卷 87, 编号 2 (2017)

A solid product formed during thermolysis of tetraammineplatinum(II) chloride and ammonium heptamolybdate in an aqueous alkaline solution under autoclaving conditions has been studied by means of dynamic light scattering, scanning electron microscopy, X-ray diffraction analysis, and elemental analysis. The amount of free ammonia formed in the reaction has been determined by titration. The pathway of platinum(II) and heptamolybdate ions reduction by inner-sphere ammonium into the corresponding metals has been proposed.

Magnetic susceptibility and ESR properties of iron-containing Bi₂BaNb_2–2xFe_2xO_9–δ solid solutions with layered perovskite-like structure have been studied. In the diluted solid solutions, iron atoms are combined into Fe(III) dimers and tetramers with antiferro- and ferromagnetic exchange types. The exchange parameters and the distribution of aggregates in the solid solutions have been calculated as functions of the paramagnetic atoms fractions.

A method for the synthesis of TiO₂–B₂O₃–Ag composite has been proposed. The composite structure and phase composition have been determined by X-ray diffraction analysis, IR spectroscopy, and scanning as well as transmission electron microscopy. The introduction of boron oxide in the TiO₂–Ag composite enhances catalytic activity of the samples in the reactions of methyl orange photodecomposition.

Acid-base properties of 4-hydroxystyryl dyes in aqueous solution have been studied by means of chemical tristimulus colorimetry and spectrophotometry. Ionization and hydroxylation constants of the dyes have been determined using chromaticity functions of specific and CIE color difference. It has been shown that aggregation processes in the solution of 4-hydroxystyryl dyes can be observed by means of tristimulus colorimetry. A scheme of acid-base transformations of the studied dyes in the solution has been suggested, and selected spectrophotometric parameters of the equilibrium ionic and molecular forms have been determined.

Epoxidation of tetracyclododecene bridged hydrocarbons prepared via the [4+2]-condensation of bicyclo[2.2.1]hept-2-ene and its alkyl derivatives with cyclopentadiene in the presence of Н-form of synthetic mordenite has been studied. Phosphorus-molybdenum and phosphorus-tungsten heteropoly compounds doped with Co³⁺, Gd³⁺, Nd³⁺, Ce(4–x)+ (x = 0, 1) cations as well these compounds deposited on highly disperse carbon material have exhibited high activity in epoxidation of the synthesized hydrocarbons under the action of the H₂O₂·CO(NH₂)₂ adduct. Structures of the new bridged polycyclic epoxides have been elucidated by IR as well as ¹Н and ¹³С NMR spectroscopy.

The application of bis-(4-nitrophenyl)phosphorylazide–1,8-diazabicyclo[5.4.0]undec-7-ene system for direct transformation of polyfunctional derivatives of pyrimidin-4(3H)-one in the corresponding 4-azidopyrimidines has been suggested for the first time. Using this system, novel 4-azido-6-(2,6-dihalo-α-methoxybenzyl)-5-methyl-2-(nitroamino)pyrimidines have been obtained in good yield under mild conditions.

Alkylation of 4-(phenylthio)-1H-pyrazol-5-ols with methyl bromoacetate has afforded a series of phenyl pyrazolyl sulfides which have been oxidized into sulfones. The resulting esters have been hydrolyzed into the corresponding acids. The synthesized compounds potentially exhibit biological activity.

Reactions of 1-acylamino-2,2-dichloroacrylonitriles, diethyl 1-acylamino-2,2,2-trichloroethyl-phosphonates and 1-acylamino-2,2-dichloroethenylphosphonium salts with natural alkaloid cytisine have been studied. A series of novel multifunctional cytisine derivatives containing pharmacophore 1,3-oxazole moiety have been obtained. Composition and structure of the synthesized compounds have been confirmed by mass spectrometry and NMR spectroscopy data.

Transformations of the derivatives of 2-substituted 5-(1,2,3-thiadiazol-4-yl)-3-furoic acid under the action of bases has been studied. In the presence of potassium tert-butylate in THF, the studied compounds decompose with the cleavage of the thiadiazole ring, liberation of nitrogen, and formation of labile acetylene thiolates. In the presence of methyl iodide, these salts form stable 2-methylthioethynylfurans. Under the action of sodium ethylate in ethanol, thiadiazole ring of ethyl [2-methyl-5-(1,2,3-thiadiazol-4-yl)]-3-furoate is split to form the corresponding sodium acetylene thiolate. Under the action of ethanol, two molecules of this salt give bis(furyl)dithiafulvene. In the DMF–potassium carbonate system, acetylene thiolates react with primary and secondary amines giving thioamides of (4-ethoxycarbonyl-5-methylfur-2-yl)acetic acid. Treating of ethyl 2-methyland 2-N-morpholinomethyl-5-(1,2,3-thiadiazol-4-yl)-3-furoates with hydrazine hydrate leads to hydrazinolysis of the ester group and cleavage of thiadiazole ring resulting in the formation of hydrazides of 4-hydrazinocarbonylfur-2-ylacetic acid. In the case of ethyl 2-acetoxymethyl- and 2-(4-nitrophenoxy)methyl-5-(1,2,3-thiadiazol-4-yl)-3-furoates, thiadiazole ring is retained and exclusively hydrazinolysis of the ester groups is observed.

