Title: Process for the manufacture of an aromatic diether and corresponding processes for the manufacture of poly-aryl-ether-ketones

Technical area

The invention relates to a process for the production of aromatic diether(s). The invention also relates to a method for producing poly-aryl-ether-ketones from at least some of these aromatic diethers.

Prior art

Various industrial processes for the manufacture of poly-aryl-ether-ketones are known from the prior art, such as poly-ether-ether-ketones, poly-ether-ketone-ketones, or else poly-ether-ketone copolymers. ether-ketones and poly-ether-diphenyl-ether-ketones.

A first known route for the manufacture of poly-aryl-ether-ketone polymers is based on nucleophilic substitution and has for example been described in WO 86/07599. The process consists of the polycondensation of a difluorinated monomer with a monomer comprising two phenol functions in a solvent, for example diphenylsulfone, at high temperatures (between 280°C and 320°C)

A second known route is based on an electrophilic substitution reaction between aromatic acid chlorides and aromatic ethers in the presence of a Lewis acid, and has for example been described in US 4,816,556. In particular, the process for manufacturing poly-ether-ketone-ketones can be based on diphenyl ether, or alternatively on 1,4-bis(4-phenoxybenzoyl)benzene, as starting monomer in the polymerization reaction. In US 4,816,556, 1,4-bis (4-phenoxybenzoylbenzene) was synthesized by electrophilic substitution between terephthaloyl chloride and excess diphenyl ether in the presence of aluminum trichloride (Lewis acid) in ortho-dichlorobenzene (solvent).

It is also known from Ke, Y. & al. (1998), Investigations of the practical routes, structure, and properties for poly(aryl ether ketone ketone) polymers. J.Appl. Polym. Self., 67: 659-677. doi:10.1002/(SICI)1097-

4628(19980124)67:4<659::AID-APP9>3.0.CO;2-P, an experimental process for the production of 1,4-bis(4-phenoxybenzoyl)benzene, produced by the nucleophilic route. In this publication, the process was implemented by mixing 0.10 mol of a compound of formula (I):

[Chem 1]

, 0.20 mol of phenol and 0.3 mol of anhydrous potassium carbonate in 270 ml of dimethylacetamide and 60 ml of toluene, with stirring and a nitrogen atmosphere. The mixture is gradually heated for 1 hour until it reaches a temperature of 158°C. Residual water from the reaction mixture is removed. The reaction mixture is maintained at a temperature of 158° C. for 1 hour, then at a temperature of 162° C. for 2 hours. The reaction medium is then poured into pure water and the precipitate is filtered and air-dried for a period of 24 hours at 108°C. Two recrystallizations from toluene are carried out and a product having a melting point of 224° C. is obtained with a yield of 90%, without any indication of purity. However, the literature indicates that the melting point of 1,4-bis(4-phenoxybenzoyl)benzene should be 215°C. This process also has several drawbacks: it uses large quantities of solvents, in particular dimethylacetamide, which present a risk to human health because they are harmful (by contact/inhalation) and CMR (can harm the fetus). In addition, dimethylacetamide has a high boiling point (165°C) which makes the drying step of the product obtained complicated. Finally, the water produced during the reaction is soluble in the dimethylacetamide but is difficult to separate from it, which makes the recycling of the solvent to be reused in subsequent processes complicated.

Goals

The aim of the invention is to propose an improved process for the manufacture of aromatic diether(s), which can in particular be deployed on an industrial scale.

According to certain embodiments, the aim of the invention is to propose a method making it possible to manufacture aromatic diether(s) of high purity and with a high yield.

The invention also aims to provide an improved process for the manufacture of poly-aryl-ether-ketone from said aromatic diethers.

Presentation of the invention

The invention relates to a process for the manufacture of an aromatic diether comprising the reaction of a compound A comprising at least two halogenated aromatic groups with a compound B, B being an aromatic alkoxide, optionally in the presence of a compound C playing the role reaction solvent. The molar proportion of compound B relative to compound A is at least 2:1 and the molar quantity of compound C relative to compound A is, where applicable, at most equal to 10:1.

This process makes it possible to obtain aromatic diethers in a very concentrated reaction mixture, or even in mass, which makes it possible to optimize volumetric productivity (quantity of material produced per unit volume of equipment). In addition, the inventors have noticed that, extremely surprisingly, the process makes it possible to obtain the aromatic diether with a yield that is at least equivalent, and in many cases better, than that of processes according to the prior art and with a good purity.

In certain embodiments, compound A is a compound having the chemical formula:

[Chem 2]

in which :

i is an integer ranging from 1 to 3 and n is an integer equal to 0 or 1;

Xi and X2 independently designate a halogen atom;

Ar and for all i, An, independently denote a divalent aromatic group, substituted or unsubstituted; and,

for any i, Zi independently denotes an oxygen atom, a sulfur atom, an alkylene group, such as -CH2- or isopropylene (-C(CH3)2-), a carbonyl group or a sulfonyl group.

Preferably, Xi and X2 denote the same halogen atom. Even more preferentially, they both designate a chlorine or a fluorine.

Preferably Ar and for all i, An, independently denote a divalent aromatic group chosen from the list consisting of: 1,3-phenylene, 1,4-phenylene, 1,1'-divalent biphenyl in positions 4,4', 1, 1′-biphenyl divalent in the 3,4′ positions, 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene, and more preferably denote independently 1,3-phenylene and 1,4-phenylene.

Preferably for all i, Zi independently denotes an oxygen atom or a carbonyl group, and even more preferably denotes a carbonyl group.

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

- i is equal to 2 and n is equal to 1;

- Xi and X2 both denote a chlorine atom or a fluorine atom;

- Ar and Ar2 both denote a 1,4-phenylene group;

- An denotes a 1,3-phenylene or 1,4-phenylene group; and

- Zi and Z2 both denote a carbonyl group.

In certain embodiments, compound B has the chemical formula: Ar'-O- (III), in which:

Ar' denotes a monovalent aromatic group, substituted or not, preferentially denotes a monovalent aromatic group chosen from the list consisting of: phenyl, biphenyl and naphthylene. Compound B can in particular be the phenolate.

In certain embodiments, the molar proportion of compound B relative to compound A is less than or equal to 3:1, preferably less than or equal to 2.5:1, even more preferably less than or equal to 2.3:1, and most preferably about 2:1.

According to certain embodiments, the compound B is obtained by deprotonation of the aromatic alcohol B”, conjugate acid of the aromatic alcoholate B, by a base reacted with B”, in-situ or not, to provide the compound B, said base being preferably chosen from the list consisting of: aromatic or aliphatic alkoxide salts, carbonate salts, metal hydrides, and alkali metals.

The base reacted with B″ can in particular be a linear or branched alkoxide salt comprising from 3 to 10 carbon atoms. Preferably, said base is chosen from the list consisting of salts of:

iso-propanolate, 1,2-dimethylpropanolate, 1,1-dimethylpropanolate, 2,2-dimethylpropanolate, 1,1,2-trimethylpropanolate, 1,2,2-tri-methylpropanolate, 1-ethyl-2-methylpropanolate, 1- ethylpropanolate, n-butanolate, iso-butanolate, sec-butanolate, tert-butanolate, 2-methylbutanolate, 3-methylbutanolate, 1,2-dimethylbutanolate, 1,3-dimethylbutanolate, 2,3-dimethylbutanolate, 1,1-dimethyl- butanolate, 2,2-dimethylbutanolate, 3,3-dimethylbutanolate, 1-ethylbutanolate, 2-ethylbutanolate, 1-propylbutanolate, 1, 1,3,3-tetramethylbutanolate, n-pentanolate, 2-pentanolate, 2-methylpentanolate, n- hexanolate, 2-hexanolate, 3-methylpentanolate, 4-methyl-pentanolate, 2-ethylpentanolate, 2-ethylhexanolate, 2-propylheptanolate, n-heptanolate, 2-heptanolate, 3-heptanolate, n-octanolate, and their mixture;

more preferably said base can be chosen from the list of iso-propanolate, n-butanolate, tert-butanolate, n-heptanolate and n-octanol salts, and mixtures thereof.

