Polyazido-methyl Derivatives of Prominent Oxadiazole and Isoxazole Scaffolds: Synthesis, Explosive Properties, and Evaluation

Recently, different nitrato-methyl-substituted oxadiazoles have been described as potential melt-cast explosives. In this work, corresponding N-O heterocyclic-based compounds with azido-methyl functionalities were synthesized. In each case, the explosophoric azide group is inserted by chlorine-azide exchange during the last synthetic step. All synthesized compounds show interesting characteristics for various applications in the field of energetic materials as energetic plasticizers or as melt-cast explosives. The compounds were extensively analyzed by IR, EA DTA, and multinuclear NMR spectroscopy. Furthermore, the solid compounds 4,4',5,5'-tetrakis(azidomethyl)-3,3'-bisisoxazole (2) and 3,3'-bis(azidomethyl)-5,5'-bis(1,2,4-oxadiazole) (4) were characterized using X-ray diffraction. In addition, the sensitivities toward friction and impact were determined with BAM standard techniques, and the energetic performances of all synthesized azido-methyl compounds were calculated using the EXPLO5 code. The properties were compared to recently published, structurally related compounds.