MX2008006908A - Method for the hydrogenation of nitriles to primary amines or aminonitriles, and catalysts suited therefor - Google Patents

Abstract

The invention relates to a method for hydrogenating oligonitriles containing at least two nitrile groups in the presence of a catalyst which is pre-treated by being contacted with a compound A prior to the hydrogenation process, said compound A being selected among alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogen carbonates, alkaline earth metal hydrogen carbonates, ammonium hydrogen carbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, alkaline earth metal dihydrogen phosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, alkaline earth metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formates, alkaline earth metal formates, ammonium formate, alkali metal oxalates, alkaline earth metal oxalates, and ammonium oxalate.

Description

METHOD FOR THE HYDROGENATION OF NITRILES TO PRIMARY OR AMMONITRIL AMINES AND CATALYSTS APPROPRIATE FOR THEM The invention relates to a process for hydrogenating olymptyols having at least two nitpyl groups in the presence of a catalyst which, before the beginning of hydrogenation, is previously treats it by contacting it with a compound A which is selected from alkali metal carbonates, alkaline earth metal carbonates, hydrogen or hydrogen dt? ammonium,? x? cdro? ndtob of alkaline metal torreo, carboxylates of alkali metal, carboxylates d incidí alkaline earth, cdrb? xiia those of ammonium, di i trogenfosfa os alkali metal, di hiroshrosphosphate alkaline earth metal, iobldlob alkali metal, alkaline earth metal and ammonium phosphate, alkali alkali acetates, Jiieidi dicalo ui iino terreo, dcetdt? of ammonium, alkaline metal formats, metal dicdiià © tero formats, únüidlo uc aiuuii ± u, oxaidLU ue alkali alkaline, oxa l of alkaline earth metal and ammonium oxalate. The SP also invested in alogammas or diiiinoni tr iiüb ÜÜÍUÜI O UO? Iiy? Ni Go using Oble process, and with the use of dp catalysts as defined in the i i. .ii'i. , ''. í. It is complex, or complex, and oligonit ilos. The invention further relates to a catalyst comprising a metal of groups 8 to 10 of the Periodic Table which, prior to use, is pretreated with a compound A which is selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogencarbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, earth alkali metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, earth alkali metal dihydrogen phosphates , alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, alkaline earth metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, metal formats alkaline earth, alkali metal ammonium, oxaial, alkali metal? and ammonium oxalate, excluding cobalt or nickel catalysts previously treated with alkali metal carbonates or alkali metal hydrogencarbonates. ! i p ¡; fnf p sf r c? i.-i (I O? H co n u n D Í OCP .SO for preparing this catalyst, which comprises treating a metal of groups 8 to 10 of the Periodic Table with a compound A which is selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogencarbonates, hydrogen carbonate alkaline earth metal, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, earth alkali metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, alkali metal dihydrogenphosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates , alkali metal phosphates, alkaline earth metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, alkaline earth metal formats, ammonium formate, alkali metal oxalates , alkaline earth metal oxalates and ammonium oxalate, excluding processes for Prepare cobalt or nickel catalysts previously treated with alkali metal carbonates or alkali metal hydrogencarbonates. The amines that have at least two groups and one airnnnitp have different uses and, apart from in iz-i i í--. í (i? (-? i (i) t, f- > (] < - > n r o LPÍ (i on O (OSPÍ GIH. rtopiit s surfactants and pharmaceuticals, they are used especially as a starting material for polyamides. Generally they are prepared by hydrogenating nitriles. Nitriles having more than one nitrile group -CN in the molecule are referred to below as oligonitriles. When all the nitrile groups present in the molecule are hydrogenated, which is referred to below as complete hydrogenation, oligoamines are obtained. When they are not made, but rather some of the nitrile groups present in the molecule are hydrogenated, referred to below as partial hydrogenation, aminonitriles are obtained. In schematic terms: R- (CN) a-? A '- >; (Í_NK-R- (CN) y-lu'-> R- (NH2) n (1) where (a) is partial hydrogenation and (b) complete, and R means organic radical, N means integer from 2 to 20, X, and denote integer> 1, where x + y = n For example, the partial hydrogenation of adiponitrile (DNA) provides aminocapronitrile (ACN) which is further processed to provide caprolactam which is polymerized to provide nylon-6 The complete hydrogenation provides hexamethylenediamine (HMD) which is used for the preparation of nylon-6,6., - &pi drnination is typically assumed with hydrogen on nickel or cobalt catalysts which are preferably present in the form of a metal sponge, for example in the Raney® nickel form or Raney® cobalt. The partial and complete hydrogenation generally proceeds in succession in a random mixture of aminonitrile, oligoamines and other by-products, for example a mixture of aminonitrile (ACN) and diamine (HMD) and also by-products in the hydrogenation of dinitriles (DNA ). The suppression of complete hydrogenation or the establishment of a desired non-random aminonitrile / oligoamine ratio is possible in view of specific configurations of the hydrogenation, for example adulteration of catalyst with noble metals or additional use of fluorides or cyanides. These processes for partial hydrogenation are described, for example, in US 5 151 543, WO 99/47492, Us 5 981 790, WO 00/64862, WO 01/66511 and WO 03/000651. One possibility is the pre-treatment or conditioning of the hydrogenation catalyst. For example, the aforementioned WO 01/66511 describes the hydrogenation of nitrile groups to amino groups, for example ~ The dropping of dinitriles to inonytrimides or diamines, - > •, - rridrosis on a hydrogenation catalyst (e.g.

