Benzoyl Peroxide → 4-Bromo-3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester

HRID 19054Notes

Reaction equation

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

Participants

Conditions

Temperature: 25 °C

Procedure

A solution of 3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester (1.41 g, 5.45 mmol) in carbon tetrachloride (30 mL) was treated with N-bromosuccinimide (1.07 g, 6.01 mmol) and benzoyl peroxide (0.15 g). The reaction was then warmed to reflux for 5 h. At this time, the reaction was cooled to 25° C. and then placed in the freezer over the weekend. At this time, the reaction was removed from the freezer and allowed to thaw. The resulting precipitate was removed by filtration. The filtrate was concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes) afforded impure 4-bromo-3-(3-chloro-2-fluoro-phenoxy)-but-2-enoic acid ethyl ester (1.59 g, 86%) as a white solid. The material was used without further purification.

Workup

temperatureThe reaction was then warmed
temperatureto reflux for 5 h
customAt this time, the reaction was removed from the freezer
customThe resulting precipitate was removed by filtration
concentrationThe filtrate was concentrated in vacuo
customPurification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes)

Sources & evidence

ORD record: ord-90743fa93f484cdf8377947ed34feb74
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07741327B2

Reaction notes

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