Near-infrared phototherapy agent as well as preparation method and application thereof

Abstract

The invention provides a near-infrared phototherapy agent as well as a preparation method and application thereof, the near-infrared phototherapy agent is obtained by covalent coupling of a benzobisthiadiazole (BBTD) derivative and a boron dipyrromethene (BODIPY) dye molecule, and the near-infrared phototherapy agent has NIR-II photothermal conversion and efficient ROS (reactive oxygen species) generation capabilities. The near-infrared phototherapy agent breaks through the limitation of a traditional phototherapy system, has the characteristics of high photothermal conversion efficiency (50.3%), near-infrared two-region absorption, low biotoxicity and the like, can synchronously activate photothermal therapy (PTT) and photodynamic therapy (PDT) under the synergistic excitation of a 660nm LED light source and 1060nm laser, and provides an innovative solution for precise synergistic treatment of deep tumors.

Description

Technical Field

[0001] The present invention relates to a phototherapy agent, and more particularly to a near-infrared phototherapy agent and a preparation method and application thereof. Background Art

[0002] Malignant tumors are serious diseases that threaten human health and life, and are a leading cause of death worldwide. Traditional treatments, such as surgery, chemotherapy, and radiotherapy, are invasive and have significant toxic side effects. The search for and discovery of new therapies and drugs for treating tumors is a major challenge.

[0003] Photothermal therapy uses near-infrared light to activate photothermal agents to generate localized high temperatures to ablate tumors, but thermal tolerance can easily lead to recurrence of residual cells. Photodynamic therapy relies on photosensitizers to produce reactive oxygen species (such as singlet oxygen) to kill cancer cells, but the hypoxic microenvironment of tumors severely restricts its efficacy. A synergistic treatment system integrating PTT and PDT can overcome the limitations of a single modality, but the excitation bands of existing combined schemes are mostly located in the visible light region with poor tissue penetration depth, resulting in limited treatment efficiency. Therefore, the development of multifunctional nanoplatforms excited by near-infrared light (especially the NIR-II region, 1000-1700nm) to achieve simultaneous activation of PTT / PDT has become a key research direction for improving the efficacy of precision treatment of deep-seated tumors. Summary of the Invention

[0004] The purpose of the present invention is to provide a near-infrared phototherapy agent and a preparation method thereof, so as to solve the problem that the excitation band of existing phototherapy agents is mostly located in the visible light region with poor tissue penetration depth, resulting in low efficacy in precise treatment of deep tumors.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A near-infrared phototherapy agent, the structural formula of which is shown below:

[0007]

[0008] The preparation method of the near-infrared phototherapy agent comprises the following steps:

[0009] (1) 3-Octyl-1H-pyrrole and di-tert-butyl dicarbonate were dissolved in acetonitrile, and 4-dimethylaminopyridine was slowly added with stirring at room temperature. The mixture was stirred at room temperature for 1 hour. The reaction solution was evaporated to dryness, and the solid was dissolved with petroleum ether and purified by neutral alumina column chromatography to obtain compound 1. The structure of compound 1 is as follows:

[0010]

[0011] (2) 2,2,6,6-tetramethylpiperidine was dissolved in dry tetrahydrofuran solution, protected by nitrogen, and pre-cooled at -78°C for 10 minutes. Then, a tetrahydrofuran solution of n-butyl lithium (2.5 mol / L) was added. After the reaction was continued, compound 1 was added. After the reaction was continued for 2 hours, triethyl borate was added. Finally, the reaction was allowed to proceed at room temperature for 10 hours. After the reaction was completed, a saturated ammonium chloride solution was added to the reaction flask to quench the reaction. The reaction liquid was extracted with dichloromethane and water. The organic phase was evaporated to dryness, and the solid was dissolved with ether and petroleum ether, and then recrystallized. The filter cake was filtered under reduced pressure to obtain compound 2. The structure of compound 2 is as follows:

[0012]

[0013] (3) Compound 2, 4-bromo-4'-(6-bromohexyloxy)biphenyl, and tetrakis(triphenylphosphine)palladium were dissolved in a toluene solution and added to a reaction flask. Anhydrous potassium carbonate was dissolved in a mixed solution of water and ethanol and added to the reaction flask under nitrogen protection and reacted at 90°C for 24 hours. After the reaction, water and dichloromethane were added for extraction. The organic phase was collected, dried over anhydrous sodium sulfate, and filtered under reduced pressure. The filtrate was evaporated to dryness to obtain a crude product, which was separated and purified by column chromatography to obtain compound 3. The structure of compound 3 is as follows:

[0014]

[0015] (4) 2,2,6,6-tetramethylpiperidine was dissolved in a dry tetrahydrofuran solution. Under nitrogen protection, a tetrahydrofuran solution of n-butyl lithium (2.5 mol / L) was added at -78°C. After the reaction was allowed to react at low temperature for 50 min, compound 3 was added to the reaction flask. After further reaction, tributyltin chloride was added and the reaction was continued at room temperature for another 10 h. After the reaction was completed, the reaction solution was evaporated to dryness, petroleum ether was added to dissolve the product, and insoluble impurities were removed by filtration under reduced pressure. The filtrate was evaporated to dryness to obtain compound 4. The structure of compound 4 is as follows:

[0016]

[0017] (5) Compound 4 was dissolved in toluene, and 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) and bis(triphenylphosphine)palladium dichloride were added. The mixture was reacted at 90°C for 24 h under nitrogen protection. After the reaction, the solvent was evaporated and the mixture was separated and purified by column chromatography to obtain compound 5. The structure of compound 5 is as follows:

[0018]

[0019] (6) Compound 5 and trimethylsilyl azide were dissolved in tetrahydrofuran under nitrogen protection, and tetrabutylammonium fluoride was added dropwise at 0°C. Finally, the mixture was reacted at room temperature in the dark for 24 hours. After the reaction, the reaction solution was evaporated to dryness, and the remaining solid was recrystallized from petroleum ether to obtain a pure blue product, compound 6. The structure of compound 6 is as follows:

[0020]

[0021] (7) Compound 6 was dissolved in dichloromethane, trifluoroacetic acid was quickly added in an ice bath, and then the mixture was allowed to react at room temperature for 3 h. After the reaction, the reaction was quenched with saturated sodium bicarbonate aqueous solution, extracted with dichloromethane, and the crude product was separated and purified by column chromatography using dichloromethane as the eluent to obtain compound 7. The structure of compound 7 is as follows:

[0022]

[0023] (8) 2,4-Dimethylpyrrole and p-hydroxybenzaldehyde were dissolved in dichloromethane, protected by nitrogen, and trifluoroacetic acid was added at 0°C. After reacting at room temperature for 3 hours, 2,3-dichloro-5,6-dicyanobenzoquinone was slowly added to the reaction; after continuing to react at room temperature for 1 hour, triethylamine and boron trifluoride ether solution were slowly added at 0°C and reacted at room temperature for 10 hours. The reaction was terminated by aqueous quenching method. After separation by dichloromethane and water two-phase extraction system, the organic phase was washed with saturated sodium chloride solution and concentrated by rotary evaporation. Finally, silica gel column chromatography technology was used for separation and purification to obtain compound 8. The structure of compound 8 is as follows:

[0024]

[0025] (9) Compound 8 and 4-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzaldehyde) were added to toluene and placed in a completely sealed Dean-Stark apparatus. Acetic acid and piperidine were slowly added dropwise with stirring at 140°C. The reaction was allowed to proceed for 5 h in the dark, and the reaction was completed when the reaction solution turned blue-green. The reaction solution was extracted, evaporated, and the crude product was separated and purified by silica gel column chromatography. After elution with dichloromethane and methanol, a copper-yellow pure product, compound 9, was obtained. The structure of compound 9 is as follows:

[0026]

[0027] (10) Compound 9, propargyl bromide, and anhydrous potassium carbonate were dissolved in acetonitrile and reacted at 70°C for 10 h. After the reaction, the acetonitrile was completely evaporated to dryness, and the organic phase was extracted with ethyl acetate and water. The organic phase was evaporated to dryness and purified by column chromatography to obtain a brown product, Compound 10. The structure of Compound 10 is as follows:

[0028]

[0029] (11) Compound 7, Compound 10, cuprous thiophene-2-carboxylate, and tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine were weighed and dissolved in tetrahydrofuran. The mixture was reacted at room temperature for 4 h under nitrogen protection. After the reaction, the solvent was evaporated to dryness, and the crude product was separated and purified by flash column chromatography. The product was eluted with methanol and dichloromethane to obtain the green pure product compound BBTD-BD, which is the near-infrared phototherapy agent of the present invention. Its structure is as follows:

[0030]

[0031] The synthetic route of the near-infrared phototherapy agent of the present invention is as follows:

[0032]

[0033]

[0034] Preferably, in step (1), the molar ratio of 3-octyl-1H-pyrrole, di-tert-butyl dicarbonate, and 4-dimethylaminopyridine is 1:1.9:1.25;

[0035] Preferably, in step (2), the molar ratio of compound 1, 2,2,6,6-tetramethylpiperidine, n-butyl lithium, and triethyl borate is 1:1.25:1.15:1.3;

[0036] Preferably, in step (3), the molar ratio of compound 2, 4-bromo-4'-(6-bromohexyloxy)biphenyl, anhydrous potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1.2:1:3:0.05;

[0037] Preferably, in step (4), the molar ratio of compound 3, 2,2,6,6-tetramethylpiperidine, n-butyllithium, and tributyltin chloride is 1:2.1:2:2.2;

[0038] Preferably, in step (5), the molar ratio of compound 4, 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole), and bis(triphenylphosphine)palladium dichloride is 2.5:1:0.3;

[0039] Preferably, in step (6), the molar ratio of compound 5, trimethylsilyl azide, and tetrabutylammonium fluoride is 1:2.5:2.5;

[0040] Preferably, in step (7), the volume ratio of dichloromethane to trifluoroacetic acid is 1:1;

[0041] Preferably, in step (8), the molar ratio of 2,4-dimethylpyrrole, p-hydroxybenzaldehyde, trifluoroacetic acid, 2,3-dichloro-5,6-dicyanobenzoquinone, triethylamine and boron trifluoride ether is 2.5:1:0.15:1:10:11;

[0042] Preferably, in step (9), the molar ratio of compound 8, 4-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzaldehyde), acetic acid and piperidine is 1:3.5:60:35;

[0043] Preferably, in step (10), the molar ratio of compound 9, propyne bromide, and anhydrous potassium carbonate is 1:3:3;

[0044] Preferably, in step (11), the molar ratio of compound 7, compound 10, cuprous thiophene-2-carboxylate and tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine is 1:2.5:1:0.15;

[0045] The present invention also provides the use of the near-infrared photothermal agent BBTD-BD in the preparation of anti-tumor drugs.

