Method for Production of Laurolactam Verfahren Zur Herstellung Von Laurolactam Procédé De Fabrication De Laurolactame

(19) TZZ ¥___T

(11) EP 2 223 911 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C07D 201/04 (2006.01) C07D 225/02 (2006.01) 24.09.2014 Bulletin 2014/39 C07B 61/00 (2006.01)

(21) Application number: 08853278.3 (86) International application number: PCT/JP2008/071044 (22) Date of filing: 19.11.2008 (87) International publication number: WO 2009/069522 (04.06.2009 Gazette 2009/23)

(54) METHOD FOR PRODUCTION OF LAUROLACTAM VERFAHREN ZUR HERSTELLUNG VON LAUROLACTAM PROCÉDÉ DE FABRICATION DE LAUROLACTAME

(84) Designated Contracting States: • SHIMOMURA, Hideo AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Ube-shi HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT Yamaguchi 755-8633 (JP) RO SE SI SK TR • YASUMATSU, Ryouta Ube-shi (30) Priority: 29.11.2007 JP 2007308746 Yamaguchi 755-8633 (JP) • II, Nobuhiro (43) Date of publication of application: Ube-shi 01.09.2010 Bulletin 2010/35 Yamaguchi 755-8633 (JP)

(73) Proprietor: Ube Industries, Ltd. (74) Representative: Cabinet Plasseraud Ube-shi 52, rue de la Victoire Yamaguchi 755-8633 (JP) 75440 Paris Cedex 09 (FR)

(72) Inventors: (56) References cited: • KUGIMOTO, Junichi WO-A1-2007/125002 WO-A1-2007/125002 Ube-shi WO-A1-2008/096873 WO-A1-2008/096873 Yamaguchi 755-8633 (JP) GB-A- 1 148 013 JP-A- 2003 081 930 • KAWAI, Joji JP-A- 2003 081 930 JP-A- 2003 321 453 Ube-shi JP-A- 2006 219 470 JP-B1- 43 012 153 Yamaguchi 755-8633 (JP)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 223 911 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 2 223 911 B1 2

Description Furthermore, since cyclododecanone reacts with concentrated sulfuric acid to form a byproduct, the oxime- TECHNICAL FIELD forming reaction must be completed for eliminating residual cyclododecanone, butdue to hydrophobicity of iso- [0001] The present invention relates to a process for 5 propylcyclohexane, a mass transfer rate is low in an oil- producing laurolactam from cyclododecanone and hy- water interface, leading to a longer oxime-forming reac- droxylamine by an industrially convenient process. tion. As a whole, the process involves many steps of separation, recovery and recycling of solvents and, there- BACKGROUND ART fore, requires considerably large equipment expenses 10 and energy. [0002] A common industrial process for producing an [0005] Another industrial process is that commercially amide compound involves Beckmann rearrangement of developed by Ube Industries-EMS. This process utilizes a corresponding oxime compound. For example,ε- the fact that cyclohexanone oxime and caprolactam are caprolactam which is industrially useful is produced by good solvents for cyclododecanone oxime and laurol- Beckmann rearrangement of cyclohexanone oxime. Re- 15 actam, respectively (for example, see Patent Reference arrangement catalysts used are generally concentrated 2). Specifically, a mixture of cyclododecanone and cy- sulfuric acid and oleum. Since these strong acids must clohexanone is blended with an aqueous solution of hy- be used in the stoichiometric amounts or more, they form droxylamine to produce oximes. Cyclohexanone oxime a large amount of ammonium sulfate as a byproduct dur- produced has a low melting point and is a good solvent ing neutralization. Although laurolactam, which is a start- 20 for cyclododecanone oxime, so that the reaction can be ing material for Nylon 12, is also produced in a similar conducted at 100 °C or lower and at an ambient pressure. manner, the process is more complex because cyclodo- Furthermore, cyclohexanone oxime is adequately hy- decanone oxime as an intermediate product has a high drophilic for the oxime-forming reaction to quickly pro- meltingpoint. In producing ε-caprolactam, both cyclohex- ceed, and the mixture is transferred to the rearrangement anone oxime and ε-caprolactam have a relatively lower 25 step without residual cyclohexanone or cyclododecan- melting point, so that oxime formation or rearrangement one. A rearrangement catalyst used is concentrated sul- can be conducted in a solvent-free system, but produc- furic acid or oleum. Whereas laurolactam produced has tion of laurolactam requires a reaction solvent. This re- a high melting point, it is highly soluble in caprolactam action solvent must be able to substantially dissolve cy- having a low melting point. Therefore, the reaction can clododecanone oxime and be inert to concentrated sul- 30 be carried out even at a temperature of 100 °C or lower. furic acid or oleum, and therefore the selection of the The resulting rearrangement reaction solution is neutral- solvent is considerably restricted. ized with ammonia water and then extracted with an or- [0003] Only two processes are known for industrially ganic solvent. Caprolactam can be dissolved in water to producing laurolactam from cyclododecanone and an some extent, but is extracted into an organic solvent due aqueous solution of hydroxylamine. One is a process 35 to salting-out effect of ammonium sulfate. Next, a large commercially developed by Degussa Company. This amount of water is added to the solution containing ex- method is as follows. Cyclododecanone is converted into tracted laurolactam and caprolactam, and caprolactam an oxime using isopropylcyclohexane as a solvent, and is extracted into the aqueous phase. From the separated after separating layers, a resulting solution of cyclodo- organic phase, the organic solvent is recovered and lau- decanone oxime in isopropylcyclohexane is slowly add- 40 rolactam is purified by distillation. The aqueous phase is ed to concentrated sulfuric acid at a low temperature to concentrated and after removing impurities, caprolactam prepare a solution of a cyclododecanone oxime sulfate is purified. adduct in sulfuric acid. After separating and recovering [0006] This process is excellent in that laurolactam and isopropylcyclohexane, the residual solution of cyclodo- caprolactam can be produced together. However, as a decanone oxime sulfate adduct in sulfuric acid is heated 45 process for producing laurolactam, it has the following to initiate Beckmann rearrangement of the oxime. After problems; (1) separation and purification of caprolactam the rearrangement reaction, water is added to the system requires large amounts of equipment expenses, resulting to dilute sulfuric acid, and then, the laurolactam produced in low investment efficiency and the process involves op- is extracted with an organic solvent. Here, the extraction erations of low energy efficiency such as concentration solvent may be isopropylcyclohexane or cyclododecan- 50 of an aqueous solution of caprolactam; (2) there is a re- one. The extraction solvent is recovered by distillation striction to a production ratio of laurolactam/caprolactam; from the resulting extraction solution and then laurol- and(3) caprolactamis a low-value-added productin com- actam in the residue is purified by distillation (see, Patent parison with laurolactam and an use efficiency of hydrox- Reference No. 1). ylamine is low. [0004] This process does not generate ammonium sul- 55 [0007] Recently, there have been intensely investigat- fate as a byproduct in the rearrangement reaction step, ed rearrangement catalysts which do not require a large but requires enormously large facilities and energy for amount of sulfuric acid or oleum. As a system containing treating a large amount of waste diluted sulfuric acid. a strong acid, there have been reported a mixture of rhe-

