JPS5839144B2 - Method for producing carbonic acid monoester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a carbonic acid monoester salt that is easy to handle.

That is, the present invention is a method for producing a carbonic acid monoester salt, which is characterized by adding alcohol to an inert solvent slurry of an alkali metal carbonate in a carbon dioxide atmosphere.

(In the formula, R represents a hydrocarbon residue and M represents an alkali metal.

) is expected to have a wide range of uses as a synthetic intermediate for a variety of compounds such as agricultural chemicals, medicines, and dyes.

Conventionally, this compound has been produced by a method in which alcohol and an alkali metal are reacted to obtain alcoholade, and this is reacted with carbon dioxide gas.

However, such a method has the drawbacks of complicated operations and poor yield.

This tendency is particularly noticeable when the raw material alcohol is not a monohydric lower alcohol.

The present inventors prepared alcohol and alkali metal carbonate (hereinafter simply referred to as carbonate) in a carbon dioxide atmosphere.

) reacts very easily when brought into contact with carbonic acid monoester salts (hereinafter simply referred to as ester salts).

) and bicarbonate, and the ester salt obtained by this reaction shows superior reactivity compared to bicarbonate and carbonate, and it is possible to preferentially react only the ester salt by selecting reaction conditions. I learned something.

However, when producing a carbonate monoester salt by this reaction, if the alcohol and carbonate are directly mixed and then the reaction is carried out in a carbon dioxide atmosphere, the product tends to aggregate and coagulate, and it is difficult to stir, transport, or use the product. There was a drawback that it caused inconvenience at different times.

Therefore, many difficulties were involved in implementing it on an industrial scale.

The present inventors have conducted extensive research in order to obtain an ester salt that prevents coagulation and coagulation of the product and is easy to handle.

As a result, by adding an inert solvent to the carbonate and - creating an inert solvent slurry of the bicarbonate, adding alcohol to the slurry in a carbon dioxide atmosphere prevents the coagulation and condensation of the product. We discovered that this can be done and completed the present invention.

That is, the present invention provides alcohol, alkaline earth carbonate,
A method for producing a carbonic acid monoester salt is characterized in that when producing the carbonic acid monoester salt by the reaction of carbonic acid gas and carbonic acid gas, alcohol is added to an inert solvent slurry of an alkali metal carbonate in a carbonic acid gas atmosphere.

In the present invention, when producing a carbonate monoester salt by the reaction of alcohol, alkali metal carbonate, and carbon dioxide gas,
The biggest feature of this method is that an inert solvent slurry of carbonate is first created, and then alcohol is added to the slurry under a carbon dioxide gas atmosphere.

Alcohol can be added in various ways.

Of course, it can be added instantly, or it can be added sequentially.

If the alcohol is added instantaneously, if the amount of inert solvent is extremely small, or if the reaction system is not sufficiently stirred, agglomeration or coagulation of the product may occur.

Even in such a case, such trouble can be prevented by sequentially adding alcohol for 15 minutes or more.

That is, it is a more preferred embodiment to add alcohol sequentially.

When adding the alcohol sequentially, the addition can be carried out continuously or intermittently.

As the alcohol used in the present invention, any compound having an alcoholic hydroxyl group can be used without any restriction, and primary, secondary and tertiary alcohols, monohydric, dihydric and higher polyhydric alcohols can be used. It can be used.

Specifically, methyl alcohol, ethyl alcohol, isopropyl alcohol, t-butyl alcohol/l/, 71
) alcohol, flopargyl alcohol, benzyl alcohol, phenethyl alcohol, cyclohexel alcohol, ethylene glycol, flopylene glycol,
Examples include diethylene glycol, 1,4-butanediol, glycerin, sorbitol, and the like.

Alcohol can be used alone or diluted with an inert solvent.

The carbonate used in the present invention is preferably an alkali metal carbonate, particularly sodium carbonate or potassium carbonate.

The amount of carbonate to be added to alcohol is 0 per 1 hydroxyl group of alcohol in order to increase the conversion rate of alcohol.
．． It is desirable that the amount is 5 times the mole or more, preferably 1 times the mole or more.

