Dipyrazolodioxadiazocines as Easily Storable and “Ready to Use” Precursors for in Situ Generation of Enolate-Iminium 1,4-Dipoles: an Atom-Economical Approach Topyrazolo[5,1-d][1,3,5]Dioxazines

The work was supported by Russian Science Foundation, project № 19-13-00290

A Base-Controlled Reaction of 2-Cyanoacetamidines (3,3-Diaminoacrylonitriles) with Sulfonyl Azides as a Route to Nonaromatic 4-Methylene-1,2,3-triazole-5-imines

Reactions of 2-cyanoacetamidines with sulfonyl azides were shown to take place via two different pathways to form a mixture of 1-substituted 5-amino-1,2,3-triazoles 3 and novel 4-methylene-1H-1,2,3-triazole-5(4H)-imine derivatives 4–14. In the absence of a base, 5-amino-1,2,3-triazoles 3 are formed as the only products. The presence of 1.2 equiv. of sodium ethoxide or DBU switches the reaction outcome while involving the cyano group, resulting (after a 1,5-protic shift) in triazoles 4–14 as the only products. The methods were elaborated for the selective and efficient synthesis of triazoles 3 and 4-methylene-1,2,3-triazole-5-imines 4–14 including one-pot synthesis from sodium azide and sulfonyl chlorides. The unusual structure of 4–14 compounds was confirmed by X-ray data and 2D 1H–15N and 1H–13C NMR spectra. The formation of the products was explained by the presence of two strong hydrogen bonds N···H and O···H in these molecules. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimWe gratefully acknowledge financial support of this work by the Russian Science Foundation (18‐13‐00161)

Synthesis, recyclization under the action of methanol and analgetic activity of N'-(5-aryl-2-oxofuran-3(2H)-ylidene)furan-2-carbohydrazides

Received: 14.11.22. Revised: 21.11.22. Accepted: 21.11.22. Available online: 01.12.22.The synthesis method for obtaining methyl 5-aryl-1-(furan-2-carbonyl)-1H-pyrazole-3-carboxylates developed.Five new compounds not previously described in the literature were obtained.Some of the compounds obtained have been found to have significant analgetic effects.New methyl 5-aryl-1-(furan-2-carbonyl)-1H-pyrazole-3-carboxylates were obtained via decyclization reaction of N'-(5-aryl-2-oxofuran-3(2H)-ylidene)furan-2-carbohydrazides under the action of methanol. Starting N'-(5-aryl-2-oxofuran-3(2H)-ylidene)furan-2-carbohydrazides were obtained by intramolecular cyclization of substituted 4-aryl-2-[2-(furan-2-ylcarbonyl)hydrazinylidene]-4-oxobutanoic acids in propionic anhydride. The structure of the compounds obtained was confirmed by the 1H NMR spectroscopy, IR spectrometry and elemental analysis methods. Analgesic activity of some obtained compounds was studied by the “hot plate” method on outbred white mice of both sexes with intraperitoneal injection.This study was performed under financial support of the “Rational Use of the Earth Interior” Perm Scientific Educa-tional Center 2023 and Ministry of Science and Higher education of Russian Federation FSEG-2022-0012