反应详情

温度

0 °C

N-BuLi (21.3 mL, 2.5 M in hexane, 53.2 mmol) was added dropwise to a solution of i-Pr2NH (5.9 g, 58.5 mmol) in THF (80 mL) at −78° C. The solution was stirred at 0° C. for 1 h. A solution of 2-bromo-5-methoxypyridine (10 g, 53.2 mmol) in THF (30 mL) was added dropwise to the LDA solution at −78° C. The mixture was stirred at −78° C. for 2 h and poured onto an excess of dry ice and allowed to warm to RT before being treated with NaOH (5% a.q., 100 mL). The mixture was washed with DCM and acidified to pH 4 by addition of HCl (6 N, 20 mL). The solids were collected by filtration to give the product of 2-bromo-5-methoxyisonicotinic acid (10 g, yield: 83%). 1H-NMR (DMSO-d6, 400 MHz) δ 8.34 (s, 1H), 7.70 (s, 1H), 3.92 (s, 3H). MS (M+H)+: 232/233.

1. stirringThe mixture was stirred at −78° C. for 2 h
2. temperatureto warm to RT
3. washThe mixture was washed with DCM
4. additionacidified to pH 4 by addition of HCl (6 N, 20 mL)
5. filtrationThe solids were collected by filtration