The base reacted with B can also be a carbonate salt.

The base reacted with B″ can in particular be an alkali metal salt. Preferably, the base is a sodium or potassium salt or a mixture of sodium and potassium salts.

The base reacted with B″ can also be sodium metal or potassium metal, preferably sodium metal.

In some embodiments, the molar ratio of base reacted with B” to B” is less than or equal to 1:1.

According to certain embodiments, compound C has a polarity measured at 20° C. greater than or equal to 3 Debyes, preferably greater than or equal to 3.5 Debyes.

According to certain embodiments, compound C is chosen from the list consisting of: C1-C6-alkyl-2-pyrrolidones, in particular N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone,

sulfoxides, in particular dimethyl sulfoxide or diethyl sulfoxide,

sulfones, in particular dimethylsulfone, diethylsulfone, diisopropylsulfone, diphenylsulfone or else tetramethylene sulfone,

nitriles, in particular acetonitrile, propionitrile or benzonitrile,

N-dimethylamides, in particular dimethylacetamide or dimethylformamide, and their mixture.

According to particular embodiments, compound C can be diphenylsulfone.

According to certain embodiments, the molar proportion of compound C relative to compound A is less than or equal to 7.5:1, preferably less than or equal to 5:1, even more preferably less than or equal to 3:1. According to embodiments, compound A is reacted with compound B, in the absence of any solvent.

According to embodiments, compound A is reacted in the molten state with compound B.

The process according to the invention also relates to a process for the manufacture of a poly-aryl-ether-ketone polymer comprising: the manufacture of an aromatic diether as described above and the reaction of said aromatic diether with a compound D comprising at least two acyl chloride groups.

According to certain embodiments, compound D is a compound having the chemical formula:

[Chem 3]

in which: j is an integer ranging from 1 to 3 and m is an integer equal to 0 or 1;

Ar and for any j, Ah independently denote a divalent aromatic group, substituted or unsubstituted, preferably denotes a divalent aromatic group chosen from the list consisting of: 1,3-phenylene, 1,4-phenylene, 1,1'-divalent biphenyl in the 4,4' positions, 1,1'-divalent biphenyl in the 3,4', 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene positions; and,

for any j, ¾ independently denotes an oxygen atom, a sulfur atom, an alkylene group, such as -CH 2- or isopropylene (-C(CH3)2-), or a sulfone, preferentially Zj denotes an atom of 'oxygen.

According to certain embodiments, said aromatic diether is chosen from the list consisting of:

[Chem 4]

age; and, compound D is selected from the list of compounds consisting of:

[Chem 6]

their mixture.

Detailed description of the invention

Compound A comprises at least two halogenated aromatic groups. An aromatic group is a group comprising a conjugated ring with a stability (due to delocalization) significantly greater than that of a hypothetical localized structure. The aromatic groups of compound A are advantageously aromatic hydrocarbons.

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

The aromatic groups may also independently comprise other substituent(s) of one or more remaining hydrogen atom(s), this/these other substituent(s) being chosen among: alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali metal or alkaline earth metal sulfonate, alkylsulfonate, alkali metal or alkaline earth metal phosphonate, amine and quaternary ammonium.

According to certain embodiments, the aromatic groups can also independently comprise a single other substituent of a hydrogen atom, this substituent preferably being: an aryl or an alkali metal sulfonate.

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

According to certain embodiments, compound A may be a compound having the chemical formula:

[Chem 8]

In this formula:

- i is an integer ranging from 1 to 3 and n is an integer equal to 0 or 1;

- Xi and X2 independently designate a halogen atom,

- Ar and for all i, An, independently denote a divalent aromatic group, substituted or not; and,

- for any i, Zi independently designates an oxygen atom, a sulfur atom, an alkylene group, such as -CH2- or isopropylene (-C(CH3)2-), a carbonyl group or a sulphonyl group.

Preferably, in the compound of formula (II):

- Xi and X2 can denote the same halogen atom; X1 and X2 can in particular both denote a chlorine or a fluorine;

- Ar and for any i, An, may independently designate a divalent aromatic group chosen from the list consisting of: 1,3-phenylene, 1,4-phenylene, 1,1'- divalent biphenyl in positions 4,4', 1 ,1'-divalent biphenyl at 3,4' positions,

1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene; Ar and for any i, An may in particular independently designate 1,3-phenylene and 1,4-phenylene;

- For any i, Zi can independently designate an oxygen atom or a carbonyl group; for any i, Zi can in particular denote a carbonyl group. According particular embodiments, compound A may be compound Ai, A2, A3 or A4 as defined in the examples, or else a mixture of these compounds.

Compound B is an aromatic alcoholate. Compound B comprises an aromatic group which is advantageously a hydrocarbon.

The aromatic ring comprises at least one alcoholate function substituting a hydrogen atom. The aromatic ring may in particular possess a single alcoholate function. Alternatively, the aromatic ring can have two alcoholate functions.

The aromatic ring of B may also comprise other substituent(s) of remaining hydrogen atom(s), this/these other substituent(s) being chosen ) from: alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali metal or alkaline-earth metal sulfonate, alkylsulfonate, alkali metal or alkaline-earth metal phosphonate, amine and quaternary ammonium. In particular, the aromatic ring of B can comprise a single other substituent of a hydrogen atom, this substituent preferably being: an aryl or an alkali metal sulfonate.

According to certain embodiments, compound B is a compound having the chemical formula:

Ar'-O (III).

In this formula, Ar' denotes a monovalent aromatic group, substituted or not. Preferably, Ar' denotes a monovalent aromatic group chosen from the list consisting of: phenyl, monovalent biphenyl and naphthyl.

According to particular embodiments, compound B is the phenolate.

The molar ratio of compound B to compound A is at least 2:1. Indeed, the reaction of B with A generates, in a desired manner, a double substitution reaction of two molecules of B with one molecule of A, to form an aromatic diether.

According to certain embodiments, the molar proportion of compound B relative to compound A is less than or equal to 3:1, preferably less than or equal to 2.5:1, even more preferably less than or equal to 2.3:1, and most preferably about 2:1.

The reaction medium is called "reaction mixture", once the two reagents, i.e. compound A and compound B, have been brought into contact.

The "reaction time" is the time during which the reactants are allowed to react with each other.

Once the reaction is complete at the desired conversion, preferably until complete conversion of compound A to products, the reaction mixture becomes referred to as a "product mixture".

The "reaction temperature" corresponds to the temperature of the reaction mixture during the reaction time.

The "reaction pressure" corresponds to the pressure exerted on the reaction mixture during the reaction time.

The reaction can be carried out in a reactor. The reactor can for example be a glass reactor, a reactor whose internal wall is made of glass or else a reactor made of stainless metallic materials, or coated with PTFE. Preferably, the reaction can be carried out in a reaction mixture essentially comprising no water.

Preferably, the reaction can be carried out in an atmosphere essentially comprising no water or oxygen, for example under a nitrogen or argon atmosphere.

