JPH07252278A - Production of phosphinyl carboxylic acid - Google Patents

Abstract

PURPOSE:To industrially and advantageously obtain in high purity a colorless phosphinyl carboxylic acid useful as a reactive flame retardant owing to including no impurities such as yellow phosphors, etc., by pretreating an organic dichlorophosphine, a raw material, with a chlorinating agent. CONSTITUTION:At first, an organic dichlorophosphine of the formula, R<1>-PCl2 [R<1> is an alkyl or a (substituted) aryl], [e.g.; dichloro(phenyl)phosphine], is pretreated with a chlorinating agent (preferably chlorine) to convert impurities such as yellow phosphorus, etc., into phosphorus trichloride. Then, the pretreated organic dichlorophosphine is reacted with (meth)acrylic acid of the formula I (R<2> is H or methyl) to obtain phosphonyl carbonyl chloride which is hydrolyzed to obtain the objective compound of the formula II. Here, the pretreatment with the chlorinating agent is preferably carried out by adding 1-1.5 mole equivalent chlorinating agent based on an expected amount of impurities at a room temperature under an inert atmosphere and stirring and reacted to age at 90-130 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing phosphinylcarboxylic acid, which is useful as an organophosphorus compound intermediate which imparts high functionality such as flame retardancy and antistatic property to fibers and plastics. is there. In particular, the present invention relates to a method for producing such a phosphinylcarboxylic acid without coloring and with high purity.

[0002]

2. Description of the Related Art Recently, flame resistance of fibers and plastics,
It is required to impart high functionality such as antistatic property. The phosphinylcarboxylic acid derivative is a compound useful as an intermediate of an organophosphorus compound for imparting the functionality thereof, and is particularly useful as a bifunctional reactive flame retardant that can be used in the synthesis of polyester. It is known that this phosphinylcarboxylic acid derivative is produced by reacting dichloro (phenyl) phosphine with acrylic acid and then hydrolyzing the obtained reaction mixture. (Zhural Obsh. Khim. 37,455-460.1
967, USP 4,769,182, JP-A-53-82757)

[0003]

However, organic dichlorophosphine as a starting material generally contains a small amount of lower phosphorus oxides such as yellow phosphorus as impurities, and is particularly manufactured industrially. Many of these impurities are present in seaweed. When phosphinylcarboxylic acid is produced using this raw material, impurities such as yellow phosphorus remain in the obtained product and the product is colored, which significantly reduces the commercial value. Further, there is a risk of ignition due to yellow phosphorus or the like adhering to the inside of the reaction vessel after the reaction.

In view of the above facts, the present inventors have earnestly studied a method for producing high-purity phosphinylcarboxylic acid containing no impurities such as yellow phosphorus and lower oxides of phosphorus.
Industrially available organic dichlorophosphine is pretreated with a chlorinating agent to remove impurities such as yellow phosphorus and lower oxides of phosphorus present in the organic dichlorophosphine into phosphorus trichloride, and then the organic dichlorophosphine is removed. The present invention was completed based on the finding that a high-purity phosphinylcarboxylic acid having a small amount of phosphorus and the like can be obtained by using it and performing the subsequent reaction. Therefore, an object of the present invention is to provide a method for producing a non-coloring phosphinylcarboxylic acid in which impurities such as yellow phosphorus hardly remain.

[0005]

That is, the present invention is based on the general formula (1)

[0006]

Embedded image R ¹ -PCl ₂

An organic dichlorophosphine (wherein R ¹ represents an alkyl group, a substituted or unsubstituted aryl group) and the general formula (2)

[0008]

[Chemical 5]

(Formula (3) in which R ² represents a hydrogen atom or a methyl group) is reacted with (meth) acrylic acid to form a phosphonylcarbonyl chloride, which is then hydrolyzed.

[0010]

[Chemical 6]

A method for producing phosphinylcarboxylic acid, characterized in that the organic dichlorophosphine is pretreated with a chlorinating agent in the method for producing phosphinylcarboxylic acid. .

