Abstract: The present invention relates to a process for the preparation of toluenediamine, in which dinitrotoluene is reacted with hydrogen in the presence of a catalyst. The dinitrotoluene required by this process has a content of carbon dioxide, in either physically dissolved or chemically bonded form, of not more than 0.175 mol %, based on the molar amount of the dinitrotoluene.

Abstract: The invention is directed to a method of producing one or more 4-aminodiphenylamine intermediates comprising the steps: a. bringing an aniline or aniline derivative and nitrobenzene into reactive contact; and b. reacting the aniline and nitrobenzene in a confined zone at a suitable time and temperature, in the presence of a mixture comprising a strong organic base, or equivalent thereof, and an oxidant comprising hydrogen peroxide in an amount of from about 0.01 to about 0.60 moles of hydrogen peroxide to moles of nitrobenzene.

Abstract: A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

Abstract: Compounds containing phenolic hydroxy groups are removed from a gas stream which contains at least one aromatic amine generated during the gas-phase hydrogenation reaction of the corresponding nitroaromatic compounds with hydrogen, by adsorption on a basic solid.

Abstract: Method for the production of supported activated metal catalysts, whereby an alloy, a metal powder, a pore builder is dispersed in a water, the dispersion is sprayed on a support which is the dried, calcined and activated. The catalysts can be used for organic transformations, i.e. for hydrogenation reactions.

Abstract: A method for producing aniline or toluenediamine is disclosed which comprises forming a dispersion comprising hydrogen gas bubbles dispersed in a liquid medium comprising either nitrobenzene or dinitrotoluene, wherein the hydrogen gas bubbles have a mean diameter less than 1 micron; and subjecting the dispersion to hydrogenation reaction promoting conditions comprising pressure less than about 600 kPa and temperature less than about 200° C., whereby at least a portion of the nitrobenzene or dinitrotoluene is hydrogenated to form aniline or toluenediamine, respectively. A system for carrying out the method is also disclosed.

Abstract: Aromatic amines are produced by adiabatic hydrogenation of nitroaromatic compounds in the gas phase on one or more fixed catalysts. The nitroaromatic reactant is passed over the catalyst under pressure and at elevated temperature with hydrogen, water, optionally nitrogen and substantially in the absence of the aromatic amine produced from the nitroaromatic.

Abstract: The present invention relates to a process for the preparation of toluenediamine, in which dinitrotoluene is reacted with hydrogen in the presence of a catalyst. The dinitrotoluene required by this process has a content of carbon dioxide, in either physically dissolved or chemically bonded form, of not more than 0.175 mol %, based on the molar amount of the dinitrotoluene.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: A hydrogenation process of chloronitrobenzene. The hydrogenation process comprises the steps of producing a nanosized boron-containing nickel catalyst, wherein a ratio of the amount of the boron atom to the amount of the nickel atom in the nanosized boron-containing nickel catalyst is of about 0.1-0.9. Then, the nanosized boron-containing nickel catalyst is placed into a reactor with a chloronitrobenzene an alcohol solvent having carbon number less than four per a molecular and a hydrogenation process is performed to hydrogenating the chloronitrobenzene in hydrogen with a reaction pressure of about 5-40 atm and a reaction temperature of about 40-150° C.

Abstract: The invention describes a process for the production of aromatic amines by the catalytic hydrogenation of aromatic nitro compounds, with the process being characterized by at least one catalytic hydrogenation step and the catalyst consists at least of a monolithic support and a catalytically active coating.

Abstract: The invention is directed to a method of producing one or more 4-aminodiphenylamine intermediates comprising the steps: a. bringing an aniline or aniline derivative and nitrobenzene into reactive contact; and b. reacting the aniline and nitrobenzene in a confined zone at a suitable time and temperature, in the presence of a mixture comprising a strong organic base, or equivalent thereof, and an oxidant comprising hydrogen peroxide in an amount of from about 0.01 to about 0.60 moles of hydrogen peroxide to moles of nitrobenzene.

