反应详情

To a stirred solution of 3-chloro-2-hydroxypyridine-5-carboxylic acid (1 g, 5.762 mmol) in benzene (16 mL) and MeOH (4 mL) was added dropwise TMSCHN2 (3.17 mL, 6.338 mmol) at 0° C., and the resulting mixture was stirred overnight at room temp. The reaction mixture was quenched by the addition of AcOH and the mixture was evaporated off. The residue was suspended in water and precipitate was collected. The crude solid was washed with Et2O, and dried under a reduced pressure to give 728.1 mg (67%) methyl 3-chloro-2-hydroxypyridine-5-carboxylate as a white crystalline powder. IR (KBr) 1655, 1282, 1245, 769 cm−1; 1H-NMR (400 MHz, DMSO-d6) δ3.79 (s, 3H), 8.01 (s, 1H), 8.06 (s, 1H); MS (FAB) m/z 188 (M++1); Anal. Calcd. for C7H6ClNO3: C, 44.82; H, 3.22; Cl, 18.90; N, 7.47. Found: C, 44.74; H, 3.22; Cl, 19.00; N, 7.34.

1. customThe reaction mixture was quenched by the addition of AcOH
2. customthe mixture was evaporated off
3. customprecipitate was collected
4. washThe crude solid was washed with Et2O
5. customdried under a reduced pressure