反应详情

A solution of 3-bromo-2-fluorobenzoic acid (6.86 g, 31.32 mm 1), triethylamine (5.24 mL, 37.59 mmol) and DPPA (7.45 mL, 34.46 mmol) in t-BuOH (30 mL) was stirred at reflux for 20 hours. After cooling to ambient temperature, the solvent was removed under reduced pressure. The residue was dissolved in ethyl acetate (100 mL), washed with brine, dried (sodium sulfate), filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (4:1 hexane/ethyl acetate) to give tert-butyl 3-bromo-2-fluorophenylcarbamate (6.0 g, 66.0%) as an oil.

1. temperatureat reflux for 20 hours
2. customthe solvent was removed under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate (100 mL)
4. washwashed with brine
5. dry with materialdried (sodium sulfate)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by flash chromatography on silica gel (4:1 hexane/ethyl acetate)