JPS63297390A - Production of phosphonitrilic acid ester - Google Patents

Abstract

PURPOSE:To obtain the titled compound which is used as an intermediate of heat-resistant materials, with industrial advantage, by allowing phosphonitrile oligomers to react with a specific N-(hydroxyphenylmaleimide) in the presence of a pyridine derivative and a base. CONSTITUTION:1mol. of phosphonitrile chloride oligomer of formula I (n is an integer of 3 or more) is allowed to react with 1 or more moles of N-(hydroxyphenyl)maleimide of formula II (R is halogen, lower alkyl, lower alkoxy) and O or higher mole of a hydroxyl compound of the formula: HO-Y (Y is halogen, lower alkyl, aryl) in an arbitrary order, in the presence of a pyridine derivative of formula III (Q<1>, Q<2> are lower alkyl, form pyrolidine ring together with an N atom), and an inorganic or a tertiary amine to give the subject compound of formula IV (X is Cacute angle, OY; p is integer of 1-2n; q is integer of 0-2n-1; p+q=2n).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a new method for producing phosphonitrile esters and intermediates thereof, which are raw materials for polymers with excellent heat resistance and flame retardancy.

"Prior art" Phosphonitrile chloride oligomers having a cyclic or linear structure (where n in the formula is an integer of 3 or more), especially n
Cyclic phosphonitrile chloride oligomers having 3 or 4, or phosphonitrile floras containing them as main components
Phosphonitrile esters obtained by reacting an ideoligomer mixture with a hydroxyl compound, or polymers obtained by polymerizing them, have excellent heat resistance, cold resistance, lubricity, electrical insulation, and chemical properties. Due to its stability, it is widely used as a variety of industrial materials.

Among these phosphonitrile esters, hexakis (4-maleimidophenoxy) represented by the formula (A in formula 1 represents)
Cyclotriphosphazene, or tris-(4-maleimidophenoxy)- represented by the formula % (T in the formula represents)
The polymer obtained by thermally polymerizing trisphenoxycyclotriphosphazene (trisphenoxycyclotriphosphazene) has excellent heat resistance and flame retardancy, and the carbon mis laminated with this polymer does not burn at all even when heated to 300°C in oxygen gas. It is said that it does not.

These compounds are described in U.S. Pat. No. 4,550,177 or in the Journal of Polymer Science.
ce): Polymer chemical version (Po17mer Chemis)
try Edition) Volume 22, pages 827-9
43 (11184), etc., and according to these documents, compound CI) is produced according to the following formula.

0 sentences C1 Edge 2 EOOE (However, E in formula 1 is ) (However, G in the formula is ) (However, L in the formula.

δ ) One number (However, M in the formula.

In addition, compound (n) is produced by the same process except that the amount of the nitrophenoxy group bonded in the first reaction of the above formula is replaced by a phenoxy group.

That is, the methods described in these documents involve a reaction between a cyclic phosphonitrile chloride trimer (hereinafter abbreviated as r3PNcJ) and 4-nitrophenolate, or a reaction between 4-nitrophenolate and phenolate;
It is a very complicated process that involves many steps: hydrogen reduction of the nitro group under pressure, maleamidation of the generated amino group, and generation of the target product by dehydration and ring opening, and the final yield is also low. This is an economically unviable method.

The present inventors previously proposed a phosphonitrile oligomer represented by the formula (wherein n is an integer of 3 or more) in Japanese Patent Application No. 61-201319 as a method for solving the above-mentioned drawbacks. N-(4-hydroxyphenyl)maleimide compound represented by the formula (wherein R is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy, or a lower alkoxy-lower alkyl group) in 1 molar proportion of 1 molar proportion or more of An alkyl group that may have a halogen atom or an alkoxy group, an alkenyl group or an alkyl group that may have a side chain, an aralkyl group that may have a halogen atom, a lower alkyl group, or a lower alkoxy group, or cycloalkyl group.) 0 molar proportion or more of a hydroxy compound represented by
A formula characterized by reacting in any order (however, R and n in the formula are as described above, or are a chlorine atom or a Y〇- group, p is an integer from 1 to 2n, and q is an integer from 0 to 2n-1, and p
+q is 2n. ) proposed a method for producing phosphonitrile esters.

However, this method also has the disadvantage of requiring a long time.

