反应详情

温度

120 °C

A mixture of 6-bromo-3-methoxypicolinic acid (1.84 g, 7.93 mmol) and 3-fluorobenzene-1,2-diamine (1.0 g, 7.93 mmol) was stirred in PPA (3 mL) on a pre-heated oil-bath at 120° C. for 14 h. The mixture was poured to ice-water and basified to pH=8 with Na2CO3. Then the mixture was filtrated to collect the brown solid as 6-bromo-2-(4-fluoro-1H-benzo[d]imidazol-2-yl)pyridin-3-ol (900 mg, yield: 37%). The filtrated was extracted with ethyl acetate, and the organic layer was washed with brine and dried over Na2SO4. After concentrated, the residue was purified by column chromatography to give the product of 2-(6-bromo-3-methoxypyridin-2-yl)-4-fluoro-1H-benzo[d]imidazole (350 mg, yield: 14%). 1H-NMR (CDCl3, 400 MHz) δ 10.43˜10.56 (m, 1H), 7.46 (d, J=8.8 Hz, 1H), 7.33 (d, J=8.8 Hz, 1H), 7.21˜7.30 (m, 2H), 6.90˜6.98 (m, 1H), 4.05 (s, 3H). MS (M+H)+: 322/324.

1. filtrationThen the mixture was filtrated