KR20080098435A - Process for preparing bis-phthalonitrile monomer - Google Patents

Abstract

The present invention relates to a process for the preparation of bis-phthalonitrile monomers having oligophenyl ether spacer chains, wherein the bis-phthalonitrile is n in formula (I):

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The method comprises (i) reacting 3-alkoxyphenol and m-dihalobenzene in the presence of a base and a catalyst composition comprising a copper salt and a ligand to yield 1,3-bis (3-alkoxyphenoxy) benzene (Ii) reacting the obtained 1,3-bis (3-alkoxyphenoxy) benzene with a dealkylating agent to give 1,3-bis (3-hydroxyphenoxy) benzene, and (iii) obtaining 1,3-bis [3- (3,4-dicyanophenoxy) phenoxy] by reacting one 1,3-bis (3-hydroxyphenoxy) benzene with 4-nitrophthalonitrile in the presence of a base Obtaining benzene.

Description

Process for producing bis-phthalonitrile monomers {PROCESS FOR PRODUCTION OF A BIS-PHTHALONITRILE MONOMER}

The present invention relates to a process for the preparation of bis-phthalonitrile monomers having oligophenyl ether spacer chains, wherein the monomers are represented by formula (I):

More specifically, the present invention relates to a new process for preparing monomers in which n is 2. In another aspect, the present invention relates to the use of the intermediate product obtained by the process according to the invention in the process of obtaining a bis-phthalonitrile monomer of formula (I) wherein n is 4 or 6.

Phtharonitrile (PN) resins were originally developed in the early 1980s by the US Naval Research Institute as high temperature substitutes for polyimide resins. PN resins are thermosets derived from bis-phthalonitrile monomers. Such monomers cause polymerization in addition mode reactions which form triazine networks in the presence of a curing agent. Fully cured resins exhibit good thermal and oxidative stability and retain long-term mechanical properties at high temperatures. Moreover, the benzene ring which forms the skeletal structure of the said monomer is very stable. The combination of these properties means that the composite produced is highly fire resistant.

Various phthalonitrile monomers and polymers are described in a number of patents and patent applications, which patents generally teach methods for making and polymerizing phthalonitrile monomers. The disclosed monomers typically have two phthalonitrile groups, one of which is present at each end of the spacer chain to which they are linked. The monomer may be cured, and as a result crosslinking may occur between cyano groups.

U.S. Pat. No. 4,587,325 discloses, in Examples 1 and 5, two bis-phthalonitrile monomers, namely 4,4'-bis (3,4-dicyanophenoxy) biphenyl of formula (II) and formula (III). 1,3-bis (3,4-dicyanophenoxy) benzene of

The monomers are prepared by reacting 4-nitrophthalonitrile with aromatic diols, and both monomers can be used as precursors in the preparation of PN resins. However, these monomers have the disadvantage that the processing temperature is relatively high and the processing window is narrow due to the high melting point of the monomers. The melting point of 4,4'-bis (3,4-dicyanophenoxy) biphenyl is about 235 ° C and the melting point of 1,3-bis (3,4-dicyanophenoxy) benzene is about 184 ° C.

International patent application WO 03/091312 teaches that bis-phthalonitrile monomers having oligomeric or polymeric aromatic ether spacer chains will be more useful in PN resins because they are expected to have a relatively low melting point. Compounds having a wide window between the melting point and the curing temperature are preferred for controlling the rate of curing and the viscosity at curing. The thermoset also has physical properties such as toughness and processability, with improved spacer chains between terminal phthalonitrile moieties compared to shorter systems. In general, toughness and brittleness are improved with lower crosslink density. This can be accomplished by using PN monomers with longer spacer chain lengths. In this patent application, the inventors have described the hydroxyterminated aromatic ether oligomers formed by reacting m-dihydroxy aromatic compounds such as resorcinol with m-dihalo aromatic compounds such as 1,3-dibromobenzene. An example for preparation is disclosed. The reaction is carried out by Ullmann synthesis in the presence of copper salts and cesium carbonate. The chain length of the aromatic ether oligomer is controlled by the molar ratio of m-dihydroxy aromatic and m-dihalo aromatic compounds. The hydroxy terminated aromatic ether oligomers further react with 4-nitrophthalonitrile to form bis-phthalonitrile monomers of formula (I), wherein the ether spacer chain is theoretically 2, 4, 6, or 8 wherein Corresponding to n includes 3, 5, 7 or 9 aromatic groups on average.

