Method for preparing aromatic diethers and method for preparing corresponding polyaryl ether ketones

Abstract

The present invention relates to a method for producing an aromatic diether, comprising the reaction of compound A containing at least two halogenated aromatic groups with compound B (where B is an aromatic alcoholate) in the presence of compound C which optionally acts as a reaction solvent, wherein the molar ratio of compound B to compound A is at least 2:1 and the molar amount of compound C to compound A is 10:1 where appropriate. The present invention also relates to a method for producing a polyaryletherketone.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing aromatic diether(s).

[0002] The present invention also relates to a method for producing polyaryl ether ketones from at least some of these aromatic diethers. Background Technology

[0003] Various industrial methods for producing copolymers of polyaryl ether ketones, such as polyether ether ketones, polyether ketone ketones, or polyether ether ketones and polyether diphenyl ether ketones, are known from the prior art.

[0004] The first known route for the preparation of polyaryl ether ketone polymers is based on nucleophilic substitution and is described, for example, in WO 86 / 07599. The method consists of the polycondensation of a difluoro monomer and a monomer containing two phenolic functional groups in a solvent, for example, diphenyl sulfone, at high temperatures (280°C to 320°C).

[0005] A second known route is based on electrophilic substitution reactions between aromatic acid chlorides and aromatic ethers in the presence of a Lewis acid, as described, for example, in US 4 816 556. In particular, methods for preparing polyether ketones can be based on diphenyl ether, or alternatively 1,4-bis(4-phenoxybenzoyl)benzene, as starting monomers for polymerization reactions. In US 4 816 556, 1,4-bis(4-phenoxybenzoylbenzene) was synthesized by electrophilic substitution between terephthaloyl chloride and an excess of diphenyl ether in the presence of aluminum trichloride (Lewis acid) in ortho-dichlorobenzene (solvent).

[0006] The literature [Ke, Y. et al. (1998), Investigations of the practical routes, structure, and properties for poly(aryl ether ketone ketone) polymers. J. Appl. Polym. Sci., 67: 659-677. doi:10.1002 / (SICI)1097-4628(19980124)67:4<659::AID-APP9>3.0.CO;2-P] also discloses an experimental method for preparing 1,4-bis(4-phenoxybenzoyl)benzene via a nucleophilic route. In the aforementioned publication, the method comprises 0.10 mol of the compound of formula (I) below in 270 mL of dimethylacetamide and 60 mL of toluene while stirring under a dinitrogen atmosphere:

[0007] [Chemical Formula 1]

[0008]

[0009] This was carried out by mixing 0.20 mol of phenol and 0.3 mol of anhydrous potassium carbonate. The mixture was slowly heated for 1 hour until it reached a temperature of 158°C. Residual water was removed from the reaction mixture. The reaction mixture was maintained at a temperature of 158°C for 1 hour and then at a temperature of 162°C for 2 hours. The reaction medium was then poured into pure water, the precipitate was filtered out, and it was air-dried at 108°C for 24 hours. Two recrystallizations from toluene were performed, and a product having a melting point of 224°C was obtained in a yield of 90%, although the purity was not indicated. However, the aforementioned literature indicates that the melting point of 1,4-bis(4-phenoxybenzoyl)benzene should be 215°C. This method also has several disadvantages: it uses large quantities of solvents, particularly dimethylacetamide, which poses a risk to human health because it is harmful (by contact / inhalation) and is classified as CMR (potentially harmful to the fetus). Furthermore, dimethylacetamide has a high boiling point (165°C), which complicates the step of drying the generated product. Finally, the water produced during the reaction is soluble in dimethylacetamide but difficult to separate from it, which complicates the recycling of the solvent for reuse in subsequent processes.

[0010] Objectives

[0011] One object of the present invention is to provide an improved method for producing aromatic diether(s) that can be used particularly on an industrial scale.

[0012] According to specific embodiments, the object of the present invention is to provide a method for producing high-purity aromatic diether(s) in high yield.

[0013] The object of the present invention is also to provide an improved method for producing polyaryl ether ketones from the aromatic diethers.

[0014] Description of the invention

[0015] The present invention relates to a method for preparing an aromatic diether comprising the reaction of compound B (where B is an aromatic alkoxide) and compound A comprising at least two halogenated aromatic groups in the presence of compound C, which optionally acts as a reaction solvent. The molar ratio of compound B to compound A is at least 2:1, and the molar amount of compound C to compound A is 10:1 or less when appropriate.

[0016] This method makes it possible to obtain aromatic diethers from a highly concentrated reaction mixture or even in bulk, which enables the optimization of bulk productivity (the amount of material produced per unit volume of equipment). Furthermore, the inventors have noted, entirely surprisingly, that the method enables the obtaining of aromatic diethers with a yield and good purity that is at least equivalent to and, in many cases, better than that of methods according to the prior art.

[0017] In certain embodiments, compound A is a compound having the following chemical formula:

[0018] [Chemical Formula 2]

[0019]

[0020] In the above formula,

[0021] i is an integer in the range of 1 to 3, and n is an integer equivalent to 0 or 1;

[0022] X1 and X2 independently represent halogen atoms;

[0023] Ar and, for any i, Ar i represents an independently substituted or unsubstituted divalent aromatic group; and

[0024] For any i, Z imeans independently an oxygen atom, a sulfur atom, an alkylene group, e.g. -CH2- or isopropylene (-C(CH3)2-), a carbonyl group, or a sulfonyl group.

[0025] First of all, X1 and X2 refer to the same halogen atom. Even more preferentially, they both refer to chlorine or fluorine.

[0026] First of all, Ar and, for any case i, Ar i means a divalent aromatic group selected from the list consisting of 1,3-phenylene, 1,4-phenylene, 1,1'-biphenyl (divalent at 4,4' positions), 1,1'-biphenyl (divalent at 3,4' positions), 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene, and more preferentially means independently 1,3-phenylene and 1,4-phenylene.

[0027] First of all, for any i, Z i means independently an oxygen atom or a carbonyl group, and more preferentially a carbonyl group.

[0028] According to certain embodiments, in formula (II) of compound A:

[0029] - i is equivalent to 2, and n is equivalent to 1;

[0030] - X1 and X2 both mean chlorine atoms or fluorine atoms;

[0031] - Ar and Ar2 both refer to a 1,4-phenylene group;

[0032] - Ar1 means a 1,3-phenylene or 1,4-phenylene group; and

[0033] - Z1 and Z2 both represent carbonyl groups.

[0034] In certain embodiments, compound B has the following chemical formula:

[0035] Ar'-O- (III),

[0036] In the above formula,

[0037] Ar' means a substituted or unsubstituted monovalent aromatic group, and preferentially means a monovalent aromatic group selected from the following list: phenyl, biphenyl, and naphthylene. Compound B may be a phenoxide in particular.

[0038] In certain embodiments, the molar ratio of compound B to compound A is 3:1 or less, preferentially 2.5:1 or less, more preferentially 2.3:1 or less, and very preferably about 2:1.

[0039] According to specific embodiments, compound B is obtained by deprotonating an aromatic alcohol B", which is the conjugate acid of aromatic alkoxide B, in situ or ex situ to obtain compound B, with a base reacted with B", said base being primarily selected from the following list: salts of aromatic or aliphatic alkoxides, carbonate salts, metal hydrides and alkali metals.

