反应详情

A colourless solution of Intermediate 39b (120 mg, 0.224 mmol) and pyridinium p-toluenesulfonate (169 mg, 0.673 mmol) in MeOH (5 mL) was stirred at 40° C. for 90 min. The solution was concentrated in vacuo, suspended in water (3 mL) and sat. aq. NaHCO3 solution (3 mL), then extracted with DCM (2×5 mL). The combined organics were passed through a hydrophobic frit, concentrated in vacuo and azeotroped with toluene (2×5 mL) to leave the title compound as a white solid (100 mg, 99%). LCMS (Method 3): Rt 4.01 min, m/z 450, 452 [MH+].

1. concentrationThe solution was concentrated in vacuo
2. extractionsat. aq. NaHCO3 solution (3 mL), then extracted with DCM (2×5 mL)
3. concentrationconcentrated in vacuo
4. customazeotroped with toluene (2×5 mL)