of poly(aryl-ether-ketone) (PEEK) in the forms of films and graphite fiber reinforced composites. The influence of the film's crystallinity on electron radiation stability was evaluated using X-ray diffraction, DSC, FTIR, and mechanical property tests. The mechanical properties of the composites material were evaluated after electron radiation and after electron radiation followed by thermal cycling simulating 30 years in geosynchronous orbit.

  1. Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

    OpenAIRE

    Grzegorz Mlostoń; Paulina Grzelak; Maciej Mikina; Anthony Linden; Heinz Heimgartner

    2015-01-01

    Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresp...

  2. Insulin like growth factor 2 regulation of Aryl Hydrocarbon Receptor in MCF-7 breast cancer cells

    OpenAIRE

    Justin K. Tomblin; Salisbury, Travis B.

    2013-01-01

    Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancer proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IG...

  3. No evidence of somatic aryl hydrocarbon receptor interacting protein mutations in sporadic endocrine neoplasia

    DEFF Research Database (Denmark)

    Raitila, A; Georgitsi, M; Karhu, A; Tuppurainen, K; Mäkinen, M J; Birkenkamp-Demtröder, K; Salmenkivi, K; Orntoft, T F; Arola, J; Launonen, V; Vahteristo, P; Aaltonen, L A

    2007-01-01

    Germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene were recently observed in patients with pituitary adenoma predisposition (PAP). Though AIP mutation-positive individuals with prolactin-, mixed growth hormone/prolactin-, and ACTH-producing pituitary adenomas as well as non-secreting pituitary adenomas have been reported, most mutation-positive patients have had growth hormone-producing adenomas diagnosed at relatively young age. Pituitary adenomas are also compon...

  4. Anaerobic Aryl Reductive Dehalogenation of Halobenzoates by Cell Extracts of “Desulfomonile tiedjei”

    OpenAIRE

    DeWeerd, Kim A.; Suflita, Joseph M.

    1990-01-01

    We studied the transformation of halogenated benzoates by cell extracts of a dehalogenating anaerobe, “Desulfomonile tiedjei.” We found that cell extracts possessed aryl reductive dehalogenation activity. The activity was heat labile and dependent on the addition of reduced methyl viologen, but not on that of reduced NAD, NADP, flavin mononucleotide, flavin adenine dinucleotide, desulfoviridin, cytochrome c3, or benzyl viologen. Dehalogenation activity in extracts was stimulated by formate, C...

  5. Lineage-dependent effects of aryl hydrocarbon receptor agonists contribute to liver tumorigenesis

    OpenAIRE

    Harrill, Joshua A.; Parks, Bethany B; Wauthier, Eliane; Rowlands, J. Craig; Reid, Lola M; Thomas, Russell S.

    2015-01-01

    Rodent cancer bioassays indicate that the aryl hydrocarbon receptor (AHR) agonist, 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD), causes increases in both hepatocytic and cholangiocytic tumors. Effects of AHR activation have been evaluated on rodent hepatic stem cells (rHpSCs) versus their descendants, hepatoblasts (rHBs), two lineage stages of multipotent, hepatic precursors with overlapping but also distinct phenotypic traits. This was made possible by defining the first successful culture co...

  6. An Alternative Synthetic Approach to 3-Alkylated/Arylated 5-Nitropyridines.

    Science.gov (United States)

    Le, Song Thi; Asahara, Haruyasu; Nishiwaki, Nagatoshi

    2015-09-01

    An alternative method for the synthesis of 3-alkylated/arylated 5-nitropyridines was developed involving a three-component ring transformation of 3,5-dinitro-2-pyridone on treatment with aldehyde in the presence of ammonium acetate. This method facilitates the modification of the substituent at the 3-position by changing the precursor aldehyde. The use of solid ammonium acetate instead of ammonia as the nitrogen source renders the synthetic method more practical and user-friendly. PMID:26244697

  7. Aryl hydrocarbon receptor ligand effects in RBL2H3 cells

    DEFF Research Database (Denmark)

    Maaetoft-Udsen, Kristina; Shimoda, Lori M. N.; Frøkiær, Hanne; Turner, Helen

    2012-01-01

    The aryl hydrocarbon receptor (AHR) mediates toxic effects of dioxin and xenobiotic metabolism. AHR has an emerging role in the immune system, but its physiological ligands and functional role in immunocytes remain poorly understood. Mast cells are immunocytes that are central to inflammatory responses and release a spectrum of pro-inflammatory mediators including histamine, mast cell proteases, and pro-inflammatory cytokines such as IL-6 upon stimulation. The aim was to investigate the AHR in m...

