阅读说明：本技术 含全氟环丁烷单体的制备方法 (Preparation method of perfluorocyclobutane-containing monomer ) 是由 R·兴特 D·高盛 L·布拉干特 M·格雷戈里 S·米勒范蒂 E·安特努西 J·波里诺 于 2020-05-05 设计创作，主要内容包括：本发明涉及一种用于制备多官能芳族化合物的多步法以提供缩聚聚合物,所述多官能芳族化合物包含两个带有易发生缩聚反应的反应性基团的苯环,所述方法使用经济的原材料,并具有高的选择性和总产率。(The present invention relates to a multi-step process for preparing a polyfunctional aromatic compound comprising two benzene rings having reactive groups susceptible to polycondensation reaction, using economical raw materials, and having high selectivity and overall yield, to provide a polycondensation polymer.)

1. A process for the preparation of a compound having the general formula [ formula (I) ]:

wherein each G and G', equal to or different from each other, is independently selected from the group consisting of

-halogen selected from F, Cl, Br, I, in particular-F, -Cl;

--NR_H ¹R_H ²wherein R is_H ¹And R_H ²Independently is H or C₁-C₆A hydrocarbyl group, preferably H;

--OH；

-a nitrile group of the formula-CN and-NO₂Nitro group of (1);

- -COY, wherein Y is- -X, X is a halogen selected from F, Cl, Br, I, in particular- -F, - -Cl; -OH; -OR_H ³、-NR_H ¹R_H ²Wherein R is_H ³Is C₁-C₁₂Hydrocarbyl, especially C₁-C₆Alkyl or C₆-C₁₂An aryl group; and R is_H ¹And R_H ²Have the meanings detailed above; preferably Y is OH;

--SO₂y ', wherein Y' is-OH or-X ', X' is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

- -E- -Ar- -X "wherein X" is hydrogen, - -OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl; -E-is a divalent bridging group selected from the group consisting of: key, C₁-C₆A carbon-containing bridging group; a sulfur-containing bridging group; exemplary embodiments of-E-are notably: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-, and-SO₂-; ar-is a divalent aromatic radical, in particular an (optionally substituted) phenyl group (-Ph-), for example, where the bonds in Ph-may be in the ortho, meta or para position, preferably in the para position, relative to one another,

-a group of formula

Wherein X^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °;

wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

each n, equal to or different from each other, is an integer from 1 to 3, preferably from 1 to 2, more preferably n ═ 1,

the method comprises the following steps:

step (a): reacting an anion having the formula [ formula (II) ]:

a step in which G "is a group G or G' as described above, or a precursor thereof, is reacted with tetrafluoroethylene at a temperature of at most 115 ℃ and a pressure of at least 4 bar, so as to obtain a compound having the formula [ formula (III) ]:

step (b): a step of thermal treatment of at least one compound having formula (III) obtained from step (a) at a temperature exceeding 150 ℃ for dimerization, so as to obtain a compound having formula [ formula (IV) ]:

wherein G "and G '" are each a group G or G' as described above, or a precursor thereof, it being understood that when G "and G '" are a group G or G' as described above, the compound having formula (IV) meets the requirements of the compound having formula (I); and

step (c): optionally, a step of reacting the compound having formula (IV) under suitable conditions to convert the precursor groups G "and G '" of formula (IV) into groups G and G', to obtain the compound having formula (I) above.

2. The process of claim 1, wherein providing the anion of formula (II) is achieved by reacting the corresponding phenol derivative of formula (IIp) with a base:

wherein n and G' have the meaning as indicated in claim 1, and wherein the base is selected from alkali metals or alkali metal hydroxides.

3. The process according to claim 1 or 2, wherein compound (II) is provided in step (a) in a substantially anhydrous form, i.e. in a form comprising a residual amount of water of less than 500ppm, preferably less than 200ppm, even more preferably less than 50 ppm.

4. The process of any one of the preceding claims, wherein step (a) is carried out in the presence of a polar organic solvent, in particular selected from the group consisting of: aliphatic ethers, such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, diamyl ether, diisoamyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, dioxane, Tetrahydrofuran (THF).

5. The process of claim 4, wherein in step (a) the reaction temperature is maintained at a temperature of at most 115 ℃, preferably at most 110 ℃, even more preferably at most 100 ℃ and/or at least 45 ℃, preferably at least 55 ℃; and/or wherein in step (a) the reaction pressure is at least 4 bar, preferably at least 4.5 bar, even more preferably at least 5 bar, and/or at most 30 bar, preferably below 27 bar, even more preferably 25 bar.

6. The process of any of the preceding claims, wherein step (b) is carried out using only one compound of formula (III) and/or wherein the reaction in step (b) is carried out under an inert atmosphere, typically a nitrogen atmosphere, at a pressure above atmospheric pressure and/or at a reaction temperature of at least 155 ℃, preferably at least 160 ℃ and/or less than 210 ℃, preferably less than 205 ℃, even more preferably less than 200 ℃.

7. The process according to any one of the preceding claims, wherein G "in formula (III) is a group G or G', and wherein the process of the invention leads to the target product having formula (I) by the sequence of step (a) and step (b), and wherein G" is a halogen preferably selected from the group consisting of F, Cl, Br, I, in particular-F, -Cl.

8. The process of any one of claims 1 to 6, wherein G "in formula (III) is different from the groups G and G', and G" is preferably selected from the group consisting of:

-hydrogen;

-halogen selected from F, Cl, Br, I, in particular-F, -Cl;

-C₁-C₃alkyl, especially methyl (-CH)₃)；

-C₁-C₃Alkoxy radicals, especially of the formula-OR_alkWherein R is_alkIs C₁-C₃Alkyl, especially of the formula-OCH₃A group of (1).

