Showing papers in "Russian Chemical Bulletin in 1963"
TL;DR: In this article, a method was developed for the synthesis of 4-substituted 2,6-di-t-butylphenols by the reduction of the corresponding quinols with lithium aluminum hydride.
Abstract: 1.
A method was developed for the synthesis of 4-substituted 2,6-di-t-butylphenols by the reduction of the corresponding quinols with lithium aluminum hydride.
2.
Some new inhibitors of free-radical reactions were prepared, and some of their properties were studied.
43 citations
21 citations
19 citations
TL;DR: In the presence of BF3, benzylideneaniline reacts with ethoxyacetylene, ketene, and vinyl ethyl sulfide according to the mechanism of the diene synthesis with the formation of quinoline derivatives as discussed by the authors.
Abstract: Benzylideneaniline in the presence of BF3 reacts with ethoxyacetylene, ketene, and vinyl ethyl sulfide according to the mechanism of the diene synthesis with the formation of quinoline derivatives.
16 citations
TL;DR: In this article, it was shown that the electron-withdrawing effect of two trifluoromethyl groups is more powerful than the effect due to one phosphono group.
Abstract: 1.
In competition for conjugation with an olefinic bond the phosphono group has a mote powerful electronwithdrawing effect than the trifluoromethyl group. The reaction of diethyl perfluoropropenylphosphonate with various nucleophilic reagents leads to products in which a fluorine atom in theβ -position relative to the phosphono group is replaced.
2.
It was found that the electron-withdrawing effect of two trifluoromethyl groups is more powerful than the effect due to one phosphono group: in the reaction of diethyl perfluoroisobutenylphosphonate with nucleophilic reagents it is theα-fluorine atom that is replaced; in the case of diethyl α-hydrohexafluoroisobutenylphosphonate, addition products are formed with nucleophilic reagents, i.e. α-substituted-α, β-dihydrohexafluoroisobutylphosphonic esters.
13 citations
TL;DR: The absolute rate constants of the reactions of oxygen atoms with methane and ethane at different temperatures were measured in this paper, showing that the activation energies of CH2 and H2O were equal to 7800 and 5200 cal/mole, respectively, and the pre-exponentials, equal to 3.4 · 10−11 and 0.9 · 9−11, respectively.
Abstract: 1.
The absolute rate constants of the reactions of oxygen atoms with methane and ethane at different temperatures were measured.
2.
The activation energies of the reactions of oxygen atoms with methane and ethane equal to 7800 and 5200 cal/mole, and the pre-exponentials, equal to 3.4 · 10−11 and 0.9 · 10−11, respectively, were determined.
3.
There are two main directions of the reaction of oxygen atoms with methane, firstly, the formation of CH2 and H2O, and secondly, the formation of CH2O and H2.
4.
The main direction of the reaction of oxygen atoms with ethane involves the rupture of the C-C bond and the formation of CH2O, H2, and CH2.
11 citations
TL;DR: The stereoselective synthesis of trans olefins was effected when the phosphorylid molecule contained an electron-accepting substituent on the ylid C atom as mentioned in this paper.
Abstract: 1.
Steric control of the Wittig reaction can be effected by changing the reaction conditions and the structures of the starting compounds.
2.
Stereoselective synthesis of cis olefins from alkylideneor benzylidene-triphenylphosphoranes and aldehydes can be effected in presence of Lewis bases. The maximum relative yield of cis olefins is attained by carrying out the reaction in N,N-dimethylformamide in presence of Br− and I−, which form complexes with phosphoranes.
3.
The stereoselective synthesis of trans olefins was effected when the phosphorylid molecule contained an electron-accepting substituent on the ylid C atom. Thus, irrespective of the external conditions, the reaction ofα-(triphenylphosphoranylidene)alkanoic esters with aldehydes gives only the corresponding trans olefins.
10 citations
10 citations
TL;DR: In this article, a phase diagram for the system Y2O3-ZrO2 in the solid phase, differing from that of Duwez and co-authors by the presence of a compound Y2Zr2O7, by the absence of a single phase region of the monoclinic solid solution, and also by the different position of the phase boundaries of the solid solutions in the system.
Abstract: 1.
A new phase diagram is proposed for the system Y2O3-ZrO2 in the solid phase, differing from that of Duwez and co-authors by the presence of a compound Y2Zr2O7, by the absence of a single-phase region of the monoclinic solid solution, and also by the different position of the phase boundaries of the solid solutions in the system.
