Kilogram-level preparation method of organic photoelectric halogenated intermediate reagent

Abstract

The invention discloses a kilogram-level preparation method of an organic photoelectric halogenated intermediate reagent, and belongs to the technical field of organic synthesis and organic photoelectric materials.The kilogram-level preparation method of the organic photoelectric halogenated intermediate reagent comprises the following steps that thiophene derivatives and an organic solvent are stirred to be uniform; then adding a brominating agent in batches, carrying out bromination reaction, and carrying out purification treatment after the reaction is finished, so as to finally prepare the target product, namely the organic photoelectric halogenated intermediate reagent. The purity of the intermediate reagent prepared through the method is larger than or equal to 95%, the yield is larger than or equal to 70%, kilogram-level large-scale production is achieved, the technical difficulty and cost are reduced, the supply chain stability is enhanced, and the requirements for high-quality halogenated intermediates in the fields of organic solar cells and the like are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic synthesis and organic optoelectronic materials, and particularly relates to a kilogram-level preparation method of an organic optoelectronic halogenated intermediate reagent. BACKGROUND

[0002] Conjugated polymer materials have great application potential in new-generation electronic devices such as organic solar cells, flexible display screens and field effect transistors due to their unique photoelectric properties, and have become a research hotspot in the field of new materials. The precise synthesis of such materials highly depends on halogenated aromatic or olefin intermediates with clear structures, and the purity and stability of the intermediates directly determine the molecular weight, conjugation length and photoelectric properties of the conjugated polymers. However, the existing preparation technology of halogenated intermediates cannot meet the needs of industrial production, and there are many technical bottlenecks to be solved.

[0003] At the laboratory synthesis level, the traditional method generally faces the problem of poor stability of the product. Most halogenated intermediates (such as bromothiophene derivatives) are prone to thermal decomposition at room temperature. DSC analysis shows that the decomposition of some halogenated intermediates releases as much as 950 J·g -1 , which poses a serious safety hazard. At the same time, such compounds are sensitive to oxygen and moisture, and need to be stored in a low-temperature environment of -23℃, which greatly limits their transportation and application range. In terms of reaction control, halogenation reactions usually need to strictly maintain a narrow pH window of 2-4. Traditional batch reactions cannot avoid local pH fluctuations, resulting in a significant increase in by-products and a target product yield of only 50%-76%.

[0004] When trying to scale up the laboratory process to kilogram-level production, more systematic problems are exposed. First, there are limitations in heat and mass transfer. The strong exothermic nature of bromination and other reactions can cause a 15%-30% further decrease in yield due to local overheating caused by uneven mixing in batch production. Second, traditional glass reactors have serious leakage problems, which not only cause raw material loss rates of more than 20%, but also bring environmental and safety risks. In addition, existing processes generally rely on corrosive reagents such as thionyl chloride and noble metal catalysts, which not only increase production costs, but also generate a large amount of toxic waste liquid, with subsequent treatment costs accounting for more than 30% of total production costs.

[0005] In terms of quality control, conjugated polymer synthesis has very high requirements for the purity of halogenated intermediates (HPLC purity ≥98%). However, the impurity content of products from traditional processes often exceeds 2.0%. This is due to problems such as incomplete magnesium-halogen exchange in batch reactions, and purification methods such as column chromatography are difficult to adapt to large-scale production, resulting in low raw material utilization. At the same time, existing processes have problems such as complicated operation, high energy consumption and poor batch stability. For example, batch reactions require frequent heating and cooling cycles, with an energy utilization rate of less than 40%.

[0006] As conjugated polymer materials enter the industrialization stage, the demand for halogenated intermediates has jumped from the gram level to the kilogram level, making the limitations of traditional processes increasingly prominent.

[0007] Therefore, there is an urgent need to develop a kilogram-scale preparation process that is highly safe, meets purity standards, is environmentally friendly, and can be stably scaled up. This process has significant academic value and economic implications for overcoming the bottleneck in the industrialization of conjugated polymers. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention proposes a kilogram-scale preparation method for organic photoelectric halogenated intermediate reagents.

[0009] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions: A method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale basis, comprising the following steps: Thiophene derivatives and organic solvents are stirred evenly, and then brominating agents are added in batches to carry out bromination reactions. After the reaction is completed, purification is performed to finally prepare the target product, namely the organic photoelectric halogenated intermediate reagent.

[0010] Optionally, the thiophene derivative is selected from any one of 2,2'-bithiophene, 4,4,9,9-tetra(4-hexylphenyl)-indargenop[1,2-b:5,6-b']dithiophene, 4,4,9,9-tetradodecyl-4,9-dihydro-s-indargenop[1,2-b:5,6-b']dithiophene, 4,4,9,9-tetraoctyl-4,9-dihydro-s-indargenop-[1,2-b:5,6-b']dithiophene, 5,7-bis(thiophen-2-yl)-1,3-bis(2-ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione, and 3-hexylthiophene.

[0011] Optionally, the organic solvent is selected from at least one of chloroform, tetrahydrofuran, dichloromethane, N,N-dimethylformamide, petroleum ether, ethyl acetate, or glacial acetic acid.

[0012] Furthermore, the ratio of the thiophene derivative to the organic solvent is 1.2-6 mol : 1-12 L.

[0013] Optionally, the brominating agent is N-bromosuccinimide (NBS).

[0014] Furthermore, the molar ratio of the N-bromosuccinimide to the thiophene derivative is 2.5-25:1.2-6.

[0015] Optionally, the bromination reaction is carried out at a temperature of -10-50℃ for 5-20 hours.

[0016] Optionally, the purification process comprises the following steps: The reaction solution is filtered under reduced pressure, and the filtrate is separated into organic and aqueous phases. The organic phase is washed with water and dried by rotary evaporation. The filter cake is washed with water. The filtrate and the filter cake are combined, and the resulting solid is purified by column chromatography to obtain the target product.

[0017] Further, the eluent used in the column chromatography is dichloromethane or petroleum ether.

[0018] An organic optoelectronic halogenated intermediate reagent prepared by the above preparation method.

[0019] Technical solution two: A kilogram-scale preparation method of an organic optoelectronic halogenated intermediate reagent, comprising the following steps: (1) Under the protection of an inert gas, a halogenated thiophene derivative is reacted with a butyllithium reagent at low temperature to obtain a thiophene lithium salt intermediate; (2) The thiophene lithium salt intermediate is reacted with a diketone compound at low temperature to obtain an addition product, and then the addition product is reacted with a reducing agent to obtain a target halogenated intermediate crude product; or, The thiophene lithium salt intermediate is reacted with bromoiso-octane at low temperature to obtain a target halogenated intermediate crude product; (3) The crude product is purified to obtain a high-purity halogenated intermediate reagent. Optionally, the halogenated thiophene derivative in step (1) is selected from any one of 3-chloro-2-(2-ethylhexyl)thiophene, 3-fluoro-2-(2-ethylhexyl)thiophene, and 3-chlorothiophene. The low temperature is -78℃ to -60℃. The inert gas is nitrogen. Optionally, in step (2), the diketone compound is benzo[1,2-B:4,5-B']dithiophene-4,8-dione, and the low temperature is -78℃ to -60℃. Optionally, in step (2), the reducing agent is tin dichloride dihydrate, and the reaction temperature is above 50℃. Optionally, in step (3), 200-mesh silica gel is used as the packing material, and petroleum ether is used as the eluent.

[0020] Technical solution three: A kilogram-scale preparation method of an organic optoelectronic halogenated intermediate reagent, comprising the following steps: (1) reacting a carbazole derivative with an alkali hydroxide in an organic solvent to obtain a carbazole salt intermediate; (2) reacting the carbazole salt intermediate with an alkylating agent to obtain an alkylated product; (3) purifying the alkylated product by column chromatography to obtain a high-purity halogenated intermediate reagent. Optionally, the carbazole derivative in step (1) is 2,7-dibromocarbazole; The alkali hydroxide is potassium hydroxide; The organic solvent is dimethyl sulfoxide. Optionally, the alkylating agent in step (2) is any one of 4-methylbenzenesulfonic acid-9-heptadecyl ester, 1-bromo-octane, and 1-bromo-hexane, and the reaction temperature is 60-90°C. Compared with the prior art, the present application has the following advantages and technical effects: 1. Reducing the technical difficulty of experiment: through the fine operation process and the optimization of reaction conditions, the present application significantly reduces the technical threshold of the synthesis of halogenated intermediate reagent, making the production process more stable and controllable.

[0021] 2. Improving production efficiency: the preparation method of the present application simplifies the steps, shortens the reaction time, and improves the yield of the product. The yield of most products can reach more than 70%, and the yield of some products can even reach 95%.

[0022] 3. Reducing production cost: through independent research and development of raw material synthesis technology and optimization of process route, the present application greatly reduces the production cost of halogenated intermediate reagent, and reduces the dependence on foreign raw materials.

[0023] 4. Enhancing the stability of supply chain: the present application realizes the independent production of key raw materials, effectively avoids the influence of international market fluctuation on the supply chain, and improves the stability and continuity of production.

[0024] 5. Realizing kilogram-scale production: the method provided by the present application can stably realize kilogram-scale production, meet the needs of industrial application, and lay a solid foundation for large-scale industrialization of halogenated intermediate reagent.

[0025] 6. Stable and reliable product quality: through strict quality control and detection by multiple characterization means, the halogenated intermediate reagent prepared by the present application has high purity and good stability, and can meet the requirements of high-end application fields. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of the present application, are used to provide a further understanding of the present application, and the illustrative embodiments thereof and their description serve to explain the present application without imposing undue limitation on the present application. In the drawings: Figure 1 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)benzo[l,2-B:4,5-B']dithiophene prepared for Example 1; Figure 2 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)benzo[l,2-B:4,5-B']dithiophene prepared for Example 1; Figure 3 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 3,3',5,5'-tetrabromo-2,2'-bithiophene prepared for Example 3; Figure 4 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 3,3'-dibromo-2,2'-bithiophene prepared for Example 4; Figure 5 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 2,7-dibromo-9-(l-octylnonyl)-9H-carbazole prepared for Example 5; Figure 6 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 4,4,9,9-tetrakis(4-hexylphenyl)-2,7-dibromo-indaceno[2,3-b]thiophene prepared for Example 6; Figure 7 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 2,7-dibromo-4,4,9,9-tetradodecyl-4,9-dihydro-s-indaceno[l,2-b:5,6-b']dithiophene prepared for Example 7; Figure 8 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 2,7-dibromo-4,4,9,9-tetradodecyl-4,9-dihydro-s-indaceno[l,2-b:5,6-b']dithiophene prepared for Example 7; Figure 9 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 2,7-dibromo-9,9-dioctylfluorene prepared for Example 9; Figure 10 NMR spectra of hydrogen and carbon and MALDI-TOF-MS test pattern of 1,3-bis(5-bromothiophenyl)-5,7-bis(2-ethylhexyl)benzo[l,2-c:4,5-c']dithiophene-4,6-dione prepared for Example 10; Figure 11NMR hydrogen spectrum, carbon spectrum and MALDI-TOF-MS test spectrum of 3-chloro-2-(2-ethylhexyl)thiophene prepared for Example 11; Figure 12 NMR hydrogen spectrum, carbon spectrum and MALDI-TOF-MS test spectrum of 2,7-dibromo-9,9-dihexylfluorene prepared for Example 12; Figure 13 NMR hydrogen spectrum, carbon spectrum and MALDI-TOF-MS test spectrum of 1,3-dibromo-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c'-]dithiophene-4,8-dione prepared for Example 13; Figure 14 NMR hydrogen spectrum, carbon spectrum and EI-MS test spectrum of 2,5-dibromo-3-hexylthiophene prepared for Example 14; Figure 15 NMR hydrogen spectrum, carbon spectrum and MALDI-TOF-MS test spectrum of 2-bromothiophene-3-carboxylic acid prepared for Example 15. DETAILED DESCRIPTION

[0027] The detailed description set forth below is intended as a description of various example embodiments of the application and is not intended to represent the only embodiments in which the application can be practiced. The detailed description is intended only to provide a further example of the subject matter described in the following claims.

[0028] The raw materials used in the present application are all commercially available.

[0029] The technical solutions of the present application are further described below through examples.

