DE1618549A1 - Process for the dimerization of organic compounds - Google Patents

Description

Folder 21211 - Dr.F / hr
Case 0.19241

BBSOHRBIBUNO to the patent application of

BSfERIAL CHEMICAL INDUSTRIES LIMITBD, London, Great Britain,

concerning:

"Process for the dimerization of organic compounds"

Priority"

April 18, 1966 - »No. 16 906 - Great Britain ~

© The invention relates to the dimerization I of organic compounds which are acceptors reactions in Michael, in particular e _f ß ~ unsaturated olefiniseh worshipers, amides and nitriles.

The expression "acceptors in Miol & eftl reactions * means compounds which have & i @ a® group of the general formula" -OCR-, in which the group R ®iss @ is those which activate the double-layered structure. Example © for; CLOHE connections eind in ^tt Org @ nio Name Eeactlone "voa X && uoh and Kazm, 1964," John Wiley g · Bonn on page; 516 _^? ». Ame

: Λ618549

Reactions in Organic Chemistry "by A.R. Surrey, 2nd edition, 1961, Academic Press, pages 173 and 174, and in "Name Index of Organic Reactions" by J.B «öowan and Φ.S. Wheeler, 1960, Longman, pp. 169-172 find eu. Such compounds are hereinafter referred to as "Michael acceptors".

It has now been found that Michael acceptors are among Use of a catalyst can be dimerized from a mixture or from a compound of a Metallealz or -komplex and a metal alkyl or -aryl consists.

Thus, according to the invention, a method for the dimerization of Michael acceptors is proposed, which is carried out thereby is that they are brought into contact with .a catalyst which is composed of a mixture or a compound consists of a metal alkene or complex and an aluminum alkyl or aryl.

The method according to the invention is particularly focused on dimerization of α, ß-olefinically unsaturated esters, amides and nitriles and especially applicable to the dimerization of acrylonitrile.

The catalyst consists of a mixture or a compound of a salt or complex of a metal and a metal alkyl or aryl. The salt of the metal can be a salt an inorganic acid such as a halide, a salt of an organic acid such as the salt of an aliphatic acid such as acetic acid, the salt an organic enol or phenol, for example acetylacetone or p ~ Krβsol, or a salt of an acidic ionic

BATH

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.18-18549 - 3-

be dew resin. The metal complex may consist of a Tf-bound metal complex, such as BB _y of a complex with cyclooctadiene or acrylonitrile, or au · a complex with koordlnativen metal-oxygen-metal-sulfur, metal-nitrogen or metal-phosphorus bonds, such as from a complex in which the ligand is propylene oxide, diethyl sulfide, dimethyl sulfoxide, triethylamine or triphenyl phosphine. The metal in the metal salt or complex can be, for example, copper or one of the transition metals, such as cobalt, iron, nickel, titanium, vanadium or chromium. As specific examples of metal salts or complexes, copper d

(I) -haloride, copperClIJ-aoetylacetonate, cobalt (II) -aoetylacetonate, nickel (II) -acetylacetonate, OhrQm (III) -acetylacetonate, iron (III) -acetylaeetonate, copper (II5-glycinate, Nidcel (O) -biB - (cycloocta-1 _f 5-diene>, Palladiuia (II) -ohloridtrläthylamin, copper (II) -acetat, titanium tetrachloride or tetra-n-butyltitanate.

When aluminum alkyls or aryls may be used, for example, the aluminum alkyls, in which di © alkyl group is preferably a lower alky! Is group, for example a Alkylgrupp © having 1 to 4 carbon atoms, and the Aluminiumaryl @, ± n Danen the Ary! Group one phenyl -, substituted © is phenyl, diphenyl or naphthyl group. _{Triethyaluminium 9} triisobutylaluminum, diethylaluminum chloride, ethylaluminum dichloride, tryphenylaluminum or thoxydiethylaluminum should be mentioned as special examples of aluminum alkyls or aryls.

Cocatalysts such as those used in Ziegler reactions ₉ can also be used.

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The catalyst can also be a mixture of the metal! ζ or complex and the metal alkyl or aryl in various Behavioral sneezes exist. There can be a ratio of metal ales or complexes to metal alkyl or aryl of 10: 1 to 1:10 can be used. However, it is preferred to use the two components in approximately the same proportions to use. Desired case β can do both Metallaalz or the metal complex as well as the metal alkyl or -aryl be a mixture of such components.

The catalyst can be used in an amount from 0.001 to 10.0 Wt .- ^, based on the weight of the Miohael acceptor used, be used.

