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61.
The kinetics of benzoin oxidation to benzil over MnO2/Al2O3 was studied by investigation of the effect of initial concentration of reactant and product, catalyst mass and also temperature on the reaction rate. On the basis of obtained experimental data a rate law for the kinetics of reaction was proposed and then the reaction rate constants and activation energy of reaction were computed. Finally a simple reaction mechanism was proposed for the reaction. Also it has been shown that the rate controlling step of oxidation of benzoin to benzil is removal of hydrogen from the α-C-atom. 相似文献
62.
Javad Azizian Fatemeh Sheikholeslami Javad Hosseini Mohammadkazem Mohammadi Behrooz Mirza 《Journal of heterocyclic chemistry》2012,49(2):413-416
Tetrahydroindeno [1,2‐b]pyrrole‐3‐carboxylate were synthesized in a one‐pot procedure by the reaction of 1,3‐dicarbonyl and activated carbonyl compounds such as benzyl or ninhydrin in ethanol/water in the presence of ammonium acetate. J. Heterocyclic Chem., (2011). 相似文献
63.
64.
A Sharp Jump in Photocatalytic Activity of Elemental Sulfur for Dye Degradation in Alkaline Solution
Elemental sulfur is a low-cost and abundant substance as one of the largest by-products of the oil industry which was widely used in many industrial activities. Cyclo-octasulfur (S8) is one of the sulfur allotropes that is a very stable substance in standard conditions. In this study, we report a low-cost and fast method for the degradation of methyl violet in water under visible light and also sunlight by using elemental sulfur (S8). The results show that sulfur is a good photocatalyst which operates under visible light and can be utilized for degradation of methyl violet. The photocatalytic degradation of methyl violet in acidic, neutral, and alkaline media was investigated, and it was found that the photocatalytic efficiency increases dramatically in alkaline solution. The effects of the initial concentration of the dye, photocatalyst dosage, solution pH, and photocatalyst reusability were investigated. The kinetics of the reaction were studied in detail, and the photocatalytic rate equation was presented. 相似文献
65.
Javad Azizian Khadijeh Yadollahzadeh Hasan Tahermansouri Akram Sadat Delbari 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1844-1852
Abstract Dialkyl-2-(dialkoxyphosphonyl)-3-(1,6-dihydro-6-oxo-4-propylpyrimidin-2-ylthio) succinates and dialkyl-2-(dialkoxyphosphonyl)-3-(1,6-dihydro-6-oxopyrimidin-2-ylthio) succinates were synthesized in moderate to high yields using a novel, facile, and one-pot condensation of dialkyl acetylenedicarboxylates, trialkylphosphites, and thiouracil derivatives. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT 相似文献
66.
Dr. Elmira Mohammadi Lukáš Petera Dr. Homa Saeidfirozeh Antonín Knížek Dr. Petr Kubelík Dr. Roman Dudžák Dr. Miroslav Krůs Dr. Libor Juha Prof. Svatopluk Civiš Rémi Coulon Dr. Ondřej Malina Dr. Juri Ugolotti Dr. Václav Ranc Prof. Michal Otyepka Prof. Jiří Šponer Dr. Martin Ferus Dr. Judit E. Šponer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(52):12075-12080
Terrestrial volcanism has been one of the dominant geological forces shaping our planet since its earliest existence. Its associated phenomena, like atmospheric lightning and hydrothermal activity, provide a rich energy reservoir for chemical syntheses. Based on our laboratory simulations, we propose that on the early Earth volcanic activity inevitably led to a remarkable production of formic acid through various independent reaction channels. Large-scale availability of atmospheric formic acid supports the idea of the high-temperature accumulation of formamide in this primordial environment. 相似文献
67.
Ali Ramazani Abbas Azizian Maryam Bandpey Nader Noshiranzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2731-2734
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 2,2,2-trichloroethanol leads to vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce the corresponding chlorine-containing stabilized phosphorus ylides. An intermolecular Wittig reaction of the chlorine-containing stabilized phosphorus ylides with ninhydrin leads to the corresponding highly electron-poor chlorine-containing alkenes. 相似文献
68.
The article describes ionic liquids [bmim][NO3] in the presence of 30% mol CuI as efficient media for the domino Knoevenagel–hetero–Diels–Alder reaction of o-propargyloxy benzaldehydes as unactivated terminal alkynes with some active methylene compounds. Short reaction time, easy workup, good to excellent yields, and mild conditions are advantages of this new media. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
69.
Javad Azizian Javad Hosseini Mohammadkazem Mohammadi Fatemeh Sheikholeslami 《合成通讯》2013,43(23):3472-3479
A mild and efficient synthesis of highly substituted pyrroles using the reaction of triphenylphosphine, α-diketone, ammonium acetate, and dialkyl acetylenedicarboxylates is described. 相似文献
70.
Saeid Azizian Zahra Niknam Elisabetta Rombi 《Journal of Dispersion Science and Technology》2013,34(2):206-212
In the present study, the adsorption of pentafluorophenol from aqueous solution onto granular activated carbon, powdered activated carbon, and activated carbon cloth has been investigated from the equilibrium and kinetic points of view. To the best of our knowledge, the removal of pentafluorophenol from aqueous solution onto activated carbon have not been reported in the literature. The experimental equilibrium data, suitably fitted by the Toth, Langmuir-Freundlich, and Redlich-Peterson isotherms, have shown that the cloth and powdered carbons exhibit the highest adsorption capacity. For all the investigated samples, the experimental kinetic data have been satisfactorily interpreted by a pseudo-second-order model. From the fitting results it has been observed that the highest rate constant and initial rate of adsorption is shown by powdered activated carbon. 相似文献