DE102004063381A1 - Producing 3-pentenonitrile comprises isomerizing 2-methyl-3-butenonitrile and separating (Z)-2-methyl-2-butenonitrile and 2-methyl-3-butenonitrile - Google Patents

Abstract

Producing 3-pentenonitrile comprises isomerizing a 2-methyl-3-butenonitrile feed stream in the presence of a dissolved or dispersed catalyst, distilling the product stream to separate an overhead stream (2) from a catalyst-containing bottoms stream, distilling stream (2) to obtain an overhead stream enriched in (Z)-2-methyl-2-butenonitrile and a bottoms stream (5), and distilling stream (5) to produce a bottoms stream containing 3-pentenonitrile and an overhead stream containing 2-methyl-3-butenonitrile.

Description

The The present invention relates to a process for the preparation of 3-Pentenitrile by isomerization of streams containing 2-methyl-3-butenenitrile.

In the production of adiponitrile, an important intermediate in nylon production, 1,3-butadiene is first converted to pentenenitriles with hydrogen cyanide in the presence of nickel (0), which is stabilized with phosphorous ligands. In addition to the main products of hydrocyanation, 3-pentenenitrile and 2-methyl-3-butenenitrile, numerous secondary components are also obtained. Examples of these are 2-pentenenitriles, 2-methyl-2-butenenitriles, C ₉ nitriles and methylglutaronitrile. 2-Methyl-3-butenenitrile is produced in significant quantities. Thus, depending on the catalyst used, the molar ratio of formed 2-methyl-3-butenenitrile to 3-pentenenitrile can be up to 2: 1.

In a second hydrocyanation is then 3-pentenenitrile with hydrogen cyanide to adiponitrile on the same nickel catalyst with addition a Lewis acid implemented. For the second hydrocyanation, it is essential that the 3-pentenenitrile preferably is free of 2-methyl-3-butenenitrile. Hydrocyanation of 2-methyl-3-butenenitrile would become methylglutaronitrile to lead, that an undesirable By-product represents. Accordingly, in an economic procedure for the preparation of adiponitrile a separation of 3-pentenenitrile and 2-methyl-3-butenenitrile.

Around 2-methyl-3-butenenitrile also for the production of adiponitrile to be able to use Methods for the isomerization of 2-methyl-3-butenenitrile were added linear pentenenitrile, in particular 3-pentenenitrile, proposed.

So describes US 3,676,481 the discontinuous, batchwise isomerization of 2-methyl-3-butenenitrile in the presence of Ni (0), a phosphite ligand and certain Lewis acids. After isomerization, the resulting product mixture is distilled off from the catalyst system. Disadvantages of this process are the high residence times during isomerization, the high thermal load of the thermally sensitive catalyst during the isomerization and during the subsequent distillation. The high thermal load of the catalyst leads to an undesirable degradation of the catalyst.

The prioritized, not previously published German patent application DE 103 11 119.0 BASF AG describes a process for the isomerization of 2-methyl-3-butenenitrile to linear pentenenitrile in the presence of a system containing Ni (0) catalysts and Lewis acids. During the isomerization, a mixture comprising 2-methyl-3-butenenitrile and linear pentenenitrile is removed from the reaction mixture by distillation. A disadvantage of this method is that the withdrawn Pro product stream still contains significant amounts of unreacted 2-methyl-3-butenenitrile.

all known processes for the isomerization of 2-methyl-3-butenenitrile is common that 2-methyl-3-butenenitrile because of the thermodynamic Balance position not complete can be converted to 3-pentenenitrile. Unreacted 2-methyl-3-butenenitrile must for an economic exercise of the process are fed back to the isomerization step. In the isomerization of 2-methyl-3-butenenitrile is but as a byproduct (Z) -2-methyl-2-butenenitrile, which is formed upon recycling of 2-methyl-3-butenenitrile in the circulation stream aufpegeln, since in the separation of 3-pentenenitrile from the Isomerisierungsproduktstrom by distillation because of the very similar vapor pressures together with the 2-methyl-3-butenenitrile passes.

US 3,865,865 describes the separation of 2-methyl-2-butenenitrile from a mixture with 2-methyl-3-butenenitrile. The separation is carried out by treating the mixture of nitriles with an aqueous solution consisting of sulfite and bisulfite ions. This forms the bisulfite adduct of 2-methyl-2-butenenitrile, which merges into the aqueous phase. The resulting organic phase is thereby depleted to 50% of the original content of 2-methyl-2-butenenitrile. The method according to US 3,865,865 is cumbersome because a phase separation of an organic from an aqueous phase is required. Moreover, this separation is difficult to integrate into an overall process for the production of adiponitrile. A further disadvantage of this process is that the organic phase obtained must first be completely freed from water before further use in hydrocyanation reactions using nickel (0) catalysts with phosphorus (III) -containing ligands, otherwise the phosphorus (III) - containing ligands irreversibly hydrolyzed and thus inactivated. Another disadvantage of this method is that the obtained bisulfite adducts for the purpose of further use of the conjugated nitriles, as in US 3,865,865 described, only under drastic conditions and with only moderate yield gap are bar.

task Thus, the present invention is a process for production of 3-pentenenitrile by isomerization of 2-methyl-3-butenenitrile available with the catalyst for isomerization in a simple manner can be separated from the reaction mixture and recycled and both the separation of (Z) -2-methyl-2-butenenitrile from 2-methyl-3-butenenitrile as well as the repatriation of the of (Z) -2-methyl-2-butenenitrile depleted 2-methyl-3-butenenitrile allows becomes. The method should preferably be technically simple and economical feasible be in a total process for the production of adiponitrile integrate.

These Task is achieved by a process for the preparation of 3-pentenenitrile solved.

Embodiment I

• (a) Isomerisierung eines Eduktstroms, der 2-Methyl-3-butennitril enthält, an mindestens einem gelösten oder dispergierten Isomerisierungskatalysator zu einem Strom 1, der den mindestens einen Isomerisierungskatalysator, 2-Methyl-3-butennitril, 3-Pentennitril und (Z)-2-Methyl-2-butennitril enthält,
• (b) Destillation des Stromes 1 unter Erhalt eines Stromes 2 als Kopfprodukt, der 2-Methyl-3-butennitril, 3-Pentennitril und (Z)-2-Methyl-2-butennitril enthält, und eines Stromes 3 als Sumpfprodukt, der den mindestens einen Isomerisierungskatalysator enthält,
• (c) Destillation des Stromes 2 unter Erhalt eines Stromes 4 als Kopfprodukt, der gegenüber dem Strom 2 an (Z)-2-Methyl-2-butennitril, bezogen auf die Summe aller Pentennitrile im Strom 2, angereichert ist, und eines Stromes 5 als Sumpfprodukt, der gegenüber dem Strom 2 an 3-Pentennitril und 2-Methyl-3-butennitril, bezogen auf die Summe aller Pentennitrile im Strom 2, angereichert ist,
• (d) Destillation des Stromes 5 unter Erhalt eines Stromes 6 als Sumpfprodukt, der 3-Pentennitril enthält, und eines Stromes 7 als Kopfprodukt, der 2-Methyl-3-butennitril enthält.

The method is characterized in an embodiment I by the following method steps:

• (a) isomerization of a feed stream containing 2-methyl-3-butenenitrile to at least one dissolved or dispersed isomerization catalyst into a stream 1 containing at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile,
• (b) distillation of the stream 1 while receiving a stream 2 as a top product containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, and one stream 3 as the bottom product containing the at least one isomerization catalyst,
• (c) distillation of the stream 2 while receiving a stream 4 as a top product, facing the stream 2 an (Z) -2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched, and a stream 5 as the bottom product, opposite the stream 2 to 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched,
• (d) distillation of the stream 5 while receiving a stream 6 as a bottom product containing 3-pentenenitrile and a stream 7 as a top product containing 2-methyl-3-butenenitrile.

reactant stream

In Process step (a) finds an isomerization of a reactant stream, the 2-methyl-3-butenenitrile contains on at least one isomerization catalyst instead.

• (e) Hydrocyanierung von 1,3-Butadien an mindestens einem Hydrocyanierungskatalysator mit Cyanwasserstoff unter Erhalt eines Stromes 8, der den mindestens einen Hydrocyanierungskatalysator, 3-Pentennitril, 2-Methyl-3-butennitril, 1,3-Butadien und Reste Cyanwasserstoff enthält,
• (f) ein- oder mehrfache Destillation des Stromes 8 unter Erhalt eines Stromes 9, der 1,3-Butadien enthält, eines Stromes 10, der den mindestens einen Hydrocyanierungskatalysator enthält, und eines Stromes 11, der 3-Pentennitril und 2-Methyl-3-butennitril enthält,
• (g) Destillation des Stromes 11 unter Erhalt eines Stromes 12 als Sumpfprodukt, der 3-Pentennitril enthält, und eines Stromes 13 als Kopfprodukt, der 2-Methyl-3-butennitril enthält.

In a particular embodiment of the process according to the invention, the educt stream is obtainable by the following process steps:

• (e) hydrocyanation of 1,3-butadiene on at least one hydrocyanation catalyst with hydrogen cyanide to give a stream 8th containing at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile, 1,3-butadiene and hydrogen cyanide radicals,
• (f) one or more distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile,
• (g) distillation of the stream 11 while receiving a stream 12 as a bottom product containing 3-pentenenitrile and a stream 13 as a top product containing 2-methyl-3-butenenitrile.

In process step (e), hydrocyanation of 1,3-butadiene initially takes place on at least one hydrocyanation catalyst with hydrogen cyanide to produce the stream of starting material, with the result that a stream is obtained 8th containing the at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile and unreacted 1,3-butadiene.

When Hydrocyanation catalyst is preferably a homogeneous nickel (0) catalyst used stabilized with phosphorous ligands.

The phosphorus ligands of the nickel (0) complexes and the free ones Phosphorus-containing ligands are preferably selected from mono- or bidentate phosphines, phosphites, phosphinites and phosphonites.

These phosphorus-containing ligands preferably have the formula 1: P (X ¹ R ¹ ) (X ² R ² ) (X ³ R ³ ) (I)

Under Compound I becomes a single within the meaning of the present invention Compound or a mixture of different compounds of the aforementioned Formula understood.

According to the invention X ¹ , X ² , X ^{3 are} independently oxygen or single bond. If all of the groups X ^1, X are single bonds ² and X ^3, compound I is a phosphine of the formula P (R ¹ R ² R ³⁾ with the definitions of R ^1, R ² and R ³ in this description represents ,

If two of the groups X ^1, X ² and X ³ are single bonds and one for oxygen, compound I is a phosphinite of formula P (OR ¹⁾ (R ²⁾ (R ³⁾ or P (R ¹⁾ (OR ² ) (R ³ ) or P (R ¹ ) (R ² ) (OR ³ ) with the meanings given below for R ¹ , R ² and R ³ .

If one of the groups X ^1, X ² and X ³ represents a single bond and two oxygen, compound I is a phosphonite of formula P (OR ¹⁾ (OR ²⁾ (R ³⁾ or P (R ¹⁾ (OR ² ) (OR ³ ) or P (OR ¹ ) (R ² ) (OR ³ ) with the meanings given for R ¹ , R ² and R ³ in this description.

In a preferred embodiment, all of the groups X ^1, X is oxygen ² and X ³ should give compound I is advantageously a phosphite of the formula P (OR ¹⁾ (OR ²⁾ (OR ³⁾ with the definitions of R ^1, R ² and R ³ represents the meanings mentioned below.

According to the invention, R ¹ , R ² , R ³ independently of one another represent identical or different organic radicals. As R ¹ , R ² and R ³ are independently alkyl radicals, preferably having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, Aryl groups, such as phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, 2-naphthyl, or hydrocarbyl, preferably having 1 to 20 carbon atoms, such as 1,1'-biphenol, 1,1'- Binaphthol into consideration. The groups R ¹ , R ² and R ³ may be connected to each other directly, ie not solely via the central phosphorus atom. Preferably, the groups R ¹ , R ² and R ^{3 are} not directly connected to each other.

In a preferred embodiment, groups R ¹ , R ² and R ^{3 are} radicals selected from the group consisting of phenyl, o-tolyl, m-tolyl and p-tolyl. In a particularly preferred embodiment, a maximum of two of the groups R ¹ , R ² and R ^{3 should be} phenyl groups.

In another preferred embodiment, a maximum of two of the groups R ¹ , R ² and R ^{3 should be} o-tolyl groups.

As particularly preferred compounds I, those of the formula Ia (o-tolyl-O-) _w (m-tolyl-O-) _x (p-tolyl-O-) _y (phenyl-O-) _z P (Ia) where w, x, y and z denote a natural number and the following conditions apply: w + x + y + z = 3 and w, z ≤ 2.

Such compounds Ia are, for example, (p-tolyl-O -) (phenyl-O-) ₂ P, (m-tolyl-O -) (phenyl-O-) ₂ P, (o-tolyl-O -) (phenyl-) O-) _2P, (p-tolyl-O-) ₂ (phenyl-O-) P, (m-tolyl-O-) ₂ (phenyl-O-) P, (o-tolyl-O-) ₂ ( Phenyl-O-) P, (m-tolyl-O -) (p-tolyl-O) (phenyl-O-) P, (o-tolyl-O -) (p-tolyl-O -) (phenyl-O -) P, (o-tolyl-O -) (m-tolyl-O -) (phenyl-O-) P, (p-tolyl-O-) ₃ P, (m-tolyl-O -) (p-) Tolyl-O-) ₂ P, (o-tolyl-O -) (p-tolyl-O-) ₂ P, (m-tolyl-O-) ₂ (p-toluyl-O-) P, (o-tolyl -O-) ₂ (p-Tolyl-O-) P, (o-tolyl-O -) (m-tolyl-O -) (p-tolyl-O) P, (m-tolyl-O-) ₃ P , (o-Tolyl-O -) (m-tolyl-O-) ₂ P (o-tolyl-O-) ₂ (m-tolyl-O-) P, or mixtures of such compounds.

Mixtures containing (m-tolyl-O-) ₃ P, (m -olyl-O-) ₂ (p-tolyl-O-) P, (m-tolyl-O -) (p-tolyl-O-) ₂ P and (p-tolyl-O-) ₃ P can be, for example, by reacting a mixture containing m-cresol and p-cresol, in particular in a molar ratio of 2: 1, as obtained in the distillative workup of petroleum, with a phosphorus trihalide, such as phosphorus trichloride , receive.

In another, likewise preferred embodiment, the phosphites of the formula Ib which are described in more detail in DE-A 199 53 058 are suitable as phosphorus-containing ligands: P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) With
R ¹ : aromatic radical having a C ₁ -C ₁₈ -alkyl substituent in the o-position to the oxygen atom which connects the phosphorus atom with the aromatic system, or with an aromatic substituent in o-position to the oxygen atom, the phosphorus atom with the aromatic System, or aromatic system fused to the oxygen atom linking the phosphorus atom to the aromatic system,
R ² : aromatic radical having a C ₁ -C ₁₈ -alkyl substituent in the m-position to the oxygen atom which connects the phosphorus atom with the aromatic system, or with an aromatic substituent in m-position to the oxygen atom, the phosphorus atom with the aromatic The system combines, or with an aromatic system fused in m-position to the oxygen atom linking the phosphorus atom to the aromatic system, wherein the aromatic radical in the o-position to the oxygen atom connecting the phosphorus atom to the aromatic system, a hydrogen atom wearing,
R ³ : aromatic radical having a C ₁ -C ₁₈ alkyl substituent in the p-position to the oxygen atom connecting the phosphorus atom to the aromatic system, or having an aromatic substituent in p-position to the oxygen atom linking the phosphorus atom to the aromatic atom System combines, wherein the aromatic radical in the o-position to the oxygen atom which connects the phosphorus atom with the aromatic system, carries a hydrogen atom,
R ⁴ : aromatic radical which carries in the o, m and p position to the oxygen atom which connects the phosphorus atom to the aromatic system, other than the substituents defined for R ¹ , R ² and R ³ , wherein the aromatic radical in the position ortho to the oxygen atom connecting the phosphorus atom to the aromatic system carries a hydrogen atom,
x: 1 or 2,
y, z, p: independently 0, 1 or 2, with the proviso that x + y + z + p = 3.

Preferred phosphites of the formula Ib can be found in DE-A 199 53 058. As radical R ¹ are advantageously o-tolyl, o-ethyl-phenyl, on-propyl-phenyl, o-isopropyl-phenyl, on-butyl-phenyl, o-sec-butyl-phenyl, o- tert-butyl-phenyl, (o-phenyl) -phenyl or 1-naphthyl groups into consideration.

As the radical R ² are m-tolyl, m-ethyl-phenyl, mn-propyl-phenyl, m-isopropyl-phenyl, mn-butyl-phenyl, m-sec-butyl-phenyl, m-tert Butyl-phenyl, (m-phenyl) -phenyl or 2-naphthyl groups are preferred.

As radical R ³ are advantageously p-tolyl, p-ethyl-phenyl, pn-propyl-phenyl, p-isopropyl-phenyl, pn-butyl-phenyl, p-sec-butyl-phenyl, p- tert-butyl-phenyl or (p-phenyl) -phenyl groups into consideration.

Radical R ⁴ is preferably phenyl. Preferably, p is equal to zero. For the indices x, y, z and p in connection Ib the following possibilities arise:

Preferred phosphites of the formula Ib are those in which p is zero and R ¹ , R ² and R ^{3 are} independently selected from o-isopropyl-phenyl, m-tolyl and p-tolyl, and R ^{4 is} phenyl.

Particularly preferred phosphites of the formula Ib are those in which R ^{1 is} the o-isopropylphenyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table above; also those in which R ^{1 is} the o-tolyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; furthermore those in which R ^{1 is} the 1-naphthyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; also those in which R ^{1 is} the o-tolyl radical, R ^{2 is} the 2-naphthyl radical and R ³ the p-tolyl radical is with the indices listed in the table; and finally those in which R ^{1 is} the o-isopropylphenyl radical, R ^{2 is} the 2-naphthyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; as well as mixtures of these phosphites.

• a) ein Phosphortrihalogenid mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Dihalogenophosphorigsäuremonoesters,
• b) den genannten Dihalogenophosphorigsäuremonoester mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Monohalogenophosphorigsäurediesters und
• c) den genannten Monohalogenophosphorigsäurediester mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Phosphits der Formel Ib.

Phosphites of the formula Ib can be obtained by

• a) reacting a phosphorus trihalide with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a dihalophosphoric acid monoester,
• b) reacting said dihalophosphoric acid monoester with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a monohalophosphoric diester and
• c) reacting said Monohalogenophosphorigsäurediester with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a phosphite of formula Ib.

The Implementation can be carried out in three separate steps. Likewise two of the three steps are combined, so a) with b) or b) with c). Alternatively you can all of steps a), b) and c) are combined with each other.

In this case, one can easily determine suitable parameters and amounts of the alcohols selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof by a few simple preliminary experiments.

As phosphorus trihalogenide are basically all phosphorus trihalides, preferably those in which as the halide Cl, Br, I, in particular Cl, is used, and mixtures thereof. It is also possible to use mixtures of different identically or differently halogen-substituted phosphines as the phosphorus trihalide. Particularly preferred is PCl ₃ . Further details on the reaction conditions in the preparation of phosphites Ib and for workup can be found in DE-A 199 53 058.

The Phosphites Ib can also in the form of a mixture of different phosphites Ib as a ligand be used. Such a mixture may, for example, in the Production of the phosphites Ib incurred.

auf, worin bedeuten
X¹¹, X¹², X¹³, X²¹, X²², X²³ unabhängig voneinander Sauerstoff oder Einzelbindung
R¹¹, R¹² unabhängig voneinander gleiche oder unterschiedliche, einzelne oder verbrückte organische Reste
R²¹, R²² unabhängig voneinander gleiche oder unterschiedliche, einzelne oder verbrückte organische Reste,
Y BrückengruppeHowever, it is preferred that the phosphorus-containing ligand is polydentate, in particular bidentate. Therefore, the ligand used preferably has the formula II

in which mean
X ¹¹ , X ¹² , X ¹³ , X ²¹ , X ²² , X ^{23 are} independently oxygen or single bond
R ¹¹ , R ^{12 are} independently identical or different, single or bridged organic radicals
R ²¹ , R ²² independently of one another are identical or different, individual or bridged organic radicals,
Y bridge group

Under Compound II becomes a single within the meaning of the present invention Compound or a mixture of different compounds of the aforementioned Formula understood.

In a preferred embodiment, X ¹¹ , X ¹² , X ¹³ , X ²¹ , X ²² , X ^{23 may be} oxygen. In such a case, the bridging group Y is linked to phosphite groups.

In another preferred embodiment, X ¹¹ and X ^{12 can be} oxygen and X ^{13 is} a single bond or X ¹¹ and X ^{13 is} oxygen and X ^{12 is} a single bond such that the phosphorus atom surrounded by X ¹¹ , X ¹² and X ^{13 is the} central atom of a phosphonite. In such a case, X ²¹ , X ²² and X ^{23 may be} oxygen or X ²¹ and X ²² oxygen and X ²³ a single bond or X ²¹ and X ²³ oxygen and X ²² a single bond or X ²³ oxygen and X ²¹ and X ²² a single bond or X ^{21 is} oxygen and X ²² and X ^{23 represent} a single bond or X ²¹ , X ²² and X ^{23 represent} a single bond, so that the phosphorus atom surrounded by X ²¹ , X ²² and X ²³ central atom of a phosphite, phosphonite, phosphinite or phosphine, preferably of a phosphonite, can be.

In another preferred embodiment, X ¹³ may be oxygen and X ¹¹ and X ^{12 may be} a single bond or X ¹¹ oxygen and X ¹² and X ^{13 may be} a single bond such that the phosphorous atom surrounded by X ¹¹ , X ¹² and X ^{13 is the} central atom of a phosphonite. In such a case, X ²¹ , X ²² and X ^{23 can be} oxygen or X ²³ oxygen and X ²¹ and X ²² a single bond or X ²¹ oxygen and X ²² and X ²³ a single bond or X ²¹ , X ²² and X ²³ a single bond in that the phosphorus atom surrounded by X ²¹ , X ²² and X ^{23 can be the} central atom of a phosphite, phosphinite or phosphine, preferably of a phosphinite.

In another preferred embodiment, X ¹¹ , X ¹² and X ^{13 may represent} a single bond such that the phosphorus atom surrounded by X ¹¹ , X ¹² and X ^{13 is the} central atom of a phosphine. In such a case, X ²¹ , X ²² and X ²³ oxygen or X ²¹ , X ²² and X ^{23 may represent} a single bond such that the phosphorus atom surrounded by X ²¹ , X ²² and X ^{23 is the} central atom of a phosphite or phosphine, preferably a phosphine , can be.

Bridging group Y is preferably substituted, for example with C ₁ -C ₄ alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups, preferably those having 6 to 20 carbon atoms in the aromatic system, in particular pyrocatechol, bis (phenol) or bis (naphthol).

The radicals R ¹¹ and R ¹² may independently of one another represent identical or different organic radicals. Advantageously suitable radicals R ¹¹ and R ^{12 are} aryl radicals, preferably those having 6 to 10 carbon atoms, which may be unsubstituted or monosubstituted or polysubstituted, in particular by C ₁ -C ₄ -alkyl, halogen, such as fluorine, chlorine, bromine , halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R ²¹ and R ²² may independently represent identical or different organic radicals. Suitable radicals R ²¹ and R ^{22 are} aryl radicals, preferably those having 6 to 10 carbon atoms, into consideration, which may be unsubstituted or monosubstituted or polysubstituted, in particular by C ₁ -C ₄ -alkyl, halogen, such as fluorine, chlorine, bromine , halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R ¹¹ and R ¹² may be singly or bridged. The radicals R ²¹ and R ²² may also be singly or bridged. The radicals R ¹¹ , R ¹² , R ²¹ and R ²² may all be individually bridged and two individually or all four bridged in the manner described.

In a particularly preferred embodiment, the in US 5,723,641 mentioned compounds of formula I, II, III, IV and V into consideration. In a particularly preferred embodiment, the in US 5,512,696 mentioned compounds of the formula I, II, III IV, V, VI and VII, in particular the compounds used there in Examples 1 to 31, into consideration. In a particularly preferred embodiment, the in US 5,821,378 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV and XV, in particular the compounds used there in Examples 1 to 73, into consideration.

In a particularly preferred embodiment, the in US 5,512,695 mentioned compounds of formula I, II, III, IV, V and VI, in particular the compounds used there in Examples 1 to 6, into consideration. In a particularly preferred embodiment, the in US 5,981,772 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII and XIV, in particular the compounds used there in Examples 1 to 66, into consideration.

In a particularly preferred embodiment, the in US 6,127,567 mentioned compounds and there used in Examples 1 to 29 compounds into consideration. In a particularly preferred embodiment, the in US 6,020,516 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX and X, in particular the compounds used there in Examples 1 to 33, into consideration. In a particularly preferred embodiment, the in US 5,959,135 mentioned compounds and there used in Examples 1 to 13 compounds into consideration.

In a particularly preferred embodiment, the in US 5,847,191 mentioned compounds of formula I, II and III into consideration. In a particularly preferred embodiment, the in US 5,523,453 mentioned compounds, in particular those in formula 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 21 shown Compounds, into consideration. In a particularly preferred embodiment, the compounds mentioned in WO 01/14392, preferably those in formula V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XXI, XXII, XXIII.

In a particularly preferred embodiment the compounds mentioned in WO 98/27054 are suitable. In a particularly preferred embodiment the compounds mentioned in WO 99/13983 come into consideration. In a particularly preferred embodiment the compounds mentioned in WO 99/64155 come into consideration.

In a particularly preferred embodiment, those in the German patent application DE 100 380 37 considered compounds. In a particularly preferred embodiment, those in the German patent application DE 100 460 25 considered compounds. In a particularly preferred embodiment, those in the German patent application DE 101 502 85 considered compounds.

In a particularly preferred embodiment, those in the German patent application DE 101 502 86 considered compounds. In a particularly preferred embodiment, those in the German patent application DE 102 071 65 considered compounds. In a further particularly preferred embodiment of the present invention, the phosphorus-containing chelate ligands mentioned in US 2003/0100442 A1 come into consideration.

In a further particularly preferred embodiment of the present invention, the non-prepublished German patent application file reference DE 103 50 999.2 from 30.10.2003 mentioned phosphorus chelating ligands into consideration.

The described compounds I, Ia, Ib and II and their preparation are known per se. As a phosphorus-containing ligand can also Mixtures containing at least two of the compounds I, Ia, Ib and II.

In a particularly preferred embodiment of the process according to the invention, the phosphorus-containing ligand of the nickel (0) complex and / or the free phosphorus-containing ligand is selected from tritolyl phosphite, bidentate phosphorus-containing chelate ligands, and the phosphites of the formula Ib P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) wherein R ¹ , R ² and R ^{3 are} independently selected from o-isopropylphenyl, m-tolyl and p-tolyl, R ^{4 is} phenyl; x is 1 or 2, and y, z, p are independently 0, 1 or 2, with the proviso that x + y + z + p = 3; and their mixtures.

