反応 #47509

反応方程式

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

N-bromosuccinimide

benzoyl peroxide

→

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

収率 40.0%

溶媒

carbon tetrachloride

反応条件

後処理

1. 1
   その他Nitrogen gas was bubbled through the mixture for 5 min
2. 2
   温度the resulting mixture was heated
3. 3
   温度to reflux for 4 h
4. 4
   その他was then placed in the refrigerator overnight
5. 5
   その他The solids formed
6. 6
   その他were removed by filtration
7. 7
   濃縮the filtrate concentrated in vacuo
8. 8
   その他The crude product obtained
9. 9
   その他was purified

実験手順

To a stirred mixture of (E)-3-(2,3-difluoro-phenoxy)-but-2-enoic acid ethyl ester (8.01 g, 0.033 mol) in carbon tetrachloride (30 mL) under a nitrogen atmosphere was added N-bromosuccinimide (8.91 g, 0.050 mol) and benzoyl peroxide (810 mg, 0.003 mol). Nitrogen gas was bubbled through the mixture for 5 min, and the resulting mixture was heated to reflux for 4 h. The reaction mixture was then placed in the refrigerator overnight. The solids formed were removed by filtration and the filtrate concentrated in vacuo. The crude product obtained was purified using flash column chromatography (silica gel (100-200 mesh), ethyl acetate/hexanes) to afford (E)-4-bromo-3-(2,3-difluoro-phenoxy)-but-2-enoic acid ethyl ester (4.20 g, 40%) as a yellow oil.

出典