WO2014196686A1 - Organometallic compound, method for preparing same, and method for preparing carbonic acid ester using same - Google Patents

Abstract

An organometallic compound of the present invention is characterized by being represented by chemical formula 1 below. The organometallic compound can improve the reactivity of carbon dioxide and alcohol, thereby preparing carbonic acid ester at a high yield. [Chemical formula 1] M_a ³⁺[M_b(OR₁)₅]₃ ^- In chemical formula 1, M_a is cerium, M_b is group 4 or 14 metal, and R₁ is a hydrocarbon group having 1 to 10 carbon atoms.

Description

Organometallic compound, preparation method thereof and preparation method of carbonate ester using same

The present invention relates to an organometallic compound, a method for preparing the same, and a method for preparing a carbonate ester using the same. More specifically, the present invention relates to a novel organometallic compound capable of producing carbonic acid esters in high yield by improving the reactivity of carbon dioxide and alcohol, a method for preparing the same, and a method for preparing carbonic acid esters using the same.

Carbonate esters are useful monomers for the production of polycarbonates, and a lot of researches on their preparation have been conducted. Conventionally, carbonate esters have been prepared through reaction with alcohol using phosgene as a carbonyl source. However, this method not only has a problem of using very harmful phosgene, but also a problem due to the use of chlorine-based solvents and the treatment of by-product neutral salts.

In order to solve the problems caused by the use of phosgene, a method for preparing a carbonate ester using carbon monoxide as a carbonyl source has been developed. However, when carbon monoxide is used as the carbonyl source, the reaction rate and yield are low, the high risk of explosion due to the use of toxic carbon monoxide at high pressure, and high cost is required to ensure stability. In addition, there is a fear that side reactions such as carbon monoxide being oxidized to generate carbon dioxide.

In addition, a method of producing dimethyl carbonate by reacting carbon dioxide with ethylene oxide and the like to synthesize cyclic carbonate and reacting with methanol has been developed. This method is excellent because there is no harmful effect on carbon dioxide as a raw material, and no corrosive substances such as hydrochloric acid are used or no corrosive substances are generated. However, side reactions in which ethylene glycol is produced may occur, and there are limitations related to plant location due to difficulty in safe transport of ethylene oxide or ethylene oxide, which is a raw material of ethylene oxide.

Recently, a method of preparing a carbonate by reacting carbon dioxide with an organometallic compound has been studied. It was found that the carbonate was separated from the mixture produced by the above method, and the residual liquid was able to regenerate the organometallic compound through reaction with alcohol. That is, since the organometallic compound used in the reaction can be recycled, it can be reused in the carbonate forming reaction and there is no problem due to transportation. As such organometallic compounds, compounds of the same type as Sn (R) ₂ (OR ') ₂ (R, R': different alkyl groups) having a central metal of tin and having two alkyl groups and an alkoxy group have been disclosed. Patent 2010-523783, 2006-548937, 2006-513613, 2006-095140, 2005-511122, 2003-556375, 2001-396545, 2001-396537 and the like). However, known organometallic compounds have a problem of low reactivity and low yield of carbonate ester production.

An object of the present invention is to provide a novel organometallic compound and a method for producing the same that can be produced in high yield by improving the reactivity of carbon dioxide and alcohol.

Another object of the present invention is to provide a method for directly synthesizing carbonate esters from alcohols and carbon dioxide using the organometallic compounds.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the invention relates to organometallic compounds. The organometallic compound is characterized in that represented by the following formula (1):

[Formula 1]

^{_{M a 3+ [M b (OR}} 1) 5] 3 -

In Formula 1, M _a is cerium, M _b is a Group 4 or 14 metal, R ₁ is a hydrocarbon group having 1 to 10 carbon atoms.

In embodiments, M _b may be titanium (Ti), tin (Sn), or zirconium (Zr).

In embodiments, R ₁ may be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or a phenyl group.

Another aspect of the invention relates to a method for producing the organometallic compound. The preparation method is to prepare a dissimilar metal alkoxide represented by the following formula (4) by reacting the alkali metal alkoxide represented by the formula (2) and the metal alkoxide represented by the formula (3); And preparing an organometallic compound represented by Chemical Formula 1 by reacting the dissimilar metal alkoxide and a halogenated metal compound represented by Chemical Formula 5.

