JP2006151891A - Preparation method of cyclic carbonate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method whereby cyclic carbonate can be prepared in a high yield through a reaction carried out near room temperature. <P>SOLUTION: In the method for preparing the cyclic carbonate through the reaction between an epoxy compound and carbon dioxide, the reaction is carried out in the presence of an indium or tin catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel method for producing a cyclic carbonate.

  Cyclic carbonates (cyclic carbonates) including ethylene carbonate, propylene carbonate, butylene carbonate and the like are widely used as electrolytes for lithium ion secondary batteries.

Conventionally, various methods for synthesizing cyclic carbonates have been proposed. For example, in a method for producing alkylene carbonate, a method for producing alkylene carbonate is known, wherein at least one of 3-octahedral smectite and / or alkali metal-containing 3-octahedral smectite is used as a catalyst. (Patent Document 1).
JP 2003-96074 A

  However, these conventional techniques basically require reaction at a high temperature, and there is room for further improvement in terms of reaction at room temperature.

  Therefore, the main object of the present invention is to provide a method capable of producing a cyclic carbonate in a high yield even by a reaction near room temperature.

  As a result of repeated studies in view of the problems of the prior art, the present inventor has found that the above object can be achieved by employing a catalyst in a specific combination, and has completed the present invention.

  That is, this invention concerns on the manufacturing method of the cyclic carbonate shown below.

  1. A method for producing a cyclic carbonate by reacting an epoxy compound and carbon dioxide, wherein the reaction is carried out in the presence of an indium-based catalyst and a tin-based catalyst.

2. Item 2. The production method according to Item 1, wherein the indium-based catalyst is at least one of indium halide InX ₃ (where X represents a halogen atom).

3. The tin-based catalyst is represented by the general formula R _4-a SnX ′ _a (wherein R is an alkyl group or an aromatic hydrocarbon group and may have a substituent. X ′ is a halogen atom. Or an alkoxy group which may have a substituent, wherein a represents 1, 2 or 3).

4). 1) The indium-based catalyst is at least one of indium halide InX ₃ (where X represents a halogen atom), and 2) the tin-based catalyst is represented by the general formula R ₂ SnX ′ ₂ (where R Represents an alkyl group or an aromatic hydrocarbon group which may have a substituent, and X ′ represents a halogen atom or an alkoxy group which may have a substituent. Item 3. The method according to Item 1, wherein the compound is at least one compound, and 3) at least one of X and X ′ is iodine.

  5. The epoxy compound is represented by the following formula (1);

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
A compound represented by
The cyclic carbonate is represented by the following formula (2);

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
The manufacturing method of said claim | item 1 which is a compound shown by these.

  6). Item 2. The method according to Item 1, wherein the reaction is performed at a temperature of 100 ° C or lower.

  7. Item 2. The method according to Item 1, wherein the reaction is performed at a temperature of 30 ° C or lower.

  According to the production method of the present invention, a cyclic carbonate can be synthesized from an epoxy compound in a high yield under milder conditions by using an indium catalyst and a tin catalyst in combination.

  The production method of the present invention is a method for producing a cyclic carbonate by a reaction between an epoxy compound and carbon dioxide, wherein the reaction is performed in the presence of an indium-based catalyst and a tin-based catalyst.

  As a starting material, an epoxy compound which may have a substituent and carbon dioxide are used.

  More specifically, the epoxy compound is represented by the following formula (1).

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
The compound shown by can be used suitably.

  Although it does not specifically limit as an alkyl group, For example, C1-C10 alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, are especially preferable. More preferably, it is a C4-C8 alkyl group (from a butyl group to an octyl group).

  The alkyl group may have a substituent. Examples of the substituent include various substituents such as methyl group, ethyl group, phenyl group, ether group, nitro group, sulfo group, amide group, amino group, carboxyl group, halogen group, hydroxy group, and ester group. .

  Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, and a methicyl group.

  The aromatic hydrocarbon group may have a substituent. Examples of the substituent include the various substituents mentioned above.

In the present invention, a cyclic carbonate corresponding to R ^{1 to} R ⁴ is obtained. That is, the following formula (2);

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
Can be obtained. Therefore, the R ^{1 to} R ⁴ of the epoxy compound that is the starting material may be appropriately selected according to the type of the target cyclic carbonate. In particular, in the present invention, it is preferable that at least one of R ^{1 to} R ⁴ is a hydrogen atom.

  Carbon dioxide may be used in an equivalent amount or more that reacts with the epoxy compound used. Generally, carbon dioxide (carbon dioxide) may be introduced into the reaction system so that the partial pressure of carbon dioxide is 1 to 60 atm, preferably 10 to 50 atm.

