<<

USOO6706924B2 (12) United States Patent (10) Patent No.: US 6,706,924 B2 Schelhaas et al. (45) Date of Patent: Mar. 16, 2004

(54) PROCESS FOR THE PRODUCTION OF Ullmann's Encyclopedia of Industrial Chemistry, 5" ed., 15-NAPHTHALENEDIAMINE vol. A A13 (month unavailable) 1989, pp. 487-497, Hydro (75) Inventors: Michael Schelhaas, Köln (DE); Katrin genation and Dehydrogenation, Paul N. Rylander. Joschek, Köln (DE); Manfred Jautelat, Burscheid (DE); Joachim Ohira, Noriyuki et al: “Organiotellurims. Part IV. Reduction Zechlin, Düsseldorf (DE); Dietmar of aromatic nitro compounds to amines by benzenetellurol” Wastian, Dormagen (DE) Chem. Lett. (1984), (6),853–4, XP002198319 * Run 14, 16, (73) Assignee: Bayer Aktiengesellschaft, Leverkusen in Tabelle 1, Seite 85 *. (DE) * J. Bornstein et al: “The synthesis of alpha-amino-o-tolu (*) Notice: Subject to any disclaimer, the term of this aldehyde diethylacetal and its attemted Conversion to patent is extended or adjusted under 35 pseudoindole' Journal of the American Chemical Society., U.S.C. 154(b) by 209 days. vol. 78, No. 1, 1956, pp. 83–36, XP002148447. (21) Appl. No.: 10/028,892 *E. Bellasio et al: “The reaction of Phthalazino 2,3-b phthalazine-t, 12(H, 14H)-diones with nitrous ”. Far (22) Filed: Dec. 18, 2001 maco, Edizione Scientifica, vol. 30, No. 5, 1975, pp. (65) Prior Publication Data 343–352, XP002148448, Societa Chimica Italiana, Pavia., US 2002/0103401A1 Aug. 1, 2002 IT. (30) Foreign Application Priority Data RÖmpp Lexikon Chemie, Georg Thieme Verlag, Stuttagart, Dec. 22, 2000 (DE) ...... 1OO 64 779 10" edition, (month unavailable) 1997, pp. 891-892 “Dehy Oct. 5, 2001 (DE) ...... 101 49 041 drierung” and pp. 1831-1832 “Hydrinden'. (51) Int. Cl." ...... C07C 211/58; C07C 209/60 (52) U.S. Cl...... 564305; 564/416 * cited by examiner (58) Field of Search ...... 564/305, 416 (56) References Cited Primary Examiner Shailendra Kumar U.S. PATENT DOCUMENTS (74) Attorney, Agent, or Firm-Joseph C. Gil 4,973,758 A 11/1990 Behre et al...... 564/394 (57) ABSTRACT FOREIGN PATENT DOCUMENTS The invention relates to a process for the production of GB 1499699 2/1978 JP 56-59.738 5/1981 1,5-naphthalenediamine and to the intermediates 4-(2- JP 4-154745 5/1992 nitrophenyl)butyronitrile, 5-nitro-3,4-dihydro-1(2H)- naphthyl-imine, 5-nitroso-1-naphthylamine, 5-nitro-1- OTHER PUBLICATIONS naphthylamine, 4-(2-aminophenyl)-butyronitrile, 5-amino Cameron et al, Aust. J. Chem., vol 29, pp. 2499-2509, 3,4-dihydro-1(2H)-naphthalene imine, 4-(2-nitrophenyl) 1976.* ethylbutyrate and 4-(2-nitrophenyl)butyramide obtainable Nomenclature of Inorganic Chemistry Recommendation (month unavailable) 1990, Chapter 1-3.8.1 pp. 41-43, during the process. Groups of element in the Periodic Table and their subdivi Sions, edited by G.J. Leigh. 11 Claims, No Drawings US 6,706,924 B2 1 2 PROCESS FOR THE PRODUCTION OF c) aromatisation of the nitro imine and/or nitro enamine 15-NAPHTHALENEDIAMINE formed in step b) to give 5-nitro-1-naphthylamine and/or 5-nitroSo-1-naphthylamine, The invention relates to a process for the production of d) hydrogenation of the 5-nitro-1-naphthylamine and/or 1,5-naphthalene diamine by the reaction of ortho 5-nitroSo-1-naphthylamine formed in step c) to give nitrotoluene with an acrylic acid derivative, and to the 1,5-naphthalenediamine. intermediate products 4-(2-nitrophenyl)butyronitrile, 4-(2-Nitrophenyl)butyronitrile is produced from ortho 5-nitro-3,4-dihydro-1(2H)-naphthylimine, 5-nitroso-1- nitrotoluene and acrylonitrile preferably at temperatures of naphthylamine, 5-nitro-1-naphthylamine, 4-(2- -10° C. to 100° C. It is particularly preferred to operate at aminophenyl)butyronitrile, 4-(2-nitrophenyl)ethylbutyrate, 20° C. to 75 C., especially preferably attemperatures of 30 4-(2-nitrophenyl)butyl butyrate, 4-(2-nitrophenyl)- C. to 60° C. butyramide and 5-amino-3,4-dihydro-1(2H)-naphthalene The reaction is performed with base catalysis. Oxides, imine obtainable during the process. hydroxides and carbonates of lithium, Sodium, potassium, Various processes for the production of 1,5- rubidium, caesium, magnesium, calcium, Strontium, barium naphthalenediamine are already known in the literature. In 15 or aluminium, and mixtures thereof, can be used as bases. general, the preparation of 1,5-naphthalenediamine Starts Sodium hydroxide and potassium hydroxide are particularly from naphthalene which is suitably substituted. Thus, in Suitable. In a preferred embodiment, the aqueous Solutions JP-A2-07 278 066, the synthesis of 1,5-naphthalenediamine are used in combination with a phase transfer catalyst. These via an amine-bromine eXchange on 1,5-bromoamino phase transfer catalysts are e.g. quaternary ammonium Salts. naphthalene is described. The required educt is produced by Suitable ammonium compounds are tetraalkylammonium bromination of 1-nitronaphthalene in this process. halides and Sulfates, Such as tributylmethyl In JP-A2-04 154745, JP-A2-56 059 738 and DE-A1-2 ammonium chloride, trioctylammonium chloride, tetrabuty 523 351, the synthesis of 1,5-naphthalenediamine in com lammonium chloride or tetrabutylammonium hydrogen Sul bination with 1,8-naphthalenediamine by the reduction of a fate. The use of appropriate tetra alkyl- or mixture of 1,5- and 1,8-dinitronaphthalene is described. In 25 tetraarylphosphonium Salts, Such as tetramethylphospho DE-C1-3 840 618, the synthesis of 1,5-naphthalenediamine nium bromide and tetraphenyl-phosphonium bromide is also by alkaline of disodium naphthalene-1,5- Suitable, as is the use of Solubility promoters, Such as disulfonate and Subsequent reaction with ammonia is polyethylene glycol dimethyl ethers. described. In principle, water and all organic Solvents that are stable All these processes have the disadvantage that the in bases are Suitable as the Solvents. Aromatic Solvents, Such product, or an intermediate produced during the process, is as benzene, toluene, Xylene, chlorobenzene, or obtained as a mixture of isomers containing other isomers in nitrotoluene, and also dimethyl Sulfoxide, dimethyl forma addition to the 1.5 isomer, which have to be separated off. In mide and aliphatic hydrocarbons, Such as ligroin, addition, the process described in DE-C1-3 840 618 in cyclohexane, pentane, hexane, heptane or octane, are pref particular takes place under very Severe and corrosive reac 35 erably