JPH08176164A - Method for producing arylphosphoric acid chlorides - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for producing an arylphosphoric acid dichloride or diarylphosphoric acid chloride with high selectivity and high yield. A method for producing arylphosphoric acid dichloride or diarylphosphoric acid chloride by reacting phenol or a substituted phenol with phosphorus oxychloride using a quaternary phosphonium salt as a catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to medicines, agricultural chemicals, plasticizers,
The present invention relates to a novel method for producing arylphosphoric acid chlorides, particularly arylphosphoric acid dichloride or diarylphosphoric acid chloride, which are useful as intermediates for flame retardants of synthetic fibers.

[0002]

2. Description of the Related Art Conventionally, as a method for producing arylphosphoric acid chlorides, a method of reacting phenols with phosphorus oxychloride in the absence of a catalyst (Ber. 72.2121 (1)
939), J. Am. Chem. Soc. 78,25
68-2569 (1956), US Pat. No. 2,84
4,582, Trudy Tallin. Poli
teh. Inst. Ser. A. No. 97,166
Pp. 2-1682. (1958)), and metal chlorides,
A method of reacting in the presence of amines and various catalysts is known.

As a method of using a metal chloride as a catalyst, for example, aluminum chloride (Trudy Tally) is used.
n. Politekh. Inst. Ser. No. A.
97, 1662-1682 (1958), Net
h. Appl. 6, 611, 298 (1967
Year), Metody Poluck. Khim. Rea
ktivov. Prep. No. 18,207-209
Page (1969)), sodium chloride, calcium chloride, potassium chloride (Zhur. Obschei. Khi
m. 26, 3060 to 3066 (1966)) and the like as a catalyst.

Examples of the method using amines as a catalyst include a method using N, N-dimethylaniline, 1-methylimidazole, diethylamine hydrochloride, pyridine (US Pat. No. 3,965,220) as a catalyst. To be

Other catalysts include, for example, urea, 1,
Urea such as 1,3,3-tetramethylurea and 1,3-diphenylurea (U.S. Pat. No. 3,772,414 (19
1973)), ammonium salts such as ammonium sulfate, ammonium chloride, ammonium sulfate and ammonium acetate (Ger. Offen. 2, p. 230, p. 913 (1
972)), a quaternary ammonium salt (JP-A-5-13).
2491), ethyl-N-ethyl carbamate,
Carbamates such as isopropyl carbamate and ethyl-N-phenyl carbamate (Ger. Offen.
2,230, 912 (1972)), N-methylpyrrolidone (US Pat. No. 3,790,649), magnesium (Bril. 734, 764 (1955)).
Year), Pr. Nauk. Lnst. Technical O
rg. Twozyw. Sziuccznych Pol
technology. Wroclaw. 17, 3-22 (19
1975)) or a method of selectively producing phenylphosphoric acid chloride by reacting with magnesium oxide as a catalyst at a molar ratio of phenol to phosphorus oxychloride of 0.33 (Ger. (East)). Thirteen
4, 104 (1979)).

[0006]

However, in the above-mentioned prior art, when the reaction is carried out without a catalyst,
The reaction rate becomes slow, the raw materials phenols and phosphorus oxychloride tend to remain unreacted, a large amount of triaryl phosphates by-products are produced, and the yield of the mono- or diaryl phosphate, which is the target substance of the present invention, becomes low. . When using aluminum chloride as a catalyst, the aluminum compound adheres to the inner wall of the reactor and becomes troublesome after the reaction, and when magnesium oxide is used as a catalyst, phosphorus oxychloride remains as an unreacted substance, When magnesium is used as a catalyst, hydrogen gas is generated due to contact with heat, water, and acidic substances such as hydrochloric acid, which is very dangerous. Further, when using a catalyst other than the above, the reaction rate is higher than that in the case of using no catalyst, but there is a drawback that a large amount of triaryl phosphates by-products are produced.

