WO2011110349A2

WO2011110349A2 - Process for the preparation of dicarboxylic acids or dicarboxylic acid esters by metathesis

Info

Publication number: WO2011110349A2
Application number: PCT/EP2011/001187
Authority: WO
Inventors: Alfred Westfechtel; Arno Behr; Jessica PÉREZ GOMES
Original assignee: Emery Oleochemicals Gmbh
Priority date: 2010-03-10
Filing date: 2011-03-10
Publication date: 2011-09-15
Also published as: DE102010010984A1; WO2011110349A3

Abstract

The present invention relates to a process for the preparation of dicarboxylic acids or dicarboxylic acid esters comprising the following process steps: A1 provision of at least the following reactants: a1 - a first aliphatic compound having 5 to 40 carbon atoms with in each case at least one functional group of the general formula (I) and (II), wherein R¹ is a saturated or unsaturated aliphatic group having 2 to 20, preferably 4 to 16 and particularly preferably 6 to 12 carbon atoms and R² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms formula (I) and (II) and a2 at least one further aliphatic compound which differs from the first aliphatic compound, chosen from the group consisting of a2a a compound of the general formula (III) in which n is chosen from 1, 2, 3, 4 and 5; a2b a compound of the general formula (IV) in which R³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms and R⁴ and R⁵ independently of each other are a saturated alkylene group having 1 to 14 carbon atoms, preferably having 1 to 10 carbon atoms and very particularly preferably 1 to 5 carbon atoms; A2 provision of at least one organometallic catalyst based on ruthenium; A3 bringing into contact of the reactants and the catalyst to obtain a product mixture and the catalyst; A4 separating off of the catalyst; A5 optionally division of the product mixture into products P_i, i being a natural number, and the reactants which remain; the process being a metathesis reaction, and the dicarboxylic acid obtainable therefrom and the dicarboxylic acid ester obtainable therefrom, a process for the preparation of a polymer and the polymer obtainable by this process.

Description

PROCESS FOR THE PREPARATION OF DICARBOXYLIC ACIDS

OR DICARBOXYLIC ACID ESTERS BY METATHESIS

The present invention relates to a process for the preparation of dicarboxylic acids and dicarboxylic acid esters, the dicarboxylic acid obtainable therefrom and the dicarboxylic acid ester obtainable therefrom, a process for the preparation of a polymer and the polymer obtainable by this process.

The availability of fossil organic raw materials both as a source of energy and for the preparation of organochemical starting materials is decreasing. The so-called "renewable raw materials", which have already gained considerably in importance in the chemical industry in the last decades, in particular fats and oils of plant or animal origin, form a suitable alternative. These so-called oleochemicals are prepared from regeneratable sources. They in general furthermore have the advantage of a good biodegradability and are moreover neutral in their carbon dioxide balance.

Fatty acid derivatives are conventionally prepared via a transesterification of natural fats and oils (glycerol esters of fatty acids) with low molecular weight alcohol. Although more than 95 % of all chemical reactions of fatty acid esters, e.g. the reaction of fatty alcohols and fatty amines, proceed on the carboxyl functionality, reactions can also take place at the carbon-carbon double bonds. There may be mentioned here as examples hydrogenation, epoxidation, ozonolysis, hydroformylation and dimerization.

In view of the need to change industrial processes which is described above, many problems are still unsolved at present, or their solution is in need of improvement. With respect in particular to the synthesis of dicarboxylic acids or dicarboxylic acid esters, which are often employed as a monomer in polycondensation reactions, the known processes as a rule have at least one, often several or even all of the disadvantages outlined in the following, beyond that stated above: high energy consumption

many by-products, which under certain circumstances must be disposed of, e.g. distillation bottom product,

- low efficiency because of many reaction stages,

low catalyst efficiency.

From there arises the continuing need for improvement in and alternatives to the known processes in order to reduce, and preferably to overcome, at least one, if possible all of the disadvantages referred to and therefore to at least partly overcome the disadvantages emerging from the prior art.

There is furthermore the constant desire for more efficient production processes, e.g. for the preparation of reactants of longer chain length for polycondensates, with which material properties can be advantageously adjusted by copolymerization of corresponding amounts of these longer-chain compounds.

There is also the desire for environmentally-friendlier production processes which at the same time are highly universal, in particular with respect to the diversity of the products which can be prepared with them.

There is furthermore the desire to be able to provide production processes with a lower energy consumption and "carbon footprint" than the known petrochemical processes. There is furthermore the desire to provide a production process in which the functional groups present on the ends of the target molecule do not have to be protected with protective groups in the production process.

It should further be possible to carry out the reaction in as few reactors as possible.

The present invention was furthermore based on the object of providing a "shorter" path, compared with petrochemical preparation processes, to chemical starting substances with a longer chain length for the preparation of polycondensates. "Shorter" here means any simplification of the synthesis, for example by fewer reaction steps, fewer purification steps or fewer after-treatment measures, or lower energy consumption, or two or more of the abovementioned simplifications.

The present invention was additionally based on the further object of providing a preparation process which as far as possible manages without the use of the expensive inert gas technique.

A further object of the present invention was to provide a synthesis process which is suitable for the use of renewable raw materials as starting substances.

