Abstract: Five kinds of novel β-cyclodextrin derivatives modified by thiadiazole were synthesized by the reaction of 5-alkyl-2-amino-1,3,4-thiadiazole and mono-6-deoxy-6-(p-tolylsulfonyl)-β-cyclodextrin at 80 ℃ under a nitrogen atmosphere for 2 d. The method had high yields and good separation effect. The structures of the compounds were confirmed by IR, ¹H NMR, ¹³C NMR, UV, MS and elemental analysis. In ¹H NMR spectra of cyclodextrin modified by 2-amino-1,3,4-thiadiazole, it was found that the chemical shift of thiadiazole ring shifted to upfield due to diamagnetic shielding effect caused by cyclodextrin. Other spectroscopic results were also in accordance with the theoretical value. The results indicate that this method affords a general way to synthesize β-cyclodextrin derivatives modified by thiadiazole. The biological activities of compounds 1 and 2 were screened. The results show that some compounds(2d, 2e) have strong antibacterial activities.

Key words: 1,3,4-Thiadiazole, Cyclodextrin, Synthesis, Antibacterial activity