used. tion conditions. ortho-Nitrotoluene is particularly preferably used as educt The object of the present invention is therefore to provide and, at the same time, as Solvent, and in an excess of a Simple process for the production of 1,5- ortho-nitrotoluene of 1 to 40 equivalents, especially 5 to 20 naphthalenediamine, by which 1,5-naphthalenediamine can equivalents, based on acrylonitrile. be produced in just a few steps, starting from basic 40 The cyclisation of 4-(2-nitrophenyl)butyronitrile to chemicals, without other isomers forming in Significant 5-nitro-3,4-dihydro-1-naphthylamine or the tautomeric quantities and having to be separated off. 5-nitro-3,4-dihydro-1(2H)-naphthylimine is performed in A process has now been found, by which 1,5- Substance or in an inert Solvent in the presence of Strong naphthalenediamine can be prepared simply, in just a few . Suitable Solvents are linear, branched or cyclic ali StepS and largely as a pure isomer, Starting from Ortho 45 phatic hydrocarbons, Such as ligroin or cyclohexane, nitrotoluene and acrylic acid derivatives, Such as e.g. pentane, hexane, heptane, octane and aromatic Solvents Such acrylonitrile, two inexpensive basic chemicals. as nitrotoluene. It is preferred to operate in Substance or in The object is achieved according to the invention by a ortho-nitrotoluene. proceSS for the production of 1,5-naphthalenediamine con Suitable acids are Strong Lewis or Bronsted acids, Such as taining a step in which ortho-nitrotoluene is reacted with an 50 e.g. aluminium chloride, boron trifluoride, , acrylic acid derivative. phosphoric acid, polyphosphoric acid, phosphorus Preferred acrylic acid derivatives are acrylic acid esters, pentoxide, methaneSulfonic acid, trifluoromethaneSulfonic Such as e.g. methyl acrylate and ethyl acrylate, acrylamide acid, trifluoroacetic acid or mixtures of antimony pentafluo and acrylonitrile. ride and fluorosulfuric acid. Mixtures of the acids can also The object is achieved according to the invention in 55 be used. particular by a process for the production of 1,5- The acid is generally used in 0.1 to 100 mole equivalents, naphthalenediamine containing a step in which ortho based on 4-(2-nitrophenyl)-butyronitrile. Preferably, 0.5 to nitrotoluene is reacted with acrylonitrile to give 4-(2- 20 equivalents are used, particularly preferably 1 to 10 nitrophenyl)butyronitrile. equivalents. In a first preferred embodiment, the process for the 60 The reaction is generally carried out attemperatures of 0 production of 1,5-naphthalene-diamine contains the follow C. to 200° C., preferably between 40° C. and 150° C., ing steps: particularly preferably between 60° C. and 110° C. a) reaction of ortho-nitrotoluene with acrylonitrile to give The nitro imine and/or nitro enamine formed in Step b), 4-(2-nitrophenyl)-butyronitrile, which is sensitive to hydrolysis, is preferably first converted b) cyclisation of the 4-(2-nitrophenyl)butyronitrile 65 to the nitroketone 5-nitro-3,4-dihydro-1 (2H)- formed in step a) to the nitro imine and/or nitro naphthalenone, e.g. by hydrolysis, and the nitroketone is enamine, isolated. The isolation takes place e.g. by phase Separation. US 6,706,924 B2 3 4 The nitroketone is then converted back to the nitro imine mbH, Weinheim, 5' edition 1989, vol. A13, chapter and/or nitro enamine in step c) by reaction with ammonia, “Hydrogenation and Dehydrogenation', Sub-chapter 1.2 preferably in the presence of ammonium Salts. Such as “Catalysts”, p. 488). Preferred catalysts are the metals of ammonium chloride, and then aromatised. The aromatisa groups 8-10 of the periodic table (G. J. Leigh editor), tion then preferably takes place in ammonia as the Solvent. Nomenclature of Inorganic Chemistry, Recommendations The aromatisation or dehydrogenation of the nitro enam 1990, Blackwell Scientific Publications, Oxford, Chapter ine 5-nitro-3,4-dihydro-1-naphthylamine or of the nitro I-3.8.1 “Groups of Elements in the Periodic Table and their imine 5-nitro-3,4-dihydro-1(2H)-naphthylimine to 5-nitro Subdivision, p. 41–43), copper or chromium on a Suitable 1-naphthylamine or 5-nitroSo-1-naphthylamine or a mixture support with a metal content of 0.01 to 50 wt.%, preferably of the compounds is carried out, e.g. in an inert Solvent, in 0.1 to 20 wt.%, based on the total weight of the catalyst. the presence of a catalyst. In addition to the dehydrogenated Catalysts containing one or more of the above-mentioned product 5-nitro-1-naphthylamine, 5-nitro So-1- metals can also be used. Preferred metals are, in particular, naphthylamine formally resulting from Symproportionation platinum, palladium and rhodium, platinum and palladium can also be produced in the proce SS. 1,5- 15 being particularly preferred. Other preferred catalysts are Naphthalenediamine is also formed in traces. The products Raney nickel and Supported nickel catalysts. The above can be further processed in any mixing ratioS. Suitable mentioned metals or their compounds can also be used in Solvents are ammonia and linear, branched or cyclic ali pure form as a Solid. Palladium black and platinum black can phatic hydrocarbons Such as ligroin or cyclohexane, and also be mentioned as examples of a metal in pure form. acetonitrile and aromatic Solvents Such as benzene, toluene, The catalysts can be used in batchwise proceSS Variants in Xylene, nitrobenzene, nitrotoluene or chlorobenzene. The quantities of 0.01 to 50 wt.%, based on 5-nitro- or 5-nitroso aromatisation can also be performed in the absence of a 1-naphthylamine used, preferably in quantities of 0.01 to 20 Solvent. wt.