A contribution towards achieving at least one of the abovementioned objects is made by the subject matter of the classifying claims. The sub-claims dependent upon these claims are preferred embodiments of the present invention.

The present invention provides a process for the preparation of dicarboxylic acids or dicarboxylic acid esters, comprising the following process steps:

Al provision of at least the following reactants: al a first aliphatic compound having 5 to 40, preferably 10 to 30 and particularly preferably 15 to 25 carbon atoms with in each case at least one functional group of the general formula (I) and (II), wherein R¹ is a saturated or unsaturated aliphatic group having 2 to 20, preferably 4 to 16 and particularly preferably 6 to 12 carbon atoms and R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1 , 2 or 3 carbon atoms

\ /

C=C

I / \

R

(I) O

I I

C-O-R^'

(Π)

and a2 at least one further aliphatic compound which differs from the first aliphatic compound, chosen from the group consisting of a compound of the general formula (III)

^H2n^Cn C_nH_2n

(III) in which n is chosen from 1, 2, 3, 4 and 5; a2b a compound of the general formula (IV)

O

5 I I 3

R-O-C R-C-O-R

(IV) in which R³ is a hydrogen atom or, particularly preferably, an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms and R⁴ and R⁵ independently of each other are a saturated alkylene group having 1 to 14 carbon atoms, preferably having 1 to 10 carbon atoms and very particularly preferably 1 to 5 carbon atoms; provision of at least one organometallic catalyst based on ruthenium; A3 bringing into contact of the reactants and the catalyst to obtain a product mixture and the catalyst;

A4 separating off of the catalyst;

A5 optionally division of the product mixture into products Pj, i being a natural number, and the reactants which remain; the process being a metathesis reaction.

The provision of the substances can in principle take place in any desired sequence or also in the case of at least two substances at least with a time overlap or even simultaneously. In one embodiment, the provision of the substances takes place in the abovementioned sequence.

According to the invention, a "dicarboxylic acid ester" is understood as meaning an ester of a dicarboxylic acid, the term "dicarboxylic acid ester" including both the monoester and the diester of a dicarboxylic acid. A "metathesis reaction" is understood as meaning a reaction in which mutual exchange of molecule constituents takes place. Generally, a metathesis can be represented as follows:

A-B + C-D→ A-D + C-B In the narrower sense used here, a metathesis reaction is understood as meaning an olefin metathesis reaction. In this, alkenes are converted in the presence of a catalyst or several catalysts. The mutual exchange of molecule constituents takes place in this context at the carbon-carbon double bond. Under suitable conditions, a metathesis reaction can also be carried out between an alkene and an alkyne, which leads to 1,3-dienes. A further olefin metathesis reaction is a cyclization olefin metathesis, in which long-chain dienes with terminal double bonds cyclize intramolecularly.

The process according to the invention preferably relates to a metathesis reaction in which a polymer is not formed. A polymer is a collective name for chemical compounds of which the structure is built up from several identical structural units, also called recurring units, in which the structure of the ends of the polymer can deviate from the structure of the structural units between the ends. According to the invention, at least one first aliphatic compound al and a further aliphatic compound a2 which differs from the first aliphatic compound al are provided, the compound al preferably being an unsaturated fatty acid or an unsaturated fatty acid ester and the compound a2 preferably being an unsaturated dicarboxylic acid or an unsaturated dicarboxylic acid ester or an unsaturated dicarboxylic acid anhydride.

According to the invention, mono- or polyunsaturated monocarboxylic acids or dicarboxylic acids or esters thereof, in particular alkyl esters thereof, are preferably employed as the first aliphatic compound al. Particularly preferably according to the invention, unsaturated fatty acids or esters thereof, preferably alkyl esters thereof, are employed as the aliphatic compound al . In this context, the fatty acids can be mono- or polyunsaturated, the use of monounsaturated fatty acids or of esters thereof, in particular of alkyl esters thereof, being most preferred. Examples of suitable aliphatic compounds al which may be mentioned are, in particular, undecylenic acid, myristoleic acid, palmitoleic acid, petroselic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, icosenic acid, cetoleic acid, erucic acid, nervonic acid, linoleic acid, a-linolenic acid, γ-linolenic acid, calendula acid, punicic acid, a-elaeostearic acid, β-elaeostearic acid, arachidonic acid, timnodonic acid, clupanodonic acid and cervonic acid, the use of oleic acid and alkyl esters thereof, in particular the use of oleic acid methyl ester, being particularly preferred. A mixture of at least two of the abovementioned fatty acids or fatty acid esters can optionally also be employed as the aliphatic ester al .