Ee is already known to dimerize, for example, acrylonitrile through the use of certain catalysts, such as, for example, phosphines. In such dimerizations, however, the main product is the dimer, the molecule of which is formed by linking the ß-carbon atom of the olefinic compound of one molecule of the monomer with the α-carbon atom of the olefinic bond of another molecule of the monomer. Such a dimerization is conveniently referred ^{to as n} head-to-tail ^{n dimerization.} Thus, under the influence of a phosphine catalyst, the acrylonitrile mainly gives 1,3-dioyanobutene-3. Using the catalyst system of the present invention, however, there is a much greater tendency for "head-to-head" dimerization to occur. Thus, if acrylonitrile is used, significant amounts of 1,4-diyanobutene-2 or 1,4-disloyanobutene-1 are obtained. In certain cases, particularly when a copper salt is used as the metal salt, the dimeric product consists almost entirely of the "head-to-head dimer".

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If the monomer to be dimerized, for example, is an α, β-olefinically unsaturated ester, amide or nitrile, then the "head-to-head * * dimerization gives a molecule with a linear carbon structure, whereas the" head-to-tail "dimerization gives a molecule In certain cases the linear dine compounds are industrially more valuable than the branched dimeric compounds, for example, the linear 1,4-dicyanobutenes obtained by the process of the present invention in the dimerization of acrylonitrile can easily be obtained Adiponitrile can be hydrogenated. Hexamethylene diamine can easily be obtained from adiponitrile by hydrogenation. This diamine is an industrially important intermediate for the production of synthetic linear fiber-forming polyamides. For example, this diamine can be obtained by polycondensation with adipic acid. an-Sohwanz ^ Dimer of acrylonitrile, 1,3-dicyanobutene-3, in the hydrogenation of a-methylglutaronitrile, which upon further hydrogenation ₉ 2-Methylpentaraethylendiamin yields a compound of considerably lesser industrial importance as hexamethylenediamine.

Ss was also fnd @ s _g dae® can be hydrogenated in the execution of erfindungsgamässen traversed in the presence of hydrogen or a hydrogen delators tin cheap rate of the product, ie, "that the olefinic double bond, which is present in the dimer duroh be replaced a saturated carbon bond can. This represents a further feature of the invention "Thus, when acrylonitrile geaäss the present traversing» _f n mm Preparation of 4 ~ i ~ DiayÄno is dimerislert and these Eeftktion in Otgenwmxt

is carried out by hydrogen, then the product can sum part, consist of adiponitrile.

The inventive method can, either in the liquid Phase or in the gas phase, Bs is preferably carried out under anhydrous conditions. Bs an inert solvent can also be used. ale Examples of suitable solvents are the saturated aliphatic and cycloaliphatic solvents ^ Hydrocarbons, aromatic hydrocarbons, ohlo- " riert ^ solvents and "ether" as special examples Bensoli toluene and chloroform should be mentioned for solvents.

If desired, the process can be carried out in an inert Atmosphere, as s.B ·. under a nitrogen atmosphere, if desired it can also be carried out under pressure are executed. Press τοη at & osphärisohem Druok to 30 atmospheres can be used.

The reaction may be carried out to 200 ° C +, but in many cases it 1st sweok- ψ bulky to carry out the process at ordinary temperature at a temperature of -60 tone. Response times of 2 to 30 minutes can be used. Once the reaction has progressed to the desired degree, the dinerized product or - in cases in which hydrogen is present as a reactant - the hydrogenated product is isolated by some sweeping measure.For example, dilute acid can be added to the catalyst »Whereupon the reaction milk is filtered to remove any polymeric material and the product of the unchanged export material and byproducts

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is separated off by fractional distillation.

The invention is further illustrated by the following examples explained. The examples are not to be interpreted in a limiting sense. All parts and details are given in Gto weight auegedrttokt, unless otherwise stated. The ratio of parts by weight to parts by yolua is expressed in kgtl

In all examples, the reactions were under one Run a nitrogen atmosphere unless otherwise specified iet.

example 1

Hydrogen was -aoetylacetonat by a Gemieoh of 0.255 parts of copper (II), 0.25 parts Aluainiuatriisobutyl and 8 parts of acrylonitrile in 10 parts by volume of chloroform for 20 hours at 1O ⁰ C hindurohgeleitet. At the end of the reaction, 2.3 parts of 1,4-uioyanobutene-2 were obtained after unreacted acrylonitrile had been driven off.

Example 2

A mixture of 0.167 parts of cobalt (II) aeetylaoetonate, 0.16 part of alumina triisohutyl and 3 parts of acrylonitrile in 4 parts by volume of benzene was stirred for 48 hours kept at room temperature. At the end of the reaction, the product was subjected to "Gae ^? LUeei ^ © ite chromatography, and it was shown that it is made from non-converted acrylonitrile, the cia-l, 4-dicyanobutene-l and trane-l, 4-dioyanobutene-2 contained, consisted »

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Example 3

A mixture of 0.6 part of nickel (II) aoetylaoetonate, 0.45 part of aluminum triobutyl and 8 parts of acrylonitrile in 5 parts by volume of toluene was ^{kept at 160 0} O for 24 hours in a closed tube. The product consisted of unreacted acrylonitrile, a small amount of polymer em- material _Ψ cis-l ^ -dicyanobutene-l, trans-dicyanobutene-2 and methylene glutaronitrile.

