JPH0853396A - Production of aryl-substituted alkylene carbonate - Google Patents

Abstract

PURPOSE:To produce an aryl-substituted alkylene carbonate in high yield under mild reactional conditions. CONSTITUTION:This method for producing an aryl-substituted alkylene carbonate is to react an aryl-substituted alkylene oxide with carbon dioxide in the presence of alcohols in an amount of 0.2-1 based on the aryl-substituted alkylene oxide in reacting the aryl-substituted alkylene carbonate with the carbon dioxide in the presence of a bromide and/or a chloride of an alkali metal as a catalyst and producing the aryl-substituted alkylene carbonate.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention relates to a process for producing aryl-substituted alkylene carbonate from aryl-substituted alkylene carbonate and carbon dioxide. More specifically, a method for producing an aryl-substituted alkylene carbonate at a high reaction rate and yield by reacting an aryl-substituted alkylene oxide with carbon dioxide under relatively mild conditions using an alkali metal bromide and / or chloride as a catalyst. Regarding

[0003]

2. Description of the Related Art For example, bismuth, germanium, tellurium compounds (JP-A-57-49614) and selenium compounds (JP-A-5-58) are used as catalysts for producing styrene carbonate from styrene oxide and carbon dioxide.
No. 8-222079) and the like have been proposed. However, in these methods, since the reaction is carried out under a pressure of 50 Kg / cm2, the cost of equipment such as a reactor is high, and it cannot be said that the method is economically advantageous. The yield is as low as 70%.

Further, a method using a catalyst comprising a quaternary phosphonium salt and an alcohol (Japanese Patent Laid-Open No. 59-13776).
Issue gazette). However, in this method, since an expensive quaternary phosphonium salt is used as a catalyst, it is necessary to pay sufficient attention to its recovery and reuse, and there is a drawback that even a slight loss causes an increase in cost.

[0005]

DISCLOSURE OF THE INVENTION The present invention uses an inexpensive alkali metal bromide and / or chloride as a catalyst when an aryl-substituted alkylene oxide is reacted with carbon dioxide to produce an aryl-substituted alkylene carbonate, Moreover, it is an object of the present invention to provide a method for producing an aryl-substituted alkylene carbonate, which is economically advantageous, in which the reaction temperature and the reaction pressure are milder and a high reaction rate and a high yield are obtained.

[0006]

That is, the present invention uses an aryl-substituted alkylene carbonate and carbon dioxide in an amount of 0.2 to 1 times the amount of an aryl-substituted alkylene oxide by using an alkali metal bromide and / or chloride as a catalyst. A method for producing an aryl-substituted alkylene carbonate which is economically advantageous in that the reaction rate is high under mild conditions and the aryl-substituted alkylene carbonate can be produced in a high yield, which is characterized by reacting in the presence of an alcohol. It is provided.

The aryl-substituted alkylene oxide has the following general formula (1):

[0008]

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(In the formula, R ¹ is a hydrogen atom or a carbon number of 1 to 1.
4 is an alkyl group, and R ² is an aromatic hydrocarbon group. ) Is used. As a specific example, a compound in which R ¹ is hydrogen is styrene oxide, p
-Bromo styrene oxide, p-methyl styrene oxide, p-butyl styrene oxide and the like and examples of the compound in which R ¹ is an alkyl group include α-methyl styrene oxide and the like.

The reaction between the aryl-substituted alkylene oxide and carbon dioxide proceeds according to the following formula (2).

[0011]

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In the method of the present invention, as the alkali metal bromide and / or chloride used as a catalyst,
Bromides of sodium, potassium, rubidium, cesium, and lithium, and chlorides, which are relatively inexpensively available and stable, and thus can be easily recovered and reused. From the viewpoint of cost, bromide and / or chloride of sodium and potassium are particularly preferable.

The amount of the catalyst used is 0.001 mol% to 1 with respect to 1 mol of the starting aryl-substituted alkylene oxide.
0 mol%, preferably 0.01 mol% to 5 mol%
In general, the larger the amount used, the higher the reaction accelerating effect. However, there is a limit to the improvement of the effect, and even if it is used too much, the excess amount is reduced due to the limitation of the amount dissolved in the reaction solution. Since the proportional effect cannot be obtained, it is practically within the range of the saturated dissolution amount in the reaction solution.