  8. A theoretical mechanistic investigation of asymmetric aziridination by N-Aryl-O-acylhydroxylamines.

    Science.gov (United States)

    Chaves, Humberto T.; Lobo, Ana M.; Prabhakar, Sundaresan; Rzepa, Henry S.

    1995-04-01

    This paper reports a theoretical investigation of the most probable mechanism for the asymmetric aziridination of olefins by N-aryl-O-acylhydroxylamines. The transition states of two possible mechanisms (Scheme 2) were studied. The transition state for pathway 2 (oxaziridine as intermediate) has a lower energy of activation than the energy of the transition state for pathway 1. The anionic transition state of pathway 2 is more stable than the neutral transition state.

  9. Brönsted acid catalyzed direct oxidative arylation of 1,4-naphthoquinone

    Directory of Open Access Journals (Sweden)

    Katarzyna Kap?on

    2014-01-01

    Full Text Available An inexpensive straightforward approach to direct oxidative twofold C-H arylation of 1,4-naphthoquinone catalyzed by readily available Brönsted acids was developed. Under the simple and easily achievable reaction conditions, electron-rich aromatics undergo Friedel-Crafts type functionalization to furnish 2-arylonaphthoquinones in good yields. The attempt to rationalize the scope and limitation of the approach based on desktop PC DFT calculation and reactivity indexes theory was taken up.

  10. Association between aryl hydrocarbon receptor genotype and survival in soft tissue sarcoma

    OpenAIRE

    Matullo, Giuseppe; Vineis, Paolo; Guarrera, Simonetta

    2004-01-01

    PURPOSE: Accumulating evidence shows that germline polymorphisms may affect survival in cancer. The purpose of this study was to investigate the association between polymorphisms in a group of candidate genes and survival with soft tissue sarcoma. PATIENTS AND METHODS: We measured single nucleotide polymorphisms in the metabolizing, detoxifying, and DNA repair pathways in 120 newly diagnosed patients with soft tissue sarcoma. We assessed polymorphisms in the aryl hydrocarbon receptor (AhR-Arg...

  11. [3+2] Cycloadditions of Aryl Cyclopropyl Ketones by Visible Light Photocatalysis

    Science.gov (United States)

    Lu, Zhan; Shen, Meihua; Yoon, Tehshik P.

    2011-01-01

    We report a new method for the formal [3+2] reaction of aryl cyclopropyl ketones with olefins to generate highly substituted cyclopentane ring systems. The key initiation step in this process is the one-electron reduction of the ketone to the corresponding radical anion, which is accomplished using a photocatalytic system comprising Ru(bpy)32+, La(OTf)3?, and TMEDA. PMID:21214249

  12. Spectral and catalytic properties of aryl-alcohol oxidase, a fungal flavoenzyme acting on polyunsaturated alcohols

    OpenAIRE

    Ferreira, P.; Medina, M.; Guillén, F.; Martínez, M.J.; Berkel, W.J.H., van; Martínez, A.T.

    2005-01-01

    Spectral and catalytic properties of the flavoenzyme AAO (aryl-alcohol oxidase) from Pleurotus eryngii were investigated using recombinant enzyme. Unlike most flavoprotein oxidases, AAO does not thermodynamically stabilize a flavin semiquinone radical and forms no sulphite adduct. AAO catalyses the oxidative dehydrogenation of a wide range of unsaturated primary alcohols with hydrogen peroxide production. This differentiates the enzyme from VAO (vanillyl-alcohol oxidase), which is specific fo...

  13. Aryl Hydrocarbon Receptor–Independent Toxicity of Weathered Crude Oil during Fish Development

    OpenAIRE

    Incardona, John P.; Carls, Mark G.; Teraoka, Hiroki; Sloan, Catherine A.; Collier, Tracy K.; Scholz, Nathaniel L.

