Abstract: A method for preparing an aryl substituted p-phenylenediamine substance is provided. A structural formula of the aryl substituted p-phenylenediamine substance is shown as Formula (I?), where each of R? and R? is phenyl or o-methylphenyl, and R? is same as or different from R?; and the method comprises that: a raw material A and a raw material B are reacted in the presence of a hydrogen acceptor and a catalyst to form the aryl substituted p-phenylenediamine substance, the raw material A having a structure shown as Formula (I), the raw material B being cyclohexanone and/or o-methylcyclohexanone and the hydrogen acceptor being a hydrogen acceptor capable of accepting hydrogen for conversion into the raw material B. Raw materials are low in cost and readily available; use of a large amount of water for post-treatment is avoided. The reaction condition is relatively mild, and corrosion to equipment is avoided.

Abstract: This invention relates to a polyolefin composition comprising one or more of the following formulae: wherein the PO is the residual portion of a vinyl terminated macromonomer (VTM) having had a terminal unsaturated carbon of an allylic chain and a vinyl carbon adjacent to the terminal unsaturated carbon; R1 is a hydrogen atom, an aryl group, or an alkyl group, wherein the aryl group or alkyl group can include one or more heteroatoms, an alkyl or aryl amino group, a polyalkylamino group; wherein the VTM is a vinyl terminated macromonomer.

Abstract: A sulfur-containing palladium-carbon catalyst prepared by loading palladium on an active carbon, mixing the palladium-carbon catalyst with a solvent to form a slurry, adding a sulfide to the slurry to treat the loaded palladium under a predetermined temperature, and removing liquid and drying to obtain the catalyst. The sulfur-containing palladium-carbon catalyst is suitable for making phenylene diamine rubber antioxidant with improved productivity and selectivity.

Abstract: A process for preparing alkylated p-phenylenediamine having the steps of reacting aniline and nitrobenzene in presence of a complex base catalyst to obtain 4-aminodiphenylamine intermediates, hydrogenating the 4-aminodiphenylamine intermediates to 4-aminodiphenylamine in presence of a hydrogenation catalyst, and reductively alkylating the 4-aminodiphenylamine to alkylated p-phenylenediamine.

Abstract: An object is to provide a process for providing hydrogen or heavy hydrogens conveniently without the necessity of large-scale equipment and a process capable of performing hydrogenation (protiation, deuteration or tritiation) reaction conveniently without the use of an expensive reagent and a special catalyst. The production process includes a process for producing hydrogen or heavy hydrogens, containing subjecting water or heavy water to mechanochemical reaction in the presence of a catalyst metal, and a process for producing a hydrogenated (protiated, deuterated or tritiated) organic compound, containing subjecting an organic compound and water or heavy water to mechanochemical reaction in the presence of a catalyst metal.

Abstract: A process for synthesizing 2-methoxymethyl-1,4-benzenediamine, its derivatives of formula (IV) and the salts thereof, which comprises a reductive amination step. The preferred final product is 2-methoxymethyl-1,4-benzenediamine of formula (IV-a). These compounds may be used as primary intermediates in compositions for dyeing keratin fibers.

Abstract: The present invention relates to a process for preparing unsymmetric secondary tert-butylamines by continuous amination in the gas phase, wherein tert-butylamine is converted over hydrogenation catalysts in the presence of an alcohol or aldehyde and hydrogen.

Abstract: The present application relates to a process for preparing unsymmetric secondary tert-butylamines which, as well as the tert-butyl radical, also comprise an alkyl, cycloalkyl or benzyl radical. They are prepared by reacting corresponding aldehydes with tert-butylamine and hydrogen in the presence of hydrogenation catalysts (reductive amination) in the liquid phase.

Abstract: A process for synthesizing 2-methoxymethyl-1,4-benzenediamine, its derivatives of formula (IV) and the salts thereof, which comprises a reductive amination step. The preferred final product is 2-methoxymethyl-1,4-benzenediamine of formula (IV-a). These compounds may be used as primary intermediates in compositions for dyeing keratin fibers.

Abstract: [Problem] The present invention aims to provide a novel organometallic compound that can be used as a general-use highly active catalyst with superior selectivity for functional groups. [Means for Solving Problem] The present invention relates to an organometallic compound having a novel specific structure of general formula (1): and to a general-use highly active catalyst used in reductive amination reaction with superior selectivity for functional groups that comprises said organometallic compound, and to a process for preparing amine compounds by reductive amination reaction using said catalyst.

