反应详情

温度

90 °C

2-Bromopyridine (0.475 mL, 0.78 g, 4.9 mmol) and 2,6-dimethoxy-3-pyridineboronic acid (1.09 g, 6.0 mmol, excess) were dissolved in THF (25 mL) at RT. Aqueous solution of K2CO3 (1.65 g in 10 mL of water, 12 mmol, excess) was added, followed by Pd(PPh3)4 (295 mg, 0.25 mmol). The mixture was stirred at 90° C. for 20 h under argon to give yellow solution. Organic solvent was removed under reduced pressure and the residue was extracted with dichloromethane and water. Evaporation of organic phase provided red oil that was purified by chromatography on silica gel eluting with CH2Cl2/MeOH 0 to 0.2%. The fractions containing pure product were collected, while those containing impurities were again purified by chromatography using the same conditions. After three chromatographic purifications the total yield was 965 mg (4.39 mmol; 90%) of yellow oil that crystallized as yellow solid on standing. Anal. Calcd for C12H12N2O2.0.2H2O (MW 219.84): C, 65.56; H, 5.69; N, 12.74. Found: C, 65.74; H, 5.63; N, 12.53. 1H NMR (400 MHz, CD2Cl2): 8.64 (d, J 4.0, 1H), 8.32 (d, J 8.0, 1H), 8.03 (d, J 8.0, 1H), 7.74 (t, J 8.0, 1H), 7.19 (m, 1H), 6.47 (d, J 8.0, 1H), 4.06 (s, 3H), 4.00 (s, 3H). 13C NMR (100 MHz, CD2Cl2): 163.24, 160.16, 154.36, 149.44, 142.44, 136.01, 123.97, 121.38, 114.30, 102.02, 53.75, 53.52.

1. customto give yellow solution
2. customOrganic solvent was removed under reduced pressure
3. extractionthe residue was extracted with dichloromethane and water
4. customEvaporation of organic phase
5. customprovided red oil that
6. customwas purified by chromatography on silica gel eluting with CH2Cl2/MeOH 0 to 0.2%
7. additionThe fractions containing pure product
8. customwere collected, while those containing impurities
9. customwere again purified by chromatography
10. customAfter three chromatographic purifications the total yield was 965 mg (4.39 mmol; 90%) of yellow oil that crystallized as yellow solid