Raney® nickel or cobalt) that are conditioned in advance. The conditioning is carried out by mixing the catalyst with a strong mineral base. hicrexides ^ c alkaline metals or alkaline earth metals) in a solvent in which the base is rarely soluble. DE 102 07 926 A1 describes the preparation of primary amines by hydrogenation of nitriles, in which the nitrile, hydrogen and, if appropriate, ammonia are converted onto a cobalt or nickel catalyst. The catalyst is modified ex situ (before the hydrogenation reaction) by adsorption of an alkali metal carbonate or hydrogen carbonate. Preference is given to nitriles of the formula R-CN wherein R = saturated or unsaturated hydrocarbon groups. There is no mention of the hydrogenation of dinitriles or other oligonitriles nor of the possibility of partial rather than complete hydrogenation; in the examples, only mononitriles are hydrogenated: lauronitrile to dodecylamine or oylnitrile to oleylamine. The known processes have at least one of the following disadvantages: the ratio of aminotritil / oligoamine, is iwi r, the ratio of hydr? And partial a-puxeta, has low control capacity, the selectivity in a partial hydrogenation is low: instead of the desired inonitriles, the hydrogenation proceeds completely to the oligoamines, - large quantities of secondary products are obtained and are difficult to remove, additional toxic substances are used and have to be removed from a expensive and inconvenient way and disposed separately, - the adulteration with noble metal makes the catalyst more expensive, the hydrogenation of mononitriles can not be directly applied to the hydrogenation of dinitriles. It was an object of the invention to remedy the disadvantages outlined. The intention was to provide a process for hydrogenating nitriles having at least two nitrile groups, with which it is possible to prepare amines or aminonitriles, that is, the process was to allow complete or partial hydrogenation. In particular, the possibility was to exist maintenance up to the full low hydrogenation degree. In addition, the intention was for a level to occur ba of secondary products. The process was to not need any toxic substances, for example cyanides, and to be operable without adulteration of expensive noble catalyst metal. Consequently, the hydrogenation process specified in the beginning has been found. Likewise, the oligoa and ammonitriles obtainable with it were found, and also the use of the catalysts for complete or partial hydrogenation of oligonitriles. Additionally the catalyst defined in the beginning has been found, and also a process for its preparation. Preferred embodiments of the invention can be taken from the subclaims. All the pressures specified below are absolute pressures. Suitable oligonitriles which can be used in the hydrogenation process according to the invention are adiponitrile (DNA), succmonitrile, io-diacetonitrile, suberonitop or imododropionitrile (bis [cyanoethyl] amine). Also useful aromatic amines such as m-xylylenediamma or ortho-, meta- or para-phthamitryl. Suitable oligonucleotides having at least three nitplo groups are, for example, nitplotrisacetonitrile t c ib i dnorne til] amine), iLr? Lol? _bpr opioni Go IOI (tris. {cyanoethyl] amine), 1, 3, 6-trithiohexane or 1,2,4-trichlorobutane. Preferred oligonitriles are those having two nitrile groups. Particularly preferred dinitrisols are those having terminal nitrile groups, ie, alpha, omega-dinitriles. Particular preference is given to using adiponitrile. In a preferred embodiment mentioned herein as complete hydrogenation, in the process, all nitrile groups present in the nitrile molecule and hydrogenated to amino groups (complete hydrogenation) to form an oligoamine. This oligoamine no longer comprises any nitriium groups. Preference is given to hydrogenating an alpha, omega-dinitrile by complete hydrogenation to provide an alpha, omega-diamine. In particular, adiponitrile (DNA) is hydrogenated to hexamethylenedia ina (HMD). In an equally preferred embodiment mentioned herein as partial hydrogenation, in the process, only some of the nitrile groups present in the nitrile molecule are hydrogenated to amino groups (partial hydrogenation) to obtain an aminonitrile. ~. a partial hydrogenation of oligonitriles that have three nitrile groups, it is possible to obtain a diammomononitrile or a monoammodinitrile depending on whether one or two of the three nitrile groups are hydrogenated to the ammo group. Preference is given to hydrogenating an alpha, omega-dimethyl by means of parental hydrogenation to provide an alfra, omega-a monitrile. In particular, adiponitrile is hydrogenated to provide ammocapronitplo (ACN). In the hydrogenation, the oligonitrile is reacted with hydrogen or a gas comprising hydrogen on the catalyst (see below). The hydrogenation can be carried out, for example, in suspension (hydrogenation by suspension) or on a fi xed bed, mobile or fluidized, for example on a fixed bed or on a fluidized bed. These modalities are known to those skilled in the art. In general, hydrogen gas or a mixture of hydrogen and an inert gas such as nitrogen or argon is used. Alternatively, and depending on the established pressure and temperature conditions, the hydrogen or mixture may also be present in dissolved form. When complete hydrogenation is complete, the hydrogen can be used in excess; in the case of partial hydrogenation, the amount of hydrinogen Required in estequio étricos terms for this