JP7460117B2 - Method for producing phosphonic acid ester - Google Patents

Description

The present invention relates to a method for producing a phosphonate ester.

Various resins such as polyolefin resins are used in various industrial products, such as building materials, materials for electrical equipment, vehicle parts, automobile interior parts, and household goods, depending on their characteristics such as mechanical properties, thermal properties, and moldability. It is used for such things. However, these resins generally have the disadvantage of being easily combustible. For this reason, flame retardants are usually added to these resins.

Phosphonate esters have high flame retardancy, so they can be added in relatively small amounts to impart flame retardancy. Therefore, by using them, it is possible to minimize the deterioration of the mechanical properties and thermal properties of the resin. In addition, phosphonate esters have good compatibility with resins, so they do not impair the optical properties of transparent resins, and there is no risk of damaging the appearance due to blooming, etc.

As a method for producing phosphonate esters, Patent Document 1 reports a method in which orthophenylphenols and phosphorus trichloride are subjected to a dehydrochlorination reaction at 120°C or higher in the presence of a super strong acid to obtain 10-chloro-10H-9-oxa-10-phosphaphenanthrene, which is then subjected to an esterification reaction with phenols to increase the oxidation number of phosphorus using an oxidizing agent. However, this method is expensive in view of the complexity of the reaction pathway, the treatment of the hydrogen chloride generated, the reaction time, etc.

The manufacturing method reported in Patent Document 2 is a method that can easily carry out the reaction at room temperature or below, and is a cost-effective method. However, this method requires the use of toxic substances such as carbon tetrachloride and carbon tetrabromide as halogenating agents, and also requires the removal and disposal of toxic by-products such as chloroform and bromoform.

Japanese Patent Application Publication No. 2007-223934 JP 2009-108089 A

The present invention aims to provide a method for producing phosphonate esters in which the toxicity of the materials used and by-products is lower. Preferably, the present invention also aims to provide a method for producing phosphonate esters in which the removal of by-products is easier.

As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by a method including a step of reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a trihalogenoisocyanurate, and a step of reacting the product obtained in the step with a hydroxyl group-containing compound in the presence of an organic amine. Based on this finding, the present inventors have conducted further research and have completed the present invention. That is, the present invention encompasses the following aspects.

Item 1. General formula (I):

[In the formula: n is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group. ]
A method for producing a phosphonic acid ester represented by
(a) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is reacted with trihalogenoisocyanurate to form the general formula (II):

[In the formula: X represents a halogen atom. ]
and (b) the compound represented by the general formula (II) and the general formula (III):

[In the formula, m is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
and reacting a compound represented by the formula (I) with a compound represented by the formula (I) in the presence of an organic amine.

Item 2. The method according to item 1, wherein the amount of the organic amine used is 4 moles or more per mole of the trihalogenoisocyanurate.

Item 3. The method according to item 1 or 2, wherein the amount of the organic amine used is 4 to 8 moles per mole of the trihalogenoisocyanurate.

Item 4. Item 4. The production method according to any one of Items 1 to 3, wherein the organic amine is a trialkylamine.

Item 5. The method according to any one of items 1 to 4, wherein the organic amine is triethylamine.

Item 6. Item 6. The production method according to any one of Items 1 to 5, wherein the trihalogenoisocyanurate is trichloroisocyanurate.

Section 7. General formula (I):

[In the formula, n is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
A method for producing a phosphonic acid ester represented by the following formula:
(b') reacting a reaction mixture of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a trihalogenoisocyanurate with a compound represented by the general formula (III):

[In the formula, m is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
and reacting a compound represented by the formula (I) with an organic amine in the presence of the compound represented by the formula (I).

According to the present invention, it is possible to provide a method for producing a phosphonic acid ester in which the materials used and by-products have lower toxicity. Furthermore, according to the present invention, it is also possible to provide a method for producing a phosphonic acid ester in which by-products can be more easily removed.

In this specification, the expressions "contain" and "include" include the concepts of "contain," "include," "consist essentially of," and "consist only of."

