Catalytic oxidation of chlorpromazine and related phenothiazines. Cation radicals as the reactive intermediates in sulfoxide formation

Abstract

The aerial oxidation of various phenothiazines to the corresponding sulfoxides is catalysed by nitric oxide and related nitrogen oxides. The reactive intermediate in the catalytic autoxidation is the phenothiazine cation radical which is subsequently transformed to the sulfoxide by nitrate present in the reaction medium. These results are pertinent to any further discussion of the activity and/or metabolism of phenothiazine-based drugs.