Reaktion #324664

Reaktionsgleichung

chloro-trimethyl-silane

2,5-dibromo-1,3-dimethylbenzene

n-butyllithium

→

title compound

(4-Bromo-3,5-dimethylphenyl)trimethylsilane

Lösungsmittel

diethylether

tetrahydrofuran

n-hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring for 2 hours the reaction
2. 2
   Sonstigeis quenched by addition of saturated aqueous NH4Cl solution
3. 3
   ExtraktionThe mixture is extracted with diethylether
4. 4
   TrocknenThe organic phase is dried (MgSO4)
5. 5
   Einengenconcentrated
6. 6
   SonstigeThe residue is chromatographed on silica gel (cyclohexane/ethyl acetate 99:1→90:10)

Vorschrift

A solution of 2,5-dibromo-1,3-dimethylbenzene (500 mg) in diethylether (3 mL) and tetrahydrofuran (2.5 mL) is cooled to −78° C. and treated dropwise with n-butyllithium (200 μL of a 10 M solution in n-hexane). The mixture is stirred for 1 hour and treated dropwise with chloro-trimethyl-silane (275 μL). After stirring for 2 hours the reaction is quenched by addition of saturated aqueous NH4Cl solution. The mixture is extracted with diethylether. The organic phase is dried (MgSO4) and concentrated. The residue is chromatographed on silica gel (cyclohexane/ethyl acetate 99:1→90:10) to give the title compound. Yield: 260 mg; Mass spectrum (ESI+): m/z=279 [M+Na]+.

Quelle