Efficient process for preparation of organoaluminum compound

Abstract

To provide an efficient process for preparation of organoaluminum compounds.SOLUTION: The present invention relates to an efficient process for the production of organoaluminum chlorides from dialkyl aluminum hydrides of various qualities.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an efficient process for producing organoaluminum chlorides from dialkylaluminum hydrides of various qualities. [Background technology]

[0002] Organoaluminum compounds, in particular halogenated organoaluminum compounds, are generally known and are widely applied, for example, in the production of polymers such as polyolefins, for example homopolymers and copolymers of ethylene, or as (co)catalysts in the metathesis of olefins.

[0003] Non-Patent Document 1 discloses the hydrogen chloride exchange reaction between alan (AlH3) and aluminum trichloride. However, this document does not mention aluminum compounds containing alkyl groups.

[0004] Typically, organoaluminum chlorides are prepared by the reaction of a trialkylaluminum compound with aluminum trichloride or certain chloroaluminum compounds such as dialkylaluminum chlorides or alkylaluminum dichlorides. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Wiberg, Schmidt; Zeitung fuer Naturforschung, 6b, p. 460-461 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above procedures require the employment of trialkylaluminum compounds, which, at least with some alkyl substituents, are difficult to prepare.

[0007] In view of the above, there is therefore a need for a readily available process for preparing organoaluminum chlorides. [Means for solving the problem]

[0008] To this end, a compound of formula (I): R 1 n AlCl (3-n) (I) (In the formula, R 1 represents alkyl or cycloalkyl unsubstituted or singly substituted with phenyl, and n is 0.5 to 2.5, preferably 0.8 to 1.2 or 1.4 to 1.6 or 1.8 to 2.2, for example, 1 or 1.5 or 2. Provided herein is a process for preparing a compound of the formula: The process includes at least a compound of formula (II): R 1 2AlH (II) with aluminum trichloride. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The scope of the present invention encompasses all intercombinations of the various definitions of substituents, of the regions of suitable or preferred embodiments, ie also combinations between particular and preferred regions.

[0010] Whenever "including," "for example," and "such as" are used in this specification, they mean "including, but not limited to," or "for example, but not limited to," respectively.

[0011] As used herein, aluminum trichloride refers to water-free aluminum trichloride, where water-free refers to a water content of less than 1% by weight, preferably less than 1%.

[0012] As known to those skilled in the art, the compounds of formulae (I) and (II) can exist in dimeric or oligomeric, preferably dimeric or trimeric structures with hydrides or chlorides as bridging ligands, which forms are also encompassed by the general formulae (I) and (II).

[0013] For example, when n is 1.5, formula (I) includes compounds containing the following structure: [ka]

[0014] As used herein, and unless otherwise specified, "alkyl" may be branched or unbranched.

[0015] As used herein, and unless otherwise specified, "cycloalkyl" may be partially or fully cyclic.

[0016] "Alkyl" is preferably an unsubstituted or singly substituted, preferably unsubstituted, C2-C 18 -alkyl, and even more preferably phenyl, represents C2-C8-alkyl, unsubstituted or singly substituted, preferably unsubstituted. The subscripts on the carbon atoms indicate the number of carbon atoms excluding the carbon atoms of any phenyl substituents. Specific examples of C2-C8-alkyl are ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, isooctyl, n-decyl, n-dodecyl, where ethyl, isobutyl, n-butyl, sec-butyl, n-hexyl, 2-ethylhexyl and n-octyl are preferred, and isobutyl is even more preferred.

[0017] "Cycloalkyl" is preferably C3-C 18-cycloalkyl, even more preferably C5-C 18 -cycloalkyl, which are unsubstituted or singly substituted with phenyl, preferably unsubstituted. The subscripts to the carbon atoms indicate the number of carbon atoms, excluding the carbon atoms of any phenyl substituents that may be present. C5-C 18 Examples of -cycloalkyl are cyclopentyl, cyclohexyl, methylcyclohexyl, with cyclohexyl being preferred.

[0018] Preferred compounds of formula (I) are diethylaluminium chloride (DEAC) and ethylaluminium dichloride (EADC), ethylaluminium sesquichloride (EASC), diisobutylaluminium chloride (DIBAC) and isobutylaluminium dichloride (IBADIC) and isobutylaluminium sesquichloride, and mixtures of the above.

[0019] Preferred compounds of formula (II) are di-isobutylaluminum hydride (DIBAH), diethylaluminum hydride.

[0020] The molar ratio of the compound of formula (II) to aluminum trichloride depends on the desired reaction product of formula (I) being prepared, but typically is 1 mole of R present in the desired compound of formula (I). 1 The amount of aluminum trichloride used is selected to be 0.25 to 0.4 mol, preferably 0.3 mol, per mol of aluminum trichloride.

