JPH051084A - Production of high-purity diaryl chlorophosphate - Google Patents

Abstract

PURPOSE:To provide a method for producing a diaryl cholorophosphate in high yield and purity. CONSTITUTION:The subject method is to produce a diaryl chlorophosphate composed of the first step for reacting an alkyl alcohol expressed by the formula R<1> OH (R<1> is 1-4C alkyl group) with phosphorus oxychloride and producing an alkyl dichlorophosphate expressed by the formula R<1>O-P(O)Cl2, the second step for reacting the aforementioned alkyl dichlorophosphate with an aqueous solution of phenols expressed by the formula HOAr (Ar is aryl group) or their metallic salts and producing an alkyl diaryl phosphate expressed by the formula R<1>O-P(O)(OAr)2 and the third step for subsequently reacting the resultant alkyl diaryl phosphate with phosphorus pentachloride and producing the diaryl chlorophosphate expressed by the formula (ArO)2-P(O)Cl.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing high-purity diarylchlorophosphate, and more particularly to a method for producing high-purity diarylchlorophosphate useful as an intermediate for medicines, agricultural chemicals and the like.

[0002]

BACKGROUND OF THE INVENTION Conventionally, diarylhalophosphates are
It is known as an organophosphorus compound that is useful as an intermediate for medicines and agricultural chemicals and as a raw material for resin additives. Regarding the manufacturing method, for example, in Japanese Patent Publication No. 2-503084,
A method for producing an alkyldiarylphosphite by first reacting an alkyldihalophosphite with a phenol to produce an alkyldiarylphosphite and then halogenating the resulting alkyldiarylphosphite is disclosed. However, this method relates to the production of an alkyldiarylphosphite, and since the starting material, an alkyldihalophosphite, such as ethyldichlorophosphite, is trivalent phosphorus, it has poor stability and may be oxidized. The alkyldiarylphosphite produced in the middle of the process also has the same properties. In the next chlorination step, a solvent different from that used in the previous step must be used, and a solvent having no reactivity with the halogen used, such as carbon tetrachloride or chlorobenzene, is industrially applicable. It was not always advantageous, and improvements were required.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As a result of research in view of such conventional techniques, the present inventor has produced alkyldichlorophosphate by reacting alkyl alcohol with phosphorus oxychloride, and then producing the alkyldichlorophosphate. Diaryl chlorophosphate can be obtained in high yield and high purity by chlorinating alkyl diaryl phosphate formed by reacting phosphate with phenols using phosphorus pentachloride with onium salt as a catalyst, and further by the final step. The present invention has been completed by finding that the produced phosphorus oxychloride can be repeatedly used as a raw material.

[0004]

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

[0005]

Embedded image R ¹ OH (1) (wherein, R ¹ represents an alkyl group having 1 to 4 carbon atoms) is reacted with phosphorus oxychloride to give a compound represented by the formula (2)

[0006]

Embedded image The first step of producing an alkyldichlorophosphate represented by R ¹ O—P (O) Cl ₂ (2) (wherein R ¹ represents the same as above), and then the alkyldichlorophosphate. And formula (3)

[0007]

## STR00008 ## HOAr (3) (wherein Ar represents an aryl group) is reacted with an aqueous solution of a phenol or a metal salt thereof to give a compound of formula (4)

[0008]

Embedded image The second step of producing an alkyldiarylphosphate represented by R ¹ O—P (O) (OAr) ₂ (4) (wherein R ¹ represents the same as above), and then the alkyl The diaryl phosphate is reacted with phosphorus pentachloride to give a compound of formula (5)

[0009]

Embedded image A method for producing diarylchlorophosphate, which comprises a third step of producing a diarylchlorophosphate represented by (ArO) ₂ -P (O) Cl (5).

In the method for producing diarylchlorophosphate of the present invention, it is preferable to use an onium salt as a reaction catalyst in the third step, and phosphorus oxychloride by-produced in the third step is used in the first step. it can.

The present invention will be described in detail below. The method for producing the diarylchlorophosphate according to the present invention is represented by the following reaction formula.

