The Experts below are selected from a list of 534 Experts worldwide ranked by ideXlab platform

Avinash Desai - One of the best experts on this subject based on the ideXlab platform.

Surya Prakash H Rao - One of the best experts on this subject based on the ideXlab platform.

Monika Wujec - One of the best experts on this subject based on the ideXlab platform.

  • influence of the solvent description on the predicted mechanism of sn2 reactions
    Journal of Physical Chemistry B, 2008
    Co-Authors: Monika Wujec, Agata Siwek, Joanna Dzierzawska, Michal Rostkowski, Rafal Kaminski, Piotr Paneth
    Abstract:

    The influence of the implicit solvent model on transition state structures of two SN2 reactions of biochemical importance is presented. In the considered mEthyl transfer reaction, we show experimentally that the rate constant in blood serum is about 60% slower than in the aqueous solution and that the implicit solvent model with slightly modified parameters for water captures correctly the energetics of this reaction. With the example of the reaction between 4-mEthyl-1,2,4-triazol-3-thione and Ethyl Bromoacetate, we show that relative stabilities of the conformationally different transition states depend upon the solvent inclusion strategy.

  • cyclization of 1 4 mEthyl 4h 1 2 4 triazol 3 yl sulfanyl acetyl thiosemicarbazides to 1 2 4 triazole and 1 3 4 thiadiazole derivatives and their pharmacological properties
    Collection of Czechoslovak Chemical Communications, 2005
    Co-Authors: Alicja Maliszewskaguz, Monika Wujec, Anna Chodkowska, Ewa Jagiellowojtowicz, Liliana Mazur, Maria Dobosz, Monika Pitucha, Anna E Koziol
    Abstract:

    By the reaction of 4-mEthyl-4 H -1,2,4-triazole-3-thiol with Ethyl Bromoacetate, Ethyl [(4-mEthyl-4 H -1,2,4-triazol-3-yl)sulfanyl]acetate ( 1 ) was obtained. This compound was converted to [(4-mEthyl-4 H -1,2,4-triazol-3-yl)sulfanyl]acetohydrazide ( 2 ). In the reaction of 2 with isothiocyanates, new thiosemicarbazides 3a - 3g were obtained. The cyclization of 3a - 3g in 2% aqueous solution of sodium hydroxide led to the formation of 4 H -1,2,4-triazole-3(2 H )-thione derivatives 4a - 4g , whereas the cyclization in acid media led to the formation of 2-amino-1,3,4-thiadiazole derivatives 5a - 5g . Molecular structure was confirmed by X-ray structure analysis of 3a , 4g , 5a and 5g . Compounds 4a , 4b and 4g were investigated pharmacologically to determine their effect on the central nervous system (CNS) in mice.

Bektas H. - One of the best experts on this subject based on the ideXlab platform.

  • Syntheses and biological activities of new hybrid molecules containing different heterocyclic moieties
    'Wiley', 2013
    Co-Authors: Ceylan S., Bektas H., Bayrak H., Demirbas N., Alpay-karaoglu S., Ülker S.
    Abstract:

    PubMed: 240385194-Aryl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-(thi)oles 5-7, obtained starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases 12-24 by the reaction with several heterocyclic amines in the presence of formaldehyde. The synthesis of S-alkylated compounds 8-11 was performed from the reaction of the corresponding triazol-5-thioles with various alkyl halides. The condensation of carbo(thio)amides 2-4 with 4-chlorophenacyl bromide afforded the corresponding 1,3-thia(oxa)zol-2(3H)-ylidene]pyridine-3- carbohydrazides 25-27. 1,3-Thia(oxa)zolidine derivatives 28-30 were obtained from the cyclization reaction between compounds 2-4 and Ethyl Bromoacetate. All newly synthesized compounds were screened for their antimicrobial, antiurease, and antilipase activities. The biological activity studies revealed that all the compounds screened showed good or moderate antimicrobial, antiurease, and/or antilipase activity. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  • Synthesis and anticancer evaluation of some new 4-amino-3-(p-methoxybenzyl) -4,5-dihydro-1,2,4-triazole-5-one derivatives
    'Walter de Gruyter GmbH', 2008
    Co-Authors: Bekircan O., Kucuk M., Kahveci B., Bektas H.
    Abstract:

    4-Amino-3-p-methoxybenzyl-5-oxo-4,5-dihydro-1,2,4-triazol-1-yl-acetic acid Ethyl ester (2) was prepared from 4-amino-4,5-dihydro-1H-1,2,4-triazole-5-one (1) and Ethyl Bromoacetate. Compound 3 was synthesized by the condensation of 2 with hydrazine hydrate. The treatment of compound 3 with various aromatic aldehydes resulted in the formation of arylidene hydrazides as cis-trans conformers 4a-g. Thiosemicarbazide derivative 5 was prepared by the reaction of compound 3 with phenylisothiocyanate. Cyclization of 5 with sodium hydroxide resulted in the formation of compound 6. Treatment of 6 with benzyl bromide gave compound 7. Four of the newly synthesized compounds were screened for their anticancer activity against a panel of 60 cell lines derived from nine cancer types, namely, non-small cell lung, colon, breast, ovarian, leukemia, renal, melanoma, prostate and CNS cancers at a fixed dose of 10 ?M. © 2008 Verlag der Zeitschrift für Naturforschung

Mohamed M. Abdalla - One of the best experts on this subject based on the ideXlab platform.

