M. G. Pervova

Reactions of epoxides derived from internal perfluoroolefins with o-phenylenediamine and 2-aminophenol

The reactions of epoxy derivatives of internal perfluoroolefins with o-phenylenediamine and 2-aminophenol in dioxane gave 23–67% of the corresponding 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-2H-1,4-benzoxazin-2-ols, respectively. When N,N-dimethylacetamide was used as a solvent, the main reaction pathway was anionic isomerization of epoxides into ketones which were then converted into 2-perfluoroalkylbenzimidazoles (in the reactions with o-phenylenediamine) or 2-hydroxy-N-perfluoroalkanoylanilines (in the reactions with 2-aminophenol). The reaction of 3,4-epoxydodecafluorohexane with 2-aminophenol in N,N-dimethylacetamide was accompanied by unusual cyclization to afford 2-pentafluoropropanoyl-2-pentafluoroethyl-1,3-benzoxazolidine.

Reactivity Features of Polychlorobiphenyl Congeners in the Nucleophilic Substitution Reactions

Groups of congeners and individual congeners of polychlorobiphenyls contributing to the composition of the technical mixture “Sovol” (PCB 60, PCB 64, PCB 70, PCB 74, PCB 97, PCB 101, PCB 105, PCB 110, PCB 118, PCB 138, PCB 149, PCB 156, and PCB 163) were synthesized by the reaction of aryl-aryl coupling. The interaction of the congeners with sodium methoxide was performed and their complete conversion was proved. By means of gas chromatography-mass spectrometry the PCBs methoxy derivatives were identified. The data on the reactivity of the individual polychlorobiphenyl congeners were precised.

Determination of 1,2,3-benzotriazole in aqueous solutions and air by reaction-gas-liquid chromatography

A procedure is developed for the gas-chromatographic determination of 1,2,3-benzotriazole including preliminary derivatization with acetic anhydride in an aqueous solution followed by the extraction the derivative with toluene. The procedure is applied to the analysis of water samples, process solutions for treating metals, air of the working zone, and industrial emissions. Determination limits in water media are 0.01 mg/L and in the air of the working zone, 0.1 mg/m3.

Pyrolysis of polystyrene in coal tar and ethylene tar pitches

Pyrolysis of polystyrene in the medium of coal tar pitch and of pitch prepared from ethylene production tar was performed in the temperature range 360–420°C at atmospheric pressure.

Structure and characteristics of chitosan cobalt-containing hybrid systems, the catalysts of olefine oxidation

Cobalt-containing hybrid organo-inorganic materials based on the chitosan-SiO2, chitosan-Al2O3, and chitosan-cellulose systems were obtained. The surface structure and processes that occur during the formation of metal-containing materials, the catalytic properties of which were studied in the oxidation reactions of alkene, were investigated by EPR spectroscopy using a stable pH-sensitive nitroxyl radical, 4-dimethylamino-2-ethyl-5,5-dimethyl-2-(pyridin-4-yl)-2,5-dihydro-1H-imidazole-1-oxyl, as the adsorbed probe molecules.

Synthesis and biological evaluation of novel 5-aryl-4-(5-nitrofuran-2-yl)-pyrimidines as potential anti-bacterial agents

A facile two-step synthetic approach to fluorinated and non-fluorinated 5-aryl-4-(5-nitrofuran-2-yl)-pyrimidines from readily available 5-bromo-4-(furan-2-yl)pyrimidine has been developed. All synthesized compounds were screened in vitro for their antibacterial activities against twelve various bacterial strains. It is demonstrated that some of these compounds exhibited significant antibacterial activities against strains Neisseria gonorrhoeae and Staphylococcus aureus, comparable and even higher with that commercial drug Spectinomycin.

Synthesis of 5-(het)aryl- and 4,5-di(het)aryl-2-(thio)morpholinopyrimidines from 2-chloropyrimidine via SNH and cross-coupling reactions

It has been shown that various combinations of nucleophilic aromatic substitution of hydrogen (SNH), SNipso and the microwave-assisted Suzuki cross-coupling reactions are a versatile method for the synthesis of 5-(het)aryl-2-(thio)morpholinopyrimidine and 4,5-di(het)aryl-2-(thio)morpholinopyrimidine derivatives. All synthesized pyrimidines were found to be active in micromolar concentrations in vitro against Mycobacterium tuberculosis H37Rv.

An interdisciplinary approach to the problem of neutralization of man-made polychlorinated biphenyls

19 Currently, biological methods of degradation of manmade polychlorinated biphenyls (PCBs) are becoming increasingly important in connection with the selection of new efficient PCB degrading strains. The most successful studies in the field of biodegrada tion of PCBs are associated with the use of low chlo rinated PCB congeners [1, 2]. It has been found that the biodegradability of PCB congeners increases with decreasing number of chlorine atoms in the initial sub strates. At the same time, interest persists in the search for surfactants capable of transferring more hydropho bic medium and high chlorinated PCB congeners into an aqueous medium in order to create stable emulsions available for efficient operation of bacterial strains [3, 4].

New synthesis of Dialkyl carbonates from alkylene carbonates and titanium alkoxides

Dialkyl carbonates are used in industry as organic solvents, fuel additives, lubricants in refrigerating units, and heat carriers. A conventional procedure for the preparation of dialkyl carbonates is based on the reaction of alcohols with phosgene which is very toxic. Phosgene-free syntheses of organic carbonates are extensively developed; they include oxidative carbonylation of alcohols [1, 2], reactions of alcohols with urea [3, 4], reactions of oxiranes with carbon dioxide [5, 6], and reactions of inorganic carbonates with alkyl halides [5] or alcohols [7, 8]. Also, mutual transformations of alkyl carbonates are possible. We now propose a new phosgene-free synthesis of dialkyl carbonates via reaction of alkylene carbonates with titanium alkoxides. An advantage of the proposed procedure is that it ensures simultaneous preparation of two important products, dialkyl carbonate and alkyl titanate derivative [dialkyl alkanediyl titanate or bis(alkanediyl) titanate]. The latter can be used as curing agent for epoxy resins or as precursor for the synthesis of nanosized titanium dioxide. The titanium-containing residue can be decomposed by treatment with dilute sulfuric acid to regenerate the diol. The reactions were carried out with a number of alkyl titanates and alkylene carbonates. A mixture of 45.62 g (0.2 mol) of tetraethyl titanate and 40.8 g (0.4 mol) of propylene carbonate was slowly heated and distilled through a column, and a fraction boiling in the range from 120 to 130°C was collected. Yield of diethyl carbonate 40.59 g (86%), nD = 1.384 (published data [9]: nD = 1.384). Found, %: C 50.84; H 8.45. Calculated, %: C 50.85; H 8.47.

A new application of derivatives of polychlorobiphenyls and polyethylene glycols

The reaction of congeners of Sovol technical mixture of polychlorobiphenyls with polyethylene glycols was studied. Mixtures of hydroxy and mono(polyethylene glycol)oxy derivatives were obtained. The mixtures synthesized, which are of low hazard, were used as additives to industrial oil to improve its tribological characteristics.