%, particularly preferably in quantities of 0.01 to 10 wt. Suitable catalysts are dehydrogenation catalysts, which 25 %. When the reaction is carried out continuously, for are described in the literature (Rompp Lexikon Chemie; example in a Stirred vessel with powdered catalyst or in the Georg Thieme Verlag, Stuttgart, 10" edition 1997, p. 891, trickle phase on a fixed bed catalyst, loads of 0.01 to 500 g, chapter “Dehydrierung', 1 section; Ullmann's Encyclope preferably 0.1 to 200 g, particularly preferably 1 to 100 g of dia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, 5-nitro- or 5-nitroSo-1-naphthylamine perg catalyst per hour Weinheim, 5' edition 1989, vol. A13, chapter “Hydrogena can be set. tion and De hydroge nation”, Sub - chapter 2, The reaction temperatures are generally -20° C. to 150 “Dehydrogenation”, p. 494-497). These include the metals C., particularly -10° C. to 80° C.; the hydrogen pressure is of groups 8-10 of the periodic table (G. J. Leigh editor), generally 0.1 to 150 bar, particularly 0.5 to 70 bar, especially Nomenclature of Inorganic Chemistry, Recommendations 35 preferably 1 to 50 bar. 1990, Blackwell Scientific Publications, Oxford, Chapter The same catalyst is preferably used for the aromatisation I-3.8.1 “Groups of Elements in the Periodic Table and their and the Subsequent hydrogenation, it being possible for the Subdivision, p. 41–43), especially platinum, palladium, two steps to be performed in one reaction vessel. ruthenium and iridium, iron, cobalt, nickel and combinations All the reaction steps in this preferred embodiment of the thereof. The metals can also be used together with other 40 process can be carried out continuously or batchwise, e.g. in metals, Such as lanthanum, Scandium, Vanadium, chromium, Stirred vessel reactors or tubular reactors. molybdenum, tungsten, manganese, tin, Zinc, copper, Silver In a Second preferred embodiment, the process for the or indium. The above metals can be present as pure production of 1,5-naphthalenediamine contains the Steps elements, as oxides, Sulfides, halides, carbides or nitrides or 45 a) reaction of ortho-nitrotoluene with acrylonitrile to give can be used in combination with organic ligands. Suitable as 4-(2-nitrophenyl)-butyronitrile, ligands are hydrocarbon compounds with donor groups, b) reduction of the 4-(2-nitrophenyl)butyronitrile formed Such as e.g. amines, nitrites, phosphines, thiols, thioethers, in Step a) to give 4-(2-aminophenyl)butyronitrile, alcohols, ethers or carboxylic acids. The catalysts are c) cyclisation of the 4-(2-aminophenyl)butyronitrile optionally applied to a Support material. Suitable Support 50 formed in Step b) to the amino imine and/or amino materials are activated charcoal, aluminium oxide, Silicon enamine, dioxide, Zirconium oxide, Zinc oxide or Zeolites. d) aromatisation of the amino imine and/or amino enam Work is optionally performed in the presence of an ine formed in Step c) to give 1,5-naphthalenediamine. oxidising agent Such as oxygen or air. The reaction is 55 4-(2-Nitrophenyl)butyronitrile is prepared from ortho generally carried out at temperatures of 50° C. to 250 C., nitrotoluene and acrylonitrile as in Step a) of the first preferably at 100° C. to 200° C. preferred embodiment. The reduction of the nitro group to the product 1,5- This compound is then reduced to 4-(2-aminophenyl) naphthalenediamine takes place by hydrogenation in the butyronitrile. The transformation can be performed by 60 hydrogenation in the presence of a hydrogenation catalyst. presence of Suitable hydrogenation catalysts. Practically all heterogeneous catalysts that are known as Practically all heterogeneous catalysts that are known as hydrogenation catalysts are Suitable as hydrogenation cata hydrogenation catalysts are Suitable as hydrogenation cata lysts for the process according to the invention (Römpp lysts for the process according to the invention (Römpp Lexikon Chemie; Georg Thieme Verlag, Stuttgart, 10" edi Lexikon Chemie; Georg Thieme Verlag, Stuttgart, 10" edi 65 tion 1997, p. 1831, chapter “Hydrierung'; Ullmann's Ency tion 1997, p. 1831, chapter “Hydrierung'; Ullmann's Ency clopedia of Industrial Chemistry, VCH Verlagsgesellschaft clopedia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, Weinheim, 5' edition 1989, vol. A13, chapter US 6,706,924 B2 S 6 “Hydrogenation and Dehydrogenation', Sub-chapter 1.2 phase Separation. The aminoketone is then converted back to “Catalysts”, p. 488). Preferred catalysts are the metals of the amino imine and/or amino enamine in Step d) by reaction groups 8-10 of the periodic table (G. J. Leigh editor), with ammonia, preferably in the presence of ammonium Nomenclature of Inorganic Chemistry, Recommendations chloride, and then aromatised. The aromatisation then pref 1990, Blackwell Scientific Publications, Oxford, Chapter erably takes place in ammonia. I-3.8.1 “Groups of Elements in the Periodic Table and their The aromatisation of 5-amino-3,4-dihydro-1- Subdivision, p. 41–43), copper or chromium on a Suitable naphthylamine or the imine tautomer 5-amino-3,4-dihydro support with a metal content of 0.01 to 50 wt.%, preferably 1(2H)-naphthylimine to 1,5-naphthalenediamine is per 0.1 to 20 wt.%, based on the total weight of the catalyst. formed in the same way as the aromatisation of the nitro Catalysts containing one or more of the above-mentioned compounds 5-nitro-3,4-dihydro-1-naphthyl-amine or metals can also be used. Preferred metals are, in particular, 5-nitro-3,4-dihydro-1(2H)-naphthylimine (step c) of the first platinum, palladium and rhodium, platinum and palladium preferred embodiment). being particularly preferred. Other preferred catalysts are The reaction is carried out in an inert Solvent in the Raney nickel and Supported nickel catalysts. The above presence of a catalyst. Suitable Solvents are ammonia and mentioned metals or their compounds can also be used in 15 linear, branched or cyclic aliphatic hydrocarbons, Such as pure form as a Solid. Palladium black and platinum black can ligroin or cyclohexane, and also acetonitrile and aromatic be mentioned as examples of a metal in pure form. Solvents Such as benzene, toluene, Xylene, nitrobenzene, In another embodiment, the nitro group can be reduced by nitrotoluene or chlorobenzene. reaction with metal hydrides, optionally with the addition of Suitable catalysts are dehydrogenation catalysts, which additives, or by reaction with base metals. Such as iron. are described in the literature (Römpp Lexikon Chemie; Preferred metal hydrides are sodium borohydride, potas Georg Thieme Verlag, Stuttgart, 10" edition 1997, p. 891, sium borohydride, lithium borohydride, sodium chapter “Dehydrierung, 1 section; Ullmann's Encyclope cyanoborohydride, lithium cyanoborohydride, lithium alu dia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, minium hydride and diisobutylaluminium hydride. Suitable Weinheim, 5' edition 1989, vol. A13, chapter “Hydrogena additives are nickel Salts, tellurium compounds and anti 25 tion and De hydroge nation”, Sub - chapter 2, mony compounds. “Dehydrogenation”, p. 494-497). These include the metals Preferred base metals for the reaction under acid condi of groups 8-10 of the periodic table (G. J. Leigh editor), tions are iron, Zinc, magnesium, aluminium and tin, iron and Nomenclature of Inorganic Chemistry, Recommendations Zinc being particularly preferred. Suitable Solvents for this 1990, Blackwell Scientific Publications, Oxford, Chapter purpose are water or alcohols or mixtures of alcohols I-3.8.1 “Groups of Elements in the Periodic Table and their acidified with acids Such as , hydrochloric acid, Subdivision, p. 41–43), especially platinum, palladium, Sulfuric acid or ammonium chloride. Suitable alcohols are ruthenium and iridium, iron, cobalt, nickel and combinations methanol, ethanol, n-propanol, isopropanol, n-butanol, Sec.