反应详情

The product of Example 91G (36 mg, 0.0568 mmol) was treated with 1:1 v/v methylene chloride/trifluoroacetic acid (3 mL) at room temperature for one hour then concentrated by rotary evaporation. The residue was dissolved in ethyl acetate (50 mL), washed with saturated aqueous sodium hydrogencarbonate (25 mL), water (25 mL), and brine (25 mL) then dried over magnesium sulfate, filtered, and concentrated by rotary evaporation. Purification by silica gel flash chromatography eluting with 3:97 methanol/methylene chloride afforded the title compound as a white solid (22 mg, 0.0412 mmol, 73%). 1H NMR (300 MHz, DMSO-D6) δ ppm 1.31 (d, J=6.99 Hz, 6 H) 1.45 (d, J=7.35 Hz, 3 H) 3.01-3.20 (m, 1 H) 5.07-5.26 (m, 1 H) 5.57 (s, 2 H) 6.61 (d, J=8.46 Hz, 2 H) 6.83 (d, J=8.46 Hz, 1 H) 7.11 (d, J=8.82 Hz, 2 H) 7.17-7.43 (m, 5 H) 7.54-7.64 (m, 2 H) 7.69 (dd, J=8.46, 1.10 Hz, 1 H) 7.89 (d, J=1.47 Hz, 1 H) 8.43 (t, J=4.23 Hz, 2 H) 8.74 (d, J=7.72 Hz, 1 H) 9.88 (s, 1 H); MS (ESI+) m/z 534 (M+H)+, 1067 (2M+H)+; MS (ESI−) m/z 532 (M−H)−.

1. concentrationthen concentrated by rotary evaporation
2. dissolutionThe residue was dissolved in ethyl acetate (50 mL)
3. washwashed with saturated aqueous sodium hydrogencarbonate (25 mL), water (25 mL), and brine (25 mL)
4. dry with materialthen dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated by rotary evaporation
7. customPurification by silica gel flash chromatography
8. washeluting with 3:97 methanol/methylene chloride