Of the Process step (e) may be in any suitable manner known to those skilled in the art Apparatus be performed. For the Reaction come thus usual Equipment, such as those in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 20, John Wiley & Sons, New York, 1996, pages 1040 to 1055, such as stirred tank reactors, Loop reactors, gas circulation reactors, bubble column reactors or tubular reactors, each optionally with devices for removing heat of reaction. The Reaction can be carried out in several, such as two or three, apparatuses.

In a preferred embodiment the method according to the invention have reactors with backmixing characteristics or cascades of reactors with backmixing characteristics proved to be advantageous. Particularly advantageous are cascades from reactors with backmixing characteristics proved in terms of the dosage of hydrogen cyanide in Querstromfahrweise be operated.

The Hydrocyanation can be carried out in the presence or absence of one solvent carried out become. If a solvent is used, so should the solvent at the given reaction temperature and the given reaction pressure liquid and inert the unsaturated Compounds and the at least one catalyst. In general be as a solvent Hydrocarbons, for example benzene or xylene, or nitriles, for example acetonitrile or benzonitrile. Preferably however, becomes a ligand as a solvent used.

The Reaction can be batch, continuous or semi-batch carried out become.

The hydrocyanation reaction can be carried out by the apparatus with all reactants is equipped. However, it is preferred if the device is filled with the catalyst, the unsaturated organic compound and optionally the solvent. Preferably, the gaseous hydrogen cyanide floats above the surface of the reaction mixture or is passed through the reaction mixture. Another procedure for equipping the device is to fill the device with the catalyst, hydrogen cyanide and optionally the solvent and slowly add the unsaturated compound to the reaction mixture. Alternatively, it is also possible that the reactants are introduced into the reactor and the reaction mixture is brought to the reaction temperature at which the hydrogen cyanide is added liquid to the mixture. In addition, the hydrogen cyanide may also be added prior to heating to reaction temperature. The reaction is carried out under conventional hydrocyanation conditions for temperature, atmosphere, reaction time, etc.

Preferably hydrocyanation is carried out continuously in one or more stirred process steps carried out. If a plurality of process steps are used, then it is preferred that the method steps are connected in series. The product of a process step directly into the next Ver procedural step transferred. Of the Hydrogen cyanide can be added directly in the first process step or be supplied between the individual process steps.

If the inventive method performed in semibatch mode is, it is preferred that in the reactor, the catalyst components and 1,3-butadiene are introduced while hydrogen cyanide is over the Reaction time is metered into the reaction mixture.

The Reaction is preferably at absolute pressures of 0.1 to 500 MPa, especially preferably 0.5 to 50 MPa, in particular 1 to 5 MPa performed. The Reaction is preferably at temperatures of 273 to 473 K, especially preferably 313 to 423 K, in particular at 333 to 393 K performed. there have average mean residence times of the liquid reactor phase in the range of 0.001 to 100 hours, preferably 0.05 to 20 hours, particularly preferably 0.1 to 5 hours, in each case per reactor, as proved advantageous.

The Reaction can be in one embodiment in liquid Phase in the presence of a gas phase and optionally a solid suspended phase become. It can the starting materials hydrogen cyanide and 1,3-butadiene each liquid or gaseous be dosed.

The Reaction can in a further embodiment in the liquid phase carried out be, the pressure in the reactor is such that all starting materials like 1,3-butadiene, Hydrogen cyanide and the at least one catalyst added liquid and be present in the reaction mixture in the liquid phase. there may be a solid suspended phase in the reaction mixture, which also added together with the at least one catalyst can be, for example consisting of degradation products of the catalyst system, containing inter alia nickel (II) compounds.

In process step (e) becomes a stream 8th which contains 3-pentenenitrile, 2-methyl-3-butenenitrile containing at least one catalyst and unreacted 1,3-butadiene.

The current 8th which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile containing at least one catalyst and unreacted 1,3-butadiene is then transferred to a distillation apparatus in step (f). In this distillation apparatus is a single or multiple distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile.

The Distillation of process step (f) can take place in two stages, as in DE-A-102 004 004 720, process steps (b) and (c). The distillation of process step (f) can also be carried out according to DE-A-102 004 004729, Process steps (b) and (c) take place.

The distillation (s) of process step (f) may be carried out in any suitable apparatus known to those skilled in the art. Suitable for the distillation are apparatuses as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, which can also be operated as dividing wall columns. These distillation devices are each equipped with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, multiphase spiral tube evaporators, natural circulation evaporators or forced circulation flash evaporators, and with devices for condensing the vapor stream. The individual distillations can one in each case in several, such as two or three apparatuses, advantageously in each case perform in a single apparatus.

The Distillation (s) can / can each also single-stage in the sense of a partial evaporation of the feed stream respectively.

Of the Pressure in process step (f) is preferably 0.001 to 10 bar, more preferably 0.010 to 1 bar, in particular 0.02 to 0.5 bar. The distillation (s) is / are carried out in such a way that the temperature (s) in the bottom of the distillation apparatus (s) preferably From 30 to 200 ° C, more preferably 50 to 150 ° C, in particular 60 to 120 ° C, is / amount. The distillation (s) is / are carried out so that the condensation temperatures at the top of the distillation apparatus preferably -50 to 150 ° C, especially preferably -15 to 60 ° C, in particular 5 to 45 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also maintained in the bottom of the distillation apparatus (s).

The current 11 is then subjected to distillation in a further process step (g). This distillation can be carried out in any suitable apparatus known to the person skilled in the art. Suitable for the distillation are apparatuses as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, which can also be operated as dividing wall columns. These distillation devices are each equipped with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, multiphase spiral tube evaporators, natural circulation evaporators or forced circulation flash evaporators, and with devices for condensing the vapor stream. The distillation can be carried out in several, such as two or three apparatus, advantageously in a single apparatus. The distillation can also be carried out in one stage in the sense of partial evaporation of the feed stream.

Of the Pressure in process step (g) is preferably 0.001 to 100 bar, more preferably 0.01 to 20 bar, in particular 0.05 to 2 bar. The distillation is carried out so that the temperature in the Bottom of the distillation apparatus preferably 30 to 250 ° C, especially preferably 50 to 200 ° C, in particular 60 to 180 ° C, is. The distillation is carried out so that the condensation temperature at the top of the distillation apparatus, preferably -50 to 250 ° C, especially preferably 0 to 180 ° C, in particular 15 to 160 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In process step (g) becomes a stream 12 as the bottom product containing 1,3-pentenenitrile and electricity 13 as the top product containing 2-methyl-3-butenenitrile. The current 13 is preferably used as Eduktstrom in the process according to the invention for the preparation of 3-pentenenitrile.

In further preferred embodiments of the method according to the invention, the stream obtained in process step (e) 8th transferred directly into the process step (g). In this process step (g), a stream is then obtained via the bottom, which contains essentially 3-pentenenitrile and the at least one hydrocyanation catalyst. In addition, a stream containing essentially 2-methyl-3-butenenitrile and 1,3-butadiene is obtained overhead. This stream, which is rich in 2-methyl-3-butenenitrile and 1,3-butadiene, can likewise be used as reactant stream in the process according to the invention for the preparation of 3-pentenenitrile. If this starting material stream is used in the process according to the invention, the content of 2-methyl-3-butenenitrile in this stream is preferably 10 to 90% by weight, particularly preferably 20 to 85% by weight, in particular 30 to 80% by weight. -%, in each case based on the electricity.

Alternatively, it is also possible to obtain the current obtained in process step (e) 8th in the process step (f) to deplete only 1,3-butadiene. About the bottom of the process step (f) then becomes a stream 11a which contains substantially 3-pentenenitrile, 2-methyl-3-butenenitrile and the at least one hydrocyanation catalyst. This stream 11a is then then further worked up in the process step (g) with separation of 3-pentenenitrile and the at least one hydrocyanation on the one hand and on the other hand of 2-methyl-3-butenenitrile on the other hand. The stream resulting from process step (g) 13a at the top of the distillation contains essentially 2-methyl-3-butenenitrile. This stream 13a can also be used as Eduktstrom in the process according to the invention for the preparation of 3-pentenenitrile.

In a further embodiment, the stream 8th from process step (e) in process step (f) only depleted in 1,3-butadiene and transferred to process step (g) where there is a stream in the sump 12 with 3-pentenenitrile and the hydrocyanation catalyst.

In a further embodiment of the present invention, a starting material stream is used which originates from a hydrocyanation of process step (e) and a subsequent work-up in process step (f), wherein in process step (f) optionally only a depletion of 1,3-butadiene is carried out , The resulting electricity 11b is then converted into process step (a) of the process according to the invention. The one in this stream 11b The hydrocyanation catalyst contained is then preferably used as the at least one isomerization catalyst in process step (a) of the process according to the invention. A suitable Lewis acid may additionally be added, as described, for example, in DE-A-102 004 004 696.

In a further embodiment of the present invention, it is possible for the educt stream used in process step (a) according to the invention to correspond to the stream 11 of the method step (f) corresponds, so that a separation of the stream 11 in the process step (g) is omitted.

In a further embodiment of the process according to the invention, the stream is the educt stream 8th used in step (e). In this case, therefore, the process steps (f) and (g) in the production of the feed stream for the inventive method omitted.

Process step (a)

In process step (a), an isomerization of the reactant stream which comprises 2-methyl-3-butenenitrile takes place on at least one isomerization catalyst. This is a current 1 containing the isomerization catalyst, unreacted 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile.

• a) Nickel(0),
• b) eine Nickel(0) als Ligand komplexierende, dreibindigen Phosphor enthaltende Verbindung und gegebenenfalls
• c) eine Lewis-Säure durch.

According to the invention, the isomerization is carried out in the presence of a system containing

• a) nickel (0),
• b) a nickel (0) ligand complexing, trivalent phosphorus-containing compound and optionally
• c) a Lewis acid.

The Production of nickel (0) containing catalyst systems can take place according to known methods.

When Ligands for the isomerization catalyst can the same phosphorus ligands as for the in process step (e) used Hydrocyanierungskatalysator be used. Consequently For example, the hydrocyanation catalyst may be identical to the isomerization catalyst be. The selection of ligands for the However, reactions in process steps (a) and (e) do not have to be necessarily be the same.

Farther contains the system optionally a Lewis acid.

in the For the purposes of the present invention, a Lewis acid is a single Lewis acid or a mixture of several, such as two, three or four Lewis acids, understood.

Suitable Lewis acids are inorganic or organic metal compounds in which the cation is selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium , Zirconium, niobium, molybdenum, cadmium, rhenium and tin. Examples are ZnBr ₂ , Znl ₂ , ZnCl ₂ , ZnSO ₄ , CuCl ₂ , CuCl, Cu (O ₃ SCF ₃ ) ₂ , CoCl ₂ , Col ₂ , Fel ₂ , FeCl ₃ , FeCl ₂ , FeCl ₂ (THF) ₂ , TiCl ₄ (THF) ₂ , TiCl ₄ , TiCl ₃ , ClTi (Oi-propyl) ₃ , MnCl ₂ , ScCl ₃ , AlCl ₃ , (C ₈ H ₁₇ ) AlCl ₂ , (C ₈ H ₁₇ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl, (C ₆ H ₅ ) ₂ AlCl, (C ₆ H ₅ ) AlCl ₂ , ReCl ₅ , ZrCl ₄ , NbCl ₅ , VCl ₃ , CrCl ₂ , MoCl ₅ , YCl ₃ , CdCl ₂ , LaCl ₃ , Er (O ₃ SCF ₃ ) ₃ , Yb (O ₂ CCF ₃ ) ₃ , SmCl ₃ , B (C ₆ H ₅ ) ₃ , TaCl ₅ , such as in US 6,127,567 . US 6,171,996 and US 6,380,421 described. Also contemplated are metal salts such as ZnCl ₂ , Col ₂ and SnCl ₂ as well as organometallic compounds such as RAlCl ₂ , R ₂ AlCl, RSnO ₃ SCF ₃ and R ₃ B where R is an alkyl or aryl group such as in US 3,496,217 . US 3,496,218 and US 4,774,353 described. Furthermore, according to US 3,773,809 as promoter, a metal in cationic form selected from the group consisting of zinc, cadmium, beryllium, aluminum, gallium, indium, thallium, titanium, zirconium, hafnium, erbium, germanium, tin, vanadium, niobium, scandium, chromium, molybdenum , Tungsten, manganese, rhenium, palladium, thorium, iron and cobalt, preferably zinc, cadmium, titanium, tin, chromium, iron and cobalt, wherein the ionic part of the compound may be selected from the group consisting of halides, such as fluoride, chloride, bromide and iodide, anions of lower fatty acids having from 2 to 7 carbon atoms, HPO ₃ ^2- , H ₃ PO ^2- , CF ₃ COO ^- , C ₇ H ₁₅ OSO ₂ ^- or SO ₄ ^2- . Furthermore are out US 3,773,809 as suitable promoters borohydrides, organoborohydrides and boric acid esters of the formula R ₃ B and B (OR) ₃ , wherein R is selected from the group consisting of hydrogen, aryl radicals having between 6 and 18 carbon atoms, with alkyl groups having 1 to 7 carbon atoms substituted aryl radicals and with cyano-substituted alkyl groups having 1 to 7 carbon atoms substituted aryl radicals, preferably triphenylborane called. Furthermore, as in US 4,874,884 described, synergistically effective combinations of Lewis acids are used to increase the activity of the catalyst system. Suitable promoters may be selected, for example, from the group consisting of CdCl ₂ , FeCl ₂ , ZnCl ₂ , B (C ₆ H ₅ ) ₃ and (C ₆ H ₅ ) ₃ SnX, with X = CF ₃ SO ₃ , CH ₃ C ₆ H ₄ SO ₃ or (C ₆ H ₅ ) ₃ BCN are selected, wherein the ratio of promoter to nickel is a range of preferably from about 1:16 to about 50: 1.

For the purposes of the present invention, the term Lewis acid also includes those in US 3,496,217 . US 3,496,218 . US 4,774,353 . US 4,874,884 . US 6,127,567 . US 6,171,996 and US 6,380,421 mentioned promoters.

When particularly preferred Lewis acids among the above-mentioned in particular metal salts, particularly preferred Metal halides, such as fluorides, chlorides, bromides, iodides, in particular Chlorides, of which in turn zinc chloride, iron (II) chloride and Iron (III) chloride are particularly preferred.

• – beispielsweise eines Kohlenwasserstoffs, wie Hexan, Heptan, Oktan, Cyclohexan, Methylcyclohexan, Benzol, Decahydronaphthalin
• – beispielsweise eines Ethers, wie Diethylether, Tetrahydrofuran, Dioxan, Glykoldimethylether, Anisol,
• – beispielsweise eines Esters, wie Ethylacetat, Methylbenzoat, oder
• – beispielsweise eines Nitrils, wie Acetonitril, Benzonitril, oder
• – Gemischen solcher Verdünnungsmittel durchgeführt werden.

The isomerization can be carried out in the presence of a liquid diluent,

• For example, a hydrocarbon such as hexane, heptane, octane, cyclohexane, methylcyclohexane, benzene, decahydronaphthalene
• For example, an ether such as diethyl ether, tetrahydrofuran, dioxane, glycol dimethyl ether, anisole,
• For example, an ester such as ethyl acetate, methyl benzoate, or
• For example, a nitrile such as acetonitrile, benzonitrile, or
• - Mixtures of such diluents are carried out.

In a particularly preferred embodiment comes an isomerization in the absence of such a liquid diluent into consideration.

Farther it has proved to be advantageous if the isomerization in Process step (a) in a non-oxidizing atmosphere, such as For example, under a protective gas atmosphere of nitrogen or a Noble gas, such as argon, carried out becomes.

Of the Process step (a) may be in any suitable manner known to those skilled in the art Apparatus be performed. For the Reaction come this customary equipment such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 20, John Wiley & Sons, New York, 1996, pages 1040 to 1055, such as stirred tank reactors, Loop reactors, gas circulation reactors, bubble column reactors or tubular reactors. The reaction can be carried out in several, such as two or three apparatuses.

In a preferred embodiment the method according to the invention becomes isomerization in a compartmented tubular reactor carried out.

In a further preferred embodiment the method according to the invention the isomerization is done in at least two series Reactors carried out, wherein the first reactor has substantially stirred tank characteristics and the second reactor designed so is that it has substantially tube characteristic.

In a particularly preferred embodiment the method according to the invention the isomerization is carried out in a reactor, wherein the reactor has the characteristics of a stirred tank cascade, the 2 to 20 stirred kettles, in particular 3 to 10 stirred kettles, equivalent.

The reaction can be carried out in an embodiment of the process according to the invention in a distillation apparatus, wherein the isomerization reaction takes place at least in the bottom region of the distillation apparatus. Any distillation apparatus known to the person skilled in the art, as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, is suitable Sieve tray columns, bubble tray columns, packed columns, Packed columns, which can also be operated as dividing wall columns. These distillation devices are each equipped with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, multiphase spiral tube evaporators, natural circulation evaporators or forced circulation flash evaporators, and with devices for condensing the vapor stream. The distillation with simultaneous reaction can be carried out in several, such as two or three apparatus, advantageously in a single apparatus. The distillation can also be carried out in one stage in the sense of partial evaporation of the feed stream.

Of the Process step (a) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 16 bar, in particular 10 mbar to 6 bar performed. The Temperature is in process step (a) preferably 25 to 250 ° C, especially preferably from 30 to 180 ° C, in particular 40 to 140 ° C.

The Composition of the withdrawn stream in terms of molar ratio of 2-methyl-3-butenenitrile to linear pentenenitrile and thus the The degree of conversion of 2-methyl-3-butenenitrile used depending on from the composition of the supplied stream on technical simple way by the temperature, the catalyst concentration, the residence time and the design of the reactor can be adjusted. In a preferred embodiment the method according to the invention The conversion rate with the help of these measures is based on values in the range From 10 to 99%, particularly preferably from 30 to 95%, in particular from 60 to 90%, set.

Process step (b)

In process step (b), the stream obtained in process step (a) 1 distilled. This gives you as a top product a stream 2 containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile. In addition, in step (b), a stream 3 obtained as a bottom product containing the at least one isomerization catalyst.

Of the Process step (b) of the process of the invention may be in any suitable distillation apparatus known to those skilled in the art are carried out. For the Distillation suitable apparatuses, such as those in: Kirk-Othmer, Encyclopaedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, also referred to as Dividing wall columns can be operated. These distillation facilities are each provided with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, Multiphase spiral tube evaporator, natural circulation evaporator or forced circulation flash evaporator, and equipped with devices for the condensation of the vapor stream. The Distillation can be carried out in several, such as two or three apparatuses, advantageously perform in a single apparatus. The distillation can also single-stage in the sense of partial evaporation of the feed stream respectively.

Of the Process step (b) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 6 bar, in particular 10 mbar to 500 mbar performed. The Distillation is done that the temperature in the bottom of the distillation apparatus is preferably 25 to 250 ° C, more preferably 40 to 180 ° C, in particular 60 to 140 ° C, is. The distillation is carried out so that the temperature at Head of the distillation apparatus preferably -15 to 200 ° C, especially preferably 5 to 150 ° C, in particular special 10 to 100 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In a particularly preferred embodiment of the present invention, the distillation of the stream carried out in process step (b) takes place 1 under pressure and temperature conditions in which the isomerization catalyst present in the mixture is less than or not active in process step (a).

In a preferred embodiment of the present invention, the stream obtained in process step (b) 3 containing the at least one isomerization catalyst, at least partially recycled to process step (a).

In a further embodiment of the method according to the invention, the method steps (a) and (b) take place in the same device. It is also possible that the electricity 3 containing the at least one isomerization catalyst, is not removed from the process step (b) and in the ge common device of the process steps (a) and (b) dwells.

Alternatively, it is also possible that the stream derived from process step (b) 3 , which contains the at least one isomerization catalyst, is used at least partially for the preparation of the reactant stream used in accordance with the invention in process step (e). In process step (e), this at least one isomerization catalyst then functions as a hydrocyanation catalyst.

Procedural document (c)

In process step (c) there is a distillation of the stream 2 instead of. This is a stream 4 obtained as the top product, the opposite to the stream 2 an (Z) -2-methyl-2-butenenitrile with respect to the sum of all in electricity 2 enriched pentenenitriles is enriched. In addition, a stream 5 obtained as bottom product, opposite to the stream 2 an (Z) -2-methyl-2-butenenitrile with respect to the sum of all in electricity 2 depleted pentenenitriles contained depleted.

Of the Process step (c) may be in any suitable manner known to those skilled in the art Device performed become. For the distillation are suitable apparatuses, such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, also called dividing wall columns can be operated. These distillation devices are each provided with suitable devices for evaporation, such as falling film evaporators, thin film evaporators, multiphase spiral tube evaporators, Natural circulation evaporator or forced circulation evaporator, as well equipped with devices for the condensation of the vapor stream. The Distillation can be carried out in several, such as two or three apparatuses, advantageously perform in a single apparatus. The distillation can also single-stage in the sense of partial evaporation of the feed stream respectively.

Of the Process step (c) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 6 bar, in particular 10 mbar to 500 mbar performed. The Distillation is done that the temperature in the bottom of the distillation apparatus is preferably 25 to 250 ° C, more preferably 40 to 180 ° C, in particular 60 to 140 ° C, is. The distillation is carried out so that the temperature at Head of the distillation apparatus preferably -15 to 200 ° C, especially preferably 5 to 150 ° C, in particular 10 to 100 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In a particularly preferred embodiment of the process according to the invention, the process steps (b) and (c) are carried out together in a distillation apparatus, wherein the stream 3 containing the at least one isomerization catalyst as the bottom product, the stream 4 containing (Z) -2-methyl-2-butenenitrile as the top product and the stream 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile can be obtained on a side draw of the column.

In a further preferred embodiment of the process according to the invention, the process steps (a), (b) and (c) are carried out together in a distillation apparatus. This is the current 4 containing (Z) -2-methyl-2-butenenitrile as the top product. The current 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile is obtained at a side draw of the distillation column. The isomerization catalyst preferably remains in the bottom of the distillation column in this embodiment.

Process step (d)

The stream obtained in process step (c) 5 which contains 3-pentenenitrile and 2-methyl-3-butenenitrile is then transferred to another distillation apparatus. In this distillation device is the power 5 in a 3-pentenenitrile stream, which is taken as the bottom product, and a 2-methyl-3-butenenitrile stream which is taken from the top, separated.

The process step (d) can be carried out in any suitable device known to the person skilled in the art. Suitable for the distillation are apparatuses as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, which can also be operated as dividing wall columns. These distillation devices are each provided with suitable evaporation devices such as falling film evaporators, thin film evaporators, multiphase helical tubes steamer, natural circulation evaporator or forced circulation evaporator, and equipped with devices for condensing the vapor stream. The distillation can be carried out in several, such as two or three apparatus, advantageously in a single apparatus. The distillation can also be carried out in one stage in the sense of partial evaporation of the feed stream.

Of the absolute pressure in process step (d) is preferably 0.001 to 100 bar, more preferably 0.01 to 20 bar, in particular 0.05 to 2 bar. The distillation is carried out so that the temperature in the Bottom of the distillation apparatus preferably 30 to 250 ° C, especially preferably 50 to 200 ° C, in particular 60 to 180 ° C, is. The distillation is carried out so that the condensation temperature at the top of the distillation apparatus, preferably -50 to 250 ° C, especially preferably 0 to 180 ° C, in particular 15 to 160 ° C, is.

In a particularly preferred embodiment the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus

In a particularly preferred embodiment of the process according to the invention, process step (d) and process step (g) are carried out in the same distillation apparatus. The streams fall 6 and 12 such as 7 and 13 together. Further, in this preferred embodiment, the stream 5 directly into the common device of the method steps (d) and (g) out. In this case, the feed points of the streams 5 and 11 in the case of a distillation column as a distillation device be the same or different.

In a further embodiment of the process according to the invention, the process steps (c) and (g) are carried out in a common distillation column, wherein the process step (d) is omitted, the stream 2 from process step (b) and electricity 11 from process step (f) in process step (g) are guided, in process step (g) of the stream 4 as overhead product, containing (Z) -2-methyl-2-butenenitrile, the stream 12 as the bottom product containing 3-pentenenitrile and the stream 13 as a side draw stream containing 2-methyl-3-butenenitrile.

In the inventive method according to embodiment I, it is possible that the current 2 is returned directly to the process step (g) and the reactant stream is driven directly into the process step (c), wherein a stream 5a from process step (c) is recycled to the isomerization of process step (a).

Alternatively, it is also possible to use the electricity 2 directly in the process step (g) and to drive the reactant stream in step (c), wherein the stream 5 from process step (c) is returned to the process step (f).

Alternatively, it is also possible that the electricity 2 is returned directly to the process step (g) and the reactant stream in process step (c) is driven and the stream 5 from process step (c) is returned to process step (e).

embodiment II

• (a') Isomerisierung eines Eduktstroms, der 2-Methyl-3-butennitril enthält, an mindestens einem gelösten oder dispergierten Isomerisierungskatalysator zu einem Strom 1', der 3-Pentennitril, 2-Methyl-3-butennitril, den mindestens einen Isomerisierungskatalysator und (Z)-2-Methyl-2-butennitril enthält,
• (b') Destillation des Stromes 1' unter Erhalt eines Stromes 2', der (Z)-2-Methyl-2-butennitril, 2-Methyl-3-butennitril enthält und in den Isomerisierungsschritt (a') zurückgeführt wird, eines Stromes 3' als Sumpfprodukt, der den mindestens einen Isomerisierungskatalysator enthält und in den Isomerisierungsschritt (a') zurückgeführt wird, und eines Stromes 4', der 3-Pentennitril enthält, an einem Seitenabzug der Destillationskolonne.

A further subject of the present invention is a process for the preparation of 3-pentenenitrile according to an embodiment II, which is characterized by the following process steps:

• (a ') Isomerization of a reactant stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerization catalyst into a stream 1' which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile containing at least one isomerization catalyst and (Z) -2-methyl-2-butenenitrile,
• (b ') Distillation of the stream 1' while receiving a stream 2 ' which comprises (Z) -2-methyl-2-butenenitrile, 2-methyl-3-butenenitrile and is recycled to the isomerization step (a ') of a stream 3 ' as the bottom product containing the at least one isomerization catalyst and recycled to the isomerization step (a '), and a stream 4 ' containing 3-pentenenitrile on a side draw of the distillation column.

Of the Eduktstrom, in the process step (a ') of the inventive method according to the embodiment II can be used according to the methods described above Production of the educt stream for the inventive method according to embodiment I am getting.

For the process step (a ') according to embodiment II, the same conditions apply as for method step (a) according to the embodiment I, in particular with regard to the catalyst complex used and the free ligand.

Of the absolute pressure in process step (b ') is preferably 0.001 to 100 bar, more preferably 0.01 to 20 bar, in particular 0.1 to 2 bar. The distillation is carried out so that the temperature in the sump the distillation apparatus preferably 25 to 250 ° C, especially preferably 40 to 180 ° C, in particular 60 to 140 ° C, is. The distillation is carried out so that the condensation temperature at the top of the distillation apparatus, preferably -50 to 250 ° C, especially preferably 0 to 150 ° C, in particular 10 to 100 ° C, is.

