DE10155520A1 - Process for the preparation of n-butyraldehyde, n-butanol and 2-ethylhexanol from 1,3-butadiene-containing hydrocarbon streams - Google Patents

Abstract

The present invention relates to a method for producing n-butyraldehyde, 2-ethylhexyl alcohol and/or n-butanol from 1,3-butadiene-containing hydrocarbon streams, which comprises the following steps: a) reacting 1,3-butadiene with an amine of general formula (I) to form an amine of formula (II), whereby, in said formulae (I) and (II), the substituents R<sp>1</sp> and R<sp>2</sp> independently represent hydrogen or an appropriate organic radical from the group alkyl, alkenyl, cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl and aralkyl, or R<sp>1</sp> and R<sp>2</sp> form a 3-to 7-membered heterocycle together with the nitrogen atom, which optionally comprises one or several double bonds and optionally one other heteroatom from the group N, O and S, in the presence of an amide of formula (III), in which R<sp>3</sp> and R<sp>4</sp> independently have the meaning indicated in the amines (I) and (II) for R<sp>1</sp> and R<sp>2</sp> and M represents an alkali metal; b) isomerizing the amine (II) to form an amine of formula (IV), in which R<sp>1</sp> and R<sp>2</sp> have the meaning indicated in the formulae (I) and (II) and c) releasing n-butyraldehyde as well as the amine of formula (I) by hydrolysis of said amine (IV) with water.

Description

The present invention relates to a process for the preparation of n-butyraldehyde from 1,3-butadiene-containing hydrocarbon streams. In the method according to the invention the 1,3-butadiene is added to amines, the resulting alkylamine can be removed Hydrolyze isomerization to an enamine to n-butyraldehyde. By hydrogenating n-Butyraldehyde is accessible to n-butanol, as are other products from various Reaction reactions, for example 2-ethylhexanol.

n-Butyraldehyde and n-butanol are large products of the chemical industry and can be found versatile use. n-Butyraldehyde is used worldwide in quantities of over 4 million t / year produces and serves as starting material for the production of various Secondary products.

On an industrial scale, n-butyraldehyde is now practically exclusively produced by Hydroformylation of propene, for which various processes exist that essentially use cobalt or rhodium hydroformylation catalysts, (Kirk-Othmer: Encyclopedia of Chemical Technology, 4th ed., Volume 4, pp. 741-746, John Wiley & Sons, New York 1992).

n-Butanol is one of the most important quantitative products of n-butyraldehyde and is obtained from this by hydrogenation. n-Butanol is widely used as Solvents, for example for paints, are used.

Other processes for the production of n-butanol, such as the hydrogenation of crotonaldehyde, which, in turn, is generated by aldol condensation of acetaldehyde are now only of historical interest or have such as the microbiological production of n-butanol due to the fermentation of molasses, only regional importance (Kirk-Othmer: Encyclopedia of Chemical Technology, 4th Edition, Volume 4, pp. 694-696, John Wiley & Sons, New York 1992). The process for the preparation of n-butyraldehyde and n-propanol, in particular the hydroformylation of propene require high investments, for example for the Construction of high-pressure plants for cobalt-catalyzed hydroformylation or for the purchase of the expensive rhodium catalyst, the equipment for its handling at the Hydroformylation and used up, rhodium-containing Catalyst solutions. Furthermore, for the production of n-butyraldehyde after Hydroformylation process syngas plants are available that the Hydroformylation supply the required synthesis gas. Another disadvantage of Hydroformylation is the high amount of by-product Isobutyraldehyde, due to its limited quantity of possible uses has only a low value.

2-ethylhexanol is produced on an industrial scale using an aldol reaction of n-butyraldehyde subsequent hydrogenation of the aldol product (Kirk-Othmer: Encyclopedia of Chemical Technology, 4th Edition, 1991, Vol. 1, p. 893; Ullmann 's Encyclopedia of techn. Chemistry, 4th edition, 1974, volume 4, p. 214). The alcohol is used to make the Plasticizer bis (2-ethylhexyl) phthalate.

It is understood that there is a need for processes that produce n- Enable butyraldehyde or n-butanol and not the disadvantages of the process according to Have state of the art. In particular, such a method is said to be easy Accessible, inexpensive raw materials.

1,3-butadiene is a basic chemical used in large quantities in that of steam crackers generated C4 cut occurs. Although in the meantime the most diverse procedures for Recovery of C4 cuts were developed, this is still comparatively available in large quantities and is still considered an inexpensive raw material. butadiene C4 cutting is also a raw material that is difficult to handle. This is because about both the tendency of 1,3-butadiene to dimerize and Polymerization reactions than on the formation of mixtures of 1,2- and 1,4-adducts in addition reactions due to the presence of two conjugated double bonds in the 1,3-butadiene molecule (Kirk-Othmer: Encyclopedia of Chemical Technology, 4th ed., Volume 4, pp. 676-683, John Wiley & Sons, New York 1992).

It is known from US 3,391,192 that amines with 1,3-butadiene in the presence of Alkali metal amides react to the corresponding allylamines. Falk et al. (J. Org. Chem. 37, 4243 (1972)) examined the lithium amide-catalyzed addition of amines of butadiene depending on the solvent and amine. Kakuno and Hattori (J. Catal. 85 (1984) 509) described the catalyzed reaction of butadiene and amines with Solid base catalysts such as MgO or CaO. The reaction mixture is in a circulating gas reactor passed over a fixed bed at a total pressure of 100 torr. According to US 4,675,307 are strongly basic hydrotalcites as catalysts for the Suitable for hydroamination. Also the use of transition metal complexes as Catalysts for the addition of amines to 1,3-butadiene are from a variety of Publications and patent applications known.

A disadvantage of all known processes for the addition of amines to 1,3-butadiene lies mainly in the fact that in addition to the desired 1,4-addition product (N-but-2- enylamine) an undesirably high amount of the branched 1,2-addition product (N- (2- Methyl-prop-2-enylamine) is formed. The formed with the previously known methods Amount of 1,2-addition product is in a range for large-scale processes is not or hardly tolerable. An isomerization following the addition reaction of the 1,2-addition product to the 1,4-addition product cannot be avoided. Furthermore is it is necessary - in the event that from the amines obtained in the addition reaction Production of butyraldehyde is desired - that obtained after the 1,4-addition Rearrange allylamine to the double bond isomer enamine N-but-1-enylamine. Out the linear n-butyraldehyde is accessible to it in a hydrolysis reaction.

The double bond rearrangement mentioned is a known reaction that occurs in the scientific and patent literature is described. There have already been a number of reagents examined The isomerization of 1-N-pyrrolidino-2-propene with basic heterogeneous oxide catalysts such as MgO, CaO or BaO is described by Hattori et al. (J. Catal. 65, 245 (1980). Hubert (J. Chem. Soc. (C), 2048 (1968)) leads the Rearrangement of allylamines in the presence of supported potassium amide Alumina through. In addition to the heterogeneous catalysts mentioned homogeneous catalysts for the isomerization of allylamines in the liquid phase. Strong bases soluble in the organic medium, such as potassium tert-butoxide have been developed by Price et al. (Tetrahedron Lett. 69 (1962)), Sauer (Tetrahedron Lett. 2863 (1966)) and Martinez (Tetrahedron 34, 3027 (1978)) for the conversion of allylamines Enamines examined.

In addition to these base-catalyzed reactions, there are also reactions Transition metal compounds described.

Isomerizations of Secondary and Tertiary Allylamines with Rhodium Diphosphine Complexes to enamines or imines have been described by Otsuka et al. (J. Am. Chem. Soc. 106, 5208 (1984)) and Schmid et al. (Helv. Chim. Acta 73, 1258 (1990), Helv. Chim. Acta 74, 370 (1991)). From US-A 4,861,890, EP-A 068 506 and EP-A 257 411 and from Otsuka (Org. Synth. 67, 33 (1989)) it is known that β, γ-unsaturated amines isomerize with rhodium-diphosphine complexes to enamines, which after hydrolysis in their corresponding aldehydes are transferred.

A rearrangement of allylamines catalyzed by cobalt-phophine complexes is described in JP-A 79/5907 and by Otsuka (J. Am. Chem. Soc. 100, 3949 (1978)). Next Molybdenum (Tatsumi et al. J. Organomet. Chem. 25Z 105 (1983)) or ruthenium compounds (EP-A 398 132; Doering et al. J. Am. Chem. Soc. 107, 428 (1985)) can be used.

A process for the preparation of n-butyraldehyde or n-butanol starting from 1,3- Butadiene and a dialkylamine is disclosed in DE-A 44 31 528 by the applicant. First 1,3-butadiene is reacted with a dialkylamine and then that 1,2-addition product N- always formed in relatively high amounts of about> 10% by weight 1-Methyl-prop-2-enylamine isomerized to the 1,4-addition product. The 1,4- Addition product N-but-2-enylamine is isomerized to N-but-1-enylamine and so formed enamine hydrolyzed and optionally hydrogenated, after which n-butyraldehyde or n-butanol is obtained.

The process according to DE-A 44 31 528 provides n-butyraldehyde in good yields and high purity, but has a comparatively complex sequence of several Reaction steps on. For example, there are two different isomerization reactions necessary (a scaffold isomerization of 1,2- to 1,4-adduct and one Double bond isomerization from allylamine to enamine). It would be desirable, to have a process that is less complex to carry out and n- Butyraldehyde and / or n-butanol provides comparable yield and purity.

Furthermore, the method according to DE-A 44 31 528 requires an optimum Result of the use of 1,3-butadiene, that of the other, available in the C4 cut Products of the cracking process was exempted. It is also the use of a C4 cut possible. However, an undesirably high proportion of by-products is formed, the product yield is generally lower than when using 1.3- Butadiene. Finally, in the hydrolysis of the enamine in a Side reaction butylated insert amine (carrier amine) is formed, causing the carrier amine is lost and has to be replaced by a new substrate.

The present invention is therefore based on the object of a method for Production of n-butyraldehyde and / or n-butanol to find the above Disadvantages of the method listed in DE-A 44 31 528 does not have. The The method should in particular be applicable on an industrial scale.

• a) Umsetzen von 1,3-Butadien mit einem Amin der allgemeinen Formel
  
  R¹R²NH I
  
  zu einem Amin der Formel
  
  
  wobei in den Formeln I und II die Substituenten R¹ und R² unabhängig voneinander für Wasserstoff oder einen geeigneten organischen Rest aus der Gruppe Alkyl, Alkenyl, Cycloalkyl, Alkoxyalkyl, Aminoalkyl, Monoalkylaminoalkyl, Dialkylaminoalkyl, Aryl und Aralkyl stehen, oder R¹ und R² gemeinsam mit dem Stickstoffatom einen 3-7-gliedrigen Heterocyclus bilden, der gegebenenfalls ein oder mehrere Doppelbindungen sowie gegebenenfalls ein weiteres Heteroatom aus der Gruppe N, O und S aufweist,
  in Anwesenheit eines Amids der Formel
  
  MNR³R⁴ III
  
  in der R³ und R⁴ unabhängig voneinander die bei dem Amin I und dem Amid II für R¹ und R² gegebene Bedeutung haben und M für ein Alkalimetall steht;
• b) Isomerisieren des Amins II zu einem Amin der Formel
  
  
  in der R¹ und R² die bei den Formeln I und II gegebene Bedeutung haben;
• c) Freisetzen von n-Butyraldehyd sowie des Amins der Formel I durch Hydrolyse des Amins IV mit Wasser.

