I. E. Efremova

Reactions of 2-benzylidene-3-methyl-4-nitro-2,5-dihydrothiophene 1,1-dioxide with CH acids

Abstract2-Benzylidene-3-methyl-4-nitro-2,5-dihydrothiophene 1,1-dioxide reacted with acyclic CH acids (acetylacetone, diethyl malonate, and its derivatives) according to the 1,4-addition pattern, whereas reactions of the title compound with cyclohexane-1,3-dione and 5,5-dimethylcyclohexane-1,3-dione (dimedone) were complicated by subsequent intramolecular heterocyclization leading to thieno[3,2-b]chromene derivatives.

Bromonitrothiolene-1,1-dioxides in a ‘halogen dance’ reaction

The chemical behavior of 4-bromo-3-methyl-4-nitro-2- and 2-bromo- 3-methyl-4-nitro-3-thiolene-1,1-dioxides in different solvents has been studied. These dioxides can undergo halo- and prototropic rearrangements, simultaneously in polar solvents, under very mild conditions. These transformations lead to another isomer, 2-bromo-3-methyl-4-nitro-2-thiolene-1, 1-dioxide and products of disproportionation, such as 2,4-dibromo-3-methyl-4-nitro-2-thiolene-1,1-dioxide and Δ2- and Δ3-nitrothiolene dioxides.

Reactions of aroylhydrazines with nitrosulfodienes of the 2-benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide series

Reactions of s-trans-nitrosulfodienes of the 2-benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide series with aroylhydrazines occur as nucleophilic 1,4-addition to give the aza-Michael adducts. Activity of the studied substrates depends on the nature of the substituents in the benzene ring of benzylidene fragment. Previously unexplored representatives of the 2-benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxides have been synthesized.

Heterocycles’ ring-opening in reactions of 3-methyl-4-nitro-3-thiolene-1,1-dioxide with substituted hydrazines

4-Nitro-3-thiolene-1,1-dioxides are the active heterocyclic sulfonitroalkenes able to interact with nucleophiles by the addition, vinyl substitution or salt formation pathways. The direction and effectiveness of these processes are determined by the nature of the substituents in the sulfolene ring, the reagents nature, and the reaction conditions [1, 2]. Thus, the addition of arylamines to the multiple bond of 3-methyl-4-nitro-3thiolene-1,1-dioxide I proceeds in refluxing ethanol. More active nucleophiles, aroylhydrazines, react at room temperature to give corresponding Michael adducts [3]. Tightening of the reaction conditions of nitrothiolene dioxide I with benzoylhydrazine at equimolar ratio in refluxing ethanol unexpectedly results in the formation of the novel open-chain structure, (2-nitroethylsulfonyl)propanone benzoylhydrazone II. The reactions of nitrosulfolene I with the more basic substituted hydrazines, semicarbazide and phenylhydrazine, give rise to similar linear nitroalkylsulfones III and IV even at room temperature. DOI: 10.1134/S107036321206028X

Halo Derivatives of 2,4-Dinitrothiolene 1,1-Dioxides: Synthesis and Structure

Procedures were developed for preparing representatives of a new type of halonitrothiolene 1,1-dioxides: mono- and dihalo derivatives of 2,2,4-tri- and 2,4-dinitro-3-thiolene 1,1-dioxides. An X-ray diffraction study showed that 2,5-dinitro-2,3-dichloro-3-thiolene 1,1-dioxide molecules exist in the crystal as enantiomeric pairs; the five-membered rings have the envelope conformation, with deviation of the sulfur atom from the ring plane; the halogen atom and nitro group at the multiple bond are essentially coplanar with the ring.

Synthesis of new bicyclic compounds containing fused sulfolane and pyrazolidine rings

Abstract3-Aryl-6а-methyl-6-nitro-1-carbamoylhexahydrothieno[2,3-d]pyrazole-4,4-dioxides, novel original bicyclic species consisting of fused pyrazolidine and sulfolane rings, and 1,4-adducts were obtained by reacting 2-benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide and its derivatives with semicarbazide.

Reactions of 1-nitrocyclohexene with N,N-binucleophiles

A modification of 1-nitrocyclohexene synthesis is proposed; its reaction with phenylhydrazine and benzoic acid hydrazide is shown to afford monoadducts, and with hydrazine hydrate, bisaduct. With diphenylguanidine occurs heterocyclization to 1-phenyl-2-N-phenylamino-4,5,6,7-tetrahydrobenzimidazole, whose structure is confirmed by the X-ray diffraction data. The analysis performed for this compound of the electron density distribution function in the crystal made it possible to estimate the charge distribution, π-electrons delocalization nature, and the role of N-H…N, C-H…H-C and C-H…C interactions in the formation of the crystal packing.

Synthesis and Structure of Bromonitrothiolene 1,1-Dioxides

A procedure was developed for preparing mono- and dibromo derivatives of 4-nitro-2- and 3-thiolene 1,1-dioxides, and their structures were studied. The molecular geometry and structural parameters of 4-bromo-3-methyl-4-nitro-2-thiolene 1,1-dioxide were determined by single crystal X-ray diffraction.

5-bromo-2,3-dihydro-4-methyl-3-nitrothiophene 1,1-dioxide.

The title compound, C(5)H(6)BrNO(4)S, crystallizes in the centrosymmetric space group P2(1)/c. Three weak C-H.O hydrogen bonds dominate the packing of the molecules in the solid. These weak hydrogen bonds and a short intermolecular O...Br contact of 3.003 (2) A are discussed using a Mulliken population analysis.

Synthesis of bicyclic systems containing fused sulfolane and isoxazolidine rings

A method was developed based on reactions of 2-benzylidene-3-methyl-4-nitro-3-thiolene 1,1-dioxide and its substituted analogs with hydroxylamine and N-methylhydroxylamine for the synthesis of 3-aryl-6а-methyl-6-nitrohexahydrothieno[2,3-d]isoxazole 4,4-dioxides – new representatives of original bicyclic structures combining condensed isoxazolidine and sulfolane rings. The structures of the obtained compounds were established by methods of IR spectroscopy, one-dimensional 1Н and 13С NMR spectroscopy, two-dimensional 1Н–13С HMQC and 1Н–13С HMBC experiments, and X-ray structural analysis.