A partial discharge of the stream 2 ' is optionally indicated to avoid accumulation of (Z) -2-methyl-2-butenenitrile. The residual current is returned in step (a ').

In a variant of the present method according to embodiment II, the reactant stream instead of in method step (a ') in the process step (b ') guided.

The current 2 ' which leaves process step (b ') in the process according to embodiment II according to the invention, may optionally be subjected to distillation in a further optional process step (c'). In this case, a stream which is enriched in (Z) -2-methyl-2-butenenitrile is preferably formed 5 ' and a stream depleted in (Z) -2-methyl-2-butenenitrile 6 ' , where the electricity 5 ' is preferably returned to the process step (a ').

The optionally to be carried out process step (c ') can also be carried out in the apparatus of process step (a'), wherein then in process step (a ') a distillation apparatus is used, in whose bottom the isomerization reaction takes place, via the bottom of the distillation apparatus, the stream 1' is withdrawn and overhead of the distillation apparatus of the (Z) -2-methyl-2-butenenitrile rich stream 6 ' is deducted.

According to obtain in the method according to embodiment I and II 3-pentenenitrile. For the purposes of the present invention, the term 3-pentenenitrile is used single isomer of 3-pentenenitrile or a mixture of two, three, four or five various such isomers understood. Isomers are cis-2-pentenenitrile, trans-2-pentenenitrile, cis-3-pentenenitrile, trans-3-pentenenitrile, 4-pentenenitrile or mixtures thereof, preferably cis-3-pentenenitrile, trans-3-pentenenitrile, 4-pentenenitrile or their mixtures, for the purposes of the present invention, both in each case individually, as well as in the mixture as 3-Pentenenitril be called, into consideration.

With the method according to the invention There are advantages associated with it. So is in an integrated process for Production of adiponitrile, for example, the return of unreacted 2-methyl-3-butenenitrile from isomerization economically necessary because the degree of conversion of 2-methyl-3-butenenitrile limited to 3-pentenenitrile by the thermodynamic equilibrium is. The return requires that (Z) -2-methyl-2-butenenitrile, which aufpegelt in the 2-methyl-3-butenenitrile cycle, separated becomes. The separation takes place in the process according to the invention by distillation for the separation of 2-methyl-3-butenenitrile and (Z) -2-methyl-2-butenenitrile preferably only after implementation from step (a) in step (c) to specifically losses of value products to minimize.

The inventive method according to a preferred embodiment of the embodiment I is based on the 1 explained in more detail:
In a reactor R1, hydrogen cyanide and 1,3-butadiene are fed in the presence of a nickel (0) catalyst. Hydrocyanation takes place in the reactor to produce a current 8th instead of. This stream 8th Contains 3-pentenenitrile, 2-methyl-3-butenenitrile, the hydrocanization catalyst and unreacted 1,3-butadiene. Subsequently, the electricity 8th converted into a distillation column K1, in the overhead 1,3-butadiene (stream 9 ) from the stream 8th Will get removed. In the bottom of the distillation column K1 is a stream 10 obtained containing the hydrocyanation catalyst. At the side of the distillation column K1 is a stream 11 obtained containing 3-pentenenitrile and 2-methyl-3-butenenitrile. This stream 11 is then transferred to a distillation column K2.

In the distillation column K2 there is a separation of the stream 11 into a stream 12 containing 3-pentenenitrile and a stream 13 containing 2-methyl-3-butenenitrile.

The current 13 is then transferred to an isomerization apparatus R2. In this isomerization apparatus R2 is carried out isomerization of 2-methyl-3-butenenitrile, which in the stream 13 is included in an isomerization catalyst. The current originating from this isomerization 1 contains 3-pentenenitrile, 2-methyl-3-butenenitrile, (Z) -2-methyl-2-butenenitrile and the isomerization catalyst.

This stream 1 is then separated in a distillation apparatus K3. At the same time, the current is formed 3 containing the isomerization catalyst (bottoms). At the top of the distillation apparatus K3 is the stream 2 taken. This stream 2 Contains 3-pentenenitrile, (Z) -2-methyl-2-butenenitrile and 2-methyl-3-butenenitrile. This stream 2 is then transferred to a distillation column K4.

In this distillation column K4 there is a separation of the stream 2 in (Z) -2-methyl-2-butenenitrile formed during isomerization (stream 4 ). In addition, in the distillation column K4 in the bottom of the stream 5 obtained, which contains 3-pentenenitrile and 2-methyl-3-butenenitrile. This stream 5 is transferred to the distillation column K2, wherein from the stream 5 in the distillation column, the 3-pentenenitrile is recovered.

The streams 9 and 10 can be completely, partially or not recycled to the reactor R1. The same applies to the electricity 3 in the direction of reactor R2. These variants are not in 1 displayed.

The inventive method according to a preferred embodiment of the embodiment II is based on the 2 explained in more detail:
In a reactor R1, hydrogen cyanide and 1,3-butadiene are fed in the presence of a nickel (0) catalyst. Hydrocyanation takes place in the reactor to produce a current 8th instead of. This stream 8th Contains 3-pentenenitrile, 2-methyl-3-butenenitrile, the hydrocanization catalyst and unreacted 1,3-butadiene. Subsequently, the electricity 8th transferred into a distillation column K1, in the overhead 1,3-butadiene from the stream 8th is removed (electricity 9 ). In the bottom of the distillation column K1 is a stream 10 obtained containing the hydrocyanation catalyst. At the side of the distillation column K1 is a stream 11 obtained containing 3-pentenenitrile and 2-methyl-3-butenenitrile. This stream 11 is then transferred to an isomerization device R2.

Isomerization catalyst (stream 3 ' ) and 2-methyl-3-butenenitrile (stream 2 ' ), each originating from the distillation column K2, introduced. Isomerization takes place in the isomerization device R2. The resulting electricity 1' is then transferred to the distillation apparatus K2, in which the stream 1' is split into a stream 2 ' (2-methyl-3-butenenitrile), which is recycled to R2, a stream 3 ' (Isomerization catalyst), which is recycled to R2, and into a stream 4 ' containing 3-pentenenitrile.

By supplying an isomerization catalyst-containing stream to R2 may optionally necessary discharges from the stream 3 ' be balanced so that the Ni (0) content remains constant in R2.

The streams 9 and 10 can be completely, partially or not recycled to the reactor R1.

These return and discharge variants are in 2 not illustrated.

Embodiment III

In the embodiment III are hydrocyanation and isomerization Ni (0) catalysts of such Used ligands that catalyze the process steps a *) and e *).

at the nickel (0) complexes preferred as the catalyst, which phosphorus-containing ligands and / or free phosphorus-containing ligands contain, it is preferably homogeneous dissolved nickel (0) complexes.

The phosphorus ligands of the nickel (0) complexes and the free ones Phosphorus-containing ligands are preferably selected from the group of mono- or bidentate phosphines, phosphites, phosphinites and Phosphonites, preferably the mono- or bidentate phosphites, phosphinites and phosphonites, more preferably the mono- or bidentate phosphites and phosphonites, especially the monodentate phosphites, phosphinites and phosphonites, most preferably the monodentate phosphites and phosphonites.

These phosphorus-containing ligands preferably have the formula I: P (X ¹ R ¹ ) (X ² R ² ) (X ³ R ³ ) (I)

Under Compound 1 becomes a single within the meaning of the present invention Compound or a mixture of different compounds of the aforementioned Formula understood.

According to the invention X ¹ , X ² , X ^{3 are} independently oxygen or single bond. If all of the groups X ^1, X are single bonds ² and X ^3, compound I is a phosphine of the formula P (R ¹ R ² R ³⁾ with the definitions of R ^1, R ² and R ³ in this description represents ,

If two of the groups X ^1, X ² and X ³ are single bonds and one for oxygen, compound I is a phosphinite of formula P (OR ¹⁾ (R ²⁾ (R ³⁾ or P (R ¹⁾ (OR ² ) (R ³ ) or P (R ¹ ) (R ² ) (OR ³ ) with the meanings given below for R ¹ , R ² and R ³ .

If one of the groups X ^1, X ² and X ³ represents a single bond and two oxygen, compound I is a phosphonite of formula P (OR ¹⁾ (OR ²⁾ (R ³⁾ or P (R ¹⁾ (OR ² ) (OR ³ ) or P (OR ¹ ) (R ² ) (OR ³ ) with the meanings given for R ¹ , R ² and R ³ in this description.

In one embodiment, all of the groups X ^1, X ² and X ³ should be oxygen, so that compound I is a phosphite of the formula P (OR ¹⁾ (OR ²⁾ (OR ³⁾ with the definitions of R ^1, R ² and R ³ meanings given below.

According to the invention, R ¹ , R ² , R ³ independently of one another represent identical or different organic radicals. As R ¹ , R ² and R ³ are independently alkyl radicals, preferably having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, Aryl groups, such as phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, 2-naphthyl, or hydrocarbyl, preferably having 1 to 20 carbon atoms, such as 1,1'-biphenol, 1,1'- Binaphthol into consideration. The groups R ¹ , R ² and R ³ may be connected to each other directly, ie not solely via the central phosphorus atom. Preferably, the groups R ¹ , R ² and R ^{3 are} not directly connected to each other.

In one embodiment, groups R ¹ , R ² and R ^{3 are} radicals selected from the group consisting of phenyl, o-tolyl, m-tolyl and p-tolyl. In one embodiment, a maximum of two of the groups R ¹ , R ² and R ^{3 should be} phenyl groups.

In another embodiment, a maximum of two of the groups R ¹ , R ² and R ^{3 should be} o-tolyl groups.

As compounds I, those of the formula Ia (o-tolyl-O-) _w (m-tolyl-O-) _x (p-tolyl-O-) _y (phenyl-O-) _z P (Ia) where w, x, y and z denote a natural number and the following conditions apply: w + x + y + z = 3 and w, z ≤ 2.

Such compounds Ia are, for example, (p-tolyl-O -) (phenyl-O-) ₂ P, (m-tolyl-O -) (phenyl-O-) ₂ P, (o-tolyl-O -) (phenyl-) O-) _2P, (p-tolyl-O-) ₂ (phenyl-O-) P, (m-tolyl-O-) ₂ (phenyl-O-) P, (o-tolyl-O-) ₂ ( Phenyl-O-) P, (m-tolyl-O -) (p-tolyl-O) (phenyl-O-) P, (o-tolyl-O -) (p-tolyl-O -) (phenyl-O -) P, (o-tolyl-O -) (m-tolyl-O -) (phenyl-O-) P, (p-tolyl-O-) ₃ P, (m-tolyl-O -) (p-) Tolyl-O-) ₂ P, (o-tolyl-O -) (p-tolyl-O-) ₂ P, (m-tolyl-O-) ₂ (p-toluyl-O-) P, (o-tolyl -O-) ₂ (p-Tolyl-O-) P, (o-tolyl-O -) (m-tolyl-O -) (p-tolyl-O) P, (m-tolyl-O-) ₃ P , (o-Tolyl-O -) (m-tolyl-O-) ₂ P (o-tolyl-O-) ₂ (m-tolyl-O-) P, or mixtures of such compounds.

Mixtures containing (m-tolyl-O-) ₃ P, (m -olyl-O-) ₂ (p-tolyl-O-) P, (m-tolyl-O -) (p-tolyl-O-) ₂ P and (p-tolyl-O-) ₃ P can be, for example, by reacting a mixture containing m-cresol and p-cresol, in particular in a molar ratio of 2: 1, as obtained in the distillative workup of petroleum, with a phosphorus trihalide, such as phosphorus trichloride , receive.

In one embodiment, the phosphites of the formula Ib which are described in more detail in DE-A 199 53 058 are suitable as phosphorus-containing ligands: P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) With
R ¹ : aromatic radical having a C ₁ -C ₁₈ -alkyl substituent in the o-position to the oxygen atom which connects the phosphorus atom with the aromatic system, or with an aromatic substituent in o-position to the oxygen atom, the phosphorus atom with the aromatic System, or aromatic system fused to the oxygen atom linking the phosphorus atom to the aromatic system,
R ² : aromatic radical having a C ₁ -C ₁₈ -alkyl substituent in the m-position to the oxygen atom which connects the phosphorus atom with the aromatic system, or with an aromatic substituent in m-position to the oxygen atom, the phosphorus atom with the aromatic The system combines, or with an aromatic system fused in m-position to the oxygen atom linking the phosphorus atom to the aromatic system, wherein the aromatic radical in the o-position to the oxygen atom connecting the phosphorus atom to the aromatic system, a hydrogen atom wearing,
R ³ : aromatic radical having a C ₁ -C ₁₈ alkyl substituent in the p-position to the oxygen atom connecting the phosphorus atom to the aromatic system, or having an aromatic substituent in p-position to the oxygen atom linking the phosphorus atom to the aromatic atom System combines, wherein the aromatic radical in the o-position to the oxygen atom which connects the phosphorus atom with the aromatic system, carries a hydrogen atom,
R ⁴ : aromatic radical which carries in the o, m and p position to the oxygen atom which connects the phosphorus atom to the aromatic system, other than the substituents defined for R ¹ , R ² and R ³ , wherein the aromatic radical in the position ortho to the oxygen atom connecting the phosphorus atom to the aromatic system carries a hydrogen atom,
x: 1 or 2,
y, z, p: independently of one another 0, 1 or 2, with the proviso that x + y + z + p = 3,

Preferred phosphites of the formula Ib can be found in DE-A 199 53 058. As radical R ¹ are advantageously o-tolyl, o-ethyl-phenyl, on-propyl-phenyl, o-isopropyl-phenyl, on-butyl-phenyl, o-sec-butyl-phenyl, o- tert-butyl-phenyl, (o-phenyl) -phenyl or 1-naphthyl groups into consideration.

As the radical R ² are m-tolyl, m-ethyl-phenyl, mn-propyl-phenyl, m-isopropyl-phenyl, mn-butyl-phenyl, m-sec-butyl-phenyl, m-tert Butyl-phenyl, (m-phenyl) -phenyl or 2-naphthyl groups are preferred.

As radical R ³ are advantageously p-tolyl, p-ethyl-phenyl, pn-propyl-phenyl, p-isopropyl-phenyl, pn-butyl-phenyl, p-sec-butyl-phenyl, p- tert-butyl-phenyl or (p-phenyl) -phenyl groups into consideration.

Radical R ⁴ is preferably phenyl. Preferably, p is equal to zero. For the indices x, y, z and p in connection Ib the following possibilities arise:

Preferred phosphites of the formula Ib are those in which p is zero and R ¹ , R ² and R ^{3 are} independently selected from o-isopropyl-phenyl, m-tolyl and p-tolyl, and R ^{4 is} phenyl.

Particularly preferred phosphites of the formula Ib are those in which R ^{1 is} the o-isopropylphenyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table above; also those in which R ^{1 is} the o-tolyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical with those mentioned in the table indices; furthermore those in which R ^{1 is} the 1-naphthyl radical, R ^{2 is} the m-tolyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; also those in which R ^{1 is} the o-tolyl radical, R ^{2 is} the 2-naphthyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; and finally those in which R ^{1 is} the o-isopropylphenyl radical, R ^{2 is} the 2-naphthyl radical and R ^{3 is} the p-tolyl radical having the indices mentioned in the table; as well as mixtures of these phosphites.

• a) ein Phosphortrihalogenid mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Dihalogenophosphorigsäuremonoesters,
• b) den genannten Dihalogenophosphorigsäuremonoester mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Monohalogenophosphorigsäurediesters und
• c) den genannten Monohalogenophosphorigsäurediester mit einem Alkohol ausgewählt aus der Gruppe bestehend aus R¹OH, R²OH, R³OH und R⁴OH oder deren Gemische umsetzt unter Erhalt eines Phosphits der Formel Ib.

Phosphites of the formula Ib can be obtained by

• a) reacting a phosphorus trihalide with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a dihalophosphoric acid monoester,
• b) reacting said dihalophosphoric acid monoester with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a monohalophosphoric diester and
• c) reacting said Monohalogenophosphorigsäurediester with an alcohol selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof to obtain a phosphite of formula Ib.

The Implementation can be carried out in three separate steps. Likewise two of the three steps are combined, so a) with b) or b) with c). Alternatively you can all of steps a), b) and c) are combined with each other.

In this case, one can easily determine suitable parameters and amounts of the alcohols selected from the group consisting of R ¹ OH, R ² OH, R ³ OH and R ⁴ OH or mixtures thereof by a few simple preliminary experiments.

As phosphorus trihalogenide are basically all phosphorus trihalides, preferably those in which as the halide Cl, Br, I, in particular Cl, is used, and mixtures thereof. It is also possible to use mixtures of different identically or differently halogen-substituted phosphines as the phosphorus trihalide. Particularly preferred is PCl ₃ . Further details on the reaction conditions in the preparation of phosphites Ib and for workup can be found in DE-A 199 53 058.

The Phosphites Ib can also in the form of a mixture of different phosphites Ib as a ligand be used. Such a mixture may, for example, in the Production of the phosphites Ib incurred.

auf, worin bedeuten
X¹¹, X¹², X¹³, X²¹, X²², X²³ unabhängig voneinander Sauerstoff oder Einzelbindung
R¹¹, R¹² unabhängig voneinander gleiche oder unterschiedliche, einzelne oder verbrückte organische Reste
R²¹, R²² unabhängig voneinander gleiche oder unterschiedliche, einzelne oder verbrückte organische Reste,
Y Brückengruppe.It is also possible that the phosphorus ligand is polydentate, in particular bidentate. Then, the ligand used has, for example, the formula II

in which mean
X ¹¹ , X ¹² , X ¹³ , X ²¹ , X ²² , X ^{23 are} independently oxygen or single bond
R ¹¹ , R ^{12 are} independently identical or different, single or bridged organic radicals
R ²¹ , R ²² independently of one another are identical or different, individual or bridged organic radicals,
Y bridge group.

Under Compound II becomes a single within the meaning of the present invention Compound or a mixture of different compounds of the aforementioned Formula understood.

In one embodiment, X ¹¹ , X ¹² , X ¹³ , X ²¹ , X ²² , X ^{23 may be} oxygen. In such a case, the bridging group Y is linked to phosphite groups.

Alternatively, X ¹¹ and X ^{12 may be} oxygen and X ^{13 is} a single bond or X ¹¹ and X ^{13 is} oxygen and X ^{12 is} a single bond such that the phosphorus atom surrounded by X ¹¹ , X ¹² and X ^{13 is the} central atom of a phosphonite. In such a case, X ²¹ , X ²² and X ^{23 may be} oxygen or X ²¹ and X ²² oxygen and X ²³ a single bond or X ²¹ and X ²³ oxygen and X ²² a single bond or X ²³ oxygen and X ²¹ and X ²² a single bond or X ^{21 is} oxygen and X ²² and X ^{23 represent} a single bond or X ²¹ , X ²² and X ^{23 represent} a single bond, so that the phosphorus atom surrounded by X ²¹ , X ²² and X ²³ central atom of a phosphite, phosphonite, phosphinite or phosphine, preferably of a phosphonite, can be.

Alternatively, X ¹³ may be oxygen and X ¹¹ and X ^{12 may be} a single bond or X ^{11 is} oxygen and X ¹² and X ^{13 may be} a single bond such that the phosphorous atom surrounded by X ¹¹ , X ¹² and X ^{13 is the} central atom of a phosphonite.

In such a case, X ²¹ , X ²² and X ^{23 can be} oxygen or X ²³ oxygen and X ²¹ and X ²² a single bond or X ²¹ oxygen and X ²² and X ²³ a single bond or X ²¹ , X ²² and X ²³ a single bond in that the phosphorus atom surrounded by X ²¹ , X ²² and X ^{23 can be the} central atom of a phosphite, phosphinite or phosphine, preferably of a phosphinite.

In another embodiment, X ¹¹ , X ^12, and X ^{13 may represent} a single bond such that the phosphorus atom surrounded by X ¹¹ , X ^12, and X ^{13 is the} central atom of a phosphine. In such a case, X ²¹ , X ²² and X ²³ oxygen or X ²¹ , X ²² and X ^{23 may represent} a single bond such that the phosphorus atom surrounded by X ²¹ , X ²² and X ^{23 is the} central atom of a phosphite or phosphine, preferably a phosphine , can be.

Bridging group Y is preferably substituted, for example with C ₁ -C ₄ alkyl, halogen, such as fluorine, chlorine, bromine, halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups, preferably those having 6 to 20 carbon atoms in the aromatic system, in particular pyrocatechol, bis (phenol) or bis (naphthol).

The radicals R ¹¹ and R ¹² may independently of one another represent identical or different organic radicals. Advantageously suitable radicals R ¹¹ and R ^{12 are} aryl radicals, preferably those having 6 to 10 carbon atoms, which may be unsubstituted or monosubstituted or polysubstituted, in particular by C ₁ -C ₄ -alkyl, halogen, such as fluorine, chlorine, bromine , halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R ²¹ and R ²² may independently represent identical or different organic radicals. Suitable radicals R ²¹ and R ^{22 are} aryl radicals, preferably those having 6 to 10 carbon atoms, into consideration, which may be unsubstituted or monosubstituted or polysubstituted, in particular by C ₁ -C ₄ -alkyl, halogen, such as fluorine, chlorine, bromine , halogenated alkyl, such as trifluoromethyl, aryl, such as phenyl, or unsubstituted aryl groups.

The radicals R ¹¹ and R ¹² may be singly or bridged. The radicals R ²¹ and R ²² may also be singly or bridged. The radicals R ¹¹ , R ¹² , R ²¹ and R ²² may all be individually bridged and two individually or all four bridged in the manner described.

In one embodiment, the in US 5,723,641 mentioned compounds of formula I, II, III, IV and V into consideration. In one embodiment, the in US 5,512,696 mentioned compounds of the formula I, II, III IV, V, VI and VII, the compounds used there in Examples 1 to 31, into consideration. In one embodiment, the in US 5,821,378 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV and XV, the compounds used therein in Examples 1 to 73, into consideration.

In one embodiment, the in US 5,512,695 mentioned compounds of formula I, II, III, IV, V and VI, the compounds used there in Examples 1 to 6, into consideration. In one embodiment, the in US 5,981,772 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII and XIV, the compounds used therein in Examples 1 to 66, into consideration.

In one embodiment, the in US 6,127,567 mentioned compounds and there used in Examples 1 to 29 compounds into consideration. In one embodiment, the in US 6,020,516 mentioned compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX and X, the compounds used there in Examples 1 to 33, into consideration. In one embodiment, the in US 5,959,135 mentioned compounds and there used in Examples 1 to 13 compounds into consideration.

In one embodiment, the in US 5,847,191 mentioned compounds of formula I, II and III into consideration. In one embodiment, the in US 5,523,453 compounds mentioned therein in formula 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and 21 , considering. In one embodiment, the compounds mentioned in WO 01/14392, the compounds shown there in formula V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XXI, XXII, XXIII , considering.

In one embodiment, the compounds mentioned in WO 98/27054 come into consideration. In a Embodiment, the compounds mentioned in WO 99/13983 come into consideration. In one embodiment, the compounds mentioned in WO 99/64155 come into consideration.

In one embodiment, those in the German patent application DE 100 380 37 considered compounds. In one embodiment, those in the German patent application DE 100 460 25 considered compounds. In one embodiment, those in the German patent application DE 101 502 85 considered compounds.

In one embodiment, those in the German patent application DE 101 502 86 considered compounds. In one embodiment, those in the German patent application DE 102 071 65 considered compounds. In a further embodiment of the present invention, the phosphorus-containing chelate ligands mentioned in US 2003/0100442 A1 come into consideration.

In a further embodiment of the present invention, the non-prepublished German patent application file reference DE 103 50 999.2 from 30.10.2003 mentioned phosphorus chelating ligands into consideration.

The described compounds I, Ia, Ib and II and their preparation are known per se. As a phosphorus-containing ligand can also Mixtures containing at least two of the compounds I, Ia, Ib and II.

In a particularly preferred embodiment of the process according to the invention, the phosphorus-containing ligand of the nickel (0) complex and / or the free phosphorus-containing ligand are selected from the phosphites of the formula Ib P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) wherein R ¹ , R ² and R ^{3 are} independently selected from o-isopropylphenyl, m-tolyl and p-tolyl, R ^{4 is} phenyl; x is 1 or 2, and y, z, p are independently 0, 1 or 2, with the proviso that x + y + z + p = 3; and mixtures thereof, ie mixtures of 2 or more, preferably 2 to 10, particularly preferably 2 to 6, of the compounds of the formula Ib.

• (a*) Isomerisierung eines Eduktstroms, der 2-Methyl-3-butennitril enthält, an mindestens einem gelösten oder dispergierten Isomerisierungskatalysator zu einem Strom 1, der den mindestens einen Isomerisierungskatalysator, 2-Methyl-3-butennitril, 3-Pentennitril und (Z)-2-Methyl-2-butennitril enthält,
• (b*) Destillation des Stromes 1 unter Erhalt eines Stromes 2 als Kopfprodukt, der 2-Methyl-3-butennitril, 3-Pentennitril und (Z)-2-Methyl-2-butennitril enthält, und eines Stromes 3 als Sumpfprodukt, der den mindestens einen Isomerisierungskatalysator enthält,
• (c*) Destillation des Stromes 2 unter Erhalt eines Stromes 4 als Kopfprodukt, der gegenüber dem Strom 2 an (Z)-2-Methyl-2-butennitril, bezogen auf die Summe aller Pentennitrile im Strom 2, angereichert ist, und eines Stromes 5 als Sumpfprodukt; der gegenüber dem Strom 2 an 3-Pentennitril und 2-Methyl-3-butennitril bezogen auf die Summe aller Pentennitrile im Strom 2, angereichert ist,
• (d*) Destillation des Stromes 5 unter Erhalt eines Stromes 6 als Sumpfprodukt, der 3-Pentennitril enthält, und eines Stromes 7 als Kopfprodukt, der 2-Methyl-3-butennitril enthält.
• (h*) Katalysatorregenerierung zur Aufstockung der Nickel(0)-Gehaltes der Teilströme 14 aus Strom 3 bzw. 16 aus Strom 10 unter Erzeugung eunes Stroms 18,
• (i*) gegebenenfalls unter Zusatz eines Verdünnungsmittels F zu Strom 18 unter Erzeugung von Strom 19,
• (j*) Extraktion des Stromes 18, ggf Stromes 19, bezüglich der Katalysatorkomponenten und/oder Störkomponente(n) durch Zusatz eines Dinitrilstroms 20 und eines Kohlenwasserstoffstroms 21 unter Erzeugung zweier nichtmischbarer Phasen 22 und 23, wobei Strom 22 den überwiegenden Teil der Katalysatorkomponenten und Strom 23 den überwiegenden Teil der Störkomponente(n) enthält,
• (k*) destillative Abtrennung des Kohlenwasserstoffes von den Katalysatorkomponenten aus Strom 22 unter Erzeugung eines Stroms 25, der den überwiegenden Teil der Katalysatorkomponenten enthält und ggf. teilweise oder ganze Rückführung des Stroms 25 in die Verfahrensschritte (a*) oder (e*).

