A fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, its preparation method and applications

Abstract

The present invention belongs to the technical field of fluorescent and sensing materials, and particularly relates to a fluorescent material with a 2-arylbenzofuro[2,3- d pyrimidinone structure, a preparation method thereof, and an application thereof. The fluorescent material provided by the present invention has a structural general formula as #imgabs0#, R1 is a group such as methyl, ethyl or hydrogen, and R2 is a group such as hydrocarbon group, halogen, methyl, morpholinyl, formyl, nitro or alkoxy group. R2 is singly substituted or polysubstituted on the benzene ring. The fluorescent material provided by the present invention has a 2-arylbenzofuro[2,3- d pyrimidinone structure, and its special structure leads to the formation of intermolecular double hydrogen bonds. By adjusting the formation and breakage of hydrogen bonds, the adjustment of the size of the molecular conjugate system can be completed, and the reversible conversion of AIE-ACQ can be realized. The fluorescent material disclosed by the present invention can be used for the identification of latent fingerprints on the surface of articles and the detection of harmful biogenic amines in spoiled food.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent and sensing materials, and particularly relates to a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, a preparation method thereof, and an application thereof. Background Art

[0002] Disclosing the information of this background art section is intended to enhance the understanding of the overall background of the present invention, and it is not necessarily regarded as an admission or an indication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] The fluorescence phenomenon refers to the phenomenon that a material absorbs light energy and enters an excited state after being irradiated by light, and during the process of the excited state returning to the ground state, the energy is released in the form of photons, emitting an outgoing light with a wavelength longer than that of the incident light. Fluorescent materials have been widely used in many fields such as the chemical industry, textile industry, and pharmaceutical industry. Fluorescent labels made of fluorescent materials are widely used in wall switches, emergency evacuation channels, civil air defense projects, etc.; organic electroluminescent devices (ELDs) made of fluorescent materials are widely used in electronic products such as mobile phones and computers; in addition, fluorescent materials are also widely used in the synthesis of fluorescent dyes, fluorescent brighteners, fluorescent coatings, etc. Among them, organic small molecule fluorescent materials have a wide variety of types, diverse structures, and the emission color can be adjusted by introducing unsaturated groups such as double bonds and benzene rings and various chromophores. In recent years, organic small molecule fluorescent materials have made important progress in biomedical research and development and life process research, and have attracted wide attention.

[0004] Organic small molecule fluorescent materials are mainly divided into two categories according to the luminescence mechanism: aggregation-caused quenching (ACQ) type and aggregation-induced emission (AIE) type. Aggregation-caused quenching fluorescent materials often have a large conjugated system and show strong luminescence in dilute solutions, while the luminescence weakens or disappears in concentrated solutions or in the aggregated state; aggregation-induced emission fluorescent materials do not emit light or emit weakly in dilute solutions, while showing strong luminescence in the aggregated state. However, the ACQ phenomenon limits the application of aggregation-caused quenching fluorescent materials in the aggregated state; at the same time, aggregation-induced emission fluorescent materials are not suitable for applications in dilute solution systems either. Summary of the Invention

[0005] In order to solve the disadvantages and deficiencies of the prior art, the first object of the present invention is to provide a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure.

[0006] The second object of the present invention is to provide a method for preparing a fluorescent material having a 2-arylbenzofuro[2,3-d]pyrimidinone structure.

[0007] The third object of the present invention is to provide the application of the above fluorescent material in fingerprint identification and / or detection of bioorganic amines in food.

[0008] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0009] A fluorescent material having a 2-arylbenzofuro[2,3-d]pyrimidinone structure, the general formula of which is shown as follows:

[0010]

[0011] Wherein, in the formula, R1 is a group such as methyl, ethyl or hydrogen; R2 is a group such as hydrocarbon group, halogen, methyl, morpholinyl, formyl, nitro or alkoxy group; wherein, R2 is a single substitution or multiple substitutions on the benzene ring.

[0012] Preferably, the halogen is fluorine, chlorine or bromine, etc.; the alkoxy group is methoxy group, etc.