Preferably, the reaction mixture can be stirred for all or part of the reaction time. Thus, the reactor is preferably provided with a stirring device such as a mechanical stirrer (which may, for example, comprise one or more blades) or a recirculation loop with a pump.

According to certain embodiments, the reaction can be carried out in the presence of a compound C acting as a solvent. Reactants and/or intermediate reaction compounds and/or reaction products can dissolve therein, at least partially. In these embodiments, the molar amount of compound C relative to compound A is at most equal to 10:1, that is to say that the reaction is carried out in a concentrated reaction mixture. This has the particular effect of limiting as much as possible the introduction of impurities due to the solvent into the reaction mixture.

The solvent can be chosen from the list consisting of: alcohols, linear or branched, comprising from 3 to 10 carbon atoms, C1-C6-alkyl-2-pyrrolidones, sulfoxides, sulfones, nitriles, N-dimethylamides and their mixture.

The solvent can in particular be an alcohol, linear or branched, comprising from 3 to 10 carbon atoms. Alcohol is preferably non-aromatic.

As explained below, the solvent alcohol can in particular be generated during a step of deprotonation of the aromatic alcohol, conjugated with the aromatic alkoxide B, by an alkoxide salt. The solvent alcohol can be chosen from the list consisting of: iso-propanol, 1,2-dimethylpropanol, 1,1-dimethylpropanol,

2.2-dimethylpropanol, 1,1 ,2-trimethylpropanol, 1,2,2-tri-methylpropanol, 1-ethyl-2-methylpropanolat, 1-ethylpropanolat, n-butanol, iso-butanol, sec-butanol, tert-butanol, 2-methylbutanol, 3-methylbutanol , 1,2-dimethylbutanol, 1,3-dimethylbutanol, 2,3-dimethylbutanol, 1,1-dimethyl-butanol, 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-methyl-pentanol, 2-ethylpentanol, 2-ethylhexanol, 2-propylheptanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, and their mixture.

Preferably, the solvent alcohol can be chosen from the list consisting of: iso-propanol, n-butanol, tert-butanol, n-heptanol, n-octanol, and their mixture.

The solvent can also be a C1-C6-alkyl-2-pyrrolidone, the alkyl group comprising from 1 to 6 carbons. Advantageously, the C1-C6-alkyl-2-pyrrolidone can be N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone.

The solvent can also be a sulfone. Advantageously, the sulfone can be dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone or even tetramethylene sulfone. According to particularly advantageous embodiments, the solvent can be diphenylsulfone.

The solvent can also be a nitrile. Advantageously, the nitrile can be acetonitrile, propionitrile or benzonitrile.

The solvent can also be an N-dimethylamide. Advantageously, the N-dimethylamide is dimethylacetamide or dimethylformamide.

According to certain embodiments, the solvent has a polarity measured at 20° C. greater than or equal to 3 Debyes, preferably greater than or equal to 3.5 Debyes. This level of polarity allows better solubilization of reactants and reaction intermediates, which facilitates the nucleophilic substitution reaction. The molar proportion of compound C relative to compound A is less than or equal to 10:1. Thus, the process makes it possible to obtain aromatic diethers in a very concentrated reaction mixture, even in mass, therefore makes it possible to optimize the volume production . In addition, the aromatic diether can be obtained with a yield that is at least equivalent, and in many cases better, than that of processes according to the prior art and with good purity.

The molar proportion of compound C relative to compound A can preferably be less than or equal to 7.5:1, more preferably less than or equal to 5:1 and extremely

preferred, less than or equal to 3:1.

In certain embodiments, compound C may be an “ACS grade” solvent, i.e. having the purity limits defined by the American Chemical Society (A.C.S) purity limits. Compound C may have a purity greater than or equal to 95%, or greater than or equal to 96%, or greater than or equal to 97%, or greater than or equal to 98%, or greater than or equal to 99%. Compound C may in particular not be a solvent of high purity of the grades type used in analytical chemistry.

In certain embodiments, certain purity parameters for compound C can nevertheless be controlled. Compound C must in particular not exceed certain quantities, typically less than 100 ppm, preferably less than 50 ppm, in halide ions (Cl, F), in alkaline ions (Na+, K+), in metal ions (Fe(II), Fe(III)) and water.

According to other embodiments, the reaction can be carried out in the absence of any solvent. The reaction of the reaction mixture is then referred to as a “mass” reaction. This embodiment has the advantage

additional to avoid any step of recycling the reaction solvent, step a priori necessary if the process is brought to an industrial scale. It also has the advantage of limiting the pressure increase inside the reactor.

According to certain embodiments, the reaction temperature is such that compound A and compound B are in the molten state and/or dissolved in the reaction mixture for all or part of the reaction time.

Advantageously, compound A is in the molten state (above the melting point) and compound B is dissolved in molten compound A and/or, where appropriate, in compound C acting as 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.

According to certain embodiments, the reaction temperature is such that the aromatic diether, the desired product of the reaction of compound A with compound B, is in the molten state and/or dissolved in molten compound A for all or part of the reaction time. In particular, the aromatic diether can be in the molten state and/or 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.

According to certain particular embodiments, in particular in the modes where compound A can be compound Ai, A2, A3 or A4, as defined in the examples, the reaction mixture is brought to a temperature of at least 165° C., preferably at least 170°C or 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.

According to certain embodiments, the reaction time is between 5 minutes and 5 days, preferably between 10 minutes and 24 hours, more preferably between 30 minutes and 5 hours.

According to some embodiments, compound A is added to compound B or to the mixture of B and C.

According to certain embodiments, the reaction of compound A with compound B is carried out at atmospheric pressure or close to atmospheric pressure.

Compound B can be obtained by deprotonation of aromatic alcohol B”, conjugate acid of aromatic alcoholate B. B” then has the chemical formula: Ar’-OH (Ilia).

According to a particular embodiment, B″ is phenol.

Compound B” can be deprotonated by a base suitable for the deprotonation of aromatic alcohols.

The base can be chosen from the list consisting of alcoholate, aromatic or aliphatic salts, carbonate salts, metal hydrides, and alkali metals.

The base can in particular be chosen from the salts of alkoxides, linear or branched, comprising from 3 to 10 carbon atoms. In this embodiment, the base by reacting with a proton becomes an alcohol which can, if kept in the reaction mixture, act as a solvent. The base can preferably be chosen from the list consisting of salts of: iso-propanolate, 1,2-dimethylpropanolate, 1,1-dimethylpropanolate, 2,2-dimethylpropanolate, 1,1,2-trimethylpropanolate, 1,2,2- tri-methylpropanolate, 1-ethyl-2-methylpropanolate, 1-ethylpropanolate, n-butanolate, iso-butanolate, sec-butanolate, tert-butanolate, 2-methylbutanolate, 3-methylbutanolate, 1,2-dimethylbutanolate, 1,3- dimethylbutanolate, 2,3-dimethylbutanolate, 1,1-dimethyl-butanolate, 2,2-dimethylbutanolate, 3,3-dimethylbutanolate, 1-ethylbutanolate, 2-ethylbutanolate, 1-propylbutanolate, 1, 1,3,3-tetramethylbutanolate, n-pentanolate, 2-pentanolate, 2-methylpentanolate, n-hexanolate, 2-hexanolate, 3-methylpentanolate, 4-methyl-pentanolate, 2-ethylpentanolate, 2-ethylhexanolate, 2-propylheptanolate, n-heptanolate, 2-heptanolate, 3-heptanolate, n-octanolate, and their mixture;

more preferably said base is chosen from the list of iso-propanolate, n-butanolate, tert-butanolate, n-heptanolate and n-octanol salts, and mixtures thereof.