9. The method of claim 8, wherein G "is hydrogen, and step (c) comprises at least one step selected from the group consisting of:

-step (C-1): electrophilic aromatic substitution, wherein the hydrogen G "atom is reacted with an electrophile selected from the group consisting of:

(i)X-R'_hycreactant, wherein X ═ Cl, Br, bound to R'_hycSp of a radical³-hybrid carbon, and R'_hycIs containing said sp³C of hybridized carbon₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And which may contain one or more aromatic groups;

(ii)X-C(O)-R”_hycreaction, wherein X ═ Cl, Br, and R "_hycIs C₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And which may contain one or more aromatic groups;

(iii)X-SO₂-R^* _hyca reactant, wherein X ═ Cl, Br, and R^* _hycIs C₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And it may compriseOne or more aromatic groups; preferably X-SO₂-R*_ArWherein X is Cl, Br and wherein R is_ArIs C₆-C₁₈An aromatic group which may be substituted;

-step (C-2): sulfonation, in particular with concentrated sulfuric acid or chlorosulfonic acid, which gives compounds of the formula (I) having the formula-SO as detailed in claim 1₂The group G/G 'of Y';

-step (C-3): nitration, in particular with a nitronium ion, for example by reaction of concentrated sulfuric acid with nitric acid, possibly followed by a reduction step, to give a compound of formula (I) having the formula-NR as detailed in claim 1_H ¹R_H ²The group G/G' of (1).

10. The method of claim 8, wherein G "is a halogen selected from F, Cl, Br, I, in particular-F, -Cl, and wherein step (c) comprises at least one step selected from the group consisting of:

(j) an alkali metal hydroxide (NaOH, koh.) to obtain a compound having formula (I) wherein G/G' is-OH;

(jj) CN-containing Compounds (NaCN, KCN, K)₄[Fe(CN)₆]...) to give the corresponding CN-substituted compound, wherein (jj-1) can be hydrolyzed to give a compound of formula (I) wherein G/G' is a group of formula-COY as detailed in claim 1, or (jj-2) can be reacted with an o-aminophenol derivative of formula

To provide a compound having formula (I), wherein G/G' is a group having the formula

Wherein X^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °;

wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

(jjj) base (alkyl) amide (KNH)₂、NaNH₂...) to give a compound of formula (I) wherein G/G' is of formula-NR as detailed in claim 1_H ¹R_H ²A group of (a);

-step (C-5): reacting with Mg or Li to form the corresponding organomagnesium or organolithium compound having formula (I), wherein G/G' is of the formula-MgX^MgOr a group of-Li, wherein X^MgIs halogen, preferably Cl or Br, which can be further reacted to give derivatives having formula (I) wherein G/G' is a group of formula-E-Ar-X "as detailed in claim 1, wherein X" is hydrogen or halogen.

11. The method of claim 8, wherein G "is C₁-C₃Alkyl, and wherein step (c) comprises at least one step selected from the group consisting of:

-step (C-6): oxidation, e.g. in KMnO₄In the presence of a base of formula (I), wherein G/G' is a group of formula-COY as detailed in claim 1, wherein said group of formula-COY can be reacted with an o-aminophenol derivative of formula

To provide a compound having formula (I), wherein G/G' is a group having the formula

Wherein X^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °;

wherein X DEG is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Cl.

12. The method of claim 8, wherein G "is C₁-C₃Alkoxy, and wherein step (c) comprises at least one step selected from the group consisting of:

-step (C-7): (ii) hydrolysis to provide a compound having formula (I) wherein G/G' is a group of formula-OH.

13. A compound having the general formula [ formula (I) ]:

formula (I), wherein G and G' are:

(A) -a group of formula-E-Ar-X ", wherein X" is hydrogen, -OH, -X ° -C (O) X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from Cl, Br, I, especially-Cl; -E-is a divalent bridging group selected from the group consisting of: key, C₁-C₆Exemplary embodiments of carbon-containing or sulfur-containing bridging groups (-E-) are notably: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-, and-SO₂-) according to the formula (I); or

(B) -a group of formula

Wherein X' is hydrogen, -OH, -X ° -, -C (O) X^#Wherein X is^#is-OH or-X °;

wherein X DEG is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Cl.

14. The compound of claim 13, selected from the group consisting of:

a compound (I-I) having the following formula:

a compound (I-ii) having the formula:

a compound (I-iii) having the formula:

a compound (I-iv) having the formula:

a compound (I-v) having the formula:

a compound (I-vi) having the formula:

a compound (I-vii) having the formula:

a compound (I-viii) having the following formula:

a compound (I-ix) having the formula:

a compound (I-x) having the formula:

a compound (I-xi) having the formula:

15. a process for preparing a polycondensation polymer, the process comprising:

-preparing a compound having formula (I) according to the process of any one of claims 1 to 12; and

polycondensing it with at least one further compound having at least two reactive groups capable of reacting with the groups G and G' of the compound of formula (I) by a condensation reaction,

wherein the polycondensation polymer is preferably a polymer selected from the group consisting of: polyimides, polyamides and polyamideimides, and the compounds having the formula (I) are those in which G and G' are of the formula-NH₂A compound of the group (1).

16. A process for preparing a polycondensation polymer, the process comprising:

-polycondensing at least one compound according to any one of claims 13 and 14 with at least one further compound having at least two reactive groups capable of reacting with the groups G and G' of the compound of formula (I) by a condensation reaction.

17. A polycondensation polymer comprising repeat units derived from at least one compound of any one of claims 13 and 14.

Technical Field

The present invention relates to a process for the preparation of perfluorocyclobutane-containing monomers, certain perfluorocyclobutane-containing monomers prepared therefrom, and a process for preparing polymers using the same.

Background

Extensive research has been conducted in the past on Perfluorocyclobutyl (PFCB) Aryl Ether Polymers resulting from thermal [2 pi +2 pi ] ring dimerization of aryltrifluorovinyl Ether monomers or from polycondensation of bifunctional intermediates of Perfluorocyclobutyl Aryl Ether dimers, as notably described in IACONO, Scott et al, Science and Technology of Perfluorocyclobutyl Aryl Ether Polymers [ Perfluorocyclobutyl Aryl Ether polymer Science and Technology ]. j.polym.sci.part a: polym.chem. Polymer chemistry 2007, Vol.45, No. 5705-.

One of the key aspects of the success of PFCB aryl ether polymer-based processes in this field is to provide monomers and intermediates having a purity suitable for use in polycondensation reactions by an economically viable process, using potentially readily available and inexpensive chemicals as starting materials, and employing high yield/high selectivity chemistry.

For example, US 5021602 (DOW CHEMICAL COMPANY) 4/06/1991 describes a process for THE preparation of a compound having THE formula:

wherein R and R 'are groups linked to the perfluorocyclobutane ring by the molecular structure X and X', in particular R and R 'are phenylene groups and X' are the-O-moieties of an ether; g and G 'are any reactive groups, where n and n' are integers, by the formula G_n-R-X-CF＝CF₂Wherein these latter compounds are preferably formed by a process comprising the steps of:

(a) formed of the formula (G')_n-R-X^-Wherein G "is a functional group G or a group that is readily modified to produce a group G;

(b) reacting said salt with a compound of formula Q-CF₂-CF₂-1, 2-dihalo-1, 1,2, 2-tetrafluoroethane reaction of Q, at least one Q being iodine or bromine and the remainder being chlorine, iodine or bromine, to obtain a compound having the formula (G ")_n-R-X-CF₂-CF₂-a compound of-Q; and

(c) the latter compound is dehalogenated in the presence of a metal reagent such as Zn or Mg.

The process for introducing the trifluorovinyl group in the precursor into the perfluorocyclobutyl derivative involves the use of expensive halogen/fluorine derivatives in the sequence of nucleophilic substitution and subsequent dehalogenation, which may affect the overall yield of the process, and which may lead to the presence of bromine/iodine-containing by-products in the final perfluorocyclobutyl derivative, which may negatively affect its reactivity as monomer, and/or the properties/thermal stability of the polymer obtained therefrom.

An alternative method of producing perfluorocyclobutane containing compounds is provided in US 5442030 (dupont DE NEMOURS AND COMPANY) 15/08/1995, wherein the PFCB ring is directly bonded to the aromatic carbon of the adjacent benzene ring through a C — C bond. In this document, the catalyst is prepared by reaction between Pd (P.phi.)₃)₄The p-nitro or m-nitro iodobenzene and Zn are added into the obtained product of the iodine trifluoroethylene to react under the catalysis to obtain the corresponding formula CF₂＝CF-Φ-NO₂Wherein Φ is benzeneRadical, which is dimerized to O₂N-Φ-PFCB-Φ-NO₂(wherein PFCB is perfluorocyclobutane), and then by reaction with SnCl₂/NaBH₄Is converted into an amino compound. However, the electron withdrawing effect exerted by the nitro group on the PFCB moiety bonded directly to the aromatic carbon results in at least partial defluorination of the PFCB group, thereby producing a perfluorocyclobutene moiety.

There remains a need in the art for efficient processes for preparing perfluorocyclobutyl-diaryl ether monomers starting from readily and economically available precursors and yielding compounds with high purity and high yield.

Disclosure of Invention

Accordingly, the present invention relates to a process for the preparation of a compound having the general formula [ formula (I) ]:

wherein each G and G', equal to or different from each other, is independently selected from the group consisting of

-halogen selected from F, Cl, Br, I, in particular-F, -Cl;

--NR_H ¹R_H ²wherein R is_H ¹And R_H ²Independently is H or C₁-C₆A hydrocarbyl group, preferably H;

--OH；

-nitrile group of formula-CN and of formula-NO₂Nitro group of (1);

- -COY, wherein Y is- -X, X is a halogen selected from F, Cl, Br, I, in particular- -F, - -Cl; -OH; -OR_H ³、-NR_H ¹R_H ²Wherein R is_H ³Is C₁-C₁₂Hydrocarbyl, especially C₁-C₆Alkyl or C₆-C₁₂An aryl group; and R is_H ¹And R_H ²Have the meanings detailed above; preferably Y is OH;

--SO₂y ', wherein Y' is-OH or-X ', X' is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

- -E- -Ar- -X "wherein X" is hydrogen, - -OH, - -X ° -, - -C (O) X^#Wherein X is^#is-OH or-X °; wherein X DEG is selected from F, Cl, Br, I, TeHalogen other than-F, -Cl; -E-is a divalent bridging group selected from the group consisting of: key, C₁-C₆A carbon-containing bridging group; a sulfur-containing bridging group; exemplary embodiments of-E-are notably: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-, and-SO₂-; ar-is a divalent aromatic radical, in particular an (optionally substituted) phenyl group (-Ph-), for example, where the bonds in Ph-may be in the ortho, meta or para position, preferably in the para position, relative to one another,

-has the formulaIn which X is^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

each n, equal to or different from each other, is an integer from 1 to 3, preferably from 1 to 2, more preferably n ═ 1,

the method comprises the following steps:

step (a): reacting an anion having the formula [ formula (II) ]:

a step in which G "is a group G or G' as described above, or a precursor thereof, is reacted with tetrafluoroethylene at a temperature of at most 115 ℃ and a pressure of at least 4 bar, so as to obtain a compound having the formula [ formula (III) ]:

step (b): a step of thermal treatment of at least one compound having formula (III) obtained from step (a) at a temperature exceeding 150 ℃ for dimerization, so as to obtain a compound having formula [ formula (IV) ]:

wherein G "and G '" are each a group G or G' as described above, or a precursor thereof, it being understood that when G "and G '" are a group G or G' as described above, the compound having formula (IV) meets the requirements of the compound having formula (I); and

step (c): optionally, a step of reacting the compound having formula (IV) under suitable conditions to convert the precursor groups G "and G '" of formula (IV) into groups G and G', to obtain the compound having formula (I) above.

The applicant has surprisingly found that the above process is effective in providing compound (I) in high yields, notably as detailed above, as monomer for polycondensation reactions, using inexpensive and readily available tetrafluoroethylene for the synthon of the perfluorocyclobutane group, providing the target compound in high yields and eliminating the brominated and iodinated impurities with said halogen in the perfluorocyclobutane ring.

Detailed Description

As mentioned above, the process of the invention is used for the preparation of the compounds of formula (I) as detailed above, which comprise at least one functional group G or G' on each phenyl ring of said formula (I), as detailed above. Although more than one functional group may be present, it is generally believed that the best performance is obtained when each n is 1, i.e. formula (I) has only one functional group on each phenyl ring.

As mentioned above, G and G' are independently selected from the functional moieties listed above, which may be advantageously used to polymerize, or further modify, compound (I) in a polycondensation or other type of reaction, given the possible incorporation into the polymer chain.

The nature of the group G or G' will be chosen depending on the use of the molecule (I): in particular, since the compounds of formula (I) have proven to have utility as monomers for incorporation into polycondensation polymers, the nature of the groups will depend on the targeted properties of the polycondensation polymer.