[0013] Furthermore, double hydrogen bonds can be formed between the molecules of the fluorescent material, as shown in the following formula:

[0014]

[0015] By adjusting the formation and breakage of hydrogen bonds between the molecules of the fluorescent material, the regulation of the size of the molecular conjugate system can be completed, and the fluorescence emission in the solution and solid states can be realized, that is, the reversible conversion of AIE-ACQ can be realized.

[0016] The preparation method of the above fluorescent material having a 2-arylbenzofuro[2,3-d]pyrimidinone structure adopts the following steps, and is prepared by carrying out a condensation reaction between ethyl 2-amino-3-amidobenzofuran-5-carboxylate and a substituted benzaldehyde in the presence of a catalyst and a solvent, and separating and purifying after the reaction. The reaction formula is:

[0017]

[0018] R1 in the formula (I) is a group such as methyl, ethyl or hydrogen; R2 in the formula (II) is a group such as hydrocarbon group, halogen, methyl, morpholinyl, formyl, nitro or alkoxy group; wherein, R2 in the formula (II) is a single substitution or multiple substitutions on the benzene ring.

[0019] Preferably, when R2 in the formula (II) is a single substitution on the benzene ring, the compounds represented by the formula (II) are benzaldehydes such as 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 4-formylbenzaldehyde, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 4-bromobenzaldehyde, 4-methylbenzaldehyde, 4-morpholinobenzaldehyde or 4-nitrobenzaldehyde; when R2 in the formula (II) is a multi-substitution on the benzene ring, the compounds represented by the formula (II) are benzaldehydes such as 2,3,4-trimethoxybenzaldehyde.

[0020] Further, the catalyst is iodine or copper oxide.

[0021] Further, the solvent is anhydrous ethanol, dimethyl sulfoxide, N,N-dimethylformamide or N-methylpyrrolidone, etc.

[0022] Further, the molar ratio of ethyl 2-amino-3-amidobenzofuran-5-carboxylate, substituted benzaldehyde, and catalyst is 1:(1 - 1.2):(0.05 - 0.2).

[0023] Further, the conditions for the condensation reaction are a temperature of 80 - 100 °C and a time of 10 - 6 hours. The preferred conditions are a temperature of 80 °C and a time of 10 hours or a temperature of 100 °C and a time of 6 hours.

[0024] Further, when the substituted benzaldehyde is benzaldehydes such as 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde or 4-formylbenzaldehyde, after the condensation reaction, the method of separation and purification is: removing the catalyst, filtering the solid by suction to obtain the crude product, and recrystallizing to obtain the pure product;

[0025] When the substituted benzaldehyde is benzaldehydes such as 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 4-bromobenzaldehyde, 4-methylbenzaldehyde, 4-morpholinobenzaldehyde, 4-nitrobenzaldehyde or 2,3,4-trimethoxybenzaldehyde, after the condensation reaction, the method of separation and purification is: removing the catalyst, filtering the solid by suction to obtain the crude product, refluxing the crude product under alkaline conditions, adjusting to weakly acidic after the reaction is completed, and filtering and drying the precipitated solid to obtain the pure product.

[0026] An application of the above-mentioned fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure or the 2-arylbenzofuro[2,3-d]pyrimidinone structure fluorescent material prepared by the above-mentioned preparation method.

[0027] The fluorescent material can be used for fingerprint identification and the detection of biogenic amines.

[0028] Advantageous effects: Aiming at the problem that current fluorescence materials based on the ACQ mechanism cannot be used in the aggregated state, while fluorescence materials based on the AIE mechanism cannot be used in solution, the present invention provides a fluorescence material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, a preparation method thereof, and an application thereof. The fluorescence material has a 2-arylbenzofuro[2,3-d]pyrimidinone structure. The special structure in the molecules of this type of fluorescence material leads to the formation of intermolecular double hydrogen bonds. By adjusting the formation and breakage of hydrogen bonds, the size of the molecular conjugate system can be adjusted, and fluorescence emission in both solution and solid states can be achieved, that is, reversible conversion between AIE and ACQ can be realized. The preparation method of the fluorescence material is simple and easy to operate, which is conducive to large-scale preparation. The unique molecular structure enables the fluorescence material to be used for the identification of latent fingerprints on the surface of articles and the detection of harmful biogenic amines in spoiled food. Description of the Drawings

[0029] The attached drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. Hereinafter, the embodiments of the present invention will be described in detail in conjunction with the attached drawings, wherein:

[0030] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material A synthesized in Example 1.

