反应详情

To a mixture of Intermediate 119b (550 mg) in water (3 mL) and EtOAc (6 mL) was added NaOH (132 mg, 3.30 mmol). After 10 min stirring, 2,2,2-trichloroethyl chloroformate (273 μL, 1.98 mmol) was added and the reaction mixture was stirred at RT for 2 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 0-80% EtOAc in cyclohexane, to afford the title compound (175 mg). LCMS (Method 4): Rt 4.54 min, m/z 508, 510 [MH+].

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