[0046] The beneficial effects of the present invention are:

[0047] By covalently coupling a benzobithiadiazole (BBTD) derivative with a boron dipyrrole (BODIPY) dye, this team successfully constructed a multifunctional molecule capable of both NIR-II photothermal conversion and efficient ROS generation. This molecule transcends the limitations of traditional phototherapy systems. Under the synergistic excitation of a 660nm LED light source and a 1060nm laser, it can simultaneously activate photothermal therapy (PTT) and photodynamic therapy (PDT), providing an innovative solution for the precise, synergistic treatment of deep-seated tumors.

[0048] Ultraviolet-visible-near-infrared absorption spectroscopy reveals that the aqueous solution of the phototherapy agent of the present invention has an absorption peak at 1147 nm, demonstrating strong absorption in the near-infrared region II. The photothermal conversion efficiency reached 50.3% under 1060 nm excitation, and excellent singlet oxygen generation was demonstrated under 660 nm LED irradiation. In vitro photothermal and photodynamic therapy tests demonstrated promising results.

[0049] The near-infrared photothermal agent BBTD-BD based on benzobisthiadiazole dyes of the present invention has the characteristics of high photothermal conversion efficiency, near-infrared absorption capacity in the second region, low biological toxicity, etc. 2 ) laser and 606nm LED safe dose irradiation effectively induced cell apoptosis, significantly inhibited tumor growth, and achieved good photothermal therapy effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the nuclear magnetic spectrum of the near-infrared photothermal agent BBTD-BD prepared in Example 11.

[0051] Figure 2 This is the mass spectrum of BBTD-BD.

[0052] Figure 3 is the normalized visible-near infrared absorption curve of BBTD-BD aqueous solution.

[0053] Figure 4 The BBTD-BD aqueous solution described in Example 11 was exposed to a 1060 nm laser (1.0 W / cm 2 ) Linear fitting plot of the natural logarithm of the driving temperature and the time under irradiation.

[0054] Figure 5 The singlet oxygen production of BBTD-BD, where (a) is a graph showing the change in ultraviolet absorption of the aqueous solution of DPBF in the control group under laser (660 nm) irradiation over time; (b) is a graph showing the change in ultraviolet absorption of the aqueous solutions of BBPD-BD and DPBF under laser (660 nm) irradiation over time.

[0055] Figure 6 This is the result of BBTD-BD cytotoxicity experiment. DETAILED DESCRIPTION

[0056] In the following examples, various processes and methods not described in detail are conventional methods known in the art, and all reagents used without indicating their sources and specifications are commercially available as analytical or chromatographically pure.

[0057] Nuclear magnetic resonance spectra were measured using an Oxford Spectroscopy BUXI-INMR NMR spectrometer, and mass spectra were measured using a Bruker Daltonik Apex Ultra Fourier transform ion cyclotron resonance ultrahigh resolution mass spectrometer. Ultraviolet-visible-near-infrared (UV-Vis-NIR) absorption spectra were measured on a Shimadzu UV-3600 spectrometer, and infrared thermal imaging was captured using a Fluke Ti401 PRO thermal imager.

[0058] Example 1: Synthesis of Compound 1

[0059]

[0060] 3-Octyl-1H-pyrrole (4.00 g, 22.3 mmol, 1 eq) and di-tert-butyl dicarbonate (9.25 g, 42.4 mmol, 1.9 eq) were dissolved in 60 mL of acetonitrile. 4-Dimethylaminopyridine (681 mg, 5.6 mmol, 0.25 eq) was slowly added with stirring at room temperature and stirred for 1 hour. The reaction solution was evaporated to dryness, and the solid was dissolved in petroleum ether and purified by neutral alumina column chromatography using pure petroleum ether as the eluent to obtain a colorless oily product with a yield of 60.67%. Compound 1: 1 H NMR (400MHz, DMSO-d6) δ7.14–7.11(m,1H),6.96(s,1H),6.14–6.10(m,1H),2.34(t,J=7. 5Hz,2H),1.53(s,9H),1.51–1.44(m,2H),1.25(d,J=6.5Hz,10H),0.85(t,J=6.8Hz,3H). 13 C NMR (100MHz, DMSO-d6) δ128.13,120.26,116.72,113.66,83.70,31.78,30.25,29.30,29.22,29.17,28.03,27.96,27.38,26.66,22.59,14.47.

