Russian Journal of General Chemistry最新文献

A new series of thiazolidine-2,4-dione derivatives incorporating a 1,3,4-oxadiazole moiety linked to various substituted benzylidene fragments was synthesized and evaluated for their antibacterial properties. The synthetic route involves the stepwise formation of thiazolidine-2,4-dione, 3-fluoro-4-(trifluoromethyl)benzohydrazide, and subsequent cyclization with POCl₃ to form the key 1,3,4-oxadiazole intermediate. Further condensation with aromatic aldehydes furnished final derivatives. Structures were confirmed using spectroscopic techniques including IR, NMR (¹H and ¹³C), and mass spectrometry. Biological evaluation showed promising antibacterial activity comparable to streptomycin. Structure-activity relationship (SAR) analysis indicated that electron-withdrawing substituents enhanced antibacterial efficacy. These findings suggest the potential of the synthesized derivatives as antibacterial agents.

To date, the reported synthetic methods for 2-hydrazino-4,6-dimethylpyrimidine have not been sufficiently convenient and have yielded less than optimal results. In this study, we report an optimized three-step synthesis of 2-hydrazino-4,6-dimethylpyrimidine starting from 4,6-dimethylpyrimidine-2-thiol with the yield of 88.4%. The advantages of this procedure include the elimination of precious metal catalysts, simplified operation, short reaction time, and significantly enhanced yields. Meanwhile, we speculate that the plausible mechanism underlying the formation of 2-hydrazino-4,6-dimethylpyrimidine involves the lone pair of electrons on the nitrogen atom of hydrazine hydrate initially attacking the C=N double bond in the pyrimidine ring through a 1,2-nucleophilic addition, forming an unstable transition-state intermediate. This intermediate subsequently undergoes proton transfer and cleavage of the α-bond, resulting in the elimination of the ethyl 2-hydrosulfonylacetate moiety and the formation of 2-hydrazino-4,6-dimethylpyrimidine.

A new series of acylated and alkylated derivatives of pyran-3-ylidene-1,5-benzodiazepine has been prepared, and their structures were confirmed using NMR spectroscopy. Additionally, five pyran-3-ylidene-1,5-benzodiazepine compounds were analyzed through single-crystal X-ray diffraction. Hirshfeld surface analysis was performed using several key parameters, including normalized contact distance (d_norm), external (d_e) and internal (d_i) distances, curvature, and fragment patches, which enabled detailed visualization of electron density and intermolecular interactions. Molecular docking studies were conducted to assess the binding affinities of these benzodiazepine derivatives to the gamma-aminobutyric acid (GABA) receptor [Protein Data Bank (PDB) identification code: 6HUP], using valium as a reference ligand. The absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling demonstrated that most compounds complied with Lipinski’s rules, exhibited good permeability through human colon carcinoma (Caco-2) cells, and showed low hepatotoxic and carcinogenic potential. The high passive permeability through Madin–Darby canine kidney (MDCK) cells and the absence of mutagenicity further support the potential of these compounds for development. Overall, the derivatives displayed improved profiles for advancement as clinical candidates based on in silico predictions, indicating that further experimental validation is required.

Derivatives of pyridoxine and 3-hydroxypyridine containing azidomethyl groups at various positions of the pyridine ring have been synthesized. The synthesized compounds exhibit high antimycotic activity against reference and clinical strains of mycelial and yeast fungi, which exceeds the activity of the known drug fluconazole. The cytotoxic properties of the obtained compounds against conditionally normal and tumor cell lines, as well as the acute toxicity of the lead compound in mice, have been investigated.

This work presents the results of kinetic study of thermocatalytic degradation of decalin, acting as a model compound of cycloalkanes characteristic for the composition of heavy oil residues. The kinetic scheme of the process based on elementary stages including formation and subsequent transformation of primary molecular products was proposed and substantiated for the first time. HYmmm zeolite modified with sodium tetrachloroferrate was used as a catalytic system. The dynamics of product formation was quantitatively analyzed by chromatography-mass-spectrometry and gas chromatography to determine the dependence of the molar fraction of decalin and its derivatives on the contact time with the catalyst at 550°C. It was found that the process proceeds through the formation of primary molecular products: naphthalene, butylcyclohexane, 1-methyl-2-propylcyclohexane and 1,2-diethylcyclohexane, which are intermediate compounds and undergo further transformations to form gaseous hydrocarbons C₁–C₄, components of gasoline and kerosene-gasoil fractions. A reaction mechanism including the formation of a catalytically active complex of decalin with the catalyst and its subsequent transformations by several routes was proposed. The applied kinetic approach allowed to adequately describe the experimental data and to determine the rate constant of the process (k = 0.42±0.02 s^–1). The obtained results can be used for prediction of selectivity of thermocatalytic processing of heavy oil feedstock and optimization of technological parameters.

