反应详情

温度

-78 °C

To a solution of R-(−)-4-benzyl-2-oxazolidinone (15.0 g, 84.65 mmol) in THF (200 mL) was added nBuLi (2.5M in hexanes, 34 mL, 84.65 mmol) dropwise at −78° C. The solution was stirred at −78° C. for 30 min and then bromo acetyl bromide (18.65 g, 7.8 mL, 124.15 mmol) was added. The solution was allowed to warm to 25° C. overnight (19 h). An aliquot was taken and TLC (1:2 EtOAc-hexane) indicated that reaction was complete. It was diluted in ethyl acetate (200 mL) and the organic layer was washed with saturated aqueous NaHCO3 (2×50 mL). The organic layer was dried over MgSO4, filtered and concentrated to obtain a crude brown oil (24.6 g). The crude product was purified by flash chromatography, eluent: 1:4 EtOAc-hexane, to furnish (4R)-4-benzyl-3-(bromoacetyl)-1,3-oxazolidin-2-one as a colorless oil (19.9 g, 79.6%). Mass Spectrum (+ESI): 300, 299 (M+H)+.

1. temperatureto warm to 25° C. overnight (19 h)
2. washthe organic layer was washed with saturated aqueous NaHCO3 (2×50 mL)
3. dry with materialThe organic layer was dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. customto obtain a crude brown oil (24.6 g)
7. customThe crude product was purified by flash chromatography, eluent