    2005-01-01

    Polycyclic aromatic hydrocarbons (PAHs), derived largely from fossil fuels and their combustion, are pervasive contaminants in rivers, lakes, and nearshore marine habitats. Studies after the Exxon Valdez oil spill demonstrated that fish embryos exposed to low levels of PAHs in weathered crude oil develop a syndrome of edema and craniofacial and body axis defects. Although mechanisms leading to these defects are poorly understood, it is widely held that PAH toxicity is linked to aryl hydrocarb...

  14. Photoinduced intramolecular substitution reaction of aryl halide with carbonyl oxygen of amide group

    CERN Document Server

    Park, Y T; Kim, M S; Kwon, J H

    2002-01-01

    Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl)acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

  15. Aryl hydrocarbon receptor activation by cAMP vs. dioxin: Divergent signaling pathways

    OpenAIRE

    Oesch-Bartlomowicz, Barbara; Huelster, Andrea; Wiss, Oliver; Antoniou-Lipfert, Patricia; Dietrich, Cornelia; Arand, Michael; Weiss, Carsten; Bockamp, Ernesto; Oesch, Franz

    2005-01-01

    Even before the first vertebrates appeared on our planet, the aryl hydrocarbon receptor (AHR) gene was present to carry out one or more critical life functions. The vertebrate AHR then evolved to take on functions of detecting and responding to certain classes of environmental toxicants. These environmental pollutants include polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene), polyhalogenated hydrocarbons, dibenzofurans, and the most potent small-molecular-weight toxicant known, 2,3,7,8-...

  16. Different regulation of aryl hydrocarbon receptor-regulated genes in response to dioxin in undifferentiated and neuronally differentiated human neuroblastoma SH-SY5Y cells.

    Science.gov (United States)

    Imran, Saima; Ferretti, Patrizia; Vrzal, Radim

    2015-11-01

    Some environmental pollutants derived from industrial processes have been suggested to be responsible for neurological impairment in children, especially in heavily polluted areas. Since these compounds are usually activators of aryl hydrocarbon receptor (AhR), it would be important to better understand the molecular pathways downstream of AhR leading to neural deficits. To this purpose, appropriate in vitro human neural model is much needed. Here we have investigated whether undifferentiated and neuronally differentiated human neuroblastoma cells, SH-SY5Y cells, can provide a suitable model for monitoring AhR activity induced by environmental pollutants, focusing on 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD), a known activator of AhR. Further characterization of differentiated SH-SY5Y showed an increase in AhRR (aryl hydrocarbon receptor repressor), no change in ARNT1 (AhR nuclear translocator 1), and a decrease in ARNT2 expression with differentiation; in contrast, AhR was undetectable in both undifferentiated and differentiated cells. Nonetheless, treatment of parental as well as differentiated SH-SY5Y cells with TCDD resulted in the induction of AhR-regulated genes, CYP1A1 and CYP1B1; AhRR expression was also affected, but to a much smaller extent. These results indicate that undifferentiated SH-SY5Y are less sensitive to TCDD than neuronally differentiated ones, suggesting a higher resistance of the undifferentiated tumor cells to toxic insults. They also suggest that TCDD in these cells may not act via direct activation of AhR that is undetectable in SH-SY5Y as well as in differentiated neurons. Hence, these cells do not provide an appropriate model for studying ligand-mediated activation of AhR. PMID:26567990

  17. Synthesis and thermal degradation characterization of novel poly(phosphazene-aryl amides

    Directory of Open Access Journals (Sweden)

