反应详情

A solution of (±)-6-hydroxy-2-methoxy-2,5,7,8-tetramethylchroman, prepared as described in Example 1 from 1.0 mole of trimethylhydroquinone in 1250 ml. of acetone, 1000 ml. of H2O and 8.30 ml. of conc. HCl was heated at reflux under N2. The solvent was removed by distillation until the distilling head temperature reached 95°. The suspension was cooled to 70°, diluted with 800 ml. of acetone, cooled to ca. 15° and stripped of solvent at reduced pressure and 30° to ca. 1000 ml. The resulting suspension was cooled, filtered and dried to give (±)-2,6-dihydroxy-2,5,7,8-tetramethylchroman as a grey-tan powder, m.p. 105°-107°.

1. temperatureat reflux under N2
2. customThe solvent was removed by distillation until the distilling head temperature
3. customreached 95°
4. temperatureThe suspension was cooled to 70°
5. additiondiluted with 800 ml
6. temperatureof acetone, cooled to ca. 15°
7. temperatureThe resulting suspension was cooled
8. filtrationfiltered
9. customdried