Example 4

A mixture of 0.48 parts of chromium (III) acetylacetonate, 0.42 parts Aluminiumtriieobutyl and 8 parts of acrylonitrile in 5 parts by volume of toluene was 24 hours in a sealed tube to 16O ⁰ C held The product consisted of non-em acrylonitrile uragesetzt , a small amount of polymeric material, cis ~ 1,4-dicyanobutene-l, trans-1,4-dicyanobutene-2 and methylene glutaronitrile.

Example 5

A mixture of 0.4 parts of iron acetylacetonate (III) 0.32 parts Aluminlumtriisobutyl and 8 parts of acrylonitrile in 5 parts by volume of toluene was "kept for 24 hours at 160 ⁰ C, the product consisted of non-uaigesetztem acrylonitrile polymeric material , cie-l, 4-dicyanobutene-l and methylene glutaronitrile.

Example 6

0.1 part by volume of aluminum triisobutyl was added at -10 ° C. to a solution of 0.1 part by volume of titanium tetrahydrofuran and 0.5 part by volume of dimethyl sulfoxide in 5 parts by volume of toluene. 5 parts by volume of acrylonitrile were then added , and the mixture was left at room temperature for 15 hours and then 2 1/2 hours

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maintained at 7O ⁰ C. The mixture was brought to room temperature

cooled, and with 2 parts by volume of aqueous 2N hydrochloric acid decomposed. The organic layer contained ole- and trans-1,4-dleyanobutene-1 and a lane l, 4-Dieyanobut®n-2 and Adiponitrile what by gas / liquid chromatography was determined. The remainder of 0.15 was filing, when the solvent and the unreacted acrylonitrile removed under vacuum.

Example 7 G

0.1 Vol.teil triisobutylaluminum was added to a solution of 0.1 Vol.teil fetra-n-butyl titanate in 5 parts by volume of toluene at -1O ⁰ C. 5 parts by volume of acrylonitrile were added and the mixture was kept at room temperature for 18 hours under Rübxea. The mixture was decomposed with 2 parts by volume of aqueous 2N hydrochloric acid, whereupon the organic layer was separated off. Gas-liquid chromatography of the organic layer showed the presence of cis- * and trans-1,4-dicyanobutene-1 in. Since the solvent and the unreacted acrylonitrile were distilled off under vacuum, a residue of 0.19 ropes was obtained "'■ '''λ

Example 8

0.2 parts Vanadylaoatylaoetoaat were dissolved in 9 ropes toluene under stirring and under nitrogen, was cooled and the solution to -1O ⁰ C. Ban has a bargain AIumittiumtriisobutyl dissolved in 5 filing of toluene was added. The Sticketoffatmosphäre was replaced with hydrogen, followed by 4 feile acrylonitrile was added dropwise at -1O ⁰ O have been specified. The temperature was set at 2O ⁰ O stelgengelasfien "and the stirred mixture was heated for 2 hours to reflux.

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Gas-liquid chromatography was used in the reaction mixture obtained . ois-1,4-Dioyanobutene-2 found.

Example 9

Hydrogen was passed through a mixture of 0.255 filing copper (II) ~ ao9tylacetonat, O _t 25 parts of aluminum triisobutyl in 10 parts by volume und.5 parts Aorylnitril chloroform at 1O ⁰ C passed 20 hours. At the end of the reaction, 2.3 parts of an oily residue were obtained after the non-converted aorylnitrile had been driven off. When left to stand, O ₉ 4 parts of a crystalline pesticide separated out from the residue, which was determined by determining the melting point ( 76 ⁰ G) and it was shown by gas liquid chromatography that it was 1,4-dioyanobutene "

Pat «tan sayings: BATH ORIGINAL

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Claims (1)

Claims characterized by being the same Brings catalyst into contact, the au © eiü @ m © & ®r a combination of a Met & lleaXs or and consists of an aluminum alkyl or aryl, 2ο method according to claim I ₅ thereby gekenfigeiehnet, that used as a Miohael acseptor acrylonitrile 3ο method according to 'claim 1 or 2, characterized in that dasβ the catalyst from an Öemiech or a compound of a metal & la or »complex and an aluminum alkyl " 4ο method according to one of claims 1 to 3, characterized characterized in that the alkyl group of the alurainium alkyl Contains 1 to 4 carbon atoms 5 · Method according to one of Claims 1 to 4 »thereby characterized that, as aluminum alkyl, aluminum triieo- butyl is used. · '. "" 6. The method according to any one of claims 1 to 5, characterized in that the catalyst comprises the two components contains in approximately equal amounts. 7. The method according to any one of claims 1 to 6, characterized in that the reaction in the presence of hydrogen or a hydrogen donor is carried out BADORiGfNAL 109808/21 4 5 8. The method according to any one of claims 1 to 7, characterized characterized in that the reaction is inert in the presence Solvent is running. .Rl IfT, BATH ORIGINAL 109808 / 2U5