JPH0826053B2 - Method for producing quaternary phosphonium inorganic acid salt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a corresponding quaternary phosphonium carbonate by reacting a phosphine with a carbonic acid diester,
By further mixing this with an inorganic acid and decarboxylation,
It relates to a method for producing a quaternary phosphonium inorganic acid salt.

The quaternary phosphonium inorganic acid salt obtained by the method of the present invention is useful in various fields such as various catalysts such as phase transfer catalysts, electrolytes for aqueous and organic electrolytic solutions, various additives, and chemicals. It is an organic compound.

[Conventional technology]

As a method of synthesizing a quaternary phosphonium salt, a method of quaternizing a phosphine with an alkyl halide, a dialkyl sulfuric acid or the like under heating is generally adopted. Further, in the case of producing a quaternary phosphonium salt in which anion species are variously changed, a method of anion exchange of a quaternary phosphonium halide (chloride, bromide, iodide) is usually adopted. For example, according to the reaction formula shown below, a method of converting a quaternary ammonium bromide into a quaternary phosphonium hydroxide (reaction 1a) and then neutralizing the quaternary phosphonium bromide with an inorganic acid (reaction 1b). By reacting with a corresponding inorganic acid salt and selecting a solvent in which the corresponding inorganic acid salt is insoluble (reaction 2), and reacting a quaternary phosphonium bromide with an alkali metal salt of an inorganic acid to precipitate or extract the inorganic acid salt. The method (reaction 3), and the method of reacting a quaternary phosphonium bromide with a silver salt of an inorganic acid to precipitate silver bromide to obtain the desired product from the solution (reaction 4) can be exemplified.

R_FourP Br → R_FourP OH  (Reaction 1a) R_FourP OH + H A → R_FourP A + H₂O (Reaction 1b) R_FourP Br + H A → R_FourP A ↓ + HBr (Reaction 2) R_FourP Br + Na A → R_FourP A ＋ NaBr (Reaction 3) R_FourP Br ＋ Ag A → R_FourP A + AgBr ↓ (Reaction 4) As a method for producing quaternary phosphonium hydroxide by reaction 1a
Quaternary phosphonium bromide dissolved in a suitable solvent
Reacts with quaternary phosphonium hydroxide type ion exchange resins
The quaternary phosphonium bromide in a liquid medium.
For reaction with potassium metal hydroxide, electrochemical method
Br bromine ion₂To obtain hydroxide by separating as
Methods, and methods using silver compounds are known.
It

[Problems to be solved by the invention]

However, any method according to Reaction 1a is an expensive method as a method for producing a quaternary phosphonium hydroxide, and it is generally difficult to completely remove the bromine ion in the quaternary phosphonium hydroxide, so that according to Reaction 1b Problems often occur in the purity of the neutralized product. Further, in the methods of Reactions 2 and 3, it is quite difficult to remove the bromine ion in the intended quaternary phosphonium inorganic acid salt, and it is unsuitable as a production method for obtaining a high-purity quaternary phosphonium inorganic acid salt. is there. The method based on reaction 4 is considered to be preferable as a method for carrying out a quantitative reaction, but the silver salt of an inorganic acid as a raw material is extremely expensive, and it is hard to say that it can be industrially adopted.

Although the quaternary phosphonium bromide has been described above as an example, the same is true when other halides, sulfates, etc. are used, and generally, a method for producing various anion-exchanged salts with high efficiency and high purity is known. Absent.

[Means for solving problems]

The present inventors have reached the present invention by establishing a new technique relating to an industrial production method that enables efficient production as compared with the conventional method and enhances the purity of the target product.

That is, the present invention relates to a method for producing a quaternary phosphonium inorganic acid salt, comprising the steps of: (a) reacting a phosphine with a carbonic acid diester to produce a corresponding quaternary phosphonium carbonate (b). A quaternary phosphonium inorganic acid characterized by being subjected to a two-step process of mixing the incoming quaternary phosphonium carbonate with an inorganic acid to remove carbon dioxide gas outside the system to produce a corresponding inorganic acid salt. It proposes a salt production method.

