Bromobenzene → 4-Bromo-2,6-dimethylbiphenyl

HRID 252245

Reaktionsgleichung

Reaktionsgleichung von HRID 252245
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]=1

Komponenten

6

Versuchsvorschrift

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).

Aufarbeitung

  1. stirringwhile stirring for 2 hours
  2. stirringthe mixture stirred at room temperature for 16 hours
  3. customThe tetrahydrofuran was evaporated under reduced pressure
  4. customthe crude product purified by column chromatography (SiO2, heptane)

Quellen und Nachweise

ORD-Eintrag
ord-64351bf6b77c47379671e216238805c3
Quelldatensatz
uspto-grants-2011_01
Patentnummer
US07868030B2

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