JP3348464B2 - Purification method of hydroxybenzoic acid esters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound of the general formula (1) useful as a polymerizable recording material.

[0002]

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(Wherein, X represents a chlorine or bromine atom, R represents a hydrogen or methyl group, and n represents an integer of 2 to 9.)
And a method for purifying hydroxybenzoic acid esters substituted with a methacryloyl or acryloyl group represented by the formula

[0004]

2. Description of the Related Art A methacryloyl or acryloyl group-substituted hydroxybenzoic acid ester represented by the general formula (1) is represented by the general formula (3)

[0005]

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Wherein X and n are as defined above, and hydroxyalkyl 3-halo-4-hydroxybenzoate and methacrylic acid, methacrylic halide, acrylic acid or acrylic halide, etc. Is obtained by reacting

On the other hand, the general formula (3)
As a method for synthesizing the represented 3-halo-4-hydroxybenzoic acid hydroxyester, (A) esterification reaction of 3-halo-4-hydroxybenzoic acid with alkanediol,
(B) Transesterification of a lower alkyl 3-halo-4-hydroxybenzoate with an alkanediol is practical in terms of availability of raw materials.

However, in both of the methods (A) and (B), the alkanediol involved in the esterification reaction has two hydroxyl groups chemically present in the same environment at both ends of the carbon chain. Even if the reaction temperature, the charging ratio of the reaction reagent, etc. are devised, the alkanediol monoester, that is, 3-halo-4- represented by the general formula (3),
It is extremely difficult to selectively obtain only hydroxybenzoic acid hydroxyalkyl ester. In addition, the general formula (2)

[0009]

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(Wherein X and n have the same meanings as described above), and alkanediol dibenzoates are inevitably produced.

Further, according to the knowledge obtained by the present inventors, alkanedibenzoates are compounds that are extremely difficult to remove even by recrystallization operations using various solvents. It is not easy to obtain a 3-halo-4-hydroxybenzoic acid hydroxyalkyl ester represented by the general formula (3). If an attempt is made to obtain a high-purity target product, the yield becomes extremely low.

On the other hand, the following reaction using 3-halo-4-hydroxybenzoic acid hydroxyalkyl ester containing alkanediol dibenzoate as an impurity, ie, methacrylic acid, methacrylic halide, acrylic acid,
When the reaction proceeds with an acrylic acid halide or the like, the reaction product contains, in addition to the target methacryloyl or acryloyl group-substituted hydroxybenzoic acid ester represented by the general formula (1), the alkanediol diamine represented by the general formula (2) Benzoates will be included.

[0013]

DISCLOSURE OF THE INVENTION The present invention relates to at least methacryloyl or acryloyl group-substituted hydroxybenzoic acid esters represented by the general formula (1) and a compound represented by the general formula (2):
It is an object of the present invention to provide a method for removing high-purity methacryloyl or acryloyl group-substituted benzoates by removing alkanediol dibenzoates from a mixture containing alkanediol dibenzoates represented by the formula:

[0014]

SUMMARY OF THE INVENTION The present invention provides, as a solute, at least a methacryloyl or acryloyl group-substituted hydroxybenzoate represented by the general formula (1) and an alkanediol dibenzoate represented by the general formula (2). To a solution of a water-insoluble organic solvent containing both of the above, an aqueous solution of an alkali metal hydroxide, an alkali metal carbonate, or an alkali metal bicarbonate having a pH of 8 to 12 containing one or two or more thereof is added by the general formula (2). Purification of methacryloyl or acryloyl group-substituted hydroxybenzoates represented by the general formula (1), wherein the alkanediol dibenzoates represented by the formula (1) are selectively transferred to an aqueous layer and removed from an organic solvent solution. About the law.

