反应详情

温度

80 °C

A mixture of 2-ethoxycarbonyl-3-methoxycarbonyl-but-2-enoic acid ethyl ester (15 g, 61.5 mmol), dimethylformamide diethyl acetal (11.1 mL, 64.5 mmol) and DMF (15 mL) was heated at 80° C. for 5 h. After the mixture was cooled, 200 mL of benzene was added, and the resulting mixture was washed several times with 1 M HCl and water. The organic layer was dried over MgSO4 and concentrated to give an orange solid, which was recrystallized from hexanes/CCl4 to give 8.1 g of the title compound as a bright yellow solid. 1H NMR (CDCl3, 200 MHz): δ=6.70 (d, 1H, J=13.2 Hz), 5.66 (d, 1H, J=13.4 Hz), 4.10-4.40 (m, 4H), 3.88 (s, 3H), 2.96 (br s, 6H), 1.20-1.40 (m, 6H).

1. temperatureAfter the mixture was cooled
2. washthe resulting mixture was washed several times with 1 M HCl and water
3. dry with materialThe organic layer was dried over MgSO4
4. concentrationconcentrated
5. customto give an orange solid, which
6. customwas recrystallized from hexanes/CCl4