The process for the preparation of bis-phthalonitrile monomers disclosed in WO 03/091312 exhibits at least the following disadvantages. The reaction conditions used in the examples form a product comprising a complex mixture of bis-phthalonitrile monomers with widely distributed spacer chain lengths. The product obtained is also separated from the acidic aqueous solution, so that all water insoluble byproducts such as hydroxy and halogen terminated oligomers remain in the product. This can lead to great difficulties in controlling the reaction of the product in the curing step. Therefore, such mixtures are not preferred as precursors for PN resins that require good thermal and oxidative stability with improved physical properties.

It has been found to be a need for a process for the preparation of high purity bis-phthalonitrile monomers having oligomeric aromatic ether spacer chains. The present invention unexpectedly provides a new process for producing bis-phthalonitrile monomers of formula (I) wherein n is 2, for example producing a product of high purity higher than 98%. The method of the present invention comprises the following steps:

i) reacting 3-alkoxyphenol and m-dihalobenzene in the presence of a base and a catalyst composition comprising a copper salt and a ligand to obtain 1,3-bis (3-alkoxyphenoxy) benzene,

Ii) reacting the 1,3-bis (3-alkoxyphenoxy) benzene obtained in step (i) with a dealkylating agent to obtain 1,3-bis (3-hydroxyphenoxy) benzene , And

Iii) 1,3-bis (3-hydroxyphenoxy) benzene obtained in step (ii) is reacted with 4-nitrophthalonitrile in the presence of a base to give 1,3-bis [ Obtaining 3- (3,4-dicyanophenoxy) phenoxy] benzene.

In step (i) of the process according to the invention the 3-alkoxyphenol is reacted with m-dihalobenzene to form 1,3-bis (3-alkoxyphenoxy) benzene as illustrated in the following reaction scheme (IV). do:

Wherein R is a lower alkyl group such as methyl, ethyl, propyl or butyl group or an alkylaryl group such as benzyl group and X is halogen such as bromine or iodine. Thus, the alkoxy is preferably an arylalkoxy such as methoxy, ethoxy, propoxy, butoxy or benzyloxy and the halo is likewise iodo or bromo. In the preferred embodiment of the present invention, the 3-alkoxyphenol is 3-methoxyphenol, and the m-dihalobenzene is likewise preferably 1,3-dibromobenzene. Suitable molar ratios are, for example, 2-3 moles of 3-alkoxyphenol per 1 mole of m-dihalobenzene. In an embodiment of the invention, the reaction comprises one or more polar aprotic solvents such as dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide and / or N-methyl-2-pyrrolidone (aprotic solvent) in the presence of. Most preferred solvent is N-methyl-2-pyrrolidone. The reaction is carried out as Ullmann ether synthesis using a base and a catalyst. Suitable bases are alkali and alkaline earth metal bicarbonates, carbonates, hydroxides and alcoholates. Carbonates are generally preferred bases and the most preferred carbonate is potassium carbonate. Suitable amounts of base are from 0.5 to 2 moles relative to 1 mole of 3-alkoxyphenol present in the reaction medium. The catalyst is a Ullmann ether catalyst, for example a metal salt such as a copper salt. Most preferred copper salts are copper iodide (I) and / or copper bromide (I). Still other suitable copper compounds include, but are not limited to, copper chloride (I), copper (II) bromide, copper (II) sulfate and copper (II) acetate. Suitable amounts of catalyst are generally in the range of 0.1 to 10 mol%, for example 0.5 to 2 mol%, calculated on the basis of the moles of m-dihalobenzene. The activity of the reaction can be further enhanced, for example, by adding appropriate ligands to better dissolve the copper salts in the reaction medium. Several effective ligands have been developed for copper catalyzed Ullmann ether synthesis, including aliphatic diamines, 1,10-phenanthroline and derivatives thereof, bidentate and monodentate phosphines, amino acid derivatives and 2,2,6 , 6-tetramethylheptan-3,5-dione and the like. In particular N, N-dimethylglycine has proven to be an effective ligand under the reaction conditions of step (I) of the present invention. Suitable amounts of ligands are from 0.3 to 20 mol%, for example from 1 to 6 mol%, calculated on the molar basis of m-dihalobenzene.

