تفاعل #47509

معادلة التفاعل

(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

المردود 40.0%

المذيبات

carbon tetrachloride

ظروف التفاعل

المعالجة

1. 1
   أخرىNitrogen gas was bubbled through the mixture for 5 min
2. 2
   درجة الحرارةthe resulting mixture was heated
3. 3
   درجة الحرارةto reflux for 4 h
4. 4
   أخرىwas then placed in the refrigerator overnight
5. 5
   أخرىThe solids formed
6. 6
   أخرىwere removed by filtration
7. 7
   تركيزthe filtrate concentrated in vacuo
8. 8
   أخرىThe crude product obtained
9. 9
   أخرىwas purified

الإجراء التجريبي

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.

المصدر