STUDIES ON REACTIONS OF LAWESSON′S REAGENT WITH PHENYLTHIOUREA AND OXAMIDE

Abstract Lawesson's reagent reacted with phenylthiourea in toluene at 110°C to give a product of ring-opening (2) instead of a 4-membered ring 2a. Its structure was determined by X-ray diffraction analysis. A mechanism is proposed to explain the formation of compound 2. The O-S exchange reaction of Lawesson's reagent with oxamide in acetonitrile was also investigated. Key Words: Lawesson's reagentPhenylthioureaOxamidemolecular structure