Abstract: Processes comprising: (i) providing a reactant selected from the group consisting of primary alcohols, secondary alcohols, aldehydes, ketones and mixtures thereof; and (ii) reacting the reactant with hydrogen and a nitrogen compound selected from the group consisting of ammonia, primary amines, secondary amines and mixtures thereof, in the presence of a catalyst comprising a zirconium dioxide- and nickel-containing catalytically active composition, to form an amine; wherein the catalytically active composition, prior to reduction with hydrogen, comprises oxygen compounds of zirconium, copper, nickel and cobalt, and one or more oxygen compounds of molybdenum in an amount of 5.5 to 12% by weight, calculated as MoO3.

Abstract: Catalyst systems consisting of supported or unsupported transition metal catalysts which have modifiers on the surface. The modifiers have sulphur-containing functionalities (G0). In addition, the modifiers may have a spacer (Sp) and a Bronsted-basic, Bronsted-acidic or Lewis-basic functionality (G1). The catalyst systems may be used for hydrogenation, reductive alkylation and reductive amination.

Abstract: The process comprises reacting a compound of formula (II), where R is a hydroxyl protecting group, and the asterisk indicates an asymmetric carbon atom, with diisopropylamine in the presence of a reducing agent; optionally converting the resulting intermediate into a salt and, if so desired, isolating it; removing the hydroxyl protecting group; and if so desired, separating the desired (R) or (S) enantiomer, or the mixture of enantiomers and/or converting the obtained compound into a pharmaceutically acceptable salt thereof. Tolterodine is a muscarinic receptor antagonist useful in treating urinary incontinence and other symptoms of urinary bladder hyperactivity.

Abstract: The present invention relates to novel dihydronaphthalene compounds, compositions, methods for using the same, and processes for preparing the same. The present invention also relates to novel total synthesis approaches for preparing these compounds. In addition, the present invention relates to methods of producing quantities of isomers of these compounds and separating and purifying them using chiral separation techniques. The present invention also relates to methods of producing quantities of a single isometric compound without the need for chiral separation techniques.

Abstract: This application claims the benefit of German priority Application No. 10138140.9, filed on Aug. 9, 2001, and International Application No. PCT/EP02/08748, filed on Aug. 6, 2002. The invention relates to the production of amines by the reaction of aldehydes or ketones with ammonia or primary or secondary amines in the presence of a hydrogen-donor and the presence of homogeneous metal catalysts of the eighth sub-group under mild conditions.

Abstract: Disclosed are catalysts, the catalytically active mass of which contains 22 to 40 percent by weight of oxygen-containing compounds of zirconium, calculated as ZrO2, 1 to 30 percent by weight of oxygen-containing compounds of copper, calculated as CuO, 15 to 50 percent by weight of oxygen-containing compounds of nickel, calculated as NiO, the molar ratio between nickel and copper being greater than 1, 15 to 50 percent by weight of oxygen-containing compounds of cobalt, calculated as CoO, and less than 1 percent by weight of an alkali metal, calculated as alkali metal oxide, prior to being treated with hydrogen. Also disclosed is a method for the production of amines by reacting primary and secondary alcohols, aldehydes, or ketones with hydrogen and nitrogen compounds selected from the group ammonia, primary and secondary amines, in the presence of said catalysts at an elevated temperature and an elevated pressure.

Abstract: A method for the preparation of a compound of formula (VI): in which R2 is an optionally substituted C1–C6 alkyl; R4 is H, OH, an optionally substituted C1–C6 alkyl or an optionally substituted C1–C6 alkoxy; R5 is an optionally substituted aryl, an optionally substituted aralkyl, or an optionally substituted alkyl; and R6 is H or an optionally substituted C1–C6 alkyl; the method including the step of subjecting a ketone of formula (V) in which R2, R4 and R5 are as defined above, to reductive amination with an amine of formula R3NH2 in which R3 is an optionally substituted alkyl, and a reductant to form the compound of formula (VI), wherein the reaction is conducted in the presence of a supercritical fluid or a liquefied gas.

