Vol 86, No 7 (2016)

Solubility in the systems CdX₂–H₂O–Solv (X = Br, I; Solv = dimethyl sulfoxide, N,N-dimethyl acetamide, N,N-dimethyl formamide, and 1,4-dioxane) at 25°C was measured by the isothermal saturation method. A relation between the shape of the solubility isotherm and the structure of the binary solvent depending on its composition was found. Positions of solubility maxima and isotherms inflection points in the most cases correlate with destruction of intermolecular associates formed by solvent components.

The solid solutions La_1–YYb_yAlO₃ (y = 0.01–0.20) and La_1–0.397xYb_0.067xCa_0.33xMn_xAl_1–xO₃ (x = 0.01–0.10) were studied by magnetic dilution method. The state of paramagnetic elements and the character of exchange interactions between them were determined on the basis of examination of magnetic properties. Clustering of manganese atoms in the La_1–0.397xYb_0.067xCa_0.33xMn_xAl_1–xO₃ solid solution, as distinct from the La_1–0.67xCa_0.33xMn_xAl_1–xO₃ solid solutions studied before, is determined by the presence of ytterbium atoms in the perovskite structure of the complex oxides under study.

Study of aluminum powder alkylation with ethyl bromide in the presence of ethylaluminum sesquibromide and copper(I) iodide has revealed that binary systems based on an organometallic compound and a transition metal compound are efficient promotors of direct synthesis of organoaluminum compounds as well. Major conclusions drawn in a series of studies on non-transition metals (Zn, Cd, and Al) alkylation with organic halides in the presence of the binary systems are summarized.

Regardless of pH and a solvent nature the reactions of (E)-1-(β-aroylvinyl)pyridinium bromides with hydrazine led to the formation of pyrazole derivatives. The salts reacted with thiourea via intermediate formation of 4-arylpyrimidine-2-thiol to give (Z)-2-[(β-aroylvinyl)sulfanyl]-4-arylpyrimidines. In the case of N,N'-diphenylthiourea the reaction provided 6-aryl-3-aroyl-1-phenylpyridinium bromides. Pyridine hydrobromide liberated in the reaction course has a major influence on the process chemoselectivity.

Reactions of derivatives of diethyl 1-acylamino-2,2,2-trichloroethylphosphonates with different pharmacophore aminoalkanols afforded new 5-hydroxyalkylamino-1,3-oxazole derivatives. The latter are promising substrates for producing new 4-phosphorylated peptidomimetics containing alcohol residues.

The reaction of 6-methyl-2-(2-oxo-2-phenylethylidene)-2,3-dihydropyrimidine-4(1H)-one with arylhydrazines leads in high yields to the corresponding hydrazones, in which the ethylidene fragment of the starting compound is transformed to the ethylene fragment. By oxidation of the hydrazones with hydrogen peroxide or selenium dioxide the corresponding 6-methyl-2-[2-phenyl-2-(arylhydrazono)acetyl]-3H-pyrimidine-4-ones were synthesized.

2-, 4-, 6-, 7-, and 8-substituted quinolines were synthesized in 78–95% yield by the reaction of 1,3- butanediol with anilines in the presence of iron catalysts in carbon tetrachloride.

A series of 3-(furyl)-3-(diethoxyphosphoryl)acrylates was synthesized by the reaction of 2- and 3-furoyl phosphonates with ethoxycarbonylmethylenetriphenylphosphorane. It was shown that in all cases diethoxyphosphoryl and ester groups were in trans-position with respect to the double bond disregarding the structure of the furan fragment. Potassium fluoride catalyzed addition of nitromethane to the compounds synthesized was studied. It was found that this reaction proceeded regioselectively to form 2-[(furyl)(diethoxyphosphoryl) methyl]-3-nitropropanoic acids.

Smectic phase of formyl derivatives of azobenzene has been identified by means of polarization thermomicroscopy using a miscibility criterion. The study of dielectric properties and simulation of dipole moments and Kirkwood correlation factors have revealed that azobenzene and biphenyl derivatives containing hydroxy end group in the aliphatic terminal substituent can form supramolecules and linear associates stabilized by hydrogen bonds. The sorbents based on the studied liquid crystals have exhibited high structural selectivity with respect to isomers of various organic compounds. Thermodynamic manifestations of the specific mesogen–non-mesomorphic sorbate interactions have been revealed.

[FeLX₂]Y [L = N,N'-ethylenebis(salicylimine) (salen), N,N'-ethylenebis(acetylacetonylimine) (acen), or N,N'-ethylenebis(3-methyloxysalicylimine) (vanen); X = imidazole or N-methylimidazole; Y = BF₄, ClO₄, or BPh₄] compounds have been prepared and studied by means of EPR and magnetic susceptibility measurements at 5–300 K. It has been shown that the different electron-donating properties of acen and salen planar ligands result in different spin states of Fe(III) ions. Intermolecular π-interactions of the outer-sphere BPh₄ ion affect the complexes spin state as well.