The present invention will be described in detail below. In the production method of the present invention, first, as a first-step reaction, the organic dichlorophosphine of the general formula (1) is treated with a chlorinating agent, then reacted with (meth) acrylic acid, and then the second step.
A hydrolysis reaction is performed as a step reaction. The organic dichlorophosphine represented by the general formula (1), which is the raw material for the first stage reaction, may be any one that is industrially available. Examples of the dichlorophosphine include dichloro (phenyl) phosphine, dichloro (o-methylphenyl) phosphine, dichloro (m-methylphenyl).
Phosphine, dichloro (p-methylphenyl) phosphine, dichloro (p-ethylphenyl) phosphine, dichloro (p-propylphenyl) phosphine, dichloro (p-butylphenyl) phosphine, dichloro (p-octylphenyl) phosphine, dichloro (p -Dodecylphenyl) phosphine, dichloro (p-octadecylphenyl) phosphine, dichloro (methyl) phosphine,
Dichloro (ethyl) phosphine, dichloro (propyl)
Examples thereof include phosphine, dichloro (butyl) phosphine, dichloro (octyl) phosphine, dichloro (decyl) phosphine and dichloro (octadecyl) phosphine. Examples of the chlorinating agent include chlorine, phosphorus pentachloride, thionyl chloride, sulfuryl chloride and the like, and chlorine is preferable. In addition, examples of the compound of the general formula (2) which is another raw material include acrylic acid and methacrylic acid.

The first feature of the production method according to the present invention is that yellow phosphorus or a lower oxide of phosphorus contained in the organic dichlorophosphine used in the first-step reaction is reacted with a chlorinating agent to be converted into phosphorus trichloride. It is to be. Since impurities such as yellow phosphorus can be removed in the initial stage, there is no danger of yellow phosphorus adhering to the reaction vessel and ignition after the next reaction, and yellow phosphorus remains in the product. It is possible to obtain a high-purity organic dichlorophosphine without having to do so. Also,
The converted phosphorus trichloride reacts with water in the hydrolysis reaction during the reaction to form phosphorous acid, which can be separated from the product after the reaction is completed.

The treatment with such a chlorinating agent may be carried out by adding a chlorinating agent such as chlorine to organic dichlorophosphine under stirring in an inert atmosphere. The addition amount of the chlorinating agent varies depending on the amount of impurities such as yellow phosphorus in the organic dichlorophosphine in the raw material, but is 1 to 2.0 with respect to the assumed amount of impurities
Double molar equivalent, preferably 1 to 1.5 times molar equivalent may be added. However, if the amount of impurities such as yellow phosphorus is added in excess of the reaction equivalent, the reaction yield decreases, so the amount may be set within the above industrial range. Also, when impurities such as yellow phosphorus in the organic dichlorophosphine cannot be sufficiently removed by the chlorinating agent, it is removed even if an oxidizing agent such as hydrogen peroxide is added during the hydrolysis reaction which is the second reaction. be able to. The temperature for the addition of the chlorinating agent may be room temperature, and 60 to 150 ° C., preferably 90 to 130 after addition.
Aging reaction is performed at ℃. The aging time is usually 0.5
There is no particular limitation as long as it is time or more.

The first reaction according to the present invention is carried out in an inert atmosphere and (meth) acrylic acid is added dropwise to the organic dichlorophosphine treated with the above chlorinating agent with stirring, but this is not always necessary. There is no need to limit it. The molar ratio of (meth) acrylic acid to 1 mol of organic dichlorophosphine is 1.0 to 2.0 mol, preferably 1.0 to 1.5 mol. The reaction conditions vary depending on the raw materials used, but the reaction is usually carried out at a temperature of 10 to 150 ° C., preferably 50 to 120 ° C.
C, time 0.5-10 hours, preferably 2-5 hours. After completion of the dropping reaction, aging treatment is performed at a temperature of 60 to 150 ° C.
It is preferably carried out at 90 to 130 ° C. for 0.5 to 10 hours, preferably 1 to 5 hours. The reaction is usually performed without a solvent, but a solvent may be used if necessary. The solvent is, for example, toluene, xylene, chlorobenzene or the like.

