Photochemistry of chlorpromazine [2-chloro-N-(3-dimethylaminopropyl)phenothiazine] in propan-2-ol solution

Abstract

In oxygen-free propan-2-ol solution electronically excited chlorpromazine [2-chloro-N-(3-dimethylaminopropyl)phenothiazine] undergoes a carbon–chlorine bond fission to form free radicals which react with the solvent to produce promazine, isopropoxypromazine, hydrogen chloride, and acetone. In oxygen-saturated solution energy transfer occurs from excited chlorpromazine to molecular oxygen to produce excited singlet oxygen. Under these conditions chlorpromazine does not undergo any permanent photochemical change.