The compound represented by the general formula (1) is 3
2-acryloyloxyethyl ester, 3-acryloyloxypropyl ester, 4-acryloyloxybutyl ester of -chloro-4-hydroxybenzoic acid,
5-acryloyloxypentyl ester, 6-acryloyloxyhexyl ester, 2-methacryloyloxyethyl ester, 3-methacryloyloxypropyl ester, 4-methacryloyloxybutyl ester, 5-methacryloyloxypentyl ester, 6-
Methacryloyloxyhexyl ester, 9-methacryloyloxynonyl ester or 2-acryloyloxyethyl ester of 3-bromo-4-hydroxybenzoic acid, 3-acryloyloxypropyl ester, 4-acryloyloxybutyl ester, 5-acryloyloxypentyl ester, 6-acryloyloxyhexyl ester, 2-methacryloyloxyethyl ester, 3-methacryloyloxypropyl ester, 4-
Examples include methacryloyloxybutyl ester, 5-methacryloyloxypentyl ester, 6-methacryloyloxyhexyl ester, and 9-methacryloyloxynonyl ester.

The compounds represented by the general formula (2) include 1,2-bis (3-chloro-4-hydroxybenzoyloxy) ethane and 1,3-bis (3-chloro-4-hydroxybenzoyloxy) propane , 1,4-bis (3
-Chloro-3-hydroxybenzoyloxy) butane,
1,5-bis (3-chloro-4-hydroxybenzoyloxy) pentane, 1,6-bis (3-chloro-4-hydroxybenzoyloxy) hexane, 1,9-bis (3-chloro-4-hydroxybenzoyl) Oxy) nonane, 1,2-bis (3-bromo-4-hydroxybenzoyloxy) ethane, 1,3-bis (3-bromo-4-
(Hydroxybenzoyloxy) propane, 1,4-bis (3-bromo-4-hydroxybenzoyloxy) butane, 1,5-bis (3-bromo-4-hydroxybenzoyloxy) pentane, 1,6-bis (3- Bromo-4
-Hydroxybenzoyloxy) hexane and the like.

There is no particular limitation on the mixing ratio of the compound of the general formula (1) and the compound of the general formula (2).
Since it is an object of the present invention to obtain a compound of the general formula (1) with high purity, the purification is simpler as the proportion of the compound of the general formula (2) is smaller, but usually the general formula (1) The ratio of the compound is 70% or more, and the ratio of the compound of the general formula (2) is 3
If the mixture is 0% or less, the desired product of high purity, that is, the compound of the general formula (1) can be obtained relatively easily and economically by the method of the present invention.

Specific examples of the water-insoluble organic solvent for dissolving the compounds of the general formulas (1) and (2) include:
Chloroform, tricrene, tetrachloroethylene,
Aliphatic hydrocarbons such as 1,2-dichloroethane, aromatic hydrocarbons such as benzene, toluene and xylene, ethyl acetate, propyl acetate, and acetates such as butyl acetate;
And ketones such as methyl isobutyl ketone.
The amount of the organic solvent to be used is determined in consideration of the solubility of the solvent and the size of the partition coefficient, but is generally 0.5 to 10 times the weight of the solute, and is 1 in consideration of economy and operability. To about 3 times by weight.

The alkali used for preparing the aqueous alkali solution having a pH of 8 to 12 for extracting the alkanediol dibenzoates of the general formula (2) is sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, carbonate carbonate. Sodium hydrogen carbonate and potassium hydrogen carbonate. Alternatively, carbon dioxide may be blown into the aqueous alkali hydroxide solution. The alkaline aqueous solution may be adjusted in advance in a separate container and then added to the organic solvent solution. Alternatively, after adding water to the organic solvent solution, alkalis may be added to adjust the pH. The optimum pH is slightly different depending on the structures of the general formula (1) and the general formula (2), but is generally from about pH 8 to 12, more preferably from 9 to 10 when the organic solvent solution and the alkali aqueous solution are sufficiently mixed and contacted. .5. If the pH is too low, the purification efficiency will decrease. On the other hand, if the pH is too high, the selectivity of the extraction is lowered and the compound of the general formula (1), which is the target substance, flows out to the aqueous layer, and the liquid is emulsified to separate the organic layer and the aqueous layer. It will be difficult. The pH may be adjusted by first adding water to the organic solvent solution and then gradually adding alkali hydroxide or alkali carbonate alone, but industrially, a mixed aqueous solution of alkali hydroxide and alkali bicarbonate, It is convenient to use a mixed aqueous solution of alkali and alkali bicarbonate.

