반응 #47332

반응 방정식

3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester

N-bromosuccinimide

benzoyl peroxide

→

4-bromo-3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester

수율 86.4%

용매

carbon tetrachloride

반응 조건

후처리

1. 1
   온도The reaction was then warmed
2. 2
   온도to reflux for 5 h
3. 3
   기타At this time, the reaction was removed from the freezer
4. 4
   기타The resulting precipitate was removed by filtration
5. 5
   농축The filtrate was concentrated in vacuo
6. 6
   기타Purification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes)

실험 절차

A solution of 3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester (1.41 g, 5.45 mmol) in carbon tetrachloride (30 mL) was treated with N-bromosuccinimide (1.07 g, 6.01 mmol) and benzoyl peroxide (0.15 g). The reaction was then warmed to reflux for 5 h. At this time, the reaction was cooled to 25° C. and then placed in the freezer over the weekend. At this time, the reaction was removed from the freezer and allowed to thaw. The resulting precipitate was removed by filtration. The filtrate was concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes) afforded impure 4-bromo-3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester (1.59 g, 86%) as a white solid. The material was used without further purification.

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