反应详情

4-Acetamido-2,6-dimethylanisole (7, 8.6 g, 44.3 mmol) and acetic acid (30 mL) were placed in a round-bottom flask under an argon atmosphere. Bromine (2.7 mL, 44.3 mmol) was added dropwise to the solution, after which the reaction mixture was stirred at room temperature for about 3 h, and then concentrated. The residue was diluted with methylene chloride and carefully washed sequentially with saturated aq. sodium bicarbonate and brine, and dried (MgSO4). Removal of solvents gave a brown-colored solid which was recrystallized from methylene chloride-hexanes to yield 4-acetamido-3-bromo-2,6-dimethylanisole (10.3 g, 85% yield) as an off-white solid, mp 152°-153° C. Spectral data: 1H NMR: δ 2.18 (s, 3H), 2.24 (s, 3H), 2.35 (s, 3H), 3.66 (s, 3H), 7.55 (br s, 1H), 7.9 (s, 1H); 13C NMR: δ 16.1, 16.8, 24.6, 60.1, 114.5, 122.0, 130.5, 131.3, 131.5, 153.6, 168.1; CI-HRMS: calcd. for C11H15BrNO2 (M+H+) 272.0286, fnd. 272.0284.

1. concentrationconcentrated
2. additionThe residue was diluted with methylene chloride
3. washcarefully washed sequentially with saturated aq. sodium bicarbonate and brine
4. dry with materialdried (MgSO4)
5. customRemoval of solvents
6. customgave a brown-colored solid which
7. customwas recrystallized from methylene chloride-hexanes