AN EVALUATION OF THE STRUCTURAL REQUIREMENTS FOR THE SEPARATION OF PROPRANOLOL ENANTIOMERS ON PIRKLE PHASES FOLLOWING ACHIRAL DERIVATIZATION

The chromatographic performance of a series of isocyanate and isothiocyanate derivatives of (±)-propranolol has been investigated on three Pirkle-type chiral stationary phases (CSP's), 3,5-dinitrobenzoylphenylglycine (PHE), 3,5-dinitrobenzoylleucine (LEU) and phenethylpropylurea (PEPU). The reaction yield is independent of the substituent group but is affected by choice of solvent. The urea or thiourea derivative group formed is responsible for any separation observed on the amino acid based phases, the retention being related to structure. The structure-retention relationship is not apparent for the π-basic PEPU phase, moreover resolution is not simply related to retention for all three phases. Inversion of elution order of the enantiomers is observed with certain derivatives on the LEU column. The naphthyl and nitrophenyl derivatives generally exhibit enhanced retention, with the naphthylurea derivative generally giving the best resolution on these phases. © 1990 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.