purpose can be introduced by measuring. The amount of catalyst in the hydrogenation per suspension is generally from 1 to 30% by weight, preferably from 5 to 25% by weight, based on the content of the hydrogenation reactor. In the case of supported catalysts, the support material is included in the calculation. When the hydrogenation is carried out on a fixed bed or a fluidized bed, the amount of catalyst, if appropriate, has to be adjusted in a customary manner. The hydrogenation is preferably carried out in the liquid phase. The reaction mixture typically comprises at least one solvent; Suitable examples are amines, alcohols, ethers, amides or hydrocarbons. The solvent preferably corresponds to the reaction product to be prepared, that is, an oligoamine or aminonitrile is used as the solvent. Suitable amines are, for example, hexamethylenediamine or ethylenediamine. Suitable alcohols are preferably those having 1 to 4 carbon atoms, for example methanol or ethanol. Suitable ethers are, for example, methyl tert-butyl ether (MTBE) or tetrahydrofuran (THF). Useful amides are, for example, those with 1 to 6 carbon atoms. Suitable hydrocarbons are, for example, alkanes such as hexanes or cyclohexane, and also aromatics, for example toluene or the xylenes. The amount of solvent in the reaction mixture is typically from 0 to 90% by weight. If the solvent and product are identical, the amount of solvent can be more than 99% by weight. In the case of a complete hydrogenation, the reaction can also be carried out in the absence of an additional solvent in product mode, for example in the case of complete hydrogenation of DNA in HMD. Preference is also given to carrying out the hydrogenation with the addition of water. The water present in the feed materials, for example as an impurity or in the Raney® catalyst to prevent self-ignition, can be removed in advance. In hydrogenation, it is further possible to use ammonia or another base, for example alkali metal hydroxides, for example in aqueous solution. If this is the case, the amount of ammonia or base is generally 1 to % by weight, based on oligonitrile. Ammonia is also suitable as a solvent.

The reaction temperature is typically 30 to 250 ° C, preferably 50 to 150 ° C and in particular 60 to 110 ° C. The pressure is typically from 1 to 300 bar, preferably from 2 to 180 bar, in particular from 2 to 85 bar and more preferably from 5 to 35 bar. The process can be operated continuously, semicontinuously (by semilots) or discontinuously (by batches), for which all types of common reactor for hydrogenation reactions are appropriate. The reaction mixture is worked up to the product (diamine or ammonium) in a customary manner, for example by distillation. Whether the hydrogenation proceeds as a complete or partial hydrogenation and in which ratio of oligoa plus (complete hydrogenation) and ammonitriles (partial hydrogenation) are present in the resulting reaction mixture depends on factors including reaction temperature, pressure and time, the composition and amount of the catalyst, the type and amount of the oligonitrile, the amount of hydrogen, and the type and amount of any additives used, such as ammonia or other bases. Typically, a lower reaction temperature, a lower pressure, a lower amount of hydrogen and especially a shorter reaction time favor partial hydrogenation over complete hydrogenation. The designation of the element groups in the Periodic Table of the Elements (PTE) used below corresponds to the new IUPAC system, that is, the groups are numbered in series of 1 = hydrogen and alkaline metals to 18 = noble gases. See, for example, inside the front cover in the CRC Handbook of Chemistry and Physics, 86th edition 2005, CRC Press / Taylor & Francis, Boca Ratón FL, USA. The catalyst preferably comprises at least one metal M of groups 8 to 10 of the Periodic Table (Faith, Ru, Os, Co, Rh, Go, Ni, Pd, Pt). As the metal M, it preferably comprises iron, cobalt, nickel or mixtures thereof. Particular preference is given to cobalt and nickel, especially nickel. The metals mentioned are preferably in the oxidation state of zero, but may also have other oxidation states. Metal sponge catalysts, for example those in accordance with Raney®, are particularly preferred. In the process, the catalyst is preferably a nickel sponge catalyst or a cobalt sponge catalyst (each Raney®). For preparing these highly active catalysts particularly suitable for hydrogenations, nickel or cobalt is typically alloyed with Al, Si, Mg or Zn metal, frequently with Al, and the alloy is ground and the metal other than nickel or cobalt is separated with alkali. This leaves a skeleton-like metal sponge, known as Raney® nickel catalysts or Raney® cobalt. Raney® catalysts are also commercially available, for example from Grace. In order to prevent self ignition of the pyrophoric Raney® catalysts, they are kept wet with, for example, water. Before the catalyst is used in the inventive hydrogenation, this water can be removed. In addition to the M metals mentioned, the catalyst may comprise at least one additional metal D selected from groups 1 to 7 of the Periodic Table. The additional D metals are also referred to as adulteration metals or promoters. The adulteration allows the activity and selectivity of the catalyst to be varied as required. As the additional metal D, the catalyst preferably comprises at least one of the metals titanium, zirconium, chromium, molybdenum, tungsten and manganese.