In one embodiment, the present invention provides a method for producing a phosphonic acid ester represented by general formula (I), comprising: (a) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; a step of reacting with trihalogenoisocyanurate to obtain a compound represented by general formula (II), and (b) a compound represented by general formula (II) and a compound represented by general formula (III). It relates to a manufacturing method (herein sometimes referred to as "manufacturing method of the present invention"), which includes a step of reacting with the organic amine in the presence of an organic amine. This will be explained below.

The compound to be produced in the production method of the present invention has the general formula (I):

[In the formula, n is 1 or 2. R represents an optionally substituted hydrocarbon group.]
It is a phosphonic acid ester represented by the formula:

From the viewpoint of the heat resistance of the phosphonate ester, n is preferably 2.

The hydrocarbon group represented by ^R1 is not particularly limited and may be either chain (straight-chain or branched) or cyclic (monocyclic, condensed polycyclic, bridged or spirocyclic). For example, a cyclic hydrocarbon group having a side chain may be mentioned. The hydrocarbon group may be either saturated or unsaturated.

The hydrocarbon group represented by ^R1 may be substituted. For example, a hydrogen atom of the hydrocarbon group represented by ^R1 may be substituted with a hydrocarbon group such as an alkyl group, a cycloalkyl group, an allyl group, an aryl group, an alkylaryl group, or an arylalkyl group. For example, _-CH2- of the hydrocarbon group represented by ^R1 may be substituted with a functional group such as a sulfonyl group. In addition, a main chain constituent atom or a ring constituent atom of the hydrocarbon group represented by ^R1 may be substituted with a heteroatom. The number of substitutions is not particularly limited, and may be, for example, 0 to 6, 0 to 3, or 0 to 1.

The number of carbon atoms in ^R1 is not particularly limited, but is, for example, 1 to 18. When R1 has a substituent, the number of carbon atoms includes the number of carbon atoms in the substituent.

The hydrocarbon group represented by ^R1 is a monovalent group when n is 1. In this case, the phosphonate ester represented by general formula (I) is a phosphonate ester represented by general formula (IA):

It is a phosphonic acid ester represented by

When n is 2, the hydrocarbon group represented by R ¹ is a divalent group. In this case, the phosphonic acid ester represented by the general formula (I) has the general formula (IB):

It is a phosphonic acid ester represented by

The optionally substituted hydrocarbon group represented by R ¹ is, for example, an alkyl group or an alkylene group (these are collectively referred to as an alkyl/lene group). The same applies to other groups hereinafter. ), ary(l/lene) group, cycloalkyl(l/lene) group, heteroalkyl(l/lene) group, heteroary(l/lene) group or heterocycloalkyl(l/lene) group, in which the substituent is Indicates what may be included.

The alkyl(ylene) group may be either a linear or branched alkyl(ylene) group. Specific examples include, for example, a methylene group, an ethylene group, a propylene group, an isopropyl group, a butylene group, an isobutyl group, a pentylene group, an isopentylene group, a neopentylene group, a hexylene group, a heptyllene group, an octylene group, a nonylene group, and a decilene group. That is, in the present invention, an unsubstituted alkyl(ylene) group can be suitably used. The number of carbon atoms in these alkyl(ylene) groups is preferably about 1 to 12, and more preferably 2 to 6.

The aryl(ylene) group may be any of cyclic groups (monocyclic, condensed polycyclic, bridged, and spiro) which may have a substituent. Examples include monocyclic, bicyclic, and tricyclic aryl(ylene) groups such as phenyl(ylene), pentalenyl(ylene), indenyl(ylene), naphthalenyl(ylene), azulenyl(ylene), phenalenyl(ylene), and biphenylenyl groups, and alkylaryl(ylene) groups such as propyldiphenylenyl. R ¹ is preferably an aryl(ylene) group having 6 to 18 carbon atoms, such as a phenyl(ylene), propyldiphenylenyl, and naphthyl(ylene). In the present invention, a phenyl(ylene) group is more preferred.

The cycloalkyl(ylene) group may be any of cyclic groups (monocyclic, condensed polycyclic, bridged, and spiro hydrides) which may have a substituent. Examples include a cyclopropyl(ylene) group, a cyclobutyl(ylene) group, a cyclopentyl(ylene) group, a cyclohexyl(ylene) group, a cycloheptyl(ylene) group, and a cyclooctyl(ylene) group. ^R1 is preferably a cycloalkyl(ylene) group having 3 to 8 carbon atoms.

