This study reports the preparation of 1-amino-1,2,3-triazole-3-oxide (DPX2) and its transformation to 1,2,3,4-tetrazine-1-oxide. DPX-2 provides insight into a novel N-oxide/N-amino high-nitrogen system, being the first energetic material in this class. The ability of this material to undergo a nitrene insertion forming 1,2,3,4-tetrazine-1-oxide was also studied, and evidence for this material, the first non-benzoannulated 1,2,3,4-tetrazine-1-oxide, is presented. The existence of both of these materials opens new strategies in energetic materials design. DPX2 was characterized chemically (Infrared, Raman, NMR, X-ray) and as a high explosive in terms of energetic performances (detonation velocity, pressure, etc.) and sensitivities (impact, friction, electrostatic). DPX-2 was found to possess good thermal stability and moderate sensitivities, indicating the viability of N-amino N-oxides as a strategy for the preparation of new energetic materials.