JPH0123467B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing organic carbonates from epoxides, carbon dioxide gas, and organic carbonates easily and in high yield using a novel catalyst. Conventionally, when producing organic carbonates (cyclic carbonates) by reacting epoxides with carbon dioxide gas, certain Lewis acids, Lewis acid-amine catalysts, ammonium salts, phosphates, etc. are used as catalysts. That has already been suggested. However, some of these methods require high temperatures and high pressures, require special equipment and complicated operations, and are therefore unsatisfactory as industrial methods. In addition, some of them did not reach industrially satisfactory yields, leading to a large loss of valuable raw materials (epoxides) and requiring complicated purification steps. The present inventors have conducted various studies on catalysts for producing epoxides, carbon dioxide gas, and organic carbonates easily and in high yields. The present invention was achieved by developing a new catalyst with excellent catalytic activity. The method for producing organic carbonates of the present invention uses the following as a catalyst: represents an integer of 1 to 4, h represents an integer of 1 to 4, and (g+h)=5. ] A catalyst consisting of an organobismuth compound main catalyst represented by the following and a nitrogen-containing organic base and/or a phosphorus-containing organic base co-catalyst, (2) General formula RkGeLl...() [wherein R is a lower alkyl group, a phenyl group or a lower alkyl-substituted phenyl group, X represents a halogen atom, k represents an integer of 1 to 3, l represents an integer of 1 to 3, and (k+l)=4. ] An organic germanium compound main catalyst represented by
Catalyst consisting of a nitrogen-containing organic base and/or a phosphorus-containing organic base cocatalyst, (3) General formula RmTeXn...() [In the formula, R is a lower alkyl group, a phenyl group, or a lower alkyl-substituted phenyl group, and X is a halogen m represents an integer of 1 to 3, n represents an integer of 1 to 3, and (m+n)=4. [In the formula, R is a lower alkyl group, a phenyl group, or a lower alkyl-substituted phenyl group, X is a halogen atom, and m is 1 n represents an integer of 1 to 3, and (m+n)=4. ] Reacting epoxides with carbon dioxide using an organometallic compound catalyst selected from a catalyst consisting of an organotellurium compound main catalyst represented by the following and a nitrogen-containing organic base and/or a phosphorus-containing organic base co-catalyst. This method is characterized by the following. The reaction for producing organic carbonates of the present invention is shown below using a general formula (in the formula,
R ¹ to ^{R 4} each represent hydrogen, a hydrocarbon group, or a hydrocarbon group having a substituent or a substituent atom. Examples of the raw material epoxides used in the method of the present invention include ethylene oxide, propylene oxide, butylene oxide, alkylene oxide, styrene oxide, epichlorohydrin, and cyclohexene oxide. The organometallic compound used as a catalyst (main catalyst) in the method of the present invention is an organobismuth compound represented by the above general formula (), an organogermanium compound represented by the general formula (), and an organometallic compound represented by the general formula (). selected from organic tellurium compounds. Specifically, in the organometallic compounds represented by these general formulas () to (), R is an alkyl group such as a methyl group, an ethyl group, a propyl group, a phenyl group, or an alkyl-substituted phenyl group such as a tolyl group. and X is Cl, Br, or I, which are variously combined in the above general formula to form the respective compounds. Specific examples of such compounds include, for example, Ph ₃ BiBr ₂ (in the formula, Ph represents a phenyl group. The same as below),
Ph ₃ GeBr, Ph ₂ GeBr ₂ , Me ₃ GeCl (in the formula, Me represents a methyl group. The same applies hereinafter), Me ₃ GeBr,
Examples include (CH ₃ Ph) ₂ TeCl ₂ and Me ₂ TeI ₂ . Furthermore, the organometallic compounds represented by the general formulas (), (), and () can also be produced by mixing substances that can be raw materials for these compounds in a reaction system or the like. Therefore,
What is added to the reaction system etc. does not necessarily need to be a complete compound represented by each general formula. For example, it is recognized that when metallic tellurium and CH ₂ I are mixed, a compound represented by the general formula () is partially produced according to the reaction formula below,
Instead of using the compound represented by the general formula (), these raw materials can be added to the reaction system to generate these compounds in the reaction system to carry out the reaction. Te+2CH ₃ I → (CH ₃ ) ₂ TeI _2The catalyst in the method of the present invention can be used alone as a catalyst when it is a metal compound represented by the above general formula (), but it can be used alone as a catalyst. In the case of a compound represented by the formula, a specific cocatalyst is combined with the compound to form a catalyst. Further, even in the case of a metal compound represented by the general formula (), the catalytic effect is improved if the metal compound is combined with a specific co-catalyst to form a catalyst. Cocatalysts to be combined include nitrogen-containing organic bases (for example, primary, secondary and tertiary aliphatic amines, aromatic amines, pyridine, quinoline, morpholine, etc.), phosphorus-containing organic bases (for example, various phosphines), ) is used. Two or more of these organic bases can also be used in combination as a cocatalyst. A preferred embodiment of carrying out the method of the present invention is
A predetermined amount of raw material epoxide and a catalyst are placed in a sealable pressure-resistant container, the container is sealed, and carbon dioxide gas is applied to the container at a predetermined pressure, followed by heating and stirring at a predetermined temperature. Since carbon dioxide gas is absorbed by the reaction and the pressure decreases, the end of the reaction can be easily determined by the time when the reaction decrease stops. As for the reaction conditions, the temperature is usually 90 to 230℃, preferably 100 to 230℃.
The temperature is 160°C, and the pressure is usually 30 to 250 Kg/cm ² , preferably 50 to 120 Kg/cm ² . The amount of catalyst used for both main catalyst and cocatalyst is based on the raw material epoxide.
It is usually 0.1 to 100 mol%, and the amount of carbon dioxide charged is 1 to 3 times the amount of the raw material epoxide by mole. After the reaction is completed, the product is cooled, the catalyst is separated and removed by filtration, and the product is purified by distillation to obtain the desired organic carbonate. The method of the present invention uses the specific catalyst, and since the catalyst has high activity, organic carbonates can be easily obtained in high yield. Furthermore, the catalyst can be easily separated from the reaction product of the present invention by filtration or decantation, and the resulting organic carbonates can be easily purified by distillation. The organic carbonates obtained by the method of the present invention can be used as various solvents, raw materials for carbonate resin monomers, and the like. Furthermore, these organic carbonates are useful as raw materials for glycols (eg, ethylene glycol, etc.). That is, if organic carbonates are hydrolyzed using, for example, an alkali catalyst, corresponding glycols can be obtained. Next, an example will be given and explained. Examples 1 to 6 Various epoxides and catalysts shown in Table 1 were charged into a stainless steel autoclave with an internal volume of 200 ml, and CO ₂ gas was injected under pressure at 50 atm, then heated and stirred at a temperature of 120°C. The reaction was carried out for the time indicated in 1. The catalyst was removed from the reaction product by filtration and purified by distillation. The yield of the organic carbonate obtained is shown in Table 1.
It was as shown in.

