Photochemical Ring-expansion Reaction of 1,2-Benzisothiazolinones

Article abstract of DOI:10.1246/bcsj.58.3131

The photochemical reaction of a series of 2-aryl-1,2-benzisothiazol-3(2H)-ones (1) under deaerated conditions was found to give dibenzo<1,4>thiazepin-11(10H)-ones (2).A mechanism through a biradical species is proposed for the photoreaction.When the photolysis of 1 was carried out in the presence of oxygen, 2-aryl-1,2-benzisothiazol-3(2H)-one-1-oxides (11) were formed together with compounds 2.