Synthesis and Biological Evaluation of Some Novel Arylidene Hydrazides Derivatives

Abstract

There has been considerable interest in the development of novel compounds with anticonvulsant, antioxidant, antibacterial, and antifungal activities. The present study explores the antimicrobial activity of some new arylidene hydrazide derivatives and correlates the effect on the antimicrobial potency by varying the substituents on hydrazide part of the arylidine hydrazide. Hydrazones possessing an azomethine–NHN=CH- proton constitute an important class of compounds for new drug developments; therefore, a series of arylidene hydrazides were synthesized with various aromatic aldehydes/ketones. The synthesis of title compounds was affected as outlined in the scheme. In this scheme O-chloro benzoic acid on reaction with aniline through Ullmann Reaction gave N-phenyl anthranilic acid. The esterification product of N-phenyl anthranilic acid followed by reaction with hydrazine hydrate yielded 2-phenyl amino benzoic acid hydrazide. These hydrazides were give arylidine hydrazide as title compounds. A total of 11 compounds were synthesized. The synthetic methods used are simple, rapid, and economical found to be accurate and reproducible. All the intermediates and title compounds were characterized by running TLC, determining M.P. and spectral studies such as IR and 1H-NMR. The synthesized compounds showed mild-to-moderate antibacterial activity against Gram-positive Bacillus subtilis (MTCC441), Bacillus cereus (MTCC-7190) and Gram-negative Escherichia coli and antifungal activity against Candida albicans and Aspergillus fumigates (ATTC 9197). The bio-screening data revealed that 4b, 4f, 4g, 4h, and 4j moiety exhibited good antibacterial activity against all where 4a and 4c showed good antifungal activity. Among the compounds, 4a and 4c exhibited good antioxidant activity too.