The advancement of heterostructure materials is vital for improving supercapacitor performance. 2D graphitic carbon nitride (g-C₃N₄) has drawn interest in energy storage owing to its layered structure, tunable bandgap, metal-free nature, high stability, low cost, and simple synthesis. Composite materials are also widely explored for their versatile properties. Herein, SnNb₂O₆/g-C₃N₄ heterostructure was synthesized via hydrothermal method and characterized by XRD, Raman spectroscopy, FE-SEM, and TEM for detailed structural and morphological analysis. Electrochemical properties were analyzed using cyclic voltammetry, galvanostatic cycling, and impedance spectroscopy. The SnNb₂O₆/g-C₃N₄ heterostructure exhibits an enhanced specific capacitance (217 F/g at 10 mV/s, 172 F/g at 0.5 A/g) than SnNb₂O₆ alone, demonstrating its strong potential as an electrode material in supercapacitor devices.

Many chemists are keen to advocate improved materials and fragments for the fabrication of solar devices with enhanced photochemical conversion efficiency. Here, we focused on the fabrication of polyaniline-based nanocomposite designs that were transformed to expand them technologically through allied hybrid materials. These nanocomposite materials are very operative in present-day energy storage devices because of their amplified dynamic catalytic surface area and boosted charge transfer from the counter electrode to the electrolyte, which demonstrates potential candidate to be employed as the counter electrode in dye-sensitized solar cells. Consequently, an inclusive investigation of polyaniline-based counter electrode as an intrinsic conducting polymer has been accelerated in photovoltaic solar cells, which exploits the skills of electrochemical tools to transform solar radiation effectively into electrical power, which will signifyan eco-friendly and high-demand energy source towards low carbon emissions. This could be an imminent revolution that benefits administrators to preserve control, and a balanced tactic to further gain practical requirements.

We present an innovative catalytic system employing secondary phosphine oxide (SPO)-stabilized palladium-gold nanoalloys (SPO-Au/Pd-NPs) for the sustainable synthesis of aromatic amines in aqueous media. This engineered catalyst demonstrates exceptional chemoselectivity (>99% in most cases) and activity (TOF up to 4.759 h^–1) in the hydrogenation of diverse nitroarenes and N-heterocycles. Mechanistic studies reveal that the synergistic interplay between the bimetallic Pd/Au nanoalloy core and SPO ligands enables: (1) spatial confinement of reactants through alloy effect, (2) dual activation pathways for both molecular hydrogen and nitro groups, and (3) water-mediated proton transfer networks that suppress undesired side reactions. Notably, the aqueous environment facilitates a unique self-assembly process where hydration layers organize reactant molecules at the catalyst interface, achieving near-quantitative yields (>99%) under mild conditions (25°C, 1 atm H₂). The catalyst’s heterogeneous nature permits phase separation post-reaction, enabling efficient recovery with retained activity (>95% over 6 cycles) through simple decantation. This protocol eliminates the need for organic solvents or energy-intensive procedures, establishing a new paradigm for green amine synthesis with atomic precision.

Protection of the aldehyde group of 2-(alkylthio)-4,6-dichloro-pyrimidine-5-carbaldehydes changes the selectivity of their reaction with arylhydrazines, which is apparently associated with a steric hindrances and change in the sequence of interaction of these compounds. In this work, the effect of the protective group and the structure of arylhydrazine on the reaction result was studied. The reaction conditions were optimized and a series of 6-(alkylthio)-2-aryl-2H-pyrazolo[3,4-d]pyrimidines without impurity of isomer 1 were obtained in good yields.

Reversible molecular photoswitches, which undergo controlled transitions between well-defined isomeric states, constitute essential building blocks for advanced photoresponsive systems. Although azobenzene (AB) derivatives represent a prototypical class of such switches, their traditional activation by UV irradiation imposes critical constraints, notably limited penetration depth in biological tissues/materials and potential photodamage effects, thereby hindering their widespread implementation. These inherent limitations have stimulated intensive research into visible light-triggered AB photoswitches, opening new avenues for diverse applications across materials science and biomedical fields. This review systematically outlines molecular design strategies for achieving visible light-driven isomerization in AB derivatives, including: para-substituted azobenzenes, bridged azobenzenes, ortho-substituted azobenzenes, azoheteroarenes, BF₂-coordinated azobenzenes, two-photon absorption, and upconverting nanoparticles. Furthermore, we critically examine existing challenges and propose future directions for developing AB derivatives that can be activated within the biologically favorable 650–900 nm “phototherapeutic window.”