New and Facile Synthesis of Substituted Pyrrole, Pyridine, Pyrazolo[4,3-b] Pyridine, Pyrano[3,2-c] Quinoline, Napthopyran, Naphthodipyran and Coumarin Derivatives

Several new pyrazolo[4,3-b] pyridines 7a, b were prepared by reacting arylidenemalononitriles 1a, c or 1i, j with 4-nitrosoantipyrine 4. Reacting 1a, b, d with 4-azidomethylcarbonylantipyrine 8 give 2-aminopyrrole 14. Pyrano[3,2-c] quinolines 20a, b and 23 were obtained by reacting 4-hydroxyquinoline 15 with 1g, h, 2b respectively. Reaction of 1 with naphthalenediols 24, 27 and 29 yield naphthodipyrans 26a, b, 28a, b and 30a, b respectively. Spironaphthodipyrans 32, 33 and spironaphthopyrans 36, 37 were prepared through reaction of 2a with naphthalenediols 24, 27, 34 and 35 respectively. Condensation of thioxothiazole 38 with 3,5-dibromo-2-hydroxybenzaldehyde give 2Hchromene-3-carboxamide 42. 38 also reacted with 1c and 2a to give 3,5-dicyanopyridines 45 and 47 respectively. Reaction of 2-cyano-N’-(1-thiophen-2-yl)ethylidene) acetohydrazide 49 with 1a, b afforded 3,5-dicyanopyridines 53.