JPH0748352A - Production of quinophthalonedicarboxylic acid having high purity - Google Patents

Abstract

PURPOSE:To obtain quinophthalonedicarboxylic acid having high purity and useful as an intermediate for pigment, etc., by hydrolyzing and neutralizing a specific quinophthalonedicarboxylic acid anhydride with an alkaline compound to obtain a solubilized product, removing insoluble impurities by filtration and adding an acid to precipitate the free acid. CONSTITUTION:This quinophthalonedicarboxylic acid having high purity and expressed by the formula III can be produced by adding an aqueous solution of an alkaline compound (e.g. sodium hydroxide) to a quinophthalonedicarboxylic acid anhydride expressed by the formula I (X is H, halogen or alkyl), heating the liquid mixture to 50 deg.C after confirming the adjustment of pH to 12.9, stirring for 2hr at 50-52 deg.C to effect the hydrolysis and neutralization of the compound and form a solubilized quinophthalone compound salt expressed by the formula II (Y and Z are cation), removing insoluble impurities from the product by filtration, adding an acid (e.g. sulfuric acid) to adjust the pH to 1.95, heating at 90 deg.C, keeping at the temperature for 2hr, adding water to precipitate crystals, collecting the crystal by filtration and drying the product.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing quinophthalone dicarboxylic acid useful as an intermediate for a dye.

[0002]

2. Description of the Related Art The following general formula (I)

[0003]

[Chemical 4] The quinophthalone dicarboxylic acid anhydride represented by the formula (wherein X represents a hydrogen atom, a halogen atom, or an alkyl group) is an important compound as an intermediate for a dye for liquid crystals or a disperse dye. However, since the compound of the general formula (I) is poorly soluble in an organic solvent, a recrystallization method or a chromatographic method conventionally known as a purification method cannot be used, and industrial purification is practically impossible. It was Therefore, the compound of general formula (I) is of low purity because it is unpurified, and the dye derived using the compound as an intermediate contains a large amount of impurities and is unstable in quality. It was Among the impurities, particularly, the compound represented by the general formula (IV)

[0004]

[Chemical 5] The compound represented by the formula (wherein X has the same meaning as in formula (I)) is also sparingly soluble in an organic solvent, and the compound is derived from the compound of formula (I). The removal of this compound was essential because it hinders the performance of various dyes. Therefore, as a method for purifying quinophthalone compounds,
The compound of the general formula (I) is reacted with a secondary amine to give a compound of the general formula (V)

[0005]

[Chemical 6] (In the formula, X has the same meaning as X in formula (I), R
₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms,
It represents an alkoxyalkyl group or a hydroxyalkyl group. ) Is formed into a solvent-soluble amic acid, and the solvent-insoluble impurities represented by the general formula (IV) are removed by filtration to obtain a highly pure amic acid solution. In addition, a high-purity general formula (I) is obtained by hydrolysis treatment.
A method for obtaining the above quinophthalone dicarboxylic acid anhydride has been proposed (described in JP-A Nos. 01-306404 and 01-319480). However, in the method described in this publication, the secondary amine used is generally harmful, so it is difficult to dispose of the aqueous amine solution generated by hydrolysis of the amic acid solution, and the flammability of the organic solvent used However, it is not an industrially preferable method.

[0006]

The object of the present invention is to purify the quinophthalone dicarboxylic acid anhydride represented by the general formula (I), which is an important compound as an intermediate for dyes for liquid crystals or disperse dyes. The present invention provides a method for producing high-purity quinophthalone dicarboxylic acid.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that quinophthalone dicarboxylic acid anhydride of the general formula (I) is solubilized by a novel method so that impurities are insoluble. The present invention has been accomplished by finding a method for producing a high-purity quinophthalone dicarboxylic acid by removing it as a substance. That is, the present invention provides the following general formula (I)

[0008]

[Chemical 7] (In the formula, X represents a hydrogen atom, a halogen atom, or an alkyl group.) The quinophthalone dicarboxylic acid anhydride represented by the formula is hydrolyzed and neutralized with an alkaline compound to give the following general formula (II)

[0009]

[Chemical 8] (In the formula, Y and Z represent a cation, and X represents the same meaning as in the general formula (I).) The quinophthalone compound represented by the formula was solubilized as a salt, insoluble impurities were filtered off, and then the filtrate was filtered. An acid is added to give the following general formula (III)