[0012]

Embedded image First step formula (6) R ¹ OH + P (O) Cl ₃ → R ¹ OP (O) Cl ₂ + HCl

[0013]

Embedded image Second step formula (7) R ¹ OP (O) Cl ₂ + 2HOAr → R ¹ OP (O) (OAr) ₂ + 2HCl

[0014]

Embedded image Third step formula (8) R ¹ OP (O) (OAr) ₂ + PCl ₅ → (ArO) ₂ P (O) Cl + P (O) Cl ₃ + R ¹ Cl (wherein R ¹ is as defined above) Represents the same)

The first step according to the present invention relates to a method for producing an alkyldichlorophosphate by reacting an alkyl alcohol represented by the formula (1) with phosphorus oxychloride. As the alkyl alcohol represented by the formula (1), an alkyl alcohol having 1 to 4 carbon atoms is used, for example, methanol, ethanol, 1-propanol, 2-
Examples include propanol, 2-methyl-2-propanol, allyl alcohol, ethylene oxide and the like.

The reaction is usually carried out by gradually mixing phosphorus oxychloride and the alkyl alcohol in equimolar amounts,
The reaction temperature is usually from -10 to 10 ° C, preferably 0 ° C or lower. In addition, a reaction solvent may be present in order to facilitate industrial implementation, and it is preferable to use a solvent in which generated hydrogen halide is difficult to dissolve, such as benzene, toluene and xylene. . After the reaction, if a solvent is used, the solvent is distilled off.

Next, in the second step according to the present invention, the alkyldichlorophosphate, which is the reaction product of the first step, is reacted with the phenol represented by the formula (3) or an aqueous solution of a metal salt thereof to obtain an alkyldiaryl. It is a method for producing phosphate. In this reaction, for example, when phenol is used, the dehydrochlorination agent must be used in the solvent, but when using the aqueous metal salt solution, it is not necessary to use the dehydrochlorination agent.

The reaction is carried out by mixing the alkyldichlorophosphate obtained in the previous step, the phenols and, if necessary, a dehydrochlorinating agent in a solvent at a ratio in the vicinity of the reaction equivalent of the formula (7) and heating. Alternatively, the alkyl dichlorophosphate and the aqueous metal salt solution of the above phenols are heated and stirred in a solvent such as dichloromethane. The reaction temperature is generally 0 to 100 ° C, preferably 10 to 90 ° C.

The phenols represented by the formula (3) used in this reaction are not particularly limited.
Phenol, 2-chlorophenol, 2,4-dichlorophenol, 2,5-dichlorophenol, 3,4-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2-bromophenol , 4-cresol and the like.

Examples of the dehydrochlorinating agent include trimethylamine, triethylamine, tripropylamine, dimethylaniline, diethylaniline, pyridine, potassium carbonate, sodium carbonate, sodium hydroxide, etc., but industrially 5 to 50 It is preferred to use a% aqueous sodium hydroxide solution.

When an aqueous solution of 5 to 50 wt% sodium hydroxide is used as the dehydrochlorinating agent, there is no problem in the next step even if the diaryl phosphate obtained by partially or completely hydrolyzing the alkyl diaryl phosphate is produced depending on the reaction temperature. Be converted.

That is, a mixture of the alkyl diaryl phosphate produced in the second step and the diaryl phosphate produced as a by-product in the second step, or the diaryl phosphate produced by hydrolysis of the alkyl diaryl phosphate produced in the second step is Can be chlorinated by reacting with phosphorus pentachloride in the third step. Further, as the metal salt aqueous solution of phenol represented by the formula (3) used in the reaction of the second step, an alkali metal or alkaline earth metal salt aqueous solution is used.

As the reaction solvent, benzene, toluene,
Examples thereof include aromatic hydrocarbons such as chlorobenzene, halogenated hydrocarbons such as tetrachloroethylene and dichloromethane, dialkylketone compounds such as acetone and methyl ethyl ketone, and toluene and dichloromethane are industrially preferable. After completion of the reaction, the solvent is distilled off after washing.

Next, in the third step according to the present invention, the alkyldiarylphosphate produced in the second step, or the mixture of the alkyldiarylphosphate produced in the second step and the diarylphosphate produced as a by-product in the second step, or By the chlorination step of reacting phosphorus pentachloride with the diaryl phosphate produced by hydrolysis of the alkyl diaryl phosphate produced in the second step,
The present invention relates to a method for producing diarylchlorophosphate.

