Macrocyclic expanded porphyrin fluorescent dye and preparation method thereof

Abstract

The invention discloses a macrocyclic expanded porphyrin fluorescent dye, which has a chemical structure as shown in a general formula A or a tautomer and a configurational isomer thereof. The synthesis process of the fluorescent dye is simple, convenient and efficient, raw materials are low in cost and easy to obtain, and reaction conditions are high in controllability; the molecular structure contains a plurality of modifiable sites, so that the performance can be accurately regulated and controlled; the fluorescent dye has a high molar extinction coefficient (epsilon 535 nm is approximately equal to 0.76 * 10 < 5 > M <-1 > cm <-1 >), a great Stokes shift (about 136 nanometers), a large emission wavelength (lambda em is equal to 661 nm) and good stability in a tetrahydrofuran solution.

Description

TECHNICAL FIELD

[0001] The application belongs to dyes and its preparation method, and particularly relates to a macrocyclic expanded porphyrin fluorescent dye and a preparation method thereof. BACKGROUND

[0002] In recent decades, organic fluorescent dye molecules have attracted great interest of researchers in the research fields of medical fluorescence imaging, lasers and quantum technology. Under this background, the precise construction of novel light-emitting molecules and the precise regulation of their light-emitting performance are of great significance both in basic research and in applied research.

[0003] As a kind of excellent light-emitting molecule, BODIPY has a wide application in fluorescence imaging, display and the like due to its high emission quantum yield, narrow fluorescence emission bandwidth and adjustable spectral properties. However, the traditional BODIPY functional molecules still have some property defects. For example, the Stokes shift of the traditional BODIPY molecules is small, and the absorption wavelength is difficult to reach the near-infrared region. In the past few decades, researchers have found that the structural modification of the BODIPY parent body can significantly regulate its photophysical properties, thereby optimizing the property defects of the BODIPY functional molecules. Among all the modification methods, the introduction of aryl, alkyne or alkenyl substituents is an effective strategy to realize the red shift of the spectral band and improve the quantum yield.

[0004] The diversity of structural modification of the BODIPY core enables researchers to prepare a series of small molecule BODIPY derivatives covering the spectral range between ultraviolet-visible-near infrared regions. Most of these BODIPY molecules have high fluorescence quantum yield and good light stability. However, the performance of such molecules still has some deficiencies, for example, their Stokes shift is generally less than 1000 cm -1 , which will cause the wavelength of excitation light and emission light to overlap in the application of biological imaging, and it is difficult to distinguish the two during detection; in addition, the emission light may be absorbed by itself, thereby reducing the fluorescence intensity and affecting the detection accuracy. SUMMARY

[0005] The present application aims at overcoming the deficiencies in the prior art, and provides a macrocyclic expanded porphyrin fluorescent dye with good stability and fluorescence performance, and a preparation method of the macrocyclic expanded porphyrin fluorescent dye, which is simple, efficient and controllable in reaction.

[0006] Technical scheme: The macrocyclic expanded porphyrin fluorescent dye provided by the application is a chemical structure of general formula A or a tautomer, a configuration isomer thereof:

[0007]

[0008] wherein R 1 is selected from any one of hydrogen, methyl, alkanyl, cycloalkanyl, heterocycloalkanyl, unsaturated hydrocarbon, halogenated, hydroxyl, methoxyl, acetyl, carboxyl, amino, cyano, nitro, aryl, heteroaryl, aralkyl;

[0009] R 2 is selected from any one of hydrogen, methyl, alkanyl, cycloalkanyl, heterocycloalkanyl, unsaturated hydrocarbon, halogenated, methoxyl, acetyl, carboxyl, aryl, heteroaryl, aralkyl;

[0010] R 3 is selected from any one of hydrogen, methyl, alkanyl, cycloalkanyl, heterocycloalkanyl, unsaturated hydrocarbon, halogenated, hydroxyl, methoxyl, acetyl, carboxyl, amino, cyano, nitro, aryl, heteroaryl, aralkyl.

