Title of Invention	A PROCESS FOR HYDROGENATING AROMATIC COMPOUNDS IN WHICH AT LEAST ONE AMINC GROUP IS BONDED TO AN AROMATIC NUCLEUS
Abstract	(57) Abstract: The present invention relates to a process for hydrogenating aromatic compound in which at least one amino group is bomded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compounds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and ,if required at least one metal of subgroup I,VII or VIII in an amount of from O.Ol to 30% by weight, based on the total weight of the catalyst applied to a carrier and the carrier has a mean pore diameter of at least O-lμn and a surface area of not more than 15m2/g and is selected from the Group consisting of active carbon. silicon carbide, alumina, nlica titanium dioxide, zirconium dioxide. magnesium dioxide, zinc oxide and mixtures therefore, pereferably alumine and zirconium dioxide ,the hydrogonation can be carried out in the presence of a solvent or diluent. PRICE: THIRTY RUPEES

Title of Invention

A PROCESS FOR HYDROGENATING AROMATIC COMPOUNDS IN WHICH AT LEAST ONE AMINC GROUP IS BONDED TO AN AROMATIC NUCLEUS

Abstract

(57) Abstract: The present invention relates to a process for hydrogenating aromatic compound in which at least one amino group is bomded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compounds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and ,if required at least one metal of subgroup I,VII or VIII in an amount of from O.Ol to 30% by weight, based on the total weight of the catalyst applied to a carrier and the carrier has a mean pore diameter of at least O-lμn and a surface area of not more than 15m2/g and is selected from the Group consisting of active carbon. silicon carbide, alumina, nlica titanium dioxide, zirconium dioxide. magnesium dioxide, zinc oxide and mixtures therefore, pereferably alumine and zirconium dioxide ,the hydrogonation can be carried out in the presence of a solvent or diluent. PRICE: THIRTY RUPEES