In view of the above facts, the present inventors have conducted extensive studies and as a result, as a result of reacting phenols and phosphorus oxychloride with a quaternary phosphonium salt as a catalyst, the production of triaryl phosphate was suppressed, Unreacted phosphorus oxychloride does not remain, and industrially simple operation allows
The inventors have found that arylphosphoric dichloride or diarylphosphoric chloride can be respectively selected as the target arylphosphoric chlorides and can be obtained in high yield, and have completed the present invention. That is, an object of the present invention is to provide a method for producing arylphosphoryl chlorides which is rational and industrially advantageous.

[0008]

That is, the present invention is characterized by reacting phenols having a substituent in the phenol nucleus or having no substituent and phosphorus oxychloride with a quaternary phosphonium salt as a catalyst. The present invention relates to a method for producing arylphosphoryl chlorides.

The present invention will be described in detail below. The method for producing arylphosphoric chlorides to be provided by the present invention comprises reacting phenols having a substituent in the phenol nucleus or having no substituents with phosphorus oxychloride using a quaternary phosphonium salt as a catalyst. Characterize above.

The quaternary phosphonium salt used in the catalyst of the present invention is not particularly limited, but examples thereof include a halogenated quaternary phosphonium salt represented by the following general formula (I).

[0011]

Embedded image (R ¹ R ² R ³ R ⁴ ) PX (I) (wherein R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms, the same or different alkyl groups or phenyl groups, and X is a halogen). Represents an atom.)

In the above general formula (I), R ¹ , R
The alkyl group of ² , R ³ and R ⁴ has 20 carbon atoms.
Hereafter, a linear or branched alkyl group of preferably 1 to 10, more preferably 1 to 8, is desirable.

As a specific example of the halogenated quaternary phosphonium salt represented by the above general formula (I), a halogenated quaternary phosphonium salt which is usually industrially easily available is preferable. For example, tetramethylphosphonium chloride, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium fluoride, tetrabutylphosphonium chloride,
Tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, tetrabutylphosphonium fluoride, tetraethylphosphonium chloride, tetraethylphosphonium bromide, tetraethylphosphonium iodide, tetraethylphosphonium fluoride, tetrahexylphosphonium chloride, tetrahexylphosphonium bromide, tetrahexylphosphonium iodide , Tetrahexylphosphonium fluoride, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltrimethylphosphonium iodide, benzyltrimethylphosphonium fluoride, benzyltriethylphosphonium chloride, benzyltriethylphosphonium bromide, Jill triethyl phosphonium iodide, benzyltriethylammonium phosphonium fluoride, cetyl trimethyl phosphonium chloride, cetyl trimethyl bromide, cetyl trimethyl phosphonium iodide, cetyl trimethyl phosphonium fluoride, tributyl octyl phosphonium chloride, tributyl-octyl phosphonium bromide,
Tributylbenzylphosphonium chloride, tributylbenzylphosphonium bromide, trihexylethylphosphonium chloride, trihexylethylphosphonium bromide, trioctylmethylphosphonium chloride, trioctylmethylphosphonium bromide, triphenylbutylphosphonium chloride, triphenylbutylphosphonium bromide, benzyldimethylcetylphosphonium Examples thereof include chlorides, and among these, a quaternary phosphonium salt containing chlorine or bromine is most preferable.

The quaternary phosphonium salt used in the catalyst of the present invention is a compound other than the compound represented by the above general formula (I), such as tetrabutylphosphonium diethylphosphorodithioate, tetrabutylphosphonium benzotriazo. Rate, tetraethylphosphonium hydroxide, and the like.

The amount of the quaternary phosphonium salt used is not particularly limited, but is usually 0.01 per 1 mol of the phenols.
~ 5g, preferably 0.5-5g. The catalyst amount is 0.
If it is less than 01 g, the reaction time will be long if it is less than 5 g
If the amount exceeds the above range, the effect on the amount used is saturated, and it is not preferable in terms of separation and economy.