[0031] Figure 2 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material B synthesized in Example 2.

[0032] Figure 3 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material C synthesized in Example 3.

[0033] Figure 4 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material D synthesized in Example 4.

[0034] Figure 5 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material E synthesized in Example 5.

[0035] Figure 6 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material F synthesized in Example 6.

[0036] Figure 7 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material G synthesized in Example 7.

[0037] Figure 8 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material H synthesized in Example 8.

[0038] Figure 9 is the nuclear magnetic resonance hydrogen spectrum of the fluorescence material I synthesized in Example 9.

[0039] Figure 10 1H NMR spectrum of the fluorescent material J synthesized in Example 10.

[0040] Figure 11 Intermolecular hydrogen bond between two molecules in the crystal structure of the fluorescent material A synthesized in Example 1.

[0041] Figure 12 Intermolecular hydrogen bond between two molecules in the crystal structure of the fluorescent material B synthesized in Example 2.

[0042] Figure 13 Fluorescence aggregation-induced quenching test of the fluorescent material A synthesized in Example 1 in solvents.

[0043] Figure 14 Aggregation-induced emission test of the fluorescent material A synthesized in Example 1 in solvents.

[0044] Figure 15 Fluorescence intensity of the fluorescent material A synthesized in Example 1 in different pH buffer solutions.

[0045] Figure 16 Fluorescence test diagrams of the fluorescent material A synthesized in Example 1 in crystal and amorphous forms.

[0046] Figure 17 Example diagram of the application of the fluorescent material A synthesized in Example 1 in fingerprint recognition.

[0047] Figure 18 Example diagram of the application of the fluorescent material A synthesized in Example 1 in putrescine detection.

[0048] Figure 19 Example diagram of the application of the fluorescent material A synthesized in Example 1 in cadaverine detection. Detailed implementation manners

[0049] The specific details of the present invention are further elaborated in the following description for a full understanding of the present invention. The terms used in the description of the present invention are only for explaining the advantages and features of the present invention and are not intended to limit the present invention.

[0050] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meaning as understood by those skilled in the technical field of the present invention. Without special instructions, the drugs or reagents used in the present invention are used according to the product instructions or the conventional usage methods in the relevant field. Now, the technical solutions of the present invention will be further described with reference to the accompanying drawings of the specification and the specific implementation manners.

[0051] Example 1

[0052] A preparation method of a fluorescent material having a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0053] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 2-hydroxybenzaldehyde (0.122 g, 1.0 mmol), and iodine (0.253 g, 1 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of absolute ethanol as the solvent. The above system is refluxed at 80 °C for 10 hours.

[0054] (2) After the reflux reaction is completed and monitored by TLC to be complete, cool the reaction solution to room temperature. Add an excess of 5% aqueous Na2S2O3 solution to the reaction solution to remove the excess iodine. Filter the solid to obtain the crude product. Wash the product with 50% aqueous ethanol solution and recrystallize it from tetrahydrofuran to obtain the pure product.

[0055]

[0056] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 1 shown, and the structure characterization data of the product are as follows: 1 1H NMR (DMSO-d6, 400 MHz) ppm: 12.39 (s, 1H), 8.37 (d, J = 1.72 Hz, 1H), 8.10 (dd, J1 = 7.96 Hz, J2 = 1.56 Hz, 1H), 7.99 (dd, J1 = 8.64 Hz, J2 = 1.80 Hz, 1H), 7.78 (d, J = 8.68 Hz, 1H), 7.42 (m, 1H), 7.01 (d, J = 8.28 Hz, 1H), 6.97 (t, J = 7.20 Hz, 1H), 4.30 (q, J = 7.12 Hz, 2H), 1.30 (t, J = 7.12 Hz, 3H); HRMS (ESI) calcd. for C 19 H 13 N2O5 [M - H] - 349.0830, found: 349.0824. FT-IR (KBr) ν max / cm -1 3440, 3085, 2966, 1736, 1676, 1528, 1239, 1098, 742.

