Photochemical behaviour of carbamates structurally related to herbicides in aqueous media: Nucleophilic solvent trapping versus radical reactions

Abstract

Irradiation of N-aryl O-aryl carbamates has been carried out in H 2O/CH3CN (1: 1 v/v) solutions at λ>290 nm. When chlorine is on the N-aryl ring, halogen-substituted products are found. These photoproducts derive from the trapping of the intermediate radical cation by water and, even, by acetonitrile leading to phenols and N-arylacetamides (photo-Ritter products), respectively. Unsubstituted N-aryl carbamates slowly undergo photo-Fries reaction. © 2014 Monica Passananti et al.