A typical procedure of step (i) can be described as follows:

3-alkoxyphenol, such as 3-methoxyphenol, is placed in the reaction vessel. A solvent, such as N-methyl-2-pyrrolidone, is added in an amount greater than or equal to sufficient to dissolve the reactant and product. A base such as potassium carbonate is added in the range of 0.5 to 2 moles, for example with respect to 1 mole of 3-alkoxyphenol, and finally a sufficient amount of a suitable solvent such as toluene can be removed in an azeotropic manner to remove the water formed during the reaction. To the mixture. Most preferably, a stream of inert gas such as nitrogen or argon is passed through the reaction vessel. The temperature is raised to 130-170 ° C to distill off the toluene-water azeotrope. The reaction mixture is maintained at 130-170 ° C. for 1-4 hours to distill off the remaining water and toluene. To 1 mole of 3-alkoxyphenol, 0.3-0.5 mole of m-dihalobenzene, such as 1,3-dibromobenzene, is added, and then calculated based on the mole of m-dihalobenzene, copper iodide (I) 0.5-2 mol% of a catalyst such as and 1-6 mol% of a ligand such as N, N-dimethylglycine are added. The reaction mixture is stirred at 100-160 ° C. for 5-24 hours or until the reaction is complete. After cooling to 20-40 ° C., a suitable solvent such as toluene is added and the inorganic salts are filtered out of the mixture. The filtrate is first washed with an aqueous base such as 10% NaOH, then with water and finally with an aqueous 1% NaCl solution. Subsequently, the solvent / water is removed by distillation under vacuum at, for example, 30 mbar at 60-100 ° C. to give 1,3-bis (3-alkoxyphenoxy) benzene, which is further purified or, where appropriate, purified. Use in step (ii).

In the step (ii) of the process according to the invention, the 1,3-bis (3-alkoxyphenoxy) benzene obtained in step (i) is dealkylated as exemplified in the following reaction scheme (V) to 1, Obtain 3-bis (3-hydroxyphenoxy) benzene:

Wherein R is the same as described above. According to the literature, there are a wide variety of reagents useful for cleaving alkylaryl ethers, for example sulfonic anhydride, NaS in N-methyl-2-pyrrolidone, NaCN in dimethyl sulfoxide, AlBr ₃ , AlCl ₃ , BBr ₃ , BCl ₃ and 48% HBr and Pd / C for H ₂ and benzyl ether. A suitable method for dealkylating 1,3-bis (3-alkoxyphenoxy) benzene as shown in scheme (V) is to use, but not limited to, a mixture of 48% hydrobromic acid and acetic acid as a splitting agent. Acetic acid is preferably added as anhydride to reduce the water content of the mixture to increase the reaction rate. Suitable amounts of 48% hydrobromic acid and acetic anhydride are 1 to 6 parts by weight, for example 2 to 3 parts by weight, relative to 1 part by weight of 1,3-bis (3-alkoxyphenoxy) benzene present.

A typical procedure of step (i) can be described as follows:

48% bromination of 1,3-bis (3-alkoxyphenoxy) benzene, such as 1,3-bis (3-methoxyphenoxy) benzene, obtained in step (i) of the present invention with respect to 1 part by weight of the ether oligomer It is mixed with 2-3 parts by weight of hydrochloric acid, and the mixture is heated to 80 to 100 ° C. Subsequently, 2-3 parts by weight of acetic anhydride are added to the reaction mixture for 10 to 60 minutes at 80 to 100 ° C with respect to 1 part by weight of the ether oligomer. The reaction mixture is stirred at 100-115 ° C. for 4-20 hours or until the reaction is complete. After cooling to 20-40 ° C., suitable solvents such as water and methyl isobutyl ketone are added. After stirring at 20-40 ° C., the phases are separated and the organic layer is washed with water. Finally the organic layer is evaporated at 60-100 ° C., for example under a vacuum of 30 mbar, to give 1,3-bis (3-hydroxyphenoxy) benzene, which is further purified or, if appropriate, without purification. Used in step (iii).

