反应详情

To a solution of Intermediate 61c (0.15 g, 0.36 mmol) in EtOAc (1.8 mL) was added 1N aqueous NaOH solution (0.6 mL, 0.60 mmol) followed by 2,2,2-trichloroethylchloroformate (54.0 μL, 0.40 mmol). The reaction was stirred at RT overnight then treated with another portion of 1N aqueous NaOH solution (0.3 mL, 0.30 mmol) followed by 2,2,2-trichloroethylchloroformate (27.0 μL, 0.20 mmol). After stirring for another 4 h, the mixture was diluted with EtOAc and water. The aqueous layer was then extracted with EtOAc (2×). The combined organic layers were washed with brine, dried (Na2SO4), filtered and evaporated in vacuo. The residue was purified by FCC, using 0-25% EtOAc in cyclohexane, to give the title compound (176 mg, 84%). LCMS (Method 3): Rt 5.35 min, m/z 592, 594 [MH+].

1. stirringAfter stirring for another 4 h
2. extractionThe aqueous layer was then extracted with EtOAc (2×)
3. washThe combined organic layers were washed with brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. customevaporated in vacuo
7. customThe residue was purified by FCC