Preparation of bonded cellulose 3,5-dimethylphenylcarbamate chiral stationary phase with a new spacer and its application to the resolution of benzoin

Cellulose 3,5-dimethylphenylcarbamate was regioselectively bonded to macroporous silica gel at 6-position of the primary hydroxyl group on the glucose unit of cellulose with hexamethylene diisocyanate as a new spacer to form a new chiral stationary phase (CSP). The primary composition of mobile phase was hexane/ethanol or hexane/isopropanol. Then the tetrahydrofuran (THF) or dichloromethane was added into such mobile phase and the effects of content of THF and dichloromethane on the separation were investigated. It was found that when increasing the content of THF and dichloromethane, the capacity factors of benzoin enantiomers were decreased, while the separation changes little. The separation factors were over 1.2 under all experimental conditions. The prepared CSP were stable under different mobile phases, even with 23% tetrahydrofuran in mobile phase.