According to a particular embodiment of the process according to the invention (alternative a2a), anhydrides of unsaturated dicarboxylic acids can be employed as a further aliphatic compound a2 which differs from the first aliphatic compound al. Examples of suitable anhydrides of unsaturated dicarboxylic acids which may be mentioned are, in particular, maleic anhydride, 3-hexenoic anhydride, 5-decenoic anhydride or 4-octenoic anhydride. Mixtures of these anhydrides of dicarboxylic acids can also be employed as a further aliphatic compound a2. According to another particular embodiment of the process according to the invention (alternative a2b), unsaturated dicarboxylic acids or unsaturated dicarboxylic acid esters can furthermore be employed as a further aliphatic compound a2 which differs from the first aliphatic compound al , the use of unsaturated dicarboxylic acid esters, in particular the dicarboxylic acid diesters, being particularly preferred. Dicarboxylic acid esters can be obtained, for example, by esterification of unsaturated dicarboxylic acids. Examples of suitable unsaturated dicarboxylic acid esters which may be mentioned are, for example, but-2-ene-l,4-dicarboxylic acid dimethyl ester, hex-3-ene-l,6-dicarboxylic acid dimethyl ester or oct-4-ene-l,8-dicarboxylic acid dimethyl ester. Mixtures of these unsaturated dicarboxylic acid esters can also be employed as a further aliphatic compound a2.

At least one organometallic catalyst based on ruthenium is furthermore provided in process step A2. An "organometallic catalyst" is understood as meaning an organoelemental compound with at least one direct metal-carbon bond, that is to say a metal complex which is formed by a single or double bond. These metal complexes contain ligands connected to the metal atom. Further information on this is generally known to the person skilled in the art and can be looked up, for example, in Rompp-Chemie-Lexikon, version 2.0, Stuttgart/New York, Georg Thieme Verlag 1999, under the key word "Organometallic Compounds".

Organometallic catalysts based on ruthenium are suitable according to the invention, in particular those which are known as metathesis catalysts. Examples are given below, diagrams and abbreviated names known in technical circles being used because of the complex systematic naming. For unambiguous definition, the CAS numbers of the catalysts - if available - are additionally given (from left to right and top to bottom): 172222-30-9; 246047-72-3; 250220-36-1 ; 894423-99-5; 536724-67-1; 1031262-76-6; 1031262-76-6; 1031262-71-1 ; 934538-04-2; 934538-12-2; 1031262-71-1

Neolyst Μ31' Neolyst M51^b Neolyst AF08043^C Neolyst AFOJMMiF Neolyst M42^c

Neolyst M41^c Neolyst AF080S1' Neolyst AFOeOO^ Neolyst AF08010^C Neolyst AF0801

According to process step A3, the reactants and the catalyst are now brought into contact to obtain a product mixture and the catalyst. They can be brought into contact in principle by any method and manner which appears to be suitable to the person skilled in the art. According to a particularly preferred embodiment, they are brought into contact by simple mixing, optionally with stirring. According to a further preferred embodiment, process step A3 is carried out in a reactor tank or a continuously operated tube or zone reactor.

In principle all separating steps which are known to the person skilled in the art and appear to be suitable are suitable for process step A4, the separating off of the catalyst. According to a preferred embodiment, precipitations, dialysis processes, membrane separations, distillation or evaporation processes, centrifuging processes or filtration processes are suitable as separation processes.

In the next optional process step A5, the product mixture is divided into products Pj and any reactants which may remain, i being a natural number. According to a further preferred embodiment, at least one of the products P; obtained with the process according to the invention contains at least one unsaturated carbon-carbon bond. In particular, unsaturated dicarboxylic acids and unsaturated dicarboxylic acid esters can be obtained by cross metathesis between the unsaturated carboxylic acid according to component al and the unsaturated dicarboxylic acid or the unsaturated dicarboxylic acid ester or the unsaturated dicarboxylic acid anhydride according to component a2. These unsaturated dicarboxylic acids or unsaturated dicarboxylic acid esters can optionally be reacted in further process steps by hydrogenation to give saturated dicarboxylic acids or to give saturated dicarboxylic acid esters. Secondary reactions in which, optionally additionally to a hydrogenation, the dicarboxylic acids obtained are partially or completely esterified, the dicarboxylic acid esters obtained are at least partially hydrolysed or the dicarboxylic acid esters obtained are at least partially subjected to a transesterification are furthermore conceivable.

Process steps Al to A5 can be carried out in succession. Process steps which follow one another can equally well be combined and at least partly overlap in time sequence, i.e. the following process step is started before the preceding one has ended completely. If the configuration comprises an at least partly continuous process procedure, the overlapping in time of two or more process steps is often accompanied by a spatial overlapping of the process steps in the reaction region. A tube reactor into which substances, e.g. reactants, catalyst, are fed through inlets and substances, e.g. products, by-products, or similar, are discharged through outlets can be regarded, for example, as a reaction region. According to a further preferred embodiment of the process according to the invention, the weight content of the catalyst lies in a range of from 0.3 to 8 wt.%, preferably 0.5 to 5 wt.% and particularly preferably 0.8 to 4 wt.%, in each case based on the total amount of the reactants. According to a further preferred embodiment of the process according to the invention, at least a part of the process is carried out at a temperature in a range of from 0 to 140 °C, preferably from 20 to 100 °C and still more preferably from 60 to 80 °C.

According to a further preferred embodiment of the process according to the invention, at least a part of the process is carried out under a pressure in a range of from 0.5 to 10 bar. Particularly preferably, the process is carried out under a pressure of about 1 bar, that is to say in the range of from 800 to 1,200 mbar, more preferably from 900 to 1,100 mbar, or under a pressure of 1,000 mbar. If at least one of the reactants is gaseous under a pressure of 1 ,000 mbar, the process according to the invention can be carried out under an increased pressure. An absolute pressure in a range of from 1 to 10 bar, preferably 1.5 to 8 bar, more preferably from 1.5 to 6 bar is particularly preferred here.

