反应详情

温度

-78 °C

To a toluene (300 mL) solution of 2,5-dibromopyridine (10.0 g, 42.2 mmol) was added dropwise n-butyl lithium (2.55 M n-hexane solution, 18.2 mL, 46.4 mmol) on a dry ice-ethanol bath (−78° C.) under nitrogen atmosphere, which was stirred for 2 hours at −78° C. N,N-dimethylformamide (3.7 g, 50.6 mmol) was then added dropwise thereto and stirred for 10 minutes at −78° C. Sodium borohydride (3.20 g, 84.4 mmol) and methanol (20.0 mL) were then added and stirred for 30 minutes at room temperature. Water was added to the reaction solution, which was then extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride, and the solvent was evaporated under a reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:heptane=1:1→2:1) to obtain the title compound (4.70 g, 59.2%).

1. stirringstirred for 10 minutes at −78° C
2. stirringstirred for 30 minutes at room temperature
3. extractionwas then extracted with ethyl acetate
4. washThe organic layer was washed with saturated aqueous sodium chloride
5. customthe solvent was evaporated under a reduced pressure
6. customThe residue was purified by silica gel column chromatography (ethyl acetate:heptane=1:1→2:1)