Clean synthesis process of blue fluorescent material

Abstract

The invention belongs to the field of chemical synthesis, and particularly relates to a clean synthesis process of a blue fluorescent material, which comprises the following steps: S10, boric acid esterification reaction and C-Br bond excitation and activation: adding a material into an open water environment reaction system, and treating by adopting an ultrasonic device, so that boric acid esterification and C-Br bond excitation and activation of the material are completed, and a reaction product is obtained; obtaining an initial mixture A; s20, catalytic coupling reaction: transferring the initial mixture into a closed reaction system, adding a catalytic medium into the closed reaction system, and maintaining the closed reaction system in an inert gas environment, so that the initial mixture A is subjected to coupling reaction to obtain a target mixture B containing a blue fluorescent material; and S30, separation and purification: separating and purifying the target mixture B to obtain the blue fluorescent material with the purity of more than 99.5%. The clean synthesis process disclosed by the invention has the advantages of high efficiency, low cost, clean production and the like, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis, specifically relating to a clean synthesis process for a blue fluorescent material. Background Technology

[0002] 4,7-Bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole (CAS No.: 1555684-46-2), also known as 4,7-bis(4-(tert-butyl)phenyl)-2-isobutyl-2H-benzo[d][1,2,3]triazole, is a blue organic fluorescent compound with the following structural formula: .

[0003] Literature reports that 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole, as an organic fluorescent compound material, can be applied to wavelength conversion encapsulation materials, wavelength conversion encapsulation material layers, solar cell modules, etc. (such as patents CN105684163A and JP6026683B2 applied for by Nitto Denko Corporation).

[0004] Although it has broad application prospects, the synthesis process of 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole is relatively complex and the synthesis route is long, resulting in a long synthesis time, as shown in Chinese patent CN106008375A. In addition, the solvents used in the synthesis process cannot be fully recovered, which is very environmentally unfriendly. This limits the application scope of this organic fluorescent compound material at present, and may affect the research and development of related industries. Summary of the Invention

[0005] The purpose of this invention is to provide a clean synthesis process for blue fluorescent materials. This method has advantages such as high efficiency, low cost, and clean production, and has broad application prospects in industries such as photovoltaics and liquid crystal displays.

[0006] This invention provides a clean synthesis process for blue fluorescent materials, comprising the following steps: S10, Ultrasonic-assisted borate esterification reaction and C-Br bond activation: In an open aquatic reaction system, the material is added and treated with an ultrasonic device to complete the borate esterification and C-Br bond activation, resulting in an initial mixture A. S20, sodium carbonate and palladium catalyst synergistically achieve efficient coupling reaction: Catalytic coupling reaction: Add catalytic medium to the open water environment reaction system in S10, seal the open water environment reaction system, evacuate, inject inert gas, so that the initial mixture A completes the coupling reaction, and obtain the target mixture B containing blue fluorescent material; S30. Post-processing: The target mixture B is separated and purified to obtain a blue fluorescent material with a purity greater than 99.5%.

[0007] Furthermore, in S10, the materials added to the open aquatic reaction system include, by molar parts, 4,7-dibromo-2H-2-isobutylbenzotriazole A, 4-tert-butylphenylboronic acid B, and carbonate; wherein the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to 4-tert-butylphenylboronic acid B is 1:1 to 10, and the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to carbonate is 1:1 to 10.

[0008] Furthermore, in S10, the ultrasonic device is an ultrasonic device with a water bath heating function. During processing, the frequency of the ultrasonic wave is 28 kHz-40 kHz, the water bath heating temperature is 36℃-85℃, and the processing time using the ultrasonic device is 5 min-15 min.

[0009] Furthermore, in S20, the catalytic medium is an ethanol solution of a palladium catalyst.

[0010] Furthermore, in S20, the catalytic coupling reaction time is not less than 25 min, and the temperature of the catalytic coupling reaction is 70℃-90℃.

[0011] Furthermore, S30 includes: S31, Water quenching: After S20, the target mixture B containing blue fluorescent material is added to water and stirred for 5 min-20 min to quench it. S32. Extraction and complete recovery of solvent: The target mixture B is extracted using an extractant to obtain the extract phase and the residual phase. S33. Functional filtration separation to obtain high-purity target product: The extraction phase in S32 is purified to obtain a blue fluorescent material with a purity greater than 99.5%.

[0012] Furthermore, in S32, the remaining phase after extraction is dehydrated by anhydrous magnesium sulfate and then distilled and condensed to recover ethanol.

[0013] Furthermore, S33 includes the distillation of the extract phase and the purification of the target product.

