Photochemical generation of 2-arylbenzazetes from 1,2,3-benzotriazines: structure of 2-arylbenzazete dimers

Abstract

2-Arylbenzazetes are produced by photolysis of 4-arylbenzotriazines (1) and can be intercepted in cyclo-addition reactions; the benzazetes dimerise thermally to give the angular dimers (2) and, in the presence of Lewis acids, the linear dimers (5).