SYNTHESIS OF NEW HETEROCYCLES CONTAINING BENZIMIDAZOLE MOIETY OF EXPECTED BIOLOGICAL ACTIVITY

摘要

Benzimidazoles are well known for their bio-activity in several directions e.g. as bactericides, fungicides, pesticides, as well as herbicides. Therefore, it is intended, in the present work, to synthesize some new substituted-benzimidazoles, and primido-benzimidazoles for bio-evaluation. Thus, 2-cyanomethylbenzimidazole I, reacts with ethyl ortho-formate to give alkoxymethylene-2-(2-benzimidazole)acrylonitrile II. The yields are generally higher in acetic anhydride. II undergoes the reaction with anilines to give the anilino derivatives III which cyclise to primido [1,2-a] benzimidazole derivatives IV. The formation of pyrazoles V via the reaction with hydrazines is also investigated. Structure of the synthesized products is elucidated by microanalysis and spectral data.