The method is characterized in an embodiment III by the following method steps:

• (a *) isomerization of a feed stream containing 2-methyl-3-butenenitrile to at least one dissolved or dispersed isomerization catalyst to a stream 1 containing at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile,
• (b *) distillation of the stream 1 while receiving a stream 2 as a top product containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, and one stream 3 as the bottom product containing the at least one isomerization catalyst,
• (c *) Distillation of the stream 2 while receiving a stream 4 as a top product, facing the stream 2 an (Z) -2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched, and a stream 5 as bottom product; the opposite of the stream 2 to 3-pentenenitrile and 2-methyl-3-butenenitrile based on the sum of all pentenenitriles in the stream 2 , enriched,
• (d *) Distillation of the stream 5 while receiving a stream 6 as a bottom product containing 3-pentenenitrile and a stream 7 as a top product containing 2-methyl-3-butenenitrile.
• (h *) catalyst regeneration to increase the nickel (0) content of the partial streams 14 out of electricity 3 respectively. 16 out of electricity 10 generating eunes electricity 18 .
• (i *) if necessary with the addition of a diluent F to power 18 generating electricity 19 .
• (j *) Extraction of the stream 18 , if necessary electricity 19 , with respect to the catalyst components and / or interfering component (s) by addition of a dinitrile stream 20 and a hydrocarbon stream 21 generating two immiscible phases 22 and 23, wherein current 22 the major part of the catalyst components and electricity 23 contains most of the interfering component (s),
• (k *) distillative separation of the hydrocarbon from the catalyst components from electricity 22 generating a current 25 containing the major part of the catalyst components and optionally partial or total recycling of the stream 25 in the process steps (a *) or (e *).

reactant stream

In Process step (a *) finds an isomerization of a reactant stream, the 2-methyl-3-butenenitrile contains on at least one isomerization catalyst instead.

• (e*) Hydrocyanierung von 1,3-Butadien an mindestens einem Hydrocyanierungskatalysator mit Cyanwasserstoff unter Erhalt eines Stromes 8, der den mindestens einen Hydrocyanierungskatalysator, 3-Pentennitril, 2-Methyl-3-butennitril, 1,3-Butadien und Reste Cyanwasserstoff enthält,
• (f*) ein- oder mehrfache Destillation des Stromes 8 unter Erhalt eines Stromes 9, der 1,3-Butadien enthält, eines Stromes 10, der den mindestens einen Hydrocyanierungskatalysator enthält, und eines Stromes 11, der 3-Pentennitril und 2-Methyl-3-butennitril enthält,
• (g*) Destillation des Stromes 11 unter Erhalt eines Stromes 12 als Sumpfprodukt, der 3-Pentennitril enthält, und eines Stromes 13 als Kopfprodukt, der 2-Methyl-3-butennitril enthält.

In a particular embodiment of the process according to the invention, the educt stream is obtainable by the following process steps:

• (e *) Hydrocyanation of 1,3-butadiene on at least one hydrocyanation catalyst with hydrogen cyanide to give a stream 8th containing at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile, 1,3-butadiene and hydrogen cyanide radicals,
• (f *) one or more distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile,
• (g *) Distillation of the stream 11 while receiving a stream 12 as a bottom product containing 3-pentenenitrile and a stream 13 as a top product containing 2-methyl-3-butenenitrile.

Process step e *)

In process step (e *), hydrocyanation of 1,3-butadiene initially takes place on at least one hydrocyanation catalyst with hydrogen cyanide to produce the starting material stream, with the result that a stream is obtained 8th containing the at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile and unreacted 1,3-butadiene.

Of the Process step (e *) may be in any suitable, known to those skilled Apparatus performed become. For the reaction thus come usual Equipment, such as those in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 20, John Wiley & Sons, New York, 1996, pages 1040 to 1055, such as stirred tank reactors, Loop reactors, gas circulation reactors, bubble column reactors or tubular reactors, each optionally with devices for removing heat of reaction. The Reaction can be carried out in several, such as two or three, apparatuses.

In a preferred embodiment the method according to the invention have reactors with backmixing characteristics or cascades of reactors with backmixing characteristics proved to be advantageous. Particularly advantageous are cascades from reactors with backmixing characteristics proved in terms of the dosage of hydrogen cyanide in Querstromfahrweise be operated.

The Hydrocyanation can be carried out in the presence or absence of one solvent carried out become. If a solvent is used, so should the solvent at the given reaction temperature and the given reaction pressure liquid and inert the unsaturated Compounds and the at least one catalyst. In general be as a solvent Hydrocarbons, for example benzene or xylene, or nitriles, for example acetonitrile or benzonitrile. Preferably however, becomes a ligand as a solvent used.

The Reaction can be batch, continuous or semi-batch carried out become.

The Hydrocyanation reaction can be carried out by the device equipped with all reactants becomes. However, it is preferred if the device with the catalyst, the unsaturated one organic compound and optionally the solvent is filled. Preferably, the gaseous floats Hydrogen cyanide over the surface the reaction mixture or is passed through the reaction mixture. A further procedure for loading the device is filling the device with the catalyst, hydrogen cyanide and optionally the solvent and slowly feeding the unsaturated compound to the reaction mixture. Alternatively, it is also possible that the reactants are introduced into the reactor and the reaction mixture is brought to the reaction temperature at which the hydrogen cyanide liquid is added to the mixture. In addition, the hydrogen cyanide even before heating be added to the reaction temperature. The reaction is taking place conventional hydrocyanation conditions for temperature, atmosphere, reaction time, etc. performed.

Preferably hydrocyanation is carried out continuously in one or more stirred process steps carried out. If a plurality of process steps are used, then it is preferred that the method steps are connected in series. The product of a process step directly into the next Transferred process step. Of the Hydrogen cyanide can be added directly in the first process step or be supplied between the individual process steps.

When the process according to the invention is carried out in the semibatch mode, it is preferred that the catalyst components and 1,3-butadiene are introduced into the reactor, while hydrogen cyanide is metered into the reaction mixture over the reaction time.

The Reaction is preferably at absolute pressures of 0.1 to 500 MPa, especially preferably 0.5 to 50 MPa, in particular 1 to 5 MPa performed. The Reaction is preferably at temperatures of 273 to 473 K, especially preferably 313 to 423 K, in particular at 333 to 393 K performed. there have average mean residence times of the liquid reactor phase in the range of 0.001 to 100 hours, preferably 0.05 to 20 hours, particularly preferably 0.1 to 5 hours, in each case per reactor, as proved advantageous.

The Reaction can be in one embodiment in liquid Phase in the presence of a gas phase and optionally a solid suspended phase become. It can the starting materials hydrogen cyanide and 1,3-butadiene each liquid or gaseous be dosed.

The Reaction can in a further embodiment in the liquid phase carried out be, the pressure in the reactor is such that all starting materials like 1,3-butadiene, Hydrogen cyanide and the at least one catalyst added liquid who and in the reaction mixture in the liquid phase. there may be a solid suspended phase in the reaction mixture, which also added together with the at least one catalyst can be, for example consisting of degradation products of the catalyst system, containing inter alia nickel (II) compounds.

In process step (e *) becomes a current 8th which contains 3-pentenenitrile, 2-methyl-3-butenenitrile containing at least one catalyst and unreacted 1,3-butadiene.

Process step f *)

The current 8th which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile containing at least one catalyst and unreacted 1,3-butadiene is then transferred to a distillation apparatus in process step (f *). In this distillation apparatus is a single or multiple distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile.

The Distillation of the process step (f *) can take place in two stages, as in DE-A-102 004 004 720, process steps (b *) and (c *). The Distillation of the process step (f *) can also according to DE-A-102 004 004729, process steps (b *) and (c *) take place.

The Distillation (s) of process step (f *) can (in) Any suitable, known in the art apparatus are performed. For the Distillation suitable apparatuses, such as those in: Kirk-Othmer, Encyclopaedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, also referred to as Dividing wall columns can be operated. These distillation facilities are each provided with suitable evaporation devices, such as falling film evaporators, Thin film evaporator, Multiphase spiral tube evaporator, natural circulation evaporator or forced circulation flash evaporator, and equipped with devices for the condensation of the vapor stream. The Individual distillations can each be done in several, like two or three devices, advantageously in a single apparatus carry out.

The Distillation (s) can / can each also single-stage in the sense of a partial evaporation of the feed stream respectively.

Of the Pressure in process step (f *) is preferably 0.001 to 10 bar, more preferably 0.010 to 1 bar, in particular 0.02 to 0.5 bar. The distillation (s) is / are carried out in such a way that the temperature (s) in the bottom of the distillation apparatus (s) preferably From 30 to 200 ° C, more preferably 50 to 150 ° C, in particular 60 to 120 ° C, is / amount. The distillation (s) is / are carried out so that the condensation temperatures at the top of the distillation apparatus preferably -50 to 150 ° C, especially preferably -15 to 60 ° C, in particular 5 to 45 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also maintained in the bottom of the distillation apparatus (s).

The current 11 is then subjected to distillation in a further process step (g *). This distillation can be carried out in any suitable apparatus known to the person skilled in the art. For suitable for distillation are apparatuses such as those described in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, bubble tray columns , Packed columns, packed columns, which can also be operated as dividing wall columns. These distillation devices are each equipped with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, multiphase spiral tube evaporators, natural circulation evaporators or forced circulation flash evaporators, and with devices for condensing the vapor stream. The distillation can be carried out in several, such as two or three apparatus, advantageously in a single apparatus. The distillation can also be carried out in one stage in the sense of partial evaporation of the feed stream.

Of the Pressure in process step (g *) is preferably 0.001 to 100 bar, more preferably 0.01 to 20 bar, in particular 0.05 to 2 bar. The distillation is carried out so that the temperature in the Bottom of the distillation apparatus preferably 30 to 250 ° C, especially preferably 50 to 200 ° C, in particular 60 to 180 ° C, is. The distillation is carried out so that the condensation temperature at the top of the distillation apparatus, preferably -50 to 250 ° C, especially preferably 0 to 180 ° C, in particular 15 to 160 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In process step (g *) becomes a current 12 as the bottom product containing 1,3-pentenenitrile and electricity 13 as the top product containing 2-methyl-3-butenenitrile. The current 13 is preferably used as Eduktstrom in the process according to the invention for the preparation of 3-pentenenitrile.

In a further embodiment of the present invention, it is possible for the educt stream used in the process step (a *) according to the invention to correspond to the stream 11 of the process step (f *) corresponds, so that a separation of the stream 11 in the process step (g *) is omitted.

Process step (a *)

In process step (a *), an isomerization of the educt stream which comprises 2-methyl-3-butenenitrile takes place on at least one isomerization catalyst. This is a current 1 containing the isomerization catalyst, unreacted 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile.

• • Nickel(0) und
• • eine Nickel(0) als Ligand komplexierende, dreibindigen Phosphor enthaltende Verbindung

durch.According to the invention, the isomerization is carried out in the presence of a system containing

• • Nickel (0) and
• A nickel (0) ligand-complexing trivalent phosphorus-containing compound

by.

The Production of nickel (0) containing catalyst systems can take place according to known methods.

When Ligands for the isomerization catalyst will be the same phosphorus-containing Ligands as for the hydrocyanation catalyst used in process step (e *) used. Thus, the hydrocyanation catalyst is identical to the isomerization catalyst.

Of the Catalyst in process steps (a *) and (e *) is essentially Lewis acid free, i.e. Lewis acid is not added to the catalyst at any time, preferably contains the catalyst is not a Lewis acid.

By Lewis acid is meant inorganic or organic metal compounds in which the cation is selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, copper, zinc, boron, aluminum, yttrium, Zirconium, niobium, molybdenum, cadmium, rhenium and tin. Examples are ZnBr ₂ , Znl ₂ , ZnCl ₂ , ZnSO ₄ , CuCl ₂ , CuCl, Cu (O ₃ SCF ₃ ) ₂ , CoCl ₂ , Col ₂ , Fel ₂ , FeCl ₃ , FeCl ₂ , FeCl ₂ (THF) ₂ , TiCl ₄ (THF) ₂ , TiCl ₄ , TiCl ₃ , ClTi (Oi-propyl) ₃ , MnCl ₂ , ScCl ₃ , AlCl ₃ , (C ₈ H ₁₇ ) AlCl ₂ , (C ₈ H ₁₇ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl, (C ₆ H ₅ ) ₂ AlCl, (C ₆ H ₅ ) AlCl ₂ , ReCl ₅ , ZrCl ₄ , NbCl ₅ , VCl ₃ , CrCl ₂ , MoCl ₅ , YCl ₃ , CdCl ₂ , LaCl ₃ , Er (O ₃ SCF ₃ ) ₃ , Yb (O ₂ CCF ₃ ) ₃ , SmCl ₃ , B (C ₆ H ₅ ) ₃ , TaCl ₅ , RAlCl ₂ , R ₂ AlCl, RSnO ₃ SCF ₃ and R ₃ B where R is an alkyl or aryl group, B (C ₆ H ₅ ) ₃ and (C ₆ H ₅ ) ₃ SnX, with X = CF ₃ SO ₃ , CH ₃ C ₆ H ₄ SO ₃ or (C ₆ H ₅ ) ₃ BCN such as in US 6,127,567 . US 6,171,996 . US 6,380,421 . US 3,496,217 . US 3,496,218 . US 4,774,353 . US 3,773,809 . US 3,496,217 and US 4,874,884 described.

• – beispielsweise eines Kohlenwasserstoffs, wie Hexan, Heptan, Oktan, Cyclohexan, Methylcyclohexan, Benzol, Decahydronaphthalin
• – beispielsweise eines Ethers, wie Diethylether, Tetrahydrofuran, Dioxan, Glykoldimethylether, Anisol,
• – beispielsweise eines Esters, wie Ethylacetat, Methylbenzoat, oder
• – beispielsweise eines Nitrils, wie Acetonitril, Benzonitril, oder
• – Gemischen solcher Verdünnungsmittel durchgeführt werden.

The isomerization can be carried out in the presence of a liquid diluent,

• For example, a hydrocarbon such as hexane, heptane, octane, cyclohexane, methylcyclohexane, benzene, decahydronaphthalene
• For example, an ether such as diethyl ether, tetrahydrofuran, dioxane, glycol dimethyl ether, anisole,
• For example, an ester such as ethyl acetate, methyl benzoate, or
• For example, a nitrile such as acetonitrile, benzonitrile, or
• - Mixtures of such diluents are carried out.

In a particularly preferred embodiment comes an isomerization in the absence of such a liquid diluent into consideration.

Farther it has proved to be advantageous if the isomerization in Process step (a *) in a non-oxidizing atmosphere, such as For example, under a protective gas atmosphere of nitrogen or a Noble gas, such as argon, carried out becomes.

Of the Process step (a *) may be in any suitable, known to those skilled Apparatus performed become. For the reaction come to this standard equipment such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 20, John Wiley & Sons, New York, 1996, pages 1040 to 1055, such as stirred tank reactors, Loop reactors, gas circulation reactors, bubble column reactors or tubular reactors. The reaction can be carried out in several, such as two or three apparatuses.

In a preferred embodiment the method according to the invention becomes isomerization in a compartmented tubular reactor carried out.

In a further preferred embodiment the method according to the invention the isomerization is done in at least two series Reactors carried out, wherein the first reactor has substantially stirred tank characteristics and the second reactor designed so is that it has substantially tube characteristic.

In a particularly preferred embodiment the method according to the invention the isomerization is carried out in a reactor, wherein the reactor has the charac teristics of a stirred tank cascade, the 2 to 20 stirred kettles, in particular 3 to 10 stirred kettles, equivalent.

The Reaction can be in one embodiment the method according to the invention be carried out in a distillation apparatus, wherein the isomerization reaction takes place at least in the bottom region of the distillation apparatus. Suitable is any distillation apparatus known to the person skilled in the art, such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, Page 334-348, such as sieve tray columns, bubble tray columns, Packed columns, packed columns, which can also be operated as dividing wall columns. These Distillation devices are each provided with suitable devices for evaporation, such as falling film evaporators, thin film evaporators, multiphase spiral tube evaporators, Natural circulation evaporator or forced circulation evaporator, as well equipped with devices for the condensation of the vapor stream. The Distillation with simultaneous reaction can be in several, such as two or three apparatus, advantageously in a single Perform apparatus. The distillation can also single-stage in the sense of partial evaporation the feed stream done.

Of the Process step (a *) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 16 bar, in particular 10 mbar to 6 bar performed. The Temperature is in process step (a *) preferably 25 to 250 ° C, especially preferably from 30 to 180 ° C, in particular 40 to 140 ° C.

The composition of the withdrawn stream in terms of the molar ratio of 2-methyl-3-butenenitrile to linear pentenenitrile and thus the degree of conversion of 2-methyl-3-butenenitrile used, depending on the composition of the supplied stream in a technically simple manner by the temperature, the catalyst concentration, the residence time and the design of the reactor can be adjusted. In a preferred embodiment of the process according to the invention, the degree of conversion with the aid of these measures to values in the range from 10 to 99%, particularly preferably from 30 to 95%, in particular from 60 to 90%, discontinued.

Process step (b *)

In process step (b *), the stream obtained in process step (a *) becomes 1 distilled. This gives you as a top product a stream 2 containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile. In addition, in step (b *) a current 3 obtained as a bottom product containing the at least one isomerization catalyst.

Of the Process step (b *) of the process according to the invention can in each suitable distillation apparatus known to those skilled in the art are carried out. For the Distillation suitable apparatuses, such as those in: Kirk-Othmer, Encyclopaedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, also referred to as Dividing wall columns can be operated. These distillation facilities are each provided with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, Multiphase spiral tube evaporator, natural circulation evaporator or forced circulation flash evaporator, and equipped with devices for the condensation of the vapor stream. The Distillation can be carried out in several, such as two or three apparatuses, advantageously perform in a single apparatus. The distillation can also single-stage in the sense of partial evaporation of the feed stream respectively.

Of the Process step (b *) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 6 bar, in particular 10 mbar to 500 mbar performed. The Distillation is done that the temperature in the bottom of the distillation apparatus is preferably 25 to 250 ° C, more preferably 40 to 180 ° C, in particular 60 to 140 ° C, is. The distillation is carried out so that the temperature at Head of the distillation apparatus preferably -15 to 200 ° C, especially preferably 5 to 150 ° C, in particular 10 to 100 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In a particularly preferred embodiment of the present invention, the distillation of the stream carried out in process step (b *) takes place 1 under pressure and temperature conditions in which the isomerization catalyst present in the mixture is less than or not active in process step (a *).

In a preferred embodiment of the present invention, the stream obtained in process step (b *) becomes 3 containing the at least one isomerization catalyst, at least partially recycled to the process step (a *).

In a further embodiment of the method according to the invention, the method steps (a *) and (b *) take place in the same apparatus. It is also possible that the electricity 3 containing at least one isomerization catalyst, is not removed from the process step (b *) and in the common device of the process steps (a *) and (b *) dwells.

Process step (c *)

In process step (c *) there is a distillation of the stream 2 instead of. This is a stream 4 obtained as the top product, the opposite to the stream 2 an (Z) -2-methyl-2-butenenitrile with respect to the sum of all in electricity 2 enriched pentenenitriles is enriched. In addition, a stream 5 obtained as bottom product, opposite to the stream 2 an (Z) -2-methyl-2-butenenitrile with respect to the sum of all in electricity 2 depleted pentenenitriles contained depleted.

The process step (c *) can be carried out in any suitable device known to the person skilled in the art. Suitable for the distillation are apparatuses as described, for example, in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, which can also be operated as dividing wall columns. These distillation devices are each equipped with suitable evaporation devices, such as falling-film evaporators, thin-film evaporators, multiphase spiral tube evaporators, natural circulation evaporators or forced circulation flash evaporators, and with devices for condensing the vapor stream. The distillation can be carried out in several, such as two or three apparatus, advantageously in a single apparatus. The distillation can also single-stage in the sense a partial evaporation of the feed stream.

Of the Process step (c *) of the process according to the invention is preferably at an absolute pressure of 0.1 mbar to 100 bar, particularly preferred 1 mbar to 6 bar, in particular 10 mbar to 500 mbar performed. The Distillation is done that the temperature in the bottom of the distillation apparatus is preferably 25 to 250 ° C, more preferably 40 to 180 ° C, in particular 60 to 140 ° C, is. The distillation is carried out so that the temperature at Head of the distillation apparatus preferably -15 to 200 ° C, especially preferably 5 to 150 ° C, in particular 10 to 100 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus.

In a particularly preferred embodiment of the process according to the invention, the process steps (b *) and (c *) are carried out together in a distillation apparatus, wherein the stream 3 containing the at least one isomerization catalyst as the bottom product, the stream 4 containing (Z) -2-methyl-2-butenenitrile as the top product and the stream 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile can be obtained on a side draw of the column.

In a further preferred embodiment of the process according to the invention, the process steps (a *), (b *) and (c *) are carried out together in a distillation apparatus. This is the current 4 containing (Z) -2-methyl-2-butenenitrile as the top product. The current 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile is obtained at a side draw of the distillation column. The isomerization catalyst preferably remains in the bottom of the distillation column in this embodiment.

Process step (d *)

The current obtained in process step (c *) 5 which contains 3-pentenenitrile and 2-methyl-3-butenenitrile is then transferred to another distillation apparatus. In this distillation device is the power 5 in a 3-pentenenitrile stream, which is taken as the bottom product, and a 2-methyl-3-butenenitrile stream which is taken from the top, separated.

Of the Process step (d *) may be in any suitable, known to those skilled Device performed become. For the distillation are suitable apparatuses, such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed., Vol. 8, John Wiley & Sons, New York, 1996, pages 334-348, such as sieve tray columns, Bubble tray columns, packed columns, packed columns, also called dividing wall columns can be operated. These distillation devices are each provided with suitable devices for evaporation, such as falling film evaporators, thin film evaporators, multiphase spiral tube evaporators, Natural circulation evaporator or forced circulation evaporator, as well equipped with devices for the condensation of the vapor stream. The Distillation can be carried out in several, such as two or three apparatuses, advantageously perform in a single apparatus. The distillation can also single-stage in the sense of partial evaporation of the feed stream respectively.

Of the absolute pressure in process step (d *) is preferably 0.001 to 100 bar, more preferably 0.01 to 20 bar, in particular 0.05 to 2 bar. The distillation is carried out so that the temperature in the Bottom of the distillation apparatus preferably 30 to 250 ° C, especially preferably 50 to 200 ° C, in particular 60 to 180 ° C, is. The distillation is carried out so that the condensation temperature at the top of the distillation apparatus, preferably -50 to 250 ° C, especially preferably 0 to 180 ° C, in particular 15 to 160 ° C, is.

In a particularly preferred embodiment the method according to the invention be the above temperature ranges both on the head than also observed in the bottom of the distillation apparatus

In a particularly preferred embodiment of the process according to the invention, the process step (d *) and the process step (g *) are carried out in the same distillation apparatus. The currents fall 6 and 12 such as 7 and 13 together. Further, in this preferred embodiment, the stream 5 directly into the common device of the process steps (d *) and (g *) out. In this case, the feed points of the streams 5 and 11 in the case of a distillation column as a distillation device be the same or different.

In a further embodiment of the method according to the invention, the method steps (C *) and (g *) carried out in a common distillation column, wherein the process step (d *) is omitted, the stream 2 from process step (b *) and electricity 11 from process step (f *) in process step (g *) are performed, in process step (g *) of the stream 4 as overhead product, containing (Z) -2-methyl-2-butenenitrile, the stream 12 as the bottom product containing 3-pentenenitrile and the stream 13 as a side draw stream containing 2-methyl-3-butenenitrile.

In the inventive method according to embodiment III, it is possible that the current 2 is returned directly to the process step (g *) and the reactant stream is driven directly into the process step (c *), wherein a stream 5a from process step (c *) is returned to the isomerization of process step (a *).

Alternatively, it is also possible to use the electricity 2 directly back into the process step (g *) and to drive the reactant stream in step (c *), wherein the stream 5 from process step (c *) in the process step (f *) is returned.

Alternatively, it is also possible that the electricity 2 is returned directly to the process step (g *) and the reactant stream in process step (c *) is driven and the stream 5 from process step (c *) in the process step (e *) is returned.

Process step h *):

Of the Process step h *) includes a process for the production of Nickel (0) -phosphorus ligand complexes, containing at least one nickel (0) central atom and at least one phosphorus ligands.

in the The following are the terms reductive catalyst synthesis / regeneration and redox catalyst synthesis / regeneration synonymous.

Process step h ₁ *):

A preferred embodiment of process step h *), referred to herein as process step h ₁ *), is characterized in that a hydrous nickel (II) halide dried by azeotropic distillation (previously dry after Azeodest naturally) is reduced in the presence of at least one phosphorus ligand.

azeotropic

In the azeotropic distillation is a hydrous nickel (II) halide used. Hydrous nickel (II) halide is a nickel halide, which is selected is from the group of nickel chloride, nickel bromide and nickel iodide, containing at least 2 wt .-% water. Examples include nickel chloride dihydrate, nickel chloride hexahydrate, an aqueous one solution of nickel chloride, nickel bromide trihydrate, an aqueous solution of Nickel bromide, nickel iodide hydrates or an aqueous solution of nickel iodide. In the case of nickel chloride are preferred nickel chloride hexahydrate or an aqueous one solution used by nickel chloride. In the case of nickel bromide and nickel iodide are preferred, the aqueous solutions used. Particularly preferred is an aqueous solution of nickel chloride.

in the Trap of an aqueous solution is the concentration of nickel (II) halide in water per se not critical. A proportion of the nickel (II) halide has proven to be advantageous on the sum of the weight of nickel (II) halide and water of at least 0.01 wt .-%, preferably at least 0.1 wt .-%, more preferably at least 0.25 wt .-%, particularly preferably at least 0.5 wt .-% proved. A proportion of the nickel (II) halide is advantageous the sum of the weight of nickel (II) halide and water in the range of at most 80 wt .-%, preferably at most 60% by weight, more preferably at most 40 wt .-% proved. For practical reasons, it is an advantage Proportion of nickel halide in the mixture of nickel halide and Not to exceed water which gives a solution under the given temperature and pressure conditions. In the case of an aqueous solution Of nickel chloride, it is therefore for practical reasons of Advantage, at room temperature to a proportion of nickel halide the weight sum of nickel chloride and water of at most 31% by weight to choose. At higher Temperatures can correspondingly higher Selected concentrations are arising from the solubility of nickel chloride in water.

The hydrous nickel (II) halide is dried prior to reduction by azeotropic distillation net. In a preferred embodiment of the present invention, the azeotropic distillation is a process for removing water from the corresponding hydrous nickel (II) halide by adding thereto a diluent whose boiling point in the case of non-azeotrope formation of the diluent with water under the pressure conditions the distillation referred to above is higher than the boiling point of water and liquid at this boiling point of the water or which forms an azeotrope or heteroazeotrope with water under the pressure and temperature conditions of the distillation referred to below, and the mixture containing the hydrous nickel ( II) halide and the diluent, with the separation of water or said azeotrope or said heteroazeotrope from this mixture and to obtain an anhydrous mixture containing nickel (II) halide and said diluent is distilled.

