(R)-4-Benzyl-2-oxazolidinone → (R)-4-Benzyl-3-pent-4-enoyloxazolidin-2-one

Temperature

-78 °C

To a solution of (4R)-4-(phenylmethyl)-1,3-oxazolidin-2-one (50 g, 282 mmol) in THF (300 mL) was dropwise added n-BuLi in THF (2.4 M, 176 mL, 423 mmol) under nitrogen at −78° C., and the resulting mixture was stirred at −78° C. for 1 hour. Then 4-pentenoyl chloride (49 mL, 423 mmol) was dropwise added. After stirring at −78° C. for another 1 hour, the reaction mixture was allowed to warm up to room temperature and stirred overnight. After diluting with water, the mixture was extracted with ethyl acetate (2×400 mL). The combined ethyl acetate extracts were washed with brine, dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude residue was purified by silica gel column chromatography (ethyl acetate:petroleum ether=1:10) to afford the title compound (68 g, 93%) as a light yellow oil. MS (ES+) C15H17NO3 requires: 259, found: 260 [M+H]+.

1. customat −78° C.
2. stirringAfter stirring at −78° C. for another 1 hour
3. temperatureto warm up to room temperature
4. stirringstirred overnight
5. extractionthe mixture was extracted with ethyl acetate (2×400 mL)
6. washThe combined ethyl acetate extracts were washed with brine
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe crude residue was purified by silica gel column chromatography (ethyl acetate:petroleum ether=1:10)

ORD record

ord-8663e16441d94f74915145d1548c2864

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09434700B2