New Synthesis of Optically Active O-Aryl O-Ethyl Phenylphosphonothionates

Abstract

  The mixed anhydride method was applied to synthesize O-aryl O-ethyl phenylphosphonothionate. The reaction of O, O-diethyl phosphorochloridate with O-ethyl phenylphosphonothioic acid afforded O, O-diethyl phosphoric O-ethyl phenylphosphonothioic anhydride in a good yield. This anhydride was converted to O-aryl O-ethyl phenylphosphonothionates by reacting with the appropriate sodium phenoxide. This esterification occurred without racemization and produced optically pure O-ethyl O-(4-nitrophenyl) phenylphosphonothionate (EPN) and O-(4-cyanophenyl) O-ethyl phenylphosphonothionate (cyanofenphos).