Enantioresolution of dihydropyridine substituted acid by supercritical fluid chromatography on hypercarb® with Z-(L)-arginine as chiral counter ion

Abstract

SummaryA chromatographic method is described for separation of substituted dihydropyridines on Hypercarb, porous-graphitic carbon as support and methanol-modified carbon dioxide containing Tween 60 | deactivation additive, as mobile phase.Enantiomers of a dihydropyridine substituted acid were resolved after addition of Z-(L)-arginine as ion-pairing counter ion. A 0.2 mM concentration was sufficient to achieve a resolution factor > 2 or baseline resolution. The system was used to estimate the minor enantiomer below 0.1% level.

Supercritical Fluid and Unified Chromatography

“…They studied effects of temperature, pressure, and density of CO 2 mobile phase on retention and chiral selectivity. Gyllenhaal and Karlsson separated substituted dihydropyridines on Hypercarb using Tween 60 as a deactivation additive and (Z)-(L)-arginine as counterion (153).…”

Columns in analytical‐scale supercritical fluid chromatography: From traditional to unconventional chemistries

“…Due to the specific interactions, PGC columns were used primarily for the separation of isomers and compounds with closely similar structures, for example, isosorbide-5-mononitrate [186], aromatic isomers [187], metoprolol and related amino alcohols [188], plasticizers [189][190][191], plant diterpene esters [192], flower fingerprinting [193], nitrosamines [194,195], and essential oils [196]. PGC columns were also used for chiral separation in the presence of a chiral selector in the mobile phase, as shown in the case of dihydropyridine using N-benzyloxycarbonyl-L-arginine as a chiral selector [197,198], benzoxazine using β-cyclodextrin as chiral selector [199], several pharmaceuticals using β-cyclodextrin as chiral selector [200], and beta blockers using L-(+)-tartaric acid as chiral selector [198].…”

Chiral separations in sub‐ and supercritical fluid chromatography

“…In ref. [6], an achiral SP, Hypercarb (a porous graphitic carbon based SP), was used combined with a chiral selector Z-(L)-arginine (i. e., benzyloxycarbonyl-L-arginine). Initially, the authors aimed to separate a mixture of pyridine, clevidipine, and an acidic degradation product of the latter in nonchiral SFC using methanol and Tween-60 as mobile phase modifiers.…”