1H-1,2,3-Triazolo[4,5-b]pyridine (1,2,3-Triazolo(5,4-b)pyridine) may be used:as starting reagent in the synthesis of 2,4,8,10-tetranitro-5H-pyrido[3″,2″:4′,5′] [1,2,3] triazolo [1′,2′:1,2] [1,2,3]- triazolo [5,4-b]-pyridin-6-ium inner saltin the pesticide synthesisas an entry to mesoionic heteropentalene derivatives