反应详情

A solution of ethyl 3-(4-fluorophenyl)-2-oxopropanoate (4 g, 19.03 mmol, 1.00 equiv) and triethoxymethane (16 mL) in acetic anhydride (5 mL) was stirred at 130° C. overnight. The reaction mixture was cooled to room temperature and then concentrated under vacuum. The residue was purified on a silica gel column eluted with 0-10% of ethyl acetate in petroleum ether to give 700 mg (14%) of (E)-ethyl 4-ethoxy-3-(4-fluorophenyl)-2-oxobut-3-enoate as a yellow oil. 1H-NMR (300 MHz, DMSO-d6): δ 7.71 (s, 1H), 7.32-7.28 (m, 2H), 7.09-7.05 (m, 2H), 4.23 (q, J=7.0 Hz, 2H), 4.16 (q, J=8.0 Hz, 2H), 1.37-1.20 (m, 6H) ppm.

1. concentrationconcentrated under vacuum
2. customThe residue was purified on a silica gel column
3. washeluted with 0-10% of ethyl acetate in petroleum ether