The second characteristic of the production method according to the present invention is that in the second step reaction in which the reaction product obtained in the first step reaction is subsequently hydrolyzed, an oxidizing agent is present in the hydrolysis step, or It is to apply an oxidizing agent treatment after the hydrolysis is completed. As a result, yellow phosphorus and lower oxides of phosphorus, which are trace impurities present in the organic dichlorophosphine that could not be completely removed by the chlorinating agent, are reacted in the presence of an oxidant to form phosphorous acid and phosphoric acid. Since it is converted into a water-soluble oxophosphoric acid, etc., this can be easily removed.

There are three possible modes for carrying out such hydrolysis reaction and oxidant treatment: 1. Add the reaction solution obtained in the first step reaction to water used for hydrolysis in the presence of an oxidizing agent; 2. After adding the reaction solution obtained in the first reaction to water used for hydrolysis, an oxidant is added and reacted. The product obtained by the hydrolysis reaction is redissolved, and an oxidizing agent is added and reacted; and the like, but the methods 1 and 2 are preferably applicable.

In addition, in the method of adding the oxidizing agent in the method of 1, the oxidizing agent is partially dissolved in water for hydrolysis in advance, and the rest is added simultaneously with the reaction solution. An excess amount of the oxidizing agent is simultaneously added to water for hydrolysis; an excessive amount of the oxidizing agent is dissolved in water for hydrolysis and the reaction solution is added; and the like. The aspect of or is preferably applicable. Further, the aging treatment may be carried out after the completion of the second stage reaction. It should be noted that addition of an oxidizing agent in the first-step reaction between the organic dichlorophosphine and the (meth) acrylic acid should be avoided because it partially oxidizes or hydrolyzes the organic dichlorophosphine and reduces the yield.

Examples of the oxidizing agent to be used include hydrogen peroxide, perchloric acid, sodium hypochlorite, nitric acid, sulfuric acid, chlorine and the like, but hydrogen peroxide is preferable. The amount of the oxidizing agent added is 0.01 to 1 mol of organic dichlorophosphine.
It is 1.50 mol, preferably 0.05 to 0.50 mol. The water used for the hydrolysis reaction is 2 to 50 times mol, preferably 10 to 30 times mol, relative to 1 mol of the reaction product obtained in the first reaction.

The second-stage hydrolysis reaction is preferably carried out in an inert atmosphere as in the previous step, and the reaction temperature is 0 to 100.
C., preferably 40 to 90.degree. C., reaction time 0.5 to 24 hours, preferably 2 to 10 hours. After completion of the hydrolysis reaction, crystals are precipitated by cooling with stirring. The precipitate is filtered by a conventional method, washed with water and dried to obtain the final product of the present invention, phosphinylcarboxylic acid of the general formula (3).

