A method for preparation of C-diformylmethylnitropyrazoles

Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 230–231, January, 1993.     

Synthesis of 4-(N-azolyl)-3,5-dinitropyrazoles

NH-Azoles selectively substitute 4-positioned nitro group in 3,4,5-trinitro-1H-pyrazole in aqueous NaOH to furnish 4-(N-azolyl)-3,5-dinitropyrazoles.     

Effect of intramolecular energy transfer on the rate of unimolecular isomerization: HCN --HNC

This paper reports calculations of the rate of isomerization of HCN - HCN based on the theory of Gary and Rice as extended by Zhao and Rice. The major task is to determine the effect of intramolecular energy transfer on the prediction of the rate of isomerization. Both the full three-dimensional (3D) system and the reduced two-dimensional (2D) system obtained from freezing CN bond at 1.159 A are analyzed to check the validity of the freezing bond approximation. Meanwhile, RRKM rates are calculated to test RRKM choice of the transition state by comparing to Gary-Rice three-state model. The comparison shows that the rates from 2D model and 3D model are differing up to 20% with 2D rates consistently larger. The intramolecular energy transfer modifies the isomerization rate for HCN system up to 30% that is modestly small by the expectation. The isomerization rate predicted from RRKM theory is greater than those of Gary-Rice three-state model theory up to 65%, and it overstimates the rates under all consider     

Chemistry of 2,4,6-trinitrobenzonitrile. 1. Nitro group substitution in 2,4,6-trinitrobenzonitrile under the action of anionic nucleophiles. Factors favoring substitution of the ortho-nitro group

The direction of the nitro group substitution (the ratio of the ortho/para substitution) in 2,4,6-trinitrobenzonitrile under the action of anionic nucleophiles (MeO^–, RS^–, and N₃ ^–) as well as of HCl was studied. The factors favoring ortho substitution were revealed.     

Nitropyrazoles

A method of synthesizing nitro derivatives of lH,4H-pyrazolo[4,3-c]pyrazole is developed, and some of its transformations are studied. 3-Methyl-6-nitro-, 3-carboxy(methoxy-carbonyl, carbamoyl)-6-nitro-, 3-amino-6-nitro-, 3-nitro-, 3,6-dinitro-, 1,4-diacetonyl-3,6-dinitro-, and lH,4H-3-aminopyrazolo[4,3-c]pyrazoles were obtained from 1H,4H-3 -methylpyrazolo[4,3-c]pyrazole. Unsubstituted 1H,4H-pyrazolo[4,3-c]pyrazole, the first member of this series, was obtained for the first time. The compounds prepared were characterized by¹H,¹³C,¹⁴N, and¹⁵N NMR spectroscopy. NH-Acidity and basicity of the series of pyrazolo[4,3-c]pyrazoles synthesized is studied and the effect of the fused pyrazole ring on these properties is examined.Deceased March 18, 1989.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1108–1113, June, 1993.     

Phase transfer catalysis in the chemistry of aliphatic nitrocompounds

The methylation of trinitromethane (TNM) Na-salt under phase transfer catalysis (PTC) conditions was studied in a two-phase system (aqueous solution of TNM Na-salt-CH₃I). The obtained data revealed a relationship between the yield of the methylation product (1,1,1-trinitroethane) and the nature of the phase transfer catalyst and the degree of TNM anion transfer to the organic phase. The kinetic measurements showed that higher efficiency of methylation was achieved under PTC conditions than occurs in a homogeneous reaction due to the fact that the reaction proceeded in the CH₃I medium.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1086–1088, June, 1993.     

Interphase analysis in the chemistry of aliphatic nitro compounds. 1. Alkylation of alkali metal salts of trinitromethane under interphase catalysis conditions in solid phase-liquid systems

Methylation of trinitromethane salts was studied under interphase catalysis conditions in a solid phase (a trinitromethane salt)-liquid (methyl iodide) system in the presence of interphase transfer catalysts — onium salts, cyclic and acyclic polyethers. The dependence of the yield of the methylation product-1,1,1-trinitroethane — on the nature of the catalyst was also investigated, and based on this, catalysts were found, in whose presence the methylation process is realized more effectively than under homogeneous conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1816–1819, August, 1990.