G. P. Popova

Nitropyrazoles 20. Synthesis and transformations of 1-methoxymethyl-3,4,5-trinitropyrazole

Abstract1-Methoxymethyl-3,4,5-trinitropyrazole, synthesized from 3,4,5-trinitropyrazole by the action of methoxymethyl chloride, was involved into the nucleophilic substitution reaction with N-nucleophiles (aliphatic amines, hydrazine derivatives). The reaction was effected regioselectively with substitution of the nitro group at position 5 in good yields. The thus obtained 5-R-substituted compounds under acid hydrolysis conditions give N-unsubstituted 5-R-3,4-dinitropyrazoles.

Quantum-chemical study of the reactivity of di- and trinitropyrazoles

Quantum chemistry methods (DFT B3LYP/6-31G* (3-21G)) were used to calculate the three-dimensional and electronic structure of 4-chloro-3,5-dinitro- and 3,4,5-trinitropyrazoles, as well as their model σ-complexes. Possible reasons for the peculiar reactivity of 3,4,5-trinitropyrazole, 4-chloro-3,5-dinitropyrazole, and their derivatives were examined.

Nitropyrazoles 22. On reactivity of 3,5-dinitro-4-(phenylsulfonyl)pyrazole and its N -methyl derivative

Abstract3,5-Dinitro-4-(phenylsulfonyl)pyrazole (5) obtained by oxidation of 3,5-dinitro-4-(phenylthio)pyrazole with 30% H2O2 in AcOH was involved into nucleophilic substitution reaction with thiophenol, which proceeded with substitution of the phenylsulfonyl group at position 4. N-Methyl-3,5-dinitro-4-(phenylsulfonyl)pyrazole obtained by methylation of 5 with dimethyl sulfate was involved into nucleophilic substitution reaction with thiophenol, p-bromophenol, and morpholine with the regioselective substitution of the nitro group at position 5 to form 5-R-3-nitro-4-(phenylsulfonyl)pyrazoles.