JPH08259504A - Method for producing aromatic carbonic acid ester - Google Patents

Abstract

(57) [Summary] [Purpose] When an aromatic carbonic acid ester is produced by transesterification or disproportionation, a highly active catalyst is used,
To provide a method for efficiently producing a target aromatic carbonic acid ester in a high yield. [Structure] A dialkyl carbonate and a phenol are transesterified to form an arylalkyl carbonate and / or a diaryl carbonate, and an arylalkyl carbonate and a phenol are transesterified to form a diaryl carbonate or a disproportionation reaction of an arylalkyl carbonate. To produce a diaryl carbonate, a catalyst of the general formula (I) R ¹ _n Sn (OR ² ) _4-n ... (I) [R ¹ and R ² are an alkyl group, an aryl group or an aralkyl group, n Indicates 1 to 3. ] The tin compound represented by
It is a method for producing an aromatic carbonic acid ester, which uses a product that is heat-treated at 0 to 250 ° C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic carbonic acid ester, more specifically, when an arylalkyl carbonate or a dialkyl carbonate is produced by reacting a dialkyl carbonate with a phenol or its acetic acid ester, or It has a high activity as a catalyst when an arylalkyl carbonate is reacted with a phenol or an acetic acid ester thereof to produce a diaryl carbonate or when an arylalkyl carbonate is disproportionated to produce a diaryl carbonate. The present invention relates to a method for efficiently producing a target aromatic carbonic acid ester in a high yield by using a material that does not decompose itself in a reaction system and does not decompose carbonic acid esters.

[0002]

2. Description of the Related Art In recent years, aromatic carbonic acid esters such as diphenyl carbonate have been attracting attention as raw materials for polycarbonate by transesterification (melt polymerization method) without using methylene chloride or phosgene. It is known that this aromatic carbonic acid ester is conventionally produced from phenols and phosgene, but this method uses highly toxic phosgene and produces a neutral salt such as sodium chloride as a by-product. However, there are drawbacks, and therefore various methods for producing aromatic carbonates without using phosgene have been tried in recent years. For example, a method for producing a diaryl carbonate by oxidative carbonylation of phenols with carbon monoxide,
Specifically, (1) a method using a catalyst system in which palladium, manganese, a quaternary ammonium salt and quinone are combined (JP-A-2-104564), (2) a combination of palladium, cobalt, a quaternary ammonium salt and quinone Using the above catalyst system (JP-A-2-142754),
(3) A method of using a catalyst system in which palladium is combined with an alkali metal iodide or an alkaline earth metal iodide or onium iodide compound and zeolites (JP-A-1-165551), (4) Palladium, A method using a catalyst system in which cobalt, a quaternary ammonium salt, quinone and CO ₂ are combined (JP-A-4-221347) has been proposed.

However, in all of these methods, the reaction rate and yield are extremely low, there is a risk of explosion due to the use of a mixed gas of carbon monoxide and oxygen, and toxic carbon monoxide is used. It has the drawback that it must be done. Therefore, in order to improve such drawbacks, a transesterification method using an aliphatic carbonic acid ester such as dimethyl carbonate, which is advantageous in terms of toxicity and safety, as a carbonylation source has been developed. In this method, an aromatic carbonate ester can be obtained with extremely high efficiency when combined with a method for efficiently removing alcohol by-produced in the reaction. The transesterification reaction using a dialkyl carbonate such as dimethyl carbonate as a raw material and an arylalkyl carbonate such as carbon phenylmethyl as an intermediate product is one of the most promising methods for producing diaryl carbonate such as diphenyl carbonate. Is represented by the following reaction formula.

