The Synthesis of the Locating Substitution Derivatives of Chitosan by Click Reaction at the 6-Position of Chitin

Abstract EN

A novel method to prepare the macrocyclic compound locating substitution derivatives of chitosan was investigated, by using cyclodextrin as the model of macrocyclic compound.

The method combines the advantages of activated 6-OH of chitin and high efficiency of click reaction.

Chitin C6-OH p-toluenesulfonate (CTN-6-OTs) was generated and subsequently transferred to chitin C6-N3 via nucleophilic substitution.

Afterwards, β-cyclodextrin was immobilized at 6-OH of chitin via click reaction to afford CTN-6-CD.

Ultimately, CTS-6-CD was obtained by removing the acetyl group of chitin unit.

The structures and properties of these products were characterized by FTIR, TG, and XRD, respectively.

It was found that CTN-6-CD synthesized at the optimum conditions has an immobilized loading of 1.6126×10-4 mol/g and that of the corresponding CTS-6-CD, generated by removal of the acetyl group, was 1.6891×10-4 mol/g.