反应 #1435766

反应方程式

hydrochloric acid

(S)-2-tert-Butoxycarbonylamino-3-hydroxy-propionic acid

sodium hydride

2,5-difluoro-nitrobenzene

→

(S)-2-tert-butoxycarbonylamino-3-(4-fluoro-2-nitro-phenoxy)-propionic acid

收率 52.0%

溶剂

dimethylformamide

dimethylformamide

反应条件

后处理

1. 1
   workup.STIRRINGAfter additional 3 hours of stirring at 0° C. the mixture
2. 2
   workup.ADDITIONwas poured on ice/water
3. 3
   萃取Extraction with ethylacetate and chromatography on silicagel with ethylacetate/heptane 1:1

实验过程

5.00 g (24.4 mmol) (S)-2-tert-Butoxycarbonylamino-3-hydroxy-propionic acid in 5 ml dimethylformamide were added to a suspension of 2.25 g (51.7 mmol) sodium hydride (55%) in 5 ml dimethylformamide at 0° C. The suspension was stirred for 1 hour and then 4.5 ml (26.8 mmol) 2,5-difluoro-nitrobenzene was added. After additional 3 hours of stirring at 0° C. the mixture was poured on ice/water. The ph was adjusted to 1 by adding 7 ml 25% aqueous hydrochloric acid. Extraction with ethylacetate and chromatography on silicagel with ethylacetate/heptane 1:1 yielded 4.35 g (52%) (S)-2-tert-butoxycarbonylamino-3-(4-fluoro-2-nitro-phenoxy)-propionic acid as yellow solid, MS m/e (%): 343.0 (M−H+, 100).

来源