Abstract: A novel precious metal doped porous metal catalyst is disclosed. The precious metal is present in from 0.01 to 1.5 weight percent and distributed throughout the particles of porous metal to provide a surface to bulk ratio distribution of not greater than 60. The present invention is further directed to a process of forming said doped catalyst and to improved processes of catalytic hydrogenation of organic compounds.

Abstract: Nitrated aromatic compounds are continuously catalytically hydrogenated into their corresponding aromatic amines in the presence of an effective amount of a nickel or nickel/aluminum catalyst, the nickel catalyst being essentially devoid of aluminum values and the nickel/aluminum catalyst containing up to 5.5% by weight of aluminum values; the subject hydrogenation is thus conducted under conditions such as to limit the formation of nickel aluminates and the nickel or nickel/aluminum catalyst is continuously catalytically active for at least three days.

Abstract: A process for the preparation of an enantiomerically enriched chiral amine of formula (10), or the opposite enantiomer thereof, from an inline of formula (11) 1

Abstract: A process for the catalytic hydrogenation of an organic compound, in particular a labile organic compound, in the presence of a support catalyst with a coating containing ruthenium as active metal and a total of 1.01 to 30 wt. % of active metals. Higher stereoselectivity and a greater catalyst shelf life may be obtained by using a support catalyst of which the oxide, carbide, nitride or siliceous support material has a BET (N2) surface area smaller than 10 m2/g, particularly preferably 0.1 to 5 m2/g, prior to loading with at least one active metal diatomaceous earth with a BET (N2) surface area greater than 2 m2/g is excluded and the ruthenium content thereof makes up at least 50 wt. %, preferably at least 99 wt. % of the active metals. The process and the catalysts are particularly suitable for the hydrogenation of polyfunctional compounds such as hydroxycarbonyl compounds and aromatic amines.

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: Hydrogenation catalyst containing, as the carbon support, a carbon black with an H content of >4000 ppm and, as the catalytically active component, palladium and/or platinum or bi- or multi-metallically doped or alloyed palladium and/or platinum is prepared by addition of metal salt solutions to a suspension of the carbon black with an H content of >4000 ppm, hydrolyzing the metal salt solutions by using a basic compound and carrying out complete deposition of the metal by reduction with a reducing agent. The hydrogenation catalyst can be employed for the hydrogenation of nitroaromatics.

Abstract: The present invention provides a single step process for the preparation of p-aminophenol by hydrogenation of nitrobenzene in presence of an aqueous acid over a mono or bimetallic nickel catalyst at a temperature in the range of 80-120° C. for a period of 1 to 4 hrs. The resulting reaction mixture is extracted with an organic solvent like ethyl acetate, cyclohexane or toluene to separate the aqueous layer containing PAP and neutralizing it with ammonia solution to recover the solid p-aminophenol.

Abstract: Raney nickel catalysts obtainable by a process in which the melt of an alloy comprising 50 to 94 wt. % aluminum, 10 to 50 wt. % nickel, 0 to 20 wt. % iron, 0 to 15 wt. % cerium, cerium mixed metal, vanadium, niobium, tantalum, chromium, molybdenum or manganese and, optionally, further glass-forming elements is allowed to solidify rapidly with a cooling rate of >104 K/s and the rapidly solidified alloy is then subjected to a treatment with organic or inorganic bases are described. A process for the preparation of the Raney nickel catalysts mentioned and their use in the hydrogenation of organic compounds, in particular aromatic nitro compounds, are furthermore described.

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 process for preparing a supported metal catalyst composition which comprises impregnating microspheroidal support particles with a solution of at least one catalytically active metal, or precursor, drying the impregnated support particles and then treating the mobile metal, or precursor in a mobile state with a liquid comprising at least one reducing agent to deposit and immobilize the metal, or its precursor, in the support particles such that the metal, or its precursor, is distributed in the support particle in a layer below the surface of the support particle, the layer being between an inner and an outer region having a lower concentration of metal or precursor. Also, a composition comprising microspheroidal support particles having at least one catalytically active metal or precursor thereof distributed in a layer below the surface of the particles, the layer being between an inner and an outer region of the support particle each having a lower concentration of metal or precursor.

Abstract: The invention relates to a process for the preparation of amines by hydrogenation of nitro compounds, which comprises carrying out the hydrogenation in a vertical reactor whose length is greater than its diameter, having a downward-facing jet nozzle arranged in the upper region of the reactor through which the starting materials and the reaction mixture are fed in, and having an outlet at any desired point of the reactor, through which the reaction mixture is fed back to the jet nozzle in an external circuit by means of a conveying means, and having flow reversal in the lower region of the reactor.