[0040] The base reacting with B" may be a linear or branched alkoxide salt comprising 3 to 10 carbon atoms, in particular. Preferably, the base is selected from the list of the following salts:

[0041] Isopropoxide, 1,2-dimethylpropoxide, 1,1-dimethylpropoxide, 2,2-dimethylpropoxide, 1,1,2-trimethylpropoxide, 1,2,2-trimethylpropoxide, 1-ethyl-2-methylpropoxide, 1-ethylpropoxide, n-butoxide, isobutoxide, secondary-butoxide, tertiary-butoxide, 2-methylbutoxide, 3-methylbutoxide, 1,2-dimethylbutoxide, 1,3-dimethylbutoxide, 2,3-dimethylbutoxide, 1,1-dimethylbutoxide, 2,2-dimethylbutoxide, 3,3-dimethylbutoxide, 1-ethylbutoxide, 2-ethylbutoxide, 1-propylbutoxide, 1,1,3,3-tetramethylbutoxide, n-pentoxide, 2-pentoxide, 2-methylpentoxide, n-hexoxide, 2-hexoxide, 3-methylpentoxide, 4-methylpentoxide, 2-ethylpentoxide, 2-ethylhexoxide, 2-propylheptoxide, n-heptoxide, 2-heptoxide, 3-heptoxide, n-octoxide, and mixtures thereof;

[0042] More preferably, the base may be selected from a list of salts of isopropoxide, n-butoxide, tertiary-butoxide, n-heptoxide, n-octoxide, and mixtures thereof.

[0043] The base that reacts with B" can also be a carbonate salt.

[0044] The base reacting with B" may be an alkali metal salt in particular. Preferably, the base is a sodium or potassium salt or a mixture of sodium and potassium salts.

[0045] The base that reacts with B" can also be sodium metal or potassium metal, preferentially sodium metal.

[0046] According to certain embodiments, the molar ratio of the base reacting with B" to B" is 1:1 or less.

[0047] According to specific embodiments, compound C has a polarity of 3 Debye or more, preferentially 3.5 Debye or more, measured at 20°C.

[0048] According to specific embodiments, compound C is selected from the following list: C1-C6-alkyl-2-pyrrolidones, in particular N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone,

[0049] Suloxides, in particular dimethyl sulfoxide or diethyl sulfoxide,

[0050] Sulfones, in particular dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone or tetramethylene sulfone,

[0051] Nitriles, especially acetonitrile, propionitrile, or benzonitrile,

[0052] N-dimethylamides, particularly dimethylacetamide or dimethylformamide,

[0053] and a mixture of these.

[0054] According to certain embodiments, compound C may be diphenyl sulfone.

[0055] According to certain embodiments, the molar ratio of compound C to compound A is 7.5:1 or less, preferentially 5:1 or less, and more preferentially 3:1 or less.

[0056] According to certain embodiments, compound A is reacted with compound B in the absence of any solvent.

[0057] According to certain embodiments, compound A reacts with compound B in a molten form.

[0058] The method according to the present invention also relates to a method for preparing a polyaryl ether ketone polymer, comprising the steps of preparing an aromatic diether as described above and reacting the aromatic diether with a compound D comprising at least two acyl chloride groups.

[0059] According to certain embodiments, compound D is a compound having the following chemical formula:

[0060] [Compound 3]

[0061]

[0062] In the above formula, j is an integer in the range of 1 to 3, and m is an integer equivalent to 0 or 1;

[0063] Ar and, for any j, Ar j means an independently substituted or unsubstituted divalent aromatic group, and primarily means a divalent aromatic group selected from the list consisting of 1,3-phenylene, 1,4-phenylene, 1,1'-biphenyl (divalent at the 4,4' positions), 1,1'-biphenyl (divalent at the 3,4' positions), 1,4-naphthylene, 1,5-naphthylene, and 2,6-naphthylene; and

[0064] For any j, Z j independently means an oxygen atom, a sulfur atom, an alkylene group, e.g. -CH2- or isopropylene (-C(CH3)2-), or a sulfone; preferentially, Z j means oxygen atom.

[0065] According to specific embodiments, the aromatic diether is selected from a list consisting of the following:

[0066] [Chemical Formula 4]

[0067]

[0068] [Chemical Formula 5]

[0069] or a mixture of these; and

[0070] Compound D is selected from a list of compounds consisting of the following:

[0071] [Chemical Formula 6]

[0072]

[0073] [Chemical Formula 7]

[0074] Or a mixture of these. Specific details for implementing the invention

[0075] Detailed description of the present invention

[0076] Compound A contains at least two halogenated aromatic groups.

[0077] An aromatic group is a group containing a conjugated ring that has significantly greater stability (due to delocalization) than that of a hypothetical localized structure. Advantageously, the aromatic groups of compound A are aromatic hydrocarbons.

[0078] Each halogenated aromatic group has at least one halogen atom substituting for a hydrogen atom. Advantageously, each halogenated aromatic group has a single halogen atom substituting for a hydrogen atom.

[0079] Aromatic groups may also independently comprise other substituent(s) for one or more residual hydrogen atoms(s), and these other substituent(s) are selected from: alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, amine, and quaternary ammonium.

[0080] According to specific embodiments, aromatic groups may also independently comprise a single different substituent for a hydrogen atom, wherein the substituent is preferentially as follows: an aryl or alkali metal sulfonate.

[0081] According to certain embodiments, compound A may have only two halogenated aromatic groups.

[0082] According to certain embodiments, compound A may be a compound having the following chemical formula:

[0083] [Chemical Formula 8]

[0084]

[0085] In the above formula,

[0086] - i is an integer in the range of 1 to 3, and n is an integer equivalent to 0 or 1;

[0087] - X1 and X2 independently represent halogen atoms;

[0088] - Ar and, for any i, Ar i represents an independently substituted or unsubstituted divalent aromatic group; and

[0089] - For any i, Z i means independently an oxygen atom, a sulfur atom, an alkylene group, e.g. -CH2- or isopropylene (-C(CH3)2-), a carbonyl group, or a sulfonyl group.

[0090] First of all, in the compound of formula (II):

[0091] - X1 and X2 can mean the same halogen atom; X1 and X2, in particular, can mean both chlorine or fluorine;

[0092] - Ar and, for any i, Ar i may independently mean a divalent aromatic group selected from the list consisting of 1,3-phenylene, 1,4-phenylene, 1,1'-biphenyl (divalent at 4,4' positions), 1,1'-biphenyl (divalent at 3,4' positions), 1,4-naphthylene, 1,5-naphthylene, and 2,6-naphthylene; and Ar and, in any case of i, Ar i can particularly mean 1,3-phenylene and 1,4-phenylene independently;

[0093] - For any i, Z i can independently mean an oxygen atom or a carbonyl group; for any i, Z i It can specifically mean a carbonyl group.

[0094] According to specific embodiments, compound A is compounds A1, A2, A3 or as defined in the examples. A4, or it may be a mixture of these mixtures.

[0095] Compound B is an aromatic alkoxide. Compound B advantageously contains an aromatic group that is a hydrocarbon.

[0096] The aromatic ring contains at least one alkoxide functional group substituted for a hydrogen atom. The aromatic ring may specifically have a single alkoxide functional group. Alternatively, the aromatic ring may have two alkoxide functional groups.

[0097] The aromatic ring of B may also comprise other substituents for one or more residual hydrogen atoms(s), and these other substituents are selected from: alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkylsulfonate, alkali or alkaline earth metal phosphonate, amine, and quaternary ammonium. In particular, the aromatic ring of B may comprise a single other substituent for a hydrogen atom, and this substituent is preferentially as follows: aryl or alkali metal sulfonate.

[0098] According to certain embodiments, compound B is a compound having the following chemical formula:

[0099]

[0100] In the above formula, Ar' means a substituted or unsubstituted monovalent aromatic group. Primarily, Ar' means a monovalent aromatic group selected from a list consisting of: phenyl, monovalent biphenyl, and naphnyl.

[0101] According to certain embodiments, compound B is a phenoxide.

[0102] The molar ratio of compound B to compound A is at least 2:1. This is because the reaction between B and A primarily causes a double substitution reaction between two molecules of B and one molecule of A to form an aromatic diether.

[0103] According to specific embodiments, the molar ratio of compound B to compound A is 3:1 or less, preferentially 2.5:1 or less, more preferentially 2.3:1 or less, and very preferably about 2:1.

[0104] The reaction medium is referred to as a "reaction mixture" when two reagents, namely compound A and compound B, are placed in contact.

[0105] "Reaction time" refers to the time it takes for reagents to react with each other.

[0106] If the reaction is completed with the desired conversion, primarily the total conversion of compound A into its products, the reaction mixture is subsequently referred to as the "product mixture."