[Method for solving the L problem] As a result of research to improve the method described in the specification of Japanese Patent Application No. 61-201319, the inventors found that the phosphonitrile chloride oligomer or some of its chlorine atoms The reaction between the 70-partially substituted oligomer substituted by the Y〇- group and in which a chlorine atom remains and N-(4-hydroxyphenyl)maleimide is performed using a strong inorganic base or a tertiary
When a class amine is used as a deoxidizing agent, a catalytic amount of the formula (in formula 1, Ql and Q2 are the same or different lower alkyl groups, or together with the nitrogen atom to which they are bonded, a pyrrolidine ring, The present invention was based on the discovery that the reaction proceeds extremely easily due to the presence of a pyridine derivative represented by ), which may constitute a piperidine ring or a morpholine ring, and that the reaction is completed in several hours even at room temperature.

That is, the present invention provides 1 molar proportion of the phosphonitrile chloride oligomer represented by formula 1 (wherein n is an integer of 3 or more),
It is a lower alkoxy group or a lower alkoxy lower alkyl group. 1 molar proportion or more of N-(hydroxyphenyl)maleimides represented by A good aryl group, an alkyl group that may have a side chain and may have a halogen atom or an alkoxy group.

An alkenyl group or alkynyl group that may have a side chain.

It is an aralkyl group or a cycloalkyl group that may have a halogen atom, a lower alkyl group, or a lower alkoxy group. ] in any order with 0 molar proportion or more of a hydroxy compound represented by the formula (wherein R and n in formula 1 are as described above, X is a chlorine atom or a 10Y group, and P is an integer from O to 2n, q is an integer from O to 2n-1, and p+q is 2n. The step of reacting phenyl)maleimides is carried out in a catalytic amount (however, Ql in the formula
and Q2 are the same or different lower alkyl groups,
or they may constitute a pyrrolidine ring, piperidine ring or morpholine ring together with the nitrogen atom to which they are bonded. A method for producing the above-mentioned phosphonitrile esters, characterized by:

(Procedure) Reaction of a phosphonitrile chloride oligomer or an OY partially substituted oligomer in which a portion of its chlorine atoms has been substituted with a 10Y group and a chlorine atom remains, and N-(4-hydroxyphenyl)maleimide. is carried out at room temperature using a pyridine derivative of formula (V) as a catalyst in an inert organic solvent in the presence of a strong Kuroiso base or a tertiary amine as a deoxidizing agent.The zero reaction time is usually a few hours. be.

N-(4) for phosphonitrile chloride oligomer
The amount of -hydroxyphenyl)maleimides used is appropriately adjusted depending on the desired degree of substitution of the maleimidophenoxy substituted product. The appropriate amount to be used for the OY partially substituted oligomer is an equivalent amount to the chlorine atoms remaining in the oligomer, or an amount slightly in excess of the amount.

The reaction between a phosphonitrile chloride oligomer or an oligomer in which some of its chlorine atoms have been substituted with a group and in which chlorine atoms remain, and a hydroxy compound represented by HOY is 1.
Either the two are reacted in an inert organic solvent in the presence of a tertiary amine as a deoxidizing agent, or the hydroxy compound is reacted in the form of a metal phenolate or metal alcoholite. The reaction using a tertiary amine can proceed at room temperature, but is preferably heated at the reflux temperature of the melt for about 3 to 8 hours.

When reacting phenolates or alcoholates, a solution of them dissolved in phenols, alcohols, or inert organic solvents as raw materials is added to a solution of chlorine atom-containing oligomers, and the solution is left at room temperature for about 1 to 5 hours. Then, it is preferable to react for about 0.5 to 2 hours under reflux of the solvent.

Further, the reaction between the salt IIM child-containing oligomer and the hydroxy compound can also proceed in a solvent using an alkali metal carbonate as a deoxidizing agent.

When using a strong inorganic base or a specific tertiary amine as a deoxidizing agent, the pyridine derivative of formula (V) can also act as a catalyst in the reaction between the chlorine atom bonded to the phosphonitrile oligomer and phenols. Since these deoxidizers and catalysts work effectively, it is extremely advantageous to apply these deoxidizers and catalysts to this reaction.

In the synthesis of fully substituted maleimidophenoquine or partially substituted maleimidophenoxy,
In the substitution reaction, after the substitution reaction is completed, the tertiary amine hydrochloride or metal chloride, which is a byproduct of the substitution reaction, is filtered out.
The solvent can be completely distilled off from the filtrate to remove the q-substituted product, and if necessary, the desired product can be purified by performing operations such as washing, neutralization, and recrystallization.

(Phosphonitrile chloride oligomer) The phosphonitrile chloride oligomer used as a raw material in the present invention is a reaction product of phosphorus pentachloride and ammonium chloride, that is, a mixture of various oligomers in the form of Depending on the intended use of the product, this mixture can also be used as is.