2 3 EP 2 223 911 B1 4 nium peroxide ammonium salt and trifluoromethane sul- removing catalyst and the like. Since it is highly miscible fonic acid (Non-Patent Reference 1), indium triflate (Non- with water, a process for dehydrating materials for rear- Patent Reference 2) and ytterbium triflate (Non-Patent rangement becomes complex. Therefore, for establish- Reference 3). Known methods utilizing a system containing a practically feasible industrial process, solvents and ing an acid and a dehydrating agent include a method of 5 processes must be selected, in consideration of individ- conducting rearrangement reaction using phosphorous ual steps from starting materials to a final product includ- pentoxide or a condensed phosphoric acid compound ing an oxime-forming step. and a fluorine-free sulfonic anhydride or sulfocarboxylic [0011] anhydride in a N,N-disubstituted amide compound as a solvent (Patent References 3 and 4) and a method using 10 Patent Reference 1: Japanese examined patent a zeolite catalyst pretreated with an aqueous acid-con- publication No. S52-033118 (1977-033118). taining solution (Patent Reference 5). As methods that Patent Reference 2: Japanese Laid-open patent use no acids, there have been suggested a method of publication No. H05-4964 (1993-4964). conducting rearrangement reaction in the presence of a Patent Reference 3: Japanese Laid-open patent rhenium compound and a nitrogen-containing heterocy- 15 publication No. 2001-302602. clic compound (PatentReferences 6 and 7) and a method Patent Reference 4: Japanese Laid-open patent of using zinc oxide (Patent Reference 8). Patent Refer- publication No. 2001-302603. ence 9 has disclosed a method of reacting an oxime and Patent Reference 5: Japanese Laid-open patent a carboxylic acid in a carboxylic acid solvent using cya- publication No. 2001-072658. nuric chloride (trichlorotriazine) as a dehydrating agent, 20 Patent Reference 6: Japanese Laid-open patent whereby producing an ester which is then subjected to publication No. H09-301951 (1997-301951). rearrangement reaction. Patent Reference 10 has dis- Patent Reference 7: Japanese Laid-open patent closed a method where an oxime hydrochloride is sub- publication No. H09-301952 (1997-301952). jected to rearrangement using cyanuric chloride (trichlo- Patent Reference 8: Japanese Laid-open patent rotriazine) as an initiator. 25 publication No. 2001-019670. [0008] Although some of these catalysts and manufac- Patent Reference 9: Japanese examined patent turing processes can provide a high rearrangement yield, publication No. S46-23740 (1971-23740). these methods employ special catalysts and/or solvents, Patent Reference No. 10: Japanese examined pat- for which a recovering or recycling procedure is not dis- ent publication No. S47-18114 (1972-18114). closed, and these are, therefore, unestablished as an 30 Patent Reference No. 11: Japanese Laid-open pat- industrial process. ent publication No. 2006-219470. [0009] Patent Reference 11 has described Beckmann Non-Patent Reference 1: K. Narasaka, et. al., Chem- rearrangement of an oxime compound in a polar solvent, istry Letter, pp. 489-492 (1993). wherein a rearrangement catalyst used is an aromatic Non-Patent Reference 2: J. S. Sandhu, et. al., Indian compound (1) containing, as aromatic-ring member, at 35 Journal of Chemistry, pp. 154-156 (2002). least one carbon atom having a leaving group, (2) con- Non-Patent Reference 3: J. S. Yadav, et. al., Journal taining at least three aromatic-ring members which are of Chemical Research(S), pp. 236-238 (2002). either or both of heteroatoms or/and carbon atoms having Non-Patent Reference 4: K. Ishihara, et. al., Journal an electron-withdrawing group, and (3) wherein, two of of American Chemical Sociaty, pp. 11240-11241 the heteroatoms and/or carbon atoms having an elec- 40 (2005). tron-withdrawing group are at the ortho- or para-position Non-Patent Reference 5: M. Zhu, et. al., Tetrahedron to the carbon atom having an electron-withdrawing Letters, pp. 4861-4863 (2006). group. A similar description can be found in Non-Patent Reference 4. Non-Patent Reference 5 discloses that a DISCLOSURE OF THE INVENTION phosphoric acid salt having a heterocyclic structure sim- 45 ilar to that in Patent Reference 11 is active for Beckmann SUBJECT TO BE SOLVED BY THE INVENTION rearrangement. [0010] The catalyst disclosed in Patent Reference No. [0012] An objective of the present invention is to pro- 11 is highly active for a rearrangement reaction of cy- vide a process for efficiently producing laurolactam from clododecanone oxime to provide laurolactam in a high 50 cyclododecanone and hydroxylamine by a convenient yield, and is, therefore, suitable as a rearrangement re- process. Another objective of the present invention is to action catalyst in producing laurolactam. However, the provide a process for producing laurolactam using a com- solvents used in the rearrangement reaction are polar bination of inexpensive facilities. solvents, specifically, a nitrile which is recommended as a solvent cannot be used for an oxime-forming reaction 55 MEANS TO SOLVE THE SUBJECT because it reacts with hydroxylamine to form an amidox- ime. Furthermore, since it is susceptible to hydrolysis, [0013] The present invention relates to the following the loss of the catalyst inevitably happens in the step of items.

3 5 EP 2 223 911 B1 6

[0014] consisting of alicyclic hydrocarbon, aromatic hydrocarbon and fused-aromatic-ring hydrogenated-product. 1. A process for producing laurolactam comprising [0018] 9. The process for producing laurolactam ac- the steps of: cording to the above item 7 or 8, wherein prior to the 5 oil/aqueous phase separation step, the rearrangement (a) reacting cyclododecanone with hydroxy- solvent is added. lamine in an aqueous solution in the presence of an organic solvent (hereinafter, referred to as EFFECT OF THE INVENTION "oxime-formation solvent") to produce cyclododecanone oxime (hereinafter, referred to as an 10 [0019] Since the present invention does not employ "oxime-forming step"); concentrated sulfuric acid or oleum, byproducts such as (b) separating the reaction mixture obtained af- ammonium sulfate are not produced, and the required ter the oxime-forming step into an oil and an steps such as neutralization, extraction/separation and aqueous phases and collecting a solution of cy- distillation/collection are significantly reduced in compar- clododecanone oxime of the oil phase (herein- 15 ison with the conventional methods and therefore a con- after, referred to as an "oil/aqueous phase sep- venient process for producing laurolactam is realized. aration step"); [0020] Since solvents suitable for each reaction are (c) removing the oxime-formation solvent and also selected as the oxime-formation solvent and rear- dissolved water by distillation from the solution rangement solvent, the oxime-formation and rearrange- of cyclododecanone oxime which is collected as 20 ment reaction can be completed in a short time, and lau- an oil phase in the oil/aqueous phase separation rolactam can be obtained in a high yield. step, whereby preparing a dehydrated cyclodo- [0021] Since furthermore nonpolar organic solvent sta- decanone oxime solution containing a solvent ble thermally and chemically is employed for the rear- to be used in a rearrangement reaction in the rangement solvent in a preferred embodiment of the rearrangement step (hereinafter, referred to as 25 present invention, the solvent can be readily collected in "rearrangement solvent") and the cyclodo- a high yield and recycled. decanone oxime the rearrangement solvent has a boiling point higher than the boiling point of BRIEF DESCRIPTION OF THE DRAWINGS the oxime formation solvent, a portion of the rearrangement solvent is removed by the distilla- 30 [0022] tion, and wherein a content of residual water in the dehydrated cycloclodecanone oxime solu- Figure 1 is a flowchart showing the process flows of tion to be fed to the rearrangement step is re- Examples 1 to 4. duced to 1000 ppm or less (hereinafter, referred Figure 2 is a flowchart showing the process flow of to as a "dehydration/solvent preparation step"); 35 Example 5. (d) producing laurolactam from cyclododecanone oxime by rearrangement reaction using DETAILED DESCRIPTION OF THE INVENTION trichlorotriazine as a rearrangement catalyst (hereinafter, referred to as a "rearrangement [0023] Hereafter, the present invention will be ex- step"); and 40 plained in detail. In the process for producing laurol- (e) separating and removing the rearrangement actam,it is ofvital importance to select the rearrangement solvent and the rearrangement catalyst from the catalyst and rearrangement solvent. In the present in- reaction mixture obtained after the rearrange- vention, in addition to that an efficient reaction system is ment step, and purifying the laurolactam (here- selected, the total optimization as an industrial process inafter, referred to as a "separation/purification 45 is further considered. Hereafter, each step will be ex- step"). plained. [0024] The oxime-forming step is a step to produce [0015] 6. The process for producing laurolactam ac- cyclododecanone oxime by reacting cyclododecanone cording to the above item 5, wherein in the dehydra- with hydroxylamine aqueous solution in an equivalent tion/solvent preparation step, a content of residual water 50 mole. in the cyclododecanone oxime solution to be fed to the [0025] Cyclododecanone used for a stating material rearrangement step is reduced to 100 ppm or less. can be readily available as an industrial agent. For ex- [0016] 7. The process for producing laurolactam ac- ample, Invista Company sells a mixture of cyclododecan- cording to any one of the above items 1 to 6, wherein the one and cyclododecanol, and therefore, after cyclodo- rearrangement solvent is a nonpolar solvent. 55 decanol in the mixture is converted by dehydrogenation [0017] 8. The process for producing laurolactam ac- into cyclododecanone, the product can be used. cording to the above item 7, wherein the rearrangement [0026] The other starting material, hydroxylamine, solvent is one or more solvents selected from the group which is unstable, is produced and sold as an aqueous

