A Novel Synthesis of Pyridine-2(1H)-thione, Pyrazolo[3,4-b]pyridine, Pyrido[2',3':3,4]pyrazolo[1,5-a]pyrimidine, Thieno[2,3-b]pyrdine, and Pyrido[3',2':4,5]thieno[3,2-d]pyrimidine Derivatives Containing a Naphthyl Moiety

6-Amino-4-naphthyl-2-thioxo-1,2-dihydropyridine-3,5-dicarbonitriles 3a, b were synthesized from the reaction of naphthaldehydes 1a, b and cyanothioacetamide (2). Compounds 3a, b were taken as starting materials for the synthesis of pyrazolo[3,4-b]pyridine 7a, b, and 8a, Pyrido-[2',3':3,4]pyrazolo[1,5-a]pyrimidine 9a, b; thieno[2,3-b]pyridine 16a-d, 18a, b, 21a-d, 24a, b, and 25a; and pyrido[3,2:4,5]thieno[3,2-d]pyrimidine 17a, b derivatives through their reactions with the corresponding reagents. All structures of the newly synthesized heterocyclic compounds were established on the basis of IR, 1H NMR, 13C NMR, mass spectra, and elemental analyses.