JP2000355595A - Production and purification of phosphine oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain a high purity phosphine oxide in a high yield which is useful e.g. for a catalyst for polymerizing alkylene oxide compounds by reacting a specific iminophosphorane with phosphorus oxychloride in an aprotic organic solvent having a dielectric constant equal to or above a specified value. SOLUTION: By reacting iminophosphoranes such as iminotris(dimethylamino) phosphorane expressed by formula I (wherein Rs are each a 1-10C hydrocarbon or two Rs on the same nitrogen atom may be combined with each other into a ring structure) with phosphorus oxychloride in an aprotic organic solvent such as toluene having a dielectric constant of >=2.2 at 20 deg.C, phosphine oxides of formula II are obtained. The aprotic organic solvent preferably is an organic solvent in which an aminophosphonium chloride of formula III is insoluble. Purification of the phosphine oxide preferably is carried out by washing a solution containing both the phosphine oxide and a water-immiscible organic solvent with water to form a phosphine oxide solution and by concentrating the solution to dryness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a phosphine oxide represented by the formula (2) by reacting an iminophosphorane represented by the formula (1) with phosphorus oxytrichloride, and a method for producing the phosphine oxide represented by the formula (2). And a method for purifying the same. The present inventors have previously proposed that the phosphine oxide is a catalyst for the polymerization of an alkylene oxide compound, a catalyst for producing an oxyalkylene derivative from an epoxy compound, or an IC.
It has been found that it is extremely effective as a curing catalyst for a raw material resin for a sealing material, and has already been filed (Japanese Patent Application No. 10-106745, Japanese Patent Application Laid-Open No. 11-302371, or Japanese Patent Application Laid-Open No. 11-322901, for example).
The phosphine oxides are compounds useful as such catalysts.

[0002]

2. Description of the Related Art Known documents relating to phosphine oxides represented by the formula (2) include, besides those described above by the present inventors, GNKoidan et al.
Journal of general chemis 55, 1453 (1985) (Journal of general chemis
try of the USSR, 55 , p1453 (1985)).

In this document, the compound [iminotris (dimethylamino) phosphorane] in which R in the iminophosphoranes represented by the formula (1) in the present application is a methyl group is called hexamethyltriamidophosphazohydride. ,
The compound [Tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide] in which R in the phosphine oxide represented by the formula (2) in the present application is a methyl group is tris [tris (N, N-dimethylamide). ) Phospazo] is called phosphate. Also, the expression in the present application
R in the aminophosphonium chloride represented by (3)
However, the compound [aminotris (dimethylamino) phosphonium chloride] which is a methyl group is called hexamethyltriamidophosphazohydride hydrochloride, and [H
N = P (NMe ² ) ³ ] · HCl, but the same compound. Here, the expressions of the present application are used for the above three compounds.

This reference describes the reaction of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide with methyl iodide. It discloses a method for producing tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide, which is a raw material for the reaction. There, the molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is exactly 6: 1.
Then, to the petroleum ether solution of the phosphorane, a petroleum ether solution of phosphorus oxytrichloride was added dropwise with stirring at 20 ° C. for 30 minutes (the time is not specified). The precipitate of (dimethylamino) phosphonium chloride was separated, the precipitate was washed with petroleum ether, the filtrate was concentrated and the residue was crystallized from a small amount of petroleum ether to give an isolated yield of 85% in tris.
It states that [tris (dimethylamino) phosphoranylideneamino] phosphine oxide was obtained.

However, when the present inventors performed this method under the same conditions, as shown in Comparative Example 5 below,
After the addition of phosphorus oxytrichloride was completed at 20 ° C. for 30 minutes, the target product was hardly formed. Thereafter, the reaction yield was about 60% even when the reaction temperature was raised to 40 ° C. and the reaction was performed for 24 hours, and the reaction yield was only about 73% when the reaction was further performed for 48 hours.

[0006] In addition, the document only mentions "crystallized from a small amount of petroleum ether" but does not give a detailed explanation of recrystallization. The present inventors firstly separated the precipitate by filtration from the reaction solution obtained by reacting at 40 ° C. for 48 hours as described above, and concentrated the filtrate to dryness to obtain a solid, as described in the above literature. Tried crystallization.

[0007] As shown in Comparative Example 6, only a small amount of crystals were deposited after cooling to -10 ° C, and crystals were finally obtained at an extremely low temperature of -20 ° C. The isolated yield of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide of this crystal was as low as 20%,
Moreover, a large amount of chlorine ions (about 600 ppm)
Was included. This residual chlorine ion becomes a very serious problem when the phosphine oxide is used as a curing catalyst for the above-mentioned raw material resin composition for an IC encapsulant, which requires electrical insulating properties.

In producing tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide by reacting iminotris (dimethylamino) phosphorane with phosphorus oxytrichloride, one molecule of iminotris is added to one molecule of phosphorus oxytrichloride. When one molecule of (dimethylamino) phosphorane reacts, one molecule of hydrogen chloride is produced at the same time. This hydrogen chloride immediately reacts with iminotris (dimethylamino) phosphorane to produce ionic aminotris (dimethylamino)
Produces phosphonium chloride. Therefore, stoichiometrically, 6 moles of iminotris (dimethylamino) phosphorane are required to react all three chlorines of one mole of phosphorus oxytrichloride. That is, 6HN = P (NMe ² )
³ + O = PCl ³ → O = P [N = P (NMe ² ) ³ ] ³ + 3 [H ² NP ⁺ (NMe ² ) ³ ] C
l ^- represented by.

As shown in Comparative Example 7 below, in the purification method described in the literature, when an imino (dimethylamino) phosphorane is used in excess of a stoichiometric amount in order to increase the reaction yield, it remains unreacted. The phosphorane could not be sufficiently removed, resulting in a decrease in the purity of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide after recrystallization.

