Effect of water on product yields of 2-azidobenzoic acid photolysis in aprotic solvents

The effect of water admixtures on the formation of 2-oxo-(3H)-azepine-3-carboxylic acid and 2,1-benzisoxazol-3(1H)-one in the photolysis of 2-azidobenzoic acid in aprotic solvents has been investigated. It has been shown that the addition of nucleophilic agents to the reaction mixture determines the yields of not only 3H-azepines, the products of benzene ring expansion, but also the intramolecular cyclization product 2,1-benzisoxazol-3(1H)-one. Participation of the formed 2,1-benzisoxazol-3(1H)-one in the reaction has been suggested as an explanation of the effect of nucleophilic compounds (water, ethanol, and 2,1-benzisoxazol-3(1H)-one) on the product yield of the monomolecular reaction.