Reacción #47509

Ecuación de reacción

(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

Rendimiento 40.0%

Disolventes

carbon tetrachloride

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroNitrogen gas was bubbled through the mixture for 5 min
2. 2
   Temperaturathe resulting mixture was heated
3. 3
   Temperaturato reflux for 4 h
4. 4
   Otrowas then placed in the refrigerator overnight
5. 5
   OtroThe solids formed
6. 6
   Otrowere removed by filtration
7. 7
   Concentraciónthe filtrate concentrated in vacuo
8. 8
   OtroThe crude product obtained
9. 9
   Otrowas purified

Procedimiento

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.

Fuente