Process for Pd-catalyzed hydroxycarbonylation of diisobutene: ratio of 3,5,5-trimethylhexanoic acid/H2O

Abstract

Process for Pd-catalyzed hydroxycarbonylation of diisobutene: ratio of 3,5,5-trimethylhexanoic acid/H.sub.2O.

Claims

1. A process comprising: a) adding diisobutene to form a reaction mixture, b) adding a compound comprising Pd, wherein the Pd is capable of forming a complex to the mixture, c) adding to the mixture ligand L1: ##STR00004## d) adding to the mixture 3,5,5-trimethylhexanoic acid and water, wherein the ratio based on the volumes used is in the range from 1.0/1.0 to 1.8/0.2, e) feeding CO into the mixture, f) heating the reaction mixture such that the diisobutene is converted to the compound P1: ##STR00005##

2. The process according to claim 1, wherein the compound in process step b) is selected from: PdCl.sub.2, PdBr.sub.2, Pd(acac).sub.2, Pd(dba).sub.2 (dba=dibenzylideneacetone) or PdCl.sub.2(CH.sub.3CN).sub.2.

3. The process according to claim 1, wherein the process further comprises g) adding CF.sub.3SO.sub.3H.

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 20 bar to 60 bar.

6. The process according to claim 1, wherein the amount of 3,5,5-trimethylhexanoic acid added per 1 mmol of diisobutene is in the range from 0.3 ml to 0.4 ml.

Description

(1) The object of the invention was to provide a process affording good conversion in the Pd-catalyzed hydroxycarbonylation of diisobutene (DIBN).

(2) The object is achieved by the process as follows.

(3) Process comprising the process steps of:

(4) a) addition of diisobutene,

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

(6) c) addition of the ligand L1:

(7) ##STR00001##

(8) d) addition of 3,5,5-trimethylhexanoic acid and water, wherein the ratio based on the volumes used is in the range from 0.75/1.25 to 1.8/0.2,

(9) e) feeding in CO,

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

(11) ##STR00002##

(12) In one variant of the process, the compound in process step b) is selected from: PdCl.sub.2, PdBr.sub.2, Pd(acac).sub.2, Pd(dba).sub.2 (dba=dibenzylideneacetone), PdCl.sub.2(CH.sub.3CN).sub.2.

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

(14) In one variant of the process, the process comprises the additional reaction step g):

(15) g) addition of CF.sub.3SO.sub.3H.

(16) 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.

(17) 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 20 bar to 60 bar, preferably in the range from 30 bar to 50 bar.

(18) In one variant of the process, the ratio of 3,5,5-trimethylhexanoic acid/water based on the volumes used is in the range from 1.0/1.0 to 1.8/0.2.

(19) In one variant of the process, the amount of 3,5,5-trimethylhexanoic acid added per 1 mmol of diisobutene is in the range from 0.3 ml to 0.4 ml.

(20) The invention is elucidated in more detail by means of working examples below.

(21) ##STR00003##

(22) A 4 mL vial was charged with [Pd(acac).sub.2] (3.05 mg, 0.25 mol %), L1 (20.64 mg, 1.0 mol %) and oven dried stirring bar. 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. H.sub.2O (0.5 ml), 3,5,5-trimethylhexanoic acid (1.5 ml), diisobutene (DIBN) (4.0 mmol) and CF.sub.3SO.sub.3

(23) (7.5 mol %) were added to the vial by 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 pressure of CO was increased to 40 bar at room temperature. The reaction was conducted at 120 C. for 20 h. On conclusion of the reaction, the autoclave was cooled down to room temperature and cautiously decompressed. Isooctane (100 l) was then added as internal standard. Conversion was measured by GC analysis.

(24) The experiment described above was repeated with variation of the ratio of 3,5,5-trimethylhexanoic acid/water. All other parameters were maintained.

(25) The results are compiled in the following table.

(26) TABLE-US-00001 3,5,5-Trimethylhexanoic Conversion Entry acid/water (mL/mL) (%) 1 0/2 25 2 0.2/1.8 45 3 0.5/1.5 49 4 1.0/1.0 84 5 1.50/0.5 87 6 1.8/0.2 72