The Starting mixture can in addition to the water-containing nickel (II) halide contain further constituents, such as ionic or nonionic, organic or inorganic compounds, especially those homogeneously monophasic or miscible with the starting mixture the starting mixture soluble are.

In accordance with the invention the hydrous nickel (II) halide with a diluent whose Boiling point is higher under the pressure conditions of distillation as the boiling point of water and that at that boiling point of water liquid is present.

The pressure conditions for the subsequent distillation are not critical per se. Pressures of at least 10 ^-4 MPa, preferably at least 10 ^-3 MPa, in particular at least 5 × 10 ^-3 MPa, have proven to be advantageous. It is advantageous to have pressures of at most 1 MPa, preferably at most 5 × 10 ^-1 MPa, in particular at most 1.5 × 10 ^-1 MPa.

In dependence from the pressure conditions and the composition of the to be distilled Mixture then sets the distillation temperature. At this Temperature is the diluent preferably liquid in front. For the purposes of the present invention, the term thinner both a single diluent as well as a mixture of such diluents understood, wherein in the case of such a mixture as in the present invention refer to this mixture physical properties mentioned.

Farther has the diluent preferably under these pressure and temperature conditions Boiling point in the case of non-azeotrope formation of the diluent higher with water than that of water, preferably at least 5 ° C, in particular at least 20 ° C, and preferably at most 200 ° C, in particular at most 100 ° C.

In a preferred embodiment you can use diluents which form an azeotrope or heteroazeotrope with water. The amount of diluent compared to the The amount of water in the mixture is not critical per se. Advantageous you should be more fluid thinner than the quantities to be distilled off by the azeotropes corresponds to excess diluent as Bottom product remains.

Puts a diluent which does not form an azeotrope with water, so is the amount of diluent across from the amount of water in the mixture is not critical per se.

The used diluents is selected in particular from the group consisting of organic nitriles, aromatic Hydrocarbons, aliphatic hydrocarbons and mixtures the aforementioned solvent. In terms of of the organic nitriles are preferably acetonitrile, propionitrile, n-butyronitrile, n-valeronitrile, Cyanocyclopropane, acrylonitrile, crotonitrile, allyl cyanide, cis-2-pentenenitrile, trans-2-pentenenitrile, cis-3-pentenenitrile, trans-3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenenitrile, Z-2-methyl-2-butenenitrile, E-2-methyl-2-butenenitrile, ethylsuccinonitrile, Adiponitrile, methylglutaronitrile or mixtures thereof. In terms of The aromatic hydrocarbons may preferably be benzene, toluene, o-xylene, m-xylene, p-xylene or mixtures thereof. Aliphatic hydrocarbons may preferably be selected from the group the linear or branched aliphatic hydrocarbons, particularly preferably from the group of cycloaliphatic compounds, such as cyclohexane or methylcyclohexane, or mixtures thereof. Especially preferred are cis-3-pentenenitrile, trans-3-pentenenitrile, adiponitrile, Methylglutaronitrile or mixtures thereof used as a solvent.

If an organic nitrile or mixtures containing at least one organic nitrile is used as the diluent, it has proved advantageous to select the amount of diluent in such a way that in the finished mixture, the proportion of the nickel (II) halide in the total weight of nickel (II) halide and diluent is at least 0.05% by weight, preferably at least 0.5% by weight, more preferably at least 1% by weight .-% is.

Puts as a diluent an organic nitrile or mixtures containing at least one organic Nitrile, it has proved to be advantageous, the amount of thinner to choose that way in the finished mixture, the proportion of nickel (II) halide the sum of the weight of nickel (II) halide and diluent at the most 50% by weight, preferably at most 30% by weight, more preferably at most 20 wt .-% is.

Distilled according to the invention the mixture containing the hydrous nickel (II) halide and the Diluents, with separation of water from this mixture and with preservation an anhydrous mixture containing nickel (II) halide and the said diluent. In a preferred embodiment will be first the mixture is prepared and then distilled. In a another preferred embodiment is the hydrous nickel halide, particularly preferably the aqueous solution of nickel halide while the distillation gradually to the boiling diluent added. This can make the formation of a process technically difficult To be handled, greasy solid essentially avoided become.

in the Case of pentenenitrile as a diluent you can the distillation advantageous at a pressure of at most 1 megapascal, preferably 0.5 megapascals.

in the Case of pentenenitrile as a diluent the distillation can preferably be carried out at a pressure of at least 1 kPa, preferably at least 5 kPa, particularly preferably 10 kPa, carry out.

The Distillation can be advantageous by single-stage evaporation, preferably by fractional distillation in one or more, such as 2 or 3 distillation apparatus. Thereby come for the distillation customary equipment for this such as in: Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 7, John Wiley & Sons, New York, 1979, pages 870-881, such as sieve tray columns, bubble tray columns, Packed columns, packed columns, Columns with side draw or dividing wall columns.

The Distillation may be discontinuous or continuous.

reduction

The Process for the preparation of nickel (0) phosphorus ligand complexes, containing at least one nickel (0) central atom and at least one phosphorus-containing ligands, by reduction is preferably in Presence of a solvent carried out. The solvent is selected in particular from the group consisting of organic nitriles, aromatic Hydrocarbons, aliphatic hydrocarbons and mixtures the aforementioned solvent. In terms of of the organic nitriles are preferably acetonitrile, propionitrile, n-butyronitrile, n-valeronitrile, cyanocyclopropane, acrylonitrile, crotonitrile, Allyl cyanide, cis-2-pentenenitrile, trans-2-pentenenitrile, cis-3-pentenenitrile, trans-3-pentenenitrile, 4-pentenenitrile, 2-methyl-3-butenenitrile, Z-2-methyl-2-butenenitrile, E-2-methyl-2-butenenitrile, Ethyl succinonitrile, adiponitrile, methylglutaronitrile or mixtures used of it. In terms of The aromatic hydrocarbons may preferably be benzene, toluene, o-xylene, m-xylene, p-xylene or mixtures thereof. Aliphatic hydrocarbons may preferably be selected from the group the linear or branched aliphatic hydrocarbons, particularly preferably from the group of cycloaliphatic compounds, such as cyclohexane or methylcyclohexane, or mixtures thereof. Especially preferred become cis-3-pentenenitrile, trans-3-pentenenitrile, adiponitrile, methylglutaronitrile or mixtures from it as a solvent used.

Preferably becomes an inert solvent used.

The Concentration of the solvent is preferably 10 to 90% by mass, more preferably 20 to 70% by mass, in particular 30 to 60% by mass, in each case based on the finished Reaction mixture.

In a particular embodiment in the present invention, the solvent is identical to the diluent, that in the above-described process according to the invention for the preparation the anhydrous mixture containing the nickel (II) halide and the diluent, is used.

In the method according to the invention is the concentration of the ligand in the solvent is preferably 1 to 90 wt .-%, particularly preferably 5 to 80 wt .-%, in particular 50 to 80% by weight.

The in the method according to the invention used reducing agent is preferably selected from the group consisting of metals that are more electropositive than nickel are, metal alkyls, electric current, complex hydrides and Hydrogen.

If in the method according to the invention as a reducing agent, a metal that is more electropositive than nickel is used, this metal is preferably selected from the group consisting of sodium, lithium, potassium, magnesium, calcium, Barium, strontium, titanium, vanadium, iron, cobalt, copper, zinc, cadmium, Aluminum, gallium, indium, tin, lead and thorium. Especially preferred here are iron and zinc. Is aluminum as a reducing agent used, so it is advantageous if this by reaction with a catalytic amount of mercury (II) salt or metal alkyl preactivated becomes. It is preferred for the preactivation triethylaluminum in an amount of preferably 0.05 to 50 mol%, more preferably 0.5 to 10 mol%. The reducing metal is preferably finely divided, the term "finely divided" meaning that Metal in a particle size of less as 10 mesh, more preferably less than 20 mesh becomes.

If in the method according to the invention As reducing agent, a metal is used which is more electropositive is as nickel, so is the amount of metal preferably 0.1 to 50 wt .-%, based on the reaction mass.

If in the method according to the invention When reducing agents metal alkyls are used, it is preferably lithium alkyls, sodium alkyls, magnesium alkyls, in particular Grignard reagents, zinc alkyls or aluminum alkyls. Particularly preferred are aluminum alkyls, such as trimethylaluminum, Triethylaluminum, triisopropylaluminum or mixtures thereof, especially triethylaluminum. The metal alkyls can be used in Substance or dissolved in an inert organic solvent, such as hexane, heptane or toluene.

If in the method according to the invention complex hydrides are used as reducing agents, so be preferably metal aluminum hydrides, such as lithium aluminum hydride, or Metal borohydrides, such as sodium borohydride used.

The molar ratio the redox equivalents between the nickel (II) source and the reducing agent is preferably 1: 1 to 1: 100, more preferably 1: 1 to 1:50, in particular 1: 1 to 1: 5.

• – 2 bis 60 Gew.-%, insbesondere 10 bis 40 Gew.-% Pentennitrile,
• – 0 bis 60 Gew.-%, insbesondere 0 bis 40 Gew.-% Adipodinitril,
• – 0 bis 10 Gew.-%, insbesondere 0 bis 5 Gew.-% andere Nitrile,
• – 10 bis 90 Gew.-%, insbesondere 50 bis 90 Gew.-% phosphorhaltiger Ligand und
• – 0 bis 2 Gew.-%, insbesondere 0 bis 1 Gew.-% Nickel(0).

In the method according to the invention, the ligand to be used can also be present in a ligand solution which has already been used as catalyst solution in hydrocyanation reactions such as step e *) or isomerization reactions such as step a *) and depleted in nickel (0). Such currents are the currents 3 respectively. 10 either partially or independently selected partial streams 14 (from partial flow 3 ) or partial flow 16 (from partial flow 10 ) in stage h *) and the following stages, if necessary i *), j *) and k *). The possibly remaining partial flows 15 (from electricity 3 ) and 17 (from electricity 10 ) are not constrained by h *), i *), j *) and k *), but are directly attributed to stage a *) or e *). This "back-catalyst solution" generally has the following composition:

• From 2 to 60% by weight, in particular from 10 to 40% by weight, of pentenenitriles,
• From 0 to 60% by weight, in particular from 0 to 40% by weight, of adiponitrile,
• From 0 to 10% by weight, in particular from 0 to 5% by weight, of other nitriles,
• - 10 to 90 wt .-%, in particular 50 to 90 wt .-% phosphorus ligand and
• - 0 to 2 wt .-%, in particular 0 to 1 wt .-% nickel (0).

Of the contained in the reverse catalyst solution free ligand can thus according to the inventive method again be converted to a nickel (0) complex.

In a particular embodiment In the present invention, the ratio of the nickel (II) source is to phosphorus-containing ligand 1: 1 to 1: 100 conditions from nickel (II) source to phosphorus-containing ligand are 1: 1 to 1: 3, in particular 1: 1 to 1: 2.

The inventive method can be done at any pressure. For practical reasons are pressures between 0.1 bara and 5 bara, preferably 0.5 bara and 1.5 bara, prefers.

The inventive method can be carried out in batch mode or continuously.

In the method according to the invention Is it possible, without surplus on nickel (II) halide or reducing agents, such as zinc, to work so that their separation after nickel (0) complex formation not necessary is.

• (1) Trocknung eines wasserhaltigen Nickel(II)-halogenids durch Azeotropdestillation,
• (2) Vorkomplexierung des azeotrop getrockneten Nickel(II)-halogenids in einem Lösemittel in Gegenwart eines phosphorhaltigen Liganden,
• (3) Zugabe mindestens eines Reduktionsmittels zu der aus Verfahrensschritt (2) stammenden Lösung oder Suspension bei einer Zugabetemperatur von 20 bis 120 °C,
• (4) Rühren der aus Verfahrensschritt (3) stammenden Suspension oder Lösung für bei einer Umsetzungstemperatur von 20 bis 120 °C.

In a particular embodiment of the present invention, the method according to the invention comprises the following method steps:

• (1) drying a hydrous nickel (II) halide by azeotropic distillation,
• (2) precomplexing of the azeotropically dried nickel (II) halide in a solvent in the presence of a phosphorus ligand,
• (3) adding at least one reducing agent to the solution or suspension originating from process step (2) at an addition temperature of 20 to 120 ° C,
• (4) stirring the suspension or solution derived from process step (3) at a reaction temperature of 20 to 120 ° C.

The Precomplexing temperatures, addition temperatures and reaction temperatures can, respectively independently from each other, 20 ° C up to 120 ° C be. Particularly preferred are in the precomplexing, addition and reaction temperatures from 30 ° C to 80 ° C.

The Vorkomplexierungszeiträume, Addition periods and implementation periods can, each independently from each other, 1 minute to 24 hours. The precomplexing period is especially 1 minute to 3 hours. The addition period is preferably 1 minute to 30 minutes. The implementation period is preferably 20 minutes to 5 hours.

Process step h ₂ *):

Another preferred embodiment of process step h *), described here as process step h ₂ *), involves increasing the nickel (0) content of the streams 14 respectively. 16 eg by stirring in nickel powder. This is free phosphorus ligand in the streams 14 respectively. 16 used as a complexing partner or added fresh ligand.

The catalyst compounds may be prepared from nickel powder with a suitable source of halide initiator such as a halide or an alkyl substituted halide of phosphorus, arsenic or antimony such as CH ₃ PCl ₂ , CH ₃ AsCl ₂ or CH ₃ SbCl ₂ , or a suitable metal halide. elemental halogen, such as chlorine, bromine or iodine or the corresponding hydrogen halides or thionyl halide are produced. Metal halides to be used in the invention are the halides of Cr, Ni, Ti, Cu, Co, Fe, Hg, Sn, Li, K, Ca, Ba, Sc, Ce, V, Mn, Be, Ru, Rh, Pd, Zn. Cd, Al, Th, Zr and Hf. The halide may be chloride, bromide or iodide. Particularly suitable halide sources are PX ₃ , TiX ₄ , ZrX ₄ , HfX ₄ or HX, where X is chloride, bromide or iodide. When carrying out the reaction according to the invention, it is also possible to use mixtures of 2 or more initiators or catalysts.

The catalyst regeneration can batchwise, for example in batch mode analog US 3,903,120 , or continuously analog US 4,416,825 at temperatures of 0 to 200 ° C, preferably 25 to 145 ° C, more preferably 50 to 100 ° C are performed. The residence time of the catalyst can be varied within wide limits and is generally between 15 minutes and 10 hours, preferably 20 minutes and 5 hours, more preferably 30 minutes and 2 hours.

When carrying out process step h ₂ *) instead of process step h ₁ *), the process steps i *), j *) and k *) may possibly be omitted in whole or in part.

Process step i *):

If necessary, you can get electricity 18 before step i) by distillation, for example at pressures of 0.1 to 5000, preferably 0.5 to 1000 and in particular 1 to 200 mbar (abs.) and temperatures of 10 to 150, preferably 40 to 100 ° C - or other suitable measures constrict, for example, to 50 to 95, preferably 60 to 90% of its original volume. In a particularly preferred embodiment, this stream after concentration contains up to 10 wt .-%, that is 0 to 10 wt .-%, preferably 0.01 to 8 wt .-% pentenenitriles.

Step i *): Add the non-polar aprotic liquid F

In step i *) you add the stream 18 Add a non-polar aprotic liquid F, causing a current 19 receives. In this case, liquid means that the compound F is present in liquid form at least under the pressure and temperature conditions prevailing in step i *); under other pressure and temperature conditions F can also be solid or gaseous.

Suitable nonpolar (or apolar) aprotic liquid F are all compounds which are liquid under the conditions of step i *) and which comprise the catalyst, for example the Ni (0) complex with phosphorus-containing ligands and / or the free phosphorus-containing ligands, chemically or physically not or not significantly change. Compounds suitable as liquid F do not contain any ionizable proton in the molecule and generally have low relative dielectric constants (ε _r <15) or low electric dipole moments (μ <2.5 Debye).

Suitable are in particular hydrocarbons, for example, unhalogenated or halogenated, and - in particular tertiary - amines, and carbon disulfide.

In a preferred embodiment is the liquid F is a hydrocarbon K *. Suitable are aliphatic, cycloaliphatic or aromatic hydrocarbons K *. Suitable as aliphatic hydrocarbons e.g. linear or branched alkanes or alkenes of 5 to 30, preferably 5 to 16 C atoms, in particular pentane, hexane, heptane, Octane, nonane, decane, undecane and dodecane (all isomers, respectively).

Suitable cycloaliphatic hydrocarbons have, for example, 5 to 10 C atoms, such as cyclopentane, cyclohexane, cycloheptane, cycloocatane, cyclononane and cyclodecane. Substituted, in particular C _1-10 alkyl-substituted cycloaliphatic compounds such as methylcyclohexane are also suitable. Aromatic hydrocarbons are preferably those having 6 to 20 C atoms, in particular benzene, toluene, o-, m- and p-xylene, naphthalene and anthracene. It is also possible to use substituted, preferably C _1-10 -alkyl-substituted aromatics such as ethylbenzene.

Especially preferably, the hydrocarbon K * is selected from those below for the Hydrocarbon K compounds mentioned. Very particularly preferred the hydrocarbon K * is identical to the hydrocarbon K, i. one uses for the extraction in step j *) and as liquid F the same hydrocarbon.

Embodiment of adding the liquid

The non-polar aprotic liquid F can be the current 18 be added in conventional mixing devices. Preferably, because procedurally particularly, the non-polar aprotic liquid F is mixed with the stream in step i *) 18 in a stirred tank or a pumped circulation.

The non-polar aprotic liquid is preferred with the stream 18 intimately mixed. Suitable stirred vessels are customary liquid mixers which can be provided with intensive mixing mixing elements and / or static or movable internals.

The Use of a pumped circulation is also preferred. He usually becomes so operated that the ratio from Umpumpmenge to ejection the Umpumpkreis, 0.1: 1 to 1000: 1, preferably 1: 1 to 100: 1 and more preferably 2: 1 to 25: 1. As a circulation pump own e.g. Gear pumps or other common Pump. Preferably, the circulation pump works against an overflow, the at a defined pressure of e.g. 3 to 10 bar (abs.) Opens.

Provided the same hydrocarbon is used in step i *) and j *) you can in each case fresh hydrocarbon deploy. Likewise, one can use the hydrocarbon used in step i *) in step j *), or that used in step j *) Return hydrocarbon after step i *) and continue to use it there.

In a very particularly preferred embodiment, the liquid F is a partial stream of the stream 22 (Catalyst-enriched hydrocarbon K, see below) obtained at step j *). This means that in step j *) a part of electricity 22 is diverted and the diverted part in step i *) the current 18 inflicts. Accordingly, in this embodiment, a part of the stream becomes 22 driven in a circle.

In another, also preferred embodiment is the non-polar aprotic liquid F dosed directly into a residence time line (see below), for example at the beginning.

The inflict the liquid F is usually carried out at temperatures from 0 to 150, preferably 10 to 100 and especially 20 to 80 ° C, and pressures of 0.01 to 100, preferably 0.1 to 10 and in particular 0.5 to 5 bar (abs.).

The required amount of liquid F can vary within wide limits. It is usually lower as the amount of hydrocarbon K used, in step j *) is extracted, but may be larger. The amount is preferably the liquid F 0.1 to 200% by volume, in particular 1 to 50% by volume and especially preferably 5 to 30 vol.%, based on the amount of in step j *) used for the extraction of hydrocarbon K.

optional Treatment with ammonia or amine

If step h *) contains a redox regeneration, then possibly power 18 or electricity 19 or during step i *) or during step j *) itself, ammonia or a primary, secondary or tertiary aromatic or aliphatic amine are added. Aromatic includes alkylaromatic, and aliphatic includes cycloaliphatic.

It was found that by this ammonia or amine treatment, the content of catalyst, in particular nickel (0) complex or ligand in the extraction (step j *)) in the second enriched with dinitriles phase (stream 23 ), that is, in the extraction, the distribution of the Ni (0) complex or the ligands on the two phases in favor of the first phase (stream 22 ) postponed. The ammonia or amine treatment improves the catalyst enrichment in the stream 22 ; this means lower catalyst losses in the catalyst circulation and improves the economics of Hydrocyanierung.

Thus, in this embodiment of the extraction, treatment of the stream 18 or of electricity 19 preceded by ammonia or an amine or takes place during the extraction. The treatment during the extraction is less preferred.

Especially prefers adds the ammonia or the amine together with the nonpolar aprotic liquid F to. In particular, the addition of the liquid F and the ammonia takes place or amine in the same mixing device.

The amines used are monomines, diamines, triamines or higher-performance amines (polyamines). The monoamines usually have alkyl radicals, aryl radicals or arylalkyl radicals having 1 to 30 carbon atoms; suitable monoamines are, for example, primary amines, for example monoalkylamines, secondary or tertiary amines, for example dialkylamines. Suitable primary monoamines are, for example, butylamine, cyclohexylamine, 2-methylcyclohexylamine, 3-methylcyclohexylamine, 4-methylcyclohexylamine, benzylamine, tetrahydrofurfurylamine and furfurylamine. Suitable secondary monoamines are, for example, diethylamine, dibutylamine, di-n-propylamine and N-methylbenzylamine. Suitable tertiary amines are, for example, trialkylamines having C _1-10 -alkyl radicals, such as trimethylamine, triethylamine or tributylamine.

Suitable diamines are, for example, those of the formula R ¹ -NH-R ² -NH-R ³ , where R ¹ , R ² and R ³ independently of one another are hydrogen or an alkyl radical, aryl radical or arylalkyl radical having 1 to 20 C atoms. The alkyl radical can also be cyclic, in particular linearly or in particular for R ² . Examples of suitable diamines are ethylenediamine, propylenediamines (1,2-diaminopropane and 1,3-diaminopropane), N-methylethylenediamine, piperazine, tetramethylenediamine (1,4-diaminobutane), N, N'-dimethylethylenediamine, N-ethylethylenediamine, 1,5-diaminopentane, 1,3-diamino-2,2-diethylpropane, 1,3-bis (methylamino) propane, hexamethylenediamine (1,6-diaminohexane), 1,5-diamino-2-methylpentane, 3 (Propylamino) propylamine, N, N'-bis (3-aminopropyl) piperazine, N, N'-bis (3-aminopropyl) piperazine and isophoronediamine (IPDA).

When Triamines, tetramines or higher functional Amines are useful e.g. Tris (2-aminoethyl) amine, tris (2-aminopropyl) amine, Diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), isopropyltriamine, dipropylenetriamine and N, N'-bis (3-aminopropyl-ethylenediamine). aminobenzylamines and amino hydrazides having 2 or more amino groups are also suitable.

Of course you can also mixtures of ammonia with one or more amines, or Use mixtures of several amines.

Prefers one uses ammonia or aliphatic amines, in particular trialkylamines with 1 to 10 carbon atoms in the alkyl radical, e.g. Trimethylamine, triethylamine or tributylamine, as well as diamines such as ethylenediamine, hexamethylenediamine or 1,5-diamino-2-methylpentane.

Especially preferably ammonia is alone, i. particularly preferably used one beside ammonia no amine. Anhydrous ammonia is very special prefers; Anhydrous means a water content below 1 Wt .-%, preferably below 1000 and especially below 100 ppm by weight.

The molar ratio from amine to ammonia can be varied within wide limits usually at 10000: 1 to 1: 10000.

The Amount of the ammonia or amine used depends i.a. to Type and amount of catalyst, e.g. of the nickel (0) catalyst and / or the ligands, and - if so co-used - after Type and amount of Lewis acid, which is used in the hydrocyanation as a promoter. Usually is the molar ratio from ammonia or amine to Lewis acid at least 1: 1. The upper limit this molar ratio is usually not critical and is for example 100: 1; the surplus However, ammonia or amine should not be so large that the Ni (0) complex or its Decompose ligands. The molar ratio is preferably ammonia or amine to Lewis acid 1: 1 to 10: 1, more preferably 1.5: 1 to 5: 1, and in particular about 2: 1. If you use a mixture of ammonia and amine, these molar ratios apply for the Sum of ammonia and amine.

The Temperature in the treatment with ammonia or amine is usually not critical and amounts to for example 10 to 140, preferably 20 to 100 and in particular 20 to 90 ° C. The pressure is usually not critical.

The ammonia or the amine can the stream 18 gaseous, liquid (pressurized) or dissolved in a solvent. Suitable solvents are, for example, nitriles, in particular those which are present in the hydrocyanation, and furthermore aliphatic, cycloaliphatic or aromatic hydrocarbons, such as are used in the process according to the invention as extractant, for example cyclohexane, methylcyclohexane, n-heptane or n-octane.

The ammonia or amine addition is carried out in conventional devices, for example those for gas introduction or in liquid mixers. The thereby precipitating in many cases solid can either in the stream 18 remain, that is, the extraction is fed to a suspension, or separated as described below.

optional Separation of solids

In a preferred embodiment, solids that precipitate in step i *) of the process, prior to extraction (step j *)) from the stream 19 separated.

Thereby let yourself in many cases further improve the extraction performance of the process according to the invention, often accumulating solids reduce the separation efficiency the extraction devices. It was also found that a solids separation prior to extraction in some cases undesirable Mulmbildung significantly reduced or completely suppressed.

Prefers the solids separation is designed such that solid particles with a hydraulic diameter greater than 5 microns, especially greater than 1 micron and especially preferably greater than 100 nm, are separated.

to Solid separation can be customary Use processes such as filtration, cross-flow filtration, Centrifugation, sedimentation, classification or preferably decanting, for what common Devices such as filters, centrifuges or decanters are used can.

temperature and pressure in solids separation are usually not critical. For example, in the above or below mentioned Temperature or pressure ranges work.

The solids separation may take place before, during or after the - optional - treatment of the stream 18 or the current 19 with ammonia or amine. The separation during or after the ammonia or amine treatment is preferred, and thereafter particularly preferred.

If the solids are separated during or after the ammonia or amine treatment, the solids are mostly in the stream 18 sparingly soluble compounds of ammonia or amine with the Lewis acid or the promoter used. If ZnCl _{2 is} used, for example, substantially sparingly soluble ZnCl ₂ · 2NH ₃ precipitates during the ammonia treatment.

Provided separating the solids before the ammonia or amine treatment or if there is no treatment with ammonia or amine, the solids are usually nickel compounds the oxidation state + II, for example, nickel (II) cyanide or the like cyanide-containing nickel (II) compounds, or Lewis acids or their compounds. The compounds mentioned can For example, because their solubility e.g. by temperature change was reduced.

optional holdup

The current 19 as discharge from step i *) can be transferred directly to step j *), for example through a pipeline. It means directly that the mean residence time of electricity 19 in the pipeline is less than 1 min.

However, in a preferred embodiment, the method according to the invention is characterized in that the stream 19 after step i *) and before step j *) is passed through a residence time. The residence time course is therefore after the addition of the liquid F and before the extraction.

