反应详情

温度

0 °C

1-Bromo-3,5-dimethoxybenzene (10.9 g, 50 mmol) was dissolved in 100 mL of acetic anhydride and cooled to 0° C. A cooled solution of 70% HNO3 (6.4 mL, 100 mmol) in 20 mL of acetic anhydride was added dropwise and the resulting mixture was stirred for 1 hour at 0° C. and for 3 hours at room temperature. The reaction mixture was poured into ice-water with strong stirring and the yellow solid was filtered and washed with water. The solid as a mixture of two isomers was separated by silica gel column (ISCO, hexane/EtOAc, 0-30%, 40 min) to give 3.3 g (25%) of pure 5-bromo-1,3-dimethoxy-2-nitro-benzene as an yellow solid. 1H-NMR (DMSO-d6, 400 MHz): δ 7.17 (s, 2H), 3.89 (s, 6H).

1. stirringwith strong stirring
2. filtrationthe yellow solid was filtered
3. washwashed with water
4. additionThe solid as a mixture of two isomers
5. customwas separated by silica gel column (ISCO, hexane/EtOAc, 0-30%, 40 min)