反应详情

A mixture of Intermediate 42a (230 mg, 0.300 mmol) and pyridinium p-toluenesulfonate (226 mg, 0.900 mmol) in MeOH (3 mL) was stirred at RT for 15 h. Pyridinium p-toluenesulfonate (113 mg, 0.450 mmol) was added and the mixture stirred at 50-55° C. for 8 h. The cooled mixture was diluted with sat. aq. NaHCO3 solution and extracted with DCM (3×15 mL). The combined organics were dried and concentrated in vacuo. The residue was purified by FCC, using 0-14% MeOH in DCM, to give the title compound as a white powder after freeze-drying (163 mg, 82%). LCMS (Method 5): Rt 3.33 min, m/z 665.3 [MH+]. 1H NMR (400 MHz, d6-DMSO): 1.28 (9H, s), 1.82-2.27 (11H, m), 2.31-2.39 (1H, m), 3.10-3.17 (1H, m), 3.71 (2H, q, J 5.1), 3.96-4.05 (3H, m), 4.79-4.89 (2H, m), 5.37-5.41 (1H, m), 6.34 (1H, s), 6.95-6.99 (1H, m), 7.05-7.15 (3H, m), 7.24-7.43 (6H, m), 7.75 (1H, d, J 9.9), 8.11 (1H, s), 8.25 (1H, br d).

1. stirringthe mixture stirred at 50-55° C. for 8 h
2. extractionextracted with DCM (3×15 mL)
3. customThe combined organics were dried
4. concentrationconcentrated in vacuo
5. customThe residue was purified by FCC