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LOW-PRESSURE HYDROFORMYLATION OF DIISOBUTENE

20230192580 · 2023-06-22

    Inventors

    Cpc classification

    International classification

    Abstract

    Low-pressure hydroformylation of diisobutene

    A hydroformylation process for preparing 3,5,5-trimethylhexanal comprising reacting 2,4,4-tri-methylpent-2-ene with H.sub.2 and CO in a reaction zone in the presence of one or more free organ-ophosphite ligands of the general formula (1)

    ##STR00001##

    wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are not H at the same time, and R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are not H at the same time, and R.sup.11, R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.11, R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are not H at the same time, and a homogeneous rhodium catalyst complexed with one or more organophosphite ligands of the general formula (I) at a pressure of 1 to 100 bar abs and a temperature of from 50 to 200° C.

    Claims

    1-14. (canceled)

    15. A hydroformylation process for preparing 3,5,5-trimethylhexanal comprising reacting 2,4,4-trimethylpent-2-ene with H.sub.2 and CO in a reaction zone in the presence of one or more free organophosphite ligands of general formula (I) ##STR00007## wherein, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are not H at the same time, and R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are not H at the same time, and R.sup.11, R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are each independently H, C.sub.1- to C.sub.9-alkyl or C.sub.1- to C.sub.9-alkoxy and R.sup.11, R.sup.12, R.sup.13, R.sup.14 and R.sup.15 are not H at the same time, and a homogeneous rhodium catalyst complexed with one or more organophosphite ligands of the general formula (I) at a pressure of 1 to 100 bar abs and a temperature of from 50 to 200° C.

    16. The process according to claim 15, wherein a mixture comprising 2,4,4-trimethylpent-1-ene and 2,4,4-trimethylpent-2-ene is converted to 3,5,5-trimethylhexanal.

    17. The process according to claim 16, wherein the ratio of 2,4,4-trimethylpent-1-ene to 2,4,4-trimethylpent-2-ene in the mixture used is in the range from 99 : 1 to 1 : 99.

    18. The process according to claim 15, wherein the total amount of 2,4,4-trimethylpent-1-ene and 2,4,4-trimethylpent-2-ene of the total amount of olefin in the feed to the reaction zone is from 10 to 100%.

    19. The process according to claim 15, wherein the hydroformylation is carried out at a temperature of 80 to 150° C.

    20. The process according to claim 15, wherein the hydroformylation is carried out at a pressure of 5 to 80 bar abs.

    21. The process according to claim 15, wherein the molar ratio of the total amount of organophosphite ligands of the general formula (I) in the reaction zone to the total amount of rhodium in the reaction zone is in the range from 1 : 1 to 100 : 1.

    22. The process according to claim 15, wherein the rhodium concentration in the reaction zone is in the range of 20 to 250 ppmw based on the total weight of the liquid phase in the liquid phase in the reaction zone.

    23. The process according to claim 15, wherein the one or more organophosphite ligands of the general formula (I) are one or more of the following compounds: TABLE-US-00007 Organophosphite ligand of general formula (I) R.sup.1, R.sup.6, R.sup.11 R.sup.3 R.sup.8, R.sup.13 R.sup.2, R.sup.4, R.sup.5, R.sup.7, R.sup.9, R.sup.10, R.sup.12, R.sup.14 R.sup.15 I) Methyl Methyl H II) Methyl H H III) Ethyl Ethyl H IV) Ethyl H H V) n-Propyl n-Propyl H VI) n-Propyl H H VII) Isopropyl Isopropyl H VIII) Isopropyl H H IX) n-Butyl n-Butyl H X) n-Butyl H H XI) sec-Butyl sec-Butyl H XII) sec-Butyl H H XIII) Isobutyl Isobutyl H XIV) Isobutyl H H XV) tert-Butyl tert-Butyl H XVI) tert-Butyl H H XVII) Methoxy Methoxy H XVIII) Methoxy H H XIX) Ethoxy Ethoxy H XX) n-Propoxy n-Propoxy H XXI) n-Propoxy H H XXII) Isopropoxy Isopropoxy H XXIII) Isopropoxy H H XXIV) n-Butoxy n-Butoxy H XXV) n-Butoxy H H XXVI) sec-Butoxy sec-Butoxy H XXVII) sec-Butoxy H H XXVIII) Isobutoxy Isobutoxy H XXIX) Isobutoxy H H XXX) tert-Butoxy tert-Butoxy H XXXI) tert-Butoxy H H XXXII) n-Nonyl H H .

    24. The process according to claim 15, wherein the molar ratio of H.sub.2 to CO fed to the reaction zone is from 2 : 1 to 1 : 2.

    25. The process according to claim 15, wherein the rhodium catalyst is at least partially formed in the reaction zone by reacting a rhodium precursor with one or more organophosphite ligands of the general formula (I), CO and H.sub.2.

    26. The process according to claim 25, wherein the rhodium precursor is rhodium carbonyls, rhodium(I) salts, rhodium(II) salts, rhodium(III) salts or mixtures of two or more of the aforementioned precursors.

