US 20090292100A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2009/0292100 A1 Fiene et al. (43) Pub. Date: Nov. 26, 2009 (54) PROCESS FOR PREPARING (86). PCT No.: PCT/EP07/57646 PENTAMETHYLENE 1.5-DIISOCYANATE S371 (c)(1), (75) Inventors: Martin Fiene, Niederkirchen (DE): (2), (4) Date: Jan. 9, 2009 (DE);Eckhard Wolfgang Stroefer, Siegel, Mannheim (30) Foreign ApplicationO O Priority Data Limburgerhof (DE); Stephan Aug. 1, 2006 (EP) .................................. O61182.56.4 Freyer, Neustadt (DE); Oskar Zelder, Speyer (DE); Gerhard Publication Classification Schulz, Bad Duerkheim (DE) (51) Int. Cl. Correspondence Address: CSG 18/00 (2006.01) OBLON, SPIVAK, MCCLELLAND MAIER & CD7C 263/2 (2006.01) NEUSTADT, L.L.P. CI2P I3/00 (2006.01) 194O DUKE STREET CD7C 263/10 (2006.01) ALEXANDRIA, VA 22314 (US) (52) U.S. Cl. ........... 528/85; 560/348; 435/128; 560/347; 560/355 (73) Assignee: BASFSE, LUDWIGSHAFEN (DE) (57) ABSTRACT (21) Appl. No.: 12/373,088 The present invention relates to a process for preparing pen tamethylene 1,5-diisocyanate, to pentamethylene 1,5-diiso (22) PCT Filed: Jul. 25, 2007 cyanate prepared in this way and to the use thereof. US 2009/0292100 A1 Nov. 26, 2009 PROCESS FOR PREPARING ene diisocyanates, especially pentamethylene 1,4-diisocyan PENTAMETHYLENE 1.5-DIISOCYANATE ate. Depending on its preparation, this proportion may be up to several % by weight. 0014. The pentamethylene 1,5-diisocyanate prepared in 0001. The present invention relates to a process for pre accordance with the invention has, in contrast, a proportion of paring pentamethylene 1,5-diisocyanate, to pentamethylene the branched pentamethylene diisocyanate isomers of in each 1.5-diisocyanate prepared in this way and to the use thereof. case less than 100 ppm. 0002 The preparation of pentamethylene diisocyanate 0015 The present process therefore further provides a from 1.5-pentanediamine is known perse and can be effected mixture consisting of at least two different pentamethylene without phosgene (T. Lesiak, K. Seyda, Journal für Praktische diisocyanate isomers, of which the main constituent is pen Chemie (Leipzig), 1979,321 (1), 161-163) or by reaction with tamethylene 1,5-diisocyanate, and the isomer present in phosgene (e.g. DE 2625075). Smaller amounts is present in amounts of not more than 100 0003. DE 1900514 (corresponding to GB 1225450) ppm, with the proviso that the sum is 100% by weight. describes the two-stage preparation of pentamethylene 1.5- 0016. The present process further provides a mixture con diisocyanate from caprolactam by conversion to the hydrox sisting of pentamethylene 1,5-diisocyanate and pentamethyl amic acids and the Subsequent phosgenation thereof. ene 1,4-diisocyanate, where the proportion of pentamethyl 0004. The yield reported in this document for the conver ene 1,4-diisocyanate amounts to not more than 10 000 ppm, sion of caprolactam to pentamethylene 1,5-diisocyanate is preferably 7500 ppm, more preferably 5000 ppm, even more only approx. 32%. preferably 2500 ppm, in particular 1000 ppm, especially 500 0005 Caprolactam is prepared on the industrial scale ppm and even 100 ppm, and the proportion of pentamethylene either in several stages from benzene by ring hydrogenation 1,5-diisocyanate makes up the remainder to 100% by weight. to cyclohexane, oxidation to cyclohexanone and Beckmann 0017 Consequently, the pentamethylene 1,5-diisocyanate rearrangement with hydroxylamine, or from 1,4-butadiene by prepared in accordance with the invention has virtually exclu hydrocyanation and selective hydrogenation and Subsequent sively two primary isocyanate groups and therefore exhibits a cyclization to the caprolactam. In both cases, the basis is a more homogeneous reactivity in conversions of the isocyan hydrocarbon from petrochemistry. ate groups, for example in the preparation of polyurethanes. 0006. This is therefore a petrochemistry-based prepara Branched pentamethylene diisocyanate isomers, in contrast, tion over five stages in each case, proceeding from benzene or have one primary and one secondary isocyanate group, which from butadiene. are of different reactivity. 0007. The preparation of 1,5-pentanediamine is known by 0018. The pentamethylene 1,5-diisocyanate obtained by enzymatic decarboxylation of lysine with, for example, the process according to the invention generally has a color lysine decarboxylase (EP 1482055A1 or JP 2004-222569A) number of not more than 15 APHA to DIN ISO 6271. in a cell-free system or by thermal or catalytic decarboxyla 0019. The inventive step b) consists of a conversion of tion (G. Gautret de la Moriciere, G. Chatelus, Bull. Soc. lysine to 1.5-pentanediamine. Chim. France, 1969, 12, 4421-4425) or by hydrogenation of 0020 Lysine can be used in pure form or can actually be the corresponding nitriles (for example EP 161419 or WO formed in the course of the reaction (see below for step a)). In 2003/99768). addition, lysine can in the form of an aqueous solution, buffer 0008 1.5-Pentanediamine has to date not been available Solution or in the form of alysine-containing reaction mixture on the industrial scale. with alysine content of preferably from at least 5% by weight 0009 WO 2006/005603 describes a biochemical process up to the solubility limit in the particular reaction mixture at for preparing 1,4-butanediamine from ornithine with the aid the particular temperatures. In general, the content may be up of ornithine decarboxylase and the use thereof as a starting to 45% by weight, preferably up to 40, more preferably up to compound for polyamide preparation. 