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Experimental results of studying the morphology, phase composition, magnetic and catalytic properties of vanadium-antimony-containing aluminum oxide samples in the reaction of oxidative dehydrogenation of propane (ODP) with carbon dioxide are presented. It has been shown that in the X-ray diffraction patterns of vanadium-aluminum and antimony-vanadium-aluminum oxide catalysts with a vanadium content of less than 15 and an antimony content of less than 5 wt.%, respectively, only peaks belonging to γ-Al2O3 are observed. It is assumed that the absence of V2O5 peaks is due to the presence of vanadium oxide in these catalysts in a highly dispersed amorphous state in the form of polymer structures (VOx)n. In the X-ray diffraction patterns of the catalyst with the composition 5%Sb-15%V/Al2O3, peaks characteristic of the Sb2O3 and SbVO4 phases are observed. According to the EPR spectra, vanadium ions in the +4 oxidation state are identified as vanadyl ions VO2+. It has been shown that the introduction of antimony into the composition of a vanadium-aluminum oxide catalyst increases the amount of vanadyl ions VO2+ and its activity in the ODP reaction. It was found that samples of the used γ-Al2O3 carrier are inactive in the ODP reaction and acquire this activity after introducing vanadium into them. The introduction of antimony into vanadiumcontaining aluminum oxides enhances the catalytic activity and significantly increases their selectivity in the ODP reaction. The thermodynamics of the reactions of formation of vanadium-antimony oxide structures and ODP with their participation have been studied. [ABSTRACT FROM AUTHOR]

As a result of the research of the reaction of 3,4-dihydro-2H-pyrano-dimethylacetylene carbinol (also with its Csp-substituted derivatives) of iodo-alkylation on clinoptilolite in the presence of (NaK)4CaAl6Si30O72 and crystalline iodine, 3-iodine-2-[(2-methyl-4- organyl-but-3-in-2-yl)oxy]oxane was prepared. This method of preparation of heterocyclic compounds allows the reaction to be carried out in the absence of solvents, which reduces the amount of reagents and allows obtaining a product with high purity and high yield (67.5%). It was established that the latter under the conditions of the Kucherov reaction turn into heterocyclic compounds. Thus, effective regioselective methods for the synthesis of dioxin derivatives have been developed. This fact is probably related and is obviously explained by the intramolecular cyclization of the resulting intermediate-ketohydroxyester, i.e. tandem hydrolysis of C–I and hydration of C≡C bonds of the reaction products. The yield of 2-benzyl-3,3-dimethylhexahydro-4aH-piran[2,3-b][1,4]dioxin-2-ol is higher than that of structural analogues. It should also be noted that the synthesized compounds have an increased reactivity, and are rich in nucleophilic centers. Based on experimental data, it was established that the compounds obtained in this way are stable and do not undergo hydrolysis. Some physicochemical properties of the synthesized compounds were given, their composition and structure were confirmed by elemental analysis data, and all synthesized compounds were identified by IR and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The synthesis of heterocyclic compounds by the Hantzsch reaction is proposed. The synthesis involves the reactions of 1-(chloromethoxy)prop-2-ene and 1-(chloromethoxy)prop-2-yne with thioacetamide, thiourea, and phenylthiourea and results in the preparation in high yields of previously unknown imidothioates, which are promising intermediates. The proposed efficient regioselective synthesis of new types of compounds by the reaction of α-chloroaldehydes and ketones with thioamides and thioureas can be used to prepare thiazole derivatives. If the reaction is stopped at the stage of formation of intermediate imidothioates and isothioureas, the product of alkylation of the starting compounds at the sulfur atom can be obtained. The reactions of 1-(chloromethoxy)prop-2-ene and 1-(chloromethoxy)prop-2-yne with thioacetamide, thiourea, and its N-phenyl derivative in methanol at room temperature leads to the formation of the target imidothioates in yields of up to 62.5%. A typical reaction with phenylthiourea is performed in dry acetone under reflux for 1 h in the presence of a catalytic amount of MgSO4 with the subsequent alkalization with aqueous NaOH and purification of the target products by column chromatography. The yields of the products depend their structure: the yields of the propargyl derivatives (prop-2-yn-1-yloxy)methyl ethanimidothioate, (prop-2-yn-1-yloxy)methyl carbamimidothioate, and (prop-2-yn-1-yloxy)methyl N-phenylcarbamimidothioate are higher compared to their allyl analogs (prop-2-en-1-yloxy)methyl ethanimidothioate, (prop-2-en-1-yloxy)methyl carbamimidothioate, and (prop-2-en-1-yloxy)methyl N-phenylcarbamimidothioate. The synthesized compounds are hydrolytically stable, have an increased reactivity, and are also rich in nucleophilic centers. The composition and structure of the products were confirmed by elemental analysis and IR and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The change of the pressure drop in a fixed bed of NаХ zeolite is considered depending on the flow rate of the incoming gas. A new method of adsorption gas purification with optimal performance mode of adsorber is proposed. The essence of the method is that while maintaining the pressure drop in the fixed bed of zeolite NaX, conditions are created for the possibility to completely exhaust the adsorption capacity of the adsorbent during adsorption of H2S/NO2 /CO2 gas mixtures. A system of equations describing the pressure drop during gas-phase adsorption in a fixed bed of the adsorbent is proposed. [ABSTRACT FROM AUTHOR]