[0010] The thus disclosed Tris [Tris
In the method for producing (dimethylamino) phosphoranylideneamino] phosphine oxide, both the reaction yield and the isolation yield are low, the purification method requires an extremely low temperature, and the removal of ionic compounds generated in the reaction. If one of the reactants is excessively used to improve the reaction yield, it cannot be sufficiently removed, so that it is extremely insufficient as an industrial production method.

[0011]

A first object of the present invention is to produce a phosphine oxide represented by the formula (2) by reacting an iminophosphorane represented by the formula (1) with phosphorus oxytrichloride. Another object of the present invention is to provide a method for producing the phosphine oxides in a high yield by improving the reaction yield. Further, a second object of the present invention is to provide a purification method capable of removing unreacted raw materials, ionic impurities, and the like by an industrially realistic method, and obtaining the phosphine oxides in high yield and high purity. It is to provide a method.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object. As a result, an iminophosphorane represented by the formula (1) was reacted with phosphorus oxytrichloride to obtain a compound represented by the formula In producing the phosphine oxides represented by (2), the reaction solvent is changed to petroleum ether (dielectric constant at 20 ° C. is 1.85 to 1.95) and the dielectric constant at 20 ° C. is 2.2 or more. It has been found that the use of a certain aprotic organic solvent significantly increases the reaction rate, and the phosphine oxides can be obtained in high yield.

Further, 1 part by mass of petroleum ether is 1.
Although it is a good solvent for dissolving 5 parts by mass or more of the phosphine oxides, as shown in Comparative Example 8 below, when the reaction solution reacted with a petroleum ether solvent is washed with a small amount of water, It was found that most of the phosphine oxides migrated to the aqueous phase and little remained in the petroleum ether phase.

Surprisingly, however, in the case of a reaction solution using a specific solvent, for example, o-dichlorobenzene, the phosphine oxide can be washed with water as shown in Example 8 below. Most of the compounds remained in the organic phase, and it was found that the aminophosphonium chlorides represented by the formula (3) formed by the reaction and the by-product unknown compounds were almost completely transferred to the aqueous phase. On the contrary, more surprisingly, when used in a stoichiometric amount or more as shown in Example 8, almost no iminophosphorane represented by the formula (1) remaining unreacted in the reaction solution also contains water. It has also been found that it will move into a phase.

Thus, the dielectric constant at 20 ° C. is 2.
When two or more aprotic organic solvents are used as the reaction solvent, the reaction rate increases, the reaction yield increases, and the formula
It is possible to produce the phosphine oxides represented by the formula (2), and it is possible to increase the purity of the solution containing the phosphine oxides and the specific organic solvent without substantially lowering the isolation yield only by washing with water. The effect was found and the present invention was completed.

That is, the first of the present invention is the following formula (1)

[0017]

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(Wherein R is the same or different and has 1 to 1 carbon atoms)
10 hydrocarbon groups, two R on the same nitrogen atom
Are bonded to each other to form a ring structure) with phosphorus oxytrichloride represented by the following formula (2)

[0019]

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In the production of the phosphine oxides represented by the formula (wherein R is the same as R in the formula (1)), an aprotic compound having a dielectric constant of not less than 2.2 at 20 ° C. is used as a reaction solvent. A method for producing the phosphine oxides, comprising using an organic solvent.

Further, the second aspect of the present invention is that at least the formula (2)
A solution containing the phosphine oxides represented by and an organic solvent substantially immiscible with water is washed with water to obtain a solution of the phosphine oxides, or the solution is concentrated to dryness to obtain the phosphine oxides as a solid. A method for purifying phosphine oxides, characterized in that:

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the production method and purification method of the present invention, the chemical structural formula of a phosphine oxide is represented by the formula
This is represented by (2), which is one limit structural formula.
Although the expressed phosphorus atom and an oxygen atom double bonds between, becomes anion electrons biased on an oxygen atom, forms generated cations on phosphorus atoms - limiting structure of (P ^{+ -O)} Can take. This cation on the phosphorus atom can also be totally delocalized through a conjugated system. The phosphine oxides represented by the formula (2) in the production method and the purification method of the present invention should be understood as a resonance hybrid including all of them.

The iminophosphoranes represented by the formula (1), the phosphine oxides represented by the formula (2), and the following formula (3) in the production method and the purification method of the present invention.

[0024]

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(Wherein R is the same as R in formulas (1) and (2)), R in the same or different aminophosphonium chlorides having 1 to 10 carbon atoms A hydrocarbon group. Specifically, this R is, for example, methyl,
Ethyl, n-propyl, isopropyl, allyl, n-butyl, sec-butyl, tert-butyl, 2-butenyl, 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, isopentyl, tert-butyl Pentyl, 3-methyl-2-butyl, neopentyl, n-hexyl, 4-methyl-2-pentyl, cyclopentyl, cyclohexyl, 1-heptyl,
3-heptyl, 1-octyl, 2-octyl, 2-ethyl-
1-hexyl, 1,1-dimethyl-3,3-dimethylbutyl
(Commonly known as tert-octyl), nonyl, decyl, phenyl,
4-toluyl, benzyl, 1-phenylethyl, or 2
And aliphatic or aromatic hydrocarbon groups such as -phenylethyl.

In the iminophosphoranes represented by the formula (1), the phosphine oxides represented by the formula (2), and the aminophosphonium chlorides represented by the formula (3), two When R is bonded to each other to form a ring structure containing a nitrogen atom, the cyclic amino group is a cyclic secondary amino group containing 4 to 6 carbon atoms in the ring, and -NR ² is a nitrogen atom. And a 5- to 7-membered cyclic secondary amino group containing As those cyclic secondary amino groups,
For example, a pyrrolidin-1-yl group, a piperidin-1-yl group,
Or a morpholin-4-yl group or the like, and further substituted with an alkyl group such as methyl or ethyl. In the iminophosphoranes, the phosphine oxides, and the aminophosphonium chlorides, all possible nitrogen atoms may have such a ring structure or may be a part thereof.

