Synthesis and Characterization of Pyrazole-Triazolone Compound with Exceptional Heat Resistance

Efficiently constructing structures with high thermal stability is a key objective in the development of energetic compounds. However, the existing synthesis processes for heat-resistant energetic materials are frequently hampered by their complexity and low yields. This study presents a significant breakthrough in addressing these challenges. It successfully synthesizes 4-amino-5-(3-amino-1H-pyrazole-4-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one (APTO) using a streamlined two-step process, achieving an impressive high yield of 87.5 %. The structure was determined through X-ray single crystal diffraction analysis, revealing a nearly planar intramolecular structure. Hirshfeld surface analysis, weak interaction analysis, and aromaticity analysis were conducted, illustrating a substantial presence of hydrogen bonds and π - π stacking interactions within and between molecules. These interactions contribute significantly to exceptional thermal stability of ATPO. Furthermore, the thermal stability of ATPO was confirmed through DSC analysis, exhibiting a decomposition temperature as high as 365.2°C. This temperature surpasses that of the heat-resistant explosive HNS (325°C), further validating its excellent thermal stability. The construction of this conjugated structure offers valuable guidance for the future structural design of heat-resistant energetic materials. It opens up possibilities for the development of novel compounds with improved thermal stability based on similar conjugated architectures.