[0011] Preferably, the structure of the macrocyclic expanded porphyrin fluorescent dye is as follows:

[0012]

[0013] The preparation method of the macrocyclic expanded porphyrin fluorescent dye comprises the following steps:

[0014] Step one, under nitrogen protection, compound I-1, I-2, tetrakis triphenyl phosphine palladium and potassium carbonate are dissolved in a mixture of 1,4-dioxane and water for reflux reaction, after the reaction is completed, extraction, drying, evaporation of solvent under reduced pressure, purification, drying under reduced pressure, and then a colorless oily liquid I-3 is obtained;

[0015] Step two, under nitrogen protection, the obtained colorless oily liquid I-3 is added into tetrahydrofuran and methanol solvent, stirred and dissolved, then sodium methoxide is slowly added and stirred for reaction, after the reaction is completed, extraction, drying, evaporation of solvent under reduced pressure, and then green solid I-4 is obtained after chromatographic separation;

[0016] Step three, under nitrogen protection, the obtained green solid I-4 is dissolved in dichloromethane solution, the reaction liquid is reacted under catalysis of boron trifluoride ether, then 2,3-dichloro-5,6-dicyanoquinone is added, after the reaction is completed, triethylamine is added, the solvent is evaporated under reduced pressure, and then the obtained crude product is purified by column chromatography with silica gel, the obtained crude product is washed with methanol, and then green solid I-6 is obtained after drying under reduced pressure;

[0017] Step four, under nitrogen protection, the obtained green solid I-6 is dissolved in toluene with triethylamine and boron trifluoride ether for reflux reaction, after the reaction is completed, the solvent is evaporated under reduced pressure, and then the obtained crude product is purified by column chromatography with silica gel, the obtained crude product is washed with n-hexane, and then the macrocyclic expanded porphyrin fluorescent dye is obtained after drying under reduced pressure;

[0018] The structure of I-1 is as follows: The structural formula of I-2 is: The structural formula of I-3 is: The structural formula of I-4 is: The structural formula of I-5 is:

[0019] The structural formula of I-6 is:

[0020] Further, the reaction route is as follows:

[0021]

[0022] Further, in step one, the molar ratio of compound I-1, I-2, tetrakis triphenylphosphine palladium and potassium carbonate is 1:2-3:0.05-0.1:7-8.

[0023] Further, in step one, the volume ratio of 1,4-dioxane and water is 20:1-2.

[0024] Further, in step one, the temperature of the reflux reaction is 80-90 DEG C, and the time of the reflux reaction is 6-10h.

[0025] Further, in step two, the molar ratio of I-3 and sodium methoxide is 1:10-12.

[0026] Further, in step three, the molar ratio of I-3, I-4 and 2,3-dichloro-5,6-dicyano benzoquinone is 1:1-2:2-3.

[0027] Further, in step four, the molar ratio of I-6, triethylamine and boron trifluoride etherate is 1:8:8-9.

[0028] Preparation principle: raw materials I-1 and I-2 are subjected to Suzuki coupling reaction under the action of palladium catalyst to obtain I-3, then the Boc protecting group on the pyrrole of I-3 is removed to obtain I-4, I-4 is subjected to dehydration condensation reaction with 3,5-di-tert-butylbenzaldehyde under the catalysis of acid to obtain I-6, then complexation with boron trifluoride etherate to obtain the target dye molecule.

[0029] Beneficial effects: compared with the prior art, the present application has the following remarkable features:

[0030] 1. The fluorescent dye synthesis process is simple and efficient, the raw material cost is low and easy to obtain, and the reaction condition is controllable;

[0031] 2. The molecular structure contains multiple modification sites, which is convenient for precise performance control;

[0032] 3. The fluorescent dye has a high molar extinction coefficient (ε 535nm≈0.76×10 5 M -1 cm -1 ), extremely large Stokes shift (approximately 136 nanometers), and relatively large emission wavelength (λ). em =661nm) and good stability. Attached Figure Description

[0033] Figure 1 This is the high-resolution mass spectrum of fluorescent dye I of the present invention;

[0034] Figure 2 This is the 1H NMR spectrum (298K) of the fluorescent dye I of this invention;

[0035] Figure 3 This is the HH COSY spectrum of the fluorescent dye I of this invention;

[0036] Figure 4 This is the carbon NMR spectrum (298K) of the fluorescent dye I of the present invention;

[0037] Figure 5 This is the NMR fluorine spectrum of the fluorescent dye I of this invention;

[0038] Figure 6 This is the boron NMR spectrum of the fluorescent dye I of this invention;

[0039] Figure 7 This is an X-ray single-crystal diffraction pattern of the fluorescent dye I of the present invention, wherein (a) is a front view and (b) is a side view;

[0040] Figure 8 These are the ultraviolet absorption spectra of the fluorescent dye I of the present invention in different solvents;

[0041] Figure 9 These are the fluorescence spectra of the fluorescent dye I of the present invention in different solvents;

[0042] Figure 10 These are fluorescence lifetime spectra of the fluorescent dye I of the present invention in different solvents, wherein (a) is n-hexane, (b) is toluene, (c) is chloroform, and (d) is tetrahydrofuran. Detailed Implementation

[0043] Unless otherwise specified, all materials and reagents used in the embodiments are commercially available.

