反应详情

温度

65 °C

A solution of i-PrMgCl (27.49 mL, 2M in THF, 55 mmol.) was added dropwise to commercially available 1,3-dibromo-2-methyl-benzene (12.5 g, 50 mmol) at RT under argon and then heated at 65° C. for 1.5 h. The mixture was added via syringe to a suspension of dry ZnCl2 (6.83 g, 50 mmol.) in dry THF (20 ml) and cooled to 0° C. under argon. The resulting suspension was stirred at RT for 30 min. Then 2-bromo-pyridine (4.78 ml, 50 mmol.) and PdCl2*dppf (2.03 g) were added and the mixture was refluxed for 2 h. The reaction mixture was then quenched by the addition of a 5% solution of citric acid (200 ml) and extracted with ethyl acetate (2×250 ml). The combined organic layers were consecutively washed with a 5% solution of citric acid (150 ml) and brine (150 ml), dried over Na2SO4, filtered and evaporated under reduced pressure. The crude material was chromatographed on silica gel. Yield: 7.7 g, 78%.

1. temperaturecooled to 0° C. under argon
2. temperaturethe mixture was refluxed for 2 h
3. customThe reaction mixture was then quenched by the addition of a 5% solution of citric acid (200 ml)
4. extractionextracted with ethyl acetate (2×250 ml)
5. washThe combined organic layers were consecutively washed with a 5% solution of citric acid (150 ml) and brine (150 ml)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated under reduced pressure
9. customThe crude material was chromatographed on silica gel