DE1109674B - Process for the preparation of liquid oligomers from 1,3-dienes - Google Patents

Description

Process for the preparation of liquid oligomers from 1,3-dienes It is known that one of aluminum alkyls or aluminum alkyl halides and Chromium or titanium halide catalysts that convert 1,3-dienes to cyclic hydrocarbons, such as cyclododecatriene (1,5,9) or cyclooctadiene (1,5) polymerize.

So in the German Auslegeschrift 1 050 333 a method for Manufacture of cyclododecatrienes (1,5,9) among other cyclic hydrocarbons with at least 8 carbon atoms and at least two double bonds in the ring. It converts 1,3-dienes in the presence of a catalyst composed of titanium halides and alkyl aluminum halides are formed. In this process, yields of up to achieved to about 800 / o. In addition, high molecular weight, partly rubbery, undistillable polymers that are insoluble in many common solvents that can significantly disrupt the continuous implementation of the process.

Based on the suggestion of the older, unpublished patent 1 086 226 the formation of the high molecular weight polymers mentioned can be suppressed, if compounds with a semipolar double bond are added to the catalyst.

It has now been found that liquid oligomers of 1,3-dienes in the presence of one containing a titanium compound and an organic aluminum halide Let the catalyst be produced advantageously if you also use a metal from I. to III. Group of the Periodic Table or any substance related to the organic Aluminum halides K omplexverbindungen forms, applies, but the use a complex-forming compound that contains a semipolar double bond is excluded is when butadiene- (1,3) in the presence of catalysts from aluminum alkyl halides and titanium halides is reacted.

A benefit of the new process is that the proportion of the resulting high molecular weight, rubbery polymers is kept low. This makes the continuous Implementation of the procedure is made much easier. The next to the cyclic trimers of the starting materials generally in minor amounts with the higher, partly liquid, highly unsaturated and probably also cyclic Oligomers are namely in the common solvents, such as ethers, hydrocarbons, Chlorinated hydrocarbons or carbon disulfide, easily soluble. Through their presence in the reaction mixture the viscosity of the reaction solution is increased only insignificantly. In contrast to this, the rubber-like, higher polymers in solvents such as Benzene, making the whole reaction mixture is transformed into a highly viscous mass that is difficult to handle.

Another advantage of the new process is that now Alkyl aluminum dihalides can then also be used as catalyst components can, if one uses titanium tetrahalides for the preparation of the catalyst. According to German Auslegeschrift 1 050 333, alkylaluminum dihalides can be used Use only if a titanium halide of a lower valence grade is used as the second Component is used. Catalysts made from alkyl aluminum dihalides and a titanium tetrahalide, the 1,3-dienes convert almost exclusively into rubbery high molecular weight products. Surprisingly, you now get with the mentioned additives trimers of the starting materials in yields that are sometimes even better than with the known methods. The use of alkyl aluminum dihalides is desirable insofar as smaller amounts of valuable substances are used for their production Aluminum trialkyls are needed as For the production of Dialkyl aluminum halides.

Titanium tetrahalognides are therefore desirable starting materials for the catalyst manufacture because they are the most readily available titanium halides are. If, as in the known case, dialkyl aluminum halides and a titanium tetrahalide used, the yields increase with the use of additives according to the invention.

In addition to the cyclic trimers, the partly liquid, interfere with highly unsaturated and probably also cyclic higher oligomers the continuous implementation of the process is not and is also valuable intermediates for further reactions.

Finally, there is also the speed of reaction in the new way of working higher than with the known methods.

1,3-dienes suitable as starting materials are, for example, isoprene, 2,3-dimethylbutadiene- (1,3), cyclohexadiene- (1,3) and especially butadiene- (1,3). They do not need to be pure, but can also be mixed with others, under substances indifferent to the conditions of the procedure are used.

So can a gas mixture that can be obtained by dehydration of butane or Butene obtained can be used directly in the reaction.

Suitable titanium compounds are titanium (IV) acid esters, in particular those derived from lower alcohols, such as titanium tetramethylate, titanium tetraethylate and titanium tetrapropylate, also titanium tri and tetra halides, such as titanium trichloride, Titanium tribromide, titanium tetrabromide and especially titanium tetrachloride, as well as titanium ester halides, such as diethoxytitanium dichloride and triethoxytitanium chloride. But also organotitanium halides, such as bis-cyclopentadienyl titanium (IV) chloride and dialkyl titanium (IV) dihalides usable.

