Preparation And Application Of Cellulose Tris-cinnamate Coated Chiral Stationary Phases With Different Supports

Chiral stationary phases (CSPs) are the key to enantiomer separation. The topic of thispaper is preparation and application of cellulose tris-cinnamate coated CSPs with differentsupports by high-performance liquid chromatography (HPLC).Firstly, the preparation of binaphthol-bonded chiral stationary phase was studied. Twodifferent binaphthol-bonded chiral stationary phases were synthesized by the reaction ofBINOL with different amounts of the epoxy silane coupling agent. The enantioseparation ofsome binaphthyl compounds have been performed on the homemade binaphthol-bondedCSPs.Cellulose tris-cinnamate was synthesized from cellulose and cinnamoyl chloride. Thenthis cellolose derivative was coated on five small-pore silica supports, including native silicagel, aminopropylsilanized silica, binaphthol-bonded silica, and β-cyclodextrin-bonded silica.The obtained CSPs were applied to the enantioseparation of some probe solutes such asnaproxen, trans-9,10-dihydrophenanthrene-9,10-diol,1,1’-binaphthyl-2,2’-O,O’-methylene,hydrobenzoin, benzoin,2-phenylethanol,1-(6-methoxy-2-naphthyl)-ethanol, and flavanone.The effects of silica support and chromatographic condition on the enantioseparation of thesecompounds were discussed. The first three compounds obtained favorable enantioseparationeven bare small-pore silica was used as the support. Besides，the mechanism of chiralrecognition of CSPs has been discussed by analyzing the thermodynamic parameters of(trans-9,10-dihydrophenanthrene-9,10-diol.It is worth of being mentioned that cellulose tris-cinnamate exhibited betterenantioseparation ability to naproxen than cellulose tris(3,5-dimethylphenylcarbamate)(Chiralcel OD-H) or amylose tris(3,5-dimethylphenylcarbamate)(Chiralpak IA). This resultprovided an idea that cellulose tris-cinnamate coated on bare silica gel can be prepared forsome special purpose.Finally, this paper attempts to separate the enantiomers of naproxen by ordinary pressurechromatographic column. Cellulose tris-cinnamate was coated on the100mesh silica gel, and then packed into a glass tube. Naproxen was enantioseparated on this column. The separationefficiency was evaluated by HPLC.