In the reaction, alkyl diaryl phosphate and diaryl phosphate or a mixture thereof and phosphorus pentachloride are heated and reacted without solvent. In the present invention, the reaction rate can be increased by using an onium salt as the catalyst. Moreover, the chlorination according to the present invention cannot be carried out with chlorine gas. In the chlorination according to the present invention, the diaryl phosphate produced as a by-product or produced in the previous step can be easily chlorinated.

The onium salt is not particularly limited, but for example, a quaternary ammonium salt, a phosphonium salt, a pyridinium salt or the like is used. Specific examples thereof include ammonium salts such as trioctylmethylammonium chloride, tetra-n-butylammonium chloride, triethylbenzylammonium chloride, tetraethylammonium chloride, tri-n-butylethylphosphonium bromide, tetra-n-butylphosphonium bromide, and tri-n-butylphosphonium bromide. Examples thereof include phosphonium salts such as -n-octylethylphosphonium bromide and pyridinium salts such as laurylpyridinium bromide and n-ethylpyridinium bromide.

The reaction temperature is usually 80 to 150 ° C, preferably 100 to 120 ° C. The reaction time is usually 5 to 2
It is 4 hours, preferably 10 to 16 hours. After the completion of the reaction, an oily substance is obtained by cooling, and phosphorus by-product by-product is collected under reduced pressure. In the present invention, the recovered phosphorus oxychloride can be recycled and used in the first step, which is one of the industrially advantageous production methods.

In order to make the diarylchlorophosphate produced by the present invention highly pure, the unwashed onium salt and unrecovered by-product phosphorus oxychloride present as impurities therein are subjected to halogenated carbonization with a hydrocarbon solvent. It can be purified with a mixed solvent of hydrogen-based solvents. The hydrocarbon solvent may be any solvent that does not dissolve diarylchlorophosphate, and examples thereof include n-hexane and cyclohexane. The halogenated hydrocarbon solvent may be any solvent which can dissolve diaryl chlorophosphate, and examples thereof include methylene dichloride, chloroform and tetrachloroethylene. The mixing ratio of this solvent is 10 to 20 wt% of halogenated hydrocarbon solvent.
%, The hydrocarbon solvent is 80 to 90 wt%.

This mixed solvent is mixed at a ratio of 1 to 2 times by weight with respect to the diaryl chlorophosphate, and dissolved by heating. Cool at −10 ° C., crystallize and separate solvent in N ₂ atmosphere. The crystals are dried to obtain high-purity diaryl chlorophosphate.

[0030]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 First step (production of O-ethyldichlorophosphate) 750 m equipped with a stirrer, thermometer, dropping funnel, and condenser
483.0 g of phosphorus oxychloride in a 4-necked round bottom flask
(3.15M) was charged and cooled to 0 ° C. The prepared ethanol (138.2 g, 3.00 M) was added dropwise to the dropping funnel over 90 minutes while maintaining the temperature at 0 ° C. Chlorine gas generated at the same time as the dropping was absorbed in water. 0 ° C after dropping
After aging for 1 hour, the temperature was raised to 50 ° C. under reduced pressure of 50 mmHg and dehydrochlorination was carried out. As a result, 517.9 g of residual liquid was obtained. As a result of analyzing this liquid with a gas chromatograph,
O-ethyldichlorophosphate 81.0 wt%, O,
It was a mixed solution containing 4.0 wt% of O-diethyl chlorophosphate and 7.1 wt% of phosphorus oxychloride. Using an Oldershaw type rectification column, this is 70 ° C, 24 mmHg
The rectification was carried out to obtain O-ethyldichlorophosphate having a purity of 98.2 wt%.

Second step (production of O-ethyl-O, O-bis (2,4-dichlorophenyl) phosphate) 500 equipped with a stirrer, dropping funnel, thermometer and cooler.
In a ml four-necked round bottom flask, 68.5 g (0.420 M) of 2,4-dichlorophenol, 100 ml of water, 99
17.0 g (0.420M) of wt% caustic soda and 170 ml of dichloromethane were added and mixed. Then, 33.2 g of O-ethyldichlorophosphate produced in the previous step
(0.200M) was added dropwise at 30 ° C or lower for 1 hour. After completion of dropping, the mixture was aged at the same temperature for 1 hour, and then the organic layer and the aqueous layer were separated. The organic layer was washed with 100 ml of water, dehydrated with Glauber's salt, and dichloromethane was evaporated at 70 ° C for 2 mm.
It was distilled to Hg to obtain 80.0 g of a colorless oily substance.
This colorless oily substance contained 10 wt% of O, O-bis (2,4dichlorophenyl) phosphate.

