JP3796781B2 - Process for producing aromatic dialdehydes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing aromatic dialdehydes.
[0002]
Aromatic dialdehydes are useful compounds widely used as various polymers, dyes, and raw materials for medicines and agricultural chemicals.
[0003]
[Prior art]
Many methods have been reported as methods for producing aromatic dialdehydes. For example, a method of directly oxidizing the side chain of xylenes, a method of reducing aromatic dicarboxylic acid dichloride, a method of hydrolyzing α, α, α ′, α′-tetrahalogenoxylenes, and the like are known.
[0004]
However, it is known that the method of directly oxidizing xylenes has a low yield. Further, the method of reducing aromatic dicarboxylic acid dichloride is economically disadvantageous because aromatic dicarboxylic acid dichloride as a raw material is expensive.
[0005]
On the other hand, methods for hydrolyzing α, α, α ′, α′-tetrahalogenoxylenes have been known for a long time, and it is known that corresponding aromatic dialdehydes can be obtained in high yield. . For example, Organic Synthesis Coll. IV 807 (1963) reports a method of hydrolysis using potassium oxalate in the presence of ethanol. JP-A-54-95532 discloses a reaction using a phase transfer catalyst, a carboxylate and an organic base in order to improve productivity to obtain aromatic dialdehydes in a relatively high yield. Yes.
[0006]
[Problems to be solved by the invention]
However, Organic Synthesis Coll. In the method described in IV 807, although the reaction can be performed under mild conditions, the use of expensive potassium oxalate, the long reaction time, and the use of a large amount of ethanol aqueous solution, the productivity of aromatic dialdehydes is high. It is economically disadvantageous because it is extremely low. In the method described in JP-A-54-95532, a large amount of expensive carboxylate must be used, which is economically disadvantageous.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly productive and economical method for producing aromatic dialdehydes by a simple operation under mild conditions. .
[0008]
[Means for Solving the Problems]
As a result of intensive studies on a method for producing aromatic dialdehydes, the present inventors have found that α, α, α ′, α′-tetrahalogenoxylenes are used as alkali metal salts or alkalis as neutralizing agents under normal pressure. By using an earth metal salt and hydrolyzing in the presence of a phase transfer catalyst and a water-soluble alcohol solvent or ether solvent having a boiling point of 120 ° C. to 250 ° C. as an additive solvent, economically under mild conditions The inventors have found that the corresponding aromatic dialdehydes can be easily produced, and have completed the present invention.
[0009]
That is, the present invention provides an alkali metal salt using the hydrolysis reaction as a neutralizing agent under normal pressure when hydrolyzing α, α, α ′, α′-tetrahalogenoxylenes to produce the corresponding aromatic dialdehydes. Or an aromatic dialdehyde characterized by being carried out in the presence of a phase transfer catalyst using an alkaline earth metal salt and a water-soluble alcoholic or etheric solvent having a boiling point of 120 ° C to 250 ° C as an additive solvent Is the method.
[0010]
The present invention is described in further detail below.
[0011]
In the method of the present invention, α, α, α ′, α′-tetrahalogenoxylenes are compounds having ο-, m-, and p-xylene in the skeleton structure, and two halogens bonded to two methyl groups of xylene. Means. In some cases, the benzene nucleus may have a substituent. As halogen, chlorine or bromine is usually used. These α, α, α ′, α′-tetrahalogenoxyxylenes are produced by a known technique. For example, α, α, α ′, α′-tetrabromo-ο-xylene is produced by a method of brominating o-xylene under heating conditions or a method of brominating under ultraviolet light irradiation.
[0012]
The α, α, α ′, α′-tetrahalogenoxylenes thus obtained may be used after recrystallization with methylene chloride or a mixed solvent of toluene and hexane, or may be used unpurified. It doesn't matter.
[0013]
The amount of water used in the hydrolysis reaction carried out in the present invention is 1 to 3 in weight ratio with respect to α, α, α ′, α′-tetrahalogenoxyxylenes. Even if the reaction is stopped in the middle and the reaction is continued for a long time, a sufficient yield may not be obtained. On the other hand, although the use of an excessive amount of water improves the reaction rate, the production amount of aromatic dialdehydes per unit volume is reduced, which may lead to a decrease in productivity.