As a heteroalkyl(ru/lene) group, at least one of the carbon atoms constituting the alkyl(ru/lene) group is replaced by a heteroatom (particularly at least one of an oxygen atom, a nitrogen atom, and a sulfur atom). Examples include groups. Most preferably, R ¹ is a heteroalkyl(ru/lene) group having 1 to 12 carbon atoms in which the hetero atom is replaced with an oxygen atom. More specifically, 3-oxapenty (ru/ren), 3,6-dioxaoctyl (ru/ren), 3,6,9-trioxaundecyl (ru/ren), 1,4-dimethyl-3- Oxa-1,5-pentyl(ru/lene), 1,4,7-trimethyl-3,6-dioxa-1,8-octyl(ru/lene), 1,4,7,10-tetramethyl-3 , 6,9-trioxa-1,11-undecyl(ru/ren) and the like. In this heterocycloalkyl(ru/ren) group, at least one of the carbon atoms constituting the cycloalkyl(ru/lene) group is replaced by a heteroatom (particularly at least one of an oxygen atom, a nitrogen atom, and a sulfur atom). The following groups are mentioned. R ¹ is preferably a 5-membered or 6-membered cyclic heteroary(le/lene) group. More specifically, a piperidinediyl group, a pyrrolidinediyl group, a piperazidiyl group, an oxetanediyl group, a tetrahydrofurandiyl group, etc. are preferable.

Examples of the heteroaryl(aryl) group include a group in which at least one of the carbon atoms constituting the aryl(aryl) group is replaced with a heteroatom (particularly at least one of an oxygen atom, a nitrogen atom, and a sulfur atom). ^R1 is preferably a 5- or 6-membered cyclic heteroaryl group. More specifically, furandiyl group, pyrrolidinediyl group, pyridinediyl group, pyrimidinediyl group, quinolidinediyl group, isoquinolinediyl group, and the like are more preferred.

Specific examples of phosphonate esters represented by general formula (IA) include compounds represented by the following formulas (1) to (8).

Specific examples of the phosphonic acid ester represented by the general formula (IB) include compounds represented by the following formulas (9) to (18).

The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide used in step (a) has the formula (IV):

It is a compound represented by:

The trihalogenoisocyanurate used in step (a) has the general formula (V):

[In the formula, X ¹ , X ² and X ³ are the same or different and each represents a halogen atom.]
The trihalogenoisocyanurate may be a single type, or a combination of two or more types.

The halogen atom represented by X ¹ , X ² and X ³ is not particularly limited, and examples thereof include a chlorine atom and a bromine atom.

As the trihalogenoisocyanurate, a compound (trichloroisocyanurate) in which ^X1 , ^X2 and ^X3 in general formula (V) are all chlorine atoms is particularly preferred from the viewpoints of handleability, economic efficiency, etc. Trichloroisocyanurate is readily available as a disinfectant/bactericide for swimming pools, for example, sold as "Star Trichloron PG (granular available chlorine 90%)" by Nankai Chemical Co., Ltd. and "Neochlor 90W (granular available chlorine 90%)" by Shikoku Kasei Co., Ltd.

From the viewpoints of yield, ease of synthesis, etc., the amount of trihalogenoisocyanurate used is usually 0.1 to 1 mole, preferably 0.2 to 0.6 moles, and particularly preferably 0.3 to 0.4 moles per mole of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

The reaction in step (a) can be carried out in the presence of a solvent, if necessary. Examples of solvents include common aprotic organic solvents such as hydrocarbon solvents such as benzene, toluene, xylene, and n-hexane; ether solvents such as tetrahydrofuran and dioxane; and ester solvents such as ethyl acetate and butyl acetate. Solvents can be used. Among these, hydrocarbon solvents are preferred, and toluene is particularly preferred. A single solvent may be used, or a plurality of solvents may be used in combination.

The reaction temperature in step (a) is preferably 50° C. or lower from the viewpoint of reaction yield, purity, etc. The reaction temperature is preferably 0-40°C, more preferably 0-20°C (especially after all the trihalogenoisocyanurate has been added).