Third Step (Production of O, O-bis (2,4dichlorophenyl) chlorophosphate) In a 200 ml four-necked round bottom flask equipped with a stirrer, a condenser and a thermometer, the oil produced in the second step was added. Substance 80.0g
And phosphorus pentachloride 45.8 g (0.22 M) and trioctylmethylammonium chloride (TOMAC) 2.
00g was put and it heated up to 100 degreeC. Then, the contents were reacted at 110 ° C. for 16 hours. After completion of the reaction, the reaction product was cooled and the by-product phosphorus oxychloride was collected at 70 ° C. and 35 mmHg to obtain 91.9 g of an oily substance of O, O-bis (2,4-dichlorophenyl) chlorophosphate. As a result of analysis by gas chromatography, the purity of O, O-bis (2,4-dichlorophenyl) chlorophosphate was 85.2 w.
At t%, the yield from O-ethyldichlorophosphate was 96.3%.

Dichloromethane content (wt%) is 13
% Dichloromethane / hexane mixed solvent (75 ml) was dissolved while warming the obtained O, O-bis (2,4-dichlorophenyl) chlorophosphate having a purity of 85.2 wt% (45.0 g). When this was cooled to -10 ° C, crystals were precipitated. It is filtered in a nitrogen atmosphere and dried 3
7.5 g of crystals were obtained. The purity of this crystal is 96.0w.
At t%, the recovery rate was 93.8%.

Example 2 First step (production of O-ethyldichlorophosphate) The same procedure as in Example 1 was performed.

Second step (production of O, O-bis (2,4-dichlorophenyl) phosphate) 500 equipped with a stirrer, a dropping funnel, a thermometer and a cooler.
In a ml four-necked round bottom flask, 68.5 g (0.420 M) of 2,4-dichlorophenol, 100 ml of water, 99
17.0 g (0.420 M) of wt% caustic soda and 170 ml of chloroform were added and mixed. Then, 33.2 g of O-ethyldichlorophosphate produced in the previous step
(0.200M) was added dropwise at 30 ° C or lower for 1 hour. After completion of the dropping, the mixture was aged at 50 ° C. for 24 hours, and then the organic layer and the aqueous layer were separated. The organic layer was washed with 100 ml of water, dehydrated with Glauber's salt, and chloroform was evaporated with an evaporator at 70 ° C, 2 mm.
It was distilled to Hg to obtain 71.5 g of an oily substance. The main component of this oily substance was O, O-bis (2,4 dichlorophenyl) phosphate.

Third Step (Production of O, O-bis (2,4dichlorophenyl) chlorophosphate) In a 200 ml four-necked round bottom flask equipped with a stirrer, a condenser and a thermometer, the oil produced in the second step was added. Substance 71.5g
And phosphorus pentachloride 45.8g (0.22M) and TOMA
C2.00 was added and the reaction was carried out in the same manner as in Example 1. As a result, 85.6 g of an oily substance of O, O-bis (2,4-dichlorophenyl) chlorophosphate was obtained. The purity before purification was 83.1 wt%, and the yield from O-ethyldichlorophosphate was 87.6%.

Example 3 First step (production of O-ethyldichlorophosphate) The same procedure as in Example 1 was performed.

Second step (O-ethyl-O, O-bis (p
-Chlorophenyl) phosphate production) 500 m with stirrer, condenser, thermometer, dropping funnel
54.0 g of p-chlorophenol in a 4-necked flask of 1 l
(0.420M), water 100ml, 99wt% caustic soda 17.0g (0.420M), dichloroethane 170
ml was added and mixed. Then, 33.2 g (0.200 M) of O-ethyldichlorophosphate produced in the previous step
Was added dropwise at 30 ° C. or lower for 1 hour, and after completion of the addition, aging was performed for 1 hour. After separating the organic layer and the aqueous layer, the organic layer is washed with water 100
After washing with water (ml) and dehydration with Glauber's salt, dichloromethane was distilled off with a rotary evaporator to obtain 64.3 g of colorless and odorless oily substance.

