Xanthene derivatives, mixtures containing them, preparation methods and corresponding uses

Abstract

The present invention relates to novel xanthene derivatives of formula (I) or formula (II), to mixtures comprising them, to processes for preparing said compounds or said mixtures and to corresponding uses.

Description

Technical Field

[0001] The present invention relates to the field of xanthene derivatives.

[0002] More specifically, the present invention relates to a series of specific xanthene derivatives, processes for preparing them, and corresponding uses. Background Art

[0003] Xanthene and its derivatives are known chromophores.

[0004] Xanthene has the chemical formula:

[0005] [Chemical Formula 1]

[0006]

[0007] A xanthene derivative that is particularly well-known for its fluorescent properties is fluorescein, with the chemical formula:

[0008] [Chemical Formula 2]

[0009]

[0010] Fluorescein and its derivatives have been used in many fields, especially as tracers for dyeing water or as markers for biomolecules (peptides, antibodies, nucleotides, oligonucleotides, hormones, lipids, etc.). In the case of their use as markers for biomolecules, fluorescein or its derivatives are generally grafted to the molecule of interest by covalent bonding, usually through groups that react with amine functional groups.

[0011] According to more or less complex reaction schemes, the synthesis of many other xanthene derivatives is known from the prior art: see, for example, the doctoral thesis Kotásková, Michaela. Synthesis of new xanthene derivatives. 2013.

[0012] Object of the Invention

[0013] The object of the present invention is to propose a new series of xanthene derivatives and several associated uses.

[0014] According to at least some embodiments, the object is to propose compounds having fluorescent properties.

[0015] According to at least some embodiments, the object is to propose compounds that can be used as radical initiators.

[0016] According to at least some embodiments, the object is to propose compounds for improving the adhesion of aromatic or semi-aromatic polymer matrices to substrates.

[0017] According to at least some embodiments, an object of the present invention is to provide compounds for improving the compatibility between an aromatic or semi-aromatic polymer matrix and other additional aromatic, semi-aromatic, or aliphatic polymer matrices.

[0018] Another object of the present invention is to provide a process for manufacturing this new series of xanthene derivatives.

[0019] Another object of the present invention is to provide possible uses of this new series of derivatives. Summary of the Invention

[0020] The present invention relates to compounds having the following chemical formula:

[0021] [Chemical Formula 3]

[0022]

[0023] [Chemical Formula 4]

[0024]

[0025] Wherein:

[0026] R 0 represents: a charge of +, -H or -OH;

[0027] i is an integer having a value from 0 to 3;

[0028] j, k and l are independently integers having a value from 0 to 4;

[0029] R 1 i , for any i, R 2 j , for any j, R 3 k , for any k, R 4 l , for any l, are independently selected from:

[0030] alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, especially carboxylic acid ester, amide, especially primary amide, halogen, imide, nitro and aliphatic compounds containing nitro functional groups, nitrile and aliphatic compounds containing nitrile functional groups, carbonyl, alkali metal or alkaline earth metal sulfonate, alkyl sulfonate (sulfonate), alkali metal or alkaline earth metal phosphonate, amine, and quaternary ammonium.

[0031] According to certain embodiments, i, j, k and l are all equal to 0.

[0032] According to certain embodiments, R 0 is: -OH.

[0033] According to certain embodiments, R0 is: -H.

[0034] According to certain embodiments, R 0 is: +.

[0035] The present invention also relates to a process, in particular for obtaining compounds of formula (I) and / or (II). This process involves reacting compound (III) with compound (IVa) or (IVb) in the presence of a Lewis acid.

[0036] Compound (III) has the chemical formula:

[0037] [Chemical formula 5]

[0038]

[0039] Compound (IVa) has the chemical formula:

[0040] [Chemical formula 6]

[0041]

[0042] Compound (IVb) has the chemical formula:

[0043] [Chemical formula 7]

[0044]

[0045] wherein i, j, l, R 1 i , R 2 j , R 3 k and R 4 l are as defined above;

[0046] This process is used to obtain a product mixture comprising the compounds as described above.

[0047] According to certain embodiments, i, j, k and l are all equal to 0.

[0048] According to certain embodiments, the reaction of the compound of formula (III) with the compound of formula (IVa) or, respectively, the compound of formula (IVb) is carried out in a reaction solvent. The reaction solvent is preferably an aprotic solvent. The reaction solvent is more preferably selected from: dichloromethane, carbon disulfide, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene or a mixture thereof. The reaction solvent is most preferably o-dichlorobenzene.

[0049] According to certain embodiments, the Lewis acid is selected from: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, iron chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride. Preferably, the Lewis acid is selected from: aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, iron chloride, gallium trichloride, and molybdenum pentachloride. Most preferably, the Lewis acid is aluminum trichloride.

[0050] According to certain embodiments, the molar amount of the compound of formula (III) is 2 to 6 relative to the molar amount of the compound of formula (IVa) or, respectively, the compound of formula (IVb). Preferably, the molar amount of the compound of formula (III) is 2 to 4 relative to the molar amount of the compound of formula (IVa) or, respectively, the compound of formula (IVb).

[0051] According to certain embodiments, the molar amount of the Lewis acid is 0.25 to 2 relative to the sum of the molar amounts of the compound of formula (III) and the compound of formula (IVa) or, respectively, the compound of formula (IVb). Preferably, the molar amount of the Lewis acid is 0.3 to 1.5 relative to the molar amount of the compound of formula (III) or, respectively, the compound of formula (IVb).

