JPH0648988A - Production of tetrakis(3-@(3754/24)3,5-dialkyl-4--hydroxyphenyl) propionyloxyalkyl) methane - Google Patents

Abstract

PURPOSE:To readily separate a catalyst after completion of reaction, to obtain a slightly colored tetrakis[3(3,5-dialkyl-4-hydroxyphenyl) propionyloxyalkyl]metliane and to shorten reaction time by using a specific alkali catalyst in transesterification reaction. CONSTITUTION:An alkyl-beta-(3,5-dialkyl-4-hydroxyphenyl)--propionate[preferably methyl-beta-(3,5-di-t-butyl-4-hydroxyphenyl) propionate and (B) a methane derivative tetrasubstituted with an alkyl containing hydroxyl group at the end (e.g. pentaerythritol) are subjected to transesterification reaction in the presence of (C) an alkali catalyst (preferably lithium hydroxide) composed of an alkaline (earth) metal hydroxide or an alkaline (earth) metal carbonate preferably under reduced pressure at 100-300 deg.C to give the objective compound. The reaction is preferably carried out in the molar ratio of the compound A/B of (4.1-4.0/1 and by dividedly adding the component C at two or more stages.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to tetrakis [3-] which is widely used as an antioxidant for polyolefins and the like.
It relates to a method for producing (3,5-dialkyl-4-hydroxyphenyl) propionyloxymethyl] methane.

[0002]

2. Description of the Related Art Conventionally, a method for producing tetrakis [3- (3,5-dialkyl-4-hydroxyphenyl) propionyloxyalkyl] methane is alkyl-β-
A method of transesterifying (3,5-dialkyl-4-hydroxyphenyl) propionate with pentaerythritol and the like in the presence of a catalyst, if necessary under reduced pressure, at a temperature of 120 to 200 ° C. For example, a method using an organic tin compound such as dibutyltin oxide as a catalyst (JP-A-1-265058, JP-A-2-292239, JP-A-3-11038) or potassium-t-butoxide as a catalyst. Method (JP-A-56-994)
44, JP-A-56-139438) and the like are disclosed.

[0003]

However, the method of using the above-mentioned organotin compound as a catalyst causes coloring of the product and separation of the catalyst is difficult. To separate, the catalyst is decomposed with oxalic acid or the like and then extracted. However, the reaction time was long.

In the method using potassium t-butoxide as a catalyst, the reaction time is short, but the coloring of the product is large, and in order to separate the catalyst, it is necessary to neutralize the catalyst and then filter.

The problem to be solved by the present invention is that tetrakis [3- (3,5-dialkyl-4-), in which the catalyst can be easily separated after completion of the reaction, the product is not colored, and the reaction time is short. It is to provide a method for producing (hydroxyphenyl) propionyloxyalkyl] methane.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that by using an alkali metal or alkaline earth metal hydroxide or an alkali metal or alkaline earth metal carbonate as a catalyst. The inventors have found that the above problems can be solved and completed the present invention.

That is, the present invention relates to alkyl-β- (3,5
-Dialkyl-4-hydroxyphenyl) propione-
(A) and a methane derivative (B) tetra-substituted with an alkyl group having a hydroxyl group at the terminal, and a hydroxide of an alkali metal or an alkaline earth metal or a carbonate of an alkali metal or an alkaline earth metal (C). ) Is present, tetrakis [3-
A method for producing (3,5-dialkyl-4-hydroxyphenyl) propionyloxyalkyl] methane is provided.

Alkyl-β- (3,5-used in the present invention
The dialkyl-4-hydroxyphenyl) propionate (A) (hereinafter, referred to as “propionic acid ester (A)”) is not particularly limited, but for example, one represented by the following general formula (1) may be used. Can be mentioned.

General formula (1)

[Chemical 1]

(Wherein R ₁ represents a branched alkyl group having 3 or 4 carbon atoms, and R ₂ represents a linear or branched alkyl group having 1 to 4 carbon atoms). Can be mentioned.

