Catalyst-free 1,3-dipolar cycloaddition of 3-nitrochromen with sodium azide: a facile method for the synthesis of 4-aryl-1,4-dihydrochromeno[4,3-d][1,2,3]triazole derivatives

1,3-Dipolar cycloaddition of 3-nitrochromen with sodium azide under catalyst-free conditions afforded 4-aryl-1,4-dihydrochromeno[4,3-d][1,2,3]triazole derivatives at 80 °C in DMSO is described. The generality of this reaction was demonstrated by synthesizing an array of 4-aryl-1,4-dihydrochromeno[4,3-d][1,2,3]triazole derivatives. Clean reaction conditions, easy isolation, and good yields of the triazoles are the salient features of the methodology.