Abstract: A novel precious metal doped porous metal catalyst is disclosed. The precious metal is present in from 0.01 to 1.5 weight percent and distributed throughout the particles of porous metal to provide a surface to bulk ratio distribution of not greater than 60. The present invention is further directed to a process of forming said doped catalyst and to improved processes of catalytic hydrogenation of organic compounds.

Abstract: The present invention relates to the production of aminodiphenyl-amines resulting in good yields and high purity levels when aromatic amines are reacted with nitrohalobenzenes in the presence of a palladium catalyst and a base and the product thus obtained is subsequently hydrogenated with hydrogen.

Abstract: A process for preparing a supported catalyst comprising a transition metal selected from palladium, platinum, nickel, cobalt or copper on an aerogel support, which includes the steps of providing a mixture containing an alkoxide precursor of the aerogel, a chelate complex of the transition metal with a chelating agent having Si(OR)3 anchor groups, and an organic solvent in which the chelate complex is soluble; hydrolyzing the mixture by admixing it with water to form a gel; and converting the gel under supercritical conditions into the transition metal aerogel-supported catalyst. The supported catalyst has an especially homogeneous distribution of the metal component and is suitable, for example, for use as a hydrogenation catalyst.

Abstract: The present invention relates to a hydrogenation process for the preparation of aromatic amino compounds containing directly on the aryl ring or in a side chain one or more entities that may also undergo hydrogenation, such as carbon multiple bonds, nitrile groups, imino groups or carbonyl groups. The preparation is carried out by catalytic hydrogenation of the corresponding aromatic nitro compounds in the presence of a phosphorus-modified noble metal catalyst. The invention relates also to the use of modified noble metal catalysts for the hydrogenation of aromatic nitro compounds containing carbon multiple bonds and/or substituted by nitrile, imino or carbonyl groups.

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: One object of the invention is a process for the catalytic hydrogenation of aromatic nitro compounds in solution or in melt in the presence of hydrogen and at least one noble metal catalyst, nickel catalyst or cobalt catalyst, in which process a catalytic amount of at least one vanadium compound is present, wherein the vanadium has the oxidation state 0, II, IV or V. It has been found that in the catalytic hydrogenation of aromatic nitro compounds the accumulation of hydroxylamines can be almost completely prevented by the addition of catalytic amounts of vanadium compounds, which usually results in concentrations of <1% hydroxylamine. The resulting hydrogenated products are whiter (purer) than those obtained without the addition of the vanadium compound because almost no azo or azoxy compounds are obtained. The hydrogenation, in particular the final phase, proceeds faster than without said addition. Accordingly, substantial advantages with respect to quality constancy and economy are obtained.

Abstract: Aromatic amines are produced by catalytic hydrogenation of corresponding aromatic nitro compounds in the gas phase, by carrying out the hydrogenation in the presence of catalysts which, besides palladium, vanadium and lead, contain in addition molybdenum, tungsten and/or rhenium on a ceramic support having a BET surface area of less than 40 m.sup.3 /g, at temperatures of from 180.degree. C. to 500.degree. C. in a catalyst bed and in a molar ratio of hydrogen to the nitro group or nitro groups of 3:1 to 30:1.

Abstract: A process for the production of aromatic amines by catalylic hydrogenation.

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: Disclosed is a method for producing bis(3-amino-4-hydroxyphenyl) compounds, which comprises reducing bis(3-nitro-4-hydroxyphenyl) compounds with hydrazines in the presence of a catalyst. The method produces bis(3-amino-4-hydroxyphenyl) compounds of high quality under mild conditions at high yields. The products can be isolated and purified in a simple manner to have a higher purity. The method is suitable to industrial-scale production of the products.

Abstract: A method for the hydrogenation of aromatic nitrocompounds to aromatic amines, which comprises mixing an aromatic nitrocompound, hydrogen gas and a solvent together under elevated pressure and temperature to form a homogenous mixture in a supercritical or near-critical state and bringing the resulting homogenous mixture into contact with a catalyst to form the aromatic amine product.

Abstract: An apparatus and method for converting hydrazine, substituted hydrazines and/or other nitrogen-containing explosive materials, particularly unsymmetric dimethyl hydrazine (UDMH), to ammonia or ammonia and the corresponding amines by hydrogenation are disclosed. The hydrazines are diluted with a suitable carrier fluid, preferably water, mixed with hydrogen, then hydrogenated in a catalyst reactor, followed by separation of the commercially valuable ammonia and amines. Separated carrier fluid and hydrogen gas may be recycled in to the process to conserve energy and reduce waste. Recycled carrier fluid may be used to preheat the diluted hydrazine prior to hydrogenation. Ammonia may be dissociated and the resultant hydrogen recycled into the hydrogenation process. The apparatus is sized for disassembly and transport for shipping to hydrazine disposal sites.