[Formula 2]

M _c OR ₁

[Formula 3]

M _b (OR ₁ ) ₄

[Formula 4]

M _c ⁺ [M _b (OR ₁ ) ₅ ] ^-

[Formula 5]

M _a (X) ₃

In Formulas 2 to 5, M _a , M _b and R ₁ are as defined in Formula 1, M _c is an alkali metal, X is a halogen atom.

In embodiments, the molar ratio of the halogenated metal compound represented by Formula 5 and the dissimilar metal alkoxide represented by Formula 4 may be about 1: about 2 to about 1: about 4.

In embodiments, the reaction of the alkali metal alkoxide and the metal alkoxide may be carried out at a temperature of about 100 to about 200 ℃.

In embodiments, the reaction of the dissimilar metal alkoxide and the halide metal compound may be performed at a temperature of about 100 to about 200 ℃.

Another aspect of the invention relates to a method for producing a carbonate ester. The production method is characterized in that in the presence of the organometallic compound, the carbon 1 to 10 alcohol and carbon dioxide to react.

In an embodiment, the reaction can be carried out at a temperature of about 130 to about 200 ° C. and a pressure of about 10 to about 200 bar.

The present invention is a novel organometallic compound capable of producing carbonic acid esters in high yield by improving the reactivity of carbon dioxide and alcohol, and a method of preparing the same, and a method of directly synthesizing carbonic acid esters from alcohols and carbon dioxide using the organometallic compound. It has the effect of providing the invention.

1 is a ¹ H-NMR spectrum of the organometallic compound prepared according to Preparation Example 1 of the present invention.

Hereinafter, the present invention will be described in detail.

The organometallic compound according to the present invention may be represented by the following Chemical Formula 1.

[Formula 1]

^{_{M a 3+ [M b (OR}} 1) 5] 3 -

In Formula 1, M _a is cerium, M _b is a Group 4 or 14 metal, preferably titanium (Ti), tin (Sn), or zirconium (Zr), R ₁ is a hydrocarbon having 1 to 10 carbon atoms The group may be, for example, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, and specifically, may be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or a phenyl group. Here, the oxygen atoms (O) of the metal atoms (M _a and M _b ) and the alkoxy group (OR ₁ ) may be connected by covalent bonds and coordination bonds, as shown in Formula 1a.

[Formula 1a]

In Formula 1a, M _a , M _b and R ₁ are as defined in Formula 1, and the arrow means a coordination bond.

The organometallic compound of the present invention is prepared by reacting an alkali metal alkoxide represented by the following Chemical Formula 2 and a metal alkoxide represented by the following Chemical Formula 3 to produce a dissimilar metal alkoxide represented by the following Chemical Formula 4; And reacting the dissimilar metal alkoxide and the halogenated metal compound represented by Chemical Formula 5 to prepare an organometallic compound represented by Chemical Formula 1.

[Formula 2]

M _c OR ₁

[Formula 3]

M _b (OR ₁ ) ₄

[Formula 4]

M _c ⁺ [M _b (OR ₁ ) ₅ ] ^-

[Formula 5]

M _a (X) ₃

In Formulas 2 to 5, M _a , M _b and R ₁ are as defined in Formula 1, M _c is an alkali metal, for example, sodium (Na), potassium (K) and the like, X is a halogen atom, For example, it is a chlorine atom (Cl), a bromine atom (Br).

In embodiments, the alkali metal alkoxide represented by the formula (2) and the metal alkoxide represented by the formula (3), for example, about 1: 1: 0.5 to about 1: molar ratio of about 2, specifically in an equimolar ratio , Bimetal alkoxide represented by Chemical Formula 4 by reflux at a temperature of about 100 to about 200 ° C., for example, about 110 to about 150 ° C., for example, for about 2 to about 4 hours. ) Can be prepared.

Next, after the halogenated metal compound represented by Formula 5 is added to the prepared dissimilar metal alkoxide, as shown in Scheme 1, at a temperature of about 100 to about 200 ° C, for example, about 110 to about 150 ° C, for example For example, the organometallic compound represented by Chemical Formula 1 may be prepared by reflux reaction for about 10 to about 15 hours. In addition, the prepared organometallic compound may be obtained in a solid state through a conventional cooling, filtration, and purification process.