[0010]

[Chemical 9] (In the formula, X represents the same meaning as in the general formula (I).) A high-purity quinophthalone dicarboxylic acid represented by the formula is precipitated.
The present invention relates to a method for producing high-purity quinophthalone dicarboxylic acid.
The high-purity quinophthalone dicarboxylic acid represented by the general formula (III) produced in the present invention can be easily produced by a known method to produce a high-purity quinophthalone dicarboxylic acid anhydride represented by the general formula (I). You can The quinophthalone dicarboxylic acid anhydride represented by the general formula (I) used in the present invention is a crude product, and the alkyl group represented by the substituent X includes a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Represents a hydrocarbon group having 1 to 10 carbon atoms such as a group and its halogen, acylalkoxy or hydroxy substitution product, and examples of the halogen atom include fluorine, chlorine, bromine and iodine. The crude quinophthalone dicarboxylic acid anhydride of the general formula (I) is hydrolyzed and neutralized with an alkaline compound in a solvent to give a compound of the general formula (I
It is solubilized as the carboxylate salt represented by I). Although the solvent may or may not be used, it is preferable to use it in consideration of dissolving the alkaline compound and solubilizing the generated carboxylate. Here, the cation represented by Y and Z of the compound represented by the general formula (II) is not particularly limited, but is preferably a metal cation, more preferably a lithium cation, a sodium cation, a potassium cation and the like. Can be mentioned.

Any solvent can be used as long as it dissolves the alkaline compound. A particularly preferred solvent is water. However, a mixture of alcohols such as methanol, ethanol, ethylene glycol, methyl cellosolve, ethyl cellosolve and diethylene glycol, or ethers such as ethylene glycol dimethyl ether and dioxane with water may be used as a solvent. The amount of the solvent used is 1 to 100 times by weight, preferably 3 to 30 times by weight that of the crude product of the general formula (I). The alkaline compound used in the present invention may be any one that is soluble in water, but is preferably a metal hydroxide or a metal carbonate. Examples of metal hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. Examples of metal carbonates include potassium carbonate, sodium carbonate, lithium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate and the like. These alkaline compounds can be used alone, but a mixture of a plurality of the compounds can also be used. A compound of general formula (I)
The temperature when reacting with an alkaline compound in a solvent is 0 ° C.
It is preferably not lower than 80 ° C and lower than 60 ° C industrially. If the temperature is too low, the reactivity is poor, and if the temperature is too high, the general formula (V
I) (Chemical formula 10)

[0012]

[Chemical 10] (In the formula, X has the same meaning as X in formula (I).)
The production amount of quinophthalone monocarboxylic acid represented by is increased, and there is a problem that the purity is lowered, which is not preferable. A reaction time of 24 hours is sufficient, and preferably 4 hours or less. Furthermore, when the compound of the general formula (I) is reacted with an alkaline compound in a solvent, the salt of the quinophthalone compound represented by the general formula (II), which is a product, is solubilized, and the compound of the general formula (IV) is obtained. It is important to adjust the pH of the solution so that the impurities mainly composed of are insoluble. Considering these, the pH of the solution is 1
It is preferably 2.0 or more and less than 13.2, particularly 12.5-1.
3.0 is preferable. If the pH is too low, the reaction between the compound of the general formula (I) and the alkaline compound will be incomplete, and if the pH is too high, the general formula (IV)
1)

[0013]

[Chemical 11] (In the formula, X has the same meaning as X in formula (I).)
It is not preferable because the main impurities represented by are dissolved and it becomes difficult to separate by filtration from the solution containing the salt of the quinophthalone compound of the general formula (II). The filter medium used for filtering and separating impurities mainly containing the compound of the general formula (IV) from the solution containing the salt of the quinophthalone compound represented by the general formula (II) is a material that is not attacked by an alkaline solution. Anything is fine. A filter cloth whose base material is polypropylene or fluororesin is preferable. Further, in order to reduce the filtration resistance that appears when the solvent-insoluble impurities of the general formula (IV) are deposited on the surface of the filter medium, a filter aid is laid on the surface of the filter medium, or the general formula (I) and an alkaline compound are added. The reaction solution may be charged with the filter aid and suspended, and then filtered. As the filter aid, commercially available Celite is usually used. The type of Celite is not particularly limited, and Celite-545, Celite-535, Celite-503, and Celite-500 can be usually used. After removing insoluble impurities by filtration, the compound of the general formula (II)