Compounds of the formula are used as organoaluminum components Al2RnX6-2 into consideration, where R is an aliphatic or aromatic radical, X is halogen and n is a number from 1 to 5. Suitable compounds include (C2 H5) 2 Al2 Cl4 (often simply referred to as ethyl aluminum dichloride), (C2 H5) 4 Al2 CI2 (also called diethyl aluminum chloride), (C2 Hó) 3Al2 C1 3 (ethyl aluminum sesquichloride), (C4H9) 2Al2Cl4, (C6Hs) Al2Cls and (C6 H5) 3Al2Cl3.

The preferred compounds are those containing lower alkyl groups with up to 6 carbon atoms or phenyl radicals and chlorine as halogen atom.

The additives mentioned reduce the tendency of the aluminum compound, To form high molecular weight products, degrade and at the same time promote the emergence of liquid oligomers. Suitable metals from I. to III. Periodic group Systems are, for example, lithium, sodium, potassium, rubidium, cesium, beryllium, Magnesium, calcium, strontium, barium, zinc, cadmium, aluminum, cerium, gallium, indium and thallium.

The compounds that complex compounds with organic aluminum halides must be able to fill the octet gap that the aluminum in the monomeric Has the form of the organic aluminum halides to fill up. Suitable complexing agents of this type are, for example, the salts of the alkali and alkaline earth metals, in particular whose Halides, also organic compounds of elements of V. and VI. Main group ' such as ether (e.g. diethyl ether, anisole, diphenyl ether), thioether (e.g. diethyl sulfide, Dibenzyl sulfide, diphenyl sulfide), amines, such as diphenylamine or dimethylaniline, or Phosphines such as tributylphosphine or triphenylphosphine. Heterocyclic compounds, in which one or more of the elements mentioned is a heterocyclic member Systems can also be used. Quinoline, carbazole, diphenyl oxide or phenothiazine, for example, are useful.

The molar ratio in which the substances mentioned in the formation of the Catalyst are used, is expediently titanium compound to organic Aluminum halide to complexing agent or metal such as 1: 2 2: 1 and is preferably within the limits of 1: 3 to 10: 1.5 to 50. The optimum quantitative ratio can be for a given organic aluminum halide and complexing agent or easily identify a given metal through experimentation. It is also possible, the defined complex compounds of aluminum alkyl halides and one of the to use the above complexing agents. Such complex compounds, as opposed to to the aluminum alkyl halides are usually no longer self-igniting, allow a safer handling of the catalyst than with the known methods.

Suitable solvents in the presence of which the process is expedient is carried out, are z. B.

Benzene, toluene, xylene, chlorobenzene, heptane, cyclohexane, isooctane and Cyclododecatriene (l, 5.9). It is recommended to use water-free and carefully cleaned Use solvents. The aromatic hydrocarbons are preferred. Mixtures of solvents can also be used with good success.

The solvent is generally used in 0.1 to 5 times Amount based on the 1,3-diene.

The process can be carried out within a wide temperature range, namely carry out approximately between -50 and +150 "C. The preferred reaction temperature lies between +20 and + 100 ° C.

The reaction is usually carried out under atmospheric pressure; but you can also work under reduced or increased pressure. That’s how it’s sometimes elevated pressures, for example up to 10 atm, are required when using low-boiling Used starting materials and applying increased reaction temperatures.

To carry out the process, the catalyst components, i.e. the titanium compound, the organic aluminum halide and the additive, expediently in the solvent provided for the reaction and in an inert gas atmosphere united and mixed. It is often advantageous to "develop" the catalyst first. This can be B. done by the catalyst components for some time in a Ball or vibrating mill thoroughly mixed. The optimal amount of time to mix depends, among other things, on the components used and can be defined by a Easily identify attempt. One can also develop the catalyst by just one or two of the catalyst components with the intended solvent for some time intimately mixed and the other components added to the suspension thus obtained, z. B. the additive gives.

The 1,3-diene is introduced into the catalyst mixture obtained, whereupon the reaction begins with considerable evolution of heat. The desired reaction temperature is made by appropriate supply of the starting material and, if necessary, by cooling adhered to. The reaction temperature is maintained to complete the reaction after the feed of the starting material has ended, it is expedient to keep it upright for some time. Then the catalyst is destroyed, e.g. B. by carefully adding a small amount Amount of water or an alcohol or by adding a larger amount of acetone the reaction mixture, whereby small amounts of high molecular weight products are separated off. After the catalyst has decomposed, the mixture is worked up in the usual way, z. B. by shaking with water and distillation of the organic phase their separation from the aqueous or, if the decomposition by alcohol or Water was made by distillation after separation of the solid constituents.