For example, when looking for monomers suitable for incorporation into polyimide, polyamide, polyamideimide structures, in compounds having formula (I), G and G' may advantageously be-NR_H ¹R_H ²Wherein R is_H ¹And R_H ²Independently is H or C₁-C₆A hydrocarbyl group, preferably H; -has the formulaIn which X is^zis-NH₂。

When looking for monomers suitable for incorporation into polyamide, polybenzoxazole, polyester structures, G and G' may advantageously be:

- -COY group, wherein Y is- -X, X is a halogen selected from F, Cl, Br, I, in particular- -F, - -Cl; -OH; -OR_H ³、-NR_H ¹R_H ²Wherein R is_H ³Is C₁-C₁₂Hydrocarbyl, especially C₁-C₆Alkyl or C₁-C₁₂An aryl group; and R is_H ¹And R_H ²Have the meanings detailed above; preferably Y is OH;

-cyano having the formula-CN; or

--OH。

When looking for monomers suitable for incorporation into polyarylether structures, G and G' may advantageously be — OH; having the formula-SO₂Y 'wherein Y' is-OH or-X ', X' is a halogen selected from F, Cl, Br, I, in particular-F, -Cl; or a group-E-Ar-X ", as detailed above.

In particular, when looking for monomers that are particularly suitable for incorporation into polyarylethersulfone structures, G and G' may be selected from the group consisting of those of formula-SO₂Y 'wherein Y' is-OH or-X ', X' is a halogen selected from F, Cl, Br, I, in particular-F, -Cl; and is selected from the group-E-Ar-X ", as detailed above, wherein E is-SO₂-, and X "is-OH or a halogen selected from F and Cl.

Generally, the process of the invention will therefore be used to prepare compounds having formula (Ia):

wherein G and G' are para on the aromatic ring. It is still further preferred that G and G' are the same for the compound of the specific formula (Ia).

Certain compounds of formula (I) as detailed above are novel and are further objects of the present invention. Specifically, compounds having formula (I) (and preferably formula (Ia)) wherein G and G' are:

(A) -a group of formula-E-Ar-X ", wherein X" is hydrogen, -OH, -X ° -C (O) X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from Cl, Br, I, especially-Cl; -E-is a divalent bridging group selected from the group consisting of: key, C₁-C₆Exemplary embodiments of carbon-containing or sulfur-containing bridging groups (-E-) are notably: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂-) according to the formula (I); or

(B) -has the formulaWherein X "is hydrogen, -OH, -X ° -C (O) X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

are further objects of the present invention.

Exemplary embodiments of the compounds of the present invention are notably:

a compound (I-I) having the following formula:

a compound (I-ii) having the formula:

a compound (I-iii) having the formula:

a compound (I-iv) having the formula:

a compound (I-v) having the formula:

a compound (I-vi) having the formula:

a compound (I-vii) having the formula:

a compound (I-viii) having the following formula:

a compound (I-ix) having the formula:

a compound (I-x) having the formula:

a compound (I-xi) having the formula:

all of these compounds can be used as monomers/precursors for the preparation of polyaryletherketones, polyarylethersulfones, benzoxazoles, polyimides, and the like.

As mentioned above, in the first step of the present invention, the anion having formula (II) is reacted with tetrafluoroethylene.

As mentioned above, in the compound of formula (II), G "is a group of formula G or G' as described above, or a precursor thereof. The latter expression should be interpreted to mean that, when the group G "is different from the groups G and G 'targeted in the process of the invention, the precursor group means a group representing the group that can be converted by appropriate chemistry into the targeted group G or G' of formula (I).

When G "is a group G or G', the process of the invention leads to the target product having formula (I) by the sequence of step (a) and step (b), as detailed above.

Exemplary embodiments of the G' group according to this variant are notably halogens selected from F, Cl, Br, I, in particular-F, -Cl.

When G "is different from groups G and G ', the choice of group G" will therefore depend on the target group G/G' intended to be included in the compound (I) to be prepared, as well as the functionalization chemistry that forms the basis of step (c), which therefore becomes a mandatory additional step of the process of the invention.

Exemplary embodiments of the G "group according to this variant are notably:

-hydrogen;

-halogen selected from F, Cl, Br, I, in particular-F, -Cl;

-C₁-C₃alkyl, especially methyl (-CH)₃)；

-C₁-C₃Alkoxy radicals, especially of the formula-OR_alkWherein R is_alkIs C₁-C₃Alkyl, especially of the formula-OCH₃A group of (1).

When G "is hydrogen, step (c) advantageously comprises at least one step selected from the group consisting of:

-step (C-1): electrophilic aromatic substitution, wherein the hydrogen G "atom is reacted with an electrophile selected from the group consisting of:

(i)X-R'_hycreactant, wherein X ═ Cl, Br, bound to R'_hycSp of a radical³-hybrid carbon, and R'_hycIs containing said sp³C of hybridized carbon₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And which may contain one or more aromatic groups; this reaction can give compounds of formula (I) having the formula-R as detailed above_hycThe group G/G'; r'_hycOxidation of the pendant group may give a compound of formula (I) having a group G/G' of formula-COY as detailed above; r'_hycSuitable selection of groups may result in a compound of formula (I) having a group G/G 'of formula-E-Ar-X' as detailed above, wherein-E-comprises sp³-hybrid carbon;

(ii)X-C(O)-R”_hycreaction, wherein X ═ Cl, Br, and R "_hycIs C₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And which may contain one or more aromatic groups; this reaction can give compounds of formula (I) having the formula-C (O) -R "_hycThe group G/G'; r'_hycSuitable selection of groups may result in compounds of formula (I) having groups G/G' of formula-E-Ar-X "as detailed above, wherein-E-is a-C (O) -group;

(iii)X-SO₂-R^* _hyca reactant, wherein X ═ Cl, Br, and R^* _hycIs C₁-C₁₈A possibly substituted hydrocarbon group which may comprise one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-and-SO₂And which may contain one or more aromatic groups; preferably X-SO₂-R*_ArWherein R is_ArIs C₆-C₁₈An aromatic group which may be substituted; this reaction gives a compound of formula (I) having a group G/G 'of formula-E-Ar-X' as detailed above, wherein-E-is-SO₂-a group;

-step (C-2): sulfonation, in particular with concentrated sulfuric acid or chlorosulfonic acid, which gives compounds of the formula (I) having the formula-SO as detailed above₂The group G/G 'of Y'; sulfonation, preferably with oleum, concentrated sulfuric acid or Cl-SO₂-OH, to give a compound of formula (I) having the formula-SO₃H or SO₂A group G/G 'of Cl, which may be further functionalized to provide a compound having formula (I) having a group G/G' of formula-E-Ar-X "as detailed above, wherein E ═ SO₂-；

-step (C-3): nitration, in particular with a nitronium ion, for example by reaction of concentrated sulfuric acid and nitric acid, in situ, may give compounds of the formula (I) having the formula-NO as detailed above₂The group G/G'; this step may be followed by reduction of the produced-NO₂(ii) a compound having formula (I) having the formula-NR as detailed above_H ¹R_H ²The group G/G' of (1).