[0052] According to certain embodiments, the process comprises:

[0053] - at least one step of separating the compound of formula (I) or, respectively, the compound of formula (II) from at least one other product mixture; and optionally

[0054] - at least one step of purifying the compound of formula (I) or, respectively, the compound of formula (II).

[0055] According to certain embodiments, the process comprises a solid / liquid separation step to recover a liquid containing the compound of formula (I) or, respectively, the compound of formula (II) in a major amount, and a wet cake containing the compound of formula (I) or, respectively, the compound of formula (II) in a minor amount.

[0056] The present invention also relates to a mixture of compounds, which comprises:

[0057] - the compound of formula (I) as described above;

[0058] - a compound of the following formula:

[0059] [Chemical formula 8]

[0060]

[0061] [Chemical formula 9]

[0062]

[0063] or a mixture thereof, wherein i, j, k, R 1 i , R 2 j , and R 3 k are as defined in compound (I).

[0064] According to certain embodiments, in this mixture, the compound of formula (I) accounts for 0.01 mol% to 10 mol%, based on the total number of moles of the compounds of formula (I), (IX-i) and (IX-ii).

[0065] According to certain embodiments, in this mixture, the compound of formula (I) accounts for 90 mol% to 90.99 mol%, based on the total number of moles of the compounds of formula (I), (IX-i) and (IX-ii).

[0066] The present invention also relates to a mixture of compounds, comprising:

[0067] - a compound of formula (II) as described;

[0068] - a compound of the following formula:

[0069] [Chemical formula 10]

[0070]

[0071] [Chemical formula 11]

[0072]

[0073] or a mixture thereof,

[0074] wherein i, j, l, R 1 i , R 2 j and R 4 k are as defined in compound (II).

[0075] According to certain embodiments, in this mixture, the compound of formula (II) accounts for 0.01 mol% to 10 mol%, based on the total number of moles of the compounds of formula (II), (IX-i) and (IX-ii).

[0076] According to certain embodiments, in this mixture, the compound of formula (II) accounts for 90 mol% to 90.99 mol%, based on the total number of moles of the compounds of formula (II), (IX-i) and (IX-ii).

[0077] Finally, the present invention relates to the use of the compounds of formula (I) or formula (II) as chromophores, as radical generators, or as adhesion promoters and / or coupling agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 represents a first reaction scheme for obtaining the desired compound of formula (V) from a mixture of diphenyl ether and terephthaloyl chloride in the presence of aluminum trichloride.

[0079] Figure 2 represents an alternative reaction scheme for the reaction scheme shown in Figure 1 for obtaining the desired compound of formula (V) from a mixture of diphenyl ether and terephthaloyl chloride in the presence of aluminum trichloride.

[0080] Figure 3 represents a reaction scheme for obtaining the compound of formula (VIII), which is obtained by a major competing reaction from a mixture of diphenyl ether and terephthaloyl chloride in the presence of aluminum trichloride.

[0081] Figure 4 represents the HPLC / MS chromatogram of the mixture obtained according to Example 1, which mixture substantially contains the compound of formula (V). The x-axis represents the elution time and is expressed in minutes (min). The y-axis represents the ion abundance and is expressed in milli-arbitrary units (mAU).

[0082] Figure 5 represents the mass spectrum of the mixture obtained according to Example 1, which mixture by HPLC / MS substantially contains the compound of formula (VI). The x-axis represents the elution time and is expressed in minutes (min). The y-axis represents the ion abundance and is expressed in milli-arbitrary units (mAU).

[0083] Figure 6 represents the UV / IR absorption spectrum of the compound of formula (V). The x-axis represents the wavelength and is expressed in nanometers (nm). The y-axis represents the absorption (dimensionless).

[0084] Figure 7 represents the UV / IR absorption spectrum of the compound in form (V) or in form (VI) at different pH values. The x-axis represents the wavelength and is expressed in nanometers (nm). The y-axis represents the absorption (dimensionless). DETAILED DESCRIPTION

[0085] The present invention will now be described in more detail and in a non-limiting manner in the following description.

[0086] ​​​​​​​This process involves reacting a compound of formula (III) with a compound of formula (IVa) or, respectively, a compound of formula (IVb) in the presence of a Lewis acid; the compound (III) is an aromatic ether having the following chemical formula:

[0087] [Chemical formula 12]

[0088]

[0089] The compound (IVa) is an aromatic acyl chloride having the following chemical formula:

[0090] [Chemical formula 13]

[0091]

[0092] And the compound of formula (IVb) is an aromatic acyl chloride having the following chemical formula:

[0093] [Chemical formula 14]

[0094]

[0095] Wherein:

[0096] i is an integer having a value from 0 to 3;

[0097] j, k, and l are independently integers having a value from 0 to 4;

[0098] R 1 i , for any i, R 2 j , for any j, R 3 k , for any k, R 4 l , for any l, is independently selected from: alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, especially carboxylic acid ester, amide, especially primary amide, halogen, imide, nitro, and aliphatic compounds containing a nitro functional group, nitrile, and aliphatic compounds containing a nitrile functional group, carbonyl, alkali metal or alkaline earth metal sulfonate, alkyl sulfonate (salt), alkali metal or alkaline earth metal phosphonate, amine, and quaternary ammonium salt.

