反应详情

Acetic anhydride (3.11 ml, 3.37 g, 33 mmol) was added dropwise to a stirred, cooled (0° C.) solution of 3-bromo-4methoxyaniline (6.06 g, 30 mmol) in dichloromethane (60 ml). The mixture was stirred at room temperature for 90 minutes, methanol (10 ml) was added and the mixture was stirred at room temperature for 30 minutes. The solvent was evaporated under reduced pressure, saturated aqueous sodium hydrogen carbonate (100 ml) and water (50 ml) were added and the mixture was extracted with ethyl acetate (3×100 ml). The combined organic fractions were washed with aqueous hydrochloric acid (1M, 100 ml), saturated aqueous sodium hydrogen carbonate (100 ml) and brine (100 ml), dried (MgSO4) and evaporated under reduced pressure. The residue was recrystallized from ethyl acetate (20 ml)/hexane (50 ml) and the solid was collected and dried in vacuo to give the title compound as a tan solid (6.41 g, 88%), 1H NMR (360 MHz, CDCl3) δ 7.68 (1H, d, J=2.5 Hz), 7.45 (1H, dd, J=8.8, 2.5 Hz), 7.36 (1H, br s), 6.84 (1H, d, J=8.8 Hz), 3.87 (3H, s), and 2.16 (3H, s).

1. stirringthe mixture was stirred at room temperature for 30 minutes
2. customThe solvent was evaporated under reduced pressure, saturated aqueous sodium hydrogen carbonate (100 ml) and water (50 ml)
3. additionwere added
4. extractionthe mixture was extracted with ethyl acetate (3×100 ml)
5. washThe combined organic fractions were washed with aqueous hydrochloric acid (1M, 100 ml), saturated aqueous sodium hydrogen carbonate (100 ml) and brine (100 ml)
6. dry with materialdried (MgSO4)
7. customevaporated under reduced pressure
8. customThe residue was recrystallized from ethyl acetate (20 ml)/hexane (50 ml)
9. customthe solid was collected
10. customdried in vacuo