REACTIONS OF OXIDIZED THIOUREAS WITH AMINE NUCLEOPHILES1

Abstract A route for the convenient, cost effective synthesis of di- and tri-substituted guanidines from thioureas has been developed. The key transformation involves activation of the sulfur through S-oxidation followed by displacement of the activated sulfur by an amine nucleophile (oxidation/displacement). This preparation is experimentally facile and results in good isolated yields of desired guanidines. No noxious substances or sensitive intermediates are generated. The reaction time is short and overall yield of desired guanidine from thiourea is good.