4 7 EP 2 223 911 B1 8 solution of a hydroxylamine salt such as hydroxylamine ple, due to the above reason, disadvantageous are chain sulfate and hydroxylamine carbonate. Before the reac- hydrocarbons such as n-hexane, n-octane, isooctane, n- tion, a base such as ammonia water is added to the so- decane and n-dodecane, water-soluble alcohols and lution to liberate hydroxylamine, which is to be used. An ethers having 1 to 2 carbon atoms such as methanol, aqueous solution of hydroxylamine in which hydroxy- 5 ethanol and ethyleneglycol. lamine has been already liberated may be fed to the ox- [0031] Therefore, the oxime-formation solvent prefer- ime-forming step, but generally, an aqueous solution of ably includes, for example, alicyclic hydrocarbon, fused- a hydroxylamine salt (preferably, sulfate) and a base aromatic-ring hydrogenated-product, aromatic hydrocar- (preferably, ammonia water) are fed to an oxime-forming bon, middle and higher alcohols, ethers, glymes, esters reactor to liberate hydroxylamine in the reactor. 10 and the like. As necessary, surfactant and the like may [0027] Since cyclododecanone oxime produced has a be added to these solvents to increase the rate of oxime- high melting point, the oxime-forming reaction requires formation. a solvent. One of the requirements as a reaction solvent [0032] If those having modest hydrophilicity are select- is higher solubility for dissolving cyclododecanone oxi- ed, it is possible to use middle and higher alcohols, me. When a solubility parameter as defined by the fol- 15 ethers, glymes (polyether obtained by condensing ethyl- lowing equation is used as an index, a solvent having the ene glycol), esters and the like without adding surfactant parameter of 7.5 to 13.0, particularly 8.0 to 12.5 exhibits and the like. high solubility for dissolving cyclododecanone oxime. [0033] As the middle and higher alcohols, preference [0028] Here, a solubility parameter indicates strength is given to monoalcohols having 3 to 12 carbons and of an intermolecular binding force such as hydrogen20 these alcohols are preferred due to their good balance bond, and generally the higher parameter shows the between hydrophilicity and hydrophobicity. They include, higher polarity. Compounds having close solubility pa- for example, 1-propanol, 2-propanol, 1-butanol, 2-buta- rameter values exhibit high compatibility. This parameter nol, isobutyl alcohol, tertiary butyl alcohol, amyl alcohol, can be calculated from ΔHv, a standard boiling point and isoamyl alcohol, hexanol, pentanol, heptanol, octanol, density data, and ΔHv can be estimated from a molecular 25 decanol, dodecanol, cyclohexanol, cyclooctanol, cy- structure. Herein, some solvents were measured for a clododecanol and the like. solubility of cyclododecanone oxime and compared it [0034] As ethers, preference is given to those having with a calculated solubility parameter to determine an a solubility parameter not lower than 7.5 and they include, index. for example, anisole, anethole, allyl ethyl ether, allyl phe- 30 nyl ether, cresol methyl ether, methoxynaphthalene, ethoxynaphthalene and benzofuran. [0035] As glymes (glycol diethers), preferable use is made on them except those having extremely high sol- wherein δ: solubility parameter, ΔHV: evaporation en- ubility with water and they include, for example, thalpy change, R: gas constant, T: absolute temperature, 35 monoglyme, t-butyl glyme, butyl diglyme, triglyme and V: molar volume. tetraglyme. [0029] Solvents which are reactive with cyclododecan- [0036] As esters, preference is given to carboxylate one and/or hydroxylamine must be excluded even if they ester and it includes, for example, methyl acetate, ethyl are good solvent exhibiting high dissolving power to cy- acetate, propyl acetate, hexyl acetate, benzyl acetate, clododecanone oxime. For example, ketones or alde- 40 methyl propionate, ethyl propionate, methyl isovalerate, hydes cannot be used because they react with hydroxy- ethyl isovalerate, methyl isobutyrate, ethyl octanoate, di- lamine to form ketoximes or aldoximes, respectively. Ni- ethyl succinate, dimethyl succinate, diethyl oxalate, die- trile reacts with hydroxylamine to form amidoximes. thyl glutarate, methyl benzoate, ethyl benzoate, diethyl Amides also react with hydroxylamine to form adducts phthalate and dibutyl phthalate. with the hydroxylamine. Furthermore, amines react with 45 [0037] Although alicyclic hydrocarbon, fused-aromat- cyclododecanone to form Schiff bases. These solvents ic-ring hydrogenated-product and aromatic hydrocarbon are excluded, even if they exhibit high solubility for dis- are nonpolar solvent, they are usable and surfactant may solving cyclododecanone oxime. be added as necessary. Since aromatic hydrocarbon, [0030] Usable solvents for oxime formation are those fused-aromatic-ring hydrogenated-product, alicyclic hy- that exhibit high solubility for dissolving cyclododecan- 50 drocarbon having a side chain(s) and the like are also one oxime and are inert to cyclododecanone and/or hy- usable as the rearrangement solvent described later, droxylamine. However, highly hydrophobic solvents lead they are preferred in the respect of simplification of steps. to a slow oxime-formation rate and thus a longer reaction [0038] As the aromatic hydrocarbon, preference is giv- time. On the other hand, highly hydrophilic solvents are en to benzene, toluene, xylene, ethylbenzene, propyl- soluble in an aqueous phase and thus must be recovered 55 benzene, butylbenzene, trimethylbenzene, tetramethyl- from both oil and aqueous phases, which is disadvanta- benzene and cyclohexylbenzene, and particular prefer- geous in the aspects of facilities and energy. For exam- ence is given to benzene, toluene, xylene. As the fused- aromatic-ring hydrogenated-product, preference is given