[0107] "Reaction temperature" corresponds to the temperature of the reaction mixture during the reaction time.

[0108] "Reaction pressure" refers to the pressure applied to the reaction mixture during the reaction time.

[0109] The reaction can be carried out in a reactor. The reactor may be, for example, a glass reactor, a reactor with glass inner walls, or a reactor made of stainless metal materials, or a reactor lined with PTFE.

[0110] First of all, the reaction can be carried out in a reaction mixture that substantially does not contain any water.

[0111] In particular, the reaction can be carried out in an atmosphere that substantially does not contain any water or oxygen, for example, under a nitrogen or argon atmosphere.

[0112] In particular, the reaction mixture may be stirred for all or part of the reaction time. Accordingly, the reactor is preferably provided with a recirculation loop having a stirring device, such as a mechanical stirrer (which may include, for example, one or more blades) or a pump.

[0113] According to certain embodiments, the reaction may be carried out in the presence of compound C acting as a solvent. Reagents and / or reaction intermediates and / or reaction products may be at least partially dissolved therein. In these embodiments, the molar ratio of compound C to compound A is 10:1 or less, i.e., the reaction is carried out as a concentrated reaction mixture. This has the effect of minimizing the incorporation of solvent-mediated impurities into the reaction mixture in particular.

[0114] The solvent may be selected from the following list: linear or branched alcohols comprising 3 to 10 carbon atoms, C1-C6-alkyl-2-pyrrolidones, sulfoxides, sulfones, nitriles, N-dimethylamides, and mixtures thereof.

[0115] The solvent may be a linear or branched alcohol, particularly one comprising 3 to 10 carbon atoms. The alcohol is preferentially non-aromatic. As described below, the solvent alcohol may be generated during the step of deprotonating an aromatic alcohol, particularly a conjugate of aromatic alkoxide B, into an alkoxide salt. The solvent alcohol may be selected from the following list: isopropanol, 1,2-dimethylpropanol, 1,1-dimethylpropanol, 2,2-dimethylpropanol, 1,1,2-trimethylpropanol, 1,2,2-trimethylpropanol, 1-ethyl-2-methylpropoxide, 1-ethylpropoxide, n-butanol, isobutanol, secondary-butanol, tertiary-butanol, 2-methylbutanol, 3-methylbutanol, 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,3-dimethylbutanol, 1,1-dimethylbutanol, 2,2-dimethylbutanol, 3,3-dimethylbutanol, 1-ethylbutanol, 2-ethylbutanol, 1-propylbutanol, 1,1,3,3-tetramethylbutanol, n-pentanol, 2-pentanol, 2-methylpentanol, n-hexanol, 2-hexanol, 3-methylpentanol, 4-methylpentanol, 2-ethylpentanol, 2-ethylhexanol, 2-propylheptanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol and mixtures thereof.

[0116] Primarily, the solvent alcohol may be selected from the following list: isopropanol, n-butanol, tertiary-butanol, n-heptanol, n-octanol, and mixtures thereof.

[0117] The solvent may also be C1-C6-alkyl-2-pyrrolidone, where the alkyl group comprises 1 to 6 carbons. Advantageously, C1-C6-alkyl-2-pyrrolidone may be N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone.

[0118] The solvent may also be a sulfone. Advantageously, the sulfone may be dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone, or tetramethylene sulfone. According to certain advantageous embodiments, the solvent may be diphenyl sulfone.

[0119] The solvent may also be a nitrile. Advantageously, the nitrile may be acetonitrile, propionitrile, or benzonitrile.

[0120] The solvent may also be N-dimethylamide. Advantageously, the N-dimethylamide is dimethylacetamide or dimethylformamide.

[0121] According to certain embodiments, the solvent has a polarity of 3 Debye or higher, preferentially 3.5 Debye or higher, measured at 20°C. This level of polarity enables better dissolution of reagents and reaction intermediates, and thus promotes nucleophilic substitution reactions.

[0122] The molar ratio of compound C to compound A is 10:1 or less. Therefore, the above method makes it possible to produce aromatic diethers in a highly concentrated reaction mixture or even in bulk, and thus enables the optimization of mass production. Furthermore, aromatic diethers can be obtained with at least equivalent and, in many cases, better yield and good purity than those in the prior art methods.

[0123] The molar ratio of compound C to compound A may be, preferentially, 7.5:1 or less, more preferably 5:1 or less, and very preferably 3:1 or less.

[0124] In certain embodiments, compound C may be an "ACS grade" solvent, that is, a solvent having purity limits defined by the American Chemical Society (ACS) purity limits. Compound C may have a purity of 95% or more, or 96% or more, or 97% or more, or 98% or more, or 99% or more. Compound C may not be a high-purity solvent of grades used particularly in analytical chemistry.

[0125] In certain embodiments, specific purity parameters for compound C can nevertheless be controlled. Compound C is particularly halide ions (Cl- , F - ), alkali metal ions (Na + , K + ), metal ions (Fe(II), Fe(III)) and specific amounts of water, typically less than 100 ppm, preferably less than 50 ppm.

[0126] According to other embodiments, the reaction may be carried out in the absence of any solvent. The reaction of the reaction mixture is hereinafter referred to as a "bulk" reaction. This embodiment has the additional advantage of not requiring any step of recirculating the reaction solvent, which would, in principle, be necessary when the method is scaled up to an industrial scale. This also has the advantage of limiting the increase in internal reactor pressure.

[0127] According to specific embodiments, the reaction temperature is such that compounds A and B are in a molten form and / or are dissolved in the reaction mixture for all or part of the reaction time. Advantageously, compound A is in a molten form (above the melting point) and compound B is dissolved in the molten compound A and / or, where appropriate, in compound C acting as a solvent for at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90% of the reaction time.

[0128] According to specific embodiments, the reaction temperature is such that the aromatic diether, which is the desired product of the reaction of compound A and compound B, is in a molten form and / or is dissolved in the molten compound A for all or part of the reaction time. In particular, the aromatic diether may be in a molten form and / or be dissolved in the molten compound A for at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% of the reaction time.

[0129] According to any specific embodiment, compound A is compound A1, A2, A3 or as defined in the examples. In particular, in embodiments that may be A4, the reaction mixture is heated to a temperature of at least 165°C, preferentially at least 170°C, at least 180°C, or at least 190°C for at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% of the reaction time.

[0130] According to specific embodiments, the response time is 5 minutes to 5 days, preferentially 10 minutes to 24 hours, and more preferentially 30 minutes to 5 hours.

[0131] According to specific embodiments, compound A is added to compound B or a mixture of B and C.

[0132] According to specific embodiments, the reaction between compound A and compound B is carried out at atmospheric pressure or near atmospheric pressure.

[0133] Compound B can be obtained by deprotonation of the aromatic alcohol B", which is the conjugate acid of the aromatic alkoxide B. B" subsequently has the following chemical formula: Ar'-OH (IIIa).

[0134] According to a specific embodiment, B" is phenol.

[0135] Compound B" can be deprotonated with a base suitable for the deprotonation of aromatic alcohols.

[0136] The above base may be selected from a list consisting of aromatic or aliphatic alkoxide salts, carbonate salts, metal hydrides, and alkali metals.

[0137] The above base may be selected from salts of linear or branched alkoxides, particularly those comprising 3 to 10 carbon atoms. In this embodiment, the base is an alcohol that can act as a solvent when maintained in the reaction mixture by reaction with a proton. The above base may primarily be selected from a list consisting of the following salts: isopropoxide, 1,2-dimethylpropoxide, 1,1-dimethylpropoxide, 2,2-dimethylpropoxide, 1,1,2-trimethylpropoxide, 1,2,2-trimethylpropoxide, 1-ethyl-2-methylpropoxide, 1-ethylpropoxide, n-butoxide, isobutoxide, secondary-butoxide, tertiary-butoxide, 2-methylbutoxide, 3-methylbutoxide, 1,2-dimethylbutoxide, 1,3-dimethylbutoxide, 2,3-dimethylbutoxide, 1,1-dimethylbutoxide, 2,2-dimethylbutoxide, 3,3-dimethylbutoxide, 1-ethylbutoxide, 2-ethylbutoxide, 1-propylbutoxide, 1,1,3,3-tetramethylbutoxide, n-pentoxide, 2-pentoxide, 2-methylpentoxide, n-hexoxide, 2-hexoxide, 3-methylpentoxide, 4-methylpentoxide, 2-ethylpentoxide, 2-ethylhexoxide, 2-propylheptoxide, n-heptoxide, 2-heptoxide, 3-heptoxide, n-octoxide, and mixtures thereof;

[0138] More preferably, the above base is selected from a list of salts of isopropoxide, n-butoxide, tertiary-butoxide, n-heptoxide, n-octoxide, and mixtures thereof.