Of these, one having 1 carbon atom such as methyl, ethyl, n-propyl, isopropyl, tert-butyl, tert-pentyl or 1,1-dimethyl-3,3-dimethylbutyl
Preferred are up to 8 aliphatic hydrocarbon groups, more preferably methyl groups. These iminophosphoranes represented by the formula (1) are described in EP-0921128 or GNKoidan et al., Zh.
h. Khim., 50 , pp. 679-680 (1980). Compounds in which R in the iminophosphoranes is a methyl group are also commercially available and easily available.

The first aspect of the present invention is to react an iminophosphorane represented by the formula (1) with phosphorus oxytrichloride,
This is a method for producing a phosphine oxide represented by the formula (2) using an aprotic organic solvent having a dielectric constant of not less than 2.2 at 20 ° C. as a reaction solvent.

The feature of the production method of the present invention resides in that an aprotic organic solvent having a dielectric constant of not less than 2.2 at 20 ° C. is used as a reaction solvent. 20 ° C as reaction solvent
When an aprotic organic solvent having a dielectric constant of less than 2.2 is used, the reaction rate decreases extremely under the same mild conditions, and a side reaction proceeds when the reaction temperature is increased to increase the reaction rate. As a result, the desired phosphine oxide represented by the formula (2) cannot be obtained in high yield. Examples of such a solvent include petroleum ether (1.
85-1.95: This value represents the dielectric constant at 20 ° C .; the same applies hereinafter), hexane (1.89), decane (1.99),
Examples thereof include 1-hexene (2.06), 1-octene (2.08), cyclohexane (2.05), and decalin (2.19), which are not preferable as a reaction solvent.

Specific examples of the aprotic organic solvent having a dielectric constant of not less than 2.2 at 20 ° C. used as a solvent in the production method of the present invention are described in “Solvent Handbook (1982), published by Kodansha: Asahara. As described in Teruzo et al., Ed.), For example, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, and hexachloroethane, for example, benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene, normal propylbenzene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, mesitylene, tetralin, butylbenzene, p-xylene Cymene, cyclohexylbenzene, 1,4-diethylbenzene, 1,3-diisopropylbenzene, or dodecylbenzene Examples thereof include aromatic hydrocarbons such as benzene, for example, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, bromobenzene, o-dibromobenzene, 1-bromo-2-chlorobenzene, 1-bromonaphthalene, and 1-chloronaphthalene. , 2-
Chlorotoluene, 2-bromotoluene, 2,4-dichlorotoluene, 1-bromo-2-ethylbenzene, 2-chloro-o
-Halogenated aromatic hydrocarbons such as -xylene or 1,2,4-trichlorobenzene, for example, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxyethane, diethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, Examples include ethers such as 1,4-dioxane, anisole, and phenetole, such as methyl formate, ethyl formate, propyl formate, isobutyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, and ethyl propionate. Esters such as methyl butyrate, methyl benzoate, isopentyl benzoate, or ethyl cinnamate; and nitro compounds such as nitromethane, nitroethane, or nitrobenzene. Acetonitrile, propionitrile, benzonitrile, N, N- dimethylformamide,
Examples include polar compounds such as N-methylpyrrolidone, dimethylsulfoxide, and hexamethylphosphoric triamide.

In addition to these, the dielectric constant at 20 ° C. is 2.
If not less than 2 and do not inhibit the production method of the present invention,
Any aprotic organic solvent may be used, and these aprotic organic solvents may be used alone or in combination of two or more. Further, these aprotic organic solvents are mixed with an aprotic organic solvent having a dielectric constant at 20 ° C. of less than 2.2, and as a result, the solvent system having a dielectric constant at 20 ° C. of 2.2 or more is obtained. Should be understood to be "aprotic organic solvent having a dielectric constant of not less than 2.2 at 20 ° C." in the production method of the present invention.

Of these, those which do not dissolve the aminophosphonium chloride represented by the following formula (3) are preferable. For example, benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene,
N-propylbenzene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, mesitylene, tetralin, butylbenzene, p-cymene, cyclohexylbenzene, 1,4-diethylbenzene, 1,3-diisopropylbenzene Or aromatic hydrocarbons such as dodecylbenzene, for example, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, bromobenzene,
o-dibromobenzene, 1-bromo-2-chlorobenzene,
1-bromonaphthalene, 1-chloronaphthalene, 2-chlorotoluene, 2-bromotoluene, 2,4-dichlorotoluene, 1-bromo-2-ethylbenzene, 2-chloro-o-xylene, or 1,2,4- Halogenated aromatic hydrocarbons such as trichlorobenzene; for example, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxyethane, diethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisole, or phenetole; Ethers and the like.

Of these, those which are substantially immiscible with water, as described in the purification method of the present invention, are more preferable, for example, benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, Ethylbenzene, normal propylbenzene, cumene, 1,2,3
-Trimethylbenzene, 1,2,4-trimethylbenzene,
Mesitylene, tetralin, butylbenzene, p-cymene,
Cyclohexylbenzene, 1,4-diethylbenzene,
Aromatic hydrocarbons such as 1,3-diisopropylbenzene and dodecylbenzene; for example, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, bromobenzene, o-dibromobenzene, 1-bromo-2-chlorobenzene, -Bromonaphthalene, 1-chloronaphthalene, 2-chlorotoluene, 2-bromotoluene, 2,4-dichlorotoluene, 1-bromo-2-ethylbenzene, 2-chloro-o-xylene, or 1,2,4-triene Halogenated aromatic hydrocarbons such as chlorobenzene. More preferred are toluene, chlorobenzene, dichlorobenzene, and 2,4-dichlorotoluene.

