KR19990015824A - Method for preparing phosphinylcarboxylic acid and derivatives thereof - Google Patents

Abstract

When an alkyl (or aryl) phosphinic acid and a hydrogen (or alkyl) substituted acrylic acid are mixed and phosphorus trichloride is added dropwise to prepare phosphinylcarboxylic acid and its derivatives, there is little exotherm and hydrochloric acid per unit time. The reaction can be allowed to occur under mild conditions, and side reactions that produce by-products hardly occur, so that high-purity phosphinylcarboxylic acid and its derivatives can be produced in high yield.

Description

Method for preparing phosphinylcarboxylic acid and derivatives thereof

[Industrial use]

The present invention relates to a process for preparing phosphinylcarboxylic acid and derivatives thereof used as a non-halogen flame retardant, and more particularly, to a mixture by mixing alkyl (or aryl) phosphinic acid and hydrogen (or alkyl) substituted acrylic acid. And it relates to a process for producing phosphinylcarboxylic acid and its derivatives represented by the following formula (1) through dropwise addition of phosphorus trichloride to the mixture.

[Formula 1]

In the above formula, R ₁ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms, and R ₂ is a group consisting of an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 18 carbon atoms R ₃ is selected from the group consisting of a hydrogen atom and a methyl group, R ₄ and R ₅ are each independently a group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a hydroxy alkyl group having 1 to 10 carbon atoms It is selected from.

[Private Technology]

Since halogen-based flame retardants are toxic in combustion, there is a recent movement to regulate their use in developed countries such as the United States and Europe. Accordingly, the development of inorganic flame retardants and phosphorus flame retardants as non-toxic flame retardants has been active. For example, US Pat. Nos. 4,138,433 and 4,742,088, and Japanese Patent Laid-Open Nos. Hei 5-194562 and Hei 7-179482 disclose a method for producing a non-halogen flame retardant containing no halogen element.

Japanese Patent Laid-Open Nos. 7-188264, 6-32792 and 4-364196 disclose the preparation of 3-hydroxyphenylphosphinyl propionic acid compounds in which R ₁ and R ₂ are both hydrogen atoms in the compounds represented by the above formula (1). Methods and purification methods thereof have been disclosed. The compound is a white powdery compound, which can effectively impart flame retardancy and antistatic property to a synthetic resin such as polyester or polyamide simultaneously, and to various properties such as viscosity, melting temperature, heat resistance and color of the synthetic resin. Has the advantage of not affecting.

A general method for preparing a compound represented by Chemical Formula 1 may be represented by Scheme 1 below.

Scheme 1

In the above scheme, R ₁ to R ₅ are as defined above.

As shown in the above scheme, conventionally, by adding dropwise hydrogen (or alkyl) substituted acrylic acid represented by the formula (3) to dichloroalkyl (or aryl) phosphine represented by the formula (2) to prepare a compound represented by the formula (4), A method of preparing phosphinylcarboxylic acid and its derivatives represented by Chemical Formula 1 by hydrolysis or alcohol decomposition of the compound represented by Chemical Formula 4 was used. However, the method has a number of problems, firstly, the dichloroalkyl (or aryl) phosphine has a peculiar odor and is highly reactive to react with air in the air to generate hydrochloric acid. Not only is this difficult, it is also less workable. Secondly, since the physical properties of the final product and the starting material of hydrogen (or alkyl) substituted acrylic acid may be polymerized by itself, the method is preferably performed at 60 to 80 ° C. The heat generated in the reaction of the dichloroalkyl (or aryl) phosphine and the hydrogen (or alkyl) substituted acrylic acid should be removed, otherwise the physical properties of the final product is lowered and side reactions predominantly occur. Third, a large amount of hydrochloric acid is generated per unit time during hydrolysis or alcohol decomposition, and it is difficult to maintain the temperature of 60 to 80 ° C. with severe exothermic heat.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to use a small amount in situ inside the reactor without using dichloroalkyl (or aryl) phosphine directly By generating the reaction quantitatively, the calorific value and hydrochloric acid generation can be minimized per unit time, and side reactions that generate by-products hardly occur, so that phosphinyl carboxylic acid or its derivatives can be produced in high yield. It is to provide a method for producing the main acid or derivatives thereof.

In order to achieve the object of the present invention as described above, the present invention comprises the steps of preparing a mixture by mixing a compound represented by the formula (5) and a compound represented by the formula (3), by adding dropwise phosphorus trichloride to the mixture represented by the formula (4) Phosphinyl represented by Formula 1, comprising preparing a compound, and hydrolyzing or alcohol-decomposing the compound represented by Formula 4 by adding a compound selected from the group consisting of water, alcohol and hydroxyalcohol. Provided are methods for preparing carboxylic acid or derivatives thereof.