The 1,3-bis (3-hydroxyphenoxy) benzene obtained in step (ii) is subjected to 4-nitrope as illustrated in the following reaction scheme (VI) in step (iii) of the process according to the invention. Reaction with dealonitrile affords 1,3-bis [3- (3,4-dicyano-phenoxy) phenoxy] benzene:

Bis-phthalonitrile monomers with phenyl ether spacer chains are typically prepared by dissolving hydroxy terminated aromatic ether and 4-nitrophthalonitrile in a solvent and heating in the presence of a base. The reaction is carried out in a polar aprotic solvent such as dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, or N-methyl-2-pyrrolidone. Suitable bases are alkali and alkaline earth metal bicarbonates, carbonates, hydroxides and alcoholates. Carbonates are preferred bases and most preferred carbonate is potassium carbonate. Suitable amounts of 4-nitrophthalonitrile and the base are 2-3 moles relative to 1 mole of 3-bis (3-hydroxyphenoxy) benzene present in the reaction medium.

A typical procedure of the above step can be described as follows:

1,3-bis (3-hydroxyphenoxy) benzene is mixed with a solvent such as N, N-dimethylformamide in an amount greater than or equal to sufficient to dissolve the reactant and the product. Subsequently, bases such as 4-nitrophthalonitrile and potassium carbonate are added in a ratio of 2 to 3 mol relative to 1 mol of 1,3-bis (3-hydroxyphenoxy) benzene. A stream of inert gas such as nitrogen or argon is passed through the reaction vessel. The temperature is raised to 25-80 ° C. and maintained for 3-12 hours or until the reaction is complete. The hot reaction mixture is filtered to remove inorganic salts. In an amount greater than or equal to sufficient to precipitate the desired product from the mixture, a suitable precipitant such as methanol is added to the filtrate. The mixture is then stirred until the product crystallizes, for example at a temperature of -10 to 30 ° C. The solid product is collected and washed with a suitable solvent such as methanol. The crude product obtained is further purified by recrystallization in a suitable solvent such as a mixture of N, N-dimethylformamide and methanol to give 1,3-bis [3- with a purity of> 98%, for example. (3,4-dicyanophenoxy) phenoxy] benzene is obtained.

According to the novel process of the present invention, a high-purity bis-phthalonitrile monomer such as 1,3-bis [3- (3,4-dicyanophenoxy) phenoxy] benzene having a melting point of about 120 ° C can be prepared. Can be. Thus, the process of the present invention provides at least the following advantages: (1) PN resin systems based on 1,3-bis [3- (3,4-dicyanophenoxy) phenoxy] benzene, for example, Because of this relatively low melting point, the 4,4′-bis (3,4-dicyanophenoxy) biphenyl and 1,3-bis (3,4-dicyanophenoxy) disclosed in Formulas (II) and (III) C) shows lower process temperatures and wider process windows compared to resin systems based on PN resins such as benzene, and (2) the high purity of the product, the difficulty of controlling the reaction in the curing step is substantially reduced or In some cases, it can be completely eliminated.

Further, 1,3-bis (3-hydroxyphenoxy) benzene, which is the intermediate obtained in step (II), is Ullmann ether using 3-alkoxyhalo aromatic compound, as illustrated in the following reaction scheme (VII). By reaction and dealkylation, it is useful to prepare hydroxy terminated aromatic ether oligomers with much longer oligophenyl ether spacer chains:

In the above formula, R and X are suitably the same as defined above. An example of a suitable 3-alkoxyhalo aromatic compound is 3-methoxybromobenzene. Other preferred reagents, bases, dealkylating agents and reaction conditions are as described above. The resulting hydroxy terminated aromatic ether oligomer can be further reacted with 4-nitrophthalonitrile to produce a bis-phthalonitrile monomer of formula (I) with n = 4. The resulting hydroxy terminated aromatic ether oligomer is also subjected to a second reaction with the 3-alkoxyhalo aromatic compound and a second dealkylation to produce a hydroxy terminated aromatic ether oligomer, followed by reaction with 4-nitrophthalonitrile. It is possible to produce a bis-pronalonitrile monomer of formula (I) wherein n is 6.

