反应详情

温度

-78 °C

A stirred solution of 3,5-di-tert-butyl-4-hydroxyacetophenone (Apim Chemicals, Ltd.) (4 g) in dry methylene chloride (250 mL) is cooled to -78° C. and di-isopropyl ethylamine (7.3 mL) is added followed by trimethylsilyl trifluoromethanesulphonate (Aldrich Chemical Co.) (8.0 mL). The mixture is stirred at -78° C. for 10 minutes and is allowed to warm to ambient temperature over 1 hour. The mixture is cooled again to -78° C. and dry acetone (4.05 mL) is added dropwise. After stirring for 25 minutes, the mixture is washed with 1N aqueous hydrochloric acid and brine. The organic solution is dried over anhydrous sodium sulfate and the solvent is removed under reduced pressure. The crude product is dissolved in methanol-1N aqueous HCl mixture (10:1, v/v, 200 mL) and the homogenous solution is stirred for 1 hour at room temperature. Methanol is removed under reduced pressure; the mixture is washed with methylene chloride. The organic extracts are washed: with aqueous sodium bicarbonate, brine, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The crude product is crystallized from hexane to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hydroxy-3-methyl-butan-1-one as orange crystals. Two additional crystallizations give product of analytical purity, mp 113°-14° C.

1. temperatureto warm to ambient temperature over 1 hour
2. temperatureThe mixture is cooled again to -78° C.
3. stirringAfter stirring for 25 minutes
4. washthe mixture is washed with 1N aqueous hydrochloric acid and brine
5. dry with materialThe organic solution is dried over anhydrous sodium sulfate
6. customthe solvent is removed under reduced pressure
7. dissolutionThe crude product is dissolved in methanol-1N aqueous HCl mixture (10:1, v/v, 200 mL)
8. stirringthe homogenous solution is stirred for 1 hour at room temperature
9. customMethanol is removed under reduced pressure
10. washthe mixture is washed with methylene chloride
11. washThe organic extracts are washed
12. dry with materialwith aqueous sodium bicarbonate, brine, dried over anhydrous sodium sulfate
13. customthe solvent is removed under reduced pressure
14. customThe crude product is crystallized from hexane