As the raw material phenols of the present invention, those having a substituent in the phenol nucleus or having no substituent are used, and examples thereof include compounds represented by the following general formula (II).

[0017]

Embedded image

(In the formula, R ⁵ and R ⁶ represent a hydrogen atom, the same or different alkyl group, a halogen atom or a phenyl group.)

In the above general formula (II), R ⁵ , R
^{As the 6-} alkyl group, a linear or branched alkyl group having 8 or less carbon atoms, preferably 1-4, and more preferably 1-2, is desirable.

Specific examples of the phenols represented by the above general formula (II) include phenol and substituted phenols. Examples of substituted phenols include o
-Cresol, m-cresol, p-cresol, 2,
4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, o-ethylphenol, m-ethylphenol,
p-ethylphenol, o-isopropylphenol,
Alkylphenols such as m-isopropylphenol, p-isopropylphenol, p-tert-butylphenol, arylphenols such as p-phenylphenol, 2,4-dichlorophenol, 3-chlorophenol, 2,4-dibromophenol, 3 Examples thereof include halogenated phenols such as -bromophenol, and other substituted phenols are not limited.

An object of the present invention is to obtain arylphosphoric acid dichloride or diarylphosphoric acid chloride as the desired arylphosphoric acid chlorides. In the present invention, the reaction product of the arylphosphoric acid dichloride and the diarylphosphoric acid chloride mixed is obtained by the reaction of the phenols represented by the general formula (II) with phosphorus oxychloride. By adjusting the molar ratio of phosphorus oxychloride and phenols (phosphorus oxychloride / phenols), arylphosphoric acid dichloride and / or diarylphosphoric acid chloride can be selectively obtained in high yield.

That is, in order to selectively obtain the reaction product arylphosphoric dichloride in a high yield, the molar ratio of phosphorus oxychloride / phenols as a raw material may be increased,
It is usually 0.9 to 5, preferably 0.9 to 3. As the molar ratio of phosphorus oxychloride / phenols exceeds 5, the production of arylphosphoric acid dichloride increases, and the amount of unreacted phosphorus oxychloride remains increases, which is not preferable.

Further, in order to selectively obtain the reaction product diarylphosphoric acid chloride in a high yield, the molar ratio of phosphorus oxychloride / phenols as a raw material may be reduced, and usually 0.4 to 0.9. , Preferably 0.5 to 0.9. If the phosphorus oxychloride / phenols molar ratio is less than 0.4, the amount of triarylphosphoric acids as a by-product is increased, which is not preferable.

The reaction temperature of the phenols and phosphorus oxychloride is not particularly limited, but is usually 80 to 160 ° C. because the liquid-liquid reaction is preferable.

By distilling the reaction solution thus obtained under reduced pressure, diarylphosphoric acid chloride and arylphosphoric acid dichloride can be obtained as independent components. Further, by repeatedly using the arylphosphoric acid dichloride obtained by vacuum distillation in the present invention, the diarylphosphoric acid chloride can be selectively produced.

[0026]

In the present invention, the method for producing arylphosphoryl chlorides by reacting phenols with phosphorus oxychloride proceeds according to the following reaction formula (1).

[0027]

Embedded image

(Wherein R ⁵ and R ⁶ are hydrogen atoms, the same or different alkyl groups, halogen atoms or phenyl groups, n
Represents 1 or 2. )

In the present invention, in the above reaction, the presence of the quaternary phosphonium salt as a catalyst promotes the reaction and suppresses side reactions such as formation of triaryl phosphate, whereby the desired product can be produced in a high yield. . Although the details of this reaction mechanism are unknown, it is believed that the quaternary phosphonium salt acts as an interlayer transfer catalyst in the contact layer of the reaction system to generate hydrogen chloride and accelerate the reaction.