[0061] Example 2: Synthesis of Compound 2

[0062]

[0063] Weigh 2,2,6,6-tetramethylpiperidine (632 mg, 4.5 mmol, 1.25 eq) and dissolve it in 10 mL of dry tetrahydrofuran solution. Protect with nitrogen. Precool the reaction flask at -78 ° C for 10 minutes, then slowly add 1.65 mL of n-butyl lithium tetrahydrofuran solution (2.5 mol / L). Continue to react at low temperature for 50 minutes, then add 15 mL of compound 1 (1.00 g, 3.6 mmol, 1 eq) in dry tetrahydrofuran solution. Continue to react for 2 hours, then add triethyl borate (679 mg, 4.7 mmol, 1 eq). Finally, the reaction flask is reacted at room temperature for 10 hours. After the reaction is completed, 50 mL of saturated ammonium chloride solution is added to the reaction flask to quench the reaction. The reaction liquid is extracted with dichloromethane and water. After evaporating the organic phase, the solid is dissolved with ether and petroleum ether and then recrystallized. The filter cake is filtered under reduced pressure to obtain white powder compound 2. Compound 2: 1H NMR (400MHz, DMSO-d6) δ8.03(s,2H),7.07(d,J=0.7Hz,1H),6.33(d,J=1.6Hz,1H),2.33(t ,J=7.5Hz,2H),1.52(s,9H),1.50–1.42(m,2H),1.30–1.20(m,10H),0.85(t,J=6.8Hz,3H). 13 C NMR (100MHz, CDCl3) δ149.96,127.13,121.94,119.70,83.75,31.35,29.93,28.87,28.80,28.74,27.51,25.88,22.15,14.02.

[0064] Example 3: Synthesis of Compound 3

[0065]

[0066] Compound 2 (2.00 g, 6.2 mmol, 1.2 eq), 4-bromo-4'-(6-bromohexyloxy)biphenyl (2.13 g, 5.2 mmol, 1 eq), and tetrakis(triphenylphosphine)palladium (298 mg, 258 μmol, 0.05 eq) were dissolved in 90 mL of toluene and added to a reaction flask. Potassium carbonate (2.14 g, 15.5 mmol, 3 eq) was dissolved in a mixture of 4 mL of water and 4 mL of anhydrous ethanol and added to the reaction flask. The mixture was reacted at 90°C under nitrogen for 24 h. After the reaction, water and dichloromethane were added for extraction. The organic phase was collected, dried over anhydrous sodium sulfate, and filtered under reduced pressure. The filtrate was evaporated to dryness to obtain the crude product, which was isolated and purified by column chromatography using a 2:1 ratio of dichloromethane to petroleum ether as the eluent to obtain the white product, Compound 3, in a yield of 50.18%. Compound 3: 1 H NMR(400MHz,DMSO-d6)δ7.60(t,J=7.5Hz,4H),7.34(d,J=7.8Hz,2H),7.09(s,1H ),7.01(d,J=8.1Hz,2H),6.17(s,1H),4.01(t,J=6.2Hz,2H),3.55(t,J=6.5Hz,2H ),2.38(t,J=7.4Hz,2H),1.88–1.78(m,2H),1.78–1.69(m,2H),1.58–1.50(m,2H) ,1.47(d,J=12.8Hz,4H),1.33(s,9H),1.31–1.21(m,10H),0.85(t,J=6.1Hz,3H). 13C NMR (100MHz, CDCl3) δ158.65,149.50,139.47,134.82,133.41,132.91,129.42,128.06,126.75,125.81,119.21,115.81,114.80, 83.26,67.85,33.87,32.75,31.97,30.30,29.54,29.50,29.35,29.18,28.00,27.76,26.83,25.39,22.75,14.19.HRMS(ESI):m / z calcd.for C 35 H 48 BrNNaO3[M+Na] + 632.2705, found 632.2710.

[0067] Example 4: Synthesis of Compound 4

[0068]

[0069] 2,2,6,6-Tetramethylpiperidine (340 mg, 2.4 mmol, 2.1 eq) was weighed and dissolved in 15 mL of dry tetrahydrofuran under nitrogen. The reaction flask was placed at -78°C and pre-cooled for 10 minutes. After that, 917.02 μL of a 2.5 mol / L solution of n-butyllithium in tetrahydrofuran was slowly added. The reaction was continued at low temperature for 50 minutes. Compound 3 (1.00 g, 3.6 mmol, 1 eq) was dissolved in 15 mL of dry tetrahydrofuran and slowly added to the reaction flask. The reaction was continued for 2.5 hours. Tributyltin chloride (679 mg, 4.6 mmol, 2.2 eq) was added, and the reaction flask was allowed to react at room temperature for 10 hours. After the reaction, the reaction solution was evaporated to dryness, dissolved in petroleum ether, and filtered under reduced pressure to remove insoluble impurities. The filtrate was evaporated to dryness to obtain compound 4, which was directly used in the next step without further purification.