The amount of a single additional metal D is typically from 0 to 15% by weight, preferably from 0 to 10% by weight, based on the metal M. The catalyst can be present as such, for example as pure metal or alloy, in the form of fine particles or as a metal sponge (Raney®). It is also possible to use it sustainably. Suitable supports are inorganic support materials such as alumina, 1 magnesia or silica, and also carbon. Also suitable are supports, comprising catalytically active metal oxides or those active as an adulterant, for example zirconium dioxide, manganese oxide (II), zinc oxide or chromium (VI) oxide. The supported catalysts can be prepared in a customary manner, for example by impregnation, coprecipitation, ion exchange or other processes. In the case of supported catalysts, the support typically forms from 20 to 99% by weight, preferably from 50 to 90% by weight, of the supported catalyst. In accordance with the invention, the catalyst, prior to the start of hydrogenation, is pretreated by contacting a compound a. Compound A is selected from alkali metal carbonates, carbonates of alkaline earth metal, ammonium carbonate, alkali metal hydrogen carbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, earth alkali metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, dihydrogen phosphates alkaline earth metal, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, earth alkali metal phosphates and ammonium phosphate, metalalkaline acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, formats of alkaline earth metal, ammonium formate, alkali metal oxalates, alkaline earth metal oxalates and ammonium oxalate. According to the invention, compounds A also include hydrates (for example those comprising water as constitution water and / or those comprising water as water of crystallization) and any basic carbonates of the compounds mentioned above. A of compound. Basic alkaline earth metal carbonates or oxocarbonates also include, for example, magnesium carbonate basic Mg (OH)? • 4 MgC03 • 4 H20 1 o The catalyst preferably comprises from 0.01 to 25% by weight, in particular from 0.5 to 15% by weight and more preferably from 1 to 105 by weight of alkali metal, alkaline earth metal or ammonium, based on the previously treated catalyst. In this case, alkali metal or alkaline earth metal or ammonium are considered as such, ie, without carbonate, hydrogencarbonate, oxocarbonate, carboxylated k, dihydrogenphosphate, hydrogen phosphate or phosphate radical and the support material is included in the calculation in the case of supported catalysts. The alkali metal in the compound a is preferably selected from lithium, sodium, potassium and cesium, in particular sodium, potassium or cesium, more preferably cesium. The alkaline earth metal is preferably selected from magnesium and calcium. In particular, the compound to be used is sodium carbonate, potassium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, cesium hydrogencarbonate, magnesium hydrogen carbonate, hydrogen carbonate, calcium, ammonium hydrogencarbonate, magnesium oxocarbonate or mixtures thereof, preferably mixtures thereof or cesium carbonate, cesium hydrogen carbonate or cesium carbonate, cesium hydrogencarbonate in mixtures with sodium carbonate, potassium carbonate, magnesium carbonate, decalcium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium hydrogencarbonate, calcium hydrogencarbonate, hydrogencarbonate of ammonium and / or magnesium oxocarbonate. In the case of alkali metals, phosphates and hydrogen phosphates are also preferred. The carboxylates are preferably selected from the formats, acetates, propionates, butanoates, pentanoates, hexanoates, and also dicarboxylates such as oxalates, malonates and succinates, glutyarates and adiptados. When the corresponding acids are discussed, what is meant is, for example, formic acid, acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, oxalic acid, masonic acid, succinic acid, glutamic acid and atypical acid . It is also possible to use a mixture comprising alkali metal and alkaline earth metal compounds. In this mixture, the proportion of alkaline earth metal compounds is, for example, from 1 to 99% by weight. The catalyst can be previously treated outside of the reactor used for the hydrogenation, or in the hydrogenation reactor before the start of the actual hydrogenation. It is also possible to pretreat a catalyst that has already been used in advance in a hydrogenation, that is, spent catalyst can be regenerated by contacting it with the compound A. In a preferred embodiment of the hydrogenation process, the catalyst is pretreated by contacting it with a solution or suspension of compound A. The preferred solvent or suspension medium is water, but the organic solvents already mentioned above for hydrogenation are also