An efficient synthesis of quinazolines: a theoretical and experimental study on the photochemistry of oxime derivatives

A new photochemical method for the preparation of quinazolines (2) through irradiation of [2-(methyleneamino)phenyl]methanone oximes (1) is reported. The photoreaction has been studied in depth by experimental, theoretical and photochemical methods. A six-electron electrocyclic ring closure mechanism, followed by water loss, is proposed and rationalized to explain the formation of quinazolines (2).