JP2002053573A - Method for producing alkylene carbonate compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for synthesizing an alkylene carbonate from an alkylene oxide by using supercritical carbon dioxide without using a metal catalyst. SOLUTION: This method for producing an alkylene carbonate comprises reacting an alkylene oxide with carbon dioxide kept under >=60 kg/cm2 pressure in the presence of a polar organic solvent having amide group or sulfinyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a polar organic solvent having an amide group or a sulfonyl group under supercritical carbon dioxide or subcritical carbon dioxide conditions without using a homogeneous or heterogeneous metal catalyst. And a method for efficiently synthesizing a carbonate by reacting an alkylene oxide.

(Prior Art) In recent years, the deterioration of the global environment due to global warming has become a serious problem, and internationally, it has been required to reduce the amount of carbon dioxide by suppressing the use of fossil energy. . As one of the methods for reducing the amount of carbon dioxide, development research on many carbon dioxide fixing technologies has been carried out. The reaction of synthesizing alkylene carbonate from alkylene oxide has been attracting attention for a long time, and there are many studies. However, the contents reported so far are often reported under reaction conditions using a solid acid catalyst, an alkali metal salt catalyst, a homogeneous organic metal catalyst, or the like. For example, a method for producing an alkylene carbonate using a carboxylic acid type cation exchange resin having an alkyl group-substituted ammonium cation as a counter cation (JP-A-7-206846),
Process for producing alkylene carbonate using catalyst comprising tungsten oxide or molybdenum oxide (JP-A-7-206847) Production of alkylene carbonate using anion exchange resin having tertiary amine functional group or quaternary ammonium functional group as catalyst Method (JP-A-7-2
06848), Synthesis of aryl-substituted alkylene carbonates catalyzed by alkali metal salts (JP-A-8-5339)
6), a method for producing alkenyl ether carbonate using a phase transfer organometallic complex catalyst (US Pat. No. 5,095,1)
24). However, it is difficult to design a catalyst that functions in carbon dioxide, it is very difficult to handle because the catalyst is unstable to moisture in the air, and it is difficult to separate the product from the catalyst ( In particular, with respect to organometallic complex catalysts), there are problems such as expensive catalysts and by-product formation. In particular, when a metal-based catalyst harmful to the natural environment is used, there are many problems such as treatment of a waste catalyst.

(Problem to be Solved by the Invention) The reaction of synthesizing alkylene carbonate from alkylene oxide and carbon dioxide is economical and a meaningful method from the viewpoint of the global environment, but is aimed at reducing the environmental load. In order to achieve such industrial production, it is required to develop a new process that does not use a metal catalyst, which has various problems. In the present invention, as a result of intensive studies to solve these problems, a polar solvent having an amide group or the like has found a specific function of promoting the synthesis of alkylene carbonate in carbon dioxide, and the present invention has been completed. Reached.

(Means for Solving the Invention)
The present invention is a novel method for producing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide in the presence of a polar solvent having an amide group or a sulfinyl group. By carrying out the present invention, it has become possible to produce an alkylene carbonate with extremely high efficiency without using any conventionally required metal catalyst. Less than,
The method for producing an alkylene carbonate compound according to the present invention will be described in detail. The alkylene oxide used as a raw material in the present invention is represented by the following general formula (1)
[Formula 1]

## STR1 ## (In the above formula, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different groups, and each may be hydrogen or a substituted or unsubstituted aryl group having 1 to 15 carbon atoms,
Represents an alkyl group, an alkenyl group, a cycloalkyl group, or an arylalkyl group. The substituents referred to herein include a halogen atom, an amino group, a nitro group, a carbonyl group, a carboxyl group, an alkoxy group, an acetoxy group, a hydroxyl group, a mercapto group, a sulfone group and a sulfonyl group. ).

