反应详情

To a solution of methyl 2-hydroxy-3-[(phenylcarbonyl)oxy]benzoate (42.1 g, 155 mmol) in N,N-dimethylformamide (300 mL) was added 1,2-dibromoethane (135 mL, 1550 mmol) and cesium carbonate (76 g, 232 mmol), and the reaction mixture was stirred at room temperature under nitrogen for 6.5 h. The volume of the reaction mixture was reduced by half in vacuo, and then partitioned between water (500 mL) and ethyl acetate (500 mL). The layers were separated, and the organic layer was washed with brine (200 mL), dried over anhydrous magnesium sulfate and concentrated. The crude precipitate was triturated with 50% diethyl ether/hexanes (200 mL). The solid was washed with 50% diethyl ether/hexanes (2×200 mL) and isolated to give 30.6 g (52% over 2 steps) of methyl 2-[(2-bromoethyl)oxy]-3-[(phenylcarbonyl)oxy]benzoate as an off-white powder: 1H NMR (400 MHz, CDCl3): 8.23-8.21 (m, 2H), 7.77 (dd, J=1.6, 7.6 Hz, 1H), 7.68-7.64 (m, 1H), 7.53 (t, J=6.0 Hz, 2H), 7.39 (dd, J=1.8, 8.0 Hz, 1H), 7.25 (t, J=6.4 Hz, 1H), 4.31 (t, J=6.4 Hz, 2H), 3.93 (s, 3H), 3.52 (t, J=6.4 Hz, 2H).

1. custompartitioned between water (500 mL) and ethyl acetate (500 mL)
2. customThe layers were separated
3. washthe organic layer was washed with brine (200 mL)
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated
6. customThe crude precipitate was triturated with 50% diethyl ether/hexanes (200 mL)
7. washThe solid was washed with 50% diethyl ether/hexanes (2×200 mL)
8. customisolated