Specific examples thereof include methyl-β- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate, ethyl-β- (3,5-di-t-butyl-4)
-Hydroxyphenyl) propionate, n-propyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, i-propyl-β- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate, n-butyl-β- (3,5-di-t-butyl-4)
-Hydroxyphenyl) propionate, t-butyl-
β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, methyl-β- (3,5-di-i-
Propyl-4-hydroxyphenyl) propionate,
Ethyl-β- (3,5-di-i-propyl-4-hydroxyphenyl) propionate, methyl-β- (3,5
-Di-sec-butyl-4-hydroxyphenyl) propionate, ethyl-β- (3,5-di-sec-butyl-4-hydroxyphenyl) propionate and the like, among which methyl-β- (3,5- Di-t-butyl-
4-Hydroxyphenyl) propionate is preferable because of its excellent yield and the usefulness of the final purified product obtained as an antioxidant.

Further, as the methane derivative (B) tetra-substituted with an alkyl group having a hydroxyl group at the terminal used in the present invention (hereinafter referred to as "methane derivative (B)"), specifically, pentaerythritol is used. Can be mentioned.

Further, a hydroxide of an alkali metal or an alkaline earth metal or a carbonate of an alkali metal or an alkaline earth metal (C) (hereinafter, "alkali catalyst (C)").
Examples of) include, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, barium carbonate, among which the yield is high. From the point of view, hydroxide is preferable, and lithium hydroxide is particularly preferable because the yield thereof is extremely high.

The transesterification reaction between the propionic acid ester (A) and the methane derivative (B) in the present invention is carried out with the propionic acid ester (A) and the methane derivative (B) in the presence of an alkali catalyst (C). However, the proportion of the propionic acid ester (A) and the methane derivative (B) used is usually a stoichiometric amount of the propionic acid ester (A) or less than that of the methane derivative (B). It is an excessive amount. In this case, the amount of the alkali catalyst (C) used is usually such that the molar ratio (C) / (B) to the raw material methane derivative (B) is (0.01 to 0.5) /1.0. is there.

Among them, the molar ratio (A) / (B) is (5.0 to 5.0) in that unreacted propionic acid esters can be less mixed during the purification of the product after the reaction such as recrystallization.
It is preferably in the range of 4.0) /1.0. In this case, the amount of the alkali catalyst (C) used is such that the molar ratio (C) / (B) to the raw material methane derivative (B) is (0.05 to 0.3) / 1 from the viewpoint that the progress of the reaction can be accelerated. A range of 0.0 is preferable.

In the transesterification reaction, the propionic acid ester (A) and the methane derivative (A) are mixed in a molar ratio (A) / (B) of (4.1 to 4.0) /1.0. B) and the addition of the alkali catalyst (C) in two or more steps, the unreacted propionic acid ester does not remain in the product, and an extremely high yield can be obtained. preferable.

As a specific example of adding the alkali catalyst (C) in two or more steps, 50 to 75% by weight of the total amount of the alkali catalyst (C) used is charged at the start of the transesterification reaction, and the rest is added. 50 to 25% by weight of the above may be added after 1/4 of the time required for the reaction to 3/4 of the time.

The transesterification reaction carried out in the present invention is an equilibrium reaction, and the progress of the reaction is facilitated by taking out the produced alcohol out of the system. Therefore, the reaction temperature is 100 or higher than the boiling point of the alcohol to be produced.
The range of ˜300 ° C. is preferred.

The reaction may be carried out under atmospheric pressure, but it may be carried out at a relatively low temperature and under reduced pressure in order to facilitate the distillation of alcohol and to suppress the occurrence of side reactions. Preferably, specifically, 100 to 100 at 20 to 100 mmHg.
The range of 200 ° C. is included.

The reaction solvent does not have to be particularly used, but if necessary, the reaction may be carried out using a polar solvent having a high boiling point such as dimethylformamide, dimethylsulfoxide and sulfolane.

