JP2678665B2 - Process for producing diarylphosphine halide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a) Object of the invention Industrial field of application The present invention is an arylalkylphosphine or the like which is used alone or led to a phosphonium compound or a transition metal complex and widely used as a reaction reagent or a catalyst. Of the asymmetric phosphine compound, polystyrene pendant phosphine compound, bis (diphenylphosphino) ethane and bis (diphenylphosphino) propane, which are useful as raw materials for bidentate phosphine compounds.

Conventional technology For the synthesis of diphenylphosphine chloride, the redistribution reaction of phenyldichlorophosphine obtained by the Friedel-Crafts reaction of phosphorus trichloride and benzene is often used, but the yield of the redistribution reaction itself is low, and %, And operation is complicated [(Chemish Berchte (Ch
em.Ber) 94, 2122 (1961)]. There is also a method of using triphenylphosphine to cause chlorine to act under high temperature conditions, but it is not common because many impurities are generated [Organic Reaction, Vol. 6, page 321 (1951)]. Furthermore, in the laboratory, a method of reacting triphenylphosphine with metallic lithium in a tetrahydrofuran solvent and then chlorinating with phosgene is also simple and useful, but it is of little industrial value [Chemical Abstract Volume 57 2
256e]. There is also a method in which phosphorus trichloride is allowed to act on diphenylphosphine hydroxide without a solvent, but the reaction yield is as low as 59%, which is not practical on an industrial scale (Journal of Organic Chemistry. Chemistry) Vol. 30, p. 2393 (1965)].

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Various methods for synthesizing diarylphosphine halides have been proposed as described above, and they are produced on an industrial scale. However, there are difficulties in operability and economy. Therefore, the development of an effective manufacturing method to replace this is desired.

The present invention is to provide a method for producing a target diarylphosphine halide with high purity and high yield by an industrially easy operation.

(B) Structure of the Invention Means for Solving the Problems The inventors of the present invention have made extensive studies to solve such problems. As a result, they have found a method for industrially extremely advantageous production of diarylphosphine halides. That is, the present invention relates to the general formula (In the formula, R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group.) A general formula PX ₃ (III) obtained by diluting a diarylphosphine hydroxide with an inert solvent is used. A general formula, characterized in that the reaction is carried out by dropping into a phosphorus halide represented by (In the formula, R and X are the same as defined above.) The present invention relates to a method for producing a diarylphosphine halide.

The synthetic method of the diarylphosphine halide in the present invention is shown below by a reaction formula.

(In the formula, R and X are the same as above.) Hereinafter, the production method of the present invention will be described in more detail.

a) Synthesis of compound of formula (II) A known diarylphosphine hydroxide of formula (II), which is a starting material compound of compound of formula (I), is a dialkyl represented by general formula (RO) ₂ POH as shown in the following reaction formula. General formula for phosphite Grignard reagent represented by or a general formula It can be obtained easily and with high purity by reacting with an organometallic reagent such as the lithium reagent shown in. Since the compound of formula (II) can be subjected to a halogenation reaction without purification treatment, its significance is extremely large.

(In the formula, R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, and X represents a halogen atom.) B) Synthesis of compound of formula (I) Directly to the diarylphosphine hydroxide of formula (II), the formula (II
The phosphorus halide of I) may be used. Examples of the halogen atom of the formula (III) include chlorine and bromine.
As the compound I), phosphorus trichloride and phosphorus tribromide are preferable. Since this reaction is accompanied by heat generation, in order to control heat generation smoothly, it is essential to drop the compound of formula (II) into the compound of formula (III) diluted with an inert organic solvent to carry out the reaction. . Such an operation is an indispensable condition, and when the compound of the formula (III) is dropped, conversely, as in Comparative Example 1 described later, a side reaction is accompanied and the yield is lowered as in the above-mentioned conventional technique.

The solvent used here can be arbitrarily selected from aromatic solvents such as benzene, toluene and xylene, aliphatic groups such as hexane, pentane and octane, and inert organic solvents such as dichloromethane, chloroform and dichloroethane. . As the reaction agent used in the halogenation reaction of the present invention, phosphorus pentachloride, phosphorus oxychloride, acetyl chloride, thionyl chloride and the like are considered in addition to phosphorus trichloride and phosphorus tribromide described above. However, phosphorus pentachloride has a poor yield due to complex formation, phosphorus oxychloride does not react at all, and acetyl chloride abnormally produces a high-boiling substance, and the yield of the target product is also extremely poor. Further, thionyl chloride is produced only as an abnormal product having a high boiling point.
Therefore, they are difficult to use.

