反应详情

DMTCl (0.9 g, 2.66 mmol) was added to a stirred solution of 21 (0.6 g, 2.35 mmol) in 25 ml of anhydrous pyridine. After being stirred at room temperature for 4 hrs the reaction was quenched with MeOH (2 ml) and concentrated to an oil. The oil was partition between dichloromethane and 10% citric acid. The organic phase was washed with saturated NaCl, dried over Na2SO4 and concentrated. The resulting material was chromatographed on silica eluting with a gradient of methanol (5-7.5%) in ethyl acetate. Concentration of the pure product fractions afforded 1.2 g (91%) of 22 as a white amorphous solid. 1H NMR (DMSO-d6): δ 10.78 (s, 1H), 7.77 (d, J=7.2 Hz, 1H), 7.27 (m, 5H), 6.97 (d, J=7.2 Hz, 1H), 6.84 (m, 4H), 4.66 (d, J=4.8 Hz, 1H), 4.01 (m, 1H), 3.78 (m, 2H), 3.73 (s, 6H), 3.73 (m, 1H), 3.09 (m, 2.89 (m, 1H), 2.12 (m, 1H), 2.09 (s, 3H), 1.02 (d, J=6.3 Hz, 3H).

1. customwas quenched with MeOH (2 ml)
2. concentrationconcentrated to an oil
3. customThe oil was partition between dichloromethane and 10% citric acid
4. washThe organic phase was washed with saturated NaCl
5. dry with materialdried over Na2SO4
6. concentrationconcentrated
7. customThe resulting material was chromatographed on silica eluting with a gradient of methanol (5-7.5%) in ethyl acetate