After the reaction is complete, the product can be separated very easily from the alkali catalyst by filtration. Also,
Then, the product is purified by recrystallization to obtain a product. In the present invention, this recrystallization can be extremely easily performed.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Methyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate 146 g (0.5 mol),
15.5 g (0.114 mol) of pentaerythritol and 0.63 g (0.015 mol) of lithium hydroxide were added to 5 parts.
Place in a 00 ml flask and heat to 130 ° C with stirring,
The system was kept under a reduced pressure of 20 to 30 mmHg for 1 hour to distill off most of the water and the produced methanol.

Then, the temperature is raised to 180 ° C. and the temperature is increased to 50 m.
Stirring was continued for 6 hours under reduced pressure of mHg to cause a reaction. 100
After cooling to ℃, it was filtered to separate lithium hydroxide as a catalyst, and tetrakis [3- (3,5-di-t-butyl-4-
A product containing (hydroxyphenyl) propionyloxymethyl] methane was obtained.

As a result of analysis by liquid chromatography, the yield of tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane in the product was 94 mol%. . The obtained product was colorless, and the content of propionic acid esters in the product was 9% by weight.

Then, the product was purified by recrystallization using twice the weight of 95% ethanol (a mixed solution of 95 parts by weight of ethanol and 5 parts by weight of water, the same applies hereinafter). The yield of the obtained purified product by recrystallization was 94.4 mol%, and the yield in all steps was 88.7 mol%.

Example 2 146 g (0.5 mol) of methyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), 17.0 g (0.125 mol) of pentaerythritol and hydroxylation. 0.32 g (0.008 mol) of lithium was placed in a 500 ml flask, heated to 130 ° C. with stirring, and the inside of the system was reacted for 1 hour under a reduced pressure of 20 to 30 mmHg, and most of the produced methanol was formed. Removed.

Then, the temperature is raised to 180 ° C. and the temperature is increased to 50 m.
The mixture was stirred under reduced pressure of mHg for 4 hours. Further, 0.32 g (0.008 mol) of lithium hydroxide was added, and 180 hours for 2 hours.
Stirring was continued for 2 hours at 50 ° C. and 50 mmHg for reaction. After cooling to 100 ° C., filtration was performed to separate lithium hydroxide as a catalyst to obtain a product containing tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane. .

As a result of analysis by liquid chromatography, the yield of tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane in the product was 93 mol%. . The obtained product was colorless, and the content of propionic acid esters in the product was 2% by weight.

Next, the product was purified by recrystallization using twice the weight of 95% ethanol.
The yield of the obtained purified product in the recrystallization step was 92.8 mol%, and the yield in all the steps was 86.3 mol%.

Example 3 The reaction was carried out in the same manner as in Example 1 except that the same number of moles of calcium hydroxide was used instead of lithium hydroxide, and after the completion of the reaction, the catalyst calcium hydroxide was separated by filtration. Tetrakis [3- (3,5-di-t-butyl-4-
A product containing (hydroxyphenyl) propionyloxymethyl] methane was obtained. The product obtained was colorless.

Example 4 The reaction was carried out in the same manner as in Example 1 except that the same molar number of lithium carbonate was used instead of lithium hydroxide.
After the completion, filtration was performed to separate lithium carbonate as a catalyst to obtain a product containing tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane. The product obtained was colorless.

Example 5 The reaction was carried out in the same manner as in Example 1 except that the same molar number of calcium carbonate was used instead of lithium hydroxide, and after the completion of the reaction, the catalyst calcium carbonate was separated by filtration. A product containing tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane was obtained. The product obtained was colorless.