suitable. Compound A can be used in solid form and the corresponding solution or suspension can be prepared by adding the solvent or suspension medium. The content of compound A in dicyha aqueous or non-aqueous solution or suspension is typically from 1 to 90% by weight. Especially in a suspension hydrogenation, the contact can be effected in a simple manner by stirring the catalyst in the solution or suspension of compound A, in which case the amount of catalyst is appropriately from 4 to 95% by weight, based on the solution or suspension of compound A. Subsequently, the excess solution or suspension can be removed, for example by decanting or filtration. It is advantageous to wash the catalyst then once or more than once with one or more different organic liquids in order to remove the adhering water. For example, the previously treated catalyst, separated by filtration or decantation can be washed once or more once with an alcohol such as methanol or ethanol, and then with a hydrocarbon, for example cyclohexane, or with an ether. Consequently, in the hydrogenation process, the catalyst is preferably contacted with an aqueous solution or suspension of compound a, the catalyst is removed and subsequently washed with at least one organic liquid in order to remove the water. The contact (suspension formation), removal (filtration, decanting) and washing are carried out appropriately under inert gas. The pressure and temperature for the contact are generally not critical. For example, it is possible to work at room temperature (20 ° C) and ambient pressure. The contact duration depends, for example, on the desired content of compound A in the catalyst, and especially the adsorption behavior of the catalyst, its external and internal surface area and the material of the catalyst. catalyst support used if appropriate. It is, for example, 5 min. at 5 hours, preferably 10 minutes. to 2 hours. Alternatively, the contact can be configured so that the compound a is formed in situ before or during the treatment of the catalyst. To this end, a suspension or solution of catalyst, water, or other suspension medium or solvent already mentioned above and a compound A * is prepared, a carbon dioxide or the corresponding carboxylic acid or phosphoric acid is introduced into this suspension or solution . In the case of carbonates, hydrogencarbonates and oxocarbonates, compound A * is an alkali metal, alkaline earth metal or ammonium compound other than compounds A. In the case of carboxylates and phosphates, it may be carbonates, hydrogen carbonates or oxocarbonates and also the hydroxides of alkali metals, ferrous alkaline metals or ammonium. The compound A * preferably comprises water-soluble salts, for example the halides, nitrates or sulfates of alkali metals, ferrous alkali metals or ammonium. The reaction with the introduced CO 2 or the acid provided forms of the desired, or carboxylated carbonates, hydrogen carbonates or oxocarbonates, dihydrogen phosphates, hydrogen phosphates or phosphates A of compound A *. The reaction with the CO 2 or the acid can be carried out, for example at room temperature and ambient pressure. Accordingly, in this embodiment of the process, compound A is formed in situ by introducing carbon dioxide or a chargexyl acid or phosphoric acid into a solution or suspension that the catalyst and a compound A * which, in the case of carbonates, hydrogen carbonates and oxocarbonates, is an alkali metal, alkaline earth metal or ammonium compound different from the compounds A. The catalyst can also be contacted in another way, for example by mixing the untreated catalyst with solid compound A, by application of composite drum A solid towards the untreated catalyst, or by spraying the untreated catalyst with a solution or suspension of the compound A. The catalyst previously treated with the compound A is dried, i.e., any solvent or suspension medium used is removed, from a customary way Alternatively, the catalyst can also be used in wet or suspended form; For example, the previously treated catalyst, after washing with the organic liquid, can be left in the washing liquid used final and this suspension can be used. The oligoamines or aminonitriles obtainable by the hydrogenation process according to the invention also form part of the subject matter of the invention. The invention further provides the use of catalysts as described above for complete or partial hydrogenation of oligonucleotides. Preference is given to the use of catalysts for alpha hydrogenation, omega-dinitriles to alpha, omega-diamines. It is particularly preferred that the catalyst be used for complete hydrogenation of adiponitrile to hexamethylenediamine. Preference is also given to the use of catalysts for partial hydrogenation of alpha, omega-dinitriles to alpha, or ega-aminonitriles. It