Vol 86, No 12 (2016)

The process of formation of iron hydrosilicates (Mg²⁺,Fe³⁺)_2–3Si₂O₅(OH)₄ was studied. It was shown that the stage of coprecipitation of magnesium and iron hydroxides in the presence of silica nanoparticles forms poorly crystallized layered Mg–Fe double hydroxides having Fe³⁺ ions in the octahedral sites. Hydrothermal treatment of the mixtures of coprecipitated hydroxides and silica nanoparticles gives rise to layered hydrosilicates, where Fe³⁺ ions occupy both the octahedral (preferentially) and tetrahedral sires. The possibility of the formation and a fairly stable existence of the variable-composition layered hydrosilicate (Mg²⁺,Fe³⁺)_2–3Si₂O₅(OH)₄ was shown to correlate with the stability range of its precursor brucite-like Mg–Fe layered double hydroxide.

Ammonium salts bearing but-2-ynyl and phenacyl or 2-(naphth-2-yl)-2-oxoethyl moieties at the nitrogen atom underwent Stevens rearrangement to form substituted furan-3-amines. Quaternization of the latter afforded appropriate iodomethylates.

Ionic liquids with 1-butyl-3-alkylimidazolium (alkyl = C₄H₉, C₈H₁₇, or C₁₀H₂₁) cation and Br^–, BF₄^–, or PF₆^– anions have been obtained. Composition and structure of the compounds have been confirmed by elemental analysis and IR spectroscopy data. Electrical conductivity of solutions of the synthesized compounds in acetonitrile has been studied, and association constant as well as equivalent electrical conductivity at infinite dilution have been calculated. Thermal stability of the prepared ionic liquids in air at 25–500°С has been studied.

Methods of synthesis of trifluoromethylfuryl derivatives of phosphonocarboxylic acids are studied. By addition of diethyl hydrogen phosphite to alkyl 3-(5-trifluoromethylfur-2-yl)acrylate under the conditions of the Pudovik reaction the corresponding derivative of 3-phosphonopropionic acid was prepared. Diethyl (5-trifluoromethylfur-2-yl)methanephosphonate in presence of potassium tert-butylate reacts with ethyl acrylate to form trifluoromethylfuryl derivative of 4-phosphonobutyric or 4-phosphonopimelic acid depending on the reaction conditions. In the products of reaction of the alkyl 3-(5-trifluoromethylfur-2-yl)-3-(diethoxyphosphoryl) propionate with ethyl acrylate in the presence of potassium tert-butylate formation of trifluoromethylfuryl derivative of the 3-phosphonoadipic acid is detected. 3-(5-Trifluoromethylfur-2-yl)-3-(diethoxyphosphoryl) propionic acid and its acid chloride are synthesized. The latter compound is used for acylation of glycine to form the corresponding N-acyl derivative. It is suggested that such compounds may be transported in the cell using usual channels of transportation of the amino acids and short peptides.

A new approach to obtaining of caged bicyclic phosphonate, 4-hydroxy-3-trifluoromethyl-3-ethoxycarbonyl-8-(1-phenylhydrazonoethyl)-5,6-benzo-2,7,1-dioxaphosphabicyclo[3.2.1^1.5]octane, based on hydrolysis of 2,5-dioxobenzo[f]1,3,2-dioxaphosphepine derivative bearing 5-methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl substituent at the phosphorus was developed. The hydrolysis process includes elimination of P(II) atom and intramolecular cyclization involving endocyclic carbonyl group of the phosphepine. Structure of the caged phosphonate was established by NMR and XRD methods.

Copper(II) complexes with synthetic oligonucleotides consisting of repeating adenine–thymine and guanine–cytosine complementary base pairs have been studied by UV spectroscopy and simulated by DFT quantum chemical calculations at the B3LYP/6-311G++(d,p) level of theory with inclusion of solvation (hydration) effects. The obtained data suggest selective interaction of copper(II) ions with guanine–cytosine complementary pairs, followed by DNA cross-linking at those sites.

