Synthesis Of Furazan[3,4-b]Pyrazine Energetic Compounds And Investigation Of Cycloaddition To Synthesize Tetrazole

Both furazan and tetrazole energetic compounds usually show large positive heats of formation, high density, good oxygen balance, remarkable insensitivity and thermal stability. They are researched actively in recent years.3,4-Diaminofurazan (DAF) was synthesized from glyoxal via diaminoglyoxime (DAG) as an intermediate. The effect of temperature on the yield of DAF and the mechanism forming DAF were investigated.5,6-Diaminofurazan [3,4-b] pyrazine(DAFP) were synthesized from DAF by three steps including condensation, chlorination, amination reactions.5,6-Di(trinitroe-thylamino)furazano[3,4-b]pyrazine(DNFP) was synthesized via hydroxymethyl with formaldehyde, then condensation with trinitromethane(NF) using DAF as staring material.1,2,3-Triazole[4,5-e]furazan[3,4-b]pyrazine-6-oxides(TNFPO) was obtained through the nitration of DAFP with100%HNO3,(CF3CO)2O. DAFP was nitriated with100%HNO3, H2SO4to generate5-amine-6-nitraminofurazan[3,4-b]pyrazine(ANFP).3-Amine-4-nitrofuraz-an(ANF) was prepared from DAFP by using30%H2O2, H2SO4as the oxidant.1H-tetrazole could be synthesized by [3+2] cycloaddition reaction from primary amine, sodium azide and triethyl orthlformate. In this paper,5-aminotetrazole(5-AT),3,4-diaminofur-azan(DAF) and1,5-diaminotetrazole(DAT) as substrates were studied, respectively.5-AT was treated with sodium azide and triethyl orthlformate to afford5-(tetrazole-1-yl)-1H-tetrazo-le. A new synthetic method using DAF as staring material in four steps including oxidation, cycloaddition, nucleophilic substitution and cycloaddition was designed to prepare3,4-Di(1H-tetrazole-1-yl)furazan(TTF).1’-Amine-1’H-1,5’-bitetrazole(ATT) was synthesized from DAT via amino protection, cycloaddition and deprotection reactions. The reaction mechanism and optimal cycloadditon conditions were also explored.The structures of target compounds were characterized by IR,1H NMR,13C NMR and MS. The detonation velocity, detonation pressure, the heats of formation and density were calculated by DFT/B3LYP method. For furazan[3,4-b]pyrazine energetic compound, multiple nitro enhance the heats of formation.