- thereof. The metals can also be used together with other butanol, tert-butanol or cyclohexanol. Methanol and ethanol metals, Such as lanthanum, Scandium, Vanadium, chromium, are particularly preferred. 35 molybdenum, tungsten, manganese, tin, Zinc, copper, Silver The cyclisation to 5-amino-3,4-dihydro-1-naphthylamine or indium. The above metals can be present as pure or the imine tautomer 5-amino-3,4-dihydro-1(2H)- elements, as oxides, Sulfides, halides, carbides or nitrides or naphthylimine is performed in the same way as the cycli can be used in combination with organic ligands. Suitable as sation of the nitro compound (step b in the first preferred ligands are hydrocarbon compounds with donor groupS. Such embodiment). However, owing to the basicity of the amino 40 as e.g. amines, nitrites, phosphines, thiols, thioethers, group in 4-(2-aminophenyl)butyronitrile, at least one mole alcohols, ethers or carboxylic acids. The catalysts are equivalent of acid (based on 4-(2-aminophenyl) optionally applied to a Support material. Suitable Support butyronitrile) must also be added. Preferably, 1.5 to 21 materials are activated charcoal, aluminium oxide, Silicon equivalents of acid are used, particularly preferably 1.5 to 11 dioxide, Zirconium oxide, Zinc oxide or Zeolites. equivalents. 45 Work is optionally performed in the presence of an The reaction is carried out in Substance or in an inert Oxidising agent Such as Oxygen or air. Solvent in the presence of Strong acids. Suitable Solvents are The reaction is generally carried out at temperatures of linear, branched or cyclic aliphatic hydrocarbons, Such as 50° C. to 250° C., preferably at 100° C. to 200° C. ligroin or cyclohexane, pentane, hexane, heptane, octane and All the reaction steps in this preferred embodiment of the aromatic Solvents Such as nitrotoluene. It is preferred to 50 process can be performed continuously or batchwise, e.g. in work in Substance or in ortho-nitrotoluene. Stirred vessel reactors or tubular reactors. Suitable acids are Strong Lewis or Bronsted acids, Such as In a third preferred embodiment, the process for the e.g. aluminium chloride, boron trifluoride, Sulfuric acid, production of 1,5-naphthalene-diamine contains the StepS phosphoric acid, polyphosphoric acid, phosphorus a) reaction of ortho-nitrotoluene with acrylonitrile to give pentoxide, methaneSulfonic acid, trifluoromethaneSulfonic 55 4-(2-nitrophenyl)-butyronitrile, acid, trifluoroacetic acid or mixtures of antimony pentafluo ride and fluorosulfuric acid. Mixtures of the acids can also b) cyclisation of the 4-(2-nitrophenyl)butyronitrile be used. formed in step a) to the nitro imine and/or nitro The reaction is generally carried out at temperatures of 0 enamine, C. to 150° C., preferably between 60° C. and 110° C. 60 c) reduction of the nitro imine and/or nitro enamine After the cyclisation, the reaction mixture is convention formed in Step b) to give the amino imine and/or amino ally neutralised. This is achieved e.g. by adding Sodium enamine, hydroxide solution. d) aromatisation of the amino imine and/or amino enam The amino imine and/or amino enamine formed in step c) ine formed in Step c) to give 1,5-naphthalenediamine. is preferably first converted to the aminoketone 5-amino-3, 65 4-(2-Nitrophenyl)butyronitrile is prepared from ortho 4-dihydro-1(2H)-naphthalenone, e.g. by hydrolysis, and the nitrotoluene and acrylonitrile in the same way as in Step aminoketone is isolated. The isolation takes place e.g. by a) of the first preferred embodiment. US 6,706,924 B2 7 8 This compound is then cyclised to give 5-nitro-3,4- 4-(2-Nitrophenyl)butyronitrile is then cyclised to 5-nitro dihydro-1-naphthylamine or the tautomeric 5-nitro-3,4- 3,4-dihydro-1-naphthylamine or the tautomeric 5-nitro-3,4- dihydro-1(2H)-naphthylimine in the same way as in step b) dihydro-1(2H)-naphthylimine as in step b) of the first pre of the first preferred embodiment. ferred embodiment. The 5-nitro-3,4-dihydro-1- The compound 5-nitro-3,4-dihydro-1-naphthylamine or naphthylamine and/or 5-nitro-3,4-dihydro-1(2H)- the tautomeric 5-nitro-3,4-dihydro-1(2H)-naphthylimine is naphthylimine is then converted to the nitroketone 5-nitro now reduced to give 5-amino-3,4-dihydro-1-naphthyl-amine 3,4-dihydro-1(2H)-naphthalenone, e.g. by hydrolysis, and or the tautomeric 5-amino-3,4-dihydro-1 (2H)- the nitroketone is isolated. The isolation of the nitroketone naphthylimine. 1O takes place e.g. by phase Separation. The transformation can be performed by hydrogenation in The compound 5-nitro-3,4-dihydro-1(2H)-naphthalenone the presence of a hydrogenation catalyst. Practically all heterogeneous catalysts that are known as hydrogenation is now reduced to give 5-amino-3,4-dihydro-1(2H)- catalysts are Suitable as hydrogenation catalysts for the naphthalenone. process according to the invention (Rómpp Lexikon Che 15 The transformation can be performed by hydrogenation in mie; Georg Theme Verlag, Stuttgart, 10" edition 1997, p. the presence of a hydrogenation catalyst. Practically all 1831, chapter “Hydrierung”; Ullmann's Encyclopedia of heterogeneous catalysts that are known as hydrogenation Industrial Chemistry, VCH Verlagsgesellschaft mbH, catalysts are Suitable as hydrogenation catalysts for the Weinheim, 5' edition 1989, vol. A13, chapter “Hydrogena process according to the invention (Römpp Lexikon Che tion and Dehydrogenation', Sub-chapter 1.2 "Catalysts', p. mie; Georg Thieme Verlag, Stuttgart, 10" edition 1997, p. 488). Preferred catalysts are the metals of groups 8-10 of the 1831, chapter “Hydrierung”; Ullmann's Encyclopedia of periodic table (G. J. Leigh editor), Nomenclature of Inor Industrial Chemistry, VCH Verlagsgesellschaft mbH, Weinheim, 5' edition 1989, vol. A13, chapter “Hydrogena ganic Chemistry, Recommendations 1990, Blackwell Sci 25 entific Publications, Oxford, Chapter I-3.8.1 “Groups of tion and Dehydrogenation', Sub-chapter 1.2 "Catalysts', p. Elements in the Periodic Table and their Subdivision, p. 488). Preferred catalysts are the metals of groups 8-10 of the 41–43), copper or chromium on a Suitable Support with, a periodic table (G. J. Leigh editor), Nomenclature of Inor metal content of 0.01 to 50 wt.