Abstract: A method of preparation of 5-amino-3,4-dinitropyrazole (1) from 3(5)-methyl-5(3)-nitro- and 3(5)-methyl-4,5(3)-dinitropyrazoles was developed, the key step of which was the Hofmann rearrengement of nitro- and dinitropyrazolecarboxamides. The protonation of 5-amino- 3,4-dinitropyrazole was studied by spectral methods (UV spectroscopy, NMR spectroscopy). In spite of low basicity of the amino group, compound 1 undergoes N-arylation, N-nitration, and annulation reactions with formation of dinitropyrazolo[5,1-a]pyrimidine derivatives and hitherto unknown dinitroimidazo[1,2-b]pyrazole derivatives. Diazotization of 1 leads to 5-diazo-3,4-dinitropyrazole (19), which exists in the form of the internal salt. Some reactions of this compound were studied and the formation of the corresponding 5-halogeno(azido)- 3,4-dinitropyrazoles under the action of the halide and azide ion was shown. Dinitropyrazolo- [5,1-c][1,2,4]triazine and 7-hydroxydinitro-4,7-dihydropyrazolo[5,1-c][1,2,4]triazine deriva- tives were obtained by the action of active methylene compounds on the betaine 19.

Cite: Dalinger I.L. , Vatsadse I.A. , Shkineva T.K. , Popova G.P. , Ugrak B.I. , Shevelev S.A.
Nitropyrazoles 18. Synthesis and transformations of 5-amino-3,4-dinitropyrazole
Russian Chemical Bulletin. 2010. V.59. N8. P.1631-1638. DOI: 10.1007/s11172-010-0287-9 WOS Scopus OpenAlex

Identifiers:

≡ Web of science:	WOS:000285876500022
≡ Scopus:	2-s2.0-79951757800
≡ OpenAlex:	W2524384849

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