[0004]

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In this reaction, the equilibrium of each stage is inclined to the raw material system, and the reaction does not proceed simply by mixing the compounds to be reacted. However, by adding an appropriate catalyst and heating to increase the reaction rate, and by sequentially removing each product by means such as reactive distillation, and moving the equilibrium to the production system, good selectivity and conversion can be obtained. It is possible to obtain By the way, various catalysts have been proposed up to now as catalysts for this reaction, but all of them have some problems and are not always sufficiently satisfactory. For example,
(1) Method using organic titanium or organic tin as a catalyst (Japanese Patent Publication No. 59-34170, Japanese Patent Publication No. 56-425)
77, JP-A-54-48733), (2)
A method using Zr (acac) ₄ , Fe (acac) ₃ (acac: acetylacetonato ligand) as a catalyst and acetylacetone as a cocatalyst (Japanese Patent Publication No. 1-5588), (3) Pb (OH) ₂ · 2PbCO ₃ method of using a lead compound such as a catalyst (KOKOKU 1-3181 discloses), (4) Fe (OCOCH 3) 3 the method of using the catalyst made mainly (JP 61-172852 JP), etc. Is proposed.

However, the above method (1) has a drawback that the catalytic activity is insufficient and the reaction rate is slow, and the method (2) has a slow reaction rate and also has a problem in the reaction system. It has a drawback that a large amount of by-products derived from acetylacetone produced in step 1 are produced. On the other hand, the method (3) has a drawback that the reaction rate is slow and the catalyst is basic, so that it causes decomposition of the aliphatic carbonate ester as a raw material or the aliphatic aromatic carbonate ester as an intermediate. is there. Further, in the method (4), Fe (OCOCH ₃ ) ₃ is unstable in properties,
Not commercially available and difficult to prepare and obtain. In addition,
Basic iron acetate having an Fe-OH bond is stable and commercially available. However, this one causes decomposition of carbonic acid ester similarly to the lead catalyst of the above (3), and acetic acid produced in the reaction system. There is a defect that a by-product is generated.

[0007]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the prior art, and produces a arylalkyl carbonate or a dialkyl carbonate by reacting a dialkyl carbonate with a phenol or an acetic acid ester thereof. Alternatively, when an arylalkyl carbonate is reacted with a phenol or an acetic acid ester thereof to produce a diaryl carbonate, or when an arylalkyl carbonate is disproportionated to produce a diaryl carbonate, it has a high activity as a catalyst, It is an object of the present invention to provide a method for efficiently producing a target aromatic carbonate ester in a high yield by using a substance that does not decompose itself in the reaction system and does not decompose carbonates.

[0008]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above-mentioned object, as a catalyst,
It has been found that the purpose can be achieved by using a specific tin compound. The present invention has been completed based on such findings. That is, according to the present invention, when (1) a dialkyl carbonate and a phenol or an acetic acid ester thereof are transesterified to produce an arylalkyl carbonate and / or a diaryl carbonate, a catalyst represented by the general formula (I) R ¹ _n Sn (OR ² ) _4-n ... (I) [In the formula, R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, and they may be the same or different from each other, and n is Indicates an integer of 1 to 3. ] A method for producing an aromatic carbonate ester (hereinafter, referred to as the first invention), characterized by using a tin compound represented by the following formula, which is heat-treated at a temperature of 180 to 250 ° C, and (2) an arylalkyl carbonate When a diaryl carbonate is produced by transesterification with a phenol or its acetic acid ester, a tin compound represented by the above general formula (I) that has been heat-treated at a temperature of 180 to 250 ° C. is used as a catalyst. A method for producing an aromatic carbonic acid ester (hereinafter referred to as the second invention), and (3) a disproportionation reaction of an arylalkyl carbonate to produce a diaryl carbonate, wherein the above-mentioned general formula is used as a catalyst. A method for producing an aromatic carbonic acid ester, which comprises using a tin compound represented by (I) which has been heat-treated at a temperature of 180 to 250 ° C. (hereinafter, There is provided a) that 3 of the invention. In the first invention, the general formula (II)

[0009]

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[In the formula, R ³ and R ⁴ each represent an alkyl group, and they may be the same or different from each other. A dialkyl carbonate represented by] the general formula ^{(III) Ar 1 -OH ··· (} III) wherein, Ar ¹ represents an or without aryl group having a substituent. ] By transesterification with a phenol or its acetic ester represented by the following general formula (IV)

[0011]

