DE2052730A1 - Process for the preparation of aliphatic aminonitriles - Google Patents

Description

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, DR.-INQ. H. FINCKE β Munich β. ηι / τ

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IMPBRIAI CHEMICAL INDUSTRIES LIMITED London, United Kingdom

Process for the production of τοη aliphatic aminonitriles

Addition to patent application P 19 04 613 * 0 Priority t 27. 10. 1969 - Great Britain

The invention, which is an improvement or modification of the in the German patent application F 19 04 613 * 0 described Processes refers to a process for the preparation of τοη aliphatic aminonitriles, in particular Aminocapronitrile, which Muflerst valuable · intermediates for the production of fiber-forming polymers such as S.B · polyamides «sindο

In the German patent application P 19 04 613 * 0 a process for the production of aliphatic diamines is described, in which an aliphatic dinitrile under pressure and at an elevated temperature in the presence of a Ziegler catalyst, which is a metal from Group VIII de contains, is treated with hydrogen. In the description, the use of Ziegler catalysts is recommended,

101122/21 ORIGINAL INSPECTED

the particular combinations of aluminum tralkylenes and cobalt alkanoates, some of the examples that aminonitriles can be formed as by-products.

The invention now relates to a process for the preparation of aliphatic aminonitriles, in which an aliphatic dinitrile is treated with hydrogen under pressure and at an elevated temperature in the presence of a Ziegler catalyst consisting of a combination of an aluminum tralkyl and cobalt alkanoate The characteristic is that the parameters of temperature, pressure, temperature and amount of catalyst are selected so that the molar yield of aliphatic aminonitriles exceeds 50 pounds.

The Ziegler used in the process according to the invention Catalyst can be a «combination of the following substances *

A a KObaltftlkmnoat, i.e. a cobalt ale of a fatty acid, especially a fatty acid with 5 or more carbon atoms, dl a straight or a tertiary chain on * «Eist, as s.B. Taleric acid, isoraleric acid, hexanoic acid or Ootanaäurei

B "is an aluminum trialkyl, for example triethyl-, tri-alumina -.- or tributylaluminium and ge # eb« n «nf» lls

einXljputd, who with the combination of A and B can coordinate * Solohe Llganden are e.B.i Xther, like », B. Diethyl ether and tetrahydrofuran} Alcohol · like s, B. Ethyl alcohol, methyl alcohol and butyl alcohol} Phenols such as s.B. phenol and

ORIQINAL INSPECTED

Amines, especially tertiary amines, for example triethylamine and pyridine; Phosphines such as triphenylphosphine and 1,2-bis (diphenylphosphino) ethane; Sulfides, such as s.B. Thiodioxanj and nitriles such as acetonitrile and benzonitrile.

The Ziegler catalyst is prepared by bringing components A and B together, optionally in the presence of a solvent, such as B. Hydrocarbon such as cyclohexane or benzene, or an ether such as tetrahydrofuran, and the reaction proceed either with a free blanket of warmth or under cooling. The word "combination" simply means that components A and B are brought together.

The parameters selected to carry out the procedure depend on the particular catalyst used. In particular, the activity of the catalyst is determined by the selection de · ligands (C) influenced, where; those, who Strong sheet metal donors are, more powerful, tend to be a to give complete hydrogenation to the diamines al * the. weak electron donors.

For any particular catalyst, the rate of reaction is reproducible and easy to determine; the to achieve of more than 50 # aminonitrile necessary conditions can be easily determined. The. Parameters of the temperature, the pressure, the time and the amount of catalyst can, for example can be selected according to one of the following methods.

1. The amount of catalyst can be limited and / or the. Temperature can be kept at such a level that the hydrogenation progresses gradually,

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there is a period during which aminonitrile represents the main constituent of the resulting mixture if the reaction is terminated within this period of time will. By sampling and analyzing during the hydrogenation can be a favorable time for the Termination to be determined.