[0014]

[Chemical 12] (In the formula, Y and Z represent a cation, and X represents the same meaning as in the general formula (I).) The acid added to the alkaline filtrate containing the salt of the quinophthalone compound represented by the formula is an inorganic acid. Any of them may be used, but hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like are preferable.
Non-volatile acid is more preferable in consideration of workability,
Sulfuric acid is particularly preferable. The concentration of the acid is not particularly limited, but if added at a high concentration, the acid precipitate forms a block and hinders stirring, so it is preferable to add at a concentration of 1 to 50 wt%. Further, the rate of adding the acid is not particularly limited, and depending on the case, the acid is added dropwise over a period of time. The dropping charging time is usually 1 minute to 10 hours. The pH of the solution is preferably 1.5 or more and less than 2.5 when an acid is added to the alkaline filtrate of the compound of the general formula (II) to precipitate the high-purity quinophthalone dicarboxylic acid represented by the general formula (III). Especially, the pH is preferably 1.8 to 2.0. If the pH is too low, a large amount of water is used to remove the acid from the obtained filter cake after the reaction is completed, which is not suitable for industrialization. If the pH is too high, the general formula (I
The reaction of the compound of I) with the acid is incomplete, which is not good.

When an acid is further added to the alkaline filtrate of the compound of the general formula (II) to precipitate the high-purity quinophthalonedicarboxylic acid of the general formula (III), the reaction temperature is not particularly limited. However, it is preferable to heat the reaction solution in consideration of promotion of the reaction, completion of the reaction in a short time, and the like. The reaction temperature is preferably 40 ° C. or higher,
More preferably, it is 80 ° C. or higher. A reaction time of 24 hours is sufficient, and preferably 4 hours or less.
The filtration temperature of the precipitate represented by the general formula (III) after the reaction is preferably 50 ° C. or lower. Also, the filter material used is
Any material can be used as long as it has resistance to the reaction solution, but a filter cloth whose base material is polypropylene, fluororesin or cotton can be used.

The high-purity quinophthalone dicarboxylic acid represented by the general formula (III) obtained in the present invention is solid, or is dissolved in an organic solvent which can form an azeotrope with water and heated for dehydration, or a dehydrating agent is used. By doing so, the high-purity quinophthalone dicarboxylic acid anhydride represented by the general formula (I) can be easily produced. Here, the temperature for dehydration by heating is not particularly limited as long as it is a temperature at which dehydration can be performed. Any organic solvent may be used as long as it is azeotropic with water, and examples thereof include toluene and nitrobenzene. Examples of the dehydrating agent include polyphosphoric acid and sulfuric acid.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples. In addition, the ultraviolet-visible absorption spectrum of the reaction liquid of the crude product of quinophthalone dicarboxylic acid anhydride and the alkaline compound was measured in the range of 300 nm to 600 nm. The UV-visible absorption spectra of the crude product of quinophthalone dicarboxylic acid anhydride and quinophthalone dicarboxylic acid were measured in the range of 300 nm to 600 nm for a dilute solution of about 1 mg of the sample dissolved in 100 ml of o-chlorophenol. The measuring device is UV-240 (Shimadzu Corporation)
Manufactured) was used. The purity of the compound was measured by thin layer chromatography. Example 1 Formula (a) (Chemical Formula 13)

[0018]