As can be seen from the above reaction formula (1), in the above reaction, the reaction product is produced as a mixture of diarylphosphoric acid chloride and arylphosphoric acid dichloride. As described above, when the feed molar ratio (phosphorus oxychloride / phenols) of the raw materials is large, dichloro aryl chloride dichlorides are formed, and conversely, when the mixing molar ratio of the raw materials is small, monochloro diaryl phosphate chlorides are formed. It will be easier.

Therefore, which product is selected is
The reaction may be carried out by setting the conditions depending on the purpose of use of the intended product, together with the selection of the starting phenol compound. After completion of the reaction, the desired product is recovered by separation and purification according to a conventional method.

[0032]

The present invention will be described in detail below with reference to examples.

Example 1 In a 25 ml Erlenmeyer flask equipped with a rotor and a condenser, 3.07 g (0.02 M) of phosphorus oxychloride and 2.
35 g (0.025 M) and 0.025 g of tetraethylphosphonium bromide (TEPB) are charged and the temperature is raised with stirring. The bath temperature was set to 140 ° C. and the reaction was carried out for 4 hours. It was confirmed by gas chromatography that the starting material of phenol had been consumed, and the reaction was terminated and 4.05 g of a colorless transparent liquid was obtained.

As a result of gas chromatographic analysis of the obtained colorless transparent liquid, the content of diphenylphosphoric acid chloride was 42.4%, the content of phenylphosphoric acid dichloride was 54.5%, and the content of triphenylphosphoric acid. Is 1.1%
Met.

The colorless transparent liquid was distilled under reduced pressure to obtain 82 ° C. /
Phenylphosphoric acid dichloride 1.8 at 0.8 mmHg
9 g was obtained. Furthermore, at 132 ° C./0.3 mmHg, 1.72 g of diphenylphosphoric acid chloride was obtained. At this time, the residue of the kettle was 0.4 g.

The yield of diphenylphosphoric acid chloride obtained by distillation was 32.0% (yield based on phosphorus oxychloride), and the yield of phenylphosphoric acid dichloride was 44.8.
% (Yield based on phosphorus oxychloride).

Example 2 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M), and tetrabutylphosphonium bromide (TB
PB) 0.025 g was charged and reacted at 140 ° C. for 7 hours to obtain 4.12 g of a colorless transparent liquid.

Example 3 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M), and tetrabutylphosphonium iodide (TB
PI) (0.025 g) was charged and reacted at 140 ° C. for 6 hours to obtain 4.14 g of a yellow transparent liquid.

Example 4 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M), and tetrahexylphosphonium bromide (T
HPB) (0.025 g) was charged and reacted at 140 ° C. for 10 hours to obtain 4.12 g of a colorless transparent liquid.

Example 5 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M) and 0.025 g of trihexylethylphosphonium bromide (THEPB) were charged and reacted at 140 ° C. for 8 hours to obtain 4.14 g of a colorless transparent liquid.

Example 6 By the same operation as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M) and 0.025 g of tributylbenzylphosphonium chloride (TBBPC) were charged and reacted at 140 ° C. for 8 hours to obtain 4.03 g of a colorless transparent liquid.

Example 7 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M) and 0.025 g of triphenylbutylphosphonium bromide (TPBPB) were charged and reacted at 140 ° C. for 8 hours to obtain 3.87 g of a colorless transparent liquid.

Example 8 By the same operation as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M) and 0.025 g of tributyloctylphosphonium chloride (TBOPC) were charged and reacted at 140 ° C. for 8 hours to obtain 4.05 g of a colorless transparent liquid.

Example 9 In the same manner as in Example 1, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M) and 0.025 g of tetrabutylphosphonium diethylphosphorodithioate (TBPEP) were charged, and 1
The reaction was carried out at 40 ° C. for 8 hours to obtain 3.92 g of a colorless transparent liquid.

Table 1 shows the results of gas chromatographic analysis of the crude liquids obtained in Examples 1 to 9 before distillation.

