Synthetic method of fluorine-containing polyester monomer dicarboxylic acid
2,2-bis(4-carboxyphenyl)hexafluoropropane was prepared by diazotization and Sandmeyer reaction, which solved the problem of low yield and low purity in the preparation of fluoropolymers, and achieved the feasibility of industrial production.
Patent Information
- Application Number
- CN202510429936.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-07-11
AI Technical Summary
In the prior art, the preparation reaction conditions of fluoropolymers are harsh, the operating risk is high, the yield is low, and the purity is low, making it difficult to achieve industrial production.
2,2-bis(4-aminophenyl)hexafluoropropane was prepared by diazotization, Sandmeyer reaction and intercalated carbonaceous reaction, and the reaction conditions were optimized to improve yield and purity.
It provides a synthesis method with simple and easy operation, high yield and high product purity, which is suitable for actual industrial production.
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Figure CN120289288A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of compound preparation, and particularly relates to a method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid. Background Art
[0002] Aromatic polyaryl esters have excellent thermal stability, chemical stability, mechanical properties, and good transparency. They are an excellent functional material and are widely used in fields such as aerospace, microelectronics, automotive and machinery industries, medical supplies, and daily necessities. 2,2-Bis(4-carboxyphenyl)hexafluoropropane is one of the important raw materials for synthesizing fluorine-containing aromatic polyaryl esters. It can be used to prepare new fluorine-containing polyaryl ester materials with high temperature resistance and better comprehensive performance, which is of great significance for the synthesis of fluorine-containing polyaryl esters. Therefore, the oxidation of 2,2-bis(4-methylphenyl)hexafluoropropane is very important in the chemical industry. Many bulk chemicals and fine chemicals such as benzoic acid and terephthalic acid are obtained by the oxidation of aromatic compounds with oxygen in the liquid phase. The oxidation reaction of aromatic hydrocarbons has received extensive attention in recent years.
[0003] However, at present, due to problems such as relatively harsh reaction conditions, high operation risks, generation of a large amount of wastewater and waste gas, low yield, and low purity in the preparation of high-end fluoropolymers in China, it is not conducive to industrial development. Therefore, it mainly relies on imports from abroad, which restricts the development process of the domestic fluorine-containing materials industry.
[0004] Therefore, providing a method for synthesizing 2,2-bis-(4-hydroxyphenyl)hexafluoropropane that is simple and easy to operate, has a high yield, high product purity, and can be applied to actual industrial production is a problem that needs to be solved by those skilled in the art. Summary of the Invention
[0005] To solve the single limitation of existing fluorine-containing materials, the present invention provides a method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid. This synthesis method is simple and easy to operate, has a high yield, high product purity, and can be applied to actual industrial production.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] A method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid uses 2,2-bis(4-aminophenyl)hexafluoropropane as a raw material. After diazotization and Sandmeyer reaction to obtain intermediate I, and then through carbonylation insertion reaction, 2,2-bis(4-carboxyphenyl)hexafluoropropane is obtained;
[0008] The specific reaction route is as follows:
[0009]
[0010] Preferably, the reagents used for diazotization are nitrite and acid;
[0011] Among them, the molar ratio of the nitrite, the acid and 2,2-bis(4-aminophenyl)hexafluoropropane is 2-10:4-10:1, preferably 2.1-4:4.5-6:1.
[0012] Preferably, the nitrite is any one of sodium nitrite or alkyl nitrite;
[0013] The acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, perchloric acid and fluoboric acid.
[0014] Preferably, the reaction temperature of the diazotization is 0-5°C, and the feeding time is 0.5-1 h.
