JP2869529B2 - Synthesis method of tertiary carboxylic acid using platinum carbonyl catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for synthesizing a tertiary carboxylic acid or an ester thereof, and more particularly to a tertiary carboxylic acid or an ester thereof having a carbon atom increased by one by reacting carbon monoxide with a raw material. To a method for synthesizing

[0002]

BACKGROUND OF THE INVENTION Tertiary carboxylic acids are generally synthesized by the reaction of high pressure carbon monoxide with olefins in strong acids.
However, in such a synthesis method, since the reaction conditions are high temperature and high pressure, polymerization of the raw materials cannot be avoided, and dimer or trimer carboxylic acid is by-produced as a product, and furthermore, tertiary The carboxylic acid selectivity is not high.

[0003] Derivatives of tertiary carboxylic acids are difficult to be hydrolyzed because they have two alkyl groups at the α-position of the carboxyl group, and are used as high-grade paints and high-grade surfactants having acid resistance, heat resistance and weather resistance. Attention has been paid. However, if the secondary carboxylic acid is slightly mixed, the acid resistance, heat resistance and weather resistance of the product are drastically reduced because the hydrolysis resistance of the secondary carboxylic acid is lower by one digit.

[0004]

Accordingly, an object of the present invention is to provide a method for selectively synthesizing a tertiary carboxylic acid or an ester thereof having one more carbon atom than the starting material under mild conditions. Main purpose.

[0005]

The present inventors have conducted various studies to find a new method that can solve or alleviate the problems of the prior art as described above. As a result of intensive studies on the method of selectively synthesizing a tertiary carboxylic acid or an ester thereof, the presence of a platinum carbonyl catalyst in synthesizing a tertiary carboxylic acid by reacting carbon monoxide with a raw material such as an olefin in a strong acid. It has been found that, when the reaction is carried out below, a tertiary carboxylic acid having one more carbon atom than the raw material can be selectively synthesized at a high yield even under normal temperature and normal pressure. That is, the present invention provides a method for synthesizing the following tertiary carboxylic acid or an ester thereof and a platinum carbonyl catalyst therefor.

[0006] 1. In reacting carbon monoxide with at least one compound selected from the group consisting of olefins, alcohols, dienes, diols and saturated hydrocarbons in a strong acid to synthesize a tertiary carboxylic acid or an ester thereof, the reaction is carried out using platinum. A synthesis method, which is performed in the presence of a carbonyl catalyst.

[0007] 2. Item 3. The tertiary carboxylic acid according to item 1, wherein the strong acid is at least one selected from the group consisting of sulfuric acid, sulfuric acid-phosphoric acid, hydrogen fluoride, fluorosulfuric acid, boron trifluoride / water complex, and trifluoromethanesulfonic acid. Or a method for synthesizing the ester thereof.

[0008] 3. Platinum carbonyl catalyst is used in a strong acid in the presence of platinum (II) oxide, platinum (IV) oxide, platinum hydroxide (I
Item 1) which is formed by the reaction of at least one of I), platinum (IV) hydroxide and platinum powder with carbon monoxide.
3. The method for synthesizing a tertiary carboxylic acid or an ester thereof according to item 1.

4. Platinum oxide (II), platinum oxide (I
V) A platinum carbonyl catalyst for a carbonylation reaction obtained by reacting at least one of platinum (II) hydroxide, platinum (IV) hydroxide and platinum powder with carbon monoxide in a strong acid.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Platinum carbonyl catalyst In the present invention, a platinum carbonyl catalyst is used as a catalyst for synthesizing a tertiary carboxylic acid or an ester thereof, that is, as a catalyst for a carbonylation reaction of a starting compound.

