Hydrochloric Acid → methyl 4-(4-chlorophenyl)-2,4-dioxobutanoate

Participants

Reaction Steps

Dimethyl oxalate (15.27 g, 0.129 mol) and 4′-chloroacetophenone (20.0 g, 0.129 mol) were charged to a 500 mL round-bottom flask, with provisions made for magnetic stirring, and diluted with methanol (300 mL). Sodium methoxide (25% in methanol, 70 mL) was added in one portion. The reaction was stirred at room temperature for 16 hours. The reaction became an insoluble mass during this time. The solid was mechanically broken up, then concentrated hydrochloric acid (70 mL) was added, and the white suspension was stirred vigorously at room temperature for sixty minutes. The suspension was cooled to 0° C. and held for 30 minutes. The soild was filtered, and the filter cake was washed with cold water (100 mL). Upon drying, methyl 4-[4-(chloro)phenyl]-2,4-dioxobutanoate was obtained (16.94 g, 54.4%) as the enol: 1H NMR (CDCl3/300 MHz) 7.94 (d, J=8.66 Hz, 2H), 7.48 (d, J=8.66 Hz, 2H), 7.04 (s, 1H), 3.95 (s, 3H), 3.48 (s, 1H).

Provenance & Evidence