[0015] Preferably, when X = Br, the catalyst used in the Sandmeyer reaction is a cuprous salt, and the reagent is hydrobromic acid; among them, the molar ratio of the cuprous salt and 2,2-bis(4-aminophenyl)hexafluoropropane is 0.1-10:1, preferably 1.1-2:1, and the molar ratio of the cuprous salt and hydrobromic acid is 1:1-5, preferably 1:1.1-1.5;
[0016] Or when X = I, the reagent for the Sandmeyer reaction is sodium iodide or potassium iodide, and the molar ratio of the sodium iodide or potassium iodide and 2,2-bis(4-aminophenyl)hexafluoropropane is 1-10:1, preferably 1-2:1.
[0017] Preferably, the cuprous salt is cuprous bromide.
[0018] Preferably, the carbonylation reaction is to dissolve intermediate I, a catalyst, and a ligand in a solvent and water, introduce carbon monoxide, heat up and react for a period of time, then cool the mixture to room temperature and normal pressure, neutralize it with hydrochloric acid multiple times, and take the organic phase for recrystallization to obtain 2,2-bis(4-carboxyphenyl)hexafluoropropane.
[0019] Preferably, the mass ratio of the catalyst and intermediate I in the carbonylation reaction is 0.001-0.1:1, preferably 0.005-0.01:1, and the mass ratio of the catalyst and the ligand in the carbonylation reaction is 1:1-10, preferably 1:3-5;
[0020] The reaction temperature of the carbonylation is 0-200°C, and the reaction time is 5-24 h, preferably 20-150°C.
[0021] Preferably, the catalyst is a palladium catalyst;
[0022] The ligand is at least one of triphenylphosphine, trimethylphosphine, triethylphosphine, tri-tert-butylphosphine, 1,1'-bis(diphenylphosphino)ferrocene, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, tricyclohexylphosphine, 1,1'-binaphthol, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl.
[0023] Preferably, the solvent is at least one of dichloromethane, dichloroethane, toluene, xylene, triethylamine, dimethylformamide, dimethylacetamide and dimethyl sulfoxide, and the amount of the solvent is 5-10 times the mass of the raw material 2,2-bis(4-aminophenyl)hexafluoropropane.
[0024] Preferably, the palladium catalyst is at least one of palladium dichloride, tetrakistriphenylphosphine palladium, bis(triphenylphosphine)palladium dichloride, palladium acetate, bis(triphenylphosphine)palladium acetate, 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, palladium acetylacetonate, palladium trifluoroacetate and palladium trifluoromethanesulfonate.
[0025] Preferably, the intermediate I can be subjected to a cyanation reaction to obtain the intermediate II, which is then hydrolyzed to obtain 2,2-bis(4-carboxyphenyl)hexafluoropropane.
[0026] Preferably, in the cyanation reaction, the molar ratio of the cyanation reagent to the intermediate I is 0.1-10:1, preferably 0.15-1.5:1, the mass ratio of the catalyst, the base and the intermediate I is 0.001-0.1:1-2:1, preferably 0.001-0.01:1-2:1, and the reaction conditions are: 100-150°C for 1-2h;
[0027] The hydrolysis conditions are: reaction at 80-180°C for 3-10h, preferably 100-140°C.
[0028] Preferably, the cyanation reagent is at least one of sodium cyanide, potassium cyanide, zinc cyanide, cuprous cyanide, trimethylsilyl cyanide, acetone cyanohydrin, potassium ferrocyanide and potassium ferrocyanide;
[0029] The catalyst is a palladium catalyst;
[0030] The base is at least one of sodium carbonate, potassium carbonate and cesium carbonate;
[0031] The hydrolysis is alkaline solution hydrolysis or acid solution hydrolysis.
[0032] Preferably, the solvent in the cyanation reaction is at least one of dichloromethane, dichloroethane, toluene, xylene, triethylamine, dimethylformamide, dimethylacetamide and dimethyl sulfoxide;
[0033] Preferably, the palladium catalyst is at least one of palladium dichloride, tetrakis(triphenylphosphine)palladium, bis(triphenylphosphine)palladium dichloride, palladium acetate, bis(triphenylphosphine)palladium acetate, 1,1'-bis(diphenylphosphino)ferrocene dichloride, palladium acetylacetonate, palladium trifluoroacetate, and palladium trifluoromethanesulfonate.