%, preferably 0.1 to 20 wt. ganic Chemistry, Recommendations 1990, Blackwell Sci %, based on the total weight of the catalyst. Catalysts entific Publications, Oxford, Chapter I-3.8.1 “Groups of containing one or more of the above-mentioned metals can Elements in the Periodic Table and their Subdivision, p. also be used. Preferred metals are, in particular, platinum, 41–43), or copper and/or chromium on a Suitable Support palladium and rhodium, platinum and palladium being par with a metal content of 0.01 to 50 wt.%, preferably 0.1 to ticularly preferred. Other preferred catalysts are Raney 20 wt.%, based on the total weight of the catalyst. Catalysts nickel and Supported nickel catalysts. The above-mentioned 35 containing one or more of the above-mentioned metals can metals or their compounds can also be used in pure form as also be used. Preferred metals are, in particular, platinum, a Solid. Palladium black and platinum black can be men palladium and rhodium, platinum and palladium being par tioned as examples of a metal in pure form. ticularly preferred. Other preferred catalysts are Raney The final aromatisation of 5-amino-3,4-dihydro-1- 40 nickel and Supported nickel catalysts. The above-mentioned naphthylamine or the tautomeric 5-amino-3,4-dihydro-1 metals or their compounds can also be used in pure form as (2H)-naphthylimine to 1,5-naphthalene diamine is per a Solid. Palladium black and platinum black can be men formed in the same way as in step d) of the Second preferred tioned as examples of a metal in pure form. embodiment. The 5-amino-3,4-dihydro-1(2H)-naphthalenone produced All the reaction steps in this preferred embodiment of the 45 in the reduction is then converted to 5-amino-3,4-dihydro proceSS can be carried out continuously or batchwise, e.g. in 1-naphthylamine and/or 5-amino-3,4-dihydro-1 (2H)- Stirred vessel reactors or tubular reactors. naphthylimine by reacting with ammonia, preferably in the In a fourth preferred embodiment the process for the presence of ammonium chloride. production of 1,5-naphthalenediamine contains the Steps: 50 The final aromatisation of 5-amino-3,4-dihydro-1- a) reaction of ortho-nitrotoluene with acrylonitrile to give naphthylamine and/or the tautomeric 5-amino-3,4-dihydro 4-(2-nitrophenyl)-butyronitrile, 1(2H)-naphthylimine to 1,5-naphthalenediamine is per b) cyclisation of the 4-(2-nitrophenyl)butyronitrile formed in step a) to the nitro imine and/or nitro formed as in Step d) of the Second preferred embodiment. enamine, conversion to the nitroketone 5-nitro-3,4- 55 The conversion of the 5-amino-3,4-dihydro-1(2H)- dihydro-1(2H)-naphthalenone, and isolation of the naphthalenone to 5-amino-3,4-dihydro-1-naphthylamine nitroketone, and/or 5-amino-3,4-dihydro-1(2H)-naphthylimine and the c) reduction of the nitroketone formed in Step b) to give Subsequent aromatisation are preferably carried out in one the aminoketone 5-amino-3,4-dihydro-1 (2H)- naphthalenone, 60 reaction vessel. All the reaction steps in this preferred embodiment of the d) conversion of the aminoketone formed in Step c) to the amino imine and/or amino enamine and aromatisation process can be performed continuously or batchwise, e.g. in to give 1,5-naphthalenediamine. Stirred vessel reactors or tubular reactors. 4-(2-Nitrophenyl)butyronitrile is prepared from ortho 65 The processes according to the invention based on Ortho nitrotoluene and acrylonitrile in the same way as in Step a) nitrotoluene and acrylonitrile can be illustrated in idealised of the first preferred embodiment. form by the following reaction diagram:

US 6,706,924 B2 11 12 In a fifth preferred embodiment, the process for the The acid is generally used in 0.1 to 100 mole equivalents, production of 1,5-naphthalene-diamine contains the Steps: based on 4-(2-nitrophenyl)-butyric acid derivative. a) reaction of ortho-nitrotoluene with an acrylate or Preferably, 0.5 to 20 equivalents are used, particularly acrylamide to give 4-(2-nitrophenyl)butyrate or 4-(2- preferably 1 to 10 equivalents. nitrophenyl)butyramide, The reaction is generally carried out attemperatures of 0 b) cyclisation of the butyrate or butyramide formed in step C. to 150° C., preferably between 60° C. and 110° C. a) to give 5-nitro-3,4-dihydro-1(2H)-naphthalenone, The amination of 5-nitro-3,4-dihydro-1 (2H)- c) amination of the 5-nitro-3,4-dihydro-1(2H)- naphthalenone to the nitro imine and/or nitro enamine takes naphthalenone formed in step b) to give 5-nitro-3,4- place by reaction with ammonia, preferably in the presence dihydro-1-naphthylamine or the tautomeric 5-nitro-3, of ammonium Salts. Such as ammonium chloride. 4-dihydro-1(2H)-naphthylimine, The aromatisation or dehydrogenation of the nitro enam d) aromatisation of the 5-nitro-3,4-dihydro-1- ine 5-nitro-3,4-dihydro-1-naphthylamine or of the nitro naphthylamine or the tautomeric 5-nitro-3,4-dihydro-1 imine 5-nitro-3,4-dihydro-1(2H)-naphthylimine to 5-nitro (2H)-naphthylimine formed in step c) to give 5-nitro 15 1-naphthylamine or 5-nitroSo-1-naphthylamine or a mixture 1-naphthylamine and/or 5-nitroSo-1-naphthylamine, of the compounds is carried out, e.g. in an inert Solvent, in e) hydrogenation of the 5-nitro-1-naphthylamine and/or the presence of a catalyst. In addition to the dehydrogenated 5-nitroSo-1-naphthylamine formed in step d) to give product 5-nitro-1-naphthylamine, 5-nitroSo-1- 1,5-naphthalenediamine. naphthylamine formally resulting from Symproportionation 4-(2-Nitrophenyl)butyrates or 4-(2-nitrophenyl) can also be produced in the proce SS. 1,5- butyramides are produced from Ortho-nitrotoluene and acry Naphthalenediamine is also formed in traces. The products lates or acrylamides preferably attemperatures of -10°C. to can be further processed in any mixing ratioS. Suitable 100° C., It