Synthesis of 6I-O-(4-Methylbenzenesulfonyl)-β-cyclodextrin

An improved procedure has been proposed for the synthesis of 6I-O-(4-methylbenzenesulfonyl)-β-cyclodextrin by reaction of β-cyclodextrin with p-toluenesulfonyl chloride in aqueous alkali. Repeated use of unreacted p-toluenesulfonyl chloride and reduction of the volume of water by half in combination with optimized conditions make it possible to obtain the target product in up to 58% yield without loss of purity.