Cyclic amidines. Part 25. Intramolecular cyclodehalogenation of diazabenz[a]anthracenes and diazabenzo[c]phenanthrenes

Abstract

A previously unrecorded intramolecular cyclization which occurred during the palladium-catalysed hydrogenolysis of suitably disposed dichloroheterocycles [e.g. 7-chloro-6-(2-chlorophenyl)-5,12-diazabenz[a]anthracene (3) to 9,14-diazadibenz[a,e]aceanthrylene (1) and 6-chloro-7-(2-chloro-phenyl)-5,8-diazabenzo[c]phenanthrene (9) to 9,14-diazadibenz[a,e]acephenanthrylene (13)] is reported.