As residence time, for example, pipelines, static mixers, stirred or unstirred containers or container cascades, as well as combinations of these elements. The residence time distance is preferably dimensioned and configured such that the mean residence time of the stream 19 in the residence time is at least 1 min, preferably at least 5 min.

The optional solid separation described above can also take place in the residence time. The residence time section is used as a calming zone, in which the solid can settle. To this Way, the residence time section acts as a decanter or cross-flow filter. It can be used with devices for promotion and / or be provided for the discharge of solids.

As mentioned, in a preferred embodiment, the non-polar aprotic liquid F is metered directly into the residence time segment, for example at the beginning thereof. In this embodiment, it is particularly preferable to choose a residence time interval which is an intimate thorough mixing of electricity 18 and fluid F guaranteed. As also already described, the residence time segment can be a phase separation of the stream 19 cause.

The Residence time range is usually at temperatures from 0 to 200, preferably 10 to 150 and especially 20 to 100 ° C, and pressing 0.01 to 100, preferably 0.1 to 10 and in particular 0.5 to 5 bar (abs.), operated.

In a preferred embodiment of the invention, the flow velocity of the stream 19 in all pipelines used in the process according to the invention at least 0.5, in particular at least 1 and more preferably at least 2 m / s.

The current obtained in step a) 19 is extracted, optionally after the treatment with ammonia or amines, and / or after the solids separation and / or after passing through the residence time, in step j *).

Step j *):

process principle

The process according to the invention is suitable for the extractive purification of Ni (0) complexes which contain phosphorus-containing ligands and / or free phosphorus-containing ligands into electricity 19 or possibly electricity 18 when step i *) is not carried out, adding a C6 dinitrile such as adiponitrile (ADN), 2-methylglutaronitrile (MGN) or 2-ethylsuccinonitrile (ESN) to the interfering component (s) does not increase the formation of the hydrocyanation accessible C5 mononitriles such as E-2-methyl-2-butenenitrile and / or Z-2-methyl-2-butenenitrile trigger.

In addition, the catalyst losses are reduced in the extraction, in which a hydrocarbon K in the stream 21 is fed to a feed point, which is closer to the outlet of the extract than to the feed point of the feed stream 18 respectively. 19 lies. The feed point of the dinitrile (Strom 20 ) is closer to the drain point of the raffinate than the feed point of the feed stream 18 respectively. 19 lies. Herein is closer to understand in the sense of the number of theoretical separation stages between two points. Between the feed points of the streams 18 respectively. 19 and 21 are usually 0 to 10, preferably 1 to 7 theoretical extraction (separation) stages (back-extraction zone for the catalyst); between the feed points of the streams 18 respectively. 19 and 20 are usually 1 to 10, preferably 1 to 5 theoretical extraction (separation) stages (cleaning zone with respect to interfering component (s)).

As a rule, at a temperature T (in ° C) a first phase [raffinate; electricity 22 ], facing the stream 18 enriched in said Ni (0) complexes or ligands, and a second phase [extract; electricity 23 ; Enriched interfering component (s)], compared to the current 18 enriched in dinitriles. In most cases the first phase is the lighter phase, ie the upper phase, and the second phase is the heavier phase, ie the lower phase.

The Contains upper phase after the phase separation, preferably between 50 and 99% by weight, particularly preferably between 60 and 97 wt .-%, in particular between 80 and 95 wt .-%, of the hydrocarbon used for the extraction.

The Lewis acid, which is optionally contained (namely in the production of redox catalyst regeneration in process step h ₁ *)) in the feed stream of the extraction, preferably remains mostly and most preferably completely in the lower phase. Here completely means that the residual concentration of the Lewis acid in the upper phase is preferably less than 1 wt .-%, more preferably less than 0.5 wt .-%, in particular less than 500 ppm by weight.

The Removal of the interfering component (s) improves process selectivity because less of the hydrocyanation not accessible C5 mononitriles are formed (reduction of Fehlisomerisierungen).

A particular advantage of embodiment III is that dinitriles such as ADN, MGN, ESN, which form in small amounts in process step e *) and thus in the stream 10 enriched, at least partially carried out with the lower phase of the extraction.

One Another particular advantage of the use of process step j *) consists in that as educt in process step e *) stabiliastorhaltiges Butadiene can be used. Such a stabilizer may, for example tert-butyl catechol. This stabilizer is about the Subphase of the extraction carried out. Thus, no catalyst damaging Levels of stabilizer leveled up in the catalyst loop become.

A further particular advantage is that in process step h *) a redox regeneration of the catalyst for increasing the Ni (0) value according to h ₁ *) can be carried out, since the resulting Lewis acid is discharged via the lower phase of the extraction becomes. Otherwise, this Lewis acid would lead to increased dinitrile formation in the first hydrocyanation (process step e *)).

The lower phase of the extraction can be prepared in a suitable manner, so that the dinitriles contained therein can be used again as feed for the extraction. Such work-up can, for example, be carried out by distillation (DE-A-10 2004 004683, Strom 7 from step c)).

design the extraction

The can extractive tasks preferably solved by adding a countercurrent extraction column with a back extraction zone is used. However, they are also identically acting combinations of any suitable apparatus known to those skilled in the art, such as countercurrent extraction columns, Mixer-settler cascades or combinations of mixer-settler cascades with columns, for example a series connection of two countercurrent extraction columns (for example, a for the cleaning with respect to interfering component (s), the other for the back extraction of the catalyst). Particularly preferred is the use of countercurrent extraction columns, in particular equipped with sheet metal packages as dispersing elements are. In a further particularly preferred embodiment the extraction is carried out in countercurrent in compartmented, stirred extraction columns executed.

Concerning the direction of dispersion, in a preferred embodiment of the method, the Koh Hydrogen as a continuous phase and the current 18 the hydrocyanation used as a disperse phase. This usually shortens the phase separation time and reduces the formation of scum. However, the reverse direction of dispersion is also current 18 as continuous and hydrocarbon as disperse phase, possible. The latter is especially true if the Mulmbildung by previous solids separation (see below), higher temperature in the extraction or phase separation or use of a suitable hydrocarbon is reduced or completely suppressed. Usually one chooses the more favorable for the separation efficiency of the extraction device dispersion.

In the extraction, the following ratios of feeds are set:
electricity 20 to the sum of electricity 18 or 19 and electricity 21 in the range of 0.01 to 10 kg / kg, preferably 0.05 to 5 kg / kg. electricity 21 to electricity 20 in the range of 0.05 to 20 kg / kg, preferably 1 to 10 kg / kg. electricity 21 to electricity 18 respectively. 19 in the range of 0.05 to 20 kg / kg, preferably 0.5 to 8 kg / kg.

Of the absolute pressure during the extraction is preferably 10 kPa to 1 MPa, more preferably 50 kPa to 0.5 MPa, in particular 75 kPa to 0.25 MPa (absolute).

The Extraction is preferably carried out at a temperature of -15 to 120 ° C, in particular 20 to 100 ° C and particularly preferably carried out 30 to 80 ° C. It was found that at higher Temperature of extraction, the Mulmbildung is lower.

design the phase separation

The Phase separation can be spatial and temporally depending on the apparatus design as the last Part of the extraction. For phase separation can usually a wide range of pressure, concentration and temperature are selected, being the for the particular composition of the reaction mixture optimal parameters easily determined by a few simple preliminary tests.

The Temperature T in the phase separation is usually at least 0 ° C, preferably at least 10 ° C, more preferably at least 20 ° C. Usually it is at most 120 ° C, preferably at most 100 ° C, most preferably at most 95 ° C. For example you lead the phase separation at 0 to 100 ° C, preferably 60 to 95 ° C by. It was found that at higher temperature the phase separation Mulmbildung is lower.

Of the Phase separation pressure is usually at least 1 kPa, preferably at least 10 kPa, more preferably 20 kPa. Usually amounts to he at most 2 MPa, preferably at most 1 MPa, more preferably at most 0.5 MPa absolute.

The phase separation time, ie the time span from the mixing of the current 18 with the hydrocarbon (extractant) to the formation of a uniform upper phase and a uniform lower phase, can vary within wide limits. The phase separation time is generally 0.1 to 60, preferably 1 to 30 and in particular 2 to 10 min. In large-scale implementation of the method according to the invention is usually a phase separation time of a maximum of 15, especially a maximum of 10 min technically and economically useful.

It was found that the phase separation time in particular when using long-chain aliphatic alkanes such as n-heptane or n-octane as Hydrocarbon K advantageously reduced.

The Phase separation may occur in one or more skilled in the art Phase separations known devices are performed. In an advantageous embodiment you can perform the phase separation in the extraction device, for example in one or more mixer-settler combinations or by equipment an extraction column with a calming zone.

at the phase separation receives one two liquid Phases, of which one phase has a higher proportion of the nickel (0) complex with phosphorus ligands and / or free phosphorus ligands, based on the total weight of this phase, has as the other Phase or other phases. The other phase is enriched the interfering component (s).

dinitrile

electricity 20 , which is fed as extraction feed stream, contains predominantly dinitriles, preferably C6-Dinitriles, particularly preferably adiponitrile (ADN), 2-methylglutaronitrile (MGN), 2-ethylsuccinonitrile (ESN) or mixtures thereof. The Gehlat this stream of dinitriles is preferably greater than 50 wt .-%, more preferably greater than 70 wt .-%, particularly preferably greater than 90 wt .-%. Processes for the preparation of dinitriles, especially C6-dinitriles are known per se. One such method is described in DE-A-10 2004 004683. Such produced streams of C6-dinitriles, especially the streams 15 . 16 and 17 from process step h) from DE-A-10 2004 004683 are generally suitable for use here as a stream 20 to be used.

Of the Addition of dinitriles is preferably carried out to the extent that a phase separation in the extraction stage k *) takes place.

Hydrocarbon

The hydrocarbon is the extractant. It preferably has a boiling point of at least 30 ° C., particularly preferably at least 60 ° C., in particular at least 90 ° C., and preferably at most 140 ° C., particularly preferably at most 135 ° C., in particular at most 130 ° C., in each case at a pressure of 10 ⁵ Pa absolute.

Especially preferably, a hydrocarbon, wherein in the sense of the present Invention hereunder a single hydrocarbon, as well as a Mixture of such hydrocarbons is understood, for the separation, in particular by extraction of adiponitrile from a mixture, containing adiponitrile and the catalyst containing Ni (0), can be used, which has a boiling point in the range between 90 ° C and 140 ° C. From after separation according to this NEN mixture containing the adiponitrile can be advantageous obtained by distillative removal of the hydrocarbon, the use of a hydrocarbon with a boiling point in the said area a particularly economical and technical easy separation by the possibility the condensation of the distilled hydrocarbon with river water allowed.

Suitable hydrocarbons are, for example, in US 3,773,809 , Column 3, lines 50-62. Preferably, a hydrocarbon selected from cyclohexane, methylcyclohexane, cycloheptane, n-hexane, n-heptane, isomeric heptanes, n-octane, iso-octane, isomeric octanes such as 2,2,4-trimethylpentane, cis- and trans-decalin or their mixtures, in particular of cyclohexane, methylcyclohexane, n-heptane, isomeric heptanes, n-octane, isomeric octanes such as 2,2,4-trimethylpentane, or mixtures thereof; into consideration. Cyclohexane, methylcyclohexane, n-heptane or n-octane are particularly preferably used.

All particularly preferred are n-heptane or n-octane. For these hydrocarbons is the unwanted Mulmbildung particularly low. Mulm becomes an area of incomplete phase separation understood between the upper and lower phases, usually a liquid / liquid mixture, in which also solids can be dispersed. Excessive clogging is undesirable because it hinders the extraction and u.U. the extraction device can be flooded by the muck, whereby they do not do their separation task to fulfill more can.

Of the used hydrocarbon is preferably anhydrous, wherein anhydrous a water content of less than 100, preferably below 50, especially below 10 ppm by weight means. The hydrocarbon can be dried by suitable methods known in the art, for example by adsorption or azeotropic distillation. The drying can in a method of the invention take place upstream step.

Process step k *):

In process document (k *) finds a distillation of the stream 22 to obtain a stream containing the at least one catalyst 25 and a stream containing the extractant 24 instead of.

This Process step essentially serves to recover the catalyst and the extractant.

Of the Process step (k *) may be in any suitable, known to those skilled Apparatus performed become. The distillation of process step k *) is preferred in one or more evaporation stages and rectification columns / distillation columns instead of.

As internals for the rectification columns / distillation columns are preferably structured Sheet metal packing, structured fabric packing, bubble trays, dual-flow trays or packing of packing or combinations of two or more of these classes of separating internals. The rectification column distillation column of process step k *) can be carried out with one or more liquid or gaseous side draws. The rectification column distillation column from process step k *) can be carried out as a dividing wall column with one or more existing gaseous or liquid side draws.

The one or more evaporator stages or the rectification column / distillation column of the method step k *) in particular with falling-film evaporator, thin-film evaporator, natural circulation evaporator, Forced circulation flash evaporator and multiphase spiral tube evaporator equipped be.

In a further embodiment the method according to the invention is at least one of the evaporator units of process step k *) operated with a divided bottom, wherein one of a first sump the relevant evaporator stage in relation to the bottom draw stream generally large circulating current goes to the evaporator, the liquid Outflow from the evaporator but not directly into the sump returns but into a second swamp that is separate from the first swamp, fields, from the second sump receives the bottom take-off stream and the remaining surplus From the evaporator circulating flow into the first sump overflow, where as the bottom draw stream from the second sump a mixture is obtained which is opposite to the Deduction from the first swamp is depleted in low boilers.

Of the absolute pressure in process step k *) is preferably 0.001 to 2 bar (a), particularly preferably 0.01 to 0.5 bar (a), in particular 0.09 to 0.12 bar (a). The distillation is carried out so that the temperature in the bottom of the distillation apparatus preferably 40 to 150 ° C, particularly preferably 70 to 120 ° C, in particular 80 to 100 ° C, is. The distillation is carried out so that the temperature at Head of the distillation apparatus preferably -15 to 100 ° C, especially preferably 0 to 60 ° C, in particular 20 to 50 ° C, is. In a particularly preferred embodiment of the method according to the invention be the above temperature ranges both on the head than also respected in the swamp.

at the separation of the extractant to recover the catalyst according to method step k *) may optionally 3-pentenenitrile as an intermediate for distillation are given. This solvent change possibly has the advantage that an effective depletion of the extractant from the high-boiling catalyst stream at evaporator temperatures possible low enough to accommodate the particular nickel catalyst used, especially when chelating ligands are not used thermally damage and to conserve thermally when using monodentate ligands, the pressure is still high enough compared to the Catalyst components comparatively low-boiling extractants at the top of the evaporator stage or distillation column still at usual Cooling water temperatures from 25 to 50 ° C condense to be able to. The solvent change In addition, if appropriate, has the advantage that the flowability and the single phase of the catalyst solution is ensured, since dependent of temperature and residual content of extractant - without the Addition of 3-pentenenitrile - optionally Catalyst components can crystallize out. This affects 3-pentenenitrile, for example, the extractants cyclohexane or methylcyclohexane or heptane or n-heptane, depending on the pressure conditions, only with difficulty or because of the formation of a minimum vapor pressure azeotrope not completely is separable, with a proportion of preferably up to 10 wt .-%, particularly preferably up to 5 wt .-%, in particular up to 1 wt .-%, based to the total amount of extractant feed to the extraction column in process step j *), not disturbing the process according to the invention out.

The current obtained in process step k *) 24 , containing the extractant, in a preferred embodiment of the process according to the invention is at least partially recycled to the extraction step j *). This is the recycled electricity 24 if appropriate, before the extraction step j *), so that the water content in this stream is preferably less than 100 ppm by weight, more preferably less than 50 ppm by weight, in particular less than 10 ppm by weight.

The current obtained in process step k *) 25 , containing the catalyst, in a further preferred embodiment of the process according to the invention is at least partially recycled to the hydrocyanation of process step e *) or in the isomerization of process step a *). In a preferred embodiment of the process according to the invention, the proportion of extractant in the stream 25 preferably less than 10 wt .-%, more preferably less than 5 wt .-%, in particular less than 1 wt .-%, based on the total amount of electricity 25 ,

In the following, preferred embodiments of the catalyst flow guidance through the process stages a *) to k *) will be described with reference to the diagrams 1 to 5. The process step i *) is not included in Schemes 1 to 5, but can in each case between h *) and j *) are performed. In Schemes 1 to 5, the method step h *) in the embodiment as a method step h ₁ *) is described by way of example. Alternatively, the embodiment can also be carried out as method step h ₂ *). In these cases, the nickel (II) chlorides would be replaced by nickel powder, the reducing agent (Red.) Is eliminated as well as the Lewis acid (LS). ADN is synonymous with dinitrile streams; Heptane synonymous with hydrocarbons as extractant. Cat. Means catalyst complexes plus free ligand. The dashed lines in Schemes 1 to 5 indicate optional bypass partial streams of the catalyst streams.

A special embodiment of the process with respect to the catalyst flow is shown in Scheme 1. Accordingly, the catalyst-leading Steps summarized in a single catalyst circuit. The chronological order the process steps is based on the first hydrocyanation e *), f *), a *), b *), c *), h *), if necessary i *), j *), k *), before returning e *) is fed. It may optionally be a partial stream of the catalyst pass the steps h *), i *), j *) and k *) past directly into e *). The process stage a *) is here with not separated mixture from 2-methyl-3-butenenitrile and 3-pentenenitrile, i. d *) or g *) is executed after a *).

A another particular embodiment of the process with respect to the catalyst flow is shown in Scheme 2. Accordingly, the catalyst-leading Steps summarized in a single catalyst circuit. The chronological order the process steps is based on the first hydrocyanation e *), f *), a *), b *), c *), h *), if necessary i *), j *), k *), before returning e *) is fed. In this case, if appropriate, a partial stream of the catalyst at the stages h *), i *), j *) and k *) are returned directly to e *). Process stage a *) is here depleted with respect to 3-pentenenitrile 2-methyl-3-butenenitrile fed, i. d *) or g *) is executed before a *).

A another particular embodiment of the process with respect to the catalyst flow is shown in Scheme 3. Accordingly, a catalyst flow over stages e *) and f *) driven in a circle. From this stream, a partial flow is discharged and as catalyst feed for the stage a *) is used. Subsequently, this stream is complete, if necessary partly, by stages b *), c *), h *), if necessary i *), j *) and k *) back to e *). The isomerization stage a *) is treated with 3-pentenenitrile depleted 2-methyl-3-butenenitrile fed, i. d *) or g *) is executed before a *). Likewise, but also d * or g * is executed after a * become.

A another particular embodiment of the process with respect to the catalyst flow is shown in Scheme 4. Accordingly, two catalyst circuits are built. catalyst circuit 1 includes stages e *) and f *), catalyst circuit 2 stages a *), b *), c *). From both streams become partial flows, optionally also the respective total catalyst flows over the Steps h *), optionally i *), j *) and k *) to the catalyst of interfering component (s) to clean and / or to increase the Ni (0) content. It is the over the Extraction driven fraction from catalyst circuit 2 is preferably greater than from catalyst circuit 1. Optionally, the entire stream from catalyst circuit 2 driven by the extraction. The two Catalyst circuits are only over the stages h *), optionally i *), j *) and k *) are coupled together. The division of the current from k *) to feed a *) or e *) usually corresponds to the ratio the feed streams to h *) from a *) and e *). The isomerization a *) is with respect. Fed 3-pentenenitrile depleted 2-methyl-3-butenenitrile, i.e. d *) or g *) is executed before a *). Likewise, but also d * or g * is executed after a * become.

A another particular embodiment of the process with respect to the catalyst flow is shown in Scheme 5. Accordingly, a catalyst cycle over the stages a *), b *), c *), h *), if necessary i *), j *) and k *). For this catalyst circuit a substream is withdrawn before h *) and thus the first hydrocyanation e *) operated. about f *), the current is returned to h *). Possibly can the return also directly to a *). Also a partial flow of the isomerization catalyst circuit can be traced back from c *) directly to a *). The isomerization stage a *) is treated with 3-pentenenitrile depleted 2-methyl-3-butenenitrile fed, i. d *) or g *) is executed before a *). Likewise, but also d * or g * is executed after a * become.

The The present invention will be described with reference to the following Examples closer explained.

embodiments

Cyanwasserstoff:

Cyanwasserstoff

T3PN:

trans-3-Pentennitril

C3PN:

cis-3-Pentennitril

4PN:

4-Pentennitril

E2M2BN:

(E)-2-Methyl-2-butennitril

T2PN:

trans-2-Pentennitril

C2PN:

cis-2-Pentennitril

ADN:

Adipodinitril

MGN:

Methylglutarnitril

VSN:

Valeriansäurenitril

VCH:

4-Vinylcyclohexen

BD:

1,3-Butadien

TBC:

tert.-Butylbrenzkatechin

C2BU:

cis-2-Buten

LS:

Lewis-Säure

The following abbreviations are used in the examples:

Hydrogen cyanide:

Hydrogen cyanide

T3PN:

trans-3-pentenenitrile

C3PN:

cis-3-pentenenitrile

4PN:

4-pentenenitrile

E2M2BN:

(E) -2-methyl-2-butenenitrile

T2PN:

trans-2-pentenenitrile

C2PN:

cis-2-pentenenitrile

ADN:

adiponitrile

MGN:

methylglutaronitrile

VSN:

valeronitrile

VCH:

4-vinylcyclohexene

BD:

1,3-butadiene

TBC:

tert-butylcatechol

C2BU:

cis-2-butene

LS:

Lewis acid

In The examples show the process steps in a chronological order Order indicated and thus deviate from the name in the Description and in the claims from. Not closer in% or ppm are wt .-% and wt ppm.

Example 1:

Example 1 is based on 3 clarified.

In Example 1, a catalyst system based on nickel (0) complexes with a mixture of ligands is used for the hydrocyanation of butadiene. The ligand mixture for hydrocyanation contains about 60 mol% of tri (m / p-tolyl) phosphite and 40 mol% of the chelate phosphonite 1:

• (1) 10 kg/h flüssiger unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff,
• (2) 22 kg/h handelsübliches BD, enthaltend 0,25% C2BU, das durch Kontakt mit Aluminiumoxid behandelt wurde, um Wasser und Stabilisator TBC zu entfernen,
• (3) 8 kg/h rückgeführtes BD aus K2a in Schritt (2) (Strom 9), so dass als gesamter BD-Zulauf zum Reaktor R1 ein Strom von 30 kg/h enthaltend 90% BD, 5% C2BU sowie 5% 1-Buten erhalten wird,
• (4) 21 kg/h Nickel(0)-Katalysatorlösung, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 10a aus der Kolonne K2b

In one step (1) the following streams are run in a loop reactor R1 of 25 l volume, which is equipped with a nozzle, momentum exchange tube, external pumping circulation and in a heat exchanger located in Umpumpkreislauf to dissipate the reaction energy and is heated to 357 K:

• (1) 10 kg / h of liquid unstabilized hydrogen cyanide liberated by the distillation of water,
• (2) 22 kg / h of commercial BD containing 0.25% C2BU treated by contact with alumina to remove water and TBC stabilizer.
• (3) 8 kg / h of recirculated BD from K2a in step (2) (Electricity 9 ), so that the total BD feed to the reactor R1 is a stream of 30 kg / h containing 90% BD, 5% C2BU and 5% 1-butene,
• (4) 21 kg / h of nickel (0) catalyst solution obtained as stream as described below in this example 10a from the column K2b

The withdrawn from the reactor R1 stream 8th (63 kg / h) contains in total 11% BD and C2BU, corresponding to a conversion of 79% BD, and in total 63% pentenenitriles, 31% T3PN, 29% 2M3BN and small amounts of Z2M2BN and E2M2BN as well as further pentenenitrile isomers (T2PN , C2PN, C3PN, 4PN), as well as the catalyst components and catalyst degradation products and MGN.

electricity 8th gets in one step (2) a distillation column K2a is operated, which is operated with boosting and stripping section and is equipped with a falling film evaporator and a separate bottom, and Ko includes structured packing structures that produce 10 theoretical plates. Column K2a is operated at the top with a direct condenser which consists of a column shot equipped with structured packing with total catch cup, pumped circulation and external heat exchanger. The column K2a is operated at an absolute top pressure of 2.0 bar, 288 K head temperature and 363 K bottom draw temperature.

Overhead of the column K2a becomes the stream 9 obtained, which is metered as described above as a recycle stream in the reactor R1. The reflux ratio at the top of the column K2a is adjusted so that the current 9 contains about 100 ppm 2M3BN.

About the bottom of the column K2a 59 kg / h of a stream 1b obtained, the 2.9% BD, 4.6% C2BU, 67% pentenenitrile and additionally contains the catalyst components. C2BU is significantly enriched in relation to BD compared to the feed.

electricity 1b will be within the step (2) in a distillation column K2b driven, which is operated in driven mode and is equipped with falling film evaporator, top condenser with post-condenser and column internals with structured packing that produce 10 theoretical plates. The column is operated at an absolute top pressure of 150 mbar, 329 K top temperature and 373 K bottom draw temperature. The vapor stream of the column is partially condensed at 308 K and treated with a post-condenser at 263 K. The so depleted of 2M3BN and other pentenenitriles BD stream 2c is compressed in a compressor V2 to an absolute pressure of 1.2 bar. The compressed gas stream is largely recovered at 279 K to give a stream 2e (5 kg / h) condensed, with a partial flow 2d (47 Nl / h, containing 44% C2BU) is disposed of gaseous. electricity 2e is liquid returned to the condensate tank of the column K2a.

At the column K2b is in a gaseous side draw the current 11 recovered (40 kg / h), containing about 100 ppm BD, 46% 2M3BN and 48% T3PN, and to a lesser extent E2M2BN and Z2M2BN among other pentenenitrile isomers. The position of the side take-off is selected so that below the side take-off in a stripping section, the component 2M3BN in the current recovered via the sump 10 depleted in relation to T3PN.

In the column K2b 13 kg / h of a catalyst stream are driven, as described in Example 1 according to the German patent application entitled "Process for the preparation of dinitriles" BASF AG (B03 / 0525) described as bottom withdraw the column K4 from step (4) containing in total 73% pentenenitriles, 0.5% Ni (0), 18% ligand mixture and about 5% ADN.

At the column K2b is the bottom of the catalyst stream 10 containing 0.5% Ni (0), about 100 ppm 2M3BN and 73% residual pentenenitriles. The current 10 is split into partial flow 10a (21 kg / h), which is returned to the reactor R1. The other part ( 10b ) (5.4 kg / h) is fed to a regeneration according to DE-A-103 51 002, used after regeneration, for example in the hydrocyanation of 3-pentenenitrile as described in Example 1 according to DE-A-102 004 004 683 to become.

The current 11 gets in one step (3) to a distillation column K3 driven, which is equipped with circulation evaporator and top condenser and with structured packing that produce 30 theoretical plates. The column K3 is operated at an absolute top pressure of 180 mbar, 345 K head temperature and 363 K bottom draw temperature.

In the column K3 39 kg / h recycle stream 5 from the column K5 in step (5) containing 54% T3PN, 23% 2M3BN and 16% Z2M2BN, and minor amounts of other pentenenitrile isomers.