[0046]

[Table 1]

Example 10 In a 25 ml Erlenmeyer flask equipped with a rotor and a condenser, 3.07 g (0.02 M) of phosphorus oxychloride and 2.
35 g (0.025 M) and 0.0125 g of tetraethylphosphonium bromide are charged, and the temperature is raised with stirring. The bath temperature was set to 140 ° C. and the reaction was carried out for 9 hours. It was confirmed by gas chromatography that the raw material phenol had run out, and the reaction was completed, and a colorless transparent liquid was added (3.91 g).
I got

Example 11 In the same manner as in Example 10, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M), and tetraethylphosphonium bromide 0.0
5 g was charged and reacted at 140 ° C. for 6 hours to obtain 4.05 g of a colorless transparent liquid.

Example 12 By the same operation as in Example 10, 3.07 g of phosphorus oxychloride
(0.02M), phenol 2.35g (0.025
M), and tetraethylphosphonium bromide 0.1
25 g was charged and reacted at 140 ° C. for 4 hours to obtain 4.37 g of a yellow transparent liquid.

Comparative Example 1 A 25 ml Erlenmeyer flask equipped with a stirrer, a thermometer, and a cooling tube was charged with 3.07 g (0.02 M) of phosphorus oxychloride and 2.35 g (0.025 M) of phenol, and the mixture was heated with stirring. Warm. When the internal temperature was about 140 ° C, reflux was caused and chlorine gas was slowly generated. The internal temperature was gradually raised so as to reflux, the temperature was raised to 200 ° C., and the reaction was carried out for 31 hours. The end point of the reaction was confirmed by confirming that the raw material phenol was exhausted by gas chromatography analysis.
4.21 g of a colorless transparent liquid was obtained.

The results of gas chromatograph analysis of the crude liquids obtained in Examples 10 to 12 and Comparative Example 1 are shown in Table 2.

[0052]

[Table 2]

Example 13 A 25 ml Erlenmeyer flask equipped with a rotor and a condenser was charged with 1.73 g (0.01125 M) of phosphorus oxychloride, 2.35 g (0.025 M) of phenol, and 0.125 g of tetraethylphosphonium bromide. , Raise the temperature with stirring. The bath temperature was set to 140 ° C. and the reaction was carried out for 13 hours. It was confirmed by the gas chromatograph that the raw material phenol was exhausted, and the reaction was made the end point.
1 g was obtained.

Example 14 By the same procedure as in Example 13, 1.92 g of phosphorus oxychloride
(0.0125 M), phenol 2.35 g (0.02
5M), and tetraethylphosphonium bromide 0.
125 g was charged and reacted at 140 ° C. for 10 hours to obtain 3.42 g of a colorless transparent liquid.

Example 15 By the same procedure as in Example 13, 2.30 g of phosphorus oxychloride
(0.015M), 2.35 g of phenol (0.025
M), and tetraethylphosphonium bromide 0.1
25 g was charged and reacted at 140 ° C. for 7 hours to obtain 3.40 g of a colorless transparent liquid.

Example 16 In the same manner as in Example 13, 2.68 g of phosphorus oxychloride
(0.0175 M), phenol 2.35 g (0.02
5M), and tetraethylphosphonium bromide 0.
125 g was charged and reacted at 140 ° C. for 5 hours to obtain 3.87 g of a colorless transparent liquid.

Example 17 In the same manner as in Example 13, 3.44 g of phosphorus oxychloride was used.
(0.0225M), phenol 2.35g (0.02M)
5M), and tetraethylphosphonium bromide 0.
125 g was charged and reacted at 140 ° C. for 2 hours to obtain 4.49 g of a colorless transparent liquid.

Example 18 In the same manner as in Example 13, 3.84 g of phosphorus oxychloride was used.
(0.025M), 2.35 g of phenol (0.025M)
M), and tetraethylphosphonium bromide 0.1
25 g was charged and reacted at 140 ° C. for 2 hours to obtain 5.14 g of a colorless transparent liquid.

