反应详情

温度

-2 °C

Methyl 3-(3,4-dimethylphenyloxy)-2,2-dimethylpropionate (Intermediate A8, 23.6 g, 0.100 mol) was added dropwise over 30 min to rapidly stirred chlorosulfonic acid (46.6 g, 0.400 mol) while the reaction temperature was maintained at −2° C. The reaction mixture was then poured into a stirred mixture of 300 g ice and 300 mL of dichloromethane. The aqueous phase was extracted with additional dichloromethane, and the combined organic layers were washed with water, 0.5 M sodium bicarbonate (×2), and water. The solvent was removed at aspirator pressure and the residue was purified by several passes of flash chromatography (silica gel: hexanes→2% ethyl acetate in hexanes) to yield 9.6 g (29%) of the title compound.

1. extractionThe aqueous phase was extracted with additional dichloromethane
2. washthe combined organic layers were washed with water, 0.5 M sodium bicarbonate (×2), and water
3. customThe solvent was removed at aspirator pressure
4. customthe residue was purified by several passes of flash chromatography (silica gel: hexanes→2% ethyl acetate in hexanes)