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

2-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.     

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 (pK _a 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.     

2-Benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide and Its Analogs in Aza-Michael Reaction

2-Benzylidene-3-methyl-4-nitro-3-thiolene-1,1-dioxide and its analogs have been introduced in the aza-Michael reaction with hydrazine derivatives. Novel polysubstituted nitrosulfolenes have been obtained; their structures have been confirmed using ¹Н NMR and IR spectroscopy as well as X-ray diffraction analysis.     

Synthesis,x-ray diffraction and spectral studies of the nitrone form of 3-methyl-4-nitro-2-oximino-3-thiolene-1,1-dioxide

Stabilization of the NH-nitrone grouping in oximino compounds is promoted by the inclusion of the conjugated system in the heterocycle. IR spectroscopy fails to distinguish between the oxime and nitrone forms of oximino compounds. The best evidence for the existence of the nitrone form is provided by x-ray diffraction examination of the monocrystals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2312–2319, October, 1989.     

Synthesis of sulfolanopyranochromenones by the reaction of 2-benzylidene-3-methyl-4-nitro-2,5-dihydrothiophene 1,1-dioxides with 4-hydroxycoumarin

Chemistry of Heterocyclic Compounds - A number of tetracyclic compounds with annulated nitrosulfolane and pyranochromenone rings were synthesized by reacting...     

Crystal and Molecular Structure of 4-Nitro-2-oximino-3-phenylamino-3-thiolene-1,1-dioxide

The present publication reports the results of X-ray diffraction (XRD) analysis of 4-nitro-2-oximino-3-phenylamino-3-thiolene-1,1-dioxide crystals (I). The synthesis and the useful properties of this class of compounds are reviewed in [1]. It is noteworthy that previously [2] an X-ray structure analysis has been performed for another compound from this class, 3-methyl-4-nitro-2-oximino-3-thiolene-1,1-dioxide (II), which was assumed to exist in nitrone form. The XRD data for compound I disprove this assumption.     

The absence of nitrone form in re-determined crystal structure of 2-hydroxyimino-3-methyl-4-nitro-2,5-dihydrothiophene 1,1-dioxide

Crystal and molecular structures of 2-hydroxyimino-3-methyl-4-nitro-2,5-dihydrothiophene-1,1-dioxide C₅H₆N₂O₅S (I) have been re-determined by single crystal X-ray diffraction analysis. The structure of I (space group P2₁2₁2₁, a = 6.124(1) Å, b = 9.205(2) Å, c = 14.884(3) Å, Z = 4) was solved by the direct method and refined anisotropically in the full-matrix approximation to R = 0.064 using all 1756 measured independent reflections (automated diffractometer CAD-4, λCuK_α, anomalous scattering taken into account). This study proves that the compound I contains a disordered group H-O-N=C, but not the isomeric nitrone group O←N(H)=C, as it has been concluded by the workers who pioneered single crystal X-ray diffraction study of I and erroneously took the second low-occupied oxygen position of the disordered hydroxyimine group for H at N atom.     

Sulfur resistance of supported metals in 3-thiolene-1,1-dioxide hydrogenation

Supported platinum metals are deactivated in the liquid phase hydrogenation of 3-thiolene-1,1-dioxide. The sulfur resistance of Rh and Pd is by 1–2 orders of magnitude higher than that of Pt, Ir, Ru and Os. The metal resistance normalized to its surface area does not depend on its dispersity and the nature of the support.     

Palladium activity in 3-thiolene-1,1-dioxide hydrogenation in the presence of alkalis

Surface acidity/Basicity of mixed oxides of La and Zn activated at three different temperatures were determined. The data have been correlated with the catalytic activity for liquid phase reduction of cyclohexanone in isopropanol.