[0021] The compound of formula (II) may be employed in the form of a pure substance, for example having a purity of 98% or more by weight, however, it has been found that a lower purity, for example a purity of less than 80% to 98% by weight, is equally applicable.

[0022] Typically, these qualities are obtained as reaction residues generated by preparing dialkylaluminum hydrides by reacting aluminum with an alkene and hydrogen, followed by distillation or filtration, in a manner known to those skilled in the art.

[0023] Such qualities include (unreacted) aluminum, aluminum oxide, as well as iron, zirconium, titanium, and oxides of iron, zirconium and titanium.

[0024] It has been found that these components do not significantly interfere with the reactions in the present invention.

[0025] The reaction of the compound of formula (II) with aluminum trichloride can be carried out as a neat material or in the presence of a non-coordinating solvent.

[0026] As used herein, "non-coordinating solvent" means that the solvent molecule does not contain oxygen, sulfur, or nitrogen atoms. For example, non-coordinating solvents include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane (each of the foregoing may be in the form of various possible pure isomers or isomeric mixtures), mineral oil, or various mixtures of the foregoing aliphatic hydrocarbon solvents. Preferred non-coordinating solvents include n-pentane, iso-pentane, pentane, n-hexane, iso-hexane, hexane, n-heptane, iso-heptane, heptane, where heptane is preferred.

[0027] The process can be carried out either batchwise or continuously, but is preferably carried out batchwise.

[0028] The reaction time in a batch process and the residence time in a continuous process are, for example, from 30 seconds to 24 hours, preferably from 30 minutes to 12 hours.

[0029] The process of the present invention can be carried out in a variety of reactors capable of carrying out such types of reactions, such as, for example, a cylindrical reactor equipped with a mixing nozzle for a continuous process, or a stirred tank for a batch process.

[0030] The process according to the invention is for example carried out at a temperature of -20 to 150°C, preferably at a temperature of 0 to 130°C, even more preferably at a temperature of 15 to 125°C.

[0031] There is no strict restriction on the reaction pressure, but step 1) can be carried out at a pressure of 1000 hPa to 5 MPa, preferably 900 hPa to 1 MPa, and even more preferably normal pressure.

[0032] Without wishing to be bound by theory, it is speculated that during the reaction, aluminum hydride, AlH3, is formed, which decomposes to form gaseous hydrogen and finely dispersed aluminum.

[0033] In order to remove the latter and other solid impurities (impurities formed during the reaction or impurities previously introduced with the reactants into the reaction), the process of the invention may further comprise an additional step of purifying the compound of formula (I).

[0034] This can be accomplished by a variety of means known to those skilled in the art for separating solids or other impurities from the desired compound of formula (I), such as filtration, centrifugation, or decanting, and / or distillation, with distillation being preferred.

[0035] The compounds of formula (I) prepared in the present invention can be used in oligomerization and polymerization reactions, for example, with C2-C 20 They are particularly useful for employment as catalysts or cocatalysts in the oligomerization and polymerization of olefins, preferably isobutene, butadiene or ethylene or propylene, in the presence or absence of olefins, as well as in the metathesis of oligomers or polymers.

[0036] As used herein, "oligomer" is intended to mean a compound containing from 2 to 8 structural (repeating) units derived from one or more olefins employed in an "oligomerization" reaction.

[0037] As used herein, "polymer" is intended to mean a compound containing nine or more structural (repeating) units, e.g., 9 to 500,000, derived from one or more olefins employed in a "polymerization" reaction.

[0038] Therefore, one embodiment of the present invention is a C2-C 20 The present invention relates to metathesis, oligomerization and polymerization reactions in the presence or absence of olefins, preferably the oligomerization or polymerization of olefins, more preferably the oligomerization or polymerization of isobutene, butadiene, ethylene or propylene, in which the compound of formula (I) prepared according to the present invention is employed as a (co)catalyst.

[0039] The main advantage of the present invention is that the compounds of formula (I) can be prepared from organoaluminum hydrides of various qualities in a smooth and efficient reaction.

[0040] The following examples are intended to illustrate the invention without, however, limiting it thereto.

[0041] experiment: Summary Analysis method Sample preparation: An appropriate amount of sample was weighed into a flask and diluted with an inert solvent. The organoaluminum compounds were decomposed by adding acetate buffer and an appropriate amount of EDTA solution. Heating on a hot plate aided in the formation of aluminum-EDTA complexes and evaporation of the organic solvent.

[0042] Determination of Aluminum Content: This procedure was applied to all organoaluminum compounds. During sample preparation, aluminum was complexed with excess EDTA. Zn 2+ The solution was used to back-titrate excess EDTA to determine aluminum content.

[0043] Determination of chloride content: This procedure can be applied to reaction products containing chloride, which was made available in ionic form by sample preparation. Chloride was titrated potentiometrically with silver nitrate solution. Two independent measurements were carried out. The absolute chloride content in the sample was calculated from the amount of silver nitrate consumed.