[0057] Example 2

[0058] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0059] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-hydroxybenzaldehyde (0.122 g, 1.0 mmol), and iodine (0.253 g, 1 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of absolute ethanol as the solvent. The above system is refluxed at 80 °C for 10 hours.

[0060] (2) After the reflux reaction is completed and monitored by TLC to be complete, cool the reaction solution to room temperature. Add an excess of 5% aqueous Na2S2O3 solution to the reaction solution to remove the excess iodine. Filter the solid to obtain the crude product. Wash the product with 50% aqueous ethanol solution, and recrystallize it from tetrahydrofuran after drying to obtain the pure product.

[0061]

[0062] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 2 shown, and the structure characterization data of the product are as follows: 1 1H NMR (DMSO-d6, 500 MHz) ppm: 12.95 (s, 1H), 10.41 (s, 1H), 8.45 (d, J = 1.55 Hz, 1H), 8.14 (d, J = 8.15 Hz, 2H), 8.04 (dd, J1 = 8.65 Hz, J2 = 1.75 Hz, 1H), 7.83 (d, J = 8.60 Hz, 1H), 6.92 (d, J = 8.80 Hz, 2H), 4.36 (q, J = 7.05 Hz, 2H), 1.37 (t, J = 7.12 Hz, 3H). MS (ESI): m / z = 349 [M - H] - ; HRMS (ESI) calcd. for C 19 H 13 N2O5 [M - H] - 349.0830, found: 349.0828; FT-IR (KBr) ν max / cm-1 3476, 3412, 2977, 1683, 1525, 1288, 1080, 830, 755, 621.

[0063] Example 3

[0064] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0065] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-fluorobenzaldehyde (0.124 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0066] (2) After the reflux reaction is completed, monitor the reaction by TLC until it is complete. Remove copper oxide by hot filtration. Cool the reaction solution to room temperature, and a large amount of solid precipitates. Filter the solid to obtain the crude product. The crude product is refluxed in a 10% aqueous potassium carbonate solution. After the reaction is completed, add hydrochloric acid to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. Filter and dry to obtain the pure product.

[0067]

[0068] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 3 shown, and the structural characterization data of the product are as follows: 1 1H NMR (400 MHz, D2O + NaOD): δ = 8.17 (d, J = 1.80 Hz, 1H), 7.77 - 7.69 (m, 2H), 7.60 (dd, J1 = 8.56 Hz, J2 = 1.88 Hz, 1H), 7.26 (d, J = 8.56 Hz, 1H), 6.93 - 6.82 (m, 2H). 13 13C NMR (100 MHz, D2O): δ = 175.05, 171.00, 169.92, 164.85, 162.39, 161.26, 153.29, 132.80, 132.77, 131.49, 129.69, 129.60, 126.54, 122.25, 121.70, 114.80, 114.58, 110.25, 98.99.

[0069] Example 4

[0070] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0071] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-chlorobenzaldehyde (0.141 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0072] (2) After the reflux reaction is completed, the reaction is monitored by TLC until it is complete. Copper oxide is removed by hot filtration. The reaction solution is cooled to room temperature, and a large amount of solid precipitates. The solid is filtered by suction to obtain the crude product. The crude product is refluxed in an aqueous solution of 10% potassium carbonate. After the reaction is completed, hydrochloric acid is added to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. The solid is filtered by suction and dried to obtain the pure product.

[0073]

[0074] The nuclear magnetic resonance hydrogen spectrum of the fluorescent material prepared in this example is as Figure 4 shown, and the structure characterization data of the product are as follows: 1 HNMR(400MHz,D2O+NaOD):δ=8.27(d,J=1.80Hz,1H),7.77(m,3H),7.40(d,J=8.5Hz,1H),7.15(dt,J=9.3,1.9Hz,2H). 13 C NMR(100MHz,D2O+NaOD):δ=175.16,171.00,169.86,160.96,153.35,135.30,134.91,131.61,128.71,127.82,126.67,122.34,121.82,110.30,99.39.