In a preferred embodiment of the present invention, it is preferable to intermittently add trihalogenoisocyanurate to a liquid containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and a solvent. By adjusting the amount added each time, the liquid temperature can be easily controlled within the above range.

The reaction time in step (a) is not particularly limited and is, for example, 10 minutes to 8 hours, preferably 30 minutes to 4 hours.

By step (a), a compound of the general formula (II):

[In the formula, X represents a halogen atom.]
A compound represented by the formula:

The halogen atom represented by X is determined according to the halogen atom in the trihalogenoisocyanurate used in step (a). When trichloroisocyanurate is used, X is a chlorine atom.

The trihalogenoisocyanurate used in step (a) and the cyanuric acid produced as a by-product in step (a) are substances with relatively low toxicity, and therefore, according to the invention, the materials used and the by-products It is possible to provide a method for producing a phosphonic acid ester with lower toxicity.

The progress of the reaction in step (a) can be monitored by conventional methods such as chromatography. Furthermore, the structure of the product can be identified by elemental analysis, MS (ESI-MS) analysis, IR analysis, ¹ H-NMR, ¹³ C-NMR, etc. After the reaction in step (a) is completed, the solvent is distilled off, and the product can be isolated and purified by a conventional method such as chromatography or recrystallization. can be directly subjected to step (b) without isolation and purification. From this point of view, the present invention provides that, in place of step (a) and step (b), (b') 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trihalogenoisocyanurate are used. It also relates to a production method comprising a step of reacting a reaction mixture of the above with a compound represented by general formula (III) in the presence of an organic amine. Step (b') will be explained below together with step (b).

In steps (b) and (b'), a compound of general formula (III):

[In the formula, m is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
The compound represented by the general formula (III) may be used alone or in combination of two or more kinds.

When m is 1, a phosphonate ester in which n is 1 in the general formula (I) is obtained. When m is 2, a phosphonate ester in which n is 2 in the general formula (I) is obtained.

^R1 is as defined above.

From the viewpoint of yield, ease of synthesis, etc., the amount of the compound represented by general formula (III) to be used is determined based on 1 mole of the compound represented by general formula (II). The amount is usually 0.2 to 3 mol, preferably 0.5 to 2 mol, particularly preferably 0.8 to 1.2 mol, in terms of hydroxyl group in the compound.

The organic amine used in steps (b) and (b') is not particularly limited, but examples thereof include tertiary amines such as trimethylamine (TMA), triethylamine (TEA), tripropylamine (TPA), tributylamine (TBA), pyridine, N,N-dimethylaniline, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene, and 4-dimethylaminopyridine. Among these, preferred are trialkylamines such as TMA, TEA, TPA, and TBA, and from the viewpoints of ease of use, cost, and the like, particularly preferred is triethylamine. The organic amine may be one type alone or two or more types in combination.

Cyanuric acid, which is a by-product of step (a), is not necessary for general organic solvents and water, and is therefore difficult to remove from the reaction system. By using an organic amine, it is possible to convert part or all of the cyanuric acid into a water-soluble salt. The water-soluble salt can be easily removed by a water washing step. The organic amine can also be easily recovered by acid-base extraction. Therefore, according to the present invention, it is possible to provide a method for producing a phosphonic acid ester that makes it easier to remove the by-products.

The amount of organic amine used is, for example, 3 moles or more per mole of trihalogenoisocyanurate from the viewpoint of yield, ease of synthesis, etc. The amount used is more preferably 4 mol, from the viewpoint of converting more cyanuric acid (preferably almost all of the cyanuric acid) into water-soluble salts and making removal of by-products easier. The amount is more preferably 5 mol or more. Taking cost into consideration, the amount used is preferably 4 to 20 mol, more preferably 4 to 10 mol, even more preferably 4 to 8 mol, particularly preferably 4 to 6 mol.

The reactions in steps (b) and (b') can be carried out in the presence of a solvent, if necessary. Examples of the solvent that can be used include general aprotic organic solvents, such as hydrocarbon solvents, such as benzene, toluene, xylene, and n-hexane; ether solvents, such as tetrahydrofuran and dioxane; and ester solvents, such as ethyl acetate and butyl acetate. Among these, preferred are hydrocarbon solvents, and particularly preferred is toluene. The solvents may be used alone or in combination.