Examples of the phosphinylcarboxylic acid of the general formula (3) which is the final product of the present invention include 3- [hydroxy (phenyl) phosphinyl] propionic acid and 3- [hydroxy (p-methylphenyl) phosphinyl] propion. Acid, 3- [hydroxy (p-ethylphenyl) phosphinyl] propionic acid, 3- [hydroxy (p-propylphenyl) phosphinyl] propionic acid, 3- [hydroxy (p-butylphenyl) phosphinyl] propionic acid, 3- [ Hydroxy (p-octylphenyl) phosphinyl] propionic acid, 3- [hydroxy (p-dodecylphenyl) phosphinyl] propionic acid, 3- [hydroxy (p-octadecylphenyl) phosphinyl]
Propionic acid, 3- [hydroxy (phenyl) phosphinyl] -2-methylpropionic acid, 3- [hydroxy (p-methylphenyl) phosphinyl] -2-methylpropionic acid, 3- [hydroxy (p-ethylphenyl)
Phosphinyl] -2-methylpropionic acid, 3- [hydroxy (p-propylphenyl) phosphinyl] -2-
Methylpropionic acid, 3- [hydroxy (p-butylphenyl) phosphinyl] -2-methylpropionic acid, 3
-[Hydroxy (p-octylphenyl) phosphinyl] -2-methylpropionic acid, 3- [hydroxy (p
-Dodecylphenyl) phosphinyl] -2-methylpropionic acid, 3- [hydroxy (p-octadecylphenyl) phosphinyl] -2-methylpropionic acid, 3-
[Hydroxy (m-methylphenyl) phosphinyl]-
2-Methylpropionic acid, 3- [hydroxy (o-methylphenyl) phosphinyl] -2-methylpropionic acid, 3- [hydroxy (methyl) phosphinyl] methylpropionic acid, 3- [hydroxy (ethyl) phosphinyl] methylpropionic acid , 3- [hydroxy (butyl)
Phosphinyl] methylpropionic acid, 3- [hydroxy (dodecyl) phosphinyl] methylpropionic acid, 3-
Examples thereof include, but are not limited to, [hydroxy (tetradecyl) phosphinyl] methylpropionic acid and 3- [hydroxy (octadecyl) phosphinyl] methylpropionic acid.

[0022]

As described above, impurities such as yellow phosphorus contained in the organic dichlorophosphine are treated with a chlorinating agent to react the organic dichlorophosphine with (meth) acrylic acid to generate phosphinylcarbonyl chloride, and then ,
The product is hydrolyzed to give phosphinylcarboxylic acid. In this case, impurities such as yellow phosphorus contained in the organic dichlorophosphine can be converted into phosphorus trichloride to obtain high-purity, uncolored phosphinylcarboxylic acid without affecting the subsequent reaction. When the chlorinating agent cannot completely remove the lower phosphorus compound such as yellow phosphorus, which accompanies the organic dichlorophosphine by reacting in the presence of an oxidizing agent during or after the hydrolysis step of the above reaction, Without interfering with the reactivity of the target intermediate product, it is oxidized and converted to phosphorous oxo acid such as phosphoric acid, which can be easily separated, resulting in high-purity, colorless phosphinylcarboxylic acid. Obtainable.

[0023]

The present invention will be described in more detail with reference to the following examples. Example 1 89.5 g (0.50 mol) of dichloro (phenyl) phosphine was charged into a flask with a stirrer that had been replaced with nitrogen, and 1.25 g of chlorine was blown thereinto at room temperature in about 20 minutes. At this time,
There was a temperature rise of about 10 ° C. Then, the organic dichlorophosphine was heated to 100 ° C., and then an aging reaction was performed for 4 hours. After the completion, the solution is heated to 80 ° C. and acrylic acid 3
9.7 g (0.55 mol) was reacted dropwise with stirring for about 2 hours. After completion of the dropping, an aging reaction was performed at 120 ° C. for 1 hour. After completion of the aging reaction, the reaction solution is cooled to room temperature. The reaction liquid cooled to room temperature was added dropwise to 250 ml of water preheated to 80 ° C. in about 2 hours. After the dropping was completed, an aging reaction was carried out at 80 ° C. for about 30 minutes, followed by cooling. White crystals were precipitated when the reaction solution was around 70 to 75 ° C. 10 more
It cooled to ℃ and obtained the target object. After filtering the obtained target substance, it was sufficiently washed with water and dried at 100 ° C. for 5 hours to obtain 95.4 g of white crystals. The yield was 89.1% based on dichloro (phenyl) phosphine. ¹ H
As a result of analysis by -NMR and mass spectrum, it was confirmed to be 3- [hydroxy (phenyl) phosphinyl] propionic acid. The purity was 98.9%.

