反应详情

温度

0 °C

nBuLi (13.8 ml, 22 mmol, 1.6 M in hexane) was added dropwise into a 0° C. solution of diisopropylamine (3.39 ml,24 mmol) in THF (34 ml). The reaction mixture was stirred at 0° C. for 15 minutes then cooled to −75 ° C. and treated slowly with a solution of methyl 4-phenylbutyrate (3.56 g, 20 mmol) in THF (10 ml). After 30 minutes stirring at −75° C., trimethylchlorosilane ( 5.06 ml, 40 mmol) was added dropwise and the reaction mixture was allowed to warm up to room temperature. After 30 minutes, reaction mixture was concentrated, the residue was taken up in CH2Cl2 (100 ml), the resulting precipitate was filtered, filtrate was cooled to 13° C. and subsequently treated slowly with a solution of N-fluorodibenzenesulfonimide (6.3 g, 20 mmol) in CH2Cl2 (50 ml). After 3 hours stirring at room temperature, the reaction mixture was washed with H2O (2 times). The aqueous phase was extracted with CH2Cl2, the combined organic phases were dried over Na2SO4 and concentrated. The residue was chromatographed over silica gel (hexane-ethylacetate 99:1 then 98:2) to provide (RS)-2-fluoro-4-phenyl-butyric acid methyl ester (2.47 g, 63%) as a colorless oil, MS: m/e=196.1 (M+).

1. temperaturethen cooled to −75 ° C.
2. stirringAfter 30 minutes stirring at −75° C.
3. temperatureto warm up to room temperature
4. waitAfter 30 minutes
5. customreaction mixture
6. concentrationwas concentrated
7. filtrationthe resulting precipitate was filtered
8. temperaturefiltrate was cooled to 13° C.
9. stirringAfter 3 hours stirring at room temperature
10. washthe reaction mixture was washed with H2O (2 times)
11. extractionThe aqueous phase was extracted with CH2Cl2
12. dry with materialthe combined organic phases were dried over Na2SO4
13. concentrationconcentrated
14. customThe residue was chromatographed over silica gel (hexane-ethylacetate 99:1