Abstract: A method for stabilizing DAR during storage, comprising storing DAR in the presence of a reducing agent having a standard redox potential of not less than -0.20 volt and not more than 0.34 volt, in a proportion of not less than 100 ppm and not more than 10,000 ppm of DAR. The present invention improves storage stability of DAR. This in turn results in easy handling and long-term preservation of DAR. Thus, a high quality polymer PBO can be easily produced and the invention greatly contributes to the industrial field.

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: 2-Amino-6-chlorophenyl-alkylsulfanes are prepared in a particularly advantageous manner by hydrogenating 2-chloro-6-nitrophenyl-alkylsulfanes catalytically in the presence of a solvent without the addition of a further sulfur compound, and the novel compound 2-amino-6-chlorophenyl-isopropylsulfane is provided.

Abstract: The present invention relates to a process for the preparation of aromatic amino compounds which are substituted by a least one group comprising at least one unsaturated carbon-carbon bond, by catalytic hydrogenation of corresponding aromatic nitro compounds in the presence of a modified noble metal catalyst, wherein the noble metal catalyst used is platinum modified with a metal selected from the group consisting of lead, mercury, bismuth, germanium, cadmium, arsenic, antimony, silver and gold, and to novel noble metal catalysts for use in this process.

Abstract: An improvement in a process for the preparation of a p-aminodiarylamine by reduction of the corresponding nitroso or nitro compound with hydrogen in a hydrogenator in the presence of a catalyst is disclosed. The invention includes equipping the hydrogenator with filtration means capable of separating the p-aminodiarylamine product from the catalyst, whereby the p-aminodiarylamine product can be removed from the hydrogenator while the catalyst is retained therein, thereby permitting the reaction to be run semicontinuously or continuously.

Abstract: 2-Trifluoromethoxy-aniline, which can be used as an intermediate for example for preparing pharmaceuticals and agrochemicals, is obtained in very good yields and high purity by nitrating in a first step 1,2-dichlorotrifluoromethoxy-benzene at temperatures between -20.degree. C. and +80.degree. C. and catalytically hydrogenating the resulting nitration products (exclusively 1,2-dichloro-5-nitro-4-trifluoromethoxy-benzene and 1,2-dichloro-3-nitro-4-trifluoromethoxy-benzene) in a 2nd step, it being possible to isolate the aniline intermediates corresponding to the two nitrobenzene derivatives; the nitrobenzene and aniline derivatives mentioned, being novel compounds, are also part of the subject matter of the invention.

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: 4-Aminodiphenylamines are produced by reacting optionally substituted aniline with optionally substituted nitrobenzene in the presence of water and/or alcohols and organic and/or inorganic bases and then catalytically hydrogenating the resultant nitro- and/or nitrosodiphenylamine in the presence of water, wherein the catalytic hydrogenation of the reaction mixture is performed in the presence of 25 to 80 wt. % of water, relative to the weight of the reaction mixture from the condensation reaction, the hydrogenation catalyst is removed from the hydrogenation mixture once absorption of hydrogen has ceased, 10 to 100 vol. % of aromatic solvent, relative to the total volume of the hydrogenation mixture, are optionally added to the hydrogenation mixture, the resultant organic phase is separated in order to isolate the 4-aminodiphenylamine and the aqueous phase is returned to the initial reaction mixture.

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.

Abstract: Aromatic amines are produced by catalytic hydrogenation of nitroaromatic compounds in the gas phase. The catalyst includes palladium and lead on graphite or on a graphite-containing coke support. From 30 to 6000 equivalents of hydrogen for each equivalent of nitro groups are contacted with the catalyst during this process.

Abstract: Novel aminoalkyloximes of the formula ##STR1## wherein: a. X is hydrogen, loweralkyl, loweralkoxy, halogen, trifluoromethyl, or a group of the formula ##STR2## wherein Y is hydrogen or loweralkyl, and p is 1 or 2; b. A is a group of the formula ##STR3## c. R.sup.1 and R.sup.2 are independently hydrogen or lowerakyl; and d. m is 2 to 6 and n is 0, or 2 to 6, inclusive, serotonin reuptake inhibitors, useful for treating depression and obsessive compulsive disorders are described. Also described are precursors of and processes for the preparation of such aminoakyloximes.

Abstract: A process for preparing substituted aromatic azo compounds is provided which comprises contacting a nucleophilic compound and an azo containing compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the azo containing compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 10.degree. C. to about 150.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1. In another embodiment, the substituted aromatic azo compounds are further reacted with a nucleophilic compound in the presence of a suitable solvent system, a suitable base and a controlled amount of protic material at a temperature of about 70.degree. C. to about 200.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1 to produce a substituted aromatic amine.