The use amount of these is not particularly limited, but is usually 500 parts by mass or less, preferably 1 to 100 parts by mass, per 1 part by mass of phosphorus oxytrichloride as a raw material.
More preferably, it is 1.5 to 50 parts by mass. Some of the liquid phosphorus oxytrichloride may be insoluble therein.

In the production method of the present invention, the molar ratio of the iminophosphorane represented by the formula (1) to phosphorus oxytrichloride is not particularly limited, but is usually 5 to 12,
It is preferably from 6 to 10, more preferably from 6.1 to 8.
0. The reaction temperature is not uniform depending on the amount of the solvent, the molar ratio of the raw materials, and the like, but is usually -10 to 200C, preferably 0 to 150C, more preferably 15 to 100C.
° C. In the reaction, the temperature can be set in multiple stages, for example, at a lower temperature in the initial stage and at a higher temperature in the final stage. The reaction can be carried out under reduced pressure, normal pressure or increased pressure, but usually at normal pressure. The reaction time is
It is not uniform depending on the reaction temperature and other factors, but it is usually 0.1.
1 to 100 hours, preferably 0.5 to 50 hours,
More preferably, it is 1 to 30 hours.

Depending on the type and amount of the solvent used, or the type of iminophosphoranes represented by the formula (1), the aminophosphonium chlorides represented by the formula (3) are contained in the reaction solution thus obtained. May be precipitated as a solid or may be dissolved. The method for removing the phosphonium chlorides in such a state is not particularly limited, and any method can be used.In general, when the phosphonium chlorides are precipitated as a solid, the reaction solution is subjected to solid-liquid separation as it is. When the phosphonium chlorides are dissolved, a method of once distilling off the solvent and then adding an organic solvent in which the phosphonium chlorides are insoluble to carry out solid-liquid separation can be carried out.

The solid-liquid separation may be performed by any method, but generally, a general-purpose method such as filtration, centrifugation or decantation is used, and filtration is particularly preferable. If necessary, the filter cake is washed with the aprotic organic solvent or the organic solvent in which the phosphonium chlorides are insoluble, and the washing solution can be combined with the filtrate.

Examples of the organic solvent in which the phosphonium chlorides are insoluble include normal pentane, normal hexane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methylpentane, normal heptane, normal octane, , 3,3-trimethylpentane, isooctane, normal nonane, 2,2,5-trimethylhexane, or saturated aliphatic hydrocarbons such as normal decane, for example, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, Examples include alicyclic hydrocarbons such as ethylcyclohexane, p-menthane, bicyclohexyl, or decalin, such as benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene, normal propylbenzene, Cumene, 1,2,3-bird Methylbenzene, 1,
2,4-trimethylbenzene, mesitylene, tetralin,
Butylbenzene, p-cymene, cyclohexylbenzene,
Examples include aromatic hydrocarbons such as 1,4-diethylbenzene, 1,3-diisopropylbenzene, and dodecylbenzene, for example, chlorobenzene, o-dichlorobenzene,
m-dichlorobenzene, bromobenzene, o-dibromobenzene, 1-bromo-2-chlorobenzene, 1-bromonaphthalene, 1-chloronaphthalene, 2-chlorotoluene, 2-
Bromotoluene, 2,4-dichlorotoluene, 1-bromo-
2-ethylbenzene, 2-chloro-o-xylene, or 1,
Examples include halogenated aromatic hydrocarbons such as 2,4-trichlorobenzene, and examples thereof include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxyethane, diethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran,
Examples include ethers such as 1,4-dioxane, anisole, and phenetole, but are not limited thereto.

The phosphonium chlorides separated here as solids are described in EP-0921128 or GNKoidan et al., Z
hhim Obshch.Khim., 50 , pp. 679-680 (1980), can be regenerated to the iminophosphoranes represented by the formula (1), It can also be recycled as part or all of the iminophosphoranes represented by 1).

In the mother liquor from which the aminophosphonium chlorides represented by the formula (3) have been removed in this way, the iminophosphoranes represented by the formula (1) remain unreacted or remain when used in excess. Exists. The method for removing the phosphoranes is not particularly limited and can be carried out by any method.However, usually, after concentrating and drying the mother liquor, the phosphoranes are distilled off at normal pressure or under reduced pressure, or as described below. Then, a method of washing the mother liquor with water or the like can be carried out.

The thus-obtained dry solid or the solution after washing with water contains the phosphine oxide represented by the formula (2) with sufficiently high purity, and may be used as it is for the following purpose. The water contained in a small amount may be removed by a desiccant or distillation, and the solution after the water washing may be used as a concentrated solution or a dry solid except for a part or all of the solvent.

A second aspect of the present invention is to wash a solution containing at least the phosphine oxide represented by the formula (2) and an organic solvent which is substantially immiscible with water by washing with water, or as a solution of the phosphine oxide. This is a method for purifying the phosphine oxides by which the solution is concentrated to dryness to obtain the phosphine oxides as a solid.

The organic solvent which is essentially immiscible with water in the purification method of the present invention is an organic solvent used for ordinary extraction and the like, does not dissolve in water to a problematic degree, and is easily separated from the aqueous phase. You can do it. In addition, the partition ratio of the phosphine oxide represented by the formula (2) to the organic solvent phase with respect to the aqueous phase is high, and no chemical change occurs even when the phosphine oxide is brought into contact with the phosphine oxide.