The reaction temperature in steps (b) and (b') is preferably 50°C or less from the viewpoints of reaction yield, purity, etc. The reaction temperature is preferably 0 to 40°C.

In a preferred embodiment of the present invention, an organic amine is added intermittently or continuously dropwise to a liquid containing a compound represented by general formula (II), a compound represented by general formula (III), and a solvent. is preferred. By adjusting the amount added per time or the dropping rate, the liquid temperature can be easily kept within the above range.

The reaction time of steps (b) and (b') is not particularly limited, and is, for example, 10 minutes to 8 hours, preferably 30 minutes to 4 hours.

Through step (b) or (b'), a phosphonic acid ester represented by general formula (I), which is the target compound for production, is produced.

The progress of the reactions in steps (b) and (b') can be followed by a conventional method such as chromatography. The structure of the product can be identified by elemental analysis, MS (ESI-MS) analysis, IR analysis, ¹ H-NMR, ¹³ C-NMR, etc. In the production method of the present invention, preferably, after the reactions in steps (b) and (b') are completed, the salt of the organic amine and the cyanurate can be easily removed by washing with water or an aqueous solution. Thereafter, a phosphonic acid ester with high purity (for example, a purity of 90% or more, preferably a purity of 95% or more, more preferably a purity of 98% or more) can be easily obtained by appropriate methods such as distillation of the solvent and recrystallization.

The resulting phosphonate ester can be suitably used as a flame retardant for resins, etc.

The present invention will be described in detail below based on Examples, but the present invention is not limited to these Examples.

(1) Identification and Purity Measurement of Phosphonic Acid Esters The phosphonic acid esters synthesized in the following Examples and Comparative Examples were identified and purified by the following method.

(1-1) Purity Purity was confirmed using photodiode array (PDA) liquid high performance chromatography with three-dimensional UV detector (Alliance HPLC system: manufactured by Waters).

(1-2) Elemental analysis Carbon and hydrogen are analyzed using an elemental analyzer (EA1110: manufactured by CE Instruments), and after wet decomposition using a microwave sample decomposition device (ETHOS1: manufactured by Milestone General), a high-frequency coupled plasma emission analyzer is used. (ICP-OES, 720ES: manufactured by Varian), elemental analysis of each compound was performed for phosphorus.

(1-3) LC/ms (ESI)
The molecular weight of each compound was measured by high performance liquid chromatography with a mass spectrometer (LC/ms, ACQUITY UPLC (ESI): manufactured by Waters).

(1-4) NMR
Hydrogen nuclear magnetic resonance ( ¹ H-NMR, 300MHz) spectrum and phosphorus nuclear magnetic resonance ( ³¹ P-NMR, 109MHz) were measured using a nuclear magnetic resonance absorption analyzer (JNM-AL300: manufactured by JEOL Ltd.), and the structure was analyzed. I did it.

(2) Production of phosphonate esters
(2-1) Example 1
9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (68.4g, 0.316mol) and 300ml of toluene were added to a four-neck flask equipped with a stirrer, a dropping funnel with a side tube, and a thermometer, and the mixture was stirred and cooled to below 20°C under a nitrogen atmosphere. Trichloroisocyanurate (TCCA) (24.5g, 0.105mol) was added intermittently 10 times to proceed with chlorination. When TCCA was added, the temperature inside the flask rose rapidly, and the progress of the reaction was confirmed. TCCA was added appropriately so that the temperature inside the flask was always below 40°C. After addition, the mixture was stirred for another hour at below 20°C to complete the reaction. Phenol (30.4g, 0.323mol) was then added, and triethylamine (TEA) (56.2g, 0.555mol [molar ratio TEA:TCCA=5.27:1]) was added dropwise from a dropping funnel with a side tube at such a rate that the temperature inside the flask was always below 40°C. After the addition was completed, the mixture was stirred for 1 hour to complete the reaction. The reaction solution was washed with tap water, and then washed with a 1% aqueous phosphoric acid solution and saturated saline. The reaction solution was concentrated under reduced pressure using an evaporator to obtain a crude product as a slightly yellow solid. The crude product was then recrystallized with methanol-water to obtain a compound represented by the following formula (A) as a white crystalline powder (88.8g, 0.288mol, yield 91%).