5 9 EP 2 223 911 B1 10 to tetralin, decalin and dihydronaphthalene, and particu- an oxime-forming reactor to a separator, where the oil lar preference is given to tetralin and decalin. In addition, and the aqueous phases are separated and drained. De- as the alicyclic hydrocarbon, preference is given to ali- pending on the type of the oxime-forming reactor, the oil cyclichydrocarbon having aside chain(s) andpreference phase and the aqueous phase may be drained separately is given to isopropylcyclohexane, methylcyclohexane, 5 from the reactor. When oxime formation is conducted dimethylcyclohexane and ethylcyclohexane, preference using an aqueous solution of hydroxylamine sulfate (hy- is given to isopropylcyclohexane. droxylamine prepared by Rashig method, also called as [0039] In the oxime-formation solvent, the rearrange- ammonium sulfite method, where an aqueous solution ment solvent described later may be present and mixed of ammonium nitrate is reduced by sulfur dioxide in the with the oxime-formation solvent unless it reacts with cy- 10 presence of hydrogen sulfate ions, into hydroxyamide- clododecanone and/or hydroxylamine. N,N-disulfate, which is then hydrolyzed to obtain hydrox- [0040] Although the oxime-forming reaction may be ylamine sulfate) and ammonia water, ammonium sulfate conducted at a high temperature, the reaction at a tem- is obtained as a byproduct from the separated aqueous perature of100 °C or higherrequires a pressurizedvessel phase. This ammonium sulfate is called as oxime am- because hydroxylamine is used as an aqueous solution. 15 monium sulfate, which is purified more easily than am- The reaction is, therefore, preferably conducted at 100 monium sulfate as a byproduct in the rearrangement step °C or lower and under the ambient pressure. On the other described in "BACKGROUND ART" (called as rear- hand, the reaction at a lower temperature leads to reduc- rangement ammonium sulfate) and can be thus sold in tion in a reaction rate. A temperature is, therefore, pref- the market. When hydroxylamine prepared by HPO erably 60 °C or higher, more preferably 75 °C or higher. 20 method wherein hydroxylamine phosphate is prepared [0041] The reaction time of the oxime-forming reaction is used, ammonium sulfate is not formed even in the ox- varies depending on the oxime-formation solvent and its ime-forming step. Furthermore, for the purpose of recov- temperature. However, the time is 0.5 hours to 10 hours, ering the oxime-formation solvent dissolved in the aque- preferably 1 hour to 6 hours in the case of conducting ous phase, the oxime-formation solvent and cyclodo- the reaction using the above-mentioned monoalcohol 25 decanone oxime may be extracted with a hydrophobic having 3 to 12 carbons as the solvent at 75 °C. In the solvent from the aqueous phase. case of shorter reaction time, unreacted hydroxylamine [0044] The subsequent dehydration/solvent prepara- and cyclododecanone would remain. Although the unre- tion step is a step for removing the oxime-formation sol- acted starting materials may be recycled to a step for vent and dissolved water in the solution of cyclododecan- producing the starting materials and the like, a recycling 30 one oxime which has been collected as an oil phase in facility would be required, which is not preferred. In the the oil/aqueous phase separation step, and for convert- case of longer reaction time, it is not preferred because ing the solvent in the cyclododecanone oxime solution equipment for the oxime-forming reaction would become into a solvent system suitable for the subsequent rear- longer and larger. rangement reaction step. The removal of the oxime-for- [0042] An oxime-forming reactor may be a common 35 mation solvent and the dissolved water is conducted by reactorsuch as batch reactor, semi-batch reactor,tubular distillation. The oxime-formation solvent distillate is col- reactor and tank flow reactor, and particularly continuous lected and recycled to the oxime-forming step, and used stirred tank flow reactor (CSTR) is suitable. When CSTR as the solvent of cyclododecanone solution to be sup- is used, an aqueous solution of hydroxylamine is fed to plied to the oxime-formation reaction. Water is also re- a first reactor and a cyclododecanone solution is fed to 40 moved so that the concentration of water content in the the final reactor, and it is desirable that an aqueous phase cyclododecanone oxime solution to be transferred to the is transferred to the latter reactor and an oil phase is rearrangement step becomes 1,000 ppm or less, prefer- transferred to the former reactor sequentially so that re- ably 100 ppm or less. actants are completely reacted without remaining unre- [0045] The rearrangement solvent may be added after acted reactants. 45 removing the oxime-formation solvent (for example, by [0043] In the subsequent oil/aqueous phase separa- means of distillation as described above) or before re- tion step, a reaction mixture after the oxime-forming step moving. In the case of adding the rearrangement solvent is separated into an oil phase and an aqueous phase to before removing the oxime-formation solvent, the rear- obtain the oil phase in which cyclododecanone oxime is rangement solvent has a boiling point higher than that of dissolved. In the step, it is also preferred to add the re- 50 the oxime-formation solvent, and furthermore, when the arrangement solvent (on the premise that it goes into oil rearrangement solvent is hydrophobic, preferably non- phase) and carry out the oil/aqueous phase separation, polar solvent, it may be added to the oxime-formation which will be explained in detail for the dehydration/sol- solvent before the oil/aqueous phase separation. After vent preparation step. The oil phase and the aqueous theoil/aqueous phaseseparation, bymeans of distillation phase can be separated by a commonly used separation 55 the oxime-formation solvent with lower boiling point is method such as standing separation, centrifugation sep- distilled and removed, and at the same time the dissolved aration and cyclone separation, but in an industrial con- water is removed by distillation. In this step, a portion of tinuous process, a reaction mixture is transferred from the rearrangement solvent is distilled away. The solvent