[0099] Preferably, in the foregoing formulas, R 1 i , for any i, R 2 j , for any j, R 3 k , for any k, R 4 l, for any l, independently selected from: alkyl, aryl, ether, thioether, carboxylic acid, ester, especially carboxylic acid ester, amide, especially primary amide, imide, nitro and aliphatic compounds containing nitro functional groups, nitrile and aliphatic compounds containing nitrile functional groups, carbonyl, alkali metal or alkaline earth metal sulfonate, alkyl sulfonate (salt), alkali metal or alkaline earth metal phosphonate and tertiary amine.

[0100] According to this notation, R i 0 means that the phenyl group (R i 0 is located thereon) has no substituents; R i 1 means that the phenyl group (R i 1 is located thereon) contains exactly one substituent; R i 2 means that the phenyl group (R i 2 is located thereon) contains exactly two substituents, and each of the two substituents can be independently selected from each other, and so on. In certain embodiments, the process involves reacting diphenyl ether with terephthaloyl chloride or isophthaloyl chloride in the presence of a Lewis acid, such as aluminum trichloride (AlCl3).

[0101] Without wishing to be bound by theory, the inventors believe that the reaction for obtaining the compounds according to the present invention occurs according to the reaction scheme in Figure 1 and / or the reaction scheme in Figure 2 . For the sake of simplicity, the reaction schemes in Figure 1 and Figure 2 represent an example of a mixture of diphenyl ether and terephthaloyl chloride in the presence of aluminum trichloride, but are not intended to be limited to these compounds. The ortho and para positions of the phenyl groups of diphenyl ether are particularly activated by the mesomeric effect, which will explain why electrophilic substitution mainly occurs at the para and ortho positions. According to the reaction in Figure 1 and Figure 2 involves two intermolecular electrophilic substitutions and one intramolecular electrophilic substitution (cyclization). More specifically, the reaction involves an intermolecular electrophilic substitution of the hydrogen on the ortho position of the phenyl group of the diphenyl ether molecule, followed by an intramolecular 6-atom cyclization of the hydrogen on the ortho position of another phenyl group of the diphenyl ether molecule, and another intermolecular electrophilic substitution of the hydrogen on the ortho position of another phenyl group of the diphenyl ether. Subsequently, the following compound of the following formula is obtained:

[0102] [Chemical formula 15]

[0103]

[0104] Since the -OH group of the compound of formula (V) is unstable under acidic conditions, the following carbocation of the following formula can be formed:

[0105] [Chemical formula 16]

[0106]

[0107] The reduced form of the carbocation of formula (VI) is the following compound of the following formula:

[0108] [Chemical formula 17]

[0109]

[0110] For Figure 1 and Figure 2 in the reaction shown, the main competing reaction is the reaction according to the reaction sequence in Figure 3 For Figure 1 and 2 , Figure 3 also illustrates an example of a mixture of diphenyl ether and terephthaloyl chloride in the presence of aluminum trichloride. The reaction according to Figure 3 involves an intermolecular electrophilic substitution of two hydrogen atoms of the phenyl group at the para position of the diphenyl ether molecule. Thus, the following compound of the following formula is obtained:

[0111] [Chemical formula 18]

[0112]

[0113] For the 6-atom cyclization to occur, it is crucial that the aromatic ether of formula (III) has hydrogen atoms at the ortho position of each phenyl group. In addition, it is also crucial that the aromatic ether compound of formula (III) has hydrogen atoms at the para position of at least one phenyl group. The other positions of the phenyl group of the aromatic ether of formula (III) may or may not be substituted.

[0114] Certain parameters can be more favorable for the reaction to synthesize the compounds according to the present invention (such as the reaction sequences according to Figure 3 ) compared to the competing reactions (mainly such as the reaction sequence according to Figure 1 or Figure 2 ).

[0115] These parameters can be the intrinsic characteristics of the reagents: the ortho and para positions of the aromatic ether of formula (III) can be more or less activated, depending on the nature and position of its possible substituents, due to the electron-donating or electron-withdrawing effects of the said possible substituents.

[0116] For example, for an aromatic ether of the following formula:

[0117] [Chemical formula 19]

[0118]

[0119] where X is an electron-donating group, this electron-donating group X enables the activation of the phenyl group carrying this group X (in bold), which promotes polysubstitution on the aromatic ring.

[0120] These parameters may also be certain reaction variables as explained hereinafter in certain preferred embodiments.

[0121] In one embodiment, the reaction is carried out without a solvent. The reaction is then called a bulk reaction.

[0122] In another embodiment, the reaction is carried out in a reaction solvent. The reaction solvent is preferably an aprotic solvent.

[0123] A protic solvent is a solvent containing at least one hydrogen atom bonded to an oxygen or nitrogen atom and capable of donating a proton to a reagent. Conversely, an aprotic solvent is a solvent that is not a protic solvent.

[0124] The aprotic solvents used herein may be particularly selected from methylene chloride, carbon disulfide, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, and mixtures thereof.

[0125] o-Dichlorobenzene is the most preferred solvent.

[0126] The Lewis acids that can be used include, for example, aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, iron chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride. Aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, iron chloride, gallium trichloride, and molybdenum pentachloride are preferred. Aluminum trichloride is particularly preferred.

[0127] In the presence of a Lewis acid, the reaction between the compound of formula (III) and the compound of formula (IVa) or formula (IVb) to produce the compound of formula (I) or formula (II) can be carried out in a reactor. The reaction can be carried out in a reactor. The reactor can be, for example, a glass reactor, a reactor with a glass inner wall, or a reactor made of stainless metal material or lined with PTFE.

