Diethyl Oxalate → Ethyl 6-dimethylamino-2,4-dioxo-5-phenyl-5-hexenoate

Participants

Reaction Steps

A suspension of sodium ethoxide was prepared by addition of ethanol (1.6 ml) to a stirred suspension of sodium hydride (1.3 g 50% dispersion, washed with petroleum spirit 40°-60° C.) in ether (50 ml) under nitrogen. A solution of 4-dimethylamino-3-phenyl-3-buten-2-one (4.8 g) and diethyl oxalate (5.2 ml) in ether (50 ml) was added to the stirred sodium ethoxide suspension at 5° to 10° C. and the resulting clear solution was stirred for 2 hours at room temperature, then cooled and treated with glacial acetic acid (2.5 ml) and water (50 ml). Ethyl acetate was added to dissolve the solid which formed and the solvent layer was washed with water, dried, and evaporated. The solid residue was recrystallised from ethyl acetate-petroleum spirit (60°-80° C.) to give ethyl 6-dimethylamino-2,4-dioxo-5-phenyl-5-hexenoate (mp 110° C.).

Provenance & Evidence