Synthesis, characterization and antimicrobial activity of 1,3,4-oxadiazole bearing 1H-benzimidazole derivatives

Abstract2-(Phenoxymethyl)-1H-benzimidazole (3) obtained by acidic condensation of o-phenylene diamine with phenoxyacetic acid, was reacted with ethyl chloroacetate under anhydrous condition to get ethyl [2-(phenoxymethyl)-1H-benzimidazol-1-yl]acetate (4). The ethyl [2-(phenoxymethyl)-1H-benzimidazol-1-yl]acetate (4) on treatment hydrazine hydrate gave 2-[2-(phenoxymethyl)-1Hbenzimidazol-1-yl]acetohydrazide (5). The acid hydrazide group of 5 was cyclocondensed with various aromatic acids in presence of phosphorous oxychloride to get the titled compounds (6a–p). The structures of all the compounds were established on the basis of elemental and spectral analysis. The synthesized compounds were evaluated for their antimicrobial activity. The compound 6d, 6f, 6h and 6d, 6h and 6I a is most active compounds against Escherichia coli and Staphylococcus aureus respectively. The compound 6d, 6f and 6l is most active against Candida albicans and Aspergillus flavus