Reaktion #630081

Reaktionsgleichung

2,5-dimethyl-2,5-dichlorohexane

thiophene

→

4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thiophene

Lösungsmittel

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile cooling with ice
2. 2
   Temperaturagain cooled with ice
3. 3
   ExtraktionThe mixture is extracted three times with ether
4. 4
   Waschenthe organic phase is washed with saturated sodium bicarbonate solution
5. 5
   Sonstigedried
6. 6
   Sonstigeevaporated
7. 7
   FiltrationThe thus-obtained black oil is firstly filtered over silica gel (eluting agent hexane)
8. 8
   workup.DISTILLATIONsubsequently distilled in a water-jet vacuum

Vorschrift

90 g of 2,5-dimethyl-2,5-dichlorohexane and 195 ml of thiophene are dissolved in 400 ml of hexane. 54 ml of titanium tetrahcloride are slowly added dropwise thereto while cooling with ice, the mixture is warmed to 40° C. for 1.5 hours, again cooled with ice and the dark red mixture is treated cautiously with ice-water. The mixture is extracted three times with ether, the organic phase is washed with saturated sodium bicarbonate solution, dried and evaporated. The thus-obtained black oil is firstly filtered over silica gel (eluting agent hexane) and subsequently distilled in a water-jet vacuum. There are obtained 18.5 g of 4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thiophene as a colorless liquid, b.p. 95°-96° C./10 mm.

Quelle