When G "is a halogen selected from F, Cl, Br, I, in particular-F, -Cl, step (c) advantageously comprises at least one step selected from the group consisting of:

-a step (C-4) of carrying out nucleophilic substitution by reaction of:

(j) an alkali metal hydroxide (NaOH, koh.) to obtain a compound having formula (I) wherein G/G' is-OH;

(jj) CN-containing Compounds (NaCN, KCN, K)₄[Fe(CN)₆]...) to give the corresponding CN substituted compound, wherein (jj-1) can be hydrolyzed to provide a compound having formula (I) wherein G/G' is a group of formula-COY as detailed above, or (jj-2) can be reacted with a compound of formulaTo provide a compound having the formula (I)Wherein G/G' is of the formulaIn which X is^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

(jjj) base (alkyl) amide (KNH)₂、NaNH₂...) to give a compound of formula (I) wherein G/G' is of formula-NR_H ¹R_H ²The group of (a), as detailed above;

-step (C-5): reacting with Mg or Li to form the corresponding organomagnesium or organolithium compound having formula (I), wherein G/G' is of the formula-MgX^MgOr a group of-Li, wherein X^MgIs halogen, preferably Cl or Br, which can be further reacted to form derivatives having formula (I) wherein G/G' is a group of formula-E-Ar-X ", as detailed above, wherein X" is hydrogen or halogen, as detailed above, preferably hydrogen.

When G' is C₁-C₃When alkyl, step (c) advantageously comprises at least one step selected from the group consisting of:

-step (C-6): oxidation, e.g. in KMnO₄In the presence of a base to provide a compound having formula (I), wherein G/G' is a group of formula-COY, as detailed above; the group of formula-COY, as detailed above, may be reacted with a compound of formulaTo provide a compound having the formula (I), wherein G/G' is formulaIn which X is^zis-NH₂；-NO₂；-OH、-X°°、-C(O)X^#Wherein X is^#is-OH or-X °; wherein X DEG is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Cl.

When G' is C₁-C₃When alkoxy, step (c) advantageously comprisesAt least one step selected from the group consisting of:

-step (C-7): hydrolysis, for example in the presence of acetic/hydrobromic acid, to provide a compound of formula (I) wherein G/G' is a group of formula-OH.

Providing an anion of formula (II) can be achieved by reacting the corresponding phenol derivative of formula (IIp) with a base:

wherein n and G "have the same meaning as indicated above.

In general, monosubstituted phenols with a group G "in the para position will be preferred.

Either base may be used to extract an acidic proton from a compound having formula (IIp); in particular, hydroxides of alkali metals or alkaline earth metals can be used. Although the reaction between the compound of formula (IIp) and the base may be carried out in an aqueous medium, compound (II) is generally provided in substantially anhydrous form in step (a) of the process of the present invention, i.e. in a form comprising a residual amount of water of less than 500ppm, preferably less than 200ppm, even more preferably less than 50 ppm.

Step (a) is typically carried out in the presence of a polar organic solvent; in particular, it has been found that ether solvents are particularly effective, being able to suitably dissolve the compound of formula (II), while having sufficient solvation and pK_aCharacteristic to favour the substitution reaction leading to the corresponding trifluorovinyl ether derivative, notably to-O-CF₂-CF₂-H-substituted addition reactions or even the formation of other higher molecular weight derivatives. Among the aliphatic ethers, the polar organic solvents found to be particularly effective in step (a) are notably diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, diamyl ether, diisoamyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether; dioxane, Tetrahydrofuran (THF), with THF being particularly preferred. Mixtures of one or more of the above solvents may be used.

In step (a), the reaction temperature is maintained at a temperature of at most 115 ℃, preferably at most 110 ℃, even more preferably at most 100 ℃. The lower limit of the reaction temperature in step (a) is generally adjusted to achieve reasonable reaction kinetics; temperatures of at least 45 c, preferably at least 55 c, are therefore generally preferred.

In step (a), the reaction pressure is at least 4 bar, preferably at least 4.5 bar, even more preferably at least 5 bar. For practical reasons, the upper limit of the reaction pressure in step (a) is generally adjusted to below 30 bar, typically below 27 bar, even more preferably 25 bar. Generally, in step (a), an excess of gaseous Tetrafluoroethylene (TFE) may be added to produce an initial reaction pressure, and then the pressure is gradually decreased as TFE reacts; alternatively, TFE can be added subsequently, either continuously or stepwise, to balance the pressure drop due to the progress of TFE conversion. It has been found that maintaining a pressure above 4 bar at a substantially constant set point pressure value by adding, preferably continuously adding, TFE is a preferred embodiment for controlling the selectivity of the reaction and maintaining substantially constant reaction conditions throughout step (a).

The process of the present invention comprises step (b): dimerizing at least one compound having formula (III) obtained from step (a) by heat treatment at a temperature exceeding 150 ℃. Generally, in the target compound (I), the groups G and G' are identical, so step (b) is preferably carried out using only one compound of formula (III) as detailed above. Nevertheless, the alternative of using a mixture of two different compounds of formula (III) is also included; the resulting dimerization product is thus a mixture of compounds which produce the variable groups G "and G'".

The reaction in step (b) is generally carried out in an inert atmosphere, generally in a nitrogen atmosphere. Pressures above atmospheric, for example, pressures of 1.5 bar, preferably 2.0 bar, even more preferably 2.5 bar may be preferred. The reaction temperature is generally at least 155 ℃ and preferably at least 160 ℃. While higher temperatures may favor the kinetics of dimerization, temperatures below 210 ℃, preferably below 205 ℃, even more preferably below 200 ℃ are preferred to minimize side reactions, e.g., leading to decomposition of compounds.

