反应详情

A mixture of 40 g (0.12 mol) of the compound of Example 6 and 24.0 g (0.60 mol) of sodium hydroxide in 240 ml. of water was heated at reflux for 18 hours. 48 ml of glacial acetic acid was added to the solution and heating was continued for an additional 8 hours. The suspension was allowed to stand at 0° overnight and the white precipitate was collected, washed with icecold water and dried to yield 24.7 g (100%) of crude product. Recrystallization from 80% aqueous acetic acid afforded, after drying at 100°/0.05 mmHg, 21.2 g (86%) of white crystals, m.p. 292° (dec.) (lit. m.p. 293°) which was identical with an authentic sample.

1. temperatureat reflux for 18 hours
2. temperatureheating
3. waitto stand at 0° overnight
4. customthe white precipitate was collected
5. washwashed with icecold water
6. customdried