Method for removing impurities using ionic liquids.

A process for the extractive removal of optionally substituted phenol, 3-hydroxypyrazole, 2-hydroxypyridine, hydroquinone, resorcinol, catechol; alcohol C1-C20 glycol, glycerol, optionally substituted aniline, N-alkyl C1-C20, N, N-di-alkyl C1-C20, P-alkylphosphine C1-C20, P, P-di-alkylphosphine C1-C20, phenylphosphine , diphenylphosphine, hydrazine, hydroxylamine, sulfonic acid, sulfinic acid, phosphoric acid, carboxylic acid or amino acid aprotic solvents by means of ionic liquids of the formula [K] n + [a] n -, wherein n is 1, 2 or 3; [K] + is selected from the group consisting of: * quaternary ammonium cations of the formula [NR 1, R 2, R 3, R 4] + (Ia) * cations quaternary phosphonium of formula [PR 1, R 2, R 3, R 4] + (Ib) wherein R 1, R 2, R 3, R 4 are each C1-C12 or phenyl-C1-C4 alkyl, where the aliphatic radicals may bear from 1 to 4 substituents selected from the group consisting of halogen, amino, cyano, C1-C4 alkoxy and the phenyl ring may bear the abovementioned substituents and also C1-C6, carboxylate and sulfonate groups; R 1 and R 2 may be taken together to form a C4-C5 alkylene radical which may be substituted by C1-C4alkyl, halogen, cyano or C1-C4 alkyl; * Imidazolinium cations of formula (See formula) * pyridinium cations of the formula (See formula) * pyrazolium cations of the formula (See formula) * quinolinium cations of the formula (See formula) * thiazolium cations of the formula (See formula) * triazinium cations of the formula (See formula) wherein the index n R and R x substituents have the following meanings: n is 0, 1, 2, 3 or 4; R is hydrogen, C1-C12 alkyl or phenyl-C1-C4 alkyl, where the aliphatic radicals may bear from 1 to 4 substituents selected from the group consisting of halogen, amino, cyano, C1-C4 alkoxy and the phenyl ring may bear the substituents mentioned above and C1-C6 alkyl, carboxylate and sulfonate groups; R x is C1-C6 alkyl, halogen, amino, cyano, C1-C4 alkoxy, carboxylate or sulfonate; [A] n- is the partly or fully deprotonated anion of an organic or inorganic protic acid HnA (III), wherein n is a positive integer and indicates the charge on the anion.