反应详情

A solution of Intermediate 24a (134 mg, 0.36 mmol) was formed in THF (10 mL). DIPEA (125 μL, 0.72 mmol) was added followed by the dropwise addition of a solution of 2,2,2-trichloroethylchloroformate (50 μ□L, 0.36 mmol) in THF (2 mL). The mixture was stirred at RT for 4 h, then partitioned between EtOAc/water and extracted with EtOAc. The combined organics were dried over Na2SO4, filtered and concentrated in vacuo. Purification by FCC, using 0-10% MeOH in EtOAc, gave the title compound (200 mg, 99%) as a colourless film. LCMS (Method 4): Rt 2.59, m/z 543, 545 [MH+].

1. custompartitioned between EtOAc/water
2. extractionextracted with EtOAc
3. dry with materialThe combined organics were dried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customPurification by FCC