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[Wherein R represents R ³ or R ⁴ , and A
r ¹ , R ³ and R ⁴ are the same as above. ] Arylalkyl carbonate represented by and / or general formula (V)

[0013]

[Chemical 4]

[In the formula, Ar ¹ is the same as above. ] The diaryl carbonate represented by these is manufactured. In the second invention, the general formula (VI)

[0015]

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[In the formula, Ar ² represents an aryl group with or without a substituent, and R ⁵ represents an alkyl group. ] By the transesterification reaction of the arylalkyl carbonate represented by the above with the phenols represented by the above general formula (III) or an acetic acid ester thereof, the general formula (VII)

[0017]

[Chemical 6]

[In the formula, Ar ¹ and Ar ² are the same as above. ] The diaryl carbonate represented by these is manufactured. On the other hand, in the third invention, the arylalkyl carbonate represented by the general formula (VI) is subjected to a disproportionation reaction to obtain the general formula (VIII).

[0019]

[Chemical 7]

[In the formula, Ar ² is the same as above, and the two Ar ² may be the same or different. ] The aromatic diaryl represented by this is manufactured. In this disproportionation reaction, one kind of arylalkyl carbonate represented by the general formula (VI) may be used for disproportionation, or two different kinds may be used for disproportionation. In the first invention, in the dialkyl carbonate represented by the above general formula (II) used as a raw material, the alkyl group represented by R ³ and R ⁴ may be linear, branched or cyclic. Good, particularly those having 1 to 10 carbon atoms are preferable. Specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group,
Examples thereof include n-hexyl group, isohexyl group and cyclohexyl group. R ³ and R ⁴ may be the same or different.

Specific examples of the dialkyl carbonate represented by the above general formula (II) include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, dicyclohexyl carbonate, methyl ethyl carbonate,
Examples thereof include methyl propyl carbonate, methyl butyl carbonate, ethyl propyl carbonate, ethyl butyl carbonate, propyl butyl carbonate, and among these, dimethyl carbonate is particularly preferable.

In the first and second inventions, Ar ¹ in the phenols represented by the above general formula (III) used as a raw material represents an aryl group such as a phenyl group or a naphthyl group. A suitable substituent may be introduced into the group. Here, as the substituent,
For example, halogen atom such as chlorine atom or bromine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-
A butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, and other alkyl groups having 1 to 6 carbon atoms, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-
Butoxy group, isobutoxy group, sec-butoxy group, t
—C1-C6 alkoxy groups such as butoxy group, nitro groups and cyano groups. One of these substituents may be introduced, or two or more thereof may be introduced.

Specific examples of the phenols represented by the above general formula (III) include phenol, α-naphthol, β-naphthol, various cresols, various chlorophenols, various ethylphenols, various n-propylphenols, various isopropyls. Phenol, various butylphenols, various methoxyphenols, various ethoxyphenols, various n-propoxyphenols, various isopropoxyphenols, various butoxyphenols, various nitrophenols, various cyanophenols, various xylenols, etc. It is suitable. In the present invention, these acetic acid esters of phenols can also be used as a raw material like phenols. On the other hand, in the second and third invention, in a carbon arylalkyl represented by the general formula (VI) used as a raw material, Ar ² is a or without aryl group having a substituent, the above Ar ¹ The same as those exemplified in the explanation can be mentioned, and R ⁵ is an alkyl group, and the same ones as exemplified in the explanation of R ³ and R ⁴ can be mentioned.

Specific examples of the arylalkyl carbonate represented by the general formula (VI) include phenylmethyl carbonate, phenylethyl carbonate, phenylpropyl carbonate, phenylbutyl carbonate, phenylpentyl carbonate, phenylhexyl carbonate and phenylcyclohexyl carbonate. Can be mentioned,
Of these, phenylmethyl carbonate is particularly preferable.
In the method of the present invention, in any of the above-mentioned first invention, second invention and third invention, the catalyst of the general formula (I) R ¹ _n Sn (OR ² ) _4-n ... (I [In the formula, R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, which may be the same or different from each other, and n represents an integer of 1 to 3. ] The thing which heat-processed the tin compound represented by these at the temperature of 180-250 degreeC is used.