Examples of such organic solvents that are substantially immiscible with water include, for example, methylene chloride, chloroform,
Examples thereof include halogenated aliphatic hydrocarbons such as 2-dichloroethane, 1,1-dichloroethane, and hexachloroethane, for example, benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene,
N-propylbenzene, cumene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, mesitylene, tetralin, butylbenzene, p-cymene, cyclohexylbenzene, 1,4-diethylbenzene, 1,3-diisopropylbenzene Or aromatic hydrocarbons such as dodecylbenzene, for example, chlorobenzene, o-
Dichlorobenzene, m-dichlorobenzene, bromobenzene, o-dibromobenzene, 1-bromo-2-chlorobenzene, 1-bromonaphthalene, 1-chloronaphthalene, 2-
Chlorotoluene, 2-bromotoluene, 2,4-dichlorotoluene, 1-bromo-2-ethylbenzene, 2-chloro-o
Halogenated aromatic hydrocarbons such as -xylene or 1,2,4-trichlorobenzene, for example, propyl formate, isobutyl formate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate,
Methyl butyrate, methyl benzoate, isopentyl benzoate,
Or esters having 4 or more carbon atoms, such as ethyl cinnamate. In addition, any organic solvent may be used as long as the purification method of the present invention is not hindered.

Of these, preferred are aprotic organic solvents which have a dielectric constant at 20 ° C. of 2.2 or more and in which the aminophosphonium chloride represented by the formula (3) is insoluble, for example, benzene, toluene, o -Xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene, normal propylbenzene, cumene, 1,2,3
-Trimethylbenzene, 1,2,4-trimethylbenzene,
Mesitylene, tetralin, butylbenzene, p-cymene,
Cyclohexylbenzene, 1,4-diethylbenzene,
Aromatic hydrocarbons such as 1,3-diisopropylbenzene and dodecylbenzene; for example, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, bromobenzene, o-dibromobenzene, 1-bromo-2-chlorobenzene, -Bromonaphthalene, 1-chloronaphthalene, 2-chlorotoluene, 2-bromotoluene, 2,4-dichlorotoluene, 1-bromo-2-ethylbenzene, 2-chloro-o-xylene, or 1,2,4-triene Halogenated aromatic hydrocarbons such as chlorobenzene. More preferred are toluene, chlorobenzene, and o-dichlorobenzene.

In the purification method of the present invention, at least the formula
The solution containing a phosphine oxide represented by (2) and an organic solvent that is substantially immiscible with water is a solution containing at least the two components, and other components unless the purification method of the present invention is inhibited. May be present. Further, the phosphine oxides once separated from this solution are
It may be a solution formed by dissolving in an organic solvent that is substantially immiscible with water.

Further, this solution is prepared by converting an iminophosphorane represented by the formula (1) and phosphorus oxytrichloride into an aprotic compound having a dielectric constant of not less than 2.2 at 20 ° C. and substantially not mixing with water. An organic solvent which is further reacted with an organic solvent in which the aminophosphonium chlorides represented by the formula (3) are insoluble as a reaction solvent to form a solid compound represented by the formula (2) which is formed simultaneously with the phosphine oxides represented by the formula (2): 3)
May be a solution in which the phosphonium chlorides are removed by solid-liquid separation from a reaction solution containing the aminophosphonium chlorides represented by the following formula: After performing using an aprotic organic solvent that is at least 2 as a reaction solvent,
A solution obtained by removing the solvent from the solution obtained by performing the solid-liquid separation described in the production method of the present invention by a method of distilling off the solvent and the like, and replacing the solution with a desired organic solvent substantially immiscible with water. I do not care.

In such a solution, an iminophosphorane represented by the formula (1) and phosphorus oxytrichloride were added at 20 ° C.
Is an aprotic organic solvent having a dielectric constant of 2.2 or more and substantially immiscible with water, and further reacted by using an organic solvent in which aminophosphonium chlorides represented by the formula (3) are insoluble as a reaction solvent. A solution obtained by removing the phosphonium chlorides by solid-liquid separation from a reaction solution containing a solid aminophosphonium chloride represented by the formula (3), which is formed simultaneously with the phosphine oxides represented by the formula (2); A solution in which the phosphonium chlorides are removed by solid-liquid separation from a reaction solution containing the phosphine oxides obtained by reacting the phosphoranes with respect to phosphorus oxytrichloride in a molar ratio of 6 to 10 in the reaction. Is more preferred.

As a method of washing with water in the purification method of the present invention, a method of sufficiently contacting water with a solution containing at least a phosphine oxide represented by the formula (2) and an organic solvent substantially immiscible with water is used. Any method may be used. Usually, the reaction can be carried out by adding water to the solution, stirring sufficiently, separating the organic phase and the aqueous phase, and then removing the aqueous phase.

The amount of water in the water washing is not particularly limited, but is usually at most 5 parts by mass per 1 part by mass of the solution. It is also possible to wash several times with such an amount of water. Preferably, the solution is washed 2 to 5 times with 0.05 to 1.0 parts by weight of water per 1 part by weight of the solution. The temperature and time of water washing are not particularly limited, but the temperature is usually 10 to 80 ° C, preferably 15 to 40 ° C,
The time is usually within 3 hours, preferably 0.01 to 1 hour, more preferably 0.05 to 0.5 hour. The solution of the phosphine oxide represented by the formula (2) thus washed with water contains the phosphine oxide with higher purity, and may be used for the next purpose as it is. It can also be concentrated to dryness and taken out as a solid.

If necessary, the dried solid can be purified. The dry solid may have the solvent completely removed or a small amount of solvent remaining. In these dry solids, trace amounts of impurities remaining after being dissolved even after washing with water are present. The method for further purifying these dry solids is not particularly limited. However, hydrocarbons are added to the dry solids to dissolve the phosphine oxides represented by the formula (2), and a small amount of solids (impurities) remaining insoluble are removed. The method of removing by solid-liquid separation is preferable and effective, and is also practical.