[0070] Example 5: Synthesis of Compound 5

[0071]

[0072] Compound 4 was dissolved in 20 mL of toluene and placed in a round-bottom flask. 4,8-Dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (156 mg, 444 μmol, 1 eq) and bis(triphenylphosphine)palladium dichloride (93 mg, 133 μmol, 0.3 eq) were weighed and added to the reaction flask. The mixture was reacted at 90°C for 24 h under nitrogen protection. After the reaction, the solvent was evaporated and the product was purified by column chromatography using petroleum ether:ethyl acetate = 20:1 to obtain a crude product. The crude product was dissolved in petroleum ether and recrystallized to obtain a blue-green compound 5 with a yield of 23.71%. Compound 5: 1 H NMR (400MHz, CDCl3) δ7.64–7.50(m,12H),7.02–6.95(m,4H),6.49–6.41(m,2H),4.02(dt,J=7.5,3.7Hz,4H),3.44(td,J=6.8,2.3Hz,4 H),2.28(t,J=8.0Hz,4H),1.96–1.79(m,8H),1.47–0.94(m,24H),0.87(d,J=2.3Hz,9H),0.83(q,J=3.5Hz,6H),0.79(d,J=2.3Hz,9H). 13 C NMR (100MHz, CDCl3) δ158.74,153.36,153.27,149.23,139.80,139.73,137.65,137.30,1 33.32,132.71,132.59,130.61,130.41,129.58,128.11,125.96,124.26,124.03,115.31, 114.85,83.27,82.83,67.88,33.88,32.76,31.86,31.82,29.96,29.90,29.68,29.41,29. 36,29.31,29.23,29.19,28.00,26.98,26.88,26.67,25.40,22.69,14.15.HRMS(ESI):m / z calcd.forC 76 H 95 Br2N6O6S2[M+H] + 1411.5095,found 1409.5116.

[0073] Example 6: Synthesis of Compound 6

[0074]

[0075] Compound 5 (400 mg, 283 μmol), trimethylsilyl azide (82 mg, 708 μmol), and 10 mL of ultra-dry tetrahydrofuran were placed in a round-bottom flask under nitrogen. The reaction was stirred in a 0°C ice bath for 10 minutes, followed by the slow dropwise addition of 708 μL of tetrabutylammonium fluoride. The reaction was then allowed to react at room temperature in the dark for 24 hours. After completion of the reaction, the reaction solution was evaporated to dryness, and the remaining solid was recrystallized from petroleum ether to obtain the pure blue product, Compound 6, in a 90% yield. Compound 6: 1 H NMR (400MHz, CDCl3) δ7.64–7.51(m,12H),7.02–6.95(m,4H),6.45(dd,J=10 .0,2.0Hz,2H),4.06–3.98(m,4H),3.34–3.26(m,4H),2.28(t,J=7.9Hz,4H) ,1.84(t,J=6.9Hz,4H),1.71–1.61(m,4H),1.53–1.43(m,8H),1.41–0.88(m ,24H),0.88(d,J=1.9Hz,9H),0.82(d,J=6.5Hz,6H),0.79(d,J=2.0Hz,9H). 13 C NMR (100MHz, CDCl3) δ158.73,153.36,153.27,149.22,139.80,139.72,137.64,137.29,1 33.33,132.71,132.58,130.61,130.41,129.58,128.11,125.95,124.26,124.02,115.31, 114.84,83.26,82.83,67.87,51.46,31.85,31.82,29.96,29.90,29.68,29.40,29.36,29. 30,29.22,29.19,28.88,26.98,26.88,26.67,26.59,25.78,22.68,14.14.HRMS(ESI):m / z calcd.for C 76 H 94 N 12 O6S2[M] + 1334.6855, found 1334.6861.

[0076] Example 7: Synthesis of Compound 7

[0077]

[0078] Compound 6 (300 mg) was thoroughly shaken and dissolved in 2 mL of dichloromethane. The reaction apparatus was placed in an ice bath and stirred for 10 minutes, followed by the rapid addition of 2 mL of trifluoroacetic acid. The mixture was then allowed to react at room temperature for 3 hours. After completion of the reaction, the reaction was quenched with 200 mL of saturated sodium bicarbonate. Stirring was performed until a large amount of bubbles were released. After the bubbles disappeared, the pH was measured with pH paper. When the pH was weakly alkaline, dichloromethane was added to extract the reaction solution. The organic phase was collected and evaporated to dryness. The crude product was separated and purified by column chromatography using dichloromethane as the eluent to obtain the yellow pure product, Compound 7, in an 80% yield. Compound 7: 1 H NMR (400MHz, CDCl3) δ10.57(s,2H),8.09–7.34(m,12H),6.99(d,J=8.2Hz,4H),6.74(s,2H),4.02(t,J=6.3Hz,4H),3.30( t,J=6.8Hz,4H),1.84(t,J=7.0Hz,4H),1.67(p,J=7.6Hz,8H),1.56–1.43(m,10H),1.38–1.16(m,22H),0.89–0.83(m,6H).

