JP2009173611A - METHOD FOR PRODUCING beta-BRANCHED ALCOHOL - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a β-branched alcohol getting a β-branched alcohol having desired chain length in high yield from a natural raw material without using a special apparatus. <P>SOLUTION: The method for producing a β-branched alcohol comprises subjecting a saturated carboxylic acid to a decarboxylation reaction in the presence of a catalyst containing an element selected from group 8, group 9 and group 10 metals and copper, to obtain an internal olefin, and subjecting the internal olefin to the hydroformylation reaction and hydrogen reduction reaction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a β-branched alcohol using a saturated carboxylic acid as a raw material.

  As a method for producing a β-branched alcohol, there is known a method obtained by subjecting alcohols derived from one or two kinds of natural raw materials to dehydration condensation reaction (Guerbe reaction) (Patent Document 1). However, this dehydration condensation reaction has a high reaction temperature, and in order to obtain a β-branched alcohol having a short side chain useful as a raw material for the surfactant, the dehydration condensation reaction must be performed at a temperature equal to or higher than the boiling point of the raw material alcohol. Therefore, dehydration operation under high pressure is required, and special equipment is required.

Another known method for producing β-branched alcohols is to oligomerize low-chain olefins such as ethylene, synthesize α-olefins, move double bond positions with an isomerization catalyst, and then hydroformylate. (Non-Patent Document 1). However, since the raw materials are not derived from natural raw materials and the synthesis via oligomerization of low chain length olefins (such as ethylene) has a distribution in the degree of polymerization, only the desired chain length olefins are obtained in high yield. There were problems such as being unable to do so.
In recent years, a method for synthesizing useful compounds from non-petroleum, that is, renewable raw materials has attracted attention from the viewpoint of environmental problems.
JP-A-9-227424 JCMol / Journal of Molecular Catalysis A: Chemical 213 (2004) 39-45

  An object of the present invention is to provide a method for producing a β-branched alcohol, which can obtain a β-branched alcohol having a target chain length in a high yield without using a special apparatus using a natural raw material. It is in.

  In the present invention, an internal olefin is obtained by decarboxylation of a saturated carboxylic acid in the presence of a catalyst containing an element selected from Group 8, Group 9, Group 10 metal and copper. Provided is a method for producing a β-branched alcohol in which a hydroformylation reaction and further a hydrogen reduction reaction are performed.

  By the production method of the present invention, it is possible to synthesize a β-branched alcohol that is suitably used as a base material such as a surfactant and an intermediate raw material for various compounds in a high yield using a naturally-available saturated carboxylic acid as a raw material. it can.

[Decarboxylation]
The decarboxylation reaction in the present invention is a reaction for obtaining an internal olefin from a saturated carboxylic acid.

  As saturated carboxylic acid used for this invention, C6-C22 saturated carboxylic acid is preferable, C6-C22 linear saturated carboxylic acid represented by general formula (I) is more preferable, and C12 More preferred are -18 linear saturated carboxylic acids.

_{CH 3 - (CH 2) a} -COOH (I)
(In the formula, a represents an integer of 4 to 20.)
Specific examples of the saturated carboxylic acid used in the present invention include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and the like.

  The internal olefin obtained by the decarboxylation reaction of the present invention refers to a compound having one carbon-carbon double bond at a place other than both ends of the molecule and having one fewer carbon atoms than the saturated carboxylic acid of the raw material. An internal olefin represented by the formula (II) is preferred.

