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.