DE10231291A1 - Production of dicarboxylic acid, e.g. adipic acid, from acrylic acid involves reacting a diester of the diacid with acrylic acid, separating acrylate esters from the product, dimerizing acrylate esters and converting into diacid - Google Patents

Abstract

A method for the production of 6C dicarboxylic acids (I) from acrylic acid involves reacting diesters of (I) with acrylic acid to give (I) and acrylate esters, separating (I) from the reaction mixture, dimerizing the acrylate esters to diesters of n-butene dicarboxylic acid and converting these diesters into (I). A method for the production of dicarboxylic acids of formula HOOC-(n-C 4H x)-COOH (I) from acrylic acid involves: (a) reaction of diesters of formula R 1>OOC-(n-C 4H x)-COOR 2> (II) with acrylic acid to give (I) and a mixture of acrylate esters of formula C 2H 3COOR 1> and C 2H 3COOR 2>; (b) separation of (I) from the reaction mixture; (c) dimerization of the acrylate esters to give diesters of n-butene dicarboxylic acid; and (d) cleavage of these diesters to give (I). x : 6 or 8; and R 1>, R 2>1-4C alkyl, aryl or heteroaryl.

Description

• a) einen Dicarbonsäurediester der Formel (II) R¹-OOC-(n-C₄H_X)-COO-R² (II) mit x: 6 oder 8 R¹, R² unabhängig voneinander C₁-, C₂-, C₃-, C₄-Alkyl, Aryl, Heteroaryl und gleich oder unterschiedlich sein können mit Acrylsäure umsetzt unter Erhalt einer Dicarbonsäure der Formel (I) und einem Gemisch von Acrylsäureester der Formel C₂H₃-COOR¹ und C₂H₃-COOR², wobei R¹ und R² die genannten Bedeutungen haben,
• b) die in Schritt a) erhaltene Dicarbonsäure der Formel (I) aus dem in Schritt a) erhaltenen Reaktionsgemisch abtrennt,
• c) die in Schritt a) erhaltenen C₂H₃-COOR¹, C₂H₃-COOR² oder deren Gemische unter Erhalt von n-Butendicarbonsäurediester dimerisiert und
• d) die in Schritt c) erhaltenen Dicarbonsäurediester in die entsprechende Dicarbonsäure der Formel (I) spaltet.

The present invention relates to a process for the preparation of a dicarboxylic acid of the formula (I) H-OOC- (nC ₄ H _x ) -COO-H (I) With
x: 6 or 8
starting from acrylic acid
characterized in that one

• a) a dicarboxylic acid diester of the formula (II) R ¹ -OOC- (nC ₄ H _X ) -COO-R ² (II) with x: 6 or 8 R ¹ , R ² independently of one another C ₁ -, C ₂ -, C ₃ -, C ₄ -alkyl, aryl, heteroaryl and can be identical or different with acrylic acid to give a dicarboxylic acid of the formula (I ) and a mixture of acrylic acid esters of the formula C ₂ H ₃ -COOR ¹ and C ₂ H ₃ -COOR ² , where R ¹ and R ^{2 have} the meanings mentioned,
• b) the dicarboxylic acid of the formula (I) obtained in step a) is separated from the reaction mixture obtained in step a),
• c) the C ₂ H ₃ -COOR ¹ , C ₂ H ₃ -COOR ² or mixtures thereof obtained in step a) are dimerized to give n-butenedicarboxylic acid diester and
• d) the dicarboxylic acid diesters obtained in step c) are cleaved into the corresponding dicarboxylic acid of the formula (I).

Processes for the preparation of dimethyl n-butene-dicarboxylate, ie dicarboxylic acid diester (II) with x = 6 and R ¹ = R ² = methyl, starting from methyl acrylate are known per se.

So describes US 3,013,066 in Examples XX and XXI the dimerization of methyl acrylate in the presence of ruthenium chloride as a catalyst. In Example XX, dimethyl n-butenedicarboxylate is obtained after separation by distillation from the product mixture as fraction II in a yield of only 24% and in Example XXI as fraction III in a yield of only 37%, based in each case on methyl acrylate used ,

US 4,638,084 in Example I describes the dimerization of methyl acrylate in the presence of chlorobis (ethylene) rhodium (I) dimer and silver tetrafluoroborate as a catalyst. With a conversion of 100%, dimethyl n-butenedicarboxylate was obtained in a yield of only 60%, based on the methyl acrylate used, determined by means of NMR.

