Fluorothiophene cyano compound and preparation method thereof
By optimizing the synthesis route and developing novel purification methods, the production cost of fluorothiophene cyano compounds has been successfully reduced, the cost problem in the prior art has been solved, and the efficient and low-cost synthesis of fluorothiophene cyano compounds has been achieved.
Patent Information
- Application Number
- CN202411810799.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-03-18
AI Technical Summary
The existing fluorothiophene cyano compounds are expensive to produce and lack effective synthetic methods.
By optimizing the synthesis route and developing novel purification methods, the cost of fluorogenic acid was successfully reduced, and the corresponding thiophene cyano compound was designed and synthesized. Specific steps include the reaction using anhydrous potassium fluoride, tetraphenylphosphine bromide and phthalyl chloride, followed by acidification and extraction, and finally further reaction and purification by malonitrile and anhydrous sodium acetate.
The synthesis of low-cost fluorothiophene cyano compounds has been achieved, the process flow has been simplified, the product yield has been improved, and the foundation has been laid for large-scale production.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic photoelectric materials, in particular to a fluorothiophene cyanide compound and a preparation method thereof. Background Art
[0002] Organic solar cells (OSCs) are a promising photovoltaic technology with advantages such as flexibility, light weight, low cost, semi-transparency, solution processability and high-throughput roll-to-roll production. In the past three decades, researchers have devoted themselves to the design and development of active materials such as electron donors and electron acceptors, and the energy conversion efficiency of organic solar cells has been improved to more than 20%.
[0003] In recent years, scientists have designed and synthesized a series of new non-condensed ring small molecule receptors with non-covalent interactions, aiming to build a system with simple synthesis, high efficiency and good stability, focusing on the core scientific issues in the field of organic solar cells, and have systematically studied their optical, electrical and device performance. The study found that the introduction of fluorine atoms into thiophene cyanide compounds synthesized fluorinated thiophene cyanide non-condensed ring small molecules with stronger electron-pulling ability and better optoelectronic properties.
[0004] Small molecules with halogenated thiophene cyanide as structural unit have developed rapidly in receptor materials. For this type of non-condensed ring small molecule receptor structural unit, it is relatively simple and is a good type of photosensitizer with good stability and high molar extinction coefficient, and has specific advantages in the synthesis steps. In particular, fluorinated thiophene cyanide compounds are expected to show better performance. However, fluorinated thiophene cyanide compounds are usually very expensive. The reason is that the corresponding fluorinated raw acid is very expensive, usually priced at 400-1000 yuan / g. In addition, there is no literature reporting the synthesis of corresponding F-substituted thiophene cyanide compounds.
[0005] The present invention synthesizes the fluorothiophene cyanide compound on the basis of reducing the cost of raw materials. Summary of the invention
[0006] The purpose of the present invention is to provide a fluorothiophene cyanide compound and a preparation method thereof to solve the problems raised in the above-mentioned background technology; the present invention successfully synthesizes low-cost fluoro raw acid by optimizing the synthesis route and pioneeringly developing a product purification method, and further designs and synthesizes the corresponding thiophene cyanide compound.
[0007] To achieve the above object, the present invention provides the following technical solutions:
[0008] The present invention provides a method for preparing a fluorine-containing thiophene compound, wherein the structural formula of the fluorine-containing thiophene compound is as follows:
[0009]
[0010] Specifically, the synthesis method of the compound of formula III is as follows:
[0011]
[0012] The specific steps include:
[0013] S01, dispersing the compound of formula VI, anhydrous potassium fluoride, tetraphenylphosphine bromide and phthaloyl chloride in a solvent of sulfolane, then heating to 180°C, reacting for 1-5 hours, stopping heating, cooling the reaction mixture to room temperature, pouring the mixture into water, extracting the mixture with ether, spinning off most of the solvent under normal pressure after extraction, and then distilling the mixture under normal pressure to obtain the product (compound of formula VII);
[0014] S02. Disperse the compound of formula VII in 1 mol / L sodium hydroxide solution, reflux for 1-4 h, cool, and then extract with ether. Acidify the extracted aqueous phase with 1-6 mol / L hydrochloric acid, adjust the pH to 1-2, and then extract the aqueous phase with dichloromethane to obtain a white solid, which is the compound of formula III.
[0015] Furthermore, in step S01, the molar ratio of the compound of formula VI to potassium fluoride, tetraphenylphosphine bromide and phthaloyl chloride is 1:3-10:0.05-0.2:1.0-1.5, and the mass volume ratio of the compound of formula VI to cyclopentane sulfone is 1:5-30.