Comparative Example 1 Methyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate 124.0 g (0.432)
Mol), 13.12 g of pentaerythritol (0.02
50 mol), 50 ml of dimethylformamide and 2.83 g (0.025 mol) of potassium t-butoxide.
Place in a 0 ml flask, 87 ° C for 10 minutes, 90 ° C /
After stirring at 30mmHg for 1 hour, 140 ℃ / 20m
The reaction was continued by stirring at mHg for 6 hours. After cooling to 100 ° C., it was neutralized with acetic acid, filtered and filtered with tetrakis [3
A product containing-(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane was obtained.

As a result of analysis by liquid chromatography, the yield of tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane in the product was 87%. Moreover, the obtained product was black.

Next, the product was purified by recrystallization using twice the weight of 95% ethanol, but only a slightly yellowish purified product was obtained, and the purity was also poor. .

Therefore, 95% isopropyl alcohol (a mixed solution of 95 parts by weight of isopropyl alcohol and 5 parts by weight of water) in an amount twice as much as the weight of the product obtained by carrying out a similar reaction and neutralizing filtration. Recrystallize using
After heating and drying under reduced pressure at 40 ° C., the product obtained was further purified by recrystallization using twice the weight of 95% ethanol on a weight basis. The yield of the obtained purified product in the recrystallization step was 87 mol%, and the yield in all the steps was 75.7 mol%.

Comparative Example 2 Methyl β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate 120.0 g (0.458)
Mol), pentaerythritol 13.8 g (0.10)
1 mol) and 0.83 g of dibutyltin oxide (0.
0031 mol) in a 500 ml flask, 195
2 hours at 40 ° C and 2 hours at atmospheric pressure at ℃
The reaction was continued by stirring at mmHg for 12 hours. 100 ° C
After cooling to room temperature, it is filtered and tetrakis [3- (3,5-di-t
A product containing -butyl-4-hydroxyphenyl) propionyloxymethyl] methane was obtained.

As a result of analysis by liquid chromatography, the yield of tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxymethyl] methane in the product was 84%. The product obtained was yellow.

Next, the product was purified by recrystallization using twice the weight of 95% ethanol. The resulting purified product contained 0.0% dibutyltin oxide.
It was found that tin ions corresponding to 8 g were contained and dibutyltin oxide was not removed. Therefore, the product was treated with an oxalic acid aqueous solution and then recrystallized with 95% ethanol to obtain a purified product.

[0041]

INDUSTRIAL APPLICABILITY According to the present invention, tetrakis [3- (3,5-dialkyl-4-hydroxyphenyl) propionyloxymethyl] methane which is easily separated from the catalyst and has no color is obtained.

Claims (4)

[Claims] 1. Alkyl-β- (3,5-dialkyl-
4-hydroxyphenyl) propionate (A) and a methane derivative (B) tetra-substituted with an alkyl group having a hydroxyl group at the terminal are prepared by using a hydroxide of an alkali metal or an alkaline earth metal or an alkali metal or an alkaline earth. A process for producing tetrakis [3- (3,5-dialkyl-4-hydroxyphenyl) propionyloxyalkyl] methane, which comprises performing a transesterification reaction in the presence of a metal carbonate (C). 2. Alkyl-β- (3,5-dialkyl-
4-hydroxyphenyl) propionate (A) is methyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, which is tetra-substituted with an alkyl group having a hydroxyl group at the terminal. The method according to claim 1, wherein the methane derivative (B) is pentaerythritol. 3. The method according to claim 1, wherein the alkali metal or alkaline earth metal hydroxide or alkali metal or alkaline earth metal carbonate (C) is lithium hydroxide. 4. Alkyl-β- (3,5-dialkyl-
The 4-hydroxyphenyl) propionate (A) and the methane derivative (B) tetra-substituted with an alkyl group having a hydroxyl group at the terminal have a molar ratio (A) / (B) of (4.1 to
4.0) /1.0, and adding the alkali metal or alkaline earth metal hydroxide or alkali metal or alkaline earth metal carbonate (C) in two or more steps. Item 4. The method according to Item 1, 2 or 3.