Specifically, styrene oxide,
Alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and halogenopropylene oxide, and cyclic oxides having these substituents;
Cyclohexylene oxide, alicyclic oxides such as cyclohexylene oxides having a substituent, and arylalkyl oxides such as styrene oxides having a substituent, but in the present invention, are limited to only these alkylene oxides. Not carbon atoms
Any compound having at least one three-membered ring formed by one and one oxygen atom in its structural formula, a so-called epoxy compound, may be used. In the present invention, one or more of these are subjected to the reaction. Therefore, the alkylene carbonate produced in the present invention is a carbonate produced from the alkylene oxide and represented by the general formula (2)

[0007] (Wherein, R ₁ , R _2, R ₃ and R ₄ may be the same or different groups, and each may be hydrogen or a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms;
Represents an aryl group, an alkenyl group, a cycloalkyl group, or an arylalkyl group. Further, the substituent referred to herein is a halogen atom, an amino group, a nitro group, a carbonyl group, an alkoxy group, an acetoxy group, a carboxyl group, a hydroxyl group, a mercapto group, a sulfone, a sulfonyl group, or the like. ).

As specific examples, styrene carbonate, ethylene carbonate, propylene carbonate,
Butylene carbonate, vinyl ethylene carbonate,
Chloromethyl ethylene carbonate, chloropropylene carbonate, cyclohexane carbonate, cyclopentane carbonate, styrene carbonate and the like are exemplified.

The solvent used in the present invention is an organic compound having an amide group or a sulfinyl group.

[Chemical Formula 3] (R ₅ and R ₆ each represent an alkyl group, an aryl group, or a cycloalkyl group having a substituent. Further, the substituent referred to herein is a halogen atom, an alkoxy group, an acetoxy group, a carboxyl group, or an amide group. R7 is hydrogen or an alkyl group, an aryl group, or a cycloalkyl group each having a substituent, and the substituents are a halogen atom, an alkoxy group, an acetoxy group, a carboxyl group, or an amide group.) Is an organic compound having an amide group. . The general formula (4)

## STR4 ## (R ₈ and R ₉ each represent a substituted alkyl group, an aryl group, or a cycloalkyl group. Further, the substituents are a halogen atom, an alkoxy group, an acetoxy group, a carboxyl group, and an amide group.) It is an organic compound having a sulfinyl group. Furthermore, some compounds may be organic compounds composed of a combination of [Chemical Formula 3] and [Chemical Formula 4] in a single molecule.

As an example, N, having an amide group,
N-dimethylformamide, N, N-dimethylacetamide,
N, N-diethylformamide, N, N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, N, N'-
Dimethyl ethylene urea, or dimethyl sulfoxide having a sulfinyl group, and the like.In the present invention,
Any organic compound having a molecular weight of 1000 or less composed of C, H, N, O, S, P, and X (halogen) having an amide group or a sulfinyl group in the structural formula may be used. However, 1) that the above-mentioned alkylene oxide and these organic compounds sufficiently act as a solvent within the range of the boiling point or lower; 2)
3) It is desirable not to be strongly basic. In addition, it is not necessary for use, but it is preferable to remove water contained in the organic compound in advance, since hydrolysis of the alkylene oxide does not occur.

In the present invention, these organic compounds and alkylene oxide are mixed and dissolved, and reacted with supercritical carbon dioxide. The amount of the organic compound added is not particularly limited, but it can be preferably used in an amount of 2 mol or less, more preferably in a range of 0.02 to 1 equivalent, based on 1 equivalent of the alkylene oxide. Preferably, it is used in the range of 0.1 to 0.6 equivalent.

The reaction usually proceeds suitably in a temperature range of 50 to 300 ° C, more preferably in a temperature range of 50 to 200 ° C, and most preferably in a temperature range of 70 to 180 ° C. Although there is no particular limitation, since by-products are usually generated at a temperature higher than the boiling point of the alkylene oxide and the organic compound, it is efficient to perform the reaction at a temperature lower than the boiling point. However, when the boiling point of the alkylene oxide is 50 ° C. or lower, alkylene carbonate can be produced even when the reaction is carried out at a temperature of 0 ° C. or higher.
In that case, it is preferable to carry out the reaction near the boiling point of the added organic compound.