【table】

[Table] Examples 7 to 18 Using various organogermanium compounds and cocatalysts listed in Table 2, and reaction conditions listed in Table 2,
Others followed the method described in Examples 1 to 7.
Various epoxides were reacted with carbon dioxide gas. The epoxide yield was as shown in Table 2.

【table】

[Table] Examples 19 to 31 Using various organic tellurium compounds or their raw materials listed in Table 3, and various cocatalysts, and under the reaction conditions listed in Table 3, other conditions described in Examples 1 to 7. Propylene oxide (0.05 mol) according to the method of
was reacted with CO ₂ injected at 50 Kg/cm ² . The results (organic carbonate yield) were as shown in Table 3.

[Table] As is clear from the above examples, if the catalyst of the present invention is appropriately selected and used, epoxide and carbon dioxide gas can be easily reacted to produce organic carbonates in high yield.

Claims (1)

[Claims] 1. As a catalyst, (1) general formula RgBiXh [wherein R is a lower alkyl group,
phenyl group or lower alkyl substituted phenyl group, X is a halogen atom, g is an integer of 1 to 4, h is an integer of 1 to 4, (g+
h)=5. ] A catalyst consisting of an organic bismuth compound main catalyst represented by the following formula and a nitrogen-containing organic base and/or a phosphorus-containing organic base co-catalyst, (2) a catalyst with the general formula RkGeXl [wherein R is a lower alkyl group,
phenyl group or lower alkyl-substituted phenyl group, X is a halogen atom, k is an integer of 1 to 3, l is an integer of 1 to 3, and (k+
l)=4. A catalyst consisting of an organogermanium compound main catalyst represented by the following formula and a nitrogen-containing organic base and/or a phosphorus-containing organic base co-catalyst, (3) General formula RmTeXn [wherein R is a lower alkyl group, a phenyl group, or a lower alkyl group] represents a substituted phenyl group, X represents a halogen atom, m represents an integer of 1 to 3, n represents an integer of 1 to 3, and (m+
n)=4. ], and (4) a catalyst consisting of an organic tellurium compound represented by the general formula RmTeXn [wherein R is a lower alkyl group, a phenyl group, or a lower alkyl-substituted phenyl group, X is a halogen atom, and m is 1 to 3 n is an integer from 1 to 3, and (m+
n)=4. ] Reacting epoxides with carbon dioxide gas using an organometallic compound catalyst selected from a catalyst consisting of an organotellurium compound main catalyst represented by the following and a nitrogen-containing organic base and/or a phosphorus-containing organic base co-catalyst. A method for producing organic carbonates characterized by: