An inhibitor, a radioactive probe, and an application targeting platelet-derived growth factor receptor β

Abstract

The present invention relates to an inhibitor targeting platelet-derived growth factor receptor β (PDGFRβ), a radioactive probe and their applications, belonging to the fields of nuclear medicine imaging agents and radionuclide radiotherapy agents. The inhibitor of the present invention is at least one of the compounds shown by formula I, and the radioactive probe is at least one of the compounds shown by formula II. The radioactive probe targeting PDGFRβ provided by the present invention can specifically target tumors with high expression of PDGFRβ, and has good tumor uptake and rapid in vivo metabolism properties. The radioactive probe targeting PDGFRβ provided by the present invention has a good tumor-to-background ratio, can be rapidly metabolized and excreted from the body through the kidneys, and has important clinical application value for the early and accurate diagnosis and targeted radiotherapy of PDGFRβ-positive tumors and screening of beneficiaries of anti-angiogenic treatment strategies.

Description

Technical Field

[0001] The present invention relates to an inhibitor targeting platelet-derived growth factor receptor β (PDGFRβ), a radioactive probe and applications thereof, belonging to the fields of nuclear medicine imaging agents and radionuclide radiotherapy agents. Background Art

[0002] Platelet-derived growth factor receptor β (PDGFRβ) is a transmembrane receptor tyrosine kinase that can bind to family members of platelet-derived growth factor such as PDGF-BB and PDGF-DD, initiate intercellular information transmission, increase mitotic activity, anti-apoptotic activity, actin reorganization and cell migration, and play an important role in angiogenesis. PDGFRβ is lowly expressed in most normal cells, but highly expressed in different tumors and is related to tumor progression (tumor cell migration, metastasis and proliferation as well as angiogenesis), and is a potential target for developing tumor imaging agents.

[0003] The tumor vascular system is an important factor affecting the efficacy of tumor treatment. Tumors not only obtain oxygen and nutrients from the host through newly formed tumor blood vessels, but also continuously transmit metastatic cells to the host through the new blood vessels, and at the same time release tumorigenic cytokines and angiogenic factors, ultimately leading to tumor infiltration and migration. Tumor neovascularization is different from normal blood vessels in structure and physiology. The tumor vascular system of most solid tumors develops rapidly and has the characteristics of large endothelial gaps, abnormal or absent basement membranes, abnormal pericyte morphology and strong vascular permeability. Targeted therapy against related receptors of tumor angiogenesis has become a new method for tumor treatment in recent years. The overexpression of PDGFRβ is related to abnormal angiogenesis, and thus has become a potential marker for anti-angiogenic treatment strategies in highly vascular tumor diseases such as liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer and colorectal cancer.

[0004] Nuclear medicine positron emission tomography / X-ray computed tomography (PET / CT), as a radionuclide imaging technology, uses radioactive probes to non-invasively visualize tumor lesions and microenvironments at the molecular level, and has the advantages of being real-time, dynamic, quantitative, highly sensitive and high-resolution. PET / CT can play multiple roles such as early diagnosis, efficacy evaluation and prognosis judgment of tumors by using radioactive probes. At the same time, radioactive probes can target and kill tumors using radioactive therapeutic radionuclides, and have excellent clinical therapeutic value.

[0005] There have been many reports on the development of radioactive probes targeting PDGFRβ. Although the reported radioactive probes targeting PDGFRβ can image tumors, they have certain drawbacks: high non-specific uptake in normal tissues (especially the kidneys), resulting in a high radioactive dose burden and damage; most probes are antibody-based probes, with the drawback of high immunogenicity and cannot be used repeatedly. By modifying the structure of the compound, the in vivo metabolic properties of the probe can be improved, and the non-specific uptake in normal tissues can be reduced; using small molecule probes can overcome the drawbacks of antibody probes: compared with antibody probes, small molecule probes have the advantages of small molecular weight, good tumor permeability, fast clearance of non-target uptake, and low immunogenicity, and are the preferred choice for the design of radioactive probes. However, due to the extremely high R & D difficulty of small molecule probes compared with polypeptide / antibody probes, so far, there has been no report on small molecule radioactive probes targeting PDGFRβ at home and abroad.