[0139] The above base may also be a carbonate salt. The carbonate salt may be in particular in the form of a powder, and the powder has a particle size distribution such that D90 has a value in the range of 45 micrometers to 250 micrometers and D99.5 has a value of 710 micrometers or less, and the particle size distribution is measured by laser diffraction according to standard ISO 13320:2009.

[0140] In certain embodiments where the base is a salt, the base may be an alkali metal salt in particular. Primarily, the salt may be a sodium salt, a potassium salt, or a mixture of sodium and potassium salts.

[0141] The above base may also be sodium metal, lithium metal, or potassium metal, preferentially sodium metal.

[0142] The above base may also be sodium hydride, lithium hydride, or potassium hydride.

[0143] The deprotonation step of B" can be performed in situ or ex situ for the reaction between compound A and compound B.

[0144] According to certain embodiments, the molar ratio of the base to B" is 1:1 or less. This advantageously ensures a quantitative reaction of the base.

[0145] According to a first variant, the method comprises the following steps in succession: a first step of deprotonating B" with a base to form compound B, and a second step of reacting compound B with compound A in the presence of compound C, which optionally acts as a reaction solvent.

[0146] Between the first and second steps, a step of removing excess B" and / or any solvent(s) used or generated during the first step, and / or water may be advantageously performed if necessary.

[0147] According to the second variation, the base, compound B, compound A, and, if appropriate, compound C can be mixed together in any order to form a reaction mixture.

[0148] When the reaction completes the desired conversion, the reaction mixture is referred to as the "product mixture." The product mixture is purified, and the aromatic diether can be isolated as described below.

[0149] The reaction product residue obtained from the reaction of compound A and compound B can be purified by methods well known to those skilled in the art, comprising one or more distillation steps, one or more solid / liquid separation steps, one or more washing steps, one or more extraction steps, and one or more recrystallization steps.

[0150] In embodiments where the reaction of compound A and compound B is carried out with compound C acting as a reaction solvent, the solvent can be removed to obtain a solvent-free residue of the reaction products.

[0151] If the aromatic diether is sufficiently insoluble in the reaction solvent, it can be recovered through any solid / liquid separation means. Solid / liquid separation may be performed in one or more consecutive steps, each step selected from the group consisting of: centrifugal filtration, precipitation, centrifugal gradient separation, vacuum filtration, pressure filtration, and gravity filtration. The solid / liquid separation temperature must be sufficiently low to reduce the solubility of the aromatic diether in the reaction solvent.

[0152] Alternatively and advantageously, the reaction solvent can be removed by distillation or by replacement with another solvent having a lower boiling point.

[0153] In the first place, when A is reacted with B in the presence or absence of compound C, the solvent-free residue of the reaction products can be purified through one or more washing steps or by sublimation or crystallization.

[0154] A method for purifying reaction product residues containing 1,4-bis(4-phenoxybenzoyl)benzene and / or 1,3-bis(4-phenoxybenzoyl)benzene is described below. However, those skilled in the art will know how to apply these methods, particularly how to select solvents to be used for other aromatic diethers prepared according to the present invention.

[0155] The step of washing the residue containing 1,4-bis(4-phenoxybenzoyl)benzene and the residue containing 1,3-bis(4-phenoxybenzoyl)benzene may include the addition of a washing solvent (and the selection of a corresponding temperature), wherein 1,4-bis(4-phenoxybenzoyl)benzene and / or 1,3-bis(4-phenoxybenzoyl)benzene is slightly soluble, but impurities, such as salts and / or unreacted reagents (particularly phenoxides), are soluble. Advantageously, the residue is placed in contact with a protic washing solvent, such as water or a water / methanol mixture (95 / 5), at room temperature (25°C) for a sufficient contact time.

[0156] In certain embodiments, the residue may be ground into fine particles to improve the washing solvent / residue contact surface area if necessary.

[0157] In certain embodiments, the residue is suspended in the washing solvent while stirring to maintain contact between the washing solvent and the residue for a sufficient amount of time.

[0158] The residue / washing solvent mixture is subsequently separated by solid / liquid separation means, for example, by filtration or centrifugation. The solid phase can advantageously be dried to remove any trace amount of solvent.

[0159] 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene can advantageously be dissolved in an extraction solvent, such as chloroform or acetone, at room temperature. After solid / liquid separation, the liquid phase essentially containing 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene can be recovered, and the purified product can finally be obtained by removing the extraction solvent (distillation). Advantageously, 1,4-bis(4-phenoxybenzoyl)benzene can be extracted with chloroform. Advantageously, 1,3-bis(4-phenoxybenzoyl)benzene can be extracted with acetone.

[0160] In certain embodiments, the residue may be purified by a final recrystallization step. In these embodiments, the residue undergoes primarily only a single recrystallization step. This is possible due to the fact that the reaction mixture was produced in a highly concentrated medium, or even in bulk, due to the relatively low levels of impurities generally removed.

[0161] 1,4-bis(4-phenoxybenzoyl)benzene can also be advantageously recrystallized from toluene.

[0162] 1,3-bis(4-phenoxybenzoyl)benzene can also be advantageously recrystallized from methanol.

[0163] The purity of aromatic diethers can be determined by a number of general characterization methods, particularly nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), high-performance liquid chromatography (HPLC) and / or ultra-high-performance liquid chromatography (UPLC).

[0164] Preferably, the aromatic diether is obtained with a purity of 95% or more, preferably 99% or more, and more preferably 99.9% or more as evaluated by NMR (molar percentage).

[0165] Alternatively, aromatic diethers are obtained with a purity of 95% or more, preferably 99% or more, more preferably 99.9% or more, as evaluated by HPLC (mass percentage).

[0166] The aromatic diether obtained according to embodiments of the present invention can subsequently be used to perform an electrophilic polymerization reaction to produce a polyaryl ether ketone (PAEK) polymer, and the aromatic diether is reacted with compound D comprising at least two acyl chloride groups.

[0167] Compound D may be a compound having the following chemical formula:

[0168] [Chemical Formula 9]

[0169]

[0170] In the above formula, j is an integer in the range of 1 to 3, and m is an integer equivalent to 0 or 1;

[0171] Ar and, for any j, Ar j represents an independently substituted or unsubstituted divalent aromatic group; and

[0172] For any j, Z j means independently an oxygen atom, a sulfur atom, an alkylene group, such as -CH2- or isopropylene (-C(CH3)2-), or a sulfone.

[0173] First of all, Ar and, for any j, Ar j means a divalent aromatic group selected from the list consisting of: 1,3-phenylene, 1,4-phenylene, 1,1'-biphenyl (divalent at the 4,4' positions), 1,1'-biphenyl (divalent at the 3,4' positions), 1,4-naphthylene, 1,5-naphthylene, and 2,6-naphthylene.

[0174] First of all, for any j, Z j means oxygen atom.

[0175] According to specific embodiments, compound D may be selected from the following list: phthaloyl dichloride, isophthaloyl dichloride, terephthaloyl dichloride, or a mixture thereof. Preferably, compound D may be selected from the following list: isophthaloyl dichloride, terephthaloyl dichloride, or a mixture thereof.

[0176] According to any specific embodiment, the aromatic diether synthesized according to the present invention may be selected from the following list: 1,4-bis(4-phenoxybenzoyl)benzene, 1,3-bis(4-phenoxybenzoyl)benzene, or a mixture thereof.