As mentioned above, the method of the invention may or may not comprise a further step (C).

According to a first embodiment of the invention, the compound having formula (II) is a phenoxide salt (i.e. G ═ H) and the process of the invention comprises the further step (1-C) of reacting G ═ H to provide compound (I), wherein the groups G/G' are selected from the groups listed above.

According to a first variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" ═ H, and the process comprises a step (1V-C) comprising:

-step (1V-C-1): under electrophilic nitration conditions, usually in HNO₃/H₂SO₄In the presence of (a) to obtain a compound having formula (I) wherein G and G' ═ NO, by reacting a compound having formula (IV) wherein G ═ H₂；

-step (1V-C-2): reacting said compound under reducing conditions, for example in the presence of hydrazine and a Pd/C catalyst, to obtain a compound having formula (I) wherein G and G' are-NH₂。

According to a second variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Br, -Cl, and said process comprises a step (2V-C) comprising:

-step (2V-C-1): reacting a compound having formula (IV) wherein G' is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Br, -Cl, with a compound having formula MeNH₂Wherein Me is a monovalent metal cation, in the presence of ammonia,

thereby obtaining a compound having formula (I) wherein G and G' are-NH₂。

Depending on the starting material of the formula (II), the compounds of the formula (I) may be mixtures of positional isomers, in which G and G' -NH₂The groups are independently located at the ortho, meta or para position on each phenyl ring of compound (I).

According to a third variant, the process of the invention comprises reacting in step (a) a compound having formula (II), wherein G "is equal to G/G 'and G" is a halogen selected from the group consisting of F, Cl, Br, I, in particular-F, -Br, -Cl, thereby obtaining a compound having formula (I), wherein G and G' are halogens selected from F, Cl, Br, I; this method notably:

advantageously does not comprise any step (C) since the target compound (I) is a compound wherein G and G' are halogen; and is

Preference is given to a process in which n ═ 1 and G/G'/G "is in the para position with respect to the oxygen atom in compounds (I) and (II).

According to a fourth variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" ═ H, and the process comprises a step (4V-C) comprising:

-step (4V-C-1): reacting a compound of formula (IV) (wherein G ═ H) under electrophilic sulfonation, notably with concentrated H₂SO₄Or with a halosulfonic acid to obtain a compound having formula (I) wherein G/G' is a group-SO₂Y ', Y' is-OH or-X ', X' is a halogen selected from F, Cl, Br, I, in particular-F, -Cl;

-optionally step (4V-C-2): halogenating the compound of formula (IV) to obtain the corresponding compound, wherein the group-SO₂Y 'in Y' is-Br, -Cl or-F;

-step (4V-C-3): reacting the compound of formula (I) thus obtained (wherein G/G' is a group-SO)₂Y ') with an aromatic compound of formula Ar-X DEG, wherein X DEG is hydrogen or a halogen selected from F, Cl, Br, I, in particular-F, -Cl, to obtain a compound of formula (I), wherein G/G ' is a group of formula-E-Ar-X ', as detailed above.

According to a fifth variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" is a hydrogen atom (G "═ H), and said process comprises a step (5V-C) comprising:

-step (5V-C-1): having the formula (IV)Compound (wherein G ═ H) and X-R'_hycReaction of reactants, wherein X ═ Cl, Br, bound to R'_hycSp of a radical³-hybrid carbon, and R'_hycIs C₁-C₁₈Possibly substituted hydrocarbon radicals, including said sp³-hybrid carbon comprising one or more groups having the formula: - (CH)₂)_m-, where m is an integer of 1 to 3; and-C (CH)₃)₂And which comprises one or more aromatic groups;

to obtain compound (I) having the group G/G 'of formula-E-Ar-X' as detailed above.

According to a sixth variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" ═ H, and the process comprises a step (6V-C) comprising:

-step (6V-C-1): using X-C (O) -R'_hycThe reactants react a compound having formula (IV) (wherein G ═ H) with (ii) an acyl group, wherein X ═ Cl, Br, and R ″) "_hycIs C₁-C₁₈A possibly substituted hydrocarbon radical comprising one or more groups of formula: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (CH)₃)₂-, and-SO₂And which comprises one or more aromatic groups;

to obtain a compound having formula (I) having a group G/G 'of formula-E-Ar-X' as detailed above, wherein-E-is-C (O) -.

According to a seventh variant, the process of the invention comprises reacting in step (a) a compound having formula (II) wherein G "is a precursor of G/G' and G" ═ H, and the process comprises a step (7V-C) comprising:

-step (7V-C-1): reacting a compound of formula (IV) (wherein G ═ H) with (iii) a compound of formula X-s (o)₂-R’”_hycWherein X ═ Cl, Br, and R'_hycIs C₁-C₁₈A possibly substituted hydrocarbon radical comprising one or more aromatic groups;

to obtain a compound having the formula (I)The group G/G 'of formula-E-Ar-X' as detailed above, wherein-E-is-S (O)₂-。

The present invention further relates to certain novel perfluoro-containing cyclobutyl monomers of the formula (I) as described in detail above, wherein G and G ' are radicals of the formula-E-Ar-X ' and X ' is hydrogen, -OH, -X ° -, -C (O) X^#，X^#is-OH or-X °; wherein X DEG is a halogen selected from Cl, Br, I, especially-Cl; -E-is a divalent bridging group selected from the group consisting of: key, C₁-C₆A carbon-containing bridging group or a sulfur-containing bridging group; exemplary embodiments of-E-are notably: - (CH)₂)_m-, where m is an integer of 1 to 3; -C (O) -, -C (CH)₃)₂-, and-SO₂-; -Ar-is a divalent aromatic group, in particular an (optionally substituted) phenyl group (-Ph-), e.g. wherein the linkages in-Ph-may be in ortho-, meta-or para-position, preferably in para-position, relative to each other.

In addition, the present invention relates to a method for preparing a polycondensation polymer, the method comprising:

-preparing a compound having formula (I) according to the process as detailed above; and

-polycondensing it with at least one further compound having at least two reactive groups capable of reacting with the groups G and G' of the compound having formula (I) by a condensation reaction.