The base can also be a carbonate salt. The carbonate salt may in particular be in the form of a powder, the powder having a

particle size distribution such that D90 has a value ranging from 45 micrometers to 250 micrometers and D99.5 has a value less than or equal to 710 micrometers, the particle size distribution being measured by laser diffraction, according to the ISO 13320 standard: 2009.

In the embodiments, where the base is a salt, the salt can in particular be an alkali metal salt. Preferably, the salt can be a sodium salt, a potassium salt or a mixture of sodium and potassium salts.

The base can also be sodium metal, lithium metal or potassium metal, preferably sodium metal.

The base can also be sodium hydride, lithium hydride or potassium hydride.

The B” deprotonation step can be implemented in-situ or not with respect to the reaction of compound A with compound B.

According to certain embodiments, the molar proportion of said base relative to B″ is less than or equal to 1:1. This makes it possible to advantageously ensure a quantitative reaction of said base.

According to a first variant, the process comprises successively: a first stage of deprotonation of B″ with a base to form compound B, and a second stage of reacting compound B with compound A, optionally in the presence of a compound C acting as reaction solvent.

Between the first and the second step, a step for removing excess B″, and/or any solvent(s) used or generated during the first step, and/or water, can advantageously, if necessary, be implemented.

According to a second variant, the base, the compound B”, the compound A, and if necessary the compound C, can be mixed with each other in any order to form the reaction mixture.

Once the reaction is complete at the desired conversion, the reaction mixture becomes referred to as a "product mixture". The mixture of products can be purified and the isolated aromatic diether as described below.

The residue of the reaction products, obtained by the reaction of compound A with compound B, can be purified by methods well known to those skilled in the art, including one or more distillation stages, one or more distillation stages.

solid/liquid separation, one or more washing steps, one or more extraction steps and one or more recrystallization steps.

In the embodiments where the reaction of compound A with compound B has been carried out with compound C acting as reaction solvent, the latter can be eliminated so as to obtain a solvent-free residue of the reaction products.

In the case where the aromatic diether is sufficiently insoluble in the reaction solvent, it can be recovered by any means of solid/liquid separation.

The solid/liquid separation can be carried out in one or more successive stages, each stage being chosen from the group comprising: centrifugal filtration, sedimentation, centrifugal decantation, vacuum filtration, pressure filtration and gravity filtration. The solid/liquid separation temperature must be sufficiently low so as to reduce the solubility of the aromatic diether in the reaction solvent.

Alternatively and advantageously, the reaction solvent can be removed by distillation or also by displacement with another solvent having a lower boiling point.

Preferably, the solvent-free residue of the reaction products, whether A has been reacted with B in the presence or absence of compound C, can be purified by one or more washing steps or be purified by sublimation or crystallization.

Purification methods for residues of reaction products comprising 1,4 bis(4-phenoxybenzoyl)benzene and/or 1,3 bis(4-phenoxybenzoyl)benzene are explained below. A person skilled in the art would however be able to adapt these methods, in particular to choose the solvents to be used, for other aromatic diethers produced according to the invention.

A step of washing the residue comprising 1,4 bis(4-phenoxybenzoyl)benzene and the residue comprising 1,3 bis(4-phenoxybenzoyl)benzene may comprise the addition of a washing solvent (and choice of a corresponding temperature) in which 1, 4 bis (4-phenoxybenzoyl) benzene and / or 1, 3 bis (4-phenoxybenzoyl) benzene are poorly soluble, but in which impurities, such as salts and / or reagents do not unreacted (especially the phenolate), are soluble. The residue is

advantageously brought into contact with a convenient washing solvent, such as water or a water/methanol mixture (95/5) at room temperature (25°C) for a sufficient contact time.

In some embodiments, the residue can be ground into fine particles, if necessary, so as to improve the washing solvent/residue contact surface.

In certain embodiments, a suspension of residue in the washing solvent is implemented with stirring, so as to be able to maintain the residue in contact with the washing solvent for a sufficient period of time.

The residue/washing solvent mixture is then separated by a solid/liquid separation means, for example by filtration or else by centrifugation. The solid phase can advantageously be dried so as to eliminate any trace of solvent.

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 ambient temperature. After a solid/liquid separation, a liquid phase essentially containing 1,3 bis(4-phenoxybenzoyl)benzene and/or 1,4 bis(4-phenoxybenzoyl)benzene can be recovered, the purified product finally being able to be obtained by elimination extraction solvent (distillation). The 1,4 bis(4-phenoxybenzoyl)benzene can advantageously be extracted with chloroform. 1,3 bis(4-phenoxybenzoyl)benzene can advantageously be extracted with acetone.

In some embodiments, the residue can be purified by a final recrystallization step. In these embodiments, the residue preferentially undergoes only a single recrystallization step. This is generally made possible due to the relatively low rate of impurities to be eliminated, partly due to the fact that the reaction mixture was implemented in a very concentrated medium, or even in bulk.

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

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

The purity of the aromatic diether can be determined by a number of standard characterization methods, including nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), high performance liquid chromatography (HPLC) and/or liquid chromatography. liquid phase Ultra High Performance IDE (UPLC).

Preferably, the aromatic diether is obtained with a purity greater than or equal to 95%, preferably greater than or equal to 99% and more preferably greater than or equal to 99.9%, evaluated by NMR (% molar).

Alternatively, the aromatic diether is obtained with a purity greater than or equal to 95%, preferably greater than or equal to 99% and more preferably greater than or equal to 99.9%, evaluated by HPLC (% by mass).

The aromatic diether obtained according to the embodiments of the invention can then be used to carry out an electrophilic polymerization reaction so as to manufacture a polyaryletherketone (PAEK) polymer, the aromatic diether being reacted with a compound D comprising at least two acyl chloride groups.

Compound D can be a compound having the chemical formula:

[Chem 9]

in which: j is an integer ranging from 1 to 3 and m is an integer equal to 0 or 1;

Ar and for any j, Ah independently denote a divalent aromatic group, substituted or unsubstituted; and,

for any j, ¾ independently denotes an oxygen atom, a sulfur atom, an alkylene group, such as -CH 2- or isopropylene (-C(CH3)2-), or a sulfone.

Preferably, Ar and for all j, Ah designate a divalent aromatic group chosen from the list consisting of:

1,3-phenylene, 1,4-phenylene, 1,1'-divalent biphenyl at 4,4'-positions, 1,1'-divalent biphenyl at 3,4'-positions, 1,4-naphthylene, 1,5- naphthylene and 2,6-naphthylene.

Preferably, for all j, Z\ denotes an oxygen atom.

According to certain embodiments, compound D can be chosen from the list consisting of: phthaloyl dichloride, isophthaloyl dichloride, terephthaloyl dichloride or their mixture. Preferably, compound D can be chosen from the list consisting of: isophthaloyl dichloride, terephthaloyl dichloride or a mixture thereof.

According to certain particular embodiments, the aromatic diether synthesized according to the invention can be chosen from the list consisting of: 1,4 bis(4-phenoxybenzoyl)benzene, 1,3 bis(4-phenoxybenzoyl)benzene, or their mixed.

Thus, in the embodiment in which the PAEK is a poly-ether-ketone-ketone, the difunctional aromatic acyl chloride can be a phthaloyl dichloride, a terephthaloyl dichloride, an isophthaloyl dichloride or their mixture and the aromatic diether: 1,4 bis(4-phenoxybenzoyl)benzene, 1,3 bis(4-phenoxybenzoyl)benzene, or a mixture thereof.