[0044] purity Purity was measured by gas chromatography. EXAMPLES

[0045] All manipulations were carried out under protective gas using the Schlenk technique.

[0046] 1) Preparation of isobutylaluminum dichloride The flask was charged with 34.40 g of diisobutylaluminum hydride (DIBAH, minimum purity 96 wt% DIBAH) at 25°C. Then 21.30 g of aluminum trichloride was added in one portion, causing the internal temperature to increase to 48°C. The external heating temperature was increased to 30°C and a second amount of aluminum trichloride was added in one portion, but no further temperature increase was observed. The reaction mixture was heated to 80°C and stirred at this temperature for 2 hours. After heating at 80°C for 1 hour, a grey solid formed. The external heating temperature was increased to 120°C. Finally, the reaction mixture was distilled at 10 mbar. A clear, colorless liquid was obtained. Yield: 65.3 g (87% of theoretical) Analytical data: 17.80m / m% Al, 46.34m / m% Cl, 99.23n / n% Isobutane

[0047] 2) Preparation of isobutylaluminum dichloride The flask was charged with 88.79 g of diisobutylaluminum hydride (DIBAH content of 91.4%, total solids content calculated for Al at 10% corresponds to 8.6% by weight) at 25° C. Then 55.50 g of aluminum trichloride was added in one portion, causing the internal temperature to increase to 34° C. The external heating temperature was increased to 30° C. and a second amount of aluminum trichloride was added in one portion, but no further increase in temperature was observed. The reaction mixture was heated to 110° C. and stirred at this temperature for 2 hours. The external heating temperature was increased to 120° C. 25 g of high boiling saturated oil (Parol) was added and the reaction mixture was distilled at 10 mbar. A clear, colorless liquid was isolated. Yield: 171.8 g (87% of theoretical) Analytical data: 17.54m / m% Al, 46.63m / m% Cl, 99.91n / n% Isobutane

Claims

1. Formula (I): R １ ｎ AlCl （３－ｎ） (I) (In the formula, R １ represents alkyl or cycloalkyl unsubstituted or singly substituted with phenyl, n is 0.5 to 2.5, preferably 1 or 1.5 or 2. A process for preparing a compound of the formula The process comprises at least a compound of formula (II): 2 １ ２ Alｨ (99) with aluminum trichloride.

2. R １ is unsubstituted or singly substituted with phenyl; ２ ~C １８ - alkyl, more preferably phenyl, ２ ~C ８ 2. The process of claim 1, wherein n represents -alkyl, even more preferably ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, isooctyl, n-decyl, n-dodecyl, where ethyl, isobutyl, n-butyl, sec-butyl, n-hexyl, 2-ethylhexyl and n-octyl are even more preferred, and isobutyl is most preferred.

3. 2. The process of claim 1, wherein the compound of formula (I) is selected from the group consisting of diethylaluminum chloride (DEAC) and ethylaluminum dichloride (EADC), ethylaluminum sesquichloride (EASC), diisobutylaluminum chloride and isobutylaluminum dichloride.

4. 2. The process of claim 1, wherein the compound of formula (II) is selected from the group consisting of di-isobutylaluminum hydride (DIBAH) and diethylaluminum hydride.

5. The molar ratio of the compound of formula (II) to aluminum trichloride is 1 mol of R １ The process according to any one of claims 1 to 4, wherein 0.25 to 0.4 mol, preferably 0.30 mol, of aluminium trichloride is selected to be employed relative to

6. The process according to any one of claims 1 to 5, wherein the purity of the compound of formula (II) is equal to or greater than 80% by weight, preferably equal to or greater than 98% by weight, or is anywhere between 80% and less than 98% by weight.

7. 7. The process according to any one of claims 1 to 6, wherein the purity of the compound of formula (II) is between 80% and less than 98% by weight and represents a reaction residue from the preparation of a dialkylaluminum hydride.

8. 8. The process according to any one of claims 1 to 7, wherein the reaction of the compound of formula (II) with aluminium trichloride may be carried out as a neat material or in the presence of a non-coordinating solvent.

9. The process according to any one of claims 1 to 8, wherein the process is carried out batchwise or continuous, preferably batchwise.

10. The process according to any one of claims 1 to 9, wherein the temperature of the reaction is from -20 to 150°C, preferably from 0 to 130°C, even more preferably from 15 to 125°C.

11. 11. The process according to any one of claims 1 to 10, wherein the process comprises as a further step purifying the compound of formula (I), preferably by filtration, centrifugation or decantation, and / or by distillation, whereby distillation is even more preferred.

12. A process for the metathesis of oligomers or polymers, or the oligomerization and polymerization of olefins, in which the compound of formula (I) prepared in the present invention is employed as a catalyst or cocatalyst.

Images