_{H- (CH 2) b -CH =} CH- (CH 2) c -H (II)
(In the formula, b and c each independently represent an integer of 1 to 18, and the sum of b and c is 3 to 19.)
In the decarboxylation reaction of the present invention, from the viewpoint of obtaining an internal olefin with high selectivity from a saturated carboxylic acid in one step, a catalyst containing an element selected from Group 8, Group 9, Group 10 metal and copper is used. Examples of the Group 8, 9 and 10 metals include Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, etc., Ni, Rh, Pd, Ir, Pt are preferable, and Rh is more preferable. . Specific examples of the catalyst containing an element selected from Group 8, Group 9, Group 10 metal and copper include [RhCl (CO) ₂ ] ₂ , (Ph ₃ P) ₂ Rh (CO) Cl, (Ph ₃ P) ₂ NiCl ₂ , (Ph ₃ P) ₂ PdCl ₂ , (Ph ₃ P) ₂ PtCl ₂ , (Ph ₃ P) ₂ Ir (CO) Cl, (Ph ₃ P) ₃ CuCl (wherein Ph is phenyl [RhCl (CO) ₂ ] ₂ , (Ph ₃ P) ₂ PdCl _{2 and the} like are preferable.

  Further, these catalysts include N-heterocyclic carbene-based ligands such as N-heterocyclic carbene, pyridine-based ligands such as 2,2-bipyridyl and pyridine, arsenic-based ligands, acetonitrile, benzonitrile, and the like. It is preferably used in combination with a ligand such as a nitrile ligand, an isonitrile-based ligand, or an organophosphorus ligand, and more preferably an organophosphorus ligand. Examples of organophosphorus ligands include dimethylphenylphosphine, diethylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, cyclohexyldiphenylphosphine, tricyclohexylphosphine, triisopropylphosphine, tributylphosphine, tri-t-butylphosphine, and tribenzyl. Examples include phosphine, triphenylphosphine, tris (para-methoxyphenyl) phosphine, 1,2-bis (diphenylphosphino) ethane, dimethylphenylphosphine, diethylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, 1,2 -Bis (diphenylphosphino) ethane is preferred. These ligands may be used alone or in combination of two or more.

  From the viewpoint of obtaining good catalyst stability and reaction rate, the amount of the ligand used is a group 8, group 9, group 10, metal or copper in terms of an element selected from group 8, group 10, group 10 metal and copper. It is preferably in the range of 0.1 to 1000 mol in terms of ligand molecule, and more preferably in the range of 0.2 to 500 mol, with respect to 1 mol of the compound.

  In the present invention, from the viewpoint of obtaining good selectivity of the internal olefin, it is preferable to perform the decarboxylation reaction in the presence of an acid anhydride. Examples of the acid anhydride include acetic anhydride and propionic anhydride, and acetic anhydride is preferable. The amount of acid anhydride used is preferably in the range of 0.01 to 10 mol, preferably 0.2 to 2 mol, per mol of saturated carboxylic acid, from the viewpoint of obtaining good selectivity for internal olefins. A range is more preferred.

  The reaction temperature for the decarboxylation reaction is preferably from 100 to 300 ° C, more preferably from 180 to 300 ° C, from the viewpoint of obtaining good selectivity for the internal olefin. In order to improve the yield of internal olefins, it is desirable to employ conditions that maintain the produced olefin in the system during the decarboxylation reaction. For this reason, the reaction is preferably carried out in a closed system, and the reaction pressure is preferably normal or pressurized.

[Hydroformylation reaction]
The hydroformylation reaction in the present invention is not particularly limited. For example, the internal olefin obtained by the decarboxylation reaction is modified with a ligand such as an organophosphorus compound such as a group 8, 9, or 10 metal compound. And a method of reacting with hydrogen and carbon monoxide in the presence of a catalyst comprising a Group 8, Group 9, or Group 10 metal complex and converting it to an aldehyde.

  The Group 8, 9, and 10 metal compounds used in the hydroformylation reaction have catalytic ability to promote the hydroformylation reaction of internal olefins from the beginning, or acquire such catalytic ability under hydroformylation reaction conditions Examples thereof include rhodium compounds, cobalt compounds, ruthenium compounds, iron compounds and the like that have been conventionally used as catalysts in hydroformylation reactions. Among these compounds, it is preferable to use a cobalt compound or a rhodium compound from the viewpoint that the reaction conditions of the hydroformylation reaction are mild.