[0016] Furthermore, in step S02, the molar ratio of the compound of formula VII to sodium hydroxide is 1:2-10.
[0017] The present invention also provides a fluorothiophene cyano compound, the structure of which is shown in Formula I or Formula II:
[0018]
[0019] Furthermore, the process route for synthesizing the fluorothiophene cyano compound using the above-mentioned fluorothiophene carboxylic acid is as follows:
[0020]
[0021]
[0022] Furthermore, the method specifically includes the following steps:
[0023] S03, placing the raw acid represented by formula III in thionyl chloride or a mixed solution of chloroform and thionyl chloride and refluxing for 2-6 hours to obtain a compound represented by formula IV;
[0024] S04, dispersing aluminum chloride in dichloromethane or chloroform, then dropping malonyl chloride, continuing stirring for 30 minutes, dropping a dichloromethane solution of the compound of formula IV, heating under reflux for 8-16 hours, verifying that the reaction is complete by thin layer chromatography, quenching the reaction, extracting with dichloromethane to obtain a crude product, and purifying to obtain a compound of formula V;
[0025] S05. Disperse the compound of formula V, malononitrile and anhydrous sodium acetate in dimethyl sulfoxide, react for 1-3 hours, precipitate, filter and column to obtain the compound of formula I and the compound of formula II.
[0026] Furthermore, in step S03, the molar ratio of the raw acid to thionyl chloride is 1:3-10, and the molar volume ratio of the raw acid to chloroform is 0.5-10:1.
[0027] Furthermore, in step S04, the molar ratio of aluminum chloride to the raw acid in step S03 is 3-5:1, the molar ratio of malonyl chloride to the raw acid in step S03 is 3-6:1; and the molar ratio of the raw acid to dichloromethane or chloroform in step S03 is 1:5-30.
[0028] Furthermore, in step S04, the molar ratio of the compound of formula IV to dichloromethane or chloroform in the dichloromethane or chloroform solution of the compound of formula IV is 1:50-100.
[0029] Furthermore, in step S05, the molar ratio of the compound of formula V, malononitrile and anhydrous sodium acetate is 1:1-3:1.5-3, and the volume ratio of the compound of formula V to dimethyl sulfoxide is 1:20-100.
[0030] Furthermore, in step S05, hydrochloric acid is used for precipitation, and the molar ratio of the compound of formula V to hydrochloric acid is 1:2-6.
[0031] Compared with the prior art, the present invention has the following beneficial effects:
[0032] The present invention provides a simple and efficient synthesis method of a novel fluorine-containing thiophene compound. On the one hand, the synthesis of expensive raw acid is simplified, and the two-step reaction steps are optimized, which is simple and easy to operate. In addition, a more reasonable purification method is adopted according to the product properties to improve the yield. On the other hand, the obtained raw acid is designed and synthesized to obtain a fluorine-containing thiophene nitrile compound. The present invention is the first synthesis of the above-mentioned compound, and the synthesis method is simple and easy to realize large-scale synthesis. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 is the nuclear magnetic resonance spectrum of the intermediate compound of formula VII in Example 1;
[0034] Figure 2 is the nuclear magnetic resonance spectrum of the intermediate compound of formula III in Example 1;
[0035] Figure 3 is the nuclear magnetic resonance spectrum of the intermediate compound of formula V in Example 2;
[0036] Figure 4 The NMR spectra of the compound of formula Ⅰ and the compound of formula Ⅱ in Example 2 are shown in FIG. DETAILED DESCRIPTION
[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0038] Example 1
[0039] Synthesis of compound of formula III
[0040] The synthetic reaction formula of the compound of formula III is as follows:
[0041]
[0042] (1) Synthesis of intermediate compound of formula VII
[0043] The compound of formula VI (60g, 389.3mmol), anhydrous potassium fluoride (113.1g, 1946.3mmol), tetraphenylphosphine bromide (14.7g, 35.0mmol), phthalic acid chloride (84.6g, 416.5mmol) and 1200mL sulfolane were added to a 3L reaction bottle in sequence, stirred for 5min and then gradually heated to 180°C. This reaction is exothermic, and the temperature should be prevented from rising too fast, otherwise the reaction will fail if it rises to more than 200°C. After refluxing for 2h, the reaction was stopped, cooled to room temperature, poured into 2L cold water, and then extracted with ether (500ml*3), part of the solvent was removed by rotation under normal pressure, and directly placed in a flash chromatography column, eluted with ether, and about 1L of ether was required. The eluent was still distilled at normal pressure to obtain 120g of colorless liquid. LC verified that the effective component was about 42%, and no further treatment was performed. The yield of pure product was about 98%. NMR testing requires continued evaporation of ether to obtain the NMR spectrum shown in Figure 1 .