EP-A-475 386 describes the dimerization of methyl acrylate in the presence of specific rhodium complexes as a catalyst. According to Example 4, a conversion of 97% to n-butenedicarboxylic acid dimethyl ester is achieved, determined by means of NMR.

As a technically important product however usually not n-butene-dicarboxylic acid dimethyl ester asked, but a dicarboxylic acid (I), especially adipic acid, so dicarboxylic acid (I) with x = 6. adipic acid represents an important intermediate in the manufacture of polymer plasticizers, of polyesterols, for example for polyurethanes, and a starting monomer for the production of technically important polymers such as Nylon6.6.

According to US 3,013,066 , Examples XX and XXI, the n-butenedicarboxylic acid dimethyl ester obtained in the dimerization can then be hydrogenated to the dimethyl adipate after separation from the product mixture and the adipic acid can be obtained by saponification of the adipic acid diester.

This in US 3,013,066 The process described for the production of adipic acid starting from methyl acrylate thus disadvantageously comprises a large number of process steps for the production of four intermediates, namely acrylic acid, methyl acrylate, dimethyl n-butene-dicarboxylate, dimethyl adipate, and it must be taken into account that in addition to the acrylic acid esterification and the hydrogenation of the n-butene-dicarboxylic acid dimethyl ester to form adipic acid dimethyl ester, a separation step is required, as is the removal of the obtained adipic acid from the product mixture after the saponification of the adipic acid dimethyl ester.

In addition, the described in the As is known, processes for dimerization of methyl acrylate initially used Acrylic acid through Esterification can be prepared, likewise at least one separation step is necessary to obtain the ester in pure form.

The present invention was the The object of the present invention is to provide a method for manufacturing a dicarboxylic acid (I), especially adipic acid, from acrylic acid made possible in a technically simple and economical manner.

Accordingly, the method defined at the outset found.

According to the invention, step a) uses acrylic acid with a dicarboxylic acid diester of the formula (II) R ¹ -OOC- (nC ₄ H _x ) -COO-R ² (II) With
x: 6 or 8
around.

In formula (II), R ₁ , R _{2 are,} independently of one another, C ₁ -, C ₂ -, C ₃ -, C ₄ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , s-butyl, t-butyl, preferably methyl, aryl, such as phenyl, or heteroaryl, preferably R ¹ , R ^{2 are,} independently of one another, C ₁ -, C ₂ -, C ₃ -, C ₄ -alkyl, such as methyl, ethyl , n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, in particular Methyl.

R ¹ , R ² can be different. In a preferred embodiment, R ¹ , R ^{2 are the} same. In a particularly preferred embodiment, R ¹ and R ^{2 are the} same and both represent methyl.

In the case of x = 8, this represents the dicarboxylic of the formula (II) underlying dicarboxylic acid adipic acid.

The corresponding adipic acid diesters of the formula (II) and their preparation are known per se. So they can adipic for example by double carbonylation of butadiene in the presence from alcohols such as methanol.

In a preferred embodiment you can in step c) in the process according to the invention obtained butenedicarboxylic acid ester to adipic acid diesters hydrogenate. This hydrogenation can be carried out in a manner known per se, for example homogeneously or heterogeneously, preferably catalyzed heterogeneously.

Coming as heterogeneous catalysts preferably those considered as the catalytically active component a precious metal from Group 8 of the Periodic Table of the Elements, such as Palladium, ruthenium, rhodium, iridium, platinum, nickel, cobalt, copper, preferably palladium.

These metals can be in unsupported form, for example as suspension catalysts, preferably in the case of nickel or Cobalt can be used.

These metals can be in a supported form, for example on activated carbon, metal oxides, transition metal oxides, in particular aluminum oxide, silicon dioxide, preferably used as fixed bed catalysts become.

The one obtained from this hydrogenation adipic can advantageously be used in step a).

In the case of x = 6, this represents the dicarboxylic of the formula (II) underlying dicarboxylic acid n-butenedicarboxylic acid or is a mixture of isomeric n-butenedicarboxylic acid esters.