Alternatively, the cyclic 3-hydrocarbon (3PNC) purified and isolated from it
) or a cyclic tetramer (4PNC) can be used alone or in an appropriate mixture.

(Maleimide derivative) Examples of N-(hydroxyphenyl) used in the present invention and leimides include N-(4-hydroxyphenyl)
Maleimide, N-(2-methyl-4-hydroxyphenyl)maleimide, N-(2,6-dimethyl-4-hydroxyphenyl)maleimide, N-(3,5-dimethyl-
4-hydroxyphenyl)maleimide, N-(3,6-
dimethyl-4-hydroxyphenyl)maleimide, N-
(2-ethyl-4-hydroxyphenyl)maleimide,
N-(2,6-danityl-4-hydroxyphenyl)maleimide, N-(2-methyl-3-ethyl-4-hydroxyphenyl)maleimide, N-(2-propyl-4-
hydroxyphenyl)maleimide, N-(2-butyl-
4-hydroxyphenyl)maleimide, N-(2-methoxy-4-hydroxyphenyl)maleimide, N-(2
-Methyl-3-methoxy-4-hydroxyphenyl)maleimide, N-(2-ethoxy-3-ethyl-4-hydroxyphenyl)maleimide, N-(2-propoxy-
3-methyl-4-hydroxyphenyl)maleimide, N
-(2-butoxy-6-methyl-4-hydroxyphenyl)maleimide)', N-(2-chloro-4-hydroxyphenyl)maleimide, N-(2,6-dichloro-4-
Examples include, but are not limited to, hydroxyphenyl)maleimide.

(Hydroxy compound) Examples of the hydroxy compound used in the present invention include methanol, ethanol, n-propyl alcohol, I-
Propyl alcohol, 2,2゜2-trifluoroethanol, octafluoropentyl alcohol, allyl alcohol, propargyl alcohol, cyclohexanol, phenol, p-cresol, m-cresol, 0-
□ Sole, p-chlorophenol, m-chlorophenol, O-chlorophenol, p-bromophenol, m-bromophenol, 0-bromophenol, p
Examples include, but are not limited to, -methoxyphenol, m-methoxyphenol, and O-methoxyphenol.

(Tertiary Amine) Examples of the tertiary amine used in the present invention include methyldiethylamine, triethylamine, tripropylamine, tributylamine, N,N-diethylpropylamine, N,N-dimethylbutylamine, N,N- Dimethyloctylamine.

N,N-dimethyldodecylamine, N,N-dimethylstearylamine, N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N-
Dimethylbenzylamine.

N-methylpyrrolidine, N-methylpiperidine, N,N
'Dimethylpiperazine, quinuclidine (formula (X)
This is an example of a tertiary amine corresponding to ), N,N-dimethylaniline, N,N-diethylaniline, N,N-dimethyltoluidine.

Examples include, but are not limited to, pyridine, α-picoline, β-picoline, γ-picoline, 5-ethyl-2-picoline, trimethylpyridine, quinoline, inquinoline, etc. Two or more types of grade amines can also be used in combination.

The amount of these tertiary amines used is determined by the amount of N-(4-
The amount of the hydroxyphenyl)maleimides or/and the hydroxy compound is expected to be at least 1.2 to 2 equivalents, and the use of more than that is meaningless.

In addition, the substitution of the chlorine atom bonded to the nucleus of the phosphonitrile chloride oligomer with a group or OY group is performed after the substitution has proceeded to approximately the number of chlorine atoms originally bonded to the oligomer nucleus, and then the reaction If a tertiary amine hydrochloride is present in the system, the amount of tertiary amine used can be saved by blowing ammonia gas into it.

(S strong base) Examples of strong inorganic bases used in the present invention include:

There are hydroxides of alkali metals and alkaline earth metals, carbonates of alkali metals, etc., and sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium hydroxide, etc. are easily used.

The appropriate amount of these strong inorganic bases to be used is equivalent to or slightly in excess of the active chlorine atom to be converted to M, and it is convenient to use them as an aqueous solution.
It can also be used in solid form, for example in the form of flakes or powder.

(Catalyst) The catalyst represented by formula (V) used in the present invention is 1, for example, 4-dimethylaminopyridine.

4-diethylaminepyridine, 4-pyrrolidinopyridine, 4-piperidinopyridine, etc. are preferred.