2.
The minimum amount of Y2O3 needed for complete stabilization of ZrO2 depends to a considerable extent on the roasting temperature.
3.
The reduction in the temperature of the polymorphic transformation of zirconium dioxide roasted with small additions of stabilizing oxides can be explained by the change in the repulsive force between the cations in the ZrO2 lattice due to the formation of a monoclinic substitutional solid solution of zirconium dioxide, the degree of reduction in the temperature of polymorphism depending on the size of this change.
8 citations
6 citations
TL;DR: In this article, the first monomolecular benzene layer screens the adsorptive field of the carbon black, for practical purposes, completely, and the properties of benzene and methyl alcohol in the adorbed and frozen state differ from the properties in the volume condensed phases.
Abstract: 1.
In contrast with water, adsorbed benzene and methyl alcohol cover the surface of carbon black with continuous adsorbed films. The first monomolecular benzene layer screens the adsorptive field of the carbon black, for practical purposes, completely.
2.
The properties of benzene and methyl alcohol in the adsorbed and frozen state differ from the properties of the volume condensed phases.
3.
From preliminary data, the molecular areas of nitrogen on layers of benzene and methyl alcohol preadsorbed on carbon black are greater than on the surface of the original black.
TL;DR: The free radical 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxide can be smoothly esterified at the hydroxyl group without the free valence being affected.
Abstract: 1.
The free radical 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxide can be smoothly esterified at the hydroxyl group without the free valence being affected.
2.
The 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxide esters ofp-toluenesulfonic, phenylcarbamic, and 3,5-dinitrobenzoic acids have been synthesized.
TL;DR: The influence of substituents on the mechanism of the rearrangement of azoxy compounds into para and ortho-hydroxy compounds has been studied in this article, and two types of ortho rearrangements of azcxy compounds have been found: intermolecular, which is the most usual, and intramolecular taking place with the participation of the external medium.
Abstract: 1.
The influence of substituents on the mechanism of the rearrangement of azoxy compounds into para-and ortho-hydroxyazo compounds has been studied.
2.
Regardless of the structure of the azoxy compounds, their para-rearrangement always takes place by an intermolecular mechanism.
3.
Two types of ortho-rearrangement of azcxy compounds have been found: intermolecular, which is the most usual, and intramolecular, taking place with the participation of the external medium.
4.
The mechanism of the para-and ortho-rearrangements of azoxy compounds has been discussed.
TL;DR: In this paper, the conjugated nitrofluorination of olefins was studied, which provides a convenient method for the synthesis of various β-fluoro nitro compounds.
Abstract: The conjugated nitrofluorination of olefins was studied. This reaction provides a convenient method for the synthesis of various β-fluoro nitro compounds.
TL;DR: When the appropriate ethers containing fluorinated groups react with sulfuric acid or aluminum halides, 2-hydro- and 2-halo-hexafluoroisobutyryl halides are obtained as mentioned in this paper.
Abstract: 1.
When the appropriate ethers containing fluorinated groups react with sulfuric acid or aluminum halides, 2-hydro- and 2-halo-hexafluoroisobutyryl halides are obtained.
2.
It was shown that in the fluorocarbonyl group of the acid fluorides obtained fluorine can be smoothly replaced by chlorine or bromine by the action of the appropriate aluminum halide.
3.
Perfluorodimethylketene is formed in the pyrolysis of perfluoroisobutenyl methyl ether.
TL;DR: The absolute values of the rate constants of the elementary reaction of oxygen atoms with n-butane in the temperature range of 40 −195° were measured in this paper, and an activation energy of the reaction of 4100 cal/mole and a value for the preexponent of 1.3·10−11.
Abstract: 1.
The absolute values of the rate constants of the elementary reaction of oxygen atoms with n-butane in the temperature range of 40–195° were measured.
2.
We obtained an activation energy of the rate constant of the reaction of 4100 cal/mole and a value for the pre-exponent of 1.3·10−11.
3.
The main directions of the reaction of oxygen atoms with n-butane are reactions leading to the formation of formaldehyde and acetaldehyde, proceeding with rupture of a C-C bond.
TL;DR: In this article, a new method was proposed for increasing the antioxidant efficiency of chemical compounds of the hydroquinone class by aminomethylation, and four Mannich base derivatives of the base derivatives were synthesized by this method.
Abstract: 1.