[0079] Example 8: Synthesis of Compound 8

[0080]

[0081] Weigh 2,4-dimethylpyrrole (2.5 g, 52.5 mmol) and p-hydroxybenzaldehyde (2.57 g, 21.02 mmol) and dissolve them in 250 mL of dichloromethane. Protect with nitrogen and add 100.35 μL of trifluoroacetic acid at 0°C. After the reaction is allowed to react at room temperature for 3 hours, dissolve 2,3-dichloro-5,6-dicyanobenzoquinone (4.77 g, 21.0 mmol) in 20 mL of ethyl acetate solution and slowly add it to the reaction at 0°C. After continuing to react at room temperature for 1 hour, slowly add 14.61 mL of triethylamine and 14.65 mL of boron trifluoride ether solution at 0°C and react at room temperature for 10 hours. The reaction was terminated by aqueous quenching, and after separation by a two-phase extraction system of dichloromethane and water, the organic phase was washed with a saturated sodium chloride solution and concentrated by rotary evaporation. Finally, silica gel column chromatography was used with dichloromethane: petroleum ether = 1:2 as the eluent to separate and purify the orange-yellow product, Compound 8. Compound 8: 1 NMR (400MHz, CDCl3) δ7.16–7.09(m,2H),6.98–6.92(m,2H),5.98(s,2H),5.03(s,1H),2.55(s,6H),1.44(s,6H).

[0082] Example 9: Synthesis of Compound 9

[0083]

[0084] Compound 8 (520 mg, 1.53 mmol) was weighed and dissolved in 50 mL of toluene in a round-bottom flask. 4-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzaldehyde (1.44 g, 5.35 mmol) was added to the toluene and a completely sealed Dean-Stark apparatus was added. The reaction was stirred at 140°C for 10 minutes, and then 4 mL of acetic acid and 4 mL of piperidine were slowly added dropwise. The reaction was allowed to proceed for 5 hours in the dark, and the reaction was completed when the reaction solution turned blue-green. The reaction solution was evaporated to dryness and saturated sodium bicarbonate was added to neutralize the base in the reaction system. After separation by a two-phase extraction system of dichloromethane and water, the organic phase was washed with saturated sodium chloride solution and concentrated by rotary evaporation. The crude product was finally separated and purified by silica gel column chromatography. After elution with dichloromethane:methanol = 50:1, the copper-yellow pure product compound 9 was obtained with a yield of 27.82%. Compound 9: 1 H NMR (400MHz, CDCl3) δ7.62–7.51(m,6H),7.20(s,1H),7.17–7.10(m,3H),6.94(ddd,J=10.4,8.6,1.6Hz,6H),6.59(s,2H),5.59(s,1H),4.17(t ,J=4.9Hz,4H),3.92–3.86(m,4H),3.79–3.74(m,4H),3.72–3.65(m,8H) ,3.57(ddd,J=6.1,3.6,1.5Hz,4H),3.39(d,J=1.5Hz,6H),1.48(s,6H). 13 C NMR (100MHz, CDCl3) δ159.60,152.62,141.92,135.72,133.69,129.93,129.11,117.58,117.37, 116.12,114.97,77.16,72.04,70.94,70.77,70.66,69.84,67.55,59.18,14.97.HRMS(ESI):m / z calcd.for C 47 H 55 BF2N2O9[M] + 840.3963,found 840.3958.

[0085] Example 10: Synthesis of Compound 10

[0086]

[0087] Use a graduated cylinder to transfer 50 mL of acetonitrile to a flask. Add compound 9 (375 mg, 446 μmol), propargyl bromide (160 mg, 1.34 mmol), and anhydrous potassium carbonate (185 mg, 1.34 mmol) and shake thoroughly to dissolve. The reaction system is then placed in a 70°C oil bath for 10 hours and monitored. After completion, the acetonitrile is completely evaporated to dryness, and the organic phase is extracted with ethyl acetate and water. The organic phase is evaporated to dryness and purified by column chromatography using a dichloromethane:methanol ratio of 50:1 to afford the brown product, compound 10, in a 90% yield. Compound 10: 1 H NMR (400MHz, CDCl3) δ7.65–7.52(m,6H),7.25–7.20(m,3H),7.18(s,1H),7.13–7. 06(m,2H),6.94(d,J=8.2Hz,4H),6.61(s,2H),4.77(d,J=2.2Hz,2H),4.17(d,J=5. 0Hz,4H),3.91–3.86(m,4H),3.76(dd,J=6.0,3.8Hz,4H),3.72–3.65(m,8H),3.57 (d,J=4.1Hz,4H),3.39(d,J=1.8Hz,6H),2.57(s,1H),1.48(s,6H).HRMS(ESI):m / z calcd.forC 50 H 57 BF2N2O9[M] + 878.4120, found 878.4109.

[0088] Example 11: Synthesis of compound BBTD-BD

[0089]

[0090] Compound 7 (100 mg, 88 μmol), compound 10 (193 mg, 220 μmol), cuprous thiophene-2-carboxylate (14 mg, 88 μmol), and tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (7 mg, 13 μmol) were dissolved in 10 mL of tetrahydrofuran and reacted at room temperature for 4 h under nitrogen. After completion of the reaction, the solvent was evaporated to dryness, and the crude product was purified by flash column chromatography using methanol:dichloromethane = 1:70 to obtain the green pure product compound BBTD-BD in a yield of 19.4%. BBTD-BD: 1H NMR (400MHz, DMSO-d6) δ11.53(s,2H),8.27(s,2H),7.83(d,J=8.0Hz,4H),7.70 –7.62(m,8H),7.55(d,J=8.5Hz,10H),7.49(s,2H),7.40(d,J=16.2Hz,4H),7.3 1(d,J=8.2Hz,4H),7.21(d,J=8.3Hz,4H),7.03(d,J=8.4Hz,8H),7.00(d,J=8.3 Hz,4H),6.92(s,4H),6.77(s,2H),5.22(s,4H),4.41(t,J=6.9Hz,4H),4.15(t,J =4.4Hz,8H),3.99(t,J=6.3Hz,4H),3.76(t,J=4.4Hz,8H),3.59(dd,J=6.2,3.5 Hz,8H),3.55–3.50(m,16H),3.43(dd,J=5.9,3.6Hz,8H),3.23(s,12H),2.57(t, J=7.8Hz,4H),1.86(t,J=7.5Hz,4H),1.72(s,4H),1.45(s,20H),1.32(d,J=7.4 Hz,4H),1.16–1.08(m,8H),1.04(s,12H),0.76(t,J=7.2Hz,6H).HRMS(ESI):m / z calcd.for C 166 H 192 B2F4N 16 O 20 S2[M] 3+ 964.1360,found964.1357.

