反应详情

温度

125 °C

Under argon, 201 ml (1.39 mol) of tert-butyl prop-2-enoate were added dropwise to a solution of 100 g (463 mmol) of 1-bromo-2-methyl-3-nitrobenzene, 322 ml (2.31 mol) of triethylamine, 28.18 g (92.58 mmol) of tri-2-tolylphosphine and 10.39 g (46.29 mmol) of palladium(II) acetate in 2 liters of DMF, and the mixture was then stirred at 125° C. for 36 h. After cooling to room temperature, the reaction mixture was stirred with saturated aqueous ammonium chloride solution, and the organic phase was separated off. The aqueous phase was extracted three times with tert-butyl methyl ether, and the combined organic phases were washed with saturated sodium chloride solution and dried over sodium sulphate. After filtration, the solvent was removed to dryness under reduced pressure. The residue obtained was purified by flash chromatography on silica gel (mobile phase petroleum ether/ethyl acetate 9:1). This gave 89 g (338 mmol, 73% of theory) of the intermediate tert-butyl (2E)-3-(2-methyl-3-nitrophenyl)prop-2-enoate as a colourless solid.

1. temperatureAfter cooling to room temperature
2. customthe organic phase was separated off
3. extractionThe aqueous phase was extracted three times with tert-butyl methyl ether
4. washthe combined organic phases were washed with saturated sodium chloride solution
5. dry with materialdried over sodium sulphate
6. filtrationAfter filtration
7. customthe solvent was removed to dryness under reduced pressure
8. customThe residue obtained
9. customwas purified by flash chromatography on silica gel (mobile phase petroleum ether/ethyl acetate 9:1)