This object is achieved by a process for the preparation of n-butyraldehyde from 1,3-butadiene with the following steps:

• a) reacting 1,3-butadiene with an amine of the general formula
  
  R ¹ R ² NH I
  
  to an amine of the formula
  
  
  where in the formulas I and II the substituents R ¹ and R ² independently of one another represent hydrogen or a suitable organic radical from the group alkyl, alkenyl, cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl and aralkyl, or R ¹ and R ² together with the nitrogen atom form a 3-7-membered heterocycle which optionally has one or more double bonds and optionally a further heteroatom from the group N, O and S,
  in the presence of an amide of the formula
  
  MNR ³ R ⁴ III
  
  in which R ³ and R ⁴ independently of one another have the meanings given for amine I and amide II for R ¹ and R ² and M represents an alkali metal;
• b) isomerizing the amine II to an amine of the formula
  
  
  in which R ¹ and R ^{2 have} the meaning given in the formulas I and II;
• c) release of n-butyraldehyde and the amine of the formula I by hydrolysis of the amine IV with water.

In one embodiment of the present invention, after hydrolysis in Sub-step c) hydrogenated n-butyraldehyde to n-butanol. This hydrogenation can be in a preferred embodiment carried out simultaneously with the hydrolysis of the enamine and these two process steps thus to a single process step c) be summarized.

The partial reactions a) and b) can also preferably be summarized in such a way that unreacted amine II and optionally, from a hydrolysis of amines II and IV, but not preferred, also a residue of amine IV in the combined reaction step a) plus b) recycled and parallel to the synthesis of II from I and 1,3-butadiene II to IV isomerized.

The process according to the invention for the preparation of n-butyraldehyde and / or n-butanol is composed of 3 partial reactions a) to c). The partial reactions a) and b) can optionally be separated from one another using different catalysts or coupled avoiding refurbishment steps and using the same Catalyst or the same type of catalyst can be carried out. But it can also the partial reactions b) and c) are combined into a single process step.

In this application, the expression "process stage" is used on the one hand for a Plant unit used, in each of which one of the partial reactions a) to c) on the or the catalyst or catalysts used in this plant unit expires. "Process stage" on the other hand denotes a plant unit in which several, in particular 2 of these partial reactions, side by side on the or in this plant unit used catalyst or catalysts expire.

Is the catalyst used in a plant unit (or that in a plant unit catalysts used), for example, able to, among the present Reaction conditions according to the isomerization of allylamine II to enamine IV React partial reaction b) and the hydrolysis / hydrogenation according to partial step c), wherein the sequence of these partial reactions in the plant unit is not spatially separate can be separated in this application from the implementation of the Partial reactions b) and c) spoken in a single process step. A The plant unit can have both a single reactor and several in series switched reactors include those with the same or optionally with different catalysts are filled and in the same mode of operation and at the same or different temperature and pressure conditions are operated. As The operating mode is, for example, working in the liquid phase a homogeneous catalyst that works in the liquid phase using a Understand heterogeneous catalyst or working in the gas phase. It follows that in this application, for example, then not from a single implementation Process stage is spoken when in the individual, successive reactors Catalysts are used alone to catalyze a particular sub-reaction are capable of working in these reactors with different operating modes or if different temperatures occur when a partial reaction is carried out compared to the previous partial reaction.

In the addition reaction of the amine with 1,3-butadiene, the eductamine is mixed with a 1,3-butadiene-containing mixture implemented. This happens in the presence of one Alkali metal amide as a catalyst.

• a) C4-Schnitte, die großtechnisch bei der thermischen oder katalytischen Spaltung von Erdölfraktionen, wie z. B. Benzinen, insbesondere Naphtha, anfallen (Steamcracken; siehe z. B. K. Weissermel und H.-J. Arpe, Industrielle Organische Chemie, 4. Aufl. 1994, VCH Verlagsgesellschaft, Seiten 70-76);
• b) Kohlenwasserstoffströme aus der Dehydrierung von sogenanntem LPG oder LNG, vorzugsweise C4-Schnitten daraus, wobei der C4-Anteil des LPG-Stroms vor oder nach der Dehydrierung vom LPG-Strom abgetrennt wird. Ein LNG-Strom mit hohem C1 und C2 kann dabei z. B. über ein MTO-Verfahren zuvor in C4 überführt werden.

The 1,3-butadiene-containing mixtures preferably come from the following sources:

• a) C4 cuts, the industrial scale in the thermal or catalytic splitting of petroleum fractions, such as. B. gasoline, in particular naphtha, occur (steam cracking; see, for example, BK Weissermel and H.-J. Arpe, Industrial Organic Chemistry, 4th ed. 1994, VCH Verlagsgesellschaft, pages 70-76);
• b) hydrocarbon streams from the dehydrogenation of so-called LPG or LNG, preferably C4 cuts thereof, the C4 fraction of the LPG stream being separated from the LPG stream before or after the dehydrogenation. An LNG stream with high C1 and C2 can z. B. previously transferred to C4 using an MTO process.

LPG means Liquified Petroleum Gas. Such liquefied gases are defined for example in DIN 51 622. They generally contain the Hydrocarbons propane, propene, butane, butene and their mixtures, which in Oil refineries as by-products in the distillation and cracking of petroleum and in the Natural gas processing during gasoline separation. LNG means Liquified Natural Gas (natural gas). Natural gas mainly consists of saturated hydrocarbons, which ever have different compositions according to their origin and in general be divided into three groups. Natural gas from pure natural gas deposits consists of Methane and little ethane. Natural gas from oil deposits also contains larger ones Amounts of higher molecular hydrocarbons such as ethane, propane, isobutane, butane, Hexane, heptane and by-products. Natural gas from condensate and distillate deposits contains not only methane and ethane, but also to a considerable extent higher boiling Components with more than 7 carbon atoms. For a more detailed description of Liquefied gases and natural gas can be found in the relevant keywords in Römpp, Chemistry lexicon, 9th edition.

The LPG and LNG used as the starting mixture (feedstock) include in particular so-called field butanes, how to get the C4 fraction of the "moist" portions of natural gas as well as the associated petroleum gases, which by drying and cooling to about -30 ° C in liquid form can be separated from the gases. By low temperature or Pressure distillation is used to obtain the field butanes, the composition of which depends on Deposit fluctuates, but generally about 30% isobutane and about 65% n- Contain butane.

Suitable processes for the dehydrogenation of hydrocarbons are, for example, in DE-A-10 04 7642. Can also be used for the dehydrogenation of alkanes US 4,788,371, WO 94/29021, US 5,733,518, EP-A-0 838 534, WO 96/33151 or WO 96/33150 to get expelled.

The MTO mentioned above stands for methanol-to-olefin. It is related to the MTG (Methanol-To-Gasoline) process. It is a process for the dehydration of methanol over suitable catalysts, whereby an olefinic hydrocarbon mixture is formed. Even C ₁ feed streams can thus be converted into olefin mixtures, for example via methanol and the MTO process, from which the C ₄ components can be separated off by suitable methods. The separation can take place, for example, by distillation. For the MTO process, reference can be made to Weissermel, Arpe, Industrielle organic Chemie, 4th edition 1994, VCH-Verlagsgesellschaft, Weinheim, p. 36 ff.

• a) C4-Schnitte aus der sogenannten GTL-Technologie, beispielsweise der Fischer- Tropsch-Synthese.
• b) beliebige Mischungen aus den vorgenannten Kohlenwasserstoffströmen.

The methanol-to-olefin process is also described, for example, in PJ Jackson, N. White, Technologies for the conversion of natural gas, Austr. Inst. Energy Conference 1985.

• a) C4 sections from the so-called GTL technology, for example the Fischer-Tropsch synthesis.
• b) any mixtures of the aforementioned hydrocarbon streams.

Preferred C4 cuts have the following composition (in% by weight): 1. C4 cracker cuts 1,3-butadiene
25-60, preferably 35-50, particularly preferably 40-45;
Butenes (isobutene, 1-butene, trans-2-butene, cis-2-butene):
35-70, preferably 40-60;
Butanes (n-butane, isobutane):
3-12, preferably 5-10;
Alkynes (vinyl acetylene, 1-butyne):
0-4, preferably 0 - <2, particularly preferably 0 - <1;
Other (e.g. 1,2-butadiene, C5 components such as pentanes):
0-2, preferably 0-1.

A typical C4 cracker cut composition (in% by weight) is e.g. B .:
1,3-butadiene: 42.3
Butenes: 47, 5
Butanes: 8.7
Alkynes: 0.8
Others: 0.7. 2. Hydrocarbon mixtures from the dehydrogenation of n-butane 1,3-butadiene:
3-40, preferably 5-30, particularly preferably 7-15;
Butenes (1-butene, trans-2-butene, cis-2-butene):
35-70, preferably 40-60;
n-butane:
35-70, preferably 40-60;
Alkynes (vinyl acetylene, 1-butyne):
0-1, preferably 0-0.5, particularly preferably 0-0.2;
Other (e.g. 1,2-butadiene):
0-1, preferably 0-0.5.

A typical composition (in% by weight) of C4 from an n-butane dehydrogenation is e.g. B .:
1,3-butadiene: 8
Butenes: 46
Butanes: 45
other: <1 3. Hydrocarbon mixtures from the dehydrogenation of field butanes 1,3-butadiene:
1-20, preferably 2-15, particularly preferably 3-10;
Butenes (1-butene, trans-2-butene, cis-2-butene, i-butene):
50-90, preferably 60-80;
Butanes (n-butane, i-butane):
15-50, preferably 20-40;
other:
0-1, preferably 0-0.5.

A typical composition (in% by weight) of C4 from an n-butane dehydrogenation is e.g. B .:
1,3-butadiene: 6
Butenes: 66
Butanes: 27
other: 1

A hydrocarbon feed stream which is less than 2% by weight, contains in particular less than 1% by weight of compounds which, according to the MSAD Have a pKs value less than 30.

Such connections are e.g. B. to H ₂ O, alcohols or oxo compounds, but also hydrocarbons such. B. 1-butyne, cyclopentadiene and vinyl acetylene.

[For the definition of the MSAD scale see ("Mc Ewen-Streitwieser-Applequist-Dessy scale") z. B. in D. J. Cram, Fundamentals of Carbonion Chemistry, Acad. Press, 1965].

These substances can interfere with the process in that they form amide III protonate and an increased amount of alkali metal to maintain catalysis is necessary. They are not a fundamental chemical problem.

Surprisingly, the method according to the invention enables the implementation of the Ammonia or amine with the 1,3-butadiene-containing mixture an olefin selectivity, based on all olefins in the mixture, greater than 90%, in particular greater than 95%, entirely particularly greater than 98% of the corresponding n-butenylamine as a hydroamination product to obtain. The 1,3-butadiene-containing mixture reacts almost exclusively with 1,3- Butadiene. Furthermore, the use of Alkali metal amides <10%, based on the 1,4-addition product, formed on 1,2-addition product.

• 1. Verwendung der erfindungsgemäß benutzten Alkalimetallkatalysatoren,
• 2. Verwendung eines Unterschuß an 1,3-Butadien - bevorzugt ist ein molares Verhältnis 1,3-Butadien im butadienhaltigen Gemisch: sekundärem Amin von 0,95 : 1 bis 1 : 10, besonders bevorzugt von 0,9 : 1 bis 1 : 2 bzw. ein molares Verhältnis 1,3-Butadien im butadienhaltigen Gemisch: primärem Amin von 1,9 : 1 bis 1 : 5, besonders bevorzugt ist 1,8 : 1 bis 1 : 1 -,
• 3. Wahl des Temperaturfensters von 20 bis 130°C, vorzugsweise 70 bis 100°C
• 4. Einstellung einer aktuellen Konzentration an 1,3-Butadien im Reaktionsgemisch von < 3, bevorzugt < 1, besonders bevorzugt < 0,5 Gew.-%.

