L. V. Lapshina

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.

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.

The interaction of 3-methyl-4-nitro-3-thiolene-1,1-dioxide with aliphatic amines

The reactions of 3-methyl-4-nitro-3-thiolene-1,1-dioxide with highly basic amines (pKa of HB+ = 8.97–13.27), morpholine, piperazine, piperidine, cyclohexylamine, diphenylguanidine, and guanidine, proceed via deprotonation of methylene group at the C2 atom of sulfolene ring with formation of ammonium thiolene nitronates. The products were characterized by IR, UV, and NMR (1H, 13C, 2D) spectroscopy methods.

Reactions of 1-nitrocyclohexene with alicyclic amines

The interaction of 1-nitrocyclohexene with alicyclic amines can proceed via nucleophilic addition at the carbon-carbon double bond (morpholine, piperazine) to form aza-Michael products or as deprotonation (piperidine, azepane) to give ammonium salts, 2-cyclohexene-1-nitronates. The preferred reaction pathway is determined by the amine basicity.