反应详情

温度

0 °C

To solution of 4-bromo-2-nitro-benzoic acid (9 g, 36.58 mmol) in dimethylformamide (36 mL) cooled to 0° C. were added 1,8-diazabicyclo[5.4.0]und-7-ene (28.09 mL, 182.9 mmol) and MeI (11.4 mL, 182.5 mmol). The reaction mixture was stirred at 0° C. for 15 min and at r.t. for 48 h. The mixture was poured into water and extracted with EtOAc (2×). The combined organic phases were washed with water (2×), dried (Na2SO4) and concentrated to dryness. The crude product was purified by flash chromatography (hexanes to EtOAc/hexanes (4:6)) to give 4-bromo-2-nitro-benzoic acid methyl ester (8.62 g, 33.147 mmol, 90%). 1H-NMR (CDCl3, 400 MHz) 8.02 (s, 1H), 7.81 (dd, J=2.3, 10.5 Hz 1H), 7.66 (d, J=8.2 Hz, 1H), 3.92 (s, 3H).

1. extractionextracted with EtOAc (2×)
2. washThe combined organic phases were washed with water (2×)
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated to dryness
5. customThe crude product was purified by flash chromatography (hexanes to EtOAc/hexanes (4:6))