[0030] Example 1 Preparation of 4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-B:4,5-B']dithiophene The preparation process of 4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-B:4,5-B']dithiophene is as follows: In a 20 L four-port reaction flask, install a mechanical stirring device, insert a -100 ℃-40 ℃ thermometer, and place the reaction flask in a cold bath tank filled with ethanol. At room temperature, add 1150.3 g (5.0 mol) of 3-chloro-2-(2-ethylhexyl) thiophene and 2 L of tetrahydrofuran, start stirring at 260 rpm. Use a high-purity nitrogen cylinder to blow nitrogen into the reaction flask as a protective condition, fully stir and continue to ventilate for 10 minutes, then connect the balloon to ensure a positive pressure of inert atmosphere in the system, add liquid nitrogen to the cold bath tank to cool the reaction flask, and keep the temperature in the reaction flask below -78 ℃. 2.2 L of 2.5M butyllithium tetrahydrofuran solution (5.5 mol) is added to the constant pressure dropping funnel, the constant pressure dropping funnel valve is opened, and the butyllithium tetrahydrofuran solution is slowly added to the system. The temperature of the reaction system should be controlled below -60 ℃ during the addition process. After the addition is completed, continue to stir for 2 h while controlling the temperature in the reaction flask between -60 ℃ and 40 ℃. Dissolve 550.68 g (2.5 mol) of benzo[1,2-B:4,5-B']dithiophene-4,8-dione in 1 L of tetrahydrofuran and add it to the constant pressure dropping funnel. Add liquid nitrogen to lower the temperature in the reaction flask to -78 ℃, open the constant pressure dropping funnel valve, and slowly add the benzo[1,2-B:4,5-B']dithiophene-4,8-dione tetrahydrofuran solution to the system. The temperature of the reaction system should be controlled below -60 ℃ during the addition process. After the addition is completed, do not add liquid nitrogen, and after the reaction system naturally warms up to room temperature, continue to stir overnight. Remove the reaction flask from the cold bath tank, install a condensing device, and place the reaction flask in a constant temperature bath circulating tank. Dissolve 542 g (2.4 mol) of tin dichloride dihydrate in 1200 mL of 10% dilute hydrochloric acid, stir well, and then add it to the constant pressure dropping funnel. Open the constant pressure dropping funnel valve and slowly add the tin dichloride dihydrate solution to the system. After the addition is completed, open the condensing device and cool it with a circulating cooler. Set the circulating temperature of the constant temperature bath tank to 65 ℃, control the temperature of the system in the reaction flask above 50 ℃, and continue to stir for 1 hour. Turn off the heating switch of the constant temperature bath circulating tank, and when the temperature in the kettle decreases to room temperature, add 3.6 L of ethyl acetate to the reaction flask, stir for 10 minutes, and separate the phases. After the lower aqueous phase is removed, add 5 L of water and repeat the stirring and phase separation twice. Remove the remaining organic phase, add 800 g of anhydrous magnesium sulfate, stir for 30 minutes to dry and remove water, use a 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle to filter the magnesium sulfate solids under reduced pressure, collect the filtrate, and use a rotary evaporator to concentrate the filtrate under reduced pressure to obtain a brown solid.A chromatographic column with a diameter of 15 cm was taken, 50 cm effective height of 200 mesh silica gel was used as the packing material, and petroleum ether was used as the eluent. The target product 4,8-bis[5-(2-ethylhexyl)-4-chloro-2-thienyl]benzo[1,2-B:4,5-B']dithiophene 1292.1 g was obtained by column chromatography with a yield of 78%, and the purity was 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is as shown in FIG. 1. Figure 1

[0031] Example 2 Preparation of 4,8-bis(4-fluoro-5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-B:4,5-B']dithiophene The preparation process of 4,8-bis(4-fluoro-5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-B:4,5-B']dithiophene is as follows: ​In a 20 L four-port reaction flask, install a mechanical stirring device, insert a -100℃-40℃ thermometer, and place the reaction flask in a cold bath tank filled with ethanol. At room temperature, add 1070.6 g (5.0 mol) of 3-fluoro-2-(2-ethylhexyl) thiophene and 2 L of tetrahydrofuran, start stirring at 260 rpm. Use a high-purity nitrogen cylinder to blow nitrogen into the reaction flask as a protective condition, stir thoroughly and continue to ventilate for 10 minutes, then add liquid nitrogen to the cold bath tank to cool the reaction flask, keep the temperature in the reaction flask below -78℃, add 2.2 L of 2.5M butyllithium tetrahydrofuran solution (5.5 mol) to the constant pressure dropping funnel, open the constant pressure dropping funnel valve, slowly add the butyllithium tetrahydrofuran solution to the system, control the temperature of the reaction system during the addition process to be not higher than -60℃. After the addition is completed, continue to stir for 2 h while controlling the temperature in the reaction flask between -60℃ and -40℃. Dissolve 550.68 g (2.5 mol) of benzo[1,2-B:4,5-B']dithiophene-4,8-dione in 1 L of tetrahydrofuran and add it to the constant pressure dropping funnel. Add liquid nitrogen to lower the temperature in the reaction flask to -78℃, open the constant pressure dropping funnel valve, and slowly add the benzo[1,2-B:4,5-B']dithiophene-4,8-dione tetrahydrofuran solution to the system. During the addition process, control the temperature of the reaction system to be not higher than -60℃. After the addition is completed, do not add liquid nitrogen, and after the reaction system naturally warms up to room temperature, continue to stir overnight. Remove the reaction flask from the cold bath tank, install a condensing device, and place the reaction flask in a constant temperature bath circulating tank. Dissolve 542 g (2.4 mol) of tin dichloride dihydrate in 1200 mL of 10% dilute hydrochloric acid, stir thoroughly, and then add it to the constant pressure dropping funnel. Open the constant pressure dropping funnel valve and slowly add the tin dichloride dihydrate solution to the system. After the addition is completed, open the condensing device and the cold machine, set the circulating temperature of the constant temperature bath tank to 65℃, control the temperature of the system in the reaction flask to be above 50℃, and continue to stir for 1 hour. Turn off the heating switch of the constant temperature bath circulating tank, and after the temperature in the kettle decreases to room temperature, add 3.6 L of ethyl acetate to the reaction flask, stir for 10 minutes, and separate the phases. Remove the lower aqueous phase, then add 5 L of water and stir to separate the phases twice. Remove the remaining organic phase, add 800 g of anhydrous magnesium sulfate and stir for 30 minutes to dry and remove water. Use a 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle to filter the magnesium sulfate solids under reduced pressure, collect the filtrate, and use a rotary evaporator to concentrate the filtrate under reduced pressure to obtain a brown solid.A chromatographic column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, and petroleum ether was used as the eluent. The target product was obtained by preliminary purification by column chromatography with a crude yield of 78%. The target product, 4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo[1,2-B:4,5-B']dithiophene 1199.1 g, was a dark yellow viscous liquid with a purity of 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and its corresponding spectrum is shown in FIG. 1. Figure 2