Scheme 1

In the manufacturing process, the molar ratio of the halogenated metal compound represented by Chemical Formula 5 and the dissimilar metal alkoxide represented by Chemical Formula 4 is about 1: about 1 to about 1: about 5, for example, about 1: about 2 to about 1 : About 4, specifically about 1: about 3 to about 1: about 3.5. By-products can be minimized in the above range.

The method for preparing carbonate ester using the organometallic compound according to the present invention is characterized in that the carbonate ester is directly prepared by reacting carbon dioxide having 1 to 10 carbon atoms and carbon dioxide which are environmentally friendly raw materials in the presence of the organometallic compound.

Alcohol used in the present invention may be represented by the following formula (6).

[Formula 6]

R ₂ OH

In Chemical Formula 6, R ₂ is a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms.

Specific examples of the alcohol may include methanol, ethanol, propanol, butanol, pentanol, hexanol, phenol, and the like, but are not limited thereto.

In addition, the carbonate ester may be represented by the following formula (7).

[Formula 7]

R ₂ OCOOR ₂

In Chemical Formula 7, R ₂ is as defined in Chemical Formula 6.

The reaction can be carried out by a conventional batch reaction, and can be carried out at a temperature of 130 to 200 ℃, for example 140 to 190 ℃ and pressure conditions of 10 to 200 bar, for example 40 to 150 bar. In the above range, the reaction rate is fast and carbonate ester can be produced in high yield.

Batch reactions are typically carried out in consideration of conversion and reactor volume and are liquid phase processes that do not overheat.

In addition, the reaction of the present invention is a reaction that does not require a separate solvent using an alcohol having 1 to 10 carbon atoms as a liquid reactant and carbon dioxide and a solid organometallic compound as a gaseous reactant. That is, it may be a homogeneous reaction in which carbon dioxide and an organometallic compound are dissolved and reacted with the alcohol. The stirring of the reactor may use a magnetic bar or the like, and may be performed at a stirring speed of about 300 to about 1,000 rpm, for example 400 to 500 rpm, and a reaction time condition of 0.5 to 24 hours, for example 1 to 3 hours. However, in consideration of the state of the organometallic compound and the viscosity of the solvent, it is preferable to carry out in a region where the mass transfer at the interface between the carbon dioxide and the alkyl alcohol is maximum. Such a reaction can be easily carried out by those skilled in the art.

In an embodiment, the organometallic compound may be used in an amount of about 1 to about 30 moles, for example about 5 to about 15 moles, based on 100 moles of alkyl alcohol. Carbonate ester can be manufactured in high yield in the said range.

In addition, the pressure of the carbon dioxide may be about 10 to about 200 bar, for example about 40 to about 150 bar. Carbonate ester can be manufactured in high yield in the said range.

Carbonate ester production method of the present invention is economical because no separate organometallic compound regeneration process is required.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

Preparation Example 1 Preparation of Organometallic Compound

0.6 g (15 mmol) of potassium was stirred with 11.5 g (155 mmol) of 1-butanol at room temperature, and then reacted for 20 minutes, and then refluxed and cooled at 120 ° C. for 1 hour, followed by potassium butoxide. (KOBu) was prepared. To the prepared potassium butoxide (KOBu) 1.7 g (15 mmol) and 1-butanol mixture was added 5.2 g (15 mmol) of Ti (OBu) ₄ as a metal alkoxide, refluxed at 120 ° C. for 3 hours, and then cooled. To prepare a dissimilar metal alkoxide (KTi (OBu) ₅ ) represented by the following Chemical Formula 4a. To 6.8 g (15 mmol) of the prepared double metal alkoxide and 1-butanol mixture, 1.25 g (5 mmol) of cerium chloride (CeCl ₃ ) was added and refluxed at 120 ° C. for 12 hours in a nitrogen atmosphere, followed by cooling, filtration and After purification, the solvent was evaporated to obtain an organometallic compound represented by Chemical Formula 1b in the form of a white solid (yield: 23%). Metals and alkoxy groups of the prepared organometallic compounds were identified using an Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) and nuclear magnetic resonance spectroscopy (NMR). 1 and Table 1 show the results of ¹ H-NMR spectra and ICP-AES elemental analysis, respectively (Ce: Ti (molar ratio) = about 1: 3).

