G. A. Chmutova

Synthesis of Novel Arylthio Derivatives of Mucochloric Acid

Stable reaction products of mucochloric acid with aromatic and heterocyclic thiols were synthesized and characterized. Under basic conditions the reactions proceeded with the substitution of the chlorine atom(s) by arylthiogroup(s), while in an acidic medium the hydroxy group at C 5 was substituted. Different types of new sulfur-containing products of di- and trisubstitution on the basis of mucochloric acid were obtained. In one case a new acyclic product—di-p-tolyl-2,3-bis-(p-tolylthio)butanedithioate—was isolated. The structure of all synthesized compounds was confirmed by IR, 1 H, and 13 C NMR spectroscopy; three compounds were characterized by single crystal X-ray diffraction.

The Nature of the Interaction of Organoselenium Molecules with Diiodine

The electronic structure of charge-transfer complexes of organoselenium compounds with diiodine has been studied at several levels of theory (Hartree-Fock, second order Møller-Plesset, and density functional theory). The complexation energies, optimized geometries, and the topology of the electron density and its Laplacian distribution, including domain averaged properties, have been analyzed. Special attention was paid to the influence of basis set superposition error on the energy of complexation. A tendency of organoselenium molecules to form more covalent intermolecular bonds with electron acceptors than with nitrogen atoms or other conventional electron donors has been revealed. The changes in atomic charges under complexation follow the main trends expected for the charge transfer. By means of the interacting quantum atoms (IQA) approach it has been found that the Se···I interaction is dominated by its quantum mechanical exchange-correlation contribution, the electrostatic interaction having a minor, repulsive role. IQA data have also been used to explain the value of the Se···I-I valence angle, as well as the topological charges on the iodine atoms in the complexes studied.

Tautomerism and acid-base properties of formyl derivatives of 1-phenyl-3-methyl-4,5-dihydropyrazol-5-one and its thio analog

A single-crystal X-ray diffraction study showed that 1-phenyl-3-methyl-4-formyl-4,5-dihydropyrazol-5-one occurs in the solid phase as two conformers of the NH tautomer. The acidity and basicity constants of 1-phenyl-3-methyl-4-formyl-4,5-dihydropyrazol-5-one and its analog, -5-thione, in 50% aqueous dioxane were measured. PM3 calculations qualitatively explan the differences in the tautomerism and acid-base properties of 4-formylpyrazolone (-pyrazolethione) and the corresponding compounds without the formyl substituent.

S=o…s=o Interactions as a Driving Force for Low-Temperature Conformational Rearrangement of Stable H-Bonding {S(O)-Ch2-Ch2-OH···}2 Synthon in two Modifications of Diastereomeric Pinanyl Sulfoxides Co-Crystal

GRAPHICAL ABSTRACT For the triclinic and monoclinic modifications of diastereomeric pinanyl sulfoxides co-crystal, remarkable alterations in unit cell parameters by transition from 293 to 150 К were ascertained. Such alterations are accompanied by conformational restructuring of a stable hydrogen-bonded synthon from an “unfolded” to a “folded” form. The driving force of this restructuring is the tendency to form S=O…S=O interactions, which show up in the low-temperature phases of both polymorphs. These are well-supported by the methods of quantum chemistry (DFT, B97-D/6-31G(d,p), AIM All).

First example of the synthesis of S,O-macroheterocycle based on 2(5H)-furanone and 2,2´-oxydiethanethiol

A base-catalyzed reaction of 3,4-dichloro-5-methoxy- and 3,4-dichloro-5-ethoxy-2(5H)-furanones with 2,2´-oxydiethanethiol gave thiols and bis-thioethers of 2(5H)-furanone series. A new S,O-macroheterocyclic compound containing a 18-membered oxathiamacrocycle and two 2(5H)-furanone fragments was synthesized based on the thiols in an aqueous solution of potassium hydroxide, which was characterized by X-ray diffraction.

Synthesis and structure of the products of the reactions of 3-chloro-5-methoxy-4-[(4-methylphenyl)sulfanyl]-2(5H)-furanone with N,N-binucleophilic agents

Reactions of 3-chloro-5-methoxy-4-[(4-methylphenyl)sulfanyl]-2(5H)-furanone with different nitrogen-containing binucleophilic agents were studied. The reaction with hydrazine monohydrate resulted in the formation of 1,5-dihydro-2H-pyrrol-2-one and pyridazin-3(2H)-one derivatives, whereas the reaction with phenylhydrazine led exclusively to 1-phenylamino-1,5-dihydro-2H-pyrrol-2-one. The reaction with ethylenediamine resulted in the isolation of 1,2-bis[2-oxo-1,5-dihydro-2H-pyrrol-1-yl]ethane: the enantiomeric dl-pair and two poly-morphic modifications of meso-form, which were characterized by X-ray crystallography.

Acid-base properties of bis(hydrazinocarbonylmethyl) sulfoxide and its complex formation with copper(II) and nickel(II)

Behavior of physiologically active compound, bis(hydrazinocarbonylmethyl) sulfoxide, in aqueous solution has been studied by means of potentiometry, spectrophotometry, and mathematical simulation. Protolytic properties of bis(hydrazinocarbonylmethyl) sulfoxide have been described, and the formation of sodium salt has been confirmed. Composition and stability constants of bis(hydrazinocarbonylmethyl) sulfoxide complexes with copper(II) and nickel(II) have been determined, and the complexes structures have been simulated by molecular mechanics method.

1-[5-(Hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate: protolytic properties and complexation reactions

The compound with antituberculosis activity, 1-[5-(hydrazidomethylsulfinyl)pentyl]-3,5-dimethylisocyanurate, was studied in aqueous dimethyl sulfoxide by potentiometric titration, spectrophotometry, and mathematical simulation of equilibria in solution (the CPESSP program). The protolytic properties of the compound were examined. The compositions and stability constants of its complexes with copper(II) were determined. The geometries of the isocyanurate and its complexes were optimized by molecular mechanics computations.

2,4-diamino-6-(acetohydrazidomethylsulfinylmethyl)-1,3,5-triazine. State in solution, acid-base and complexing properties

Solutions of a new drug, 2,4-diamino-6-(acetylhydrazidomethylsulfonylmethyl)-1,3,5-triazine, exhibiting tuberculocidal activity were studied using the methods of pH-metry, spectrophotometry, mathematical simulation of equilibria (CPESSP software), and molecular mechanics. Protolytic properties of the compound in the medium of aqueous dimethylsulfoxide (40 vol % of DMSO) were characterized. The composition of the copper(II) complex of this compound was determined and its stability constants were calculated. Based on the absorption spectra in the UV and visible regions the complexing ability of 2,4-diamino-6-(acetylhydrazidomethylsulfonylmethyl)-1,3,5-triazine toward nickel(II) and cobalt(II) were characterized in comparison with copper(II) under the same conditions.

Electrochemical reduction of mucochloric acid and its 5-alkoxy derivatives

Abstract5-Alkoxy-3-chloro-2(5H)-furanones were synthesized by the electrochemical reduction of 5-alkoxy derivatives of mucochloric acid in acetonitrile on the lead electrode in the presence of acetic acid as a proton donor. A combined analysis of the experimental data and quantum chemical calculation of intermediates indicates the EEDC mechanism of reduction, including the tandem transfer of two electrons with chloride ion elimination at the stage of transfer of the second electron and protonation.