  The production method of the present invention is carried out in the presence of an indium catalyst and a tin catalyst. That is, the reaction is performed under conditions of a mixed system of both catalysts. This makes it possible to obtain a cyclic carbonate in a high yield even in a reaction under temperature conditions near room temperature. If both of them lack a tin-based catalyst, ring opening of the epoxy compound occurs, and as a result, a polymerized product is formed by a polymerization reaction. Further, when the indium catalyst is missing, the reaction does not proceed. Therefore, when either one is missing, the target product cannot be obtained.

The indium-based catalyst can be appropriately selected from indium metal or an indium compound. In the present invention, it is particularly desirable to use at least one of indium halide InX ₃ (where X represents a halogen atom). Among these, at least one of InCl ₃ , InI ₃ and InBr ₃ is more preferable, and InCl ₃ is most preferable.

  The form of the indium-based catalyst is not limited, but can be generally used in the form of particles (powder). The particle size in this case is not particularly limited, but in general, it may be appropriately set within a range of an average particle size of about 10 to 200 μm. Further, if necessary, it can be appropriately supported on a known carrier such as alumina, silica, zirconia, activated carbon and the like.

  The amount of the indium-based catalyst used can be appropriately set according to the type of indium-based catalyst used, the type of epoxy compound used, etc., but is generally about 0.01 to 10 mol% with respect to the epoxy compound. In particular, 0.1 to 5 mol% is desirable.

The tin-based catalyst is not particularly limited, but is particularly represented by the general formula R _4-a SnX ′ _a (wherein R is an alkyl group or an aromatic hydrocarbon group and may have a substituent) X ′ represents a halogen atom or an optionally substituted alkoxy group, a represents 1, 2 or 3. It is desirable to use at least one compound represented by the following formula:
The alkyl group is not limited, but an alkyl group having about 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a butyl group is particularly preferable. More preferably, it is a C4-C8 alkyl group (from a butyl group to an octyl group).

  The alkyl group may have a substituent. Examples of the substituent include various substituents as mentioned above.

  As an alkoxyl group, C1-C8 alkoxyl groups, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a phenoxy group, are preferable, for example.

  The alkoxy group may have a substituent. Examples of the substituent include various substituents as mentioned above.

  Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, and a methicyl group.

  The aromatic hydrocarbon group may have a substituent. Examples of the substituent include various substituents as mentioned above.

As the halogen atom, for example, I, Cl, Br and the like can be preferably employed. In this case, it is preferable that at least one of X and X ′ is iodine in relation to the indium catalyst. Therefore, for example, when InCl ₃ is used as the indium-based catalyst, R _4-a SnI _a is preferably used as the tin-based catalyst.

More specifically, the tin-based catalyst is Bu ₂ SnI ₂ (Bu: represents a butyl group; the same shall apply hereinafter), Bu ₂ SnBr ₂ , Bu ₂ SnCl ₂ , Oct ₂ SnI ₂ (Oct: represents an octyl group). The same shall apply hereinafter), Ph ₂ SnI ₂ or the like. In the present invention, Bu ₂ SnI ₂ can be particularly preferably used.

  Although the form of the tin-based catalyst is not limited, it can usually be used in a liquid or granular (powdered) form. The particle size in this case is not particularly limited. Further, if necessary, it can be appropriately supported on a known carrier such as alumina, silica, zirconia, activated carbon and the like.

  Although the usage-amount of a tin-type catalyst can be suitably set according to the kind of tin-type catalyst to be used, the kind of epoxy compound to be used, etc., generally 0.02-20 mol% normally with respect to an epoxy compound, In particular, the content is desirably 0.2 to 10 mol%.

  Further, the use ratio of the indium-based catalyst and the tin-based catalyst is not particularly limited, but in general, the molar ratio of indium-based catalyst: tin-based catalyst is preferably about 1: 1 to 3.

  The reaction phase may be any of a liquid phase reaction, a gas phase reaction, a liquid phase-gas phase, and the like. Generally, the production method of the present invention is a two-phase or three-phase reaction because carbon dioxide is a gas phase among the starting materials and the others are a liquid phase or a solid phase.

  In the present invention, raw materials other than carbon dioxide (especially epoxy compounds and catalysts) can be dissolved or dispersed in a solvent. As a solvent, it can determine suitably according to the kind etc. of epoxy compound to be used. In particular, in the present invention, for example, polar solvents (particularly aprotic polar solvents) such as dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), acetonitol, tetrahydrofuran and the like can be suitably used. When using a solvent, the concentration of the epoxy compound or the like can be adjusted as appropriate.

  The reaction format can be appropriately selected from known reaction formats such as continuous, batch, and semi-batch. Further, the catalyst contact method is not limited, and any of a fixed bed, a fluidized bed, a suspension bed and the like can be employed.