The very high selectivity is achieved by one or more of the following measures:

• 1. Use of the alkali metal catalysts used according to the invention,
• 2. Use of a deficit of 1,3-butadiene - a molar ratio of 1,3-butadiene in the butadiene-containing mixture: secondary amine is preferred from 0.95: 1 to 1:10, particularly preferably from 0.9: 1 to 1: 2 or a molar ratio of 1,3-butadiene in the butadiene-containing mixture: primary amine from 1.9: 1 to 1: 5, particularly preferred is 1.8: 1 to 1: 1 -,
• 3. Choice of the temperature window from 20 to 130 ° C, preferably 70 to 100 ° C.
• 4. Setting a current concentration of 1,3-butadiene in the reaction mixture of <3, preferably <1, particularly preferably <0.5% by weight.

The reaction conditions are particularly preferably selected such that 1,3-butadiene 98%, in particular 99%, of the 1,3-butadiene-containing mixture is removed.

The remaining components of the 1,3- Butadiene-containing mixture can after separation and optionally cleaning processed and used for other purposes. For example, these remaining ingredients again in a steam cracker or an alkane dehydrogenation be returned.

Contain the remaining components of the 1,3-butadiene-containing mixture used still small amounts of 1,3-butadiene, these constituents are preferably fed to a 1,3-butadiene partial hydrogenation stage.

In particular, the constituents remaining after the implementation has been carried out of the 1,3-butadiene-containing mixture used when the reaction was carried out complete removal of the 1,3-butadiene after its separation as a so-called Raffinate I can be processed further.

Such a raffinate I obtained according to the invention contains n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene, isobutene, less than 1% by weight, in particular less than 0.5% by weight, very particularly 0-0.1% by weight of 1.3 butadiene, 0-0.1% by weight of alkynes and optionally residues of other components (e.g. traces of C5 components).

The method according to the invention is thus also a method for producing a 1,3- Butadiene-free mixture (i.e. 1,3-butadiene content less than 1% by weight, in particular less than 0.5% by weight, very particularly less than 0.1% by weight), e.g. B. raffinate I, from the corresponding 1,3-butadiene-containing mixture, which is used in the splitting of petroleum fractions was obtained (e.g. a C4 cut).

If the reaction conditions are not carefully selected or on top of each other coordinated, it can happen that some of the 1,3-butadiene-containing Mixture contained butenes reacted with the primary and / or secondary amine. This is particularly the case at temperatures> 150 ° C. This creates sec- butylated amines, which are generally undesirable.

Amines or mixtures thereof which can be used in the process according to the invention are amines of the formula

R ¹ R ² NH I

in which R ¹ and R ² independently of one another represent hydrogen or a suitable organic radical from the group alkyl, alkenyl, cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl and aralkyl, or R ¹ and R ² together with the nitrogen atom represent a 3rd Form a 7-membered heterocycle which optionally has one or more double bonds and optionally a further heteroatom from the group N, O and S.

Since the amine is split off and returned after the reaction has ended, the size of the or the organic substituents are not critical. The amine I only needs one for the addition reaction has sufficient reactivity.

It is preferred if R ¹ and R ² independently of one another from the group consisting of hydrogen, C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl, C ₃ -C ₂₀ cycloalkyl, C ₃ -C ₂₀ cycloalkenyl , C ₆ -C ₁₀ aryl and C ₇ -C ₁₁ aralkyl optionally substituted with C ₁ -C ₄ alkyl groups.

In particular, the amine is selected from the group consisting of ammonia, mono- and dialkylamines with C ₁ -C ₆ alkyl, C ₂ -C ₆ alkyl and C ₄ -C ₇ cycloalkyl substituents and C ₁ -C ₆ -N -Alkylanilinen.

Some amines to be used according to the invention are listed below by way of example:
Methylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, iso-butylamine, sec-butylamine, tert-butylamine, iso-pentylamine, 3-methyl-2-butylamine, n-hexylamine, octylamine, 2-ethylhexylamine , Decylamine, tert-hexylamine 1,1,3, tetramethylbutylamine, allylamine, 2-butenylamine, 3-pentenylamine, hexylamine, n-heptylamine, cyclopentylamine, cyclohexylamine, methylcyclohexylamine, cyclooctylamine, cyclodecylamine, benzylamine, 2-phenylethylamine, 4- Methoxyphenylethylamine, aniline, toluidine, 2-diethylaminoethylamine, dimethylaminopropylamine, 2-aminoethanol, 1-amino-2-propanol, 3-aminopropanol-1,2-aminobutanol-1, dimethylamine, diethylamine, dipentylamine, di-n-hexylamine di-2 -ethylhexylamine, N-methylbutylamine, N-ethylbutylamine, di-2-methoxyethylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-methylethylamine, N-methylbutylamine, di-2-methoxyethylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, N-ethylyl , Dicyclohexylamine, N-ethylaniline, diamylamine, di-n-octylamine, allylmethylamine, 2-butene ylethylamine, dialkylamine, N-methylbenzylamine, allylmethyllylamine, pyrrolidine, piperidine, 4-methylpiperidine, morpholine, 2,6-dimethylmorpholine, imidazole, 2-methylimidazole, 4-methylimidazole, piperazine, 1-ethylpiperazine, pyrazole, ethylenediamine, 1,3-ethylenediamine Diaminopropane, 1,2-propyl diamine, neopentane diamine, hexamethylene diamine, diethylene triamine.

The amines used are generally of technical origin and contain up to 0.1 mol% of impurities such as. B. H ₂ O, tertiary amines - z. B. dibutylmethylamine in dibutylamine, and alcohols, amides, enamines or nitriles. Amines of technical quality, such as B. offered by BASF or Air Products are generally of sufficient quality.

Preferred amines are piperazine, mono-n-butylamine and di-n-butylamine. The the most preferred amine is di-n-butylamine. It is, for example, from BASF AG the product no. 208.056 offered.

As a catalyst in the addition of 1,3-butadiene to ammonia, a primary or secondary amine, an alkali metal amide is used as the catalyst. Preferably the metal amide (III) is derived from the amine (I) which is reacted with the butadiene in the aminoalkylation reaction. The substituents R ³ and R ⁴ in formula (III) are identical to the substituents R ¹ and R ² in formula (I).

The alkali metal amides used correspond to the general formula

MNR ³ R ⁴ III

in which M denotes Li, Na, K, Rb or Cs, preferably Li, Na or K, more preferably Na or K, in particular Na, and R ³ and R ⁴ independently of one another have the meaning of the substituents R given in connection with formula I. ¹ and R ² have.

Alloys of the alkali metals can also be used with one another. A Pre-cleaning of the alkali metals before use in the reaction is not necessary. So can technical alkali metal, as z. B. from the companies Métaux-Spéciaux, Chemmetall, Callery Chem. Comp., PA or Alkali Metals Ltd., Hyderabad, India is offered be used. The alkali metal is usually contaminated by hydroxides, oxides, Alkaline earth metals, halides and - in the case of lithium - nitrides.

Examples of alkali metal alkylamides are NaHNC ₂ H ₅ , NaN (C ₂ H ₅ ) ₂ , KHNC ₂ H ₅ , KN (C ₂ H ₅ ) ₂ , LiHNC ₂ H ₅ , LiN (C ₂ H ₅ ) ₂ , LiN (iso- C ₃ H ₇ ) ₂ , NaN (iso-C ₃ H ₇ ) ₂ , NaN (nC ₄ H ₉ ) ₂ , NaHN (iso-C ₃ H ₇ ) and NaHN (iso-C ₅ H ₁₁ ).

Na (H) N (nC ₄ H ₉ ) and K (H) N (nC ₄ H ₉ ) are particularly preferred for the hydroamination of n-butylamine with the 1,3-butadiene-containing mixture, and for the hydroamination of di- n-Butylamine with the 1,3-butadiene-containing mixture are particularly preferred NaN (nC ₄ H ₉ ) ₂ and KN (n-C ₄ H ₉ ) ₂ , with NaN (nC ₄ H ₉ ) _{2 being} particularly preferred.

The alkali metal amides used according to the invention are prepared as in Houben-Weyl, Methods of Organic Chemistry, 4th edition, Volume XI / 2 (nitrogen compounds II and III), Verlag Thieme, Stuttgart, p. 182ff., In US Pat. No. 4,595,779 , WO 93/14061, DE-A-21 17 970, DRP 615.468, GB-A-742 790, DE-A-2613 113, US-A-2,750,417, J. Wollensak, Org. Synth. 43 (1963), page 45ff, or CA Brown, J. Am. Chem. Soc. 95 (3) (1973), page 982ff, described by reacting the alkali metal with the corresponding amine in the presence of an unsaturated compound such as. B. 1,3-butadiene, isoprene, naphthalene, pyridine or styrene, by reacting an alkali amide of ammonia MNH ₂ or hydride with the corresponding amine or by reacting an organometallic compound such as. B. n-BuLi, MeLi, PhNa, naphthalides of Li, Na and K or graphite compounds such as C ₈ K and C ₂₄ K with the corresponding amine.

As a rule, the procedure is such that the catalyst (or the corresponding Alkali metal, the corresponding metal hydride or the corresponding Organometallic compound such as n-butyllithium as a catalyst precursor) in the corresponding amine dissolves or suspended.

The catalyst can be used as a solution, as a suspension or supported on a typical catalyst support such as e.g. B. SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , activated carbon, MgO, MgAl ₂ O ₄ are present. The catalyst is preferably present as a solution or suspension, particularly preferably as a solution.

The hydroamination reaction is carried out as described below:
1,3-butadiene is in the form of a 1,3-butadiene-containing mixture which is obtained by splitting petroleum fractions, preferably in the form of a 1,3-butadiene-containing mixture having a composition as described above, with ammonia, a primary amine and / or a secondary amine implemented under hydroaminating conditions.

Of course, it is also possible to use pure butadiene, which has no or only small amounts of has usual, in its manufacture accompanying products in which Use the inventive method. However, a large part of the advantages are lost of the method according to the invention, in particular the simplification of the method Because of the unnecessary purification step of the butadiene.

In the reaction of the 1,3-butadiene-containing mixture with a secondary amine the result of the hydroamination step is a tertiary amine, the one Has n-butenyl substituents, depending on the reaction with a primary amine selected reaction conditions with either a secondary amine or tertiary amine one or two n-butenyl substituents or a mixture thereof. In the case of choosing Ammonia as an amine gives a primary, secondary or tertiary amine with a two or three n-butenyl substituents or mixtures thereof.

In the process according to the invention, the 1,3-butadiene is generally converted into the N-but-2- enylamine II formed; this can be in the (E) and (Z) form, the (E) form is preferred. The double bond isomer corresponding N-but-3-enylamine is only in small amounts of generally <10% by weight, this also being used in step b) Enamine IV is hydrolyzed and therefore does not interfere.

Particularly preferred amines are mono- and dialkylamines such as monoethylamine, Diethylamine, n-butylamine, di-n-butylamine, piperazine, t-butylamine and isopropylamine.

Starting from 1,3-butadiene and di-n-butylamine is preferred in one Embodiment of stage a) of the process according to the invention di-n-butyl-n-but-2- Get enylamine.