    Z. P. Zhao

    2012-04-01

    Full Text Available New fully aromatic poly(phosphazene-aryl amides were prepared by polycondensation reaction of our synthesized aromatic diamine: 1,1,3,5-tetraphenoxy-4,6-bis(4-aminophenoxyoligocyclotriphosphazene (monomer 1 with terephthaloyl dichloride. Their chemical structure and composition were characterized by elemental analysis, 1H and 31P NMR (Nuclear Magnetic Resonance, and FT-IR (Fourier transform infrared spectroscopy, whereas their thermal degradation properties were determined by DSC (Differential Scanning Calorimetry and TGA (Thermal Gravimertic Analysis techniques. The solid residues of all samples were analysed by FT-IR and SEM (Scanning Electron Microscopy. Compared to conventional PPTA (poly(p-phenylene terephthamide, PPAA (poly(phosphazene-aryl amide shows excellent thermal stability and solubility in polar protic solvents. All poly(phosphazene-aryl amides show two thermal degradation in the temperature range 150–600°C. The monomer 1, due to its structure, shows the first maximum rate of thermal decomposition temperature around 150–350°C, which may be due to the decomposition of the P–O–C bone. Morphology of the solid residues by Scanning Electron Microscope exhibit that the granular of the solid residues gradual disappearance with the increase of monomer 1 content. The surface layer of PPAA solid residues has been grumous, for the syneresis of P–O–P took place.

  18. Peroxidative metabolism of carcinogenic N-arylhydroxamic acids: implications for tumorigenesis.

    OpenAIRE

    Malejka-Giganti, D.; Ritter, C L

    1994-01-01

    Peroxidative oxidations of chemical carcinogens including N-substituted aryl compounds could result in their metabolic activation because the products react with cellular molecules and lead to cytotoxicity, mutagenicity, and carcinogenicity. In vivo, peroxidative activities are chiefly of neutrophilic leukocyte origin. Neutrophils may be attracted to the site(s) of exposure to carcinogen and, via phagocytosis and respiratory burst, release oxidants that catalyze carcinogen activation and/or c...

  19. 4-Aryl-3,5-bis(arylethynyl)aryl-4H-1,2,4-triazoles: multitasking skeleton as a self-assembling unit.

    Science.gov (United States)

    Pastor, M Jesús; Torres, Iván; Cebrián, Cristina; Carrillo, José Ramón; Díaz-Ortiz, Ángel; Matesanz, Emilio; Buendía, Julia; García, Fátima; Barberá, Joaquín; Prieto, Pilar; Sánchez, Luis

    2015-01-19

    The synthesis of a series of 4-aryl-3,5-bis(arylethynyl)aryl-4H-1,2,4-triazoles derivatives is reported and the influence exerted by peripheral substitution on the morphology of the aggregates generated from these 1,2,4-triazoles is investigated by SEM imaging. The presence of paraffinic side chains results in long fibrillar supramolecular structures, but unsubstituted triazoles self-assemble into thinner ribbons and needle-like aggregates. The crystals obtained from methoxy-substituted triazoles have been utilised to elaborate a model that helps to justify aggregation of the investigated 1,2,4-triazoles, in which the operation of arrays of C-H???? non-covalent interactions plays a significant role. The results presented herein demonstrate the ability of simple molecules to behave as multitasking scaffolds with different properties, depending on peripheral substitution. Thus, although 1,2,4-triazoles without long paraffinic side chains exhibit optical waveguiding behaviour, triazoles endowed with peripheral paraffinic side chains exhibit hexagonal columnar mesomorphism. PMID:25413614

  20. Direct arylation of benzene with aryl bromides using high-temperature/high-pressure process windows: expanding the scope of C-H activation chemistry.

    Science.gov (United States)

    Pieber, Bartholomäus; Cantillo, David; Kappe, C Oliver

    2012-04-16

    A detailed investigation on the direct arylation of benzene with aryl bromides by using first-row transition metals under high-temperature/high-pressure (high-T/p) conditions is described. By employing a parallel reactor platform for rapid reaction screening and discovery at elevated temperatures, various metal/ligand/base combinations were evaluated for their ability to enable biaryl formation through C-H activation. The combination of cobalt(III) acetylacetonate and lithium bis(trimethylsilyl)amide was subjected to further process intensification at 200?°C (15?bar), allowing a significant reduction of the catalyst/base loading and a dramatic increase in catalytic efficiency (turnover frequency) by a factor of 1000 compared to traditional protocols. The high-throughput screening additionally identified novel nickel- and copper-based metal/ligand combinations that favored an amination pathway competing with C-H activation, with the addition of ligands, such as 1,10-phenanthroline, having a profound influence on the selectivity. In addition to metal-based catalysts, high-T/p process windows were also successfully applied to transition-metal-free systems, utilizing 1,10-phenanthroline as organocatalyst. PMID:22396386