35 and most preferably up to 30% by weight. 0010. It was an object of the present invention to prepare 0021. The lysine (2,6-diaminohexanoic acid) used for the pentamethylene 1,5-diisocyanate which can be prepared process according to the invention originates from preferably from renewable raw materials. biological material and may be present in the form of the D 0011. This object is achieved by a process for preparing enantiomer, in the form of the Lenantiomer or in the form of pentamethylene 1,5-diisocyanate, in which any mixture of these enantiomers, for example in the form of b) lysine is converted to 1.5-pentanediamine and a racemate, preferably in the form of the Lenantiomer (S)- c) the 1.5-pentanediamine thus obtained is converted to pen 2,6-diaminohexanoic acid. tamethylene 1,5-diisocyanate. 0022. It can be used infree form or as an internal salt, in the 0012. The advantage of the process according to the inven form of its anion as a carboxylate, or mono- or diprotonated in tion is based on independence from mineral oil as the raw the form of its mono- or diammonium salt, for example as the material basis in the preparation of the pentamethylene 1.5- chloride. diisocyanate. In addition, the pentamethylene 1,5-diisocyan 0023. In addition, the lysine can be used in the form of its ate prepared in this way has less color than that prepared ester, for example as the methyl, ethyl, n-propyl, isopropyl. conventionally, since it is subjected to less thermal stress. n-butyl, sec-butyl or isobutyl ester. 0013. As a result of the inventive selection of the raw 0024 Step b) is preferably a decarboxylation. material basis of lysine or renewable raw materials, the pro 0025. In one possible decarboxylation, lysine, if appropri cess according to the invention affords at least virtually iso ate dissolved or Suspended in a solvent, is heated at a tem merically pure pentamethylene 1,5-diisocyanate, whereas the perature above 80°C., preferably above 100° C., more pref pentamethylene 1,5-diisocyanate prepared by the conven erably above 120° C., even more preferably above 150° C. tional route comprises a proportion of isomeric pentamethyl and in particular above 180° C. (thermal decarboxylation). US 2009/0292100 A1 Nov. 26, 2009 0026. The temperature may be up to 250°C., preferably up metal oxides, hydroxides, carbonates or hydrogencarbonates, to 23.0°C., more preferably up to 210°C. and most preferably preferably sodium hydroxide solution, potassium hydroxide up to 200° C. Solution, sodium hydrogencarbonate, Sodium carbonate, 0027. If appropriate, pressure can be applied in order to potassium hydrogencarbonate, calcium hydroxide, milk of keep any solvent present in the reaction mixture. lime or potassium carbonate (catalytic decarboxylation). 0028. Examples of solvents are aromatic and/or (cyclo) 0040 Especially when lysine is used in the form of an aliphatic hydrocarbons and mixtures thereof, halogenated ester, preferably of the methyl ester, performance of the reac hydrocarbons, esters, ethers and alcohols. tion as a dealkoxycarbonylation under so-called “Krapcho' 0029 Preference is given to aromatic hydrocarbons, (cy conditions is preferred, in which case a nucleophile, prefer clo)aliphatic hydrocarbons, alkyl alkanoates, alkoxylated ably an iodide or bromide, more preferably an iodide, is added alkyl alkanoates and mixtures thereof. to the reaction mixture which is heated under these reaction 0030 Particular preference is given to mono- or polyalky conditions. lated benzenes and naphthalenes, alkyl alkanoates and 0041. However, particular preference is given to perform alkoxylated alkyl alkanoates, and mixtures thereof. ing the decarboxylation with the aid of an enzyme. 0031 Preferred aromatic hydrocarbon mixtures are those 0042. The enzymes are preferably lyases (E.C. 4.--...-), which comprise predominantly aromatic C7- to C-hydro more preferably carbon-carbon lyases (E.C. 4.1.-...-) and most carbons and may comprise a boiling range of from 110 to preferably carboxy lyases (E.C. 4.1.1.-) 300° C.; particular preference is given to toluene, o-, m- or 0043. Examples Thereof are: p-Xylene, trimethylbenzene isomers, tetramethylbenzene iso EC 4.1.1.1 pyruvate decarboxylase mers, ethylbenzene, cumene, tetrahydronaphthalene and EC 4.1.1.2 oxalate decarboxylase mixtures comprising them. EC 4.1.1.3 oxaloacetate decarboxylase 0032 Examples thereof are the Solvesso(R) brands from EC 4.1.1.4 acetoacetate decarboxylase ExxonMobil Chemical, particularly Solvesso(R) 100 (CAS EC 4.1.1.5 acetolactate decarboxylase No.