[0128] According to certain variants, the materials introduced into the reactor in the process of the present invention are substantially the following, or consist of the following: the compound of formula (III), the compound of formula (IVa) or respectively the compound of formula (IVb), the reaction solvent, and the Lewis acid.

[0129] Preferably, the reaction can be carried out in a reaction mixture that substantially does not contain any water.

[0130] Preferably, 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).

[0131] The reaction mixture can be prepared by mixing the components (the compound of formula (III), the compound of formula (IVa) or respectively the compound of formula (IVb), the Lewis acid and the reaction solvent) in any order.

[0132] According to the first embodiment, an initial mixture containing the compound of formula (III) and the compound of formula (IVa) or respectively the compound of formula (IVb) in a reaction solvent (and preferably consisting of the compound of formula (III) and the compound of formula (IVa) or respectively the compound of formula (IVb) in a reaction solvent) is first prepared. The initial mixture can be prepared in particular by mixing the three components in any order. For example, the reaction solvent can first be introduced into the reactor, and then the compound of formula (III) and the compound of formula (IVa) or respectively the compound of formula (IVb) can be added successively. Subsequently, the Lewis acid is added to this initial mixture.

[0133] Preferably, the Lewis acid is added in solid form. Alternatively, the Lewis acid can also be added in the form of a suspension or a colloid, i.e., in the form of a heterogeneous mixture of solid particles of the Lewis acid in a solvent. Advantageously, the solvent of the suspension or colloid is the reaction solvent mentioned above. The Lewis acid can also be added in solution form, i.e., in the form of a homogeneous mixture of the Lewis acid in a solvent. Preferably, the solvent of the solution is the reaction solvent mentioned above.

[0134] According to the second embodiment, an initial mixture containing the compound of formula (IVa) or respectively the compound of formula (IVb) and the Lewis acid in a reaction solvent (and preferably consisting of the compound of formula (IVa) or respectively the compound of formula (IVb) and the Lewis acid in a reaction solvent) is first prepared. The initial mixture can be prepared by mixing the three components in any order. Subsequently, the compound of formula (III) is added to this initial mixture. The compound of formula (III) can be added in liquid form or in solution form, preferably in the reaction solvent mentioned above.

[0135] In the third embodiment, an initial mixture containing the compound of formula (III) and the Lewis acid in a reaction solvent (and preferably consisting of the compound of formula (III) and the Lewis acid in a reaction solvent) is first prepared. The initial mixture can be prepared by mixing the three components in any order. Subsequently, the compound of formula (IVa) or respectively the compound of formula (IVb) is added to this initial mixture. It can be added in the form of a suspension, a colloid, or a solution, preferably in the reaction solvent mentioned above.

[0136] In certain embodiments:

[0137] - The molar amount of the compound of formula (IVa) or, respectively, the compound of formula (IVb) is 2% to 11%, and preferably 3% to 8%, based on the sum of the molar amounts of the reaction solvent, the compound of formula (III), the compound of formula (IVa) or, respectively, the compound of formula (IVb), and the Lewis acid introduced into the reactor;

[0138] - The molar amount of the compound of formula (III) is 5% to 40%, and preferably 8% to 25%, based on the sum of the molar amounts of the reaction solvent, the compound of formula (III), the compound of formula (IVa) or, respectively, the compound of formula (IVb), and the Lewis acid introduced into the reactor;

[0139] - The molar amount of the Lewis acid is 4% to 45%, and preferably 8% to 30%, based on the sum of the molar amounts of the reaction solvent, the compound of formula (III), the compound of formula (IVa) or, respectively, the compound of formula (IVb), and the Lewis acid introduced into the reactor;

[0140] - The molar amount of the compound of formula (III) is 2 to 6, and preferably 2 to 4, based on the molar amount of the compound of formula (IVa) or, respectively, the compound of formula (IVb) introduced into the reactor; and

[0141] - The molar amount of the Lewis acid is 0.25 to 2, and preferably 0.3 to 1.5, based on the sum of the molar amounts of the compound of formula (III) and the compound of formula (IVa) or, respectively, the compound of formula (IVb) introduced into the reactor;

[0142] Preferably, the reaction mixture is stirred during at least a part of the reaction step. Thus, the reactor is preferably equipped with stirring means, such as a mechanical stirrer (which may comprise, for example, one or more blades) or a recirculation loop comprising a pump.

[0143] The reaction step between the compound of formula (III) and the compound of formula (IVa) or, respectively, the compound of formula (IVb) can (preferably with stirring) be maintained for a period of time to complete the reaction to the desired extent.

[0144] Once the reaction is completed to the desired extent, the reaction mixture is referred to as the "product mixture". The product mixture contains the desired product of the following formula:

[0145] [Chemical formula 20]

[0146]

[0147] Or, respectively, the desired product of the following formula:

[0148] [Chemical formula 21]

[0149]

[0150] wherein i, j, k, l, R 1 i , R 3 k and R 4 l are as defined above for the compounds of formulae (III), (IVa), and (IVb).

[0151] Preferably, during at least a part of the reaction, the temperature of the reaction mixture is less than or equal to 79 °C. According to certain variants, the temperature of the reaction mixture is less than or equal to 55 °C, or less than or equal to 50 °C, or less than or equal to 40 °C, or less than or equal to 30 °C, or less than or equal to 20 °C, or less than or equal to 10 °C, or less than or equal to 5 °C, or less than or equal to 0 °C, or less than or equal to -5 °C, or less than or equal to -10 °C.