[0034] Preferably, the alkali solution is a solution of a common inorganic base compound, preferably sodium hydroxide or potassium hydroxide;
[0035] The acid solution is a solution of a common inorganic acid compound, preferably hydrochloric acid or sulfuric acid.
[0036] Preferably, the solvent in the hydrolysis is at least one of water, toluene, dioxane, xylene, dimethyl sulfoxide, glycerol, ethylene glycol, ethylene glycol dibutyl ether, and N-methylpyrrolidone.
[0037] The complete reaction route of the present invention is as follows:
[0038]
[0039] Compared with the prior art, the present invention has the following beneficial effects:
[0040] The present invention provides a method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid. Using 2,2-bis(4-aminophenyl)hexafluoropropane as a raw material, intermediate I is obtained through diazotization and Sandmeyer reaction, and then dicarboxylic acid - 2,2-bis(4-carboxyphenyl)hexafluoropropane is prepared through carbonylation insertion reaction (if X is a cyano group, intermediate I is first subjected to a cyanation reaction to generate intermediate II, and then 2,2-bis(4-carboxyphenyl)hexafluoropropane is obtained by hydrolysis under acidic and alkaline conditions). This synthesis method is simple and easy to operate, has a high yield, and a high product purity, and can be applied to actual industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. The drawings in this description are only embodiments of the present invention.
[0042] Figure 1 It is the nuclear magnetic hydrogen spectrum of the product of Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0043] The following describes the embodiments of the present invention. The examples of the embodiments are shown in the drawings. The embodiments described with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation to the present invention.
[0044] Example 1
[0045] A method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid, specifically comprising the following steps:
[0046] (1) Add a mixture of 2,2-bis(4-aminophenyl)hexafluoropropane (33.4 g) and 37% concentrated hydrochloric acid (38 mL) to a 300 mL flask, place it in an ice bath at 0 °C, then dissolve sodium nitrite (14.5 g) in 100 mL of water, add it all to the flask together, control the feeding rate, and keep the temperature at 0 °C. The feeding is completed in about 1 h. Add urea to remove the unreacted nitrous acid, and test with potassium iodide-starch test paper until it does not turn blue rapidly. The obtained diazonium salt solution is stored below 5 °C;
[0047] Add a mixture of cuprous bromide (15.8 g) and 47% hydrobromic acid (18 mL) to a three-necked flask, heat it to boiling. The flask is equipped with a corresponding condenser and receiving flask, and the steam inlet pipe and separatory funnel are clamped spirally. Under the condition of keeping the solution boiling, slowly add the diazonium salt solution from the separatory funnel. The feeding is completed in about 30 min. Close the stopcock of the separatory funnel, open the spiral clip of the steam pipe, collect the distillate until no more organic matter distills out, separate the heavy organic layer, wash it three times with 10 mL of concentrated sulfuric acid first, then wash it again with 100 mL of water, 50 mL of 5% sodium hydroxide solution, and 100 mL of water, dry it and distill it to obtain 39.7 g of intermediate I, with a yield of 85.9%;
[0048] (2) Add the intermediate I (32.3 g) obtained in step (1), palladium dichloride (0.03 g), and triphenylphosphine (0.09 g) to a 500 mL three-necked flask. The flask is evacuated and replaced with nitrogen three times, then add toluene (150 mL) and water (50 mL), stir evenly, continuously introduce carbon monoxide (3 MPa) into the flask, and react at a temperature of 100 °C for 24 h. After the reaction is completed, cool the mixed solution to room temperature and normal pressure, add 2M hydrochloric acid (150 mL) to the mixed solution, repeat 3 times and then let it stand. Take the organic phase and recrystallize it in ethanol-water to obtain 24.4 g of white solid 2,2-bis(4-carboxyphenyl)hexafluoropropane. The relevant hydrogen spectrum is shown in Figure 1 with a yield of 88.9%.
