Sultam Thioureas Synthesized via an Alternative Ring-Forming Reaction

A method for the synthesis of sultam thioureas via a different 1,4,2-dithiazolidine 1,1-dioxide ring-forming reaction is presented here. The syntheses of nine sultam thioureas were achieved in 53–81% yield by reacting N-substituted chloromethanesulfonamides with thiocarbamoyl isothiocyanates, which were formed in situ from the reaction of 5-(disubstituted amino)-3H-1,2,4-dithiazole-3-thiones with triphenylphosphine. Importantly, this method successfully allowed the substituent of the ring nitrogen atom to be varied. Additionally, the structures of four sultam thioureas were confirmed by x-ray diffraction.