The platinum carbonyl catalyst can be produced by causing a platinum compound to absorb carbon monoxide.
Platinum compounds include platinum oxide (II) and platinum oxide (I
V), platinum hydroxide (II), platinum hydroxide (IV), platinum powder and the like can be used. Carbon monoxide can be absorbed by contacting the platinum compound with carbon monoxide in a strong acid. As the strong acid, sulfuric acid, sulfuric acid-phosphoric acid, hydrogen fluoride, boron trifluoride / water complex, fluorosulfuric acid, trifluoromethanesulfonic acid and the like can be used alone or in combination of two or more. When platinum powder is used as the platinum compound, a platinum carbonyl catalyst can be formed by coexisting an oxidizing agent such as sulfur trioxide.

Platinum chloride (I)
I), platinous (IV) chloride, chloroplatinic acid, platinous (IV) iodide, potassium platinous chloride, potassium platinous chloride and the like can be easily obtained as commercial products, but platinum carbonyl catalyst Is difficult to form.

For example, as a platinum compound, platinum oxide (I
When I) is sulfuric acid as a strong acid, the formation reaction of a platinum carbonyl catalyst is represented by the following chemical formula. In the formula, n is the number of CO coordinated to platinum (n = 1 to 6), m
Indicates the number of counter anions per platinum (m = 1 to 4).

[0014]

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The platinum carbonyl catalyst of the present invention can exhibit a sufficient catalytic activity even in the presence of oxygen. this is,
It is considered that the platinum compound is hardly oxidized.

Synthesis of Tertiary Carboxylic Acid or Its Ester A tertiary carboxylic acid or its ester is synthesized by adding a raw material compound to a strong acid solution containing a platinum carbonyl catalyst and reacting with carbon monoxide. be able to.
As the strong acid, sulfuric acid, sulfuric acid-phosphoric acid, hydrogen fluoride, boron trifluoride / water complex, fluorosulfuric acid, trifluoromethanesulfonic acid and the like can be used alone or in combination of two or more. A strong acid solution containing a platinum carbonyl catalyst obtained by contacting a platinum compound with carbon monoxide in a strong acid can be used as it is as a catalyst for producing a tertiary carboxylic acid or an ester thereof.

When a raw material compound is added to a strong acid solution containing a platinum carbonyl catalyst, a carbocation is generated. The carbocation isomerizes to a tertiary carbocation in a strong acid solution. A tertiary carboxylic acid can be synthesized by reacting carbon monoxide with a tertiary carbocation in the presence of water. When reacting carbon monoxide with a tertiary carbocation, an tertiary carboxylic acid ester can be synthesized by adding an alcohol.

When an olefin or an alcohol is added as a raw material compound to a strong acid (sulfuric acid) solution containing a platinum carbonyl catalyst, the olefin gives a proton and the alcohol gives a carbocation through dehydration followed by dehydration. The formation reaction of the tertiary carboxylic acid in this case is represented by the following chemical formula. In the formula, R, R ′ and R ″ each represent an alkyl group in a starting olefin or alcohol, R ¹ and R ² each represent an alkyl group in a reaction intermediate or product, and n represents the number of COs coordinated to platinum ( n = 1 ~
6), m is the number of counter anions per platinum (m = 1 to
4) is shown.

[0019]

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As the olefin, those having 3 or more carbon atoms, preferably 3 to 8 carbon atoms can be used, and all of terminal olefins, internal olefins and cyclic olefins can be used. Examples of the olefin include propylene, 1-butene, 2-butene, 1-hexene, and 2-olefin.
Ethyl-1-hexene, 1-octene, 1-nonene, 1
-Decene, butene dimer, butene trimer, propylene dimer, propylene trimer, cyclohexene, cyclooctene and the like can be used.

As the alcohol, one having 3 or more carbon atoms, preferably 3 to 8 carbon atoms can be used, and all of primary alcohol, secondary alcohol, tertiary alcohol and cyclic alcohol can be used. Examples of the alcohol include 1-propanol, 2-propanol, 1
-Butanol, 2-butanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-
Methyl-3-butanol, 1-hexanol, 2-hexanol, 3-methyl-3-heptanol, 1-heptanol, 2-heptanol, 3-methyl-3-hexanol, 1-octanol, 2-octanol, 2-methyl- 1-hexanol, 1-decanol, 2-dodecanol, 1-nonyl alcohol, 1-dodecanol, cyclohexanol and the like can be used.