[0006] Therefore, targeting PDGFRβ, a specific small molecule inhibitor and radioactive probe targeting PDGFRβ are provided. With the help of nuclear medicine PET / CT technology, early accurate diagnosis, efficacy evaluation and prognosis assessment of patients with hypervascular tumor diseases can be achieved, as well as screening of beneficiaries of anti-angiogenic treatment strategies. At the same time, radioactive nuclide targeted therapy can be carried out on patients who cannot be surgically resected using the radioactive probe targeting PDGFRβ of the present invention, which has important value for the clinical diagnosis and treatment of hypervascular tumors (liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer and colorectal cancer). Summary of the Invention

[0007] The object of the present invention is to provide a specific small molecule inhibitor and radioactive probe targeting PDGFRβ. For hypervascular tumors (liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer and colorectal cancer) with high expression of PDGFRβ, using the radioactive probe targeting PDGFRβ of the present invention in combination with PET / CT can achieve early accurate diagnosis, efficacy evaluation and prognosis assessment of the disease, as well as screening of beneficiaries of anti-angiogenic treatment strategies; for tumor patients who cannot be surgically resected, targeted radioactive therapy can be achieved by using the small molecule inhibitor targeting PDGFRβ of the present invention to chelate radioactive therapeutic nuclides, so as to improve the treatment effect. The present invention constructs a small molecule inhibitor and radioactive probe with high selectivity and high affinity for PDGFRβ by strategies such as constructing a core targeting group and changing different linking groups. Through experiments, it is verified that the small molecule targeted PDGFRβ inhibitor and radioactive probe constructed by the present invention have good specific targeting uptake and fast in vivo metabolic properties for tumors with high expression of PDGFRβ, have low non-specific uptake in normal tissues, and are rapidly metabolized and excreted from the body through the kidneys, obtaining a good tumor-to-background ratio.

[0008] To achieve the above object, a first aspect of the present invention provides an inhibitor targeting PDGFRβ, and the inhibitor is at least one of the compounds shown in Formula I:

[0009]

[0010] Wherein, Chelator is a bifunctional chelating agent structure, selected from any one of the following:

[0011]

[0012]

[0013]

[0014] L1 is Wherein, n1 is 0 or 1; L2 is a linking group, selected from any one of the following:

[0015]

[0016] Wherein, n2 takes an integer from 0 to 8;

[0017] L3 is Wherein, n3 is 0 or 1.

[0018] Specifically, the inhibitor is preferably selected from one of the following inhibitors 1-3:

[0019]

[0020] A second aspect of the present invention provides a radioactive probe targeting PDGFRβ, and the radioactive probe is at least one of the compounds shown in Formula II:

[0021]

[0022] Wherein, Chelate portion is a structure formed by chelation of a radionuclide with a bifunctional chelating agent, selected from any one of the following:

[0023]

[0024]

[0025]

[0026] Wherein, M is a radionuclide, and the radionuclide is a diagnostic radionuclide or a therapeutic radionuclide; the diagnostic radionuclide is Al 18 F, 68 Ga,64 Cu, 44 Sc, 89 Zr, 86 Y, 90 Y, 99m Tc, and 111 at least one of In, and the therapeutic radionuclide is 67 Cu, 177 Lu, 225 Ac, 211 At, 212 Pb, 212 Bi, 213 Bi, 161 Tb, 111 In, 153 Sm, 186 Re, and 188 at least one of Re;

[0027] L1 is wherein n1 is 0 or 1;

[0028] L2 is a linking group selected from any one of the following:

[0029]

[0030] wherein n2 is an integer from 0 to 8;

[0031] L3 is wherein n3 is 0 or 1.

