Retention of fluorinated chiral selectors in biphasic fluorinated solvent systems and its application to the separation of enantiomers by countercurrent chromatography.
Ethoxynonafluorobutane (ENFB) has been used as a component of new biphasic solvent mixtures. The suitability of several mixtures as solvent systems in countercurrent chromatography was tested. The applicability of the ENFB/2-PrOH/H(2)O mixture to the separation of enantiomers, in combination with a fluorinated chiral selector (CS), was evaluated. N-Perfluoroundecanoyl-l-proline-3,5-dimethylanilide (2), analogous to the previously used N-dodecyl-l-proline-3,5-dimethylanilide (1), was synthesized for this purpose. The capacity of the new solvent system to retain the fluorinated CS in the fluorinated phase used as stationary was examined. Chiral selector 1 was applied in analogous conditions for comparative purposes. Additionally, MTBE/phosphate buffer solvent system was also used with the two CSs. The ENFB/2-PrOH/H(2)O (25:35:40) mixture was found to be adequate in the enantioseparation of DNB-Leu and DNB-Leu-tBu. Enantioselectivity was maintained in the fluorinated solvent system without compromising eluting time. The complete separation of DNB-Leu-tBu was achieved and no leaks of CS to the mobile phase were detected.
Pérez
Anna Maria
AM
Institute for Research in Biomedicine (IRB Barcelona), Parc Cientific de Barcelona (PCB), Baldiri Reixac 10-12, E-08028 Barcelona, Spain.
Minguillón
Cristina
C
D002073:Butanes / Q000737:chemistry*; D003377:Countercurrent Distribution / Q000379:methods*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D007930:Leucine / Q000031:analogs & derivatives / Q000737:chemistry; D009579:Nitrobenzoates / Q000737:chemistry; D013237:Stereoisomerism; D005466:Fluorocarbons
D002073:Butanes; D006845:Hydrocarbons, Fluorinated; D007930:Leucine; D009579:Nitrobenzoates; C438669:ethoxynonafluorobutane; D005466:Fluorocarbons; C051872:N-(3,5-dinitrobenzoyl)leucine