6 11 EP 2 223 911 B1 12 in the cyclododecanone oxime solution as the residue of and includes cyano, trifluoromethyl, trichloromethyl, ni- this step is now substantively the rearrangement solvent, tro, halide (halogen), carbonyl and sulfonyl, preferably and the water concentration in the solution is adjusted to cyano and nitro. be 1,000 ppm or less, preferably 100 ppm or less as [0053] The rearrangement catalyst is trichlorotriazine, described in the foregoing. Then, the solvent as such is 5 which is highly active and inexpensive. transferred to the rearrangement step. [0054] Inaddition, acids such ashydrogen chloride can [0046] When in this way, the rearrangement solvent is be added as a co-catalyst to improve a rearrangement added prior to the oil/aqueous phase separation, the reaction rate. In particular, a Lewis acid is preferable be- oil/aqueous phase separation step overlaps with the de- cause it can improve a rearrangement reaction rate with- hydration/solvent preparation step. 10 out accelerating hydrolysis of cyclododecanone oxime. [0047] The dissolved water is removed by distillation. Examples of a Lewis acid generally include, but not lim- It is preferred to use two or more distillation columns as ited to, zinc chloride, aluminum chloride, antimony pen- necessary. After most of the oxime-formation solvent and tachloride and tin tetrachloride, and preference is given water are distilled away in the first distillation column, to zinc chloride and tin tetrachloride, and particularly pref- residual liquid part is transferred into the second distilla- 15 erably zinc chloride which is significantly effective in im- tion column and the oxime-formation solvent and water, proving a reaction rate. in particular water can be sufficiently removed while a [0055] The rearrangement reaction is carried out in the portion of the rearrangement solvent is distilled away. presence of the solvent. In descriptions above and below, [0048] The dehydrated cyclododecanone oxime solu- the solvent to be used for the rearrangement reaction is tion is transferred to the rearrangement step. In the re- 20 referred to as the rearrangement solvent. In more detail, arrangement step, laurolactam is formed from cyclodo- it is the solvent dissolving cyclododecanone oxime when decanone oxime by a rearrangement reaction using the the cyclododecanone oxime solution is transferred to the aromatic-ring containing compound as a rearrangement rearrangement step. The necessary requirements for the catalyst. rearrangement solvent are (1) it has excellent solubility [0049] An aromatic-ring containing compound used as 25 with cyclododecanone oxime and laurolactam; (2) it dis- a rearrangement catalyst is preferably an organic com- solves the rearrangement catalyst and does not react pound having a structure (1) containing at least one car- with the rearrangement catalyst; and (3) it is readily col- bon atom having a leaving group as a ring member of lected and recycled, and it has high stabilities thermally the aromatic ring and (2) containing at least two carbon and chemically. atoms having an electron-withdrawing group as ring30 [0056] Using the aforementioned solubility parameter members of the aromatic ring, and (3) wherein, three of as an index in respect to the solubility with cyclododecan- the nitrogen atoms and/or the carbon atoms having an one oxime, the solvents with the solubility parameter of electron-withdrawing group, each of which is a ring mem- 7.5 to 13.0, in particular 8.0 to 12.5 are employed, in ber of the aromatic ring, are at the ortho and the para which, however, those reacting with elimination groups positions to the carbon atom having a leaving group de- 35 are excluded. In the case the elimination group is, for scribed in (1). example, a halogen atom, water, alcohols, amines, mer- [0050] Preferable examples of the aromatic ring in- captans, amides and the like cannot be used. clude monocyclic or polycyclic aromatic rings such as [0057] Other solvents than the above excluded sol- benzene, biphenyl, terphenyl and triphenyl; fused poly- vents may be used as the rearrangement reaction without cyclic aromatic rings such as naphthalene, anthracene, 40 problem. Generally a polar solvent is employed to dis- fluorene, phenanthrene, azulene and pyrene; and aro- solve the rearrangement catalyst or the rearrangement matic heterocycles such as pyrrole, furan, thiophene, im- catalyst and a cocatalyst and to raise its acidity after dis- idazole, pyrazole, triazole, tetrazole, oxazole, isoxazole, solving them to increase the reaction rate of the rear- thiazole, isothiazole, furazanpyridine, pyrazine, pyrimi- rangement. In the aforementioned "Patent Reference dine, pyridazine and triazine; particularly preferably, ben- 45 No. 11," for example, nitriles are employed as a solvent. zene, pyridine, pyrimidine and triazine. However, nitriles are not preferred because they are hy- [0051] Examples of a leaving group may include hal- drolyzed to yield a corresponding amide when removing ogen (fluorine, chlorine, bromine and iodine), sulfonyloxy the catalyst, as described later. {aryl sulfonyloxy such as benzenesulfonyloxy and p-tol- [0058] Polar solvent are not preferred because they uenesulfonyloxy(tosyl) OTs; andalkanesulfonyloxy such 50 may react during the removal of catalyst and recovering as methanesulfonyloxy OMs, trifluoromethanesulfony- of solvent due to their higher boiling point and higher loxy (triflate) OTf, trichloromethanesulfonyloxy and reactivity in comparison with nonpolar solvents with the ethanesulfonyloxy and the like}, sulfonyl halide (sulfonyl same number of carbon atoms, leading to a decrease in chloride, sulfonyl bromide and the like), diazonium, and recovering ratio and degradation of quality of laurol- carbonyl halide (carbonyl chloride). Particularly preferred 55 actam. is halogen, especially chlorine. [0059] Therefore, preference is given to nonpolar sol- [0052] An electron-withdrawing group may be any vents as the rearrangement solvent. Nonpolar solvents known electron-withdrawing group without limitations facilitatethe separationand removalof catalyst, and have

7 13 EP 2 223 911 B1 14 no adverse effect on the quality of laurolactam. They are Although it is not strongly recommended that the reaction also preferred because they are recovered by distillation is conducted under an increased pressure, the reaction easily and have little loss in the recovery. Among non- can be conducted in a closed system, whereby a com- polar solvents, preference is given to aromatic hydrocar- ponent eliminated from the catalyst (for example, when bon, fused-aromatic-ring hydrogenated-product and ali- 5 the leaving group is halogen, it is hydrogen halide) is cyclic hydrocarbon (in particular, alicyclic hydrocarbon prevented from diffusing to the outside of the reaction having a side chain(s)). As the aromatic hydrocarbon, system. Employing a closed process is preferable be- preference is given to benzene, toluene, xylene, ethyl- cause a facility for adsorbing or removing the compound benzene, propylbenzene, butylbenzene, trimethylben- originated from the leaving group can be reduced and zene, tetramethylbenzene and cyclohexylbenzene, and 10 the compound originated from the leaving group itself is particular preference is given to benzene, toluene, xy- an acid which can act as a co-catalyst accelerating the lene. As the fused-aromatic-ring hydrogenated-product, rearrangement reaction. preference is given to tetralin, decalin and dihydronaph- [0064] A rearrangement reactor may be a common re- thalene, and particular preference is given to tetralin and actor such as batch reactor, tubular reactor and tank flow decalin. In addition, as the alicyclic hydrocarbon having 15 reactor, and particularly continuous stirred tank flow re- a side chain(s), preference is given to isopropylcyclohex- actor (CSTR) is suitable in the light of easy control of a ane, methylcyclohexane, dimethylcyclohexane and reaction temperature and simple operation. ethylcyclohexane, and particular preference is given to [0065] The subsequent separation/purification step is isopropylcyclohexane. a step for separating and removing the rearrangement [0060] The amount of the rearrangement catalyst var- 20 solvent and the rearrangement catalyst from the reaction ies depending on the water content in the cyclododecan- mixture after the rearrangement step to obtain purified one oxime, and is 0.01 mol% to 20 mol%, preferably 0.1 laurolactam. mol% to 5 mol% to cyclododecanone oxime. If the [0066] First, there are a distillation method and a amount of the catalyst is too small, a rearrangement rate quench method of adding water or alkali, as the method is so slow that the unreacted cyclododecanone oxime 25 for separating and removing the catalyst and cocatalyst may unfavorably remain. In contrast, the excessive from the reaction liquid. When the liberated catalyst and amount of the catalyst increases a catalyst cost, and un- cocatalyst have a lower boiling point than that of laurol- favorably increases costs for post-treatment (i.e. remov- actam, they may collected by distillation under reduced al) or recycling of the catalyst. The amount of the co- pressure and recycled to the rearrangement step; how- catalyst is 0.1 to 10 molar amount, preferably 0.5 to 5 30 ever, preference is given to the quench removal after molar amount to the catalyst. A too small amount of the completion of the rearrangement because even a trace co-catalyst is less effective in improving a rearrangement amount of the catalyst contaminating laurolactam would rate while an excessive amount of the co-catalyst cannot degrade its quality. In the case of the quench by adding further improve a rearrangement rate. water, the leaving group of the catalyst is replaced by [0061] A reaction temperature in the rearrangement 35 hydroxyl group and the catalyst migrates into aqueous- step is 50 °C to 160 °C, preferably 80 °C to 110 °C. A phase side. For example, trichlorotriazine turns into cy- too low reaction temperature is unfavorable because a anuric acid and dissolves in an aqueous-phase. Since reaction rate is reduced, leading to a longer reaction time. the acids used for the cocatalyst are also soluble in water, At a low temperature, cyclododecanone oxime is less they can be removed by washing with water. To facilitate soluble in the rearrangement solvent and the amount of 40 the removal of the catalyst, use of an alkali aqueous so- the solvent to be recovered or recycled is increased. On lution such as aqueous ammonia and aqueous sodium the other hand, a too high reaction temperature is unfa- hydroxide may be used. vorable because heat generated in the exothermic rear- [0067] Further purification of laurolactam typically in- rangement reaction may cause rapid increase in a tem- volves distillation operations (including obtaining a prod- perature to the extent that the reaction cannot be con- 45 uct as a distillate, obtaining a product as a still-bottom trolled. Furthermore, a too high reaction temperature un- product, rectification and so forth), which are preferably favorably leads to decrease in a rearrangement yield and combined as a multistage procedure. Since the rear- deterioration in product quality such as coloration prob- rangement solvent generally has a lower boiling temper- lem. ature than laurolactam, the remained still residue (still- [0062] A reaction time of the rearrangement step is 5 50 bottom product) after recovering the rearrangement sol- min to 10 hours, preferably 20 min to 4 hours. A reaction vent by distillation can be drained and distilled one or time varies depending on the type a catalyst, a catalyst more times to be purified. concentration and a reaction temperature, but the above [0068] There are no particular restrictions to the distil- reaction conditions are adjusted such that the reaction lation conditions and a distillation apparatus in the sep- can be easily controlled and a very large reactor volume 55 aration/purification step, but for preventing ring opening is not required. or polymerization of laurolactam, it is desirable that vac- [0063] The reaction can be conducted under a reduced uum distillation is conducted at a vacuum of 10 torr or pressure, an ambient pressure or an increased pressure. less such that a bottom temperature is 250 °C or lower,