The resulting hydroxy terminated aromatic ether oligomer as well as the reaction and dealkylation process with the 3-alkoxyhaloaromatic compound can be subjected to iterative reactions before reacting with the 3-alkoxyhalo aromatic compound and finally with 4-nitrophthal After the reaction with the nitrile, a bis-phthalonitrile monomer of formula (I) in which n is 8, 10, 12 or the like can be produced.

Without further effort, it is believed that one skilled in the art can, using the foregoing description, utilize the present invention to its fullest extent. Accordingly, the following preferred embodiments are merely exemplary and should not be construed as limiting the remainder of the disclosure. In the following, Examples 1 to 3 relate to the preparation of bis-phthalonitrile monomers according to the examples of steps (i) to (iii) of the process of the invention.

Example  One

500 ml three-necked reaction flask with 64.8 g of 3-methoxyphenol, 60 ml of N-methyl-2-pyrrolidone, 72.2 g of potassium carbonate, and 100 ml of toluene, equipped with a thermometer, a mechanical stirrer, a distillation apparatus, and a nitrogen inlet. Put in. Nitrogen airflow was passed through the vessel. The mixture was heated to 150 ° C. and the azeotrope of toluene-water was distilled off with the mixture. Stirring was continued at 150 ° C. for 2 hours while distilling off water and residual toluene formed during the reaction. After cooling to 140 ° C., 51.4 g of 1,3-dibromobenzene, 0.40 g of copper (I) iodide and 0.66 g of N, N-dimethylglycine were added to the reaction mixture. Stirring was continued at 140 ° C. for 11 hours until HPLC analysis indicated complete reaction. The reaction mixture was cooled to 20-25 ° C., 200 ml of toluene was added and then filtered to remove inorganic salts. The filter cake was washed twice with 40 ml of toluene and the wash was combined with the filtrate. 200 ml of 10% aqueous NaOH solution was added to the filtrate, and the mixture was stirred for 15 minutes and then separated. The organic layer was washed with 200 ml of water and finally with 200 ml of 1% NaCl aqueous solution. Finally, toluene was removed from the organic layer by evaporation under vacuum at 20 mbar at 80-85 ° C. to give 66.9 g of 1,3-bis (3-methoxyphenoxy) benzene as a reddish oil.

Example  2

65.8 g of 1,3-bis (3-methoxyphenoxy) benzene obtained in Example 1 and 170 g of 48% hydrobromic acid were placed in a 1000 ml three-necked reaction flask equipped with a thermometer, a mechanical stirrer and a condenser. The mixture was heated to 90 ° C and 162 g of acetic anhydride was added within 20 minutes using a dropping funnel at 90-105 ° C. Stirring was continued for 10 hours at 105-111 ° C. until HPLC analysis indicated complete reaction. The reaction mixture was cooled to 20-25 ° C. and 200 ml of water and 150 ml of methyl isobutyl ketone were added. The mixture was stirred for 15 minutes and then separated. The methyl isobutyl ketone layer was washed with 200 ml of water and evaporated to dryness under vacuum at 20 mbar at 80-85 ° C. to 63.3 g of 1,3-bis (3-hydroxyphenoxy) benzene as a reddish viscous oil. Obtained as.