Abstract: The present invention discloses a process for preparing 4-aminodiphenylamine, which process uses nitrobenzene and aniline as raw materials, a complex base catalyst as condensation catalyst and a powdery composite catalyst as hydrogenation catalyst, and comprises five process stages: condensation; separation I; hydrogenation; separation II; and refining. The process can be continuously carried out. By selecting a complex base catalyst to catalyze the condensation reaction and separating it prior to the hydrogenation, the problem that the complex base catalysts thermally decompose in the hydrogenation reaction is avoided, the selectable range of hydrogenation catalysts is largely enlarged so that it is possible to select cheaper hydrogenation catalyst, and the selection of production process and equipment is easier and further industrialization is easier. The complex base catalysts used in the present invention are inexpensive and have higher catalytic activity.

Abstract: 4-aminodiphenylamine is prepared by reacting carbanilide and nitrobenzene in an adequate solvent, which may be nitrobenzene, in the presence of an appropriate organic base, which may be tetramethylammonium hydroxide, alone or in mixture with an inorganic base and subsequently reducing the reaction product in the presence of an appropriate catalyst and hydrogen gas. The subsequent reduction may be carried out on the reaction mixture before the reaction mixture is subjected to separation.

Abstract: Aromatic amines are produced from aromatic hydrocarbons by a) reacting the aromatic hydrocarbon(s) with a mixture of nitric acid and sulfuric acid to generate a two-phase reaction mixture, b) separating the reaction mixture into an aqueous acid phase and an organic phase containing the nitroaromatic compounds c) washing the organic phase to purify the nitroaromatic compound(s), d) hydrogenating the nitroaromatic compound(s) in the presence of a catalyst to produce the aromatic amine(s) and water of reaction, and e) separating the water of reaction formed in step d) from the aromatic amine(s), in which the water of reaction separated in step e) is used to wash the organic phase containing the nitroaromatic compounds in step c).

Abstract: The invention pertains to an improved apparatus comprised of a monolith catalytic reactor having an inlet and an outlet and a static mixer having an inlet and an outlet thereto with the outlet of said static mixer in communication with the inlet of said monolith catalytic reactor. The invention also pertains to an improvement in a process for effecting a reaction in the monolith catalytic reactor wherein a reactant gas and reactant liquid are introduced to the inlet to the monolith catalytic reactor, reacted and, then, the reaction product passed through the outlet of the monolith catalytic reactor.

Abstract: A process for the production of aromatic amines which comprises the reduction of an aromatic compound containing at least two nitro groups with hydrogen in the presence of a catalyst is disclosed. The reaction is carried out so as to maintain up to 10% by weight of reaction intermediates (aminonitrites) and the solution produced is treated to recover the aromatic amine with a purity of over 99% and a mixture consisting of aromatic amine and reaction intermediates is recycled to the reactor.

Abstract: Liquid organic compounds are hydrogenated by a process in which the hydrogen present in the reactor contains proportions of at least one gas which is inert in the hydrogenation reaction.

Abstract: The present invention relates to a process for the preparation of nitrodiphenylamines by reaction of nitrohalogens with anilines, a base and a catalyst, and to a process for the preparation of aminodiphenylamine by hydrogenation of the nitrodiphenylamine intermediately prepared.

Abstract: Disclosed are intermediates of the formula (A) and methods of making same.

Abstract: The catalyst can be prepared by reduction of a precursor of a hydrogenation-active metal, which may be present on an oxidic support, by reaction with at least one compound of the formula (I)

Abstract: The invention is directed-to a method of producing one or more 4-aminodiphenylamine intermediates comprising the steps of bringing an aniline or aniline derivative and nitrobenzene into reactive contact and reacting the aniline and nitrobenzene in a confined zone at a suitable time and temperature, in the presence of a mixture comprising an inorganic salt or metal organic salt having a cation that would be a suitable cation of a strong inorganic base, an oxidant and an organic base, the mixture not including a reaction product of betaine and a strong inorganic base.

Abstract: The invention pertains to an improved apparatus comprised of a monolith catalytic reactor having an inlet and an outlet and a static mixer having an inlet and an outlet thereto with the outlet of said static mixer in communication with the inlet of said monolith catalytic reactor. The invention also pertains to an improvement in a process for effecting a reaction in the monolith catalytic reactor wherein a reactant gas and reactant liquid are introduced to the inlet to the monolith catalytic reactor, reacted and, then, the reaction product passed through the outlet of the monolith catalytic reactor.

