Vol 89, No 1 (2019)

A two-step procedure has been proposed for the synthesis of 1,2-bis(2-oxocycloalkyl)ethane-1,2-diones and 3,4-dioxo-4-(2-oxocycloalkyl)butanoic acid esters by condensation of cycloalkyl ketones with dimethyl oxalate or of alkyl acetates with dialkyl oxalates and cycloalkyl ketones, respectively. The structure of the synthesized compounds has been discussed on the basis of their IR, ¹H NMR, and mass spectra, and their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium strains has been estimated.

The reaction of 5-amino-3-(cyanomethyl)-1H-pyrazole-4-carbonitrile with 3-aryl-5-hydroxy-5- methyl-2,4-di(ethoxycarbonyl)cyclohexanones in acetic acid furnished previously unknown 4,5,6,7,8,9-hexahydropyrazolo[1,5-a]quinazoline derivatives.

Heterocyclization of 3-[(1H-1,2,4-triazol-3-yl)thio]pentane-2,4-dione afforded 1-(6-methylthiazolo[3,2-b][1,2,4]-triazol-5-yl)ethan-1-one, the reactions of which with hydroxylamine, hydrazincarboxamide, hydrazincarbothioamide, hydrazine hydrate and para-toluenesulfonyl hydrazide resulted in the formation of the corresponding derivatives. 1-(6-Methylthiazolo[3,2-b][1,2,4]triazol-5-yl)ethan-1-one oxime reacted with alkyl halides and phenyl isocyanate to produce the corresponding O-alkyl- and O-phenylcarbamoyl derivatives. The growth regulating activity of the compounds obtained was studied.

5-Chloromethyl-2-furoyl chloride when treated with triethyl phosphite has given 5-chloromethyl-2-furoyl phosphonate. This compound has reacted with sodium azide in the presence of potassium iodide to give 5-azidomethyl-2-furoyl phosphonate. Treatment of 5-chloromethyl-2-furoyl phosphonate with secondary amines even under mild conditions has caused cleavage of P–C bond with liberation of diethyl hydrogen phosphite and formation of 5-chloromethyl-2-furancarboxamide. Butanthiol in the presence of potassium carbonate in acetonitrile has converted the chloromethyl group into the butylthiomethyl one and simultaneously split the P–C bond with the formation of the corresponding thioester. Under the action of S-methylthiuronium iodide and triethylamine, 5-chloromethyl-2-furoyl phosphonate has been unexpectedly reduced into the 5-methyl derivative. 5-Butylthiomethyl- and 4-(N-morpholinomethyl)-2-furoul chlorides have been phosphorylated with triethyl phosphite into the corresponding 5-functionalized 2-furoyl phosphonates. The prepared furoyl phosphonates have reacted with resonance-stabilized phosphoranes to give phosphorylated derivatives of 3-(furyl)acrylates and 4-(furyl)but-3-en-2-one with trans-location of phosphoryl and carbonyl groups with respect to the double bond.

Oxidative cross-coupling of 4-acetylaminophenol (paracetamol) and its structural isomers (2- and 3-acetylaminophenols) with secondary phosphine chalcogenides at room temperature in the CCl₄–Et₃N system produced O-(acetylamino)phenyl chalcogeneophosphinates in a 80% yield.

The condensation of aryl methyl ketones with diethyl oxalate in the presence of metallic sodium or sodium hydride gave sodium 4-aryl-1-ethoxy-1,4-dioxobut-2-en-2-olates, and metal exchange of the latter with magnesium(II), zinc(II), cobalt(II), and copper(II) salts afforded the corresponding metal bis(4-aryl-1-ethoxy-1-oxobutane-2,4-dionates). The obtained complexes were tested for antibacterial activity against gram-positive and gram-negative bacteria by the agar diffusion method.

