Process for Pd-catalyzed hydroxycarbonylation of diisobutene: acetic acid/diisobutene ratio

Information

  • Patent Grant
  • 10519090
  • Patent Number
    10,519,090
  • Date Filed
    Tuesday, December 11, 2018
    5 years ago
  • Date Issued
    Tuesday, December 31, 2019
    4 years ago
Abstract
Process for Pd-catalyzed hydroxycarbonylation of diisobutene:acetic acid/diisobutene ratio.
Description

The invention relates to a process for Pd-catalyzed hydroxycarbonylation of diisobutene:acetic acid/diisobutene ratio.


Carboxylic acids including propionic acid, adipic acid and fatty acids are used in the preparation of polymers, pharmaceuticals, solvents and food additives. The routes leading to carboxylic acids generally include the oxidation of hydrocarbons, alcohols or aldehydes, the oxidative cleavage of olefins by ozonolysis, the hydrolysis of triglycerides, nitriles, esters or amides, the carboxylation of Grignard or organolithium reagents, and the halogenation and subsequent hydrolysis of methyl ketones in the haloform reaction.


The hydrocarboxylation of olefins is a highly promising and environmentally-friendly method for obtaining carboxylic acids. Acetic acid is produced by carbonylation of methanol, which is carried out with iodide. In the Koch reaction, the addition of water and carbon monoxide to alkenes is catalyzed by strong bases. This method is effective with alkenes that form secondary and tertiary carbocations, e.g. isobutylene to pivalic acid. The hydrocarboxylation occurring with the simultaneous addition of CO and H2O to alkenes/alkynes provides a direct and convenient method for synthesizing carboxylic acids.


The object of the invention was to provide a process affording good conversion in the Pd-catalyzed hydroxycarbonylation of diisobutene (DIBN). This reaction should be carried out in one step.


The object is achieved by a process according to Claim 1.


Process comprising the process steps of:


a) addition of diisobutene,


b) addition of a compound comprising Pd, wherein the Pd is capable of forming a complex,


c) addition of the ligand L1:




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d) addition of acetic acid,


wherein the acetic acid is added in an amount in the range from 5 mol to 8 mol of acetic acid per mole of diisobutene,


e) feeding in CO,


f) heating the reaction mixture such that the diisobutene is converted to the compound P1:




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In one variant of the process, the compound in process step b) is selected from: PdCl2, PdBr2, Pd(acac)2, Pd(dba)2 (dba=dibenzylideneacetone), PdCl2(CH3CN)2.


In one variant of the process, the compound in process step b) is Pd(acac)2.


In one variant of the process, the acetic acid is added in an amount in the range from 6 mol to 7 mol of acetic acid per mole of diisobutene.


In one variant of the process, the reaction mixture is heated to a temperature in the range from 80° C. to 160° C. in process step f), preferably to a temperature in the range from 100° C. to 140° C.


In one variant of the process, the CO is fed in in process step e) such that the reaction proceeds under a CO pressure in the range from 10 bar to 40 bar, preferably in the range from 10 bar to 30 bar.


In one variant of the process, this process comprises the additional process step g):


g) addition of sulfuric acid.







The invention is more particularly elucidated hereinbelow with reference to working examples.




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A 4 ml vial was charged with [Pd(acac)2] (1.94 mg, 0.25 mol %), L1 (4.92 mg, 0.375 mol %), H2SO4 (1.3 mg, 0.52 mol %) and a stirrer bar that had been dried in an oven. The vial was then sealed with septa (PTFE-coated styrene-butadiene rubber) and a phenol resin cap. The vial was evacuated and refilled with argon three times. H2O (0.23 ml), acetic acid (0.87 ml) and diisobutene (DIBN) (2.5 mmol) were added to the vial with a syringe. The vial was placed in an alloy plate, which was transferred to an autoclave (300 ml) of the 4560 series from Parr Instruments under argon atmosphere. After flushing the autoclave three times with CO, the CO pressure was increased to 15 bar at room temperature, and subsequently increased to a pressure of 25 bar with N2. The reaction was conducted at 120° C. for 3 h. On conclusion of the reaction, the autoclave was cooled down to room temperature and cautiously decompressed. Isooctane (100 μl) was then added as internal standard. Conversion was measured by GC analysis.


The above-described experiment was repeated while varying the CH3COOH/DIBN ratio. All other parameters were maintained.


The results are compiled in the following table.

















Entry
CH3COOH/DIBN (mmol/mmol)
Conversion (%)









1
4/1
75



2*
5/1
80



3*
6/1
83



4*
7/1
83



5*
8/1
81



6
9/1
78







*inventive process






As the experimental results show, the object is achieved by the inventive process.

Claims
  • 1. A process for the conversion of diisobutene to a corresponding carboxylic acid P1 comprising: a) adding diisobutene, forming a reaction mixture,b) adding a compound comprising Pd, wherein the Pd is capable of forming a complex,c) adding the ligand L1:Fe
  • 2. The process according to claim 1, wherein the compound in process step b) is selected from:PdCl2, PdBr2, Pd(acac)2, Pd(dba)2 (dba=dibenzylideneacetone), or PdCl2(CH3CN)2.
  • 3. The process according to claim 1, wherein the acetic acid is added in an amount in the range from 6 mol to 7 mol of acetic acid per mole of diisobutene.
  • 4. The process according to claim 1, wherein the reaction mixture is heated to a temperature in the range from 80° C. to 160° C. in process step f).
  • 5. The process according to claim 1, wherein the CO is fed in in process step e) such that the reaction proceeds under a CO pressure in the range from 10 bar to 40 bar.
  • 6. The process according to claim 1, wherein the process comprises the additional process step g):g) addition of sulfuric acid.
Priority Claims (1)
Number Date Country Kind
17209362 Dec 2017 EP regional
US Referenced Citations (1)
Number Name Date Kind
7138544 Springer et al. Nov 2006 B2
Foreign Referenced Citations (1)
Number Date Country
1657230 May 2006 EP
Non-Patent Literature Citations (8)
Entry
U.S. Appl. No. 16/188,995, Sang et al., filed Nov. 13, 2018.
U.S. Appl. No. 16/189,029, Sang et al., filed Nov. 13, 2018.
U.S. Appl. No. 16/215,991, Sang et al., filed Dec. 11, 2018.
U.S. Appl. No. 16/216,004, Sang et al., filed Dec. 11, 2018.
U.S. Appl. No. 16/216,020, Sang et al., filed Dec. 11, 2018.
U.S. Appl. No. 16/216,037, Sang et al., filed Dec. 11, 2018.
European Search Report dated Jun. 18, 2018 in EP 17 20 9362 (6 pages).
Brennführer, A. et al., Palladium-Catalyzed Carbonylation Reactions of Alkenes and Alkynes. CheinCatChem. 2009. vol. 1. pp. 28-41.
Related Publications (1)
Number Date Country
20190194113 A1 Jun 2019 US