8 15 EP 2 223 911 B1 16 preferably 220 °C or lower. lected by a counter flow extraction, and they were trans- [0069] As is clear from the above descriptions, each ferred to the dehydration/solvent preparation step. step in the production process of the present invention [0072] Theaqueous phase,from which2-propanol and may be a combination of two or more substeps, or, if cyclododecanone oxime were collected, was concentrat- possible, two or more steps may be conducted in the 5 ed and after the precipitated ammonium sulfate was col- same apparatus or carried out simultaneously. Although lected, it was disposed of as waste water. the present invention is preferably utilized in a continuous production process, for example, as in an industrial proc- (Dehydration/solvent preparation step) ess, some or all steps may be independently conducted. 10 [0073] This step is composed of two distillation equip- EXAMPLES ments. Cyclododecanone oxime obtained in the oil/aqueous phase separation step was transferred into the first [0070] Then, the present invention will be specifically distillation equipment, and 2-propanol and dissolved wa- explained by illustrating examples. The present exam- ter were distilled away. Distillate was recycled to the ox- ples intend to show an example of embodiments of the 15 ime-forming stepas the solventof cyclododecanone.The present invention, and the present invention is not limited residual liquid (still residue) in the first distillation equip- by the present examples. In addition, the process flows ment was transferred into the second distillation equip- of Examples 1 to 4, i.e., in the case that the oxime-for- ment, and a small amount of toluene containing water mation solvent differs from the rearrangement solvent, and 2-propanol was distilled out from the top of column are shown in Figure 1, and the process flow of Example 20 and was recycled to the first distillation equipment. As a 5, i.e., in the case that the oxime-formation solvent is result of analyzing the residual liquid by means of gas identical with the rearrangement solvent, is shown in Fig- chromatography, 2-propanol was not detected. As a re- ure 2. sult of measuring the concentration of water by Karl Fischer method, it was also found to be 50 ppm. The [Example 1] 25 residual liquid was fed to the rearrangement step.

(Oxime-forming and oil/aqueous phase separation (Rearrangement step) steps) [0074] Into a pillow type reactor with a 10 L liquid phase [0071] Into a pillow type first reactor for oxime-forma- 30 zone which was internally divided into three chambers tion with a 30 L liquid phase zone which was internally each of which was equipped with an agitating blade were divided into four chambers each of which was equipped fed the toluene solution of cyclododecanone oxime ob- with an agitating blade were fed a 15 % by weight aque- tained in the previous step and 3 % by weight solution of ous solution of hydroxylamine sulfate (Wako Pure Chem- trichlorotriazine in toluene were fed at 2,700 g/h and ical Industries, Ltd.) at 3 kg/h and the oil phase from a 35 1,000g/h, respectively, and the rearrangement reaction second reactor for oxime-formation. The reaction tem- was carried out at 90 °C (average residence time: 1.9 perature was set at 80 °C and 25 % by weight of aqueous hours). As a result of collecting a portion of outflow fluid ammonia was fed into each chamber at 63 g/h to carry and analyzing it by means of gas chromatography, the out the oxime formation reaction. The reaction mixture yield amount of laurolactam was found to be 1,039 g/h was separated into phases of liquid after toluene was 40 and the yield of laurolactam on the basis of cyclodo- added at 1 kg/h, and the oil phase composed of cyclododecanone was found to be 96.2 %. decanone, 2-propanol and toluene was transferred to the dehydration/solvent preparation step while the aqueous (Catalyst removal step) phase was fed into the second rector for oxime formation. The second rector for oxime formation was a 15 L pillow 45 [0075] The reaction mixture obtained in the rearrange- type rector which was internally divided into four cham- ment step was introduced to a stirred-tank-type washing bers, and to the second reactor were fed the above aque- tank, and washed with the water that was added in an ous phase of the oxime-formation reaction mixture and amount of 0.2 times (ratio by weight) of the rearrange- 25 % by weight of cyclododecanone in 2-propanol solu- ment liquid and separated into phases, further washed tion at 4 kg/h (equimolar amount to hydroxylamine sulfate 50 with 10 % by weight of aqueous sodium hydroxide that fed to the first reactor), the reaction temperature was set was added in an amount of 0.5 times (ratio by weight) at 80 °C and 25 % by weight of aqueous ammonia was and the oil/aqueous phase separation was carried out. fed into each chamber at 31 g/h to carry out the oxime formation reaction. The obtained reaction mixture was (Cyclododecanone collection and laurolactam purifica- separated into phases of liquid, and the oil phase was 55 tion steps) fed into the first reactor for oxime formation. To the aqueous phase, toluene was added at 650 g/h and 2-propanol [0076] The separated oil phase was introduced to a and cyclododecanone oxime dissolved in water were col- continuous vacuum distillation equipment, and water,

