反应详情

A solution containing 11.8 g (40.1 mmol) of 5-(4-methoxy-2,5-dimethylphenoxy)-2,2-dimethylpentanoic acid, methyl ester (Example 1), 40 mL of 2N potassium hydroxide and 150 mL of methanol is stirred at reflux for 18 hours overnight. The methanol is removed on a rotary evaporator and the aqueous solution diluted with water. After the aqueous solution is extracted with diethyl ether it is acidified with excess 6N hydrochloric acid solution and the precipitate is isolated with diethyl ether. The diethyl ether solution is washed with brine, dried (magnesium sulfate) and evaporated leaving a crystalline residue. Recrystallization from 50 mL of acetonitrile in the presence of charcoal affords after refrigeration, 9.7 g of the title compound as colorless crystals; mp 85°-86° C.

1. temperatureat reflux for 18 hours overnight
2. customThe methanol is removed on a rotary evaporator
3. additionthe aqueous solution diluted with water
4. extractionAfter the aqueous solution is extracted with diethyl ether it
5. customthe precipitate is isolated with diethyl ether
6. washThe diethyl ether solution is washed with brine
7. dry with materialdried (magnesium sulfate)
8. customevaporated
9. customleaving a crystalline residue
10. customRecrystallization from 50 mL of acetonitrile in the presence of charcoal