Third Step (Production of O, O-bis (p-chlorophenyl) chlorophosphate) The oily substance obtained in the second step was added to a 200 ml four-necked flask equipped with a stirrer, a condenser and a thermometer. 3g and phosphorus pentachloride 45.8g (0.220M) and TOMAC
As a result of carrying out reaction in the same manner as in Example 1 by adding 2.00 g, 75.4 g of O, O-bis (p-chlorophenyl)
Chlorophosphate was obtained. Purity before purification is 86.9w
At t%, the yield from O-ethyldichlorophosphate was 97.1%.

Example 4 Instead of the 2,4-dichlorophenol used in the second step of Example 1, 45.4 g of m-cresol (0.420) was used.
The reaction was carried out in exactly the same manner as in Example 1 except that M) was used, and as a result, 66.7 g of an oily substance of O, O-bis (3-methylphenyl) chlorophosphate was obtained. The purity before purification was 80.2 wt%, and the yield from O-ethyldichlorophosphate was 90.2%.

Example 5 The same reaction as in Example 1 was carried out except that 39.5 g (0.420 M) of phenol was used instead of 2,4-dichlorophenol in Example 1, and as a result, O, O- 58.0 g of an oily substance of diphenylchlorophosphate was obtained. The purity before purification was 88.0 wt% and the yield from O-ethyldichlorophosphate was 95.0%.

Comparative Example 1 As a result of carrying out the reaction without adding TOMAC used in the third step of Example 1, the yield of O, O-bis (p-chlorophenyl) chlorophosphate was 26.5%. .

[0043]

As described above, according to the production method of the present invention, an alkyldichlorophosphate is produced by reacting an alkyl alcohol with phosphorus oxychloride, and then the alkyldichlorophosphate is produced by reacting with a phenol. By chlorinating the alkyl diaryl phosphate with phosphorus pentachloride using an onium salt as a catalyst, the diaryl chlorophosphate can be obtained in high yield and high purity. Further, phosphorus oxychloride produced as a by-product in the final step can be repeatedly used as a raw material, which is efficient and industrially advantageous.

Claims (6)

[Claims] 1. A reaction of an alkyl alcohol represented by the formula (1): R ¹ OH (1) (wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms) with phosphorus oxychloride. Then, the first for producing an alkyldichlorophosphate represented by the formula (2): R ¹ O—P (O) Cl ₂ (2) (wherein R ¹ represents the same as above) Step, and then reacting the alkyldichlorophosphate with a phenol represented by formula (3): HOAr (3) (wherein Ar represents an aryl group) or an aqueous solution of a metal salt thereof, (4) embedded image (in the formula, R ¹ represents the same meanings as defined ^{above) R 1 O-P (O} ) (OAr) 2 (4) second step of producing an alkyl diaryl phosphates represented by, Then reacting the alkyl diaryl phosphate with phosphorus pentachloride (5) embedded image (ArO) ₂ -P (O) Cl (5) with diaryl chlorophosphate method for producing characterized in that it consists of a third step of producing a diaryl chlorophosphate represented. 2. The production method according to claim 1, wherein phosphorus oxychloride produced as a by-product from the third step is used in the first step. 3. The method according to claim 1, wherein an onium salt is used as a catalyst in the third step. 4. The production method according to claim 1, wherein the diaryl chlorophosphate produced in the third step is purified with a mixed solvent of a hydrocarbon solvent and a halogenated hydrocarbon solvent. 5. A method for producing a diarylchlorophosphate represented by the formula (5) by reacting a mixture of an alkyldiarylphosphate produced in the second step and a diarylphosphate produced as a by-product in the second step with phosphorus pentachloride. The manufacturing method according to claim 1, comprising three steps. 6. From the third step of producing the diarylchlorophosphate represented by formula (5) by reacting the diarylphosphate produced by hydrolysis of the alkyldiarylphosphate produced in the second step with phosphorus pentachloride. The manufacturing method according to claim 1, wherein