The purity of the obtained compound was 99.3%.
^1H -NMR ( _CDCl3 ): δ/ppm 7.02-7.12 (m, 3H), 7.18-7.29 (m, 4H), 7.33-7.37 (m, 1H), 7.46-7.51 (m, 1H), 7.67-7.73 (m, 1H), 7.91-8.03 (m, 3H)
- LC/ms (ESI, positive): [M+H]< ₊ ^> ; m/z = 309 (calculated for _C18H13O3P = _308.27 ).

(2-2) Example 2
The reaction was carried out in the same manner as in Example 1, except that phenol was replaced with 4-t-butylphenol (48.5 g, 0.323 mol). A compound represented by the following formula (B) (101.5 g, 0.279 mol, yield 88%) was obtained as a white crystalline powder.

The purity of the obtained compound was 99.5%.
・^1H -NMR (CDCl ₃ ): δ/ppm 1.24 (s, 9H), 6.94-6.99 (m, 2H), 7.22-7.43 (m, 5H), 7.50-7.56 (m, 1H), 7.72-7.79 (m, 1H), 7.94-8.07 (m, 3H)
・LC/ms (ESI, positive): [M+H] ⁺ ; m/z = 365 (calculated value C ₂₂ H ₂₁ O ₃ P = 364.37).

(2-3) Example 3
The reaction was carried out in the same manner as in Example 1, except that hydroquinone (17.1 g, 0.157 mol) was used instead of phenol. After dropping TEA, the reaction solution was washed with water, and a crude product insoluble in water and organic solvents was obtained. After filtration, the product was recrystallized with methyl ethyl ketone (MEK) to form a white crystalline powder with the following formula (C). A compound represented by (70.9 g, 0.132 mol, yield 84%) was obtained.

The purity of the obtained compound was 99.5%.
・^1H -NMR (CDCl ₃ ): δ/ppm 6.92-8.02 (m, 20H)
・^31P -NMR (CDCl ₃ ): δ/ppm 7.15
- Elemental analysis C66.88, H3.80, P11.40 (theoretical value C ₃₀ H ₂₀ O ₆ P ₂ = C66.92, H3.74, P11.51).

(2-4) Example 4
The reaction was carried out in the same manner as in Example 3, except that resorcinol (17.1 g, 0.157 mol) was used instead of hydroquinone. A compound represented by the following formula (D) (68.8 g, 0.128 mol, yield 82%) was obtained as a white crystalline powder.

The purity of the obtained compound was 99.8%.
^1H -NMR ( _CDCl3 ): δ/ppm 6.78-8.03 (m, 20H)
・^31P -NMR( _CDCl3 ): δ/ppm 7.02
-Elemental analysis _: C66.90, H3.98, P11.42 (theoretical value _{: C30H20O6P2 = C66.92} , H3.74, P11.51).

(2-5) Example 5
The reaction was carried out in the same manner as in Example 3, except that ethylene glycol (9.6 g, 0.155 mol) was used instead of hydroquinone. A compound represented by the following formula (E) (63.4 g, 0.129 mol, yield 83%) was obtained as a white crystalline powder.

The purity of the obtained compound was 98.8%.
^1H -NMR ( _CDCl3 ): δ/ppm 4.03-4.19 (m, 4H), 7.09-7.96 (m, 16H)
・^31P -NMR( _CDCl3 ): δ/ppm 1.11
-Elemental analysis _: C63.63, H4.00, P12.75 ₍ theoretical value _{C26H20O6P2 =} C63.68, H4.11, P12.63).

(2-6) Example 6
The reaction was carried out in the same manner as in Example 3, except that the hydroquinone was replaced with neopentyl glycol (16.1 g, 0.155 mol). A compound represented by the following formula (F) (33.0 g, 0.062 mol, yield 40%) was obtained as a white crystalline powder.