Example  3

62.2 g of 1,3-bis (3-hydroxyphenoxy) benzene obtained in Example 2, 160 ml of N, N-dimethylformamide, 70 g of 4-nitrophthalonitrile and 70 g of potassium carbonate were prepared using a thermometer, a mechanical stirrer, and a condenser. And a 500 ml three-neck reaction flask with a nitrogen inlet. Nitrogen airflow was passed through the vessel. The mixture was heated to 58-60 ° C. and stirring was continued at this temperature for 5 hours until the reaction showed complete by HPLC analysis. At this temperature, the reaction mixture was filtered to remove the inorganic salts, and the filter cake was washed twice with 30 ml of N, N-dimethylformamide. The wash was combined with the filtrate and 800 ml of methanol was added. The mixture was then stirred at 20-25 ° C. until the product crystallized. After cooling to 0-5 [deg.] C., the solid product was collected by suction filtration and washed with methanol. The crude product was recrystallized from a mixture of 180 ml of methanol and 80 ml of N, N-dimethylformamide and dried at 60 ° C. to give 47.9 g of 1,3-bis [3- (3,4-dicyanophenoxy) phenoloxy] benzene. Obtained as a pale brown powder. The product obtained had a melting point of 118-122 ° C. and a purity of 98.6% (HPLC).

Claims (33)

A method for preparing a bis-phthalonitrile monomer having an oligophenyl ether spacer chain, The bis-phthalonitrile is represented by formula (I):

