反应 #1244309

反应方程式

Lithium borohydride

Methyl (2S)-3-(dibenzylamino)-2-fluoropropanoate

→

(2S)-3-(dibenzylamino)-2-fluoro-1-propanol

收率 92.4%

溶剂

THF

THF

反应条件

后处理

1. 1
   workup.ADDITIONadded dropwise to the mixture
2. 2
   workup.ADDITIONOn completion of addition
3. 3
   温度to warm to room temperature
4. 4
   workup.STIRRINGstirred at this temperature for 3 h
5. 5
   其他consumption of starting material
6. 6
   温度The reaction mixture was cooled to 0° C.
7. 7
   其他cautiously quenched with a saturated aqueous solution of ammonium chloride (300 mL)
8. 8
   workup.ADDITIONAdditional water (400 mL) was added
9. 9
   萃取the reaction mixture was extracted with ethyl acetate
10. 10
    浓缩the organic phase was concentrated under reduced pressure
11. 11
    workup.DISSOLUTIONThe crude residue was dissolved in 2 N hydrochloric acid
12. 12
    洗涤the aqueous phase was washed twice with ether
13. 13
    萃取extracted with ethyl acetate
14. 14
    干燥dried over anhydrous sodium sulfate
15. 15
    过滤filtered
16. 16
    浓缩concentrated under reduced pressure

实验过程

Lithium borohydride (17.7 g, 0.81 mol) was suspended in THF (400 mL) under a nitrogen atmosphere and cooled to −15° C. with stirring. Methyl (2S)-3-(dibenzylamino)-2-fluoropropanoate (188.3 g, 0.62 mol) was suspended in THF (400 mL) and added dropwise to the mixture. On completion of addition, the reaction mixture was allowed to warm to room temperature and stirred at this temperature for 3 h. TLC analysis indicated complete consumption of starting material. The reaction mixture was cooled to 0° C. and cautiously quenched with a saturated aqueous solution of ammonium chloride (300 mL). Additional water (400 mL) was added then the reaction mixture was extracted with ethyl acetate and the organic phase was concentrated under reduced pressure. The crude residue was dissolved in 2 N hydrochloric acid and the aqueous phase was washed twice with ether. The aqueous phase was basified (pH=10 approx.) with 80% ammonium hydroxide in brine, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to afford (2S)-3-(dibenzylamino)-2-fluoro-1-propanol (156.6 g, 92%) as a yellow oil. 1H NMR (300 MHz, CDCl3) δ 7.15-7.38 (m, 10H), 4.65-4.78 (m, 0.5H), 4.48-4.58 (m, 0.5H), 3.50-3.82 (m, 6H), 2.70-2.88 (m, 2H).

来源