Studies On Synthesis Of Energetic Compounds Derived From Oxadiazoles

Energetic compounds based on oxadiazoles are widely concerned because of their high enthalpy of formation and high density.In this paper,some novel energetic compounds based on oxadiazole are synthesized,which are mainly composed of three parts:1.Studies on the synthesis of energetic compounds based on 3-amino-4-?4H-5-ketone-1,2,4-oxadiazole-3-ly?-1,2,5-oxadiazolAsimpleandeffectivemethodforthepreparationof3-amino-4-?4H-5-ketone-1,2,4-oxadiazol-3-yl?-1,2,5-oxadiazol?46?is presented.Compounds47⁴9 were synthesized by the simple nitration,oxidation and oxidation coupling reaction of compound 46.In addition,energetic salts 50⁵5 based on 47 and 48 were synthesized,respectively.All new compounds were characterized by IR,multinuclear NMR spectroscopy and elemental analysis.The structure of compounds 46,48 and 50 were determined by single crystal X-ray diffraction.The thermal stabilities of 47⁵5?T_d=127.25³15.75??were determined by differential scanning calorimetry?DSC?.It is worth pointing out that compound 49 not only synthesized in high yield,but also has a high thermal decomposition temperature of 315.75°C.The neutral compounds 47 and 48 exhibit good detonation performances(47:D=8644 m s^-1,P=32.5 GPa;48:D=8637 m s^-1,P=32.23 GPa)which are close to the values of RDX(D=8795 m s^-1;P=34.9 GPa)and the impact sensitivity?47:IS=15 J;48:IS=16 J?are similar to TNT?IS=15 J?,which suggests that they possess the potential to become a high-energy high-performance insensitive energetic compounds.2.Studies on the synthesis of energetic compounds based on 4,4'-2?4-amino-1,2,5-oxadiazole-3-ly?-2,2'-di?1,2,4-oxadiazole?4,4'-2?4-amino-1,2,5-oxadiazole-3-ly?-2,2'-di?1,2,4-oxadiazole??46?was synthesized by the ring-closure reaction of 3-amino-4-aminoximinofurazan and diethyl oxalate under alkaline condition.Compounds 63 and 64 were synthesized by the simple nitration,oxidation of compound 62.In addition,a serious of energetic salts 64 were synthesized,respectively.All new compounds were characterized by IR,multinuclear NMR spectroscopy and elemental analysis.The structure of compounds 63⁶5,73 and 74 were determined by single crystal X-ray diffraction.The thermal stabilities of all new compounds were studied by DSC,and their thermal stabilities,sensitivity and detonation peformance were also studied.The experimental results show that the detonation performance of the neutral compounds 63 and64 are better than that of RDX.In addition,the thermal stabilities and sensitivity of energetic salts are also well,which indicate them possess the potential to be a new type of high-performance insensitive energetic compound.3.Studies on synthesis of polynitro compounds based on oxadiazol ringsTo study the reaction of 2,2,2-trinitroethanol with 3-amino-4-?4H-5-ketone-1,2,4-oxadiazol-3-yl?-1,2,5-oxadiazol?3?and 4,4'-2?4-amino-1,2,5-oxadiazole-3-ly?-2,2'-di?1,2,4-oxadiazole??62?using Mannich reaction,single?2,2,2-trinitroethy?substituted product of 46 and bis?2,2,2-trinitroethy?substituted product of 62 were synthesized and further nitrated using the mixture of 100%nitric acid acetic anhydride.Resulting compound 77 was found to have excellent detonation(D:9550 m s^-1,P:41.9 GPa),which are similar to CL-20(D:9455 m s^-1,P:46.7 GPa)?...