[0152] The temperature must in particular be maintained below the boiling point of the reaction solvent. For this purpose, the reactor can be operated at a suitable pressure such that the temperature in the reactor can reach a higher value without boiling the solvent. In this case, the pressure in the reactor can range from 1 bar (atmospheric pressure) to 6 bar, preferably from 1.5 bar to 3 bar.

[0153] As a variant, and preferably, the reaction can be carried out at atmospheric pressure.

[0154] The temperature of the reaction mixture is maintained substantially constant during the reaction. Alternatively, it can vary during the reaction.

[0155] Once the reaction has been completed to the desired extent, the process according to the invention can comprise the steps of recovering and purifying the compound of formula (I) or, respectively, the compound of formula (II) from the product mixture. In addition to the desired product (I) or (II), the product mixture can in particular contain the Lewis acid, possibly unreacted reagents, and possibly (one or more) products resulting from competitive reactions of the type shown in the reaction scheme according to Figure 3 .

[0156] In embodiments in which a reagent of formula (IVa) is used, the product resulting from the competitive reaction has the following formula:

[0157] [Chemical formula 22]

[0158]

[0159] and / or

[0160] [Chemical Formula 23]

[0161]

[0162] wherein i, j, k, R 1 i 、R 2 j 、R 3 k are as defined above for the compounds of formulae (III) and (IVa).

[0163] In embodiments where a reagent of formula (IVb) is used, the product obtained from said competitive reaction has the following formula:

[0164] [Chemical Formula 24]

[0165]

[0166] and / or

[0167] [Chemical Formula 25]

[0168]

[0169] wherein i, j, l, R 1 i 、R 2 j 、R 4 l are as defined above for the compounds of formulae (III) and (IVb).

[0170] Compared to the desired product of formula (I) or, respectively, the desired product of formula (II), the competitive reaction products of formulae (IX-i) and / or (IX-ii), or, respectively, the competitive reaction products of formulae (X-i) and / or (X-ii) are generally less soluble in the reaction solvent. Thus, the desired product is generally completely or almost completely dissolved in the reaction solvent, while the product obtained from the competitive reaction is generally at least partially in the form of a precipitate.

[0171] To facilitate the precipitation of the product obtained from the competitive reaction, the product mixture can be subjected to various treatments aimed at minimizing its solubility while having little or no effect on the solubility of the desired product.

[0172] In particular, the product mixture can be cooled. Preferably, the cooling rate can be, for example, 1 to 10 °C / hour, 10 to 20 °C / hour, or 20 to 40 °C / hour, or 40 to 60 °C / hour, or 60 to 90 °C / hour, or 90 to 120 °C / hour, or 120 to 180 °C / hour, or greater than 180 °C / hour.

[0173] Alternatively or in addition, the product mixture can be subjected to shear stress.

[0174] Alternatively or in addition, the product mixture can be subjected to removal by distilling off a portion of the reaction solvent.

[0175] Alternatively or in addition, a compound in solid form that acts as a seed can be added to the product mixture.

[0176] In certain embodiments, the product mixture can be placed in contact with a dissociating solvent, which is a protic solvent. The dissociating solvent enables the dissociation of complexes formed by Lewis acids, especially complexes formed by the desired product and complexes formed by products resulting from competing reactions.

[0177] The dissociating solvent can be an organic solvent such as methanol, acetic acid, formic acid, ethanol, isopropanol, or benzyl alcohol. Methanol is preferred as the organic solvent.

[0178] Alternatively, the dissociating solvent can be an aqueous solution. Using an aqueous solution as the dissociating solvent is particularly advantageous for two reasons. First, the aqueous solution has a high heat capacity. This enables better dissipation of the heat generated during the highly exothermic dissociation of complexes formed by Lewis acids. Second, the dissociated Lewis acid (in the form of an ionic salt, metal hydroxide, metal alkoxide, or any other compound resulting from the reaction of the Lewis acid with the dissociating solvent) can be dissolved in the aqueous phase and thus can be recovered from the aqueous solution.

[0179] Mixtures of the above solvents can also be used, such as water-organic mixtures, for example an aqueous solution mixed with methanol.

[0180] The aqueous solution can simply be water.

[0181] The aqueous solution can also be an acidic solution, such as a solution of hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, an organic acid such as formic acid, and any combination thereof. In particular, the aqueous solution can be a hydrochloric acid solution. Preferably, the pH of the aqueous solution is less than 6, or less than 5, or less than 4, or less than 3, or less than 2, or less than 1, or less than 0. Preferably, the pH range of the aqueous solution is from 1 to 2. In particular, the dissociating solvent can be an aqueous solution containing hydrochloric acid at a concentration corresponding to such a pH value. The aqueous solution can also be a basic solution, such as a solution of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, calcium carbonate, magnesium carbonate, potassium carbonate, ammonia, or a mixture thereof. In these embodiments, the pH of the aqueous solution is preferably greater than 9, or greater than 10, or greater than 11, or greater than 12, or greater than 13, or greater than 14. Preferably, the pH range of the dissociating solvent is from 12 to 14.

[0182] In particular, the decoupling solvent may be an aqueous solution containing NaOH at a concentration corresponding to such a pH value.

[0183] In certain embodiments, solid / liquid separation can be directly performed on the product mixture obtained at the end of the reaction, or on such a reaction mixture that has undergone one or more steps for promoting the precipitation of products from competing reactions, and / or decoupling steps. Subsequently, a pasty cake and a liquid are obtained in at least one phase form.