[0032] Preparation of 3,3',5,5'-Tetrabromo-2,2'-bithiophene The preparation process of 3,3',5,5'-tetrabromo-2,2'-bithiophene is as follows: A 20 L reaction kettle was installed with a mechanical stirring device, a thermometer was inserted to measure the temperature from -10 ℃ to 80 ℃, and a condensing device was installed. The circulation tank connected to the interlayer was opened, and the circulation temperature was set to -10 ℃. 1000 g (6.0 mol) of 2,2-bithiophene, 9 L of chloroform, and 3 L of glacial acetic acid were added to the reaction kettle, and the stirring was started at a speed of 260 rpm. While keeping the temperature in the reaction bottle below 10 ℃, after 10 minutes of sufficient stirring, a total of 4450.0 g (25 mol) of N-bromosuccinimide was slowly added to the reaction bottle in 5 portions (each portion was between 800-900 g) through a feeding funnel, and 1 L of chloroform was added to rinse the feeding funnel and the wall of the reaction bottle. After 30 minutes of sufficient stirring, the condensing device was opened and the circulation was started, the circulation temperature of the thermostat tank was set to 65 ℃, and the temperature of the system in the reaction bottle was controlled to be above 50 ℃. The reaction was monitored every 2 hours by thin layer chromatography using petroleum ether:dichloromethane=1:1 as the developing agent. After 20 hours, it was found that there was no raw material left. A vacuum distillation device was built on the reaction kettle, 6 L of chloroform was distilled off, and the heating switch of the thermostat tank was turned off. After the reaction bottle was naturally cooled to room temperature, 5 L of water was added, and after sufficient stirring, the filtrate was filtered under vacuum using a 15 cm diameter ceramic Buchner funnel and a 20 L suction filter bottle. The organic phase was collected after phase separation, 1 L of water was added and washed three times, and the organic phase was rotary dried. The filter cake was washed with 2 L of water several times, and a dark yellow solid was obtained. The filtrate and the solid obtained from the filter cake were combined. A chromatographic column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, and dichloromethane was used as the eluent. The target compound, 3,3',5,5'-tetrabromo-2,2'-bithiophene 2746.6 g, was obtained by preliminary purification by column chromatography with a yield of 95%. Its corresponding spectrum is shown in FIG. 2. Figure 3

[0033] ​​Preparation of 3,3'-dibromo-2,2'-bithiophene The preparation process of 3,3'-dibromo-2,2'-bithiophene is as follows: A 10 L four-necked reaction flask was installed with a mechanical stirring device and a constant pressure dropping funnel, a thermometer was inserted at 0-100 ℃, a condensing device was installed, and the reaction flask was placed in an electric heating jacket. At room temperature, 1927.5 g (4.0 mol) of 3,3',5,5'-tetrabromo-2,2'-bithiophene, 653.9 g (10.0 mol) of zinc powder and 1 L of ethanol were added to the reaction flask, and the stirring was started at a speed of 260 rpm. 2 L of glacial acetic acid was added to the constant pressure dropping funnel, and the constant pressure dropping funnel switch was opened to slowly drop the glacial acetic acid into the reaction flask. The temperature was increased, and the temperature of the system in the reaction flask was controlled to be above 75 ℃. The reaction was monitored every 30 minutes by thin layer chromatography using petroleum ether:dichloromethane=1:1 as the developing agent. After 4 hours, it was found that there was no raw material left, and the heating switch of the constant temperature bath was turned off. After the reaction flask was naturally cooled to room temperature, the reaction system was poured into a 20 L polypropylene barrel, 5 L of water was added, and the stirring was continued for 20 minutes by mechanical stirring. The mixture was filtered through a 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle, and the filter cake was washed with 2 L of water for three times. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, dichloromethane was used as the eluent, and the target compound 3,3'-dibromo-2,2'-bithiophene was obtained by column chromatography with a yield of 95%, and the purity was 98% (see nuclear magnetic resonance hydrogen spectrum and carbon spectrum), and the corresponding spectrum is shown in Figure 4 .

[0034] Preparation of 2,7-dibromo-9-(1-octylnonyl)-9H-carbazole The preparation process of 2,7-dibromo-9-(1-octylnonyl)-9H-carbazole is as follows: In a 20 L reaction kettle, install a constant pressure dropping funnel, insert a thermometer of 0-200 °C, install a condensing device. Add 1300 g (4.0 mol) of 2,7-dibromocarbazole, 561 g (10.0 mol) of potassium hydroxide powder and 2 L of dimethyl sulfoxide into the reaction bottle at room temperature, start stirring at 260 rpm. Dissolve 2135.5 g (5.2 mol) of 4-methylbenzenesulfonic acid-9-heptadecyl ester in 4 L of dimethyl sulfoxide, and after stirring well, add it to the constant pressure dropping funnel. Open the condensing device and the cooling cycle, set the circulating temperature of the constant temperature bath to 70 °C, control the temperature of the system in the reaction bottle to be above 60 °C, continue stirring for 2 hours. Open the constant pressure dropping funnel switch, slowly add the dimethyl sulfoxide solution of 4-methylbenzenesulfonic acid-9-heptadecyl ester to the reaction bottle drop by drop, and the temperature in the reaction system should not be higher than 90 °C during the dropping process. After the dropping is completed, increase the temperature of the constant temperature bath to 90 °C, and the internal temperature to 80 °C. Monitor the reaction every 2 hours by thin layer chromatography, use petroleum ether: dichloromethane = 3:1 as the developing agent, and after 10 hours, no raw material is found, turn off the heating switch of the constant temperature bath. After the reaction bottle is naturally cooled to room temperature, add 4 L of petroleum ether to the reaction bottle, continue stirring for 10 minutes, and separate the phases after standing; the aqueous phase is extracted again with 5 L of petroleum ether, and the petroleum ether obtained before is combined, and 4 L of water is added again to stir and separate the phases twice, and the remaining organic phase is discharged, 800 g of anhydrous magnesium sulfate is added and stirred for 30 minutes to dry and remove water, a 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle are used to filter the magnesium sulfate solid under reduced pressure, the filtrate is collected, and a rotary evaporator is used to concentrate the filtrate under reduced pressure. Take a chromatography column with a diameter of 15 cm, use 50 cm of 200 mesh silica gel as the filling material, and dichloromethane as the eluent, and purify it by column chromatography to obtain the target compound 2,7-dibromo-9-(1-octyl nonyl)-9H-carbazole 1622.3 g with a yield of 72%, which is a yellow solid with a purity of 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is as shown in Figure 5