The reaction of the 1,3-butadiene-containing mixture with the amine in the presence of the Metallamids (hydroamination stage) can e.g. B. analogous to G. P. Pez et al., Pure & Appl. Chem. 57 (12), 1917-26 (1985), R. D. Closson et al., J. Org. Chem. 22 (1957), 646-9, G.M. Whitman et al., US-A-2,501,556), D. Steinborn et al., Z. Chem. 29 (1989), 333-4, D. Steinborn et al., Z. Chem. 26 (1986) 349-59 and H. Lehmkuhl et al., J. Organomet. Chem. 55 (1973), 215-20.

The reaction of the 1,3-butadiene-containing mixture with the amine in the presence of the Metallamides can also in the presence of small amounts of ammonia (less than 1 mol.% based on the amine (s) used) are carried out (analogously to DE-A-21 17 790).

In a preferred embodiment of the present invention, the manufacture of the metal amide carried out in situ, the catalytic hydroamination of the 1,3- Butadiene-containing mixture after the formation of the catalyst directly or optionally after adding the necessary amount of the amine to be reacted. You bet the amine that reacts with the 1,3-butadiene in the hydroamination reaction with a suitable organometallic compound, for example butyllithium, or an alkali metal around. The reaction with an alkali metal is preferred. The in-situ production of the Amides can thus be carried out before reaction stage a) or simultaneously with it occur.

Since the presence in the production of amides from an amine and alkali metal an electron-donating substance - for example 1,3-butadiene - is necessary Amide formation spontaneously upon addition of the 1,3-butadiene-containing mixture. The The resulting amide - which is not isolated - then acts as a catalyst in the reaction of the excess amine with the butadiene. In this embodiment, usually used the same amine in the preparation of the amide and the hydroamination, so that the amide catalyst is derived from the starting amine.

The process can be carried out in full, semi or batchwise.

In the in-situ representation of the metal amide, a dispersion of the alkali metal in the selected amine with the usual technical methods known to those skilled in the art Processes, generally by the action of shear forces, such as stirring or Ultrasound. The dispersion is preferably above the melting temperature of the alkali metal and can, for example, with a suitable stirrer, a nozzle, a reaction mixing pump or a pump and a static mixer respectively. The metal can also be injected into, or over, cold amine the gas phase can be sprayed onto cold amine. Also spraying in cold Gas with subsequent redispersion is possible.

The metal is preferably dispersed so that 50% by weight of the metal in droplets <1000 μm, particularly preferably <300 μm, in particular <100 μm. If available a coarser dispersion may result in a higher consumption of alkali metal, since this is not implemented quantitatively. If necessary, after the production of the Additional amine added to the catalyst, if this is not yet in the necessary Quantities. After the catalyst has been provided, it then optionally occurs Adjust the reaction conditions, the hydroamination reaction

To prevent butadiene polymers, the concentration of 1,3- Butadiene in the reaction mixture preferably at values <5% by weight, more preferably < 3% by weight, in particular <1% by weight.

In the method according to the invention, the use of Alkali metal amide catalysts in step a) <10%, preferably <2%, in particular <0.2% of framework isomers of N-but- (2, E) -enyldialkylamine, e.g. B N- (1-methyl-prop-2- enyldialkylamin).

The metal amide can during the reaction by z. B. β-elimination or exposure to H ₂ as described in DE-A-26 13 113 can be converted into metal hydride; in the case of β elimination, an imine is formed in parallel. This can under the action of primary or secondary amine according to DE-A-26 13 113, CA Brown, J. Am. Chem. Soc. 95 (3) (1973), 982ff or CA Brown, Synthesis (1978), 754ff, can be converted back to metal amide and H ₂ , so that the metal hydride can be regarded as a kind of "resting form" of the metal amide and therefore in the sense of the present Invention is equated with the metal amide. A metal hydride as such can also be used as a catalyst in the reaction. Usually this will then react with the amine present to form the catalytically active amide.

Furthermore, complexing agents can be used as solvents both in catalyst production and also be present in the hydroamination reaction.

It is known to use N, N, N ', N'-tetramethylethylenediamine, N, N, N', N ', N "- Pentamethyldiethylenetriamine, N, N, N ', N'-tetramethylcyclohexanediamine and Tetrahydrofuran as complexing agent, see for example J. F. Remenar (J. Am. Chem. Soc. 120 (1988), 4081ff), H. Lehmkuhl et al. (J. Organomet. Chem. 55 (1973), 215ff) and D. Steinborn et al. (Z. Chem. 29 (1989), 333ff.). Furthermore, amines with several Amine functions per molecule, such as B. N, N ', N'-tetraethylethylenediamine, N- permethylated or N-perethylated triethylene tetramine to N-permethylated or N-perethylated polyimine with molecular weights of up to 500,000 daltons, ethers and polyethers, such as B. diglyme, triglyme and the corresponding homologues, end group capped polyols - e.g. B. polyethylene glycol, polypropylene glycol, Poly-THF and complexing agents with amine N and ethereal O atoms in Molecule, such as B. 3-methoxyethylamine, 3- (2-methoxyethoxy) propylamine or N, N, N ', N'-tetramethyldiaminodiethyl ether can be used.

The hydroamination of the 1,3-butadiene-containing mixture can be carried out batchwise, semi-continuously or continuously.

In the first case, the 1,3-butadiene-containing mixture is added to the catalyst and amine and implemented. In the second case, the 1,3-butadiene-containing mixture becomes Dosed reaction mixture. In the third case, catalyst, amine and 1,3-butadiene containing mixture continuously metered.

• 1. Einsatz eines Unterschusses an Butadien, vorzugsweise eines molaren Verhältnisses 1,3- Butadien im butadienhaltigen Gemisch: sekundärem Amin von 0,95 : 1 bis 1 : 10, besonders bevorzugt von 0,9 : 1 bis 1 : 2 bzw. vorzugsweise eines molaren Verhältnisses 1,3-Butadien im butadienhaltigen Gemisch: primärem Amin von 1,9 : 1 bis 1 : 5, besonders bevorzugt von 1,8 : 1 bis 1 : 1;
• 2. Durchführen der Reaktion bei Temperaturen von 20 bis 130°C, vorzugsweise 70 bis 100°C,
• 3. Einstellen einer aktuellen Konzentration an 1,3-Butadien im Reaktionsgemisch von < 3, bevorzugt < 1, besonders bevorzugt < 0,5 Gew.-%.

By using the alkali metal amide catalysts used according to the invention, only a slight poly- or telomerization of the butadiene and hardly any 1,2-addition are achieved. This is particularly the case if one or more of the following parameters are observed:

• 1. Use of a deficit of butadiene, preferably a molar ratio of 1,3-butadiene in the butadiene-containing mixture: secondary amine from 0.95: 1 to 1:10, particularly preferably from 0.9: 1 to 1: 2 or preferably one molar ratio of 1,3-butadiene in the butadiene-containing mixture: primary amine from 1.9: 1 to 1: 5, particularly preferably from 1.8: 1 to 1: 1;
• 2. carrying out the reaction at temperatures of 20 to 130 ° C., preferably 70 to 100 ° C.,
• 3. Setting a current concentration of 1,3-butadiene in the reaction mixture of <3, preferably <1, particularly preferably <0.5% by weight.

The reaction can take place under the pressure resulting under the chosen conditions (Autoprint) can be carried out. In general, the overpressure at Reaction procedure 0 to 200 bar, in particular 2 to 100 bar, very particularly 3 to 30 bar.

All typical reaction apparatuses come into question as reactors, e.g. B. stirred kettle, Loop reactors, bubble columns, packed bubble columns, cascaded bubble columns and Stirred columns.

After the reaction, the product is e.g. B. by distillation, rectification, filtration, Membrane filtration, water washing or adsorption separated from the catalyst.

Unprotolyzed catalyst, can then be recycled if desired become.

In the batch mode, the catalyst together with the product mixture can Bottom are driven out of the reactor and worked up separately.

Another possibility is to carry out the reaction in a stirred tank.

With continuous driving, the reaction can also be carried out in a bubble column become. The 1,3-butadiene-containing mixture is expelled from below through the mixture Blown catalyst and product solution. The solution can be distilled from the catalyst removed or the catalyst can be removed from the product solution by means of a membrane. The The catalyst may not have to be removed, but can be removed during the Workup may be present or used in the next process step.

The reaction product from partial reaction a) of the process according to the invention contains, in addition to any unreacted 1,3-butadiene, the adduct II and, if appropriate, isomers of the aminooctadiene in question, hereinafter called aminooctadiene. The amino octadiene is formed by telomerization in a side reaction. In addition to these components, the reaction product from partial reaction a) can also contain small amounts of other by-products, for example octatriene and vinylcyclohexene. The formation of these by-products can be influenced by the manner in which the reaction is carried out in partial reaction a), for example by the choice of the 1,3-butadiene / R ¹ R ² NH ratio in the reaction mixture, the choice of the reaction temperature, the catalyst content and the pressure and can be further minimized if desired.

In the further course of the process according to the invention for the production of n-Butyraldehyde, the adduct II becomes catalytic to the enamine in the partial reaction b) Formula IV isomerizes, which is then in the partial reaction c) in the presence of water is hydrolyzed to n-butyraldehyde.

In a preferred embodiment of the present invention, this is after Termination of substep a) reaction mixture obtained which contains the starting material II, without previous work-up, especially without prior removal of the Amide catalyst, subjected to the isomerization after sub-step b). It was found, that the alkali metal amides, hydrides used according to the invention in partial reaction a) or other basic species that form in situ, including the isomerization of the Catalyze the resulting but-2-enylamine or but-3-enylamine to the enamine. The So isomerization is carried out directly after the aminoalkylation, then advantageously the catalyst used in step a) also in the Isomerization reaction is used. In particular, an embodiment of the Preferred method according to the invention, in which the metal amide is produced in situ and the sub-steps a) and b) coupled as described above without working up, in particular without separating the catalyst. With one The use of Na amides, in particular the use of Na-di-n-butylamide in the case of using di-n-butylamine as carrieramine, as proven particularly advantageous. It is then generally not necessary to use fresh catalyst admit.

In any case, it is preferred to use the metal amide catalyst used in a) as To use catalyst for the double bond isomerization b). If necessary fresh catalyst can be added. It is preferably the chemically identical catalyst compound, but it can also be a chemical different, but belonging to the group of alkali metal amides Catalyst compound are added.

So that the alkali metal amides in the double bond isomerization b) a catalytic Showing activity, it is often necessary to conduct isomerization at higher temperatures than carry out the addition reaction a). The temperatures used are Values from 80 to 200 ° C, preferably 100 to 150 ° C, in particular 110 to 130 ° C. The degree of isomerization of N-but-1-enyldialkylamine in N-but- 2-enyldialkylamine is> 60%, preferably> 80%, in particular> 90%.

Alternatively, unreacted but-3- from the hydrolysis of the enamine (reaction step c) enyl-, but-2-enyl and also but-1-enylamine returned to reaction step a) in the isomerization parallel to the hydroamination (reaction stage a) (Reaction step b) takes place.

The amide used as a catalyst can be added by adding alcohol or water be decomposed. The water can contain various additives, for example salts or acids, or in pure form and only the usual impurities and have additives.

For the hydrolysis of the amide, the mixture is preferably treated with H ₂ O which contains no additives. The amount of H ₂ O added is preferably chosen so that the resulting NaOH solution contains> 10%, preferably> 15% by weight, of solid NaOH. Since the amount of the amine soluble in it decreases as the content of the NaOH solution increases, it can be achieved by adjusting the NaOH content that the NaOH solution contains <1%, preferably <100 ppm, particularly preferably <10 ppm amine. The more concentrated the NaOH solution, the less amine is dissolved in it. As a result, the NaOH solution can be used in other processes, for example in the neutralization of reaction products from the production of methylenediamine from aniline and formaldehyde.

