JPS5834456B2 - Carbon Sanno Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a method for producing carboxylic acids from olefins or alcohols. ) compound, boron trifluoride, and a mineral acid.

Conventionally, as a method for producing tertiary carboxylic acids, strong acid catalysts (for example, H2SO4, H2S04BF3, H3
P04-BF3, BF3-H2O, etc.), 1 to
The so-called Koch process is carried out in which carbon monoxide is reacted with aliphatic or aliphatic olefins or alcohols at 100 atm and 0 to 70°C.

However, since these methods use strong acids at high temperatures and high pressures, it is difficult to select equipment materials that can withstand strong acids, and severe corrosion has become a problem in actual equipment.

In addition, attempts have been made to use a catalyst made by adding a copper(I) compound to concentrated sulfuric acid as a method of synthesizing carboxylic acid from carbon monoxide to olefins or alcohols at low temperature and low pressure. When the temperature exceeds 45°C, the production rate of carboxylic acid decreases rapidly, and at 50°C, no production of carboxylic acid is observed, so that satisfactory results are not always obtained.

In addition, in the presence of a sulfuric acid catalyst containing Ag(I) ions at a concentration of 80% or more, CO is added to an aliphatic saturated alcohol having 4 or more carbon atoms.
A method for producing alkylcarboxylic acids by reacting them (Japanese Patent Publication No. 48-35055) has also been proposed, but this method has the disadvantage that it is difficult to separate the reaction product by standing still.

As a result of intensive research to improve these drawbacks, the present inventors surprisingly discovered that boron trifluoride and silver(I)
(It was discovered that carboxylic acid can be produced in high yield by reacting an olefin or alcohol with carbon monoxide in an aqueous solution containing an arsenide.

That is, in the first invention, in the presence of an aqueous solution containing a silver (I) compound and boron trifluoride, the molar ratio of which is boron trifluoride 1.0/water 1.0 to 3.0, The second invention is a method for producing carboxylic acid characterized by reacting olefin or alcohol with carbon monoxide.
I) A compound containing boron trifluoride and a mineral acid, the molar ratio of which is boron trifluoride 1.0-3.0/mineral acid 0.2-1.
This is a method for producing a carboxylic acid, which is characterized by reacting an olefin or alcohol with carbon monoxide in the presence of an aqueous solution having a carbon monoxide.

Boron trifluoride and silver(I) used in the practice of this invention
The aqueous solution containing the compound is dissolved in an aqueous solution of boron trifluoride obtained by absorbing boron trifluoride in water.
Silver (I) compound is added to boron trifluoride hydrate or its aqueous solution obtained by absorbing 1 mol of boron trifluoride in 1 mol to 3.0 mol of water. Those added are suitable.

It is not preferable to use 3 moles or more of water per mole of boron trifluoride because part of the boron trifluoride decomposes into boric acid.

Further, as the type of mineral acid to be allowed to coexist in the aqueous solution of boron trifluoride, which is the second invention, phosphoric acid, sulfuric acid, hydrogen fluoride, etc. are preferable.

The purpose of using this mineral acid was to reduce the amount of boron trifluoride used, which is difficult to handle because it is a gas and is currently more expensive than general mineral acids. By using these mineral acids, the concentration of boron trifluoride in the aqueous solution consisting of boron trifluoride, water and mineral acid can be reduced to half the concentration of boron trifluoride in the boron trifluoride aqueous solution according to the first invention. Even if the amount is reduced to a certain extent, carboxylic acid is produced in a high yield comparable to that of the first invention.

Although there is no need to specifically limit the silver (I) compound,
Silver (I) reacts with carbon monoxide in an aqueous solution of boron trifluoride.
) It is necessary that the compound is a compound that produces carbonyl or silver (I) carbonyl, and in particular, silver (I) oxide is added to the above aqueous solution of boron trifluoride or an aqueous solution of boron trifluoride and a mineral acid and carbon monoxide is added. It is desirable to use silver(I) carbonyl obtained by reaction.

In addition, silver carbonate, silver sulfate, etc. can be used.

Next, the olefin or alcohol used as a raw material in the present invention is an aliphatic olefin having 3 or more carbon atoms, an alicyclic olefin, an alicyclic or aromatic compound having an aliphatic olefin as a substituent, or an alicyclic or aromatic compound having an aliphatic olefin as a substituent. Corresponding alcohols, in particular fluoropylene, n-butylene, i-7tylene, pentene, hexene, totycene, cyclopentene, cyclohexene, etc., or alcohols corresponding to said compounds, such as i-propatol, n- Butanol, 5ee-butanol, tert-butanol, pentanol, hexanol, cyclohexanol, etc. are suitable.

Furthermore, hydrocarbon mixtures obtained in petroleum refining or petrochemistry, such as olefin-containing hydrocarbon mixtures commonly referred to as C4 fraction, C5 fraction, etc., may also be used.

The reaction temperature when reacting carbon monoxide with olefin or alcohol is -20℃ to 150℃.
Although it can be carried out at a temperature range of 0°C to 120°C, it is preferably carried out at a temperature range of 10°C to 50°C.