According to a further preferred embodiment, an organic solvent is present, at least while the reactants are brought into contact. The organic solvent is furthermore preferably already present beforehand, that is to say, for example, during provision of the reactants, or during provision of the catalyst. The solvent is likewise preferably also furthermore present after the reactants and the catalyst have been brought into contact to obtain a product mixture of the catalyst, for example until the catalyst is separated off, or also beyond this. In principle any liquid organic substance which is known to the person skilled in the art and appears to be suitable is suitable as the organic solvent. Aprotic organic solvents are particularly preferably suitable, in particular aromatic hydrocarbons, such as, for example, toluene or benzene, p-xylene, chlorohydrocarbons, such as, for example, chloroform, chlorobenzene, dichlorobenzene, methylene chloride or 1 ,2-dichloroethane, furans, such as, for example, tetrahydrofuran, or 1,4-dioxane. Mixtures of at least two of these solvents can also be employed.

According to a further preferred embodiment, the process according to the invention is carried out as a two-phase reaction. A two-phase reaction is understood as meaning a reaction which has two or more different phases. These can in each case independently of each other be organic or non-organic. Particularly preferably, the first phase is homogeneously miscible with the further phase at the maximum in a content of from 0.1 to 15 wt.%, preferably from 0.1 to 10 wt.%, particularly preferably from 0.1 to 5 wt.% and very particularly preferably from 0.1 to 3 wt.%, in each case based on the total weight of the two phases. Above these contents, the first phase and the at least one further phase which differs from the first phase are not miscible.

An organic phase is understood as meaning all the process components and solvents which are soluble in each case in 100 g of water to the extent of less than 20 g, particularly preferably less than 5 g, furthermore preferably less than 2 g, most preferably less than 1 g.

According to a further preferred embodiment of the process according to the invention, the selectivity of the process in favour of products which differ from the reactants is at least 50 %, preferably at least 65 %, or at least 67 %, or at least 75 %, or at least 80 % or at least 85 % or at least 90 %.

The first and the at least one further phase of the process are furthermore preferably present during process steps A3 and A4, and optionally during further steps. It is furthermore preferable for a part of the one or the other phase to be separated off from the product mixture with the catalyst in process step A4.

According to a further preferred embodiment of the process according to the invention, at least a part thereof is conducted with stirring.

According to a further preferred embodiment of the process according to the invention, the catalyst is not symmetrically substituted. Symmetrically substituted is understood as meaning that in a spatial representation of the catalyst molecule, at least one mirror plane can be laid through the ruthenium metal centre(s), the projection on this mirror plane being imaged correspondingly to the original representation.

According to a further preferred embodiment, one or more of the following groups are covalently bonded to the ruthenium atom (Z) of the catalyst: al : a group of the following formula (V):

(V) α2: a group of the following formula (VI):

(VI) or a combination of two or more of these.

According to a further preferred embodiment, the process according to the invention has a further process step A6, in which the product mixture obtained by metathesis or the product Pj obtained by dividing, in particular the unsaturated dicarboxylic acid obtained by the metathesis or the unsaturated dicarboxylic acid ester obtained by the metathesis, is further processed. All processes which are known to the person skilled in the art and appear to be suitable are possible as process steps A6. Particularly preferred process steps in A6 are distillation processes, absorption processes, filtering processes, bleaching processes, centrifuging processes, crystallization processes, drying processes and continuing reactions. Among the possible continuing reactions which appear to be suitable, the following are particularly preferred: an epoxidation, a hydrogenation, a hydrolysis or a combination of two or more of these. A hydrogenation of the unsaturated dicarboxylic acids or dicarboxylic acid esters obtained or, in the case of dicarboxylic acid esters, a hydrolysis thereof, is particularly preferred here. A combination of hydrogenation and hydrolysis reactions is also conceivable, so that in the end saturated dicarboxylic acids can be obtained.

According to a further preferred embodiment, the process according to the invention with the process steps Al to A5 or Al to A6 is carried out as a continuous process. A continuous process is understood as meaning a process procedure in which the reactants which have not reacted to give the product according to the invention and furthermore optionally also catalysts or by-products are fed back into the process, and are thus fed to a renewed use in the process. The pollution of the environment or the emission of residual substances or both, for example, can therefore be reduced. According to a further preferred embodiment, process steps Al to A6 are carried out in a single reactor, especially if a hydrogenation is carried out in process step A6. A particularly effective and gentle large-scale industrial preparation is possible by this one- pot process.

According to a further preferred embodiment, the same catalyst is employed for carrying out process step A6, in particular during a hydrogenation, as for carrying out process step A3. This can mean, on the one hand, that a second portion of the same catalyst as in A3 is added for process step A6. Preferably, this is understood as meaning that both process step A3 and also process step A6 are carried out with the same portion of catalyst, so that in this process procedure catalyst is not fed in again in process step A6.