Abstract: The invention pertains to an improved apparatus comprised of a monolith catalytic reactor having an inlet and an outlet and a static mixer having an inlet and an outlet thereto with the outlet of said static mixer in communication with the inlet of said monolith catalytic reactor. The invention also pertains to an improvement in a process for effecting a reaction in the monolith catalytic reactor wherein a reactant gas and reactant liquid are introduced to the inlet to the monolith catalytic reactor, reacted and, then, the reaction product passed through the outlet of the monolith catalytic reactor.

Abstract: The invention is a process to regenerate monolith catalytic reactors employed in the liquid phase hydrogenation reactions, particularly those kinds of reactions involving nitroaromatic compounds. The catalytic metals in the monolith catalytic reactor are deactivated by carbonaceous and deactivating byproducts and must be regenerated to extend the catalyst service life and reduce costs. The regeneration process involves two steps: initially passing an oxidizing gaseous mixture through the monolith catalytic reactor at an elevated temperature and for a time sufficient to remove carbonaceous and deactivating byproducts; and then passing a reducing gas though the monolith catalytic reactor previously exposed to the oxidizing gas under conditions for reducing the catalytic metal to its reduced state.

Abstract: This invention provides a composition suitable for use in a reaction zone where aniline is reacted with nitrobenzene to obtain intermediates of 4-aminodiphenylamine comprising a solid support having interior channels with base material employed in the reaction loaded into the channels. The cross-sectional dimensions of the channels are such as to provide a restricted transition state with regard to the reaction and to improve the selectivity of the reaction in favor of the intermediates. The invention also provides a method for loading the base material in the solid support. The invention further provides a process for carrying out the above reaction using the above composition.

Abstract: The present invention relates to an improved for the hydrogenation of an immiscible mixture of an organic reactant in water. The immiscible mixture can result from the generation of water by the hydrogenation reaction itself or, by the addition of, water to the reactant prior to contact with the catalyst. The improvement resides in effecting the hydrogenation reaction in a monolith catalytic reactor from 100 to 800 cpi, at a superficial velocity of from 0.1 to 2 m/second in the absence of a cosolvent for the immiscible mixture. In a preferred embodiment, the hydrogenation is carried out using a monolith support which has a polymer network/carbon coating onto which a transition metal is deposited.

Abstract: A process for the preparation of substituted amines by catalytic hydrogenation of substituted organic nitro compounds with hydrogen or hydrogen-containing gas mixtures in the presence of a shaped Raney catalyst as the hydrogenation catalyst, wherein the Raney catalyst is in the form of hollow bodies or shell-activated tablets. Nickel, cobalt, copper, iron, platinum, palladium or ruthenium are preferably used as catalytically active constituents.

Abstract: Carbon monolith-supported catalysts with high leach resistance used in catalytic applications involving strong acidic and basic conditions in a pH range of from 0 to 6.5 and from 7.5 to 14, are respectively described. The leach resistance of the catalyst system originates from strong interaction between the catalyst and the unsaturated valence of the carbon surface. In addition to surprisingly high resistance to leach out, the catalysts also have substantial differential advantages in catalyst performance: catalyst activity, selectivity, and stability.

Abstract: The invention provides a process for preparing 4-aminodiphenylamine, an important starting product for synthesizing antioxidants and stabilizers in the rubber and polymer industry, by hydrogenating nitrosobenzene with hydrogen in the presence of a proton acid as catalyst and in the presence of a hydrogenating catalyst, optionally in the presence of an inert organic solvent and thermally decomposing the 4-ADPA ammonium salt produced in this way, wherein 4-ADPA is obtained. 4-aminodiphenylamine is produced in good yields and high purity by the process according to the present invention. Furthermore, no effluent is produced, which makes the process particularly economic and ecological.

Abstract: The invention is directed to a method of producing one or more 4-aminodiphenylamine intermediates comprising the steps of bringing an aniline or aniline derivative and nitrobenzene into reactive contact; and reacting the aniline and nitrobenzene in a confined zone at a suitable time and temperature, in the presence of a mixture comprising a strong base and a suitable phase transfer catalyst. Certain phase transfer catalysts may also function as the strong base.

Abstract: A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenylamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials.

Abstract: 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.

