Vol 87, No 10 (2017)

Nanocrystalline lanthanum zirconate La₂Zr₂O₇ was synthesized by the solid-phase method using preliminary mechanical activation of a La₂O₃ and ZrO₂ mixture. Processes occurring during heating the mixture of mechanoactivated lanthanum and zirconium oxides were studied using the X-ray phase analysis, IR spectroscopy, and complex thermal analysis. Synthesized lanthanum zirconate was characterized by the X-ray phase analysis and transmission electron microscopy methods.

Carbonylation of o-dibromobenzene and its derivatives in the presence of palladium phosphine complexes with NaOAc or Et₃N additive leads to the formation of phthalates in high yield under mild conditions. Correlation NMR spectroscopy data and semiempirical calculations have shown that the reactivity of the C–Br bond is enhanced with the increase in the positive charge at the carbon atom, in line with the results of kinetic experiments.

Bromination of ammonium salts containing two propargyl groups afforded bromine-substituted derivatives of pyrrolinium salts. The reactions of piperidinium and morpholinium analogs resulted in spirocyclic ammonium salts.

Reactions of methyl 3,4,6-trioxoalkanoates (3,4-dihydroxy-6-oxo-2,4-alkadienoates) with a mixture of arylamines and aromatic aldehydes or with the corresponding arylidenearylamines lead to the formation of methyl (4- alkanoyl-3-hydroxy-1,5-diaryl-1H-pyrrol-2-yl)acetates. Structure of the synthesized compounds is discussed basing on IR, ¹H NMR spectroscopy, mass spectrometry, and X-ray diffraction data.

Acylation and sulfonylation of substituted pyrazolo[3,4-d][1,2,3]triazin-4-ones, as well as reactions with acylating agents proceeding via destruction of the triazine ring are studied.

Compounds of alkyl sulfates and cationic copper(II) complexes with some organic reagents (pyridine, 1,10-phenanthroline, 2,2'-dipyridyl) were prepared, and their physicochemical characteristics (composition, thermal stability, solubility) were determined. The synthesized compounds are poorly soluble (solubility product K_S = n×10^–20–n×10^–22) and thermally stable (90–260°С). An effect of the hydrophobilicity of alkyl sulfates on the UV characteristics of the copper(II)–organic reagent systems and on the solubility of the studied compounds was evaluated.

CuLCl, CuL¹Cl, PdLCl₂, and PdL¹Cl₂ complexes [L and L¹ being (+)-camphor and (–)-carvone thiosemicarbazones, respectively] have been synthesized. The structure of binuclear [Pd₂L²²Cl₄] complex has been determined by means of X-ray diffraction. The L² ligand (dehydrogenated (–)-carvone thiosemicarbazone) is coordinated via the bridging S atom to two Pd atoms. The complexes of Cu(I) and Pd(II) presumably have polynuclear and binuclear structure, respectively. These facts are in good agreement with IR and NMR spectroscopy as well as mass spectrometry data which indicate the coordination of L and L¹ ligands via the S atom. The influence of L¹ and PdL¹Cl₂ on viability of the Hep2 cell line has been studied. The PdL¹Cl₂ complex is more cytotoxic than L¹ ligand.

A ceramic composite [78ZrO₂–21CeO₂–Y₂O₃]/La_0.85Y_0.15Al₁₁O₁₈/Al₂O₃ (zirconium dioxide submicroparticles stabilized by cerium and yttrium oxides), which consists of a matrix filled with layered submicroparticles of lanthanum hexaaluminate modified by yttrium oxide and reinforced by Al₂O₃ nanofibers, was obtained. Components of the composite were synthesized by the sol-gel method, except for Al₂O₃ nanofibers obtained by the electric explosion method. The microstructure and properties of the composite depend on the composition and methods of its formation and sintering. The composite is intended to be used as a construction material.

Crystallographic size effects occurring during the formation of zero-valence silver and gold nanoparticles dispersed in a biopolymer polysaccharide matrix (arabinogalactan) have been studied by means of X-ray diffraction analysis. The average size of the nanoparticles has been found to increase with the increase in the metal content in the nanocomposite. Stabilization of the nanoparticles by the polymer matrix is accompanied by the decrease in the unit cell parameter of the metal correlated with the decrease in the coherent scattering length.

Four new organotin (IV) complexes with general formula R₃SnL/R₂SnL₂, where R = CH₃, n-C₄H₉, C₆H₅ and L = Levofloxacin, were synthesized and characterized by elemental analyses, FT-IR and NMR (¹H and ¹³C) spectroscopy. Spectroscopic data suggested a six-coordinated geometry for diorganotin(IV) derivatives and a five-coordinated geometry for triorganotin(IV) derivatives. The value of Me–Sn–Me bond angle for di- and trimethyltin complexes using the Lockhart equation, were 150° and 116°, respectively, that corresponded to six and five-coordinate geometry, accordingly. The ligand and its complexes were screened for their antibacterial, antifungal, cytotoxic, and free radical scavenging (DPPH) antioxidant activities. The biological data indicated those as potentially bioactive in each field of the study. Accumulated data of DNA interaction with the synthesized complexes based on UV-Vis, cyclic voltammetry and viscometry suggested an intercalative mode of the interaction.

Herein, we report a series of pyridines and their sulfa drug derivatives as antimicrobial agents. Regioselective alkylation followed by hydrozinolysis of 2-pyridone 1 gave the target compounds 2 and 3. Compound 3 was cyclized with acetylacetone or heated in dry benzene to give 2-(pyrazol-1-yl)nicotinonitrile 5 and 3-amino-1H-pyrazolo[3,4-b]pyridine derivatives 6, respectively. Diazotization of compound 3 with nitrous acid at low temperature afforded tetrazolo[1,5-a]pyridine derivative 8. Compounds 6 and 7 were obtained by condensation of hydrazine derivative 3 with D-glucose and D-ribose. Acid-mediated hydrolysis and sulfurization of dicyano compound 2 gave pyridine-3,5-dicarboxamide 11 and 2-thioxopyridine 12 derivatives, respectively. The later compound was alkylated with allyl bromide, benzyl chloride and mono chloroacetic acid to produce the corresponding S-alkylated derivatives 13–15. Compound 15 underwent the Thrope–Ziegler cyclization/condensation with sulfa-drugs to give the corresponding thienopyridine 16 and sulfonamide derivatives 17–19. Antimicrobial study of the new syntheized compounds demonstrated signficant activity of compounds 8–11 and 17–19.

We report design and synthesis of a series of flavanone/chromene derivatives containing pyrazoles 6a–6h and 8a–8e with potent anti-leukemic activity. Anti-leukemic activity of novel flavanone derivatives was tested using the K562 cell line. The parental flavanone was selected as the reference compound in identification of analogues with superior anti-leukemic activity. More than two-thirds of the derivatives displayed higher activity than the initial flavanone. Positions of substituents that promoted anti-leukemic activity were identified on both the chromene and pyrazole fragments. Compounds 6b and 6c showed the highest activity against K562 cell line, with IC₅₀ values 3.0 and 0.5 μM respectively. Notably, compounds 6b and 6c displayed very high selectivity in inhibition of leukemic cells (K562) but not of healthy HEK293 cells or solid cancer cell lines HeLa, MCF7 and BT474. Moreover, both the 6b and 6c compounds were predicted to have good ADME properties.

A novel heterogeneous acidic ionic liquid based on functionalized imidazolium salt of phosphotungstic acid (H₃PW₁₂O₄₀, denoted as PW), immobilized on CuFe₂O₄@SiO₂ magnetic nanoparticles, denoted as CuFe₂O₄@SiO₂@C₃-Imid-C₄SO₃-PW, was prepared and characterized using FT-IR, SEM, EDX, and VSM techniques. High activity of the prepared material as a novel catalyst was evaluated in one-pot synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by reaction of phthalhydrazide with an aromatic aldehyde and malononitrile under solvent-free conditions. The process gave high yields of the products over short reaction time. The catalyst was efficiently recovered by magnetic decantation and used repeatedly without significant loss of its activity.

In the present study, a series of novel 1,2,3-triazoles derivatives (4a–4c) were synthesized by the 1,3-dipolar cycloaddition (click-reaction) of 1-phenyl-3-[2-(prop-2-yn-1-yloxy)phenyl substituted]-1H-pyrazole-4-carbaldehyade (3a–3c) with various aryl azides in the presence of sodium ascorbate and copper sulphate with high yields. The required precursors 3a–3c were synthesized by the reaction of 1-(2-hydroxy phenyl substituted)ethanones (1a–1c) with propargyl bromide via 1-[2-(prop-2-yn-1-yloxy)phenyl substituted] ethanone (2a–2c), followed by reaction with phenyl hydrazine. The newly synthesized 1,2,3-triazole-pyrazole derivatives were characterized by analytical and spectral data. All synthesized compounds were evaluated in vitro for their antibacterial and antifungal activity. The most active compounds 4a₅–4a₇ demonstrated a broad spectrum of antibacterial activity against all strains used for testing. Compounds (4a₄, 4b₁, 4c₁, 4c₂) demonstrated significant antifungal activity at the concentration of 10 μg/mL.

Several novel 8-hydroxy-7-iodoquinoline-5-sulfonamides bearing pyran and pyrano[2,3-d]pyrimidine derivatives were synthesized via a one-pot base catalyzed cyclocondensation reaction of N-(4-acetylphenyl)-8-hydroxy-7-iodoquinoline-5-sulfonamide with malononitrile and arylaldehydes, followed by heterocyclization of the resulting intermediates with the appropriate reagents such as carbon disulphide, formic acid, thiourea, and formamide.

A multicomponent method of the synthesis of 5-aryl-3-amino-1H-pyrazole-4-carbonitrile and 3-amino-1,2-diazaspiro[4.5]dec-3-ene-4-carbonitriles with thermal and microwave activation was developed.

Hydrolysis of 4-heteryl-3-methoxycarbonyl-2-pyrrolidones in an alkaline medium and subsequent decarboxylation of the resulting 2-pyrrolidine-3-carboxylic acids afforded 4-(pyrid-3-yl)- and 4-(1-methylbenzimidazol-2-yl)-2-pyrrolidones.

N-Formylcytisine has been synthesized and characterized using ¹H NMR spectroscopy. Two conformers of N-formylcytisine have been found to exist in the DMSO-d₆ solution. The structure of the most stable conformer has been studied by means of X-ray diffraction analysis.

Powders of CrO₂ consisting of single-domain particles were obtained by the hydrothermal method in the presence of Fe(III). Morphology and magnetic properties were studied. The powders were investigated by the Mossbauer spectroscopy and X-ray phase analysis methods.

Quantum chemical interatomic bond and atomic valence indices were extended to heavy atom compounds in terms of the relativistic quantum theory.