A contribution towards achieving at least one of the abovementioned objects is also made by a product mixture obtainable by the process described above or a product Pj obtainable by the process described above, but in particular a dicarboxylic acid obtainable by the process described above or a dicarboxylic acid ester obtainable by the process described above. A contribution towards achieving at least one of the abovementioned objects is also made by a process for the preparation of a polymer, comprising the process steps: provision of a dicarboxylic acid or a dicarboxylic acid ester obtainable by the process according to the invention described above as the monomer A; provision of a monomer B which can be polymerized with the monomer A; mixing of the monomer A with the monomer B to obtain a monomer mixture; polymerization of the monomers A and B in the monomer mixture to obtain copolymer of the monomers A and B.

In process step PI, a dicarboxylic acid or a dicarboxylic acid ester is first provided by the process according to the invention described above. In this context it is conceivable for the dicarboxylic acid or the dicarboxylic acid ester to be in the form of the product mixture obtained in process step A3 or A4, in the form of a product P; obtained in process step A5 or in the form of a reaction product obtained, for example, by hydrogenation and/or hydrolysis in process step A6.

In process step P2, a monomer B which can be polymerized with the monomer A is provided, monomers which are capable of reacting with dicarboxylic acids or dicarboxylic acid esters in a polycondensation reaction being preferred as the monomer B. Possible monomers here are, in particular, di- or polyols, which are capable of reacting with dicarboxylic acids or dicarboxylic acid esters in a polycondensation reaction to give polyesters, or di- or triamines, which are capable of reacting with dicarboxylic acids or dicarboxylic acid esters in a polycondensation reaction to give polyamides. Examples of suitable monomers B which may be mentioned are tetramethylenediamine, hexamethylenediamine, dodecanediamine, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propane-diol, 1,4- butanediol, 1 ,6-hexanediol and polypropylene glycol.

In process step P3, the monomer A is mixed with the monomer B to obtain a monomer mixture, all the mixing devices known to the person skilled in the art being possible here. In process step P4, the polymerization of the monomers A and B is then carried out in the monomer mixture to obtain a copolymer of the monomers A and B, details of such polymerization reactions being adequately known from the prior art, in particular for the polycondensation reaction between dicarboxylic acids and di- or polyols or di- or triamines. In this connection, reference may be made, for example, to DE-A-196 38 549 or to Vieweg, Miiller, Kunststoff-Handbuch, vol. VI, p. 11 et seq., Carl-Hanser-Verlag, Munich 1966.

A contribution towards achieving at least one of the abovementioned objects is also made by a polymer which is obtainable by the process described above. The present invention additionally relates to fibres, shaped articles, moulding compositions, foils or films comprising this polymer. The present invention furthermore relates to the use of this polymer in fibres, shaped articles, moulding compositions, foils or films. The present invention is explained in the following by examples which are given by way of example but are in no way limiting.

MEASUREMENT METHODS

Unless expressly stated otherwise, all the measurements are carried out in accordance with the relevant ISO standards. Unless specified otherwise there, a temperature of 23 °C, an atmospheric pressure of 1 bar and a relative atmospheric humidity of 50 % was chosen. a) Gas chromatography determination of conversion and yield

The analysis of the reaction solutions was carried out quantitatively by means of a gas chromatograph (GC) of series 6890 from Hewlett Packard GmbH. A flame ionization detector (FID; 325 °C) was used for detection of the individual components. Qualitative assignment of the chromatography retention times was carried out by comparison with pure substances. The gas chromatograph is equipped with an HP 5 capillary column (length 30 m, diameter 0.25 mm, film thickness 0.25 μπι) in combination with an autosampler. Nitrogen served as the carrier gas (v = 1.2 ml min^"1, 30 cm s^"1). The injection volume was set at 1 μΐ and the split ratio at 70:1. The heating profile of the oven of the GC method used is reproduced in the following table.

Heating rate End temperature Hold

[°C min^"1] [°C] [min]

Start - 130 6

Increase in temperature line 25 320 4

Quantitative determination of the conversions and of the yields was carried out on the basis of the peak areas by mean of internal standards. n-Pentadecane was used exclusively as the internal standard. For each metathesis reaction investigated, both the substrates and the metathesis products were measured in the presence of the internal standard in several concentrations. A calibration line was plotted by linear regression and the particular method factor was then determined. For preparation of the samples, 0.05 g of rc-pentadecane, 0.40 g of sample and 0.50 g of isopropanol, as the solvent, were weighed and analysed by gas chromatography.

In the analysis of free fatty acids, 1 ml of a solution of dimethyl acetal/dimethylformamide (DMA/DMF) and pyridine (1 :1) was added to 0.50 mg of sample. In the event of a clear solution, the sample was prepared as described above and analysed by means of gas chromatography.

