反应详情

温度

50 °C

To a solution of (±)-6-acetoxy-2-methoxy-2,5,7,8-tetramethylchroman in 2500 ml. of acetone was added 2000 ml. of H2O followed by 16.6 ml. of concentrated aqueous HCl. Solvent was distilled from the stirred mixture until the head temperature reached 90°C. The suspension was cooled in an H2O bath to 50°C. At 70°C., 2000 ml. of acetone was added, giving a clear solution. The solution was seeded occasionally until crystallization began. After 3.5 hours, 1500 ml. of H2O was added and the suspension was cooled in an ice bath. The solid was removed by filtration, washed with H2O and dried at 50°C./0.1 mmHg. to give (±)-6-acetoxy-2-hydroxy-2,5,7,8-tetramethylchroman as a granular yellow-tan solid, sintering from 114°C., m.p. 127°-132°C.

1. distillationSolvent was distilled from the stirred mixture until the head temperature
2. customreached 90°C
3. customAt 70°C.
4. additionof acetone was added
5. customgiving a clear solution
6. customThe solution was seeded occasionally until crystallization
7. additionof H2O was added
8. temperaturethe suspension was cooled in an ice bath
9. customThe solid was removed by filtration
10. washwashed with H2O
11. customdried at 50°C./0.1 mmHg