[0049] Example 2
[0050] A method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid, specifically comprising the following steps:
[0051] (1) A mixture of 2,2-bis(4-aminophenyl)hexafluoropropane (33.4 g) and 98% concentrated sulfuric acid (27 mL) was added to a 300 mL flask and placed in an ice bath at 5 °C. Then, sodium nitrite (20.7 g) was dissolved in 100 mL of water and added to the flask together. The feeding rate was controlled and the temperature was maintained at 5 °C. The feeding was completed in about 1 h. Urea was added to remove the unreacted nitrous acid, and it was tested with potassium iodide-starch test paper until it did not turn blue rapidly. The obtained diazonium salt solution was stored below 5 °C;
[0052] The diazonium salt solution was slowly added to a rapidly stirred solution of sodium iodide (16.5 g) - acetone (100 mL). After further stirring for 10 min under a nitrogen atmosphere at 20 °C, the solvent was rapidly evaporated under vacuum. The mixture was extracted with ether, washed with 5% sodium thiosulfate solution, and dried with sodium sulfate to obtain 48.4 g of intermediate I with a yield of 87.0%;
[0053] (2) Intermediate I (33.4 g) obtained in step (1), bis(triphenylphosphine)palladium dichloride (0.17 g), and 1,1'-bis(diphenylphosphino)ferrocene (0.68 g) were added to a 500 mL three-necked flask. The flask was evacuated and purged with nitrogen three times, and then dimethylacetamide (150 mL) and water (50 mL) were added and stirred evenly. Carbon monoxide (3 MPa) was continuously introduced into the flask, and the reaction was carried out at 150 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature and atmospheric pressure. 2M hydrochloric acid (150 mL) was added to the mixture three times, and then it was allowed to stand. The organic phase was recrystallized from ethanol-water to obtain 21.8 g of white solid 2,2-bis(4-carboxyphenyl)hexafluoropropane with a yield of 92.6%.
[0054] Example 3
[0055] A method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid specifically includes the following steps:
[0056] (1) A mixture of 2,2-bis(4-aminophenyl)hexafluoropropane (33.4 g) and 47% hydrobromic acid (70 mL) was added to a 300 mL flask and placed in an ice bath at 10 °C. Then, sodium nitrite (27.6 g) was dissolved in 100 mL of water and added to the flask together. The feeding rate was controlled and the temperature was maintained at 10 °C. The feeding was completed in about 1 h. Urea was added to remove the unreacted nitrous acid, and it was tested with potassium iodide-starch test paper until it did not turn blue rapidly. The obtained diazonium salt solution was stored below 5 °C;
[0057] A mixture of cuprous bromide (15.8 g) and 47% hydrobromic acid (18 mL) was added to a three-necked flask and heated to boiling. The flask was equipped with a corresponding condenser and receiver flask. The steam inlet tube and separatory funnel were clamped with a screw. Under the condition of keeping the solution boiling, the diazonium salt solution was slowly added from the separatory funnel. The feeding was completed in about 30 min. The stopcock of the separatory funnel was closed, and the screw clamp of the steam pipe was opened. The distillate was collected until no more organic matter distilled out. The heavy organic layer was separated, washed three times with 10 mL of concentrated sulfuric acid, then washed again with 100 mL of water, 50 mL of 5% sodium hydroxide solution, and 100 mL of water. After drying and distillation, 39.1 g of intermediate Ⅰ was obtained with a yield of 84.6%.
[0058] (2) Intermediate Ⅰ (32.3 g) obtained in step (1), palladium acetate (0.1 g), dimethyl sulfoxide (600 mL), potassium ferrocyanide (59.2 g), and sodium carbonate (50 g) were added to a 1 L flask, stirred evenly, and heated to 100 °C under nitrogen protection. The reaction ended after 2 hours, cooled to room temperature, diluted with 1 L of ethyl acetate and filtered. The filtrate was washed successively with 500 mL of water (2 times) and 500 mL of 5% ammonia water. The organic phase was dried with sodium sulfate to obtain intermediate Ⅱ.
