Dihydro-2H-thiopyran-3(4H)-one-1,1-dioxide – a new cyclic ketomethylenic reagent for the Dimroth-type 1,2,3-triazole synthesis

Abstract

A series of 1,5,6,7-tetrahydrothiopyrano[2,3-d][1,2,3]triazole 4,4-dioxides, new triazole-based bicyclic ring system, were prepared via base-mediated click reaction of organic azides with the readily available dihydro-2H-thiopyran-3(4H)-one-1,1-dioxide. The reaction proceeded at room temperature in 5-12 h with catalysis by base-solvent system K2CO3/DMSO. High purity products were isolated by simple filtration and no formation of side products was observed. The key structure was confirmed by an X-ray study.