During the hydrolysis of the Na salts of the acidic hydrocarbons, for. B. Na-cyclopentadienide or Na-1-butinide, these hydrocarbons, i.e. cyclopentadiene or 1-butyne released. They are also, if necessary after cleaning, as Obtained secondary yield.

The NaOH solution is separated from the organic phase in the usual way technical apparatus such as B. a phase separator. Because of the high density and The high ionic strength of the NaOH solution makes the separation very quick and easy.

If partial reaction a) and b) are not as above using the same Catalyst or the same type of catalyst (alkali metal amides) performed, so can - after removal of the catalyst used in a) - the sub-reactions b) and c) in the method according to the invention either either successively in one Reactor or be carried out in one stage in a single process step. The Execution in a single process stage is preferred. Both partial reactions b) and c) can take place both in the gas phase and in the liquid phase.

If the process according to the invention is to be used to produce n-butanol, step c) is generally carried out in such a way that adduct II is converted into n-butanol in the presence of water and hydrogen. This can be done both when step c) is carried out separately and when steps b) and c) are coupled to a single process step. Of course, n-butyraldehyde can also be prepared separately and then hydrogenated to n-butanol. This opens up the possibility of z. B. catalyzed by excess amine - together with reaction step c) to aldolize to 2-ethylhexenal, which is then hydrogenated to 2-ethylhexanol. Alternatively, reaction step c) - e.g. B. by stripping with N ₂ - so that butyraldehyde is removed from the reaction mixture and is obtained purely as a product. The butyraldehyde can then optionally be fed to a hydrogenation, an aldolization or other reactions.

By the choice of the reaction conditions, the catalyst or the acid and the choice the amount of the reactants water and Hydrogen, the reaction step c) can be controlled so that either End product n-butyraldehyde or n-butanol is selectively formed or that mixtures of these two valuable products arise as the end product of the process according to the invention.

With the exception of the amides treated above, catalysts are the Catalyze isomerization of adduct II to enamine IV, also a good catalyst for hydrolysis of enamine IV to n-butyraldehyde or for the combined Hydrolysis / hydrogenation of enamine IV to n-butanol suitable. Accordingly in one embodiment of the method according to the invention, in which the implementation the partial reaction b) and c) occurs in a single process step, preferably both for the production of the end product n-butyraldehyde and for the production of the end product n-butanol used the same catalysts.

Obtain the following explanations for carrying out reactions b) and c) unless otherwise stated, both refer to the separate implementation of these sub-steps as well as their implementation in a single process step.

Both the isomerization of adduct II to enamine IV (sub-step b)) and Hydrolysis of the enamine IV to n-butyraldehyde (sub-step c)) can be in the gas phase or be carried out in the liquid phase. When performing these reaction steps in A single process stage in the liquid phase can be both homogeneous and heterogeneous catalysts are used. If you work in the gas phase, be heterogeneous catalysts preferred.

As homogeneous catalysts for the isomerization of adduct II to enamine IV and its Hydrolysis or combined hydrolysis / hydrogenation to n-butyraldehyde and / or n-butanol a large number of Transition metal element connections are used, in particular those which elements from the Groups VI, VII and VIII of the Periodic Table of the Elements, preferably chromium, Molybdenum, tungsten, rhenium, cobalt, nickel, ruthenium, rhodium, palladium, platinum, Contain osmium and / or iridium.

Suitable catalysts are, for example, the salts of these transition metals, in particular their halides, nitrates, sulfates, phosphates, carboxylates, for example their C ₁ -C ₂₀ -carboxylates, such as formates, acetates, propionates, 2-ethylhexanoates, and also the citrates , Tartrates, malates, malonates, maleinates or fumarates, sulfonates, for example methanesulfonates, benzenesulfonates, naphthalenesulfonates, toluenesulfonates or trifluoromethanesulfonates, cyanides, tetrafluoroborates, perchlorates or hexafluorophosphates, furthermore soluble salts of the oxoalkalides, in particular the alkali metal salts, such as alkali metal oxides, Ammonium, phosphonium, arsonium or stibonium salts, the vanadium oxygen acids, rhenium oxygen acids or the perrhenium acid or the anhydrides of these acids, in particular the dirhenium heptoxide, soluble inorganic complex compounds of these elements, in particular their aquo, amine, halogen, phosphine -, Phosphite, cyano or amino complexes as well as the complexes of these transition metals with chelating agents, such as acetylacetone, dioximes, for example diacetyl dioxime, furildioxime or benzil dioxime, ethylenediaminetetraacetic acid, nitrilotriacetic acid, nitrilotriethanol, urea or thiourea, bisphenidosphinophene, bisphosphinophene, bisphosphinophene, bisphosphinophene, bisphosphinophene, bisphosphinophene, bisphosphinidene, bisphosphinidene, bisphosphinine, bisphenidenephosphine, bisphenidenephosphine, bisphenidenephosphine, bisphosphine , 8-hydroxyquinoline, crown ethers or polyalkylene glycols, and organometallic compounds of these transition metal elements, for example carbonyl complexes such as RuCl ₂ (CO) ₂ (PPh ₃ ) ₂ , HRuCl (CO) (PPh ₃ ) ₃ , HRuCl (CO) (hexyldiphenylphosphine) ₃ , RuH ₂ (CO) (PPh ₃ ) ₃ , HRh (CO) (PPh ₃ ) ₃ or IrCl (CO) (PPh ₃ ) ₃ (PPh ₃ = triphenylphosphine), further RuH ₂ (PPh) ₃ , HRhCl (PPh ₃ ) ₃ , Fe ₂ (CO) ₉ or Fe ₃ (CO) ₁₂ , organotrioxorhenium (VII) compounds such as C ₁ to C ₄ alkyltrioxorhenium (VII), in particular methyltrioxorhenium (VII), cyclopentadienyltrioxorhenium (VII) or phenyltrioxorhenium (VII).

Preferred salt-like homogeneous catalysts are the halides, especially the Chlorides, nitrates, sulfates, carboxylates and cyanides of rhodium, ruthenium, Palladium, platinum, iridium, rhenium and vanadium as well as the alkali metal, Alkaline earth metal, ammonium, alkylammonium, arylammonium, arylphosphonium and alkylphosphonium salts of vanadium acids, especially their monovanadates and the corresponding salts of rhenium acids, in particular their rhenates (IV), Rhenate (VI) and Perrhenate.

Another suitable homogeneous catalyst is dirhenium heptoxide (Re ₂ O ₇ ).

Inorganic complex compounds, which are preferred in the process according to the invention for Carrying out the partial reactions b) and c) are used, for. B. Ruthenium trichloride, rhodium trichloride or iridium hexaquoditosylate.

Transition organometallic element compounds which are preferably used according to the invention as homogeneous catalysts for carrying out the partial reactions b) and c) are, for. B. carbonyl complexes such as HRh (PPh ₃ ) ₃ (CO), HRuCl (CO) (PPh ₃ ) ₃ or H ₂ Ru (CO) ₂ (PPh ₃ ), particularly preferably RuCl ₂ (CO) ₂ (PPh ₃ ) ₃ , as well as organotrioxorhenium compounds of the formula

R ¹ -ReO ₃ V

in which R ^{1 is} a C ₁ to C ₁₀ alkyl group, an unsubstituted or a cyclopentadienyl group which is substituted by 1 to 5 C ₁ to C ₄ alkyl groups, a C ₆ to C ₁₀ aryl or a C ₇ to C _{11 is} aralkyl group. For the preparation of these organotrioxorhenium compounds, reference is made to the in Angew. Chem. 100, 420 (1988), Angew. Chem. 103, 183 (1991), J. Organomet. Chem. 297, C5 (1985), Angew. Chem. 100, 1269 (1988) and J. Organomet. Chem. 382, 1 (1990) referenced methods.

The transition metal catalysts are homogeneously soluble in the reaction medium preferably based on allylamine II, in amounts of 0.0001 to 0.5 mol%, in particular 0.00023 to 0.2 mol% used.

In a further embodiment of the method according to the invention, the Isomerization of adduct II to enamine IV and / or its hydrolysis or Hydrogenation to n-butyraldehyde and / or n-butanol in a single process step Using a heterogeneous catalyst, the method being optional can be carried out in the liquid phase or in the gas phase.

It was found that as catalysts for both the isomerization of adduct II to enamine IV as well as for the hydrolysis of enamine IV to n-butyraldehyde or for the Combined hydrolysis / hydrogenation of the enamine IV to n-butanol common per se heterogeneous hydrogenation catalysts which are essentially insoluble in the reaction medium, can be used. Of these hydrogenation catalysts, preference is given to those which have a or more elements of group Ib, VIb, VIIb and VIIIb, optionally in Combination with one or more elements from group Vb, the periodic table the elements, in particular copper, chromium, molybdenum, tungsten, rhenium, ruthenium, Cobalt, nickel, rhodium, iridium, palladium and / or platinum, optionally in Combination with iron, included.

Particularly active hydrogenation catalysts such as nickel or the platinum metals advantageous with main group elements that act as a catalyst poison, doped and on partially poisoned this way. Through this measure, a higher selectivity in the combined hydrolysis / hydrogenation of the enamine IV to n-butanol can be achieved. Suitable main group elements are e.g. B. the chalcogens, such as sulfur, selenium and Tellurium, as well as the elements phosphorus, arsenic, antimony, bismuth, tin, lead and thallium.

In the process according to the invention, z. B. so-called Precipitation catalysts are used. Such catalysts can be made by removing their catalytically active components from their salt solutions, in particular from the solutions of their nitrates and / or acetates, for example by adding Solutions of alkali metal and / or alkaline earth metal hydroxide and / or carbonate Solutions as z. B. poorly soluble hydroxides, oxide hydrates, basic salts or carbonates fails, the precipitates obtained then dry and then through Calcination at generally 300 to 700 ° C, especially 400 to 600 ° C in the relevant oxides, mixed oxides and / or mixed valence oxides, which z. B. by treatment with reducing agents such as hydrogen or hydrogen containing gases, at usually 20 to 700 ° C, especially at 20 to 300 ° C, to the metals and / or to oxidic compounds of low oxidation level reduced and converted into the actual, catalytically active form. Thereby in usually reduced until no more water is formed. In the manufacture of Precipitation catalysts that contain a support material can precipitate the catalytically active components take place in the presence of the carrier material in question. The Catalytically active components can also advantageously be used simultaneously with the Carrier material can be precipitated from the relevant salt solutions.

Hydrogenation catalysts are preferably used in the process according to the invention, which the metals or metal compounds catalyzing the hydrogenation on a Carrier material included included. In addition to the above precipitation catalysts, which in addition to the catalytically active components is also a carrier material contain, are generally suitable for the inventive method Supported catalysts in which the catalytically active components z. B. by Impregnation have been applied to a carrier material.

