Dimethylformamide → 5-Dimethylamino-3-ethoxycarbonyl-2-methoxycarbonyl-penta-2,4-dienoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-ethoxycarbonyl-2-methoxycarbonyl-but-2-enoic acid methyl ester (10 g, 43.5 mmol), dimethylformamide dimethyl acetal (6.1 mL, 45.7 mmol) and DMF (8 mL) was heated at 80° C. for 3 h. The slightly cooled solution was poured into 100 mL of benzene, and the resulting mixture was washed several times with water. The organic layer was dried over MgSO4 and concentrated to give a dark yellow solid, which was recrystallized from CCl4 to give 10.6 g of the title compound as a bright yellow solid. 1H NMR (CDCl3, 200 MHz): δ=6.77 (d, 1H, J=12.8 Hz), 5.74 (d, 1H, J=13.2 Hz), 4.34 (q, 2H, J=7.0 Hz), 3.80 (s, 3H), 3.71 (s, 3H), 2.97 (br s, 6H), 1.36 (t, 3H, J=7.0 Hz).

Provenance & Evidence