[0177] Accordingly, in an embodiment where PAEK is a polyether ketone, the difunctional aromatic acyl chloride may be phthaloyl dichloride, terephthaloyl dichloride, isophthaloyl dichloride, or a mixture thereof, and the aromatic diether may be 1,4-bis(4-phenoxybenzoyl)benzene, 1,3-bis(4-phenoxybenzoyl)benzene, or a mixture thereof.

[0178] The polymerization reaction is preferably carried out in a solvent. The solvent is preferably an aprotic solvent, which may be selected particularly from the list consisting of: methylene chloride, carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, or mixtures thereof. Ortho-dichlorobenzene is particularly preferred for producing polyether ketones.

[0179] The polymerization reaction is preferably carried out in the presence of a Lewis acid as a catalyst.

[0180] Lewis acids may be selected from the following list in particular: aluminum trichloride, aluminum tribromide, antimony chloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, tin chloride, titanium tetrachloride, and molybdenum chloride. Aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony chloride, ferric chloride, gallium trichloride, and molybdenum chloride are preferred. Aluminum trichloride is particularly preferred for producing polyether ketones.

[0181] According to certain variations, polymerization may be carried out in the same reactor used for the production of aromatic diethers. However, in preference, polymerization is carried out in a different reactor.

[0182] Polymerization can be carried out at a temperature in the range of, for example, 20 to 120°C.

[0183] A method for producing PAEK, and in particular polyether ketones, advantageously comprises one or more steps of purifying a polymer, for example, said steps are as follows:

[0184] - A step of mixing PAEK-containing polymerization reaction products with a protic solvent to provide a PAEK suspension;

[0185] - Preferably, a step of separating the PAEK polymer from the PAEK suspension by filtration and washing.

[0186] The protic solvent used for PAEK suspension can be, for example, methanol.

[0187] The PAEK polymer can then be recovered from the PAEK suspension by filtration. If necessary, the polymer can preferably be washed with a protic solvent, such as methanol, and filtered one or more times. Washing can be performed, for example, by resuspending the polymer in a solvent.

[0188] Examples

[0189] The following examples illustrate the invention but do not limit it.

[0190] Devices used for characterization

[0191] For high-performance liquid chromatography (HPLC) measurements, a Waters XterraMS C18 3.5 μm 4.6 x 150 mm column was used with a mobile phase containing the following mixture: water / acetonitrile + 0.05% trifluoroacetic acid as a gradient. Measurements were taken at 20°C at variable wavelengths.

[0192] For mass spectrometry (MS) measurements, the Waters Xevo G2-XS QTof instrument was used with the following parameters:

[0193] Sample injection by the ASAP probe (Atmospheric-pressure Solids Analysis Probe)

[0194] Ionization Mode: Positive ASAP

[0195] Mass range: 50-1000 m / z

[0196] Source temperature: 120℃

[0197] Corona current: 10 μA

[0198] Cone voltage: 50 V

[0199] Proton nuclear magnetic resonance ( 1 For H NMR measurements, Brueker Avance III (500 MHz) and Brueker Neo (600 MHz) spectrometers were used with CDCl3 as the solvent.

[0200] Carbon nuclear magnetic resonance ( 13 For C NMR measurements, Brueker Avance III 500 MHz (125 MHz) and Brueker Neo 600 MHz (150 MHz) spectrometers were used with CDCl3 as the solvent.

[0201] For melting point measurements, a Kofler bench and a Gallenkamp melting point apparatus (including capillaries) were used.

[0202] The crude yield is defined as the ratio of the number of moles of product obtained at the end of the reaction to the number of moles of dihalo compound injected.

[0203] Hereinafter, the term "purified product yield" refers to the ratio of the moles of the purified product (expected product) to the moles of the injected dihalo compound, specifically to the moles of the washed and / or extracted and / or recrystallized crude product. This yield relates to the purity assessed by NMR (mol%) or HPLC (mass%).

[0204] Examples 1: 1,4-bis(4-fluorobenzoyl)benzene

[0205] Compound A1 of the following formula:

[0206] [Chemical Formula 10]

[0207]

[0208] The product was synthesized under the following conditions: 1 equivalent (eq.) of terephthaloyl chloride (5 g; 24.6 mmol), 10 equivalents of fluorobenzene (28 g), and 2.1 equivalents of AlCl3 (6.9 g; 51.7 mmol). In this reaction, the fluorobenzene served as both a reagent and a solvent. Aluminum chloride was added to the terephthaloyl chloride dissolved in fluorobenzene in divided portions (over 10 minutes) at 25°C under stirring in an argon atmosphere. At the end of the addition of AlCl3, the reaction mixture was maintained at 60°C for 2 hours while stirring. After cooling, the resulting product mixture was poured over ice water and then the excess fluorobenzene was evaporated under vacuum on a rotary evaporator. The resulting white solid was filtered, washed several times with distilled water, 10% aqueous sodium hydroxide, and then water, and finally dried under vacuum. The expected product A1 was obtained in a yield of approximately 99.1%. Crystallization of the crude product from dimethylacetamide yielded a purified product with a yield of approximately 96% and a purity of >99.5% (NMR and MS). The product obtained in the form of white crystals is soluble in chloroform, acetone, dichloromethane, and partially methanol. The measured melting point was 220°C.

[0209] Example 2: 1,3-Bis(4-fluorobenzoyl)benzene

[0210] Compound A2 of the following formula:

[0211] [Chemical Formula 11]

[0212]

[0213] Compound A1 of Example 1 was synthesized in substantially the same manner as Compound A1, except that isophthaloyl dichloride was used instead of terephthaloyl dichloride.

[0214] After treatment similar to that applied to compound A1, compound A2 was obtained in nearly quantitative yield in the form of white crystals with a measured melting point of 181°C.

[0215] The product is soluble in common solvents. It was crystallized from toluene. The yield obtained was approximately 95%. The purity according to NMR, MS, and HPLC was approximately 99.8%.

[0216] Example 3: 1,4-Bis(4-chlorobenzoyl)benzene

[0217] Compound A3 of the following formula:

[0218] [Chemical Formula 12]

[0219]

[0220] Compound A1 of Example 1 was synthesized in substantially the same manner as Compound A1, except that chlorobenzene was used instead of fluorobenzene.

[0221] Nevertheless, specific reaction conditions were modified to provide a better yield of the expected product. The reaction conditions were as follows: 1 equivalent of terephthaloyl chloride (5 g; 24.6 mmol), 16 eq. of chlorobenzene (44.35 g (40 ml), 0.394 mol), and 2.4 eq. of AlCl3 (7.88 g, 59.1 mmol). Aluminum chloride was added to the terephthaloyl chloride dissolved in chlorobenzene in divided portions (over 10 minutes) under stirring at room temperature under an argon atmosphere. The fluorobenzene used in this reaction acts as both a reagent and a solvent. At the end of the addition of AlCl3, the reaction mixture was stirred overnight at 25°C and then at 90°C for the following 3 hours. After the same treatment as for compound A1, the expected product A3 was obtained in the form of a white powder in nearly quantitative yield. A pure product was obtained in the form of white crystals with a melting point equivalent to 259°C by crystallization of the crude product from dimethylacetamide (DMAc). The yield of the crystallized product was approximately 96%. High-temperature NMR studies showed a selectivity of exactly over 99.6%.

[0222] Example 4: 1,3-Bis(4-chlorobenzoyl)benzene

[0223] Compound A4 of the following formula:

[0224] [Chemical Formula 13]

[0225]

[0226] Compound A1 of Example 1 was synthesized in substantially the same manner as Compound A1, except that chlorobenzene was used instead of fluorobenzene and isophthaloyl dichloride was used instead of terephthaloyl dichloride. Nevertheless, specific reaction conditions were modified as detailed below.