The type of application of the catalytically active metals to the support is usually not critical and can be accomplished in a variety of ways. The Catalytically active metals can on these support materials such. B. by impregnation with Solutions or suspensions of the salts or oxides related elements, drying and subsequent reduction of the metal compounds to the metals concerned or Compounds of low oxidation level using a reducing agent, preferably with With the help of hydrogen, hydrogen-containing gases or hydrazine, applied become. Another way of applying the catalytically active metals these carriers consist of the carriers with solutions of thermally easily decomposable salts, z. B. with nitrates or with thermally easily decomposable complex compounds, for. B. Carbonyl or hydrido complexes of catalytically active metals, impregnated and the soaked carrier for the thermal decomposition of the adsorbed Heat metal compounds to temperatures of 300 to 600 ° C. This thermal Decomposition is preferably carried out under a protective gas atmosphere. suitable Protective gases are e.g. B. nitrogen, carbon dioxide, hydrogen or the noble gases. Farther can the catalytically active metals on the catalyst support by vapor deposition or be deposited by flame spraying.

The content of these supported catalysts in the catalytically active metals is in principle not critical for the success of the method according to the invention. It is for the Those skilled in the art understand that higher levels of these supported catalysts are catalytically active Metals lead to higher space-time conversions than lower contents. In general but supported catalysts are used, their content of catalytically active metals 0.1 to 80 wt .-%, preferably 0.5 to 30 wt .-%, based on the total Catalyst. Because this content information includes the entire catalyst Obtain carrier material, but the different carrier materials very much can have different specific weights and specific surfaces However, details are also fallen short of or exceeded, without this having an adverse effect on the Result of the inventive method affects. Of course you can too several of the catalytically active metals applied to the respective support material his. Furthermore, the catalytically active metals can be used, for example, by the process from DE-A 25 19 817, EP-A 147 219 and EP-A 285 420 applied to the carrier become. They are catalytic in the catalysts according to the abovementioned publications active metals as an alloy by thermal treatment and / or reduction the z. B. by impregnation on a support deposited salts or complexes of the previously mentioned metals are generated.

The activation of the precipitation catalysts as well as the supported catalysts can also be carried out in done in situ in the reaction mixture by the hydrogen present there, preferred However, these catalysts are of their use in the invention Procedure activated.

In general, the oxides of aluminum and titanium, Zirconium dioxide, silicon dioxide, diatomaceous earth, silica gel, clays, e.g. B. Montmorillonite, Silicates, such as magnesium or aluminum silicates, zeolites, such as ZSM-5 or ZSM-10- Zeolites and activated carbon can be used. Preferred carrier materials are Aluminum oxides, titanium dioxide, zirconium dioxide and activated carbon. Of course can also mixtures of different carrier materials as a carrier for in Catalysts which can be used according to the process of the invention are used.

Examples of heterogeneous catalysts which can be used for carrying out the hydrolysis and hydrogenation in a single process step are: platinum dioxide, palladium on aluminum oxide, palladium on silicon dioxide, palladium on barium sulfate, rhodium on activated carbon, rhodium on aluminum oxide, ruthenium on silicon dioxide or activated carbon, Nickel on silicon dioxide, cobalt on silicon dioxide, cobalt on aluminum oxide, carbonyl iron powder, rhenium black, Raney rhenium, rhenium on activated carbon, rhenium-palladium on activated carbon, rhenium-platinum on activated carbon, copper on diatomaceous earth, copper on silica gel, copper on titanium dioxide, copper on Zirconium dioxide, copper on magnesium silicate, copper on aluminum silicate, copper on montmorillonite, copper on zeolite, Raney copper, platinum oxide-rhodium oxide mixtures, platinum-palladium on activated carbon, buyer chromite, barium chromite, nickel-chromium oxide on aluminum oxide, dirhenium heptoxide (Re ₂ O ₇ ), Cobalt sulfide, Ni nickel sulfide, molybdenum (VI) sulfide, copper-molybdenum (VI) oxide-silicon dioxide-aluminum oxide catalysts, palladium on activated carbon catalysts partially poisoned with selenium or lead, and also the catalysts according to DE-A 39 32 332, US Pat. No. 3,449,445, EP-A 44 444, EP-A 147 219, DE-A 39 04 083, DE-A 23 21 101, EP-A 415 202, De-A 23 66 264 and EP-A 100 406.

Hydrogenation catalysts can also advantageously be used in the process according to the invention be that contain Brönsted and / or Lewisacide centers. When using Such catalysts is generally the additional addition of a Brönsted or Lewis acid not required for the reaction mixture.

As Brönsted or Lewis acidic centers z. B. the catalytically active metals themselves act if these when activating the catalyst with hydrogen or hydrogen containing gases can not be completely reduced to the metals in question. This applies z. B. for the rhenium and chromite-containing catalysts Rhenium supported catalysts contain the rhenium as a mixture of rhenium metal with rhenium compounds higher oxidation levels, the latter effects such as Lewis or Bronsted acids can unfold. Such Lewis or Brönsted acidic centers can also via the used carrier material are introduced into the catalyst. As Lewis or Brönstedacide centers containing carrier materials are, for. B. zirconium dioxide, Silicon dioxide, called silicates, clays, zeolites and activated carbon.

Therefore, are particularly preferred in the inventive method as Hydrogenation catalysts supported catalysts are used, the elements of I., VI., VII. And / or VIII. Subgroup of the Periodic Table of the Elements, especially the elements of I., VII. and VIII. Subgroup of the Periodic Table of the Elements on a Brönsted or Contain Lewis-acidic carrier material deposited. Particularly advantageous Catalysts are e.g. B. rhenium on activated carbon, rhenium on zirconium dioxide, rhenium on titanium dioxide, rhenium on silicon dioxide, copper on activated carbon, copper Silicon dioxide, copper on kieselguhr, copper on silica gel, copper on titanium dioxide, Copper on zirconium dioxide, copper on magnesium silicate, copper on aluminum silicate, Copper on bleaching earth, copper on zeolite, ruthenium on activated carbon, ruthenium on Aluminum oxide, ruthenium on silicon dioxide, ruthenium on titanium dioxide and with selenium or lead partially poisoned palladium on activated carbon catalysts.

Hydrogenation catalysts, which themselves have no such Bronsted or Lewis acid centers can have Lewis or Bronsted acid components such as zeolites, aluminum or Silicon oxides, phosphoric acid or sulfuric acid can be added. You will be in generally in amounts of 0.01 to 5 wt .-%, preferably 0.05 to 0.5 wt .-% and particularly preferably from 0.1 to 0.4 wt .-%, based on the weight of the used Catalyst added.

Furthermore, isomerization of adduct II to enamine IV and its hydrolysis or hydrogenation to n-butyraldehyde and / or n-butanol in a single process step Heterogeneous catalysts suitable for the homogeneous catalysis of these Process stage usable complex compounds from transition metal elements Group VIb and VIIIb of the Periodic Table of the Elements in heterogeneous form contain, for example those in which the transition metal element in question to a polymer matrix is fixed.

Such polymeric matrices can be resins such as styrene-divinylbenzene resins (US 3,725,489) or be phenol-formaldehyde resins to which the concerned Complexation of the transition metal element-serving ligand is preferably covalently bound are, which in turn form complexes with the relevant transition metals and immobilize them in this way. Such heterogenized, polymer-bound Transition metal complex catalysts with 2,2'-bipyridine or 1,10-phenanthroline Ligands or heterogenized phosphine or phosphite complexes of the catalytically active Transition metal elements can be produced by known literature processes. Organotrioxorhenium (VII) catalysts can e.g. B. by the method of DE-A 39 02 357 to nitrogen-containing polymers, such as polyvinylpyrrolidone, poly (2-vinylpyridine), (2- Vinylpyridine) styrene copolymers, polyacrylic acid amides, polyimides, polyamides and Polyurethanes fixed by coordinative bonding and thus heterogenized as Heterogeneous catalyst can be used according to the invention.

With the heterogeneous catalysts mentioned, the isomerization of the adduct II to Enamine IV and its hydrolysis or hydrogenation to n-butyraldehyde and / or n-butanol Both continuously and discontinuously in a single process step be performed.

The implementation of the partial reactions b) and c) in a single process step with the help the catalysts mentioned can be discontinuous, for. B. in stirred tanks, or continuously, e.g. B. in tubular reactors or loop reactors, at temperatures of im generally 80 to 150 ° C and a pressure of generally 5 to 10 bar, preferably from 10 to 60 bar. The isomerization of adduct II to enamine IV and its conversion to n-butyraldehyde and / or n-butanol in one single process step can in the presence or absence of added solvents, such as aliphatic or aromatic hydrocarbons, e.g. B. toluene, benzene or Cyclohexane, alcohols, e.g. B. butanols, especially n-butanol, higher fatty alcohols or Glycols, ethers e.g. B. dibutyl ether, tetrahydrofuran, dioxane or low molecular weight Polyalkylene glycols, halogenated aliphatic or aromatic hydrocarbons z. As chloroform, dichloromethane, chlorobenzene or dichlorobenzene, sulfoxides or Sulfones, e.g. As dimethyl sulfoxide or sulfolane.

To produce the end products n-butyraldehyde and n-butanol, water is added to the reaction mixture in a molar ratio, based on the adduct II or amine IV fed to the reactor, of generally 1: 3 to 100: 1, preferably 1: 2 to 20: 1 and particularly preferably from 1: 2 to 10: 1 added. The amine, H ₂ O or the optional solvent can either be initially charged or metered in in a controlled manner. Dosing does not have to be uniform, but is optimized so that the yield of the desired product or of the product mix - butyraldehyde, butanol, 2-ethylhexenal or 2-ethylhexanol is maximal.

If the desired end product is n-butanol, the reaction mixture is added to that Water required for the hydrolysis of enamine IV, still hydrogen in one Molar ratio, based on the adduct II fed to the reactor, of generally 1: 1 to 100: 1, preferably from 1: 1 to 10: 1 and particularly preferably from 1: 1 to 3: 1 admixed. This admixture can be used in discontinuous mode of operation Hydrogen in the reaction medium, for example with bubble columns or jet nozzles loop reactors equipped to disperse the hydrogen.

If the desired end product is a mixture of n-butanol and n-butyraldehyde, it can the quantitative ratio of these products in the product mixture, for example over the Addition of the hydrogen and / or the reaction temperature used can be set. If substoichiometric amounts of hydrogen are used, it goes without saying only some of the starting material is hydrogenated to n-butanol and by using a lower reaction temperature can speed up the hydrogenation reaction so far slowed down that only a part of the starting material is hydrogenated to n-butanol.

In the hydrogenation reaction in a so-called overhydrogenation, the butenyl residue in the resulting enamine (IV) are hydrogenated. As a result, the product is lost. In which Use of di-n-butylamine as carrieramine, in which preferably di-n-butylamide as If catalyst is used, tri-n-butylamine is formed in this overhydrogenation. In a preferred embodiment of the present invention, this tributylamine can a so-called transalkylation reaction by reaction with ammonia or Mono-n-butylamine can be converted back to di-n-butylamine, which reacts in the reaction can be used. The transalkylation reaction is carried out under the usual, the Conditions known to those skilled in the art and using the known catalysts carried out. In general, the transalkylation takes place at temperatures of 80 to 400 ° C and in the presence of dehydration catalysts and / or hydrogenation / Dehydrogenation catalysts. Suitable catalysts are in the PCT application with the Title "Process for the production of alkylamines" from June 22, 2001, file number PCT / EP / 01/07124 and the German application entitled "Procedure for Production of n-butylamines "dated March 7, 2001, file number DE 101 10 842.7 described. The catalysts disclosed therein are an integral part of the present invention and incorporated by reference.

If the process according to the invention is carried out so that the aminoalkylation in Sub-step a) and the isomerization in sub-step b) in a single process step are carried out, the hydrolysis of the enamine in substep c) is preferably carried out in In the presence of an acid. The acid can be in homogeneous or heterogeneous form are present, and the hydrolysis can be discontinuous, semi-continuous or be carried out continuously. Implementation with one in heterogeneous form acid present is preferred.

