Reactivity of 7-amino-3-tert-butyl-8-(2H-tetrazol-5-yl)pyrazolo-[5,1-c][1,2,4]triazin-4(6H)-one

Abstract

Fused derivatives of 1,2,4-triazines are widely used as biologically active compounds possessing versatile pharmacologic action [1, 2]. We synthesized lately pyrazolo[5,1-с][1,2,4]triazine derivatives and investigated their reactivity [3, 4]. We reported on the preparation of 7-amino-3-tert-butyl-8-(2Н-tetrazol-5yl)pyrazolo[5,1-с][1,2,4]-triazin-4(6Н)-one 1 from sodium azide and 7-amino-3-tert-butyl-4-oxo-4,6dihydropyrazolo[5,1-с][1,2,4]triazine-8-carbonitrile [5]. In extention of this research we studied the reactivity of compound 1 under the action of various agents. In the reaction of carboxylic acids chlorides with amine 1 in dioxane in the presence of triethylamine at 25–50С the acylation of the amino group occurs with the formation of the corresponding amides 2–4. Compounds 2–4 are white crystalline substances melting with decomposition. The composition and structure of all compounds obtained were established from the data of elemental analysis, UV, IR, Н NMR, and mass spectra. In the IR spectra of amides 2–4 a characteristic absorption band appears of the amide С=О group at 1708–1699 cm and the stretching vibration of the С=О group of pyrazolotriazine ring at 1645–1640 cm is retained. A singlet of the methyl protons in the Н NMR spectra of compounds 3 and 4 is observed at ISSN 1070-4280, Russian Journal of Organic Chemistry, 2015, Vol. 51, No. 2, pp. 292–294. © Pleiades Publishing, Ltd., 2015. Original Russian Text © L.M. Mironovich, D.V. Shcherbinin, 2015, published in Zhurnal Organicheskoi Khimii, 2015, Vol. 51, No. 2, pp. 302–304.