反应详情

The ester 5 (2 g) was dissolved in EtOH (50 mL) and aq sodium hydroxide (10 mL, 2N) was added to the solution. The mixture was heated to reflux for half an hour. After the EtOH was removed under reduced pressure, the solution was allowed to cool. The pH value was adjusted to 4 by adding 10% aq HCl dropwise. The mixture was filtered and the solid was washed with water and ethyl ether. The solid was dried to provide 27 (1.8 g, 96.6%): mp>250° C.; IR (KBr) 3450 (b), 2844, 1707, 1615, 1493, 1166, 700 cm−1; 1H NMR (300 MHz, DMSO-d6) δ 4.14 (d, 1H, J=12.6 Hz), 5.79 (d, 1H, 12.6 Hz), 7.41–7.54 (m, 6H), 7.88 (d, 1H, J=8.7 Hz), 8.03 (dd, 1H, J=8.7 Hz, J=2.1 Hz), 8.47 (s, 1H); MS (EI) m/e (rel intensity) 381 (M+, 20), 383 (19).

1. temperatureThe mixture was heated
2. temperatureto reflux for half an hour
3. customAfter the EtOH was removed under reduced pressure
4. temperatureto cool
5. additionby adding 10% aq HCl dropwise
6. filtrationThe mixture was filtered
7. washthe solid was washed with water and ethyl ether
8. customThe solid was dried