Abstract: Disclosed herein is a process for the reductive alkylation of primary amines to form secondary amines, by high pressure reaction of the primary amine with an alkylating agent and hydrogen in the presence of a catalyst which comprises metallic palladium. A process of the present invention is characterized in having high conversion rates and high selectivities, both greater than 95% on a first pass through the reactor. According to a preferred embodiment, the secondary amine produced comprises at least one 2-alkyl group bonded to the nitrogen atom of the primary amine product.

Abstract: Process for preparing an amine by reacting a primary or secondary alcohol, aldehyde or ketone with hydrogen and a nitrogen compound selected from the group consisting of ammonia and primary and secondary amines in the presence of a catalyst whose preparation has involved precipitation of catalytically active components onto monoclinic, tetragonal or cubic zirconium dioxide.

Abstract: The invention relates to the production of amines by the reaction of aldehydes or ketones with ammonia or primary or secondary amines in the presence of a hydrogen-donor and the presence of homogeneous metal catalysts of the eighth sub-group under mild conditions.

Abstract: A process for the hydrogenation of imines with hydrogen under elevated pressure in the presence of iridium catalysts and with or without an inert solvent, wherein the reaction mixture contains an ammonium or metal chloride, bromide or iodide and additionally an acid.

Abstract: Processes for the preparation of compounds having a chiral carbon substituted with an amine are disclosed. The processes include admixing a ketone with an amine in the presence of a catalyst having a chiral phosphine ligand and an acid. The admixture can also contain a reducing additive. The admixture is then exposed to hydrogen to directly and asymmetrically aminate the ketone.

Abstract: A process for producing diamines which comprises the steps of: (1) reacting a dialdehyde with ammonia and hydrogen in the presence of an alcohol and a hydrogenation catalyst to synthesize the corresponding diamine; (2) separating and recovering the alcohol by distilling the reaction mixture obtained by the step (1); (3) separating the diamine by purifying the distillation residue obtained by the step (2); and (4) feeding at least part of the alcohol recovered in the step (2) to step (1); said step (1) comprising maintaining the amount of ammonia at a level of at least 200 moles per mole of the primary amine that has formed in the step (1) and accumulated in the reaction vessel for step (1). The process can produce diamines commercially advantageously and in high yields, the diamines having little impurities.

Abstract: A catalytic transfer hydrogenation process is provided. The process can be employed to transfer hydrogenate N-substituted imines and iminium salts, which are preferably prochiral. The catalyst employed in the process is preferably a metal complex with one hydrocarbyl or cyclopentadienyl ligand and which is also coordinated to defined bidentate ligands. Preferred metals include rhodium, ruthenium and iridium. Preferred bidentate ligands are diamines and aminoalcohols, particularly those comprising chiral centres. The hydrogen donor is advantageously a mixture of triethylamine and formic acid. A process for the production of primary and secondary amines using the catalytic transfer hydrogenation of the N-substituted imines and iminium salts is also provided.

Abstract: The preparation of amines of the formula (I): R1R2CH—N R3R4  (I) in which R1, R2, R3 and R4, independently of one another, are hydrogen, straight-chain or branched C1-C12-alkyl, C3-C12-cycloalkyl, C6-C10-aryl or C7-C11-aralkyl, takes place by catalytic, reductive amination of mixtures comprising carbonyl compounds of the formula (II) and/or alcohols of the formula (III) R1—C(═O)—R2  (II) R1—CH(OH)—R2  (III) which also comprise at least 50 ppm, based on the mixtures, of halogen, with nitrogen compounds of the formula (IV): H N R3 R4  (IV) with the abovementioned meanings for R1 to R4, in the presence of Co- and/or Ni-containing catalysts, which comprises carrying out the reductive amination additionally in the presence of solid acidic cocatalysts.

Abstract: A process for the preparation of aldehydes and/or alcohols or amines by reacting olefins in the liquid phase with carbon monoxide and hydrogen, a part of these gases being dispersed in the form of gas bubbles in the reaction liquid and another part being dissolved in the reaction liquid, in the presence or absence of a primary or secondary amine and in the presence of a cobalt carbonyl, rhodium carbonyl, palladium carbonyl or ruthenium carbonyl complex dissolved homogeneously in the reaction liquid and having a phosphorus-, arsenic-, antimony- or nitrogen-containing ligand, at elevated temperatures and at 1 to 100 bar, wherein the reaction is carried out in a vertically arranged, tubular reactor comprising a reactor body and at least one circulation line, a part of the reaction liquid is fed continuously via the circulation line to at least one nozzle which is mounted in the upper part of the reactor body and is coordinated with a guide member, open at the top and bottom and bounded by parallel walls, in the

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: A novel phosphine ligand is an enantiomerically enriched compound of formula 5 or the opposite enantiomer thereof, wherein Ar1 and Ar2 represent the same or different aromatic groups of up to 20 C atoms. A transition metal complex of this ligand is useful as a catalyst in stereoselective hydrogenation.