is particularly preferred to work at 20° C. to 75° Solvents are ammonia and linear, branched or cyclic ali C., especially preferably at temperatures of 30° C. to 60° C. phatic hydrocarbons Such as ligroin or cyclohexane, and also The reaction is performed with base catalysis. Oxides, 25 acetonitrile and aromatic Solvents Such as benzene, toluene, hydroxides and carbonates of lithium, Sodium, potassium, Xylene, nitrobenzene, nitrotoluene or chlorobenzene. The rubidium, caesium, magnesium, calcium, Strontium, barium aromatisation can also be performed in the absence of a or aluminium, and mixtures thereof, can be used as bases. Solvent. Sodium hydroxide and potassium hydroxide are particularly Suitable catalysts are dehydrogenation catalysts, which Suitable. In a preferred embodiment, the aqueous Solutions are used in combination with a phase transfer catalyst. These are described in the literature (Rompp Lexikon Chemie; phase transfer catalysts are e.g. quaternary ammonium Salts. Georg Thieme Verlag, Stuttgart, 10" edition 1997, p. 891, Suitable ammonium compounds are tetraalkylammonium chapter “Dehydrierung, 1 section; Ullmann's Encyclope halides and hydrogen Sulfates, Such as tributylmethylammo dia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, nium chloride, trioctylammonium chloride, tetrabutylam 35 Weinheim, 5' edition 1989, vol. A13, chapter “Hydrogena monium chloride or tetrabutylammonium hydrogen Sulfate. tion and De hydroge nation”, Sub - chapter 2, The use of appropriate tetraalkyl- or tetraarylphosphonium “Dehydrogenation”, p. 494-497). These include the metals Salts, Such as tetramethylphosphonium bromide and of groups 8-10 of the periodic table (G. J. Leigh editor), tetraphenyl-phosphonium bromide is also Suitable, as is the Nomenclature of Inorganic Chemistry, Recommendations use of Solubility promoters, Such as polyethylene glycol 40 1990, Blackwell Scientific Publications, Oxford, Chapter dimethyl ethers. I-3.8.1 “Groups of Elements in the Periodic Table and their In principle, water and all organic Solvents that are stable Subdivision, p. 41–43), especially platinum, palladium, in bases are Suitable as the Solvents. Aromatic Solvents, Such ruthenium and iridium, iron, cobalt, nickel and combinations as benzene, toluene, Xylene, chlorobenzene, nitrobenzene or thereof. The metals can also be used together with other nitrotoluene, and also dimethyl Sulfoxide, dimethyl forma 45 metals, Such as lanthanum, Scandium, Vanadium, chromium, mide and aliphatic hydrocarbons, Such as ligroin, molybdenum, tungsten, manganese, tin, Zinc, copper, Silver cyclohexane, pentane, hexane, heptane or octane, are pref or indium. The above metals can be present as pure erably used. elements, as oxides, Sulfides, halides, carbides or nitrides or ortho-Nitrotoluene is particularly preferably used as educt can be used in combination with organic ligands. Suitable as and, at the same time, as Solvent, and in an excess of 50 ligands are hydrocarbon compounds with donor groups, ortho-nitrotoluene of 1 to 40 equivalents, especially 5 to 20 equivalents, based on the acrylic acid derivative. Such as e.g. amines, nitriles, phosphines, thiols, thioethers, The cyclisation of 4-(2-nitrophenyl)butyrates or 4-(2- alcohols, ethers or carboxylic acids. The catalysts are nitrophenyl)butyramides to 5-nitro-3,4-dihydro-1(2H)- optionally applied to a Support material. Suitable Support naphthalenone is performed in Substance or in an inert 55 materials are activated charcoal, aluminium oxide, Silicon Solvent in the presence of Strong acids. Suitable Solvents are dioxide, Zirconium oxide, Zinc oxide or Zeolites. linear, branched or cyclic aliphatic hydrocarbons, Such as Work is optionally performed in the presence of an ligroin or cyclohexane, pentane, hexane, heptane, octane and oxidising agent Such as oxygen or air. The reaction is aromatic Solvents Such as nitrotoluene. It is preferred to generally carried out at temperatures of 50° C. to 250 C., operate in Substance or in Ortho-nitrotoluene. 60 preferably at 100° C. to 200° C. Suitable acids are Strong Lewis or Bronsted acids, Such as The Subsequent hydroge nation of 5-nitro-1- e.g. aluminium chloride, boron trifluoride, Sulfuric acid, naphthylamine or 5-nitroSo-1-naphthyl-amine or a mixture phosphoric acid, polyphosphoric acid, phosphorus of these compounds to 1,5-naphthalenediamine is performed pentoxide, methaneSulfonic acid, trifluoromethaneSulfonic as in step d) of the first preferred embodiment. acid, trifluoroacetic acid or mixtures of antimony pentafluo 65 The process according to the invention based on Ortho ride and fluorosulfuric acid. Mixtures of these acids can also nitrotoluene and acrylates and acrylamides can be illustrated be used. Sulfuric acid or phosphoric acid is preferably used. in idealised form by the following reaction diagram: US 6,706,924 B2 14 50 ml glass round-bottomed flask under protective gas and the mixture is heated to 100° C. for 12 h. The cooled mixture Base -- He is poured on to ice and immediately extracted with toluene. The yield of 5-nitro-3,4-dihydro-1(2H)-naphthyl-imine is 1. X 85% according to GC (area per cent). NO2 O Example 2a o-Nitro- Acrylate or toluene acrylamide Preparation of 5-nitro-3,4-dihydro-1(2H)- X O O 1O naphthalenone

Acid NH3/Cat. 1.00 g of fluorosulfuric acid (10 mmol) are added to 1.30 He- He g of antimony(V) fluoride (6 mmol) in a 50 ml glass round-bottomed flask under protective gas and the mixture is cooled to 0° C. Then, 380 mg of 4-(2-nitrophenyl) 15 NO2 NO2 butyronitrile (2 mmol) are added carefully. The mixture 4-(2-Nitrophenyl)- 5-Nitro-3,4-dihydro heats up to about 50° C. and is stirred for a farther 12 h at butyrate or 1(2H)-naphthalenone room temperature. The mixture is poured on to ice-cold butyramide Sodium hydroxide Solution, Stirring is continued for 30 min NH2 NH2 at room temperature and then extraction is performed with toluene. Largely complete hydrolysis is made possible by the Secondary Stirring period. The organic phase is dried Cat. Cat. -- -- over Sodium Sulfate, filtered off and the Solvent is distilled off under reduced pressure. The residue is purified by chromatography on Silica gel (eluent cyclohexane/ethyl 25 NO NOx acetate 5:1 V/v). The yield of 5-nitro-3,4-dihydro-1(2H)- 5-Nitro-3,4-dihydro 5-Nitro-1-naphthylamine and/or naphthalenone is 297 mg with a GC purity of 97% (76% of 1-naphthylamine or 5-Nitroso-1-naphthylamine and/or theoretical value). 