Benzoyl Peroxide → (E)-4-bromo-3-(2,3-difluoro-phenoxy)-but-2-enoic acid ethyl ester
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]([F: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]([F:15])[C:10]=1[F:16])\[CH2:7][Br:18])[CH3:2]Participants
Procedure
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.
Workup
- customNitrogen gas was bubbled through the mixture for 5 min
- temperaturethe resulting mixture was heated
- temperatureto reflux for 4 h
- customwas then placed in the refrigerator overnight
- customThe solids formed
- customwere removed by filtration
- concentrationthe filtrate concentrated in vacuo
- customThe crude product obtained
- customwas purified
Sources & evidence
- ORD record
- ord-57afde570ecf42ffa3ed381edaac9547
- Source dataset
- uspto-grants-2010_06
- Patent number
- US07741327B2
Reaction notes
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