A Consecutive Condensation, Cyclization, and Dehydration for the Synthesis of Benzimidazopyrroloquinazolines Catalyzed by TsOH

Abstract

A consecutive condensation, cyclization, and dehydration of 2‐(1H‐benzo[d]imidazol‐2‐yl) anilines and ketonic acid in toluene catalyzed by TsOH gave a series of benzo[4,5]imidazo [1,2‐c]pyrrolo[1,2‐a]quinazolin‐3(2H)‐one derivatives in good to high yields. The structure of 3e was further confirmed unambiguously by X‐ray diffraction analysis.