反应详情

A solution of the compound (855 g, 2.41 mol) obtained in Example 16-2) and 4 M hydrochloric acid (1,4-dioxane solution, 1.25 L) in methanol (6.0 L) was stirred overnight at room temperature. The reaction mixture was concentrated under reduced pressure, a 5 M aqueous sodium hydroxide solution (500 mL) was added to the residue at 0° C., the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated sodium chloride solution and dried with anhydrous sodium sulfate. After concentration under reduced pressure, diisopropyl ether was added to the residue, and the white precipitate was collected by filtration and dried under reduced pressure to obtain the title compound (451 g, 73%) as a white solid.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. additiona 5 M aqueous sodium hydroxide solution (500 mL) was added to the residue at 0° C.
3. extractionthe mixture was extracted with ethyl acetate
4. washthe organic layer was washed with saturated sodium chloride solution
5. dry with materialdried with anhydrous sodium sulfate
6. concentrationAfter concentration under reduced pressure, diisopropyl ether
7. additionwas added to the residue
8. filtrationthe white precipitate was collected by filtration
9. customdried under reduced pressure