Benzimidazole condensed ring systems. 8 (1). Synthesis of some substituted 1-oxo-1H,5H-pyrido[1,2-a] benzimidazole-4-carbonitriles with anticipated antimicrobial activity.

As a part of research project on the syntheses of a number of pyrido[1,2-a]benzimidazole derivatives with possible antimicrobial activity, some 3-(chloro or morpholino)-acetyloxy (2,3), 3-(N,N-dimethylcarbamoyloxy) (4,5) and 3-tosyloxy-1-oxo-1H,5H-pyrido[1,2a]benzimidazole-4-carbonitrile s (6) were prepared and evaluated for such activity. Many compounds exhibited in vitro antimicrobial activity and structure-activity relationship is discussed.