Since the halogenation reaction of the diarylphosphine hydroxide of the formula (II) with the phosphorus halide of the formula (III) of the present invention is accompanied by intense heat generation, it is necessary to gradually add the diarylphosphine hydroxide to control the reaction temperature. Yes, generally 0-100 ° C, preferably 10
It is recommended to keep it at about 30 ℃.

 Next, an operation example of the halogenation reaction of the present invention will be shown.

In a nitrogen atmosphere, 0.67 mol to 1.5 mol of phosphorus halide alone or diluted with, for example, a solvent such as benzene, toluene, and hexane, and placed in a flask, the reaction solution is stirred under cooling with stirring 10 to 20 While keeping the temperature at 0 ° C., the diarylphosphine hydroxide of the formula (II) is previously diluted with a solvent such as benzene, toluene, hexane or the like in an amount of 3 times by volume and added dropwise. Then, stirring is continued for another 0.5 to 2 hours in order to mature and complete the reaction.
At this point, the conversion rate of this reaction to halogenation is almost 100%.
It is.

After the reaction, the solvent is distilled off as it is, and the diarylphosphine halide of the formula (I) can be obtained by vacuum distillation. After the reaction solvent is distilled off, n-hexane, n-heptane, n-octane and the like are added. Then, the oil-like polyphosphoric acid-like substance produced in the reaction precipitates, and this can be removed to obtain the diarylphosphine halide of the formula (I). In this reaction, since there are no by-products other than those mentioned above, the diarylphosphine halide of the formula (I) can be obtained as a substantially pure product by removing the polyphosphoric acid-like substance and then performing simple distillation under reduced pressure. Next, the production method of the present invention will be specifically described with reference to examples.

Example 1 Method for Producing Diphenylphosphine Halide 68.7 g (0.5 mol) of phosphorus trichloride dissolved in 200 ml of benzene was charged in a 1-volume four-necked flask which was replaced with nitrogen,
Cooled to 10 ° C. with stirring. 20-30 in this reaction solution
While maintaining the temperature at 0 ° C, 101 g (0.5 mol) of diphenylphosphine hydroxide dissolved in 300 ml of benzene was added dropwise. After completion of dropping, the reaction was completed by stirring for 30 minutes. Then, the insoluble matter precipitated in the reaction solution was removed by decantation, and the supernatant reaction solution was distilled under reduced pressure to obtain a diphenylphosphine chloride product having a boiling point of 135 to 140 ° C./2 mmHg and 104.5 g ( Gas chromatographic purity 99.3%) was obtained. The yield of this reaction was 94.0% based on phosphorus trichloride. The isolated diphenylphosphine chloride was confirmed to be the target compound by elemental analysis as shown below.

Analytical value C: 64.4 H: 4.3 P: 14.5 Cl: 16.7 Calculated value C: 65.32 H: 4.57 P: 14.04 Cl: 16.07 Example 2 Production method of bis (para-tolyl) phosphine chloride Phosphorus trichloride dissolved in 100 ml of benzene 34.4 g (0.25 mol) was charged into a 500 ml four-necked flask which had been purged with nitrogen, and cooled to 10 ° C with stirring. 10 in this reaction solution
While maintaining the temperature at ~ 20 ° C, bis (para-tolyl) phosphine hydroxide 57.6g (0.2
5 mol) was added dropwise. After completion of dropping, the reaction was completed by stirring for 30 minutes. The reaction solution from which insoluble matter had been removed was distilled under reduced pressure in the same manner as in Example 1, and 57.2 g of the desired bis (para-tolyl) phosphine chloride (purity 98.1 by gas chromatography) was obtained in a fraction having a boiling point of 145 to 150 ° C./2 mmHg. %)
I got The yield of this reaction is 90.2% based on phosphorus trichloride.
Met. The elemental analysis values of this product are as follows.