Examples of the cobalt compound include Co ₂ (CO) ₈ , and examples of the rhodium compound include rhodium oxides such as RhO, Rh ₂ O, Rh ₂ O ₃ , and RhO ₂ ; rhodium nitrate, rhodium sulfate, rhodium chloride, Rhodium salts such as rhodium iodide and rhodium acetate; Rh ₄ (CO) ₁₂ , Rh ₆ (CO) ₁₆ , RhCl (CO) (PPh ₃ ) ₂ , RhCl (PPh ₃ ) ₃ , RhBr (CO) (PPh ₃ ) ₂ , rhodium complex compounds such as RhCl (CO) (AsPPh ₃ ) ₂ , Rh (acac) (CO) ₂ (where acac represents an acetylacetonato ligand; the same shall apply hereinafter) and the like. acac) (CO) ₂ [rhodium acetylacetonatodicarbonyl] is more preferred.

  The organophosphorus compound used in the hydroformylation reaction is not particularly limited. For example, tricyclohexylphosphine, triisopropylphosphine, tributylphosphine, tri-t-butylphosphine, tribenzylphosphine, triphenylphosphine, tris (para-methoxy). Phenyl) phosphine, tris (para-N, N-dimethylaminophenyl) phosphine, tris (para-fluorophenyl) phosphine, tris (para-chlorophenyl) phosphine, tri-ortho-tolylphosphine, tri-meta-tolylphosphine, tri -Para-toluylphosphine, tris (pentafluorophenyl) phosphine, bis (pentafluorophenyl) phenylphosphine, diphenyl (pentafluorophenyl) phosphine Methyldiphenylphosphine, ethyldiphenylphosphine, cyclohexyldiphenylphosphine, dimethylphenylphosphine, diethylphenylphosphine, 2-furyldiphenylphosphine, 2-pyridyldiphenylphosphine, 4-pyridyldiphenylphosphine, meta-diphenylphosphinobenzenesulfonic acid or metal salts thereof , Para-diphenylphosphinobenzoic acid or a metal salt thereof, para-diphenylphosphinophenylphosphonic acid or a metal salt thereof, and tricyclohexylphosphine, triisopropylphosphine and the like are preferable. These organophosphorus compounds may be used alone or in combination of two or more.

  From the viewpoint of obtaining good catalyst stability and reaction rate, the amount of the organophosphorus compound used is 8 groups, 9 groups, 10 groups metal atoms in terms of 8 moles, 9 groups, 10 moles of metal compound, It is preferably in the range of 1 to 10000 mol in terms of phosphorus atom, more preferably in the range of 1 to 1000 mol, and still more preferably in the range of 1.5 to 100 mol.

  There are no particular restrictions on the method for preparing the Group 8, Group 9, or Group 10 metal complex. For example, the Group 8, Group 9, or Group 10 metal compound solution prepared separately using a solvent that does not affect the hydroformylation reaction, and It can be prepared by separately introducing an organophosphorus compound solution into a hydroformylation reaction system and reacting both in the system to form a complex. It can also be prepared by putting an organophosphorus compound in the above-mentioned group 8, 9, or 10 metal compound solution and then adding a solvent that does not affect the hydroformylation reaction to obtain a uniform solution.

The H ₂ / CO molar ratio of the mixed gas of hydrogen and carbon monoxide used in the hydroformylation reaction is preferably in the range of 0.1 to 10 and preferably in the range of 0.5 to 2 as the gas composition at the time of charging. It is more preferable from the viewpoint of easy maintenance of the mixed gas composition. The reaction pressure is preferably in the range of 0.1 to 10 MPa, and more preferably in the range of 0.5 to 5 MPa from the viewpoint of the reaction rate. The reaction temperature is preferably in the range of 40 to 150 ° C, and more preferably in the range of 60 to 130 ° C from the viewpoint of suppressing the deactivation of the catalyst.

  The hydroformylation reaction can be performed using a stirring reaction tank, a liquid circulation reaction tank, a gas circulation reaction tank, a bubble column reaction tank, or the like. The reaction can be performed in a continuous manner or a batch manner.

