Interaction of dicyandiamides with thioamides: Formation of 6-Alkyl(or aryl)-4-amino(or arylamino)-1,3,5-triazine-2-thiols and Amidino(or aryamidino)thioureas

Abstract

The reactions of thioacetamide and thiobenzamide with dicyandiamide and aryldicyandiamides in the presence of hydrochloric acid have been found to yield the related 6-alkyl(or aryl)-4-amino(or arylamino)-1,3,5- triazine-2-thiols and amidino(or arylamidino)thioureas. The formation of these compounds is accounted for by a mechanism involving the initial formation of a monosulphide. By rearrangement and subsequent cyclization with elimination of ammonia it forms the 1,3,5-triazines, whereas its decomposition yields amidinothiourea and the related nitrile. Synthesis of certain of these 1,3,5-triazine-2-thiols has been carried out by the stepwise replacement of all the chlorine atoms in 2,4,6-trichloro-1,3,5-triazine with methyl or phenyl, arylamino and mercapto groups.