- The pressure of carbon oxide may be normal pressure, but - in order to increase the solubility of carbon oxide or due to the boiling point of the raw material, it is desirable to carry out under high pressure, usually 1 to 1o.

It is desirable to carry out the reaction at an atmospheric pressure, preferably 1 to 20 atmospheres.

The reaction can be carried out in a batch, semi-patch or continuous manner.

In particular, in the method of the present invention, the reaction is sufficiently carried out in an aqueous solution of boron trifluoride such that the reaction product can be separated from an aqueous solution of boron trifluoride containing a silver(I) compound by simply standing still. Since the process proceeds, it is easy to separate and reuse the aqueous solution of boron trifluoride.

That is, in the method of the present invention, even when producing a low molecular weight carboxylic acid, for example, a soluble carboxylic acid such as trimethyl acetic acid, the carboxylic acid is It is possible to perform static separation of

On the other hand, if only sulfuric acid is used, static separation cannot be performed at the acid concentration normally used.
I) Even when using a solution containing the compound, the reaction will not proceed at a concentration of sulfuric acid that would separate the product;
If the sulfuric acid concentration is reduced to a uniform level, the product must be separated after adding water to reduce the sulfuric acid concentration. You can't reuse it if you throw it away later.

Therefore, facilities for concentrating the sulfuric acid are required in both cases.

Next, the present invention will be explained in detail using specific examples.

Example 1 In a 100 WLl four-eye flask, 50 ml of aqueous solutions of boron trifluoride of various compositions and 5 mmol of silver oxide (1,059
? ) to degas the inside of the flask, and then repeat the process of replacing the flask with carbon oxide gas to create a carbon monoxide atmosphere.

While keeping the flask at a predetermined temperature (35° C.), carbon monoxide is blown into the flask at a rate of 1 ml/min at one pressure until no absorption of carbon monoxide is observed.

In this case, the amount of carbon monoxide absorbed by silver varies depending on the concentration of boron trifluoride.

- Thoroughly stir the reaction solution that has absorbed carbon oxide.
After addition at a rate of rnl/min, stirring is continued at one atmosphere until carbon monoxide absorption stops.

After the reaction was completed, the reaction solution was separated into two layers, but for analysis, all the reactants were poured into ice water to separate the organic substances, and the carboxylic acid was isolated using conventional methods such as alkali treatment, followed by titration and gas chromatography. analyzed.

The results are shown in Table 1.

For comparison, experiments were conducted using only an aqueous solution of boron trifluoride and sulfuric acid without adding the QI) compound, but in both cases, the yield was lower than that of the method of the present invention. It turned out to be excellent.

Example 2 (comparative example) 50 TrL of a boron trifluoride solution (complex) having the composition shown in Table 2 and 5 mmol of silver oxide were added to a 100 rr Ll four-bottle flask, and after degassing the flask, the process of replacing with carbon oxide gas was repeated. Create a carbon monoxide atmosphere.

While keeping the flask at 35° C. (55° C. in the experiment number), carbon monoxide gas is passed through the solution at a rate of 0.1 ml/min at one atmospheric pressure until no absorption of carbon monoxide is observed.

While thoroughly stirring the solution in which carbon monoxide has been absorbed under a -carbon oxide atmosphere, 0.1 mole of t-butanol is added to 0.2 mole of t-butanol.
After addition at a rate of ml/min, stirring is continued at one atmospheric pressure until absorption of carbon monoxide stops.

After the reaction is complete, pour the reaction solution into ice water to separate the organic matter.
Furthermore, the remaining reactant** dissolved in the aqueous solution was extracted and recovered with benzene, and then analyzed in the same manner as in Example 1.

The results are shown in Table 2, and as is clear from the table, in the boron trifluoride-methanol system, the conversion rate of t-butanol and the selectivity to carboxylic acid were inferior to those in Experiment No. 1. Also, the amount of polymers increases.

Also, in the boron trifluoride-diethyl ether system, t-butanol hardly reacts, and in the boron trifluoride-pyridine system, t-butanol does not react with the boron trifluoride-diethyl ether system.
-Butanol does not react at all.

Example 3 (Comparative Example) In Example 1, the boron trifluoride solution was BF33,5H2
t-Butanol was reacted in the same manner as in Experiment No. 1 except that O was used.

The results are shown in Table 2.

Note that if H2O is less than 1 in the boron trifluoride/water molar ratio, B
F3 became gaseous and the experiment was impossible.

Claims (1)

[Scope of Claims] 1 Silver (I) (contains an arsenide and boron trifluoride, the molar ratio of which is boron trifluoride 1.0/water 1.0 to 3.0, i:. A method for producing a carboxylic acid characterized by reacting an olefin or alcohol with carbon monoxide in the presence of an aqueous solution. 2 Contains a silver (I) compound, boron trifluoride and a mineral acid, the molar ratio of which is Boron trifluoride 1.0/water 1.0-3.O
/ A method for producing a carboxylic acid, which comprises reacting an olefin or alcohol with carbon monoxide in the presence of an aqueous solution having a mineral acid content of 0.2 to 1.0.