Heterocyclic synthesis with nitriles: A new approach to Thiophene and Thieno-[2,3-d]-pyrimidine derivatives

α-Cyano-β-thiocyanatomethyl cinnamonitrile ( 1 ) was transformed into 5-acetyl-2-amino-4-phenylthiophen-3-carbonitrile ( 3 ) on refluxing in acetic/sulphuric acid mixture. Compound 3 reacted with trichloroacetonitrile, formamide, carbon disulphide and ethylorthoformate.