JP2019218288A - Method for producing cyclic aryloxyphosphazene - Google Patents

Abstract

To provide a method for producing a cyclic aryloxyphosphazene in a short time and in high yield under a mild condition by a simple operation.SOLUTION: Provided is a method for producing a cyclic aryloxyphosphazene represented by Formula (2), comprising reacting hexachlorocyclotriphosphazene with an aryl alcohol in a nitrile only or an organic solvent mixed with 40 vol.% or more and less than 100 vol.% of a nitrile in the presence of a pellet-like material of al least one hydroxide selected from the group consisting of potassium hydroxide and sodium hydroxide. [Ar is a substituted or unsubstituted aryl group.]SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a cyclic aryloxyphosphazene.

  It is known that cyclic phenoxyphosphazene is synthesized by a reaction between hexachlorocyclotriphosphazene represented by the following formula (1) and phenoxide. Usually, a method is used in which phenoxide is prepared in advance by a reaction between phenol and a base, and hexachlorocyclotriphosphazene is heated in a halogen-based organic solvent such as chlorobenzene or tetrachloroethane.

  Patent Document 1 discloses that sodium phenoxide is prepared by adding a 48% aqueous sodium hydroxide solution dropwise to a phenol monochlorobenzene solution under heating conditions and reacting while azeotropically removing water generated in the system. It is described that cyclic phenoxyphosphazene was obtained by adding hexachlorocyclotriphosphazene and reacting at 133 ° C. for 6 hours. Non-Patent Document 1 describes that phenol was reacted with sodium hydride to prepare sodium phenoxide, and then hexachlorocyclotriphosphazene was added and reacted under heating and refluxing for 48 hours. Further, in Patent Document 2, sodium phenoxide is prepared by reacting phenol and sodium hydroxide in toluene, and after distilling off the solvent and evaporating to dryness, acetonitrile and hexachlorocyclotriphosphazene are added and the mixture is heated to reflux. This describes that cyclic phenoxyphosphazene was obtained.

  Non-Patent Document 2 describes that cyclic phenoxyphosphazene was obtained by reacting hexachlorocyclotriphosphazene and phenol in THF in the presence of cesium carbonate for 24 hours, instead of preparing phenoxide in advance. .

  On the other hand, Non-Patent Document 3 discloses that cyclic phenoxyphosphazene was obtained by irradiating hexachlorocyclotriphosphazene and phenol with microwaves in acetonitrile in the presence of sodium hydroxide. Patent Document 3 discloses that by mixing hexachlorocyclotriphosphazene, phenol, potassium hydroxide, water, toluene, and polyethylene glycol sequentially, maintaining the mixture at 20 to 30 ° C. for 5 hours, and then reacting at 80 to 90 ° C. for 5 hours. To obtain cyclic phenoxyphosphazenes.

  However, in the above method, it is necessary to perform a reaction at a high temperature for a long time, the reagent is expensive, or a device for irradiating a microwave may be required. It has been desired to obtain cyclic phenoxyphosphazenes in high yield.

JP 2000-198793 A Chinese Patent Application Publication No. 103435654 Chinese Patent Application Publication No. 10195455

P. Schrogel et al., Chem. Mater., 2011, 23, 4947-4953 C. Padie et al., Russ. J. Gen. Chem., 2008, 78, 11, 2257-2264 Chengfeng Ye et al., Org. Prep. Proced. Int. 2001, 376-379

  The present invention has been made in order to solve the above problems, and has as its object to provide a method for producing a cyclic aryloxyphosphazene in a short time with a simple operation under mild conditions in a high yield. is there.

The above issues are
[1] In an organic solvent in which nitrile alone or a nitrile of 40% by volume or more and less than 100% by volume is mixed, the following formula (1):
A hexachlorocyclotriphosphazene represented by the following formula characterized by reacting an aryl alcohol in the presence of pellets of at least one hydroxide selected from the group consisting of potassium hydroxide and sodium hydroxide (2):
[In the formula (2), Ar represents an aryl group which may have a substituent. ]
A method for producing a cyclic aryloxyphosphazene represented by the formula:
[2] The method for producing a cyclic aryloxyphosphazene according to [1], wherein the reaction temperature is 20 to 90 ° C;
[3] The method for producing a cyclic aryloxyphosphazene according to [1] or [2], wherein the reaction time is 0.5 to 8 hours;
[4] The method according to any one of [1] to [3], wherein the amount of hydroxide pellets used is 4 to 20 mol per 1 mol of hexachlorocyclotriphosphazene represented by the above formula (1). A method for producing a cyclic aryloxyphosphazene;
[5] The method for producing a cyclic aryloxyphosphazene according to any one of [1] to [4], wherein the hydroxide pellets are potassium hydroxide pellets;
It is solved by providing.