[0044] (2) Synthesis of intermediate compound of formula III
[0045] The intermediate compound of formula VI (120 g, 471.9 mmol) obtained in step (1) and 1500 ml of sodium hydroxide solution (1 N) were added to a 3 L reaction bottle, heated to reflux for 2 h, TLC confirmed the absence of I2, then cooled to room temperature, extracted with ether (500 ml * 1), and the organic phase extracted obtained impurities. Then the aqueous phase was acidified to pH = 2 with 6N hydrochloric acid to obtain a large amount of white solid, which was extracted with DCM (600 ml * 3), dried over anhydrous sodium sulfate, and the solvent was removed to obtain 46.2 g of product (compound of formula III), with a yield of 81%. Its NMR spectrum shows Figure 2 .
[0046] Example 2
[0047] Synthesis of compounds of formula I and II
[0048] The overall reaction formula for the synthesis of the compound of formula I and the compound of formula II is as follows:
[0049]
[0050] (1) Synthesis of intermediate compound IV
[0051] The raw acid (6.3 g, 43.1 mmol) of formula III and thionyl chloride (20.5 g, 172.4 mmol) were dispersed in 65 ml of chloroform, 1 ml of DMF (ultra-dry solvent) was added, and then refluxed for 4 hours, cooled to room temperature, and the solvent was removed by rotation to obtain 7.5 g of a crude compound of formula IV, which was directly fed to the next step.
[0052] (2) Synthesis of intermediate compound of formula V
[0053] Dissolve anhydrous aluminum chloride (17.24g, 129.3mmol) in 100ml of anhydrous dichloromethane, then drop malonic acid chloride (23.4g, 165.8mmol) into the above solution at room temperature, then disperse the intermediate compound of formula IV into 20ml of anhydrous dichloromethane, drop it into the reaction system, heat and reflux for 12h after the addition is completed, and TLC verifies that the reaction is complete, otherwise reflux can continue. Cool to room temperature, add an ice water bath, and drop 500ml of ice water to quench the reaction, then pour into 1L of water, extract with dichloromethane (600ml*3), spin off the solvent and purify through a column, the eluent is dichloromethane, and finally 2.9g of the compound of formula V is obtained, with a two-step yield of 40%. The NMR of the obtained product is as follows Figure 3 .
[0054] (3) Synthesis of intermediate compound of formula I + compound of formula II
[0055] Add (0.7g, 4.1mmol) of the compound of formula V, malononitrile (0.41g, 6.2mmol) and 20ml of dimethyl sulfoxide to a 250ml reaction bottle, stir for 10 minutes and then add (0.51g, 6.2mmol) of anhydrous sodium acetate. Then stir at room temperature for 2h, and detect the reaction by TLC. After the reaction is completed, add 8ml of 2N hydrochloric acid dropwise, stir for 30min, pour the reaction into 500ml of water, and then extract with dichloromethane (200ml*3), then wash with water until neutral, and finally pass through a chromatography column to obtain 0.6g of the product (compound of formula I + compound of formula II), and NMR is Figure 4 .
[0056] Example 3
[0057]
[0058] (1) Synthesis of intermediate compound IV
[0059] The raw acid (60 g, 410.6 mmol) of formula III, thionyl chloride (240 g, 2017 mmol) and 1 ml of anhydrous DMF were added to the reaction bottle, and then refluxed for 3 h. The mixture was cooled to room temperature and the solvent was removed by rotation to obtain 80 g of a crude compound of formula IV, which was directly fed to the next step.
[0060] (2) Synthesis of intermediate compound of formula V
[0061] Anhydrous aluminum chloride (164.2 g, 1231.7 mmol) was dissolved in 1000 ml of anhydrous chloroform, and then malonyl chloride (260.4 g, 1847.5 mmol) was added dropwise to the above solution at room temperature. Then the intermediate compound of formula IV was dispersed in 200 ml of anhydrous chloroform and added dropwise to the reaction system. After the addition was completed, the temperature was raised and refluxed for 12 h. TLC verified that the reaction was completed, and the mixture was cooled to room temperature, an ice-water bath was added, and 500 ml of ice water was added dropwise to quench the reaction. The mixture was then poured into 3 L of water, extracted with dichloromethane (1000 ml*5), and the solvent was removed by spinning and then purified by column. The eluent was dichloromethane, and finally 38 g of the compound of formula V was obtained, with a two-step yield of 51.8%.