[Specific Description of the Invention]

Examples of the phosphine as a raw material of the present invention include trimethylphosphine, diethylmethylphosphine, triethylphosphine, tri-n-propylphosphine, tri-n.
-Butylphosphine, tri-n-pentylphosphine,
Saturated aliphatic phosphines such as tri-i-butylphosphine, di-n-butylmethylphosphine, tricyclohexylphosphine, 1,2-bis (dimethylphosphino) ethane, unsaturated aliphatic phosphines such as triallylphosphine, Aromatic phosphines such as triphenylphosphine, tribenzylphosphine, di-i-propylphenylphosphine, divinylphenylphosphine, n-butyl-diphenylphosphine, 1-ethylphosphorane, 1-phenylphosphorane, 1-phenylphosphane And alicyclic phosphines such as 1-phenylphosphane and the like.

Examples of the carbonic acid diester include dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, dipropyl carbonate, and the like, and the one having a smaller number of carbon atoms in the alkyl group such as dimethyl carbonate is preferable because the quaternization reaction proceeds rapidly.

The inorganic acid is not particularly limited, but the stronger the acid is, the faster the exchange with anion is completed as compared with carbonic acid. In addition, even if the acid is weaker than carbonic acid, anion exchange can be achieved by shifting the equilibrium little by little and taking time. Specific examples of these inorganic acids include HF, HCl, HBr, HI, HNO ₃ ,
H ₂ SO ₄ , H ₃ PO ₄ , H ₃ BO ₃ , HClO ₄ , HBF ₄ , HPF ₆ , HSbF ₆ , HAs
F ₆ , HOSO ₂ Cl, HOSO ₂ F, H ₂ CrO ₄ , H ₂ S ₂ O ₆ , HMnO ₄ , HRe
O ₄ , H ₂ SeO ₄ , HSCN and the like can be mentioned.

The quaternization reaction which is the first step is carried out at a molar ratio of phosphines to carbonic acid diester of 0.2 to 5, more preferably 0.3 to 3, in the presence or absence of a solvent, a reaction temperature of 20 to 200 ° C.,
More preferably, it is carried out at 30 to 160 ° C. Usually, when the phosphine is sufficiently converted to a quaternary compound, the unreacted phosphine or the carbonic acid diester is distilled off together with the solvent when a solvent is used, or if necessary, recrystallized with a suitable organic solvent. , Sent to the second step.

In the second step, an inorganic acid corresponding to a normal stoichiometric value is added dropwise to the quaternary phosphonium carbonate in the presence or absence of a solvent,
The carbon dioxide gas generated is removed under reduced pressure or by blowing an inert gas into the reaction system. The reaction that occurs at this time is represented by the following equation when dimethyl carbonate is used as a raw material.

(In the formula, R ₁ R ₂ R ₃ is a hydrocarbon residue of phosphine, and X is a conjugate base of an inorganic acid.) After the reaction, the by-produced alcohol and the solvent are distilled off, and the obtained solid is a quaternary compound. Phosphonium inorganic acid salt. If necessary, a highly pure product can be obtained by recrystallization or the like with an appropriate solvent.

Further, when an inorganic acid slightly in excess of the stoichiometric value is used to completely remove the carbonate ion, the excess inorganic acid can be removed by a treatment such as recrystallization.

〔The invention's effect〕

According to the method of the present invention, it is possible to efficiently produce various quaternary phosphonium inorganic acid salts, but at the same time it is also a great feature of the present invention that the desired salt can be obtained in high purity. is there.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example-1 (1st process) 9.0 g of dimethyl carbonates and tri-n were put into a stirring type autoclave.
-Filled with butylphosphine 18.5g, reaction temperature 115 ℃,
The reaction was carried out at a reaction pressure of 5.0 kg / cm ² G for 15 hours. After the reaction, the autoclave was cooled, the reaction solution was taken out and analyzed by gas chromatography. The conversion rate of tri-n-butylphosphine was 72.8%, and the solid yield after distilling off unreacted materials and solvent was 17.5 g. Was (theoretical yield 63.6%). From the elemental analysis and ¹ H-NMR, it was confirmed that this solid was 10.1 g of tri-n-butylmethylsulfonium tetrafluoroborate (theoretical yield: 92.4%, tri-n-butylphosphonium carbonate).

