Enantioseparation of racemic 4‐aryl‐3,4‐dihydro‐2(1 H )‐pyrimidones on chiral stationary phases based on 3,5‐dimethylanilides of N ‐(4‐alkylamino‐3,5‐dinitro)benzoyl L‐α‐amino acids

Three novel chiral packing materials for high‐performance liquid chromatography were prepared by covalently binding of (2S)‐N‐(3,5‐dimethylphenyl)‐2‐[(4‐chloro‐3,5‐dinitrophenyl)carbonylamino]propan‐amide ( 7 ), (2S)‐N‐(3,5‐dimethylphenyl)‐2‐[(4‐chloro‐3,5‐dinitrophenyl)carbonylamino]‐4‐methylpentanamide ( 8 ), and (2S)‐N‐(3,5‐dimethylphenyl)‐2‐[(4‐chloro‐3,5‐dinitrophenyl)carbonyl‐amino]‐2‐phenylacetamide ( 9 ) to aminopropyl silica. The resulting chiral stationary phases ( CSPs 1–3 ) proved effective for the resolution of racemic 4‐aryl‐3,4‐dihydro‐2(1H)‐pyrimidone derivatives ( TR 1–14 ). The mechanism of their enantioselection, supported by the elution order of ( S )‐ TR 13 and ( R )‐ TR 13 and molecular modeling of the complex of the slower running ( S )‐ TR 13 with CSP 1 is discussed. Chirality 15:550–557, 2003. © 2003 Wiley‐Liss, Inc.