Synthesis, Characterization, and Reactions of Pyridine-3-Carbonitrile Derivatives

2-Thioxopyridine-3-carbonitrile derivatives 6a-c reacted with several halogen containing reagents 7a-d to afford the corresponding thieno[2,3-b]pyridine derivatives 9a-l, respectively. Thieno[2,3-b]pyridines 9c, g,k used for the preparation of their corresponding carbohydrazide derivatives 10a-c which in turn, used as good synthons for the synthesis of N-phenylmethylenethieno[2,3-b]pyridine-2-carbohydrazides 13a–c, pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidinones 15a-c, 16a-c and 17 and 1,3,4-oxadiazole-2-thiols 20a-c and 21a-c via their reactions with benzaldehyde or benzylidenemalononitrile, triethylorthoformate and carbon disulfide followed by hydrazine hydrate respectively. Considering the data of IR, 1H NMR, mass spectra, and elemental analyses elucidated the chemical structures of the newly synthesized heterocyclic compounds.