[0227] At the end of the fractional addition of aluminum chloride to isoterephthaloyl chloride dissolved in chlorobenzene at room temperature, the reaction medium was stirred at this temperature for 10 hours and then at 90°C for 2 hours. After cooling and evaporating the excess chlorobenzene, the obtained solid residue was extracted with dichloromethane (DCM). The organic phase was washed twice with water, three times with 10% aqueous sodium hydroxide, and finally twice with water. It was then dried and evaporated under vacuum. The product was obtained in the form of pure white crystals (purity exceeding exactly 99.6%) with a measured melting point of 215°C, as determined by NMR and MS. The yield was approximately 96%.

[0228] Examples 5: A as a dilution reaction mixture 1 M from 1 / M 1 Mixture (Comparative Example)

[0229] A mixture of phenol (0.718 g; 2 eq.) and potassium carbonate (1.055 g; 2 eq.) was dissolved in a solvent mixture: toluene (10 mL) / NBP (10 mL) and refluxed for 1 hour (bath temperature of 130°C). After the addition of compound A1 and subsequent distillation of toluene, the reaction mixture was heated at 150°C–160°C for 2 hours. After treatment of the obtained residue with a water / methanol (95 / 5) mixture, filtration, washing with a water / methanol (95 / 5) mixture, and drying, the crude product was obtained in the form of a white powder with a yield of 81%.

[0230] Structure of the expected product, which is the aromatic diether M1 of the following formula:

[0231] [Chemical Formula 14]

[0232] ,

[0233] It was confirmed by NMR and mass spectrometry (MS) analyses.

[0234] In mass spectrometry, the presence of the monophenoxy derivative M'1 of the following formula (approx. 15% surface area ratio) was detected:

[0235] [Chemical Formula 15]

[0236]

[0237] The yield of the crystallized product from toluene was about 72%, and the purity was exactly over 99% as measured by NMR.

[0238] The measured melting point mp was as follows: 208℃.

[0239] Examples 6: A as a dilution reaction mixture 2 M from 2 / M 2 Mixture (Comparative Example)

[0240] Compound M2 of the following formula, in a manner similar to that of Example 5:

[0241] [Chemical Formula 16]

[0242] ,

[0243] Compound A1 was replaced with Compound A2 and obtained from Compound A2 under conditions similar to those described for the synthesis of M1. The difference from Example 5 is that in this case, the reaction mixture was heated to 150°C-160°C for only 30 minutes after the toluene was distilled off.

[0244] The product was obtained in the form of a white solid with an unrefined yield of about 70%.

[0245] The structure of product M2 was confirmed by NMR and mass spectrometry analyses.

[0246] In mass spectrometry, the presence of trace amounts of the monophenoxy product M2' (approx. 15%) of the following formula was detected:

[0247] [Chemical Formula 17]

[0248] .

[0249] The yield of the product crystallized from methanol was about 61%, and the purity was exactly over 99% as measured by NMR.

[0250] The measured melting point mp was as follows: 133℃.

[0251] Examples 7: A as a concentrated solution 1 M from 1 (The present invention)

[0252] In a sealed tube, phenol (2.5 equivalents) and anhydrous potassium bicarbonate (2.5 equivalents) (in powder form), followed by 0.2 mL of N-butyl-2-pyrrolidone (NBP), were injected under argon. The reaction mixture was heated at 180°C while stirring for 30 minutes. After partial cooling (about 100°C), 1 mmol (1 equivalent) of compound A1 was added.

[0253] The reaction mixture was subsequently heated at 205°C for 2 hours. The progress of the reaction was monitored by HPLC, MS, and NMR. Thus, it was indicated that the conversion to the desired product was nearly quantitative 2 hours after the completion of compound A1 addition. In addition, neither the starting product nor the monophenoxy derivative M1' was detected.

[0254] The obtained residue was treated by adding methanol and then evaporating it under vacuum on a rotary evaporator until NBP was removed (azeotropic mixture).

[0255] The unpurified product obtained in the form of a grayish-white solid was extracted with chloroform. After filtering out insoluble substances and evaporating the chloroform, the unpurified product was subsequently crystallized from toluene.

[0256] Pure product M1 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 83% and a purity of exactly over 99 mol% as measured by NMR. The measured melting point was 212°C.

[0257] Examples 8: A as a concentrated solution 2 M from 2 (The present invention)

[0258] Compound A2 was substituted for Compound A1 in a manner similar to that of Example 7, and Compound M2 was obtained from Compound A2 under conditions similar to those described for the synthesis of M1. One difference from Example 7 is that the unrefined product obtained in the form of a grayish-white solid was extracted with acetone instead of chloroform in this case.

[0259] Pure product M2 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 84% and a purity of over 99% by HPLC. The measured melting point was 133°C.

[0260] Examples 11: A using potassium alkoxide as a base 1 M from 1 (The present invention)

[0261] Phenol (2.3 eq.) and then potassium tert-butoxide (t-BuOK; 2.2 eq.) were injected into a sealed tube under argon. The reaction medium was heated at 185°C for 30 minutes while stirring. After partial cooling (about 100°C), compound A1 (1 eq.) was added.

[0262] The reaction mixture was then heated at 215°C for 2 hours. The progress of the reaction was monitored by HPLC, MS, and NMR.

[0263] Therefore, it was indicated that the desired product M1 was obtained almost quantitatively 2 hours after the end of the addition of compound A1.

[0264] The obtained residue was treated by extraction with chloroform. Insoluble substances from the product were filtered out and the chloroform was evaporated, after which the unrefined product was purified by washing with methanol (and alternatively or additionally crystallized from toluene).

[0265] Pure product M1 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of approximately 93% and a purity of exactly over 99.5% as measured by NMR. The measured melting point was 212°C.

[0266] The use of t-BuOH as a base to deprotonate phenol results in the formation of tert-butanol (t-BuOH), which acts as a solvent and facilitates the entire conversion. A second advantage of this base is that it enables the recovery / recycling of alcohol at the end of the reaction by simple distillation.

[0267] Example 12: A using potassium alkoxide as a base 2 M from 2 (The present invention)

[0268] Compound A2 was substituted for Compound A1 in a manner similar to that of Example 11, and Compound M2 was obtained from Compound A2 under conditions similar to those described for the synthesis of M1. However, the following difference regarding the post-treatment step should be noted: the crude product was extracted with acetone instead of chloroform.

[0269] The addition of compound A2 was terminated, and the desired product M2 was obtained nearly quantitatively 2 hours later (reaction progress was monitored by NMR).

[0270] Pure product M2 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 92% and a purity of exactly over 99.5% by HPLC. The measured melting point was approximately 132°C–133°C.

[0271] Example 13: A as a dilution reaction mixture 3 M from 1 / M 1 Mixture (Comparative Example)

[0272] To synthesize compound M1 from compound A3, the method was carried out substantially as in the reaction of Example 5, with A3 replaced by A1. The following conditions were used: A3 (1.9 mmol; 1 eq.), phenol (2 eq.), and potassium carbonate (2 eq.). The solvent used was a mixture of toluene (5 mL) and NBP (5 mL).

[0273] The reaction mixture was heated at 200°C for 24 hours (after distilling off toluene) (instead of 160°C for 2 hours for the fluoro derivative).

[0274] The obtained residue was treated by adding methanol and then evaporating it under vacuum on a rotary evaporator until NBP was removed (azeotropic mixture).

[0275] The expected product M1 detected by MS (approx. 70%) was obtained as a mixture having the starting material and a monophenoxy derivative of formula M1" below (approx. 15% surface area ratio):

[0276] [Chemical Formula 18]

[0277] .

[0278] These results indicate that the conversion was not completed due to the increase in temperature and the extension of the heating time. The expected pure product M1 was obtained after crystallization of the unrefined product from toluene in a yield of 57% and with a purity of exactly over 99% as measured by NMR. The measured melting point was 211°C.

[0279] Example 14: A as a dilution reaction mixture 4 M from 2 / M 2 " Mixture (Comparative Example)

[0280] Compound M2 was obtained from compound A4 by replacing compound A3 with compound A4 in a manner similar to that of Example 13, under conditions similar to those described for the synthesis of M1.

[0281] Monophenoxy derivative M2" detected in the crude product by MS of the following formula (approx. 15% area ratio):

[0282] [Chemical Formula 19]

[0283]

[0284] and obtained as a mixture containing trace amounts of starting materials (confirmed by NMR and MS).