[0044] Example 1

[0045] A method for preparing a macrocyclic extended porphyrin fluorescent dye includes the following steps:

[0046] (1) Synthesis of compound I-3:

[0047] In a 100 mL two-necked round bottom flask with a magnetic bar, compound I-1 (1.7 g, 4.29 mmol), I-2 (2.28 g, 10.81 mmol) and tetrakis triphenylphosphine palladium (304 mg, 0.26 mmol) were sequentially added, and the air in the reaction device was replaced with nitrogen three times. A 1,4-dioxane solution (100 mL) was added to the round bottom flask with a syringe, and the starting material was completely dissolved by stirring at room temperature for 10 minutes. Then, a potassium carbonate solution (4.5 g dissolved in 5 mL distilled water) was added to the reaction system with a syringe. The above reaction was stirred at 90°C for 5 hours, and then cooled to room temperature. After the reaction was completed, the solvent was first spun dry, and then 100 mL of ethyl acetate and water were added to the residue for extraction, and the aqueous phase was washed with ethyl acetate until no product residue was left. The organic phase was dehydrated with anhydrous sodium sulfate, and then the organic solvent was removed. The crude product was separated by silica gel column chromatography (eluent: PE / EA = 30 / 1) to obtain 1.91 g of colorless liquid, with a yield of 78%.

[0048] The structural formula of I-1 is: The structural formula of I-2 is: The structural formula of I-3 is:

[0049] (2) Synthesis of compound I-4:

[0050] In a 100 mL single-necked reaction flask device with a magnetic bar, compound I-3 (1.0 g, 1.76 mmol) was added, followed by 30 mL of tetrahydrofuran and 10 mL of methanol solvent, and the starting material was completely dissolved by stirring at room temperature for 10 minutes. Then, sodium methoxide (1.0 g, 18.51 mmol) was slowly added and stirred at room temperature for 3 hours. The reaction was monitored by TLC, and after the starting material completely disappeared, 100 mL of ethyl acetate and water were added for extraction, and the aqueous phase was washed with ethyl acetate until no product residue was left. The organic phase was dried with anhydrous sodium sulfate, and then the organic solvent was removed. The obtained product was separated by neutral alumina column chromatography (eluent: 100% DCM) to obtain 597 mg of green solid, with a yield of 92%.

[0051] The structural formula of I-4 is:

[0052] (3) Synthesis of compound I-6:

[0053] A 250 mL reaction flask was charged with compound I-4 (50 mg, 0.14 mmol) and I-5 (38 mg, 0.17 mmol) under nitrogen protection, followed by slow addition of 100 mL of dry dichloromethane solution. After stirring for 10 minutes, a syringe was used to add boron trifluoride etherate (9 μL, 0.07 mmol) into the flask, and the reaction was continuously stirred at room temperature for 3 hours. Then 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (79 mg, 0.35 mmol) was added, and the reaction was continuously stirred for 30 minutes under air environment. Then 0.5 mL of triethylamine was added, and stirred for about 5 minutes, followed by removal of the organic solvent, and the crude product was purified by silica gel column chromatography (eluent: DCM / MeOH = 200 / 1), to obtain macrocycle I-6 with a yield of 8%.

[0054] The structural formula of I-5 is: The structural formula of I-6 is:

[0055] (4) Synthesis of compound I:

[0056] Compound I-6 (20 mg, 18.10 μmol), triethylamine (200 μL) and boron trifluoride etherate (210 μL) were dissolved in toluene (30 mL) under nitrogen protection, and the reaction was refluxed in a 120 °C oil bath for 12 hours. After the reaction was completed, the solvent was removed by reduced pressure evaporation, and neutral alumina was used for column chromatography purification (eluent: 100% DCM). The obtained crude product was washed with n-hexane for three times, and dried by reduced pressure using an oil pump for 10 hours to obtain a green solid, which was the final fluorescent dye I with a yield of 40%.

