Mokhtar, Hassan M. Synthesis of Nitrogenous Compounds from Delta-Unsaturated 1,3-Dicarbonyl Esters .1. Substituted Pyrazoles, Isoxazoles and Oxyquinoxalines - 414-424 p. Subjects--Topical Terms: Ethyl Oxalate4-Substituted-But-3-En-2-onesEthyl 6-Aryl-2,4-Dioxo