反应详情

To a solution of 2-amino-5-bromo-3-(methyloxy)benzoic acid (16.40 g, 66.65 mmol) in H2O (80 mL), was added conc. HCl (30 mL) and THF (5 mL) at 0° C. The reaction mixture was stirred for 30 min, and then NaNO2 (14.00 g, 202.91 mmol) was cautiously added to the solution. This solution was stirred for 2 h, and then H3PO2 (22.00 g, 333.35 mmol) was cautiously added to the solution. The solution was kept stirring overnight at the room temperature (monitored by TLC), then filtered and rinsed with water (50 mL×2). The resulting solid was dried to afford 3-bromo-5-(methyloxy)benzoic acid (9.60 g, 62%). 1H NMR (400 MHz, CDCl3) δ 7.46 (t, J=1.6 Hz, 1H), 7.31 (q, J=16.8 Hz, 1H), 7.21 (t, J=16.8 Hz, 1H), 3.84 (s, 1H).

1. stirringThis solution was stirred for 2 h
2. stirringThe solution was kept stirring overnight at the room temperature (monitored by TLC)
3. filtrationfiltered
4. washrinsed with water (50 mL×2)
5. customThe resulting solid was dried