反应详情

温度

60 °C

2,5-Dibromonitrobenzene (41.5 g, 148 mmol) was dissolved in anhydrous DMF (500 ml) and sodium hydride (17.7 g of a 60% suspension in mineral oil, 443 mmol) was added under argon. Diethyl malonate (49.6 g, 295 mmol) was added dropwise over 10 minutes giving a strong exotherm (mixture rose to 60° C.). The reaction mixture was maintained at 60° C. for 6 hours then left to cool to ambient temperature and stirred for 18 hours. The resulting dark red solution was poured slowly into 2M hydrochloric acid (1500 ml) and extracted with ether (500 ml×4). The organic phases were combined, washed with brine, dried (MgSO4) and the solvent removed by evaporation. The crude oil was purified by flash chromatography eluting with isohexanes/ethyl acetate (100/0, then 95/5 and finally 80/20) to give diethyl(4-bromo-2-nitrophenyl)malonate (51 g, 96%).

1. customgiving a strong exotherm (mixture rose to 60° C.)
2. waitthen left
3. temperatureto cool to ambient temperature
4. extractionextracted with ether (500 ml×4)
5. washwashed with brine
6. dry with materialdried (MgSO4)
7. customthe solvent removed by evaporation
8. customThe crude oil was purified by flash chromatography
9. washeluting with isohexanes/ethyl acetate (100/0