The hydrocarbons used in this method include, for example, normal pentane, normal hexane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methylpentane, normal heptane, normal octane, 2,3,3 -
Trimethylpentane, isooctane, normal nonane,
A saturated aliphatic hydrocarbon such as 2,2,5-trimethylhexane or normal decane; for example, an oil such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, p-menthane, bicyclohexyl, or decalin; It is a cyclic hydrocarbon, and examples thereof include aromatic hydrocarbons such as benzene, toluene, o-xylene, m-xylene, and p-xylene.

Other than these, any hydrocarbons may be used as long as this method is not hindered. These hydrocarbons may be used alone or as a mixture. Of these, preferred are those having 5 carbon atoms such as normal pentane, normal hexane, normal heptane, normal octane, normal nonane, and normal decane.
10 to 10 saturated aliphatic hydrocarbons.

The use amount of these hydrocarbons is not particularly limited, but is usually 0.5 to 50 times by mass, preferably 1 to 20 times by mass relative to the dry solid. These hydrocarbons are added to the dry solid to dissolve the phosphine oxides represented by the formula (2). The temperature and time are not particularly limited, but the temperature is usually 10 to 100 ° C., preferably 20 to 100 ° C. To 50 ° C, and the time is usually 0.1 to 3 hours, preferably 0.5 to 2 hours. Thereafter, solids remaining after being insoluble are removed by solid-liquid separation. Any method may be used, but generally, a general-purpose method such as filtration, centrifugation, or decantation is used, and filtration is particularly preferable. The insolubles can be washed with hydrocarbons and the washings can be combined with the filtrate.

In this way, the very high-purity formula (2)
A solution of phosphine oxides represented by If necessary, the solution can be concentrated to dryness to remove the phosphine oxides as a solid.

[0056]

The present invention will be described in more detail with reference to the following examples. However, the present embodiment specifically describes the present invention, and the present invention is not limited to only these embodiments.

Example 1 Under a nitrogen atmosphere, 54.3 g of iminotris (dimethylamino) phosphorane in which R in the iminophosphoranes represented by the formula (1) is a methyl group was placed in a 300 ml glass reactor. (305 mmol), and dried o-dichlorobenzene (dielectric constant at 20 ° C is 6.
130 g were charged. While stirring and controlling the internal temperature to 20 ° C., a mixture of 7.67 g (50.0 mmol) of phosphorus oxytrichloride and 16.3 g of dried o-dichlorobenzene (phosphorus oxytrichloride concentration) was added. Is 32
% By mass) was added dropwise over 30 minutes. The molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is 6.1. At this time, a part of the reaction solution was collected.

Results of quantitative analysis by ³¹ P-NMR using deuterated dimethyl sulfoxide as a solvent and tri-normal-butyl phosphate as an internal standard compound (hereinafter the yield and purity were analyzed by this method) From the formula, tris [tris (dimethylamino) phosphoranylideneamino] in which R in the phosphine oxides represented by the formula (2) is a methyl group
Phosphine oxide was hardly formed. Thereafter, the reaction solution was heated to 40 ° C. and reacted for 24 hours. As a result, the reaction yield of the phosphine oxide with respect to phosphorus oxytrichloride was 83.6%.

In addition to the results, Examples 2 to 7 in which an aprotic organic solvent having a dielectric constant of not less than 2.2 or less than 2.2 at 20 ° C. other than o-dichlorobenzene were reacted. And the results of Comparative Examples 1 to 4 are shown in Table 1 below. Table 1 clearly shows that there is a large reaction rate difference between the two, and also shows that the former is extremely effective in improving the reaction yield of the target product.

Examples 2 to 7 and Comparative Examples 1 to 4
Was carried out in the same manner as in Example 1 except that various aprotic organic solvents shown in Table 1 were used instead of o-dichlorobenzene.

[0061]

[Table 1]

Example 8 Under a nitrogen atmosphere, a glass reactor of 500 ml was charged with 15.4 g (100 mmol) of phosphorus oxytrichloride and 154 g of dried o-dichlorobenzene. While stirring, 116 g (651 mmol) of iminotris (dimethylamino) phosphorane was added dropwise thereto over 1 hour while controlling the internal temperature to 70 ° C. or lower. The molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is 6.5.
After completion of the dropwise addition, stirring was continued at 70 ° C. for 1 hour to obtain a white slurry liquid. A part of this reaction solution was collected and subjected to quantitative analysis. The reaction yield of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide was 85.4.
%Met.

After the reaction, the obtained white slurry liquid was filtered, and the solid was washed with a small amount of o-dichlorobenzene to obtain 266 g of a filter washing liquid. The filtrate was transferred to a 300 ml separatory funnel, to which 31.9 g of water (0.12 times by mass of the filtrate) was added. After the placement, the o-dichlorobenzene phase and the aqueous phase were separated and separated. This water washing operation was similarly performed twice more.

When the obtained o-dichlorobenzene phase was analyzed, the unreacted iminotris
(Dimethylamino) phosphorane was reduced to below the detection limit, and by-products were also significantly reduced compared to before washing with water. Thereafter, the o-dichlorobenzene phase was heated to 80 ° C. and 10 mmHg.
And dried to give 50.5 g of a white solid. The purity of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide in this solid was 95.4% by mass,
The isolation yield was 83.3%. In this way, the phosphine oxide having sufficiently high purity was obtained with little loss of the phosphine oxide simply by washing the filtrate with water after filtration of the reaction solution.