In the above general formula (I), R ¹ and R ²
Are each an alkyl group, an aryl group or an aralkyl group. Here, the alkyl group may be linear, branched, or cyclic, and preferably has 1 to 12 carbon atoms. Specific examples thereof include methyl group, ethyl group, n-
Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group,
Hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group and the like can be mentioned. The aryl group is preferably one having 6 to 12 carbon atoms such as a phenyl group or a naphthyl group, and this aryl group may have a suitable substituent introduced therein. Examples of the substituent include halogen atoms of F, Cl, Br and I,
Examples thereof include lower alkyl groups such as methyl group and ethyl group, lower alkoxy groups such as methoxy group and ethoxy group, and nitro group and cyano group. One of these substituents may be introduced, or two or more thereof may be introduced. Further, the aralkyl group is preferably an aralkyl group having a carbon number of 7 to 12, such as benzyl group and phenethyl group, and the aralkyl group may have an appropriate substituent introduced on the aromatic ring. As this substituent, the same ones as exemplified in the above description of the substituent of the aryl group can be mentioned. One of these substituents may be introduced, or two or more may be introduced. Also, n is 1
3 to 3 are shown, and R ¹ and R ² may be the same or different. In the case where R ¹ is plural, R ¹ may be the same or different, if OR ² there is a plurality, the plurality of OR ² may be the same or different.

Examples of the tin compound represented by the general formula (I) include methyltin triphenoxide, dimethyltin diphenoxide, trimethyltin phenoxide, ethyltin triphenoxide, diethyltin diphenoxide, triethyltin phenoxide, butyltin trioxide. Phenoxide, dibutyltin diphenoxide, tributyltin phenoxide, octyltin triphenoxide, dioctyltin diphenoxide, trioctyltin phenoxide, methyltin trioctoxide, dimethyltin dioctoxide, trimethyltin octoxide, ethyltin trioctoxide, diethyltin dioctoxide, triethyl. Tin octoxide, butyltin trioctoxide, dibutyltin dioctoxide, tributyltin octoxide, methyltin tribenzyloxide, dimethyltin dibenzyloxide , Trimethyl-tin Benjirokishido,
Ethyltin tribenzyloxide, diethyltin dibenzyloxide, triethyltin benzyloxide, butyltin tribenzyloxide, dibutyltin dibenzyloxide, tributyltin benzyloxide, octyltin tribenzyloxide, dioctyltin dibenzyloxide, trioctyltin benzyloxide, phenyltin trimethoxide, diphenyl Tin dimethoxide, triphenyl tin methoxide, octyl tin trimethoxide, dioctyl tin dimethoxide, trioctyl tin methoxide, phenyl tin triethoxide, diphenyl tin diethoxide, triphenyl tin ethoxide, octyl tin triethoxide, dioctyl tin diethoxide, trioctyl tin ethoxide, benzyl tin trimethoxide, dibenzyl Tin dimethoxide, tribenzyl tin methoxide, benzyl tin trieth Sid, dibenzyl tin diethoxide,
Examples thereof include tribenzyl tin ethoxide. Of course, it is not limited to these.

In the present invention, these tin compounds are
It is necessary to perform heat treatment at a temperature of 80 to 250 ° C. If the treatment temperature deviates from this range or the heat treatment is not performed, a highly active substance cannot be obtained and the object of the present invention cannot be achieved. If necessary, this heat treatment may be carried out in a suitable inert solvent, or may be carried out under an atmosphere of an inert gas such as nitrogen or argon. The pressure is not particularly limited, but it is usually performed at normal pressure. The heat treatment time depends on the treatment temperature and the like and cannot be determined unconditionally, but generally 0.1 to 24 hours is sufficient. In the present invention, as the catalyst, one kind of the tin compound represented by the general formula (I) thus heat-treated may be used, or two or more kinds thereof may be used in combination. Furthermore, even if it is not the tin compound itself represented by the general formula (I), a compound that substantially forms the compound represented by the general formula (I) during the reaction is heat-treated as described above. Can also be used as a catalyst.