5-Nitro-3,4-dihydro 1,5-Naphthalenediamine 1(2H)-naphthylimine Example 3 NH2 Preparation of 5-nitro-1-naphthylamine 1.0 g of 5-nitro-3,4-dihydro-1(2H)-naphthalenone (5.2 mmol), 5.2 mg of ammonium chloride (0.1 mmol) and 10.9 35 mg of ruthenium trichloride hydrate (0.05 mmol) are placed in a 0.1 liter autoclave. 10 ml of ammonia are condensed in, the autoclave is heated to 80° C. and then the pressure is 1,5-Naphthalene increased to 200 bar with nitrogen. After stirring for 20 h diamine X = OAlkyl, OAryl, NH2, NHAIkyl, N(Alkyl)-2, NHAryl, N(Aryl), NAlkylAryl under the above conditions, cooling takes place, the preSSure 40 is carefully released and the reaction mixture is dissolved out of the autoclave with 20 ml of dichloromethane. A mixture is obtained which contains, according to GC, in The 1,5-naphthalenediamine can be phosgenated to give addition to 12% educt, 68% 5-nitro-3,4-dihydro-1- 1,5-naphthalene diisocyanate by a method that is known per naphthylamine or 5-nitro-3,4-dihydro-1 (2H)- se (DE-A1-19651 041). 45 naphthylimine, 17% 5-nitro-1-naphthylamine and traces of EXAMPLES 1,5-naphthalene diamine (GC area percentages). Embodiment 1 Example 4 Example 1 Hydrogenation of 5-nitro-1-naphthylamine Preparation of 4-(2-nitrophenyl)butyronitrile 50 8.20 g of 5-nitro-1-naphthylamine (43.6 mmol) in 35 ml 0.75 ml of 45% sodium hydroxide solution and 175 mg of of toluene are placed in a 0.1 liter autoclave with 0.5g of tributylmethylammonium chloride are placed in a 100 ml palladium on carbon (5%) and hydrogenated at 50° C. and three-neck flask with a dropping funnel, reflux condenser 40 bar hydrogen pressure for 5 h, Stirring. On completion of and internal thermometer, Stirring. At 40 C., a mixture of 1.4 ml acrylonitrile (21.15 mmol) and 25 ml ortho 55 the reaction, the cooled autoclave is depressurised and the nitrotoluene is added dropwise and maintained at this tem catalyst is filtered off. With a quantitative conversion, 6.72 perature for 3 h. The phases are separated, and the organic g of 1.5-naphthalenediamine (42.5 mmol, 97.5%) are phase is dried and filtered off. With quantitative conversion formed. of acrylonitrile, 1.61 g of 4-(2-nitro-phenyl)butyronitrile Embodiment 2 (8.5 mmol, 40%) are obtained. 60 Example 5 Example 2 Synthesis of 4-(2-aminophenyl)butyronitrile Preparation of 5-nitro-3,4-dihydro-1(2H)- naphthylimine 450 mg of 4-(2-nitrophenyl)butyronitrile, dissolved in 65 12.5 ml of methanol, are added dropwise to a mixture of 412 4 ml of concentrated sulfuric acid (75 mmol) are added to mg of iron powder (7.5 mmol) and 663 mg of ammonium 107 mg of 4-(2-nitrophenyl)-butyronitrile (0.89 mmol) in a chloride (12.5 mmol) in 12.5 ml of water at room tempera US 6,706,924 B2 15 16 ture and under protective gas in a 100 ml glass round Embodiment 4 bottomed flask. The mixture is heated for 5 hours with reflux. 25 ml of water are added to the cooled mixture and Example 8 extraction is performed with toluene. The combined toluene phases are dried and the solvent distilled off under reduced Synthesis of 5-amino-3,4-dihydro-1(2H)- preSSure. The residue is purified by column chromatography naphthalenone from 5-nitro-3,4-dihydro-1(2H)- on silica gel (eluent toluene/ 10:1 V/v). Yield: naphthalenone 276 mg (1.73 mmol, 72%). 9.18 g of iron powder and 16.64 g of ammonium chloride Example 6 in 274 ml of water are placed in a 1-liter, four-neck flask. 10 g of 5-nitro-3,4-dihydro-1(2H)-naphthalenone (52.4 mmol) Synthesis of 5-amino-3,4-dihydro-1(2H)- dissolved in 550 ml of methanol are added dropwise, naphthylimine stirring, over 3.5 hours at 25 C. On completion of the In a 50 ml glass flask, 380 mg of fluorosulfuric acid (3.8 dropwise addition, heating is performed with reflux for 3.5 mmol) are added dropwise to 122 mg of 4-(2-aminophenyl) 15 hours. After cooling, the pH is adjusted to pH 11 with butyronitrile (0.74 mmol) and 495 mg of antimony(V) aqueous ammonia Solution (25%). The product is extracted fluoride (2.29 mmol), Stirring, under argon and the mixture from the aqueous phase with chloroform, dried over Sodium is heated to 100° C. for 4 hours. After cooling, the mixture Sulfate and concentrated under vacuum. The product is is poured on to ice, directly neutralised with Sodium hydrox obtained as a reddish-brown solid in an 81% yield (6.8 g). ide solution and extracted with toluene. The yield of 5-nitro Embodiment 5 3,4-dihydro-1(2H)-naphthylimine is 77% according to GC.. 5-Amino-3,4-dihydro-1(2H)-napthylimine can also be Example 9 called 5-imino-5,6,7,8-tetrahydro-1-naphthylamine. Synthesis of 4-(2-nitrophenyl)methylbutyrate Example 6a 25 A mixture of 400 g (2.92 mol) of ortho-nitrotoluene and Synthesis of 5-amino-3,4-dihydro-1(2H)- 12.7 g (0.148 mol) of methyl acrylate is added to a mixture naphthalenone of 14.4 g of 67% potassium hydroxide solution and 1.7 g of tetrabutylammonium chloride at 40 C. and the mixture is In a 50 ml glass flask, 380 mg of fluorosulfuric acid (3.8 stirred for 1 h. The mixture is neutralised with 30% sulfuric mmol) are added dropwise to 122 mg of 4-(2-aminophenyl) acid and the phases are separated. According to GC analysis butyronitrile (0.74 mmol) and 495 mg of antimony(V) fluoride (2.29 mmol), Stirring, under argon and the mixture with an internal standard, the yield is 50%. is heated to 100° C. for 4 hours. After cooling, the mixture The organic phases of 4 identical tests are combined and is poured on to ice, neutralised with Sodium hydroxide dried over NaSO. Under a pressure of 0.1 bar, excess Solution, Stirred for 30 min at room temperature and nitrotoluene is distilled off up to an overhead temperature of extracted with toluene. As a result of the 30 min. Secondary 35 110° C. At an overhead temperature of 120–130° C., 59.1 g Stirring period, largely complete hydrolysis is made poS (265 mmol) of 4-(2-nitrophenyl)methyl butyrate are sible. The yield of 5-amino-3,4-dihydro-1 (2H)- obtained with a purity of approx. 