反应详情

温度

-78 °C

To 2-bromo-5-iodo-pyridine (2.974 g, 10.2 mmol) in a mixture of THF (15 mL) and ether (20 mL) at −78° C. is added dropwise n-butyl lithium (2.5 M in hexane, 4 L, 10.2 mmol). The mixture is stirred at −78° C. for 30 min, then acetone (anhydrous, 0.749 uL, 10.2 mmol) is added drop wise. The mixture is slowly warmed up to −50° C. over 1.5 h and is quenched with saturated ammonium chloride, extracted with ethyl acetate. The organic phase is separated, dried and rotavaped. The residue is purified by silica gel chromatography (10-20% ethyl acetate in heptane) to give the title compound as white solid (1.40 g, 64%).

1. temperatureThe mixture is slowly warmed up to −50° C. over 1.5 h
2. customis quenched with saturated ammonium chloride
3. extractionextracted with ethyl acetate
4. customThe organic phase is separated
5. customdried
6. customThe residue is purified by silica gel chromatography (10-20% ethyl acetate in heptane)