Abstract: A continuous process for the preparation of aromatic di- and/or polyamines by catalytic hydrogenation of the corresponding aromatic di- and/or polynitro compounds with hydrogen, characterized in that, in a reactor with a catalytic fixed bed or trickle bed at a pressure between 5 and 100 bar and a reaction temperature of from 100 to 220° C. a) the aromatic di- and/or polynitro compounds, optionally in the presence of a solvent, are introduced into a product stream comprising essentially recycled hydrogenated product, water and hydrogen, and b) a part of the product stream is removed continuously from the reactor system.

Abstract: The invention relates to a process for the preparation of specific salts of 1-substituted 2,4-diaminobenzenes by catalytic hydrogenation of 1-substituted 2,4-dinitrobenzenes and addition of the reaction product obtained after the hydrogenation and separated from the catalyst to an aqueous solution of an acid.

Abstract: Processes and apparatus for providing improved contaminant removal and hydrogen recovery in hydrogenation reactors, particularly in refineries and petrochemical plants. The improved contaminant removal is achieved by selective purging, by passing gases in the hydrogenation reactor recycle loop or purge stream across membranes selective in favor of the contaminant over hydrogen.

Abstract: Process for the selective hydrogenation of alphatic or aromatic substrates under supercritical or near critical conditions. Hydrogenation is effected using a heterogeneous catalyst in a continuous flow reactor containing a supercritical or near critical reaction medium and selectively of product formation is achieved by varying one or more of the temperature, pressure, catalyst and flow rate.

Abstract: This invention relates to a process for preparing indan derivatives and comprises a process for preparing cis-1-amino-2-indanol by treating (.+-.)indan-1,2-diol and/or its 2-formate derivative with specific microbes to give optically active 2-hydroxy-1-indanone, converting the optically active 2-hydroxy-1-indanone to its oxime, and treating the oxime with hydrogen or a hydrogen donor in the presence of a heterogeneous hydrogenation catalyst, a process for preparing optically active 2-hydroxy-1-indanone and/or optically active indan-1,2-diol by treating (.+-.)indan-1,2-diol and/or its 2-formate derivative with specific microbes, and a process for preparing cis-1-amino-2-indanol by treating the oxime of 2-hydroxy-1-indanone with hydrogen or a hydrogen donor in the presence of a heterogeneous hydrogenation catalyst.

Abstract: Shaped catalyst compositions are disclosed comprising (i) at least one metal selected from the group consisting of copper, manganese, zinc, nickel, cobalt and iron, (ii) calcium silicate and (iii) at least one clay material. Also disclosed are a process for preparing the foregoing shaped compositions and a process for hydrogenating aldehydes, ketone, carboxylic acids, carboxylic acid esters and nitro aroniate compounds using these shaped catalysts.

Abstract: A method for hydrogenating aromatic nitro compounds by reacting at least one aromatic nitro compound with hydrogen in two adiabatically operated fixed-bed catalytic reactors arranged in series, wherein one part of the reaction mixture from the first reactor is recirculated therein while the other part is fed into the second reactor.

Abstract: Disclosed is an improved process for preparing 1-chloro-2,4-diaminobenzene by the selective hydrogenation of 1-chloro-2,4-dinitro-benzene wherein the hydrogenation is carried out in the presence of a modified Raney nickel catalyst containing about 70 to 95 weight percent nickel, about 4 to 10 weight percent aluminum, about 0.1 to 4 weight percent molybdenum, and from 0 to about 20 weight percent cobalt. The 1-chloro-2,4-diaminobenzene is useful as an intermediate for disperse dyes and for color photography.

Abstract: This invention relates to an improvement in a process for hydrogenating a nitroaromatic composition namely dinitrotoluene by contacting the dinitrotoluene with hydrogen in a reactor employing a monolith catalyst system. Broadly the improvement resides in the continuous, essentially solventless, adiabatic hydrogenation of dinitrotoluene to toluenediamine in a plug flow reactor system incorporating the monolith catalyst. The process generally comprises the steps:introducing a feedstock comprised of dinitrotoluene and reaction product components continuously into the reactor and said feedstock having less that 30% by weight of a solvent,carrying out the hydrogenation of dinitrotoluene to toluenediamine under adiabatic conditions; and,continuously removing hydrogenated reaction product from the reactor.

Abstract: The novel primary intermediate, 1-(5-amino-2-hydroxyphenyl)ethane-1,2-diol and a method for producing same, are disclosed. The novel intermediate can be employed as a replacement for p-aminophenol in oxidation dye formulations.

