144results about "Amino preparation by hydrogen substitution" patented technology

This invention relates to a process for preparing 4-nitrodiphenylamine and 4-nitrosodiphenylamine to be used for 4-aminodiphenylamine as an intermediate of antiozonant, wherein carbanilide is reacted with nitrobenzene in the presence of an appropriate base, while simultaneously adding aniline to the mixture so as to regenerate some amounts of carbanilide as a starting material. According to this invention, 4-nitrodiphenylamine and 4-nitrosodiphenylamine can be prepared in a higher selectivity and conversion rate via a continuous reaction by recycling carbanilide, a starting material, while adding a certain amount of aniline during the process. Further, the amount of waste water can be significantly reduced compared to the conventional method without any corrosive materials harmful to the environment.

The invention relates to a method for preparing ortho-nitroaniline by kettle-type continuous operation, belonging to the organic chemical engineering field; pressure-resistant reaction kettles are sequentially connected in series, and high-order differences are formed among the reaction kettles, so as to lead the reaction material to overflow to the next-level reaction kettle; 0-nitrophenyl and ammonia water are added in a first-level reaction kettle in the pressure-resistant reaction kettle, and the mixture is reacted under the condition that the temperature in the kettle is 150 DEG C to 250 DEG C, and pressure is 3MPa to 10MPa, and then the reacted products are oil-water laminated; after water is cooled, the ortho-nitroaniline is dissolved out in a solid way and is press-filtered into filter cakes, namely, the ortho-nitroaniline is obtained. The method has simple flow, stable yield coefficient of products and less three wastes, and is easy to realize industrialization.

One aspect of the present invention relates to a method for the transition metal (e.g., Cu(I)) mediated amidation of C—H bonds using electron-rich aliphatic azides. In certain embodiments, the methods are useful for the C—H insertion of nitrenes generated and stabilized by a β-diketiminato metal catalyst. In certain embodiments, said nitrenes are generated from organoazides, or by oxidation of the corresponding amine. Another aspect of the present invention relates to olefin aziridination using said β-diketiminato metal catalysts. In addition, the methods of the present invention include stereoselective C—H bond aminations and olefin aziridinatons. In certain embodiments, the methods are conducted in an aerobic environment. In certain embodiments, the present invention relates to the use of O₂ as an oxidant, wherein water is the byproduct of oxidation; this fact avoids the generation of toxic byproducts and renders the methods atom economical.

A device and method for dissipating heat from a source of heat is described. A plurality of layers of thermally conductive materials receives a flow of heat from a source of heat. A first layer of the plurality of layers receives the flow of heat from the source of heat and redirects and transfers the flow of heat to a second of the plurality of layers. Each layer has a separate preselected thermal impedance to control a desired temperature change across the plurality of layers and to maintain a desired operating temperature of the source heat.

The invention teaches novel process steps for the rapid high yield manufacture of diphenylamines of the formula

• wherein R¹ is selected from hydrogen, alkyl, and aryl;
• wherein each R² and R³ is the same or different and each is independently selected from hydrogen, alkyl, alkoxy, aralkyl, dialkylamino, alkylarylamino and substituted or unsubstituted aryl, the substituents on aryl being each independently selected from alkyl (C₁-C₈), alkoxy (C₁-C₈), aroxy, aralkoxy and halogen; wherein n and m are each independently an integer from 1 to 5. Diphenylamines are key intermediates for the production of leuco dyes used in pressure-sensitive and heat-sensitive imaging systems. The process in at least one embodiment comprises reacting at elevated temperature an aryl halide with an aromatic amine in an organic solvent and aqueous alkaline solution and optionally in some embodiments, phase-transfer agent, followed by addition of catalytic amounts of bis[tri(t-butylphosphine)]palladium at a suitable temperature to rapidly form diphenylamine.

The invention relates to a method for preparing 1,5-diaminonaphthalene through naphthalene in one step and application of catalysts. The naphthalene generates the 1,5-diaminonaphthalene in one step in an organic solvent under the action of ammonia water, hydrogen peroxide and the catalysts, and the used catalysts are obtained in a manner that one type or several types of Ni, Mn and Mo are loaded on gamma-Al2O3 or a titanium silicon molecular sieve. Under the action of the catalysts, the naphthalene reacts with the ammonia water and the hydrogen peroxide in the solvent to compound the 1,5-diaminonaphthalene in one step. The method is simple in technological process, mild in reaction condition, easy and convenient to operate, and friendly to the environment.

A process for preparing 4-aminodiphenylamine using nitrobenzene and aniline as raw materials, a complex base catalyst as the condensation catalyst, and a powdery composite catalyst as the hydrogenation catalyst. The process has 5 process stages including condensation, hydrogenation, separation I, separation II, and refining.

