United States Patent (19) 11 Patent Number: 5,011,996 Kiel et al. 45 Date of Patent: Apr. 30, 1991

54 PROCESS FOR THE PREPARATION OF (56) References Cited AMINES U.S. PATENT DOCUMENTS 75) Inventors: Wolfgang Kiel, Odenthal; Heinz 2,298,284 i0/1942 Emerson ...... 564/397 3,366,684 1/1968 Budd ...... 564/397 X Ziemann, Leichlingen, both of Fed. Rep. of Germany 3,739,026 6/1973 Wilson, Jr...... 564/397 OTHER PUBLICATIONS 73 Assignee: Bayer Aktiengesellschaft, Adams et al., “Organic Reactions', vol. IV., pp. Leverkusen, Fed. Rep. of Germany 174-183 (1948). (21) Appl. No.: 375,762 Primary Examiner-Richard L. Raymond Attorney, Agent, or Firm-Sprung, Horn, Kramer & 22 Filed: Jul. 5, 1989 Woods 57 ABSTRACT (30) Foreign Application Priority Data Reaction products of oxo compounds and amines or Jul. 20, 1988 DE Fed. Rep. of Germany ...... 3824519 ammonia, in which at least one substituent is aromatic Oct. 13, 1988 (DE) Fed. Rep. of Germany ...... 3834,848 and monosubstituted to trisubstituted by halogen, can be catalytically hydrogenated to the respective amines, 51 Int. Cl...... C07C 209/24: CO7C 209/26; the halogen essentially being completely retained if an CO7C 209/28 Ni-containing or Co-containing catalyst is employed 52 U.S. C...... 564/321; 564/373; and the reaction is carried out in the presence of organic 564/374; 564/381; 564/397; 564/398 sulphur compounds. (58) Field of Search ...... 564/374, 384, 398, 321, 564/373, 375; 514/397 18 Claims, No Drawings 5,011,996 1 2 Weyl, loc. cit.). However, the specific hydrogenations PROCESS FOR THE PREPARATION OF AMINES indicated in the references cited do not represent a systematic investigation (page 436, paragraph 3) and in BACKGROUND OF THE INVENTION some cases show extremely moderate yields, as in the The invention relates to a process for the preparation case of p-chlorobenzyl methyl ketone which can only of amines in which at least one substient is aromatic and be converted into the respective amine in 10% of the is monosubstituted to trisubstituted by halogen. In this theoretical yield (Houben-Weyl, bottom of page 436). connection, the process starts out from reaction prod By-products have to be taken into account, especially in ucts of oxo compounds and amines or ammonia which the preparation of strongly basic amines (Houben-Weyl, carry halogen substituents in the circumstances men O age 240, paragraph 2). tioned. These reaction products are catalytically hydro genated, an Ni-containing and/or Co-containing cata SUMMARY OF THE INVENTION lyst being employed and the reaction being carried out It has now surprisingly been found that, for substan in the presence of organic sulphur compounds. tial retention of aromatically bonded halogen, the de The catalytic hydrogenation of reaction products of 15 scribed catalytic hydrogenation on Ni-containing and oxo compounds and amines or ammonia is known. Al /or Co-containing catalysts can be carried out if the dehydes and ketones may be mentioned as oxo com organic sulphur compounds described below are em pounds in accordance with the following scheme: ployed simultaneously. The invention therefore relates to a process for the 20 preparation of amines of the formula

R-CO-R2+ HN -GR-C-N (Hemiaminal) R2 R3 (I) N / OH R4 R1-CH-N R3 25 / Yr4. ; -H2O in which R1, R2 and R3 independently of one another denote hydrogen, straight-chain or branched C1-C12-alkyl, 30 C3-C8-cycloalkyl, C12-C12-aryl or C7-C10-aralkyl and (Aminal) R represents hydrogen, straight-chain or branched C1-C20-alkyl, C6-C12-aryl, C3-C8-cycloalkyl or R4 C7-C10-aralkyl, R^ Yr 35 where at least one of the radicals R to R represents R2 aryl or aralkyl which are monosubstituted to trisubstitu ted by halogen in the aromatic moiety, by catalytic Rl-co-R2 + H2N-R-G- R!