Cyanothioacetamide in the Synthesis of Heterocyclic Derivatives: Synthesis of New Thioxodihydropyridine -3-Carbonitrile, Thi-enopyridine and Pyridothienopyrimidinone Derivatives

The reaction of cyanothioacetamide 1 with a,b-unsaturated ketones 2a,b resulted in the formation of the corresponding newly synthesized 1,2-dihydro-2-thioxopyridine-3-carbonitrile derivatives 3a,b. Compounds 3a,b were used as starting materials for the synthesis of several 2-alkylthiopyridine-3-carbonitrile and thieno[2,3-b]pyridine derivatives via a wide range of reactions with different reagents. Thieno[2,3-b]pyridine derivatives 17a,b and 18a,b were used in the synthesis of pyridothienopyrimidinone derivatives.