is particularly preferred that the catalyst be used for partial hydrogenation of adiponitrile to aminocapronitrile? The invention further provides a catalyst comprising a metal of groups 8 to 10 of the Periodic Table which, prior to use, is pretreated with a compound a which is selected from alkali metal carbonates, alkaline earth metal carbonates, carbonate ammonium, alkali metal hydrogen carbonate, hydrogen carbonate alkaline earth metal, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkali metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, alkali metal dihydrogen phosphates, alkali metal hydrogen phosphates, alkali metal hydrogen phosphates earth, alkali metal phosphates, alkaline earth metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, alkaline earth metal formats, ammonium formate, metal oxalates alkaline, alkaline earth metal oxalates and ammonium oxalate. In delimitation of the aforementioned DE 102 07 926 Al, cobalt or nickel catalysts previously treated with alkali metal carbonates or alkali metal hydrogencarbonates are excluded. The catalyst preferably has at least one of the features specified above in the description of the catalyst, especially at least one of the features of claims 9 to 19. Finally, a process for preparing this catalyst is also part of the subject matter of the invention . This process comprises treating a metal of groups 8 to 10 of the Periodic Table with a compound A which is / D selects from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogencarbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, carbyloxylates ammonium, alkali metal dihydrogen phosphates, earth alkali metal dihydrogen phosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, alkali metal phosphates and ammonium phosphate, alkali metal acetates, alkali metal acetates , ammonium acetate, alkali metal formats, alkaline earth metal formats, ammonium formate, alkali metal oxalates, alkali metal oxalates and ammonium oxalate, again excluding processes for preparing cobalt or nickel catalysts previously treated with carbonates alkali metal or hydrogen carbonate alkaline metal This catalyst preparation process preferably has at least one of the features specified above in the description of the catalyst preparation. In particular, you have at least one of the particularities of claims 18 to 20. It is possible that the hydrogenation process according to the invention to prepare oligoamines or aminonitriles of oligonitriles, that is, allows complete or partial hydrogenation. The extent of complete hydrogenation can be kept low if desired. A low level of byproducts is obtained, and highly toxic substances such as cyanides are not used. Expensive noble metal adulteration of the catalyst is not required. Examples Batch hydrochlorination Examples 1-6 Process procedure: A) Catalyst preparation: Unadulterated Raney Ni (Taste B113W, 3g) was stirred vigorously with an aqueous solution of the desired modifier (amount as specified in the table) at temperature environment for 1 hour. Subsequently, the catalyst was decanted, washed 2 x 20 ml with ethanol (EtOH) 2 x 15 ml and adiponitrile. A portion of the catalyst was used to carry out elemental analysis in order to determine the modifier content (see box). B) Hydrogenation: 1.92 g of the wet DNA, modified catalyst was loaded micially in a 160 ml autoclave with blade stirrer with magnet-coupled step, electric heater, closed-circuit internal temperature control, sampling through 7-inch frit. , measurement of ammonia through rotameter, and hydrogen spraying through the surface, and 53 g of DNA were added. 17 g of NH 4 was measured and the autoclave was heated to 60 ° C with gentle stirring 850 rpm). Upon reaching this temperature, H2 was injected into the autogenous system pressure, which established a pressure of approximately 37 bar. At regular intervals, samples were taken that allowed the progress of the experiment to be discerned. The results of the hydrogenation experiments are listed in table 1.

As is evident from the examples, the randomized ACN selectivities above were achieved in all cases. What it means by previous randomizations is that, compared to the calculated ACN selectivity ([ACN] / [conversion]), more ACN is present at a certain conversion with the assumption that all nitrile groups are hydrogenated equally rapidly ("randomly"). Example: for 93.8% conversion, the calculated ACN selectivity is 40%; for 97.8% conversion, 26.1%. It is also evident that improvements in total selectivity ([HMD + ACN] / [conversion]) are achieved with Mg, Li, K and Cs compared to unadulterated Raney nickel. Potassium carbonate and cesium carbonate have a particularly clear effect. Examples 7-9 In Examples 7 and 8, Raney nickel adulterated with Cr, Fe was used instead of unadulterated Raney nickel.