--NH-R (Hemiaminal) hydrogenation of reaction products of oxo compounds OH of the formula . -H2O R-CO-R (II) R2 and nitrogen compounds of the formula Rl-C=N-R (Schiff's base) R-NH-R (III) 45 From an aldehyde or ketone and a primary or second with the abovementioned meanings for R1 to R, which ary amine or ammonia, a hemiaminal can therefore first is characterized in that an Ni-containing and/or Co be formed which can react further with a further mole containing catalyst is employed and that the reaction is cule of the amine or ammonia to give the aminal with carried out in the presence of organic sulphur com the elimination of a molecule of water or (only with 50 pounds of the formula primary amines or ammonia) can also react to give the azomethine (Schiff's base, aldimine, ketimine) with the elimination of a molecule of water. Aldimines can addi tionally be obtained in an indirect manner as reaction in which R5 and R6 independently of one another de products of aldehydes and ammonia by partial hydroge 55 note straightchain or branched C1-C12-alkyl, hydroxy nation of nitriles. All reaction products mentioned C2-C12-alkyl, carboxy-C1-C12-alkyl or phenyl and fur (hemiaminal, aminal or azomethine) can be catalytically thermore hydrogenated to give the corresponding amines (Houb R and R6 together may represent -CH= en-Weyl, Methoden der Organischen Chemie (Methods CH-CH=CH-, -(CH2)4-, -(CH2)5-, -(CH2. of Organic Chemistry), 4th edition, volume IV/lc )2-S-(CH2)2- or -(CH2)2-O-(CH2)2-, (1980), p. 127/128, 239/240 and 436). Such catalytic R6 additionally may denote hydrogen or CO-C hydrogenations should also be possible with the reten -C1-C12-alkyl and tion of halogen. However, this result is limited to the in assumes the value 0 or 1. use of palladium catalysts, and it is further pointed out that the reaction is advantageously carried out at low 65 DETAILED DESCRIPTION OF THE temperatures and using a deactivated catalyst (page INVENTION 240). Even using other catalyts, such as platinum or Straight-chain or branched C1-C1-alkyl is, for exam Raney nickel, halogen should be retained (Houben ple, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 5,011,996 3 4. tert.-butyl, amyl, hexyl, octyl, decyl or dodecyl; C1-C8 R23 denotes hydrogen, straight-chain or branched alkyl is preferred, particularly preferably C1-C4-alkyl. C1-C4-alkyl, C5-C6-cycloalkyl, phenyl or benzyl and R may furthermore also have up to 20 C-atoms and R2 represents hydrogen, methyl or ethyl. may also be, for example, palmityl, stearyl or eicosyl, In the manner according to the invention, the pre Hydroxy-alkyl carries in any position, preferably in the 5 ferred or particularly preferred oxo compounds or ni o-position, a hydroxyl group and may furthermore be trogen compound are also so combined that in their interrupted by ether oxygen in the carbon chain. Car reaction products at least one of the radicals mentioned boxy-alkyl carries in any position, preferably in the a therein is aryl or aralkyl and is monosubstituted to tri or co-position, a carboxyl group. The same preferred substituted in the aromatic part by halogen. ranges apply as for alkyl. 10 The process according to the invention is carried out C3-C8-Cycloalkyl is, for example, cyclopropyl, cy in the presence of one or more organic sulphur com clobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cy pounds of the formula (IV). Examples of such com clooctyl, which may be monosubstituted or disubsti pounds are bis-(2-hydroxyethyl) sulphide, bis-(2- tuted by methyl and/or ethyl. Preferably, cycloalkyl is hydroxypropyl) sulphide, thiodiacetic acid, thiodipropi cyclopropyl, cyclopentyl or cyclohexyl. 15 onic acid and other similarly constructed compounds, Cs-C12-Aryl is, for example, phenyl, naphthyl or their alkali metal salts and their lower esters (for exam biphenyl, preferbly phenyl. ple their dimethyl esters), thioanisole, diphenyl sul C7-C10-Aralkyl is, for example, benzyl, phenylethyl phide, dithiane, thioxane, thiophene, dimethyl sulphox or phenylpropyl, preferbly benzyl and phenylethyl. ide, methyl ethyl sulphoxide or diethylsulphoxide. The At least one of the radicals in the reaction products of 20 organic sulphur compound is employed in an amount oxo compounds with the nitrogen compounds is aryl or from 0.002-0.5 parts by weight, preferably 0.01-0.25 aralkyl and is monosubstituted to trisubstituted in the parts by weight, per part by weight of catalyst. In a aromatic moiety by halogen, such as fluorine, chlorine preferred manner, an organic sulphur compound of the or bromine, preferably fluorine or chlorine, particularly formula preferably chlorine. In the case of multiple substitution, 25 it may also be substitution by different halogen atoms. In a preferred