N-溴代丁二酰亚胺(NBS) → 4-Bromo-3-(2,4-difluoro-phenoxy)-but-2-enoic acid ethyl ester

HRID 19084笔记

反应方程式

HRID 19084 反应方程式
[CH2:1]([O:3][C:4](=[O:17])[CH:5]=[C:6]([O:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[CH:11][C:10]=1[F:16])[CH3:7])[CH3:2].[Br:18]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[CH2:1]([O:3][C:4](=[O:17])[CH:5]=[C:6]([O:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[CH:11][C:10]=1[F:16])[CH2:7][Br:18])[CH3:2]

参与物

5

反应物 2

HCID 67184N-溴代丁二酰亚胺(NBS)HCID 668948693-(2,4-Difluoro-phenoxy)-but-2-enoic acid ethyl ester

产物 1

HCID 668948514-Bromo-3-(2,4-difluoro-phenoxy)-but-2-enoic acid ethyl ester收率 81.1%

试剂、催化剂与溶剂 2

HCID 7187过氧化二苯甲酰催化剂HCID 5943四氯化碳溶剂

反应条件

温度
105 °C

实验过程

A solution of 3-(2,4-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 (10 mL). The filtrate was concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes) afforded impure 4-bromo-3-(2,4-difluoro-phenoxy)-but-2-enoic acid ethyl ester (1.45 g, 81%) as a clear oil. The material was used without further purification.

后处理

  1. temperatureThe reaction was then heated
  2. temperatureAt this time, the reaction was cooled to 25° C.
  3. customwas placed in the refrigerator overnight
  4. customAt this time, the reaction was removed from the refrigerator
  5. customThe resulting precipitate was removed by filtration
  6. washwas rinsed with carbon tetrachloride (10 mL)
  7. concentrationThe filtrate was concentrated in vacuo
  8. customPurification by Analogix flash chromatography (40 g, 2% ethyl acetate/hexanes)

来源与证据

ORD记录
ord-0a80e382673545c78d2bfafe49f2062d
来源数据集
uspto-grants-2010_06
专利号
US07741327B2

反应笔记

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