[Formula 1]

[Formula 3]

[Formula 4]

[Formula 5]

In the above formulas, R ₁ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms, and R ₂ is an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 18 carbon atoms It is selected from the group consisting of, R ₃ is selected from the group consisting of a hydrogen atom and a methyl group, R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group of 1 to 10 carbon atoms and a hydroxy alkyl group of 1 to 10 carbon atoms It is selected from the group consisting of.

The above steps are preferably carried out at -20 to 160 ℃.

The amount of the compound represented by Chemical Formula 3 is 1 to 20 equivalents to the compound represented by Chemical Formula 5, and the amount of the phosphorus trichloride is 1 to 5 equivalents to the compound represented by Chemical Formula 5, and the water, alcohol and hydroxide The amount of the compound selected from the group consisting of oxyalcohol is preferably 2 to 50 equivalents relative to the compound represented by Chemical Formula 5.

Hereinafter, the present invention will be described in more detail.

The reaction of the present invention can be represented by the following scheme 2.

Scheme 2

In the above scheme, R ₁ to R ₅ are as defined above.

As shown in the above scheme, an alkyl (or aryl) phosphinic acid represented by the formula (5) and a hydrogen (or alkyl) substituted acrylic acid represented by the formula (3) are mixed to prepare a uniform liquid mixture, and then phosphorus trichloride By the reaction of dropwise addition, dichloroalkyl (or aryl) phosphine represented by the formula (2) used as the starting material in Scheme 1 is produced in small amounts in situ inside the reactor through the following scheme 3.

Scheme 3

In the reaction of the present invention, since the dichloroalkyl (or aryl) phosphine is produced in small amounts, the reaction proceeds quantitatively, so that there is little exotherm and hydrochloric acid per unit time, the reaction occurs under moderate conditions, and side reactions generating by-products are almost impossible. It won't happen.

Conventional reactions had to be carried out at 60-80 ° C., since the physical properties of the final product were lowered and the starting material hydrogen (or alkyl) substituted acrylic acid was likely to polymerize on its own, whereas the reaction of the present invention was carried out more broadly. It may be carried out at 20 to 160 ℃.

The amount of the compound represented by Chemical Formula 3 is preferably 1 to 20 equivalents compared to the compound represented by Chemical Formula 5, and when the amount is less than 1 equivalent, the reaction is difficult to occur efficiently. The addition amount of the phosphorus trichloride is preferably 1 to 5 equivalents to the compound represented by Chemical Formula 5, when less than 1 equivalent, it is difficult to sufficiently generate dichloroalkyl (or aryl) phosphine, and when it exceeds 5 equivalents, economic efficiency is low. . The addition amount of the compound selected from the group consisting of water, alcohol and hydroxyalcohol is preferably 2 to 50 equivalents compared to the compound represented by Formula 5, so that hydrolysis or alcohol decomposition occurs most efficiently in the above range.

EXAMPLE

Preferred examples and comparative examples of the present invention are described. However, the following examples are merely examples of the present invention showing the constitution and effects of the present invention, and the present invention is not limited to the following examples.

Example 1

Into a four-necked flask equipped with a condenser, a thermometer, and a stirrer, 142 g of phenylphosphinic acid and 360 g of acrylic acid were added, and the mixture was stirred and dissolved while being heated to 70 ° C. under a nitrogen stream. After dissolution was completed, 205 g of phosphorus trichloride was added dropwise at this temperature over 2 hours. After the addition was completed, the mixture was further stirred at the temperature for 3 hours. The internal temperature was cooled to 40 ° C and hydrolyzed by dropwise addition of 710 g of pure water. After hydrolysis, the mixture was further refluxed and stirred for 2 hours to completely hydrolyze, and the aqueous solution was cooled to 20 ° C to obtain acicular compound. The compound was filtered, washed with 500 ml of pure water and dried to obtain 200 g of 3-hydroxyphenylphosphinyl propionic acid.

Example 2

142 g of phenylphosphinic acid and 129 g of methacrylic acid were added to a four-necked flask equipped with a condenser, a thermometer, and a stirrer, and the mixture was stirred and dissolved at a temperature of 90 ° C. under a nitrogen stream. After dissolution was completed, 165 g of phosphorus trichloride was added dropwise at this temperature over 1 hour. After completion of the dropwise addition, the mixture was further stirred at this temperature for 5 hours. The internal temperature was cooled to 70 DEG C and hydrolyzed by dropwise addition of 710 g of pure water. After hydrolysis, the mixture was further refluxed for 1 hour to completely hydrolyze and cooled to 20 ° C or lower to obtain a needle-like compound. The compound was filtered, washed with 800 ml of pure water and dried to obtain 203 g of 2-methyl-3-hydroxyphenylphosphinyl propionic acid.

