卷 89, 编号 9 (2019)

Alkaline hydrolysis of 3-(2-arylhydrazinylidene)-2,4-dioxoalkanoic acids (obtained by azo coupling of the condensation products of the corresponding ketones and dialkyl oxalates in the presence of sodium) afforded 3-(2-arylhydrazinylidene)-2,4-dioxoalkanoic acids. Antimicrobial activity of some of the synthesized acids against gram-positive and gram-negative bacteria was evaluated.

Cyanothioacetamide reacted with 1,1,5,5-tetrafluoroacetylacetone to give 4,6-bis(difluoromethyl)-2-thioxo-1,2-dihydropyridine-3-carbonitrile, and alkylation of the latter with α-chloroacetamides afforded 3-amino-4,6-bis(difluoromethyl)thieno[2,3-b]pyridine-2-carboxamides. The structure of the key compounds was proved using two-dimensional NMR techniques. In silico analysis of potential biological activity and bioavailability of the synthesized compounds was performed.

A series of bi- and trinuclear pyrrole derivatives was prepared by the 5 mol % ZrOCl₂ ·8H₂O-catalyzed CH-sp²-aminomethylation reaction of pyrrole with bis(1,3-oxazacycloalk-3-yl)methanes. The reaction proceeds at the positions 2, 5 or 2 of pyrrole depending on the amount of aminomethylating reagents obtained from formaldehyde and α,ω-amino alcohols (2-aminoethan-1-ol, 3-aminopropan-1-ol, 4-aminobutan-1-ol). The aminomethylation reaction of indole with bis(1,3-oxazolidin-3-yl)methane proceeds at the position 3. In the case of carbazole, N-aminomethylation proceeds under these conditions.

The reaction of methyl pheophorbide a with various alcohols in toluene in the presence of dimethylaminopyridine as a base was investigated. Under these conditions, a chemoselective transesterification of the exocyclic ring proceeds without the use of an activating agent (N-methyl-2-chloropyridinium iodide) or a catalyst (molecular iodine).

A spectral-kinetic study of photochromic functionalized nitro-substituted indoline spiropyrans in water-acetonitrile mixtures has allowed to observe for the first time the effect of negative photochromism due to the self-assembly of photochromic molecules in a mixed solvent with the formation of hydrogen bonds and proton complexes.

Conformational transformations of the orthogonal and planar forms of dialane Al₂H₄ molecule in model single-walled carbon nanotubes have been studied by the PBE/3ζ DFT method. In most cases, the effect of the nanosystem force field on the encapsulated molecule has been reflected in shortening of the Al–Al and Al–H bonds, decrease in the bond angles, and change in partial charges and bond orders which have resulted in the inversion of the relative stability of the orthogonal and planar forms as well as generation of high negative charge on the molecule of Al₂H₄ in the nanotube cavity. The decisive effect of the molecular orbital energy of the dialane@nanotube cluster on the stabilization of the planar conformation has been concluded.

Palladium(II) chloro complex with {[6-amino-2-(butylsulfanyl)pyrimidin-4-yl]oxy}acetic acid has been synthesized via the ligand substitution method. Composition and structure of the coordination compound have been elucidated from the combined data of elemental analysis and spectroscopy. The coordination of {[6-amino-2-(butylsulfanyl)pyrimidin-4-yl]oxy}acetic acid occurs via the formation of a donor-acceptor bond between the palladium(II) ion and the nitrogen atoms in position 1 of the pyrimidine rings, chloride ions entering the inner coordination sphere of the PdCl₂L₂ complex, to give trans-bis({[6-amino-2-(butylsulfanyl)pyrimidin-4-yl]oxy}-hydroxyacetyl)dichloropalladium(II).

Temperature dependences of the saturated vapor pressure of lanthanum complexes based on 2-(2-benzoxazol-2-yl)phenolate ligand have been obtained using the Knudsen effusion method. The thermodynamic parameters of vaporization have been calculated from the p−T data. Mass spectra and differential scanning calorimetry data have been obtained.

Extraction of rare-earth elements(III) ions from chloride solutions with mixtures of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and phosphoryl-containing podands in organic solvents has been studied. The observed significant synergistic effect is associated with the formation of hydrophobic mixed-ligand complexes of rare-earth elements(III). The stoichiometry of the extracted complexes has been determined, and the extraction constants have been calculated. The influence of the phosphoryl-containing podand structure, the organic solvent nature, and the aqueous phase composition on the efficiency of the extraction of rare-earth element(III) ions into the organic phase has been considered.

The features of the formation of nanocrystals in the BiFeO₃–CaFeO₃ system via glycine-nitrate combustion were studied. The crystallite size of the bismuth orthoferrite-based solid solutions (20–45 nm), as well as their particle size, were found to depend on the calcium content. The formation processes were activated in the temperature range corresponding to the melting of the surface (nonautonomous) phase.

