反应详情

Thionyl chloride (6.3 mL, 86.33 mmol) was added dropwise to a solution of 6-hydroxynicotinic acid (10.0 g, 71.94 mmol) in methanol at 0° C. The mixture was heated to reflux for 6 hours, the solvent was removed and standard extractive work up provided the title compound as a brown solid (7.5 g, 68%). m.p. 166-172° C.; 1H NMR (400 MHz, DMSO-d6) δ 3.77 (s, 3H), 6.37 (d, J=9.3 Hz, 1H), 7.79 (dd, J=2.7, 9.5 Hz, 1H), 8.04 (d, J=2.4 Hz, 1H); IR (KBr) ν 3050, 2965, 1712, 1651, 1433, 1300, 1106 cm−1; MS 154 (M+1).

1. temperatureThe mixture was heated
2. temperatureto reflux for 6 hours
3. customthe solvent was removed