反应详情

1.9 g of 4-(5-fluoro-2-methoxyphenyl)-2-hydroxy-4-methyl-2-trifluoromethyl-valeric acid ethyl ester is refluxed with 40 ml of potassium hydroxide in methanol (10%) for 2 hours. After the solvent is concentrated by evaporation in a vacuum, water is added, extracted with hexane, and the separated water phase is acidified with 6N hydrochloric acid. After extraction with ethyl acetate, the ethyl acetate phase is washed with water, dried (Na2SO4) and concentrated by evaporation. The residue is crystallized from hexane. 1.55 g of 4-(5-fluoro-2-methoxyphenyl)-2-hydroxy-4-methyl-2-trifluoromethyl-valeric acid, flash point 102-104° C., is obtained.

1. concentrationAfter the solvent is concentrated by evaporation in a vacuum, water
2. additionis added
3. extractionextracted with hexane
4. extractionAfter extraction with ethyl acetate
5. washthe ethyl acetate phase is washed with water
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated by evaporation
8. customThe residue is crystallized from hexane