Facile synthesis of acridine derivatives by ZnCl2-promoted intramolecular cyclization of o-arylaminophenyl Schiff bases.

A concise and efficient method for the synthesis of a wide range of acridine derivatives and polycyclic aza-aromatic compounds from a ZnCl2-promoted cyclization reaction of readily available o-arylaminophenyl Schiff base compounds under convenient conditions was developed. Reaction conditions and scope of the new method were examined in detail.