Facile synthesis of three low-sensitivity energetic materials based on pyrimidine backbones

Using commercially available raw materials, novel pyrimidine-based energetic compounds were synthesized, namely N-(7-oxo-6,7-dihydro-[1,2,5]oxadiazolo[3,4-d]pyrimidin-5-yl)nitramide (1), 2,4,6-triamino-5-nitropyrimidin-1-ium nitrate (2), and 4,6-diamino-5-nitro-2-oxo-2,3-dihydropyrimidin-1-ium nitrate (3). They were fully characterized using NMR (¹H and ¹³C), IR spectroscopy, and elemental analysis. The crystal structures of compounds 1 and 3 were determined using single-crystal X-ray diffraction. The decomposition temperatures of compounds 1–3 were measured to be 190.2 ​°C, 156.8 ​°C, and 234.6 ​°C, respectively. Their densities were tested to be 1.84, 1.85 ​g ​cm⁻³, and 1.81 ​g ​cm⁻³, respectively. They exhibited desirable insensitive properties, with impact sensitivity ≥15 ​J and friction sensitivity >360 ​N. In addition, the detonation performances of compounds 1–3 were calculated with detonation pressure of 26.9, 29.6 ​GPa, and 26.0 ​GPa, respectively; detonation velocity of 8089, 8644 ​m ​s⁻¹, and 7996 ​m ​s⁻¹, respectively). Simple synthetic processes and high performance make them potential candidates for low-sensitivity energetic materials.