“…In particular, azole‐annulated 1,2,3‐triazines possess activity as anti‐virals and anti‐tubercular agents, inhibitors of protoporphyrinogen oxidase, herbicides, and pesticides, among others . In view of the important biological activities of purine analogues, our research interests have been focused on the synthesis of pyrazolo[3,4‐ d ][1,2,3]triazin‐4‐ones and imidazo[4,5‐ d ][1,2,3]triazin‐4‐ones, establishing a convenient method to access a broad range of these derivatives through the one‐pot diazotization of 5‐aminoazole‐4‐carbonitrile precursors , . We found that the stability and transformations of the diazonium ion intermediate was strongly dependent on the type of azole ring and, to a lesser extent, the nature of the substituent at N‐1 …”