  Regarding the reaction conditions, the reaction temperature is not limited, but it can usually be appropriately adjusted within a range of 100 ° C. or less. In particular, in the present invention, a cyclic carbonate can be produced in a desired yield even at 30 ° C. or lower. The lower limit of the reaction temperature may be appropriately determined usually within a range of 0 ° C. or higher. The reaction atmosphere is preferably a carbon dioxide (carbon dioxide) -containing atmosphere, and the carbon dioxide partial pressure is preferably set within the pressure range. The reaction time can vary depending on the reaction temperature and the like, but is usually about 5 to 12 hours at room temperature.

  After completion of the reaction, if necessary, the reaction product is purified (extraction, distillation, etc.), separated (centrifugation, filtration, etc.) by a known method and then the target cyclic carbonate is recovered. good.

  Examples will be described below, and the features of the present invention will be described more specifically. However, the scope of the present invention is not limited to the scope of the examples.

Example 1
Cyclic carbonates were synthesized by reacting 1,2-butylene oxide and carbon dioxide.

In an autoclave (made of SUS32, capacity 50 cm ³ ) containing a magnetic rotor, acetonitrile 3 mL, 1,2-butylene oxide 0.72 g (10 mmol), Bu ₂ SnI ₂ 0.49 g (1 mmol), InCl ₃ 0.11 g (0 0.5 mmol), carbon dioxide gas of 40 atm was charged, and the mixture was stirred at room temperature (20 ° C.) for 12 hours.

Thereafter, the contents of the autoclave were taken out by adding diethyl ether and water, and further etherified by adding water and diethyl ether. The component obtained by drying the ether phase with magnesium sulfate and then concentrating was treated by silica gel column chromatography to obtain the desired product with ethyl acetate. After the ethyl acetate was distilled off under reduced pressure, the yield of the main product was determined by ¹ H-NMR. Furthermore, the product was isolated and purified by distillation. The target product was identified by ¹ H-NMR, ¹³ C-NMR and IR. As a result, it was confirmed that 0.99 g (yield: 85%) of 4-ethyl-1,3-dioxolan-2-one was produced.

Examples 2-7
A cyclic carbonate was synthesized in the same manner as in Example 1 except that the epoxy compound shown in Table 1 was used. The product and yield are shown in Table 2.

Examples 8-9
A cyclic carbonate was synthesized in the same manner as in Example 2 except that DMSO (Example 8) or DMF (Example 9) was used instead of acetonitrile as a solvent. As a result, propylene carbonate was obtained in all cases. The yield was 92% in Example 8 and 84% in Example 9.

Example 10
A cyclic carbonate was synthesized in the same manner as in Example 4 except that 0.5 mmol of Bu ₃ SnI was used instead of Bu ₂ SnI ₂ as a tin-based catalyst. As a result, the same product as in Example 4 was obtained. The yield was 77%.

Example 11
A cyclic carbonate was synthesized in the same manner as in Example 4 except that 0.5 mmol of Bu ₂ SnCl ₂ was used instead of Bu ₂ SnI ₂ as a tin-based catalyst. As a result, the same product as in Example 4 was obtained. The yield was 60%.

Claims (7)

A method for producing a cyclic carbonate by reacting an epoxy compound and carbon dioxide, wherein the reaction is carried out in the presence of an indium-based catalyst and a tin-based catalyst. The production method according to claim 1, wherein the indium-based catalyst is at least one of indium halide InX ₃ (where X represents a halogen atom). The tin-based catalyst is represented by the general formula R _4-a SnX ′ _a (wherein R is an alkyl group or an aromatic hydrocarbon group and may have a substituent. X ′ is a halogen atom. Or an alkoxy group which may have a substituent, wherein a represents 1, 2 or 3). 1) The indium-based catalyst is at least one of indium halide InX ₃ (where X represents a halogen atom), and 2) the tin-based catalyst is represented by the general formula R ₂ SnX ′ ₂ (where R Represents an alkyl group or an aromatic hydrocarbon group which may have a substituent, and X ′ represents a halogen atom or an alkoxy group which may have a substituent. The production method according to claim 1, wherein the compound is at least one kind of compound, and 3) at least one of the X and X ′ is iodine. The epoxy compound is represented by the following formula (1);

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
A compound represented by
The cyclic carbonate is represented by the following formula (2);

(However, R ^{1 to} R ⁴ are the same as or different from each other, and each represents a hydrogen atom, an alkyl group, or an aromatic hydrocarbon group that may have a substituent.)
The manufacturing method of Claim 1 which is a compound shown by these. The manufacturing method of Claim 1 which performs the said reaction under the temperature of 100 degrees C or less. The manufacturing method of Claim 1 which performs the said reaction under the temperature of 30 degrees C or less.