2. The amount of hydrogen can be limited to no more than 60 % of that amount which is necessary for complete hydrogenation to the diamine at the selected temperature and amount of catalyst.

3. With a combination of methods 1 and 2, the amount of catalyst, the amount of hydrogen and the temperature fttr any combination of these parameters is so limited that a continuous hydrogenation takes place, the au can be canceled at a point in time if amino nitrate represents the main ingredient in the resulting mixture.

Especially · Mjgler-Katalyeatoren, welohe in the case of the invention Methods that can be used are combinations of the following substance *

a cobalt salae clay fatty acids with 5 to θ carbon atoms b-Aluminum trialkyls with 2 to 5 carbon atoms in one

Any alkyl group
ο Trialkylamines with 2 to 5 carbon atoms in one

any alkyl group. *

When using these catalysts in erfindungsgemäien method has been found fled DA8 aminonitrile · are obtained in yields are f "the essential Over 50" if

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Ale molar amount of the cobalt catalyst 0.1 to 2 9 & ·

of the dinitrile, excess water

• toff old a pressure τοη 28 to 42 atm is used, the temperature is 100 to 130 ⁰ C, and the hydrogenation is continued for 1 st to 60 st depending on the amount of the catalyst ·

The molar amount of the cobalt catalyst is 0.1 to 1? T uerjettlgsa dee dinitrile, the temperature is 100 to 130 ⁰ C, the hydrogenation is allowed to proceed until hydrogenation no longer takes place, the hydrogenation pressure: 28 to SBO atm, and the amount "Of the hydrogen" is less than 60 & preferably 40 to 50 & the amount required for complete hydrogenation under these conditions.

tfungoo can carry out the process of finding in paragraphs or kqn ^ inuierlibh be executed »with the appropriate conditions given above can be used.

For operation wise in the heat, the Siegler-Katalyeaior et al. The su hyoriertnde vitrll la a heated car tairen, from which the humid help tides 3troee of an inert gas, wif bB Stiokstoff t, has been expelled. The autoclave can then be closed and pressurized with hydrogen and maintained at the temperature at which hydrogen uptake takes place. After the hydrogenation has ended, the amino nitrll formed can be purified in a known manner, for example by distillation. . . j

The dinitrile and the

ator continuously into a hedging eone I will »ia'wtloher sit hit hydrogen Ixt contact

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are brought, the crude reduction product continuously sucked off from the zone and the aminonitrile therefrom is isolated · The catalyst and the non-umgeetste Material can optionally be returned to the reduction zone will. . -

The invention is explained in more detail by the following examples, in which the prosent information is expressed in weight.

example 1

2.286 g of cobalt (II) oaproate, 8 g of triethylamine and 50 g of adiponitrile were introduced into an autoclave. The autoclave was carefully flushed with nitrogen and 0.5 ml of aluminum triisobutyl was added to the stirred contents under nitrogen, whereupon 1 ml of methylcyelohexane was added. The autoclave was flushed with hydrogen and then * ^{heated to 125 0} O with continuous stirring, the hydrogen pressure being set to 42 atmospheres after the temperature had reached; had been. The reaction was continued for 48 hours under the same conditions. The autoclave was cooled and the pressure was drained, gas / liquid chromatography gave 1.19 g of hexamethyleneimine, 11.7 g of adiponitrile, 7.9 g of hexamethylene diamine and 30 g of aminocapronitrile; The conversion of the adiponitrile was 76.6%. The molar Auebeuten bftrugen 76 f Amlnooapronitril, 19% hexamethylenediamine un * d 2,4? T hexamethyleneimine.

