Chiral resolution of the enantiomers of tetrahydronaphthalenic derivatives, new agonist and antagonist ligands for melatonin receptors, using high-performance liquid chromatography on cellulose chiral stationary phases

Abstract

Analytical HPLC methods using derivatized cellulose chiral stationary phases were developed for the separation of the enantiomers of methoxy and ethyl tetrahydronaphthalenic derivatives, new agonist and antagonist ligands for melatonin receptors. The resolution were made using normal-phase methodology with a mobile phase consisting of n-hexane–alcohol (methanol, ethanol, 1-propanol or 2-propanol) in various percentage, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). The mobile phase and the chiral stationary phase were varied to achieve the best resolution. The effects of concentration of alcohol, various aliphatic alcohols in the mobile phase were studied. The effects of substitution were analysed. Baseline separation ( R s>1.5) was easily obtained in many cases.The resolution results were complementary between the two columns.