Bromobenzene → 4-Bromo-2,6-dimethylbiphenyl
Reaction equation
C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[Br:13][C:14]1[CH:15]=[C:16]([CH3:22])[C:17](I)=[C:18]([CH3:20])[CH:19]=1>O1CCCC1.[Cl-].[Zn+2].[Cl-]>[Br:13][C:14]1[CH:15]=[C:16]([CH3:22])[C:17]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[C:18]([CH3:20])[CH:19]=1Participants
Procedure
2.5 M n-Butyllithium, in tetrahydrofuran, (1.42 ml, 3.54 mmol, 1.1 equiv.) was added dropwise to a solution of bromobenzene (0.34 ml, 3.22 mmol, 1.0 equiv.) in dry tetrahydrofuran (18 ml), under nitrogen at −78° C. and the mixture stirred for 30 minutes. Zinc chloride (0.48 g, 3.54 mmol, 1.1 equiv.) was added and the mixture allowed to warm to room temperature while stirring for 2 hours. Palladium tetrakistriphenylphosphine (0.19 g, 0.16 mmol, 0.05 equiv.) and a solution of 5-bromo-2-iodo-1,3-dimethyl-benzene (1.00 g, 3.22 mmol, 1.0 equiv.) in tetrahydrofuran (2 ml) were added and the mixture stirred at room temperature for 16 hours. The tetrahydrofuran was evaporated under reduced pressure and the crude product purified by column chromatography (SiO2, heptane). The fractions were combined to afford 4-bromo-2,6-dimethylbiphenyl, 278 mg (33% yield) as a clear oil δH (400 MHz; d4-methanol) 7.28-7.39 (3H, m), 7.18 (2H, s), 7.03 (2H, d), 1.90 (6H, s).
Workup
- stirringwhile stirring for 2 hours
- stirringthe mixture stirred at room temperature for 16 hours
- customThe tetrahydrofuran was evaporated under reduced pressure
- customthe crude product purified by column chromatography (SiO2, heptane)
Sources & evidence
- ORD record
- ord-64351bf6b77c47379671e216238805c3
- Source dataset
- uspto-grants-2011_01
- Patent number
- US07868030B2
Reaction notes
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