As the starting compound, a diene or diol, preferably one having 8 or more carbon atoms, particularly 8 to 14 carbon atoms can be used. As the diene, any compound having two double bonds in the molecule can be used. As the diol, any compound having two hydroxyl groups in the molecule can be used. Dienes and diols having 8 or more carbon atoms can react with carbon monoxide to give tertiary dicarboxylic acids or esters thereof. Examples of the diene or diol include 1,7-octadiene, 1,9-decadiene, 1,11-dodecadiene,
1,12-tridecadiene, limonene, 1,10-decanediol, 1,12-dodencandiol, 2.9-
Dimethyldecanediol or the like can be used.

As the starting compound, a saturated hydrocarbon, preferably one having 4 or more carbon atoms, especially 4 to 10 carbon atoms can be used. As the saturated hydrocarbon, all compounds having tertiary hydrogen can be used. A saturated hydrocarbon having a tertiary hydrogen can provide a tertiary carboxylic acid in the presence of a compound that generates a carbocation such as an olefin or an alcohol. That is, the carbocation abstracts the tertiary hydrogen of the saturated hydrocarbon and the newly formed carbocation reacts with the carbon monoxide to give a tertiary carboxylic acid. As the saturated hydrocarbon, for example, methylcyclohexane, methylcyclopentane, ethylcyclohexane, methylcyclopentane, methylcyclooctane, 2-ethylhexane, 3-hexylhexane and the like can be used.

The carbonylation reaction between the starting compound and carbon monoxide can proceed sufficiently at normal temperature and normal pressure. The reaction pressure is not particularly limited, but is generally about 0.1 to 10 atm, more preferably about 0.5 to 5 atm, as a carbon monoxide partial pressure. When the partial pressure of carbon monoxide is low in the presence of air and other gases, the reaction rate can be increased by increasing the pressure. The reaction temperature is not particularly limited, but is generally -10 to 60C, preferably about 5 to 40C.

The present invention can be implemented, for example, as follows. A strong acid and a platinum compound are placed in a sealable reaction vessel, air is exhausted by a vacuum pump, carbon monoxide is introduced, and the mixture is vigorously stirred. The platinum compound dissolves while absorbing carbon monoxide to form a platinum carbonyl catalyst. When a predetermined tertiary carboxylic acid synthesis material such as olefin is gradually added to the catalyst solution, it reacts with carbon monoxide. When the reaction mixture is added to ice water, a tertiary carboxylic acid is obtained, and when added to an alcohol, an ester of the tertiary carboxylic acid is obtained. The product can be extracted and separated with an organic solvent such as hexane.

[0026]

In the present invention, carbon monoxide coordinated to platinum participates in the reaction, and the coordination number of carbon monoxide in the platinum carbonyl complex determines the catalytic activity. When sulfuric acid is used as a strong acid, the coordination number of carbon monoxide decreases as the sulfuric acid concentration decreases, and the sulfuric acid concentration is preferably 70% or more from the viewpoint of catalytic activity.

[0027]

According to the present invention, an olefin in a strong acid,
When reacting carbon monoxide with at least one compound selected from the group consisting of alcohols, dienes, diols and saturated hydrocarbons to synthesize tertiary carboxylic acids or esters thereof, a platinum carbonyl catalyst is present in the reaction system. By doing so, even at normal temperature and normal pressure, a tertiary carboxylic acid having one more carbon atom than the raw material can be obtained selectively and in a high yield. The platinum carbonyl catalyst used in the present invention has an advantage that the catalytic function does not decrease even in the presence of air.

[0028]

EXAMPLE 1 To a 200 ml three-necked flask connected to a gas burette, 526 mg (2 mmol) of platinum (IV) hydroxide and 10 ml of 96% sulfuric acid were added, and the mixture was evacuated with a vacuum pump. At 1 ° C. and 1 atm, carbon monoxide was introduced and stirred vigorously. After 3 days, 150 ml of carbon monoxide had been absorbed, forming a platinum carbonyl catalyst solution.

