Synthesis of Some New Benzimidazole Derivatives of Pharmaceutical Interest

Reaction of 2-(aminomethyl) benzimidazole dihydrochloride (1) with ethyl acetoacetate was studied to give diazepinone-benzimidazole derivative (2), while, treatment of 1 with phenylhydrazono ethylacetoacetate afforded phenylhydrazino diazepinone derivative (3). On the other hand, reaction of 1 with acetyl acetone resulted in the formation of diazepine derivative (4). The reaction of 1 with ethyl cyanoacetate was studied to give 3-aminodiazepinone derivative (5). Also the reaction of 1 with acetophenone and/or benzophenone has been investigated to give the fused imidazolines 6 and 7 respectively, while the reaction of 1 with cyclopentanone gave benzimidazolyl derivative (8). Treatment of 1 with chloroacetyl chloride gave the fused pyrazinone (9). The treatment of 1 with benzoin gave the derivative (10). The structures of the hitherto unknown compounds have been confirmed from analytical and spectral data. The newly synthesized compounds were screened for antibacterial and antifungal activity