Synthesis and antimicrobial activity of novel 4-(1H-benzo[d]imidazol-2-yl)-4,5-dihydro-benzo[f][1,4]-oxazepin-3(2H) ones

A novel new series of 4-(1H-benzo[d]imidazol-2-yl)-4,5-dihydro-benzo[f][1,4]-oxazepin-3(2H)-ones (4) were synthesized by a simple reaction sequence. The reaction of 2-amino benzimidazole (1) with salicyladehydes, followed by reduction with NaBH4, and in situ chloroacetylation and cyclization with chloroacetyl chloride and triethyl amine afforded the title compounds. The structures of the newly synthesized compounds (2-4) were characterized by IR, 1H NMR, 13C NMR and mass spectral data. The title compounds (4) were screened for their   in vitro antimicrobial activity against bacterial and fungal strains by broth dilution method and agar cup bioassay method respectively. Some of the compounds exhibited good antimicrobial activity, when compared to the standard drugs.