Synthetic approaches for nitrogen bridgehead pyrido-[1,2-b][1,2,4]triazepines and annulated compounds using 4-(8-allylchromon-3-yl)-1,6-diamino-2-oxo-1,2-dihydro-pyridine-3,5-dicarbonitrile

Abstract

– Some new nitrogen bridgehead pyrido[1,2-b][1,2,4]triazepines linked 8-allylchromone moiety have been synthesized from reaction of novel 4-(8-allyl-chromon-3-yl)-1,6-diamino-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile (3) with a variety of α,γ-bifunctional electrophiles including dibenzoylmethane, ethyl benzoylacetate, 3-[bis(methylthio)methylidene]pentane-2,4-dione, 2-cyano-3,3-bis(methylthio)acrylonitrile, 2-cyano-3,3-bis(methylthio)prop-2-enamide, 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde, 2-chloro-3-formyl-quinoline, (p-methoxybenzylidene)malononitrile and ethyl 2-cyano-3-(4-methoxyphenyl)prop-2-enoate. Some novel pyrazolo[3,4-e]pyrido[1,2-b]-[1,2,4]triazepines were also synthesized. Structures of the newly synthesized products have been deduced upon the help of elemental analysis and spectral data (IR, 1H NMR, 13NMR, mass spectra).