Vol 88, No 10 (2018)

Nickel nanoparticles on the BAU-A active carbon or NaX zeolite catalyze hydrogenation of imines and enamines in a flow reactor in a gas phase or in a gas–liquid–solid catalyst system. The process occurs at atmospheric pressure of hydrogen and gives secondary or tertiary amines in a high yield.

The kinetics of dehydrochlorination of 1,1,1-trichloro-2,2-bis(4-nitrophenyl)ethane with sodium nitrite in dipolar aprotic solvents have been studied. Quantum chemical simulation of the process has been performed, and its thermodynamic parameters have been determined. The effects of dissociation and solvation on the rate constant have been considered. The reaction mechanism has been identified as E2H.

The regioselectivity of electrochemical reduction of four trichlorobiphenyls (PCB 28–30 and PCB 37) was studied by cyclic voltammetry and bulk electrolysis. The number of stages and mechanism of electrochemical reduction of each of the examined substrate were inferred on the basis of the experimental electron transfer coefficients and calculated (DFT) bond lengths and potential energy surface sections. GC/MS analysis of the controlled potential electrolysis products showed that chlorine atom in the disubstituted ring of trichlorobiphenyls is reduced more readily than in the monosubstituted ring and that the rate of chlorine reduction changes in the series o-Cl > p-Cl > m-Cl.

By chloromethylation of diethyl 2- and 3-furylmethanephosphonates 5-chloromethylfur-2(3)-ylmethanephosphonates were synthesized. The other four isomers of chloromethyl derivatives of furylmethanephosphonates were prepared by substitution of hydroxy groups in the corresponding phosphorylated furylmethanols via the reaction with thionyl chloride in the presence of pyridine. Thermal stability of these chlorides was sufficiently high, and they were involved in nucleophilic substitution of chlorine with azido group by treating with sodium azide in boiling acetonitrile in the presence of potassium iodide. No decomposition of substrates was observed. The azides obtained were reduced to amines with triphenylphosphine in ethanol.

The methods of synthesis of bifunctional (iodomethyl)fluorosilanes of general formula ICH₂SiMe_nF_3–n (n = 0, 2) have been elaborated; the structure was proved by ¹H, ¹³C, ²⁹Si NMR spectroscopy. The reaction of (iodomethyl)dimethylfluorosilane with O-trimethylsilyl derivative of N,N'-dimethylhydrazide of trifluoroacetic acid gives rise to the formation of 2,2,4,4-tetramethyl-6-(trifluoromethyl)-3,4-dihydro-2Н-1,4,5,2-oxadiasilin-4-ium iodide with tetracoordinate silicone atom.

Fluorescence and photostability against the action of UV irradiation of different porphyrins in benzene, DMF, and acetic acid media have been studied. The effect of the macroheterocycle structure on the conditions of its thermal decomposition under inert atmosphere has been investigated.

The coordination of zinc(II) tetraphenylporphine with pyridines was studied by electronic spectroscopy. Linear correlations were found between the thermodynamic and kinetic parameters of coordination in different solvents. The effect of the solvent on the stability constants of the complexes and the thermodynamics of complex formation are discussed.

The reaction of 5-(trifluoromethyl)-1,3,4-thiadiazol-2-amine with cis-dichlorobis(2,6-dimethylphenyl isocyanide)platinum(II) (cis-[PtCl₂(CNXyl)₂], Xyl = 2,6-Me₂C₆H₃) gave platinum(II) monocarbene complex whose deprotonation with an organic base generated a nucleophilic species capable of reacting with palladium(II) and platinum(II) bis(isocyanide) complexes to afford homo- and heteronuclear isocyanide/carbene structures.

Nd_1–xBi_xFeO₃ nanocrystals with crystallite size 30‒60 nm have been prepared under conditions of glycine–nitrate burning. Single-phase Nd_1–xBi_xFeO₃ nanocrystals are formed over the entire studied concentrations range if the glycine–nitrate synthesis is performed in excess of the oxidizer. Under these conditions, a continuous range of the Nd_1–xBi_xFeO₃ solid solutions (0 ≤ х ≤ 0.75) crystallized in the rhombic system (space group Pbnm) are formed without crystallization of the burning intermediates. The Nd_1–xBi_xFeO₃ solid solutions (х = 0.775, 0.8) crystallize in the rhombic system (space group Pbаm).

Synthesis of amphiphilic oligomers of acrylic acid via radical polymerization in the presence of thiols as molecular mass regulators is described. The effect of the length of the introduced hydrophobic terminal group on the critical micellization concentration of the acrylic acid oligomers has been elucidated. It has been shown that the incorporation of an antituberculous drug (prothionamide) in the micelles of acrylic acid oligomers is enhanced with the increase in the length of the hydrophobic moiety. The preparation of hydroxyapatite-filled calcium-polycarboxylate bone cements containing prothionamide (promising for the sealing of postoperative cavities) is described.