According to certain embodiments, the polycondensation polymer is a polymer selected from the group consisting of: polyimides, polyamides and polyamideimides, and the compounds having the formula (I) are those in which G and G' are of the formula-NH₂A compound of the group (b); according to this embodiment, the compound having formula (I) may be polycondensed with a polycarboxylic acid selected from the group consisting of:

dicarboxylic acids (or derivatives thereof), typically forming polyamide polymers;

polycarboxylic acids comprising at least two alpha, beta or ortho carboxylic acid groups (or derivatives thereof, in particular in the form of their anhydrides) and at least one further carboxylic acid group (or derivative thereof), typically to form polyamideimide polymers; and

polycarboxylic acids containing two pairs of α, β or ortho carboxylic acid groups (or derivatives thereof, especially in the form of their anhydrides), generally form polyimide polymers.

It is further understood that additional diamino compounds can be further used to generate copolymers of the compounds having formula (I) with other units derived from perfluorocyclobutyl groups; the relative amount of units derived from the compound having formula (I) may represent at least 1%, preferably at least 2%, more preferably at least 5% by moles with respect to the total number of moles of recurring units of the copolymer of the compound having formula (I); and/or at most 50%, preferably at most 30%, more preferably at most 20%, even more preferably at most 15%.

If the disclosure of any patent, patent application, and publication incorporated by reference conflicts with the present description to the extent that the statements may cause unclear terminology, the present description shall take precedence.

The present invention will now be described in more detail with reference to the following examples, which are intended to be illustrative only and are not intended to limit the scope of the present invention.

Preparation example 1:

steps (a) and (b): Ph-O-CF ═ CF₂Synthesis of (TFVOB-H) and dimerization to Ph-O-C₄F₆-O-Ph(DPhFCB-H)

A50 g sample of phenol was charged into a glass flask along with 210g of a 10% wt aqueous NaOH solution. The solution was stirred for 25 minutes and then the water was completely removed using a rotary evaporator to obtain a dry white powder of sodium phenolate. 390g of THF were used to dissolve sodium phenolate. The solution obtained was transferred to a 600mL stainless steel autoclave and, after purging with nitrogen and a limiting vacuum of 0.3 bar, kept at 65 ℃ at 10 bar C₂F₄Stirring was carried out for 6 hours under constant pressure. The resulting solution was transferred to a separatory funnel and washed with 1800ml of distilled water. The organic phase was separated and distilled under vacuum from 155 mbar to 2 mbar yielding 64g of a colorless liquid which was purified by F19 and H1 NMRWas characterized and determined to be trifluorovinylhydroxybenzene (TFVOB-H) with a purity of 96%. The total molar yield was 66%.

Step (b): dimerisation to Ph-O-C₄F₆-O-Ph(DPhFCB-H)

The obtained TFVOB-H was transferred to a stainless steel tank, pressurized with 3 bar of nitrogen and heated at 180 ℃ for 42 hours.

The pot was then cooled and the product obtained was recovered and distilled under vacuum at 2 mbar yielding 59g of product characterized by 19F-NMR and 1H-NMR and identified as [ (hexafluorocyclobutanediyl) bis (oxy) ] biphenyl (DPhFCB-H) with a purity of 99.2%.

Step (c):

(C-1)：O₂N-Ph-O-C₄F₆-O-Ph-NO₂(DPhFCB-NO₂) Synthesis of (2)

To a well-stirred solution of DPhFCB-1(50g, 0.144mol) in DCM (250mL) was added dropwise a mixed acid, HNO, through a dropping funnel over a period of 45 minutes at 0 deg.C₃(46g) And H₂SO₄(138g) A mixture of (a). After complete addition of the acid mixture, the reaction mass is stirred for a further 1.5 hours at 20 ℃. After completion of the reaction, it was diluted with ice-cold water (1 l) and neutralized with sodium bicarbonate. The compound was extracted with ethyl acetate (400mL X3). The organic layer was dried over sodium sulfate and concentrated by rotary evaporation. Isolation of pure compound DPhFCB-NO from ethyl acetate after crystallization₂White crystals (yield 70%, 44g), purity>98％(GC)。

(C-2)：H₂N-Ph-O-C₄F₆-O-Ph-NH₂Synthesis of (2)

To DPhFCB-NO₂(20g, 0.045mol) to a well stirred solution in MeOH (250mL) was added 10% Pd/C (0.575 g). Hydrazine hydrate solution (80%, 21.56mL) was added over a period of 1 hour using a dropping funnel. After the reagent addition was complete, the reaction mixture was refluxed for an additional 1.5 hours. The solution was then cooled to room temperature and filtered through celite. The filtrate was evaporated to remove MeOH. The obtained resin mass was dissolved in DCM and washed with water to remove excess hydrazine hydrate. The organic layer was dried over sodium sulfate and evaporated to dryness. Most preferablyEnd product DPhFCB-NH₂Was a colourless gummy liquid (85% yield, 14.8g) with a purity of 98% (HPLC).

Preparation of example 2

Step (a): a40.04 g sample of 4-bromophenol was charged into a glass flask along with 109g of 10% wt aqueous NaOH. The solution was stirred for 25 minutes and then the water was completely removed using a rotary evaporator to obtain 4-bromo-sodium phenolate as a pale yellow powder. 282g of THF were used to dissolve the sodium 4-bromo-phenol. The solution obtained was transferred to a 600mL stainless steel autoclave and, after purging with nitrogen and a limiting vacuum of 0.3 bar, kept at 65 ℃ at 10 bar C₂F₄Stirring was carried out for 6 hours under constant pressure. The resulting solution was transferred to a separatory funnel and washed with 1800ml of distilled water. The organic phase was separated and vacuum distilled from 17 mbar to 1 mbar yielding 43g of a colorless liquid, characterized by NMR F19 and H1 and identified as trifluoroethyleneoxy-4-bromo-benzene (TFVOB-Br) with a purity of 87%. The molar yield was 63%.

Step (b): the TFVOB-Br obtained was transferred to a stainless steel tank, pressurized with 3 bar of nitrogen and heated at 180 ℃ for 42 hours.

The pot was then cooled, the product obtained was recovered and distilled under vacuum at 0.27 mbar to obtain 28g of final product which was obtained by passing it through¹⁹F-NMR and¹H-NMR characterization and determination of [ (hexafluorocyclobutanediyl) bis (oxy)]Diphenyl bromide (DPhFCB-Br) with a purity of 99.5%.