Example 3

Into a four-necked flask equipped with a condenser, a thermometer, and a stirrer, 142 g of phenylphosphinic acid and 360 g of acrylic acid were added, and the mixture was stirred and dissolved while being heated to 70 ° C. under a nitrogen stream. After dissolution was completed, 205 g of phosphorus trichloride was added dropwise at this temperature over 2 hours. After the dropwise addition was completed, the mixture was further stirred at this temperature for 3 hours. The internal temperature was cooled to 60 DEG C and alcoholic decomposition was carried out by dropwise addition of 310 g of ethylene glycol. After alcohol decomposition, the internal temperature was raised to 180 ° C., and the mixture was further refluxed and stirred for 3 hours to completely decompose the alcohol, and then cooled to 100 ° C. again to distill off excess ethylene glycol at a vacuum of 30 Torr to remove 3-hydroxyethyl-phenylphosphinyl 246.7 g of propionic acid hydroxyethyl ester were obtained.

Comparative Example 1

In a four-necked flask equipped with a condenser, a thermometer, and a stirrer, 174 g of dichlorophenylphosphine was added and the temperature was raised to 60 ° C. 108 g of acrylic acid was added dropwise at this temperature to adjust the internal temperature to 60-80 ° C. After the addition was completed, the mixture was further stirred at 70 ° C for 3 hours, cooled to 40 ° C, and hydrolyzed by dropwise addition of 600 g of pure water. After hydrolysis, the mixture was further refluxed and stirred for 2 hours to completely hydrolyze and cooled to 20 ° C to obtain a needle-like compound. The compound was filtered, washed with 500 ml of pure water, and dried to obtain 165 g of 3-hydroxyphenylphosphinyl propionic acid.

Comparative Example 2

In a four-necked flask equipped with a condenser, a thermometer, and a stirrer, 174 g of dichlorophenylphosphine was added and the temperature was raised to 60 ° C. 108 g of acrylic acid was added dropwise at this temperature, and the temperature was adjusted well to 60-80 ° C. After the addition was completed, the mixture was further stirred at 70 ° C. for 3 hours, and 310 g of ethylene glycol was added dropwise to decompose alcohol. After alcohol decomposition, the mixture was cooled to 100 DEG C, and excess ethylene glycol and acrylic acid were distilled off at a vacuum of 30 Torr to obtain a 3-hydroxyphenylphosphinyl propionic acid hydroxyethyl ester mixture. The mixture was analyzed by nuclear magnetic resonance spectroscopy to find a mixture of 3-hydroxyethyl-phenylphosphinyl propionic acid hydroxyethyl ester and 3-hydroxyphenylphosphinyl propionic acid hydroxyethyl ester with a production ratio of 90 to 10.

The results of the Examples and Comparative Examples are shown in Table 1 below.

yield(%) water(%) Example 1 93 99.5 Example 2 89 99.7 Example 3 96 99.2 Comparative Example 1 77 98.2

Using the production method according to the present invention, without using dichloroalkyl (or aryl) phosphine directly, the reaction is quantitatively produced in small amounts in situ inside the reactor so that the reaction proceeds quantitatively. There is almost no hydrochloric acid and the reaction can be performed under mild conditions, and side reactions that produce by-products hardly occur, thereby making it possible to prepare high-purity phosphinylcarboxylic acid and its derivatives in high yield.

Claims (3)

Preparing a mixture by mixing a compound represented by Formula 5 with a compound represented by Formula 3; Preparing a compound represented by the following Chemical Formula 4 by dropwise addition of phosphorus trichloride to the mixture: Hydrolyzing or alcohol-degrading the compound represented by Chemical Formula 4 by adding a compound selected from the group consisting of water, alcohol and hydroxyalcohol: Method for producing a phosphinylcarboxylic acid or a derivative thereof represented by the following formula (1) comprising a. [Formula 1] [Formula 3] [Formula 4] [Formula 5] In the above formulas, R ₁ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms, and R ₂ is an alkyl group having 1 to 6 carbon atoms and an aryl group having 1 to 18 carbon atoms It is selected from the group consisting of, R ₃ is selected from the group consisting of a hydrogen atom and a methyl group, R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group of 1 to 10 carbon atoms and a hydroxy alkyl group of 1 to 10 carbon atoms It is selected from the group consisting of. The method for producing phosphinylcarboxylic acid or a derivative thereof according to claim 1, wherein the steps are performed at -20 to 160 ° C. The method of claim 1, wherein the amount of the compound represented by Formula 3 is 1 to 20 equivalents to the compound represented by Formula 5, and the amount of the phosphorus trichloride is 1 to 5 equivalents to the compound represented by Formula 5, The amount of the compound selected from the group consisting of water, alcohol and hydroxyalcohol is 2 to 50 equivalents to the compound represented by the formula (4).