98%. The isolated yield naphthalenone is 64%. corresponds to 45%. Example 6b 40 Example 10 Synthesis of 5-amino-3,4-dihydro-1(2H)- Synthesis of 5-nitro-3,4-dihydro-1(2H)- naphthalenone naphthalenone In a 20 ml Schlenk vessel, 1 g of 96% sulfuric acid (9.79 100 mg (0.45 mmol) of 4-(2-nitrophenyl)methylbutyrate mmol) is added to 100 mg of 4-(2-aminophenyl) 45 are dissolved in 1.68 g of trifluoromethanesulfonic acid and butyronitrile (0.62 mmol) under argon. The mixture is heated to 100° C. for 24 h. 5 ml of water and 5 ml of toluene heated to 100° C. for 66 h, stirring. After cooling, it is are carefully added to the cooled reaction mixture. The neutralised with aqueous ammonia Solution (ice cooling), phases are Separated and the organic phase investigated by and the product is then extracted with chloroform and gas chromatography with an internal Standard. The yield of identified using GC.. 50 5-nitro-3,4-dihydro-1(2H)-naphthalenone is 81%. Example 7 Example 10a Synthesis of 1,5-naphthalenediamine from 5-amino 3,4-dihydro-1(2H)-naphthalenone Synthesis of 5-nitro-3,4-dihydro-1(2H)- 55 naphthalenone 419.1 mg (2.6 mmol) of aminotetralon, 52 mg (0.97 mmol) of ammonium chloride and 230.5 mg (1.3 mmol) of 250 mg (1.12 mmol) of 4-(2-nitrophenyl)methylbutyrate palladium(II) chloride in 1 ml of acetonitrile are placed in a are dissolved in 5.49 g of 98% sulfuric acid and heated to 0.1 liter StainleSS Steel autoclave. 5 ml of ammonia are 100° C. for 24 h. 5 ml of water and 5 ml of toluene are added, the mixture is heated to 130 C. and then the pressure 60 carefully added to the cooled reaction mixture. The phases is increased to 200 bar with nitrogen. It is stirred under the are separated and the organic phase investigated by gas above reaction conditions for 20 h and then cooled to room chromatography with an internal Standard. The yield of temperature and the pressure is slowly released. The residue 5-nitro-3,4-dihydro-1(2H)-naphthalenone is 42%. is dissolved in a mixture of acetonitrile, toluene and What is claimed is: dichloromethane, filtered over Sodium Sulfate and then the 65 1. Process for the production of 1,5-naphthalenediamine Solvent is removed under vacuum. containing a step in which ortho-nitrotoluene is reacted with Yield: 321 mg (78%). one or more acrylic acid derivatives. US 6,706,924 B2 17 18 2. Process according to claim 1 in which methyl acrylate, b) cyclisation of the 4-(2-nitrophenyl)butyronitrile ethyl acrylate, butyl acrylate or acrylamide is used as the formed in step a) to the nitro imine and/or nitro acrylic acid derivative. enamine, 3. Process according to claim 1, containing a step in which c) reduction of the nitro imine and/or nitro enamine ortho-nitrotoluene is reacted with acrylonitrile to give 4-(2- 5 formed in Step b) to give the amino imine and/or amino nitrophenyl)butyronitrile. enamine, 4. Process for the production of 1,5-naphthalenediamine d) aromatisation of the amino imine and/or amino enam according to claim 3, containing the Steps ine formed in Step c) to give 1,5-naphthalenediamine. a) reaction of ortho-nitrotoluene with acrylonitrile to give 9. Process for the production of 1,5-naphthalenediamine 4-(2-nitrophenyl)butyronitrile, according to claim 3, containing the Steps a) reaction of ortho-nitrotoluene with acrylonitrile to give b) cyclisation of the 4-(2-nitrophenyl)butyronitrile 4-(2-nitrophenyl)-butyronitrile, formed in step a) to the nitro imine and/or nitro b) cyclisation of the 4-(2-nitrophenyl)butyronitrile enamine, formed in step a) to the nitro imine and/or nitro c) aromatisation of the nitro imine and/or nitro enamine enamine, conversion to the nitroketone 5-nitro-3,4- formed in step b) to give 5-nitro-1-naphthylamine 15 dihydro-1(2H)-naphthalenone, and isolation of the and/or 5-nitroSo-1-naphthylamine, nitroketone, d) hydrogenation of the 5-nitro-1-naphthylamine and/or c) reduction of the nitroketone 5-nitro-3,4-dihydro-1(2H)- 5-nitroSo-1-naphthylamine formed in step c) to give naphthalenone formed in Step b) to give the aminoke 1,5-naphthalenediamine. tone 5-amino-3,4-dihydro-1(2H)-naphthalenone, 5. Process according to claim 4, in which the nitro imine d) conversion of the aminoketone formed in Step c) to the and/or nitro enamine formed in Step b) is first converted to amino imine 5-amino-3,4-dihydro-1 (2H)- the nitroketone 5-nitro-3,4-dihydro-1(2H)-naphthalenone, naphthylimine and/or amino enamine 5-amino-3,4- dihydro-1-naphthylamine and aromatisation to give the nitroketone is then isolated, then converted back to the 1,5-naphthalenediamine. nitro imine and/or nitro enamine, and then aromatised in Step 25 c). 10. Process for the production of 1,5-naphthalenediamine 6. Process for the production of 1,5-naphthalenediamine according to claim 1, containing the Steps a) reaction of ortho-nitrotoluene with an acrylate or according to claim 3, containing the Steps acrylamide to give 4-(2-nitrophenyl)butyrate or 4-(2- a) reaction of ortho-nitrotoluene with acrylonitrile to give nitrophenyl)butyramide, 4-(2-nitrophenyl)-butyronitrile, b) cyclisation of the butyrate or butyramide formed in step b) reduction of the 4-(2-nitrophenyl)butyronitrile formed a) to give 5-nitro-3,4-dihydro-1(2H)-naphthalenone, in Step a) to give 4-(2-aminophenyl)butyronitrile, c) amination of the 5-nitro-3,4-dihydro-1 (2H)- c) cyclisation of the 4-(2-aminophenyl)butyronitrile naphthalenone formed in step b) to give 5-nitro-3,4- formed in Step b) to the amino imine and/or amino dihydro-1-naphthylamine or the tautomeric 5-nitro-3, enamine, 35 4-dihydro-1(2H)-naphthylimine, d) aromatisation of the amino imine and/or amino enam d) aromatisation of the 5-nitro-3,4-dihydro-1- ine formed in Step c) to give 1,5-naphthalenediamine. naphthylamine or the tautomeric 5-nitro-3,4-dihydro-1 7. Process according to claim 6, in which the amino imine (2H)-naphthylimine formed in step c) to give 5-nitro and/or amino enamine formed in step c) is first converted to 40 1-naphthylamine and/or 5-nitroSo-1-naphthylamine, the aminoke tone 5-amino-3,4-dihydro-1 (2H)- e) hydrogenation of the 5-nitro-1-naphthylamine and/or naphthalenone, the aminoketone is then isolated, then con 5-nitroSo-1-naphthylamine formed in step d) to give verted back to the amino imine and/or amino enamine and 1,5-naphthalenediamine. then aromatised in step d). 11. Process for the production of 1,5-naphthalene diiso 8. Process for the production of 1,5-naphthalenediamine 45 cyanate in which 1,5-naphthalenediamine, produced in according to claim 3, containing the Steps accordance with one of claims 1 to 10, is phosgenated. a) reaction of ortho-nitrotoluene with acrylonitrile to give 4-(2-nitrophenyl)-butyronitrile, k k k k k