涂敷三苯甲酰基纤维素酯手性固定相的制备和表征

Preparation and Characterization of Cellulose Tribenzoate as Chiral Stationary Phase for High Performance Liquid Chromatography

以微晶纤维素为原料制备三苯甲酰基纤维素酯（ＣＴＢ），通过电子透射显微分析考察涂敷ＣＴＢ手性固定相的表面分布和表面浓度，用ＣＴＢ涂敷大孔硅胶高效液相色谱法分离三对旋光异构体，（±）－α－苯乙醇对映体获得完全分离，降冰片烯乙酯和４－十六碳烷氧基－（１′－溴）正壬基苯对映体未完全分开。

Cellulose tribenzoate (CTB) was synthesized by the homogeneous reaction of benzoyl chloride with microcrystalline cellulose in pyridine and triethylamine at about 110℃, and isolated as the fraction insoluble in methanol. 4 Dimethylaminopyridine was used as hypernucleophilic acylation catalyst. Elemental analysis and IR spectra indicated that almost all hydroxy groups of the microcrystalline cellulose were converted into ester groups. Macroporous silica gel (mean particle size, 6μm; mean pore diameter, 15nm; specific surface area, 67m 2/g) was treated with a large excess of (3 aminopropyl)triethoxysilane at refluxing temperature in toluene. The silanized gel was coated with about 8.3, 16.9 and 25 wt% of CTB by using trichloromethane as solvent. The surface topographies of the packing materials thus obtained have been investigated by the scanning electron microscope. The CTB coated silica gel was slurry packed in stainless steel columns (250mm×4.6mm i. d. and 150mm×4.6mm i. d. ). Chromatographic resolution was accomplished on HP 1090 chromatograph equipped with diode array detector and Chemstation. Separation was carried out with a hexane/2 propanol (90∶10) mixture at a flow rate of 0.5mL/min at 21℃. The complete resolution of racemic phenylethanol(b) and a low degree of resolution of the enantiomers of 4 hexadecyloxylphenyl (1′ bromo) nonane(a) and ethyl norbornanate(c) have been obtained for the first time on such a chiral stationary phase.