Reactions of tin tetrachloride in a 2-propanol solution and the products of condensation of 2-(7-bromo-2-oxo-5-phenyl-3H-1,4-benzodiazepin-1-yl)acetohydrazide (gidazepam) with 4-dimethylaminobenzaldehyde, 4-brombenzaldehyde, and 2-pyridinaldehyde made it possible to obtain for the first time the corresponding tin coordination compounds by the template synthesis. The composition and structure of the complexes were determined by physicochemical methods. Tin(IV) coordination polyhedron in these complexes is the octahedron formed by four chlorine atoms, the azomethyne nitrogen atom, and the oxygen atom of the ligand carbonyl group.

Tri(o-tolyl) antimony dioximates were synthesized by the reaction of tri(o-tolyl) antimony with 5-nitrofurfural and thiophen-2-carbaldehyde oximes in ether in the presence of hydrogen peroxide or tert-butylhydroperoxide (1: 2: 1 mol). Antimony atoms in the reaction products have distorted trigonal-bipyramidal coordination with the intramolecular distances Sb···N shorter than the sum of the van der Waals radii of Sb and N by ~1 Å.

Kinetics of oxidative polymerization of three isomeric phenylenediamines in aqueous hydrochloric acid solutions initialed by ammonium persulfate has been studied, and kinetic parameters of non-catalytic and catalytic stages of polymerization have been determined. The observed effect of the isomeric substrates structure on the activation energy of the catalytic and non-catalytic stages has been explained.

We report the high yield synthesis of novel 9-benzoyl-4-methylpyrano[2,3-f]chromene-2,8-dione derivatives obtained by the reaction of 8-formyl-7-hydroxy-4-methylcoumarin with various active methylene compounds. A mechanism of the tandem Knoevenagel condensation and cyclisation reaction is proposed. Structures of all compounds were elucidated on the basis of ¹H and ¹³C NMR, and mass spectrometry, and elemental analysis.

Fibroblast growth factor receptor 1 (FGFR1) is considered a therapeutic target for multiple cancers, including gastric cancer. FGFR1 inhibitors, being ATP competitors, can prevent the kinase domain and the downstream signaling cascade from phosphorylation and thus have the potential to treat cancers associated with aberrant FGFR1 activation. However, untargeted inhibition may cause numerous side effects. Thus, a non-ATP competitive FGFR1 inhibitor should be urgently identified and explored. In this study, we designed and synthesized 17 derivatives of nordihydroguaiaretic acid (NDGA), a known ATP-independent FGFR3 inhibitor. In the kinase activity assay, 3,5-bis(2-fluorobenzylidene)piperidin-4-one (1B) showed the highest kinase inhibitory activity among all derivatives and was thus identified as a non-ATP-competitive FGFR1 inhibitor. In the biological effect evaluation, 1B restrained the FGFR−FRS2−ERK signaling pathway in a dose-dependent manner and inhibited the growth of two gastric cancer cell lines. Overall, 1B can be considered as a potential candidate for treating gastric cancer and as an outstanding lead compound for the discovery of novel non-ATPcompetitive FGFR1 inhibitors.

A novel and efficient procedure for the synthesis of pyrano[4,3-b]chromene derivatives via three-component condensation reaction of benzyl alcohol, β-naphthol, and 4-hydroxycoumarin using a catalytical amount of cerium(IV) ammonium nitrate (CAN) and a reusable ionic liquid as a catalyst at room temperature is presented. The method provides several advantages such as simple work-up, environmental friendliness and shorter reaction time along with high yields. All synthesized compounds were elucidated by comparison with authentic samples, IR, ¹H, and ¹³C NMR spectroscopy, and elemental analysis.

A series of new pyrazole-based 1,2,3-triazole derivatives were synthesized through the microwave-assisted Huisgen click reaction from 1-phenyl-3-[3-(prop-2-yn-1-yloxy)phenyl]-1H-pyrazole-4-carbaldehyde and organic azides with the use of redox system CuSO₄·5H₂O–sodium ascorbate. The method provided short reaction times and isolation of 1,4-disubstituted 1,2,3-triazoles in high yield. All the prepared compounds were evaluated for antimicrobial activity and the most of them displayed promising results.