The reaction proceeds preferably in a supercritical or subcritical carbon dioxide pressure range of usually 60 kg / cm ² or more, more preferably 60 kg / cm ^{2 to} 120 kg / cm ² . The reaction proceeds most preferably in a pressure range of 60 kg / cm ^{2 to} 90 kg / cm ² . When the pressure is 120 kg / cm ² or more, although production is possible, it is not preferable because the yield is low.

The reaction is carried out in any of a batch system, a semi-batch system and a continuous flow system. In addition, the reaction time is not particularly limited because the optimum time varies depending on the type of alkylene oside, but is generally preferably 5 minutes to 4 minutes.
It is about 8 hours, more preferably 5 minutes to 24 hours, and most preferably 30 minutes to 24 hours. The reaction efficiency can be increased by stirring during the reaction, but there is no particular need to stir. As a result of carrying out the present invention, no by-product is obtained in the produced product,
It is easily isolated and purified by the usual separation, production method of distillation, extraction and recrystallization.

[0017]

The present invention will be described in more detail with reference to the following examples. However, the present embodiment specifically describes the present invention, and the present invention is not limited to only these embodiments.

Example 1 50 mmol of styrene oxide and 50 mmol of dimethylformamide were placed in a reaction vessel (50 mL) of a stainless steel autoclave, heated to 120 ° C., and introduced with carbon dioxide to adjust the pressure to 78 kg / cm ² . The reaction was performed for 15 hours. After the completion of the reaction, the reaction vessel was cooled, and after the pressure was released, analysis was performed by gas chromatography. The yield of the obtained styrene carbonate was 60%. No by-products were formed.

Example 2 A reaction was carried out in the same manner as in Example 1. However, the test was performed with the amount of N, N-dimethylformamide being 25 mmol. The yield of the obtained styrene carbonate was 53%.

Example 3 A reaction was carried out in the same manner as in Example 1. However, the test was performed with the amount of N, N-dimethylformamide being 5 mmol. The yield of the obtained styrene carbonate was 48%.

Example 4 A reaction was carried out in the same manner as in Example 1. However, if the reaction temperature is 1
The test was performed at 60 ° C. The yield of the obtained styrene carbonate was 85%.

Example 5 A reaction was carried out in the same manner as in Example 1. However, when the reaction pressure is 7
The test was performed at 2 kg / cm ² . The yield of the obtained styrene carbonate was 45%.

Example 6 A reaction was carried out in the same manner as in Example 1. However, when the reaction pressure is 8
The test was performed at 7 kg / cm ² . The yield of the obtained styrene carbonate was 34%.

Example 7 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide, N, N-diethylformamide 50m
Performed using mol. The yield of the obtained styrene carbonate was 35%.

Example 8 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide, N, N-diethylacetamide 50m
Performed using mol. The yield of the obtained styrene carbonate was 96%.

Example 9 A reaction was carried out in the same manner as in Example 8. However, when the reaction temperature is 7
0 ° C. The yield of the obtained styrene carbonate is 5
1%.

Example 10 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide, N-methylpyrrolidone 50 mm
ol. The yield of the obtained styrene carbonate was 48%.

Example 11 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide, 50 mmol of tetramethylurea is used.
Was performed using The yield of the obtained styrene carbonate was 31%.

Example 12 A reaction was carried out in the same manner as in Example 1. However, the test was carried out using 50 mmol of N, N'-dimethylethylene urea instead of N, N-dimethylformamide. The yield of the obtained styrene carbonate was 36%.

Example 13 A reaction was carried out in the same manner as in Example 1. However, if the reaction temperature is 1
The reaction was carried out at 50 ° C. and using 50 mmol of dimethyl sulfoxide instead of N, N-dimethylformamide. The yield of the obtained styrene carbonate was 57%.

Example 14 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of 1,2-epoxyhexane was used instead of styrene oxide. The yield of the obtained 1,2-hexylethylene carbonate was 54%.

Example 15 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of phenoxypropylene oxide was used instead of styrene oxide. The yield of hexyl carbonate obtained was 8
5%.

Example 16 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of methoxypropylene oxide was used instead of styrene oxide. The yield of the obtained hexyl carbonate is 36
%Met.