[0059] Intermediate Ⅱ, sodium hydroxide (16.0 g), water (10 mL), and ethylene glycol (100 mL) were added to a 300 mL three-necked flask, stirred, and heated to 100 °C. The reaction ended after 3 hours, cooled to room temperature, and the pH was adjusted to 6 with 30% hydrochloric acid. After filtration, the filter cake was washed with 200 mL of water and dried to obtain 25.3 g of white solid 2,2-bis(4-carboxyphenyl)hexafluoropropane with a yield of 92.1%.
[0060] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for synthesizing a fluorine-containing polyester monomer dicarboxylic acid, characterized in that, Using 2,2-bis(4-aminophenyl)hexafluoropropane as the raw material, after diazotization and Sandmeyer reaction to obtain intermediate Ⅰ, 2,2-bis(4-carboxyphenyl)hexafluoropropane is obtained after carbonyl insertion reaction. The specific reaction route is as follows:
2. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 1, characterized in that, The reagents used in the diazotization are nitrite and acid; Wherein, the molar ratio of the nitrite, the acid and the 2,2-bis(4-aminophenyl)hexafluoropropane is 2-10:4-10:
1.
3. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 2, characterized in that, The nitrite is any one of sodium nitrite or alkyl nitrite; The acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, perchloric acid and fluoroboric acid.
4. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 1, characterized in that, The reaction temperature of the diazotization is 0-5°C, and the feeding time is 0.5-1h.
5. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 1, wherein When X=Br, the catalyst used in the Sandmeyer reaction is a cuprous salt, and the reagent is hydrobromic acid; wherein the molar ratio of the cuprous salt to the 2,2-bis(4-aminophenyl)hexafluoropropane is 0.1-10:1, and the molar ratio of the cuprous salt to the hydrobromic acid is 1:1-5; Alternatively, when X=I, the Sandmeyer reaction reagent is sodium iodide or potassium iodide, and the molar ratio of the sodium iodide or potassium iodide to the 2,2-bis(4-aminophenyl)hexafluoropropane is 1-10:
1.
6. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 1, characterized in that, The mass ratio of the catalyst to the intermediate I in the carbonyl insertion reaction is 0.001-0.1:1, and the mass ratio of the catalyst to the ligand in the carbonyl insertion reaction is 1:1-10; The reaction temperature of the carbonyl insertion is 0-200°C, and the reaction time is 5-24h.
7. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 6, characterized in that, The catalyst is a palladium catalyst; The ligand is at least one of triphenylphosphine, trimethylphosphine, triethylphosphine, tri-tert-butylphosphine, 1,1'-bis(diphenylphosphino)ferrocene, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, tricyclohexylphosphine, 1,1'-binaphthol, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl.
8. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 1, characterized in that, The intermediate I can be subjected to a cyanation reaction to obtain the intermediate II, and then hydrolyzed to obtain 2,2-bis(4-carboxyphenyl)hexafluoropropane.
9. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 8, characterized in that, In the cyanation reaction, the molar ratio of the cyanation reagent to the intermediate I is 0.1-10:1, the mass ratio of the catalyst, the base and the intermediate I is 0.001-0.1:1-2:1, and the reaction conditions are: 100-150° C. for 1-2 hours; The hydrolysis conditions are: reaction at 80-180° C. for 3-10 hours.
10. The synthesis method of a fluorine-containing polyester monomer dicarboxylic acid according to claim 9, characterized in that, The cyanation reagent is at least one of sodium cyanide, potassium cyanide, zinc cyanide, cuprous cyanide, trimethylsilyl cyanide, acetone cyanohydrin, potassium ferrocyanide and potassium ferrocyanide; The catalyst is a palladium catalyst; The base is at least one of sodium carbonate, potassium carbonate and cesium carbonate; The hydrolysis is alkaline solution hydrolysis or acid solution hydrolysis.