EXAMPLES

1. Synthesis and purification of the substrates a) Oleic acid Oleic acid (extra pure, Acros Organics) is percolated over neutral aluminium oxide (neutral, 50-200 μιη, Acros Organics) under argon and stored in a refrigerator under an argon atmosphere. b) Oleic acid methyl ester

300.00 g (338.98 mmol) of high oleic sunflower oil with an oleic acid content of 91.4 % (commercially obtainable from Emery Oleochemicals GmbH) are dried under 1 · 10^"3 mbar at 120 °C for 30 minutes, while stirring, cooled and then stirred with 35.79 g (1,118.64 mmol; 3 eq.) of absolute methanol (99.8 %, extra dry, Acros Organics) and with 5.59 g (103.14 mmol) of 30 wt.% strength sodium methanolate solution (pure, 5.4 M in methanol, Acros Organics) at 70 °C under an argon atmosphere for two hours. After cooling to room temperature, the glycerol phase formed is drained off and a further 5.42 g (189.16 mmol) of absolute methanol (99.8 %, extra dry, Acros Organics) are added to the phase which remains, containing oleic acid methyl ester. After stirring at a temperature of 70 °C for one hour, the excess methanol is removed under reduced pressure. After a glycerol phase which has formed again has been separated off, the phase containing oleic acid methyl ester is washed twice with 150 ml of hot doubly distilled water each time. The oleic acid methyl ester is obtained with a purity of 98 % by a fractional vacuum distillation at 160 °C under 1 10^"3 mbar. 88.49 g (298.32 mmol; 88 %) of a clear, colourless liquid were obtained. The oleic acid methyl ester is percolated over neutral aluminium oxide (neutral, 50-200 μπι, Acros Organics) under argon and stored in a refrigerator under an argon atmosphere. c) Hex-3-ene-l,6-dicarboxylic acid

1.00 g (11.62 mmol) of 3-butenoic acid (90 %, Acros Organics) and 0.22 g (0.23 mmol, 2.00 mol%) of Neolyst M2 SIMES (Umicore) are stirred in 10 ml of toluene (99+ %, Acros Organics) at a reaction temperature of 50 °C for five hours at a stirring speed of 900 rpm under reduced pressure. The residue is washed with 15 ml of n-pentane and dried under reduced pressure at a temperature of 40 °C. 0.42 g (2.96 mmol; 51 %) of a white solid is obtained. The hex-3-ene-l,6-dicarboxylic acid is stored in a refrigerator under an argon atmosphere. d) Hex-3-ene-l,6-dicarboxylic acid dimethyl ester

1.00 g (9.99 mmol) of 3-butenoic acid methyl ester and 0.19 g (0.20 mmol 2.00 mol%) of Neolyst M2 SIMES (Umicore) are stirred in 10 ml of toluene (99+ %, Acros Organics) at a reaction temperature of 50 °C for 5 hours at a stirring speed of 900 rpm under reduced pressure. The hex-3-ene-l,6-dicarboxylic acid dimethyl ester is purified by a fractional vacuum distillation. 1.10 g (6.39 mmol; 64 %) of a clear, colourless liquid are obtained. The diester is percolated over neutral aluminium oxide (neutral, 50-200 μπι, Acros Organics) under argon and stored in a refrigerator under an argon atmosphere. e) Hex-3-ene-l,6-dicarboxylic acid anhydride

0.50 g (3.47 mmol) of hex-3-ene-l,6-dicarboxylic acid are dissolved in 3 ml of tetrahydrofuran (99.6 %, Acros Organics) with the addition of 0.07 g (0.35 mmol) of magnesium chloride hexahydrate (99.0 %, Sigma Aldrich) and 0.37 g (1.71 mmol) of di- tert-butyl dicarbonate (Boc₂0 99 %, Acros Organics) and the solution is stirred at room temperature for 24 hours. The reaction solution is dissolved in 30 ml of doubly distilled water and extracted three times with 30 ml of tetrahydrofuran each time. The organic phase is separated off and dried over magnesium sulphate (97 %, Acros Organics). The solvent is removed under reduced pressure. A white solid is obtained. The cyclic anhydride is stored in a refrigerator under an argon atmosphere. f) Maleic anhydride

Maleic anhydride (99 %, Acros Organics) is employed without further purification.

2. General working instructions for the cross metathesis reactions

2.1 Metathesis of oleic acid methyl ester and hex-3-ene-l,6-dicarboxylic acid dimethyl ester

0.10 g (0.34 mmol) of oleic acid methyl ester and 0.58 g (3.37 mmol, 10 eq.) of hex-3-ene- 1 ,6-dicarboxylic acid dimethyl ester are dissolved in 2 ml of toluene. After addition of 6.40 mg (6.75-10^"3 mmol, 2.00 mol%) of Neolyst M2 SEVIES (Umicore), the reaction solution is stirred for five hours at a temperature of 50 °C with a stirring speed of 900 rpm. The metathesis products are isolated by column chromatography (cyclohexane : ethyl acetate 20 : 1— » 5 : 1). The metathesis products are characterized by means of both nuclear magnetic resonance and mass spectroscopy. The conversion and the yields are determined by gas chromatography by means of an internal standard.

Conversion of oleic acid Yield of metathesis products Selectivity

methyl ester in % in %

in %

97 73 76

Reaction conditions: 0.34 mmol of oleic acid methyl ester, oleic acid methyl ester :

hex-3-ene-l ,6-dicarboxylic acid dimethyl ester 1:10, 0.73 wt.% of toluene, 2.00 mol% of Neolyst M2 SIMES, 50 °C 5 h, 900 rpm. Metathesis of oleic acid methyl ester and hex-3-ene-l,6-dicarboxylic acid

0.10 g (0.34 mmol) of oleic acid methyl ester and 0.49 g (3.37 mmol, 10 eq.) of hex-3-ene- 1 ,6-dicarboxylic acid are dissolved in 2 ml of toluene. After addition of 9.60 mg (1.01 10^" mmol, 3.00 mol%) of Neolyst M2 SIMES (Umicore), the reaction solution is stirred for five hours at a temperature of 50 °C with a stirring speed of 900 rpm. The metathesis products are isolated by means of column chromatography (cyclohexane : ethyl acetate 20 : 1 ^→ 2 : 1). The metathesis products are characterized by means of both nuclear magnetic resonance and mass spectroscopy. The conversion and the yields are determined by gas chromatography by means of an internal standard.