  According to the present invention, cyclic aryloxyphosphazenes can be obtained in a short time and in a high yield by a simple operation under mild conditions. The cyclic aryloxyphosphazene thus obtained can be suitably used as a flame retardant, an epoxy resin curing agent, an additive for batteries, a fiber shrink-proofing agent, and the like.

2 is a ³¹ P-NMR chart of the cyclic phenoxyphosphazene obtained in Example 1.

  The present invention relates to hexachlorocyclotriphosphazene represented by the following formula (1) (hereinafter referred to as “hexachlorocyclotriphosphazene”) in an organic solvent in which nitrile alone or a nitrile of 40% by volume or more and less than 100% by volume is mixed. The presence of at least one hydroxide pellet selected from the group consisting of potassium hydroxide and sodium hydroxide (hereinafter sometimes referred to as "hydroxide pellet"). A cyclic aryloxyphosphazene represented by the following formula (2) (hereinafter sometimes referred to as “cyclic aryloxyphosphazene”) is obtained by reacting an aryl alcohol (ArOH) below.

[In the formula (2), Ar represents an aryl group which may have a substituent. ]

  As is clear from the comparison between Examples and Comparative Examples described later, when an aqueous solution of sodium hydroxide is used, the yield of the target cyclic aryloxyphosphazene is considerably low, and an organic solvent other than nitrile and 40 vol. When an organic solvent in which less than 5% of nitrile was mixed was used, a compound in which the aryloxy group was substituted by 1 to 5 was formed, and the desired cyclic aryloxyphosphazene could not be obtained in high yield. Have confirmed. On the other hand, by reacting hexachlorocyclotriphosphazene with an aryl alcohol in the presence of hydroxide pellets in an organic solvent containing nitrile alone or a nitrile of 40% by volume or more and less than 100% by volume, mildness is obtained. Under the conditions, cyclic aryloxyphosphazene can be obtained in a short time and in a high yield by a simple operation. Therefore, it is significant to adopt the configuration of the present invention.

  The hydroxide pellets used in the present invention are at least one selected from the group consisting of potassium hydroxide and sodium hydroxide. In the present invention, it is important that at least one selected from the group consisting of potassium hydroxide and sodium hydroxide is in the form of pellets, whereby the cyclic aryloxyphosphazene can be obtained by a simple operation under mild conditions. Can be produced in a short time and with high yield. As the hydroxide pellets used in the present invention, those obtained by a conventionally known method can be used, and commercially available products can be used as they are. The size of the hydroxide pellets used in the present invention is preferably 1 to 12 mm in diameter and 0.5 to 8 mm in thickness. It is preferable that the diameter is 2 to 10 mm and the thickness is 1 to 6 mm from the viewpoint of obtaining the cyclic aryloxyphosphazene in high yield. The shape of the hydroxide pellet is not particularly limited, and a shape such as a sphere, a column, a cylinder, a rectangular parallelepiped, or a cube can be used. From the viewpoint of obtaining a cyclic aryloxyphosphazene with a higher yield, the hydroxide pellets are preferably potassium hydroxide pellets.

  The amount of the hydroxide pellets used in the present invention is not particularly limited, but is preferably 4 to 20 mol per 1 mol of hexachlorocyclotriphosphazene. When the amount of the hydroxide pellets is less than 4 mol, the cyclic aryloxyphosphazene may not be obtained in a high yield, and is preferably 5 mol or more, more preferably 6 mol or more. On the other hand, the amount of the hydroxide pellets used is more preferably 15 mol or less, and even more preferably 12 mol or less.

The nitrile used in the present invention is not particularly limited, but a nitrile represented by the following formula (3) is preferable.
R ³ -CN ⁽³⁾
[In the formula (3), R ³ is a hydrocarbon group. ]

Examples of the hydrocarbon group for R ³ include an alkyl group having 1 to 15 carbon atoms that may have a substituent, an aryl group that may have a substituent, and an aralkyl group that may have a substituent. Examples of the alkyl group having 1 to 15 carbon atoms include a linear, branched or cyclic alkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, s-butyl group, t-butyl group, 1-ethylpropyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, n-heptyl group, n-octyl group , N-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, 5-propylnonyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl Group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Further, a carbon element at an arbitrary position may be substituted with a hetero atom. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group.

  Examples of the substituent of the alkyl group include a halogen atom. Examples of the substituents in the aryl group and the aryl portion of the aralkyl group include a halogen atom, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and 1 to 1 carbon atoms. One or two or more groups selected from 4 haloalkoxy groups.