The corresponding n-butenedicarboxylic acid diesters of the formula (II) and their preparation are known per se. For example, the n-butenecarboxylic acid diesters can be dimerized with acrylic acid esters, such as those mentioned in the introduction US 3,013,066 . US 4,638,084 . EP-A-475 386 or also in J. Am. Chem. Soc. 87 (1965) 5638-5645 or J. Molecular Catalysis 29 (1985) 65-76 or step c) according to the invention described below.

The acrylic acid used in step a) and process are known for their production. For example, acrylic acid by gas phase oxidation of propene or propane in the presence of heterogeneous Catalysts are obtained.

Acrylic acid esters can also be used for example Esterification of acrylic acid with the corresponding alcohols in the presence of homogeneous catalysts, such as p-toluenesulfonic acid, be preserved.

The implementation of the dicarboxylic acid ester Formula (II) with acrylic acid can be done uncatalytically.

In an advantageous embodiment comes the use of a homogeneous or heterogeneous catalyst, in particular a heterogeneous catalyst. As a catalyst, preferably an inorganic or organic, Lewis or Brönstedt acid Connection are used. In the case of organic compounds can be advantageous Find ion exchangers. In the case of inorganic compounds oxides with acid centers, such as zeolites, are advantageous.

The implementation according to step a) can be carried out in one Reactor, like a stirred tank, a boiler cascade, like a stirred tank cascade, or in a distillation device, preferably one with Reaction vessel, advantageous in a reactive distillation column, especially one with a partition become.

Leads the reaction can be carried out in a distillation apparatus in the case of implementation according to step a) in the presence of a catalyst, this catalyst is advantageous in the area between the sump and the top of the distillation device to be built in.

Step a) gives a reaction mixture comprising a dicarboxylic acid of the formula (I) and a mixture of acrylic acid esters of the formula C ₂ H ₃ -COOR ¹ and C ₂ H ₃ -COOR ² , where R ¹ and R ^{2 have} the meanings mentioned , The reaction mixture can also contain dicarboxylic acid diesters of the formula (II), acrylic acid, dicarboxylic acid monoesters of the formula R ¹ -OOC- (nC ₄ H _x ) -COOH or HOOC- (nC ₄ H _x ) - COO- R ² , where R ¹ , R ² and x have the meanings already mentioned, R ¹ OH, R ² OH, water or mixtures thereof.

According to the step according to the invention b) the resulting dicarboxylic acid of the formula (I) is separated from the from the reaction mixture obtained in step a).

The separation according to step b) can take place in a step separate from step a). Puts one, for example, in step a) one of the boilers mentioned or of the boiler cascade called, the product mixture can the boiler or from the last boiler in the boiler cascade and then through known separation operations, such as distillation, extraction or crystallization, the dicarboxylic acid in one or more steps Formula (I) separated from the reaction mixture obtained in step a) become.

Such a method is shown schematically in 1 using the example of the reaction of dimethyl adipate with acrylic acid. Mean in the drawing
MeOH: methanol
ACS: acrylic acid
ACS-ME: acrylic acid methyl ester
ADS: adipic acid
ADS-MME: Mono-adipate
ADS-DME: methyl adipate
H2O: water
Grid: Optional catalyst
In an advantageous embodiment, steps a) and b) can be carried out partially or completely together. The reaction according to step a) in a distillation device is preferred.

In an advantageous embodiment the distillation device can be operated so that the dicarboxylic acid as from the rest Reaction mixture separate component is obtained. schematically this is in drawings 2 and 4, again based on the example Implementation of dimethyl adipate with acrylic acid shown, with abbreviations have the meanings already mentioned.

In a further advantageous embodiment the distillation device can be operated so that the dicarboxylic acid and at least one of their esters, ie dicarboxylic acid monoesters, dicarboxylic acid diesters or their mixtures, as separate from the rest of the reaction mixture Component is obtained and then from this mixture dicarboxylic acid is separated. This is shown schematically in drawing 3, again by way of example based on the implementation of methyl adipate with acrylic acid shown, with abbreviations have the meanings already mentioned.

From step b) in the case of x = 8 adipic acid be preserved.