The amount of the catalyst used is 10 ⁻⁴ to 10 as tin atom based on the starting material dialkyl carbonate in the first invention and the starting materials arylalkyl carbonate in the second and third inventions. A double molar range is preferred. If this amount is less than 10 ^-4 times by mole, the reaction rate is slow and the efficiency is poor, while if it exceeds 10 times by mole, the amount of recycled catalyst increases and the efficiency also deteriorates. From the viewpoint of the balance between the reaction rate and the recycling amount of the catalyst, the tin atom is 10 ⁻³ to 10 ³ with respect to the dialkyl carbonate or the arylalkyl carbonate.
^It is particularly preferred to use the catalyst in a molar ratio of ^-1 . Although the used catalyst is usually recovered and reused,
At this time, it is desirable that the above-mentioned heat treatment is applied before use.

In the first and second aspects of the present invention, there is no particular limitation on the ratio of the raw materials phenol or its acetic acid ester and carbonic acid diester (dialkyl carbonate or arylalkyl carbonate) to be used. Phenol or its acetic acid ester is preferably used in a molar ratio of 0.1 to 10 times. If this amount is less than 0.1 times the molar amount, the recycling amount of the carbonic acid diester will be large and the efficiency will be poor, and if it exceeds 10 times the molar amount, the recycling amount of the phenols and its acetic acid ester will be large and the efficiency will also be poor. From the viewpoint of efficiency, it is more preferable to use the phenol or its acetic acid ester in a molar ratio of 4 to 8 times with respect to the carbonic acid diester. Further, the first invention and the second invention
In both the invention and the third invention, the reaction temperature is preferably selected in the range of 50 to 300 ° C. If this temperature is lower than 50 ° C., the reaction rate is too slow to be practical, and if it exceeds 300 ° C., side reactions and the like tend to occur and the yield tends to decrease. In terms of reaction rate and yield,
The more preferable reaction temperature is in the range of 120 to 200 ° C. Further, the reaction system may be either a batch system or a continuous system, but it is advantageous to take measures to remove the by-produced alcohol or dialkyl carbonate out of the system. The reactions of the first invention, the second invention and the third invention are
Since all of these reactions are extremely biased towards the raw material side,
In order to obtain the desired aromatic carbonate ester, especially diaryl carbonate in good yield, it is essential to remove the by-produced alcohol and dialkyl carbonate to the outside of the system by some method and shift the reaction equilibrium to the product side. is there. The method for removing the by-product alcohol and the by-product dialkyl carbonate is not particularly limited, but generally, a method of distilling the by-product alcohol and the by-product dialkyl carbonate at the same time as the reaction is adopted. However, when dimethyl carbonate (DMC) is used as the dialkyl carbonate in the first invention, the by-product methanol and DMC have a composition in a weight ratio of 70:30 and azeotrope at 63.5 ° C. Part of DMC is also distilled out of the system without being used in the reaction (Japanese Patent Publication No. 59-42577, Japanese Patent Application Laid-Open No. 3-291257, etc.). Therefore, a method of removing only methanol by using an azeotropic agent such as n-heptane or benzene has been proposed (Japanese Patent Laid-Open No. Sho 5).
These methods can be applied to the present invention as well as those disclosed in JP-A-4-48732 and JP-A-61-291545.

Thus, in the first invention,
The arylalkyl carbonate represented by the general formula (IV) and / or the diaryl carbonate represented by the general formula (V) can be efficiently obtained in a high yield. In this reaction, when phenol and dimethyl carbonate are used as raw materials, phenylmethyl carbonate and / or diphenyl carbonate are obtained. On the other hand, in the second invention, the general formula (VI
The diaryl carbonate represented by I) can be efficiently obtained in a high yield. In this reaction, when phenol and phenylmethyl carbonate are used as raw materials, diphenyl carbonate is obtained. In the third invention, only arylalkyl carbonate is sufficient as the reaction raw material, and when phenylmethyl carbonate is used, diphenyl carbonate is obtained.