The hydrolysis c) is carried out at a temperature of 60 to 200 ° C, preferably 80 to 160 ° C, and the system's own pressure. The implementation can be done in one or two-phase system happen.

Acids which can be used in the homogeneous reaction comprise the usual organic or inorganic acids which are known to the person skilled in the art, preferred acids being H ₂ SO ₄ , H ₃ PO ₄ , oxalic acid, formic acid and HCl.

If heterogeneous acids (“solid acids”) are used, step c) can be carried out process according to the invention on a suspension or fixed bed catalyst be performed.

Strongly acidic ion exchangers are also suitable as solid acids, in particular those of the divinylbenzene-styrene-sulfonic acid type.

Suitable for use in the method according to the present invention Solid acids have more than 50 µmol / g acidic centers with a pKa value smaller 3.3 owns and is thermally stable up to at least 400 ° C.

The number of acidic centers is determined using the Hammett titration method Dimethyl yellow [CAS-No. 60-11-7] as an indicator and n-butylamine as a probe according to H.A. Benesi and B.H. C. Winquist in Adv. Catal., Vol. 27, Academic Press 1978, pp. 100ff, certainly.

Examples of such acids include zeolites and aluminosilicates, aluminum phosphates or silica-alumophosphates, mixed acidic metal oxides and acidic metal oxides high surface, layered silicates as well as supported and unsupported Ammonium.

Preferred examples of zeolites include faujasites such as X, Y and USY zeolite, Erionite, chabazite, mordenite, offretite, clinoptiolite, pentasiles such as ZSM-5 and ZBM-10, ZSM-11, ZSM-12, MCM-22, MCM-41, MCM-48, MCM-49, MCM-56, EMT, SSZ-26, SSZ-33, SSZ-37, CIT-1, PSH-3, NU-85 Beta, the boron-containing forms, such as. B. ZBM-11, H-boron ZSM-5, H-boron beta, H-boron ZSM-11, as well as the forms containing gallium or titanium.

The zeolites mentioned are distinguished by a high number of catalytically active ones Centers, combined with a large surface. They differ in type and in the type of aftertreatment after manufacture, for example the thermal Treatment, dealumination, acid treatment, or metal ion exchange.

Suitable zeolites are described, for example, in US-A-4,375,002, US-A-4,536,602, EP-A-305 564, EP-A-101 921, DE-A-42 06 992, EP-A-133 938, EP-A-431 451, EP-A132 736, CA-A-2 092 964 and DE-A-195 30 177.

Zeolite catalysts of the pentasil type with an SiO ₂ / Al ₂ O ₃ molar ratio of greater than or equal to 10, which are disclosed, for example, in EP-A-132 736, are particularly suitable.

Aluminum phosphates and silico-alumophosphates are, for example, crystalline systems with zeolite structures or zeolite-like structures such as e.g. B. SAPO-37, AlPO ₄ -5, SAPO-5, which are described for example in DE-A-196 01 409. Amorphous systems such as B. described in DE-A-44 31 093 are suitable. They generally have the formula
Al ₂ O ₃ .P ₂ O ₅ .xSiO ₂ .

Examples of acid mixed metal oxides are in particular Al ₂ O ₃ -TiO ₂ , SiO ₂ -TiO ₂ , ZrO ₂ -TiO ₂ , Fe ₂ O ₃ -TiO ₂ , WO ₃ -TiO ₂ , MoO ₃ , TiO ₂ , Nb ₂ O ₅ -TiO ₂ , Al ₂ O ₃ -B ₂ O ₃ , SiO ₂ -Ga ₂ O ₃ , SiO ₂ -B ₂ O ₃ , SiO ₂ -Y ₂ O ₃ , SiO ₂ -ZrO ₂ , SiO ₂ -WO ₃ , SiO ₂ -MoO ₃ , ZrO ₂ -MO ₃ , ZrO ₂ -WO ₃ .

The sheet silicates that can be used as catalysts are, in particular, clays of Montmorillonite-saponite, the kaolin-serpentine and the palygorsite-sepiolite group, e.g. B. Montmorillonite, hectorite, kaolin, attapulgite, sepiolite, beidellite, Montronite, saponite, Sauconite.

The catalysts can be used in the form of powder or, preferably, in the form of shaped articles such as strands, tablets or grit. For the shaping, 2 to 60% by weight (based on the mass to be shaped) of binder can be added. Various aluminum oxides, amorphous aluminosilicates, silicon dioxide, preferably highly disperse SiO _2, such as, for example, are suitable as binders. B. silica sols, mixtures of highly disperse SiO ₂ and highly disperse Al ₂ O ₃ , highly disperse TiO ₂ and clays.

As a rule, the catalysts are used in the H form. To increase the Selectivity, the service life and the number of possible catalyst regenerations can however, various modifications are made to the catalysts.

A modification of the catalysts is that the undeformed Catalysts with alkali metals such as Na and K, alkaline earth metals such as Ca, Mg, Earth metals such as Tl, transition metals such as Mn, Fe, Mo, Cu, Zn, Cr, Precious metals and / or rare earth metals, such as B. La, Ce or Y, an ion exchange can undergo or dope.

In a preferred embodiment that is used according to the invention Catalyst powder with hydrofluoric acid (0.001 to 2 molar, preferably 0.05 to 0.5 molar) treated under reflux. After filtering and Wash out is usually dried at 100 to 160 ° C and at 400 to 550 ° C calcined.

Another special embodiment is an HCl treatment Heterogeneous catalysts after their deformation with binder. Here, the Heterogeneous catalyst usually 1 to 3 hours at temperatures between 60 and 80 ° C with a 3 to 25%, in particular with a 12 to 20% hydrochloric acid treated, then washed out, dried at 100 to 160 ° C and at 400 to Calcined at 550 ° C.

Another possibility of modifying the catalyst is the exchange with ammonium salts, e.g. B. with NH ₄ Cl, or with mono-, di- or polyamines. Here, the heterogeneous catalyst deformed with the binder is generally continuously exchanged at 60 to 80 ° C. with 10 to 25%, preferably about 20%, NH ₄ Cl solution for 2 hours in a 1:15 by weight heterogeneous catalyst / ammonium chloride solution and then dried at 100 to 120 ° C.

Another modification that can be made to aluminum-containing catalysts is dealuminization, in which some of the aluminum atoms are replaced by silicon, or the aluminum content of the catalysts is reduced by, for example, hydrothermal treatment. Hydrothermal dealumination advantageously is followed by extraction with acids or complexing agents in order to remove non-lattice aluminum formed. Aluminum can be replaced by silicon, for example using (NH ₄ ) ₂ SiF ₆ or SiCl ₄ . Examples of dealuminations of Y zeolites can be found in Corma et al., Stud. Surf. Sci. Catal. 37 (1987), pages 495 to 503.

The catalysts can be used as strands with diameters of z. B. 1 to 4 mm or as Tablets with e.g. B. 3 to 5 mm diameter for the hydroamination of the olefins deploy.

The catalysts mentioned are preferably arranged in a fixed bed and are flows through the liquid reaction mixture in the sump or trickle mode. The fixed catalyst bed can e.g. B. in tubular reactors or preferably in reactor cascades to be built in.

The n-butyraldehyde produced according to the invention can be distilled, for example Isolation can be converted to 2-ethylhexanol in a manner known per se. So n- Butyraldehyde at 80 to 130 ° C and 3 to 10 bar pressure in the presence of sodium or Potassium hydroxide are converted into the aldol product 2-ethylhex-2-enal, which then catalytically at about 200 to 250 ° C and 50 to 200 bar hydrogen pressure to 2-ethylhexanol can be reduced.

It is also possible to contain an n-butyraldehyde obtained according to the invention Reaction mixture in the manner indicated above and an aldol reaction Submit to hydrogenation and then the product from those in the original To clean the reaction mixture contained impurities by distillation.

A process variant is preferred in which butyraldehyde by acid hydrolysis of the Enamine IV is prepared as described in detail above. In the presence of the Acid or amine in the reaction mixture can be the n-butyraldehyde Aldol product 2-ethylhex-2-enal react. The reaction can be controlled so that the aldol reaction occurs preferentially. These are usually the same among other things Reaction conditions longer reaction times necessary. It is also possible to go through Increase in temperature or acid concentration compared to a high one Yield of n-butyraldehyde-based procedure a faster reaction to To achieve aldol product. The aldol product thus obtained can be prepared in a known manner for 2- Ethylhexanol are hydrogenated.

As is apparent from the above description, the inventive Procedures in different variants regarding the implementation of each Process steps and their coupling into a single one or connected to one another Process steps are carried out. So it can prove beneficial to the Isomerization of adduct II to enamine IV, hydrolysis of enamine IV to n-Butyraldehyde or the hydrogenation of butyraldehyde to n-butanol in several To carry out procedural stages. For example, it is possible to use each one of these Carry out reactions in one process step by first in one Process stage isomerizes the adduct II to the enamine IV, then the enamine IV isolated to n-butyraldehyde and then hydrogenated the n-butyraldehyde to n-butanol, or the hydrolysed butyraldehyde and then hydrogenated to n-butanol, or separated butyraldehyde or part of the resulting butyraldehyde, in aldolized in a further stage and then hydrogenated to 2-ethylhexanol. Likewise can the isomerization of adduct II to enamine IV per se in one process step be carried out and the enamine IV is then hydrolyzed to n-butyraldehyde or in a hydrolysis / hydrogenation reaction to n-butanol or a mixture of n- Butanol and n-butyraldehyde can be processed. Another variant of the The inventive method consists in the isomerization of the adduct II to Enamine IV and its hydrolysis to n-butyraldehyde in a single process step to carry out and then the n-butyraldehyde obtained in a further Process step to hydrogenate n-butanol.

If n-butanol is desired as the product and reaction step c) and the hydrogenation of the butyraldehyde to butanol are not carried out in one step, the butyraldehyde must be removed from the reaction mixture as quickly as possible. This can e.g. B. by stripping with N ₂ or distilling off. Even if n-butyraldehyde is desired, it must be quickly removed from reaction step c) after its formation.

The invention is now explained in more detail in the following examples:

EXAMPLES

Dibutylamine [Prod.-Nr. 208.056] and C ₄ cracker cuts were obtained from BASF, all other chemicals from Aldrich. GC analyzes were carried out on a 50 m DB-5 column with FID detector. GC calibration factors were determined for dibutylamine, butenyldibutylamine, butyraldehyde and 2-ethylhexenal.

example 1 Addition C4 cracker cut to dibutylamine at 60 ° C, isochoric

A suspension of 50 mmol Na (average particle size 60 μm) in 87 g di-n-butylamine was poured into a 1 liter stirred autoclave and the contents were heated to 60 ° C. after sealing. A mixture of 264 g of di-n-butylamine and 214 g of C4 cracker cut of the composition given below was then pumped in over the course of 70 minutes, so that the internal temperature of the reactor remained between 60 and 65.degree. The mixture was then stirred for 35 minutes, warmed to 90 ° C and reacted at 90 ° C for 30 minutes. Educt C4 cracker cut

Course of the experiment

The autoclave was then cooled to room temperature and the exhaust gas was released into a steel bottle cooled with dry ice. The total amount of liquid gas was 105 g of the composition given below: exhaust gas

Then 10 ml of 50% KOH solution were added to the reactor, stirred, the organic phase separated and distilled. 445 g of distillate having the following composition are obtained: Composition amine distillate

The amine distillate was then hydrogenated and analyzed. The only one available Tributylamine was N, N, N-tri-n-butylamine, isomers such as e.g. B. N, N, N-sec-butyl-di-n- Butylamine have not been identified. The chemoselectivity and regioselectivity of the addition could thus be estimated to be greater than 500: 1.

