反应详情

To a stirred mixture of 5-chloroimidazo[1,2-a]pyridine hydrochloride (1.89 g, 10.0 mmol), (5-chloro-2-methoxy)benzene boronic acid (2.07 g, 12.0 mmol), 2 M aqueous sodium carbonate (20 mL, 40 mmol) and p-dioxane (50 mL) was added tetrakis(triphenylphosphine)palladium(0) (0.58 g, 0.50 mmol) at ambient temperature. The mixture was heated at reflux for 16 h, allowed to cool to ambient temperature and diluted with ethyl acetate (50 mL) and water (20 mL). The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography eluting with a 50-80% gradient of ethyl acetate in hexanes to afford 5-(5-chloro-2-methoxyphenyl)imidazo[1,2-a]pyridine as a colorless solid in 70% yield (1.82 g): 1H NMR (300 MHz, DMSO-d6) δ7.72-7.48 (m, 4H), 7.37-7.23 (m, 3H), 6.89 (d, J=6.6 Hz, 1H), 3.74 (s, 3H); MS (ES+) m/z 259.0 (M+1), 261.0 (M+1).

1. temperatureThe mixture was heated
2. temperatureat reflux for 16 h
3. washThe organic layer was washed with brine
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was purified by column chromatography
8. washeluting with a 50-80% gradient of ethyl acetate in hexanes