HPLC enantioseparation and absolute configuration of novel anti‐inflammatory pyrrole derivatives

Abstract

The assignment of the absolute configuration of novel anti-inflammatory pyrrole derivatives has been accomplished by a combined strategy based on independent physical methods. The key step of our stereochemical characterization approach is the production at mg-scale of enantiomerically pure forms by HPLC on Chiralpak IA stationary phase.

Chiral HPLC separation and absolute configuration of novel S‐DABO derivatives

“…Example: ethyl 2-methyl-4-(2,6-dichlorophenyl)-3-oxohexanoate (7). Triethylamine (12.0 ml, 86.4 mmol) and magnesium dichloride (6.43 g, 67.5 mmol) were added to a stirred suspension of potassium 2-methylmalonate monoethyl ester (10.44 g, 56.7 mmol) in dry acetonitrile (90 ml) and stirring was continued at room temperature for 2 h. Then, a solution of the 2-(2,6-dichlorophenyl)-butyric imidazolide in the same solvent (28 ml), prepared 15 min before by a reaction between 2-(2,6-dichlorophenyl)butyric acid (6.29 g, 27.0 mmol) and N,N 0 -carbonyldiimidazole (5.25 g, 32.4 mmol) in acetonitrile (28 ml), was added.…”

Structure Control of Polysaccharide Derivatives for Efficient Separation of Enantiomers by Chromatography

“…For analytical HPLC, more efficient separations of chiral compounds (Figure ) that cannot be resolved or can be resolved to a small degree on the coated CPMs have been attained on the immobilized CPMs using the prohibited solvents. ,,− This improvement of the recognition ability may partly be due to the change in the conformation of the polysaccharide derivatives. The immobilized CPMs are also useful for separation of chiral compounds with a low solubility in a conventional eluent.…”

Direct HPLC enantioseparation of omeprazole and its chiral impurities: Application to the determination of enantiomeric purity of esomeprazole magnesium trihydrate

“…Due to the high efficiency, enantioselectivity and loading capacity of the immobilised Chiralpak IA CSP [15,[18][19][20][21][22][23][24], the analytical enantioseparations were easily scaled-up for semipreparative productions of the (S)-form of API and impurities ( Table 1). The successful transfer of the enantioseparation from a 4.6 to a 10 mm I.D.…”

“…In particular, analytical methods based on polysaccharide-based CSPs seem to be efficient routes for checking their enantiomeric purity [5,[13][14][15]20].…”