Prototropic processes in the molecules of azomethine imines with 2-pyrrolylmethylidene fragment were studied by the density functional theory (DFT) method and the most stable by energy isomers with the intramolecular hydrogen bond between the nitrogen atoms of the pyrrole and the pyrazole rings were found. The energy barriers of the reactions of intramolecular proton transfer were estimated. Based on quantum chemical calculations of the molecular structure of azomethine imine bis-chelates ML₂ [M = Ni(II), Zn(II), Cd(II)] with the coordination unit MN₂N₂ the most stable configurations of the complexes were determined.

Spectral (proton magnetic resonance and electronic absorption) parameters of the series of pyro-, meso-, and chlorin derivatives of methylpheophorbide a and kinetics of their complex formation with copper(II) nitrate in organic media have been studied.

Structure, electric and adsorption properties of carbon open-end nanotubes of (6,6) chirality consisting of 5–19 segments were studied by quantum-chemical methods AM1, PM3, LSDA/3-21G, B3LYP/6-31G. The size effects and adsorption properties of nanotubes are discussed.

A novel, magnetically recoverable carbonaceous solid acid Fe₃O₄@C-SO₃H catalyst for the conversion of carbohydrates to 5-ethoxymethylfurfural (EMF) was developed. The effect of the DMSO fraction in the ethanol-DMSO binary solvent on the distribution of the reaction products was investigated. The catalyst showed an excellent activity in the synthesis of EMF from fructose and 5-hydroxymethylfurfural (HMF). 5- Ethoxymethylfurfural was also obtained with a high yield of 64.2% in an ethanol–DMSO solvent system via one-step conversion of fructose. After reaction, the catalyst could be recovered by exposure of the reaction mixture to external magnetic field and reused several times without a loss of catalytic activity.

A series of novel {5-[4-hydroxy-3-(4-phenyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-2-yl)benzyl]- benzofuran-2-yl}(phenyl)methanones (5a–5g) were prepared by the condensation of (E)-3-{5-[(2- benzoylbenzofuran-5-yl)methyl]-2-hydroxyphenyl}-1-phenylprop-2-en-1-one (chalcone) (4a) with various substituted o-phenylene diamines in the presence of oxalic acid as catalyst. The structures of all compounds were characterized by FTIR, ¹H NMR, ¹³C NMR, and MS. The representative examples were screened in vitro for antimicrobial activity. Among all compounds 4g and 5g showed potent antibacterial activity, 4b and 5g showed good antifungal activity. The data was further compared with structure based investigations using docking studies with the crystal structure of adenosine-5'-(β,γ-imido)triphosphate (2ONJ) from Staphylococcus aureus for antibacterial activity and trypsin (1FY5) protein from Fusarium oxysporum for the antifungal activity. The score values estimated by genetic algorithm were found to have a good correlation with the experimental inhibitory potencies.

Novel 6-phenyl-6H-chromeno[4,3-b]quinoline derivatives have been prepared by reaction of 4-chloro-2-phenyl-2H-chromene-3-carbaldehyde with various aromatic amines using 5 mol % of Sc(OTf)3 in acetonitile. This is the first example of one-pot synthesis of 6-phenyl-6H-chromeno[4,3-b]quinoline from 4-chloro-2-phenyl-2H-chromene-3-carbaldehyde at ambient temperature. Preliminary evaluation of cytotoxic activity of these chromeno[4,3-b]quinoline derivatives has been carried out. Some products exhibited anti cancer activity against two carcinoma cell lines A549 and B-16.

Cyclocondensation reaction of 3-hydrazinyl-2-naphthoic acid with diphenyl-N-cyanoimidocarbonate furnished the target 2-phenoxy-benzo[g][1,2,4]triazolo[1,5-a]quinazolin-5(4H)-one (1) in high yield. Alkylation, thionation and chlorination of the lactam group in the compound 1 produced a variety of derivatives 2–17. Their structures were characterized by NMR and HREI-MS analyses.

Aurones, pyrazole and thiophene scaffolds are known for their potential antimicrobial activity. Herein, we have synthesized hybrid compounds containing three substituted (Z)-2-{[1-phenyl-3-(thiophen-2-yl)- 1H-pyrazol-4-yl]methylene}benzofuran-3(2H)-ones that had been produced from substituted (E)-1-(2-hydroxyphenyl)- 3-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]prop-2-en-1-ones in high yields. All synthesized compounds were tested in vitro for their antimicrobial activity. Several of those demonstrated promising activity against some fungal and bacterial strains.