Conversion of oleic acid Yield of metathesis products Selectivity

methyl ester in % in %

in %

78 53 67 Reaction conditions: 0.34 mmol of oleic acid methyl ester, oleic acid methyl ester :

hex-3-ene-l ,6-dicarboxylic acid 1:10, 0.77 wt.% of toluene, 3.00 mol% of Neolyst M2 SIMES, 50 °Q 5 h, 900 rpm.

Metathesis of oleic acid and hex-3-ene-l,6-dicarboxylic acid

0.10 g (0.35 mmol) of oleic acid and 0.51 g (3.54 mmol, 10 eq.) of hex-3-ene-l,6- dicarboxylic acid are dissolved in 2 ml of toluene. After addition of 13.4 mg (1.42· 10^" mmol, 4.00 mol%) of Neolyst M2 SIMES (Umicore), the reaction solution is stirred for five hours at a temperature of 50 °C with a stirring speed of 900 rpm. The metathesis products are isolated by column chromatography (cyclohexane : ethyl acetate 20 : 1→ 5 : 1). The metathesis products are characterized by means of both nuclear magnetic resonance and mass spectroscopy. The conversion and the yields are determined by gas chromatography by means of an internal standard.

Conversion of oleic acid Yield of metathesis products Selectivity

in % in % in %

70 46 66 Reaction conditions: 0.35 mmol of oleic acid, oleic acid methyl ester : hex-3-ene-l,6- dicarboxylic acid 1:10, 0.76 wt.% of toluene, 4.00 mol% of Neolyst M2 SIMES, 50 °C, 5 h, 900 rpm.

2.4 Metathesis of oleic acid methyl ester and hex-3-ene-l ,6-dicarboxylic acid anhydride

0.10 g (0.34 mmol) of oleic acid methyl ester and 0.43 g (3.37 mmol, 10 eq.) of hex-3-ene- 1 ,6-dicarboxylic acid anhydride are dissolved in 2 ml of toluene. After addition of 9.6 mg (1.01 10^"2 mmol, 3.00 mol%) of Neolyst M2 SIMES (Umicore), the reaction solution is stirred for five hours at a temperature of 50 °C with a stirring speed of 900 rpm. The solvent is removed under reduced pressure. The crude product is taken up in 5 ml of doubly distilled water, 2 drops of concentrated sulphuric acid (96 % in water, Acros Organics) are added and the mixture is stirred at room temperature for 12 hours. The reaction solution is added to 15 ml of ice-water. The aqueous phase is extracted three times with 15 ml of diethyl ether (99+ %, Acros Organics) each time. The combined organic phases are washed with 30 ml of sodium carbonate solution (99.5 %, Acros Organics) and 30 ml of doubly distilled water. After drying the combined organic phases over sodium sulphate, the diethyl ether is removed under reduced pressure. The metathesis products are isolated by column chromatography (cyclohexane : ethyl acetate 20 : 1→ 2 : 1).

Conversion of oleic acid Yield of metathesis products Selectivity

methyl ester after cleavage in %

in % in %

84 47 56

hex-3-ene-l,6-dicarboxylic acid anhydride 1:10, 0.79 wt.% of toluene, 3.00 mol% ofNeolyst M2 SIMES, 50 °C, 5 h, 900 rpm and subsequent acid cleavage of the mixed anhydride.

Metathesis of oleic acid methyl ester and maleic anhydride

0.10 g (0.34 mmol) of oleic acid methyl ester and 0.33 g (3.37 mmol, 10 eq.) of maleic anhydride are dissolved in 2 ml of 1 ,4-dioxane (99+ %, Acros Organics). After addition of 9.6 mg (1.01T0^"2 mmol, 3.00 mol%) of Neolyst M2 SIMES (Umicore), the reaction solution is stirred for five hours at a temperature of 50 °C with a stirring speed of 900 rpm. The solvent is removed under reduced pressure. The crude product is taken up in 5 ml of doubly distilled water, 2 drops of concentrated sulphuric acid (96 % in water, Acros Organics) are added and the mixture is stirred at room temperature for 12 hours. The reaction solution is added to 15 ml of ice- water. The aqueous phase is extracted three times with 15 ml of diethyl ether (99+ %, Acros Organics) each time. The combined organic phases are washed with 30 ml of sodium carbonate solution (99.5 %, Acros Organics) and 30 ml of doubly distilled water. After drying the combined organic phases over sodium sulphate, the diethyl ether is removed under reduced pressure. The metathesis products are isolated by column chromatography (cyclohexane : ethyl acetate 20 : 1→ 1 : 1).

