Synthesis and antimicrobial activity of some new benzimidazole derivatives

Reaction of 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide (1) with CS2/KOH gave oxadiazole 2 which underwent Mannich reaction to give 3. Compo und 2 was treated with hydrazine hydrate to give triazole 4 which was treat ed with both aldehydes and acetic anhydride to give 5 and 6, respectively. Carbohydrazide 1 was reacted with ethyl acetoacetate, acetylacetone and ald ehydes to give 7, 8 and 9, respectively. Cyclocondensation of 9 with thiogl ycolic and thiolactic acids gave 10 and 11, respectively. Some of these com pounds showed potential antimicrobial activities.