反应详情

温度

60 °C

To a solution of 4a (4.71 g, 16.6 mmol) in anhydrous chloroform (200 ml) under nitrogen was added triphenylphosphine dibromide (14.04 g, 33.26 mmol). The reaction mixture was heated at 60° C. overnight. The mixture was allowed to cool to room temperature then washed with saturated aqueous sodium carbonate solution, dried over sodium sulphate and concentrated in vacuo. The resulting residue was purified by flash chromatography on silica (eluent: ethyl acetate/isohexane gradient 10/90 to 30/70 [v/v]) to give 5a as a white solid (4.63 g, 81%); MW 346.27; C18H20BrNO; 1H NMR (CDCl3): 7.14-7.39 (10H, m), 4.83 (1H, d, 7 Hz), 4.01 (1H, br, t, 8 Hz), 3.73 (1H, br, d, 11 Hz), 3.60-3.48 (2H, m), 3.39 (1H, d, 12 Hz), 3.20 (1H, d, 11 Hz), 2.50 (1H, d, 10 Hz), 2.07 (2H, t, 10 Hz); LCMS: (6 min method) m/z 346 [M]+ @ Rt 2.51 min.

1. temperatureto cool to room temperature
2. washthen washed with saturated aqueous sodium carbonate solution
3. dry with materialdried over sodium sulphate
4. concentrationconcentrated in vacuo
5. customThe resulting residue was purified by flash chromatography on silica (eluent: ethyl acetate/isohexane gradient 10/90 to 30/70 [v/v])