Abstract: Disclosed is a method of making 3,5-diaminobenzotrifluoride from 4-chloro-3,5-dinitrobenzotrifluoride. A solution of 4-chloro-3,5-dinitrobenzotrifluoride in an alcohol is prepared. Separately, a slurry is prepared of a palladium catalyst on a suitable substrate, at least one equivalent of magnesium oxide per equivalent of 4-chloro-3,5-dinitrobenzotrifluoride, sufficient hydrogen-donating reducing agent to reduce the 4-chloro-3,5-dinitrobenzotrifluoride to 3,5-diaminobenzotrifluoride, and an amount of alcohol sufficient to make the slurry stirrable. The solution is added to the slurry with stirring at a rate that does not exceed the reaction rate of the 4-chloro-3,5-dinitrobenzotrifluoride so that no unreacted 4-chloro-3,5-dinitrobenzotrifluoride accumulates in the slurry. The reaction mixture is heated at about 75.degree. to about 100.degree. C.

Abstract: The invention relates to ferrocenyldiphosphine ligands containing a silylene group, ferrocenyldiphosphines bound to inorganic or polymeric organic supports by this silylene group, their preparation and also their metal complexes with transition metals such as rhodium or iridium. The invention also relates to the use of these complexes for hydrogenating organic double or triple bonds, in particular olefinic double bonds and carbon-heteroatom double bonds. The complexes are particularly suitable for enantioselective hydrogenation using chiral diphosphines and prochiral unsaturated compounds.The preparation of these immobilized ferrocenyldiphosphines has only been made possible by the provision of correspondingly functionalized ferrocenyldiphosphines. These compounds and their preparation are likewise novel.Accordingly, the invention also provides compounds of the formula I ##STR1## in which R.sub.1 is C.sub.1 -C.sub.8 alkyl, phenyl or phenyl substituted by from 1 to 3 C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.

Abstract: A process for preparing substituted aromatic amines which comprises contacting a nucleophilic compound and a substituted aromatic azo compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the substituted aromatic azo compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 70.degree. C. to about 200.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1. In another embodiment, the substituted aromatic amines of the invention are reductively alkylated to produce alkylated diamines or substituted derivatives thereof.

Abstract: A process for the production of N-alkyl anilines by the concurrent hydrogenation of a nitrobenzene to an aniline and the acylation of the aniline with acyl anhydride takes place on a continuous basis in a stirred tank reactor in which liquid product is continuously withdrawn from the reactor.

Abstract: A process for the continuous preparation of aniline by hydrogenating nitrobenzene with hydrogen is disclosed which comprises the steps of suspending, in an aniline solvent, a catalyst of palladium or palladium-platinum which is deposited on a lipophilic carbon having an oil absorbency of at least 100, and carrying out reaction at a temperature of from 150.degree. to 250.degree. C. substantially in the absence of water while aniline and water formed in said reaction are continuously distilled off as vapor from the reaction product, and the concentration of nitrobenzene in the reaction solution is maintained at 0.01% by weight or less, wherein a zinc compound is added to the reaction system as a promotor and carbon monoxide is added to the hydrogen at a concentration of 1-500 ppm.

Abstract: A method of producing 4-ADPA is disclosed wherein aniline or substituted aniline derivatives and nitrobenzene are reacted under suitable conditions to produce 4-nitrodiphenylamine or substituted derivatives thereof and/or 4-nitrosodiphenylamine or substituted derivatives thereof and/or their salts, either or both of which are subsequently reduced to produce 4-ADPA or substituted derivatives thereof. The 4-ADPA or substituted derivatives thereof can be reductively alkylated to produce p-phenylenediamine products or substituted derivatives thereof which are useful as antiozonants.

Abstract: 4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way thata) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO.sub.3, H.sub.2 SO.sub.4 and SO.sub.3 at 0 to 40.degree. C. in anhydrous H.sub.2 SO.sub.4,b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15.degree. C. to +15.degree. C. and then at 20.degree. to 40.degree. C. to give the dibenzyloxy compound andc) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.

Abstract: Aromatic diamines and polyamines are produced by a continuous process for the catalytic hydrogenation of the corresponding dinitro and polynitro compounds at elevated temperature. Heat removed from the reaction mixture may be used to produce steam with an overpressure of .gtoreq.2 bar.

Abstract: p-Amino-phenols are advantageously prepared by catalytic hydrogenation of the aromatic nitro compounds on which they are based in a reaction medium of aqueous sulphuric acid in the sense of a Bamberger rearrangement at elevated temperature by a procedure in which the reaction medium additionally contains a water-miscible organic solvent.