Abstract: N-Benzylamines are prepared by a process in which

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: Amines of the formula (I) R1R2CH—NR3R4  (I) where R1, R2, R3 and R4 are each, independently of one another, hydrogen, straight-chain or branched C1-C12-alkyl, C3-C12-cycloalkyl, C6-C10-aryl or C7-C11-aralkyl, where at least one of the radicals R1 and R2 is aryl or aralkyl whose aromatic unit is substituted by at least one halogen, are prepared by catalytic, hydrogenative amination of carbonyl compounds of the formula (II) or alcohols of the formula (III) R1—C(═O)—R2  (II) R1—CH(OH)—R2  (III) by means of nitrogen compounds of the formula (IV) HNR3R4  (IV) where R1 to R4 are as defined above, in the presence of Co- and/or Ni-containing catalysts, in the additional presence of solid acid cocatalysts and in the absence of organic sulfur compounds.

Abstract: The present invention relates to a process for preparing amines of formula (I) R1—CH2—NH2  (I), wherein R1 represents optionally branched C1-C12-alkyl, C3-C8-cycloalkyl, C6-C12-aryl or C6-C12-aryl substituted with halogen-and/or C1-C12-alkyl, C7-C10-aralkyl or C7-C10-aralkyl substituted on the aryl radical by halogen and/or C1-C12-alkyl, or an aldose residue of the formula CiH2i+1Oi in which i is 2 to 5 and wherein one hydrogen of the aldose residue is optionally replaced by a saccharide residue, by catalytically hydrogenating aldehydes of formula (II) R1—CHO  (II), wherein R1 has the meaning indicated for formula (I), in the presence of ammonia, a hydrogenation catalyst, and disodium tetraborate.

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: The present invention relates to a process for producing a trifluoromethylbenzylamine represented by the general formula (1). This process includes the step of reducing an oxime represented by the general formula (2), where R1 represents hydrogen atom, a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine, or trifluoromethyl group, where R1 is defined as above, and R2 represents hydrogen atom, an alkyl group or an aralkyl group. With this process, the trifluoromethylbenzylamine can be produced with high selectivity.

Abstract: The present invention relates to methods for the reductive amination of a carbonyl-containing compound. R1R2CO where R1 and R2 are either H, alkyl, aryl or heterocyclic etc with an amine NHR3R4 where R3 and R4 arm H, alkyl, aryl, or heterocyclic in the presence of a homogeneous iridium catalyst and gaseous hydrogen.

Abstract: The object of the present invention is to provide a method for producing substituted-1,3,5-triazine derivatives at high yield, in which at least one of carbon atoms in the ring thereof is substituted by a secondary amine group having at leat one of alkyl groups. The method of the present invention is a method for alkylation of 1,3,5-triazine derivatives, characterized by reacting 1,3,5-triazine derivatives (melamines, melamine derivatives, various kinds of guanaminde derivatives, etc.) which has at least one or more amino groups or mono-substituted amino groups on carbon atom of the ring thereof, with aldehydes or ketones alcohols in the presence of a catalyst of a metal of group VII and/or group VIII in the periodic table and a hydrogen-containing gas to alkylate said at least one of amino groups or mono-substituted amino groups.

Abstract: An alicyclic polyamine of the formula (1) ##STR1## wherein Y.sub.1 represents a saturated aliphatic hydrocarbon group and R.sub.1 through R.sub.4 are the same or different and each represents hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. The alicyclic polyamine can be obtained by subjecting a 3-formylcycloalkanone or 3-formylcycloalkenone to reductive amination reaction.

Abstract: A catalyst comprises, based on the total weight of the catalyst,0.1-6% by weight of cobalt, nickel or a mixture thereof,0.001-25% by weight of ruthenium,0-10% by weight of copper and0-5% by weight of promoterson a porous metal oxide carrier.It preferably comprises 0.1-3% by weight of cobalt and 0.1-3% by weight of nickel. It can be used in hydrogenation reactions, dehydrogenation reactions or hydrogenation/dehydrogenation reactions, in particular in the amination of alkylene oxides, alcohols, aldehydes or ketones with ammonia or primary or secondary amines.

