“…It substitutes the use of radioactive isotopes and allows the investigation of drug metabolism to be carried out in humans. 5,8 The great interest in 1,2,4-triazolo [5,1-c] [1,2,4]triazinones and their sodium salts, along with azoloannelated 1,2,4-triazines, is due to their high activity against different kinds of viruses including influenza and bird flu (culture H5N1). [9][10][11] In this article, we report the synthesis and spectral characterization of 15 N-labeled azolo-1,2,4-triazines containing bridgehead nitrogen.…”