The cyclization of acetamidine (I) with 2-cyano-3,3-bis(methylthio)-2-propenoic acid methyl ester (II) by means ot NaH in DMF gives 2-methyl-6-(methylthio)-4 oxo-1,4-dihydropyrimidine-5-carbonitrile (III), which is then condensed with 3-pyridylmethyl amine (IV) by refluxing in dimethoxyethane solution.