(A4000 by Jonson Matthey). In addition, the amount of ammonia in Examples 7 to 9 quadrupled. For the rest, the process was as above. Table 2 On Raney nickel adulterated with Cr, Fe also, CS2CO3 has a totally positive effect on the selectivity of ACN. In the case of similar conversion, 10% more ACN is formed with cesium carbonate than without modifier (7b against 8). Total totality increases by 3%. In comparison with unadulterated Ra-Ni (example 1), the selectivity of ACN with the Ra-Ni adulterated with Cr, Fe (eg 7a) is 3% higher for the same conversion; the total selectivity increases by 0.6%. The comparison of Example 7a and 9 shows that the amount of ammonia likewise has an influence on the selectivity of ACN, since 5% more of ACN is formed at the same conversion but with four times the amount of ammonia. Continuous Hydrogenation Examples 10-16 Experimental procedure: The continuous hydrogenation experiments were carried out in a stirred 270 ml autoclave equipped with 6-blade paddle stirrers, 4 x rod-type partitions and height-adjustable submersible discharge frit. DNA, liquid NH3 and H2 were introduced combined through the bottom of the autoclave. All continuous feeds were controlled by pump control and flow meters. Heating of the oil bath was controlled by means of a thermometer in the reaction medium. EtOH was measured through a T-piece to the discharge line, so that the Feeding DNA / EtOH 1:12, in order to prevent solidification of the reaction mixture. The analyzes were carried out as described above. The adulteration was applied as described above. At the beginning of the adulterated Ra-Ni experiment was introduced as a suspension in EtOH in the autoclaves, and the autoclaves were closed and made inert with nitrogen. Subsequently, the desired temperature (65 ° C) was preset and heated, and the operating pressure of hydrogen was established (55 bar) and flooded with the maximum amount of ammonia for 1 hour in order to remove the EtOH quantitatively. Next, DNA was changed and the samples were taken at regular intervals. In the case of the unadulterated Ra-Ni, the aqueous suspension was initially charged and the water was flooded with ammonia. Examples 11-14 serve to examine the influence of the amount of ammonia at constant residence time. Examples 10 to 15 serve for comparison of adulteration with unadulterated catalyst. Example 16 reproduces a section of a life time experiment with Raney nickel adulterated with Cs. Some of the parameters such as catalyst loading and residence time were varied during the operating time; the results recorded in table 3 represent the constant state after a change in parameter JO Examples 11-14 show that the excess ammonia can be reduced from 13 to 2 g / g of DNA without significantly influencing the selectivity of ACN and the total selectivity. Only at a ratio of 0.5 g / g of DNA does total selectivity fall greatly. The comparison of Example 10 and 15 provides a higher total selectivity for the catalyst adulterated with Cs with the same residence time and charge at similar conversion. further, Example 15 shows that the hydrogen activity desinuita greatly during 124 h with unadulterated Raney Ni and the selectivity of ACN rises slowly only with the conversion that falls (decline in conversion of 99 to 78%). In contrast, it can be taken from the analysis results under Example 16 that the conversion remains virtually constant between 116 and 164 h, and ACN and total selectivity were also constant at a high level.

Claims (35)

1. CLAIMS 1.- A process for hydrogenating oligonitriles having at least two nitrile groups in the presence of a catalyst which, before the beginning of the hydrogenation, is previously treated by contacting it with a compound A which is selected from alkali metal carbonates, carbonates alkaline earth metal, ammonium carbonate, alkali metal hydrogencarbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, earth alkali metal dihydrogenphosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, earth alkali metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, metal formats alkaline, alkaline earth metal formats, amoni format or, alkali metal oxalates, alkaline earth metal oxalates and ammonium oxalate.
2. 2. The process according to claim 1, wherein the nitrile is an alpha, omega-dinitrile.
3. 3. - The process according to claims 1 and 2, wherein the alpha, ometa-dinitrile is adiponitrile.
4. 4. The process according to claims 1 to 3, wherein all the nitrile groups present in the nitrile molecule are hydrogenated to amino groups (complete hydrogenation) to form an oligoamine.
5. 5. The process according to claims 1 to 4, wherein an alpha, omega-dinitrile is hydrogenated to an alpha, omega-diamine by complete hydrogenation.
6. 6. The process according to claims 1 to 3, wherein only some of the nitrile groups present in the nitrile molecule are hydrogenated to the amino groups (partial hydrogenation) to obtain an aminonitrile.
7. 7. The process according to claims 1 to 3 and 6, wherein an alpha, omega-dinitrile is hydrogenated to an alpha, omega-aminonitrile by partial hydrogenation.
8. 8. The process according to claims 1 to 7, wherein the catalyst comprises at least one metal M of groups 8 to 10 of the Table Periodic
9. 9. The process according to claims 1 to 8, wherein the catalyst comprises, as the metal M, iron, cobalt, nickel or mixtures thereof.
10. 10. The process according to claims 1 to 9, wherein the catalyst is a nickel sponge catalyst or a cobalt sponge catalyst (Raney®).
11. 11. The process according to claims 1 to 10, wherein the catalyst comprises at least one additional metal D selected from groups 1 to 7 of the Periodic Table.
12. 12. The process according to claims 1 to 11, wherein the catalyst comprises, as the additional metal D, at least one of the metals titanium, zirconium, chromium, molybdenum, tungsten and manganese.