About the top of the column K3 40 kg / h of a stream 13 containing 10 T3PN, 68% 2M3BN, 16% Z2M2BN and in total 0.1% BD and C2BU and small amounts of other pentenenitrile isomers (T2PN, C2PN, C3PN, 4PN).

About the bottom of the column K3 are 39 kg / h of the stream 12 containing in total 97% T3PN, C3PN and 4PN and small amounts of other pentenenitrile isomers (T2PN, C2PN) and about 100 ppm 2M3BN and about 1% E2M2BN.

In Example 1, a catalyst system based on nickel (0) complexes with a mixture of ligands is used for the isomerization of 2M3BN to T3PN. The ligand mixture for isomerization (im Hereinafter referred to as Isomerisierungsligand) contains mixed phosphite ligands of the class P (OR) (OR ') (OR'') with randomly distributed R, R', R '' from the group m-tolyl, p-tolyl, o-isopropylphenyl, wherein about 40 mol% of the sum of the radicals R, R ', R "are o-isopropylphenyl radicals. Such ligand mixtures are obtained by reacting a mixture of m- and p-cresol with a 2: 1 ratio of m-cresol to p-cresol and a stoichiometrically adjusted amount of o-isopropylphenol with a phosphorus trihalide.

The current 13 gets in one step (4) along with a catalyst recycle stream 3a and a catalyst supplemental stream in a reactor R2, carried out as a tubular reactor, which is heated to 393 K. 56 kg / h of a mixture containing 20% T3PN, 5% 2M3BN and other pentenenitrile isomers, 55% isomerization ligand and 0.5% nickel (0) and a low content of catalyst degradation products are fed into reactor R2 as the sum of recycled catalyst and fresh catalyst.

As product of the reactor R2 96 kg / h of electricity 1 containing 34% T3PN, 12.3% 2M3BN and minor amounts of other pentenenitrile isomers (T2PN, C2PN, C3PN, 4PN), corresponding to a conversion of 60% 2M3BN.

electricity 1 gets in one step (5) into a distillation column K5, which is operated as a reinforcing column and is equipped with falling film evaporator, top condenser, reflux divider, gaseous side draw in the bottom region of the column and column internals with structured packing which produce 30 theoretical plates. The column is operated at an absolute top pressure of 250 mbar, 353 K head temperature and 373 K bottom draw temperature.

In column K5 is recovered via bottom of the recovered catalyst stream 3 (56 kg / h) containing 20% T3PN in addition to other pentenenitriles, about 5% MGN and 0.5% Ni (0) and 54% Isomerisierungsligand. A small part of the stream 3 is used to limit the accumulation of catalyst deactivation components and MGN as a stream 3b discharged. To supplement the discharged amount of catalyst so much fresh catalyst containing 15% T3PN in addition to other pentenenitrile isomers, 1% Ni (0) and 80% Isomerisierungsligand, metered that the Ni (0) content in the catalyst feed to the reactor R2 at 0.5 % is kept.

In column K5 becomes overhead a stream 4 (0.8 kg / h), containing in total 0.5% BD and C2BU, 50% 2M3BN, 41% Z2M2BN, and small amounts of vinylcyclohexene (VCH), which is contained on the one hand in traces in the feed BD and on the other hand in small amounts in The hydrocyanation of butadiene is formed and ultimately peaks in the 2M3BN cycle of isomerization and must be discharged together with 2M3BN since the vapor pressures of 2M3BN and VCH are so close together that separation by ordinary distillation is not possible. The reflux ratio of column K5 is adjusted so that 10 ppm T3PN in the stream 4 are included. The deduction amount of electricity 4 from the top of the column K5 is adjusted so that in the top exhaust stream 13 the distillation column K3 in total 20% Z2M2BN and VCH are included.

In column K5 is via the gaseous side draw a stream 5 obtained (39 kg / h), in addition to 3-pentenenitriles essentially contains the unreacted in the isomerization 2M3BN and liquid after condensation is returned to the column K3 as described above.

Example 2:

Example 2 is based on 4 clarified.

In Example 2, a catalyst system based on nickel (0) complexes with chelate phosphite 2 as ligand is used for the hydrocyanation of BD:

• (1) 6 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1a,
• (2) 6 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1b,
• (3) 25 kg/h BD zu R1a, enthaltend 0,25% C2BU, das durch Kontakt mit Aluminiumoxid behandelt wurde, um Wasser und Stabilisator TBC zu entfernen,
• (4) 2 kg/h rückgeführtes BD aus Kolonne K2a in Schritt (2) zu R1a (Strom 9), so dass als gesamter BD-Zulauf zum Reaktor R1 ein Strom von 27 kg/h enthaltend 98% BD und in Summe 2% C2BU und 1-Buten erhalten wird,
• (5) 14 kg/h Nickel(0)-Katalysatorlösung zu R1a, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 10a aus der Kolonne K2b

In one step (1) the following streams are run in a system of two reactors R1a and R1b each of 12 l volume, each equipped with a nozzle, pulse exchange tube, external pumping circulation and in a heat exchanger located in Umpumpkreislauf to dissipate the reaction energy and are heated to 363 K:

• (1) 6 kg / h of liquid, unstabilized hydrogen cyanide freed of water by distillation to R1a,
• (2) 6 kg / h of liquid, unstabilized hydrogen cyanide freed from water by distillation to R1b,
• (3) 25 kg / h BD to R1a containing 0.25% C2BU treated by contact with alumina to remove water and TBC stabilizer.
• (4) 2 kg / h of recycled BD from column K2a in step (2) to R1a (current 9 ), so that the total BD feed to the reactor R1 is a stream of 27 kg / h containing 98% BD and a total of 2% C2BU and 1-butene,
• (5) 14 kg / h of nickel (0) catalyst solution to R1a obtained as stream as described in this example below 10a from the column K2b

The withdrawn from the reactor R1b stream 8th (54 kg / h) contains in total 4% BD and C2BU, corresponding to a conversion of 94% BD, and in total 74% pentenenitriles, of which 33% T3PN, 37% 2M3BN and small amounts of Z2M2BN and E2M2BN, among other pentenenitrile isomers and the catalyst components and catalyst degradation products and MGN.

electricity 8th gets in one step (2) supplied in a distillation column K2a, which is operated as a reinforcing column and is equipped with a falling film evaporator, as well as column packs with structured packing, which produce 4 theoretical plates. Column K2a is operated at the top with a direct condenser consisting of a packed column with packed bed with total catch cup, Umpumpkreis and external heat exchanger. The column K2a is operated at an absolute top pressure of 0.8 bar, 263 K head temperature and 393 K bottom draw temperature.

Overhead of the column K2a becomes the stream 9 obtained, which is metered as described above as a recycle stream in the reactor R1a. The reflux ratio at the top of the column K2a is adjusted so that the current 9 Contains 0.1% 2M3BN.

About the bottom of the column K2a be 52 kg / h of a stream 1b obtained containing 0.3% BD, 0.1% C2BU, 76% pentenenitriles and in addition the catalyst components.

electricity 1b will be within the step (2) in a distillation column K2b driven, which is operated in driven mode and is equipped with falling film evaporator, top condenser with post-condenser and column internals with structured packing that produce 4 theoretical plates. The column is operated at an absolute top pressure of 70 mbar, 333 K top temperature and 373 K bottom draw temperature.

At the column K2b the gaseous top takeoff becomes electricity 11 recovered (40 kg / h) containing 0.4% BD, 54% 2M3BN and 42% T3PN and to a lesser extent E2M2BN and Z2M2BN among other pentenenitrile isomers.

In the column K2b 3 kg / h of a catalyst stream are driven, containing in total 45% pentenenitriles, 1.5% Ni (0) and the chelating ligand obtained, for example, by reacting nickel (0) (cyclooctadienyl) ₂ complex with the chelate phosphite 2. At the column K2b is the bottom of the catalyst stream 10 containing 1.2% Ni (0), 0.3% 2M3BN and 17% residual pentenenitriles. The current 10 is partially returned to the reactor R1 (14 kg / h) (stream 10a ). Another part (electricity 10b ) (3.8 kg / h) is a regeneration according to DE-A-103 51 002 fed to in the hydrocyanation of 3-pentenenitrile according to the DE-A-102 004 004 683 or optionally recycled to the hydrocyanation of BD according to the inventive method.

The current 11 gets in one step (3) to a distillation column K3 driven, which is equipped with circulation evaporator and overhead condenser and with structured packing that produce 45 theoretical plates. The column K3 is operated at an absolute top pressure of 1.0 bar, 395 K head temperature and 416 K bottom draw temperature.

In the column K3 24 kg / h recycle stream 5 from the column K5 in step (5) containing 70% T3PN, 14% 2M3BN and 7% Z2M2BN as well as minor amounts of other pentenenitrile isomers.

At the top of the column K3 30 kg / h of a stream 13 containing 1% T3PN, 85% 2M3BN, 8% Z2M2BN and in total 3% BD and C2BU besides other pentenenitrile isomers and VCH. The reflux ratio of column K3 is adjusted so that 1% T3PN is obtained overhead.

About the bottom of the column K3 be 38 kg / h of the stream 12 containing in total 97% T3PN, C3PN and 4PN and about 10 ppm 2M3BN and about 2% E2M2BN and in small amounts of MGN and other pentenenitrile isomers.

In Example 2 is for the isomerization of the chelated phosphite-based nickel (0) complex used as catalyst, as for the hydrocyanation of BD described in this example.

The current 13 gets in one step (4) along with a catalyst recycle stream 3a and a catalyst replenishment stream into a reactor R2, carried out as a compartmented reactor with tube characteristics and equipped with a preheater, with which the reaction mixture is heated to 383 K. 12 kg / h of a mixture with 20% T3PN, 3% 2M3BN and other pentenenitrile isomers, 71% Li gandgemisch and 0.6% nickel (0) and a low content of catalyst degradation products are run as the sum of recirculation catalyst and fresh catalyst in the reactor R2.

As product of the reactor R2 43 kg / h of electricity 1 containing 53% T3PN, 12% 2M3BN, corresponding to a conversion of 80% 2M3BN.

electricity 1 gets in one step (5) in a distillation column K5 driven, which is equipped with falling film evaporator, top condenser, reflux divider, gaseous side draw in the bottom region of the column and column internals that produce 30 theoretical plates. The column is operated at an absolute top pressure of 377 mbar, 355 K top temperature and 368 K bottom draw temperature.

In column K5 is recovered via bottom of the recovered catalyst stream 3 (11 kg / h) containing 20% T3PN in addition to other pentenenitriles, about 1% MGN and 0.6% Ni (0) and 54% ligand. A small part (electricity 3b ) is discharged to limit the accumulation of catalyst deactivating components and MGN. To supplement the discharged amount of catalyst so much fresh catalyst containing 40% pentenenitrile isomers, 1.2% Ni (0) and 55% ligand mixture, metered that the Ni (0) content in the catalyst feed to the reactor R2 is maintained at 0.6% ,

In column K5 becomes overhead a stream 4 containing (1.4 kg / h) containing in total 18% BD and C2BU, 45% 2M3BN, 28% Z2M2BN, and small amounts of vinylcyclohexene (VCH). The reflux ratio of column K5 is adjusted so that 10 ppm T3PN in the stream 4 are included. The deduction amount of electricity 4 from the top of the column K8 is adjusted so that in the top draw stream 13 the distillation column K3 in total 10% Z2M2BN and VCH are included.

In column K5 is via the gaseous side draw a stream 5 obtained (24 kg / h), which in addition to 3-pentenenitriles essentially contains the unreacted in the isomerization 2M3BN and liquid after condensation is returned to the column K3 as described above.

Example 3:

Example 3 is based on 5 clarified.

In Example 3, a catalyst system based on nickel (0) complexes with a mixture of ligands is used for the hydrocyanation of butadiene. The ligand mixture for hydrocyanation contains about 60 mol% of tri (m / p-tolyl) phosphite and 40 mol% of the chelate 2.

• (1) 6 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1a,
• (2) 6 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1b,
• (3) 25 kg/h handelsübliches BD zu R1a, enthaltend 0,25% C2BU, das durch Kontakt mit Aluminiumoxid behandelt wurde, um Wasser und Stabilisator TBC zu entfernen,
• (4) 2 kg/h rückgeführtes BD aus Kolonne K2a in Schritt (2) zu R1a (Strom 9), so dass als gesamter BD-Zulauf zum Reaktor R1 ein Strom von 27 kg/h enthaltend 98% BD und in Summe 2% C2BU und 1-Buten erhalten wird,
• (5) 14 kg/h Nickel(0)-Katalysatorlösung zu R1a, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 10a aus der Kolonne K2b

In one step (1) the following streams are run in a system of two reactors R1a and R1b each of 12 l volume, each equipped with a nozzle, pulse exchange tube, external pumping circulation and in a heat exchanger located in Umpumpkreislauf to dissipate the reaction energy and are heated to 363 K:

• (1) 6 kg / h of liquid, unstabilized hydrogen cyanide freed of water by distillation to R1a,
• (2) 6 kg / h of liquid, unstabilized hydrogen cyanide freed from water by distillation to R1b,
• (3) 25 kg / h of commercial BD to R1a containing 0.25% C2BU treated by contact with alumina to remove water and TBC stabilizer.
• (4) 2 kg / h of recycled BD from column K2a in step (2) to R1a (current 9 ), so that the total BD feed to the reactor R1 is a stream of 27 kg / h containing 98% BD and a total of 2% C2BU and 1-butene,
• (5) 14 kg / h of nickel (0) catalyst solution to R1a obtained as stream as described in this example below 10a from the column K2b

The withdrawn from the reactor R1b stream 8th (54 kg / h) contains in total 4% BD and C2BU, corresponding to a conversion of 94% BD, and in total 74% pentenenitriles, of which 33% T3PN, 37% 2M3BN and small amounts of Z2M2BN and E2M2BN, other pentenenitrile isomers, and the catalyst components and catalyst degradation products and MGN.

electricity 8th gets in one step (2) supplied in a distillation column K2a, which is operated as a reinforcing column and is equipped with a falling film evaporator, as well as column packs with structured packing, which produce 4 theoretical plates. Column K2a is operated at the top with a direct condenser which consists of a packed column with packed bed with total catch cup, Umpumpkreis and external heat exchanger. The column K2a is operated at an absolute top pressure of 0.8 bar, 263 K head temperature and 393 K bottom draw temperature.

Overhead of the column K2a becomes the stream 9 obtained, which is metered as described above as a recycle stream in the reactor R1a. The reflux ratio at the top of the column K2a is adjusted so that the current 9 Contains 0.1% 2M3BN.

About the bottom of the column K2a be 52 kg / h of a stream 1b obtained containing 0.3% BD, 0.1% C2BU, 76% pentenenitriles and in addition the catalyst components.

electricity 1b will be within the step (2) in a distillation column K2b driven, which is operated in driven mode and is equipped with falling film evaporator, top condenser with post-condenser and column internals with structured packing that produce 4 theoretical plates. The column is operated at an absolute top pressure of 70 mbar, 333 K top temperature and 373 K bottom draw temperature.

At the column K2b the gaseous top takeoff becomes electricity 11 recovered (40 kg / h) containing 0.4% BD, 54% 2M3BN and 42% T3PN and to a lesser extent E2M2BN and Z2M2BN among other pentenenitrile isomers.

In the column K2b 5 kg / h of a catalyst stream are driven, as described in Example 1 according to DE-A-102 004 004 683 described as bottom withdrawal of the column K4 from step (4) of Example 2, containing in total 45% pentenenitriles, 1.1% Ni (0), 38% ligand mixture and about 12% ADN.

At the column K2b is the bottom of the catalyst stream 10 containing 1.2% Ni (0), 0.3% 2M3BN and 17% residual pentenenitriles. The current 10 is partially returned to the reactor R1 (14 kg / h) (stream 10a ). Another part (electricity 10b ) (3.8 kg / h) is a regeneration according to DE-A-103 51 002 fed to be used in the hydrocyanation of 3-pentenenitrile according to DE-A-102 004 004 683.

The current 11 gets in one step (3) to a distillation column K3 driven, which is equipped with circulation evaporator and overhead condenser and with structured packing that produce 45 theoretical plates. The column K3 is operated at an absolute top pressure of 1.0 bar, 395 K head temperature and 416 K bottom draw temperature.

In the column K3 28 kg / h recycle stream 5 from column K6 in step (6) containing 72% T3PN, 15% 2M3BN and 8% Z2M2BN as well as minor amounts of other pentenenitrile isomers.

At the top of the column K3 30 kg / h of a stream 13 containing 1% T3PN, 85% 2M3BN, 8% Z2M2BN and in total 3% BD and C2BU and other pentenenitrile isomers. The reflux ratio of column K3 is adjusted so that 1% of 3PN is obtained overhead.

About the bottom of the column K3 be 38 kg / h of the stream 12 containing in total 97% T3PN, C3PN and 4PN and about 10 ppm 2M3BN and about 2% E2M2BN and in small quantities MGN and other pentenenitrile isomers.

In Example 3, a catalyst system based on nickel (0) complexes with a mixture of ligands is used for the isomerization of 2M3BN to T3PN. The ligand mixture for isomerization (hereinafter referred to as isomerization ligand) contains mixed phosphite ligands of class P (OR) (OR ') (OR'') with randomly distributed R, R', R '' from the group phenyl, m-tolyl, p -Tolyl, o-tolyl, wherein more than 80 mole% of the sum of the radicals R, R ', R "are m-tolyl and p-tolyl radicals. Such ligand mixtures are obtained by reacting a mixture of m- and p-cresol (with a mixing ratio of 2: 1) of m- versus p-cresol with a phosphorus trihalide. Zinc chloride is used as the promoter for the isomerization reaction as in US 3,676,481 . US 3,852,329 and US 4,298,546 described.

The current 13 gets in one step (4) along with a catalyst recycle stream 3a and a catalyst replenishment stream into a reactor R2, carried out as a compartmented reactor with tube characteristics and equipped with a preheater, with which the reaction mixture is heated to 383 K. 12 kg / h of a mixture with 20% T3PN, 3% 2M3BN and other pentenenitrile isomers, 71% isomerization ligand and 0.6% nickel (0) and a low content of catalyst degradation products are fed into reactor R2 as the sum of recycled catalyst and fresh catalyst.

As product of the reactor R2 43 kg / h of electricity 1 containing 53% T3PN, 12% 2M3BN, corresponding to a conversion of 80% 2M3BN.

electricity 1 gets in one step (5) moved to an evaporator stage B5, which is equipped with forced circulation evaporator and top condenser. The evaporator stage B5 is operated at an absolute pressure of 510 mbar, 403 K sump discharge temperature and 366 K condensation temperature.

In evaporator stage B5, the recovered catalyst stream is returned via bottom 3 (11 kg / h), containing 20% T3PN in addition to other pentenenitriles, about 10 MGN and 0.5% Ni (0) and 61% ligand mixture. A small part (electricity 3b ) is discharged to limit the accumulation of catalyst deactivating components and MGN. To supplement the discharged amount of catalyst so much fresh catalyst is added, containing about 15% pentenenitrile, about 2.0% Ni (0), about 70% isomerization and the Promtor zinc chloride in a concentration, the molar ratio of ZnCl ₂ to nickel (0) of about 5 corresponds to maintaining the Ni (0) content in the catalyst feed to reactor R2 at 0.6%.

In the evaporator stage B5, the power is at the top condenser 2 (25 kg / h) containing 1% BD, 68% T3PN, 16% 2M3BN and other pentenenitriles and small amounts of VCH.

electricity 2 gets in one step (6) in the distillation column K6 driven, which is operated as a boost column and equipped with circulation evaporator, top condenser, and column internals that produce 30 theoretical plates. The column is operated at an absolute top pressure of 340 mbar, 357 K top temperature, 313 K in the condenser and 373 K bottom draw temperature.

At the Condenser of the column K6 is about 100 standard l / h of a gas phase Stream, which consists essentially of BD.

In column K6 is a current at the top condenser as a liquid phase 4 containing (1.1 kg / h) containing in total 5% BD and C2BU, 50% 2M3BN, 30% Z2M2BN, and small amounts of vinylcyclohexene (VCH). The reflux ratio of the column K6 is adjusted so that 1 ppm T3PN in the stream 4 are included. The deduction amount of electricity 4 from the top of the column K6 is adjusted so that in the feed to the reactor R2 in total 10% Z2M2BN and VCH are included.

In column K6, a current is generated via the bottom 5 obtained (24 kg / h), in addition to 3-pentenenitriles in essence contains the unreacted in the isomerization 2M3BN and is returned to the column K3 as described above.

Example 4:

Example 4 is based on 6 clarified.

In Example 3 is for the hydrocyanation of butadiene based on a catalyst system of nickel (0) complexes with a mixture of ligands. The ligand mixture for hydrocyanation contains about 80 mol% of tri (m / p-tolyl) phosphite and 20 mole% of the chelate phosphite 2 (see Example 2).

• (1) 5,2 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1a,
• (2) 4.0 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zu R1b,
• (3) 20 kg/h 1 BD als Strom 9 vom Kondensator des Verdampfers B1 in Schritt (2), enthaltend 92% BD, 2% T3PN, 4% 2M3BN und ca. 2% C2BU zu R1a,
• (4) 4,1 kg/h Nickel(0)-Katalysatorlösung zu R1a, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 3a aus der Verdampferstufe B5 in Schritt (5),
• (5) 3,7 kg/h Nickel(0)-Katalysatorlösung zu R1a, erhalten wie in Beispiel 3 gemäß der deutschen Patentanmeldung mit dem Titel „Verfahren zur Herstellung von Dinitrilen" der BASF AG (B03/0525) beschrieben als Sumpfabzug der Kolonne K4 aus Schritt (4) von Beispiel 2 erhalten wird, enthaltend in Summe 45% Pentennitrile, 1,1% Ni(0), 38% Ligandmischung sowie ca. 12% ADN.

In one step (1) The following streams are run in a system of three continuously operated stirred tanks R1a, R1b and R1c, each of volume 10 l, which are tempered to 373 K:

• (1) 5.2 kg / h of liquid, unstabilized hydrogen cyanide freed of water by distillation to give R1a,
• (2) 4.0 kg / h of liquid, unstabilized hydrogen cyanide freed of water by distillation to R1b,
• (3) 20 kg / h 1 BD as electricity 9 from the condenser of the evaporator B1 in step (2) containing 92% BD, 2% T3PN, 4% 2M3BN and about 2% C2BU to R1a,
• (4) 4.1 kg / h of nickel (0) catalyst solution to R1a obtained as stream as described in this example below 3a from the evaporator stage B5 in step (5) .
• (5) 3.7 kg / h nickel (0) catalyst solution to R1a, obtained as described in Example 3 according to the German patent application entitled "Process for the preparation of dinitriles" BASF AG (B03 / 0525) as the bottom draw of the column K4 from step (4) of Example 2, containing in total 45% pentenenitriles, 1.1% Ni (0), 38% ligand mixture and about 12% ADN.

Of the Reactor R1c is used as a post-reactor with the effluent from reactor R1b operated at 353K.

The withdrawn from the reactor R1c stream 8th (37 kg / h) contains 1% BD, corresponding to a conversion of 98% BD, and in total 82% pentenenitriles, of which 36% T3PN, 44% 2M3BN and small amounts of Z2M2BN and E2M2BN, as well as the catalyst components and catalyst degradation products and MGN and others pentenenitrile isomers.

electricity 8th gets in one step (2) supplied in an evaporator stage B1, which is equipped with a circulation evaporator. The evaporator stage B1 is operated at the top with a condenser, which is flushed with condensed material from the return tank. The evaporator stage B1 is operated at an absolute top pressure of 0.6 bar, 253 K condensation temperature and 363 K bottom draw temperature.

In the condensate collector the evaporator stage B1 are dosed 19.5 kg / h of commercial BD, containing 0.25% C2BU treated by contact with molecular sieve, wherein the water content of the BD used to less than 10 ppm by weight of water was removed.

From the condensate tank of the evaporator stage B1 is electricity 9 withdrawn as the sum of recycled and freshly metered butadiene and returned to the reactor R1a as previously described.

About the bottom of the evaporator stage B1 37 kg / h of a stream 11b obtained, which contains 1% BD, 82% pentenenitriles and in addition the catalyst components.

electricity 11b gets in one step (4) in a tempered to 383K reactor R2, run as a stirred tank with downstream residence time, with 2M3BN is isomerized in the presence of the nickel catalyst to T3PN.

In the reactor R2 is a pentenenitrile recycle stream 5 driven (10 kg / h) in step (6) in column 6 as the bottom product, containing 60% 2M3BN, in total 10% T3PN with further pentenenitrile isomers and VCH and in small amounts of BD.

From reactor R2 becomes a stream 1 (45 kg / h) containing 62% T3PN and 14% 2M3BN, corresponding to a conversion of 70% 2M3BN to T3PN, as well as the catalyst components.

electricity 1 gets in one step (5) into an evaporator stage B5, which is equipped with falling-film evaporator and condenser and at an absolute pressure of 50 mbar and 393 K bottom discharge temperature is operated.

The condenser of the evaporator stage B5 becomes a current 2 recovered (38 kg / h) containing 91% pentenenitrile isomers and about 1% BD and to a lesser extent E2M2BN, Z2M2BN and VCH.

At the evaporator stage B5 is the bottom of the catalyst stream 3 (7.2 kg / h) containing 1.2% Ni (0), 0.1% 2M3BN and 15% residual pentenenitriles. The current 3 is partially (electricity 3a ) returned to the reactor R1 (4.1 kg / h). The rest (electricity 3b ) is fed to a regeneration according to DE-A-103 51 002, and can be used after regeneration, for example in a hydrocyanation of 3-pentenenitrile as in Example 2 according to DE-A-102 004 004 683 or as a catalyst in the process according to the invention for the hydrocyanation of butadiene, optionally be reused after removal of zinc chloride.

The current 2 gets in one step (3) to a distillation column K3, which is equipped with forced circulation evaporator and overhead condenser and column internals that produce 30 theoretical plates. The column K3 is operated at an absolute top pressure of 120 mbar, 334 K top temperature and 352 K bottom draw temperature.

About the top of the column K3 10 kg / h of a stream 13 containing 5% T3PN, 60% 2M3BN, 4% Z2M2BN and in total 4% BD and C2BU and in the remainder predominantly VCH. The reflux ratio of the column K3 is adjusted so that 5% T3PN are obtained overhead.

About the bottom of the column K3 be 27 kg / h of the stream 12 containing in total 98% T3PN, C3PN and 4PN and about 1000 ppm 2M3BN and about 2% E2M2BN.

electricity 13 gets in one step (6) in a distillation column K6 driven, which is operated as a reinforcing column and equipped with forced circulation evaporator, top condenser, reflux divider, and column internals with structured packing, which produce 15 theoretical plates. The column K6 is operated at an absolute top pressure of 380 mbar, 361 K head temperature and 365 K bottom take-off temperature.

