The nitro group nucleophilic substitution reactions in 1-methyl-3,4,5-trinitropyrazole (MTNP) were studied
quantum chemically by DFT and MP2 methods in the gas phase and methanol (6-31G⁄⁄ basis set, PCM
approach). Also the calculations of Parr’s reactivity indices were used. It was shown that these processes
occur as synchronous bi- or trimolecular attacks by ammonia molecule or ammonia dimer. Regardless of
process type, effects of solvent are the key factors defining its direction. That distinguishes principally the
nucleophilic substitution reactions in MTNP from similar processes with 3,4,5-trinitropyrazole (TNP) participation
which occurs through substrate deprotonation.