The extraction with alkaline water can be carried out either in a batch system or a continuous system. For example, in the case of a batch method, extraction may be repeated until the content of the general formula (2) in the organic layer becomes equal to or less than the target value. After the extraction with alkaline water is completed, the organic layer is washed with water until the pH of the aqueous layer becomes neutral, and the organic solvent is distilled off to obtain a compound of the general formula (1) having high purity. If higher purity is required, it may be purified by recrystallization or the like.

[0021]

EXAMPLES Reference examples and examples of the present invention will be described below, but the present invention is not limited to these examples.

Reference Example 1 3-chloro-4-hydroxybenzoic acid 3-hydroxypropyl ester 82%, 1,3-bis (3-chloro-4
Methacrylic acid 1 in 180 g of a mixture consisting of 14% of -hydroxybenzoyloxy) propane and 4% of others.
72 g and 5 g of sulfuric acid were added and reacted at 70 ° C. for 8 hours. After completion of the reaction, 1,2-dichloroethane was added, and the organic layer was washed with aqueous sodium bicarbonate to remove unreacted methacrylic acid. Dichloroethane was distilled off to obtain 298 g of a viscous oil. HP
According to LC analysis (254 nm), the composition was 3-chloro-4.
-Hydroxybenzoic acid 3-methacryloyloxypropyl ester 76%, 1,3-bis (3-chloro-4-hydroxybenzoyloxy) propane 17% Other 7%
Met.

Example 1 To 298 g of the oily substance obtained in Reference Example 1, 240 g of 1,2-dichloroethane was added and dissolved. Sodium carbonate 20
g, an aqueous alkaline solution containing 20 g of sodium bicarbonate (pH = 9.6)
After 300 g was added and mixed well with stirring, the mixture was allowed to stand and separated, and the aqueous layer was discarded. After the operation of washing with 300 g of the alkaline aqueous solution was repeated a total of three times, the organic layer was washed with water and dichloroethane was distilled off to obtain 220 g of an oil. Its composition was 3-chloro-4-hydroxybenzoic acid 3-methacryloyloxypropyl ester 92.8%, 1,3-
Bis (3-chloro-4-hydroxybenzoyloxy)
Propane 1.2% and other 9%. Further recrystallization from acetonitrile gave white crystals of 3-chloro-4-hydroxybenzoic acid 3-methacryloyloxypropyl ester. Purity was 98.3%. Melting point 67
° C

Reference Example 2 3-Chloro-4-hydroxybenzoic acid 3-hydroxypentyl ester 88%, 1,5-bis (3-chloro-4
Methacrylic acid 172 was added to 240 g of a mixture consisting of 9% of -hydroxybenzoyloxy) pentane and 3% of others.
g and sulfuric acid (5 g) were added and reacted at 70 ° C for 8 hours. After the reaction was completed, toluene was added, and the organic layer was washed with aqueous sodium bicarbonate to remove unreacted methacrylic acid. The toluene was distilled off to obtain 305 g of a viscous oil. According to HPLC analysis (254 nm), the composition was 3-chloro-4-hydroxybenzoic acid 5-
Methacryloyloxypentyl ester 85%, 1,5
-Bis (3-chloro-4-hydroxybenzoyloxy) pentane was 12% and the others were 3%.