Example 17 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of (R) -styrene oxide was used instead of styrene oxide. The obtained styrene carbonate was an R-isomer having a three-dimensional shape, and the yield was 62%.

Example 18 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of (S) -styrene oxide was used instead of styrene oxide. The obtained styrene carbonate was an S-isomer having a three-dimensional shape, and the yield was 59%.

Example 19 A reaction was carried out under the same conditions as in Example 1 except that 50 mmol of 3-phenylpropylene oxide was used instead of styrene oxide. The yield of the obtained 3-phenylpropylene carbonate was 30%.

Example 20 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide, N, N-dimethylacetamide 50m
Performed using mol. The yield of the obtained styrene carbonate was 92%.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1. However, if the reaction pressure is 5
The test was performed at 2 kg / cm ² . The yield of the obtained styrene carbonate was 11%.

Comparative Example 2 The reaction was carried out in the same manner as in Example 1. However, the reaction was carried out at a reaction pressure of 20 kg / cm ² . The yield of the obtained styrene carbonate was 11%.

Comparative Example 3 A reaction was carried out in the same manner as in Example 1. However, instead of N, N-dimethylformamide used, acetone 50
Performed using mmol. No styrene carbonate was obtained, and the yield was 0%.

Comparative Example 4 A reaction was carried out in the same manner as in Example 1. However, the test was performed using 50 mmol of acetonitrile instead of the N, N-dimethylformamide used. No styrene carbonate was obtained, and the yield was 0%.

[0042]

According to the present invention, alkylene carbonate can be produced without using any metal catalyst by using supercritical carbon dioxide and allowing an organic compound having an amide group or a sulfinyl group to be present. In addition, since other impurities are not basically generated during this production process, it can be isolated by a simple method conventionally established in the art of crystallization, distillation, and extraction. Therefore, the manufacturing process can be simplified,
The industrial advantages are extremely large, such as the cost for the catalyst can be reduced.

Claims (14)

[Claims] 1. A method for producing an alkylene carbonate by reacting an alkylene oxide with carbon dioxide, wherein the reaction is carried out in the presence of at least one or more polar organic solvents having an amide group or a sulfinyl group. Production method. 2. The method according to claim 1, wherein the pressure of carbon dioxide is 60 kg / cm ² or more. 3. The method according to claim 1, wherein the reaction temperature is 50 ° C. or higher. 4. A polar organic solvent having an amide group, N,
N-dimethylformamide, N, N-diethylformamide,
N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, N,
4. The method according to claim 1, wherein at least one of dimethyl sulfoxide is used as N'-dimethylethylene urea or a polar solvent having a sulfinyl group. 5. The process according to claim 1, wherein the amount of the polar organic solvent used is not more than 2 equivalents relative to 1 equivalent of the starting alkylene oxide. 6. The method according to claim 1, wherein the reaction pressure is 60 kg / cm ² or more and 120 kg / cm ² or less. 7. The method according to claim 1, wherein the alkylene oside is styrene oxide and the alkylene carbonate is styrene carbonate. 8. The method according to claim 1, wherein the alkylene oside is phenoxypropylene oxide and the alkylene carbonate is phenoxypropylene carbonate. 9. The method according to claim 1, wherein the alkylene oside is methoxy propylene oxide and the alkylene carbonate is methoxy propylene carbonate. 10. The method according to claim 1, wherein the alkylene oside is 3-phenylpropylene oxide and the alkylene carbonate is 3-phenylpropylene carbonate. 11. The method according to claim 1, wherein the alkylene oside is chloropropylene oxide and the alkylene carbonate is chloropropylene carbonate. Note that halogeno represents fluorine, chlorine, bromine, and iodine. 12. The method according to claim 1, wherein the alkylene oside is 1,2-epoxyhexane and the alkylene carbonate is 1,2-hexylethylene carbonate. 13. The method according to claim 1, wherein the alkylene oside is (R) -styrene oxide and the alkylene carbonate is (R) -styrene carbonate. 14. The method according to claim 1, wherein the alkylene oside is (S) -styrene oxide and the alkylene carbonate is (S) -styrene carbonate.