The purity of the obtained compound was 98.8%.
・^1H -NMR (CDCl ₃ ): δ/ppm 0.49, 0.56 (s, 3H), 1.08 (s, 3H), 3.22-3.48, 3.56-3.63, 3.78-3.91 (m, 4H), 6.81-7.93 ( m, 16H)
・^31P -NMR (CDCl ₃ ): δ/ppm 6.01, 6.24, 11.51, 12.09
- Elemental analysis C65.44, H5.10, P11.58 (theoretical value C ₂₉ H ₂₆ O ₆ P ₂ = C65.42, H4.92, P11.63).

(2-7) Example 7
The reaction was carried out in the same manner as in Example 1, except that the amount of TEA was changed to 36.3 g, 0.359 mol [molar ratio TEA:TCCA = 3.40:1]. When washing with water, precipitation of insoluble matter (isocyanuric acid) was observed in the water layer even when water was added. However, it is considered that 3.00 molar equivalents of TEA out of the 3.40 molar equivalents of TEA used was neutralized by the generated hydrogen chloride, and the remaining 0.40 molar equivalents of TEA dissolved the precipitated cyanuric acid. For this reason, it is considered that the amount of cyanuric acid precipitated in this example was less than when TEA was not used. After filtering the reaction solution, it was washed with a 1% phosphoric acid aqueous solution and saturated saline. However, a white crystalline powder of the compound represented by formula (A) (86.6 g, 0.281 mol, yield 89%) was obtained. The purity of the obtained compound was 99.2%.

(2-8) Comparative example 1
In a stirrer-equipped four-necked flask equipped with a dropping funnel with a side tube and a thermometer, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (68.4 g, 0.316 mol), phenol (30.4 g, 0.323 mol), triethylamine (36.3 g, 0.359 mol), and 320 ml of dichloromethane were added, and the flask was stirred and cooled to below 10° C. under a nitrogen atmosphere. Carbon tetrachloride (65.0 g, 0.423 mol) was added dropwise from a dropping funnel with a side tube at a rate such that the internal temperature of the flask was always below 15°C. After the dropwise addition was completed, the mixture was stirred for 1 hour to complete the reaction. The reaction solution was washed with 2% aqueous sodium hydroxide solution and saturated brine. The reaction solution was concentrated under reduced pressure using an evaporator to obtain a pale yellow solid crude product, which was recrystallized from methanol-water to obtain the compound represented by formula (A) as a white crystalline powder (86.5 g, 0.281 mol, yield 89%). The solution distilled off by the evaporator was a mixed solution of chloroform and dichloromethane containing a small amount of carbon tetrachloride, and had to be treated as specified hazardous industrial waste. The purity of the obtained compound was 98.8%.

Claims (7)

General formula (I):

[In the formula, n is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
A method for producing a phosphonic acid ester represented by the following formula:
(a) reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a trihalogenoisocyanurate to obtain a compound of the general formula (II):

[In the formula, X represents a halogen atom.]
(b) reacting the compound represented by general formula (II) with the compound represented by general formula (III):

[In the formula, m is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group.]
in the presence of an organic amine ; and
The production method , wherein the amount of the organic amine used is 4 moles or more per mole of the trihalogenoisocyanurate . 2. The method according to claim 1, wherein the amount of the organic amine used is 4 to 20 moles per mole of the trihalogenoisocyanurate. The manufacturing method according to claim 1 or 2, wherein the amount of the organic amine used is 4 to 8 mol per 1 mol of the trihalogenoisocyanurate. The method according to any one of claims 1 to 3, wherein the organic amine is a trialkylamine. The method according to any one of claims 1 to 4, wherein the organic amine is triethylamine. The manufacturing method according to any one of claims 1 to 5, wherein the trihalogenoisocyanurate is trichloroisocyanurate. General formula (I):

[In the formula: n is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group. ]
A method for producing a phosphonic acid ester represented by
(b') The reaction mixture of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trihalogenoisocyanurate is combined with the general formula (III):

[In the formula: m is 1 or 2. R ¹ represents an optionally substituted hydrocarbon group. ]
A step of reacting the compound represented by the formula in the presence of an organic amine, and
A manufacturing method , wherein the amount of the organic amine used is 4 mol or more per 1 mol of the trihalogenoisocyanurate .