[0035] Example 6 Preparation of 4,4,9,9-tetra(4-hexylphenyl)-2,7-dibromo-indaceno[1,2-b:5,6-b']dithiophene The preparation process of 4,4,9,9-tetra(4-hexylphenyl)-2,7-dibromo-indaceno[1,2-b:5,6-b']dithiophene is as follows: ​In a 10 L three-necked reaction flask, a mechanical stirring device was installed, a thermometer was inserted to -10~80 ℃, and the reaction flask was placed in a thermostat bath. The thermostat bath circulation tank was opened, and the circulation temperature was set to -10 ℃. 1088 g (1.2 mol) of 4,4,9,9-tetra(4-hexylphenyl)-indacenodithiophene and 1 L of tetrahydrofuran were added to the reaction flask, and stirring was started at a speed of 260 rpm. After 20 minutes of sufficient stirring while keeping the temperature in the reaction flask at no higher than 0 ℃, a total of 445 g (2.5 mol) of N-bromosuccinimide was slowly added to the reaction flask in five portions through an addition funnel, and 500 mL of tetrahydrofuran was added to rinse the addition funnel and the wall of the reaction flask. The stirring was continued while keeping the temperature in the reaction flask at no higher than 0 ℃. The reaction was monitored every hour by thin layer chromatography using petroleum ether: dichloromethane = 1:1 as the developing agent. After 2 hours, the thermostat bath circulation tank cooling switch was turned off, and the reaction flask was allowed to return to room temperature naturally, and the stirring was continued. After 8 hours, it was found that no starting material remained. 2 L of water and 3 L of ethyl acetate were added to the reaction flask, and the stirring was continued for 10 minutes, and the phases were allowed to separate after standing. The aqueous phase was discharged, and 2 L of water was added again to stir and separate the phases twice. The remaining organic phase was discharged, 800 g of anhydrous magnesium sulfate was added to stir for 30 minutes to dry and remove water, and a 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle were used to filter the magnesium sulfate solids under reduced pressure. The filtrate was collected, and a rotary evaporator was used to concentrate the filtrate under reduced pressure to obtain a brown solid. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filler, petroleum ether was used as the eluent, and the target compound 4,4,9,9-tetra(4-hexylphenyl)-2,7-dibromo-indacenodithiophene was obtained by column chromatography with a yield of 89%, and the purity was 98% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 6 .

[0036] Example 7 Preparation of 2,7-dibromo-4,4,9,9-tetradodecyl-4,9-dihydro-s-indacenobis[1,2-b:5,6-b']dithiophene The preparation process of 2,7-dibromo-4,4,9,9-tetradodecyl-4,9-dihydro-s-indacenobis[1,2-b:5,6-b']dithiophene is as follows: In a 10 L three-necked reaction flask, a mechanical stirring device was installed, and a thermometer was inserted to -10 °C - 80 °C. Into the reaction flask, 1646 g (1.5 mol) of 4,4,9,9-tetradecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene, 3 L of dichloromethane and 1 L of N,N-dimethylformamide were added, and stirring was started at a speed of 260 rpm. The outer wall of the reaction flask was wrapped with tin foil to make the inside of the flask in a light-protected environment. A total of 567 g (3.1 mol) of N-bromosuccinimide was slowly added to the reaction flask in five portions through an addition funnel, and 200 mL of dichloromethane was added to rinse the addition funnel and the wall of the reaction flask, and stirring was continued. The reaction was monitored by thin layer chromatography every 1 hour, using petroleum ether as the developing agent. After 6 hours, it was found that there was no raw material left. 2 L of water and 3 L of petroleum ether were added to the reaction flask, and stirring was continued for 10 minutes, and then the phases were allowed to separate after standing; the water phase was discharged, and 2 L of water was added again to stir and separate the phases twice, and the remaining organic phase was discharged, 800 g of anhydrous magnesium sulfate was added and stirred for 30 minutes to dry and remove water, and the magnesium sulfate solid was removed by filtration under reduced pressure using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle, the filtrate was collected, and the filtrate was concentrated under reduced pressure using a rotary evaporator. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 60 cm was used as the filling material, and petroleum ether was used as the eluent, and the target compound 2,7-dibromo-4,4,9,9-tetradecyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene was obtained by column chromatography with a yield of 95%, and the purity was 98% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 7 .