  From the viewpoint of reaction rate and catalyst cost, the amount of Group 8, Group 9, or Group 10 metal complex used is in the range of 0.1 to 1000 mmol in terms of Group 8, Group 9, or Group 10 metal atoms per 1000 g of raw material. It is preferable to select such an amount, and it is more preferable to select an amount that is in the range of 1 to 100 mmol.

  When the internal olefin is hydroformylated using the Group 8, 9, or 10 metal complex of the present invention, it is preferable that a solvent be present in the reaction system. Examples of the solvent include aprotic polar solvents such as toluene, dimethyl sulfoxide, 1-methyl-2-pyrrolidinone, sulfolane, dimethylformamide, acetonitrile, acetone, 1,4-dioxane, tetrahydrofuran; methyl alcohol, ethyl alcohol, Alcohols such as propyl alcohol, isopropyl alcohol, butyl alcohol, s-butyl alcohol, t-butyl alcohol; ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol, triethylene Glycol dimethyl ether, tetraethylene glycol, tetraethylene glycol dimethyl Glycols such as ethers, polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, etc. may be mentioned polyalkylene glycols such as polyethylene glycol dimethyl ether. These solvents may be used alone or in combination of two or more. Among these, it is preferable to use an aprotic polar solvent such as toluene, dimethyl sulfoxide, acetone or tetrahydrofuran. The amount of these solvents used is preferably selected such that it is in the range of 2-50% by volume in the hydroformylation reaction mixture, and is selected in such a range that it is in the range of 5-20% by volume. More preferred.

  There are no particular restrictions on the raw material charging method in the hydroformylation reaction, but an internal olefin, separately prepared group 8, 9, 10 metal complex solution and a solvent as necessary are charged, and then hydrogen, carbon monoxide, It is preferable that the mixed gas is introduced at a predetermined pressure and stirred at a predetermined temperature to carry out the reaction in a homogeneous system.

[Hydrogen reduction reaction]
The hydrogen reduction reaction in the present invention is a reaction for obtaining a β-branched alcohol by hydrogen reduction of the aldehyde obtained by the hydroformylation reaction. This reaction is not particularly limited, and hydrogen reduction may be performed by a known method. For example, NaBH ₄ (sodium borohydride) is added for reduction, reduction using hydrogen gas in the presence of a metal catalyst, etc. Is mentioned.

In the method of hydrogen reduction by adding NaBH _4, the addition amount of NaBH ₄ is preferably added equimolar or more to the aldehyde, more preferably from 1 to 3 moles added, 1.2 to 1.5 moles additive Is more preferable. Moreover, 0-100 degreeC is preferable, as for reaction temperature, 10-50 degreeC is more preferable, and 10-30 degreeC is further more preferable.

  In the method of reducing with hydrogen gas using a metal catalyst, the metal catalyst used for hydrogen reduction is not particularly limited. However, a catalyst in which Ru, Pd, Rh, Pt is supported on alumina, activated carbon, silica, zirconia, silica alumina or the like Cu-based catalysts such as Cu-Cr, Cu-Fe, and Cu-Zn, and Ni-based catalysts such as Raney nickel, nickel / diatomaceous earth, and nickel / silica alumina are preferable. The amount of the metal catalyst added is preferably 20% by weight or less, more preferably 0.1 to 5% by weight, based on the aldehyde. Although reaction temperature changes with the catalysts to be used, 300 degrees C or less is preferable, 20-250 degreeC is more preferable, 20-150 degreeC is further more preferable. The pressure of hydrogen gas is preferably normal pressure to 30 MPa, more preferably normal pressure to 25 MPa.

  The β-branched alcohol obtained by the method of the present invention is preferably a compound represented by the general formula (III).

(In formula, d and e show the integer of 1-19 each independently, and the sum of d and e is 4-20.)
The β-branched alcohol obtained by the method of the present invention can be suitably used as an intermediate material for surfactants, various chemicals, and pharmaceuticals.

  Hereinafter, “%” represents “% by weight” unless otherwise specified.