The alcohol used as the solvent is not particularly limited and may be any one which is economically advantageous. Specific examples include aliphatic monohydric alcohols having 1 to 3 carbon atoms such as methanol, ethanol, n-propanol and i-propanol, ethylene glycol, propylene glycol, 1.3-propanediol, 1.2-butanediol. , Aliphatic dihydric alcohols such as 1.4-butanediol and 1.6-hexanediol, alicyclic dihydric alcohols such as cyclohexanediol and cyclohexanedimethanol, and benzenedimethanol (o, m, p,) Aromatic dihydric alcohol, aliphatic polyhydric alcohol such as glycerin, diethylene glycol, dipropylene glycol,
Examples thereof include polyalkylene glycols such as triethylene glycol and tripropylene glycol.

The amount of alcohols used is 0.2 to 1 times by weight that of the raw material aryl-substituted alkylene oxide. The reaction acceleration effect improves as the amount increases, but if the amount is too large, the concentration of the aryl-substituted alkylene oxide in the reaction zone becomes low and the reaction rate becomes remarkably slow, and the production amount of the aryl-substituted alkylene carbonate per reactor is low. Become.

By using an appropriate amount of alcohol, the aryl-substituted alkylene oxide, carbon dioxide, and the alkali metal halide of the catalyst are preferably dissolved, and these catalytic reactions in the reaction zone liquid are advantageously carried out. As a result, a fast reaction rate can be obtained at a low reaction temperature and a reaction pressure, as will be apparent from the examples described later.

In the reaction, the aryl-substituted alkylene oxide, the catalyst and the alcohol are usually charged in a reactor, carbon dioxide is supplied to the reactor, and the mixture is heated by stirring or the like to start the reaction. Since carbon dioxide is consumed as the reaction progresses, carbon dioxide is continuously supplied to complete the reaction.

The reaction temperature is usually in the range of 50 ° C to 200 ° C, more preferably 50 ° C to 150 ° C. The reaction pressure varies depending on the reaction temperature, the amount of carbon dioxide, the composition of the reaction solution, and the like, and the reaction pressure can be changed depending on the progress (elapsed time) of the reaction, but normally, the total pressure is 1 to 20 kg.
/ cm ² G (0.1 to 2.0 MPa), preferably 1 to 10 kg / cm ² G (0.1 to 1.0 MPa) in total pressure. The reaction time varies depending on the type of catalyst, but is usually 0.5
Time ~ 4 hours.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The amount of aryl-substituted alkylene carbonate was determined by gas chromatography.

Example: A styrene oxide 5 was added to a stainless steel autoclave equipped with a stirrer having a capacity of 300 ml.
Charge 0 g, 1.0 g potassium bromide as a catalyst, and 32.7 g triethylene glycol, and after replacing the inside of the reactor with carbon dioxide, pressurize carbon dioxide to 2 kg / cm ² G and then raise the temperature to 110 ° C. did. Although the pressure increased slightly as the temperature increased, the pressure decreased as the reaction proceeded. Therefore, carbon dioxide was continuously supplied from the bomb so that the pressure was constantly maintained at 9.5 Kg / cm ² . While maintaining this state, the reaction was continued for 2 hours. After the reaction was completed, the content was analyzed and the yield of styrene carbonate was 98.0%.

Comparative Example: As a result of carrying out the reaction in the same manner as in Example except that triethylene glycol was not charged, the yield of styrene carbonate was 0%.

Claims (4)

[Claims] 1. An aryl-substituted alkylene oxide and carbon dioxide are used as a catalyst with an alkali metal bromide and / or chloride as a catalyst, and the amount of the aryl-substituted alkylene oxide is 0.2.
A method for producing an aryl-substituted alkylene carbonate, which comprises reacting in the presence of 1 to 1 times by weight of alcohol. 2. The method according to claim 1, wherein the alcohol is a dihydric alcohol. 3. The dihydric alcohol is ethylene glycol,
3. A compound selected from propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol.
The method described in. 4. The reaction is carried out at a pressure of 1 to 20 kg / cm ² G
The method according to claim 1, wherein the method is performed in the range of (0.1 MPa to 2.0 MPa).