Réaction #47514

Équation de réaction

(E)-3-(2,5-dichloro-phenoxy)-but-2-enoic acid ethyl ester

N-bromosuccinimide

benzoyl peroxide

→

(E)-4-bromo-3-(2,5-dichloro-phenoxy)-but-2-enoic acid ethyl ester

Rendement 43.0%

Solvants

carbon tetrachloride

Conditions de réaction

Traitement

1. 1
   AutreNitrogen gas was bubbled through the mixture for 5 min
2. 2
   Températurethe resulting mixture was heated
3. 3
   Températureto reflux for 4 h
4. 4
   Autrewas then placed in the refrigerator overnight
5. 5
   AutreThe solids formed
6. 6
   Autrewere removed by filtration
7. 7
   Concentrationthe filtrate concentrated in vacuo
8. 8
   AutreThe crude product obtained
9. 9
   Autrewas purified

Mode opératoire

To a stirred mixture of (E)-3-(2,5-dichloro-phenoxy)-but-2-enoic acid ethyl ester (3.25 g, 0.012 mol) in carbon tetrachloride (20 mL) under a nitrogen atmosphere was added N-bromosuccinimide (3.20 g, 0.018 mol) and benzoyl peroxide (290 mg, 0.001 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-(2,5-dichloro-phenoxy)-but-2-enoic acid ethyl ester (1.80 g, 43%) as a yellow oil.

Source