A series of novel 2-{[1-(arenesulfonyl)-1H-indol-3-yl]-4-oxo-1,3-thiazolidin-3-yl}pyridine-4-carboxamide derivatives was designed and calculate for their computational properties like physicochemical parameters and bioactivity score. Bioactive compounds 1–8, were then synthesized, Characterized by various spercoscopic techniques and assessed for antibacterial activity against S. aureus, S. epidermidis, P. mirabilis, and E. coli. The percent viability of the cells was carried out by MTT assay using HepG2 cells. The results for antibacterial activity were observed in strong recommendation with the computation results. The synthesized compounds were found to portray better activity and lower cytotoxicity when compared to the standard drug Ciprofloxacin.

Herein, three newly synthesized theophylline (TPE) complexes with transition metal ions (Sc³⁺, Nb⁵⁺ and W⁶⁺) are characterized by FT-IR and UV-Vis spectra, magnetic and thermogravimetric analysis, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmittance electron microscopy (TEM). FT-IR spectra confirm that the metal ions coordinate to TPE chelate as a mono-dentate ligand via nitrogen atom N⁷ of the deprotonated NH group. Theophylline complexes are formed in 1 : 2 (metal: ligand) stoichiometry. According to TGA curves the complexes do not contain crystallization water outside the binding spheres. The accumulated data indicate the octahedral geometry for Sc(III) and W(VI) complexes. The Nb(V) complex is four coordinated. Sc(III) And W(VI) complexes in DMSO demonstrate non-electrolytic nature, and Nb(V) complex acts as an electrolyte. The TPE complexes are tested in vitro against bacteria (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans). The complexes exhibit high antimicrobial activity. The in vitro anticancer activity of Sc(III) complex is screened against the human hepato cellular carcinoma (HepG-2) tumor cell line.

A novel series of tetrazole fused benzoxazole derivatives 9a–9j are synthesized, and their structures are characterized by ¹H and ¹³C NMR, and mass spectra. The compounds 9a, 9b, 9g, 9h, and 9j demonstrate the highest activity. The compounds 9b and 9g exhibit good anticancer activity, in particular against MCF7, Hop62, and A-549 cell lines with the range of GI₅₀ values from <0.1 to 4.56 μM. Molecular docking study is carried out for the compounds 9a–9j, according to which the compound 9b forms one hydrogen bond with THR766 with the highest docking score (–7.33). This indicates that 9b is effeciently binging to tubulin site.

Stereoselective synthesis of (E)- and (Z)-alk-5-en-7-in-2-ones was performed by cross-coupling of alkynes with 6-chlorohex-5-en-2-one stereoisomers in the presence of PdCl₂(PrCN)₂ complex and CuI in piperidine.

New Mannich bases were synthesized by reacting bicyclo[2.2.1]hept-5-en-2-ylmethanol with secondary amines and formaldehyde. Physicochemical characteristics, composition and structure of the synthesized compounds were determined by elemental analysis, IR, ¹H, ¹³C NMR spectroscopy and mass spectrometry.

Synthesis of 5-aryl-2,2'-bipyridines with electron-donor substituents at the C⁶ position by reacting 5-substituted 6-aryl-3-(2-pyridyl)-1,2,4-triazines with 2,5-norbornadiene under high pressure conditions was performed.

2-(2,6-Difluorophenyl)-5-phenyl(2-hydroxyphenyl)-1,3,4-oxadiazoles were synthesized by cyclization of N-(2,6-difluorobenzoil) derivatives of benzohydazide or salicylhydrazide in thionyl chloride. When acylating 2-[5-(2,6-difluorophenyl)-1,3,4-oxadiazole-2-yl]phenol by acetyl or benzoyl chloride corresponding acetate and benzoate were obtained. Spectral-luminescent properties of the synthesized compounds were studied.

Physiologically and pharmacologically active het(aryl)chalcogenylacetates of tris(2-hydroxyethyl)ammonium of pharmacopeial purity have been synthesized by the reaction of het(aryl)chalcogenylacetic acids with sodium (potassium) hydroxide and triethanolamine hydrochloride by one-pot method in quantitative yield (up to 99.8%).

A mild and effective method for the synthesis of new tetraarylphosphonium zwitterions and salts containing methoxy and hydroxy groups in aryl substituents at the phosphorus atom was developed. The structure of phosphorus-containing betaines and phosphonium salts was obtained by NMR spectroscopy.

Vanadium dioxide nanoparticles were obtained by the hydrothermal synthesis method in the presence of soluble Mo and W compounds as nucleating agents and of potassium and sodium chlorides as growth limiters. The influence of modifiers nature and synthesis conditions on the phase composition of the resulting product was studied.