Binuclear antimony compounds with a bridging oxygen atom [Ph₃SbOC(O)R]₂O (R = CF₂CF₃, CF₂CF₂CF₃), [(4-МеC₆H₄)₃SbOC(O)CF₂CF₃]₂O, [(3-FC₆H₄)₃SbOC(O)R]₂O (R = C₆F₅, CF₂CF₃) have been synthesized by reacting equimolar amounts of triarylantimony, carboxylic acid and tert-butyl hydroperoxide in diethyl ether. According to X-ray diffraction data, in the molecules of compounds obtained, the Sb atoms have a trigonal bipyramid coordination with carboxylate ligands and a bridging oxygen atom in axial positions. The intramolecular distances Sb···O with a carbonyl oxygen atom are less than the sum of the van der Waals radii of Sb and O by ~0.2–0.4 Å.

New chiral 1,10-phenanthroline-derived ligands containing fragments of (+)-3-carene (L¹) and (+)-limonene (L2) natural monoterpenoids and their complexes Zn(L^1,2)Cl₂·1.5H₂O, Cd(L^1,2)Cl₂·nH₂O, Zn(L¹)Br₂·2H₂O, and Cd(L1)Br2·2H2O were synthesized. According to NMR and IR spectroscopy data, a conclusion was made about the polynuclear structure of the compounds obtained. Luminescent properties of the compounds obtained were investigated. Lifetimes of the excited states and luminescence quantum yields (φ_f) were determined. For free ligands, blue fluorescence was observed. In the case of Zn(II) and Cd(II) complexes, luminescence appeared in the green region of the spectrum.

Bimetallic Cu@Ag nanoparticles with a core–shell structure were synthesized by reduction of copper 2-[2-(2-methoxyethoxy)ethoxy]acetate with hydrazine hydrate in benzyl alcohol, followed by reducing the silver ions on the copper surface by transmetallation reaction. The sinthesized nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and optical spectroscopy methods. The effect of the synthesis conditions such as temperature, time, Ag: Cu molar ratio, the rate of silver nitrate addition, on the uniformity of silver coating on the surface of copper nuclei was studied.

The effect of preliminary annealing of semicrsytalline high-density polyethylene films on the parameters of nanoporous structure formed during deformation of polymers in physically active liquid environments via the intercrystallite crazing has been studied. Optimal conditions providing the development of a stable open-cell polymeric materials with a high level of porosity (50%) and pore size below 10 nm have been elavorated. For the first time, the in situ reduction of copper ions into copper(0) in the pores of the highdensity polyethylene nanoporous polymer matrix has been carried out using the radiation-chemical reduction method. The reaction has led to the formation of nanoscale copper particles within the polymer, which makes it possible to produce metal-polymer nanocomposites with valuable functional properties.

A series of novel 5-arylideneaminouracils is synthesized from 5-aminouracil and substituted salicylaldehydes, and characterized by spectroscopic methods. DNA interactions of model molecules are explored using molecular docking simulations that reveal that these types of molecules can act as DNA groove binders.

α-Conjugated oligoselenophenes are characterized by very low solubility in organic solvents. Their higher solubility may be achieved by introducing alkyl side chains into the β-positions of selenophene moieties. For the first time, β,β′-dihexyl sexiselenophene is synthesized according to the conventional approach. Physical and electrochemical studies of β,β′-dialkyl oligomers are analyzed and compared with corresponding thienyl oligomers.

5-Methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one, an intermediate product in the synthesis of the antiviral drug Triazid®, was obtained for the first time by condensation of 3H-1,2,4-triazol-5-amine with ethyl acetoacetate in the presence of a catalytic amount of ZnCl₂ in supercritical carbon dioxide (200 bar) under solvent-free conditions. Depending on the temperature and reaction time, the conversion was 90%.

A method for the synthesis of N⁹-substituted acridine-9-amines by reacting 9-chloroacridines with 2-(2-methyl-5- nitro-1H-imidazol-1-yl)ethanamine was developed. The synthesized compounds showed high antibacterial ability against B. subtilis bacteria compared with rivanol and metronidazole.

A model of minimum size clusters in orthophosphates has been suggested. In the case of monazite, the cluster includes a cerium(III) cation with nine oxygen atoms of the first coordination sphere, from seven neighboring phosphate anions. Its charge consists of the cation charge Q_M and the charges of the oxygen atoms Q_O =–1 a. u. The results of quantum-chemical simulation assume the possibility of the Ce(III) cation substitution with the Th(III), Th(IV) and U(IV) actinide cations. Substitution with thorium is favorable over that with uranium.