  • synthesis and serotonin antagonist and antianexity activities of pyrrolidine derivatives from 4 hydrazinyl 1 p substituted phenyl 2 5 dihydro 1h pyrrole 3 carbonitriles
    Monatshefte Fur Chemie, 2009
    Co-Authors: Mohamed M. Abdalla, Bakr F Abdelwahab
    Abstract:

    AbstractN-(p-substituted phenyl)-4-cyanopyrrolidin-3-ones and their corresponding hydrazines were prepared and used as starting materials to synthesize heterocyclic candidates as serotonin antagonist and antianexity agents. Condensation of hydrazines with selected aromatic aldehydes afforded the corresponding Schiff bases. The hydrazines were treated with phenyl isothiocyanate to afford the corresponding thiosemicarbazides, which were cyclized with Ethyl Bromoacetate to N-phenylthiazolidinones. The hydrazine was reacted with 1,2,4,5-tetrachlorophthalic anhydride to give the tetrachloroimide derivative. It was reacted with benzoyl acetonitrile, 2-(bismEthylsulfanyl-mEthylene)malononitrile, 2-ethoxymEthylenemalononitrile, or 2-cyano-3-ethoxyacrylic acid Ethyl ester to afford the corresponding pyrazoline derivatives. Schiff bases were obtained by simple condensation of the hydrazine with different carbonyl compounds. All the compounds were screened for their serotonin antagonistic and antianexity activities, and they showed high activities compared to buspirone and diazepam as controls.Graphical abstract[IMAGE]

  • Synthesis and serotonin antagonist and antianexity activities of pyrrolidine derivatives from 4-hydrazinyl-1-p-substituted phenyl-2,5-dihydro-1H-pyrrole-3-carbonitriles
    Monatshefte für Chemie - Chemical Monthly, 2008
    Co-Authors: Mohamed M. Abdalla, Bakr F. Abdel-wahab, Abdel-galil E. Amr
    Abstract:

    N -( p -substituted phenyl)-4-cyanopyrrolidin-3-ones and their corresponding hydrazines were prepared and used as starting materials to synthesize heterocyclic candidates as serotonin antagonist and antianexity agents. Condensation of hydrazines with selected aromatic aldehydes afforded the corresponding Schiff bases. The hydrazines were treated with phenyl isothiocyanate to afford the corresponding thiosemicarbazides, which were cyclized with Ethyl Bromoacetate to N -phenylthiazolidinones. The hydrazine was reacted with 1,2,4,5-tetrachlorophthalic anhydride to give the tetrachloroimide derivative. It was reacted with benzoyl acetonitrile, 2-(bismEthylsulfanyl-mEthylene)malononitrile, 2-ethoxymEthylenemalononitrile, or 2-cyano-3-ethoxyacrylic acid Ethyl ester to afford the corresponding pyrazoline derivatives. Schiff bases were obtained by simple condensation of the hydrazine with different carbonyl compounds. All the compounds were screened for their serotonin antagonistic and antianexity activities, and they showed high activities compared to buspirone and diazepam as controls. Graphical abstract

  • synthesis and reactions of thiosemicarbazides triazoles and schiff bases as antihypertensive α blocking agents
    Monatshefte Fur Chemie, 2008
    Co-Authors: Bakr F Abdelwahab, Abdel-galil E. Amr, Salwa F Mohamed, Mohamed M. Abdalla
    Abstract:

    MEthyl 2-(thiazol-2-ylcarbamoyl)acetate was synthesized and used as starting material. It was treated with hydrazine hydrate to afford the hydrazide, which was reacted with nitromethane and formaldehyde to give the saturated nitropyrimidine. The hydrazide was reacted with phenyl isothiocyanate to afford the thiosemicarbazide, which was cyclized with Ethyl Bromoacetate, sodium hydroxide, or sulfuric acid to afford N-phenylthiazolidinone, N-phenyltriazole, and thiadiazolyl derivatives. The mEthyl 2-(thiazol-2-ylcarbamoyl)acetate was coupled with diazonium salts of aniline, 4-chloroaniline, 4-bromoaniline, or 4-aminobenzenesulfonamide to afford the carbamoyl acetates, which were reacted with 2-aminobenzimidazole, 1,2,4,5-tetrachlorophthalic anhydride, and hydrazine hydrate to afford the corresponding thiazolylmalonamide, tetrachloroisoindolylimide, and tri-azole derivatives. Schiff bases and imides are newly synthesized candidates obtained via simple condensation of the hydrazide with aldehydes, 2,3-pyridinedicarboxylic anhydride, or 1,8-naphthalenedicarboxylic anhydride. The pharmacological screening showed that many of these compounds have good antihypertensive α-blocking activity and low toxicity.