The invention relates to a method for synthesizing tri-amino trinitrobenzene (TATB) by trinitrotoluene (TNT), belonging to the field of organic synthesis technology. The method comprises the following steps of: dissolving the TNT into the concentrated nitric acid, heating up, adding the saturated water solution of the sodium chlorate, reacting, cooling and filtering to obtain the TNBA; adding the TNBA into the water, stirring, adding the sodium hydroxide water solution, filtering, heating up the filter liquor to perform the decarboxylation reaction, cooling, filtering and drying to obtain the TNB; dissolving the TNB into reagent, adding the TNB into turbid liquid mixed by the ammoniation reagent, the sodium methylate and the reagent, and stirring; and heating up, cooling after the reaction, pouring into the distilled water, adjusting the PH value to be neutral or weakly acidic by the acetic acid, stewing, filtering in a pumping way, washing with water, and drying to obtain the TATB. The method takes the TNT as the raw material and uses the chrome-free technology in the oxidizing reaction to avoid the environment pollution, uses a small quantity of the reagent during the aminating reaction to increase the concentration of the reactant and optimize the dynamic conditions, and uses a small quantity of the ammoniation reagent and the sodium methylate to reduce the cost.

In the direct isobutene aminating process, isobutylene and ammonia are directly reacted to prepare tert-butyl amine in the presence of catalyst the reaction temperature of 150-280 deg.c, normal temperature or reaction pressure of 0.05-0.5 MPa, isobutylene and ammonia feeding molar ratio of 0.5-2 and isobutylene space velocity of 260-409 /hr(-1). The catalyst has aluminosilicate molecular sieve as mother body with Si/Al ratio of 30-300, specific surface area of 100-800 sq m/g and pore volume of 0.1-0.4 mg/g, and the molecular sieve is first denatured into H-molecular sieve and then denatured with one or more denaturing elements Ce, La and Ga in the weight content of 1-10 wt%. The present invention adopts catalyst with relatively low cost, and the direct aminating is in relatively low temperature or the favorable thermodynamic temperature range.

The invention provides a method for synthesizing aniline by directly oxidizing and aminating benzene by one step. The method is characterized by taking benzene as a raw material, ammonia water as an aminating agent, hydrogen peroxide as an oxidizing agent, water as a solvent and CuO/SiO2 which is obtained after silicon dioxide with microporous, mesoporous and macroporous structures is modified with metallic copper as a catalyst. The method has the characteristics that the yield of aniline is higher; the reaction conditions are mild; the catalyst preparation process is simple; the raw material is cheap and accessible; and therefore, the method is environment-friendly and has the advantages of low cost, high yield, simplicity and practicability.

The invention discloses a preparation method for tetra-alkyl ammonium hydroxide. The preparation method is implemented by the following technical scheme: performing a reaction on trialkylamine and alkyl halide in a single organic solvent to obtain tetra-alkyl ammonium halide; performing ion exchange on the tetra-alkyl ammonium halide and an oxide or a hydroxide of an alkali metal or an alkaline earth metal in the presence of an organic solvent; and obtaining the aqueous solution of the tetra-alkyl ammonium hydroxide by after-treatment. The method has the advantages of convenient raw material source, low cost, simple preparation process, high halide ion-exchange rate and the like. The tetra-alkyl ammonium hydroxide prepared by adopting the method is particularly suitable to be used as a base catalyst, which is used for the condensation of nitrobenzene and aniline for generating 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and the reduction for generating 4-aminodiphenylamine by hydrogenating. Therefore, the conversion rate of the nitrobenzene is greater than or equal to 99.5 percent and the selectivity is up to over 92 percent.

The disclosed subject matter includes a new type of chemical reactor, described as hydrogen or oxygen electrochemical pumping catalytic membrane reactor. This new type of reactor is suitable for increasing the selectivity and the conversion rate of dehydrogenation, hydrogenation, deoxidation and oxidation reactions and namely in the direct amination reaction of hydrocarbons. This reactor can be used for the production of several chemical compounds, such as the direct amination of hydrocarbons and in particular for the synthesis of aniline from benzene. The disclosed subject matter includes a device and process wherein hydrogen is removed by electrochemical pumping of the hydrogen formed or by oxygen pumping so, as hydrogen is formed, it is oxidized. This new reactor exhibits benzene to aniline conversion higher than 40%.

A disclosed method of preparing p-phenylenediamine includes the steps of: reacting urea and nitrobenzene with a base in the presence of a polar solvent to yield 4-nitrosoaniline and 4-nitroaniline; and subsequently, diluting the resulting mixed solution in an alcohol and performing hydrogenation using a catalyst, thereby providing highly pure p-phenylenediamine destitute of an ortho- or meta-isomer as a byproduct. The method has some advantages in that: the process is simplified in such a manner that the hydrogenation is performed in the presence of the hydrogenation catalyst in a single reactor (i.e., one pot) without a need of isolating 4-nitrosoaniline or purifying the product; inexpensive urea and an alkali base are used to reduce the production cost; and 4-nitrosoaniline is formed as an intermediate to yield p-phenylenediamine with a high selectivity, thereby requiring no purification process after isolation of the product.