[0014]
There is no particular limitation on the method of adding water used for the hydrolysis. For example, the entire amount may be introduced into the system from the start of the reaction, or a part thereof may be added separately after the start of the reaction.
[0015]
The additive solvent used in this reaction is a water-soluble alcohol solvent or ether solvent having a boiling point of 120 ° C. to 250 ° C., for example, dihydric alcohols such as ethylene glycol and propylene glycol, and 2-methoxyethanol. And ethylene glycol monoalkyl ethers such as 2-ethoxyethanol and 2-butoxyethanol, propylene monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, and glymes such as diglyme and triglyme.
[0016]
The above additive solvents may be used alone or in combination.
[0017]
When the boiling point of the added solvent is lower than 120 ° C., the reaction temperature is lowered, so the addition rate is deteriorated and the yield is lowered. Further, when the boiling point of the added solvent is higher than 250 ° C., not only a long time is required for solvent recovery, but also separation from the target dialdehydes becomes difficult.
[0018]
The addition amount of the solvent used in this reaction is 0.1 to 1.0 times by weight, preferably 0.1 to 0 times that of the raw α, α, α ′, α′-tetrahalogenoxyxylenes. .5 times by weight.
[0019]
The method for adding the solvent is not particularly limited, and for example, the entire amount may be introduced into the system from the start of the reaction, or a part thereof may be added separately after the start of the reaction.
[0020]
When the amount of solvent used is small, bumping occurs when the reaction temperature is reached, making it difficult to continue the reaction. In addition, when the solvent is used in excess, the reaction is not affected, but it is not only economically disadvantageous, but it takes more time than necessary for recovery of the solvent and is not efficient.
[0021]
The phase transfer catalyst used in this reaction is mainly an onium salt, and among these, a quaternary ammonium salt and a quaternary phosphonium salt are preferably used. Specific examples of the quaternary ammonium salt include tetrabutylammonium chloride, tetrabutylammonium bromide, n-octyltrimethylammonium chloride, n-octyltrimethylammonium bromide, and benzyltriethylammonium chloride. As the quaternary phosphonium salt, tetra-n-butylphosphonium chloride, ethyltrioctylphosphonium chloride and ethyltrioctylphosphonium bromide are preferably used. Among these, tetrabutylammonium bromide and benzyltriethylammonium chloride are particularly preferably used.
[0022]
The amount of the phase transfer catalyst added is 5 to 30 mol%, preferably 10 to 25 mol%, relative to the raw α, α, α ′, α′-tetrahalogenoxyxylenes. When the amount of phase transfer catalyst is small, the reaction rate decreases, and the time required for the reaction becomes long, which is disadvantageous efficiently. Moreover, if the amount of phase transfer catalyst is excessively used more than necessary, it is only economically disadvantageous.
[0023]
The hydrogen halide produced by hydrolysis is a cause of corrosion of the apparatus, and also has an adverse effect on the environment, so it must be neutralized. In this reaction, an alkali metal salt or alkaline earth metal salt is preferably used as a neutralizing agent.
[0024]
The alkali metal salt or alkaline earth metal salt used as the neutralizing agent is an inorganic salt, and examples thereof include sodium, potassium carbonate, bicarbonate, calcium carbonate, and calcium hydroxide.
[0025]
The addition amount of the neutralizing agent may be a substantial amount of hydrogen halide generated from α, α, α ′, α′-tetrahalogenoxyxylenes, but may be added excessively. For example, when calcium carbonate is added, it is preferable to add 1.0 to 1.2 times the equivalent of the generated hydrogen halide.
[0026]
There are no particular restrictions on the method of addition, but with water-soluble weakly basic salts such as sodium carbonate, it is possible to add a small amount to the system during the reaction, and with poorly soluble neutral salts such as calcium carbonate, the reaction is possible. It is preferable to add the necessary amount into the system from the start. From the viewpoint of operability and economy, it is preferable to use calcium carbonate as a neutralizing agent.