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: Tertiary aminoaryl compounds, such as N,N'dialkylaminoaryl compounds, are prepared using successive reductive steps without isolation therebetween, at high temperature and pressure. A nitroaryl compound is reduced using a ketone as both solvent and reactant in a reductive environment, and the resulting intermediate is further reacted with an aldehyde in the same reaction mixture without isolation to provide the second substituent on the amino group.

Abstract: Preparation of an N-alkyl-arylamine of the formula ##STR1## in which Ar represents an aryl radical which is optionally monosubstituted or polysubstituted by at least one of halogen and in each case optionally substituted alkyl, alkoxy or alkoxycarbonyl,R.sup.1 represents hydrogen or alkyl andR.sup.2 represents in each case optionally substituted alkyl or aryl, or, together with R.sup.1, represents alkanediyl,by reacting a nitroarene of the formulaAr--NO.sub.2 (II)with a carbonyl compound of the formulaR.sup.1 --CO--R.sup.2 (III)in the presence of hydrogen and in the presence of a catalyst at a temperature between 0.degree. C. and 200.degree. C.

Abstract: A method of producing a pantothenic acid derivative of formula (I): ##STR1## wherein each of R.sup.1 and R.sup.2 is different, and is a branched aliphatic hydrocarbon group having 3 to 5 carbon atoms, or a phenyl group; or a straight chain aliphatic hydrocarbon group having 5 to 10 carbon atoms, is provided, including methods of producing the starting materials for producing the same and novel amine derivative that can be used for the production of the pantothenic acid derivative.

Abstract: A novel process for preparing an optically active amine by asymmetric hydrogenation of an imine compound, such as an imine compound prepared by condensing benzylamine and acetophenone, in the presence of a catalytic amount of an iridium-optically active phosphine complex and benzylamine or a benzylamine derivative. The present invention provides an optically active amine of high optical purity.

Abstract: A process for producing an alkoxy-substituted tri-phenylamine comprising reacting an alkoxy-substituted cyclohexanone with a diphenylamine or an aniline, while forming said cyclohexanone in the same system from an alkoxy-substituted phenol by using said phenol as a hydrogen acceptor, in the presence of a hydrogen transfer catalyst and a catalytic amount of the alkoxy-substituted cyclohexanone corresponding to the alkoxy-substituted phenol used for the reaction, or after converting partially the alkoxy-substituted phenol to a catalytic amount of the alkoxy-substituted cyclohexanone under a hydrogen pressure in the presence of a hydrogen transfer catalyst, wherein a surface-supported catalyst is used as the hydrogen transfer catalyst.

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: The preparation of optionally substituted diphenylamine by reaction of optionally substituted aniline with optionally substituted cyclohexanone using a supported Rh catalyst containing rhodium or a combination of rhodium with another platinum metal from the group of palladium, platinum, ruthenium or iridium and which can additionally contain chromium, manganese, alkali metal and a sulphur compound is described. The catalyst of the invention is prepared from halide-free starting materials. The Rh catalyst is distinguished by a low dependence of the initial selectivity, the selectivity in the run-in state and the running-in time on the conditions of the reductive pretreatment and requires only short running-in times to the optimum state.

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 preparation of glycoloylanilide of the formula (G) ##STR1## is recited that involves reacting a nitrobenzene with hydrogen and, if desired, with a carbonyl compound, in the presence of a noble metal catalyst and a solvent, reacting the compound produced with chloroacetyl chloride, reacting the resulting product with a benzyl alcohol and with a base, or reacting the resulting compound with an O-benzylglycoloyl chloride, and debenzylating the resulting benzylglycoloylanilide product by reacting with hydrogen in the presence of a noble metal catalyst. The invention also relates to a process for the preparation of O-benzylglycoloylanilide.

Abstract: The present process involves preparing dibenzylamine through the hydrogenation of benzaldehyde in the presence of ammonia and a catalyst containing palladium using a small amount of solvent or dispersion medium. With the present process, dibenzylamine can be prepared with high selectivity in a relatively short reaction time and with complete conversion of the benzaldehyde, at which makes it commercially attractive. In the present process, a palladium-carbon catalyst is preferably used.

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.