[0014] Furthermore, the distillation of the extract phase includes distilling and condensing the extract phase in S32 to recover the extractant used in S32 and obtaining a dry distillate, which is a crude target product containing impurities; the dry distillate is added to a Buchner funnel lined with silica gel, eluted with petroleum ether for decolorization, and then eluted with cyclohexane-dichloromethane; the resulting liquid or solid-liquid mixture is distilled to remove or recover the solvent, yielding a white solid powder. The volume ratio of cyclohexane to dichloromethane is 3:1; and / or, the solvent used in the recrystallization step is ethanol.

[0015] Furthermore, the purification of the target product includes recrystallizing the white solid powder with ethanol, and obtaining transparent crystals after recrystallization, which is a blue fluorescent material with a purity greater than 99.5%.

[0016] The beneficial effects of this invention mainly include the following aspects: This invention employs a one-pot process, eliminating the need to separate intermediate products and simplifying the process operation. It uses ethanol as a solvent, which, aside from necessary consumption, can be completely recycled and reused, resulting in low cost. Furthermore, ethanol is non-toxic and environmentally friendly, enabling clean production of blue fluorescent materials. This invention possesses significant competitive advantages, is suitable for industrial production, and allows for clean and circular production, showing broad application prospects in industries such as photovoltaics and liquid crystal displays. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of a clean synthesis process for a blue fluorescent material according to the present invention.

[0018] Figure 2 The blue fluorescent material obtained in this invention 1 H NMR spectrum.

[0019] Figure 3 The blue fluorescent material obtained in this invention 13 C NMR spectrum.

[0020] Figure 4 This is the LCMS image of the blue fluorescent material obtained in this invention.

[0021] Figure 5 This is a physical image of the blue fluorescent material obtained in this invention.

[0022] Figure 6 This is a diagram showing the blue fluorescent material obtained in this invention emitting blue light under ultraviolet light irradiation. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention.

[0024] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0025] This invention provides a clean synthesis process for blue fluorescent materials, comprising the following steps: S10, Ultrasonic-assisted borate esterification reaction and C-Br bond activation: In an open aquatic reaction system, materials are added and treated with an ultrasonic device to complete the borate esterification and C-Br bond activation, resulting in an initial mixture A; the materials include carbonates, such as sodium carbonate.

[0026] S20, sodium carbonate and palladium catalyst synergistically achieve efficient coupling reaction: Add catalytic medium to the open water environment reaction system in S10, seal the open water environment reaction system, evacuate, and inject inert gas (preferably nitrogen, argon or helium) so that the initial mixture A completes the coupling reaction to obtain the target mixture B containing blue fluorescent material; it should be noted that sodium carbonate in S20 is one of the materials added in S10.

[0027] S30. Post-processing: The target mixture B is separated and purified to obtain a blue fluorescent material with a purity greater than 99.5%.

[0028] In a specific embodiment, in S10, the materials added to the open aquatic reaction system, by molar parts, include 4,7-dibromo-2H-2-isobutylbenzotriazole A, 4-tert-butylphenylboronic acid B, and carbonate; wherein the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to 4-tert-butylphenylboronic acid B is 1:1 to 10 (e.g., 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:6, 1:7, 1:8, 1:9, etc.), preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to 4-tert-butylphenylboronic acid B is 1:2 to 3, more preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to 4-tert-butylphenylboronic acid B is 1:3; The molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to carbonate is 1:1 to 10 (e.g., 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:6, 1:7, 1:8, 1:9, etc.), wherein the carbonate is an alkali metal carbonate or an alkaline earth metal carbonate; preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to carbonate is 1:2 to 6; more preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to carbonate is 1:4; preferably, the carbonate is an alkali metal carbonate or an alkaline earth metal carbonate; more preferably, the carbonate is sodium carbonate or potassium carbonate.

[0029] The open aquatic reaction system is formed by adding a certain amount of water to a Schlenk tube. The amount of water added is 1 to 10 ml (e.g., 2 ml, 3 ml, 4 ml, 5 ml, 6 ml, 7 ml, 8 ml, 9 ml, etc.) per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A. Preferably, the amount of water added is 1 to 5 ml per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A.

[0030] In the S20 catalytic coupling reaction, the closed reaction system is achieved by sealing the Schlenk tube, evacuating it, protecting it with nitrogen, and heating and stirring it at 50℃-90℃ (preferably 75℃-85℃) under a nitrogen atmosphere for 30 min (heating and stirring can be done by magnetic stirring and / or water bath heating, etc.) to complete the catalytic coupling reaction.