Full Text	The present invention relates to a process for hydrogenating aroma¬tic compounds in which at least one amino group is bonded to an aromatic nucleus. The present invention relates in particular to a process for hydro¬genating aromatic amines and diamines. The mononuclear or polynuclear, unsubstituted or substituted aromatic amines and diamines are hydrogenated to the corresponding cycloaliphatic amines and diamines with the aid of ca¬talysts which contain ruthenium and, if required, at least one further metal of subgroup I, VII or VIII on a carrier. Cycloaliphatic amines, in particular unsubstimted cyclohexylamines and dicyciohexylamines, are used for the preparation of antiaging agents for rubbers and plastics, as corrosion inhibitors and as intermediates for crop protection agents and textile assistants. Cycloaliphatic diamines are fur¬thermore used in the preparation of polyamide and polyurethane resins and are also used as curing agents for epoxy resins. It is known that cycloaliphatic amines or diamines can be prepared by catalytic hydrogenation of the corresponding mononuclear or polynuclear aromatic amines or diamines. Hydrogenation of aromatic amines and diam0 nes to the corresponding cycloaliphatic amines and diammes in the presence of hydrogenation catalysts, in particular catalysts applied to carriers, has been described in many publications. The catalysts used were, for example, Raney cobalt containing ba¬sic additives (JP 43/3180), nickel catalysts (US 4,914,239, German Patent 805,518), rhodium catalysts (BE 739376, JP 7019901, JP 7235424) and pal- ladium catalysts (US 3,520,928, EP 501 265, EP 53 181, JP 59/196843). Ruthenium catalysts (US 3,697,449, US 3,636,108, US 2,822,392, US 2,606,925, EP 501 265, EP 324 984, EP 67 058, DE 21 32 547 and Ger¬man Laid-Open Application DOS 1,106,319) are also used. DE 21 32 547 discloses a process for hydrogenating mononuclear or polynuclear aromatic diamines to the corresponding cycloaliphatic ammes, which is carried out in the presence of suspended ruthenium catalysts. EP 67 058 describes a process for the preparation of cyclohexyla-tnine by catalytic hydrogenation of the corresponding aromatic amine. The ;atalyst used is ruthenium metal in a finely divided form on activated alu¬minum pellets. After being recycled four times, the catalyst began to lose its efficiency. It is an object of the present invention to provide a process for lydrogenating compounds in which at least amino group is bonded to an iromatic nucleus, the process being capable of being carried out in particu-ar without removal, working up and recycling of the catalyst. It is a fi:rther object of the present invention to provide a process 'or hydrogenating aromatic compounds in which at least one amino group s bonded to an aromatic nucleus to give the corresponding cycloaliphatic :ompounds, only a minimum amount of byproducts being produced. It is a further object of the present invention to provide a process or hydrogenating aromatic compounds in which at least one amino group s bonded to an aromatic nucleus, high catalyst space velocities and long ca-aiyst lives being permitted. We have found that the above objects are achieved by a process or hydrogenation as claimed in the clauns. With the novel process, the aromatic compounds in which at least me amino group is bonded to an aromatic nucleus can be hydrogenated vith high selectivity to give the corresponding cycloaliphatic compounds. In particular, the formation of deamination products, for example cyclohexanes or partially hydrogenated dimerization products, such as phenyl-cyclohexylamines, is preferably virtually completely avoided. In addition, high catalyst space velocities and long catalyst lives can preferably be achieved. The catalyst space velocity is the space/time yield of the process, ie. the amount of starling material converted per unit time and per amount of catalyst present. The life means the time or the amount of converted starting material which a catalyst withstands without losing its properties and without the product properties significantly chan¬ging. COMPOUNDS With the novel process, aromatic compounds in which at least one amino group is bonded to an aromatic nucleus can be hydrogenated to give the corresponding cycloaliphatic compounds. The aromatic compounds may be mononuclear or polynuclear aromatic compounds. The aromatic com¬pounds contain at least one amino group wluch is bonded to an aromatic nucleus. Preferably, the aromatic compounds are aromatic amines or diam0 nes. The aromatic compounds may be substituted on the aromatic nucleus or the aromatic nuclei or on the amino group by one or more alkyl and/or alkoxy radicals, preferably C12o-aIkyl and/or alkoxy, particularly preferably C,,io-alkyl, m particular methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tert-butyl; among the alkoxy radicals, C1-8-aUcoxy radicals are preferred. The aromatic nucleus or the aromatic nuclei and the alkyl and alkoxy rad0 cals may be unsubstimied or substituted by halogen, in particular fluorine, or may have other suitable inert substiments. The aromatic compounds in which at least one amino group is bonded to an aromatic nucleus may also have a plurality of aromatic nuclei which are linked via an alkyl radical, preferably a methylene group. The linking alkyl chain, preferably methylene group, may have one or more alkyl substituents which may be C1-20-alkyl, preferably C1-10-alkyl, particu- larly preferably methyl, ethyl, propyl, isopropyl, butyl, sec-butyl or ten-butyl. The amino group bonded to the aromatic nucleus may likewise be substituted by one or more of the alkyl radicals described above. Particularly preferred compounds are aniline, naphthylamine, di-aminobenzenes, diamino toluenes and bis-p-aminopheiμhnethane. CATALYSTS The catalysts used according to the invention can be prepared industrially by applying ruthenium and, if required, at least one metal of subgroup I, Vn or VIII to a suitable carrier. The application can be achieved by impregnating the catalyst in aqueous metal salt solutions, such as ruthenium salt solutions, by spraying corresponding metal salt solutions onto the carrier or by other suitable methods. Suitable ruthenium salts for the preparation of the ruthenium salt solutions and suitable metal salts of subgroup I, VII or VIII are the nitrates, nitrosylnitrates, halides, carbonates, carboxylates, acetylacetonates, chlorine complexes, nitrito complexes or amine complexes of the corresponding metals, the nitrates and nitrosylnitra¬tes being preferred. In the case of catalysts which, in addition to