[0075] Example 5

[0076] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0077] (1) Weigh 0.248 g (1.0 mmol) of ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate, 0.185 g (1.0 mmol) of 4-bromobenzaldehyde, and 15.9 mg (0.2 mmol) of copper oxide and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0078] (2) After the reflux reaction is completed, the reaction is monitored by TLC until it is complete. Copper oxide is removed by hot filtration. The reaction solution is cooled to room temperature, and a large amount of solid precipitates. The solid is filtered by suction to obtain the crude product. The crude product is refluxed in an aqueous solution of 10% potassium carbonate. After the reaction is completed, hydrochloric acid is added to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. The solid is filtered by suction and dried to obtain the pure product.

[0079]

[0080] The nuclear magnetic resonance hydrogen spectrum of the fluorescent material prepared in this example is as Figure 5 shown, and the structure characterization data of the product are as follows:1 HNMR(400 MHz, D2O + NaOD): δ = 8.27 (d, J = 1.80 Hz, 1H), 7.78 (dd, J1 = 8.56 Hz, J2 = 1.88 Hz, 1H), 7.68 (m, 2H), 7.40 (d, J = 8.6, 0.8 Hz, 1H), 7.31 - 7.24 (m, 2H). 13 C NMR(101 MHz, D2O): δ = 175.20, 171.02, 169.87, 161.02, 153.38, 135.32, 131.69, 130.77, 128.92, 126.75, 123.90, 122.41, 121.88, 110.34, 99.49.

[0081] Example 6

[0082] A preparation method of a 2-arylbenzofuro[2,3-d]pyrimidinone-structured fluorescent material, comprising the following steps:

[0083] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-methylbenzaldehyde (0.120 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as a solvent; the above system is reacted at 120 °C for 6 hours.

[0084] (2) After the reflux reaction is completed, monitor the reaction by TLC until it is complete. Remove copper oxide by hot filtration. Cool the reaction solution to room temperature, and a large amount of solid precipitates. Filter the solid to obtain the crude product. The crude product is refluxed in a 10% aqueous potassium carbonate solution. After the reaction is completed, add hydrochloric acid to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. Filter and dry to obtain the pure product.

[0085]

[0086] The nuclear magnetic resonance hydrogen spectrum of the fluorescent material prepared in this example is as Figure 6 shown, and the structural characterization data of the product are as follows: 1 HNMR(400 MHz, D2O + NaOD): δ = 8.28 (d, J = 1.40 Hz, 1H), 7.71 (dd, J1 = 6.80 Hz, J2 = 1.40 Hz, 1H), 7.66 (d, J = 6.52 Hz, 2H), 7.35 (d, J = 6.8 Hz, 1H), 6.92 (d, J = 6.8 Hz, 2H), 1.92 (s, 3H). 1313C NMR (101 MHz, D2O): δ = 175.29, 171.17, 170.13, 162.26, 153.40, 140.59, 140.56, 133.58, 131.66, 131.63, 128.51, 127.42, 126.50, 122.69, 121.74, 110.34, 99.12, 20.03.

[0087] Example 7

[0088] A preparation method of a 2-arylbenzofuro[2,3-d]pyrimidinone-structured fluorescent material, comprising the following steps:

[0089] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-morpholinecarboxaldehyde (0.191 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as a solvent; the above system is reacted at 120 °C for 6 hours;

[0090] (2) After the reflux reaction is completed, TLC monitors that the reaction is complete. The copper oxide is removed by hot filtration. The reaction solution is cooled to room temperature, and a large amount of solid precipitates. The solid is filtered by suction to obtain a crude product. The crude product is refluxed in a 10% aqueous potassium carbonate solution. After the reaction is completed, hydrochloric acid is added to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. After filtration by suction and drying, a pure product is obtained.

[0091]

[0092] The nuclear magnetic resonance hydrogen spectrum of the fluorescent material prepared in this example is as Figure 7 shown, and the structural characterization data of the product are as follows: 1 1H NMR (400 MHz, D2O + NaOD): δ = 8.38 (d, J = 1.44 Hz, 1H), 7.84 (dd, J1 = 6.80 Hz, J2 = 1.40 Hz, 1H), 7.76 (d, J = 6.80 Hz, 2H), 7.50 (d, J = 6.80 Hz, 1H), 6.68 (d, J = 6.80 Hz, 2H), 3.68 - 3.58 (m, 4H), 2.79 - 2.68 (m, 4H). 13 13C NMR (100 MHz, D2O): δ = 175.23, 170.97, 170.02, 161.53, 159.67, 153.28, 131.45, 129.07, 128.93, 126.30, 122.72, 121.54, 112.58, 110.20, 98.71, 54.51.