Conversion of oleic acid Yield of metathesis Selectivity

methyl ester products after cleavage in %

in % in %

14 8 57 Reaction conditions: 0.34 mmol of oleic acid methyl ester, oleic acid methyl ester :

maleic anhydride 1:10, 0.83 wt.% of toluene, 3.00 mol% of Neolyst M2 SIMES, 50 °C, 5 h, 900 rpm and subsequent acid cleavage of the mixed anhydride. 2.6 Preparation of a polymer

0.5 g (1.93 mmol) of the 1,12-dicarboxylic acid dimethyl ester as the hydrogenation product of the unsaturated ester from Example 2.1 and 0.22 g (1.93 mmol) of 1,6- hexanediamine are stirred at 70 °C for 2 hours, with the addition of 0.05 g (0.93 mmol) of ammonium chloride. The methanol formed is removed continuously from the reaction solution. The polyamide formed is obtained quantitatively.

Claims

1. A process for the preparation of dicarboxylic acids or dicarboxylic acid esters comprising the following process steps:

Al provision of at least the following reactants:

al a first aliphatic compound having 5 to 40 carbon atoms with in each case at least one functional group of the general formula (I) and (II), wherein R¹ is a saturated or unsaturated aliphatic group having 2 to 20, preferably 4 to 16 and particularly preferably 6 to 12 carbon atoms and R² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1 , 2 or 3 carbon atoms

O

I I ₂

— C-O-R

(Π) at least one further aliphatic compound which differs from the first aliphatic compound, chosen from the group consisting of

a2a a compound of the general formula (III)

° - L ⁰

H₂„C_N C_NH_:

\— /

(III) in which n is chosen from 1 , 2, 3, 4 and 5;

a compound of the general formula (IV) O O

3 I I 4 5 I I 3

R-0-C-R-C=C-R-C-0-R

(IV)

in which R³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms and R⁴ and R⁵ independently of each other are a saturated alkylene group having 1 to 14 carbon atoms, preferably having 1 to 10 carbon atoms and very particularly preferably 1 to 5 carbon atoms;

A2 provision of at least one organometallic catalyst based on ruthenium;

A3 bringing into contact of the reactants and the catalyst to obtain a product mixture and the catalyst;

A4 separating off of the catalyst;

A5 optionally division of the product mixture into products Pj, wherein i is a natural number, and the reactants which remain; wherein the process is a metathesis reaction.

The process according to claim 1 , wherein at least one product P; contains at least one unsaturated carbon-carbon bond.

The process according to claim 1 or 2, wherein the at least one product Pi is not a polymer.

The process according to one of the preceding claims, wherein the weight content of the catalyst is in a range of from 0.3 to 8 wt.%, based on the total amount of reactants.

The process according to one of the preceding claims, wherein at least a part of the process is carried out at a temperature in a range of from 0 to 140 °C.

6. The process according to one of the preceding claims, wherein furthermore an organic solvent is present at least while the reactants are brought into contact.

7. The process according to one of the preceding claims, wherein the selectivity in favour of products which differ from the reactants is at least 50 %.

8. The process according to one of the preceding claims, wherein the catalyst is not symmetrically substituted.

9. The process according to one of the preceding claims, wherein one or more of the following groups is covalently bonded to the ruthenium atom (Z) of the catalyst: al

(VI)

10. The process according to one of the preceding claims, wherein the catalyst is chosen from the group consisting of

dichloro-[l,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]-(3-phenyl- 1 H-inden- 1 -ylidene)(tricyclohexylphosphine)ruthenium(II); [l,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene]-[2-[[(2,6- diisopropylphenyl)irnino]methyl]-4-nitrophenolyl]-[3-phenyl-lH-inden-l- ylidenejruthenium chloride; or a combination of two or more of these.

The process according to one of the preceding claims, wherein according to a further process step

A6 the product mixture obtained by metathesis or the product P; obtained by dividing is further processed.

The process according to claim 11, wherein the unsaturated dicarboxylic acid obtained by metathesis or the unsaturated dicarboxylic acid ester obtained by metathesis is further processed.

The process according to claim 12, wherein the further processing includes a hydrogenation.

The process according to claim 13, wherein process steps Al to A6 are carried out in a single reactor.

The process according to claim 14, wherein the same catalyst is employed for carrying out process step A6 as for carrying out process step A3.

A product mixture or a product P; obtainable by a process according to claim 1 to 19.

A process for the preparation of a polymer, comprising the process steps:

PI provision of a dicarboxylic acid or a dicarboxylic acid ester by a process according to one of claims 1 to 13 as the monomer A;

P2 provision of a monomer B which can be polymerized with the monomer A; P3 mixing of the monomer A with the monomer B to obtain a monomer mixture; P4 polymerization of the monomers A and B in the monomer mixture to obtain a copolymer of the monomers A and B.

18. Process according to claim 17, wherein the monomer B is a monomer which is capable of reacting with the monomer A in a polycondensation reaction.

19. Process according to claim 17 or 18, wherein the monomer B is a diol or a diamine.

20. Polymer obtainable by a process according to one of claims 17 to 19.

21. Fibres, shaped articles, moulding compositions, foils or films comprising a polymer according to claim 20.

22. Use of the polymer from claim 20 in fibres, shaped articles, moulding compositions, foils or films.