Kinetics of oxidative ammonolysis of 4-bromo-o-xylene: V. Synthesis of 4-bromophthalonitrile

Oxidative ammonolysis of 4-bromo-o-xylene on a V-Sb-Bi-Zr/γ-Al₂O₃ catalyst gives 74.82 mol % of 4-bromophthalonitrile at a high conversion of the starting xylene in a one-cycle process. The process with recirculation results in decreased number of by-products and contribution of deep oxidation and increased selectivity in 4-bromophthalonitrile up to 95.42–96.58%.     

Kinetics of oxidative ammonolysis of 4-bromo-o-xylene: III. Conversion of 4-bromo-o-tolunitrile as a substrate

Kinetics of oxidative ammonolysis of 4-bromo-o-tolunitrile on V-Sb-Bi-Zr/γ-Al₂O₃-oxide catalyst in the temperature range 633–673 K were studied. We found that the rate of conversion of 4-bromo-o-tolunitrile to the target 4-bromphthalonitrile and CO₂ was described by the half-order equation with respect to the substrate concentration and was independent of the partial pressures of oxygen and ammonia. The byproducts are 4-bromophthalimide formed through the hydrolysis of 4-bromophthalonitrile, CO₂ produced by oxidation of 4-bromo-o-tolunitrile and decarboxylation of 4-bromophthalimide, and 4-brombenzonitrile produced from 4-bromo-o-tolunitrile and 4-bromophthalimide.     

On some peculiarities of phthalimide formation in the oxidative ammonolysis of o-xylene

In the oxidative ammonolysis of o-xylene on oxide catalysts, phthalimide can be obtained from phthalodinitrile through an intermediate phthalocyanine step. The catalyst ability to form phthalocyanine can be used to estimate its selectivity to phthalimide.

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Kinetics of oxidative ammonolysis of 4-bromo-<Emphasis Type="Italic">o</Emphasis>-xylene: II. Formation of by-products

Kinetic laws of formation and expenditure of by-products in the oxidative ammonolysis of 4-bromo-o-xylene in the temperature range 633–693 K were studied. It was shown that 4-bromophthalimide formation at high concentration of ammonia occurs through hydrolysis of 4-bromophthalonitrile; carbon dioxide forms by oxidation of 4-bromo-o-xylene and decarboxylation of 4-bromophthalimide; 4-bromobenzonitrile originates from 4-bromo-o-tolunitrile and 4-bromophthalimide. At low concentration of ammonia additional formation routes of 4-bromophthalimide and CO₂ from 4-bromo-o-xylene are realized.     

A study of the oxidative ammonolysis of quinoline

The oxidative ammonolysis of quinoline has been studied. The main products are pyridine, benzene, benzonitrile, and nicotinonitrile. Free nicotinic and benzoic acids and their amides are formed in small amounts. The gaseous products of the reaction are hydrogen cyanide and oxides of carbon. The most significant factors determining the direction of the process are the content of tin oxides in the catalysts, the concentration of ammonia in the feed gases, and the temperature of the reaction.Translated from Khimiya Geterotsiklicheskikh Soedinii, Vol. 6, No. 6, pp. 794–797, June, 1970.     

Mechanism of the formation of carbon oxides under conditions of the oxidative chlorination of methane: III. Kinetics of the reaction of CCl<Subscript>4</Subscript> with oxygen on copper-containing salt catalysts

The kinetics of the oxidative dechlorination of CCl₄ on two supported catalysts for methane oxychlorination (CuCl₂-KCl and CuCl₂-KCl-LaCl₃) at 350–425°C was studied using a gradientless method. Although these catalysts exhibited different activities, the rate of reaction on them was described by one exponential equation at the same activation energy of E ≈ 26.3 kcal/mol. A two-path reaction mechanism was proposed, which involved the dissociative adsorption of initial reactants and chlorine with the formation of phosgene and the oxidation of phosgene to CO₂. The occurrence of two types of active sites on the catalyst surface was assumed.     

Interaction between the components of the reaction mixture and the surface of catalysts for the oxidative ammonolysis of propylene

A study was made of the change in the properties of tin-antimony and bismuthmolybdenum oxide catalysts during the partial reduction of their surfaces with propylene and a propylene-ammonia mixture. Different characteristics of the interaction of ammonia with the surface of the catalysts studied were established.