[0027]
This hydrolysis reaction is carried out under normal pressure. Therefore, the reaction temperature is usually in the range of 95 ° C. to 100 ° C., although there are some differences depending on the polar solvent to be added.
[0028]
Although the reaction can be carried out in an open system, it is desirable to carry out the reaction under an inert gas atmosphere such as nitrogen or argon.
[0029]
【The invention's effect】
According to the method of the present invention, aromatic dialdehydes can be produced economically from inexpensive raw materials under mild conditions without using special high-pressure equipment or the like.
[0030]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0031]
Example 1
Α, α, α ′, α′-tetrabromo-o-xylene 21.1 g as raw materials, 42.0 g of distilled water, n-butoxyethanol 5 as a raw material in a 100 ml four-necked flask equipped with a stirrer, a thermometer and a condenser 0.0 g, calcium carbonate 11.0 g and tetra-n-butylammonium bromide 3.4 g were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 96 ° C.
[0032]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. As a result, the conversion was 80.1% and the yield of orthophthalaldehyde was 76.6 mol%.
[0033]
Example 2
Α, α, α ′, α′-tetrabromo-o-xylene 21.1 g as raw materials, 42.0 g of distilled water, n-butoxyethanol 5 as a raw material in a 100 ml four-necked flask equipped with a stirrer, a thermometer and a condenser 0.0 g, calcium carbonate 11.0 g and tetra-n-octyldimethylammonium bromide 2.1 g were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 96 ° C.
[0034]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. The conversion was 85.7% and the yield of orthophthalaldehyde was 82.2 mol%.
[0035]
Example 3
Α, α, α ′, α′-tetrabromo-o-xylene 21.1 g as raw materials, 42.0 g of distilled water, 5.0 g of ethylene glycol in a 100 ml four-necked flask equipped with a stirrer, thermometer and condenser Then, 11.0 g of calcium carbonate and 3.4 g of tetra-n-butylammonium bromide were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 97 ° C.
[0036]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. The conversion was 85.1% and the yield of orthophthalaldehyde was 78.3 mol%.
[0037]
Example 4
Α, α, α ′, α′-tetrabromo-o-xylene 21.1 g as raw materials in a 100 ml four-necked flask equipped with a stirrer, thermometer and condenser, 42.0 g of distilled water, 5.0 g of diglyme, 11.0 g of calcium carbonate and 3.4 g of tetra-n-butylammonium bromide were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 97 ° C.
[0038]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. As a result, the conversion was 83.1% and the yield of orthophthalaldehyde was 79.1 mol%.
[0039]
Example 5
A bromine reaction solution (containing 156 g of α, α, α ′, α′-tetrabromoxylene) in a 1000 ml four-necked flask equipped with a stirrer, a thermometer and a cooling tube as a toluene solution, 206 g, distilled water 400 g, n -39.1 g of butoxyethanol, 94 g of calcium carbonate and 23.9 g of tetra-n-butylammonium bromide were charged, and the oil bath temperature was raised to 130 ° C under nitrogen flow while stirring (350 to 400 rpm). Toluene was removed out of the system. At this time, distilled water was distilled out of the 86 g system. The temperature of the reaction mixture liquid after removing toluene was 95 ° C.
[0040]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. As a result, the conversion was 90.3% and the yield of orthophthalaldehyde was 74.3 mol%.
[0041]
Example 6
Α, α, α ′, α′-tetrabromo-m-xylene 21.1 g as raw materials, 42.0 g of distilled water, n-butoxyethanol 5 as a raw material in a 100 ml four-necked flask equipped with a stirrer, a thermometer and a condenser 0.0 g, calcium carbonate 11.0 g and tetra-n-butylammonium bromide 3.4 g were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 96 ° C.
[0042]
In this state, the reaction was performed for 24 hours. After completion of the reaction, the reaction product was collected and analyzed by gas chromatography. The conversion was 82.1% and the yield of isophthalaldehyde was 79.6 mol%.