ruthenium, contain further metals applied to the carrier, metal salts or metal salt solutions may be applied simultaneously or in succession. Carriers coaled or impregnated with the ruthenium salt solution or metal salt solution are then dried, preferably at from 100 to 150°C, and, if desu-ed, calcined at from 200 to 600°C. The coated carriers are then activated by treating them in a gas stream which contains free hydrogen, at from 30 to 600°C, preferably from 150 to 450°C. The gas stream preferably consists of from 50 to 100% by volume of H2 and from 0 to 50% by volume of N2. If, in addition to ruthenium, one or more other metals of subgroup I, VII or VIII are also applied to the carriers, and the application is effected in succession, the carrier may, after each application or impregna¬tion, be dried at from 100 to 150°C and, if desired, calcined at from 200 to 600°C. The metal salt solutions may be applied or introduced by impregnation in any desired order. If, in addition to ruthenium, one or more fiinher metals of sub¬group I, VII or VIII are applied to the carrier, copper, rhenium, cobalt, nickel or a mixmre thereof is preferably used. The ruthenium salt solution or metal salt solution is applied to the carrier or carriers in an amount such that from 0.01 to 30% by weight, based on the total weight of the catalyst, of ruthenium and, if required, other metal or other metals of subgroup I, VII or VIII are present on the carriers. This amount is preferably from 0.2 to 15, particularly preferably about 0.5, % by weight. The total metal surface area on the catalyst is preferably from 0.01 to 10, in particular from 0.05 to 5, more particularly from 0.05 to 3 mμ/g of the catalyst. CARRIERS The carriers which can be used for the preparation of the catalysts used according to the invention are preferably those which are macroporous and have a mean pore diameter of at least 0.1 μm, preferably at least 0.5 /im, and a surface area of not more than 15, preferably not more than 10, more preferably not more than 5, especially not more than 3, mμ/g. The mean pore diameter of the carrier is preferably from 0.1 to 200 μm, in particular from 0.5 to 50 /xm. The surface area of the carrier is preferably from 0.2 to 15, in particular from 0.5 to 10, more particularly from 0.5 to 5, most particularly from 0.5 to 3, mμ per g of the carrier. The surface area of the carrier is determined according to the BET method by N2 adsorption, in particular according to DIN 66131. The mean pore diameter and the pore size distribution were determined by Hg porosi-metry, in particular according to DIN 66133. The pore size distribution of the carrier may preferably be approximately bimodal, the pore diameter distribution having maxima at about 0.6 /xm and about 20 μni in the bimodal distribution, constituting a specific embodiment of the invention. A carrier which has a surface area of about 1.75 mμ/g and this bimodal distribution of the pore diameter is particularly preferred. The pore volume of this preferred carrier is preferably about 0.53 ml/g. For example, active carbon, silicon carbide, alumina, silica, titan0 um dioxide, zirconium dioxide, magnesium dioxide, zinc oxide or mixtures thereof may be used as the macroporous carrier. Alumina and zirconium dioxide are preferred. The catalysts used according to the invention preferably have high reactivity and selectivity and a long life. When the catalysts used according to the invention are employed, the hydrogenation products are preferably obtained in high yield and purity in the hydrogenation. HYDROGENATION The hydrogenation is carried out at suitable pressures and tempera¬tures, pressures above 50, preferably from 150 to 300, bar are preferred. Preferred temperatures are from 100 to 270'C, particularly preferably from 150 to 220°C. SOLVENTS OR DILUENTS In the novel process, the hydrogenation can be carried out in the absence of a solvent or diluent, ie. in one embodiment it is not necessary to carry out the hydrogenation in solution. Preferably, however, a solvent or diluent is used in the novel process. The solvent or diluent used may be any suitable solvent or diluent. The choice is not critical; for example, in one embodiment the solvent or diluent may also contain small amounts of water. Examples of suitable solvents or diluents include straight-chain or cyclic ethers, for example tetrahydrofuran or dioxane, and ammonia and mono- or dialkylammes in which the alkyl radicals are preferably of 1 to 3 carbon atoms. Mixtures of these or other solvents or diluents may also be used. The solvent or diluent may be used in suitable amounts, prefer¬red amounts being those which lead to a 10-70% strength by weight solu¬tion of the compounds intended for the hydrogenation. Particularly preferably, the product formed in the hydrogenation by the novel process may also be used as a solvent, if necessary in addition to other solvents or diluents. In this case, some of the product formed in the hydrogenation process is mixed with the compounds to be hydrogenaied. Preferably from 1 to 30, particularly preferably from 5 to 20, times the amount, based on the weight of the compounds intended for the hydrogena¬tion, of the hydrogenation product is admixed as solvent or diluent. The hydrogenation is preferably carried out in the presence of ammonia or a mono- or dialkylamine, for example methyl-, ethyl-, propyl-, dimethyl-, diethyl- or dipropylamine. Suitable amounts of ammonia or mono- or dialkylamine are used, preferably from 0.5 to 50, particularly preferably from 1 to 20, parts by weight, based on 100 parts by weight of the compound or compounds intended for the hydrogenation. Anhydrous ammonia or an anhydrous amine is particularly preferably used. The hydrogenation process can be carried out continuously or batchwisc. In the continuous process, the amount of the compound or com¬pounds intended for the hydrogenation may be from 0.05 to 3, preferably from 0.1 to 1, 1 per liter of catalyst per hour. The hydrogenation gases used may be any desuμd gases which contain free hydrogen and do not contain any harmful amounts of catalyst poisons, for example CO. For example, reformer waste gases may be used. Pure hydrogen is preferably used as the hydrogenation gas. Accordingly the present invention provides a process for hydrogenating aromatic compounds in whicli at least one amino group is bonded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compoimds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and, if required, at least one metal of subgroup I, VII or VIII in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst applied to a carrier, and the carrier has a mean pore diameter of at least 0.1)j,m and a surface area of not more than 15mVg and is selected from the group consisting of active carbon, silicon carbide, alumina, silica titanium dioxide, zirconium dioxide, magnesium dioxide, zinc oxide and mixtures thereof, preferably alumina and zirconium dioxide; and the hydrogenation is carried out optionally in the presence of a solvent or diluent. The invention will now be described in more in detail with reference to embodiments given by way of example. EXAMPLE 1 Preparation of the catalyst ) ■■> A macroporous alumina carrier which was in ihe fonn of 8 x 8 X 3 mm rings and had a surface area of 1.75 mμ/g, determined by the BET method, a pore volume of 0.531 ml/g and a pore diameter of 0.6 μm and 20 nm with a bimodal distribution was impregnated with an aqueous n]thenium(III) nitrate solution which had a concentration of from 0.7 to 1%, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore volume of the carrier used. The carrier impregnated with the ruthemum(III) nitrate solu¬tion was then dried at 1-20°C with agitation and was reduced at 200°C in a stream of hydrogen. The catalyst thus prepared contained 0.5% by weight, based on the total weight of the catalyst, of ruthenium and had a ruthenium surface area of 0.76 mμ/g, determined by H2 pulse chemisorption (Puis Chemiesorp 2700, 35°C). HYDROGENATION 1.2 1 of the catalyst which was prepared by the above method and contained 0.5% by weight of ruthenium on a macroporous Ai203 carrier were introduced into an electrically heated flow-through reactor which was equipped with a separator. Hydrogenalion of aniline was then carried out at 230 bar and mitially ISCC without prior activation of the catalyst. The hydrogenation was carried out continuously by the liquid-phase procedure, some of the discharged hydrogenation mixmre being recycled and being mixed with the starting material upstream of the reactor. 10 times the amount, based on the amount of aniline used, of hydrogenation product was added as solvent. From 500 to 600 1 of hydrogen per hour were let down at the top of the separator. The amount of aniline fed continuously to the reactor corresponded to a catalyst space velocity of 0.6 1 per 1 of catalyst per h. Depending on the reaction temperamre, the following product compositions were obtained under steady-state reaction conditions: isomer mixture of the corresponding cycloaliphatic diamines was quantitative, the residual aromatics content being less than 0.01%. EXAMPLE 4 Preparation of the catalyst A macroporous alumina carrier which was in the form of 8 x 8 X 3 mm rings and had a surface area of 0.99 mμ/g, determined by the BET method, a pore volume of 0.529 ml/g and a pore diameter of 1 iim and 30 μm with a bimodal distribution was impregnated three times with an aqueous nickel(II) nitrate solution which had a concentration of 13.5%, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore volume of the carrier used. After each impregnation the impregnated carrier was dried at nO'C and calcined at 520*'C. The NiO/almninum oxide catalyst thus prepared was impregnated with an aqueous ruthenium(III) nitrate solution with had a concentration of from 0.7 to 1 %, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore voliune of the carrier used. The NiO/aluminimi oxide catalyst impregnated with the rutheni-um(III) nitrate solution was then dried at HCC with agitation and was reduced at 200'C in a stream of hydrogen. The catalyst thus prepared contained 0.5% by weight of rutheniimi and 11% by weight of nickel, based on the total weight of the catalyst. EXAMPLE 5 Hydrogenation was carried out as described in Example 1, except that aniline was reacted continuously in a flow-through reactor containing the 0.5% Ru/ll% Ni/AljOg catalyst. At a temperature of 190'C and a catalyst load of 0.2 kg/1 x h a total conversion was obtained and a selectivity for cyclohexylamine of 94%. EXAMPLE 6 Hydrogenation was carried out as described in Example 3, except that di-(4-aminophenyl)methane was converted quantitatively in an autoclave to a cis/trans-mixture of di-(4-aminocyclohexyl)methane. WE CLAIM: 1. A process for hydrogenating aromatic compounds in which at least one amino group is bonded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compounds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and, if required, at least one metal of subgroup I, VII or VIII in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst applied to a carrier, and the carrier has a mean pore diameter of at least 0.1 μm and a surface area of not more than 15mVg and is selected from the group consisting of active carbon, silicon carbide, alumina, silica titanium dioxide, zirconium dioxide, magnesium dioxide, zinc oxide and mixtures thereof, preferably alumina and zirconium dioxide; and the hydrogenation is carried out optionally in the presence of a solvent or diluent. 2. The process as claimed in claim 1, wherein ruthenium and, if required, at least one metal of subgroup I, VII or VIII are applied to the catalyst in an amount of from 0.2 to 15% by weight, based on the total weight of the catalyst. 3. The process as claimed in claim 1 or 2, wherein the mean pore diameter of the carrier is at least 0.5 μm. 4. The process as claimed in any one of the claims 1 to 3, wherein the pore size distribution of the carrier is approximately bimodal. 5. The process as claimed in any one of the claims 1 to 4, wherein the surface area of the carrier is not more thanlO m2/g. 6. The process as claimed in any one of the claims 1 to 5, wherein the one or more metals of subgroup I, VII or VIII are selected from the group consisting of copper, rhenium, cobalt and nickel and mixtures thereof 7. The process as claimed in any one of the claims 1 to 6, wherein the metal applied to the carrier has a surface area of from 0.01 to 10, preferably from 0.05 to 5 m2 per g of catalyst. 8. The process as claimed in any one of claims 1 to 7, wherein the catalyst consists of a macroporus alumina carrier having a surface area of 1.75 mVg. a pore volume of 0.531 ml/g, a bimodal pore size distribution with pore diameters of 0,6 μm and 20 μm, onto which carrier ruthenium is applied in an amount of about 0.5% by weight, based on the total weight of the catalyst, and the ruthenium surface area on the carrier is about 0.76 m2 per g of catalyst. 9. The process as claimed in any one of claims I to 8, wherein the aromatic amine or diamine is selected from the group consisting of aniline, naphthylamine, diaminotoluenes, bis-p-aminophenylmethane and mixtures thereof

