Enantioselective Partitioning of Racemic Ibuprofen in a Biphasic Recognition Chiral Extraction System

Enantioselective partitioning of ibuprofen enantiomers in a biphasic recognition chiral extraction system was studied. A combination of hydrophobic L-isobutyl tartrate in organic phase and hydrophilic beta-cyclodextrin derivative in aqueous phase is necessary to establish a biphasic recognition chiral extraction system. The Studies performed involve an enantioselective extraction in a biphasic system, where ibuprofen enantiomers form four complexes with the beta-cyclodextrin derivative in aqueous phase and the D(L)-isobutyl tartrate in organic phase, respectively. In these biphasic resolutions, the types and the concentrations of the extractants, pH and temperature all exert a considerable influence on the biphasic recognition process. Good enantioselectivities for ibuprofen enantiomers were obtained at pH <= 2.5 and a ratio of 2 : 1 of [L-isobutyl tartrate] to [HP-beta-CD]. Biphasic recognition chiral extraction is of strong chiral separation ability, and may be very helpful to optimize the extraction systems and realize the large-scale production of enantiomers.