The present invention provides a simple, efficient, and industrially advantageous method for the alkylation of amines. The present invention relates to a production method for N-alkylamines whereby an amine is reacted with an alcohol in the presence of a ruthenium complex represented by general formula (1): RuXY(CO)(L) (wherein X and Y can be the same or different and represent a monovalent anionic ligand, and L represents a tridentate aminodiphosphine ligand).

The invention discloses a method of preparing a benzylamine compound. The method comprises the following steps of by taking 1,3-di-tert-butylimidazolin cation contained ionic iron (III) complex with amolecular formula being [(RNCHCHNR)CH][FeBr4] (wherein R is a tertiary butyl group) as a catalyst and di-tert-butyl peroxide as an oxidizing agent, and performing oxidizing reaction on a methylbenzene/ethylbenzene compound and arylamine to synthesize the benzylamine compound. The method is wide in application range, is suitable for a methylbenzene compound containing benzyl-position primary carbon-hydrogen bonds and also suitable for an ethylbenzene compound containing benzyl-position secondary carbon-hydrogen bonds. The method is a first case that preparation of the benzylamine compound through oxidizing reaction of the methylbenzene/ethylbenzene compound and the arylamine is realized with an iron catalyst.

The invention discloses a method for directly preparing aniline through reaction between supported molybdenum dioxide catalyzed benzene and hydroxylamine salt. The method comprises the following steps: respectively adding acetic acid, water, hydroxylamine salt, benzene and a catalyst to a normal pressure reactor provided with a reflux condensation device, heating up the raw materials to 70 to 80 DEG, stirring, and ensuring that the reaction time is 2-5 hours, and obtaining the aniline, wherein the volume ratio of the acetic acid, the water to the benzene is 5:5:1; the mass ratio of the benzene to the catalyst is (5-20):1; the molar rate of the benzene to the hydroxylamine salt is 1:1; the catalyst adopts a carbon material supported molybdenum dioxide catalyst (MoO2/C for short); the mass of the active component MoO2 is 3-15 percent of the total mass of the catalyst. The method has the advantages that the selectivity of the aniline can reach 99 percent, the yield can reach 54 percent, the preparation process of the catalyst is simple, the cost is low, and the method is easy to operate .

The present invention provides a method for the synthesis of β²-amino acids. The method also provides methods yielding α-substituted β-amino aldehydes and β-substituted γ-amino alcohols. The present method according to this invention allows for increased yield and easier purification using minimal chromatography or crystallization. The methods described herein are based on an aldehyde aminomethylation which involves a Mannich reaction between an aldehyde and a formaldehyde-derived N,O-acetal (iminium precursor) and a catalyst, such as, for example, L-proline or a pyrrolidine. The invention allows for large scale, commercial preparation of β²-amino acids.

Conventional zeolite catalysts for the preparation of dimethylamine from methanol or a methylamine mixture and ammonia have a disadvantage in that the selectivity for dimethylamine is steeply lowered when the conversion of methanol becomes 95% or above. The invention aims at overcoming the disadvantage to thereby provide a novel zeolite catalyst attaining a higher selectivity for dimethylamine, a lower selectivity for trimethylamine, and a higher activity for methanol-consumption reaction. A process for preparing dimethylamine by conducting a reaction between methanol and ammonia, among methanol, a methylamine mixture, and ammonia, or between a methylamine mixture and ammonia in the presence of a zeolite catalyst in a vapor phase, wherein the reaction is conducted in the presence of a zeolite catalyst treated with a solution of an organophosphorus compound.

The invention refers to a kind of compound powder catalyst and the manufacturing method. The catalyst is made up of nickel, aluminium and other metal or nonmetal such as iron, copper, manganese, cobalt, chrome, molybdenum, boron, phosphor. The manufacturing method is: blends the nickel, aluminium and other metal or nonmetal powder and melts them, crushes into powder after cooled, then uses alkalito process them. The product has a low price, the process is simple.

The invention discloses a method for preparing allylamine compounds. The allylamine compounds are synthesized by taking an ionic iron (III) complex which has a molecular formula of [(RNCH2CH2NR)CH][FeBr4] (R is tert-butyl) and contains 1,3-di-tert-butyl imidazoline cation as a catalyst, taking di-tert-butyl peroxide as an oxidant and carrying out oxidative coupling reaction on amine compounds andallyl hydrocarbon compounds. The method disclosed by the invention has wide application range, can be used for aromatic amine containing an electron-withdrawing group, is effective for aromatic aminecontaining an electron-donating group, and is a first case of preparing the allylamine compounds through the oxidative coupling reaction of the amine compounds and the allyl hydrocarbon compounds, which is realized by an iron-based catalyst.