manner, monosubstitution or disubstitu tion by halogen is present, in a particularly preferred is employed in which manner monosubstitution by halogen. All aromatic moi Rl5 and R16 independently of one another denote eties of the radicals may furthermore carry one or two 30 straightchain or branched C-C2-alkyl, hydroxy methyl or ethyl groups, methoxy or ethoxy groups, or C2-C2-alkyl or carboxy-C1-C12-alkyl, where C1-C4-dialkylamino groups. R16 additionally may denote CO-C1-C6-alkyl and n assumes the value 0 or 1. In a preferred manner, oxo compounds of the formula In a particularly preferred manner, bis-(2-hydrox R-CO-R12 (v) 35 yethyl) sulphide is employed. The addition of the organic sulphur compound is are employed in which carried out together with the catalyst, before the addi R denotes hydrogen, straight-chain or branched tion or after the addition of the catalyst. If the catalyst C1-C4-alkyl, C3-C6-cycloalkyl, phenyl, benzyl or phen is re-used repeatedly, the organic sulphur compound in ylethyl and 40 general only needs to be added to the catalyst or to the R2 represents hydrogen, straight-chain or branched reaction mixture on the first use. The catalyst then re C1-C4-alkyl or phenyl. tains its high specific activity together with a high yield In a particularly preferred manner, oxo compounds even after repeated use many times or in a continuous of the formula procedure. However, a subsequent addition of the or 45 ganic sulphur compound is possible, but usually only R2-CO-R22 (VI) necessary, if fresh catalyst is added in place of some what spent or exhausted catalyst. are employed in which Hydrogenation catalysts employed according to the R2 denotes hydrogen, straight-chain or branched invention are Ni-containing and/or Co-containing, such C1-C4-alkyl, Cs-C6-cycloalkyl, phenyl, benzyl or phen- 0 as Nior Co on supports, Nior Co in the form of elemen ylethyl and tal Ni(Co) sponge, Ni-oxide, Co-oxide, Raney nickel, R22 represents hydrogen, methyl or ethyl. Raney cobalt or others. Supports are, for example, In a preferred manner, nitrogen compounds of the SiO2, Al2O3, pumice, carbon and other supports known formula . to those skilled in the art. However, in a preferred man 55 ner Raney catalysts, such as Raney nickel, Raney co R13-NH-R1 - (VII) balt, Raney nickeliron, Raney nickel-cobalt or Raney nickel-iron-cobalt in anhydrous or even water-moist or are furthermore employed in which solvent-moist form are employed. The Ni- and Co-con R3 denotes hydrogen, straight-chain or branched taining catalysts can also be employed together. C1-C3-alkyl, C3-C6-cycloalkyl, phenyl or benzyl and 60 The Ni-containing and/or Co-containing catalyst is R represents hydrogen, straight-chain or branched employed in an amount of 1-25% by weight, preferably C1-C4-alkyl or benzyl. 2.5-12.5% by weight, relative to the substrate to be In a particularly preferred form, nitrogen compounds hydrogenated. of the formula In a particularly preferred manner, Ni-containing 65 Raney catalysts are employed. R23-NH-R24 (VIII) The reaction medium employed can be alcohols, such as methanol, ethanol, isopropanol, butanol, aliphatic or are employed in which aromatic hydrocarbons, such as toluene, xylene, cyclo 5,011,996 S 6 hexane, isooctane and the like, ethers, such as tetrahy drofuran, such as ethyl acetate and finally the reaction EXAMPLE 1 product itself, if it is liquid at the reaction temperature. a-(p-Chlorophenyl)-ethylamine A proportion of water (for example up to 20% by weight of the total reaction medium) does not interfere, especially if the reaction medium is miscible with water. H. The hydrogenation is carried out at 30'-250 C, pref. Cl CH-CH erably at 50'-150 C, and an H2 pressure of 5-200 bar, preferably 50-150 bar. In general, the process according to the invention is 10 385 g (2.5 mol) of p-chloroacetophenone, 1125 ml of carried out so that the starting material (hemiaminal, methanol, 3.8 g of bis-(2-hydroxyethyl) sulphide and aminal or azomethine), the reaction medium, the cata also 12.5g of ammonium acetate and 25 g of Raney lyst and the organic sulphur compound are initially nickel were initially introduced into a 3 liter stirred introduced into a hydrogenation autoclave and after 15 autoclave. After displacing