Reaction of equimolar amounts of 2,4(1H,3H)-quinolinediones and diethyl acetylenedicarboxylate in absolute ethanol, containing catalytic triethylamine, gave ethyl 5,6-dihydro-2,5-dioxo-6,9-disubstituted-2H-pyrano[3,2-c]quinoline-4-carboxylates in good yields. In a different manner, reaction of two equivalents of dialkyl acetylenedicarboxylates with one equivalent of 2,4(1H,3H)-quinolinediones afforded dialkyl 2(4-oxo-1,4-dihydroquinolin-3-yl)fumarates in good yields. The structures of the products were elucidated by 1H NMR, 13C NMR, two-dimensional NMR, IR, mass spectra and elemental analyses.
د / ممتاز السيد محمد بخيت | Momtaz El-sayed Mohamed Bakheet | 10864