An efficient method for accessing carboannulated and functionalized [1,2,3]triazolo[4,5-b]pyridines

4-(N-Boc-amino)-1,2,3-triazole-5-carbaldehydes upon heating under reflux in acetic acid in the presence of pyrrolidine react with cycloalkanones, acetylacetone, 1,3-cyclohexanediones, and malononitrile resulting in annulation of the pyridine ring with the formation of new derivatives of [1,2,3]triazolo[4,5-b]pyridine.