Cascade reactions between 2-substituted-3-(4-oxo-4H-chromen-3-yl)acrylonitriles with benzylamine and p-toluidine

Abstract

Chemical transformations of the simple condensation products derived from 3-formylchromone and some active methylene compounds, was achieved by reaction with nucleophilic reagents namely benzylamine and p-toluidine to produce either 2-iminopyrane or pyrano[3,2-c]chromene derivatives. These transformations initially proceed through nucleophilic attack at C-2 of the γ–pyrone ring with concomitant addition of the carbonyl oxygen onto the nitrile function followed by further transformations depending on the substrate and the nucleophile used. The structures of the new synthesized products were deduced on the basis of their analytical and spectroscopic data.