Synthesis of 4‑Amino-5-nitro‑7<i>H</i>‑pyrazolo[3,4‑<i>d</i>][1,2,3]triazine-2-oxide\nand Its Heat-Resistant Derivatives

4-Amino-5-nitro-7<i>H</i>-pyrazolo[3,4-<i>d</i>][1,2,3]triazine-2-oxide (<b>PTO</b>) is synthesized\nvia one\nstep in this study. Subsequently, 4,7-diamino-5-nitro-pyrazolo[3,4-<i>d</i>][1,2,3]triazine-2-oxide (<b>APTO</b>), 4-oxo-5-nitro-7<i>H</i>-pyrazolo[3,4-<i>d</i>][1,2,3]triazine-2-oxide\n(<b>OPTO</b>), and several heat-resistant salts are synthesized\nthrough\nlocal structural modifications on <b>PTO</b>. Comparison of\nthermal stability between <b>PTO</b> and <b>APTO</b> indicates\nthat while the amino group has a negative impact on the thermal stability\nof <b>APTO</b>, it\nenhances the detonation performance of <b>APTO</b> and effectively\nreduces its mechanical sensitivity. Our findings provide a practical\nnew approach for constructing energetic materials with excellent stability.