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木素分子氧化性氨化反应过程中的结构变化

在一定压力和温度条件下，木素大分子和氨发生反应，生成一些氮修饰木素。为了解反应过程中木素分子结构的变化，用^1^3C和^1H-^1^3C2D-NMRHMQC技术检测了反应前后的分子谱图，结果显示反应过程中木素分子的碎裂化现象十分明显，很可能在氧化性氨化反应过程中，木素大分子表面基团发生了氧化性修饰，如一些侧链CH~3被氧化形成CHO和COOH等，然后这些基团与氨结合等；此外，芳香环结构可能通过粘康酸单体断裂形成一些酰胺类产物，但木素分子内部的高度缩合性结构没有明显的变化。     

The knoevenagel reaction of malononitrile with some cyclic β-keto-esters—II: Mechanism of formation of heterocyclic reaction products

The formation of alkoxypyridinols 3a and 3b from the Knoevenagel reaction products 2a and 2b was shown to proceed by a mechanism in which the ester CO group initiates ring closure by intramolecular nucleophilic attack on the cyano group, possibly assisted by an acidic catalyst. Opening of the oxygen ring after nucleophilic attack by a basic catalyst on the former ester carbonyl C atom results in the formation of an amide, which in turn affords the alkoxypyridinols by a conventional cyclization mechanism.     

Mechanism of the formation of carbon oxides under conditions of the oxidative chlorination of methane: IV. Kinetics of the reaction of CCl<Subscript>4</Subscript> with oxygen on copper-containing salt catalysts for methane oxychlorination at reduced partial pressures of Cl<Subscript>2</Subscript> in the reaction mixture

The kinetics of the oxidative dechlorination of CCl₄ on two supported salt catalysts for methane oxychlorination (CuCl₂-KCl and CuCl₂-KCl-LaCl₃) in the presence of methane at 350–450°C was studied using a gradientless method. It was found that, at \(P_{Cl_2 } \) > 0.15 kPa, the presence of methane in the reaction mixture had no effect on the kinetics of CCl₄ oxidation but decreased the activation energy E to ～22 kcal/mol. At \(P_{Cl_2 } \) < 0.15 kPa, the kinetic orders with respect to oxygen and chlorine changed and E decreased to ～17 kcal/mol. The rate of formation of CO₂ as a by-product of the reaction of methane oxychlorination was described by an exponential equation in combination with rate equations for the oxidation of other chloromethanes and methane. An equation consistent with the observed rate laws of this reaction in the presence of methane was derived from the previously proposed reaction scheme for the mechanism of the oxidative dechlorination of CCl₄.     

Thermal decomposition of peroxypropionyl nitrate: Kinetics of the formation of nitrogenous products

The Arrhenius expression for reaction 1, CH₃CH₂COO₂NO₂CH₃CH₂COO₂+NO₂, has been determined to be k=2×10¹⁵ exp (–12800/T)·s^–1. The free radical mechanism is the exclusive thermal decomposition mechanism of PPN. The main nitrogenous decomposition products of pure PPN are ethyl nitrate, nitrogen dioxide and methyl nitrate. In the presence of NO, ethyl nitrite is the major organitrogen product.

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CH₃CH₂COO₂NO₂CH₃CH₂COO₂+NO₂ : k=2·10¹⁵exp (–12800/T) ^–1. () - . , . NO .

     

Elucidation of the reaction mechanism for the synthesis of ZnGeN2 through Zn2GeO4 ammonolysis

Ternary II–IV–N₂ materials have been considered as a promising class of materials that combine photovoltaic performance with earth-abundance and low toxicity. When switching from binary III–V materials to ternary II–IV–N₂ materials, further structural complexity is added to the system that may influence its optoelectronic properties. Herein, we present a systematic study of the reaction of Zn₂GeO₄ with NH₃ that produces zinc germanium oxide nitrides, and ultimately approach stoichiometric ZnGeN₂, using a combination of chemical analyses, X-ray powder diffraction and DFT calculations. Elucidating the reaction mechanism as being dominated by Zn and O extrusion at the later reaction stages, we give an insight into studying structure–property relationships in this emerging class of materials.

Combining chemical analyses with detailed structural work, we decipher the reaction pathway in the ammonolysis of Zn₂GeO₄ towards ZnGeN₂.     

Visible light-induced oxidative coupling reaction: easy access to Mannich-type products

An efficient methodology for the functionalization of sp(3) C-H bond adjacent to nitrogen has been developed utilizing visible light-induced photoredox catalysis. Through optimization of solvent and light source, the reaction can be rapidly achieved to provide the desired product under mild reaction conditions.     

Kinetics and products of the reaction of diazo compounds with SO2

Data were obtained on the composition of products and kinetics of the reaction of SO₂ with Ph(R)CN₂ (R=Ph, Me) in solutions of isooctane, 1,4-di-oxane, and ethanol at 295 K. A mechanism was proposed for the process in accordance with which the sulfene being formed participates in concurrent reactions with the starting reagents. The relative rate constants for the process stages were determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2496–2500, November, 1990.