Wherein n is 2, and the method i) reacting 3-alkoxyphenol and m-dihalobenzene in the presence of a base and a catalyst composition comprising a copper salt and a ligand to obtain 1,3-bis (3-alkoxyphenoxy) benzene, Ii) reacting the 1,3-bis (3-alkoxyphenoxy) benzene obtained in step (i) with a dealkylating agent to obtain 1,3-bis (3-hydroxyphenoxy) benzene , And Iii) 1,3-bis (3-hydroxyphenoxy) benzene obtained in step (ii) is reacted with 4-nitrophthalonitrile in the presence of a base to give 1,3-bis [ Obtaining 3- (3,4-dicyanophenoxy) phenoxy] benzene Method for producing a bis-phthalonitrile monomer comprising a. The method of claim 1, The said alkoxy is methoxy, ethoxy, propoxy or butoxy, The manufacturing method of the bis-phthalonitrile monomer characterized by the above-mentioned. The method of claim 1, The said alkoxy is aryl alkoxy, The manufacturing method of the bis-phthalonitrile monomer characterized by the above-mentioned. The method of claim 3, The said aryl alkoxy is benzyloxy, The manufacturing method of the bis-phthalonitrile monomer characterized by the above-mentioned. The method according to any one of claims 1 to 4, Method for producing a bis-phthalonitrile monomer, characterized in that the halo is bromo or iodo. The method according to any one of claims 1 to 5, In the step (i), the molar ratio of the 3-alkoxyphenol to the m-dihalobenzene is 2 to 3: 1 method for producing a bis-phthalonitrile monomer. The method according to any one of claims 1 to 6, In the step (i), 0.5 to 2 moles of the base is present with respect to 1 mole of 3-alkoxyphenol. The method according to any one of claims 1 to 7, In step (i), the bis- is characterized in that the copper salt is present in an amount of 0.1 to 10 mol%, for example 0.5 to 2 mol%, calculated on the basis of moles of m-dihalobenzene. Process for the preparation of phthalonitrile monomers. The method according to any one of claims 1 to 8, In step (i), the bis-prop is characterized in that the ligand is present in an amount of 0.3 to 20 mol%, for example 1 to 6 mol%, calculated on the basis of moles of m-dihalobenzene. Process for the preparation of dealonitrile monomers. The method according to any one of claims 1 to 9, The said 3-alkoxy phenol is 3-methoxy phenol, The manufacturing method of the bis-phthalonitrile monomer characterized by the above-mentioned. The method according to any one of claims 1 to 10, The m-dihalobenzene is a 1,3-dibromobenzene method of producing a bis-phthalonitrile monomer, characterized in that. The method according to any one of claims 1 to 11, The said copper salt is iodouri (I), The manufacturing method of the bis-phthalonitrile monomer characterized by the above-mentioned. The method according to any one of claims 1 to 12, Method for producing a bis-phthalonitrile monomer, characterized in that the ligand is N, N-dimethylglycine. The method according to any one of claims 1 to 13, The 1,3-bis (3-alkoxyphenoxy) benzene is a 1,3-bis (3-methoxyphenoxy) benzene. The method according to any one of claims 1 to 14, A process for producing a bis-phthalonitrile monomer, characterized in that step (i) is carried out at a temperature of 100 to 170 ° C in the presence of a polar aprotic solvent. The method of claim 15, The polar aprotic solvent is N-methyl-2-pyrrolidone. The method for producing a bis-phthalonitrile monomer. The method according to any one of claims 1 to 16, A method for producing a bis-phthalonitrile monomer, wherein the dealkylating agent is a mixture of hydrobromic acid and acetic anhydride. The method of claim 17, 1 to 6 parts by weight of 48% hydrobromic acid, such as 2 to 3 parts by weight, and 1 to 6 parts by weight of acetic anhydride, such as 1 part by weight of 1,3-bis (3-methoxyphenoxy) benzene For example, the manufacturing method of the bis-phthalonitrile monomer characterized by using 2-3 weight part. The method according to any one of claims 1 to 18, Process for producing a bis-phthalonitrile monomer, characterized in that step (ii) is carried out at a temperature of 100 ~ 115 ℃. The method according to any one of claims 1 to 19, In step (iii), the molar ratio of 4-nitrophthalonitrile to 1,3-bis (3-hydroxyphenoxy) benzene is 2 to 3: Manufacturing method. The method according to any one of claims 1 to 20, In the step (iii), the molar ratio of the base to the 1,3-bis (3-hydroxyphenoxy) benzene is 2 to 3: 1. The method according to any one of claims 1 to 21, A method for producing a bis-phthalonitrile monomer, wherein the base is an alkali or alkaline earth metal carbonate. The method of claim 22, A method for producing a bis-phthalonitrile monomer, wherein the alkali or alkaline earth metal carbonate is potassium carbonate. The method according to any one of claims 1 to 23, A process for producing a bis-phthalonitrile monomer, wherein step (iii) is carried out at a temperature of 25 to 80 ° C. in the presence of a polar aprotic solvent. The method of claim 24, A method for producing a bis-phthalonitrile monomer, characterized in that the polar aprotic solvent is N, N-dimethylformamide. The method according to any one of claims 1 to 25, A method for producing a bis-phthalonitrile monomer, wherein the obtained 1,3-bis [3- (3,4-dicyanophenoxy) phenoloxy] benzene is recrystallized and has a purity of 98% or more after recrystallization. Use of said 1,3-bis [3- (3,4-dicyanophenoxy) phenoloxy] benzene obtained in the process according to any one of claims 1 to 26 for the preparation of phthalonitrile resins. . 19. The method of claims 1 to 18 used in the process of reacting 1,3-bis (3-hydroxyphenoxy) benzene with 3-alkoxyhalo aromatics to produce hydroxyterminated aromatic ether oligomers. Use of 1,3-bis (3-hydroxyphenoxy) benzene obtained in step (ii) of the process according to any one of the preceding claims. The method of claim 28, Use of 1,3-bis (3-hydroxyphenoxy) benzene in the process wherein said 3-alkoxyhalo aromatic compound is 3-methoxybromobenzene. The method of claim 28 or 29, 1,3-bis (3- in the step of reacting the obtained hydroxy terminated aromatic ether oligomer with 4-nitrophthalonitrile to produce a bis-phthalonitrile monomer of formula (I) wherein n is 4. Use of hydroxyphenoxy) benzene. The method of claim 28, Use of 1,3-bis (3-hydroxyphenoxy) benzene in a process of reacting the hydroxy terminated aromatic ether oligomer obtained with a 3-alkoxyhalo aromatic compound to produce a hydroxy terminated aromatic ether oligomer. The method of claim 31, wherein Use of 1,3-bis (3-hydroxyphenoxy) benzene in the process wherein said 3-alkoxyhalo aromatic compound is 3-methoxybromobenzene. 33. The method of claim 31 or 32,  1,3-bis (3- in the step of reacting the obtained hydroxy terminated aromatic ether oligomer with 4-nitrophthalonitrile to produce a bis-phthalonitrile monomer of formula (I) wherein n is 6. Use of hydroxyphenoxy) benzene.