[0062] (3) Synthesis of intermediate compound of formula I + compound of formula II
[0063] Add (0.7g, 4.1mmol) of the compound of formula V, malononitrile (0.54g, 8.2mmol) and 20ml of dimethyl sulfoxide to a 250ml reaction bottle, stir for 10 minutes, then add (0.68g, 8.2mmol) of anhydrous sodium acetate. Then stir at room temperature for 2h, and detect the reaction by TLC. After the reaction is completed, add 10ml of 2N hydrochloric acid dropwise, stir for 30min, pour the reaction into 500ml of water, and then extract with dichloromethane (200ml*3), then wash with water until neutral, and finally pass through a chromatography column to obtain 0.7g of the product (compound of formula I + compound of formula II).
[0064] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0065] It should be noted that the above content only illustrates the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.
Claims
1. A fluorothiophene cyano compound, characterized in that The structure is shown in Formula I or Formula II:
2. A method for preparing a fluorothiophene cyano compound, characterized in that: The synthetic process route of the fluorothiophene cyano compound is:
3. The method for preparing a fluorothiophene cyano compound according to claim 2, characterized in that: The specific steps include: S01, dispersing the compound of formula VI, anhydrous potassium fluoride, tetraphenylphosphine bromide and phthaloyl chloride in a solvent of sulfolane, then heating to 140-200°C, reacting for 1-5 hours, cooling to room temperature, pouring into water, extracting with ether, spinning off most of the solvent under normal pressure after extraction, and then distilling under normal pressure to obtain the compound of formula VII; S02, dispersing the compound of formula VII in 1 mol / L sodium hydroxide solution, reflux for 1-4 hours, then cooling, then extracting with ether, acidifying the aqueous phase after extraction with 1-6 mol / L hydrochloric acid, adjusting the pH to 1-2, then extracting the aqueous phase with dichloromethane to obtain a white solid, which is the compound of formula III; S03, placing the raw acid represented by formula III in thionyl chloride or a mixed solution of chloroform and thionyl chloride and reflux for 2-6 hours to obtain a compound represented by formula IV; S04, dispersing aluminum chloride in dichloromethane or chloroform, then dropping malonyl chloride, continuing stirring for 30 minutes, dropping a dichloromethane or chloroform solution of the compound of formula IV, heating under reflux for 8-16 hours, extracting and purifying to obtain the compound of formula V; S05. Disperse the compound of formula V, malononitrile and anhydrous sodium acetate in dimethyl sulfoxide, react for 1-3 hours, precipitate, filter and column to obtain the compound of formula I and the compound of formula II.
4. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S01, the molar ratio of the compound of formula VI to potassium fluoride, tetraphenylphosphine bromide and phthaloyl chloride is 1:3-10:0.05-0.2:1.0-1.5, and the mass volume ratio of the compound of formula VI to cyclopentane sulfone is 1:5-30.
5. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S02, the molar ratio of the compound of formula VII to sodium hydroxide is 1:2-10.
6. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S03, the molar ratio of the raw acid to thionyl chloride is 1:3-10, and the molar volume ratio of the raw acid to chloroform is 0.5-10:
1.
7. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S04, the molar ratio of aluminum chloride to the raw acid in step S03 is 3-5:1, the molar ratio of malonyl chloride to the raw acid in step S03 is 3-6:1; the molar ratio of the raw acid to dichloromethane or chloroform in step S03 is 1:5-30.
8. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S04, the molar ratio of the compound of formula IV to dichloromethane or chloroform in the dichloromethane or chloroform solution of the compound of formula IV is 1:50-100.
9. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S05, the molar ratio of the compound of formula V, malononitrile and anhydrous sodium acetate is 1:1-3:1.5-3, and the volume ratio of the compound of formula V to dimethyl sulfoxide is 1:20-100.
10. The method for preparing a fluorothiophene cyano compound according to claim 3, characterized in that: In step S05, hydrochloric acid is used for precipitation, and the molar ratio of the compound of formula V to hydrochloric acid is 1:2-6.