反应详情

To a stirred mixture of Intermediate 113b (1.14 g, 3.28 mmol) in water (6 mL) and EtOAc (12 mL) was added NaOH (263 mg, 6.57 mmol). After 10 min, 2,2,2-trichloroethyl chloroformate (543 μL, 3.94 mmol) was added and the reaction mixture was stirred at RT for 1 h. The aqueous layer was extracted with EtOAc (×3) and the combined organic layers were washed with brine, dried (MgSO4) and concentrated in vacuo. The resultant residue was purified by FCC on silica, using a gradient of 0-100% EtOAc in cyclohexane, to afford the title compound (1.57 g, 91%). LCMS (Method 4): Rt 3.99 min, m/z 522, 524 [MH+].

1. extractionThe aqueous layer was extracted with EtOAc (×3)
2. washthe combined organic layers were washed with brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated in vacuo
5. customThe resultant residue was purified by FCC on silica