Oxidation of benzene on a vanadium-molybdenum catalyst in the presence of thiophene

The catalytic oxidation of benzene by air oxygen on a vanadium-molybdenum mixed oxide (1 ? x)V₂O₅ · xMoO₃ (x = 0.25) over a temperature range of 200–320°C is studied. It is shown that the introduction of small amounts of thiophene into benzene inhibits the oxidation to maleic anhydride in this temperature range. It is established that the operation of the catalyst is accompanied by significant changes in its phase composition and morphology, with a few first operation cycles being characterized by a high conversion of benzene. A possible mechanism of the process is proposed.     

Synthesis of C-methyldesoxy sugars: Desoxygenation of tertiary alcohol xanthogenates and hydrozirconation of exomethylene derivatives of carbohydrates

Conclusions Two methods for the synthesis of C-methyldesoxy-sugars were proposed by desoxygenation of tertiary alcohol xanthogenates and hydrozirconation of exomethylene derivatives of carbohydrates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No, 2, pp. 441–445, February, 1986.     

Secondary metabolites of Pyricularia oryzae I. o-Nitrophenol derivatives

o-Nitrophenol derivatives have been isolated from the culture liquid of the deuteromycetePyricularia oryzae Cav.: 4-hydroxy-3-nitrophenylacetic acid, 4-hydroxy-3-nitrobenzyl alcohol, 1- and 2-(4-hydroxy-3-nitrophenyl(ethanols, N-(4-hydroxy-3-nitrophenylethyl)acetamide, and pyriculamide. This is the first time that any of these compounds has been isolated from natural sources. The o-nitrophenols obtained possess moderate growth-inhibiting activity in relation to rice shoots.All-Union Scientific-Research Institute of Phytopathology, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 811–818, November–December, 1990.     

Reactions of highly electrophilic polyfluorocarbonyl compounds with primary arylamines

C-Hydroxyalkylation of primary arylamines by highly electrophilic polyfluorocarbonyl compounds results from the direct reaction of the initial reagents and is competitively inhibited by equilibrium N-hydroxyalkylation. The presence of steric hindrances to the formation of N-hydroxyalkylation products and an increase in the ring C-nucleophilicity facilitate the C-hydroxyalkylation reaction.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 383–389, February, 1990.     

An analysis of the kinetics of the thermal modification of biotissues by speckle correlometry method

The statistical characteristics of the dynamic speckle fields associated with the scattering of coherent emission on a cartilaginous tissue during its thermal modification by laser irradiation were studied. A method for determining the energy of activation of the thermally induced processes of structural modification of scattering sites was suggested; the method is based on an analysis of the scattered light flashing index. For cartilaginous tissue, the activation energy was estimated as ≈63 kJ/mol, a value that may characterize conformational transitions in the subsystem of proteoglycan aggregates.