the air with nitrogen and closing the reactor the air is displaced with nitrogen and addition of 750 ml of liquid ammonia, the autoclave was then the nitrogen with hydrogen. After completion of pressurized with hydrogen up to a pressure of 80 bar the reaction, the reaction vessel is initially depressurized and heated to 120' C. with stirring. After reaching this and emptied; the catalyst is filtered off and may be temperature, the pressure was increased to 120 bar and re-used without a new addition of organic sulphur com 20 the consumption was compensated by further addition pounds. Otherwise, the working up is carried out in a of hydrogen. manner known to those skilled in the art. After the hydrogen uptake was complete in about 2 The process can be carried out batchwise and contin hours, the mixture was stirred further for another hour uously, for example in a pressure tube having an at under the reaction conditions indicated, then cooled to tached separator and pressure release. 25 room temperature and depressurization to atmospheric The process can furthermore be applied to the pure pressure. reaction products mentioned and to reaction mixtures in The catalyst was filtered off and the methanol was which hemiaminals, aminals or azomethines are pre distilled off. 388 g of crude product were obtained as a pared as such reaction products. residue which contained, according to gas chromato In a preferred manner, reaction mixtures in which 30 graphic analysis such reaction products are prepared are used, the result 90% of a-(p-chlorophenyl)-ethylamine ing reaction products being simultaneously hydroge 5% of a-phenethylamine nated in the manner according to the invention. 4.5% of a-(p-chlorophenyl)-ethanol and In a furthermore preferred manner, reaction mixtures 0.5% of p-chloroacetophenone (educt). are employed in which aldimines of the formula 35 For purification, the crude product was dissolved in 400 ml of toluene and washed with 100 ml of 20% R3-CH-NH (X) strength sodium hydroxide solution. The toluene solu tion was concentrated and the residue was distilled in which R3 has the abovementioned meaning, are through a packed column. 316.4 g (74% of theoretical prepared by partial hydrogenation of the underlying yield) of the desired a-(p-chlorophenyl)-ethylamine nitriles, the aldimines simultaneously being further hy were obtained as the main fraction having a boiling drogenated in a manner according to the invention. The point of 115-117 C./25 mbar and a purity of 98.7%. partial hydrogenation of the nitriles is also carried out by means of the Ni-containing and/or Co-containing EXAMPLE 2 catalyst employed according to the invention in the 45 a-(p-Chloropneny)-ethylamine presence of the organic sulphur compounds of the for mula (IV). It is surprising that, by means of the additional use of NH, the organic sulphur compounds as modification agents Cl CH-CH3 for which in other cases a deactivation is observed, the 50 described hydrogenation occurs more selectively, re producibly and above all more completely than without The reductive amination described under Example 1 this addition; the hydrogenation activity is therefore was repeated, dimethyl sulphoxide being employed in completely retained. The catalysts have a high stability. 55 the same amount instead of bis-(2-hydroxyethyl) sul Damage to the Ni-containing and/or Co-containing phide. catalysts by undesired by-products is not observed, as a After separating off the catalyst and the solvent, 386 result of which the frequent re-use described is possible. g of the crude reaction product were obtained which Furthermore, the use of very low reaction temperatures according to gas chromatographic analysis contained which make extremely long reaction times necessary is 88.5% of a-(p-chlorophenyl)-ethylamine avoided. The substantial avoidance of undesired by 5.5% of a-phenethylamine products not only increases the yield but also simplifies 4.5% of a-(p-chlorophenyl)-ethanol subsequent purification operations somewhat. 