Treatment of heterocyclic amines featuring fused rings of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine with fuming HNO3/P2O5 leads to six fully characterized explosives through multiple nitration and reduction or oxidation mechanism. Thus, 4-nitro-N-(3-nitro[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)-1,2,5-oxadiazol-3-amine (3 b, TTDNF) showed high performance (D=9180 m s(-1), P=36.7 GPa) and low impact sensitivity (IS>40 J) while N-([1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)-3-nitro-1,2,4-oxadiazol-5-amine (4 a, TTNOA) exhibited a potential cast explosive component with low melting point at 88.2 degrees C and high onset decomposition temperature at 226.2 degrees C.