Facile syntheses of pyrazole, pyridine, pyrimidine and pyrazolo [3,4-d]pyrimidine derivatives have been achieved by the reaction of j3-enamino nitrile 2a with hydrazines, phenyl isothiocyanate, thiourea and active methylene reagents. The~-cnamino ketone 2e with the same reagents affords 3,5-dimethyl heterocyclic ring systems.