Full Text

The present invention relates to a process for hydrogenating aroma¬tic compounds in which at least one amino group is bonded to an aromatic nucleus.
The present invention relates in particular to a process for hydro¬genating aromatic amines and diamines. The mononuclear or polynuclear, unsubstituted or substituted aromatic amines and diamines are hydrogenated to the corresponding cycloaliphatic amines and diamines with the aid of ca¬talysts which contain ruthenium and, if required, at least one further metal of subgroup I, VII or VIII on a carrier.
Cycloaliphatic amines, in particular unsubstimted cyclohexylamines and dicyciohexylamines, are used for the preparation of antiaging agents for rubbers and plastics, as corrosion inhibitors and as intermediates for crop protection agents and textile assistants. Cycloaliphatic diamines are fur¬thermore used in the preparation of polyamide and polyurethane resins and are also used as curing agents for epoxy resins.
It is known that cycloaliphatic amines or diamines can be prepared by catalytic hydrogenation of the corresponding mononuclear or polynuclear aromatic amines or diamines. Hydrogenation of aromatic amines and diam0 nes to the corresponding cycloaliphatic amines and diammes in the presence of hydrogenation catalysts, in particular catalysts applied to carriers, has been described in many publications.
The catalysts used were, for example, Raney cobalt containing ba¬sic additives (JP 43/3180), nickel catalysts (US 4,914,239, German Patent 805,518), rhodium catalysts (BE 739376, JP 7019901, JP 7235424) and pal-

ladium catalysts (US 3,520,928, EP 501 265, EP 53 181, JP 59/196843). Ruthenium catalysts (US 3,697,449, US 3,636,108, US 2,822,392, US 2,606,925, EP 501 265, EP 324 984, EP 67 058, DE 21 32 547 and Ger¬man Laid-Open Application DOS 1,106,319) are also used.
DE 21 32 547 discloses a process for hydrogenating mononuclear or polynuclear aromatic diamines to the corresponding cycloaliphatic ammes, which is carried out in the presence of suspended ruthenium catalysts.
EP 67 058 describes a process for the preparation of cyclohexyla-tnine by catalytic hydrogenation of the corresponding aromatic amine. The ;atalyst used is ruthenium metal in a finely divided form on activated alu¬minum pellets. After being recycled four times, the catalyst began to lose its efficiency.
It is an object of the present invention to provide a process for lydrogenating compounds in which at least amino group is bonded to an iromatic nucleus, the process being capable of being carried out in particu-ar without removal, working up and recycling of the catalyst.
It is a fi:rther object of the present invention to provide a process 'or hydrogenating aromatic compounds in which at least one amino group s bonded to an aromatic nucleus to give the corresponding cycloaliphatic :ompounds, only a minimum amount of byproducts being produced.
It is a further object of the present invention to provide a process or hydrogenating aromatic compounds in which at least one amino group s bonded to an aromatic nucleus, high catalyst space velocities and long ca-aiyst lives being permitted.
We have found that the above objects are achieved by a process or hydrogenation as claimed in the clauns.
With the novel process, the aromatic compounds in which at least me amino group is bonded to an aromatic nucleus can be hydrogenated vith high selectivity to give the corresponding cycloaliphatic compounds.

In particular, the formation of deamination products, for example cyclohexanes or partially hydrogenated dimerization products, such as phenyl-cyclohexylamines, is preferably virtually completely avoided.
In addition, high catalyst space velocities and long catalyst lives can preferably be achieved. The catalyst space velocity is the space/time yield of the process, ie. the amount of starling material converted per unit time and per amount of catalyst present. The life means the time or the amount of converted starting material which a catalyst withstands without losing its properties and without the product properties significantly chan¬ging. COMPOUNDS
With the novel process, aromatic compounds in which at least one amino group is bonded to an aromatic nucleus can be hydrogenated to give the corresponding cycloaliphatic compounds. The aromatic compounds may be mononuclear or polynuclear aromatic compounds. The aromatic com¬pounds contain at least one amino group wluch is bonded to an aromatic nucleus. Preferably, the aromatic compounds are aromatic amines or diam0 nes. The aromatic compounds may be substituted on the aromatic nucleus or the aromatic nuclei or on the amino group by one or more alkyl and/or alkoxy radicals, preferably C12o-aIkyl and/or alkoxy, particularly preferably C,,io-alkyl, m particular methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tert-butyl; among the alkoxy radicals, C1-8-aUcoxy radicals are preferred. The aromatic nucleus or the aromatic nuclei and the alkyl and alkoxy rad0 cals may be unsubstimied or substituted by halogen, in particular fluorine, or may have other suitable inert substiments.
The aromatic compounds in which at least one amino group is bonded to an aromatic nucleus may also have a plurality of aromatic nuclei which are linked via an alkyl radical, preferably a methylene group. The linking alkyl chain, preferably methylene group, may have one or more alkyl substituents which may be C1-20-alkyl, preferably C1-10-alkyl, particu-

