The mechanisms of nucleophilic substitution in 1-methyl-3,4,5-trinitropyrazole

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.