[0184] The temperature during solid / liquid separation is preferably not more than 79 °C. More preferably, the temperature during solid / liquid separation is not more than 60 °C. Even more preferably, the temperature during solid / liquid separation is not more than 30 °C.

[0185] Solid / liquid separation can be carried out in one or more consecutive steps, each step selected from: centrifugal filtration, sedimentation, centrifugal decantation, vacuum filtration, pressure filtration, and gravity filtration.

[0186] In certain embodiments, solid / liquid separation may include a step of centrifugal filtration in a centrifugal filtration device. Specifically, it has been found that centrifugal filtration is particularly fast and efficient for performing the required solid / liquid separation.

[0187] The centrifugal filtration device may particularly have a horizontal or vertical axis.

[0188] The centrifugal filtration is preferably carried out at an acceleration of: 2 to 1500 x g, more preferably 5 to 1000 x g, more particularly 10 to 800 x g.

[0189] Different acceleration values or ranges can be used in consecutive centrifugation stages, such as the loading stage, the washing stage, and / or the water removal stage. For example, a low acceleration can be applied first, followed by a high acceleration.

[0190] The pasty cake consists of wet solid material. It mainly contains the precipitated products of formula (IX-a) and / or (IX-b) from competing reactions, or respectively (X-a) and / or (X-b) from competing reactions, and in minor amounts contains the desired reaction product of formula (I) or respectively the desired reaction product of formula (II). Preferably, the compound of formula (I) or respectively the compound of formula (II) accounts for 0.01 mol% to 10 mol%, based on the total molar amount of the compounds of formula (I), (IX-i), and (IX-ii) or respectively the compounds of formula (II), (X-i), and (X-ii).

[0191] The liquid contains, in a major amount, the desired compound of formula (I) or (II), and, in a minor amount, the product resulting from a competing reaction of formula (IX-a) and / or (IX-b), or respectively the product resulting from a competing reaction of (X-a) and / or (X-b). In addition, the liquid may optionally contain unreacted compounds, and / or synthesis intermediates. Preferably, the compound of formula (I) or respectively the compound of formula (II) accounts for 90 mol% to 99.99 mol%, based on the total number of moles of the compounds of formula (I), (IX-i) and (IX-ii), or respectively the compounds of formula (II), (X-i) and (X-ii).

[0192] In certain embodiments, the desired compound of formula (I) or formula (II) can be separated by various separation techniques known to those skilled in the art. For example, fractional or non-fractional distillation of (a) solvent(s) can be carried out. Alternatively, the solvent can be replaced with water by azeotropic distillation followed by filtration. Column separation of the various compounds is also a way to obtain the compound of formula (I) or formula (II).

[0193] Due to its spectral properties, the compound of formula (I) or respectively the compound of formula (II), especially in the form in which -R0 = -OH or -R0 = (+) (carbocation) or even -R0 = -H (e.g., after reduction of the -OH group with an acid), can advantageously be used as a chromophore. It has been shown that a pH between 3 and 4 preferably leads to the form in which -R0 = -OH, where the ultraviolet-visible absorption band is at 293 nm, pH ≤ 2 preferably leads to the form in which -R0 = + and / or -R0 = -H, where the absorption band shifts from 293 nm to 304 nm, and three new absorption bands appearing at 380, 460 and 492 nm, as shown by the spectrum.

[0194] According to certain embodiments, especially in those embodiments in which the compounds according to the invention include reactive substituents, it is conceivable that the chromophore is grafted onto a biomolecule.

[0195] According to certain embodiments, the compound of formula (I) or respectively the compound of formula (II), in the form in which -R0 = -OH or -R0 = -H, can be used as a radical generator. Such a radical generator can advantageously be used as an initiator for radical reactions such as radical polymerization or grafting reactions.

[0196] Preferably, the compound of formula (I) or respectively the compound of formula (II) is in the form of -R0 = -OH.

[0197] According to certain embodiments, the compound (I) or (II) can be used as a photo-sensitive radical generator. Therefore, it can be used as a photoinitiator, especially a UV photoinitiator, in polymerization and / or crosslinking reactions. Applications in the fields of resins, coatings, inks or adhesives are envisaged.

[0198] In particular, the compound of formula (I) or of formula (II) according to the invention can advantageously replace more traditional photoinitiators, especially photoinitiators of the aminobenzophenone family (for example: Irgacure 379 (2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one; CAS No. 119344-86-4) or SpeedCure BDMB (2-benzyl-2-dimethylamino-4-morpholinophenyl propanone; CAS No. 119313-12-1), which have an absorption maximum in the 320 nm region, or photoinitiators of the benzophenone family, such as SpeedCure MBS (CAS No. 83846-85-9; benzoylmethyldiphenyl sulfide), which has two maximum absorptions at 246 nm and 315 nm.

[0199] According to certain embodiments, the compound of formula (I) or respectively the compound of formula (II) can be used as a thermo-sensitive radical generator. Therefore, it can be used as a thermal initiator in polymerization reactions and / or crosslinking reactions.

[0200] In particular, in the field of performance materials, one of the ways to extend the scope of use of thermoplastics is to carry out partial crosslinking of the polymer during its processing. Due to their aromatic nature, the compounds according to the invention have good affinity for aromatic and semi-aromatic thermoplastic matrices such as: polyimides, polycarbonates, aromatic and semi-aromatic polyamides, aromatic polysulfones, polyaryl ether ketones (such as polyether ketone ketone) and / or their copolymers. Therefore, they can be easily added to such aromatic and semi-aromatic thermoplastic matrices in such a way that free radicals are generated during their processing, thus ensuring partial crosslinking of the thermoplastic matrix.

