Studies on the Synthesis of Benzimidazo[2,1- a ]isoquinolines

The reaction of the isocoumarin derivative 1-acetylimino-3-methyl-1 H -2-benzopyran-4-carbonitrile (1a) with aromatic ortho diamines provides entry to the benzimidazo[2,1- a ]isoquinoline and related systems. Various conversions of the methyl and cyano groups in the tetracycles into amide, aldehyde and acid functions have been carried out, along with studies of electrophilic nitration.