[0285] After crystallization of the crude product from methanol, the pure product M2 (structure confirmed by NMR and MS) was obtained as a white solid with a yield of approximately 55% and a purity of exactly over 99%. The recrystallized product has the following measured melting point: 132°C.

[0286] Examples 15: A as a concentrated solution 3 M from 1 (The present invention)

[0287] To synthesize compound M1 from compound A3, the method was carried out in a manner similar to the reaction of Example 7 by substituting A3 with A1. The following conditions were used: A3 (1 mmol; 1 eq.), phenol (2.8 eq.), and anhydrous potassium bicarbonate (2.8 eq.). The solvent used was NBP (0.2 mL).

[0288] The reaction mixture was heated at 220°C for 3 hours. The progress of the reaction was monitored by HPLC, MS, and NMR. Thus, it was indicated that the conversion to the desired product was nearly quantitative 3 hours after the completion of the addition of compound A3. Post-treatment of the unrefined product was performed in the same manner as in Example 7.

[0289] Pure product M1 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 82% and a purity of exactly over 99.5% as measured by NMR. The measured melting point was 211°C.

[0290] Examples 16: A as a concentrated solution 4 M from 2 (The present invention)

[0291] The procedure was exactly the same as that of the synthesis in Example 15, except that A3 was replaced with A4, the reaction mixture was heated to 210°C instead of 220°C, and the unpurified product was extracted with acetone instead of chloroform.

[0292] Pure product M2 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 82% and a purity of over 99.5% as measured by NMR. The measured melting point was 133°C.

[0293] Example 19: A using potassium alkoxide as a base 3 M from 1 (The present invention)

[0294] Phenol (2.3 eq.) and then t-BuOK (2.2 eq.) were injected into a sealed tube under argon. The reaction medium was heated at 185°C for 30 minutes while stirring. After partial cooling (about 100°C), compound A3 (1 eq.) was added.

[0295] The reaction mixture was then heated at 220°C for 3 hours. The progress of the reaction was monitored by HPLC, MS, and NMR. Thus, it was indicated that the desired product M1 was obtained nearly quantitatively 3 hours after the addition of compound A3 was stopped.

[0296] The obtained residue was extracted with chloroform. After filtering out insoluble substances and evaporating the chloroform, the unrefined product (relatively pure by NMR) was subsequently crystallized from toluene.

[0297] Pure product M1 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 90% and a purity of exactly over 99.5% as measured by NMR. The measured melting point was 212°C.

[0298] Example 20: A using potassium alkoxide as a base 4 M from 2 (The present invention)

[0299] The procedure was exactly the same as that of the synthesis in Example 19, except that A3 was replaced with A4, the reaction mixture was heated to 205°C instead of 220°C, and in the post-treatment step, the unrefined product was extracted with acetone instead of chloroform.

[0300] After the addition of compound A2 was stopped, the desired product M2 was obtained almost quantitatively 2 hours later, which was confirmed by NMR.

[0301] Pure product M2 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 90% and a purity of exactly over 99.5% as measured by NMR. The measured melting point was 132°C.

[0302] Examples 21-24: Alkoxide counterion t-BuO - The influence of

[0303] Experiments similar to those of Examples 11, 12, 19, and 20 were performed, in which t-BuONa was used instead of t-BuOK. These were designated as Examples 21, 22, 23, and 24, respectively. Reaction times and temperatures were adjusted to obtain virtually quantitative conversions. The conditions used and the results obtained are summarized in Table 1 below:

[0304] [Table 1]

[0305]

[0306] Accordingly, a comparison of Examples 11, 12, 19, and 20 with Examples 21, 22, 23, and 24 indicates that the reaction with t-BuOK is much faster than the reaction with t-BuONa, and the reactions occur in t-BuOH / excess phenol acting as the solvent.

[0307] Examples 25: A, which removed alcohols before the reaction and used potassium alkoxide as a base 1 M from 1

[0308] Phenol (2.3 eq.) and t-BuOH (2.2 eq.) were injected into a sealed tube under argon. The reaction medium was heated at 185°C (bath temperature) for 30 minutes. After partial cooling (about 100°C), t-BuOH formed as a byproduct and excess phenol were removed by evaporation using a stream of nitrogen or argon. Compound A1 was then added.

[0309] After the total addition of compound A1, the reaction mixture was heated at 230°C (bath temperature) for 1 hour. It was noted that from T = 210°C (bath temperature), the reaction medium turned into a light brown, easily stirred suspension.

[0310] The reaction progress was monitored by NMR. Thus, it was possible to indicate that the conversion to the expected product M1 was completed 1 hour after the addition of compound A1 was stopped.

[0311] After cooling, the unrefined product formed in the form of a light brown solid was scraped and subsequently ground. To remove formed salts and any trace amounts of phenol, the obtained unrefined product was stirred in distilled water (20 mL) for 1 hour, then filtered, washed several times with distilled water, and finally with pentane. After drying in an oven at 75°C for 2 hours, the expected product M1 was obtained in the form of an off-white powder with a yield of 94% and a purity of more than 99.5% as determined by NMR.

[0312] Examples 26: A, which removed alcohols before the reaction and used potassium alkoxide as a base 3 M from 1

[0313] Phenol (2.3 eq.) and t-BuOH (2.2 eq.) were injected into a sealed tube. The reaction medium was heated at 185°C (bath temperature) for 30 minutes. After partial cooling (about 100°C), t-BuOH formed as a byproduct and excess phenol were removed by evaporation using a stream of nitrogen or argon. Compound A3 was then added.

[0314] After the total addition of compound A3, the reaction mixture was heated at 230°C for 4 hours. The progress of the reaction was monitored by NMR. Thus, it was possible to indicate that the conversion was completed 4 hours after the addition of compound A3 was stopped.

[0315] After cooling, the unpurified product formed in the form of a brown solid was stirred in distilled water (30 mL) for 6 hours. The resulting suspension was filtered and then washed several times with distilled water. After drying in an oven at 85°C for 6 hours, the expected product M1 was obtained in the form of an off-white powder with an excellent yield of about 93% and a purity of exactly over 99.3% as measured by NMR.

[0316] Examples 27: A, which removed alcohols before the reaction and used potassium alkoxide as a base 2 M from 2

[0317] Except that A2 replaced A3, the procedure was carried out exactly as in the case of the synthesis of Example 26. The experiment was performed under the following conditions: A2 (3 mmol; 1 eq.); t-BuOK (0.748 g; 2.2 eq.); phenol (0.652 g; 2.3 eq.). After post-treatment using the method described in Example 26, compound M2 was obtained in a yield of about 97%, with a purity of exactly over 99.6% as measured by NMR.

[0318] Examples 28: A, which removed alcohols before the reaction and used sodium alkoxide as a base 1 M from 1

[0319] Experiments were performed under the following conditions: HAr53 (3 mmol; 0.976 g; 1 eq.); t-BuONa (2.2 eq.); phenol (2.3 eq.).

[0320] Phenol (2.3 eq.) and t-BuOH (2.2 eq.) were injected into a reactor equipped with a cold finger and a pressure gauge. The reaction medium was heated at 185°C (bath temperature = 185°C) for 30 minutes (internal temperature of 140°C; internal pressure of 2.7 bar (pressure relative to atmospheric pressure)). After partial cooling (to about 100°C), t-BuOH formed as a byproduct and excess phenol were removed by evaporation using a stream of nitrogen. Compound A1 was then added.

[0321] After the total addition of compound A1, the reaction mixture was heated at 230°C for 2 hours (bath temperature 230°C; internal temperature 190°C; internal pressure 0.25 bar). It was noted that at an internal temperature of 170°C, the reaction mixture was in the form of a clear brown liquid and was therefore easily stirred. The progress of the reaction was monitored by NMR. Thus, it was proven that the conversion to the expected product M1 was completed 2 hours after the termination of the addition of A1.

