Synthesis of [1,2,3]Triazolo[1,5-<i>a</i>]quinoxalin-4(5<i>H</i>)-ones through Copper-Catalyzed Tandem Reactions of <i>N</i>-(2-Haloaryl)propiolamides with Sodium Azide

A simple and efficient approach for the synthesis of [1,2,3]triazolo[1,5-<i>a</i>]quinoxalin-4(5<i>H</i>)-ones is described. The methodology is based on a tandem reaction of 1-(2-haloaryl)propiolamides with sodium azide through a [3 + 2] azide–alkyne cycloaddition and intramolecular Ullmann-type C–N coupling process