SYNTHESIS AND REACTION OF FUSED POLYNUCLEAR HETEROCYCLES

Reaction of furo [2,3-b] pyridine 1 with malononitrile, ethyl cyanoacetate, formic acid/sodium acetate mixture and formamide afforded the corresponding 2,4-daimino-3-cyano-furo [2' ,3': 6,5] pyrido [2,3-b] pyridine 4, 4-amino-3-cyano-furo [2',3': 6,5] pyrido [2,3-b] pyridine-2(IH)-on 5, furo [2' ,3': 6,5] pyrido [2,3-d] pyrimidine-4(3H)-on 6 and 4-aminofuro [2’ ,3': 6,5] pyrido [2,3-d]- pyrimidine 7. Treatment of furo [2,3-d] pyrimidine-6 thione 2 with benzoyl hydrazine and ethyl chloroacetate afforded the corresponding furo [3,2-e] [1,2,4] triazolo [4,3-a]-pyridimidine 8 and 6- (carbethoxymethylthio) furo [2,3-d] pyridimidine 9 Condenstation of furo [2,3-b] pyrane 3 with acetic anhydride, acetic antydride pyridine mixture and p-chlorocinriamonitrile afforded the corresponding 6- acetamide-4H-furo [2,3-b] pyrane 10, 2-methyl-4-oxo-3,4-dihydro-5H-furo [2',3': 6,5] pyrano [2,3-d] pyrimidine 11 and 4-amino-3-cyano-5H-furo [2',3': 6,5] pyrano [2,3-b] pyridine 12. The structure of new compounds were established by analytical and spectroscopic measurements.