In the case of x = 6, step b) n-butenedicarboxylic acid be preserved.

In a preferred embodiment you can in step b) obtained butenedicarboxylic acid to adipic acid hydrogenate. This hydrogenation can be carried out in a manner known per se, for example homogeneously or heterogeneously, preferably catalyzed heterogeneously.

Coming as heterogeneous catalysts preferably those considered as a catalytically active component a precious metal from Group 8 of the Periodic Table of the Elements, such as Palladium, ruthenium, rhodium, iridium, platinum, nickel, cobalt, Copper, preferably palladium.

These metals can be in unsupported form, for example as suspension catalysts, preferably in the case of nickel or Cobalt can be used.

These metals can be in a supported form, for example on activated carbon, metal oxides, transition metal oxides, in particular aluminum oxide, silicon dioxide, preferably used as fixed bed catalysts become.

According to the invention, in step c) the acrylic esters C ₂ H ₃ -COOR ¹ , C ₂ H ₃ -COOR ² obtained in step a) or their mixtures are dimerized to give n-butenedicarboxylic acid diester.

Process for dimerization of acrylic ester under Obtaining n-butenic acid ester are known per se.

So dimerization can be beneficial be carried out in the presence of a catalyst.

In an advantageous embodiment, the use of a homogeneous catalyst, such as a catalyst containing an element of Group 8 of the Periodic Table of the Elements, in particular rhodium or ruthenium, preferably in the form of a salt, such as a chloride, or a complex compound. Such catalysts and processes for the dimerization of acrylic esters to obtain n-butenoic acid diester in the presence of such catalysts are, for example, those mentioned above US 3,013,066 . US 4,638,084 . EP-A-475 386 or also in J. Am. Chem. Soc. 87 (1965) 5638-5645 or J. Molecular Catalysis 29 (1985) 65-76.

According to the invention, the step c) is split obtained dicarboxylic acid esters into the corresponding dicarboxylic acid of formula (I).

Processes for cleaving an ester to obtain the corresponding carboxylic acid are known per se, for example from US-A-5,710,325 or US-A-5,840,959 ,

In the case of x = 6 one can be advantageous the n-butenedicarboxylic acid obtained in step d) is hydrogenated to give it of adipic acid.

This hydrogenation can in itself in a known manner, for example homogeneously or heterogeneously, preferably catalyzed heterogeneously.

Coming as heterogeneous catalysts preferably those considered as the catalytically active component a precious metal from Group 8 of the Periodic Table of the Elements, such as Palladium, ruthenium, rhodium, iridium, platinum, nickel, cobalt, copper, preferably palladium.

These metals can be in unsupported form, for example as suspension catalysts, preferably in the case of nickel or Cobalt can be used.

These metals can be in a supported form, for example on activated carbon, metal oxides, transition metal oxides, in particular aluminum oxide, silicon dioxide, preferably used as fixed bed catalysts become.

In an advantageous embodiment in the case of x = 6 one can cleave n-butenedicarboxylic acid diester according to step d) perform by using the n-butenedicarboxylic acid ester obtained in step c) in step a), this n-Butendicarbonsäurediester according to step a) to n-butenedicarboxylic acid implemented and in step b) n-butenedicarboxylic acid as the dicarboxylic acid Formula (I) is obtained.

It is particularly advantageous to hydrogenate the n-butenedicarboxylic acid obtained in step d) to obtain adipic acid.

This hydrogenation can in itself in a known manner, for example homogeneously or heterogeneously, preferably catalyzed heterogeneously.

Coming as heterogeneous catalysts preferably those considered as the catalytically active component a precious metal from Group 8 of the Periodic Table of the Elements, such as Palladium, ruthenium, rhodium, iridium, platinum, nickel, cobalt, copper, preferably palladium.

These metals can be in unsupported form, for example as suspension catalysts, preferably in the case of nickel or Cobalt can be used.

These metals can be in a supported form, for example on activated carbon, metal oxides, transition metal oxides, in particular aluminum oxide, silicon dioxide, preferably used as fixed bed catalysts become.

In a further preferred embodiment in the case of x = 6, the n-butenedicarboxylic acid diester obtained in step c) between step c) and d) hydrogenate to obtain adipic diester.