To this catalyst solution, 1-hexene (0.62 ml) was added.
(5 mmol) was added slowly, and after 30 minutes, 82 ml
Carbon monoxide reacted. The reaction mixture was added to ice water, and the product was extracted twice with n-hexane. The product was analyzed by gas chromatography, NMR, IR, and GC-MS for 2,2-
It is a 2: 1 mixture of dimethylpentanoic acid and 2-methyl-2-ethylbutanoic acid with a total yield of 0.1N,
It was confirmed to be 73% by titration with a NaOH solution.

Example 2 454 mg (2 mmol) of platinum (IV) oxide and 10 ml of 96% sulfuric acid were added to a 200 ml three-necked flask to which a gas burette was connected.
C., a mixed gas consisting of 80% of carbon monoxide and 20% of air was introduced at 1 atm.
Was absorbed to form a platinum carbonyl catalyst.

In this catalyst solution, 1-octanol 0.7
When 9 ml (5 mmol) was slowly added, 79 ml of carbon monoxide was absorbed. The reaction mixture was added to ice water, and the product was extracted with n-hexane. The products are GC, N
According to the analysis of MR, IR and GC-MS, 2,2-dimethylheptanoic acid: 2-methyl-2-ethylhexanoic acid: 2
-Methyl-2-propylpentanoic acid in a 4: 2: 1 mixture, the total yield of which was found to be 71% by 0.1 N NaOH titration.

Example 3 A 200-ml three-necked flask connected to a gas burette was replaced with carbon monoxide, and then platinum (II) hydroxide was added.
458 mg (1 mmol) and 5 ml of hydrogen fluoride were added,
Upon vigorous stirring, carbon monoxide was absorbed to form a platinum carbonyl catalyst solution. When 112 ml (5 mmol) of 1-butene was added through a gas burette, 68 ml of carbon monoxide reacted. After completion of the reaction, methanol 3
ml was added to form the methyl ester and hydrogen fluoride was distilled off. The product was extracted with hexane and analyzed by GC, NMR,
Analysis by IR or the like revealed that pivalic acid methyl ester was obtained in a yield of 53%.

Example 4 After replacing a 200 ml three-necked flask with carbon monoxide, 422 mg (2 mmol) of platinum (II) oxide and 10 ml of a boron trifluoride / water complex were added, and the mixture was vigorously stirred to give a monoxide. Carbon was absorbed to form a platinum carbonyl catalyst solution. 1,11-dodecadiene 1.1 was added to the catalyst solution.
ml (5 mmol) was added slowly and reacted with carbon monoxide. The product was extracted with benzene, and 1/5 was reduced to 0.1N
As a result of titration with a NaOH solution and analysis of the product by NMR and IR, a tertiary carboxylic acid having 14 carbon atoms containing 2,2,9,9-tetramethyldecanedicarboxylic acid as a main component was obtained in a yield of 51%. Was obtained.

Example 5 After replacing a 200 ml three-necked flask with carbon monoxide, 526 mg (2 mmol) of platinum (IV) hydroxide,
7 ml of concentrated sulfuric acid and 3 ml of fluorosulfuric acid were added and stirred vigorously to form a platinum carbonyl catalyst. 1,12 ml (5 mmol) of 1,12-dodecanediol was added and reacted with carbon monoxide. The product was extracted with benzene and 1/5
The volume is titrated with 0.1N NaOH solution and the product is
As a result of analysis by R and IR, a tertiary carboxylic acid having 14 carbon atoms and having 2,2,9,9-tetramethyldecanedicarboxylic acid as a main component was obtained in a yield of 60%.