  These nitriles may have 1 to 3 nitrile groups. Specifically, for example, acetonitrile, propionitrile, butyronitrile, valeronitrile, hexanenitrile, heptanenitrile, isobutyronitrile, 2-methylbutyronitrile, isovaleronitrile, 4-methylvaleronitrile, pivalonitrile, 2, 2-dimethylvaleronitrile, 2,2-dimethylhexanenitrile, benzonitrile, o-tolunitrile, m-tolunitrile, 4-t-butylbenzonitrile, 2- (trifluoromethoxy) benzonitrile, phenylacetonitrile, 2-phenylpropionyl Nitrile, glutaronitrile, 2-methylglutaronitrile, adiponitrile, pimeronitrile, suberonitrile, 1,3,5-pentanetricarbonitrile, 1,3,6-hexanetricarbonitrile, methoxyacetonitrile Ryl, phenoxyacetonitrile, 3-methoxypropionitrile, 3-ethoxypropionitrile, 3-butoxypropionitrile, 2,2-diphenylpropionitrile, 3,3′-oxydipropionitrile, 3,3′- (Ethylenedioxy) dipropionitrile, 1,2,3-tris (2-cyanoethoxy) propane, 1-phenylcyclopentanecarbonitrile, 1-phenylcyclohexanecarbonitrile, p-chlorobenzonitrile, p-methoxybenzonitrile And the like. The nitrile represented by the above formula (3) may be a polymer such as polyacrylonitrile. These can be used alone or in combination of two or more. Among them, at least one kind of nitrile selected from the group consisting of acetonitrile, propionitrile and isobutyronitrile is preferable.

  The amount of the nitrile used in the present invention is not particularly limited, but is preferably 1 to 100 parts by mass, more preferably 20 to 80 parts by mass, per 1 part by mass of hexachlorocyclotriphosphazene. .

  The nitrile used in the present invention can be used as a reaction solvent. Nitrile alone may be used as a reaction solvent, or nitrile may be mixed with an organic solvent and used. When mixed with an organic solvent, the nitrile is preferably at least 40% by volume and less than 100% by volume, more preferably at least 50% by volume and less than 100% by volume, based on the organic solvent.

  The organic solvent in which the nitrile is mixed can be widely selected from organic solvents other than the nitrile, for example, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, dichloromethane, 1,2-dichloroethane, 1,1-dichloroethane, halogen solvents such as sym-tetrachloroethane; ether solvents such as diethyl ether, methyl t-butyl ether and tetrahydrofuran; aliphatic hydrocarbon solvents such as n-pentane and n-hexane; benzene, toluene, o-xylene, m Aromatic solvents such as -xylene; carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate and propylene carbonate; aprotic polar solvents such as dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, etc. Is mentioned. Among them, at least one selected from the group consisting of a halogen-based solvent, an ether-based solvent and an aromatic hydrocarbon-based solvent is preferable, and at least one selected from the group consisting of a halogen-based solvent and an ether-based solvent is more preferable. Among the halogen solvents, at least one selected from the group consisting of chlorobenzene, o-dichlorobenzene and m-dichlorobenzene is preferable.

  The amount of the aryl alcohol used in the present invention is not particularly limited, but is preferably 6 to 30 mol per 1 mol of hexachlorocyclotriphosphazene. When the use amount of the aryl alcohol is less than 6 mol, the intended cyclic aryloxyphosphazene may not be obtained in high yield, and it is more preferably at least 6.1 mol. On the other hand, the use amount of the aryl alcohol is more preferably 20 mol or less, and further preferably 15 mol or less.

  The aryl alcohol used in the present invention is not particularly limited, but a compound having a phenolic hydroxyl group such as phenol and naphthol is preferably used. The compound having a phenolic hydroxyl group may have a substituent, and particularly preferably has a substituent at the para-position or the ortho-position. Examples of such a substituent include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a tert group. Alkyl groups such as -butyl group; alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group and tert-butoxy group; acetyl group and propionyl group And acyl groups such as benzoyl group; alkylsilyl groups such as trimethylsilyl group and triethylsilyl group; alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group; An aromatic ring group; an amino group; a cyano group. The substituent is preferably at least one selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group.

  In the present invention, it is preferable to remove water in the reaction system as much as possible. Further, it is preferable to replace the inside of the reaction vessel with an inert gas. The inert gas used is not particularly limited, but includes, for example, helium, argon, nitrogen and the like.

  The reaction temperature at the time of reacting hexachlorocyclotriphosphazene with the aryl alcohol is not particularly limited, but is preferably 20 to 90 ° C. When the reaction temperature is lower than 20 ° C., the intended cyclic aryloxyphosphazene may not be obtained in a high yield, and the temperature is more preferably 25 ° C. or higher, further preferably 30 ° C. or higher. On the other hand, the reaction temperature is more preferably 82 ° C or lower, further preferably 80 ° C or lower.