[0201] This crosslinking in particular makes it possible to improve the high-temperature properties of the thermoplastic matrix, possibly in the presence of other chemical compounds. For example, these properties are highly sought after in the oil and gas industry (connectors, hoses, etc.).

[0202] In addition, partial crosslinking makes it possible to limit or even eliminate the evolution of the crystallinity of semi-crystalline thermoplastic matrices, which is usually observed during aging tests or when reaching high temperatures.

[0203] According to certain embodiments, the compound of formula (I) or respectively the compound of formula (II), in the form in which -R0 = -OH or -R0 = -H, can be used as an adhesion promoter and / or coupling agent.

[0204] For example, it can be used in the field of thermoplastic composites. Thermoplastic composites generally combine a thermoplastic matrix with reinforcing fibers (continuous or discontinuous). For the purpose of facilitating fiber handling, especially to limit wear between fibers, and for the purpose of ensuring a good interface between the reinforcing fibers and the matrix, sizing of the fibers is generally necessary.

[0205] Sizing can be carried out in several ways, but the preferred way is generally by forming an aqueous dispersion. Due to its aromatic nature, the compounds according to the invention are, for example, well compatible with carbon fibers and with the following aromatic thermoplastic matrices: polyimides, polycarbonates, aromatic and semi-aromatic polyamides, aromatic polysulfones, polyetheraryl ketones, and their copolymers, thus providing good wettability.

[0206] After deposition and drying of the aqueous dispersion, during the contact of the fibers with the matrix (by mixing, impregnation, coating, etc.), the free-radical grafting reaction of the compounds according to the invention with the thermoplastic matrix can occur at the melting point of the thermoplastic matrix and thus ensure covalent bonding to the matrix.

[0207] Examples

[0208] The following three examples illustrate certain claims of the invention without limitation. The procedure followed is as follows:

[0209] In a first reactor equipped with mechanical stirring, and under a nitrogen stream of a scrubber-type neutralization system, diphenyl ether (DPE) and terephthaloyl chloride (TCl) are introduced into 1,2-dichlorobenzene (o-DCB) at room temperature. The following table shows the molar amounts of the reaction components for each example:

[0210] [Table 1]

[0211] Molar amount Example 1 Example 2 Example 3 DPE 0.8 0.6 0.8 TCl 0.3 0.2 0.3 oDCB 5.5 5.5 4.0 <![CDATA[AlCl3]]> 0.9 0.6 0.7

[0212] After dissolution, aluminum trichloride (AlCl3) is slowly added at 25 °C (Example 1), 0 °C (Example 2), or 70 °C (Example 3), respectively. Subsequently, a step of maintaining the reaction medium at the same temperature for 3 hours is followed to complete the reaction. Subsequently, the reaction medium is precipitated by transferring the reaction medium to a 3% hydrochloric acid aqueous solution at 50 °C. After removing the aqueous aluminum phase, the precipitated reaction medium is obtained. Subsequently, a solid / liquid separation step using a pressure filter is followed, where on one side there is a filter cake and on the other side there is a filtrate, the filter cake substantially containing the solids of the competing reaction of formula (VIII), and the filtrate, after evaporation, enables the separation of a mixture substantially containing the target compound V. The molar ratio of compound V and VIII in these mixtures is determined by 1 1H NMR analysis and is presented in the following table:

[0213] [Table 2]

[0214] Molar ratio Example 1 Example 2 Example 3 Target compound V 94.8 90.4 93.5 Compound VIII in competitive reaction 5.2 9.6 6.5

[0215] Characterization

[0216] HPLC / MS

[0217] The mixture obtained according to Example 1, which substantially contains the compound of formula (V), was analyzed by high performance liquid chromatography (HPLC) coupled to mass spectrometry (MS-TOF) (using APCI (atmospheric pressure chemical ionization) ionization mode in positive mode) using a Phenomenex Kinetex 2.6 μm C18 100A column. Thus, a characteristic peak was observed at 6.3 minutes, corresponding to the [M+H] adduct of the compound of formula (V). + adduct (see Figure 4 ).

[0218] The dehydrated form of the compound of formula (V), i.e., the compound of formula (VI) (-R0=+, after protonation of the -OH functional group), corresponding to a particularly stable dibenzyl-type carbocation, was also observed, having a peak at 7.7 minutes in acidic medium and being confirmed by the adduct [M+H-H2O] in MS-TOF (see Figure 5 ). + Confirmed.

[0219] UV / IR

[0220] The absorbance of the compounds of formula (V) and formula (VI) (obtained from the mixture obtained according to Example 1 and substantially containing the compound of formula (V)) was measured as follows: at a concentration of 1 g / L after dilution in 1,2-dichlorobenzene, in a quartz cell, in transmission mode on a Cary 300 UV / Visible spectrophotometer.

[0221] Figure 6 An absorption band of the compound of formula (V) was shown, with an absorption maximum at 293 nm.

[0222] As Figure 7 shown, it was observed that under acidic conditions (i.e., at pH ≤ 2), the form (VI) was favored, resulting in a shift of this absorption band to an absorption maximum at 304 nm, and the appearance of three new bands / shoulders with maxima at 380, 460, and 492 nm.