[0322] After cooling, the unpurified product formed in the form of a brown solid was stirred in distilled water (30 mL) for 6 hours. The resulting suspension was filtered and then washed several times with distilled water. After drying in an oven at 85°C for 6 hours, the expected product M1 was obtained in the form of an off-white powder with a yield of 96% and a purity of exactly over 99.4% as measured by NMR.

[0323] By comparing Examples 19 and 28, it can be concluded that the reaction works well using t-BuONa as well as t-BuOK in the absence of t-BuOH / excess phenol solvent.

[0324] Example 29: A using sodium metal as a base 3 M from 1

[0325] Phenol (0.58 g; 2.2 eq.) and then anhydrous THF (3 mL) were injected into a reactor equipped with a cold finger and a thermometer. Sodium (2.2 eq.) was then added in portions at 25°C while stirring vigorously. The generation of dihydrogen was observed. The reaction medium was stirred at 25°C until the sodium had completely disappeared over approximately 1 hour. The THF was subsequently removed by evaporation caused by heating the reaction medium to 60°C under a stream of nitrogen. After cooling, compound A3 was added.

[0326] After the total addition of compound A3, the reaction mixture was heated at 230°C (bath temperature) for 5 hours. It should be noted that from a measured internal temperature of 190°C (temperature of the reaction mixture), the reaction medium turned into a bright yellow liquid that was easily stirred.

[0327] The reaction progress was monitored by NMR. Thus, it was possible to indicate that the expected conversion rate to product M1 was approximately 65% ​​2 hours after the addition of compound A3 was stopped, and was virtually complete 5 hours after the addition of compound A3 was stopped.

[0328] After cooling, the unpurified product obtained in the form of a brown solid was stirred in distilled water (30 mL) for 3 hours. The resulting suspension was filtered and then washed several times with distilled water. After drying in an oven at 85°C for 6 hours, the expected product M1 was obtained in the form of an off-white powder with a yield of 90% and a purity of exactly over 99.3% as measured by NMR.

[0329] Examples 30-32: A using potassium alkoxide as a base in a concentrated solution in DPS 3 M from 1

[0330] Phenol (2.4 eq.), anhydrous potassium carbonate in powder form (2.3 eq.), monomer A3 (1 eq., 0.2 g), and then diphenyl sulfone (DPS) in white solid form (2.03 eq.) were injected into a sealed tube under argon. The reaction mixture was heated at 230°C for 5 hours while stirring. After only 25 minutes, the reaction mixture turned dark red in the form of an easily stirred suspension. The progress of the reaction was monitored by NMR.

[0331] After cooling, the product obtained in the form of a white to grayish-white solid was purified by a first wash with acetone to remove DPS and excess phenol, and then by a second wash with distilled water to remove formed salts: in particular KCl and excess potassium phenoxide. After drying in an oven at 75°C for 2 hours, the expected monomer M1 was obtained in the form of a white powder with NMR purity (>99%) and a yield of 96%.

[0332] It should be noted that the diphenyl sulfone used was exclusively of technical grade (Sigma-Aldrich; purity exceeding exactly 97%).

[0333] The above method was carried out exactly as in the case of the synthesis of Example 30 by varying the ratios of the starting compounds of Examples 31 and 32.

[0334] In Example 31, phenol (2.4 eq.), anhydrous potassium carbonate in powder form (2.3 eq.), monomer A3 (1 eq., 0.2 g), and then diphenyl sulfone (DPS) in white solid form (4.07 eq.) were injected into a sealed tube under argon. After two consecutive washes and drying, the expected monomer M1 was obtained in the form of a white powder, which had a purity (>99%) and a yield of 97% as determined by NMR.

[0335] In Example 32, phenol (2.3 eq.), anhydrous potassium carbonate in powder form (2.2 eq.), monomer A3 (1 eq., 0.2 g), and then diphenyl sulfone (DPS) in white solid form (4.07 eq.) were injected into a sealed tube under argon. After two consecutive washes and drying, the expected monomer M1 was obtained in the form of a white powder, which had a purity (>99%) and a yield of 96% as determined by NMR.

Claims

Claim 1 A method for preparing an aromatic diether, comprising the reaction of compound A containing at least two halogenated aromatic groups and compound B (B is an aromatic alkoxide) in the presence of compound C which optionally acts as a reaction solvent, wherein the molar ratio of compound B to compound A is at least 2:1 and the molar amount of compound C to compound A is 10:1 or less. Claim 2 A method of preparation according to claim 1, wherein compound A is a compound having the following chemical formula: In the above formula, - i is an integer in the range of 1 to 3, and n is an integer equivalent to 0 or 1; - X1 and X2 independently represent halogen atoms; - Ar and, for any i, Ar i represents an independently substituted or unsubstituted divalent aromatic group; - for any i, Z i means independently an oxygen atom, a sulfur atom, an alkylene group, a carbonyl group, or a sulfonyl group. Claim 3 In paragraph 2, in formula (II): - i is equivalent to 2, and n is equivalent to 1; - X1 and X2 both mean chlorine or fluorine atoms; - Ar and Ar2 both mean 1,4-phenylene groups; - Ar1 means 1,3-phenylene or 1,4-phenylene groups; and - Z1 and Z2 is a manufacturing method where both refer to carbonyl groups. Claim 4 A method of preparation according to any one of claims 1 to 3, wherein compound B has the following chemical formula: In the above formula, Ar' means a substituted or unsubstituted monovalent aromatic group. Claim 5 A method of manufacturing, wherein in any one of paragraphs 1 to 3, compound B is a phenoxide. Claim 6 A method according to any one of claims 1 to 3, wherein the molar ratio of compound B to compound A is 3:1 or less. Claim 7 A method of preparation according to any one of claims 1 to 3, wherein compound B is obtained by deprotonating an aromatic alcohol B", which is the conjugate acid of aromatic alkoxide B, in situ or ex situ with a base reacted with B" to obtain compound B; said base is selected from a list of salts of aromatic or aliphatic alkoxides, carbonate salts, metal hydrides and alkali metals. Claim 8 A method of preparation according to claim 7, wherein the base reacted with B" is a linear or branched alkoxide salt comprising 3 to 10 carbon atoms. Claim 9 A method of preparation in which, in claim 7, the base reacting with B" is a carbonate salt. Claim 10 A method of preparation in which, in claim 7, the base reacting with B" is an alkali metal salt. Claim 11 A method of manufacturing according to claim 7, wherein the base reacting with B" is sodium metal or potassium metal. Claim 12 A method according to claim 7, wherein the molar ratio of the base reacting with B" to B" is 1:1 or less. Claim 13 A method of manufacturing, wherein, in any one of claims 1 to 3, compound C has a polarity of 3 Debye or higher measured at 20°C. Claim 14 A method of preparation according to any one of claims 1 to 3, wherein compound C is selected from a list consisting of C1-C6-alkyl-2-pyrrolidones, sulfoxides, sulfones, nitriles, N-dimethylamides, and mixtures thereof. Claim 15 A method according to any one of claims 1 to 3, wherein the molar ratio of compound C to compound A is 7.5:1 or less. Claim 16 A method according to any one of claims 1 to 3, wherein compound A is reacted with compound B in the absence of any solvent. Claim 17 A method according to any one of claims 1 to 3, wherein compound A reacts with compound B in a molten form. Claim 18 A method for preparing a polyaryl ether ketone polymer, comprising the step of preparing an aromatic diether by the method for preparing an aromatic diether claimed in any one of claims 1 to 3; and the step of reacting the aromatic diether with a compound D comprising at least two acyl chloride groups. Claim 19 In paragraph 18, the method wherein compound D is a compound having the following chemical formula: In the above formula, j is an integer in the range of 1 to 3, m is an integer equivalent to 0 or 1; Ar and, for any j, Ar j represents an independently substituted or unsubstituted divalent aromatic group; and for any j, Z j means independently an oxygen atom, a sulfur atom, an alkylene group, or a sulfone. Claim 20 In paragraph 18, the above aromatic diether or selected from a list consisting of a mixture thereof;- said compound D is A method selected from a list of compounds comprising a mixture thereof. Claim 21 In paragraph 14, the method wherein compound C is diphenyl sulfone.

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