An efficient synthesis of [1,2,5]oxadiazolo[3,4-d]pyridazine 1,5,6-trioxides (1) from 3,4-bis(hydroxyimino)methyl)-1,2,5-oxadiazole 2-oxides using a mixture of concentrated nitric and trifluoroacetic acids has been developed. The scope of the unconventional reaction was established. The 4,7-dinitro[1,2,5]oxadiazolo[3,4-d]pyridazine 1,5,6-trioxide 1f represents a new high energy compound, unfortunately with low thermal stability. The parent [1,2,5]oxadiazolo[3,4-d]pyridazine 1,5,6-trioxide 1c was studied by single-crystal X-ray diffraction analysis which revealed a planar molecule with an unusually long intracyclic NN bond of 1.668(5) Å and unexpected exo-cyclic bond angles at the nitroxyl nitrogen atoms. In the crystal, the molecules of 1c are bound to each other by strong π-π stacking and CH⋯O hydrogen bonding interactions into a three-dimensional framework that results in a high crystal density of 1.833 gcm⁻³.

由3,4-双（羟基亚氨基）甲基）-1,2,5-恶二唑2有效合成[1,2,5]恶二唑并[3,4- d ]哒嗪1,5,6-三氧化物（1）已经开发出使用浓硝酸和三氟乙酸的混合物的氧化物。确定了非常规反应的范围。4,7-二硝基[1,2,5]恶二唑并[3,4- d ]哒嗪1,5,6-三氧化物1f代表了一种新的高能化合物，但其热稳定性很低。通过单晶X射线衍射分析研究了母体[1,2,5]恶二唑[3,4- d ]哒嗪1,5,6-三氧化物1c，揭示了具有异常长的环内N N键的平面分子1.668（5）Å和意外的exo氮氧基氮原子上的-环键角。在晶体中，1c分子通过强大的π-π堆积和C H⋯O氢键相互作用相互结合成三维框架，从而导致1.833 gcm ^-3的高晶体密度。