Reaction of α-(thio)amidoalkylation in the synthesis of α-cyano-substituted cyclic (thio)ureas and dithiocarbamates

It was shown that the reaction of the readily accessible 4-azido-, 4-acetoxy-, 4-arylsulfonyl, 4-ethoxythiocarbonylthio-,or 4-isothiocyanatohexahydropyrimidine-2-thiones/ones and 4-azidotetrahydro-1,3-thiazine-2-thiones with sodium cyanide leads to the selective formation of the corresponding 4-cyano derivatives. The diastereoselectivity of the reactions depends on the structure of the heterocycle and the solvent, and is practically independent of the nature of the leaving group. The preferableness of the axial orientation of the cyano group in the molecules of the compounds synthesized was established; this is explained by the development of the anomeric effect.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1389–1397, October, 1993.