[Chemical 13] Crude acid anhydride represented by (purity 90.3%) 6.1
0 kg and 118 liters of water at room temperature were charged into a stainless steel reactor (300 liters volume), and 4.9 kg of 49% sodium hydroxide aqueous solution was added dropwise while stirring the solution. After confirming that the pH became 12.9 with a pH meter, the content liquid was heated to 50 ° C. and stirred at 50 to 52 ° C. for 2 hours. Next, Celite-545 (Wako Pure Chemical Industries, Ltd. first-class reagent) was charged in an amount of 3.0 kg, and the mixture was stirred at 50 to 52 ° C. for 30 minutes. After cooling to 30 to 35 [deg.] C., a solvent insoluble matter was separated and removed from the solution using a glass lining filter (100 liter volume) covered with a polypropylene filter cloth as a filter material. The obtained filtrate was transferred to a glass lining reactor (200 liter volume), and then 25% sulfuric acid 1
3.2 kg was added dropwise over 35 minutes. The inner solution is 33.8
After measuring the pH at ℃ and confirming the value of 1.95,
The internal solution was heated to 90 ° C. 90 ~ 95 ℃, pH 1.
The value of 8 to 2.0 was maintained and the temperature was kept for 2 hours. Then water 5
0 liter was charged and further cooled from the outside to cool the internal solution to 50 ° C. A filter press filter machine with a polypropylene filter cloth as the filter material (filtering area 4.32)
m ²⁾ time required was filtered using was 10 minutes. The filter cake was washed with water, and the filtrate showed pH 6.5 and then dried at 80 ° C. to give quinophthalone dicarboxylic acid 4.31 k.
g was obtained. The purity was 97.0%. Before temperature rise and 50
The ultraviolet-visible absorption spectrum of the reaction solution after being kept at 52 ° C for 2 hours is shown in Fig. 1. As is clear from FIG. 1, there is almost no change in the absorbance after the heat treatment with respect to the absorbance before the temperature rise,
No alteration of quinophthalone dicarboxylate was observed.
Further, FIG. 2 shows the ultraviolet-visible absorption spectrum of the crude product of the acid anhydride represented by the formula (a) and the obtained quinophthalone dicarboxylic acid. As is clear from FIG. 2, the formula (a)
Which is present in the absorption spectrum of the crude acid anhydride represented by
nm) has disappeared in the absorption spectrum of the quinophthalone dicarboxylic acid obtained after the purification of the present invention, and it can be seen that the impurity (b) has been removed.

[0019]

[Chemical 14] Example 2 Formula (c) (Formula 15)

[0020]

[Chemical 15] 8.00 kg of acid anhydride crude product (purity 86%)
In addition, 118 liters of room temperature water was charged into a stainless reactor (300 liters volume), and the solution was stirred while stirring.
4.9 kg of 9% sodium hydroxide aqueous solution was added dropwise. p
After confirming that the pH became 12.9 with an H meter, the content liquid was heated to 50 ° C. The mixture was stirred at 50 to 52 ° C for 2 hours, then 4.0 kg of Celite-545 (Wako Pure Chemical Industries, Ltd. first-class reagent) was charged, and the mixture was stirred at 50 to 52 ° C for 30 minutes. After cooling to 30 to 35 ° C., a solvent insoluble matter was separated and removed from the solution using a glass lining filter (100 liters volume) covered with a polypropylene filter cloth as a filter material. The obtained filtrate was transferred to a glass lining reactor (200 liter volume), and then 25% sulfuric acid 1
3.2 kg was added dropwise over 35 minutes. The inner solution is 34.7
After confirming the value of 1.91 by measuring the pH at the time of ℃, the internal solution was heated to 90 ℃. 90 ~ 95 ℃, pH 1.8 ~
The value of 2.0 was maintained and the temperature was kept for 2 hours. After that, charge 50 liters of water, cool further from the outside, and
Cooled to 0 ° C. A filter press filter machine with a polypropylene filter cloth as the filter material (filtering area 4.32)
m ² ), the filtration time was 10 minutes. The filter cake was washed with water for 7 hours, and after the filtrate showed pH 6.5, it was dried at 80 ° C. to obtain 5.48 kg of quinophthalone dicarboxylic acid. The purity was 95.6%.

Comparative Example 1 In Example 1, 49% sodium hydroxide aqueous solution 4.
The same operation as in Example 1 was conducted except that 6.0 kg of a 49% aqueous sodium hydroxide solution was used instead of 9 kg to obtain 4.49 kg of quinophthalone dicarboxylic acid. The purity was 90.9%. When the visible absorption spectrum of the obtained quinophthalone dicarboxylic acid was measured, a peak at the maximum absorption wavelength of 475 nm of the compound (b) which was an impurity was observed, which shows that the impurity was not removed. Comparative Example 2 In Example 1, 6.10 kg of a crude product of the acid anhydride of formula (a) (purity 90.3%) and 118 liters of room temperature water were charged into a stainless steel reactor (300 liters volume), While the solution was being stirred, 4.9 kg of 49% aqueous sodium hydroxide solution was added dropwise. pH is 12.9 with pH meter
After confirming that
Except that while stirring at ~ 52 ° C for 2 hours, the content liquid was heated to 80 ° C and stirred at 80-83 ° C for 2 hours.
The same operation as in Example 1 was performed to obtain 4.03 kg of quinophthalone dicarboxylic acid. The purity was 88.6%. Ultraviolet of the reaction solution before heating and after keeping at 80 to 83 ° C for 2 hours-
The visible absorption spectrum is shown in FIG. As is clear from the figure, the absorbance after the heat treatment was significantly different from the absorbance before the temperature was raised, and alteration of the quinophthalone dicarboxylic acid salt was observed.