1.0% of p-chloroacetophenone (educt). EXAMPLES EXAMPLE 3 (for comparison) (The examples are not optimized; a further increase in If the reductive amination described in Examples 1 the yields and selectivities is therefore conceivable and and 2 was carried out without addition of one of the probable) sulphur compounds, 384 g of a crude product was ob 5,011,996 7 8 tained after separating off the catalyst which according EXAMPLE 6 to gas chromatographic analysis contained 69% of a-(p-chlorophenyl)-ethylamine 4-chloro-N-isopropyl-aniline 26% of a-phenethylamine and 5 4% of a-(p-chlorophenyl)-ethanol. EXAMPLE 4 N-Methyl-a-(p-chlorophenyl)-ethylamine 232 g of acetone, 255 g of 4-chloroaniline, 300 ml of 10 ethanol, 25 g of Raney nickel-iron and 2.5g of bis-(2- hydroxyethyl) sulphide were initially introduced into a 1.3 stirred autoclave. After displacing the air with nitrogen, the autoclave was pressurized with hydrogen C CH-CH up to a pressure of 60 bar and heated to 100 C. with NHCH3 15 stirring. The pressure was adjusted to 100 bar and the consumption was compensated by further addition of 154 g of p-chloroacetophenone, 450 ml of methanol, 20 hydrogen. The temperature was kept at 100 C. for g of Raney nickel and 2 g of bis-(2-hydroxyethyl) sul another hour after the end of H2 uptake. phide were initially introduced into a 1.31 stirred auto After cooling and depressurizing, the catalyst was 20 filtered off and the reaction solution was evaporated. clave. After displacing the air with hydrogen and addi The 310 g of crude product thus obtained contained, tion of 50 ml of liquid methylamine, the autoclave was according to gas chromatographic analysis: pressurized with hydrogen up to a pressure of 80 bar 82% of 4-chloro-N-isopropyl-aniline and heated to 100° C. with stirring The pressure was 8.5% of N-isopropyl-aniline adjusted to 140 bar and the consumption was compen 25 6.5% of 4-chloroaniline and sated by further addition of hydrogen. The temperature 3% of unidentified by-products. was kept at 100° C. for another hour after the end of H2 EXAMPLE 7 uptake. 3-chloro-N-nepentyl-aniline After cooling and depressurizing, the catalyst was 30 filtered off and the reaction solution was evaporated. 170 g of crude product were obtained which accord ing to gas chromatographic analysis contained 86% of N-methyl-a-(p-chlorophenyl)-ethylamine 5.5% of a-(p-chlorophenyl)-ethanol 35 C 65% of N-methyl-a-phenethylamine 172 g of pivalaldehyde, 255 g of 3-chloroaniline, 400 ml 2% of unidentified by-products. of tetrahydrofuran, 25 g of Raney nickel and 2.5 g of bis-(2-hydroxyethyl) sulphide were initially introduced EXAMPLE 5 into a 1.3 l stirred autoclave After displacing the air 3-chloro-N-isopropyl-aniline with nitrogen, the autoclave was pressurized with hy drogen up to a pressure of 80 bar and heated to 120' C. with stirring The pressure was adjusted to 140 bar and the consumption was compensated by further addition of hydrogen. The temperature was kept at 120 C. for 45 another hour after the end of H2 uptake. After cooling and depressurizing, the catalyst was filtered off and the reaction solution was evaporated. 116 g of acetone, 255 g of 3-chloroaniline, 500 ml of The 355g of crude product thus obtained contained, methanol, 20g of Raney nickel and 2 g of bis-(2-hydrox- 50 according to gas chromatographic analysis 76% of 3-chloro-N-neopentyl-aniline yethyl) sulphide were initially introduced into a 1.3 1 7.5% of N-neopentyl-aniline stirred autoclave. After displacing the air with nitrogen, 12.5% of 3-chloroaniline and the autoclave was pressurized with hydrogen up to a 4% of unidentified by-products. pressure of 80 bar and heated to 120' C. with stirring. The pressure was adjusted to 150 bar and the consump 55 EXAMPLE 8 tion was compensated by further addition of hydrogen. 3-Amino-5-(4-chlorophenyl)-2,2-dimethyl-pentane The temperature was kept at 120' C. for another hour after the end of H2 uptake. NH2 After cooling and depressurizing, the catalyst was filtered off and the reaction solution was evaporated. Cl CH-CH2-CH-CCH3)3 The 308 g of crude product thus obtained contained, according to gas chromatographic analysis: 168 g of 5-(4-chlorophenyl)-2,2-dimethyl-pentan-3-one, 77% of 3-chloro-N-isopropyl-aniline 65 160 ml of methanol, 20g of Raney nickel, 1 g of bis-(2- 12% of N-isopropyl-aniline hydroxyethyl) sulphide and 5 g of ammonium acetate 7% of 3-chloroaniline are initially introduced into a 1.3 l stirred autoclave. 