The amount of catalyst used is 1720 per mole of active chlorine atom.
The effect appears even with a small amount such as 0 mol, but a rather long reaction time is required for this amount of use.Usually, from about 1/30 mol to about 17 mol per mol of active chlorine atom.
It is suitable to use up to 20 moles, but about 1/10 mole of catalyst can also be used.

(Organic Inert Solvent) Examples of the organic inert solvent used in the present invention include, but are not limited to, benzene, toluene, monochlorobenzene, tetrahydrofuran, and dioxa.

It is convenient for operation to use these organic solvents in a ratio of about 3 to 10 mJL per gram of phosphonitrile chloride used.

[Example] The present invention will be explained in more detail with reference to Examples below.
The invention is not limited only to these examples.

Example 1 7 of a phosphonitrile chloride oligomer mixture consisting of 58.7% 3PNC, 14.5% 4PNC, and 26.3% other phosphonitrile chloride oligomers
．． 0 g (chlorine content therein was 0.12 mol) was dissolved in 50 ml of tetrahydrofuran.

Equipped with a stirrer, thermometer, reflux condenser, and dropping funnel.
22.7 g (0.12 mol) of N-(4-human, roxyphenyl)maleimide, 14.3 g (0.18 mol) of pyridine, and 0.74 g (0.74 mol) of 4-dimethylaminopyridine were placed in a 4-meter flask. , 006 mol) and 200 mJL of tetrahydrofuran, and the tetrahydrofuran solution of the above phosphonitrile chloride oligomer was added dropwise over 30 minutes while stirring. The reaction was an exothermic reaction, and the maximum temperature rose to 55°C, but no cooling operation was performed. After the completion of the reaction, in which the reaction was continued for 5 hours without any further reaction, the pyridine malate, which was a reaction by-product, was filtered off. Approximately 150 m of the solvent was distilled off from the filtrate under reduced pressure, and the resulting concentrated liquid was poured into 200 ml of ice water to precipitate a blackish brown viscous resinous substance. The aqueous layer was removed by decantation, and the remaining resinous material was dissolved by adding 50 mM of tetrahydrofuran.
This solution was again poured into 200 ml of ice water to obtain a brown viscous resinous substance.

When this was dried under reduced pressure, 24.2 g of a brown viscous resinous material was obtained, and as a result of infrared analysis and gel permeation chromatography (hereinafter abbreviated as rGPCl) analysis, this material had a structure represented by the formula It was estimated that the substance had the following properties. Moreover, the content of hydrolyzable chlorine was 0.01% or less.

Example 2 7.Og of 3PNC (chlorine content therein was 0.12 moles) was dissolved in 50 mKL of tetrahydrofuran.

Into a 500 ml 4-70 flask equipped with a stirrer, thermometer, reflux condenser and addition funnel was added 22.7 g (0,12
14.3 g (0,18 mol) of pyridine, 0.73 g (0,006 mol) of 4-dimethylaminepyridine
The 0 reaction in which 200 mJl of tetrahydrofuran and 3PNC were added dropwise over 30 minutes while stirring was an exothermic reaction, and the maximum temperature rose to 45°C, but the reaction was allowed to continue as it was without any cooling. After the completion of the 0 reaction, which was carried out for 7 hours.

Pyridine hydrochloride, a reaction by-product, was filtered off.

150 mjL of solvent was distilled off from the filtrate under reduced pressure, and the resulting concentrated solution was poured into 200 m of ice water to precipitate a blackish brown viscous resinous substance.

The aqueous layer was removed by decantation, 50 ml of tetrahydrofuran was added to dissolve the remaining resinous material, and this solution was again poured into 200 ml of ice water to obtain a light brown powdery substance. When this was dried under reduced pressure, 24.6 g of a light brown powdery substance was obtained, and the melting point of this substance was 259-2.
62.5°C, and by GPC and HPLC analysis,
It was confirmed that it was a single component, and it was also confirmed by infrared analysis that it was 2,2,4,4,6,6-hexakis(maleimidophenoxy)cyclotriphosphazene. That is, this substance is a substance expressed by the formula.

Further, the content of hydrolyzable chlorine was 0.01% or less.