[0057] The mass spectrum and nuclear magnetic resonance characterization of the fluorescent dye I obtained in this example are as follows: Figure 1 :

[0058] 1H NMR (400 MHz, Chloroform-d) δ 9.27 (s, 4H), 8.18 (d, J = 8.4 Hz, 4H), 7.70 - 7.54 (m, 6H), 7.48 (d, J = 1.8 Hz, 4H), 6.95 (d, J = 4.9 Hz, 4H), 6.43 (d, J = 5.3 Hz, 4H), 4.03 (s, 12H), 1.43 (s, 36H). 13C NMR (101 MHz, Chloroform-d) δ 159.34, 144.58, 138.63, 137.16, 136.94, 136.17, 131.34, 130.47, 129.77, 129.52, 128.79, 128.22, 127.16, 124.51, 122.04, 120.90, 63.26, 61.15, 32.94, 32.07, 29.84. HRMS (ESI) m / z [M + H] + : calcd for C 78 H 75 B2F4N4O41229.5906, found: 1229.5893.

[0059] The molecular formula of the fluorescent dye I obtained in this example is:

[0060]

[0061] The fluorescent dye I obtained in this example has a high molar extinction coefficient ε 535nm ≈0.76×10 5 M -1 cm -1 in tetrahydrofuran solution, a Stokes shift of about 136 nm, and an emission wavelength λ em = 661 nm. The dye has good chemical stability and can be stored at room temperature for more than one month without deterioration in tetrahydrofuran or other solvents or in the solid state.

[0062] As shown in Figure 1, the proton nuclear magnetic resonance spectrum of the target dye molecule shows that the number of proton integrals is exactly the same as the theoretical value, proving that the structure of the target molecule is correct. Figure 2 As shown in Figure 2, the H-H COSY spectrum of the target dye molecule shows two groups of related signals, which can be determined as the β-position protons of the pyrrole and the protons of the phenanthrene ring.

[0063] Figure 3 As shown in Figure 3, the carbon nuclear magnetic resonance spectrum of the target dye molecule shows that the number of carbon spectrum peaks is exactly the same as the theoretical value, proving that the structure of the target molecule is correct.

[0064] As shown in Figure 4, the fluorine spectrum of the target dye molecule proves that the molecule contains a fluorine atom in its structure. Figure 4 As shown in Figure 5, the fluorine spectrum of the target dye molecule proves that the molecule contains a boron atom in its structure.

[0065] Figure 5 As shown in Figure 6, the fluorine spectrum of the target dye molecule proves that the molecule contains a boron atom in its structure.

[0066] As shown in Figure 7, the fluorine spectrum of the target dye molecule proves that the molecule contains a boron atom in its structure. Figure 6 As shown in Figure 8, the fluorine spectrum of the target dye molecule proves that the molecule contains a boron atom in its structure.

[0067] Figure 7 ​​​X-ray single crystal diffraction pattern of the target dye molecule, the single crystal structure further proves the correctness of the dye molecule structure.

[0068] As Figure 8 UV absorption spectrum of the target dye molecule in different solvents, the spectrum shows that the maximum absorption wavelength of the dye molecule in different solvents is between 525-532 nm.

[0069] As Figure 9 Fluorescence emission spectrum of the target dye molecule in different solvents, the spectrum shows that the emission wavelength of the dye molecule in different solvents is between 646-665 nm.

[0070] As Figure 10 Fluorescence lifetime spectrum of the target dye molecule in different solvents, the spectrum shows that the fluorescence lifetime of the dye molecule in different solvents is between 1.31-2.53 ns.

[0071] The fluorescent dye I obtained in Example 1 is used in the field of fluorescence imaging.

[0072] Example 2

[0073] The remaining steps of this example are prepared as in Example 1, the only difference is that I-5 in Example 1 is replaced by: 2,4,6-trimethylbenzaldehyde. The structural formula of the obtained fluorescent dye is:

[0074]

[0075] The mass spectrum and nuclear magnetic resonance of the fluorescent dye obtained in this example are characterized:

[0076] 1H NMR (400 MHz, Chloroform-d) δ 9.28 (s, 4H), 8.16 (d, J = 8.4 Hz, 4H), 7.57 (dd, J = 8.4, 1.1 Hz, 4H), 7.00 (s, 4H), 6.65 (d, J = 4.1 Hz, 4H), 6.32 (d, J = 4.1 Hz, 4H), 4.01 (s, 12H), 2.41 (s, 6H), 2.39 (s, 6H), 2.17 (s, 6H). HRMS (ESI): m / z calculated for C 68 H 55 B2F4N4O4[M+H] + : 1089.4341; found: 1089.4332.