[0031] In a specific embodiment, in S10, the ultrasonic device is an ultrasonic device with a water bath heating function. During processing, the frequency of the ultrasonic wave is 28 kHz-40 kHz, the water bath heating temperature is 36℃-85℃, and the processing time using the ultrasonic device is 5 min-15 min. Specifically, the ultrasonic frequencies are 28 kHz, 29 kHz, 30 kHz, 31 kHz, 32 kHz, 33 kHz, 34 kHz, 35 kHz, 36 kHz, 37 kHz, 38 kHz, 39 kHz, etc., and the processing times using the ultrasonic device are 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, etc.

[0032] In a specific embodiment, in S20, the catalytic medium is an ethanol solution of a palladium catalyst. The amount of palladium catalyst used per gram of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 0.1% to 1% g (e.g., 0.2% g, 0.3% g, 0.4% g, 0.5% g, 0.6% g, 0.7% g, 0.8% g, etc.); the amount of ethanol used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 1 to 10 ml (e.g., 2 ml, 3 ml, 4 ml, 5 ml, 6 ml, 7 ml, 8 ml, etc.); and the palladium catalyst is dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II).

[0033] Preferably, the amount of palladium catalyst used per gram of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 0.3% to 0.5% g; and / or, the amount of ethanol used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 1 to 5 ml.

[0034] In a specific embodiment, in S20, the catalytic coupling reaction time is not less than 25 min, and the temperature of the catalytic coupling reaction is 70℃-90℃.

[0035] In one specific embodiment, S30 includes: S31. Water quenching: After S20, the target mixture B containing blue fluorescent material is added to water and stirred for 5-20 minutes to quench it.

[0036] S32. Extraction and complete solvent recovery: The target mixture B is extracted using an extractant (preferably ethyl acetate) to obtain the extract phase and the residual extract phase. It should be noted that complete solvent recovery means that, apart from unavoidable losses, all solvents such as ethanol can be recovered.

[0037] S33. Functional filtration separation to obtain high-purity target product: The extraction phase in S32 is purified to obtain a blue fluorescent material with a purity greater than 99.5%.

[0038] In one specific embodiment, in S32, the remaining phase after extraction is dehydrated by anhydrous magnesium sulfate and then distilled and condensed to recover ethanol.

[0039] In one specific embodiment, S33 includes distillation of the extract phase and purification of the target product.

[0040] In one specific embodiment, the distillation of the extract phase includes distilling and condensing the extract phase in S32 to recover the extractant used in S32 and obtaining a dry distillate, which is a crude target product containing impurities; the dry distillate is added to a Buchner funnel lined with silica gel, washed with petroleum ether for decolorization, and then washed with cyclohexane-dichloromethane. The resulting liquid or solid-liquid mixture is distilled to remove or recover the solvent, yielding a white solid powder; it is understood that removing or recovering the solvent here refers to removing the solvent or recovering pure petroleum ether, cyclohexane, and dichloromethane by distillation.

[0041] The volume ratio of cyclohexane to dichloromethane is 3:1; and / or, the solvent used in the recrystallization step is ethanol.

[0042] In one specific embodiment, the purification of the target product includes recrystallizing a white solid powder with ethanol to obtain transparent crystals, which are blue fluorescent materials with a purity greater than 99.5%.

[0043] Specifically, the extract phase was distilled and condensed to recover ethyl acetate. The distillate was a crude product containing impurities. Silica gel powder was added to a Buchner funnel, and then the crude product was spread evenly on top. It was first washed with pure petroleum ether to remove residual impurities containing colored catalyst, and then washed rapidly with cyclohexane / dichloromethane in a 3:1 ratio to flush out the product. The solvent was recovered by distillation and condensation. The large difference in boiling points between cyclohexane and dichloromethane facilitated distillation separation, yielding a blue fluorescent material, 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzo[d][1,2,3]triazole, a white solid powder. The product obtained by direct distillation was a white solid, which, after recrystallization from ethanol, yielded transparent crystals.

[0044] Example 1 The clean synthesis process for blue fluorescent materials provided by this invention includes the following steps: (1) Synthetic steps: 4,7-dibromo-2H-2-isobutylbenzotriazole A (CAS No.: 1428418-59-0; 3.33 g, about 10 mmol), 4-tert-butylphenylboronic acid B (CAS No.: 123324-71-0; 4.14 g, about 23 mmol), sodium carbonate (4.16 g, about 40 mmol), and water (20 mL) were added to a Schlenk line glass tube, placed in an ultrasonic water bath, heated to 78 °C, and sonicated for 10 min (frequency 36 kHz) to complete the borate esterification reaction and activate the C-Br bond; then, it was transferred to a magnetically stirred constant temperature heating pot, and dichloroditert-butyl-(4-dimethylaminophenyl)phosphine palladium(II) (CAS No.: 887919-35-9; 14.2 mg) in ethanol (30 mL) was added to the Schlenk line glass tube. The solution (mL) was vacuumed, protected with nitrogen, heated to 82°C, and stirred for 30 minutes to complete the coupling reaction.

