反应详情

温度

55 °C

To a solution of Intermediate 187a (377 mg, 0.51 mmol) in MeOH (5 mL) was added pyridinium p-toluenesulfonate (257 mg, 1.02 mmol) and the reaction mixture was heated at 55° C. for 3 h. The resultant mixture was poured into water and a saturated aqueous solution of NaHCO3 was added. The aqueous phase 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 3-10% MeOH in DCM, to give the title compound (250 mg, 75%). LCMS (Method 1): Rt 3.09 min, m/z 653 [MH+].

1. extractionThe aqueous phase 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