larly preferably methyl, ethyl, propyl, isopropyl, butyl, sec-butyl or ten-butyl.
The amino group bonded to the aromatic nucleus may likewise be substituted by one or more of the alkyl radicals described above.
Particularly preferred compounds are aniline, naphthylamine, di-aminobenzenes, diamino toluenes and bis-p-aminopheiμhnethane. CATALYSTS
The catalysts used according to the invention can be prepared industrially by applying ruthenium and, if required, at least one metal of subgroup I, Vn or VIII to a suitable carrier. The application can be achieved by impregnating the catalyst in aqueous metal salt solutions, such as ruthenium salt solutions, by spraying corresponding metal salt solutions onto the carrier or by other suitable methods. Suitable ruthenium salts for the preparation of the ruthenium salt solutions and suitable metal salts of subgroup I, VII or VIII are the nitrates, nitrosylnitrates, halides, carbonates, carboxylates, acetylacetonates, chlorine complexes, nitrito complexes or amine complexes of the corresponding metals, the nitrates and nitrosylnitra¬tes being preferred.
In the case of catalysts which, in addition to ruthenium, contain further metals applied to the carrier, metal salts or metal salt solutions may be applied simultaneously or in succession.
Carriers coaled or impregnated with the ruthenium salt solution or metal salt solution are then dried, preferably at from 100 to 150°C, and, if desu-ed, calcined at from 200 to 600°C.
The coated carriers are then activated by treating them in a gas stream which contains free hydrogen, at from 30 to 600°C, preferably from 150 to 450°C. The gas stream preferably consists of from 50 to 100% by volume of H2 and from 0 to 50% by volume of N2.
If, in addition to ruthenium, one or more other metals of subgroup I, VII or VIII are also applied to the carriers, and the application is

effected in succession, the carrier may, after each application or impregna¬tion, be dried at from 100 to 150°C and, if desired, calcined at from 200 to 600°C. The metal salt solutions may be applied or introduced by impregnation in any desired order.
If, in addition to ruthenium, one or more fiinher metals of sub¬group I, VII or VIII are applied to the carrier, copper, rhenium, cobalt, nickel or a mixmre thereof is preferably used.
The ruthenium salt solution or metal salt solution is applied to the carrier or carriers in an amount such that from 0.01 to 30% by weight, based on the total weight of the catalyst, of ruthenium and, if required, other metal or other metals of subgroup I, VII or VIII are present on the carriers. This amount is preferably from 0.2 to 15, particularly preferably about 0.5, % by weight.
The total metal surface area on the catalyst is preferably from 0.01 to 10, in particular from 0.05 to 5, more particularly from 0.05 to 3 mμ/g of the catalyst. CARRIERS
The carriers which can be used for the preparation of the catalysts used according to the invention are preferably those which are macroporous and have a mean pore diameter of at least 0.1 μm, preferably at least 0.5 /im, and a surface area of not more than 15, preferably not more than 10, more preferably not more than 5, especially not more than 3, mμ/g. The mean pore diameter of the carrier is preferably from 0.1 to 200 μm, in particular from 0.5 to 50 /xm. The surface area of the carrier is preferably from 0.2 to 15, in particular from 0.5 to 10, more particularly from 0.5 to 5, most particularly from 0.5 to 3, mμ per g of the carrier.
The surface area of the carrier is determined according to the BET method by N2 adsorption, in particular according to DIN 66131. The mean pore diameter and the pore size distribution were determined by Hg porosi-metry, in particular according to DIN 66133. The pore size distribution of

the carrier may preferably be approximately bimodal, the pore diameter distribution having maxima at about 0.6 /xm and about 20 μni in the bimodal distribution, constituting a specific embodiment of the invention.
A carrier which has a surface area of about 1.75 mμ/g and this bimodal distribution of the pore diameter is particularly preferred. The pore volume of this preferred carrier is preferably about 0.53 ml/g.
For example, active carbon, silicon carbide, alumina, silica, titan0 um dioxide, zirconium dioxide, magnesium dioxide, zinc oxide or mixtures thereof may be used as the macroporous carrier. Alumina and zirconium dioxide are preferred.
The catalysts used according to the invention preferably have high reactivity and selectivity and a long life. When the catalysts used according to the invention are employed, the hydrogenation products are preferably obtained in high yield and purity in the hydrogenation. HYDROGENATION
The hydrogenation is carried out at suitable pressures and tempera¬tures, pressures above 50, preferably from 150 to 300, bar are preferred. Preferred temperatures are from 100 to 270'C, particularly preferably from 150 to 220°C. SOLVENTS OR DILUENTS
In the novel process, the hydrogenation can be carried out in the absence of a solvent or diluent, ie. in one embodiment it is not necessary to carry out the hydrogenation in solution. Preferably, however, a solvent or diluent is used in the novel process. The solvent or diluent used may be any suitable solvent or diluent. The choice is not critical; for example, in one embodiment the solvent or diluent may also contain small amounts of water.
Examples of suitable solvents or diluents include straight-chain or cyclic ethers, for example tetrahydrofuran or dioxane, and ammonia and mono- or dialkylammes in which the alkyl radicals are preferably of 1 to