A new method is proposed for increasing the antioxidant efficiency of chemical compounds of the hydroquinone class by aminomethylation. Four Mannich base derivatives of hydroquinone were synthesized by this method.
2.
The relative antioxidant efficiency of the compounds synthesized was assessed by an accelerated kinetic method. All the hydroquinone derivatives investigated had a high antioxidant activity in the oxidation of methyl oleate.
TL;DR: In this paper, the thermal decomposition of Ca, Ba, Li, Rb, Ag, and Cu acetates at 473-873°K was analyzed thermodynamically.
Abstract: 1.
The thermal decomposition of Ca, Ba, Li, Rb, Ag, and Cu acetates at 473–873°K was analyzed thermodynamically. In all cases apart from Ag and Cu acetates, and regardless of the nature of the acid radical, the decomposition of the salt to the anhydride and the metal oxide was thermodynamically forbidden. The results of the calculations are confirmed by experimental data.
2.
The characteristics of the topochemical decomposition of Ca, Ba, Cd, Mg, and Zn acetates were examined: they were the lack of an induction period, the fact thatn in Erofeev's equationα=1−e−kτn is close to unity, the planar form of the reaction nucleus, and the fact that the reaction proceeds in the kinetic region. The decomposition proceeds by the growth of initial centers present in the substance and the activation energy determined experimentally is the activation energy of the growth of the reaction nuclei.
3.
In the case of the decomposition of Li, Na, K, and Rb acetates, which occurs in the melt, an interpretation is given for the effect of the nature of the metal on the activation energy and pre-exponent. The effect of thermodynamic factors on the course of the change in activation energy is discussed.
TL;DR: In this paper, the coammonolysis reactions of methylvinyldichlorosilane and co-ammonization with dimethyl- and diethyldichlormosilanes with cyclosilazanes were investigated.
Abstract: 1.
Ammonolysis reactions of methylvinyldichlorosilane and the coammonolysis of methylvinyldichlorosilane with dimethyl- and diethyldichlorosilanes were investigated.
2.
Seven new vinyl derivatives of cyclosilazanes were isolated and characterized.
TL;DR: In this paper, three ways of synthesizing polyenic dicarboxylic acids having even numbers of double bonds are proposed, and the difficulty with which the cis bond in 6-ciscorticrocin diethyl ester is isomerized is pointed out.
Abstract: 1.
Three ways of synthesizing polyenic dicarboxylic acids having even numbers of double bonds are proposed.
2.
A new method of synthesizing corticrocin diethyl ester is described.
3.
The difficulty with which the cis bond in 6-cis-corticrocin diethyl ester is isomerized is pointed out.
TL;DR: In this paper, the authors have found the temperature limits for the existence of limited solid solutions (xCe2O3·2SiO2, yLn 2O3 ·2Si O2) in an oxidizing atmosphere (in air).
Abstract: 1.
We have synthesized solid solutions in the systems Ce2O3·2SiO2-Nd2O3·2SiO2 and Ce2O3·2SiO2-La2O3·2SiO2.
2.
We have found the temperature limits for the existence of limited solid solutions (xCe2O3·2SiO2, yLn2O3 ·2SiO2) in an oxidizing atmosphere (in air). In a reducing atmosphere (H2, CO) continuous solid solutions form in these systems.
3.
We have synthesized the oxyorthosilicate of cerium Ce2O3·SiO2 in a reducing atmosphere and its solid solution with oxyorthosilicates of rare earths of the lanthanum subgroup and calcium of composition: [(0.5 Ce, 0.2 La, 0.2 Nd, 0.1 Pr)2O3·SiO2 (3CaO·SiO2)].
4.
In the synthetic ceftosil mineral cerium is in the trivalent state.
TL;DR: In this paper, the nitration and nitrosation of various 2,6-dialkylphenols have been carried out with the production of 4-nitro- and 4nitroso-2,6 -dialkylphenols.
Abstract: The nitration and nitrosation of various 2,6-dialkylphenols have been carried out with the production of 4-nitro- and 4-nitroso-2,6-dialkylphenols.
TL;DR: In this paper, it was proved that the primary reaction product is the 5-isomer, which in the process of the establishment of equilibrium is converted into the 1isomer and then into an equilibrium mixture of 1- and 2-substituted cyclopentadienes.
Abstract: 1.