Example 6 As in Example 1, 526 mg of platinum (IV) hydroxide was added to 9
A platinum carbonyl catalyst solution was prepared using 10 ml of 6% sulfuric acid. To this catalyst solution is added methylcyclohexane 0.6.
A mixture of 4 ml and 0.62 ml of 1-hexene was added slowly and reacted with carbon monoxide. The reaction mixture was added to ice water, and the product was extracted with n-hexane. The product is
According to gas chromatography, NMR, IR and GC-MS analysis, it is a 3: 1 mixture of methylcyclohexanecarboxylic acid and a tertiary carboxylic acid having 7 carbon atoms, and the yield of methylcyclohexanecarboxylic acid is titrated with 0.1N NaOH. Thereby, it was confirmed that it was 59%.

Example 7 A 200 ml three-necked flask connected to a gas burette was charged with 195 mg of platinum powder and 10 ml of sulfuric acid, and replaced with carbon monoxide. Then, 4.5 g of sulfur trioxide was added, and a platinum carbonyl catalyst solution was added. Formed. To this catalyst solution, 0.81 ml (5 mmol) of octane was gradually added, and reacted with carbon monoxide. The reaction mixture is added to ice water and the product
-Extracted with hexane. Products are gas chromatography, NM
As a result of analysis by R and IR, it was 2,2-dimethylpropanoic acid, and it was revealed that the yield was 140 mol% based on octane by titration with a 0.1 N NaOH solution.

Example 8 A predetermined amount of a platinum compound shown in Table 1 was added to 10 ml of sulfuric acid, the air (atmosphere) was replaced with 1 atm of carbon monoxide, and the mixture was vigorously stirred to form a platinum carbonyl catalyst. Thereafter, 5 mmol of 1-hexene was gradually added at 25 ° C.
Upon reaction, a tertiary carboxylic acid having 7 carbon atoms was obtained. Table 1 shows the yield of the obtained tertiary carboxylic acid having 7 carbon atoms.
Shown in

[0038]

Table 1 Amount of platinum compound added No tertiary carboxylic acid yield 15% PtO ₂ 2 mmol 73% PtO 2 mmol 72% Pt (OH) ₂ 2 mmol 72% Pt (platinum powder) 2 mmol 70%

As is evident from the results shown in Table 1, when the platinum compound is not present, the carboxylic acid yield is low, but the addition of the platinum compound accelerates the carbonylation reaction remarkably. The tertiary carboxylic acid is provided in yield.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 67/08 C07C 67/08 67/36 67/36 67/38 67/38 69/24 69/24 // C07B 61/00 300 C07B 61/00 300 (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 53/126 B01J 31/20 C07C 51/12 C07C 51/14 C07C 55/02 C07C 67/36 C07C 67/38 C07C 69/24 C07B 61/00 300 C07C 67/08

Claims (4)

(57) [Claims] 1. A tertiary carboxylic acid or an ester thereof is synthesized by reacting carbon monoxide with at least one compound selected from the group consisting of olefins, alcohols, dienes, diols and saturated hydrocarbons in a strong acid. Wherein the reaction is carried out in the presence of a platinum carbonyl catalyst. 2. The method according to claim 1, wherein the strong acid is at least one selected from the group consisting of sulfuric acid, sulfuric acid-phosphoric acid, hydrogen fluoride, fluorosulfuric acid, boron trifluoride / water complex, and trifluoromethanesulfonic acid. The method for synthesizing the tertiary carboxylic acid or the ester thereof according to the above. 3. A platinum carbonyl catalyst comprising platinum (II) oxide, platinum (IV) oxide, platinum (II) hydroxide, in a strong acid.
The method for synthesizing a tertiary carboxylic acid or an ester thereof according to claim 1, wherein the tertiary carboxylic acid or its ester is formed by a reaction of at least one of platinum (IV) hydroxide and platinum powder with carbon monoxide. 4. Platinum (II) oxide, platinum (IV) oxide,
A platinum carbonyl catalyst for a carbonylation reaction comprising reacting at least one of platinum (II) hydroxide, platinum (IV) hydroxide and platinum powder with carbon monoxide in a strong acid.