The polymerization reaction is preferably carried out in a solvent. The solvent is preferably an impractical solvent, which can in particular be chosen from the list consisting of: methylene chloride, carbon disulphide, 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 a mixture thereof. Ortho-dichlorobenzene is particularly preferred for the manufacture of poly-ether-ketone-ketone.

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

Lexis acid can in particular be chosen from the list consisting of: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic chloride, titanium tetrachloride and molybdenum pentachloride. Aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride and molybdenum pentachloride are preferred. Aluminum trichloride is especially preferred for making poly-ether-ketone-ketone

According to certain variants, the polymerization can be carried out in the same reactor as that used for the production of the aromatic diether. But preferably, the polymerization is carried out in another reactor. The polymerization can be carried out at a temperature ranging, for example, from 20 to 120°C.

The process for manufacturing PAEK, and in particular poly-ether-ketone-ketone, advantageously comprises one or more polymer purification steps, such as the steps of:

- mixing the products of the polymerization reaction containing PAEK with a protic solvent so as to provide a suspension of PAEK;

- Separation of the PAEK polymer from the PAEK suspension, preferably by filtration and washing.

The convenient solvent used for the PAEK suspension can be, for example, methanol.

The PAEK polymer can then be recovered removed from the PAEK suspension by filtration. If necessary, the polymer can be washed, preferably with a convenient solvent such as methanol, and filtered again, one or more times. The washing can be carried out for example by resuspending the polymer in the solvent.

Examples

The following examples illustrate the invention without however limiting it.

Equipment used for characterizations

For High Performance Liquid Chromatography (HPLC) measurements, a Waters XterraMS C183.5pm 4.6x150mm column was used with a mobile phase comprising a mixture: water/acetonitrile+0.05% trifluoroacetic acid, in gradient. The measurements were made at 20°C, at variable wavelengths.

For Mass Spectroscopy (MS) measurements, a Xevo G2-XS QTof WATERS apparatus was used with the following parameters:

Introduction of the sample through the ASAP probe (Atmospheric pressure Solids Analysis Probe)

Ionization mode: ASAP positive

Mass range: 50-1000 m/z

Source temperature: 120°C

Corona current: 10mA

Cone voltage: 50 V

For proton Nuclear Magnetic Resonance (1H NMR) measurements, BRUKER AVANCE III (500 MHz) and BRUKER NEO (600 MHz) spectrometers were used with CDCl3 as solvent.

For Carbon Nuclear Magnetic Resonance (13C NMR) measurements BRUKER AVANCE III 500 MHz (125 MHz) and BRUKER NEO 600 MHz (150 MHz) spectrometers were used with CDCl3 as solvent.

For melting point measurements a Kofler bench and a Gallenkamp melting point apparatus (with capillary tubes) were used.

Crude yield is understood below to mean the ratio in moles of product obtained at the end of the reaction to the number of moles of dihalogenated compound introduced.

Yield of purified product is understood below to mean the ratio in moles of purified product (expected product), that is to say of the crude product having in particular been washed and/or extracted and/or recrystallized, over the number of moles of dihalogen compound introduced. This yield is associated with a purity evaluated by NMR (% molar) or by HPLC (% by mass).

Example 1: 1,4-bis(4-fluorobenzoyl)benzene

The compound Ai of formula:

[Chem 10]

was synthesized under the following conditions: 1 equivalent (eq.) of terephthaloyl chloride (5 g; 24.6 mmol), 10 equivalents of fluorobenzene (28 g), 2.1 equivalents of AICh (6.9 g; 51.7 mmol). The fluorobenzene used in this reaction served as both reagent and solvent. Aluminum chloride was added at 25°C in small portions (for 10 min) to terephthaloyl chloride dissolved in fluorobenzene, with stirring and under an argon atmosphere. At the end of the addition of AICh, the reaction mixture was kept under stirring for 2 h at 60°C. Then, after cooling, the mixture of products obtained was poured into ice-cold water followed by evaporation of the excess fluorobenzene under vacuum using a rotary evaporator. The white solid obtained was filtered, washed several times with distilled water, with 10% aqueous sodium hydroxide, then with water and finally dried under vacuum. The expected product Ai was obtained with a yield of around 99.1%. Crystallization of the crude product in dimethylacetamide led to the purified product with a yield of around 96% and a purity > 99.5% (NMR and MS).

The product obtained in the form of white crystals is soluble in chloroform, acetone, dichloromethane and partially in methanol. Its melting point has been measured as 220°C.

Example 2: 1,3-bis(4-fluorobenzoyl)benzene

Compound A2 of formula:

[Chem 11]

was synthesized in substantially the same way as compound Ai of Example 1, except that isophthaloyl dichloride was used instead of terephthaloyl dichloride.

After treatment similar to that applied for compound Ai, compound A2 was obtained with an almost quantitative yield in the form of white crystals, having a melting point measured at 1810 C.

The product is soluble in common solvents. It was crystallized from toluene. The yield obtained was around 95%. Purity according to NMR, MS and HPLC was around 99.8%.

Example 3: 1,4-bis(4-chlorobenzoyl)benzene

Compound A3 of formula:

[Chem 12]

was synthesized in substantially the same way as compound Ai in Example 1, except that chlorobenzene was used instead of fluorobenzene.

Nevertheless, certain reaction conditions were modified, making it possible to obtain 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 AICh (7.88g, 59.1 mmol). Aluminum chloride was added to terephthaloyl chloride dissolved in chlorobenzene in small portions (for 10 minutes) with stirring under an argon atmosphere at T A. The chlorobenzene used in this reaction serves as both a reagent and a solvent. At the end of the addition of the AICb, the reaction mixture was stirred overnight at 25°C and then 3h at 90°C. After processing identical to that carried out for compound Ai, the expected product A3 was obtained with a

quasi-quantitative yield in the form of a white powder. Crystallization of the crude product from dimethylacetamide (DMAc) yielded the pure product in the form of white crystals, with a melting point equal to 259°C. The yield of crystallized product was around 96%. A high temperature NMR study showed a selectivity strictly greater than 99.6%.

Example 4: 1,3-bis(4-chlorobenzoyl)benzene

Compound A4 of formula:

[Chem 13]

was synthesized in substantially the same way as compound Ai in Example 1, except that chlorobenzene was used instead of fluorobenzene and isophthaloyl dichloride was used instead of terephthaloyl dichloride. However, some reaction conditions have been modified as detailed below.

After the end of the addition of aluminum chloride in small portions to isoterephthaloyl chloride dissolved in chlorobenzene at room temperature, the reaction medium was stirred for 10 hours at this temperature and then 2 hours at 90°C. After cooling and evaporation of the excess chlorobenzene, the solid residue obtained was extracted using dichloromethane (DCM). The organic phase was washed twice with water and three times with 10% aqueous sodium hydroxide, and finally twice with water. It was then dried and evaporated under vacuum. The expected product was obtained in the form of pure white crystals in NMR and MS (purity strictly greater than 99.6%) with a melting point measured at 215°C. The yield was around 96%.

Example 5: Mi/Mi’mixture from Ai in dilute reaction mixture (comparative)

A mixture of phenol (0.718g; 2 eq) and potassium carbonate (1055g; 2eq) was dissolved in a mixture of solvents: toluene (10 ml_)/NBP (10ml_), and brought to reflux for 1 h ( bath temperature 130°C). After the addition of compound Ai, followed by the distillation of toluene, the reaction mixture was heated at 150°C-160°C for 2h. After treating the residue obtained with a water/methanol mixture (95/5), filtration, washing with a water/methanol mixture (95/5) and drying, the crude product was obtained in the form of a white powder with a yield by 81%.