[0037] Example 8 Preparation of 2,7-dibromo-4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene The preparation process of 2,7-dibromo-4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene is as follows: In a 10 L three-necked reaction flask, a mechanical stirring device was installed, and a thermometer was inserted at -0 °C~100 °C. Into the reaction flask, 904 g (1.5 mol) of 4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno-[1,2-b:5,6-b']dithiophene, 2 L of dichloromethane and 500 mL of N,N-dimethylformamide were added, and stirring was started at a speed of 260 rpm. The outer wall of the reaction flask was wrapped with tin foil to make the bottle in a light-proof environment. A total of 570 g (3.2 mol) of N-bromosuccinimide was slowly added to the reaction flask in 5 portions through an addition funnel, and 500 mL of dichloromethane was added to rinse the addition funnel and the wall of the reaction flask, and stirring was continued. The reaction was monitored every 1 hour by thin layer chromatography, and petroleum ether:dichloromethane = 1:1 was used as the developing agent. After 6 hours, it was found that there was no raw material left. 2 L of water was added to the reaction flask and stirring was continued for 10 minutes, and then the phases were separated after standing. After the water phase was discharged, 2 L of water was added and stirred to separate the phases twice, and the remaining organic phase was discharged. All the water phases were collected and extracted once with 1 L of petroleum ether, and all the organic phases were collected, 800 g of anhydrous magnesium sulfate was added and stirred for 30 minutes to dry and remove water, and the magnesium sulfate solid was removed by filtration under reduced pressure using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle, the filtrate was collected, and the filtrate was concentrated under reduced pressure using a rotary evaporator. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, and petroleum ether was used as the eluent, and the target compound 2,7-dibromo-4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno-[1,2-b:5,6-b']dithiophene 1050.2 g was obtained by column chromatography with a yield of 92%, and the purity was 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 8

[0038] Example 9 Preparation of 2,7-dibromo-9,9-dioctylfluorene The preparation process of 2,7-dibromo-9,9-dioctylfluorene is as follows: ​In a 10 L four-necked reaction flask, a mechanical stirring device was installed, and a thermometer was inserted to measure the temperature from 0 °C to 100 °C. At room temperature, 1240.0 g (3.8 mol) of 2,7-dibromofluorene, 720.0 g (18.0 mol) of sodium hydroxide, and 4 L of dimethyl sulfoxide were added to the reaction flask, and the stirring was started at a speed of 260 rpm. While keeping the temperature in the reaction flask below 30 °C, 2220.0 g (11.5 mol) of 1-bromooctane was slowly added to the reaction flask in multiple portions through an addition funnel, and 500 mL of dimethyl sulfoxide was added to rinse the addition funnel and the wall of the reaction flask, and the stirring was continued. The reaction was monitored by thin layer chromatography every 30 minutes using petroleum ether as the developing agent, and it was found that no starting material and reaction intermediates remained after 5 hours. The filter cake was collected by vacuum filtration using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle, and the filter cake was washed with 1 L of water for three times. A chromatography column with a diameter of 15 cm was taken, and 200 mesh silica gel with an effective height of 50 cm was used as the packing material, and petroleum ether was used as the eluent. The target compound 2,7-dibromo-9,9-dioctylfluorene was obtained by column chromatography with a yield of 90%, and the product was a light yellow solid with a purity of 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 9 .

[0039] Example 10 Preparation of 1,3-bis(5-bromothiophenyl)-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione The preparation process of 1,3-bis(5-bromothiophenyl)-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione is as follows: In a 20 L three-necked reaction flask, a mechanical stirring device was installed, and a thermometer was inserted to -10-80 °C. 1153.3 g (1.9 mol) of 5,7-bis(thiophen-2-yl)-1,3-bis(2- ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione, 5 L of tetrahydrofuran and 2 L of N,N-dimethylformamide were added to the reaction flask, and stirring was started at a speed of 260 rpm. The outer wall of the reaction flask was wrapped with tin paper to make the inside of the flask in a light-proof environment. A total of 743.6 g (4.18 mol) of N-bromosuccinimide was slowly added to the reaction flask in 5 portions through an addition funnel, and 500 mL of N,N-dimethylformamide was added to rinse the addition funnel and the wall of the reaction flask, and stirring was continued. The reaction was monitored by thin layer chromatography every 1 hour, using petroleum ether: dichloromethane = 3:1 as the developing agent. After 6 hours, it was found that there was no raw material left. 2 L of water and 3 L of petroleum ether were added to the reaction flask, and stirring was continued for 10 minutes, and the phases were separated after standing; the water phase was discharged, and 2 L of water was added to stir and separate the phases twice, and the remaining organic phase was discharged, 800 g of anhydrous magnesium sulfate was added to stir for 30 minutes to dry and remove water, and the magnesium sulfate solid was removed by filtration under reduced pressure using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle, the filtrate was collected, and the filtrate was concentrated under reduced pressure using a rotary evaporator. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, and petroleum ether was used as the eluent, and the target compound 1,3-bis(5-bromothiophenyl)-5,7-bis(2- ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione was obtained by column chromatography with a yield of 92%, 1336.8 g, and a purity of 98% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 10 .

[0040] Example 11 Preparation of 3-chloro-2-(2-ethylhexyl)thiophene The preparation process of 3-chloro-2-(2-ethylhexyl)thiophene is as follows: In a 20 L four-necked reaction flask, the flask was placed in a cold bath with ethanol as medium (room temperature), a mechanical stirring device was installed, and a T-shaped stirring paddle was used. A thermometer was inserted into the side neck of the four-necked flask, and the temperature was -100°C to 80°C. The flask was ensured to be in a dry environment. 5 L of tetrahydrofuran was poured in, the stirring was started, the speed was 260 rpm, and 1185.8 g (10.0 mol) of 3-chlorothiophene was added at room temperature. A high-purity nitrogen cylinder was used to blow nitrogen into the reaction flask for ten minutes as a protection condition, and a balloon was connected to ensure that the system was in a nitrogen atmosphere with positive pressure. Liquid nitrogen was added to the cold bath device in batches, and the temperature in the reaction flask was cooled to below -78°C through the liquid nitrogen-ethanol cold bath system. The temperature change in the reaction flask was observed at all times to ensure that the temperature in the reaction flask did not exceed -78°C. 4.2 L (10.5 mol) of 2.5 M n-butyllithium tetrahydrofuran solution was slowly added dropwise. The addition rate was controlled and the temperature change was observed at all times to ensure that the temperature did not exceed -40°C. It took about 3 hours to add the n-butyllithium tetrahydrofuran solution. After the n-butyllithium tetrahydrofuran solution was added, the temperature of the reaction system was maintained at -30°C to 0°C, and the reaction was carried out for three hours. The temperature in the reaction flask was then returned to room temperature naturally, and the stirring was continued at room temperature for 3 hours. Liquid nitrogen was added to the cold bath device to make the temperature in the reaction flask below -78°C, and 2112 g (11.0 mol) of bromoiso-octane was slowly added dropwise. The addition rate was controlled and the temperature change was observed, and the temperature in the system was ensured to be not higher than -40°C during the addition. After the addition of bromoiso-octane was completed, the temperature was maintained for 2 hours, and the temperature was slowly returned to room temperature in the cold bath and stirred overnight (stirring for 12 hours). 5 L of water was slowly added and stirred for 30 minutes, and then the phases were separated. The upper organic phase was collected, and the aqueous phase was extracted once with 3 L of dichloromethane. The organic phases were combined, 600 g of anhydrous magnesium sulfate was added and stirred for half an hour, and then the magnesium sulfate solid was removed by filtration under reduced pressure using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle. The filtrate was collected and concentrated under reduced pressure using a rotary evaporator. The target product 1938.6 g was obtained in a crude yield of 84%, with a yellow liquid appearance and a purity of 98% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 11

