تفاعل #47357

معادلة التفاعل

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

N-bromosuccinimide

→

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

المردود 87.2%

المذيبات

carbon tetrachloride

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe reaction was then heated
2. 2
   درجة الحرارةAt this time, the reaction was cooled to 25° C.
3. 3
   أخرىwas placed in the refrigerator overnight
4. 4
   أخرىAt this time, the reaction was removed from the refrigerator
5. 5
   أخرىThe resulting precipitate was removed by filtration
6. 6
   غسيلwas rinsed with carbon tetrachloride (25 mL)
7. 7
   تركيزThe filtrate was concentrated in vacuo
8. 8
   أخرىPurification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes)

الإجراء التجريبي

A solution of 3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester (1.35 g, 5.57 mmol) in carbon tetrachloride (30.9 mL) was treated with N-bromosuccinimide (1.09 g, 6.13 mmol) and benzoyl peroxide (108 mg, 0.44 mmol). The reaction was then heated to reflux (105° C.) for 5 h. At this time, the reaction was cooled to 25° C. and then was placed in the refrigerator overnight. At this time, the reaction was removed from the refrigerator. The resulting precipitate was removed by filtration and was rinsed with carbon tetrachloride (25 mL). The filtrate was concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes) afforded impure 4-bromo-3-(2,5-difluoro-phenoxy)-but-2-enoic acid ethyl ester (1.56 g, 87%) as a clear oil. The material was used without further purification.

المصدر