반응 #47509

반응 방정식

(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

수율 40.0%

용매

carbon tetrachloride

반응 조건

후처리

1. 1
   기타Nitrogen gas was bubbled through the mixture for 5 min
2. 2
   온도the resulting mixture was heated
3. 3
   온도to reflux for 4 h
4. 4
   기타was then placed in the refrigerator overnight
5. 5
   기타The solids formed
6. 6
   기타were removed by filtration
7. 7
   농축the filtrate concentrated in vacuo
8. 8
   기타The crude product obtained
9. 9
   기타was purified

실험 절차

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.

출처