[0031]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples.
As will be appreciated, the invention is in no way limited by these examples.
It is not something to be done. Example 1 Dioctyl tin was added to a 200 ml three-necked flask.
Diphenoxide [(C ₈H₁₇)₂Sn (OC₆H_Five)₂] 0.
Charge 13 g (0.25 mmol) and hexadecane 3 g.
Then, the system was replaced with nitrogen. Next, heat to 240 ° C in advance
Place it in the oil bath and heat at that temperature for 6 hours.
went. After the treatment, let it cool to room temperature and then
Put 94 g in the flask, and put it in the mouth in the center of the flask.
A packed tower containing 16 g of curular sieve 4A, on the left and right mouths
Is a two-way cock and a thermometer.
I attached a condenser. Next, heat to 170 ° C in advance
Attach the flask to the oil bath and set the internal temperature to 170 ° C.
After reaching it, guide 22.5 g of dimethyl carbonate from the two-way cock.
It was turned on and the reaction started. After reacting for 3 hours, the reaction solution
Was analyzed by gas chromatography,
42 mmol of phenylmethyl acid and 3.
1 mmol was produced.

Example 2 The procedure of Example 1 was repeated, except that the catalyst heat treatment temperature was changed to 190 ° C. The results are shown in Table 1. Example 3 Example 1 was repeated except that the catalyst heat treatment temperature was changed to 210 ° C. The results are shown in Table 1. Example 4 The procedure of Example 1 was repeated, except that the heat treatment temperature of the catalyst was changed to 230 ° C. The results are shown in Table 1.

Example 5 In Example 1, instead of dioctyltin diphenoxide as a catalyst, dibutyltin diphenoxide [(C ₄ H
₉ ) ₂ Sn (OC ₆ H ₅ ) ₂ ] was used, and the same procedure as in Example 1 was performed. The results are shown in Table 1. Example 6 In Example 1, instead of dioctyltin diphenoxide as a catalyst, dioctyltin dimethoxide [(C ₈ H
₁₇ ) ₂ Sn (OCH ₃ ) ₂ ] was used, and the same procedure as in Example 1 was performed. The results are shown in Table 1.

Example 7 A 200 ml three-necked flask was charged with dioctyl tin.
Diphenoxide [(C ₈H₁₇)₂Sn (OC₆H_Five)₂] 0.
13 g (0.25 mmol) and 3 g of diphenyl carbonate are prepared.
Then, the system was replaced with nitrogen. Next, preheat to 240 ° C
Place in a heated oil bath and heat at that temperature for 6 hours.
It was. After treatment, diphenyl carbonate was distilled off under reduced pressure.
After adding 94g of phenol into the flask,
The central mouth is filled with 16 g of molecular sieve 4A.
Packing tower, two-way cocks and thermometers on the left and right mouths, and a packing tower
A Jimroth condenser was attached to the upper part. Next in advance
Place the flask in an oil bath heated to 170 ° C and
After the temperature reached 170 ° C, dimethyl carbonate was discharged from the two-way cock.
The reaction was started by introducing 22.5 g. React for 3 hours
After that, the reaction solution was analyzed by gas chromatography.
As a result, 40 mmol of phenylmethyl carbonate and dicarbonate
3.0 mmol of phenyl was formed.

Comparative Example 1 The procedure of Example 1 was repeated, except that the catalyst was not heat-treated. The results are shown in Table 1. Comparative Example 2 The procedure of Example 1 was repeated, except that the catalyst heat treatment was performed at 270 ° C. The results are shown in Table 1.

[0036]

[Table 1]

[0037]

[Table 2]

Example 8 [Reaction 1] A 100 ml three-necked flask was charged with
Octyl tin diphenoxide [(C ₈H₁₇)₂Sn (OC₆
H_Five)₂] 0.21 g (0.4 mmol) and phenol 47
g, and add a molecular sieve to the central mouth of the flask.
A packed tower containing 4 g of 4A, a two-way cock on the left and right mouths
And a thermometer, and a Dimroth condenser at the top of the packed tower.
-I put it on. After replacing the inside of the system with nitrogen, raise the temperature to 160 ° C beforehand.
Immersed in a heated oil bath, the internal temperature reached 160 ℃
At that point, 22.5 g of dimethyl carbonate was introduced from the two-way cock.
Then, the reaction was started. After reacting for 6 hours,
When analyzed by gas chromatography, carbon dioxide
Phenylmethyl 19 mmol and diphenyl carbonate 1.
9 mmol was produced.