The process can also be carried out continuously without difficulty be, for example in a coiled pipe, which one end continuously the catalyst suspended in a solvent is fed in and into which one simultaneously the diene continuously presses in at the same end. The one at the other end of the snake tube exiting reaction mixture is used continuously to destroy the catalyst To methanol and then leads the product into a continuously operating A distillation column.

The lower, liquid oligomers obtainable by the process are valuable intermediates for organic syntheses. So they can be known in Hydrate manner, e.g. B. the cyclododecatriene- (l 5.9) to cyclododecane. The hydrogenated Products can in turn be converted into dicarboxylic acids, e.g. B. dodecane-1,12-diacid, or lactams, e.g. B. Lauryllactam convert. The latter are known to be valuable Basic materials for plastics, especially polyamides and polyesters.

The higher, liquid, highly unsaturated hydrocarbons are for example as starting materials for the production of textile or mineral auxiliaries or suitable as paint and plastic bases.

The parts given in the examples are parts by weight.

Example 1 1.14 parts of titanium tetrachloride, 2 parts of aluminum powder and 3.7 parts of ethylaluminum dichloride in 90 parts of benzene Grind for 10 hours. The resulting catalyst suspension is under an argon atmosphere into a stirred vessel equipped with a thermometer, reflux condenser and gas inlet tube convicted. One passes in a rapid stream of butadiene- (1,3), whereby the temperature rises rapidly to 50 "C. The temperature is kept at 50 to 55" C by cooling. After 35 minutes, 142 parts of butadiene have been taken up by the catalyst suspension been. The mixture is stirred for a further 30 minutes, then with 10 parts of methanol decomposed and distilled. 110 parts are obtained, corresponding to 78 ovo of the theory, Cyclododecatriene- (l, 5.9) with a boiling point of 85 "C / 7 Torr (n200 = 1.5074) and 32 parts, according to 220 / o of theory, partly more fluid, higher, more unsaturated Hydrocarbons that are easily soluble in common solvents.

Example 2 A catalyst suspension of 0.57 parts is prepared Titanium tetrachloride, 3 parts of ethylaluminum dichloride and 2 parts of finely ground Zinc in 90 parts. Add to mixture at 50 to 55 "C over the course of 90 minutes 243 parts of butadiene initiated. The mixture is worked as described in Example 1, and receives 191 parts, corresponding to 790 /, the theory, cyclododecatriene- (1,5,9) and 52 parts, corresponding to 21% of theory, of highly unsaturated hydrocarbons.

If other additives and, if necessary, a different solvent are used instead of zinc, the following results are obtained: Cyclo- Additive Amount of solution dodecatriene (Parts) (parts) medium (O / o der Theory) Magnesium 1 Benzene 70 Lithium 0.2 benzene 75 Sodium chloride 0.5 chlorine benzene 86 Example 3 A catalyst solution prepared from 0.57 parts of titanium tetrachloride, 3 parts of ethylaluminum dichloride and an organic complexing agent in 100 parts of chlorobenzene is introduced at 50 to 60 ° C. butadiene. The mixture is worked up as described in Example 1 and in addition to partially liquid, higher, highly unsaturated hydrocarbons, cyclododecatriene (l, 5.9) in the following yields, based on the converted starting material: Cyclo- Parts of complexing agent dodecatrien- (l, 5.9) (° / 0 of theory) 0.3 diethyl ether 67 1.3 anisole 76 2.0 diphenyl ether 58 1.0 diethyl sulfide 90 2.5 dibenzyl sulfide 83 2.5 diphenyl sulphide 77 2.0 diphenylamine 86 1,3 triphenylphosphine 63 1.0 phenothiazine 66 If one does not add the listed complexing agents, but otherwise proceeds as described, one obtains practically exclusively rubber-like, high molecular weight products.

Example 4 The procedure is as in Example 3, but using the catalysts and solvents shown in the table below: Parts | Organic | Parts | Additive solvent cyclododecatriene (l, 5.9) Aluminum halide (0/0 of theory) 3.0 | Ethyl aluminum dichloride 2.5 diphenyl sulfide cyclododeca- 65 triene- (1,5,9) 3.0 ethyl aluminum dichloride 2.5 diphenyl sulfide (200 / o benzene t 800 /, heptane 2.2 ethyl aluminum sesquichloride 1.0 diethyl sulfide chlorobenzene 92 2.2 ethyl aluminum sesquichloride 2.5 diphenyl sulfide chlorobenzene 92 1.4 diethyl aluminum chloride 2.5 l diphenyl sulfide chlorobenzene 87 Example 5 As described in Example 1, a catalyst suspension is prepared from 1.14 parts of titanium tetrachloride, 2.8 parts of diethylaluminum chloride and 0.66 parts of lithium chloride. The reaction with butadiene (1,3) gives, after work-up according to Example 1, cyclododecatriene (l, 5.9) in 86% yield.