[0093] Example 8

[0094] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0095] (1) Weigh 2-amino-3-carbamoylbenzofuran-5-carboxylic acid ethyl ester (0.248 g, 1.0 mmol), 4-formylbenzoic acid (0.150 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0096] (2) After the reflux reaction is completed, monitor the reaction by TLC until it is complete. Remove copper oxide by hot filtration. Cool the reaction solution to room temperature, and a large amount of solid precipitates. Filter the solid by suction to obtain the crude product, and recrystallize the crude product in ethanol to obtain the pure product.

[0097]

[0098] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 8 shown, and the structural characterization data of the product are as follows: 1 1H NMR (400 MHz, D2O + NaOD): δ = 8.38 (d, J = 1.60 Hz, 1H), 8.06 - 8.04 (m, 2H), 7.93 - 7.84 (m, 2H), 7.77 (dd, J1 = 6.88 Hz, J2 = 1.52 Hz, 1H), 7.44 (d, J = 6.80 Hz, 1H), 3.67 (q, J = 7.08 Hz, 2H), 1.19 (d, J = 7.08 Hz, 3H). 13 13C NMR (101 MHz, D2O): δ = 175.21, 175.17, 171.31, 170.19, 162.17, 153.51, 139.53, 137.55, 131.80, 128.75, 127.74, 126.78, 122.32, 121.79, 110.46, 99.55, 57.35, 54.26, 18.99, 16.71, 14.85, 2.85.

[0099] Example 9

[0100] A preparation method of a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0101] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 4-nitrobenzaldehyde (0.151 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0102] (2) After the reflux reaction is completed, the reaction is monitored by TLC to be complete. The copper oxide is removed by hot filtration. The reaction solution is cooled to room temperature, and a large amount of solid precipitates. The solid is filtered by suction to obtain the crude product. The crude product is refluxed in an aqueous solution of 10% potassium carbonate. After the reaction is completed, hydrochloric acid is added to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. After suction filtration and drying, the pure product is obtained.

[0103]

[0104] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 9 shown, and the structure characterization data of the product are as follows: 1 1H NMR (400 MHz, D2O + NaOD): δ = 8.00 (d, J = 1.44 Hz, 1H), 7.70 - 7.62 (m, 2H), 7.55 (m, 3H), 7.15 (d, J = 6.80 Hz, 1H). 13 13C NMR (101 MHz, D2O): δ = 174.61, 170.60, 169.27, 158.80, 153.06, 146.78, 142.05, 131.55, 127.70, 126.90, 122.66, 121.88, 121.82, 110.20, 99.99, 54.31, 19.04, 14.92, 2.78.

[0105] Example 10

[0106] A method for preparing a fluorescent material with a 2-arylbenzofuro[2,3-d]pyrimidinone structure, comprising the following steps:

[0107] (1) Weigh ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate (0.248 g, 1.0 mmol), 2,3,4-trimethoxybenzaldehyde (0.196 g, 1.0 mmol), and copper oxide (15.9 mg, 0.2 mmol) and place them in a 50 mL reaction flask. Then add 10 mL of N,N-dimethylformamide as the solvent. The above system is reacted at 120 °C for 6 hours.

[0108] (2) After the reflux reaction is completed, the reaction is monitored by TLC until it is complete. Copper oxide is removed by hot filtration. The reaction solution is cooled to room temperature, and a large amount of solid precipitates. The solid is filtered by suction to obtain the crude product. The crude product is refluxed in an aqueous solution of 10% potassium carbonate. After the reaction is completed, hydrochloric acid is added to the reaction flask to adjust it to weakly acidic, and a large amount of solid precipitates. The solid is filtered by suction and dried to obtain the pure product.