For the purpose of further purification, this solid was dissolved by adding normal hexane to the solid by 10 times by mass and stirring for 40 minutes, and then the insoluble solid was filtered. Washed with normal hexane.
The insoluble solid weighed about 1.9 g after drying. The obtained filtrate was concentrated to dryness at 60 ° C. and 10 mmHg, and then dried under nitrogen flow.
The drying operation was performed at 80 ° C. for 5 hours. 48.
5 g, an isolated yield of 83.1% and a purity of 99.2%.
% By mass. The chloride ion concentration in this solid was measured by potentiometric titration using a chloride ion electrode.
However, the concentration was 43 ppm.

[Comparative Example 5] The method was carried out in accordance with the method described in GNKoidan et al. Under nitrogen atmosphere, 3
A 00 ml glass reactor was charged with 53.5 g (300 mmol) of iminotris (dimethylamino) phosphorane and 200 ml of dry petroleum ether (the concentration of the phosphorane was 29% by weight). While stirring, keep the internal temperature at 20
A mixture of 7.67 g (50.0 mmol) of phosphorus oxytrichloride and 25 ml of dry petroleum ether (concentration of phosphorus oxytrichloride is 32% by mass) was added dropwise to the mixture over 30 minutes while controlling the temperature at 0 ° C. did.

The molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is 6.0.
At this point, a part of the reaction solution was collected, and almost no desired product was produced. For this reason, the temperature was raised to a temperature at which the reaction liquid was refluxed (about 40 ° C.), and the reaction was continued. The yields after 24 and 48 hours were 59.8% and 73.0%. As described above, in the method described in the literature, the reaction was slow and the yield was low, as is apparent from comparison with Examples 1 to 7.

[Comparative Example 6] A reaction solution obtained by a method according to the method described in the document of GNKoidan et al. (The reaction solution obtained in Comparative Example 5) was purified by a method according to the purification method described in the document. Carried out. The white slurry of petroleum ether obtained in the reaction of Comparative Example 5 was filtered, and the solid was washed twice with 50 ml of petroleum ether. The obtained filtrate was concentrated to dryness at 30 ° C. and 150 mmHg. 21.5 g of a slightly yellowish white solid were obtained, to which 6.0 g of petroleum ether (only 28% by weight based on the solid) was added, which almost dissolved at a temperature of 25 ° C. This solution was filtered, and the filtrate was cooled to precipitate crystals. However, when the temperature was lowered to −10 ° C., only a small amount of precipitate was observed.

After further cooling to -20 ° C., a certain amount of crystals could be finally deposited. This was quickly filtered through a cold filter at −20 ° C.
Wash with about 3 g of petroleum ether cooled to 0 ° C., and 5.89 g
Was obtained as white crystals. Although this crystal was 98.2% by mass of tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide, the yield was only 20.0%, and the chloride ion concentration in the crystal was 640 ppm. It was a high value. Although recrystallization was performed with such a small amount of solvent, extremely low temperature was required for crystallization, and the yield of crystals was low.

Comparative Example 7 The amount of iminotris (dimethylamino) phosphorane used in the method of Comparative Example 5 was 57.9 g.
(325 mmol) and the temperature at which the reaction solution is refluxed (about 40
The reaction was carried out in exactly the same manner as in Comparative Example 5, except that the reaction time was 30 hours, and the purification was carried out at -20 ° C exactly as in Comparative Example 6. The molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is 6.5 (more than stoichiometric). The yield after the reaction is 7
At 5.3%, the reaction rate was clearly improved only by increasing the amount of the phosphorane used, as compared with the result of Comparative Example 5.

After recrystallization, 6.57 g of white crystals were obtained. The crystals had a purity of 94.1% by mass and a yield of 20.7%.
The purity is not sufficient even if a recrystallization operation is performed. In this crystal iminotris (dimethylamino) with unknown impurities
About 2% by mass of phosphorane was observed. The phosphorane used in excess of the stoichiometric amount in the reaction could not be sufficiently removed by this method, and remained in the crystals of the target product precipitated by the recrystallization operation.

Comparative Example 8 The reaction was performed in the same manner as in Comparative Example 5, except that the reaction time at the temperature at which the reaction solution was refluxed (about 40 ° C.) was changed to 40 hours. Carried out.
The yield after the reaction was 70.2%. The resulting white slurry of petroleum ether was filtered and the solid was washed twice with 50 ml of petroleum ether. To the obtained filtrate, water was added in an amount of 0.12 mass times the amount of the filtrate, and the two phases were thoroughly contacted by vigorous shaking to wash. After standing, the petroleum ether phase and the aqueous phase were combined. And separated from each other. This water washing operation was similarly performed twice more.

Analysis of the obtained petroleum ether phase revealed that the target substance, tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide, was hardly contained. Therefore, when the aqueous phase was analyzed, by-products and unreacted iminotris remained in the aqueous phase.
Along with (dimethylamino) phosphorane, 99% by mass of the target substance contained before washing with water was contained.

Example 9 A reaction and washing with water were carried out in the same manner as in Example 8, except that dried toluene was used instead of o-dichlorobenzene in Example 8. The toluene phase obtained after washing with water was concentrated to dryness at 60 ° C. and 50 mmHg. The obtained solid is a target substance having a purity of 93.5% by mass.
Yield was 82.9%.

Example 10 A reaction and washing with water were carried out in the same manner as in Example 8, except that dried 2,4-dichlorotoluene was used instead of o-dichlorobenzene in Example 8. The 2,4-dichlorotoluene phase obtained after washing with water was concentrated to dryness at 90 ° C. and 10 mmHg. The obtained solid was a target substance having a purity of 96.1% by mass, and the yield was 82.4%.

