Synthesis of the N-oxides of phenothiazine antipsychotic agents

Article abstract of DOI:10.1002/jps.2600820323

Chlorpromazine N-oxide, fluphenazine N(4')-oxide, prochlorperazine N(4')- oxide, sulforidazine N-oxide, and trifluoperazine N(4')-oxide were synthesized by oxidation of the designated nitrogen atom in the N-10 side chain of the respective parent drug with 3-chloroperoxybenzoic acid. In the case of trifluoperazine, a stepwise increase in the amount of oxidant yielded the N(1'),N(4')-dioxide and N(1'),N(4'),S-trioxide. The N',S-dioxides of chlorpromazine and sulforidazine were obtained by hydrogen peroxide oxidation of the appropriate parent drug.