Example 3 11 equipped with a stirrer, thermometer, reflux condenser, and dropping funnel
7°Og of 3PNC (chlorine content in it is 0.12 mol) and 200ml of tetrahydrofuran
M, 74.75 g (O,OS mol) of viridi and 0.37 g (0,003 mol) of 4-dimethylaminopyridine
After charging, a solution of 11.3 g (0.06 mol) of N-(4-hydroxyphenyl)maleimide dissolved in 50 ml of tetrahydrofuran was added dropwise over 30 minutes without stirring.The reaction was an exothermic reaction. The maximum temperature is 55
℃, but the reaction was allowed to continue for 2 hours at room temperature without any special cooling. Next, the reaction solution was filtered to remove pyridine hydrochloride, a reaction by-product. The solvent was distilled off from the liquid to obtain 16.0 g of a brown resinous substance.

As a result of quantitative determination of hydrolyzable chlorine, infrared analysis, and HPLC analysis, it was found that this brownish resinous material was a mixture of maleimidophenoxy partially substituted cyclotriphosphazene whose main component was the substance represented by the formula.

Example 4 3 10.8 g (0,
02 mol, the chlorine content in it is 0.06 mol), N-(
11.4 g (0
,06 mol), 7.15 g (0.09 mol) of pyridine.

0.37 g (0.003 mol) of 4-dimethylaminopyridine and 200 m of tetrahydrofuran were added to a 500 mM
Pour into a Tulo flask and heat to 27°C while stirring the liquid.
Stirring was continued for 5 hours at a temperature of , and then post-treatment was carried out in substantially the same manner as in Example 1 to obtain 18.2 g of a light brown solid.

As a result of infrared analysis, NMR analysis and HPLC analysis, this viscous resinous material was a mixture whose main component was a substance represented by the formula. The hydrolyzable chlorine content of this resinous material was 0.01% or less.

Example 5 7.0 g of 3 PNC (chlorine content therein was 0.12 moles) was dissolved in 50 mjL of monochlorobenzene.

50 equipped with stirrer, thermometer, reflux condenser, and dropping funnel.
In a 0mM 470 flask, 11.4 g (0.06 mol) of N-(4-hydroxyphenyl)maleimide, 5.6 g (0.06 mol) of phenol, 1 of triethylamine were added.
8.2 g (0.18 mol), 4-pyrrolidinopyridine 0
．． 89 g (0,006 mol) and 200 ml of monochlorobenzene were charged, and the above 3PNC was added while stirring.
The 0 reaction in which a monochlorobenzene solution was added dropwise over 20 minutes was an exothermic reaction, and the maximum temperature rose to 35°C, but the reaction was continued for 8 hours without any cooling operation. After the 0 reaction was completed, precipitation occurred. The triethylamine hydrochloride contained in the filtrate was filtered off, and the filtrate was sequentially washed with an aqueous hydrochloric acid solution, an aqueous sodium hydroxide solution, and water, dried by adding sodium chloride anhydride, and then monochlorobenzene was distilled off under reduced pressure. 19.3 g of light brown resinous solid was obtained.

As a result of IR absorption spectrum and HPLC analysis, it was found that this light brown powdery substance was a mixture mainly consisting of . The content of hydrolyzable chlorine was less than 0.01%.

[Effects of the Invention] According to the present invention, the reaction time for producing phosphonitrile ester can be significantly shortened.

Claims (1)

[Claims] Formula ▲ includes mathematical formulas, chemical formulas, tables, etc. ▼ (however, n in the formula is an integer of 3 or more). , tables, etc.▼ (However, R in the formula is a halogen atom, a lower alkyl group,
It is a lower alkoxy group or a lower alkoxy lower alkyl group. ) of N-(hydroxyphenyl)maleimide represented by the formula HO-Y (wherein Y has a halogen atom, a lower alkyl group, a lower alkoxy group, or a lower alkoxy lower alkyl group) an aryl group which may have a side chain, an alkyl group which may have a halogen atom or an alkoxy group, an alkenyl group or alkynyl group which may have a side chain, a halogen atom, a lower alkyl group, or (It is an aralkyl group or a cycloalkyl group that may have a lower alkoxy group.) By reacting in any order with 0 molar proportion or more of a hydroxy compound represented by the formula ▲ ▲ Numerical formula, chemical formula, table, etc. ▼ ( However, R and n in the formula are as described above, X is a chlorine atom or -OY group, p is an integer from 1 to 2n, q is an integer from 0 to 2n-1, and p+q is 2n.) When producing the phosphonitrile esters represented by
There are tables, etc.▼ (However, Q^1 and Q^2 in the formula are the same or different lower alkyl groups, or together with the nitrogen atom to which they are bonded, they constitute a pyrrolidine ring, piperidine ring, or morpholine ring. A method for producing the above-mentioned phosphonitrile esters, which is carried out using a strong inorganic base or a tertiary amine in the presence of a pyridine derivative represented by