[0045] (2) Post-processing steps: Cool to room temperature, add water (5 mL) to quench the reaction for 10 min, add ethyl acetate (15 mL) for extraction (it should be noted that the amount of ethyl acetate can be adjusted according to the actual situation), let stand, separate the liquid, take the ethyl acetate phase (extraction phase), distill to recover ethyl acetate, and obtain crude product, and recover 14.9 mL of ethyl acetate; take the extraction residue phase (extraction residue phase refers to substances other than the extraction phase) for distillation, and recover ethanol, and obtain 29.9 mL of ethanol.

[0046] The crude product was added to a Buchner funnel lined with silica gel and washed with petroleum ether to remove colored residual impurities. Then, it was rapidly rinsed with cyclohexane-dichloromethane (cyclohexane to dichloromethane volume ratio 3:1). The solvent (cyclohexane-dichloromethane) was removed by distillation, yielding a white solid powder (4.1 g), which is 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole, with a yield of 92.5%. It should be noted that the yield was obtained by dividing the actual yield by the theoretical yield. Further recrystallization with ethanol was performed. In this process, petroleum ether, cyclohexane, and dichloromethane were recovered by distillation and condensation. The recovery rates of petroleum ether, cyclohexane, and dichloromethane were calculated to be greater than 99.2%.

[0047] The prepared blue fluorescent material is 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole, which... 1 H NMR, 13 The data for 12C NMR and LCMS (ESI-MS) are as follows: 1 H NMR (600 MHz, Chloroform- d ): δ 8.05 (d, J = 6.0 Hz, 4H, 4- t -BuC6H4),7.65 (s, 2H, benzotriazole), 7.59 (d, J = 8.4 Hz, 4H,4- t -BuC6H4), 4.64 (d, J = 7.2Hz, 2H, i -Bu), 2.65 (m, 6.8 Hz, 1H, i -Bu), 1.43 (s, 18H, 2 t -Bu), 1.06 (d, J = 6.6Hz, 6H, i- Bu); such as Figure 2 As shown.

[0048] 13 C NMR (151 MHz, Chloroform-d): δ 150.82, 143.57, 134.66, 129.88,128.24, 125.71, 124.42, 63.73, 34.71, 31.42, 29.94, 20.07; e.g. Figure 3 As shown.

[0049] LCMS (ESI-MS) m / z: Theoretically, C 30 H 37 N3 + [M+H] + : 440.31; Measured value 440.7; If Figure 4 As shown.

[0050] Through testing, the 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole obtained in this invention, as shown in the following figures... Figure 5 As shown, it emits blue light under 365 nm ultraviolet light irradiation, such as Figure 6 As shown. (Attached) Figure 5 and attached Figure 6 The comparison shows that the 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole obtained in this invention emits a significant blue light before and after ultraviolet irradiation.

[0051] After testing, the purity of the 4,7-bis(4-tert-butylphenyl)-2-isobutyl-2H-benzotriazole, i.e., the blue fluorescent material obtained in this invention, is 99.8%.

[0052] Research and experiments have shown that: The molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A and 4-tert-butylphenylboronic acid B can be selected in the range of 1:1 to 10; preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A and 4-tert-butylphenylboronic acid B is 1:2 to 3, for example, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, etc.

[0053] The molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to sodium carbonate can be selected in the range of 1:1 to 10; preferably, the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to sodium carbonate is 1:2 to 6, for example, 1:3, 1:4, 1:5, etc.

[0054] The amount of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II) corresponding to each gram of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 0.1% to 1% per gram; preferably, the amount of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II) corresponding to each gram of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 0.3% to 0.5% per gram.

[0055] The amount of water used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A can be selected from 1 to 10 milliliters; preferably, the amount of water used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 1 to 5 milliliters, for example, 2 milliliters, 3 milliliters, 4 milliliters, etc.

[0056] The amount of ethanol used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A can be selected from 1 to 10 milliliters; preferably, the amount of ethanol used per millimole of 4,7-dibromo-2H-2-isobutylbenzotriazole A is 1 to 5 milliliters, for example, 2 milliliters, 3 milliliters, 4 milliliters, etc.

