A NOVEL ONE-POT FACILE SYNTHESIS OF CARBONYL-1,2,3,4-TETRAHYDRO-4,7-DIOXO-2-THIOXO-7H- PYRANO[2,3-D]PYRIMIDINES

The condensation of diethyl ethoxymethylenemalonate with appropriate 1 ,3-diaryl-2-thiobarbituric acids la-g in acetic acid leads to the form ation of the corresponding xycarbonyl-1,2,3,4-tetrahydro-4,7-dioxo-2-t hioxo-7 H-pyrano[2,3-d]pyrimidines 3a-g in a single step. Alternativel y, same compounds could be synthesised by the reaction of la-g with tr iethyl orthoformate and aniline;followed by the reaction of the result ant 5-anilinomethylene-1,3-diaryl-2-thiobarbitutric acids 2a-g with di ethyl malonate in the presence of sodium ethoxide in ethanol.