Russian Chemical Bulletin最新文献

New oligoether diamines were synthesized via the step of obtaining oligoether diacrylates, followed by their subsequent reaction with 3-aminomethyl-3,5,5-trimethylcyclohexylamine. A series of urethane-containing elastomers based on them was obtained. The polymers were evaluated by differential scanning calorimetry, and their deformation and strength characteristics were also estimated. It was demonstrated that a low glass transition temperature is characteristic of all the polymers.

The studies of the antioxidant and cryoprotective activities of bicyclic pyrrolidine derivatives containing a 2,6-di-tert-butylphenol fragment in the in vitro experiments showed the greater activity of these compounds compared to ionol. The analysis of the kinetic profile of the reactions of these compounds with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH test) and radical cation of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) showed that the first step consisted in the rapid single electron transfer (SET), which was followed by the hydrogen atom transfer (HAT). The high activity in the reaction of Fe³⁺ reduction (FRAP test) was characteristic of methyl (1S*,3R*,3aS*,6aR*)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-1-methyl-5-(2-nitrophenyl)-4,6-dioxooctahydropyrrolo[3,4-c]-pyrrole-1-carboxylate. The compounds under study were found to be able to terminate chain reactions due to the chelation of metals involved in the Fenton reaction. The compounds also exhibited prolonged antioxidant activity under autoxidation conditions and conditions of oxidative stress promoted by FeCl₂. An increase in the viability of reproductive cells of sturgeon breeds in the presence of the pyrrolidine derivatives indicated the possibility of their use as promising antioxidant protectors during hypothermic storage and under conditions of deep freezing of germ cells of economically valuable fish species.

Two new binuclear tetranitrosyl iron complexes of the composition [Fe₂L₂(NO)₄] (1, L = 4-methoxybenzenemethanethiolyl; 2, L = 4-chlorobenzenemethanethiolyl) were synthesized. Their crystals were characterized by X-ray diffraction, by IR, ESR, UV, and Mössbauer spectroscopies, and by elemental analysis. The NO-donating properties and transformations of the complexes in physiological solutions, including reactions in the presence of bovine serum albumin, were studied. The cytotoxicity of compounds 1 and 2 was studied on normal Vero cells. The effect of the complexes on enzymes was investigated taking guanylate cyclase and adenylate cyclase as examples. The results obtained allow one to recommend compound 2 for further investigations as a potential drug with vaso- and bronchodilator properties.

A new thermally stable chromophore exhibiting the intense blue fluorescence with the high quantum yield of 91%, 4-(4-(9H-carbazol-9-yl)phenyl)-2,6-bis-(4-N,N-diphenyl-aminophenyl)pyridine, was synthesized in a high yield via the three-component reaction of 4-(N,N-dimethylamino)acetophenone, 4-(9H-carbazol-9-yl)benzaldehyde, and ammonium acetate.

An approach was developed for the synthesis of polyfunctionalized pyrimidines based on analogs of 1,2,4-triketones. Acetal-substituted β-diketones are involved in the condensation with amidines in the presence of an excess of (EtO)₃B/Et₃N in acetonitrile. The conditions of the acid hydrolysis of acetal-containing pyrimidines were found to depend on the nature of substituents in diazine. The use of 1,2,4-triketone in the condensation with amidine allows the synthesis of acetylpyrimidine in one step.

When treated with cycloalkylamines (pyrrolidine, piperidine, morpholine, and N-methylpiperazine), polyfluoro-containing benzoic and salicylic acid esters undergo chemoselective nucleophilic aromatic substitution of a fluorine atom in the para position to form 4-(N-cycloalkylamino)-substituted derivatives. The hydrolysis of the latter compounds with alkali in aqueous methanol affords the corresponding acids. Methyl 3,5-difluoro-2-hydroxy-4-(piperidin-1-yl)benzoate exhibits high antibacterial activity against the N. gonorrhoeae strain, which is twice higher than that of the drug spectinomycin. N-Cycloalkyl-substituted polyfluorobenzoic acids do not show analgesic activity. The effect of the esters is comparable with the activity of the drug diclofenac. The studied compounds have a lower acute toxicity compared to the reference drug.

The reaction of styrene with butyrolactones in the presence of 2 equiv. each of AlCl₃ and Mg and catalyzed by 10 mol.% of Cp₂ZrCl₂ in tetrahydrofuran led to the corresponding 1-phenyl-4-oxaspiro[2.4]heptanes in 47–57% yield. Presumably, the intermediates are zirconacyclopropane derivatives, similar to the Kulinkovich reagents.

The reactions of 1-alkynylphosphines with Et₂Zn in the presence of catalytic amounts of Cp₂ZrCl₂ and EtMgBr proceed regio- and stereoselectively to afford (1Z)-alkenylphosphines. The oxidation and sulfonation of synthesized 1-alkenylphosphines with an aqueous solution of hydrogen peroxide or elemental sulfur give (1Z)-alkenylphosphine oxides and (1Z)-alkenylphosphine sulfides, respectively. A plausible scheme for the Zr—Mg-catalyzed 2-zincoethylzincation of 1-alkynylphosphines was proposed.

Using palladium-catalyzed arylation of (S)-2,2′-diamino-1,1′-binaphthalene (BINAM) with the halogen derivatives of naphthalene, anthracene, and anthraquinone, the corresponding N,N′-diaryl derivatives were synthesized. The dependence of the yields of the compounds on the structure of the initial halogen derivatives was shown. The synthesized compounds were studied in fluorescent enantioselective detection of amino alcohols. The synthesized derivatives demonstrate a response in the case of complex formation with some amino alcohols, but the response is most pronounced for the derivative with anthraquinone substituents. This detector can recognize enantiomers of leucinol, 2-phenylglycinol, and prolinol by different changes in the fluorescence enhancement in the presence of opposite optical isomers. In the case of 2-amino-1-propanol, fluorescence enhancement is observed only in the presence of the (S)-isomer.