Synthesis Example 1 (Production of internal olefin)
A stirrer was placed in a 10 mL eggplant type flask, stearic acid 568.7 mg (2.0 mmol), rhodium catalyst [RhCl (CO) ₂ ] ₂ 7.8 mg (0.02 mmol), dimethylphenylphosphine 31.8 mg (0.08 mmol). ) And acetic anhydride (215.1 mg, 2.10 mmol) were added, and the mixture was stirred at 250 ° C. Immediately after heating, the solid stearic acid melted and the reaction solution became homogeneous and began to bubble. After 3 hours, the heating was stopped and the mixture was allowed to stand until it reached room temperature (25 ° C.). Then, after filtration while washing with ethyl ether, 95.9 mg of n-nonadecane was added as an internal standard, and gas chromatography (GC) measurement was performed (the GC yield is the sensitivity of the internal standard and the target product). The ratio was calculated as 1.) Next, after distilling off ethyl ether under reduced pressure, 105.9 mg of anisole was added as an internal standard, and ¹ H-NMR was measured (the yield was calculated by vinyl proton of terminal olefin, vinyl proton of internal olefin, internal standard). It was obtained by comparing the integral ratio of anisole with the methyl group.

As a result of GC measurement, the raw material stearic acid remained slightly. A plurality of peaks considered to be products of decarboxylation were seen at positions very close. And from the measurement result of ¹ H-NMR, it was found that 6% of the raw material stearic acid remained, 6% of the terminal olefin and 82% of the internal olefin were present.

Synthesis example 2 (production of internal olefin)
A stirrer was placed in a 10 mL eggplant-shaped flask, and stearic acid 579.4 mg (2.0 mmol), rhodium catalyst [RhCl (CO) ₂ ] ₂ 7.6 mg (0.02 mmol), dimethylphenylphosphine 31.8 mg (0.08 mmol) ), Acetic anhydride (224.2 mg, 2.19 mmol) was added, and the mixture was stirred at 200 ° C. Immediately after heating, the solid stearic acid melted and the reaction solution became homogeneous and began to bubble. After 3 hours, the heating was stopped and the mixture was allowed to stand until it reached room temperature (25 ° C.). Then, after filtration while washing with ethyl ether, 95.9 mg of n-nonadecane was added as an internal standard, and GC measurement was performed (GC yield was calculated with the sensitivity ratio of the internal standard and target product as 1). did.). Next, after distilling off ethyl ether under reduced pressure, 109.9 mg of anisole was added as an internal standard, and ¹ H-NMR was measured (the yield was calculated by vinyl proton of terminal olefin, vinyl proton of internal olefin, internal standard). It was obtained by comparing the integral ratio of anisole with the methyl group.

As a result of GC measurement, the raw material stearic acid remained slightly. A plurality of peaks considered to be products of decarboxylation were seen at positions very close. And from the measurement result of ¹ H-NMR, it was found that 10% of raw material stearic acid remained, 20% of terminal olefin and 49% of internal olefin were present.

Synthesis Example 3 (Production of internal olefin)
A stirrer was placed in a 10 mL eggplant-shaped flask, and stearic acid 568.9 mg (2.0 mmol), rhodium catalyst [RhCl (CO) ₂ ] ₂ 7.8 mg (0.02 mmol), dimethylphenylphosphine 15.9 mg (0.04 mmol) ) Was added and stirred at 250 ° C. Immediately after heating, the solid stearic acid melted and the reaction solution became homogeneous and began to bubble. After 3 hours, the heating was stopped and the mixture was allowed to stand until it reached room temperature (25 ° C.). Then, after washing with ethyl ether and filtering, n-nonadecane was added as an internal standard, and GC measurement was performed (GC yield was calculated with the sensitivity ratio of the internal standard and the target product as 1). . Next, after ethyl ether was distilled off under reduced pressure, anisole was added as an internal standard, and ¹ H-NMR was measured (the yield was calculated by vinyl protons of terminal olefins, vinyl protons of internal olefins, anisole as internal standard). Was obtained by comparing the integration ratio with the methyl group.

As a result of GC measurement, 61% of the raw material stearic acid remained. From the measurement results of ¹ H-NMR, it was found that 21% of the terminal olefin and 14% of the internal olefin were present.