[Formula 4a]

K ⁺ [M _b (OBu) ₅ ] ^-

[Formula 1b]

_{^{Ce 3+ [Ti (OBu) 5}} ] 3 -

Table 1

	Ce	Ti
Formula weight (FW)	140.12 g / mol	47.88 g / mol
Content (% by weight)	11.02	10.95

Example 1

5 g (3.6 mmol) of organometallic compound (Ce ³⁺ [Ti (OBu) ₅ ] ₃ ⁻ ) represented by Scheme 1a in a 75 ml autoclave reactor with an external heater, 27.2 g (367.3) of 1-butanol mmol) was added and the mixture was heated to 150 ° C at the same time with stirring. Then, carbon dioxide was added to 120 bar, and the reaction was performed at 150 ° C and 120 bar for 1 hour, and then cooled to room temperature. After venting carbon dioxide and returning to normal pressure, the reaction solution was analyzed by gas chromatography, and it was confirmed that di-n-butylcarbonate was obtained in 75% yield.

Example 2

The reaction was performed in the same manner as in Example 1 except that the reaction temperature was 180 ° C. After completion of the reaction, the reaction solution was analyzed by gas chromatography. As a result, it was confirmed that di-n-butylcarbonate was obtained in 127% yield.

Example 3

The reaction was performed in the same manner as in Example 1 except that the reaction pressure was 60 bar. After completion of the reaction, the reaction solution was analyzed by gas chromatography, and it was confirmed that di-n-butylcarbonate was obtained in 69% yield.

Example 4

The reaction was carried out in the same manner as in Example 2, except that the reaction pressure was 60 bar. After completion of the reaction, gas chromatography analysis showed that di-n-butylcarbonate was obtained in 106% yield.

Comparative Example 1

The reaction was carried out in the same manner as in Example 1, except that 5 g (14.7 mmol) of the compound (Ti [OBu] ₄ ) represented by Formula 8a was used as the organometallic compound. After the completion of the reaction, gas chromatography analysis showed that di-n-butylcarbonate was obtained in 30% yield.

[Formula 8a]

Comparative Example 2

The reaction was performed in the same manner as in Comparative Example 1 except that the reaction temperature was 180 ° C. After the completion of the reaction, gas chromatography analysis showed that di-n-butyldicarbonate was obtained in 98% yield.

Comparative Example 3

The reaction was carried out in the same manner as in Comparative Example 1 except that the reaction pressure was 60 bar. After the completion of the reaction, the reaction solution was analyzed by gas chromatography. As a result, it was confirmed that di-n-butylcarbonate was obtained in 20% yield.

Comparative Example 4

The reaction was performed in the same manner as in Comparative Example 3 except that the reaction temperature was 180 ° C. After the reaction, the reaction solution was analyzed by gas chromatography, and it was confirmed that di-n-butylcarbonate was obtained in 82% yield.

Comparative Example 5

Example 1 and 5, except that 5 g (13.3 mmol) of the compound represented by the following Chemical Formula 8b (Bu ₂ Sn (OBu) ₂ ) was used as the organometallic compound, and 24.4 g (329.5 mmol) of 1-butanol was used. The reaction proceeded in the same manner. After completion of the reaction, gas chromatography analysis showed that di-n-butylcarbonate was obtained in 49% yield.

[Formula 8b]

Comparative Example 6

The reaction was carried out in the same manner as in Comparative Example 5 except that the reaction temperature was 180 ° C. After completion of the reaction, the reaction solution was analyzed by gas chromatography, and it was confirmed that di-n-butylcarbonate was obtained in 69% yield.

Comparative Example 7

The reaction was carried out in the same manner as in Comparative Example 5 except that the reaction pressure was 60 bar. After the completion of the reaction, the reaction solution was analyzed by gas chromatography, and it was confirmed that di-n-butylcarbonate was obtained in 50% yield.

Comparative Example 8

The reaction was carried out in the same manner as in Comparative Example 7 except that the reaction temperature was 180 ° C. After completion of the reaction, gas chromatography analysis showed that di-n-butyl carbonate was obtained in 60% yield.

The reaction conditions and the carbonate ester yield are shown in Table 2 below.