A series of new substituted [1,1'-biphenyl]-4-yl(3-methylbenzofuran-2-yl)methanones was prepared by Suzuki cross-coupling from (4-bromophenyl)(3-methylbenzofuran-2-yl)methanone. The obtained compounds were assayed for their in vitro antibacterial activity against different types of bacterial strains; antifungal activity was also examined by inhibitory effect against different fungal strains.

A highly efficient one-pot three-component synthesis of 2-amino-3-cyano-4H-chromenes has been developed by annulation of aldehydes, malononitrile and dimedone in the presence of Fe(ClO₄)₃/SiO₂ as a catalyst in acetonitrile under reflux conditions. The simple experimental procedure, short reaction times and high yields are the advantages of this method. A probable mechanism of the process is proposed.

Two compounds 1-[(2-carboxymethyl)benzene]-3-[2-pyridine]triazene (HL) and 1-[(2-carboxymethyl) benzene]-3-[o-aminobenzoic acid]triazene (H₂L') and two corresponding Pt(II) complexes, Pt(PPh₃)₂(L)Cl (1) and Pt(PPh₃)₂(L') (2), are theoretically studied by the density functional theory and time-dependent density functional theory. The geometric structure of complex 1 is optimized by B3LYP, PBE0, and M06 methods with the same mixed 6-31G(d)-LANL2DZ basis set. The absorption spectrum of complex 1 is simulated by the above method. As compared with the experimental data, the combination of M06/6-31G(d)-LANL2DZ and TD-M06/6-31G(d)-LANL2DZ is chosen for all other calculations including optimization of the ground-state and the lowest triplet excited state geometries, and the absorption and emission spectra. The detailed electronic transitions are analyzed to understand deeply the properties of spectra. Mobility of holes and electrons in 2 are studied computationally based on the Marcus theory. The ionization potential and electron affinity of complex 2 are calculated to evaluate qualitatively the hole- and electron-injection properties, respectively. Its potential as a dopant for phosphorescent OLEDs is explored.

Hydrazones 2–22 were synthesized via the reaction of acetophenone with isatin derivatives and anhydrous hydrazine promoted by BF3 as a Lewis acid at 0°C. Structures of the synthesized hydrazones were determined on the basis of NMR and X-ray crystallographic analyses.

Catalytic effect of three nanosized metal oxides TiO₂, Al₂O₃ and Fe₃O₄ nanoparticles in the onepot synthesis of tetrahydrobenzo[a]xanthene-11-ones by three-component reaction of β-naphthol with aromatic aldehydes and dimedone has been studied. Various reaction conditions were tested in the presence of TiO₂, Al₂O₃ and Fe₃O₄ nanoparticles. The results demonstrated that nano Fe₃O₄ was the more efficient heterogeneous catalyst than Al₂O₃ and Fe₃O₄. The reaction completed within shorter period of time under solvent-free conditions with higher yield. The catalysts used were recyclable.

a series of new tetrazole derivatives were synthesized by a reaction of triazole oxime with sodium azide catalyzed by copper acetate and isolated with high yield under mild conditions. All synthesized compounds were characterized by IR, NMR, and MS data. Evaluation of antimicrobial activity of the products against Gram-positive and Gram-negative bacterial and antifungal strains has been carried out. Among the compounds 3a, 3c, 3e, and 3f exhibited high antibacterial activity and compounds 3a, 3c, 3e demonstrated high antifungal activity.

The Biginelli reaction of β-ketoesters with aryl aldehyde and urea or thiourea in the presence of a Keplerate type giant nanoporous isopolyoxomolybdate, (NH₄)₄₂[Mo₇₂^VIMo₆₀^VO₃₇₂(CH₃COO)₃₀(H₂O)₇₂], presented as {Mo₁₃₂}, as an efficient catalyst under solvent free conditions is reported. The catalyst was synthesized according to the earlier published procedure using inexpensive and readily available starting materials. The catalyst could be recovered and reused efficiently in six cycles. Other beneficial features of this new synthetic approach include short reaction time, high yields, clean reaction profiles, and a simple work-up procedure.

A convenient green procedure have been proposed for the synthesis of 6-(2-arylvinyl)-4-hydroxy-3-(phenylsulfanyl)-2H-pyran-2-ones by condensation of 6-(arylvinyl)-4-hydroxy-2H-pyran-2-ones with S-phenyl benzenesulfonothioate in aqueous potassium hydroxide at room temperature.

Vascular endothelial growth factor-2 receptor (VEGFR-2) kinase is a promising target for the development of novel anticancer drugs. Molecular docking modeling was performed on a series of 4-aryl-1,4-dihydropyridines derivatives to evaluate the structural basis for VEGFR-2 inhibitory activity. Some 4-aryl-1,4-dihydropyridines were synthesized in the reaction of aromatic aldehydes and ethyl propiolate with anilines in acetic acid. The biological activities were evaluated against the cells A549, A431 and Hep-G2. The results indicated that 4-aryl-1,4-dihydropyridines could be the promising potential VEGFR-2 inhibitors.

The starting material 4-amino-4H-[1,2,4]triazino[5,6-b]indole-3-thiol 1 was synthesized by refluxing a mixture of isatin and thiocarbohydrazide in glacial acetic acid. Compound 1 reacted with various types of reagents including ammonia, hydrazine hydrate, semicarbazide HCl in various media to give triazino-[5,6-b]indole-3,4-diamine 2, 3-hydrazino-4H-[1,2,4]triazino[5,6-b]indol-4-amine 3 and 3,4-dihydro[1,2,4,5]-tetrazino[6',1':3,4][1,2,4]triazino[5,6-b]indole-2(1H)-one 5, respectively. Reactions of compounds 2 and 3 with ethyl chloroformate in boiling DMF led to 1H-[1,2,4]triazolo[5',1':3,4][1,2,4]triazino[5,6-b]indol-3(4H)-one 4 and compound 5, respectively. Microwave irradiation of compound 1 with maleic anhydride yielded 1-(3-mercapto-4H-[1,2,4]triazino[5,6-b]indol-4-yl)-1H-pyrrole-2,5-dione 6. Reactions of 1 with different aldehydes in EtOH-HCl gave the corresponding Schiff bases. Treatment of substrate 1 with NH₄SCN in glacial AcOH yielded N-(3-mercapto-4H-[1,2,4]triazino[5,6-b]indol-4-yl)thiourea 9 and 1H-[1,2,4]triazolo[5',1':3,4][1,2,4]-triazino[5,6-b]indole-3(2H,4H)-thione 10, respectively. Reaction of substrate 1 with phenyl isothiocyanate in refluxing dioxan gave N-(3-mercapto-4H-[1,2,4]triazino[5,6-b]indol-4-yl)-N'-phenylthiourea 11. Its reaction with ethyl cyanoacetate upon refluxing in EtONa/EtOH afforded ethyl (4-amino-4H-[1,2,4]triazino[5,6-b]-indol-3-yl)(cyano)acetate 12, which upon boiling gave ethyl 2-amino-1H-pyrazolo[5',1':3,4][1,2,4]triazino-[5,6-b]indole-3-carboxylate 13. Structures of new compounds were confirmed by elemental analysis and spectroscopic data (IR, ¹H and¹³C NMR). The newly synthesized compounds were subjected to the biological screening, which demonstrated promising results.

In the present study silica supported tungstic acid (STA) and sulphated silica tungstic acid (SSTA) were applied as efficient and cost-effective solid acid catalysts in the synthesis of N-substituted pyrrole derivatives via the Paal–Knorr reaction of 2,5-hexadione with aromatic and aliphatic amines at room temperature. The reaction completed in short time under mild conditions with high yield. The catalysts could be easily recovered upon reaction completion. Structures of all products were confirmed by elemental analysis, FT-IR, ¹H and ¹³C NMR spectra.