    27. The process according to claim 15, wherein the rhodium catalyst is used at least partially preformed.

    28. The process according to claim 15, wherein the method is carried out continuously.

    Description

    EXAMPLES

    Example 1

    [0099] Under argon, Rh(CO).sub.2(acac) (5.1 mg, 0.02 mmol) and tris(2,4-di-tert-butylphenyl) phosphite (640 mg, 0.99 mmol) were dissolved in diisobutene (20.0 g, 178 mmol; 2,4,4-trimethylpent-1-ene/ 2,4,4-trimethylpent-2-ene: 80:20 to 75:25) and filled into a 100 mL stainless steel autoclave under an argon countercurrent. Then ~5 bar CO/H.sub.2 (1:1) was applied and the autoclave heated to 100° C. over 10 min. At this temperature, the pressure was increased to 10 bar and the contents were stirred for 10 hours. The autoclave was cooled to room temperature, depressurized to atmospheric pressure and an aliquot of the reaction discharge obtained analyzed by gas chromatography. GC-Method: Optima1 column (30 m, d = 320 .Math.m, F.sub.d = 0.5 .Math.m), temperature program: 50° C. for 2 min, at 5° C./min to 90° C. and for 2 min isothermally, at 20° C./min to 250° C., helium as carrier gas. t.sub.R(2,4,4-trimethylpent-1-ene) = 5.27 min, t.sub.R(2,4,4-trimethylpent-2-ene) = 5.77 min, t.sub.R(3,5,5-trimethylhexanal) = 13.76 min).

    [0100] The following result was achieved:

    TABLE-US-00003 Conversion of diisobutene: >98% Selectivity for 3,5,5-trimethylhexanal: 97.0% Selectivity for 2,4,4-trimethylpentane: 3.0%

    Example 2

    [0101] Under argon, Rh(CO).sub.2(acac) (5.1 mg, 0.02 mmol) and tris(2,4-di-tert-butylphenyl) phosphite (640 mg, 0.99 mmol) were dissolved in toluene (2.5 mL) and filled into a 100 mL stainless steel autoclave. Then, 10 bar CO/H.sub.2 (1:1) was applied, the mixture heated to 100° C. over 10 min and stirred for 1 h. At this temperature, diisobutene (20.0 g, 178 mmol, 2,4,4-trimethylpent-1-ene/2,4,4-trimethylpent-2-ene: 80:20 to 75:25) was added in countercurrent and the mixture stirred for 6 h. The autoclave was cooled to room temperature, depressurized to atmospheric pressure and an aliquot of the reaction discharge obtained analyzed by gas chromatography. GC-Method: Optima1 column (30 m, d = 320 .Math.m, Fd = 0.5 .Math.m), temperature program: 50° C. for 2 min, at 5° C./min to 90° C. and for 2 min isothermally, at 20° C./min to 250° C., helium as carrier gas. t.sub.R(2,4,4-trimethylpent-1-ene) = 5.27 min, t.sub.R(2,4,4-trimethylpent-2-ene) = 5.77 min, t.sub.R(3,5,5-trimethylhexanal) = 13.76 min).

    [0102] The following result was achieved:

    TABLE-US-00004 Conversion of diisobutene: >95% Selectivity for 3,5,5-trimethylhexanal: 97.0% Selectivity for 2,4,4-trimethylpentane: 3.0%

    Example 3

    [0103] Under argon, Rh(CO).sub.2(acac) (5.1 mg, 0.02 mmol) and tris(2,4-di-tert-butylphenyl) phosphite (640 mg, 0.99 mmol) were dissolved in 2,4,4-trimethylpent-2-ene (20.0 g, 178 mmol) and filled into a 100 mL stainless steel autoclave under an argon countercurrent. Then ~5 bar CO/H.sub.2 (1:1) was applied and the autoclave heated to 100° C. over 10 min. At this temperature, the pressure was increased to 10 bar and the contents were stirred for 10 hours. The autoclave was cooled to room temperature, depressurized to atmospheric pressure and an aliquot of the reaction discharge obtained analyzed by gas chromatography. GC-Method: Optima1 column (30 m, d = 320 .Math.m , F.sub.d = 0.5 .Math.m) , temperature program: 50° C. for 2 min, at 5° C./min to 90° C. and for 2 min isothermally, at 20° C./min to 250° C., helium as carrier gas. t.sub.R(2,4,4-trimethylpent-1-ene) = 5.27 min, t.sub.R(2,4,4-trimethylpent-2-ene) = 5.77 min, t.sub.R(3,5,5-trimethylhexanal) = 13.76 min).

    [0104] The following result was achieved:

    TABLE-US-00005 Conversion of diisobutene: >85% Selectivity for 3,5,5-trimethylhexanal: 96.0% Selectivity for 2,4,4-trimethylpentane: 4.0%

    Example 4

    [0105] A solution of tris(2,4-di-tert-butylphenyl) phosphite L1 in 3,5,5-trimethylhexanal (10% by weight) was stirred under reflux under argon. After 1 d, 5 d, 8 d, 12 d, 21 d and 27 d, samples were analyzed by .sup.31P-NMR spectroscopy (tris(2,4-di-tert-butylphenyl) phosphite: δ = 129.9 ppm; tris(2,4-di-tert-butylphenyl) phosphate δ = -20.0 ppm).

    [0106] The following result was achieved:

    TABLE-US-00006 Reaction time [00005]embedded image.sup.31P-NMR (129.9 ppm) [00006]embedded image.sup.31P-NMR(-20.0 ppm) 1 d >99% <1% 5 d >99% <1% 8 d 99% 1% 12 d 98% 2% 21 d 97% 3% 27 d 97% 3%

    [0107] As the example shows, the ligand has high stability in the reaction product. The high stability of the ligand ensures a long service life for the process. Furthermore, the high stability of the ligands has the advantage that the formation of by-products is reduced. In addition, the ligands and/or the catalyst metal-ligand complex can be recycled into the process in the case of a continuous process regime due to their high stability.

    [0108] The examples serve to illustrate the present invention. The examples do not limit the present invention.