In column K6 becomes overhead a liquid stream 4 (0.6 kg / h) containing in total 4% BD and C2BU, 54% 2M3BN, 38% Z2M2BN, and 2.5% vinylcyclohexene (VCH). The deduction amount of electricity 4 from the top of the column K6 is adjusted so that the top takeoff stream 13 the column K3 in total 30% Z2M2BN and VCH are included. In column K6, a gaseous stream is obtained on the overhead condenser operated as a partial condenser (195 standard l / h), which contains essentially BD.

In column K6, the power is taken over the bottom 5 obtained (9.4 kg / h), in addition to 3-pentenenitriles essentially contains the unreacted in the isomerization 2M3BN and is returned to the isomerization reactor R2.

Example 5:

Example 5 is based on 7 clarified.

In Example 5 is for the hydrocyanation of BD is a catalyst system based on nickel (0) complexes used with a mixture of ligands. The ligand mixture for Hydrocyanation contains about 80 mol% of tri (m / p-tolyl) phosphite and 20 mol% of the chelate phosphonite 1 (see Example 1).

• (1) 18 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff zugleichen Teilen auf die Reaktoren R1a und R1b,
• (2) 62 kg/h BD als Strom 9 vom Kopf des Verdampfers B1 in Schritt (2), enthaltend 87% BD, 3% T3PN, 6% 2M3BqN und ca. 2% C2BU zu Reaktor R1a,
• (3) 61 kg/h Nickel(0)-Katalysatorlösung, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 3a aus der Verdampferstufe B5 in Schritt (5) zu Reaktor R1a,
• (4) 6,7 kg/h Nickel(0)-Katalysatorlösung zu R1a, erhalten wie in Beispiel 1 gemäß der deutschen Patentanmeldung mit dem Titel „Verfahren zur Herstellung von Dinitrilen" der BASF AG (B03/0525) 1 beschrieben als Sumpfabzug der Kolonne K4 aus Schritt (4) von Beispiel 2 erhalten wird, enthaltend in Summe 45% Pentennitrile, 1,1% Ni(0), 38% Ligandmischung sowie ca. 12% ADN zu Reaktor R1a, wobei der Butadien-Strom und der Katalysatorstrom vor dem Kontaktieren mit Cyanwasserstoff vorgemischt werden.

In one step (1) The following streams are run in a system of two continuously operated stirred tanks R1a and R1b, each of 50 l volume, which are heated to 363 K:

• (1) 18 kg / h of liquid, unstabilized hydrogen chloride liberated by distillation of water, equal parts to the reactors R1a and R1b,
• (2) 62 kg / h BD as electricity 9 from the head of the evaporator B1 in step (2) containing 87% BD, 3% T3PN, 6% 2M3BqN and about 2% C2BU to reactor R1a,
• (3) 61 kg / h of nickel (0) catalyst solution obtained as stream as described below in this example 3a from the evaporator stage B5 in step (5) to reactor R1a,
• (4) 6.7 kg / h of nickel (0) catalyst solution to R1a, obtained as described in Example 1 according to the German patent application entitled "Process for the preparation of dinitriles" by BASF AG (B03 / 0525) 1 as bottom withdraw the column K4 from step (4) of Example 2 containing in total 45% pentenenitriles, 1.1% Ni (0), 38% ligand mixture and about 12% ADN to reactor R1a, the butadiene stream and the catalyst stream being premixed prior to contacting with hydrogen cyanide ,

The withdrawn from the reactor R1b stream 8th (177 kg / h) contains 11% BD, corresponding to a conversion of 66% BD, and in total 64% pentenenitriles, of which 32% T3PN, 30% 2M3BN and small amounts of Z2M2BN and E2M2BN and other pentenenitrile isomers, as well as the catalyst components and catalyst degradation products.

electricity 8th gets in one step (2) supplied in an evaporator stage B1, which is equipped with a falling film evaporator. The evaporator stage B1 is operated at the top with a condenser, which is flushed with condensed material from the return tank. The evaporator stage B1 is operated at an absolute top pressure of 1.3 bar, 278 K condensation temperature and 403 K bottom draw temperature.

In the condensate collector the evaporator stage B1 are metered 37 kg / h of commercial BD, containing 0.25% C2BU treated by contact with molecular sieve, wherein the water content of the BD used to less than 5 ppm by weight of water was removed and wherein the stabilizer contained in the BD used TBC in concentrations in ppm scale in the condensate tank and the condenser flushing circuit arrives.

From the condensate tank of the evaporator stage B1 is electricity 9 withdrawn as the sum of recycled and freshly metered BD and returned to the reactor R1a as previously described.

About the bottom of the evaporator stage B1 are 152 kg / h of a stream 11b obtained containing 0.9% BD, 16% 2M3BN, 51% T3PN and other pentenenitrile isomers and, in addition, the catalyst components. The composition of the bottom product of the evaporator stage suggests a degree of conversion of 50% 2M3BN to T3PN in the bottom of the evaporator B1.

electricity 11b gets in one step (5) into an evaporator stage B5, which is equipped with falling-film evaporator and condenser and is operated at an absolute pressure of 260 mbar and 383 K bottom take-off temperature.

The evaporator stage B5 becomes a current 2 gaseous recovered (83 kg / h) containing 93% pentenenitrile isomers and about 1% BD and to a lesser extent E2M2BN, Z2M2BN and VCH. electricity 2 is transferred to the distillation column K3 in step (3) hazards.

At the evaporator stage B5 is the bottom of the catalyst stream 3 (69 kg / h) containing 0.6% Ni (0), 2% 2M3BN and 42% residual pentenenitriles. The current 3 For the most part, it is recycled to reactor R1 (61.4 kg / h) (stream 3a ). The rest (electricity 3b ) is fed to a regeneration according to DE-A-103 51 002, and can be used, for example, in the hydrocyanation of 3-pentenenitrile, as described in Example 1 according to DE-A-102 004 004 683.

The current 2 gets in one step (3) passed in gaseous form to a distillation column K3, which is equipped with Zwangsumalufentspannungsverdampfer and top condenser and with structured packing that produce 30 theoretical plates. The column K3 is operated at an absolute top pressure of 80 mbar, 375 K head temperature and 343 K bottom draw temperature.

At the top of the column K3 36 kg / h of a stream 13 containing 15% T3PN, 64% 2M3BN, 3% Z2M2BN and in total 4% BD and C2BU, the remainder containing predominantly VCH. The reflux ratio of the column K3 is adjusted so that 15% T3PN are obtained overhead.

About the bottom of the column K3 47 kg / h of the stream 12 containing in total 98% T3PN, C3PN and 4PN as well as 100 ppm 2M3BN and approximately 1% E2M2BN.

electricity 13 gets in one step (6) in a distillation column K6 driven, which is operated as a reinforcing column and equipped with forced circulation evaporator, top condenser, reflux divider, and column internals with structured packing that produce 45 theoretical plates. The column is operated at an absolute top pressure of 320 mbar, 288 K condensation temperature and 363 K bottom draw temperature.

In column K6 becomes overhead a liquid stream 4 (6.8 kg / h) containing in total 10% BD and C2BU, 80% 2M3BN, 8% Z2M2BN, and 0.5% vinylcyclohexene (VCH). The deduction amount of electricity 4 from the top of the column K6 is adjusted so that the top takeoff stream 3 the column K3 in total 15% Z2M2BN and VCH are included. In column K6, a gaseous stream is obtained on the head condenser operated as a partial condenser (263 standard l / h), which essentially contains BD.

In column K6, the power is taken over the bottom 5 obtained (28.7 kg / h), in addition to 3-pentenenitriles essentially contains the unreacted in the isomerization 2M3BN and is returned to the hydrocyanation reactor R1.

Example 6:

Example 6 is based on 8th clarified.

In Example 8 is for the hydrocyanation of BD is a catalyst system based on nickel (0) complexes used with chelate phosphonite 1 as ligand (see Example 1).

• (1) 16 kg/h flüssiger, unstabilisierter, durch Destillation von Wasser befreiter Cyanwasserstoff,
• (2) 55 kg/h BD als Strom 9 vom Kopf des Verdampfers B1 in Schritt (2), enthaltend 87% BD, 3% T3PN, 6% 2M3BN und ca. 2% C2BU,
• (3) 10 kg/h Nickel(0)-Katalysatorlösung, erhalten wie in diesem Beispiel weiter unten beschrieben als Strom 3a aus der Verdampferstufe B5 in Schritt (5), enthaltend in Summe 42% Pentennitrile, 23% Ligand, 0,9% Nickel(0), sowie jeweils ca. 10 % ADN und MGN,
• (4) 4 kg/h Nickel(0)-Katalysatorlösung zu R1, enthaltend in Summe 45% Pentennitrile, 1,5% Ni(0) und 48% Ligand.

In one step (1) The following streams are run in a continuously operated stirred tank R1 of 30 l volume, which is heated to 363 K:

• (1) 16 kg / h of liquid, unstabilized hydrogen cyanide freed by the distillation of water,
• (2) 55 kg / h BD as power 9 from the head of the evaporator B1 in step (2) containing 87% BD, 3% T3PN, 6% 2M3BN and about 2% C2BU,
• (3) 10 kg / h of nickel (0) catalyst solution obtained as stream as described below in this example 3a from the evaporator stage B5 in step (5) containing in total 42% pentenenitriles, 23% ligand, 0.9% nickel (0), and in each case about 10% of ADN and MGN,
• (4) 4 kg / h of nickel (0) catalyst solution to R1, containing in total 45% pentenenitriles, 1.5% Ni (0) and 48% ligand.

The withdrawn from the reactor R1 stream 8th (89 kg / h) contains 17% BD, corresponding to a conversion of 71% BD, and a total of 73% pentenenitriles, of which 32% T3PN, 36% 2M3BN and small amounts of Z2M2BN and E2M2BN, as well as the catalyst components and catalyst degradation products.

electricity 8th gets in one step (2) supplied in an evaporator stage B1, which is equipped with a falling film evaporator. The evaporator stage B1 is operated at the top with a condenser, which is flushed with condensed material from the return tank. The evaporator stage B1 is operated at an absolute top pressure of 1.3 bar, 278 K condensation temperature and 403 K bottom draw temperature.

In the condensate collector the evaporator stage B1 34 kg / h commercial BD dosed, containing 0.25% C2BU treated by contact with alumina, wherein the water content of the BD used to less than 10 ppm by weight Water and the TBC content less than 10 ppm was reduced.

From the condensate tank of the evaporator stage is electricity 9 withdrawn as the sum of recycled and freshly metered butadiene and returned to reactor R1a as previously described.

About the bottom of the evaporator stage B1 76 kg / h of a stream 5 obtained containing 0.8% BD, 12% 2M3BN, 69% T3PN and other pentenenitrile isomers and, in addition, the catalyst components. The composition of the bottom product of the evaporator stage corresponds to a degree of conversion of 75% 2M3BN to T3PN in the bottom of the evaporator stage B1.

electricity 5 gets in one step (5) into an evaporator stage B5, which is equipped with falling film evaporator and condenser and is operated at an absolute pressure of 220 mbar and 381 K bottom pull temperature.

The evaporator stage B5 becomes a current 2 gaseous recovered (58 kg / h) containing 97% pentenenitrile isomers and about 1% BD and to a lesser extent E2M2BN, Z2M2BN and VCH.

At the evaporator stage B5 is the bottom of the catalyst stream 3 (17 kg / h) containing 0.9% Ni (0), 0.3% 2M3BN and 42% residual pentenenitriles. The current 3 is largely returned to the reactor R1 (10 kg / h) (stream 3a ). The rest (electricity 3b ) is supplied to a regeneration according to US 2003/0100442 and can be used after the regeneration in a hydrocyanation of 3-pentenenitrile or in the process according to the invention in the hydrocyanation step of BD.

The current 2 is condensed and liquid in one step (3) was driven to a distillation column K3, which is equipped with forced circulation evaporator and top condenser and with structured packing that produce 50 theoretical plates. The column K3 is operated at an absolute top pressure of 200 mbar, 342 K top temperature and 366 K bottom draw temperature.

At the head of columns K3 becomes a stream 4 containing 10% BD, 18% Z2M2BN, 68% 2M3BN and other pentenenitrile isomers and VCH. The reflux ratio of column K3 is adjusted so that the top draw stream contains 18% Z2M2BN.

At a liquid side offtake of the column K3 8 kg / h of a stream 13 containing 0.5% T3PN, 85% 2M3BN, 5% Z2M2BN, 10% BD current 13 is returned to the evaporator stage B1.

About the bottom of the column K3 47 kg / h of the stream 12 containing in total 98% T3PN, C3PN and 4PN as well as 100 ppm 2M3BN and approximately 1% E2M2BN.

All subsequent experiments were carried out in a protective gas atmosphere.

Nickel (0) - [o-isopropylphenoxy _0.8 -m- / p-tolyl _3.2 -phosphite] ₁₈ , (isopropyl catalyst in short); corresponds to a solution of 1.0 wt .-% nickel (0) with 19 wt.% 3PN and 80 wt.% o-Isopropylphenyl _0.8 -m- / p-tolyl _3.2- phosphite.

Examples of continuous Hydrocyanation of BD to 2M3BN / 3PN

Example 7 (comparison): (Relationship BD / HCN = 1.4: 1)

2.11 mol of wet and stabilized butadiene (100 ppm water, 100 ppm TBC), 1.55 mol of HCN and 14 mmol of Ni in the form of the isopropyl catalyst are fed per hour into a pressure reactor (pressure: 15 bar, Temperature inside 105 ° C, Residence time: approx. 40 min / reactor). The HCN turnover is according to measurement analysis quantitative (titration according to Vollhard). The ratio 2M3BN / 3PN is determined the reaction output GC chromatographic (GC area percent). The relationship 2M3BN / 3PN was 1.95 / 1. The loss of Ni (0) based on formed Value product was: 0.58 kg Ni (0) / t desired product (3PN / 2M3BN).

Example 8: (Ratio BD / HCN = 1.4: 1)

2.13 mol over a bed dried from molecular sieve 4Å Butadiene, 1.53 moles of HCN and 14 mmol of Ni in the form of isopropyl catalyst are fed per hour into a pressure reactor (pressure: 15 bar, Temperature inside 105 ° C, Residence time: approx. 40 min / reactor). The HCN turnover is according to measurement analysis quantitative (titration according to Vollhard). The ratio 2M3BN / 3PN is determined the reaction output GC chromatographic (GC area percent). The relationship 2M3BN / 3PN was 1.95 / 1. The loss of Ni (0) based on formed Value product was: 0.14 kg Ni (0) / t desired product (3PN / 2M3BN).

Example 9: (Ratio BD / HCN = 1.2: 1)

2.09 mol over a bed alumina-dried butadiene, 1.67 moles of HCN and 14 mmoles of Ni in the form of the isopropyl catalyst per hour in a pressure reactor fed in (pressure: 15 bar, temperature inside 105 ° C, residence time: about 45 minutes / reactor). The HCN conversion is quantitative according to measurement analysis (titration after Vollhard). The ratio 2M3BN / 3PN of the reaction output is determined GC chromatography (GC area percent). The relationship 2M3BN / 3PN was 1.95 / 1. The loss of Ni (0) based on formed Value product was: <0.10 kg Ni (0) / t desired product (3PN / 2M3BN).

Examples of continuous Isomerization of 2M3BN to 3PN

Example 10:

A Hydrocyanierungsaustrag prepared according to Example 8 is collected and freed from excess BD by distillation. The mixture thus obtained is heated to 130 ° C for one hour. After 0, 30 min and after 1 h GC samples are removed from the reaction mixture and analyzed by GC chromatography (GC area percent).

Examples of misisomerization from 2M3BN to 2M2BN by recycled hydrocyanation catalyst

Example 11:

Out a catalyst reservoir, filled at t = 0 h with 649 g of fresh isopropyl catalyst, are continuously taken 100g isopropyl catalyst and together with 2.14 moles over a bed alumina-dried butadiene, and 1.67 moles of HCN per Hour fed into a pressure reactor (pressure: 15 bar, temperature inside 105 ° C, Residence time: approx. 45 min / reactor). The HCN conversion is quantitative according to measurement analysis (Titration to Vollhard). The value product is continuously using a Sambaydestillation separated from the catalyst and the thus obtained return catalyst returned to the reservoir. The reaction is operated for 50 h and the still hydrocyanierungsaktiven Catalyst due to incipient formation of the minor component 2M2BN, discharged. The catalyst thus obtained becomes isomerization experiments subject:

Example 12 (comparison):

10 g isomerization catalyst are supplemented with 2M3BN (15 g) and at 120 ° C for 5 h annealed. Sales of 89% 2M3BN (GC area percent) show 8.6% Missisomers (2M2BN).

Example 13:

To the isomerization catalyst from example 11 (100 g) becomes n-heptane (100 g) and adiponitrile (50 g) and the mixture is stirred (15 min). After a phase separation (30 min), the lower phase is drained off. Part of the upper phase (50 g, heptane + isomerization catalyst) is concentrated on a rotary evaporator. The residue (14 g, isomerization catalyst) is supplemented with 2M3BN (21 g) and annealed at 120 ° C for 5 h. At 95% conversion 2M3BN (GC Area Percent) show 2.0% false isomers (2M2BN).

Example 14:

The Residues of the upper phase from the first extraction (Example 12) again with adiponitrile (37.5 g) and stirred. To the phase separation is again concentrated a part of the upper phase on a rotary evaporator and the residue (9.3 g) supplemented with 2M3BN (14 g). After 5 h at 120 ° C shows up a 2M3BN turnover of 94% (GC area%) and a misisomerization of 0.7%.

Examples of misisomerization from 2M3BN to 2M2BN by continuously used isomerization catalyst

Example 15:

In a 2 l reactor, 300 g of isopropyl catalyst are charged and continuously mixed with 450g / h 2M3BN and heated to 130 ° C. at a residence time of 60 min is withdrawn continuously reactor contents and worked up by distillation and remaining in the bottom isomerization catalyst recycled. The Reaction is operated for 50 h and the isomerization still active Catalyst due to onset of misisomerization of 2M3BN discharged. The catalyst thus obtained is subjected to isomerization experiments:

Example 16:

10 g isomerization catalyst are supplemented with 2M3BN (15 g) and at 120 ° C for 5 h annealed. With a conversion of 90% 2M3BN (GC area percent), 9.8% Missisomers (2M2BN).

Example 17:

To the isomerization catalyst of Example 16 (100 g) is added n-heptane (100 g) and adiponitrile (50 g), and the mixture is stirred (15 minutes). After a phase separation (30 min), the lower Phase drained. A portion of the upper phase (50 g, heptane + isomerization catalyst) is concentrated on a rotary evaporator. The residue (14 g, isomerization catalyst) is supplemented with 2M3BN (21 g) and annealed at 120 ° C for 5 h. With a conversion of 93% 2M3BN (GC area percent), 2.4% false isomers (2M2BN) show.

Example 18:

The Residues of the upper phase from the first extraction (Example 17) again with adiponitrile (37.5 g) and stirred. To the phase separation is again concentrated a part of the upper phase on a rotary evaporator and the residue (9.3 g) supplemented with 2M3BN (14 g). After 5 h at 120 ° C shows up a 2M3BN conversion of 93% (GC area%) and a misisomerization of 0.6%.

Claims (16)

A process for the preparation of 3-pentenenitrile, characterized by the following process steps: (a) isomerization of a feedstock stream containing 2-methyl-3-butenenitrile to at least one dissolved or dispersed isomerization catalyst to a stream 1 containing the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, (b) distilling the stream 1 while receiving a stream 2 as a top product containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, and one stream 3 as the bottom product containing the at least one isomerization catalyst, (c) distilling the stream 2 while receiving a stream 4 as a top product, facing the stream 2 an (Z) -2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched, and a stream 5 as the bottom product, opposite the stream 2 to 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , is enriched, (d) distillation of the stream 5 while receiving a stream 6 as a bottom product containing 3-pentenenitrile and a stream 7 as a top product containing 2-methyl-3-butenenitrile. Process according to Claim 1, characterized in that the educt stream is obtained by the following process steps: (e) hydrocyanation of 1,3-butadiene over at least one hydrocyanation catalyst with hydrogen cyanide to obtain a stream 8th containing the at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile, 1,3-butadiene and hydrogen cyanide, (f) single or multiple distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile, (g) distillation of the stream 11 while receiving a stream 12 as a bottom product containing 3-pentenenitrile and a stream 13 as a top product containing 2-methyl-3-butenenitrile. A method according to claim 2, characterized in that process steps (d) and (g) are carried out in the same distillation apparatus, wherein the streams 6 and 12 and the streams 7 and 13 coincide. Method according to one of claims 2 or 3, dadaurch characterized in that the process steps (c) and (g) carried out in a common distillation column, wherein the process step (d) is omitted, the stream 2 from process step (b) and electricity 11 from process step (f) in process step (g) are guided, in process step (g) of the stream 4 as overhead product, containing (Z) -2-methyl-2-butenenitrile, the stream 12 as the bottom product containing 3-pentenenitrile and the stream 13 as a side draw stream containing 2-methyl-3-butenenitrile. Method according to one of claims 1 to 4, characterized in that in step (b) in stream 3 obtained at least one isomerization catalyst in the process step (a) is recycled. Method according to one of claims 1 to 5, characterized in that the method steps (b) and (c) are carried out together in a distillation apparatus, wherein the stream 3 containing the at least one isomerization catalyst as the bottom product, the stream 4 containing (Z) -2-methyl-2-butenenitrile as the top product and the stream 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile can be obtained on a side draw of the column. Method according to one of claims 1 to 5, characterized in that the method steps (a), (b) and (c) are carried out together in a distillation apparatus, wherein the stream 4 containing (Z) -2-methyl-2-butenenitrile as overhead, the stream 5 containing 3-pentenenitrile and 2-methyl-3-butenenitrile are obtained on a side draw of the distillation apparatus and the isomerization catalyst remains in the bottom of the distillation column. Method according to one of claims 1 to 7, characterized that the isomerization catalyst nickel (0), a nickel (0) as Ligand complexing, trivalent phosphorus-containing compound and optionally containing a Lewis acid. Method according to one of claims 1 to 8, characterized the pressure and the temperature are adjusted in process step (b) be that the isomerization catalyst less active than in Process step (a) or not active. Method according to one of claims 1 to 8, characterized that the hydrocyanation catalyst and the isomerization catalyst are identical. Method according to one of claims 1 to 10, characterized in that the reactant stream is obtained by the following process steps: (a *) isomerization of a feed stream containing 2-methyl-3-butenenitrile, at least one dissolved or dispersed isomerization catalyst into a stream 1 containing the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, (b *) distillation of the stream 1 while receiving a stream 2 as a top product containing 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z) -2-methyl-2-butenenitrile, and one stream 3 as the bottom product containing the at least one isomerization catalyst, (c *) distillation of the stream 2 while receiving a stream 4 as a top product, facing the stream 2 an (Z) -2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched, and a stream 5 as the bottom product, opposite the stream 2 to 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in the stream 2 , enriched, (d *) distillation of the stream 5 while receiving a stream 6 as a bottom product containing 3-pentenenitrile and a stream 7 as a top product containing 2-methyl-3-butenenitrile. (h *) catalyst regeneration to increase the nickel (0) content of the partial streams 14 out of electricity 3 respectively. 16 out of electricity 10 generating eunes electricity 18 , (i *) optionally with the addition of a diluent F to power 18 generating electricity 19 , (j *) Extraction of the stream 18 , if necessary electricity 19 , with respect to the catalyst components and / or interfering component (s) by addition of a dinitrile stream 20 and a hydrocarbon stream 21 generating two immiscible phases 22 and 23, wherein current 22 the major part of the catalyst components and electricity 23 contains the major part of the interfering component, (k *) distillative separation of the hydrocarbon from the catalyst components from electricity 22 generating a current 25 containing the major part of the catalyst components and optionally partial or total recycling of the stream 25 in the process steps (a *) or (e *), (e *) hydrocyanation of 1,3-butadiene on at least one hydrocyanation with hydrogen cyanide to obtain a stream 8th containing the at least one hydrocyanation catalyst, 3-pentenenitrile, 2-methyl-3-butenenitrile, 1,3-butadiene and hydrogen cyanide, (f *) one or more distillation of the stream 8th while receiving a stream 9 which contains 1,3-butadiene, a stream 10 containing the at least one hydrocyanation catalyst and a stream 11 containing 3-pentenenitrile and 2-methyl-3-butenenitrile, (g *) distillation of the stream 11 while receiving a stream 12 as a bottom product containing 3-pentenenitrile and a stream 13 as a top product containing 2-methyl-3-butenenitrile. Method according to claim 11, characterized in that that in process stage h *) the increase in the nickel (0) catalyst content carried out by reductive catalyst regeneration. Method according to one of claims 11 or 12, characterized that one is the catalyst guide operates as two separate catalyst circuits, the one Cycle the stages e *) and f *) and the other cycle the stages a *), b *) and c *). Method according to one of claims 11 to 13, characterized that is used as feed stream to e *) stabilizer-containing butadiene. Method according to one of claims 11 to 14, characterized in that as catalysts phosphites of the formula Ib P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) with R ¹ : aromatic radical having a C ₁ -C ₁₈ alkyl substituent in the o-position to the oxygen atom which connects the phosphorus atom with the aromatic system, or with an aromatic substituent in o-position to the oxygen atom, the phosphorus atom with the aromatic system, or with an aromatic system fused in the o-position to the oxygen atom which links the phosphorus atom to the aromatic system, R ² : aromatic radical having a C ₁ -C ₁₈ -alkyl substituent in the m-position to the oxygen atom which combines the phosphorus atom with the aromatic system, or with an aromatic substituent in m-position to the oxygen atom connecting the phosphorus atom to the aromatic system, or with an m-position to the oxygen atom containing the phosphorus atom with the aromatic system connects, fused aromatic system, wherein the aromatic radical in o-position to the oxygen atom, the phosphorus atom with the aromatic R ³ : aromatic radical having a C ₁ -C ₁₈ alkyl substituent in p-position to the oxygen atom connecting the phosphorus atom to the aromatic system or having an aromatic substituent in p-position to the oxygen atom linking the phosphorus atom to the aromatic system, wherein the aromatic radical in the position ortho to the oxygen atom which links the phosphorus atom to the aromatic system carries a hydrogen atom, R ⁴ : aromatic radical which is present in o, m and p Position to the oxygen atom connecting the phosphorus atom to the aromatic system, other than the substituents defined for R ¹ , R ² and R ³ , wherein the aromatic radical in the o-position to the oxygen atom, the phosphorus atom with the aromatic system is hydrogen, x: 1 or 2, y, z, p: independently of one another 0, 1 or 2, with the proviso that x + y + z + p = 3. Method according to one of claims 11 to 15, characterized in that as catalysts phosphites of the formula Ib P (OR ¹ ) _x (OR ² ) _y (OR ³ ) _z (OR ⁴ ) _p (Ib) wherein R ¹ , R ² and R ^{3 are} independently selected from o-isopropylphenyl, m-tolyl and p-tolyl, R ^{4 is} phenyl; x is 1 or 2, and y, z, p are independently 0, 1 or 2, with the proviso that x + y + z + p = 3; and mixtures thereof, ie mixtures of 2 or more, preferably 2 to 10, more preferably 2 to 6 of the compounds of formula Ib, is used.