[0223] Figure 7Among them, curve E1 represents the absorbance of the mother liquor (solution mère) of the mixture obtained according to Example 1 at pH = 4. Curve E2 represents the absorbance of the mother liquor at pH = 3. Curve E3 represents the absorbance of the mother liquor at pH = 2. Curve E4 represents the absorbance of the mother liquor at a pH lower than that of E3. Curve E5 represents the absorbance of the mother liquor to which twenty drops of strong acid (pH < 2) have been added.

Claims

1. A compound having the following chemical formula: [Chemical formula 26] or [Chemical formula 27] wherein: R 0 represents: charge +, -H or -OH; i is an integer with a value from 0 to 3; j, k, and l are independently integers with a value from 0 to 4; R 1 i , for any i, R 2 j , for any j, R 3 k , for any k, R 4 l , for any l, independently selected from: halogen, nitro, nitrile functional group.

2. The compound according to claim 1, wherein i, j, k, and l are all equal to 0.

3. The compound according to any one of claims 1 to 2, wherein R 0 is: -OH.

4. The compound according to any one of claims 1 to 2, wherein R 0 is: -H.

5. The compound according to any one of claims 1 to 2, wherein R 0 is: +.

6. A process for obtaining a product mixture comprising the compound according to any one of claims 1 to 5, the process involving reacting a compound of formula (III) with a compound of formula (IVa) or (IVb) in the presence of a Lewis acid; The compound (III) has the chemical formula: [Chemical formula 28] The compound (IVa) has the chemical formula: [Chemical formula 29] and the compound (IVb) has the chemical formula: [Chemical formula 30] wherein, i, j, k, l, R 1 i , R 2 j , R 3 k and R 4 l as defined in claim 1.

7. The process according to claim 6, wherein i, j, k, and l are all equal to 0.

8. The process according to any one of claims 6 and 7, wherein the reaction of the compound of formula (III) with the compound of formula (IVa) or separately with the compound of formula (IVb) is carried out in a reaction solvent.

9. The process according to claim 8, wherein the reaction solvent is an aprotic solvent.

10. The process according to claim 8, wherein the reaction solvent is selected from: dichloromethane, carbon disulfide, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, and mixtures thereof.

11. The process according to claim 10, wherein the reaction solvent is o-dichlorobenzene.

12. The process according to claim 6 or 7, wherein the Lewis acid is selected from: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, iron chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride.

13. The process according to claim 12, wherein the Lewis acid is selected from: aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, iron chloride, gallium trichloride, and molybdenum pentachloride.

14. The process according to claim 13, wherein the Lewis acid is aluminum trichloride.

15. The process according to claim 6 or 7, wherein the molar amount of the compound of formula (III) is 2 to 6 relative to the molar amount of the compound of formula (IVa) or respectively the compound of formula (IVb).

16. The process according to claim 15, wherein the molar amount of the compound of formula (III) is 2 to 4 relative to the molar amount of the compound of formula (IVa) or respectively the compound of formula (IVb).

17. The process according to claim 6 or 7, wherein the molar amount of the Lewis acid is 0.25 to 2 relative to the sum of the molar amounts of the compound of formula (III) and the compound of formula (IVa) or respectively the compound of formula (IVb).

18. The process according to claim 17, wherein the molar amount of the Lewis acid is 0.3 to 1.5 relative to the sum of the molar amounts of the compound of formula (III) and the compound of formula (IVa) or respectively the compound of formula (IVb).

19. The process according to claim 6 or 7, the process comprising - at least one step of separating the compound of formula (I) or respectively the compound of formula (II) from at least one other species of the product mixture; and optionally - at least one step of purifying the compound of formula (I) or respectively the compound of formula (II).

20. The process as described in claim 19, which process comprises a solid / liquid separation step in order to recover a liquid comprising, in major amount, a compound of formula (I) or respectively a compound of formula (II), and a wet cake comprising, in minor amount, a compound of formula (I) or respectively a compound of formula (II).

21. A mixture of compounds, comprising: - a compound of formula (I) as described in any one of claims 1 to 5; - a compound of the following formula: [Chemical formula 31] [Chemical formula 32] or a mixture thereof, wherein i, j, k, R 1 i 、R 2 j and R 3 k are as defined for compound (I); or a mixture of compounds comprising: - a compound of formula (II) as described in any one of claims 1 to 5; - a compound of the following formula: [Chemical formula 33] [Chemical formula 34] or a mixture thereof, wherein i, j, l, R 1 i 、R 2 j and R 4 l are as defined for compound (II).

22. The mixture of compounds as described in claim 21, wherein the compound of formula (I) or respectively the compound of formula (II) is present in an amount of 0.01 mol% to 10 mol%, based on the total molar amount of the compounds of formula (I), (IX-i) and (IX-ii) or respectively the compounds of formula (II), (X-i) and (X-ii).

23. The mixture of compounds as described in claim 21, wherein the compound of formula (I) or respectively the compound of formula (II) is present in an amount of 90 mol% to 99.99 mol%, based on the total molar amount of the compounds of formula (I), (IX-i) and (IX-ii) or respectively the compounds of formula (II), (X-i) and (X-ii).

24. Use of the compound as defined in any one of claims 1 to 5 as a chromophore.

25. Use of the compound as defined in any one of claims 1 to 5 as a radical generator.

26. Use of the compound as defined in any one of claims 1 to 5 as an adhesion promoter and / or coupling agent.

Images