Elemental analysis value C: 67.0 H: 5.3 P: 12.8 Cl: 14.9 Calculated value C: 67.62 H: 5.67 P: 12.45 Cl: 14.26 Example 3 Method for producing bis (para-methoxyphenyl) phosphine chloride Three dissolved in 100 ml of dichloroethane Phosphorus chloride 34.4 g (0.
25 mol) was charged into a 4-necked flask having a capacity of 500 ml and purged with nitrogen, and cooled to 10 ° C. with stirring. In this reaction solution
65.6 g of bis (para-tolyl) phosphine hydroxide dissolved in 150 ml of toluene while maintaining the temperature at 10 to 20 ° C.
(0.25 mol) was added dropwise. After completion of dropping, the reaction was completed by stirring for 30 minutes. The reaction solution from which insoluble matter had been removed was distilled under reduced pressure in the same manner as in Example 1, and 63.2 g (purity by gas chromatography) of the desired bis (para-methoxyphenyl) phosphine chloride was obtained in a fraction having a boiling point of 185 to 190 ° C / 2 mmHg. 98.6%). The yield of this reaction was 88.8% based on phosphorus trichloride. The elemental analysis values of this product are as follows.

Elemental analysis value C: 58.8 H: 4.6 P: 11.7 Cl: 13.0 Calculated value C: 59.91 H: 5.03 P: 11.03 Cl: 12.63 Example 4 Production method of diphenylphosphine bromide 135.35 g of phosphorus tribromide dissolved in 200 ml of benzene ( 0.5 mol) was charged into a 1-volume four-necked flask whose atmosphere was replaced with nitrogen,
Cooled to 10 ° C. with stirring. To the reaction solution, 101 g (0.5 mol) of diphenylphosphine oxide dissolved in 300 ml of benzene was added dropwise while maintaining the temperature at 20 to 30 ° C. After completion of dropping, the reaction was completed by stirring for 30 minutes. And
The insoluble matter that had settled in the reaction solution was removed by decantation, and the supernatant reaction solution was distilled under reduced pressure to obtain 124.0 g of the target diphenylphosphine bromide (gas chromatograph) in the fraction with a boiling point of 145 to 150 ° C / 2 mmHg. A chromatographic purity of 99.1%) was obtained. The yield of this reaction was 92.7% based on phosphorus tribromide. The isolated diphenylphosphine bromide was confirmed to be the target compound by elemental analysis as shown below.

Analytical value C: 53.9 H: 4.0 P: 11.2 Br: 30.9 Calculated value C: 54.37 H: 3.80 P: 11.68 Br: 30.14 Comparative Production Example 1 Method for producing diphenylphosphine chloride 101 g of diphenylphosphine hydroxide dissolved in 300 ml of benzene (0.5 (Mol) was charged in a 1-volume four-necked flask whose atmosphere was replaced with nitrogen, and cooled to 10 ° C. with stirring. While maintaining the reaction solution at 20 to 30 ° C, 200m of benzene
68.7 g (0.5 mol) of phosphorus trichloride dissolved in 1 was added dropwise.
After completion of dropping, the reaction was completed by stirring for 30 minutes.
Then, the insoluble matter precipitated in the reaction solution was removed by decantation, and the supernatant reaction solution was distilled under reduced pressure to obtain a diphenylphosphine halide having a boiling point of 135 to 140 ° C./2 mmHg of 74.5 g ( A gas chromatographic purity of 94.4%) was obtained. The yield of this reaction is
It was 63.7% with respect to phosphorus trichloride.

C) Effect of the Invention The production method of the present invention is superior to the conventional production method in industrial scenes, particularly in operability, yield, and purity. That is, according to the method of the present invention, it is possible to use the compound of the formula (II) as a raw material which is easily available as an industrial chemical, and the reaction operation can be carried out without special care. Further, almost no impurities are generated, and the purification and isolation operations are easy. Further, the desired diarylphosphine halide can be obtained in high yield and high purity.

Therefore, the present invention is useful as a method for producing a diarylphosphine halide on an industrial scale.

Claims (1)

(57) [Claims] (1) General formula (In the formula, R represents a hydrogen atom, a lower alkyl group or a lower alkoxy group.) A diarylphosphine hydroxide represented by general formula PX ₃ (wherein X represents a halogen atom) is diluted with an inert solvent. ) Is added dropwise to the phosphorus halide represented by the formula, and the reaction is carried out. (In the formula, R and X are the same as above.) A method for producing a diarylphosphine halide.