[0091] The compound BBTD-BD obtained above was characterized, and the results were as follows Figure 1-3 shown.

[0092] Example 12: Calculation of the photothermal conversion efficiency of the BBTD-BD prepared in Example 11

[0093] The power density of the nanostructured carbon nanotubes at 1060 nm (1.0 W / cm 2) irradiation, the temperature change of 100μmol / L aqueous solution of BBTD-BD (irradiation for 600s, then naturally cooled to room temperature, and the temperature information was recorded every 30s with an infrared thermal imager) and the photothermal conversion efficiency (η) was calculated. The measurement results are shown in Figure 4 As shown, the light-to-thermal conversion efficiency of BBTD-BD is 50.3%.

[0094] Example 13: Singlet oxygen generation of BBTD-BD prepared in Example 11

[0095] The singlet oxygen probe DPBF was used as the monitoring material to monitor the generation of singlet oxygen in BBTD-BD under laser irradiation. The aqueous solution of BBPD-BD and DPBF and the aqueous solution of the control group DPBF were irradiated with laser (660nm) and the changes in ultraviolet absorption over time were recorded. The results are as follows Figure 5 Compared with the control group, it can be seen that the characteristic peak of the BBTD-BD group at 414nm continues to decrease with the increase of illumination time, which shows that the BBTD-BD compound has a certain ability to produce active oxygen.

[0096] Example 14: Evaluation of the dark toxicity and phototoxicity of the BBTD-BD prepared in Example 11 using the human breast cancer cell line MCF 7

[0097] Cytotoxicity Assessment: MCF-7 cells (10,000 cells per well) were seeded in 96-well plates and cultured at 37°C in a 5% CO2 incubator for 24 hours. The cells were then incubated with various concentrations of BBTD-BD in DMEM high-glucose complete medium for 24 hours. Cell viability was determined using a standard MTT assay relative to the control group.

[0098] Cell phototoxicity evaluation: MCF7 cells (10,000 cells per well) were seeded in 96-well plates and cultured in a 5% CO2 incubator at 37°C for 24 hours. The cells were incubated with DMEM high-glucose complete medium containing different concentrations of BBTD-BD for 6 hours and then irradiated with a 1060 nm laser (1.0 W / cm 2 ) for 5 min, followed by 660 nm LED illumination for 5 min, and continued incubation for 18 h. Cell viability was determined relative to that of the control group using a standard MTT assay.

[0099] The test results are as follows Figure 6As shown. Analysis of the data of the non-illumination group showed that as the concentration of BBTD-BD increased, even at a concentration of 100 μmol / L, the cell activity was still high, indicating that the photothermal agent has low biological toxicity. Analysis of the data of the illumination group showed that as the concentration of BBTD-BD increased, the cell activity gradually decreased. At a concentration of 100 μmol / L, the cell activity was as low as 29%. At 1060 nm (1.0 W / cm 2 ) laser and 660nm LED safe dose irradiation effectively induced cell apoptosis, significantly inhibited tumor growth, and achieved good photothermal therapy effects.

[0100] The above description of the embodiments is to facilitate those skilled in the art to understand and use the invention, and is not intended to limit the invention. Any local changes based on this description should fall within the scope of protection of the invention.

Claims

1. A near-infrared phototherapy agent, characterized in that: Its structural formula is shown below:

2. The method for preparing the near-infrared phototherapy agent according to claim 1, characterized in that: The synthetic route is:

