반응 #47357

반응 방정식

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

수율 87.2%

용매

carbon tetrachloride

반응 조건

후처리

1. 1
   온도The reaction was then heated
2. 2
   온도At this time, the reaction was cooled to 25° C.
3. 3
   기타was placed in the refrigerator overnight
4. 4
   기타At this time, the reaction was removed from the refrigerator
5. 5
   기타The resulting precipitate was removed by filtration
6. 6
   세척was rinsed with carbon tetrachloride (25 mL)
7. 7
   농축The filtrate was concentrated in vacuo
8. 8
   기타Purification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes)

실험 절차

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.

출처