A Novel Synthesis Technology of Ethyl-β-Cyclodextrin

A novel green synthesis process about ethyl-β-Cyclodextrin have been investigated through the reaction between β-cyclodextrin and diethyl carbonate by used anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including reaction time, the molar ratio of β-cyclodextrin to diethyl carbonate, reaction temperature and contents of anhydrous potassium carbonate on the average degree of substitution of ethyl-β-cyclodextrin were carried out by a design method of orthogonal experiments. The results shown that the average degree of substitution of ethyl-β-cyclodextrin can be depend on the reaction temperature and the molar ratio of raw material primarily. The optimal maximum average degree of substitution of ethyl-β-cyclodextrin is 6.0 when the molar ratio of β-cyclodextrin to diethyl carbonate, reaction temperature, reaction time and dosage of catalyst are 1:28, 120°C, 24h and 2.0 g, respectively. The structures of ethyl-β-cyclodextrin were characterized by TLC, IR, MS, 1H-NMR and 13C-NMR, and these results are concordant with former ones which synthesized ethyl-β-cyclodextrin by diethyl sulfate or ethyl iodide.