This study optimizes the synthesis of 2-Methyl-4,5-dinitro-1,2,3-triazole-1-oxide (DNMTO) via one-pot method and pulsed ultrasound-assisted extraction, achieving an 80% yield. Comprehensive characterization reveals its low melting point, high thermal stability, and low sensitivity, making it a promising candidate for low-melting-point cast explosives with enhanced safety and energy output.

Abstract

This study presents an optimized synthesis of 2-methyl-4,5-dinitro-1,2,3-triazole-1-oxide (DNMTO), an insensitive high-energy compound, via one-pot method with pulsed ultrasound-assisted extraction (PUAE). Glyoxal reacted with methylhydrazine and hydroxylamine hydrochloride to form intermediate 2-methyltriazole (MTO, 21% yield) under CuSO₄/pyridine catalysis, followed by nitration (HNO₃/H₂SO₄, 1:3) to achieve DNMTO with 80% yield. Structural characterization by IR, elemental analysis, and single-crystal X-ray diffraction confirmed DNMTO's orthorhombic lattice (crystal space group: P bca; crystal density: 1.729 g/cm³). Thermal analysis revealed a melting point of 130.5 °C and decomposition onset at 245 °C. DNMTO exhibited low mechanical sensitivity (H ₅₀ = 53 cm, friction sensitivity = 12%) and competitive detonation performance (theoretical density: 1.793 g/cm³, velocity: 8,889 m/s, and pressure: 34.90 GPa), comparable to RDX. These results validate DNMTO as a promising insensitive explosive candidate.