(Second Step) 10.0 g of tri-n-butylmethylphosphonium carbonate was dissolved in 10.0 g of water, and 7.9 g of 42% HBF ₄ aqueous solution was gradually added. At the same time, carbon dioxide gas was vigorously generated. Degassed at 40 ℃ / 20mmHg for 2 hours to completely remove carbon dioxide, and carbonate ion is 20pp by ion chromatography.
After confirming that it was not more than m, water was distilled off. The residue is water-M
Recrystallization from a mixed solvent of eOH gave 10.1 g of tri-n-butylmethylphosphonium tetrafluoroborate (theoretical yield 92.4%, 58.8% yield based on tri-n-butylphosphine).

Example-2 (First step) 9.0 g of dimethyl carbonate and triethylphosphine as raw materials
When the same reaction as in Example 1 First Step was carried out except that 11.8 g and 10.0 g of methanol were used, 17.2 g of a solid was obtained (78.9% of theoretical yield). From elemental analysis, ¹ H-NMR, etc., it was confirmed that this solid was triethylmethylphosphonium carbonate.

(2nd step) Triethylmethylphosphonium carbonate 10.0g, 42% HBF
₄ Example-1 except that 11.3 g of aqueous solution and 10.0 g of water were used
When the same operation as in the second step was carried out, 10.8 g of triethylmethylphosphonium tetrafluoroborate (15.3% of theoretical yield, 75.2% yield based on triethylphosphine) was obtained.

Example-3 (First Step) A reaction similar to that of the first step of Example-1 was carried out except that 9.0 g of dimethyl carbonate, 17.8 g of 1-phenylphosphane were used as raw materials, and 10.0 g of methanol was used as a solvent. 19.1
g solid was obtained (71.3% of theoretical yield). Elemental analysis, ¹ H-N
It was confirmed from MR and the like that this solid was 1-methylphenylphosphanium carbonate.

(Second step) 1-methylphenylphosphanium carbonate 10.0 g and 60
% Except that 6.9 g of perchloric acid and 10.0 g of water were used.
When the same operation as in the 1st step 2 was performed, 10.9 g of methylphenylphosphanium perchlorate (94.8% of theoretical yield, 1
-67.6% yield based on phenylphosphane).

Example-4 (First Step) A reaction similar to that in the first step of Example-1 was carried out except that 9.0 g of dimethyl carbonate, 26.2 g of triphenylphosphine were used as raw materials, and 10.0 g of methanol was used as a solvent.
g of solid was obtained (theoretical yield 60.5%). Elemental analysis, ¹ H-NMR
From the above, it was confirmed that this solid was triphenylmethylphosphonium carbonate.

(2nd step) Triphenylmethylphosphonium carbonate 10.0g and 60%
The same operation as in the second step of Example 1 was carried out except that 6.2 g of perchloric acid and 100 g of ethanol were used, and 10.3 g of triphenylmethylphosphonium perchlorate (the theoretical yield was 92.8 g).
%, 56.1% yield based on triphenylphosphine).

Claims (1)

[Claims] 1. A method for producing a quaternary phosphonium inorganic acid salt, comprising the steps of: (a) reacting a phosphine with a carbonic acid diester to produce a corresponding quaternary phosphonium carbonate; (b) producing the quaternary phosphonium carbonate. A method for producing a quaternary phosphonium inorganic acid salt, which comprises performing a two-step process of producing a corresponding inorganic acid salt by removing carbon dioxide gas out of the system by mixing with an inorganic acid.