Réaction #4836

Équation de réaction

4-(1,1-dichloro-2,2,2-trifluoroethoxy)chlorobenzene

hydrogen fluoride

antimony pentachloride

→

4-(1-chloro-1,2,2,2-tetrafluoroethoxy)chlorobenzene

Rendement 89.8%

Conditions de réaction

Traitement

1. 1
   AutreA 500 ml polytetrafluoroethylene reactor equipped with stirrer
2. 2
   Températurethermometer and reflux condenser
3. 3
   AutreThe resultant hydrogen chloride is removed from the reactor through the reflux condenser
4. 4
   AutreExcess hydrogen fluoride is removed by distillation
5. 5
   workup.DISSOLUTIONthe residue is dissolved in 200 ml of methylene chloride
6. 6
   Extractionthe solution is extracted with water
7. 7
   AutreThe organic phase is separated by distillation

Mode opératoire

A 500 ml polytetrafluoroethylene reactor equipped with stirrer, thermometer and reflux condenser is charged with 55.9 g (0.2 mol) of 4-(1,1-dichloro-2,2,2-trifluoroethoxy)chlorobenzene in 100 ml of hydrogen fluoride. 3.0 g (0.01 mol; corresponding to 5 mol%) of antimony pentachloride are added at a temperature in the range from -5° C. to 0° C. The resultant hydrogen chloride is removed from the reactor through the reflux condenser. After 20 minutes at 0° C., the evolution of hydrogen chloride ceases. Excess hydrogen fluoride is removed by distillation, the residue is dissolved in 200 ml of methylene chloride and the solution is extracted with water. The organic phase is separated by distillation, affording 47.3 g (89.8% of theory) of 4-(1-chloro-1,2,2,2-tetrafluoroethoxy)chlorobenzene. Boiling point 181° C., nD25 =1.4362.

Source