Example 19 In the same manner as in Example 13, phosphorus oxychloride 11.50 was obtained.
g (0.075M), phenol 2.35g (0.02M
5M), and tetraethylphosphonium bromide 0.
125 g was charged and reacted at 130 ° C. for 1 hour. After collecting excess phosphorus oxychloride under reduced pressure at 60 ° C. and 30 mmHg, 5.61 g of a colorless transparent liquid was obtained.

The results of gas chromatograph analysis of the crude liquids obtained in Examples 13 to 19 are shown in Table 3.

[0061]

[Table 3]

Example 20 In a 25 ml Erlenmeyer flask equipped with a rotor and a condenser, 3.07 g (0.02 M) of phosphorus oxychloride, 2.70 g (0.025 M) of m-cresol, and 0.125 g of tetraethylphosphonium bromide. Is charged and the temperature is raised with stirring. The bath temperature was set to 140 ° C. and the reaction was carried out for 3 hours. It was confirmed by gas chromatography that the starting material, m-cresol, had disappeared, and the reaction had ended, and the red transparent liquid 4.9
6 g was obtained.

As a result of gas chromatographic analysis of the obtained colorless transparent liquid, the bis (3-methylphenyl) chlorophosphate content was 42.7%, and the 3-methylphenyldichlorophosphate content was 53.7%. The content rate of tris (3-methylphenyl) phosphate is 1.4.
%Met.

Example 21 In a 25 ml Erlenmeyer flask equipped with a rotor and a condenser, 3.07 g (0.02 M) of phosphorus oxychloride, 4.07 g (0.025 M) of 2,4-dichlorophenol, and tetraethylphosphonium bromide. Charge 0.125g,
The temperature is raised with stirring. Set the bath temperature to 140 ℃, 6
Allowed to react for hours. Gas chromatograph shows the raw material 2,4-
When it was confirmed that the dichlorophenol had disappeared, the reaction was terminated and 5.69 g of a colorless transparent liquid was obtained.

The colorless transparent liquid thus obtained was analyzed by gas chromatography to find that it was bis (2,4-dichlorophenyl).
The chlorophosphate content was 4.9% and the 2,4-dichlorophenyldichlorophosphate content was 76.6.
%, And the content of tris (2,4-dichlorophenyl) phosphate was 18.5%.

[0066]

As described above, the present invention uses the quaternary phosphonium salt as a catalyst by adjusting the molar ratio of phosphorus oxychloride as a raw material and phenols in the reaction of phenols with phosphorus oxychloride. As a result, the loss of phenyls and phosphorus oxychloride as raw materials is small, and the amount of triaryl phosphates, which is a by-product, is suppressed, and the target arylphosphoric dichloride and diarylphosphoric chloride can be selected with high selectivity. It is a very advantageous production method that can be obtained in yield.

Claims (4)

[Claims] 1. A process for producing arylphosphoric acid chlorides, which comprises reacting a phenol having a substituent in a phenol nucleus or a substituent having no substituent and phosphorus oxychloride with a quaternary phosphonium salt as a catalyst. 2. The method for producing arylphosphoric acid chlorides according to claim 1, wherein the arylphosphoric acid chlorides are arylphosphoric acid dichlorides or diarylphosphoric acid chlorides. 3. The method according to claim 1, wherein the reaction is carried out by increasing the molar ratio of phosphorus oxychloride / phenols as a raw material to increase the production amount of arylphosphoric acid dichloride in the reaction product.
A method for producing the arylphosphoryl chlorides described. 4. The method according to claim 1, wherein the reaction is carried out by reducing the molar ratio of phosphorus oxychloride / phenols as a raw material to increase the production amount of diaryl phosphoric acid chloride in the reaction product.
A method for producing the arylphosphoryl chlorides described.