[0043]
Example 7
As a raw material, 21.1 g of α, α, α ′, α′-tetrabromo-p-xylene, 42.0 g of distilled water, n-butoxyethanol 5 in a 100 ml four-necked flask equipped with a stirrer, a thermometer and a condenser tube 0.0 g, calcium carbonate 11.0 g and tetra-n-butylammonium bromide 3.4 g were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 96 ° C.
[0044]
In this state, the reaction was performed for 24 hours. After completion of the reaction, the reaction product was collected and analyzed by gas chromatography. The conversion was 85.1% and the yield of terephthalaldehyde was 80.5 mol%.
[0045]
Comparative Example 1
Α, α, α ′, α′-tetrabromo-o-xylene 21.1 g as raw materials in a 100 ml four-necked flask equipped with a stirrer, thermometer and cooling tube, 42.0 g of distilled water, 5.0 g of ethanol, 11.0 g of calcium carbonate and 3.4 g of tetra-n-butylammonium bromide were charged, and the oil bath temperature was raised to 90 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 85 ° C.
[0046]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was collected and analyzed by gas chromatography. The conversion was 29.3% and the yield of orthophthalaldehyde was 26.6 mol%.
[0047]
Comparative Example 2
As a raw material, 21.1 g of α, α, α ′, α′-tetrabromo-o-xylene, 42.0 g of distilled water, n-butoxyethanol (n-butoxyethanol ( 10.5 g of ethylene glycol mono-n-butyl ether) and 11.0 g of calcium carbonate were charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 96 ° C.
[0048]
The reaction was carried out for 24 hours in this state. After completion of the reaction, the reaction product was recovered and analyzed by gas chromatography. As a result, the conversion was 48.7% and the yield of orthophthalaldehyde was 44.0 mol%.
[0049]
Comparative Example 3
As a raw material, 21.1 g of α, α, α ′, α′-tetrabromo-o-xylene, 42.0 g of distilled water, and 11.0 g of calcium carbonate were added to a 100 ml four-necked flask equipped with a stirrer, a thermometer and a condenser. Then, 3.4 g of tetra-n-butylammonium bromide was charged, and the oil bath temperature was raised to 120 ° C. under nitrogen flow while stirring (350 to 400 rpm). At this time, the temperature of the reaction mixture liquid was 98 ° C.
[0050]
At this time, the reaction solution vigorously bumped and it was difficult to continue the reaction. However, the reaction was continued in this state for 24 hours. After the reaction was completed, the reaction product was recovered and analyzed by gas chromatography. The conversion was 86.6% and the yield of orthophthalaldehyde was 56.3. Mol%.

Claims (4)

In producing the corresponding aromatic dialdehyde by hydrolyzing α, α, α ′, α′-tetrahalogenoxyxylenes, the hydrolysis reaction is carried out using an alkali metal salt or alkaline earth as a neutralizing agent under normal pressure. In the presence of a phase transfer catalyst using a metal salt and a water-soluble alcohol solvent or ether solvent having a boiling point of 120 ° C. to 250 ° C. as an additive solvent, and to α, α, α ′, α′-tetrahalogenoxylenes In contrast, the amount of phase transfer catalyst added is 5 to 30 mol%, the amount of water used in the hydrolysis reaction is 1 to 3 (weight ratio), and the amount of solvent added is 0.1 to 1.0 (weight ratio). A process for producing aromatic dialdehydes, characterized in that it is carried out.  The production method according to claim 1, wherein the additive solvent is at least one selected from the group consisting of dihydric alcohols, ethylene glycol monoalkyl ethers, propion glycol monoalkyl ethers and glymes.  The additive solvent is at least one selected from the group consisting of ethylene glycol, propylene glycol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diglyme and triglyme. The manufacturing method of Claim 1 characterized by the above-mentioned. The fragrance according to claim 1, wherein the α, α, α ′, α′-tetrahalogenoxyxylenes is α, α, α ′, α′-tetrabromo-o-xylene. For the production of aromatic dialdehydes.