Reduction of nitrobenzene to aniline with carbon monoxide and water

Modified catalyst systems composed of palladium or its chloride and co-catalysts such as FeCl₃, Fe₂O₃, metallic Fe-powder, metallic Fe-wire net, iodine, pyridine or aniline, applied in the reduction of nitrobenzene to aniline in the presence of carbon monoxide and water are described. The reaction proceeds at 150–180 °C and 2.5–7 MPa gauge pressure. After 1–7 h the reaction was complete, reaching nitrobenzene conversions of 98–100%. Selectivity of the reaction with respect to aniline was also 100%.     

Spectroscopic determination of photostimulated reactions in halomethane solutions of phthalimide and its derivatives

The photochemical reactions of phthalimide, N-benzylphthalimide, 3-and 4-aminophthalimide in the presence of halomethanes have been studied. The end products of the reaction were identified. It was found that phthalimides do not undergo a chemical reaction under the action of light, and their transformations are determined by a reaction with the active products of the photodissociation of tetrachloromethane in the presence of oxygen.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 4, pp. 480–484, July–August 1987.     

Spectrophotometric determination and kinetic studies of condensation of aromatic aldehydes with 1,3-dimethylbarbituric acid

The condensation reaction of 1,3-dimethylbarbituric acid with aromatic aldehydes in ethanol has been investigated spectrophotometrically at 25–35°C. The reaction follows overall second-order kinetics, first-order each in reactant. From the dependence of the rate constants on temperature, activation parameters have been calculated. The rate of condensation increases with the presence of electron donating groups on the aromatic ring of the aldehyde. The rate-determining step involves dehydration of the aldol intermediate. The reaction was found to be catalyzed by HCl solutions. Based on this reaction, determination of 10 aromatic aldehydes in a concentration range of 0.13–70.25 μg/ml is proposed. The method was applied for determination of barbituric and 1,3-dimethylbarbituric acids also.     

Nonempirical calculations of potential-energy surfaces for nucleophilic addition of H− and F− to an acetylene molecule

The minimal energy paths for the nucleophilic addition of a hydride ion (H^–) and a fluoride ion (F^–) to a molecule of acetylene (A) have been calculated with the use of 3–21++G and 3–21+G double basis sets in the framework of the Hartree-Fock-Roothaan method. The values of the total energies of the reactants, transition states, and products have been refined by means of calculations with more complete basis sets [6–31++G// 3–21++G and 6–31++G*//3–21++G for reaction (1); 6–31+G*//3–21+G and 6–31++G**//3–21+G for reaction (2)] and by taking into account the correlation energy for reaction (1) in the framework of the SCEP/6–31++*//3–21++G method. It has been established that the activation energy of reaction (2) is 15.94 kJ/mole lower than that for reaction (1), that reaction (1) is exothermic, and that the enthalpy change accompanying reaction (2) is close to zero. The character of the distribution of the electron density along the minimal energy paths of both reactions has been analyzed, and the differences appearing as a result of the replacement of the soft nucleophile H^– by the harder nucleophile F^– have been ascertained. The results of the calculations have been compared with the results available in the literature for reaction (1).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 149–155, March–April, 1989.     

Reductive alkylation of p-phenylenediamine and its hydroquinone complex with ketones in presence of rhenium and palladium sulfides

Conclusions Conditions were found (150–200°, hydrogen pressure 110–150 atm, reaction time 3 h) for the reductive alkylation of p-phenylenediamine and its hydroquinone complex with acetone, butanone, and cyclohexanone in presence of Re₂S₇ or PdS as catalyst, and N,N'-diisopropyl-, N,N'-di-s-butyl-, and N,N'-dicyclohexyl-p-phenylenediamines and their hydroquinone complexes were obtained in 60–90% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1601–1605, July, 1968.     

Hydrosilylation and hydrogermylation of 3-OXO-1,2-Benzisothiazoline-2-(2-propynyl)-1,1-dioxide

The addition of triethylsilane and triethylgermane to N-propargylsaccharin in the presence of the Speier catalyst gives the gem adduct with trans configuration. This pathway accounts for 75–80% of the reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2889–2891, December, 1991.     

Reaction of serum albumin with dimethyl sulfoxide according to PMR spectra of frozen aqueous solutions

The reaction of human serum albumin (HSA) with dimethyl sulfoxide (DMSO) was studied by the PMR method according to the intensity of the proton signal of non-freezable water in the temperature range of 230–273°K. It was shown that the concentration of DMSO in the non-frozen liquid phase is much higher than should be expected for the simple eutectic. This is attributable to the binding of N molecules of DMSO with a molecule of HSA (at 270°K, N = 7–10). It was found that in the presence of DMSO, the amount of non-freezable water markedly increased, which is possibly due to a reaction between DMSO and proton-active centers of the protein through the intermediate water molecules.Translated from Teoreticheskaya i Ékperimental'naya Khimiya, Vol. 25, No. 1, pp. 104–108, January–February, 1989.     

Synthesis of 9-arylidene derivatives of deoxyvasicinone

A simple method has been developed for obtaining 9-arylidenedeoxyvasicinones by condensing deoxyvasicinone with aromatic aldehydes in the presence of glacial acetic acid. The yields of reaction products amount to 69–95%.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 79–81, January–February, 1998.     