4% of unidentified by-products. After displacing the air with nitrogen and addition of 5,011,996 10 500 ml of liquid ammonia, the autoclave was pressur The temperature was kept at 70° C. for another hour ized with hydrogen up to a pressure of 90 bar and after the end of H2 uptake. heated to 125 C. with stirring. The pressure was ad After cooling and depressurizing, the catalyst was justed to 120 bar and the consumption was compensated filtered off and the reaction solution was evaporated. by further addition of hydrogen. The temperature was 5 The 95 g of crude product thus obtained contained, kept at 125 C. for another hour after the end of H2 according to gas chromatographic and MS analysis: uptake. 95% of 4-amino-2,5-dichloro-benzylamine. After cooling and depressurizing, the catalyst was filtered off and the reaction solution was evaporated. EXAMPLE The 172 g of crude product thus obtained contained, 10 according to gas chromatographic analysis: 4-Chlorophenyl-phenyl-methylamine 73% of 3-amino-5-(4-chlorophenyl)-2,2-dimethyl pentane - 5% of 5-(4-chlorophenyl)-2,2-dimethyl-3-hydroxy 5 pentane CH 0.5% of dechlorinated compounds NH2 20% of educt. 162 g of 4-chlorobenzophenone, 450 ml of methanol, 10 EXAMPLE 9 20 g of Raney nickel, 1.5 g of bis-(2-hydroxyethyl) sul 2-Amino-4-chloro-benzylamine phide and 5g of ammonium acetate were initially intro CHNH2 duced into a 1.3 l stirred autoclave. After displacing the air with nitrogen and addition of 300 ml of liquid ammo NH2 nia, the autoclave was pressurized with hydrogen up to 25 a pressure of 80 bar and heatcd to 125° C. with stirring. The pressure was adjusted to 120 bar and the consump tion was compensated by further addition of hydrogen. The temperature was kept at 125 C. for another hour 152 g (1 mol) of 2-amino-4-chloro-benzonitrile, 400 ml after the end of H2 uptake. of isopropanol, 15% of Raney nickel and 1 g of bis-(2- 30 hydroxyethyl) sulphide were initially introduced into a After cooling and depressurizing, the catalyst was 1.3 1 stirred autoclave. After displacing the air with filtered off and the reaction solution was evaporated. nitrogen and addition of 150 ml of liquid ammonia, the The 160 g of crude product thus obtained contained, autoclave was pressurized with hydrogen up to a pres according to gas chromatographic and mass spectro sure of 80 bar and heated to 80 C. with stirring. The 35 scopic analysis: pressure was adjusted to 140 bar and the consumption 88% of (4-chlorophenyl)-phenyl-methyl-amine was compensated by further addition of hydrogen. The 3% of diphenyl-methylamine temperature was kept at 80 C. for another hour after 2.4% of (4-chlorophenyl)-phenyl-methane the end of H2 uptake. 3.4% of bis-(4-chlorophenyl)-phenylmethylamine After cooling and depressurizing, the catalyst was 1.3% of educt filtered off and the reaction solution was evaporated. EXAMPLE 12 The 153 g of crude product thus obtained contained, according to gas chromatographic and mass spectro 1-Amino-2-(4-chlorophenyl)-ethane scopic (GC-MS coupling) analysis: 98.5% of 2-amino-4-chloro-benzylamine and 45 <0.1% of dechlorination products. C CH2-CH-NH2 EXAMPLE 10 4-Amino-2,5-dichloro-benzylamine 50 100 g of 4-chlorobenzyl cyanide, 100 g of methanol, 5.0 g of water-moist Raney nickel and 0.75 g of bis-(2- CHNH2 hydroxyethyl) sulphide were initially introduced into a 0.71 stirred autoclave. After displacing the air with C nitrogen and addition of 30 g of ammonia, the autoclave 55 was pressurized with hydrogen up to a pressure of 100 C bar and heated to 130 C, with stirring. As soon as uptake of hydrogen was detected, the pressure was NH adjusted to 150 bar and the consumption was compen 94 g (0.5 mol) of 4-amino-2,5-dichloro-benzonitrile, 300 so sated by further addition of hydrogen. The temperature ml of methanol, 10 g of Raney nickel-iron and 1 g of was kept at 130 C. for a further 30 minutes after the bis-(2-hydroxyethyl) sulphide were initially introduced completion of H2 uptake. into a 1.3 l stirred autoclave. After displacing the air After cooling and depressurizing, the catalyst was with nitrogen and addition of 200 ml of liquid ammonia, filtered off. The reaction solution contained according the autoclave was pressurized with hydrogen up to a 65 to gas chromatographic analysis: pressure of 60 bar and heated to 70° C. with stirring. 