If the amount of carbonate charged is too large, the amount of unreacted carbonate will increase, which is often undesirable from an operational point of view.

Generally, 0.5 to 1 per 1 hydroxyl group of alcohol
．． The amount used is 5 times the mole, preferably 1.0 to 1.2 times the mole.

In order to increase the reactivity of the carbonate used, it is preferable that the particle size is smaller, and the carbonate is preferably pulverized.

However, it is preferable to use light ash obtained by roasting sodium bicarbonate obtained by the Solvay process, that is, soda carbonate, which is generally referred to as a light group, as it exhibits excellent reactivity without being particularly pulverized.

When the Wright group is used, it is easy to separate the solids after the reaction, wash the solids, etc., and has great industrial significance.

The inert solvent used to slurry the carbonate may be used without any limitation as long as it does not react with the alcohol or carbonate under the reaction conditions and does not substantially dissolve the carbonate.

When a solvent compatible with alcohol is used, it is possible to relax the stirring conditions and shorten the alcohol addition time.

Commonly used inert solvents include hydrocarbons, chlorinated hydrocarbons, ethers, esters, ketones, nitriles, substituted amides, and the like.

More specific inert solvents that are preferably used include hexane, butane, cyclohexane, benzene, toluene, dichloromethane, chloroform, carbon tetrachloride,
-dichloroethane 1 ・1, ■・-trichloroethane
Trichlorethylene, tetrachlorethylene, ■・2-
Dichloropropane, allyl chloride, butyl chloride, chlorobenzene, ethyl ether, isopropyl ether, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate,
These include diethyl carbonate, propylene carbonate, acetonitrile, propionitrile, N-N-dimethylformamide, dimethyl sulfoxide, and the like.

Furthermore, when selecting a solvent, it is desirable to consider the intended use of the obtained ester salt.

When producing an ester salt for the purpose of a synthetic intermediate, it is desirable to select a solvent suitable for the next reaction and use it as is.

In addition, some products obtained by this method are not very stable against heat, so if you want to obtain the ester salt in a dry state, it is easy to remove the residual solvent after separating the produced ester salt by filtration. It is desirable to use a solvent with a low boiling point.

Generally, a solvent having a boiling point of 120°C or lower, preferably 80°C or lower is suitable.

From an industrial standpoint, the amount of inert solvent used is preferably as small as possible.

However, when the amount of solvent is reduced, condensation tends to occur, so it is necessary to increase the stirring power or reduce the rate of addition of alcohol.

Therefore, it is desirable to determine in advance optimal conditions regarding the type of alcohol, addition rate, pressure of carbon dioxide gas, stirring conditions, type of solvent, amount used, etc.

Generally, when sufficient stirring is performed, when the solids of the generated slurry are settled, the clarified part is one part of the settling part.
It is preferable to select an inert solvent so that the ratio is /2 or more, preferably 1 or more.

In the reaction of the present invention, it is desirable to pressurize carbon dioxide gas in order to increase the reaction rate.

The higher the carbon dioxide gas pressure, the better. Generally, it is 5 kg/cniG or more, preferably 10 kg/cniG or more.

However, when using polyhydric alcohol as the alcohol,
Since agglomeration tends to occur during the reaction, it is preferable to select a pressure of 10 kg/crrtG or higher.

There is no particular restriction on the reaction temperature, and the reaction proceeds quickly and ends at room temperature under pressurized carbon dioxide gas.

Furthermore, as the reaction progresses, a gradual heat generation is observed, and the end of the reaction can be determined by the temperature change.

Hereinafter, the present invention will be explained by examples.

In Examples, reagents were purified as follows.

Alcohols were dried with anhydrous magnesium sulfate and then distilled.

Carbonates were vacuum dried at IOOO°C for 16 hours.

The solvent was dried by a conventional method and then distilled.

Example 1 115 g of light ash (manufactured by Tokuyama Soda Co., Ltd.) 532 allyl chloride was charged into an autoclave with a capacity of 500 rfLl equipped with an electromagnetic stirrer (manufactured by Nitto Autoclave Co., Ltd.).
Carbon dioxide gas was pressurized to 20 to 9/rstG.