[Reaction 2] Next, the temperature of the oil bath is adjusted to 195.
The temperature was raised to 0 ° C. and the reaction was performed for 6 hours. When the reaction solution was analyzed by gas chromatography, phenylmethyl carbonate was 13 mmol and diphenyl carbonate was 1 mol.
2 mmol was produced. [Catalyst recovery] The liquid after the reaction is heated to an oil bath temperature of 90 to 2
The product was distilled off under reduced pressure in the range of 10 ° C. Then, the distillation residue was heated at 210 ° C. for 2 hours. [Re-reaction] The catalyst residue treated as described above,
47 g of phenol was added and the reaction was carried out in the same manner as in [Reaction 1] above. When the reaction liquid after 6 hours was analyzed by a gas chromatography method, 37 mmol of phenylmethyl carbonate and 3 mmol of diphenyl carbonate were formed. From this, it was found that the heat-treated catalyst residue had much higher catalytic activity than the non-heat-treated catalyst used in the above [Reaction 1]. Further, even when the same operation was repeated 8 times, the high activity of the catalyst was maintained.

[0040]

EFFECTS OF THE INVENTION According to the present invention, a tin-based compound that has high activity during the transesterification reaction or disproportionation reaction, does not decompose in the reaction system, and does not cause decomposition of carbonic acid ester. By using the catalyst, the target aromatic carbonic acid ester can be efficiently produced in a high yield.

Front page continuation (72) Inventor Takahito Fujii 1280, Uezumi, Sodegaura, Chiba Idemitsu Kosan Co., Ltd.

Claims (7)

[Claims] 1. A method for producing an arylalkyl carbonate and / or a diaryl carbonate by transesterifying a dialkyl carbonate with a phenol or an acetic acid ester thereof to produce a arylalkyl carbonate and / or a diaryl carbonate as a catalyst, R ¹ _n Sn (OR ² ) _4-n ... (I) [In the formula, R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, which may be the same or different from each other, and n is 1 to 3; Indicates an integer. ] The manufacturing method of the aromatic carbonic acid ester characterized by using what heat-processed the tin compound represented by these at the temperature of 180-250 degreeC. 2. When a diaryl carbonate is produced by transesterifying an arylalkyl carbonate with a phenol or an acetic acid ester thereof, a catalyst of the general formula (I) R ¹ _n Sn (OR ² ) _4-n. · · (I) wherein, R ¹ and R ² are each an alkyl group, an aryl group or an aralkyl group, which may be the same with or different from each other, n represents an integer of 1-3. ] The manufacturing method of the aromatic carbonic acid ester characterized by using what heat-processed the tin compound represented by these at the temperature of 180-250 degreeC. 3. A catalyst for producing a diaryl carbonate by the disproportionation reaction of an arylalkyl carbonate.
General formula (I) R ¹ _n Sn (OR ² ) _4-n ... (I) [In the formula, R ¹ and R ² each represent an alkyl group, an aryl group or an aralkyl group, and they are the same as each other. However, they may be different, and n represents an integer of 1 to 3. ] The manufacturing method of the aromatic carbonic acid ester characterized by using what heat-processed the tin compound represented by these at the temperature of 180-250 degreeC. 4. A raw material carbonic acid diester, to which a tin compound represented by the general formula (I) is heat-treated at a temperature of 180 to 250 ° C., in a proportion of 10 ⁻⁴ to 10 times by mole as a tin atom. The method according to claim 1, which is used. 5. The method according to claim 1, wherein the dialkyl carbonate is dimethyl carbonate. 6. The method according to claim 1 or 2, wherein the phenols are phenols. 7. The method according to claim 2 or 3, wherein the arylalkyl carbonate is phenylmethyl carbonate.