Reaktion #92899

Reaktionsgleichung

p-dibromobenzene

trimethylchlorosilane

butyllithium

→

p-bromotrimethylsilylbenzene

Lösungsmittel

ether

ether

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigedoes not rise above -10° C
2. 2
   TemperaturAfter a negative Gilman test (H. Gilman, J. Swiss, J. Amer. Chem. Soc. 62: 1847 [1940]), the mixture is again cooled to -20° C.
3. 3
   Sonstigedoes not exceed -10° C
4. 4
   workup.ADDITIONAfter the addition step
5. 5
   workup.STIRRINGthe mixture is stirred for 16 hours at room temperature and another hour
6. 6
   Temperaturunder reflux
7. 7
   Waschenthoroughly washed with ether
8. 8
   EinengenThe resultant filtrate is concentrated
9. 9
   workup.DISTILLATIONdistilled with a water-jet aspirator

Vorschrift

Under argon, 94.4 g of p-dibromobenzene is cooled to -20° C. in 400 ml of absolute ether. To the solution is added dropwise 255 ml of 15% butyllithium in hexane so that the temperature does not rise above -10° C. Then the mixture is agitated for one hour at room temperature. After a negative Gilman test (H. Gilman, J. Swiss, J. Amer. Chem. Soc. 62: 1847 [1940]), the mixture is again cooled to -20° C. and 46 ml of trimethylchlorosilane in 200 ml of absolute ether is added dropwise thereto so that the temperature does not exceed -10° C. After the addition step is finished, the mixture is stirred for 16 hours at room temperature and another hour under reflux. The thus-formed precipitate is suctioned off and thoroughly washed with ether. The resultant filtrate is concentrated and then distilled with a water-jet aspirator, thus producing 65.52 g of p-bromotrimethylsilylbenzene, bp (16 torr) 103°-110° C.

Quelle