反应详情

温度

80 °C

A mixture of N-(4-carboxyphenyl)maleamic acid (5.0 g, 21.2 mmol), acetic anhydride (4 ml, 42.5 mmol) and sodium acetate (3.48 g, 42.5 mmol) Was heated at 80° C. for 3h. After heating, excess acetic anhydride was removed under reduced pressure and the residue purified by column chromatography using 0-4%. MeOH/DCM as an eluent to give 3k (33%) as a solid.15 mp: 165-168° C.; 1H NMR (400 MHz, DMSO-d6): δ 7.20 (s, 2H), 7.47 (d, J=8.4 Hz, 2H), 8.02 (d, 8.0 Hz, 2H), 12.75 (brs, 1H); HRMS (m/z): [M−H]− calcd for C11H6NO4, 216.0302; found, 216.0296.

1. temperatureAfter heating
2. customexcess acetic anhydride was removed under reduced pressure
3. customthe residue purified by column chromatography