Hydrotropic Separation of Mixtures of o‐/p‐Hydroxyacetophenones

Abstract

A new extractive separation technique has been developed for the separation of o‐/p‐hydroxyacetophenones (HAPs) using hydrotropy. Hydrotropes are freely water‐soluble organic salts which enhance solubility of otherwise water‐insoluble or sparingly soluble organic compounds in aqueous solutions. The ability of hydrotropes to differentiate even isomeric organic compounds is explored in this extractive separation. o‐/p‐HAPs were extracted from their solutions in organic solvents of different polarities using aqueous solutions of hydrotropes. The solvent nature has a significant effect on the selective extraction of both phenols. The combination of heptane and aq. Na–p‐toluene sulfonate solution gave almost pure p‐HAP in the aqueous phase, whereas with chloroform as the solvent, it was possible to extract with complete selectivity o‐HAP into the aqueous hydrotrope solutions.