Chemistry and applications of benzonaphthyridines

Abstract

Cycloadditions of benzonaphthyridines, their N-oxides and ylides from their quaternary salts are presented. Dimethylacetylenedicarboxylate, diethyl maleate, acrylonitrile and others were used as dipolarophiles. Cyclization of N-phenacylbenzonaphthyridinium bromides with ammonium acetate as well as vicarious substitution of hydrogen of benzonaphthyridine N-oxides are also reported and pathways to their formation are proposed.