74958-71-7

Thiourea derivatives of 2-[(1R)-1-aminoethyl]phenol, (1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, (1R,2R)-(1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, and (R)-1-phenylethanamine have been compared as chiral solvating agents (CSAs) for the enantiodiscrimination of derivatized amino acids using nuclear magnetic resonance (NMR) spectroscopy. Thiourea derivative, prepared by reacting 2-[(1R)-1-aminoethyl]phenol with benzoyl isothiocyanate, constitutes an effective CSA for the enantiodiscrimination of N-3,5-dinitrobenzoyl (DNB) derivatives of amino acids with free or derivatized carboxyl functions. A base additive 1,4-diazabicyclo[2.2.2]octane(DABCO)/N,N-dimethylpyridin-4-amine (DMAP)/NBu4OH) is required both to solubilize amino acid derivatives with free carboxyl groups in CDCl3 and to mediate their interaction with the chiral auxiliary to attain efficient differentiation of the NMR signals of enantiomeric substrates. For ternary systems CSA/substrate/DABCO, the chiral discrimination mechanism has been ascertained through the NMR determination of complexation stoichiometry, association constants, and stereochemical features of the diastereomeric solvates.

A new chiral stationary phase (CSP) based on macrocyclic amide receptor was prepared starting from (1R,2R)-1,2-diphenylethylenediamine. The new CSP was successfully applied to the resolution of various N-(substituted benzoyl)-α-amino amides with reasonably good separation factors and resolutions (α = 1.75 ~ 2.97 and RS = 2.89 ~ 6.82 for 16 analytes). The new CSP was also applied to the resolution of 3-substituted 1,4-benzodiazepin-2-ones and some diuretic chiral drugs including bendroflumethiazide and methylchlothiazide and metolazone. The resolution results for 3-substituted 1,4-benzodiazepin-2-ones and some diuretic chiral drugs were also reasonably good. Chirality 28:253-258, 2016.

A chiral stationary phase derived from α-(6,7-dimethyl-1-naphthyl)isobutylamine is quite effective for the liquid chromatographic separation of the enantiomers of the N-3,5-dinitrobenzoyl derivatives of α-amino acids, their esters and amides, amino alcoho