0.77% of unknown substances (4 peaks) The pressure was adjusted to 100 bar and the consump 99.01% of 1-amino-2-(p-chlorophenyl)ethane tion was compensated by further addition of hydrogen. 0.22% of unknown substances (3 peaks) 5,011,996 11 12 After cooling and depressurizing, the catalyst was EXAMPLE 13 (for comparison) filtered off and the reaction solution was evaporated. The procedure was as in Example 12, but without The 16.9 g of crude product thus obtained contained, bis-(2-hydroxyethyl) sulphide. The gas chromato according to gas chromatographic and mass spectro graphic analysis gave: 5 scopic analysis: 0.71% of unknown substances (4 peaks) 91.8% of a-(p-chlorophenyl)-N,N-dimethyl-ethyl 91.67% of 1-amino-2-(p-chlorophenyl)ethane amine, 0.03% of unknown substance 1.5% of a-(p-chlorophenyl)-N-methyl-ethylamine, 1.96% of unknown substance 5.7% of N,N-dimethyl-a-phenyl-ethylamine and 5.58% of unknown substance O 1% of unidentified by-products. 0.05% of unknown substance (total of 4 peaks) EXAMPLE 17 EXAMPLE 14 o-Chlorobenzylamine a-(3,4-dichlorophenyl)-ethylamine 15 C Cl CH-CH CH-NH2 20 C 140.6 g of o-chlorobenzaldehyde, 100 g of methanol, 94.5 g of 3,4-dichloroacetophenone, 225 ml of metha 8.49 of methanol-moist Raney nickel and 0.2 g of bis-(2- nol, 2.5g of ammonium acetate, 5g of Raney nickel and hydroxyethyl) sulphide were initially introduced into a 25 1 g of bis-(2-hydroxyethyl) sulphide were initially intro 0.71 stirred autoclave. After displacing the air with duced into a 0.71 stirred autoclave. After displacing the nitrogen and addition of 102 g of ammonia, the auto air with nitrogen and addition of 15 ml of liquid ammo clave was pressurized with nitrogen up to a pressure of nia, the autoclave was pressurized with hydrogen up to 90 bar and heated to 100' C. with stirring. The pressure a pressure of 80 bar and heated to 125 C. with stirring. was again adjusted to 90 bar and the consumption thus The pressure was adjusted to 120 bar and the consump compensated by further addition of hydrogen. The 30 tion was compensated by further addition of hydrogen. temperature was kept at 100° C. for another hour after The temperature was kept at 125 C. for another hour the completion of H2 uptake. after the end of H2 uptake. After cooling and depressurizing, the catalyst was After cooling and depressurizing, the catalyst was filtered off. The reaction solution contained according filtered off and the reaction solution was evaporated. to gas chromatographic analysis: 35 The 93 g of crude product thus obtained contained, 0.9% of benzylamine according to gas chromatographic analysis: 90.5% of o-chlorobenzylamine 87% of a-(3,4-dichlorophenyl)-ethylamine, 6.8% of o-chlorobenzyl alcohol 3% of a-phenethylamine, 4.5% of a-(3,4-dichlorophenyl)-ethanol and EXAMPLE 15 (for comparison) 5.5% of unidentified by-products. The procedure was as in Example 14, but without What is claimed is: bis-(2-hydroxyethyl) sulphide. The gas chromato 1. A process for the preparation of amines of the graphic analysis gave: formula 3.6% of benzylamine 80.2% of o-chlorobenzylamine 45 13.8% of o-chlorobenzyl alcohol R2 EXAMPLE 16 a-(p-Chlorophenyl)-N,N-dimethyl-ethylamine 50 in which R, R2 and R3 independently of one another denote hydrogen, straight-chain or branched C1-C12 (H-CH, alkyl, C3-C8-cycloalkyl, C6-C12-aryl or C7-C10 N(CH3)2 aralkyl and 55 R represents hydrogen, straight-chain or branched 15.5 g (0.1 mol) of a-(p-chlorophenyl)-ethylamine, 100 C1-C20-alkyl, C6-C12-aryl, C3-C8-cycloalkyl or ml of methanol, 13.5g of a 50% strength methanolic C7-C10-aralkyl, formaldehyde solution (0.22 mol), 2 g of Raney nickel where at least one of the radicals R1 to R' represents and 0.15 g of bis-(2-hydroxyethyl) sulphide were ini aryl or aralkyl which are monosubstituted to tri tially introduced into a 0.3 1 stirred autoclave. After substituted by halogen in the aromatic moiety, displacing the air with nitrogen, the autoclave was pres by catalytic hydrogenation of reaction products of surized with hydrogen up to a pressure of 80 bar and oxo compounds of the formula heated to 110' C. with stirring. The pressure was ad justed to 160 bar and the consumption was compensated 65 R-CO-R2 by further addition of hydrogen. The temperature was kept at 110' C. for another hour after the end of H2 and nitrogen compounds of the formula uptake. 