Eco-friendly and regiospecific intramolecular cyclization reactions of cyano and carbonyl groups in N,N-disubstituted cyanamide.

Eco-friendly, low-cost and high-yielding synthetic route toward imidazoles and oxazoles has been developed. 1-(4,6-Dimethylpyrimidin-2-yl)-2-(alkylamino)-1,5-dihydro-4H-imidazol-4-one 3a-c have been synthesized via regiospecific reaction of ethyl 2-(N-(4,6-dimethylpyrimidin-2-yl)cyanamide)acetate 1 with primary aliphatic amines in water as green solvent. While, the reaction between 4,6-dimethylpyrimidin-2-yl(2-oxo-2-phenylethyl)cyanamide 2 and primary aliphatic amines using water and/or iso-propanol as green solvents afforded 3-(4,6-dimethylpyrimidin-2-yl)-5-phenyl-1,3-oxazole-2(3H)-imine 6 and 1-(4,6-dimethylpyrimidin-2-yl)-N-alkyl-4-phenyl-1H-imidazol-2-amine 7a-d, respectively.