反应详情

The mixture of Example 2A (478 mg, 0.8 mmol) and 2,2,2-trifluoroacetic acid (616 μL, 8.0 mmol) in CH2Cl2 (10 mL) was stirred at ambient temperature overnight. Saturated aqueous Na2CO3 (20 mL) was added followed by CH2Cl2 (30 mL). The organic layer was washed with brine and concentrated. Purification by gradient flash chromatography (silica gel, 5-30% (Et3N:MeOH, 1:10)/EtOAc) afforded 340 mg (85%) of the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.32 (s, 9 H), 1.55-1.98 (m, 4 H), 2.04-2.34 (m, 2 H), 3.25-3.51 (m, 1 H), 3.59-3.87 (m, 4 H), 4.01-4.39 (m, 6 H), 7.26 (s, 1 H), 7.32 (d, J=8.73 Hz, 1 H), 7.74 (dd, J=8.73, 2.78 Hz, 1 H), 7.98 (d, J=2.38 Hz, 1 H); MS (ESI) m/z 498 (M+H)+.

1. washThe organic layer was washed with brine
2. concentrationconcentrated
3. customPurification by gradient flash chromatography (silica gel, 5-30% (Et3N:MeOH, 1:10)/EtOAc)