Comparative Synthesis Example 1
A stirrer was placed in a 10 mL eggplant-shaped flask, stearic acid 568 mg (2.0 mmol), manganese catalyst Mn ₂ (CO) ₁₀ 4 mg (0.01 mmol), dimethylphenylphosphine 8 mg (0.02 mmol), anhydrous Acetic acid 224 mg (2 mmol) was added, and the mixture was stirred at 250 ° C. Immediately after heating, the solid stearic acid melted and the reaction solution became homogeneous and began to bubble. After 3 hours, the heating was stopped and the mixture was allowed to stand until it reached room temperature (25 ° C.). Then, after filtration with washing with ethyl ether, gas chromatography (GC) measurement was performed, but no olefin was produced.

Example 1
(1) Decarboxylation reaction In a glass intubation tube, 5.69 g (20 mmol) of stearic acid, 38.8 mg (0.1 mmol) of rhodium catalyst [RhCl (CO) ₂ ] ₂ , DPPE (1,2-bis ( 39.8 mg (0.1 mmol) of diphenylphosphino) ethane) and 2.04 g (20 mmol) of acetic anhydride were added, and the inside of the stainless steel autoclave was purged with argon and sealed. The mixture was placed in a 250 ° C. salt bath and stirred for 3 hours. After returning to room temperature (25 ° C.), the reaction mixture was dissolved in hexane and filtered using silica gel. After the filtrate was concentrated, ¹ H-NMR measurement was performed. Yield 4.7 g, stearic acid conversion 99%, terminal olefin: internal olefin = 1: 1.37.

(2) Hydroformylation reaction 2.96 g (12.44 mmol) of the olefin mixture obtained in (1) was placed in a glass inner tube, and 10.7 mg (0) of rhodium catalyst Rh (acac) (CO) ₂ was added. 0.041 mmol), 4 mL of toluene and 23 mg (0.082 mmol) of tricyclohexylphosphine were added, and the inside of the autoclave was replaced with carbon monoxide. Carbon monoxide was pressurized by 1.5 MPa, and hydrogen was further pressurized by 1.5 MPa (total 3.0 MPa). The autoclave was attached to an oil bath and heated and stirred at 110 ° C. for 1 hour. After returning to room temperature (25 ° C.), the remaining carbon monoxide and hydrogen were removed, and the solvent was distilled off under reduced pressure to obtain a crude yield of 4.5 g. ^{As a result of 1} H-NMR measurement, the raw materials disappeared, and four types of aldehyde peaks were confirmed. Terminal aldehyde: internal aldehyde = 1: 3.3.

(3) Hydrogen reduction reaction 4.5 g of the aldehyde mixture obtained in (2) was dissolved in 20 mL of ethanol, 610 mg (1.3 equivalents) of NaBH ₄ was added, and the mixture was stirred at room temperature (25 ° C.) for 2 days. Water was added to the reaction mixture, and the mixture was extracted with ethyl ether and dried over MgSO _{4. Then} , the solvent was distilled off under reduced pressure, and ¹ H-NMR was measured. The crude yield was 3.02 g, the raw material disappeared, and then isolated by silica gel column chromatography (hexane / ethyl acetate = 5/1, Rf = near 0.3) to obtain 2.585 g of β-branched alcohol. White solid. Linear alcohol: β-branched alcohol = 1 / 3.39.

Claims (4)

  After obtaining an internal olefin by decarboxylation of a saturated carboxylic acid in the presence of a catalyst containing an element selected from Group 8, Group 9, Group 10 metal and copper, hydroformylation reaction is performed on the obtained internal olefin. A method for producing a β-branched alcohol, which further performs a hydrogen reduction reaction.   The process according to claim 1, wherein the saturated carboxylic acid has 6 to 22 carbon atoms.   The production method according to claim 1 or 2, wherein the decarboxylation reaction is carried out in the presence of an acid anhydride.   The manufacturing method in any one of Claims 1-3 which performs a decarboxylation reaction at the temperature of 100-300 degreeC.