13. 13. The process according to claims 1 to 12, wherein the catalyst comprises 0.01 to 25% by weight of alkali metal, alkaline earth metal or ammonium, based on the previously treated catalyst.
14. 14. The process according to claims 1 to 13, wherein the catalyst comprises Nickel adulterated with chromium and iron.
15. 15. The process according to claims 1 to 14, wherein the alkali metal in compound a is selected from lithium, sodium, potassium and cesium.
16. 16. The process according to claims 1 to 15, wherein the alkaline earth metal in compound A is selected from magnesium and calcium.
17. 17. The process according to claims 1 to 16, wherein, in compound A, the alkali metals are selected in the form of phosphates or hydrogen phosphates.
18. 18. The process according to claims 1 to 17, wherein the compound A used is a mixture comprising alkali metal and alkaline earth metal compounds.
19. 19. The process according to claims 1 to 18, wherein the catalyst is previously treated by contacting it with a solution or suspension of compound A.
20. 20. The process according to claims 1 to 19, wherein the catalyst is contacted with an aqueous solution or suspension of compound A, the catalyst is removed and subsequently washed with at least one organic liquid in order to remove the water.
21. 21. The process according to claims 1 to 20, wherein the compound A is formed in situ by introducing carbon dioxide into a solution or suspension that the catalyst and a compound A * which is an alkali metal, alkali metal compound or ammonium, different from the compounds A.
22. 22. The process according to claims 1 to 21, wherein the compound A is formed in situ by introducing ammonia or adding an aqueous solution of an alkali metal hydroxide or alkaline earth metal to a suspension or solution which is the catalyst and a carboxylic acid or phosphoric acid.
23. 23. The process according to claims 1 to 22, wherein the compound A is selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogen carbonates, alkali metal hydrogen carbonates earth, ammonium hydrogen carbonate, alkaline earth metal oxocarbonates.
24. 24. The process according to claims 1 to 22, wherein the compound a is selected from alkali metal carboxylates, carboxylates of alkaline earth metal, ammonium carboxylates, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, alkaline earth metal formats, ammonium formate, alkali metal oxalates, earth alkali metal oxalates and oxalate of ammonium.
25. 25. The process according to claims 1 to 22, wherein compound A is selected from alkali metal dihydrogen phosphates, alkaline earth metal dihydrogen phosphates, alkali metal hydrogen phosphates, alkaline earth metal hydrogen phosphates, alkali metal phosphates, phosphates of alkaline earth metal and ammonium phosphate.
26. 26. The process according to claims 1 to 25, wherein ammonia is additionally used in hydrogenation.
27. 27. The process according to claims 1 to 26, wherein a solvent is additionally used in the hydrogenation.
28. 28.- An oligoamine or an aminonitrile botenible oligonitriles by the process according to claims 1 to 27.
29. 29.- The use of catalysts in accordance with claims 1 to 28, for complete or partial hydrogenation of oligonitriles.
30. 30. The use according to claim 29, wherein the catalyst is used for complete hydrogenation of adiponitrile to hexamethylenediamine.
31. 31. The use according to claim 29, wherein the catalyst is used for partial hydrogenation of adiponitrile to aminocapronitrile.
32. 32. A catalyst comprising a metal of groups 8 to 10 of the Periodic Table which, before use, is pretreated with a compound A which is selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate , alkali metal hydrogencarbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, earth alkali metal dihydrogen phosphates, hydrogen phosphate alkali metal, alkaline earth metal hydrogen phosphates, alkali metal phosphates, earth alkali metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formats, formats of alkaline earth metal, ammonium formate, alkali metal oxalates, alkali metal oxalates and ammonium oxalate, excluding cobalt or nickel catalysts previously treated with alkali metal carbonates or alkali metal hydrogen carbonates.
33. 33. The catalyst according to claim 32, having at least one of the features according to claims 9 to 25.
34. 34.- A process for preparing the catalyst according to claims 32 and 33, which comprises treating a metal of groups 8 to 10 of the Periodic Table with a compound A selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogencarbonates, alkaline earth metal hydrocarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carbonylates, alkaline earth metal carboxylates, ammonium carboxylates, alkali metal dihydrogen phosphates, alkaline earth metal dihydrogen phosphates, alkali metal phosphates, alkali earth metal phosphates and ammonium phosphate , alkali metal acetates, alkaline earth metal acetates, acetate ammonium, alkali metal formats, alkaline earth metal formats, ammonium formate, alkali metal oxalates, alkali metal oxalates and ammonium oxalate, excluding cobalt or nickel catalysts previously treated with alkali metal carbonates or alkali metal hydrogen carbonates .
35. 35.- A process according to claim 33, which has at least one of the features according to claims 19 to 21.