[0109]

[0110] The 1H NMR spectrum of the fluorescent material prepared in this example is as Figure 10 shown, and the structure characterization data of the product are as follows: 1 H NMR(400MHz,D2O+NaOD):δ=8.46(d,J=1.24Hz,1H),7.94(dd,J1=6.84Hz,J2=1.48Hz,1H),7.59(d,J=6.84Hz,1H),7.23(dd,J1=6.96Hz,J2=0.6Hz,1H),6.80(dd,J1=7.04Hz,J2=1.08Hz,1H),3.88(s,3H),3.81(s,3H),3.67(s,3H). 13 C NMR(100MHz,D2O):δ=175.29,171.20,169.91,162.16,153.55,153.42,151.15,140.55,131.97,126.81,126.13,125.60,122.59,121.92,110.55,107.46,99.17,61.59,61.31,55.70.

[0111] Example 11

[0112] The fluorescent material prepared in Example 1 is dissolved in DMF and left open at room temperature. As the solvent slowly evaporates, crystals of the fluorescent material are obtained. A single crystal diffractometer is used for single crystal structure testing to obtain the single crystal structure of the fluorescent material. By analyzing the single crystal structure, it can be seen that the molecules of the fluorescent material form dimers in the crystal in the form of intermolecular double hydrogen bonds. Multiple dimers are arranged in parallel and form a planar stacking structure. There is a strong π-π stacking phenomenon in this structure, resulting in fluorescence quenching of the molecules. It can be seen that the formation of intermolecular double hydrogen bonds is the reason for the formation of a large planar conjugated structure by the molecules, and then π-π stacking and aggregation-induced quenching occur. Through the structural analysis of this crystal, the reason for the aggregation-induced quenching of this type of fluorescent material in the crystal state is explained.

[0113] Example 12

[0114] The fluorescent material prepared in Example 2 was dissolved in DMF and left open at room temperature. As the solvent slowly evaporated, crystals of the fluorescent material were obtained. The single-crystal structure of the fluorescent material was tested using a single-crystal diffractometer, and the single-crystal structure of the fluorescent material was obtained. By analyzing the single-crystal structure, it was found that the molecules of the fluorescent material formed dimers in the crystal in the form of intermolecular double hydrogen bonds. Multiple dimers were arranged in parallel to form a planar stacking structure, and there was a strong π-π stacking phenomenon in this structure, resulting in fluorescence quenching of the molecules. It can be seen that the formation of intermolecular double hydrogen bonds is the reason for the formation of a large planar conjugated structure by the molecules, which in turn leads to π-π stacking and aggregation-induced quenching. Through the structural analysis of this crystal, the reason for the aggregation-induced quenching of this type of fluorescent material in the crystal state can be explained.

[0115] Example 13

[0116] The fluorescent material prepared in Example 1 was dissolved in DMF to prepare solutions with different concentrations of 10 μM, 40 μM, 80 μM, 100 μM, 200 μM, and 400 μM. The fluorescence spectra of the prepared solutions were measured, and the results are as Figure 13 shown. It can be seen from this figure that the fluorescence intensity of the fluorescent material in the solution decreased significantly with the increase in concentration. It can be seen that the fluorescent material exhibits obvious aggregation-induced quenching properties in the solution.

[0117] Example 14

[0118] The fluorescent material prepared in Example 1 was dissolved in a Tris-HCl buffer solution of ethanol and water (volume ratio of ethanol to water is 8:2) with different pH values, and the concentration of the fluorescent material was 50 μM. Using an excitation wavelength of 350 nm, the fluorescence intensity of the fluorescent material at 475 nm in solutions with different pH values was measured. The results are as Figure 14 shown. It can be seen from this figure that the fluorescent material exhibits fluorescence intensity changes related to the pH value. In acidic solutions, the fluorescence of the fluorescent material will be completely quenched, and as the pH value of the solution increases, the fluorescence intensity gradually increases.

[0119] It can be seen from Figure 14 that the fluorescence of the fluorescent material will be quenched in acidic solutions. To study the fluorescence emission phenomenon caused by aggregation of the fluorescent material in acidic solutions, N,N-dimethylformamide solutions with different concentrations were prepared, and the solvent used was water. The fluorescent material was dissolved in N,N-dimethylformamide solutions with different concentrations, the concentration of the fluorescent material was 50 μM, and the pH was adjusted to 3. The fluorescence spectra and the fluorescence intensity at 475 nm of the solutions were measured, and the results are as Figure 15 shown. It can be seen from Figure 15 that in an acidic environment, with the addition of water, the fluorescent material exhibits aggregation-induced emission in dilute solutions.