[0041] Example 12 Preparation of 2,7-dibromo-9,9-dihexylfluorene The preparation process of 2,7-dibromo-9,9-dihexylfluorene is as follows: ​In a 10 L four-necked reaction flask, a mechanical stirring device was installed, and a thermometer was inserted to -10-80 ℃. At room temperature, 972.03 g (3 mol) of 2,7-dibromofluorene, 720.0 g (18.0 mol) of sodium hydroxide and 4 L of dimethyl sulfoxide were added to the reaction flask, and the stirring was started at a speed of 260 rpm. After 30 minutes of stirring, 1485.63 g (9.0 mol) of 1-bromohexane was slowly added to the reaction flask in multiple portions through an addition funnel, and 1 L of dimethyl sulfoxide was added to rinse the addition funnel and the wall of the reaction flask, and the stirring was continued. The reaction was monitored by thin layer chromatography every 30 minutes, using petroleum ether as the developing agent, and it was found that no raw material remained after 5 hours. A 15 cm diameter ceramic Buchner funnel and a 10 L suction filter bottle were used to directly suction filter the reaction system, and the filter cake was repeatedly washed with 1 L of water to obtain a brown solid, which was dissolved in petroleum ether, 300 g of anhydrous magnesium sulfate was added, and the dry petroleum ether solution was obtained by suction filtration. A chromatography column with a diameter of 15 cm was taken, 200 mesh silica gel with an effective height of 50 cm was used as the filling material, and the solution obtained by suction filtration was directly loaded for preliminary purification by column chromatography. The target compound 2,7-dibromo-9,9-dihexylfluorene was obtained in a yield of 95%, and the purity was 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 12 .

[0042] Example 13 Preparation of 1,3-dibromo-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c'-]dithiophene-4,8-dione The preparation process of 1,3-dibromo-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c'-]dithiophene-4,8-dione is as follows: In a 20 L four-necked reaction flask, a mechanical stirring device was installed, a thermometer was inserted at -10-80 °C, a constant pressure dropping funnel was installed, and the reaction flask was placed in a constant temperature bath. The constant temperature bath circulating tank was opened and the circulating temperature was set to -10 °C. 3394.27 g (11.0 mol) of 2,5-bis(2-ethylhexyl) thiophene, 3668.5 g (10.0 mol) of 2,5-dibromo thiophene-3,4-dicarbonyl chloride and 5 L of dichloromethane were added to the reaction flask, and the stirring was started at a speed of 260 rpm. After 10 minutes of sufficient stirring while keeping the temperature in the reaction flask at no higher than 0 °C, a total of 2666 g (20.0 mol) of anhydrous aluminum chloride powder was slowly added to the reaction flask in multiple portions through the addition funnel, and 1 L of dichloromethane was added to rinse the addition funnel and the wall of the reaction flask, and the stirring was continued. The reaction was monitored every 30 minutes by thin layer chromatography with petroleum ether: dichloromethane = 2:1 as the developing agent. After 2 hours, the refrigeration switch of the constant temperature bath circulating tank was turned off, and the reaction system was naturally warmed to room temperature. After 5 hours, no raw material was left. 1 L of 1 M dilute hydrochloric acid was added to the reaction flask, and the stirring was continued for 10 minutes, and then the phases were separated after standing. The organic phase was discharged, and 2 L of chloroform was added to the reaction flask for stirring and phase separation twice, and then the organic phases were combined. 1000 g of anhydrous magnesium sulfate was added for stirring for 30 minutes to dry and remove water. The magnesium sulfate solid was removed by filtration under reduced pressure using a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle, and the filtrate was collected and concentrated under reduced pressure using a rotary evaporator. A chromatography column with a diameter of 20 cm was taken, and 80 cm of 200 mesh silica gel was used as the filling material, and petroleum ether was used as the eluent. The target compound 1,3-dibromo-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c'-]dithiophene-4,8-dione was obtained by column chromatography with a yield of 30.3%, and the purity was 99% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is shown in Figure 13 .

[0043] Example 14 2,5-dibromo-3-hexylthiophene The preparation process of 2,5-dibromo-3-hexylthiophene is as follows: In a 10 L four-necked reaction flask, a mechanical stirring device was installed, a thermometer was inserted to -10~80 ℃, a condensing device was installed, and the reaction flask was placed in a constant temperature bath. Open the constant temperature bath circulating tank and set the circulating temperature to 0 ℃. Add 841.5 g (5 mol) of 3-hexylthiophene, 2 L of chloroform and 1 L of glacial acetic acid to the reaction flask, start stirring at 260 rpm. While keeping the temperature in the reaction flask below 10 ℃, after stirring for 10 minutes, slowly add a total of 4448.75 g (25 mol) of N-bromosuccinimide to the reaction flask in 5 portions through a funnel, then add 500 mL of chloroform to rinse the funnel and the wall of the reaction flask, and stir for 30 minutes. Open the condensing device and the cooling machine, set the circulating temperature of the constant temperature bath to 65 ℃, control the temperature of the system in the reaction flask to be above 50 ℃, and continue stirring. Monitor the reaction every 30 minutes by thin layer chromatography using petroleum ether: dichloromethane = 1:1 as the developing agent. After 5 hours, no starting material is found, and the heating switch of the constant temperature bath is turned off. After the reaction flask is naturally cooled to room temperature, a 15 cm diameter ceramic Buchner funnel and a 20 L suction filter bottle are used to reduce pressure filtration, and the filter cake is rinsed with 2 L of water several times to obtain a yellow solid. Take a chromatography column with a diameter of 15 cm, use 50 cm of 200 mesh silica gel as the filling material, and use petroleum ether as the eluent to purify the target compound 2,5-dibromo-3-hexylthiophene 1549.0 g by column chromatography with a yield of 95%, and the purity is 98% (see nuclear magnetic resonance hydrogen spectrum, carbon spectrum), and the corresponding spectrum is as shown in Figure 14