[0057] The reaction temperature of 4,7-dibromo-2H-2-isobutylbenzotriazole A and 4-tert-butylphenylboronic acid B can be selected within the range of 36 °C to 85 °C; preferably, the reaction temperature of 4,7-dibromo-2H-2-isobutylbenzotriazole A and 4-tert-butylphenylboronic acid B is 75 °C to 82 °C, for example, 76 °C, 77 °C, 78 °C, 79 °C, 80 °C, etc.

[0058] Comparative Example 1 Comparative Example 1 served as the control group for Example 1. The ultrasonic water bath in step S10 of Example 1 was removed, while the remaining method steps remained the same as in Example 1. After comparison, the synthesis time increased by 1 time compared to Example 1, and the yield decreased to 65.3%.

[0059] Comparative Example 2 Comparative Example 2 served as the control group for Example 1. In step S20, the reaction system was kept in an open aquatic environment, meaning the reaction system was not sealed and the reaction was carried out in an air environment. The remaining steps were the same as in Example 1. After testing, the yield was reduced to 35.6%, and the purity of the obtained blue fluorescent material was only 53.6%.

[0060] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A clean synthesis process for a blue fluorescent material, characterized in that, Includes the following steps: S10, Ultrasonic-assisted borate esterification reaction and C-Br bond activation: In an open aquatic reaction system, the material is added and treated with an ultrasonic device to complete the borate esterification and C-Br bond activation, resulting in an initial mixture A. S20, sodium carbonate and palladium catalyst synergistically achieve efficient coupling reaction: Add catalytic medium to the open water environment reaction system in S10, seal the open water environment reaction system, evacuate, inject inert gas, so that the initial mixture A completes the coupling reaction, and obtain the target mixture B containing blue fluorescent material. S30. Post-processing: The target mixture B is separated and purified to obtain a blue fluorescent material with a purity greater than 99.5%.

2. The clean synthesis process of a blue fluorescent material according to claim 1, characterized in that, In S10, the materials added to the open aquatic reaction system include, by molar parts, 4,7-dibromo-2H-2-isobutylbenzotriazole A, 4-tert-butylphenylboronic acid B, and carbonate; wherein the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to 4-tert-butylphenylboronic acid B is 1:1 to 10, and the molar ratio of 4,7-dibromo-2H-2-isobutylbenzotriazole A to carbonate is 1:1 to 10.

3. A clean synthesis process for a blue fluorescent material according to claim 1 or 2, characterized in that, In S10, the ultrasonic device is an ultrasonic device with a water bath heating function. During processing, the frequency of the ultrasonic wave is 28kHz-40kHz, the water bath heating temperature is 36℃-85℃, and the processing time using the ultrasonic device is 5 min-15 min.

4. The clean synthesis process of a blue fluorescent material according to claim 1, characterized in that, In S20, the catalytic medium is an ethanol solution of a palladium catalyst.

5. The clean synthesis process of a blue fluorescent material according to claim 4, characterized in that, In S20, the catalytic coupling reaction time is not less than 25 min, and the temperature of the catalytic coupling reaction is 70℃-90℃.

6. The clean synthesis process of a blue fluorescent material according to claim 4, characterized in that, S30 includes: S31, Water quenching: After S20, the target mixture B containing blue fluorescent material is added to water and stirred for 5 min-20 min to quench it. S32. Extraction and complete recovery of solvent: The target mixture B is extracted using an extractant to obtain the extract phase and the residual phase. S33. Functional filtration separation to obtain high-purity target product: The extraction phase in S32 is purified to obtain a blue fluorescent material with a purity greater than 99.5%.

7. The clean synthesis process of a blue fluorescent material according to claim 6, characterized in that, In S32, the remaining phase after extraction is dehydrated by anhydrous magnesium sulfate and then distilled and condensed to recover ethanol.

8. The clean synthesis process of a blue fluorescent material according to claim 6, characterized in that, S33 includes the distillation of the extract phase and the purification of the target product.

9. The clean synthesis process of a blue fluorescent material according to claim 8, characterized in that, The distillation of the extract phase includes distilling and condensing the extract phase in S32 to recover the extractant used in S32 and obtaining a dry distillate, which is a crude target product containing impurities; the dry distillate is added to a Buchner funnel lined with silica gel, washed with petroleum ether for decolorization, and then washed with cyclohexane-dichloromethane. The resulting liquid or solid-liquid mixture is distilled to remove or recover the solvent, yielding a white solid powder. The volume ratio of cyclohexane to dichloromethane is 3:

1.

10. The clean synthesis process of a blue fluorescent material according to claim 9, characterized in that, The purification of the target product involves recrystallizing a white solid powder with ethanol. After recrystallization, transparent crystals are obtained, which are blue fluorescent materials with a purity greater than 99.5%.

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