3. The preparation method according to claim 2, characterized in that: The steps include: (1) 3-octyl-1H-pyrrole and di-tert-butyl dicarbonate were dissolved in acetonitrile, 4-dimethylaminopyridine was added, and the mixture was stirred at room temperature for 1 hour; the reaction solution was evaporated to dryness, dissolved, and purified to obtain compound 1; (2) Dissolve 2,2,6,6-tetramethylpiperidine in tetrahydrofuran solution, protect with nitrogen, pre-cool at -78°C, add tetrahydrofuran solution of n-butyl lithium, add compound 1 after reaction, continue reaction for 2 hours, add triethyl borate, and react at room temperature for 10 hours; after completion of the reaction, post-process to obtain compound 2; (3) Compound 2, 4-bromo-4'-(6-bromohexyloxy)biphenyl and tetrakis(triphenylphosphine)palladium were dissolved in a toluene solution, and a water / ethanol mixed solution of potassium carbonate was added. The mixture was reacted at 90°C under nitrogen protection for 24 hours. After the reaction, compound 3 was obtained after post-treatment. (4) 2,2,6,6-tetramethylpiperidine was dissolved in tetrahydrofuran, protected by nitrogen, and pre-cooled at -78°C, followed by addition of a tetrahydrofuran solution of n-butyllithium. After the reaction, compound 3 was added, and tributyltin chloride was added after further reaction, and the reaction was continued at room temperature for 10 hours. After the reaction was completed, compound 4 was obtained by post-treatment. (5) Compound 4 was dissolved in toluene, and 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) and bis(triphenylphosphine)palladium dichloride were added. The mixture was reacted at 90°C for 24 hours under nitrogen protection. After the reaction, the solvent was evaporated and the mixture was separated and purified by column chromatography to obtain compound 5. (6) Compound 5 and trimethylsilyl azide were dissolved in tetrahydrofuran under nitrogen protection, and tetrabutylammonium fluoride was added dropwise at 0°C. The mixture was then reacted in the dark at room temperature for 24 hours. After the reaction, the reaction solution was evaporated to dryness, and the remaining solid was recrystallized from petroleum ether to obtain compound 6. (7) Compound 6 was dissolved in dichloromethane, trifluoroacetic acid was added at 0°C, and the mixture was reacted at room temperature for 3 h. After the reaction, the mixture was quenched with a saturated aqueous sodium bicarbonate solution, and then extracted and purified by column chromatography to obtain compound 7. (8) 2,4-Dimethylpyrrole and p-hydroxybenzaldehyde were dissolved in dichloromethane, protected by nitrogen, and trifluoroacetic acid was added at 0°C. After reacting at room temperature for 3 hours, 2,3-dichloro-5,6-dicyanobenzoquinone was added. After continuing to react at room temperature for 1 hour, triethylamine and boron trifluoride ether solution were added at 0°C, and the reaction was continued at room temperature for 10 hours. The reaction was terminated by aqueous quenching method, and then post-processed to obtain compound 8. (9) Compound 8 and 4-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzaldehyde) were added to toluene, and acetic acid and piperidine were added dropwise under stirring at 140°C. The mixture was reacted in the dark for 5 h. The reaction was completed when the reaction solution turned blue-green. The reaction solution was post-treated to obtain compound 9. (10) Compound 9, propargyl bromide, and anhydrous potassium carbonate were dissolved in acetonitrile and reacted at 70°C for 10 h. After the reaction, the acetonitrile was completely evaporated, and the organic phase was extracted with ethyl acetate and water. The organic phase was evaporated to dryness and purified by column chromatography to obtain compound 10. (11) Compound 7, compound 10, cuprous thiophene-2-carboxylate, and tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine were dissolved in tetrahydrofuran, and reacted at room temperature for 4 hours under nitrogen protection; after the reaction, the solvent was evaporated, and the crude product was separated and purified by flash column chromatography, and eluted with methanol and dichloromethane to obtain the near-infrared phototherapy agent.

4. The preparation method according to claim 3, wherein In step (1), the molar ratio of 3-octyl-1H-pyrrole, di-tert-butyl dicarbonate, and 4-dimethylaminopyridine is 1:1.9:1.25; in step (2), the molar ratio of compound 1, 2,2,6,6-tetramethylpiperidine, n-butyl lithium, and triethyl borate is 1:1.25:1.15:1.

3.

5. The preparation method according to claim 3, wherein In step (3), the molar ratio of compound 2, 4-bromo-4'-(6-bromohexyloxy)biphenyl, anhydrous potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1.2:1:3:0.05; in step (4), the molar ratio of compound 3, 2,2,6,6-tetramethylpiperidine, n-butyllithium, and tributyltin chloride is 1:2.1:2:2.

2.

6. The preparation method according to claim 3, characterized in that: In step (5), the molar ratio of compound 4, 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole), and bis(triphenylphosphine)palladium dichloride is 2.5:1:0.3; in step (6), the molar ratio of compound 5, trimethylsilyl azide, and tetrabutylammonium fluoride is 1:2.5:2.

5.

7. The preparation method according to claim 3, characterized in that: In step (7), the volume ratio of dichloromethane and trifluoroacetic acid is 1:1; in step (8), the molar ratio of 2,4-dimethylpyrrole, p-hydroxybenzaldehyde, trifluoroacetic acid, 2,3-dichloro-5,6-dicyanobenzoquinone, triethylamine and boron trifluoride ether is 2.5:1:0.15:1:10:

11.

8. The preparation method according to claim 3, characterized in that: In step (9), the molar ratio of compound 8, 4-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzaldehyde), acetic acid and piperidine is 1:3.5:60:35; in step (10), the molar ratio of compound 9, propargyl bromide and anhydrous potassium carbonate is 1:3:

3.

9. The preparation method according to claim 3, characterized in that: In step (11), the molar ratio of compound 7, compound 10, cuprous thiophene-2-carboxylate and tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine is 1:2.5:1:0.

15.

10. Use of the near-infrared phototherapy agent according to claim 1 in the preparation of anti-tumor drugs.

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