反应详情

温度

-25 °C

8.0 g of 3,4,5,2'-tetrafluoro-4'-(4-propylidenecyclohexyl)biphenyl in 16 ml of dichloromethane were introduced into a Teflon apparatus and cooled to -25° C. 80 ml of a 70% solution of hydrogen fluoride in pyridine were then added dropwise with stirring, and the mixture was stirred for 30 minutes at -25° C. and then for a further 1 hour at room temperature. The reaction solution was poured into a suspension of 10 g of sodium hydrogencarbonate and 200 g of ice-water. The mixture was then extracted with 3×80 ml of hexane. The combined organic extracts were washed once with 50 ml of sodium chloride solution, dried using sodium sulfate, filtered and evaporated to a residue. The crude product was purified by means of a silica-gel frit and the eluate was evaporated to a residue, giving 3,4,5,2'-tetrafluoro-4'-(4-fluoro-4-propylcyclohexyl)-biphenyl (C 73 N (48.8) I, Δε=15.3, Δn=+0.111).

1. stirringthe mixture was stirred for 30 minutes at -25° C.
2. extractionThe mixture was then extracted with 3×80 ml of hexane
3. washThe combined organic extracts were washed once with 50 ml of sodium chloride solution
4. customdried
5. filtrationfiltered
6. customevaporated to a residue
7. customThe crude product was purified by means of a silica-gel frit
8. customthe eluate was evaporated to a residue