Example 2

1.55g slnsr 20 it-Igsn (0/0) dissolution of cobalt (II) -2- * ethyl oxanoate in toluene, 50 g of adiponitrile and 5 ml of toluene were added and 0 * 55 ml Triäthylemln in sinsm autoclave with one capacity of 300 ml gsmisoht. after, dsm rinsing with Hydrogen were 0.5 ml of aluminum trisobutyl and 0.5 ml

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Toluene was added while stirring under nitrogen. The mixture was flushed with Waeeeretoff, whereupon the autoclave was closed and old hydrogen was brought to 31.5 atmospheres. The contents were 48 et at a pressure of 43 * 75 atm to 45t5 and reacted at a temperature of 120 ⁰ C 125 ble Qae / yiüeeigkeit analysis of the product showed that less than 0.3 g nioht-umgesetetes Adiponitrll templates, and that 30 "2 g of aainooapronitrile, 17 * 3 g of hexamethylene diamine and 1.56 g of hexamethylene imine were formed" wai a prosentual yield of 57.5, 32 respectively. 3.5 jC corresponded, with 9914 pounds of the adiponitrile had been consumed.

Example 3

15.65 g of a 20% (O / O) ToXuoIIösung of cobalt (II) -2-ethylhexanoate were mixed with 6 g of toluene and 4.6 g of triethylamine in an autoclave and flushed with nitrogen. 5 ml of aluminum-trisobutyl were slowly mixed in with stirring and under nitrogen, and then 49 "1 g of adiponitrile were added to this prepared catalyst under 3tioketoff" , 0 to 38.5 atmospheres and 100 ⁰ C are set. Samples of the liquid reaction chemical were taken after 3 hours / 15 min, after $ st / 40 years in the above & 8 hours / 50 min. Ctae / flftsit ~ analysis showed that the Oswlohts ratio of aminocapronyltril ml hexamethylenediamine 17, 6 and so on. 3.3, and with an AdlponitriX conversion of 23. «69 bsw. 88 ^. * 5ine more ftaaktlonsperlodt of 3 st / 50 AFTT min at 30.1 and 100 ⁰ O gave "In Terhältaie of 0.7, where the entire adiponitrile consumed w *".

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Claims (7)

PATENT CLAIMS 1. Process for the reduction of aliphatic dinitriles with hydrogen under pressure and at elevated temperature in the presence of a Ziegler catalyst, which consists of an Alurainiumtrlalkyl and a Kobaltaikanoat "according to patent ... (file number P 19 04 613" O) characterized "that the reaction conditions, ie the temperature, the pressure, the reaction time and the amount of catalyst are chosen so that the molar yield of aliphatic! Aminonitrll Exceeds 50 % . 2. The method according to claim 1 »characterized» that the Ziegler catalyst consists of a combination of an aluminum tralkyl and a cobalt salt of a fatty acid having 5 or more carbon atoms consists. 3. The method according to claim 1 or 2 »characterized» that the Zlegler catalyst consists of a combination of a cobalt alkanoate and triethyl, triisopropyl or tri-butyl aluminum consists. 4. The method according to any one of claims 1 to 3, characterized in » that the Ziegler catalyst additionally contains a ligand, the E & it of the combination of aluminum triacyl and cobalt alkanoate can coordinate. 109827/7198 5. The method according to claim 1, characterized in that the Ziegler catalyst consists of the following combination: a) a cobalt salt of a fatty acid with 5 to 8 carbon atoms, b) an aluminum trialkyl with 2 to 5 carbon atoms in one each alkyl group, and c) a trialkylamine having 2 to 5 carbon atoms in each Alkyl group. 6. The method according to claim 5, characterized in that the molar amount of the cobalt catalyst is 0.1 to 2 % that of the dinitrile, that excess hydrogen is used at 28 to 42 atmospheres, that the temperature is 100 to 130 ⁰ C, and that the hydrogenation is continued for 1 to 60 hours depending on the amount of the catalyst. 7. The method according to claim 5, characterized in that the molar amount of the cobalt catalyst is 0.1 to 1 % that of the dinitrile, that the temperature is 100 to RO ⁰ C, that the hydrogenation is allowed to proceed until no more hydrogenation takes place that the hydrogen pressure is 42 to 420 atmospheres and that the amount of hydrogen is less than 60 % and preferably 40 to 50 % of that amount which is necessary for complete hydrogenation under these conditions. 109827/2198