Example 11 Instead of o-dichlorobenzene in Example 8, dried chlorobenzene was used, and the amount of iminotris (dimethylamino) phosphorane used was 112 g (628 mmol). The reaction and water washing were carried out in the same manner as in Example 8, except that the internal temperature was controlled to 60 ° C. or lower and the reaction temperature after completion of the dropwise addition was set to 60 ° C. Iminotris (dimethylamino)
The molar ratio of phosphorane to phosphorus oxytrichloride is 6.
3. The chlorobenzene phase obtained after washing with water is 80
The solution was concentrated to dryness at 60 ° C and 60 mmHg. The resulting solid has a purity of 9
The yield was 67.3% with 4.1% by mass of the target compound.

Example 12 The method of Example 11 was repeated except that the amount of iminotris (dimethylamino) phosphorane used was
Example 11 was carried out in exactly the same manner as in Example 11, except that g (673 mmol) was used. The molar ratio of iminotris (dimethylamino) phosphorane to phosphorus oxytrichloride is 6.7. After washing with water, the solid obtained by concentrating and drying the chlorobenzene phase to dryness was the target compound having a purity of 95.9% by mass, and the yield was 80.7%.
Met.

[Examples 13 and 14] The solid obtained by concentrating and drying the o-dichlorobenzene phase after the reaction and washing with water in exactly the same manner as in Example 8 was treated with normal hexane in the method of Example 8. Was purified in the same manner as in Example 8, except that 15 parts by weight of normal heptane (Example 13) and 2 parts by weight of normal octane (Example 14) were used instead of the solid. The yield of the obtained target product was almost constant at 83%, and the purities were 98.9% by mass and 97.6% by mass, respectively.

Example 15 A reaction was carried out in exactly the same manner as in Example 8, except that the amount of water used in one water washing operation was 0.20 times the mass of the filtrate. And a water wash. The solid obtained by concentrating and drying the o-dichlorobenzene phase after washing with water was a target substance having a purity of 96.5% by mass and a yield of 79.9%.

[0080]

According to the method of the present invention, there is provided a method for producing a phosphine oxide represented by the formula (2) by reacting an iminophosphorane represented by the formula (1) with phosphorus oxytrichloride, The phosphine oxides can be used by a simple purification method, the phosphoranes can be used in a stoichiometric amount or more, and the phosphine oxides can be obtained in high yield and high purity by an industrially more realistic method. .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsuhiko Funaki, 580-32 Nagaura, Sodegaura-shi, Chiba Prefecture Mitsui Chemicals, Inc. Inventor Atsushi Shibahara 580-32 Nagaura, Sodegaura-shi, Chiba Prefecture Mitsui Chemicals, Inc. (72) Inventor Shinji Kiyono 580 32-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Inc. 580 No. ura 32, Mitsui Chemicals, Inc. BE54 WA15 WA27

Claims (11)

[Claims] [Claim 1] The following formula (1) (Wherein R is the same or different hydrocarbon group having 1 to 10 carbon atoms, and two Rs on the same nitrogen atom may be bonded to each other to form a ring structure) By reacting phosphoranes with phosphorus oxytrichloride,
The following formula (2) (Wherein R is the same as R in the formula (1)), when producing a phosphine oxide represented by the formula (1), an aprotic organic solvent having a dielectric constant of not less than 2.2 at 20 ° C. is used as a reaction solvent. A method for producing phosphine oxides, which is used. 2. The method according to claim 1, wherein R in the iminophosphoranes represented by the formula (1) and the phosphine oxides represented by the formula (2) is a methyl group. 3. The aprotic organic solvent has the following formula:
(3) 3. The method according to claim 1, wherein the aminophosphonium chlorides represented by the formula (1) are the same as Rs in the formulas (1) and (2). 4. The organic solvent according to claim 1, wherein the aprotic organic solvent is an organic solvent in which the aminophosphonium chloride represented by the formula (3) is insoluble and is substantially immiscible with water. The manufacturing method as described. 5. The method according to claim 1, wherein the number of moles of the iminophosphoranes represented by the formula (1) is in the range of 6 to 10 per mole of phosphorus oxytrichloride. Manufacturing method. 6. A solution containing at least a phosphine oxide represented by the formula (2) and an organic solvent substantially immiscible with water is washed with water to form a solution of the phosphine oxide, or the solution is concentrated to dryness. And obtaining the phosphine oxides as a solid. 7. The method according to claim 6, wherein R in the phosphine oxides represented by the formula (2) is a methyl group. 8. The organic solvent that is substantially immiscible with water is an aprotic organic solvent having a dielectric constant at 20 ° C. of 2.2 or more, and the aminophosphonium chloride represented by the formula (3) is The purification method according to claim 6 or 7, wherein the purification method is an insoluble organic solvent. 9. A solution containing at least the phosphine oxide represented by the formula (2) and an organic solvent which is substantially immiscible with water comprises the iminophosphoranes represented by the formula (1) and phosphorus oxytrichloride. An aprotic organic solvent having a dielectric constant at 20 ° C. of 2.2 or more and substantially immiscible with water, and an organic solvent in which the aminophosphonium chloride represented by the formula (3) is insoluble, 8. The purification method according to claim 6, wherein the phosphonium chlorides are removed by a solid-liquid separation from a reaction solution containing the phosphonium chlorides and the solids formed simultaneously with the phosphine oxides. . 10. The purification method according to claim 9, wherein the number of moles of the iminophosphoranes represented by the formula (1) is in the range of 6 to 10 per mole of phosphorus oxytrichloride. 11. The solution of the phosphine oxide represented by the formula (2) obtained by washing with water is concentrated to dryness,
After adding a hydrocarbon to the obtained dry solid, the insoluble remaining solid is removed by solid-liquid separation to obtain the phosphine oxide as a solution of the phosphine oxide or by concentrating the solution to dryness to obtain the phosphine oxide as a solid. The purification method according to any one of claims 6 to 10, which is characterized in that: