Heterocyclic Syntheses on the Basis of Arylation Products of Unsaturated Compounds: X. 3-Aryl-2-chloropropanals as Reagents for the Synthesis of 2-Amino-1,3-thiazole Derivatives

Meerwein reaction of arenediazonium chlorides with acrolein gave 3-aryl-2-chloropropanals which were brought into cyclocondensation with thiourea. The resulting 2-amino-5-benzyl-1,3-thiazoles were acylated with carboxylic acid chlorides and phthalic anhydride to afford, respectively, 2-acylamino-5-benzyl-1,3-thiazoles and N-(5-benzyl-1,3-thiazol-2-yl)phthalimides.     

Heterogeneous Catalytic Partial Oxidation of C3-C4 Alkanes with Nitrogen Monoxide

The possibility of making products of partial oxidation, alcohols and acids in particular, by the reaction of C₃-C₄ alkanes with nitrogen monoxide over oxide and zeolite catalysts is demonstrated. The most effective catalysts are CeO₂ and Fe-TsVK. The dependence of the rate and selectivity of the process on the reaction conditions has been established.     

Effect of the nature of the ion-exchange cation on the acidity of ZSM-5 zeolites

The acidic properties of the initial and copper-, cerium-, and cobalt-containing high-silica TsVK and TsVN zeolites of the ZSM-S type with SiO21A1203 ratios of 68 and 37, respectively, were investigated by IR spectroscopy and programmed thermal desorption of ammonia. It was shown that the introduction of copper, cerium, and cobalt cations leads to redistribution of the acid centers in the Ts VK and Ts VN zeolites according to their strength, while hardly changing their overall concentration. The strength of the Brnsted acid centers of CuTsVK, CeTsVN, and CoNTsVK zeolites correlates with their activity in the selective reduction of nitrogen oxides by hydrocarbons.     

Mechanism of the reaction of CO with NO on palladium catalysts

A mechanism has been proposed for the reaction of CO + NO + (O₂) on palladium catalysts and the elementary stages of the reaction have been subjected to thermodynamic analysis. A kinetic model of the reaction has been constructed. The model of the reaction CO + NO has been analyzed in comparison with the reaction CO + O₂; the existence of a multiplicity of stationary states and critical transitions in the system CO + NO has been demonstrated. Numerical calculation has explained the accelerating influence of oxygen and the inhibiting influence of CO on the rate of the reaction CO + NO, observed experimentally.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 4, pp. 484–489, July–August 1987.     

Catalytic Properties of Heteropolyacid-Modified ZrO2 in the Partial Oxidation of Lower Alkanes by Nitric Oxide

The partial oxidation of C₃ and C₄ hydrocarbons by nitric oxide, in particular, their oxidation to alcohols, occurs on zirconium dioxide modified by various heteropolyacids (HPA). The catalyst activity depends on the amount of deposited HPA, while the reaction selectivity relative to the partial oxidation products correlates with the acid properties of the surface, in particular, with the concentration of weak acid sites.     

Catalytic Properties of (Fe,Al)-MCM-41 in Conversion of CO and Light Alkanes with Participation of Nitrogen Oxides

We used X-ray phase analysis, IR, X-ray photoelectron, and NMR spectroscopy to characterize a synthesized mesoporous material (Fe,Al)-MCM-41. As a result of a certain combination of structural, acidic, and oxidation–reduction properties of the surface, (Fe,Al)-MCM-41 exhibits catalytic activity in reactions with participation of nitrogen oxides, in particular partial oxidation of propane by nitrogen(I) oxide to isopropanol.     

The effect of sulfur dioxide on the activity of modified mordenites in the selective reduction of Nox

The results of a comparative investigation into the activity of modified natural and synthetic mordenites in the selective reduction of NO_x by C₁ and C₃−C₄ hydrocarbons (methane and a propane-butane mixture), the effect of sulfur dioxide on the process, and the acidic characteristics of the mordenites by temperature programmed desorption of ammonia and IR spectroscopy are presented. Sulfur dioxide has practically no effect on the selective reduction of NO_x by C₃−C₄ hydrocarbons at the H forms of synthetic and previously recationized natural mordenites but substantially retards the process at the Cu-, Co-, and Cr-substituted forms and palladium-containing mordenites. The decrease in the concentration of the strong B centers in the transition from the hydrogen to the copper-containing form of the mordenites reduces their activity in selective reduction. Prior recationization of natural mordenites increases their activity, stability, and resistance to the action of sulfur dioxide. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 2, pp. 119–124, March–April, 1999.     

Synthesis of [4-amino-5-(R-benzyl)-1,3-thiazol-2-ylsulfanyl] acetic acids

Russian Journal of Organic Chemistry - (4-Amino-1,3-thiazol-2-ylsulfanyl)acetic acids were synthesized by reaction of α-thiocyanatonitriles with sulfanylacetic acid in boiling acetonitrile.     

Direct Decomposition of Nitrogen(I) Oxide on Iron-Containing Zeolite,Zirconium Oxide,and Mixed Catalysts

As a result of testing a series of catalysts based on iron-containing zeolites of different structural types (Y, M, pentasil), zirconium dioxide, and a binary support (zeolite + ZrO₂) in the reaction of direct decomposition of nitrogen(I) oxide, we have shown that the most active zeolite-based catalysts are characterized by the presence of strong acid sites on the surface.     

Selective catalytic reduction of nitrogen oxides by C1 C3, and C4 hydrocarbons

Data are given on the activity of catalysts containing polyvalent metals in the reduction of nitrogen monoxide by hydrocarbons (CH₄, C₃H₈-C₄H₁₀, C₃H₆) in excess oxygen. It was established that the catalysts H-mordenite and CeO₂-TiO₂ have the highest activity.Translated from Teoreticheskaya i Éksperimentalnaya Khimiya, Vol. 29, No. 1, pp. 92–94, January–February, 1993.