Example 2 The same procedure as in Example 1 was carried out except that 2.5 g of phosphorus pentachloride was used as the chlorinating agent, to obtain 95.6 g of white crystals. The yield is 8 based on dichloro (phenyl) phosphine.
It was 9.3%. As a result of ¹ H-NMR and mass spectrum analysis in the same manner as in Example 1, it was confirmed to be 3- [hydroxy (phenyl) phosphinyl] propionic acid. The purity was 99.0%.

Example 3 89.5 g (0.50 mol) of dichloro (phenyl) phosphine was charged into a flask equipped with a stirrer and purged with nitrogen, and 0.50 g of chlorine was blown thereinto at room temperature in about 20 minutes. At this time, there was a temperature rise of about 10 ° C. Then, this chlorine-blended dichloro (phenyl) phosphine was heated to 100 ° C., and then an aging reaction was carried out for 4 hours. After completion of the reaction, a dichloro (phenyl) phosphine solution heated to 80 ° C. was added dropwise to 39.7 g (0.55 mol) of acrylic acid with stirring for about 2 hours for reaction. After completion of the dropping, an aging reaction was performed at 120 ° C. for 1 hour. After completion of the aging reaction, the reaction solution was cooled. The yellow phosphorus content in the reaction solution at this time was 800 ppm. Then, 4.2 g of hydrogen peroxide was added in advance to 80
250g of water at ℃, the reaction solution and hydrogen peroxide 10.0g
Was dropped in about 2 hours. Thereafter, the same operations as in Example 1 were performed, and as a result, 95.2 g of white crystals were obtained. The yield was 88.9% based on dichloro (phenyl) phosphine. ¹
As a result of 1 H-NMR and mass spectrum analysis, it was confirmed to be 3- [hydroxy (phenyl) phosphinyl] propionic acid. The purity was 99.1%.

Comparative Example 1 The same procedure as in Example 1 was carried out except that no chlorinating agent was used, and as a result, yellow or orange sublimable deposits and yellow transparent droplets were formed on the upper portion of the reaction vessel after the hydrolysis reaction. Phosphorus was recognized. When the inside of the reaction vessel was exposed to air, yellow phosphorus raised a white flame and burned. In addition, as a final product 95.
7 g was obtained. The yield was 89.4% based on dichloro (phenyl) phosphine. ¹ H-NM as in Example 1
As a result of R and mass spectrum analysis, it was confirmed to be 3- [hydroxy (phenyl) phosphinyl] propionic acid. The purity was 96.8%.

[0027]

Industrial Applicability According to the method of the present invention, a highly pure and non-coloring phosphinylcarboxylic acid can be industrially produced advantageously. This compound is an extremely useful raw material for industrial intermediates of organic phosphorus compounds, reactive flame retardants, and the like. Particularly, it is useful as a bifunctional reactive flame retardant that can be used in the synthesis of polyester.

Claims (4)

[Claims] 1. An organic dichlorophosphine of the general formula (1): R ¹ -PCl ₂ (wherein R ¹ represents an alkyl group or a substituted or unsubstituted aryl group) and the general formula (2) Chemical 2] (In the formula, R ² represents a hydrogen atom or a methyl group) (meta)
Acrylic acid is reacted with phosphonyl carbonyl chloride, which is then hydrolyzed to give a compound of the general formula (3) In the method for producing phosphinylcarboxylic acid represented by, the organic dichlorophosphine is pretreated with a chlorinating agent, which is a method for producing phosphinylcarboxylic acid. 2. The method for producing a phosphinylcarboxylic acid according to claim 1, wherein the hydrolysis is carried out in the presence of an oxidizing agent, or an oxidation treatment is carried out after the hydrolysis. 3. The method for producing a phosphinylcarboxylic acid according to claim 1, wherein the phosphinylcarboxylic acid is 3- (hydroxyphenylphosphinyl) propanoic acid. 4. The method according to claim 1, wherein the chlorinating agent is chlorine.
The method for producing the phosphinylcarboxylic acid according to any one of 1.