3 carbon atoms. Mixtures of these or other solvents or diluents may also be used. The solvent or diluent may be used in suitable amounts, prefer¬red amounts being those which lead to a 10-70% strength by weight solu¬tion of the compounds intended for the hydrogenation.
Particularly preferably, the product formed in the hydrogenation by the novel process may also be used as a solvent, if necessary in addition to other solvents or diluents. In this case, some of the product formed in the hydrogenation process is mixed with the compounds to be hydrogenaied. Preferably from 1 to 30, particularly preferably from 5 to 20, times the amount, based on the weight of the compounds intended for the hydrogena¬tion, of the hydrogenation product is admixed as solvent or diluent.
The hydrogenation is preferably carried out in the presence of ammonia or a mono- or dialkylamine, for example methyl-, ethyl-, propyl-, dimethyl-, diethyl- or dipropylamine. Suitable amounts of ammonia or mono- or dialkylamine are used, preferably from 0.5 to 50, particularly preferably from 1 to 20, parts by weight, based on 100 parts by weight of the compound or compounds intended for the hydrogenation. Anhydrous ammonia or an anhydrous amine is particularly preferably used.
The hydrogenation process can be carried out continuously or batchwisc.
In the continuous process, the amount of the compound or com¬pounds intended for the hydrogenation may be from 0.05 to 3, preferably from 0.1 to 1, 1 per liter of catalyst per hour.
The hydrogenation gases used may be any desuμd gases which contain free hydrogen and do not contain any harmful amounts of catalyst poisons, for example CO. For example, reformer waste gases may be used. Pure hydrogen is preferably used as the hydrogenation gas.

Accordingly the present invention provides a process for hydrogenating aromatic compounds in whicli at least one amino group is bonded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compoimds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and, if required, at least one metal of subgroup I, VII or VIII in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst applied to a carrier, and the carrier has a mean pore diameter of at least 0.1)j,m and a surface area of not more than 15mVg and is selected from the group consisting of active carbon, silicon carbide, alumina, silica titanium dioxide, zirconium dioxide, magnesium dioxide, zinc oxide and mixtures thereof, preferably alumina and zirconium dioxide; and the hydrogenation is carried out optionally in the presence of a solvent or diluent.
The invention will now be described in more in detail with reference to embodiments given by way of example.
EXAMPLE 1 Preparation of the catalyst
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■■>

A macroporous alumina carrier which was in ihe fonn of 8 x 8 X 3 mm rings and had a surface area of 1.75 mμ/g, determined by the BET method, a pore volume of 0.531 ml/g and a pore diameter of 0.6 μm and 20 nm with a bimodal distribution was impregnated with an aqueous n]thenium(III) nitrate solution which had a concentration of from 0.7 to 1%, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore volume of the carrier used. The carrier impregnated with the ruthemum(III) nitrate solu¬tion was then dried at 1-20°C with agitation and was reduced at 200°C in a stream of hydrogen. The catalyst thus prepared contained 0.5% by weight, based on the total weight of the catalyst, of ruthenium and had a ruthenium surface area of 0.76 mμ/g, determined by H2 pulse chemisorption (Puis Chemiesorp 2700, 35°C). HYDROGENATION
1.2 1 of the catalyst which was prepared by the above method and contained 0.5% by weight of ruthenium on a macroporous Ai203 carrier were introduced into an electrically heated flow-through reactor which was equipped with a separator. Hydrogenalion of aniline was then carried out at 230 bar and mitially ISCC without prior activation of the catalyst. The hydrogenation was carried out continuously by the liquid-phase procedure, some of the discharged hydrogenation mixmre being recycled and being mixed with the starting material upstream of the reactor. 10 times the amount, based on the amount of aniline used, of hydrogenation product was added as solvent. From 500 to 600 1 of hydrogen per hour were let down at the top of the separator. The amount of aniline fed continuously to the reactor corresponded to a catalyst space velocity of 0.6 1 per 1 of catalyst per h. Depending on the reaction temperamre, the following product compositions were obtained under steady-state reaction conditions:

