Design, Synthesis and Evaluation of Antimicrobial Activities of Some Chalcone & Schiff base Derivatives Clubbed with 1H-Benzimidazole

Abstract

A series of 2-(1H-benzo[d]imidazol-2-ylthio)-3-(substitutedphenyl)-1-(substitutedphenyl) prop-2-en-1-one 3 (A-L) derivatives have been synthesized via Claisen-schmidt reaction of different aromatic aldehydes with 2- benzimidazolyl thioacetophenone 2(A-D) derivatives and these 2-mercaptobenzimidazolyl acetophenone derivatives which in turn synthesized by condensation of various acetophenones with 2-mercaptobenzimidazole 1A & 6-methoxy-2-mercaptobenzimidazole 1B. On the other hand desired Schiff base derivatives N-(3-chlorophenyl)-2-(1-(2-hydrazinyl-2-oxoethyl)-1H-benzo[d]imidazol-2-ylthio)acetamide 7(A-H) have been prepared in three successive steps which comprised of synthesis of ethyl 2-(2-(2-(3-chloro phenyl amino)-2-oxoethylthio)-1H-enzo[d]imidazol- 1-yl) acetate 5 its corresponding hydrazide N-(3-chloro phenyl)-2-(1-(2-hydrazinyl-2-oxoethyl)-1Hbenzo[d]imidazol-2-ylthio) acetamide 6 and finally Schiff base derivatives via acid catalyzed condensation reactionof various aldehydes with this hydrazide. All the synthesized compounds were characterized by IR, 1H NMR and mass spectral techniques and evaluated for their antimicrobial activity.