反应 #47357

反应方程式

3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester

N-bromosuccinimide

→

4-bromo-3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester

收率 87.2%

溶剂

carbon tetrachloride

反应条件

后处理

1. 1
   温度The reaction was then heated
2. 2
   温度At this time, the reaction was cooled to 25° C.
3. 3
   其他was placed in the refrigerator overnight
4. 4
   其他At this time, the reaction was removed from the refrigerator
5. 5
   其他The resulting precipitate was removed by filtration
6. 6
   洗涤was rinsed with carbon tetrachloride (25 mL)
7. 7
   浓缩The filtrate was concentrated in vacuo
8. 8
   其他Purification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes)

实验过程

A solution of 3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester (1.35 g, 5.57 mmol) in carbon tetrachloride (30.9 mL) was treated with N-bromosuccinimide (1.09 g, 6.13 mmol) and benzoyl peroxide (108 mg, 0.44 mmol). The reaction was then heated to reflux (105° C.) for 5 h. At this time, the reaction was cooled to 25° C. and then was placed in the refrigerator overnight. At this time, the reaction was removed from the refrigerator. The resulting precipitate was removed by filtration and was rinsed with carbon tetrachloride (25 mL). The filtrate was concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes) afforded impure 4-bromo-3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester (1.56 g, 87%) as a clear oil. The material was used without further purification.

来源