synthesis and in vitro antimicrobial activity of some pyrazolyl-1-carboxamide derivatives合成和一些pyrazolyl-1-carboxamide衍生物的体外抗菌活性.pdf

Molecules 2011, 16, 7736-7745; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis and in Vitro Antimicrobial Activity of Some Pyrazolyl-1-carboxamide Derivatives Essam Mohamed Sharshira 1,* and Nagwa Mohamed Mahrous Hamada 2 1 Department of Chemistry, Faculty of Science, Alexandria University, Alexandria 426, Egypt 2 Department of Chemistry, Faculty of Education, Alexandria University, Alexandria 21526, Egypt; E-Mail: nagwahamada2002@ * Author to whom correspondence should be addressed; E-Mail: dressamsharshira@. Received: 13 August 2011; in revised form: 25 August 2011 / Accepted: 31 August 2011 / Published: 9 September 2011 Abstract: A series of 3,5-disubstituted pyrazole-1-carboxamides were obtained by treatment of chalcones with semicarbazide hydrochloride in dioxane containing sodium acetate/acetic acid as a buffer solution. N-acetyl derivatives of pyrazole-1-carboxamides were isolated in good yields either by treatment of the carboxamide derivatives with acetic anhydride or refluxing chalcones with semicarbazide in ethanol containing few drops of acetic acid to give the corresponding hydrazones. Subsequent treatment of hydrazones with acetic anhydride gave the desired N-acetyl pyrazole-1-carboxamides derivatives. When chalcones were refluxed with dioxane containing few drops of acetic acid, 4,5-dihydropyrazole-1-carboxam