反应详情

To a solution of compound 3 (55.0 g, 0.212 mol) in MeOH/H2O (300 mL/50 mL) was added LiOH. H2O (17.8 g, 0.425 mol) in portions at 0° C. The reaction mixture was stirred at room temperature overnight and TLC showed the starting material was consumed. The solvent was removed under reduced pressure. The residue was diluted with water, and extracted with Et2O (2×1 L) to remove neutral impurities. The aqueous layer was adjusted to pH 3-4 with 1 N aq. HCl (50 mL) and extracted with EtOAc (2×1 L). The combined organic phases were washed with water (2×200 mL), brine (300 mL), dried over Na2SO4 and concentrated to afford compound 4 (35.0 g, 67%). This was used without further purification.

1. customat 0° C
2. customwas consumed
3. customThe solvent was removed under reduced pressure
4. additionThe residue was diluted with water
5. extractionextracted with Et2O (2×1 L)
6. customto remove neutral impurities
7. extractionextracted with EtOAc (2×1 L)
8. washThe combined organic phases were washed with water (2×200 mL), brine (300 mL)
9. dry with materialdried over Na2SO4
10. concentrationconcentrated