Reaction of dialkyl(or aryl) dichlorosilanes with alkali metals in presence of conjugated dienes

Summary The reaction of dialkyl(or aryl)dichlorosilanes with conjugated dienes in presence of alkali metals in a tetrahydrofuran medium leads to the formation of unsaturated sila-hydrocarbon polymers with silicon atoms in the main chain and molecular weights of 1000 or over, and also the corresponding silacyclopentenes (yields 0–10%) and divinylsilacyclopentanes (yields 10–50%). The relative amounts (yields) of these products depend both on the nature of the reactants and on the reaction conditions.Translated from Izvestiya Akademii Nauk SSR, Seriya Khimicheskaya, No. 5, pp. 840–844, May, 1964     

An efficient method for synthesis of organophosphorus compounds in aqueous media

A convenient and facile one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds is reported by the reaction of triphenylphosphine,dialkylacetylenedicarboxylates and N-H,C-H or S-H acids in the presence of polyethyleneglycol (PEG),β-cyclodextrin(β-CD),glycerine(Gly) or ethyleneglycol(EG) in water.This methodology is of interest due to the use of water as a solvent,thus minimizing the cost operational hazards,and environmental pollution.     

Addition of thiols to (-)-carvone

Polyfunctional thioterpenoids were formed in the presence of a Lewis-acid catalyst by reaction of (-)-carvone with thiols that involved the endocyclic double bond and the carbonyl.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 393–395, September–October, 2004.     

Rapid chelatometric determination of chromium(III)

Summary Chromium(III) rapidly reacts with EDTA in the presence of sodium bicarbonate at a pH of 5.3–6.0. This reaction can be used for a rapid chelatometric determination of the element.

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Zusammenfassung Chrom(III) reagiert schnell mit ÄDTA in Gegenwart von Natriumhydrogencarbonat bei pH 5,3–6,0. Dieser Reaktionsablauf wird für eine rasche chelatometrische Chrombestimmung verwendet.

     

Friedel-Crafts alkylation of indoles

The alkylation of indole and 2-methylindole with alkyl halides in the presence of a complex catalyst — dipyridinezinc chloride — was investigated. Nitromethane was used as the solvent. 3-Alkylindoles were obtained in 30–80% yields in all cases. The reaction mechanism is discussed. Data from the PMR and mass spectra are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 921–924, July, 1978.     

New reaction in the acridine series

A new reaction in the acridine series — reaction of its salt or the base with the salts or bases of N-heterocyclic compounds containing an active methyl group in the presence of sulfur — was investigated. It is shown that 9-acridinylheterylmethanes are formed as a result of this reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1384–1386, October, 1970.     

Catalytic properties of activated carbons in liquid-phase chlorination of toluene

A study has been made of the liquid phase chlorination of toluene in the presence of activated carbons derived from fruit pits. It has been shown that at moderate temperatures (303–323 K), the activated carbon is a catalyst for electrophilic chlorination of toluene in the ring. Possible mechanisms of this reaction are examined.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 6, pp. 358–361, November-December, 1996.     

Electrochemical Study of Iodide in the Presence of Barbituric Acid: Application to the Catalytic Determination of Barbituric Acid

Electrochemical oxidation of iodide has been studied in the presence of barbituric acid using cyclic voltammetry and controlled-potential coulometry. The results indicate that the barbituric acid participating in the halogenation reaction converts to an iodo derivative of the parent compound. Moreover, the results are indicative of the suitability of iodide as a mediator for the determination of barbituric acid in aqueous solutions. The quasicatalytic peak current is linearly dependent on the barbituric acid concentration. The calibration graph is parabolic, with two linear sections of 6.0 × 10^–5–1.0 × 10^–3and 1.0 × 10^–3–1.0 × 10^–2M. The relative standard deviation for ten determinations of 2.0 × 10^–4M barbituric acid is 2.1%, and the detection limit of the method is 3.97 × 10^–5M.     

Reaction of the Intermetallic Compound SmFe11Ti with Gaseous Ammonia

The reaction of the intermetallic compound SmFe₁₁Ti with ammonia at the initial NH₃ pressure of 0.6 – 0.8 MPa in the temperature range 150 – 450 °C in the presence of 10 wt % NH₄Cl as activator was studied. Depending on the reaction temperature, SmFe₁₁Ti undergoes both hydrogenation to form a hydride phase of the starting intermetallic compound and disproportionation to form a hydride phase of a new intermetallic compound. The reaction products are finely dispersed powders. The magnetic properties of the products were studied.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 881–885.Original Russian Text Copyright © 2005 by Fokin, Shul’ga, Tarasov, Fokina, Korobov, Burlakova, Shilkin.     

Reaction of trimethyliodosilane with monosubstituted acetylene derivatives

Conclusions The reaction of phenylacetylene and 1-hexyne with Me₃SiI in the presence of Mg at 170–180° gave the corresponding trimethyl(organylethynyl)silanes in 80–95% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, p. 897, April, 1981.     

Analysis of cooxidation kinetics of binary mixtures in the presence of a selective inhibitor

The analysis of the kinetics of the homolytic cooxidation of two compounds by molecular oxygen in the presence of a selective inhibitor was carried out with the intention of utilization of this process to determine the rate constant of a crossed chain propagation reaction. Boundaries between partial kinetic models of the reaction and the conditions under which these models are realized were established. The results of formal-kinetic conclusions were experimentally verified using the model of cooxidation of benzyl alcohol with cumene in the presence of p-benzoquinone.Translated from Teoreticheskaya i Éksperimental/naya Khimiya, Vol. 26, No. 5, pp. 611–615, September–October, 1990.     

Catalytic Self-Hydrogenation of Anthracene in the Presence of a Magnesium–Anthracene Adduct

The catalytic properties of cluster magnesium derivatives were studied using the self-hydrogenation reaction of unsaturated compounds as an example. In the presence of a cluster magnesium–anthracene adduct at 150–298 K, the self-hydrogenation of anthracene occurred with yields of up to 40 molecules per atom of magnesium.