Abstract: This invention provides a method for preparing 4-ADPA by charging nitrobenzene into a reaction zone under hydrogen pressure in the presence of a strong organic base and a catalyst for hydrogenation. The method provides the convenience and economy of a one-step process, while producing improved yields and selectivities. The invention further provides for various embodiments of the foregoing which are suitable for the production of 4-ADPA, and the hydrogenation or reductive alkylation to produce PPD. Important to the invention are the molar ratios of aniline to nitrobenzene and nitrobenzene to the strong organic base and the choice and use of hydrogenation catalyst.

Abstract: Aromatic amines are produced by hydrogenation of the appropriate aromatic nitro compounds in the vapour phase on fixed catalysts. The catalysts contain supported metals active in hydrogenation, the reaction is carried out under adiabatic conditions at a pressure of from 1 to 30 bar, an inlet temperature of from 200.degree. to 400.degree. C. and a maximum catalyst temperature of 500.degree. C.

Abstract: Aromatic amines are produced by hydrogenation of the associated aromatic nitro compounds in the gas phase over fixed catalysts. The catalysts contain active hydrogenation metals on supports. The reaction is conducted at a pressure of 2-50 bar and at a temperature in the range 250.degree.-500.degree. C. under adiabatic conditions. A circulating gas is passed over the catalyst, which circulating gas contains 3-150 moles of hydrogen, 2-100 moles of the amino groups to be formed per mole of nitro groups, and 2 to 6 moles of water per amino group equivalent. The amine and water formed, as well as a purification stream, are separated from the circulating gas. Thereafter the circulating gas is enriched with volatilised aromatic nitro compound and fresh hydrogen and recycled.

Abstract: The present invention relates to a process for preparing aromatic amines by reacting an aromatic nitro compound with carbon monoxide in a solvent mixture comprising water and a water-insoluble organic solvent by means of a catalyst comprising palladium and a water-soluble phosphine under a pressure of from 5 to 300 bar and at a temperature of from 50 to 200.degree. C., and separating the aqueous phase and the organic phase.

Abstract: Amine mixtures generated during the production of diaminotoluene by hydrogenating dinitrated aromatic compounds are treated to separate high boiling materials from the desired amine products. In this process, any water of reaction and any solvent are first removed from the diaminotoluene isomer mixture (TDA mixture). The low-boiling TDA isomers are then separated using a TDA isomer distillation column. In the process of the present invention, the bottom phase remaining after the initial distillation contains a mixture of m-TDA and high-boiling materials. This bottom phase is separated and concentrated until the high-boiling material content is from approximately 25 to 60 wt. %. This concentrated bottom phase is then mixed with o-TDA in a ratio of 1:1 to 1:5 and a m-/o-TDA mixture is removed by distillation. The m-/o-TDA mixture thus recovered is then returned to the TDA isomer distillation column.

Abstract: The present invention relates to a process for the preparation of hydroxycarboxylic acid amides of the general formula (1): ##STR1## in which R.sup.1 and R.sup.2 are identical or different and are hydrogen, halogen, cyano, a linear or branched alkyl, alkenyl, alkynyl or alkoxy group having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cycloalkyl group having 6 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, R.sup.3 is hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, R.sup.4 is hydrogen or a linear or branched alkyl group having 1 to 6 carbon atoms, or R.sup.3 and R.sup.4, together with the carbon atom to which they are attached, form a five- or six-membered cycloalkane ring, and n is an integer from 1 to 12, wherein an aniline of the general formula (2) ##STR2## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.

Abstract: The present invention is directed to a process for transporting toluenediamine (TDA) from a first site to a second site. The process of the invention comprises the steps of (a) providing a molten mass of TDA isomers at the first site; (b) cooling the molten mass to a temperature below the melting point, the molten mass thereby forming flowable particles of solid TDA in an inert gas; (c) providing an airtight storage vessel lined with a chemically inert liner; (d) storing the flowable particles of solid TDA in the lined storage vessel; (e) charging the storage vessel with inert gas; (f) transporting the storage vessel from the first site to the second site; and (g) remelting the TDA flowable particles in inert gas with TDA liquid that is superheated above the melting point to produce a molten TDA isomer mixture in inert gas having substantially the same isomer ratio as that of the molten mass.