反应详情

温度

-78 °C

To a solution of 1-bromo-3,5-dimethoxybenzene (2.17 g, 10 mmol) in THF (15 mL) was dropwise added n-butyl lithium (8 mL, 2.5 mol/L in hexane, 20 mmol) at −78′C. After stirring for 50 mins at −78° C., a solution of diethyl oxalate (4 g, 27 mmol) in THF (10 mL) was added. The mixture was stirred at −78° C. for another 4 h, then quenched with saturated ammonium chloride and extracted with ethyl acetate (50 mL*3). The organic layers were combined, washed by brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by chromatography on silica gel to give the title compound (1.7 g, 71%). MS (ES+) C12H14O5 requires: 238. found: 239 [M+H]+.

1. stirringThe mixture was stirred at −78° C. for another 4 h
2. customquenched with saturated ammonium chloride
3. extractionextracted with ethyl acetate (50 mL*3)
4. washwashed by brine
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by chromatography on silica gel