A series of novel 1,4-substituted bis-aralkyl and aryl 1,2,3-triazoles bearing thiophene chalcones are synthesized via the Claisen condensation of bis propargyl acetophenone intermediate with thiophene-2-carboxaldehyde followed by the Huisgen cycloaddition of the accumulated bis propargyl chalcone intermediate with various aryl and aralkyl azides. Structures of the synthesized compounds are characterized by IR, NMR and mass spectroscopy. The products are tested for antimicrobial and antioxidant activities, and some of those exhibit antibacterial and antifungal activity. The moderate to poor DPPH free radical scavenging activity is determined for some products.

The new tetradentate Schiff base N,N′-ethylene bis[1-ethyl-6-fluoro-4-imine-7-(piperazine-1-yl)-quinoline-3-carboxylic acid] (Nor-en) has been synthesized. Its chelated complexes with Co(II), Ni(II), Cu(II), Zn(II), Y(III), Zr(IV), La(III), and U(VI) are characterized using molar conductivity, magnetic moment, FT-IR, UV-Vis, ¹H NMR, and mass spectra, and thermal analysis. It is determined that the complexes have monomeric structures and exist in the octahedral configuration. The molar conductance values indicate the electrolytic nature of the complexes. According to the spectroscopic data, the complexes share the same coordination environment around the metal ions, consisting of N₂O₂ and one or two water molecules. The thermodynamic parameters (activation energy, E*, entropy, ΔS*, enthalpy, ΔH*, and Gibbs free energy, ΔG*) are calculated using Coats-Redfern and Horowitz-Metzger methods. The carried out tests indicate the compounds’ high antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Salmonella typhi. Anticancer activity of the ligand and its metal complexes is evaluated against HepG-2 cells (human Hepatocellular carcinoma) and determined to be very low.

Synthesis of a new series of pyrimidinothienocinnoline derivatives involves the reaction of 9-aminodibenzo[f, h]pyrimido[4′,5′:4,5]thieno[2,3-c]cinnoline-8-carbonitrile with formamide that gives 8-amino-dibenzo[f, h]-pyrimido[4′,5′:4,5]thieno[2,3-c]cinnoline. Reactions of the latter with morpholine, piperidine, malononitrile, phenylbromide, aromatic aldehydes, and ethyl cyanoacetate have been studied. Some synthesized compounds have been subjected to further transformations. The synthesized pyrimidinothienocinnoline derivatives are tested for their anti-inflammatory activity.

In the present study, we report the synthesis of 5-[4-(3-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenyl]-1H-tetrazole derivatives by the Michael addition of chalcones to hydrazine hydrate in presence of acetic acid under conventional heating and microwave irradiation. All the synthesized compounds are characterized by IR, NMR, and mass spectra. The products are screened for their in vitro antimicrobial activity against strains such as Staphylococcus aurous, Bacillus subtilis, Klebsiella pneumonia, Escherichia coli, Aspergillus Niger, Aspergillus flavus, and Fusarium oxysporum. Most of the compounds exhibit high activity.

The reaction of isonicotinic acid hydrazide with ethyl-, allyl-, and cinnamoyl isothiocyanates has afforded the corresponding alkylthiosemicarbazides and the products of their intramolecular heterocyclization, 1,2,4-triazoles.

Regio- and stereoselective synthesis of tribromo[(E)-2-bromo-1-(phenoxymethyl)vinyl]tellane based on the reaction of tellurium tetrabromide with propargyl phenyl ether has been elaborated. This reaction is the first example of the addition of TeBr₄ to propargyl ethers. Reduction of the product with sodium borohydride has afforded bis[(E)-2-bromo-1-(phenoxymethyl)vinyl]ditellane.

Copolymers of glycidyl methacrylate and methyl pheophorbide a of different compositions were synthesized by radical copolymerization in toluene and THF solutions. The influence of the nature of the solvent, initial weight ratio of the monomers, and amount of the copolymerization initiator on the yield of the copolymer and its structure, composition, and properties were established. Physicochemical and molecular weight characteristics of the copolymers were determined.

Chemical transformations of chlorophyll a, aimed to develop photosensitizers for the antimicrobial and anticancer therapy, as well as for boron neutron capture therapy, have been considered. Research works on the development of purpurine 18 and its analogues have been presented; derivatives with intensive absorption in the near-infrared region of the spectrum, looking promising for photodynamic anticancer therapy, have been synthesized. A large series of works on the synthesis of N-hydroxy and N-amino cycloimides of chlorin p₆ have been carried out. Carbohydrate derivatives of chlorin, containing the indicated fragments in various positions of the macrocycle, have been synthesized. The synthesis of chlorin conjugates with the closo-decaborate fragment and bis-dicarbollide of cobalt has been performed. The methods of 1,3-dipolar cycloaddition and the Sonogashira reaction have been used to obtain these conjugates. Chlorin-fullerene conjugates, including water-soluble derivatives, have been synthesized and their spectral and other physicochemical properties have been studied.