Preparation of example 3

Steps (a) and (b): see preparation example 2.

Step (c 1): NC-Ph-O-C₄F₆Synthesis of-O-Ph-CN (DPhFCB-CN)

To a well stirred solution of DPhFCB-Br (3g, 5.92mmol) in NMP (10mL) at room temperature was added K₄Fe(CN)₆(dried) (1.09g, 2.96mmol), Na₂CO₃(1.25g，11.79mmol)、Pd(OAc)₂(0.265g, 1.18 mmol). The reaction mass was then stirred under nitrogen at 120 ℃ for a further 24 hours. After completion of the reaction, it was diluted with water (100 mL). The compound was extracted with ethyl acetate (50mL X3). The organic layer was dried over sodium sulfate and concentrated by rotary evaporationAnd (4) shrinking. After column chromatography, the pure compound was isolated as a colorless liquid (yield 80%).

Step (c 2): HOOC-Ph-O-C₄F₆Synthesis of-O-Ph-COOH (DPhFCB-COOH)

To DPhFCB-CN (2g, 5.05mol) inⁿTo a well stirred solution in BuOH (6mL) was added KOH (2.8g, 44.6 mol). The reaction mixture was refluxed for 4 hours. The solution was then cooled to room temperature and diluted with water (10 mL). The solution was then acidified with dilute HCl. The precipitate was filtered and washed 4 times with water (10mL) to remove traces of mineral acid. The desired product was isolated as a white solid (60% yield).

Polymerization example 4: from DPhFCB-NH₂Synthesis of polyimide with pyromellitic acid

A double-walled round bottom flask with temperature controller was charged with 0.658g (2.59mmol) of 98% pyromellitic acid and 5.5mL of pure methanol. While flushing gently with nitrogen, the reaction medium is stirred and heated to 50 ℃. In a 50mL round bottom flask, 1.0g (2.645mmol) of 98% DPhFCB-NH was placed at ambient temperature₂Dissolved in 8.5mL of pure methanol. The solution was then placed in a dropping funnel attached to a double-walled round bottom flask and added dropwise over 15 minutes to a solution of pyromellitic acid in methanol. The reaction medium is kept under nitrogen for 1 hour 30 minutes with vigorous stirring at 50 ℃. The temperature was then reduced to 25 ℃ and stirred for an additional 30 minutes to mitigate further precipitation. The salt powder was recovered by filtration on a buchner funnel and washed 3 times with ice-cold methanol to remove unreacted starting material. The salt was then triturated and dried under vacuum at 60 ℃ overnight. The melting temperature of the salt was 240 ℃.

DPhFCB-NH₂PMA salt powder was placed in a flask attached to Kugelrohr and spun (rpm 30) under gentle flushing with nitrogen. The flask was heated and rotated at 220 ℃ for 2 hours and at 240 ℃ for 1 hour. The obtained PI powder was found to be yellow. TGA analysis showed a weight loss of 5% at a temperature of 506 ℃. FTIR analysis of the polyimide powder showed characteristic absorption bands for the imide functionality at 1390, 1720 and 1783cm^-1Here, and no characteristic absorption band of the amine function is noted.

Polymerization example 5: from DPhFCB-NH₂Synthesis of polyimide with Biphenyl Tetracarboxylic acid (BPTA)

A double-walled round bottom flask with temperature controller was charged with 0.856g (2.59mmol) of 98% biphenyltetracarboxylic acid (BPTA) and 12.6mL pure methanol. While flushing gently with nitrogen, the reaction medium is stirred and heated to 50 ℃. In a 50mL round bottom flask, 1.0g (2.645mmol) of 98% DPhFCB-NH was placed at ambient temperature₂Dissolved in 12.6mL of pure methanol. The solution was then placed in a dropping funnel attached to a double-walled round bottom flask and added dropwise over 15 minutes to a solution of BPTA in methanol. The reaction medium is kept under nitrogen for 1 hour 30 minutes with vigorous stirring at 50 ℃. The temperature was then reduced to 25 ℃ and stirred for an additional 30 minutes to mitigate further precipitation. The salt powder was recovered by filtration on a buchner funnel and washed 3 times with ice-cold methanol to remove unreacted starting material. The salt was then triturated and dried under vacuum at 60 ℃ overnight. The melting temperature of the salt was found to be 228 ℃.

DPhFCB-NH₂BPTA salt powder was placed in a flask attached to Kugelrohr and spun under a gentle purge with nitrogen (rpm 30). The pressure is equal to atmospheric pressure. The flask was then heated at 200 ℃ and rotated for 9 hours. The obtained PI powder was found to be yellow. TGA analysis showed a weight loss of 5% at a temperature of 496 ℃. FTIR analysis of the PI powder showed characteristic absorption bands for the imide functionality at 1375, 1719 and 1777cm^-1Here, and no characteristic absorption band of the amine function is noted. DSC shows melting at 348 deg.C (melting enthalpy 36.2J/g) and has a glass transition temperature of 225 deg.C.

Polymerization example 6: from DPhFCB-NH₂Synthesis of polyimide from 4,4' - (Hexafluoroisopropylidene) diphthalic anhydride (6-FDA)

In a typical polymerization, a three-necked round bottom flask equipped with a magnetic stirrer, nitrogen inlet/outlet was charged with DPhFCB-NH₂(0.851g, 2.25mmol) and N-methyl-2-pyrrolidone (NMP) (16 mL). To the stirred solution was added 4,4' - (hexafluoroisopropylidene) diphthalic anhydride (6-FDA) (1.0g, 2.25mmol) in portions, and the resulting solution was stirred at room temperature under an inert atmosphereStirring for 24 hours. The obtained poly (amic acid) solution was poured into a flat PTFE petri dish and heated in a vacuum oven at 70 ℃ for 24 hours, then at 100-275 ℃ (temperature ramp: 25 ℃/1.0 hour) and finally at 300 ℃ for 1.0 hour to obtain a transparent film. TGA analysis showed a weight loss of 5% at a temperature of 496 ℃. FTIR analysis of the polyimide film showed imide functionality at 1375, 1719 and 1777cm^-1Characteristic absorption band of (c). DSC showed a glass transition temperature of 246 ℃.