The structure of the expected product, the aromatic diether Mi of formula:

[Chem 14],

was confirmed by NMR and mass spectroscopy (MS) analyses.

In mass spectroscopy, the presence of the monophenoxylated derivative M’i was detected (surface ratio of approximately 15%) with the formula:

[Chem 15]

The yield of product crystallized in toluene was around 72%, with a purity strictly greater than 99%, as measured by NMR.

The melting point PF was measured at: 208°C.

Example 6: Mixture M2/M2' from A2 in dilute reaction mixture (comparative)

Analogously to Example 5, the compound M2 of formula:

[Chem 16]

was obtained from compound A2, under conditions analogous to those described for the synthesis of M-i, compound A2 replacing compound Ai. A difference compared to example 5 is that the reaction mixture here was heated to 1500 C-1600 C for only 30 minutes, after the distillation of the toluene.

The product was obtained in the form of a white solid with a crude yield of around 70%.

The structure of the M2 product was confirmed by NMR and mass spectroscopy analyses.

In mass spectroscopy, it was detected the presence of traces of the monophenoxylated product M2' (approximately 15%) of formula:

[Chem 17]

The yield of the product crystallized in methanol was around 61%, with a purity strictly greater than 99%, as measured by NMR.

The melting point FP was measured at: 133°C.

Example 7: Mi from Ai in concentrated solution (invention)

In a sealed tube, phenol (2.5 equivalents) and anhydrous potassium bicarbonate (2.5 equivalents), in powder form, then 0.2 mL of N-butyl-2-pyrrolidone (NBP) were introduced under argon. The reaction mixture was heated to 180°C with stirring for 30 min. After partial cooling (about 100°C), 1 mmol (1 equivalent) of compound A was added.

The reaction mixture was then heated at 205°C for 2h.

The progress of the reaction was followed by HPLC, MS and NMR. It was thus shown that the conversion to the desired product was almost quantitative 2 hours after the end of the addition of compound Ai. Furthermore, neither the starting product nor the monophenoxylated derivative M-i' were detected.

The treatment of the residue obtained was carried out by adding methanol then evaporation under vacuum of the rotary evaporator until the elimination of NBP (azeotrope).

The pro Crude product obtained in the form of an off-white solid was extracted with chloroform. After filtration of the insoluble matter and evaporation of the chloroform, the crude product was then crystallized from toluene.

The pure M1 product (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of 83% and a purity strictly greater than 99% mol, measured by NMR. The melting point was measured at 212°C.

Example 8: M2 from A2 in concentrated solution (invention)

Analogously to Example 7, compound M2 was obtained from compound A2, under conditions analogous to those described for the synthesis of Mi, compound A2 replacing compound Ai. A difference from Example 7 is that the crude product obtained as an off-white solid was here extracted with acetone instead of chloroform.

The 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 is strictly greater than 99% by HPLC. The melting point was measured at 133°C.

Example 11: M1 from Ai with a potassium alcoholate as base (invention)

Phenol (2.3 eq) then potassium tert-butanolate (t-BuOK; 2.2 eq) were introduced into a sealed tube under argon. The reaction medium was heated with stirring at 185° C. for 30 min. After partial cooling (approximately 100° C.), compound A (1 eq) was added.

The reaction mixture was then heated at 215°C for 2 hours.

The progress of the reaction was followed by HPLC, MS and NMR.

It was thus shown that the desired product M1 was obtained almost quantitatively at a time of 2 hours after the end of the addition of compound Ai.

The residue treatment obtained was carried out by extraction with chloroform. After filtration of the insolubles from the product and evaporation of the chloroform, the crude product was then purified by washing with methanol (and could alternatively or in addition be crystallized from toluene).

The pure product M1 (structure confirmed by NMR and MS) was obtained in the form of white crystals with a yield of around 93% and a purity strictly greater than 99.5%, measured by NMR. The melting point was measured at 212°C.

Using t-BuOK as a base to deprotonate phenol results in the production of tert-butanol (t-BuOH), which serves as a solvent and facilitates complete conversion. The second advantage of this base is to allow the recovery/recycling of the alcohol after the end of the reaction by simple distillation.

Example 12: M2 from A2 with a potassium alcoholate as base (invention)

Analogously to Example 11, compound M2 was obtained from compound A2, under conditions analogous to those described for the synthesis of Mi, compound A2 replacing compound Ai. Note a difference, however, concerning the processing step: the crude product was extracted with acetone instead of chloroform.

The desired product IVL was obtained almost quantitatively at a time of 2 hours after the end of the addition of compound A2 (monitoring of the progress of the reaction by NMR).

The 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 strictly greater than 99.5% by HPLC. The melting point has been measured at about 132°C-133°C.

Example 13: Mixture M1/M1” from A3 in dilute reaction mixture (comparative)

To synthesize compound M1 from compound A3, the procedure was substantially as in the reaction of Example 5, A3 replacing Ai. 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) / NBP (5 mL).

The reaction mixture was heated (after distillation of the toluene) at 200° C. for 24 hours (instead of 160° C. for 2 hours for the fluorinated derivative). The treatment of the residue obtained was carried out by adding methanol then evaporation under vacuum of the rotary evaporator until the elimination of NBP (azeotrope).

The expected product M1 detected in SM (approximately 70%) was obtained as a mixture with the starting product and the monophenoxylated derivative (area ratio of approximately 15%) of formula M-:

[Chem 18]

These results show that the conversion was not complete despite the increase in temperature and the extension of the heating time. The pure expected product Mi was obtained after crystallization of the crude product from toluene, with a yield of 57% and a purity strictly greater than 99%, as measured by NMR. The melting point was measured at 211°C.

Example 14: Mixture M2/M2” from A4 in dilute reaction mixture (comparative)

Analogously to Example 13, compound M2 was obtained from compound A4, under conditions analogous to those described for the synthesis of M-i, compound A4 replacing compound A3.The crude product was obtained as a mixture with the monophenoxylated derivative M2” detected in SM (ratio of the surfaces of approximately 15%) of formula:

[Chem 19]

and traces of starting materials (confirmed by NMR and MS).

After crystallization of the crude product in methanol, the pure product M2 (structure confirmed by NMR and MS) was obtained in the form of a white solid with a yield of around 55% and a purity strictly greater than 99%. The recrystallized product has a measured melting point of: 132°C.

Example 15: M1 from A3 in concentrated solution (invention)

To synthesize compound M1 from compound A3, the procedure was similar to the reaction of Example 7, A3 replacing Ai. 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).

The reaction mixture was heated to 220°C for 3 hours. The progress of the reaction was followed by HPLC, MS and NMR. It was thus shown that the conversion to the desired product was almost quantitative at a time of 3 h after the end of the addition of compound A3. The treatment of the crude product was carried out in the same way as in Example 7.

The 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 strictly greater than 99.5%, measured by NMR. Melting point was measured at 211°C.

Example 16: M2 from A4 in concentrated solution (invention)

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

The 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 greater than or equal to 99.5%, as measured by NMR. The melting point was measured at 133°C.

Example 19: Mi from A3 with a potassium alcoholate as base (invention)

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

The reaction mixture was then heated at 220°C for 3 hours.

The progress of the reaction was monitored by HPLC and NMR. Thus, it was shown that the desired product M1 was obtained almost quantitatively at a time of 3 hours after the end of the addition of compound A3.

The residue obtained was extracted with chloroform. After filtration of the insolubles and evaporation of the chloroform, the crude product (quite pure in NMR) was then crystallized in toluene.

