反应详情

温度

-78 °C

2,5-Dibromopyridine (10 g, 35.2 mmol) is dissolved in dry toluene (200 mL) under a nitrogen atmosphere and cooled to −78° C. n-Butyllithium (2.5M in hexanes, 2.5 mL, 38.7 mmol) is added at −78° C. over 20 minutes. The reaction mixture is stirred at −78° C. for 20 minutes. Oxetane-3-one (2.79 g, 38.7 mmol) in toluene (100 mL) is added then stirred at −78° C. for 30 minutes. Saturated aqueous ammonium chloride solution (50 mL) is added. The mixture extracted with ethyl acetate (2×200 mL), separated, washed with brine solution (50 mL) and the solvent evaporated under reduced pressure. The crude material is purified using flash chromatography (35% ethyl acetate in hexane) to give the title compound (4.2 g): 1H NMR (400 MHz, DMSO-d6):δ 4.64 (2H, d), 4.87 (2H, d), 6.68 (1H, s), 7.55 (1H, d), 8.06 (1H, dd), 8.76 (1H, d).

1. additionis added at −78° C. over 20 minutes
2. stirringthen stirred at −78° C. for 30 minutes
3. extractionThe mixture extracted with ethyl acetate (2×200 mL)
4. customseparated
5. washwashed with brine solution (50 mL)
6. customthe solvent evaporated under reduced pressure
7. customThe crude material is purified