Example 2 Addition of C4 cracker cut to dibutylamine at 90 ° C, without pressure

A dispersion of 4.80 g of Na in 2693 g of dibutylamine was placed in a 10 L autoclave with a gas stirrer, a reflux condenser and a heating jacket and heated to 90.degree. Then 2341 g of C4 cut of the composition from Example 1 were introduced within 230 minutes and the temperature was adjusted to 90 ° C. by heating / cooling. The course of the reaction was followed by GC analyzes.

The ratio of butenyldibutylamine isomers shifts with increasing runtime always in the direction of the desired but- (1, E) -enyldibutylamine. The Isomerization to the enamine occurs as a follow-up reaction to the hydroamination Catalyst.

Example 3 Addition of C4 cracker cut to dimethylamine

A suspension of 100 mmol Na in 20 ml n-dodecane was poured into a 1 l stirred autoclave and 195 g dimethylamine were injected. The mixture was then heated to 40 ° C. and 378 g of C4 cracker cut of the above composition were metered into the reactor within 140 minutes by means of 18 bar He pressure via a needle valve. The mixture was then stirred at 40 ° C for 100 minutes. Course of the experiment

The autoclave was then cooled to room temperature and an exhaust gas sample taken. It contained 52 ppm 1,3-butadiene. Then the contents of the autoclave in the Vacuum (500-3 mbar) at a heating jacket temperature of 45 ° C in a 1 l flask the dry ice cooler distilled.

280 g of distillate were collected, which was 88% by weight N- (n-butenyl) - dimethylamine isomers existed.

Example 4 Uncatalyzed, thermal hydrolysis of the dimethylbutenylamine mixture from Example 3

0.25 ml / min of a solution of dimethylbutenylamine mixture from Example 3 (44% but-1-enyldimethylamine, 12% dimethylamine) and 0.05 ml / min of H ₂ O were dissolved together with 0.15 standard liters of N ₂ / min 450 ° C heated, Al ₂ O ₃ coated ("ionized") tube of 4 mm inner diameter and 30 cm in length. The gas stream was then quenched to 2 ° C. After a running-in period of 30 minutes, the product was analyzed by GC-MS analysis (50 m DB-5).

Example 5 in situ isomerization of N-But-2-enyldibutylamine

In an example 2 analog Na-catalyzed addition of 1,3-butadiene to dibutylamine after complete addition of butadiene, the temperature was raised to 120 ° C. for 5.5 h. The proportion of n-but- (1, E) -enyl-di-n-butylamine in all n-butenyldi-n-butylamine Double bond isomers increased from 33% to 86%.

Example 6 Isomerization of but-3 and but-2-enyldibutylamine

In a 100 ml three-necked flask with magnetic stirrer, cooler and liquid thermometer, 40 ml of addition product (mixture of isomers), which was mixed with around 12% dibutylamine, together with 3 g of 5-10 mm long and 4 mm thick strands of a supported catalyst made of γ-Al ₂ O ₃ filled in irregular fill. The catalyst, which contained 5% by weight of Pr ₂ O ₃ and 0.5% by weight of Pd as the active composition, was prepared in a conventional manner by impregnating the γ-Al ₂ O ₃ strands with an aqueous solution of the catalyst components and then Drying and heating the impregnated strands produced in an air stream. To prepare the solution, a suspension of 75 ml of water and 100 g of Pr oxide was mixed with 180 g of 65% nitric acid and then with 85 g of an 11% aqueous Pd nitrate solution. The resulting solution was then made up to a volume of 1840 ml with water. The commercially available mixed oxide of the gross formula Pr ₆ O _{11 was} used as the Pr oxide. The mixture was then stirred at 200 ° C. under reflux for 7 hours. The mixtures had the following compositions:

Example 7 Hydrolysis and hydrogenation

A solution of 4.2 g (23 mmol) (1, N) - (but-2-enyl) dibutylamine, 0.23 g (0.024 mmol) HRuCl (CO) (PPH ₃ ) ₃ and 0.034 g (0.125 mmol) Triphenylphosphine was mixed with 20 g of water and stirred at 12 bar hydrogen pressure and 150 ° C. After a reaction time of 18 h, a conversion of 85% with a selectivity of 76% 1-butanol, 3% (1, N) - (but-1-enyl) dibutylamine and 21% tributylamine was obtained. Dibutylamine was recovered.

Example 8 Hydrolysis of butenyldibutylamine

1 g of the chosen catalyst, 50 ml of N-but- (1, E) -enyldibutylamine and 30 ml of H ₂ O were each reacted in a steel autoclave with stirring for 12 hours at 100 or 150 ° C. The liquid was then filtered and the organic phase analyzed.

D10-10: γ-Al ₂ O ₃ ; K10: montmorillonite; Amberlyst CSP3: styrene-divinylbenzene sulfonic acid; CP814: H-beta zeolite, calcined in air at 500 ° C for 5 h.

Claims (18)

1. A process for the preparation of n-butyraldehyde from 1,3-butadiene with the following steps: a) reacting 1,3-butadiene with an amine of the general formula

R ¹ R ² NH I

to an amine of the formula


where in the formulas I and II the substituents R ¹ and R ² independently of one another represent hydrogen or a suitable organic radical from the group alkyl, alkenyl, cycloalkyl, alkoxyalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, aryl and aralkyl, or R ¹ and R ² together with the nitrogen atom form a 3-7-membered heterocycle which optionally has one or more double bonds and optionally a further heteroatom from the group N, O and S, in the presence of an amide of the formula

MNR ³ R ⁴ III

in which R ³ and R ⁴ independently of one another have the meanings given for amine I and amide II for R ¹ and R ² and M represents an alkali metal; b) isomerizing the amine II to an amine of the formula


in R ¹ and R ^{2 have} the meaning given for formulas I and II; c) release of n-butyraldehyde and the amine of the formula I by hydrolysis of the amine IV with water. 2. The method according to claim 1, characterized in that R ¹ and R ² independently of one another from the group consisting of hydrogen, C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl, C ₃ -C ₂₀ cycloalkyl, C ₃ -C ₂₀ cycloalkenyl, optionally substituted by C ₁ -C ₄ alkyl groups, C ₆ -C ₁₀ aryl and C ₇ -C ₁₁ aralkyl, preferably from the group consisting of ammonia, mono- and dialkylamines with C ₁ -C _6- alkyl-, C ₂ -C ₆ -alkyl and C ₄ -C ₇ -cycloalkyl substituents and C ₁ -C ₆ -N-alkylanilines, in particular the amine is di-n-butylamine. 3. The method according to claim 1 or 2, characterized in that the as Alkali metal amide (III) used as catalyst of the amine (I) used is derived. 4. The method according to any one of claims 1 to 3, characterized in that the Alkali metal amide by reacting the corresponding amine with a Organometallic compound or an alkali metal and a conjugated diolefin, in particular by reaction with butyllithium or an alkali metal and 1,3- Butadiene. 5. The method according to any one of claims 1 to 4, characterized in that the Sub-step b) after sub-step a) without previous work-up, in particular without prior removal of the amide catalyst. 6. The method according to any one of claims 1 to 5, characterized in that the Preparation of the metal amide before or during the hydroamination reaction in is carried out in situ, preferably the alkali metal amide in the Hydroamination reaction used amine corresponds. 7. The method according to any one of claims 1 to 6, characterized in that the sub-step b) also takes place under catalysis by an amide compound which corresponds to the general formula MNR ³ R ⁴ (III) and which is identical to the amide compound used in sub-step a) or is different from this, is preferably identical to this. 8. The method according to claim 7, characterized in that in two substeps an identical amide catalyst is used. 9. The method according to any one of claims 1 to 8, characterized in that the Sub-step a) at temperatures of 20 to 130 ° C, preferably 70 to 100 ° C, and the sub-step b) at temperatures from 80 to 200 ° C, preferably 100 to 150 ° C, in particular 110 to 130 ° C, is carried out. 10. The method according to any one of claims 1 to 9, characterized in that a Deficit of 1,3-butadiene is used, preferably a molar ratio 1,3-butadiene in the butadiene-containing mixture: secondary amine from 0.95: 1 to 1:10, particularly preferably from 0.9: 1 to 1: 2, or a molar ratio of 1,3-butadiene in butadiene-containing mixture: primary amine from 1.9: 1 to 1: 5, particularly preferred 1, 8: 1 to 1: 1, and / or the current concentration of 1,3-butadiene in Reaction mixture is <3, preferably <1, particularly preferably <0.5% by weight. 11. The method according to any one of claims 1 to 10, characterized in that in the alkali metal amide of the formula MNR ³ R ⁴ (III) M for Li, Na, K, Rb or Cs, preferably Li, Na or K, more preferably Na or K, especially Na. 12. The method according to any one of claims 1 to 11, characterized in that the metal amide is selected from the group consisting of NaHNC ₂ H ₅ , NaN (C ₂ H ₅ ) ₂ , KHNC ₂ H ₅ , KN (C ₂ H ₅ ) ₂ , LiHNC ₂ H ₅ , LiN (C ₂ H ₅ ) ₂ , LiN (iso-C ₃ H ₇ ) ₂ , NaN (iso-C ₃ H ₇ ) ₂ , NaN (nC ₄ H ₉ ) ₂ , NaHN (iso -C ₃ H ₇ ) and NaHN (iso-C ₅ H ₁₁ ), in particular the metal amide NaN (nC ₄ H ₉ ) ₂ . 13. The method according to any one of claims 1 to 12, characterized in that the Amine is reacted with a 1,3-butadiene-containing mixture, which from the comes from the following sources: C4 cuts that are used on an industrial scale for thermal or catalytic cleavage of petroleum fractions, preferably gasolines, in particular Naphtha, accumulate hydrocarbon streams from the dehydrogenation of LPG or LNG, preferably C4 cuts from it, and C4 cuts from the GTL Technology, preferably the Fischer-Tropsch synthesis. 14. The method according to any one of claims 1 to 13, characterized in that the mixture for hydrolysis of the amide is treated with an amount of H ₂ O which is chosen so that the resulting NaOH solution> 10%, preferably> 15% % By weight of solid NaOH and the NaOH solution contains <1%, preferably <100 ppm, particularly preferably <10 ppm amine. 15. The method according to any one of claims 1 to 14, characterized in that as Catalyst an Na amide is used, which is prepared in situ, and wherein the isomerization b) directly to the aminoalkylation a) using the same catalyst without previous work-up, especially Na Di-n-butylamide can be used as the amide and di-n-butylamine as the carrieramine. 16. The method according to any one of claims 1 to 15, characterized in that Step c) is carried out so that additional hydrogen in the Reaction mixture is present and by hydrogenation of n-butyraldehyde additionally or exclusively n-butanol is formed. 17. The method according to any one of claims 1 to 16, characterized in that amine optionally formed by overhydrogenation, preferably Tri-n-butylamine, in a transalkylation reaction back to the original Carrieramine used, preferably di-n-butylamine, transferred and this is used again if necessary. 18. Process for the preparation of a 1,3-butadiene-free mixture, preferably Raffinate I, from a mixture obtained from the splitting of petroleum fractions, preferably a C4 cut, by implementing one 1,3-butadiene-containing mixture with an amine by the process according to one of the Claims 1 to 17.