[0022]

INDUSTRIAL APPLICABILITY The present invention relates to a method for producing high-purity quinophthalone dicarboxylic acid by solubilizing a quinophthalone dicarboxylic acid anhydride represented by the general formula (I) with a novel solvent.
The present invention provides a method for producing high-purity quinophthalone dicarboxylic acid, which is based on a method for removing impurities mainly composed of a compound represented by the general formula (IV), and is harmless without using an organic solvent and a secondary amine. It is safe and can easily produce high-purity quinophthalone dicarboxylic acid by controlling the pH, which greatly contributes to the quality improvement of the socially useful dyes for liquid crystals or disperse dyes.

[Brief description of drawings]

FIG. 1 is a reaction between a crude product of an acid anhydride represented by the formula (a) and an alkaline compound in Example 1, which is a reaction solution before heating and after heating to 50 ° C., and then at 50 to 52 ° C. The ultraviolet-visible absorption spectrum of the reaction liquid after heat-processing for a time is shown. The vertical axis of the figure shows the absorbance and the horizontal axis shows the wavelength. The solid line is the absorption spectrum of the reaction solution before heating, and the dotted line is 50 to 52.
The absorption spectrum of the reaction liquid after stirring at 0 ° C. for 2 hours is shown.

FIG. 2 shows an ultraviolet-visible absorption spectrum of a crude product of an acid anhydride represented by the formula (a) and an obtained quinophthalone dicarboxylic acid in Example 1. The solid line is the absorption spectrum when 1.06 mg of the obtained quinophthalone dicarboxylic acid was dissolved in 100 ml of o-chlorophenol, and the dotted line is 1.01 mg of the crude acid anhydride represented by the formula (a).
Shows an absorption spectrum when was dissolved in 100 ml of o-chlorophenol. The vertical axis of the figure shows the absorbance and the horizontal axis shows the wavelength.

FIG. 3 is a reaction mixture of Comparative Example 2 with a crude product of the acid anhydride represented by the formula (a) and an alkaline compound, the reaction solution before heating and after heating to 80 ° C., and then at 80 to 83 ° C. The ultraviolet-visible absorption spectrum of the reaction liquid after heat-processing for a time is shown. The solid line shows the absorption spectrum of the reaction solution before heating, and the dotted line shows the absorption spectrum of the reaction solution after stirring at 80 to 83 ° C. for 2 hours. The vertical axis of the figure shows the absorbance and the horizontal axis shows the wavelength.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Ito 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. Inside the Chemical Co., Ltd. (72) Inventor Keisuke Soma In the Mitsui Toatsu Chemical Co., Ltd., 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa

Claims (4)

[Claims] 1. The following general formula (I) (Chemical formula 1) (In the formula, X represents a hydrogen atom, a halogen atom, or an alkyl group.) The quinophthalone dicarboxylic acid anhydride represented by the formula is hydrolyzed and neutralized with an alkaline compound to give the following general formula (II) [Chemical 2] (In the formula, Y and Z represent a cation, and X represents the same meaning as in the general formula (I).) The quinophthalone compound represented by formula (I) was solubilized as a salt, insoluble impurities were filtered off, and then the acid was removed. In addition, the following general formula (III) (Chemical Formula 3) (In the formula, X represents the same meaning as in the general formula (I).) A method for producing a high-purity quinophthalone dicarboxylic acid, which comprises depositing a high-purity quinophthalone dicarboxylic acid. 2. The method for producing quinophthalone dicarboxylic acid according to claim 1, wherein water is used as a solvent for hydrolysis and neutralization. 3. The method for producing quinophthalone dicarboxylic acid according to claim 1, wherein the pH of the solution containing the salt of the quinophthalone compound represented by the general formula (II) is 12.0-13.2. 4. The method for producing quinophthalone dicarboxylic acid according to claim 1, wherein the pH of the solution when the acid is added and precipitated is not less than 1.5 and less than 2.5.