4-Acyloxy-4-(cyclopropylethynyl)-1-(2-ethoxyethyl)piperidines have been synthesized by reaction of 1-(2-ethoxyethyl)piperidin-4-one with cyclopropylacetylene and subsequent acylation of intermediate 4-(cyclopropylethynyl)piperidin-4-ol. The resulting esters react with β-cyclodextrin to give supramolecular inclusion complexes. The complexation is accompanied by inclusion of the N-ethoxyethyl fragment of one substrate molecule in the inner cavity of one receptor molecule. The structure of 4-acyloxy-4-(cyclopropylethynyl-1-(2-ethoxyethyl)piperidines and their inclusion complexes with cyclodextrin has been studied by NMR spectroscopy.

The interaction of copper(II) and mercury(II) nitrates with triaryl- and diarylalkylarsine oxides has been studied. The reactions in aqueous-alcoholic solution have yielded [M(OAsPh₃)₄](NO₃)₂ and [M(OAsRAr₂)₄](NO₃)₂ cationic complexes [М = Cu(II) or Hg(II), Ar = Ph, 3-МеC₆H₄, or 4-МеC₆H₄, R = Et, Pr, i-Pr, Bu, or i-Bu]. Composition and structure of the products have been elucidated by a set of chemical and physico-chemical methods. IR spectroscopy data have revealed that the bond between the ligand and the metal ion is formed via the oxygen atom of arsenyl group.

Spectral (¹H NMR and IR), optical, and voltammetry parameters of Pd(II), Pt(II), Rh(III), and Ir(III) complexes with ethylenediamine and metallated azole luminophors [2-phenylbenzoxazole, 2-phenylbenzothiazole, 2,5-diphenyloxazole, 2-(1,1'-biphenyl)-4-yl]-5-phenyloxazole, and 2-(naphthalene-l-yl)benzothiazole] have been studied. The variation in spectroscopic parameters of the complexes is related to the increase in the efficiency of donor-acceptor interaction of Pt(II) and Ir(III) with the ligands as compared to Pd(II) and Rh(III). The correlation between the energy of the metal-ligand charge transfer bands and the difference between the single-electron oxidation and reduction potentials of the complexes is observed. Quenching of the fluorescence of metallated azoles and phosphorescence of the complexes in the visible region from the metal-modified intraligand excited state are related with the increase in the efficiency of the singlettriplet conversion due to the spin-orbital interaction in platinum metals.

A series of substituted androstanopyridine derivatives 2–5 were synthesized using 17-acetyl- 1,7,8,10,11,12,13,15,16,17-decahydro-10,13-dimethyl-2H-cyclopenta[a]-phenanthren-3(6H,9H,14H)-one (progesterone, 1) as a starting material. Reaction of 1a–1d with malononitrile and aldehydes in the presence of ammonium acetate gave the corresponding amino cyanopyridine derivatives 2a–2d. The same compounds 1a–1d reacted with cyanoacetamide and aldehydes in the presence of ammonium acetate to give a mixture of 3a–3d and 4a–4d, that was separated chromatographically. The reaction of compounds 1a–1d with ethyl cyanoacetate and aldehydes led to products 5a–5d. Structures of the newly synthesized compounds were elucidated by physical and spectral methods. The synthesized compounds were tested as 5α-reductase inhibitors and anti-prostate cancer agents.

5-[(1H-Indol-3-yl)methylene]thiazolidine-2,4-dione–[1,2,3]triazole hybrid derivatives were synthesized by click chemistry reaction and screened for antimicrobial activity against Gram positive and Gram negative bacteria and fungal species. All synthesized compounds were characterized by ¹H and ¹³C NMR, IR and MS spectra. Antibacterial study indicated that several products demonstrated high activity and some products were determined to be potentially antifungal active agents.

Synthesis of novel (3-phenylisoxazol-5-yl)methyl-2H-chromene-3-carboxylates (7a–7d) and (3-phenyl-4,5-dihydroisoxazol-5-yl)methyl-2H-chromene-3-carboxylates (8a–8p) by 1,3-dipolar cycloaddition, and nitrile oxide and alkyne cycloaddition (NOAC) is presented. The products are characterised by IR, ¹H and ¹³C NMR, and ESI-MS data.

A procedure for the synthesis of composite nanocoating TiO₂/calcium phosphate structures on the titanium surface promising for biomedical application (bone implantation) has been proposed.

Electrophilic tropylation of 2-aminopyridine afforded N-(cyclohepta-2,4,6-trien-1-yl)pyridin-2-amine. The product was tested for antibacterial activity against Staphylococcus aureus no. 906 and Candida albicans ATSS 24 433.

General strategy for the synthesis of organoboron compounds containing bis(trimethylsilyl)amide substituents has been suggested.

Convenient methods for the synthesis of functionalized phosphonic acids containing piperidine moieties via the reaction of tris(trimethylsilyl) phosphite with N-substituted 4-piperidone derivatives have been developed.