Ionic liquids and their use in extraction processes.

There is provided a process for the extn. of at least one arom. compd. from a mixt. with at least one aliph. hydrocarbon, which process comprises contacting said mixt. with a salt that is in a liq. state at a temp. below 150°C, said salt having a cation which comprises an arom. nitrogen-contg. heterocyclic ring system, in which a nitrogen atom forming part of said ring system is quaternized and in which said ring system is substituted by at least one electron-withdrawing substituent. Some of said salts are novel. [on SciFinder(R)]