On the basis of the behavior of methylcyclopentadiene it was confirmed that a characteristic feature of substituted cyclopentadienes is the occurrence of thermodynamic equilibrium between isomers differing in the positions of the intracycle double bonds.
2.
The equilibrium transformations of substituted cyclopentadienes have a stagewise character, i.e. the proton migrates from the methylene group (the 5-position) and goes predominatly to the adjacent C atom.
3.
The course of the alkylation of metal derivatives of cyclopentadiene was elucidated for the first time: it was proved that the primary reaction product is the 5-isomer, which in the process of the establishment: of equilibrium is converted into the 1-isomer, and then into an equilibrium mixture of 1- and 2-substituted cyclopentadienes.
4.
Samples of all three possible methylcyclopentadienes, each almost homogeneous in isomeric composition, were prepared. They were characterized by their individual adducts with maleic anhydride and by some derivatives of these. The mixture of adducts obtained from the equilibrium mixture of cyclopentadienes was separated via their esters.
5.
The rate of diene condensation with an active dienophile is very much greater than the rates of the isomeric transformations of methylcyclopentadienes.
TL;DR: In this paper, the role of a change in the radius of the pores along the length of the pore in capillary equilibrium it a porous body has been investigated, and it has been shown that the distribution of the lengths of the gas part of a pore has an exponential character.
Abstract: The role of a change in the radius of the pores along the length of the pores in capillary equilibrium it a porous body has been investigated. In a model cn non-intersecting pores consisting of successively arranged units with random values of the length and radius, the distribution of the length of the gas part of the pores has, at least at high pressures, an exponential character.
TL;DR: In this paper, the infrared spectra of the oxide orthosilicates of the rare earth metals Ln2(SiO4)O makes it possible to divide these compounds into three groups in accordance with the existence of three structural types.
Abstract: 1.
Study of the infrared spectra of the oxide orthosilicates of the rare earth metals Ln2(SiO4)O makes it possible to divide these compounds into three groups in accordance with the existence of three structural types.
2.
Bands for the vibrations of Ln-O-Ln bonds involving “oxide ions” O2− have been identified in the spectra of some of the oxide orthosilicates. These bands are partly covalent and their covalent character increases with decrease in the basic strength of the cations in the series La→Lu (and La→Y→Sc).
3.
The suggestion that the coordination of the Ln3+ ions is different in the three structural types of oxide orthosilicate agrees with the results of the study of the phase diagrams for systems of the type (Ln′ Ln″)2(SiO4)O. The ability of compounds lying close to the “boundary” between two groups to crystallize under the influence of small quantities of additives with the structure of the neighboring group, also confirms this suggestion.
4.
Comparison of the changes in structure (coordination of the cations) with change in the ionic radius of the rare earth metal cations in the pyrosilicate and oxide orthosilicate series indicates that the magnitude of the effective radius of the cation is smaller in the latter group of compounds. This difference is attributed to the stronger electron-accepting power of the O2− anions and the partial covalent character of the bonds which it forms with the cations.
TL;DR: The route for the formation of ethane from ethanol on titanium oxide has been studied at temperatures from 360 to 410° and alcohol flow rates of 0.25, 0.50, and 0.75 h−1 in the presence of labelled ethylene of high specific activity.
Abstract: 1.
The route for the formation of ethane from ethanol on titanium oxide has been studied at temperatures from 360 to 410° and alcohol flow rates of 0.25, 0.50, and 0.75 h−1 in the presence of labelled ethylene of high specific activity (31,200 counts per minute in 1 mg BaCO3).
2.
In the reaction conditions ethane is-formed only by hydrogenolysis of ethanol, and not by hydrogenation of ethylene.
TL;DR: In this article, an investigation was made of the transformations of cyclohexane at 468-470° and the hydrogenation of benzene at 260° at a pressure of 10 atm in a fkudized bed of a catalyst containing 2% of palladium supported by fluorinated alumina.
Abstract: 1.
An investigation was made of the transformations of cyclohexane at 468–470° and the hydrogenation of benzene at 260° at a pressure of 10 atm in a fkudized bed of a catalyst containing 2% of palladium supported by fluorinated alumina.
2.
The catalyst was highly active and stable both in the dehydrogenation of cyclohexane and in the hydrogenation of benzene. In the range of space velocities investigated (1.5–3.2 h−1) scarcely any change occurred in the extents to which these two hydrocarbons were transformed.
3.
Under the hydrodynamic conditions adopted catalyst losses amounted so less than 0.5%