Example 2 600 g of toluene was added to 305 g of the oil obtained in Reference Example 2.
Was added and dissolved. 500 g of an alkaline aqueous solution (pH = 9.8) containing 20 g of sodium carbonate and 10 g of sodium bicarbonate was added and mixed well with stirring. The operation of washing with 500 g of the alkaline aqueous solution was repeated a total of four times, then, the organic layer was washed with water, and toluene was distilled off to obtain 235 g of an oil. Its composition is 3-chloro-4-
Hydroxybenzoic acid 5-methacryloyloxypentyl ester 93.6%, 1,5-bis (3-chloro-4-
(Hydroxybenzoyloxy) pentane 0.4% and other 6%. Further recrystallization with tetrachloroethylene gave white crystals of 3-chloro-4-hydroxybenzoic acid 5-methacryloyloxypentyl ester.
Purity was 98.5%. Melting point 51 ° C

Reference Example 3 90% of 3-chloro-4-hydroxybenzoic acid 6-hydroxyhexyl ester, 1,6-bis (3-chloro-4
-Hydroxybenzoyloxy) hexane 270 g of a mixture consisting of 8% and other 2% methacrylic acid 172.
g and 5 g of sulfuric acid were added and reacted at 60 ° C. for 8 hours. After the reaction was completed, toluene was added, and the organic layer was washed with aqueous sodium bicarbonate to remove unreacted methacrylic acid. When the toluene was distilled off, 330 g of a viscous oil was obtained. According to HPLC analysis (254 nm), the composition was 3-chloro-4-hydroxybenzoic acid 6-
Methacryloyloxyhexyl ester 81%, 1,6
-Bis (3-chloro-4-hydroxybenzoyloxy) hexane 12%, and others 7%.

Example 3 550 g of toluene was added to 330 g of the oily substance obtained in Reference Example 3.
Was added and dissolved. 350 g of an aqueous alkaline solution (pH = 10.5) containing 40 g of potassium carbonate and 10 g of sodium bicarbonate was added, mixed well with stirring, and allowed to stand still to separate the aqueous layer. After the operation of washing with 350 g of the alkaline aqueous solution was repeated a total of three times, the organic layer was washed with water, and toluene was distilled off to obtain 250 g of an oily substance. Its composition is 3-chloro-4-
93.4% of hydroxybenzoic acid 6-methacryloyloxyhexyl ester, 1,6-bis (3-chloro-4-
(Hydroxybenzoyloxy) hexane 1.1%, and others 5.5%. Further recrystallization with toluene 3-
White crystals of chloro-4-hydroxybenzoic acid 6-methacryloyloxyhexyl ester were obtained. Purity 9
8.2%. Melting point 62 ° C

[0028]

According to the method of the present invention, alkanediol dibenzoates can be removed from the reaction product by a simple operation to obtain high-purity methacryloyl or acryloyl group-substituted hydroxybenzoates. Accordingly, the hydroxyalkyl 3-chloro-4-hydroxybenzoate used in the reaction with methacrylic acid or acrylic acid may be one containing dialkanediol dibenzoates which are unavoidably easily produced as a by-product in the production process. It can be used for the reaction without purification.

Continuation of the front page (56) References JP-A-5-163207 (JP, A) JP-A-4-149155 (JP, A) JP-A-4-235948 (JP, A) JP-A-4-54150 (JP) , A) JP-A-5-997 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 67/58 C07C 69/84

Claims (1)

(57) [Claims] 1. A solute having at least a general formula (1): (Wherein, X represents a chlorine or bromine atom, R represents a hydrogen or methyl group, and n represents an integer of 2 to 9) and a hydroxybenzoic acid ester substituted with a methacryloyl or acryloyl group represented by the general formula (2) ) (Wherein, X represents a chlorine or bromine atom, and n represents an integer of 2 to 9.) A solution of a water-insoluble organic solvent containing both alkanediol dibenzoates represented by the following formula: An aqueous solution having a pH of 8 to 12 containing one or more alkali metal carbonates or alkali metal bicarbonates is added, and the alkanediol dibenzoates represented by the general formula (2) are selectively transferred to the aqueous layer. A method for purifying a methacryloyl or acryloyl group-substituted hydroxybenzoate represented by the general formula (1), wherein the ester is removed from an organic solvent solution.