反应详情

To ethyl 6-chloro-2-oxohexanoate (2.9 g, 15 mmol) in carbon tetrachloride (30 mL) was added bromine (0.85 mL, 16.5 mmol) and stirred at rt for 1 hour. The reaction mixture was diluted with EtOAc, washed with Na2S2O3 solution, water, brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude material was purified by column chromatography on silica gel eluting with a gradient of 0 to 10% EtOAc in hexanes to provide the desired product ethyl 3-bromo-6-chloro-2-oxohexanoate (2A) in 95% yield. 1H NMR (300 MHz, DMSO-d6) δ ppm 5.25 (1H, dd), 4.29 (2H, q), 3.71 (2H, t), 2.16 (1H, m), 1.91 (1H, m), 1.29 (3H, t).

1. washwashed with Na2S2O3 solution, water, brine
2. dry with materialdried over MgSO4
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe crude material was purified by column chromatography on silica gel eluting with a gradient of 0 to 10% EtOAc in hexanes