9 17 EP 2 223 911 B1 18 light by-products and toluene of solvent were first re- laurolactam after the rearrangement reaction was 96.5 moved. Residue in the tank was introduced to the second %, yield of laurolactam after distillation was 95.0 % and distillation equipment, and laurolactam was distilled out. its purity was 99.8% Residue in the tank was led to the third distillation equipment anddistillate consisting oflaurolactam was recycled 5 [Example 5] (Reference example) to the second distillation equipment, and a part of the residue in the tank was cut off and its major part was [0081] The oxime-formation was carried out not using recycled to the catalyst removal step. A continuous op- alcohol as the oxime-formation solvent but with toluene eration was conducted for 8 hours to obtain laurolactam as the solvent. The feeding rates of the toluene solution with purity of 99.5 %. Its yield against consumed cyclodo- 10 of cyclododecanone, the aqueous solution of hydroxy- decanone was 94.5 % by mole. lamine sulfate and aqueous ammonia were all half amount of Example 2, and the reaction temperature was [Example 2] 95 °C. After the completion of the reaction, the dissolved water in the solution was removed by extracting toluene [0077] The reaction was carried out in a similar manner 15 at a distillation rate of about 650 g/h. The concentration to Example 1 except that the feeding rate of 3 % by weight of water after the dehydration was 50 ppm, and the re- solution of trichlorotriazine in toluene at the rearrange- sidual ratio of cyclododecanone was 1.0 % by mole. The ment step was changed to 330 g/h, and additionally 10 feeding rates to a rearrangement reaction tank of the % by weight of zinc chloride in toluene/laurolactam so- cyclododecanone oxime solution, trichlorotriazine solu- lution (the ratio of toluene/laurolactam is20 tion 1/1 and zinc chloride solution were all half amount of (weight/weight)) was fed at 75 g/h. The yield of laurol- Example 2, and the rearrangement reaction was carried actam until the rearrangement step was 97.5 %, yield of out and washing with water and washing with aqueous laurolactam after distillation was 96.0 % and its purity sodium hydroxide were carried out. The yield of laurol- was 99.98 %. actam after the rearrangement reaction was 95.1 %, yield 25 of laurolactam after distillation was 94.0 % and its purity [Example 3] was 99.3 %.

[0078] After the oxime-formation reaction was carried [Comparative example 1] out in a similar manner to Example 1 except that the feeding rates of cyclododecanone/(2-propanol, toluene) 30 [0082] The reaction was carried out in a similar manner solution, hydroxylamine aqueous solution and aqueous to Example 1 except that the rearrangement solvent was ammonia at the oxime-forming step was doubled and the replaced with benzonitrile. As the passage of operation reaction temperature was 95 °C, the dehydration and sol- time benzamidoxime was detected which was generated vent replacement were carried out. While unreacted cy- by reaction of benzonitrile contained in the recycled liquid clododecanone was not detected in the residual liquid 35 to the oxime-forming step with hydroxylamine. As this after the solvent replacement, 90 ppm of water and 50 progress, an amount of cyclododecanone increased due ppm of 2-propanol were detected. to a shortage of hydroxylamine to be used for the oxime- [0079] The reaction was carried out in a similar manner formation reaction. Although the yield of laurolactam until to Example 2 except that the feeding rates of the cyclodo- the rearrangement step was initially 96.0 %, the yield decanone oxime solution obtained in the solvent replace- 40 declined to 82 % as a result of the operation after 8 hours. ment step, trichlorotriazine solution and the zinc chloride In addition, benzonitrile was hydrolyzed to yield benza- solution was doubled and the reaction temperature was mide and the like during the treatment with sodium hy- 100 °C. After washing with water and aqueous sodium droxide, and the purity of laurolactam obtained by distil- hydroxide each in an amount of twice of Example 2, dis- lation was 85 %. tillation and purification were carried out. The yield of45 laurolactam until the rearrangement step was 97.0 %, [Comparative example 2] yield of laurolactam after distillation was 95.8 % and its purity was 99.85 %. [0083] The reaction was carried out in a similar manner to Example 2 except that the rearrangement solvent and [Example 4] 50 the solvent dissolving trichlorotriazine and zinc chloride were 1-methyl-2-pyrrolidone. As a result of collecting the [0080] The reaction was carried out in a similar manner rearrangement reaction mixture and carrying out gas to Example 2 except that toluene in the Example 2 was chromatographic analysis, the yield of laurolactam was replaced with isopropylcyclohexane and 2-propanol was 27.2% and 70 % of cyclododecanone oxime remained. replaced with 2-methyl-2-propanol. While unreacted cy- 55 Even though the feeding rates of the solution of cyclodo- clododecanone was not detected in the residual liquid decanone oxime and the solution of trichlorotriazine and after the solvent replacement, 90 ppm of water and 40 zinc chloride were reduced half, and their residence time ppm of 2-methyl-2-propanol were detected. The yield of was prolong by twice, the conversion ratio of cyclodo-

10 19 EP 2 223 911 B1 20 decanone oxime was not improved. one oxime by rearrangement reaction using trichlorotriazine as a rearrangement catalyst [Comparative example 3] (hereinafter, referred to as a "rearrangement step"); and [0084] The reaction was carried out in a similar manner 5 (e) separating and removing the rearrangement to Example 1 except that merely one column of distillation solvent and the rearrangement catalyst from the for the dehydration/solvent preparation step was em- reaction mixture obtained after the rearrange- ployed. In the cyclododecanone oxime solution to be ment step, and purifying the laurolactam (here- transferred to the rearrangement step, 1,500 ppm of wa- inafter, referred to as a "separation/purification ter existed and hydrolysis of cyclododecanone oxime oc- 10 step"). curred during the rearrangement step to yield cyclododecanone. The yields until the rearrangement step were 2. The process for producing laurolactam according to 90 % for laurolactam and 6 % for cyclododecanone. Claim 1, wherein in the dehydration/solvent preparation step, a content of residual water in the cyclodo- INDUSTRIAL APPLICABILITY 15 decanone oxime solution to be fed to the rearrangement step is reduced to 100 ppm or less. [0085] An industrially advantageous and simple process for laurolactam is provided. 3. The process for producing laurolactam according to any one of Claims 1 or 2, wherein the rearrangement 20 solvent is a nonpolar solvent. Claims 4. The process for producing laurolactam according to 1. A process for producing laurolactam comprising the Claim 3, wherein the rearrangement solvent is one steps of: or more solvents selected from the group consisting 25 of alicyclic hydrocarbon, aromatic hydrocarbon and (a) reacting cyclododecanone with hydroxy- fused-aromatic-ring hydrogenated-product. lamine in an aqueous solution in the presence of an organic solvent (hereinafter, referred to as 5. The process for producing laurolactam according to "oxime-formation solvent") to produce cyclodo- Claim 3 or 4, wherein prior to the oil/aqueous phase decanone oxime (hereinafter, referred to as an 30 separation step, the rearrangement solvent is add- "oxime-forming step"); ed. (b) separating the reaction mixture obtained after the oxime-forming step into an oil and an aqueous phases and collecting a solution of cy- Patentansprüche clododecanone oxime of the oil phase (herein- 35 after, referred to as an "oil/aqueous phase sep- 1. Verfahrenzur Herstellungvon Laurolactam, welches aration step"); die Schritte aufweist, dass man (c) removing the oxime-formation solvent and dissolved water by distillation from the solution (a) Cyclododecanon mit Hydroxylamin in einer of cyclododecanone oxime which is collected as 40 wässrigen Lösung in Gegenwart eines organi- an oil phase in the oil/aqueous phase separation schen Lösungsmittels (im Folgenden als "Oxim- step, whereby preparing a dehydrated cyclodo- bildungslösungsmittel" bezeichnet) zur Herstel- decanone oxime solution containing a solvent lung von Cyclododecanonoxim (im Folgenden to be used in a rearrangement reaction in the als "Oximbildungsschritt" bezeichnet) umsetzt; rearrangement step (hereinafter, referred to as 45 (b) die nach dem Oximbildungsschritt erhaltene "rearrangement solvent") and the cyclodo- Reaktionsmischung in eine Öl- und eine wäss- decanone oxime rige Phase auftrennt und eine Lösung des Cyc- wherein the rearrangement solvent has a boiling lododecanonoxims (im Folgenden als "Öl/wäss- point higher than the boiling point of the oxime- rige Phase-Separationsschritt" bezeichnet) formation solvent, 50 sammelt; a portion of the rearrangement solvent is re- (c) dasOximbildungslösungsmittel und gelöstes moved by the distillation, and Wasser durch Destillation aus der Lösung des wherein a content of residual water in the dehy- Cyclododecanonoxims entfernt, welches als Öl- drated cyclododecanone oxime solution to be phase im Öl/wässrige Phase-Separationsschritt fedto the rearrangementstep isreduced to 1000 55 gesammelt wird, wodurch man eine entwässer- ppm or less (hereinafter, referred to as a "dehy- te Cyclododecanonoximlösung herstellt, die ein dration/solvent preparation step"); Lösungsmittel enthält, das in einer Umlage- (d) producing laurolactam from cyclododecan- rungsreaktion im Umlagerungsschritt (im Fol-