This hydrogenation can in itself in a known manner, for example homogeneously or heterogeneously, preferably catalyzed heterogeneously.

Coming as heterogeneous catalysts preferably those considered as the catalytically active component a precious metal from Group 8 of the Periodic Table of the Elements, such as Palladium, ruthenium, rhodium, iridium, platinum, nickel, cobalt, copper, preferably palladium.

These metals can be in unsupported form, for example as suspension catalysts, preferably in the case of nickel or Cobalt can be used.

These metals can be in a supported form, for example on activated carbon, metal oxides, transition metal oxides, in particular aluminum oxide, silicon dioxide, preferably used as fixed bed catalysts become.

By cleaving the adipic acid diester according to step d) can adipic acid be preserved.

In an advantageous embodiment you can cleave the adipic acid diester according to step d) perform by obtaining the adipic acid diester obtained returns in step a), this adipic acid diester according to step a) converts to adipic acid and in step b) adipic acid as dicarboxylic acid of formula (I).

In the in the inventive method conducted Distillative separations can be azeotropic occur that are too insignificant in the sense of the present invention and only minor changes of the material flows mentioned can lead. The Separation of such azeotropes while maintaining those mentioned in the steps according to the invention Fabrics can be made by methods known per se.

Claims (8)

Process for the preparation of a dicarboxylic acid of formula (I) H-OOC- (nC ₄ H _x ) -COO-H (I) with x: 6 or 8 starting from acrylic acid, characterized in that a) a dicarboxylic acid diester of the formula (II) R ¹ -OOC- (nC ₄ H _x ) -COO-R ² (II) with x: 6 or 8 R ¹ , R ² independently of one another C ₁ -, C ₂ -, C ₃ -, C ₄ -alkyl, aryl, heteroaryl and can be identical or different with acrylic acid to give a dicarboxylic acid of the formula (I ) and a mixture of acrylic acid esters of the formula C ₂ H ₃ -COOR ¹ and C ₂ H ₃ -COOR ² , where R ¹ and R ^{2 have} the meanings mentioned, b) the dicarboxylic acid of the formula (I) obtained in step a) separated from the reaction mixture obtained in step a), c) the C ₂ H ₃ -COOR ¹ , C ₂ H ₃ -OOR ² or mixtures thereof obtained in step a) dimerized to give n-butenedicarboxylic acid diester, and d) those obtained in step c ) cleaved dicarboxylic acid diester into the corresponding dicarboxylic acid of the formula (I). The method of claim 1, wherein the cleavage of n-butenedicarboxylic acid diester according to step d) carries out by one the n-butenedicarboxylic acid ester obtained in step c) returns in step a), this n-Butendicarbonsäurediester according to step a) to n-butenedicarboxylic acid implements and in step b) n-butenedicarboxylic acid as the dicarboxylic acid Formula (I) is obtained. The method of claim 1, wherein obtained in step d) n-butenedioic hydrogenated to obtain adipic acid as the dicarboxylic acid of the formula (I). The method of claim 1, wherein the cleavage of n-butenedicarboxylic acid diester according to step d) carries out by one the n-butenedicarboxylic acid ester obtained in step c) returns in step a), this n-Butendicarbonsäurediester according to step a) to n-butenedicarboxylic acid implements, in step b) receives n-butenedicarboxylic acid and hydrogenated this n-butenedicarboxylic acid to obtain adipic acid as dicarboxylic acid of formula (I). The method of claim 1, wherein the one in step c) obtained n-butenedicarboxylic acid diester between step c) and d) hydrogenated to obtain diester of adipic acid and in step d) by cleavage of the adipic acid adipic acid as dicarboxylic acid of formula (I). The method of claim 1, wherein the one in step c) obtained n-butenedicarboxylic acid diester between steps c) and d) hydrogenated to obtain adipic diester, the Cleavage of the adipic acid diester according to step d) performs, by obtaining the adipic acid diester obtained in step a) and according to step a) to adipic acid implements and in step b) adipic acid as the dicarboxylic acid Formula (I) is obtained. Process according to claims 1 to 6, wherein the radicals R ¹ and R ^{2 are} independently methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl. Process according to claims 1 to 7, wherein the radicals R ¹ and R ^{2 are the} same.