Claims

1. A macrocyclic extended porphyrin fluorescent dye, characterized in that: The chemical structure of general formula A or its tautomers and configuration isomers: Among them, R 1 Selected from any one of the following: hydrogen, methyl, alkyl, cycloalkyl, heterocycloalkyl, unsaturated hydrocarbon group, halogroup, hydroxyl, methoxy, acetyl, carboxyl, amino, cyano, nitro, aryl, heteroaryl, aralkyl; R 2 Selected from any one of the following: hydrogen, methyl, alkyl, cycloalkyl, heterocycloalkyl, unsaturated hydrocarbon group, halogenated group, methoxy group, acetyl group, carboxyl group, aryl group, heteroaryl group, aralkyl group; R 3 Selected from any one of the following: hydrogen, methyl, alkyl, cycloalkyl, heterocycloalkyl, unsaturated hydrocarbon group, halogenated group, hydroxyl, methoxy, acetyl, carboxyl, amino, cyano, nitro, aryl, heteroaryl, aralkyl.

2. The macrocyclic extended porphyrin fluorescent dye according to claim 1, characterized in that: The structural formula of the macrocyclic extended porphyrin fluorescent dye is:

3. A method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 1, characterized in that, Includes the following steps: Step 1: Under nitrogen protection, compounds I-1, I-2, tetra-triphenylphosphine palladium and potassium carbonate were dissolved in a mixture of 1,4-dioxane and water and refluxed. After the reaction was completed, the mixture was extracted, dried, the solvent was evaporated under reduced pressure, purified, and dried under reduced pressure to obtain a colorless oily liquid I-3. Step 2: Under nitrogen protection, the obtained colorless oily liquid I-3 was added to tetrahydrofuran and methanol solvent and stirred to dissolve. Then, sodium methoxide was slowly added and the reaction was stirred. After the reaction was completed, the mixture was extracted, dried, and the solvent was evaporated under reduced pressure. After separation by chromatography, green solid I-4 was obtained. Step 3: Under nitrogen protection, the obtained green solids I-4 and I-5 were dissolved in dichloromethane solution. The above reaction solution was reacted under the catalysis of boron trifluoride diethyl ether. Then, 2,3-dichloro-5,6-dicyanobenzoquinone was added. After the reaction was completed, triethylamine was added, the solvent was removed by vacuum distillation, and the product was purified by column chromatography with silica gel. The crude product was washed with methanol and dried under vacuum to obtain green solid I-6. Step 4: Under nitrogen protection, the obtained green solid I-6 was dissolved in toluene with triethylamine and boron trifluoride diethyl ether and refluxed. After the reaction was completed, the solvent was removed by vacuum distillation, and the product was purified by column chromatography with silica gel. The crude product was washed with n-hexane and dried under vacuum to obtain a macrocyclic extended porphyrin fluorescent dye. The structural formula of I-1 is: The structural formula of I-2 is: The structural formula of I-3 is: The structural formula of I-4 is: The structural formula of I-5 is: The structural formula of I-6 is:

4. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that, The reaction pathway is shown below:

5. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step one, the molar ratio of compounds I-1, I-2, tetraphenylphosphine palladium, and potassium carbonate is 1:2-3:0.05-0.1:7-8.

6. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step one, the volume ratio of 1,4-dioxane to water is 20:1 to 2.

7. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step one, the reflux reaction temperature is 80–90°C, and the reflux reaction time is 6–10 h.

8. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step two, the molar ratio of I-3 to sodium methoxide is 1:10 to 12.

9. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step three, the molar ratio of I-3, I-4 and 2,3-dichloro-5,6-dicyanobenzoquinone is 1:1 to 2:2 to 3.

10. The method for preparing the macrocyclic extended porphyrin fluorescent dye according to claim 3, characterized in that: In step four, the molar ratio of I-6, triethylamine, and boron trifluoride ethyl ether is 1:8:8-9.

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