Synthesis of 1,2,3,4-[1-N-Methyl Benzimidazole] 3-Phenyl Substituted Thiazolidine, 4-One and Carbohydrazide Derivatives for Antimicrobial Activity.

Research on benzimidazole and thiazolidine-4-one and their synthetic analogs have been revealed to posses wide range of antimicrobial activity. It was our interest to make novel derivatives of fused benzimidazole, thiazolidine-4-one nuclei and evaluate them for antimicrobial activity. Formic acid was treated with o-phenylenediamine to obtain benzimidazole which was treated with CH₃I for N-methylation. Later this compound was subjected for Vilsmeier-Haack Reaction, followed by formation of Schiff bases on treatment with various aromatic amines. The various Schiff bases were further treated with thioglycolic acid to obtain thaizolidine-4-one derivatives. (Scheme-I). In another (Scheme-II) N-methyl substituted benzimidazole-2-carbohydrazide (Vilsmeier-Haack Reaction product) followed by acidification, esterification and hydrazide formation. Finally hydrazide treated with different aldehydes to obtain carbohydrazide derivatives. The structures of synthesized derivatives were identified and characterized by m.p, TLC, IR, ¹HNMR and Mass Spectroscopy. The synthesized compounds BA-SA, BA-SN, AH-BR and AH-CL have shown significant antibacterial activity against E. coli, E.fecalis, Klebsiella and S. aureus and BA-SA, BA-SN, BA-CL and AH-CL shown significant antifungal activity against C. albicans and A. niger.