The 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 strictly greater than 99.5%, measured by NMR. Melting point was measured at 212°C.

Example 20: M2 from A4 with a potassium alcoholate as base (invention)

It was proceeded exactly as in the case of the synthesis of example 19, except that A4 replaces A3, which was heated to 205°C instead of 220°C and qiæ

for the processing step the crude product was extracted with acetone instead of chloroform.

The desired product M2 was obtained almost quantitatively at a time of 2 hours after the end of the addition of compound A2, which was confirmed by NMR.

The 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 strictly greater than 99.5%, measured by HPLC. The melting point was measured at 132°C.

Examples 21-24: Influence of the t-BuO alkoxide counterion

Experiments similar to those of Examples 11, 12, 19 and 20 were carried out, in which t-BuONa was used instead of t-BuOK. They have been entitled examples 21, 22, 23 and 24 respectively. The reaction times and reaction temperature have been adapted so as to obtain quasi-quantitative conversions. The conditions used and the results obtained are recorded in Table 1 below:

[Table 11

Thus, the comparison of examples 11, 12, 19 and 20 compared to examples 21, 22, 23 and 24 shows that the reaction with t-BuOK is much faster kinetically than the reaction with t-BuONa, the reactions taking place in t-BuOH/excess phenol acting as solvent.

Example 25: Mi from Ai with a potassium alcoholate as base and elimination of alcohols before reaction

Phenol (2.3 eq.), t-BuOK (2.2 eq) were introduced into a sealed tube under argon. The reaction medium was heated at 185° C. (bath temperature) for 30 min. After partial cooling (to about 100°C), the t-BuOH formed as a by-product as well as the excess phenol were removed by evaporation using a flux.nitrogen or argon. Compound Ai was then added.

After compound Ai was fully added, the reaction mixture was heated at 230°C (bath temperature) for 1 hour. From T=210°C (bath temperature), it was noted that the reaction medium turned into a light brown, easily stirrable suspension.

The progress of the reaction was followed by NMR. Thus it could be shown that the conversion to the expected product Mi was complete at a time of one hour after the end of the addition of compound A-i.

After cooling, the crude formed in the form of a light brown solid was scraped and then ground. To eliminate the salts formed and any traces of phenol, the crude obtained was stirred in distilled water (20 mL) for 1 h, then filtered and then washed several times with distilled water and finally with pentane. After drying in an oven at 75°C for 2 hours, the expected product Mi obtained with a yield of 94%, in the form of an off-white powder, of purity strictly greater than 99.5% in NMR.

Example 26: Mi from A3 with a potassium alkoxide as base and removal of alcohols before reaction

Phenol (2.3 eq.), t-BuOK (2.2 eq.) were introduced into a sealed tube.

The reaction mixture was heated at 185° C. (bath T = 185° C.) for 30 min. After partial cooling (to about 100°C), the t-BuOH formed as a by-product as well as the excess phenol were removed by evaporation using a nitrogen or argon stream. Compound A3 was then added.

After compound A3 was fully added, the reaction mixture was heated at 230°C for 4 hours. The progress of reaction b was monitored by NMR. Thus, it could be shown that the conversion was complete at a time of 4 hours after the end of the addition of compound A3.

After cooling, the crude formed in the form of a brown solid was stirred in distilled water (30 mL) for 6 hours. The suspension obtained was filtered and then washed several times with distilled water. After drying in an oven at 85°C

for 6 hours, the expected product Mi was obtained with an excellent yield of around 93% in the form of an off-white powder, and a purity measured by NMR strictly greater than 99.3%.

Example 27: IVb from A2 with a potassium alcoholate as base and elimination of alcohols before reaction

The procedure was exactly as in the case of the synthesis of example 26, except that A2 replaces A3. The experiment was carried out under the conditions: A2 (3 mmol; 1 eq.); t-BuOK(0.748g; 2.2 eq.); phenol (0.652g; 2.3 eq.). After treatment using the process described in Example 26, compound M2 was obtained with a yield of around 97%, a purity measured by NMR strictly greater than 99.6%.

Example 28: M1 from Ai with a sodium alcoholate as base and elimination of alcohols before reaction

The experiments were carried out under the following conditions: HAR53 (3mmol; 0.976g; 1eq.); t-BuONa (2.2 eq.); phenol (2.3 eq.).

Phenol (2.3 eq.), t-BuONa (2.2 eq.) are introduced into a reactor equipped with a thermowell and a manometer. The reaction medium was heated at 185°C (bath temperature) for 30 min (internal temperature of 140°C; internal pressure of 2.7 bars (pressure relative to atmospheric pressure). After partial cooling (to about 100°C), the t-BuCH formed as a by-product as well as the excess phenol are removed by evaporation using a flow of nitrogen Then compound Ai is added.

After compound Ai had been completely added, the reaction mixture was heated at 230° C. (bath temperature of 230° C.; internal temperature of 190° C.; internal pressure of 0.25 bar) for 2 h. It was noted that from an internal temperature of 170°C, the reaction mixture was in a state of a light brown liquid and therefore easily stirrable. The progress of the reaction was monitored by NMR. It was thus proven that the conversion to the expected product M1 was complete at a time of 2 hours after the end of the addition of A-i.

After cooling, the crude formed in the form of a brown solid was stirred in distilled water (30 mL) for 6 hours. The suspension obtained was filtered and then washed several times with distilled water. After drying in an oven at 85°C for 6 hours, the expected product Mi was obtained with a yield of 96% in the form of an off-white powder, of purity strictly greater than 99.4% measured by NMR.

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

Example 29: Mi from A3 with sodium metal as base

Phenol (0.58g; 2.2 eq.) then dry THF (3 ml_) were introduced into a reactor fitted with a thermowell and a thermometer. Sodium (2.2 eq) was then added in small portions at 25°C with stirring. An evolution of dihydrogen was observed. The reaction medium was é stirred at 25°C until the total disappearance of the sodium for about 1 hour. The THF was then removed by evaporation by heating the reaction medium to 60°C under a stream of nitrogen. After cooling, compound A3 was added.

After compound A3 was completely added, the reaction mixture was heated at 230°C (bath temperature) for 5 hours. It should be noted that from an internal temperature (temperature of the reaction mixture) measured of 190°C, the reaction medium is transformed into a state of an easily stirrable dark yellow liquid.

The progress of the reaction was followed by NMR. Thus, it could be shown that the conversion into the expected product M1 was of the order of 65% at a time of 2 hours after the end of the addition of compound A3, and was almost complete at a time of 5 hours. after the end of the addition of compound A3.

After cooling, the crude obtained in the form of a brown solid was stirred in distilled water (30 mL) for 3 hours. The suspension obtained 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 with a yield of 90%, in the form of an off-white powder, of purity strictly greater than 99.3%, measured by NMR.

Example 30-32: Mi from A3 with potassium alkoxide as base in concentrated solution in DPS.

Into a sealed tube were introduced under argon phenol (2.4 eq), anhydrous potassium carbonate in powder form (2.3 eq), monomer A3 (1 eq, 0.2 g) then diphenylsulfone (DPS) as a white solid (2.03 eq). The reaction mixture was heated with stirring at 230°C for 5 hours. After only 25 minutes, the reaction mixture turned dark red as an easily stirrable suspension. The progress of the reaction was monitored by NMR.

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

It should be noted that the diphenylsulfone used was only of technical quality (Sigma Aldrich; purity strictly greater than 97%).

The procedure was exactly as in the case of the synthesis of example 30, with different proportions of starting compounds for examples 31 and 32.

