反应详情

温度

-50 °C

n-BuLi (1.6 M in hexanes, 2.250 mL, 3.60 mmol) was added dropwise to a solution of diisopropylamine (0.556 mL, 3.90 mmol) in THF (20 mL) at −78° C. under inert gas (N2). The resulting mixture was warmed up to ˜−50° C. and stirred for 10 min and cooled again to −78° C. A solution of 3-bromo-5-fluoropyridine (528 mg, 3 mmol) in THF (5 mL) was added dropwise at this temperature. The reaction mixture turned from clear light brown to heterogenous light brown. After 30 min, DMF (0.256 mL, 3.30 mmol) was added dropwise and the resulting mixture was stirred for 30 min. The reaction was quenched by MeOH then NH4Cl (saturated solution) and warmed up to room temperature. After concentration, the residue was dissolved in CH2Cl2 and washed with NaHCO3 (Saturated solution). After drying over Na2SO4, concentration, the residue was purified by column (Heptane to CH2Cl2) and yielded slightly yellow crystal (380 mg). 1H NMR (400.3 MHz, CDCl3): δ 8.58 (s, 1H), 8.72 (s, 1H), 10.33 (s, 1H).

1. temperaturecooled again to −78° C
2. waitAfter 30 min
3. stirringthe resulting mixture was stirred for 30 min
4. customThe reaction was quenched by MeOH
5. temperatureNH4Cl (saturated solution) and warmed up to room temperature
6. concentrationAfter concentration
7. dissolutionthe residue was dissolved in CH2Cl2
8. washwashed with NaHCO3 (Saturated solution)
9. dry with materialAfter drying over Na2SO4, concentration
10. customthe residue was purified by column (Heptane to CH2Cl2)