isomer mixture of the corresponding cycloaliphatic diamines was quantitative, the residual aromatics content being less than 0.01%. EXAMPLE 4 Preparation of the catalyst
A macroporous alumina carrier which was in the form of 8 x 8 X 3 mm rings and had a surface area of 0.99 mμ/g, determined by the BET method, a pore volume of 0.529 ml/g and a pore diameter of 1 iim and 30 μm with a bimodal distribution was impregnated three times with an aqueous nickel(II) nitrate solution which had a concentration of 13.5%, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore volume of the carrier used. After each impregnation the impregnated carrier was dried at nO'C and calcined at 520*'C.
The NiO/almninum oxide catalyst thus prepared was impregnated with an aqueous ruthenium(III) nitrate solution with had a concentration of from 0.7 to 1 %, based on the weight of the solution, of metal. The volume of solution taken up by the carrier corresponded roughly to the pore voliune of the carrier used.
The NiO/aluminimi oxide catalyst impregnated with the rutheni-um(III) nitrate solution was then dried at HCC with agitation and was reduced at 200'C in a stream of hydrogen. The catalyst thus prepared contained 0.5% by weight of rutheniimi and 11% by weight of nickel, based on the total weight of the catalyst. EXAMPLE 5
Hydrogenation was carried out as described in Example 1, except that aniline was reacted continuously in a flow-through reactor containing the 0.5% Ru/ll% Ni/AljOg catalyst. At a temperature of 190'C and a catalyst load of 0.2 kg/1 x h a total conversion was obtained and a selectivity for cyclohexylamine of 94%.

EXAMPLE 6
Hydrogenation was carried out as described in Example 3, except that di-(4-aminophenyl)methane was converted quantitatively in an autoclave to a cis/trans-mixture of di-(4-aminocyclohexyl)methane.

WE CLAIM:
1. A process for hydrogenating aromatic compounds in which at least one amino group is bonded to all aromatic nucleus, selected from aromatic amines and diamines wherein at least one of these compounds is brought into contact with free hydrogen in the presence of a catalyst, the catalyst comprises ruthenium and, if required, at least one metal of subgroup I, VII or VIII in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst applied to a carrier, and the carrier has a mean pore diameter of at least 0.1 μm and a surface area of not more than 15mVg and is selected from the group consisting of active carbon, silicon carbide, alumina, silica titanium dioxide, zirconium dioxide, magnesium dioxide, zinc oxide and mixtures thereof, preferably alumina and zirconium dioxide; and the hydrogenation is carried out optionally in the presence of a solvent or diluent.
2. The process as claimed in claim 1, wherein ruthenium and, if required, at least one metal of subgroup I, VII or VIII are applied to the catalyst in an amount of from 0.2 to 15% by weight, based on the total weight of the catalyst.
3. The process as claimed in claim 1 or 2, wherein the mean pore diameter of the carrier is at least 0.5 μm.
4. The process as claimed in any one of the claims 1 to 3, wherein the pore size distribution of the carrier is approximately bimodal.

5. The process as claimed in any one of the claims 1 to 4, wherein the surface area of the carrier is not more thanlO m2/g.
6. The process as claimed in any one of the claims 1 to 5, wherein the one or more metals of subgroup I, VII or VIII are selected from the group consisting of copper, rhenium, cobalt and nickel and mixtures thereof
7. The process as claimed in any one of the claims 1 to 6, wherein the metal applied to the carrier has a surface area of from 0.01 to 10, preferably from 0.05 to 5 m2 per g of catalyst.
8. The process as claimed in any one of claims 1 to 7, wherein the catalyst consists of a macroporus alumina carrier having a surface area of 1.75 mVg. a pore volume of 0.531 ml/g, a bimodal pore size distribution with pore diameters of 0,6 μm and 20 μm, onto which carrier ruthenium is applied in an amount of about 0.5% by weight, based on the total weight of the catalyst, and the ruthenium surface area on the carrier is about 0.76 m2 per g of catalyst.
9. The process as claimed in any one of claims I to 8, wherein the aromatic amine or diamine is selected from the group consisting of aniline,
naphthylamine, diaminotoluenes, bis-p-aminophenylmethane and mixtures
thereof

Documents:

1595-mas-1996 abstract.pdf

1595-mas-1996 claims.pdf

1595-mas-1996 correspondence others.pdf

1595-mas-1996 correspondence po.pdf

1595-mas-1996 description (complete).pdf

1595-mas-1996 form-2.pdf

1595-mas-1996 form-26.pdf

1595-mas-1996 form-4.pdf

1595-mas-1996 others.pdf

1595-mas-1996 petition.pdf

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Patent Number

193904

Indian Patent Application Number

1595/MAS/1996

PG Journal Number

08/2007

Publication Date

23-Feb-2007

Grant Date

12-Sep-2005

Date of Filing

12-Sep-1996

Name of Patentee

BASF AKTIENGESELLSCHAFT

Applicant Address

67056 LUDWIGSHAFEN

Inventors:

#	Inventor's Name	Inventor's Address
1	HEINZ RUTTER	67056 LUDWIGSHAFEN
2	THOMAS RUEL	67056 LUDWIGSHAFEN
3	JOCHEM HENKELMANN	67056 LUDWIGSHAFEN
4	THIOMAS WETTLING	67056 LUDWIGSHAFEN
5	BORIS BREITSCHEIDEL	67056 LUDWIGSHAFEN
6	ANDREAS HENNE	67056 LUDWIGSHAFEN

PCT International Classification Number

C07C35/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	195 33 718.2	1995-09-12	Germany