[0120] Example 15

[0121] The fluorescent material prepared in Example 1 was dissolved in DMF and left open at room temperature. As the solvent slowly evaporated, a crystalline sample of the fluorescent material was obtained. A portion of the above solution was taken, and distilled water was added to the solution to form a large amount of precipitate. After filtering the precipitate and drying it, a precipitate sample of the fluorescent material was obtained. The fluorescence spectra of the above samples were tested, and the results are as Figure 16 shown. It can be seen that the fluorescent material does not exhibit significant fluorescence emission in the crystalline state and shows the phenomenon of aggregation-induced quenching (ACQ); while in the amorphous precipitate state, it shows significant fluorescence emission, that is, the aggregation-induced emission phenomenon (AIE).

[0122] Example 16

[0123] The fluorescent material prepared in Example 1 was dissolved in DMF, and distilled water was added to the above solution to form a large amount of precipitate. After filtering the precipitate and drying it, a precipitate sample of the fluorescent material was obtained. Mixing the precipitate sample of the fluorescent material with silica gel can obtain a well-dispersed fluorescent powder SiO2@Qufu-1. As Figure 17 shown, the SiO2@Qufu-1 powder can combine with fingerprints to display latent fingerprints on different object surfaces. The above experiments confirm that the fluorescent material can be used for the identification of fingerprints on object surfaces.

[0124] Example 17

[0125] The fluorescent material prepared in Example 1 was dissolved in tetrahydrofuran to prepare a solution with a concentration of 50 μM. Since the fluorescent material has a strong ACQ phenomenon in the tetrahydrofuran solution, the solution basically has no fluorescence. Gradually adding a putrescine solution to the above tetrahydrofuran solution of the fluorescent material, the results are as Figure 17 shown. As the putrescine is added, the fluorescence of the fluorescent material gradually increases; similarly, gradually adding a cadaverine solution to the tetrahydrofuran solution of the fluorescent material, the fluorescence intensity of the solution also gradually increases, and the results are as Figure 18 shown. Putrescine and cadaverine are harmful biogenic amines produced during the spoilage of protein foods. These amines destroy the dimers of the fluorescent material in tetrahydrofuran, resulting in a weakened ACQ effect and thus enhanced fluorescence. It can be seen that the fluorescent material prepared in the present invention can be used for the detection of the food spoilage process.

Claims

1. A fluorescent material having a 2-arylbenzofuro[2,3-d]pyrimidinone structure, characterized in that, The structural general formula of the fluorescent material is as follows: Wherein, R1 is methyl, ethyl or hydrogen; R2 is methyl, halogen, morpholinyl, formyl, nitro or methoxy; R2 on the benzene ring can be single-substituted or multi-substituted.

2. The fluorescent material according to claim 1, wherein, Double hydrogen bonds can be formed between the molecules of the fluorescent material, as shown in the following formula: 。 3. The fluorescent material according to claim 1, wherein The halogen is fluorine, chlorine or bromine.

4. A method for preparing the fluorescent material according to any one of claims 1-3, characterized in that, The fluorescent material is prepared by condensing ethyl 2- amino-3-carbamoylbenzofuran-5-carboxylate and substituted benzaldehyde in the presence of a catalyst and a solvent, and then separating and purifying after the reaction. The reaction formula is: 。 5. The preparation method according to claim 4, characterized in that, The catalyst is iodine or copper oxide.

6. The preparation method according to claim 4, characterized in that The solvent is anhydrous ethanol, dimethyl sulfoxide, N, N-dimethylformamide or N-methylpyrrolidone.

7. The preparation method of the fluorescent material according to claim 4, characterized in that, The molar ratio of ethyl 2-amino-3-carbamoylbenzofuran-5-carboxylate, substituted benzaldehyde and the catalyst is 1:(1-1.2):(0.05-0.2); the temperature of the condensation reaction is 80-100 °C, and the reaction time is 6-10 hours.

8. Use of the fluorescent material according to any one of claims 1 to 3 or / and the fluorescent material prepared by the method according to any one of claims 4 to 7, characterized in that The application is that the fluorescent material is applied to fingerprint identification or the detection of biogenic amines.

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