5,011,996 13 14 R11 denotes hydrogen, straight-chain or branched with the abovementioned meanings for R to R, C1-C12-alkyl, C3-C6-cycloalkyl, phenyl, benzyl or which is characterized in that a Ni-containing and phenyl-ethyl and /or Co-containing catalyst is employed and that R12 represents hydrogen, straight-chain or branched the reaction is carried out in the presence of or C1-C4-alkyl or phenyl. ganic sulphur compounds of the formula 8. The process according to claim 7, characterized in that, as oxo compounds, those of the formula R-S(=O)-R R21-CO-R22 which O R and R6 independently of one another denote are employed in which straight-chain or branched C1-C12-alkyl, hydroxy R2 denotes hydrogen, straight-chain or branched C2-C12-alkyl, carboxy-C1-C12-alkyl or phenyl and C1-C4-alkyl, C5-C6-cycloalkyl, phenyl, benzyl or furthermore phenylethyl and R* and R3 together may represent -CH= 15 R22 represents hydrogen, methyl or ethyl. CH-CH=CH-, -(CH2)4-, -(CH2)5-, 9. The process according to claim 1, characterized in -(CH2)5-, -(CH2)2-S-(CH2)2- or -(CH2 that, as nitrogen compounds, those of the formula )2-O-(CH2)2- Radditionally may denote hydrogen or CO-C1-C12 alkyl and 20 are employed in which n assumes the value 0 or 1. R13 denotes hydrogen, straight-chain or branched 2. The process according to claim 1, characterized in C1-C3-alkyl, C3-C6-cycloalkyl, phenyl or benzyl that organic sulphur compounds of the formula and R represents hydrogen, straight-chain or branched Ri-S(-O)-R6 25 C1-C4-alkyl or benzyl. 10. The process according to claim 9, characterized are employed in which in that, as nitrogen compounds, those of the formula Rl5 and R16 independently of one another denot straight-chain or branched C2-C12-alkyl, hydroxy C2-C2-alkyl or carboxy-C11oc C12-alkyl, where 30 R6 additionally may denote CO-C-C6-alkyl and are employed in which in assumes the value 0 or 1. R23 denotes hydrogen, straight-chain or branched C1-C4-alkyl, Cs-C6-cycloalkyl, phenyl or benzyl 3. The process according to claim 2, characterized in and that bis-(2-hydroxyethyl) sulphide is employed. 35 R2 represnts hydrogen, methyl or ethyl. 4. The process according to claim 1, characterized in 11. The process according to claim 1, characterized that Raney nickel, Raney cobalt, Raney nickel-iron, in that the organic sulphur compound is employed in an Raney nickel-cobalt or Raney nickel-iron-cobalt are amount from 0.002-0.5 parts by weight per part by employed as catalyst. weight of catalyst. 5. The process according to claim 1, characterized in 40 12. The process according to claim 11, characterized that reaction mixtures in which the reaction products of in that the organic sulphur compound is employed in an the oxo compounds and the nitrogen compounds are amount from 0.01-0.25 parts by weight per part by prepared are employed. weight of catalyst. 6. The process according to claim 1, characterized in 13. The process according to claim 1, characterized that reaction mixtures are employed in which azome in that the Ni-containing and/or Co-containing catalyst thines of the formula is employed in an amount of 1-25% by weight, relative to the substrate to be hydrogenated. R3-CH=NH 14. The process according to claim 13, characterized in that the Ni-containing and/or Co-containing catalyst in which 50 is employed in an amount of 2.5-12.5% by weight, R denotes C1-C12-alkyl, C3-C8-cycloalkyl, C6-C12 relative to the substrate to be hydrogenated. aryl or C7-C10-aralkyl, 15. The process according to claim 1, characterized are prepared by partial hydrogenation of the underly in that it is carried out at 30-250' C. ing nitriles. 16. The process according to claim 15, characterized 7. The process according to claim 1, characterized in 55 in that it is carried out at 50-150 C. that, as oxo compounds, those of the formula 17. The process according to claim 1, characterized in that it is carried out at an H2-pressure of 5-200 bar. Ril-CO-R12 18. The process according to claim 17, characterized in that it is carried out at an H2-pressure of 10-150 bar. are employed in which

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