TABLE 2

	Organometallic compounds			Alcohol	Reaction temperature (℃)	Reaction pressure (bar)	Response time (h)	yield(%)
	Kinds	mmol	g	mmol					g
Example 1	Ce 3+ [Ti (OBu) 5 ] 3 -	3.6	5	367.3	27.2	150	120	One	75
Example 2	Ce 3+ [Ti (OBu) 5 ] 3 -	3.6	5	367.3	27.2	180	120	One	127
Example 3	Ce 3+ [Ti (OBu) 5 ] 3 -	3.6	5	367.3	27.2	150	60	One	69
Example 4	Ce 3+ [Ti (OBu) 5 ] 3 -	3.6	5	367.3	27.2	180	60	One	106
Comparative Example 1	Ti [OBu] 4	14.7	5	367.3	27.2	150	120	One	68
Comparative Example 2	Ti [OBu] 4	14.7	5	367.3	27.2	180	120	One	98
Comparative Example 3	Ti [OBu] 4	14.7	5	367.3	27.2	150	60	One	61
Comparative Example 4	Ti [OBu] 4	14.7	5	367.3	27.2	180	60	One	82
Comparative Example 5	Bu 2 Sn (OBu) 2	13.2	5	329.7	24.5	150	120	One	55
Comparative Example 6	Bu 2 Sn (OBu) 2	13.2	5	329.7	24.5	180	120	One	69
Comparative Example 7	Bu 2 Sn (OBu) 2	13.2	5	329.7	24.5	150	60	One	52
Comparative Example 8	Bu 2 Sn (OBu) 2	13.2	5	329.7	24.5	180	60	One	60

Property evaluation method

(1) Yield Evaluation: After the reaction, the reaction solution was analyzed by gas chromatography.

Yield of carbonate (%) = (mol of carbonate produced / mol of organometallic compound added) × 100

From the results of Table 1, it can be seen that the organometallic compound of the present invention can be produced in a good yield, compared to the existing organometallic compounds (Comparative Examples 1 to 8) under the same reaction conditions.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (9)

1. An organometallic compound characterized by the following formula (1):

   [Formula 1]

   ^{_{M a 3+ [M b (OR}} 1) 5] 3 -

   In Formula 1, M _a is cerium, M _b is a Group 4 or 14 metal, R ₁ is a hydrocarbon group having 1 to 10 carbon atoms.
2. The organometallic compound according to claim 1, wherein M _b is titanium (Ti), tin (Sn), or zirconium (Zr).
3. The organometallic compound according to claim 1, wherein R ₁ is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or a phenyl group.
4. To prepare a heterometal alkoxide represented by the following formula (4) by reacting the alkali metal alkoxide represented by the formula (2) and the metal alkoxide represented by the formula (3); And

   A method for preparing an organometallic compound, comprising the step of reacting the dissimilar metal alkoxide and a halogenated metal compound represented by Formula 5 to produce an organometallic compound represented by Formula 1 below:

   [Formula 1]

   ^{_{M a 3+ [M b (OR}} 1) 5] 3 -

   In Formula 1, M _a is cerium, M _b is a Group 4 or 14 metal, R ₁ is a hydrocarbon group having 1 to 10 carbon atoms;

   [Formula 2]

   M _c OR ₁

   [Formula 3]

   M _b (OR ₁ ) ₄

   [Formula 4]

   M _c ⁺ [M _b (OR ₁ ) ₅ ] ^-

   [Formula 5]

   M _a (X) ₃

   In Formulas 2 to 5, M _a , M _b and R ₁ are as defined in Formula 1, M _c is an alkali metal, X is a halogen atom.
5. The method of claim 4, wherein the molar ratio of the halogenated metal compound represented by Chemical Formula 5 and the dissimilar metal alkoxide represented by Chemical Formula 4 is about 1: about 2 to about 1: about 4. 6.
6. The method of claim 4, wherein the reaction of the alkali metal alkoxide and the metal alkoxide is carried out at a temperature of about 100 ° C. to about 200 ° C. 6.
7. The method of claim 4, wherein the reaction of the dissimilar metal alkoxide and the halide metal compound is performed at a temperature of about 100 ° C. to about 200 ° C. 6.
8. A method for producing a carbonate, characterized by reacting an alcohol having 1 to 10 carbon atoms and carbon dioxide in the presence of the organometallic compound according to any one of claims 1 to 3.
9. The method of claim 8, wherein the reaction is performed at a temperature of about 130 to about 200 ° C. and a pressure of about 10 to about 200 bar.

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