反应详情

Methyl 4,6-dichloro-3-iodopicolinate (0.56 g, 1.7 mmol), vinyltributylstannane (580 μl, 0.63 g, 2.0 mmol) and bis(triphenylphosphine)palladium(II) chloride (0.12 g, 0.17 mmol) were combined in 1,2-dichloroethane (8 mL) and the mixture was sparged with a stream of nitrogen for 15 min. The reaction mixture was stirred at reflux for 21 h, cooled to room temperature, and diluted with ethyl acetate (15 mL). A solution of 20% KHF2 (10 ml) was added and the mixture was stirred for 45 minutes. The mixture was filtered through Celite. The organic phase was washed with water, washed with saturated sodium chloride, dried over sodium sulfate, and concentrated under vacuum. The crude product was purified by flash chromatography (SiO2, ethyl acetate/hexanes) to afford the title compound as a solid (0.30 g, 70%): 1H NMR (400 MHz, CDCl3) δ 7.50 (s, 1H), 6.82 (ddd, J=17.8, 11.5, 1.7 Hz, 1H), 5.66 (dd, J=11.4, 8.1 Hz, 1H), 5.55 (dt, J=17.7, 5.0 Hz, 1H), 3.92 (s, 3H); EIMS m/z 231.

1. customthe mixture was sparged with a stream of nitrogen for 15 min
2. temperatureat reflux for 21 h
3. additiondiluted with ethyl acetate (15 mL)
4. additionA solution of 20% KHF2 (10 ml) was added
5. stirringthe mixture was stirred for 45 minutes
6. filtrationThe mixture was filtered through Celite
7. washThe organic phase was washed with water
8. washwashed with saturated sodium chloride
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated under vacuum
11. customThe crude product was purified by flash chromatography (SiO2, ethyl acetate/hexanes)