11 21 EP 2 223 911 B1 22

genden als "Umlagerungslösungsmittel" be- de l’hydroxylamine dans une solution aqueuse zeichnet") einzusetzen ist, und das Cyclodode- en présence d’un solvant organique (ci-après, canonoxim, désigné par « solvant de formation d’oxime ») wobei das Umlagerungslösungsmittel einen hö- pour produire de l’oxime de la cyclododécanone heren Siedepunkt hat als den Siedepunkt des 5 (ci-après, désignée par « étape de formation Oximbildungslösungsmittels, d’oxime ») ; ein Anteil des Umlagerungslösungsmittels (b) séparation du mélange de réaction obtenu durch Destillation entfernt wird, und aprèsl’étape de formationd’oxime en une phase wobei der Restwassergehalt in der entwässer- huileuse et une phase aqueuse et recueil d’une ten Cyclododecanonoximlösung, welche in den 10 solution d’oxime de la cyclododécanone de la Umlagerungsschritt eingespeist werden soll, phase huileuse (ci-après, désignée par « étape auf 1000 ppm oder weniger verringert wird (im de séparation de phase huileuse/aqueuse ») ; Folgenden als "Entwässerungs- (c) élimination du solvant de formation d’oxime Lösungsmittelherstellungsschritt" bezeichnet); et de l’eau dissoute par distillation de la solution (d) Laurolactam aus Cyclododecanonoxim15 d’oxime de la cyclododécanone qui est recueillie durch Umlagerungsreaktion unter Verwendung sous forme de phase huileuse à l’étape de sé- von Trichlortriazin als Umlagerungskatalysator paration de phase huileuse/aqueuse, préparant (im Folgenden als "Umlagerungsschritt" be- ainsi une solution d’oxime de la cyclododécano- zeichnet) herstellt; und ne déshydratée contenant un solvant à utiliser (e) das Umlagerungslösungsmittel und den Um- 20 dans une réaction de réarrangement à l’étape lagerungskatalysator aus der Reaktionsmi- de réarrangement (ci-après, désigné par schung abtrennt und entfernt, die nach dem Um- « solvant de réarrangement ») et l’oxime de la lagerungsschritt erhalten wurde, und das Lau- cyclododécanone dans lequel le solvant de réar- rolactam aufreinigt (im Folgenden als rangement a un point d’ébullition supérieur au "Trenn/Reinigungsschritt" bezeichnet). 25 point d’ébullition du solvant de formation d’oxime, 2. Verfahren zurHerstellung von Laurolactam nach An- une portion du solvant de réarrangement est éli- spruch 1, wobei im Entwässerungs-Lösungsmittel- minée par la distillation, et herstellschritt, der Restwassergehalt in der Cyclo- dans lequel une teneur en eau résiduelle dans dodecanonoximlösung, die in den Umlagerungs-30 la solution d’oxime de la cyclododécanone dés- schritt einzuspeisen ist, auf 100 ppm oder weniger hydratée à apporter à l’étape de réarrangement reduziert wird. est réduite à 1 000 ppm ou moins (ci-après, dé- signée par « étape de préparation de 3. Verfahren zur Herstellung von Laurolactam nach ei- solvant/déshydratation ») ; nem der Ansprüche 1 oder 2, wobei das Umlage- 35 (d) production de laurolactame à partir d’oxime rungslösungsmittel ein nicht-polares Lösungsmittel de la cyclododécanone par réaction de réarran- ist. gement à l’aide de trichlorotriazine en tant que catalyseur de réarrangement (ci-après, dési- 4. Verfahren zurHerstellung von Laurolactam nach An- gnée par « étape de réarrangement ») ; et spruch 3, wobei das Umlagerungslösungsmittel ein 40 (e) séparation et élimination du solvant de réar- oder mehr Lösungsmittel ist, ausgewählt aus der rangement et du catalyseur de réarrangement Gruppe bestehend aus alicyclischen Kohlenwasser- du mélange de réaction obtenu après l’étape de stoffen, aromatischen Kohlenwasserstoffen und hy- réarrangement, et purification du laurolactame drogenierten kondensierten aromatischen Ringpro- (ci-après, désignée par « étape de dukten. 45 séparation/purification »).

5. Verfahren zur Herstellung von Laurolactam nach ei- 2. Procédé de production de laurolactame selon la re- nem der Ansprüche 3 oder 4, wobei das Umlage- vendication 1, dans lequel à l’étape de préparation rungslösungsmittel vor dem Öl/wässrige Phase-Se- de solvant/déshydratation, une teneur en eau rési- parationsschritt zugefügt wird. 50 duelle dans la solution d’oxime de la cyclododéca- none à apporter à l’étape de réarrangement est ré- duite à 100 ppm ou moins. Revendications 3. Procédé de production de laurolactame selon l’une 1. Procédé de production de laurolactame comprenant 55 quelconque des revendications 1 ou 2, dans lequel les étapes de : le solvant de réarrangement est un solvant non po- laire. (a) mise en réaction de cyclododécanone avec

12 23 EP 2 223 911 B1 24

4. Procédé de production de laurolactame selon la re- vendication 3, dans lequel le solvant de réarrange- ment est un ou plusieurs solvants choisis dans le groupe consistant en un hydrocarbure alicyclique, un hydrocarbure aromatique et un produit hydrogé- 5 né à cycle aromatique fusionné.

5. Procédé de production de laurolactame selon la re- vendication 3 ou 4, dans lequel avant l’étape de sé- paration de phase huileuse/aqueuse, le solvant de 10 réarrangement est ajouté.

13 EP 2 223 911 B1

14 EP 2 223 911 B1

15 EP 2 223 911 B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• JP S52033118 B [0011] • JP H09301952 B [0011] • JP 52033118 A [0011] • JP 9301952 A [0011] • JP H054964 B [0011] • JP 2001019670 A [0011] • JP 5004964 A [0011] • JP S4623740 B [0011] • JP 2001302602 A [0011] • JP 46023740 A [0011] • JP 2001302603 A [0011] • JP S4718114 B [0011] • JP 2001072658 A [0011] • JP 47018114 A [0011] • JP H09301951 B [0011] • JP 2006219470 A [0011] • JP 9301951 A [0011]

Non-patent literature cited in the description

• K. NARASAKA. Chemistry Letter, 1993, 489-492 • K. ISHIHARA. Journal of American Chemical Soci- [0011] aty, 2005, 11240-11241 [0011] • J. S. SANDHU. Indian Journal of Chemistry, 2002, • M. ZHU. Tetrahedron Letters, 2006, 4861-4863 154-156 [0011] [0011] • J. S. YADAV. Journal of Chemical Research(S), 2002, 236-238 [0011]