In Example 31, phenol (2.4 eq), anhydrous potassium carbonate in powder form (2.3 eq), monomer A3 (1 eq, 0.2 g) then diphenylsulfone (DPS) in the form of a white solid (4.07 eq).

After the two successive washings and drying, the expected monomer M1 was obtained in the form of a white powder, pure in NMR (>99%), with a yield of 97%.

In Example 32, phenol (2.3 eq), anhydrous potassium carbonate in powder form (2.2 eq), monomer A3 (1 eq, 0.2 g) then diphenylsulfone (DPS) in the form of a white solid (4.07 eq).

After the two successive washings and drying, the expected monomer M1 was obtained in the form of a white powder, pure in NMR (>99%), with a yield of 96%.

Claims

1. Process for the manufacture of an aromatic diether comprising the reaction of a compound A comprising at least two halogenated aromatic groups with a compound B, B being an aromatic alkoxide,

optionally in the presence of a compound C acting as reaction solvent,

the molar proportion of compound B relative to compound A being at least 2:1 and the molar quantity of compound C relative to compound A being, where appropriate, at most equal to 10:1.

2. Manufacturing process according to claim 1, in which compound A is a compound having the chemical formula:

in which :

- i is an integer ranging from 1 to 3 and n is an integer equal to 0 or 1;

- Xi and X2 independently denote a halogen atom, preferably denote the same halogen atom, and even more preferably both denote a chlorine or a fluorine;

- Ar and for all i, An, independently denote a divalent aromatic group, substituted or unsubstituted, preferably independently denote a divalent aromatic group chosen from the list consisting of: 1,3-phenylene,

1,4-phenylene, 1,1'-divalent biphenyl at 4,4' positions, 1,1'-divalent biphenyl at 3,4' positions.

-,1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene, and more preferably denote independently 1,3-phenylene and 1,4-phenylene; and,

- for any i, Zi independently denotes an oxygen atom, a sulfur atom, an alkylene group, such as -CH 2- or isopropylene (-C(CH3)2-), a carbonyl group or a sulphonyl group, preferentially Zi independently denotes an oxygen atom or a carbonyl group, and even more preferably denotes a carbonyl group.

3. Manufacturing process according to claim 2, in which in the chemical formula (II):

- i is equal to 2 and n is equal to 1;

- Xi and X2 both denote a chlorine atom or a fluorine atom;

- Ar and Ar2 both denote a 1,4-phenylene group;

- An denotes a 1,3-phenylene or 1,4-phenylene group; and

- Zi and Z2 both denote a carbonyl group.

4. Manufacturing process according to any one of claims 1 to 3, in which compound B has the chemical formula:

Ar'-O- (III),

in which :

Ar' denotes a monovalent aromatic group, substituted or not, preferably denotes a monovalent aromatic group chosen from the list consisting of: phenyl, monovalent biphenyl and naphthyl.

5. Manufacturing process according to any one of claims 1 to 4, in which compound B is the phenolate.

6. Process according to any one of claims 1 to 5, in which the molar proportion of compound B relative to compound A is less than or equal to 3:1, preferably less than or equal to 2.5:1, even more preferably less or equal to 2.3:1, and most preferably about 2:1.

7. Manufacturing process according to any one of claims 1 to 6, in which the compound B is obtained by deprotonation of the aromatic alcohol B”, conjugate acid of the aromatic alcoholate B, by a base reacted with B ”, in-situ or not, to provide compound B;

said base being preferably chosen from the list consisting of: salts of alcoholates, aromatic or aliphatic, salts of carbonates, metal hydrides, and alkali metals.

8. Manufacturing process according to claim 7, in which the said base reacted with B” is an alkoxide salt, linear or branched, comprising from 3 to 10 carbon atoms;

preferably said base is chosen from the list consisting of salts of: iso-propanolate, 1,2-dimethylpropanolate, 1,1-dimethylpropanolate, 2,2-dimethylpropanolate, 1,1,2-trimethylpropanolate, 1,2,2-tri -methylpropanolate, 1-ethyl-2-methylpropanolate, 1-ethylpropanolate, n-butanolate, iso-butanolate, sec-butanolate, tert-butanolate, 2-methylbutanolate, 3-methylbutanolate, 1,2-dimethylbutanolate, 1,3-dimethylbutanolate n -pentanolate, 2-pentanolate, 2-methylpentanolate, n-hexanolate, 2-hexanolate, 3-methylpentanolate, 4-methyl-pentanolate, 2-ethylpentanolate, 2-ethylhexanolate, 2-propylheptanolate, n-heptanolate, 2-heptanolate, 3 -heptanolate, n-octanolate, and their mixture;

more preferably said base is chosen from the list of iso-propanolate, n-butanolate, tert-butanolate, n-heptanolate and n-octanol salts, and mixtures thereof.

9. A method of manufacture according to claim 7, wherein said base reacted with B” is a carbonate salt.

10. Manufacturing process according to any one of claims 7 to 9, in which said base reacted with B” is an alkali metal salt, preferably a sodium salt, a potassium salt or a mixture of salts of e sodium and potassium.

11. Manufacturing process according to claim 7, in which the said base reacted with B” is sodium metal or potassium metal, preferably sodium metal.

12. Process according to any one of claims 7 to 11, in which the molar proportion of the said base, reacted with B”, with respect to B” is less than or equal to 1:1.

13. Manufacturing process according to any one of claims 1 to 12, in which compound C has a polarity measured at 20° C. greater than or equal to 3 Debyes, preferably greater than or equal to 3.5 Debyes.

14. Manufacturing process according to any one of claims 1 to 13, in which compound C is chosen from the list consisting of: C1-C6-alkyl-2-pyrrolidones, in particular N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone,

sulfoxides, in particular dimethyl sulfoxide or diethyl sulfoxide, sulfones, in particular dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone or even tetramethylene sulfone,

nitriles, in particular acetonitrile, propionitrile or benzonitrile,

N-dimethylamides, in particular dimethylacetamide or dimethylformamide, and their mixture.

15. Process according to any one of claims 1 to 14, in which the molar proportion of compound C relative to compound A is less than or equal to 7.5:1, preferably less than or equal to 5:1, even more preferably less or equal to 3:1.

16. Process according to any one of claims 1 to 15, in which compound A is reacted with compound B, in the absence of any solvent.

17. Process according to any one of claims 1 to 16, in which compound A is reacted in the molten state with compound B.

18. A method of making a poly-aryl-ether-ketone polymer comprising making an aromatic diether according to any one of claims 1 to 17;

reacting said aromatic diether with a compound D comprising at least two acyl chloride groups.

19. Process according to claim 18, in which compound D is a

compound having the chemical formula:

in which: j is an integer ranging from 1 to 3 and m is an integer equal to 0 or 1;

Ar and for any j, Arj independently denote a divalent aromatic group, substituted or unsubstituted, preferably denotes a divalent aromatic group chosen from the list consisting of: 1,3-phenylene, 1,4-phenylene, 1,1'-divalent biphenyl at the 4,4' positions, 1,1'-divalent biphenyl at the 3,4' positions, 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene; and,

for any j, Zj independently denotes an oxygen atom, a sulfur atom, an alkylene group, such as -CH 2- or isopropylene (-C(CH3)2-), or a sulfone, preferentially Zj denotes an atom of 'oxygen.

20. Method according to any one of claims 18 or 19, in which:

- said aromatic diether is chosen from the list consisting of:

or their mixture;

- said compound D is chosen from the list of compounds consisting of:

or their mixture.

21. Process according to any one of claims 14 and 15, in which compound C is diphenylsulfone.