不同温度下碳酸二甲酯对β-环糊精的改性研究

Modification of β-Cyclodextrin with Dimethyl Carbonate under Different Temperature

摘要:

以碳酸二甲酯和β-环糊精为原料，以无水碳酸钾为催化剂，在N,N-二甲基甲酰胺介质中，系统研究了常压和高压条件下温度在50℃~170℃范围内碳酸二甲酯对β-环糊精的改性作用。所得产品用制备型高效液相色谱分离纯化，用红外光谱、质谱和核磁共振光谱等技术进行表征。结果表明: 温度在50℃~85℃范围内，发生的是低取代的甲氧羰基化反应，主要产物是单取代的甲氧羰基化β-环糊精，收率为60.91%；在90℃~140℃范围内，甲氧羰基化和甲基化反应均有发生；而温度为160℃~170℃，以及压力约为1.40 MPa时，主要反应产物为取代度为7~9的随意甲基化β-环糊精，且收率达到80%~85%。

Abstract:

The modification effect of β-cyclodextrin by dimethyl carbonate in the temperature range of 50℃ to 170℃ was systematically studied at atmospheric and high pressure respectively, using dimethyl carbonate as green modification reagent and anhydrous potassium carbonate as alkaline catalyst in N, N-dimethylformamide. The products were purified through preparative HPLC, and characterized by means of IR, ESI-MS, 1HNMR and 13CNMR. The results showed that methoxycarbonylation derivatives with low degree of substitution were prepared in the temperature range of 50℃ to 85℃, and the major compound was mono-methoxycarbonyl-β-cyclodextrin, of which the yield reached 60.91%; the methylation and methoxycarbonylation of β-cyclodextrin occurred simultaneously in the range of 90℃ to 140℃; while when operating at the temperature from 160℃ to 170℃, and the pressure of approximately 1.40 MPa, randomly methylated β-cyclodextrins with the substitution degree range of 7 to 9 were obtained with a high yield from 80% to 85%.