When using 0.6 parts of sodium chloride as a complexing agent the yield 880 / o, while with the addition of 0.42 parts of sodium fluoride cyclododecatriene- (l, 5.9) in 840/0 but yield. Small amounts occur as by-products of partially liquid, highly unsaturated, higher hydrocarbons, the are readily soluble in common solvents.

Example 6 A catalyst suspension of 0.57 parts is prepared Titanium tetrachloride, 3 parts of ethylaluminum dichloride and 4.3 parts of cermetallic shavings in 90 parts of benzene by grinding in a ball mill for 3 hours. Into the mixture 164 parts of butadiene (1,3) are introduced in the course of 120 minutes. One works the mixture, as described in Example 1, and receives 131 parts, accordingly 800 /, the theory, Cyclododecatrien- (l, 5.9) and 33 parts, corresponding to 200/0 the Theory, higher, highly unsaturated hydrocarbons.

Example 7 A catalyst suspension consisting of 2.28 parts is prepared Titanium tetrachloride, 12 parts of ethylaluminum dichloride and 0.4 part of lithium in 140 Share benzene by ball milling for 3 hours. Into the mixture 100 parts of isoprene are entered at 45 to 50 C in the course of 3 hours, and the mixture is then stirred for a further 16 hours at this temperature. After The mixture is decomposed with 15 parts of methanol and then filtered distilled. 56.5 parts are obtained (65% of theory, based on converted isoprene) lower, liquid polymers in the boiling range 100 to 200 ° C / 5 Torr and 22 parts (25 ° / o) in the boiling range 150 to 250 ° C / 0.5 Torr.

The distillation residue (9 parts, 100 / o of theory) is in the Soluble in common solvents.

Example 8 In one of 0.66 parts of triethoxytitanium chloride, 4.2 parts Ethyl aluminum dichloride and 1 part diphenyl sulfide in 100 parts chlorobenzene Catalyst solution is passed in butadiene (1,3) for 75 minutes at 50 to 60 ° C. After adding 10 parts of methanol, the batch is distilled directly and yields 144 parts of cyclododecatriene (1,5,9), corresponding to 850/0 of theory, in addition to 25 parts higher, partially liquid, highly unsaturated hydrocarbons, accordingly 15 per cent of theory.

Example 9 In one of 0.43 parts of titanium tetrachloride, 2.8 parts Phenyl aluminum dichloride and 0.7 part diphenyl sulfide in 100 parts chlorobenzene The prepared catalyst suspension is passed at 60 to 70 ° C. in the course of 60 minutes Butadiene- (1,3) a. After adding 10 parts of methanol, the batch is distilled directly and gives 226 parts of cyclododecatriene- (1,5,9), corresponding to 820 / o of theory, in addition to 49 parts, corresponding to 180 / o of the theory, higher, partly liquid, strong unsaturated hydrocarbons.

Example 10 A catalyst suspension is prepared from 1 part of titanium trichloride, 0.2 parts aluminum and 3.9 parts phenyl aluminum sesquichloride through 3 hours Milled in 80 parts of benzene. In the mixture is for 60 minutes at 55 bis 60 "C butadiene initiated.

The yield of cyclododecatriene (1,5,9) is 245 parts, correspondingly 840 / o of theory.

Example 11 In one of 0.7 parts of titanium tetraethylate, 4 parts of ethylaluminum dichloride and 0.6 part of diphenyl sulfide in 90 parts of benzene prepared catalyst solution butadiene (1,3) is introduced at 55 to 65 ° C. in the course of 150 minutes. The batch is distilled directly after the addition of 10 parts of methanol and gives 194 parts of cyclododecatriene- (l , 5.9), corresponding to 840 / o of theory.

Claims (1)

PATENT CLAIM: Process for the production of liquid oligomers of 1,3-dienes in the presence of a titanium compound and an organic aluminum halide containing catalyst, characterized in that a metal is additionally used the I. to III. Group of the Periodic Table or any substance related to the organic Aluminum halides form complex compounds, applies, but the use a complex-forming compound that contains a semipolar double bond is excluded is when butadiene- (1,3) in the presence of catalysts from aluminum alkyl halides and titanium halides is reacted. Documents considered: German Auslegeschrift No. 1 050 333. Older patents considered: German Patent No. 1 086 226.