  The reaction time for reacting hexachlorocyclotriphosphazene with the aryl alcohol is not particularly limited, but is preferably 0.5 to 8 hours. When the reaction time is less than 0.5 hour, the target cyclic aryloxyphosphazene may not be obtained in high yield, and it is more preferably 1 hour or more. On the other hand, the reaction time is more preferably 6 hours or less, and further preferably 4 hours or less.

  As will be apparent from the examples described later, hexachlorocyclotriphosphazene is added to hexachlorocyclotriphosphazene in the presence of hydroxide pellets in an organic solvent in which nitrile alone or a nitrile of 40% by volume or more and less than 100% by volume is mixed. By reacting the aryl alcohol, a cyclic aryloxyphosphazene represented by the following formula (2) can be obtained in a short time and in a high yield by a simple operation under mild conditions.

[In the formula (2), Ar represents an aryl group which may have a substituent. ]

  In the above formula (2), Ar represents an aryl group which may have a substituent, and examples of the aryl group include a phenyl group and a naphthyl group. The aryl group may have a substituent, and particularly preferably has a substituent at the para or ortho position. As such a substituent, the substituents described in the description of the above aryl alcohol are preferably employed.

  The cyclic aryloxyphosphazene obtained by the present invention can be suitably used as a flame retardant, an epoxy resin curing agent, an additive for batteries, a fiber shrink-proofing agent, and the like.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1
[Synthesis of cyclic phenoxyphosphazene]

Cyclic chlorophosphazene (0.176 g, 0.490 mmol) was weighed and placed in an eggplant flask equipped with a stirrer, and acetonitrile (10 mL) was added thereto to prepare a dispersion. Phenol (Ar = C ₆ H ₅ , 0.289 g, 3.04 mmol) and KOH pellets (0.289 g, 4.03 mmol) having a diameter of about 8 mm and a thickness of about 4 mm were added to the dispersion. After a three-way cock equipped with an argon balloon was attached and the inside of the reactor was replaced with argon, the reactor was immersed in a hot water bath at 80 ° C. and stirred for 2 hours to react. Next, the reactor was removed from the hot water bath and allowed to cool to room temperature. The precipitate was collected by suction filtration, washed with acetonitrile (50 mL), combined with the filtrate and the washings, concentrated under reduced pressure, and dried to obtain a white solid (0.493 g). The obtained white solid was dispersed in ethyl acetate (10 mL), and the ethyl acetate layer was washed with an aqueous sodium carbonate solution (5%, 15 mL × 3 times) and a saturated saline solution (15 mL × 3 times). The organic layer was dried over sodium sulfate, concentrated under reduced pressure and dried to obtain cyclic phenoxyphosphazene (Ar = C ₆ H ₅ , 0.336 g, yield 99%) as colorless crystals.

The NMR data of the obtained cyclic phenoxyphosphazene was as follows. FIG. 1 shows a ³¹ P-NMR chart.
³¹ P NMR (CDCl ₃ , 162 MHz): δ 9.36 ppm

Examples 2 to 4, Comparative Example 1
The reaction was carried out in the same manner as in Example 1, except that the base shown in Table 1 was used and the temperature of the hot water bath was changed as shown in Table 1.

Examples 5 to 10
The reaction was carried out in the same manner as in Example 1, except that the aryl alcohol (ArOH) shown in Table 2 was used and the temperature of the hot water bath and the reaction time were changed as shown in Table 2.

Examples 11 and 12, Comparative Examples 2 to 5
The reaction was carried out in the same manner as in Example 1 except that the reaction solvent acetonitrile was changed to the solvent shown in Table 3.

Claims (5)

In an organic solvent mixed with nitrile alone or a nitrile of 40% by volume or more and less than 100% by volume, the following formula (1):
A hexachlorocyclotriphosphazene represented by the following formula characterized by reacting an aryl alcohol in the presence of pellets of at least one hydroxide selected from the group consisting of potassium hydroxide and sodium hydroxide (2):
[In the formula (2), Ar represents an aryl group which may have a substituent. ]
A method for producing a cyclic aryloxyphosphazene represented by the formula:   The method for producing a cyclic aryloxyphosphazene according to claim 1, wherein the reaction temperature is 20 to 90 ° C.   The method for producing a cyclic aryloxyphosphazene according to claim 1 or 2, wherein the reaction time is 0.5 to 8 hours.   The amount of the hydroxide pellets used is 4 to 20 mol per 1 mol of hexachlorocyclotriphosphazene represented by the above formula (1). Production method. The method for producing a cyclic aryloxyphosphazene according to any one of claims 1 to 4, wherein the hydroxide pellets are potassium hydroxide pellets.