[0044] Example 15 Preparation of 2-bromothiophene-3-carboxylic acid The preparation process of 2-bromothiophene-3-carboxylic acid is as follows: ​In a 5 L three-necked reaction flask, install a mechanical stirring device, insert a thermometer with a range of 0-200 ℃, install a constant pressure dropping funnel, and place the reaction flask in an ice water bath. At room temperature, add 719.93 g (7.2 mol) of chromium trioxide and 850 mL of water, start stirring at a speed of 260 rpm, and make sure that the chromium trioxide is fully dissolved. Add 800 mL of concentrated sulfuric acid to the constant pressure dropping funnel, and under the condition that the temperature in the flask is not higher than 20 ℃, open the switch of the constant pressure dropping funnel, slowly add the concentrated sulfuric acid to the reaction flask, and control the temperature in the reaction flask to be not higher than 30 ℃ during the dropping process. After the dropping is completed, stir for 10 hours, and obtain the Jones reagent for standby use. In a 20 L three-necked reaction flask, install a mechanical stirring device, insert a thermometer with a range of 0-200 ℃, install a constant pressure dropping funnel, and place the reaction flask in an ice water bath. At room temperature, add 1158.06 g (6 mol) of 2-bromothiophene-3-methanol and 5 L of acetone, start stirring at a speed of 260 rpm. Add the Jones reagent prepared previously to the constant pressure dropping funnel, and under the condition that the temperature in the flask is not higher than 20 ℃, open the switch of the constant pressure dropping funnel, slowly add the Jones reagent to the reaction flask, and control the temperature in the reaction flask to be not higher than 30 ℃ during the dropping process. After the dropping is completed, continue stirring. Monitor the reaction every 30 minutes by using thin layer chromatography, use dichloromethane: petroleum ether = 5:1 as the developing agent, and stop the reaction after 5 hours when no raw material is left. Add 500 mL of isopropyl alcohol to the constant pressure dropping funnel, open the switch of the constant pressure dropping funnel, and slowly add the isopropyl alcohol to the reaction flask. After the dropping is completed, continue stirring. After stirring for 30 minutes, add 5 L of water to the reaction flask, stir for 20 minutes, and separate the phases after standing. Take out the lower aqueous phase, add 5 L of water again, and separate the phases by stirring repeatedly twice, and collect the upper organic phase. Add 800 g of anhydrous magnesium sulfate, stir for 30 minutes, dry and remove water, use a 15 cm diameter ceramic Buchner funnel and a 10 L filter bottle to filter the magnesium sulfate solid under reduced pressure, collect the filtrate, and use a rotary evaporator to concentrate the filtrate under reduced pressure, and obtain a brownish gray solid. Take a chromatography column with a diameter of 15 cm, use 50 cm high 200 mesh silica gel as the filling material, and use dichloromethane as the eluent, and preliminarily purify by column chromatography to obtain the target product 2-bromothiophene-3-carboxylic acid 1018.63 g with a crude yield of 82%, and the purity is 99% (see the nuclear magnetic resonance hydrogen spectrum and carbon spectrum), and the corresponding spectrum is shown in Figure 15

[0045] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical range disclosed by the present application can be easily thought by those skilled in the art, and should be covered within the protection scope of the present application.​

Claims

1. A method for preparing organic photoelectric halogenated intermediate reagents at the kilogram scale, characterized in that, Includes the following steps: Thiophene derivatives and organic solvents are stirred evenly, and then brominating agents are added in batches to carry out bromination reactions. After the reaction is completed, purification is performed to finally prepare the target product, namely the organic photoelectric halogenated intermediate reagent.

2. The method for preparing an organic photoelectric halogenated intermediate reagent at the kilogram scale according to claim 1, characterized in that, The thiophene derivatives are selected from any one of 2,2'-bithiophene, 4,4,9,9-tetra(4-hexylphenyl)-indargenop[1,2-b:5,6-b']dithiophene, 4,4,9,9-tetradodecyl-4,9-dihydro-s-indargenop[1,2-b:5,6-b']dithiophene, 4,4,9,9-tetraoctyl-4,9-dihydro-s-indargenop-[1,2-b:5,6-b']dithiophene, 5,7-bis(thiophen-2-yl)-1,3-bis(2-ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,6-dione, and 3-hexylthiophene.

3. The method for preparing an organic photoelectric halogenated intermediate reagent at the kilogram scale according to claim 1, characterized in that, The organic solvent is selected from at least one of chloroform, tetrahydrofuran, dichloromethane, N,N-dimethylformamide, petroleum ether, ethyl acetate, or glacial acetic acid.

4. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 3, characterized in that, The ratio of the thiophene derivative to the organic solvent is 1.2-6 mol: 1-12 L.

5. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 1, characterized in that, The brominating agent is N-bromosuccinimide.

6. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 5, characterized in that, The molar ratio of N-bromosuccinimide to thiophene derivatives is 2.5-25:1.2-6.

7. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 1, characterized in that, The conditions for the bromination reaction are: reaction temperature of -10~50℃ and reaction time of 5-20h.

8. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 1, characterized in that, The purification process is as follows: The reaction solution was filtered under reduced pressure. After phase separation, the organic phase of the filtrate was washed with water and evaporated to dryness. The filter cake was washed with water. The filtrate and filter cake were combined to obtain a solid, which was then purified by column chromatography to obtain the target product.

9. The method for preparing an organic photoelectric halogenated intermediate reagent on a kilogram-scale according to claim 8, characterized in that, The eluent used in the column chromatography method is dichloromethane or petroleum ether.

10. An organic photoelectro-halogenated intermediate reagent, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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