While stirring at 1000 r, p, m, 23 g of ethanol was continuously added dropwise over 17 minutes.

No change was observed in the stirring state.

One hour after the addition was complete, the autoclave was removed.

The reaction product remained in a uniform slurry state.

Weight after drying is 92'? Met.

Infrared spectroscopic analysis of the product was performed.

Strong absorption by monosodium monoethyl carbonate and sodium bicarbonate and weak absorption by sodium carbonate were observed.

Assuming that the product consisted only of monosodium monoethyl carbonate, sodium bicarbonate, and sodium carbonate, the composition was determined from the results of neutralization titration.

Monoethyl carbonate monosodium salt 52.6% by weight, sl-lium bicarbonate 42.0% by weight, sodium carbonate 5.4%
% by weight.

Comparative Example 1 Into the autoclave of Example 1, 53 g of light ash and 23 g of ethanol and 115 f of allyl chloride were charged for 1000 liters.
, p, m while stirring 20 kg 7 cnl of carbon dioxide gas
Pressure was applied to G.

Stirring became impossible 3 minutes after the start of pressurization.

One hour after the start of pressurization, the autoclave was lifted, and colorless solids were found to have aggregated and adhered to the bottom of the autoclave and the stirring blades, and could only be peeled off with a spatula.

The weight of the solid after drying was 872.

Application example 1 The same reaction as in Example 1 was carried out.

After adding 3.21 g of triethylamine to the slurry produced and pressurizing carbon dioxide gas to 20 kg/caG, the temperature was lowered to 10 kg/caG.
The temperature was raised to 0°C and the reaction was continued for 4 hours.

The product was decomposed with water and the organic layer was analyzed by gas chromatography.

Composition: allyl ethyl ether) 45.4%, diallyl carbonate 1.6%, allyl ethyl ether 0.5%
The alichloride content was 51.2%.

(The numerical value was determined from the peak area.

) Example 2 A reaction was carried out under the same conditions as in Example 1 except that the addition time of alcohol was changed.

The results are shown in Table 1.

Example 3 In the method of Example 1, light ash 5,31 and allyl chloride 1152 were charged, and carbon dioxide gas was added at 20 kg/c.
The same procedure was carried out except that after pressurizing nlG, ethanol #2.3f was dropped instantly.

The reaction product remained in a uniform slurry state.

The weight after drying was 9.11.

Example 4 ※※
The reaction was carried out under the same conditions as in Example 1 while changing the types of alcohol and carbonate.

The results are shown in Table 2.

In either case, there was no change in the stirring state. All products remained in a slurry state.

Example 5 A reaction was carried out under the same conditions as in Example 1 except that the inert solvent was changed.

The amount of inert solvent is 120 CC. The results are shown in Table 3.

In either case, there was no change in the stirring state.

All products remained in a slurry state.

When the boiling point of the inert solvent used was 100° C. or higher (at normal pressure), a lot of the solid material was collected, thoroughly washed with chloroform, and then vacuum-dried at room temperature.

Example 6 Using alcoholic ethylene glycol 272,
The same reaction as in Example 1 was carried out by changing the carbon dioxide pressure.

The results are shown in Table 4. In either case, there was no change in the stirring state.

Claims (1)

[Claims] 1. When producing a carbonate monoester salt by the reaction of alcohol, alkali metal carbonate, and carbon dioxide gas, alcohol is added to an inert solvent slurry of alkali metal carbonate in an atmosphere of carbon dioxide gas. A method for producing a carbonate monoester salt, characterized by the following. 2. The method according to claim 1, wherein the addition of alcohol is carried out sequentially. 3. The method according to claim 1, wherein the amount of the alkali metal carbonate is 0.5 to 1.5 times the mole of the hydroxyl group of the alcohol. 4. The method according to claim 1, wherein the alkali metal carbonate is light ash. 5. The method according to claim 1, wherein an inert solvent that is compatible with alcohol is used.