Reactions of Cyanothioacetamide: Synthesis of Several New Thioxohydro-pyridine-3-carbonitrile and Thieno[2,3-b]pyridine Derivatives

Cyanothioacetamide (f 1) reacted with α,β -unsaturated carbonyl compounds 2a–d to afford thioxohydropyridine-3-carbonitriles 5a–d, which were used as the starting materials for the preparation of several thienopyridines via their reactions with active halogen-containing compounds, e.g., 2-bromo-1-phenylethanone (7a), 2-bromo-1-p-tolyl-ethanone (7b), chloroacetone (10a), α -chloroacetylacetone (10b), and chloroacetic acid ethyl ester (13). The structure of the newly synthesized heterocyclic compounds were established based on the data of elemental analyses, IR, ¹ H NMR, and mass spectra.