[0032] Specifically, the radioactive probe is preferably selected from one of the following radioactive probes 4-9:

[0033]

[0034]

[0035] The third aspect of the present invention provides the use of the above radioactive probe in the preparation of a radioactive imaging diagnostic reagent or a radionuclide therapeutic reagent. Among them, the radioactive imaging diagnostic reagent is preferably an early detection reagent, a therapeutic effect evaluation reagent, a prognosis judgment reagent, or an anti-angiogenesis therapy benefit population screening reagent for tumors with high expression of PDGFRβ; the radionuclide therapeutic reagent is preferably a therapeutic reagent for tumors with high expression of PDGFRβ; the tumor is preferably a highly vascular tumor: liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer, and colorectal cancer.

[0036] The present invention provides an inhibitor and a radioactive probe containing a core targeting group and different linking groups. The core targeting group is preferably N that selectively binds to PDGFRβ 2-(4-(4-(5-Aminopentyl)piperazin-1-yl)-3-methoxyphenyl)-N 4 -(1H-Indazol-6-yl)-5-methylpyrimidine-2,4-diamine, and the linking group is preferably Both the inhibitor and the radioactive probe showed high targeting specificity and high binding affinity for PDGFRβ.

[0037] Beneficial effects:

[0038] The PDGFRβ-targeted radioactive probe of the present invention has excellent radiochemical yield and radiochemical purity, as well as excellent in vitro stability, and has good specific targeting uptake and rapid in vivo metabolism properties for tumors with high expression of PDGFRβ. The PDGFRβ radioactive probe provided by the present invention has low non-specific uptake in normal tissues, is rapidly metabolized and excreted from the body through the kidneys, obtaining a good tumor-to-background ratio, and has important application values for the early accurate diagnosis of rich vascular tumors (liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer and colorectal cancer), screening of beneficiaries of anti-angiogenic therapy, and radioactive targeted therapy.

[0039] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this does not mean any limitation to the protection scope of the present invention. Brief description of the drawings

[0040] Figures 1-1 to 1-3 It is the mass spectrometry diagram of inhibitors 1, 2, and 3 synthesized in Example 1 of the present invention;

[0041] Figures 2-1 to 2-4 It is prepared in Example 2 of the present invention 68 Ga]Ga-1, 177 The radioactive HPLC diagram and radioactive TLC diagram of the labeling reaction solution of Lu]Lu-1;

[0042] Figures 3-1 to 3-4 It is prepared in Example 3 of the present invention 68 Ga]Ga-2, 177 The radioactive HPLC diagram and radioactive TLC diagram of the labeling reaction solution of Lu]Lu-2;

[0043] Figures 4-1 to 4-4 It is prepared in Example 4 of the present invention 68 Ga]Ga-3, 177 The radioactive HPLC diagram and radioactive TLC diagram of the labeling reaction solution of Lu]Lu-3;

[0044] Figure 5 In Example 5 of the present invention, 68 Ga]Ga-1, 68 Ga]Ga-2,68 Radioactive HPLC chromatograms of [[Ga]]Ga-3 incubated in physiological saline or mouse serum at 37 °C for different times;

[0045] Figure 6 In Example 6 of the present invention, in the absence / presence of different PDGFRβ inhibitors, the uptake of 68 [[Ga]]Ga-1, 68 [[Ga]]Ga-2, 68 [[Ga]]Ga-3 by glioblastoma cells (U87MG cells, PDGFRβ-positive) in vitro (n = 4);

[0046] Figure 7 In Example 7 of the present invention, 68 [[Ga]]Ga-1, 68 [[Ga]]Ga-2, 68 Uptake of [[Ga]]Ga-3 in tumors and normal tissues of U87MG tumor-bearing (PDGFRβ-positive) nude mice in vivo (n = 4). Detailed implementation manners

[0047] Unless otherwise specified, the raw materials and reagents mentioned in the examples of the present invention are all conventional raw materials and reagents that can be purchased on the market. The testing methods used are all conventional methods in the art, and the equipment and devices used are all conventional equipment and devices in the art.

[0048] Example 1: Preparation and characterization of PDGFRβ-targeted inhibitors 1, 2, and 3

[0049] Step 1: Preparation and characterization of PDGFRβ-targeted inhibitor 1:

[0050] The synthesis route is as follows:

[0051]

[0052] Specifically, it includes the following steps:

[0053] (1) Synthesis of compound 1:

[0054] Dissolve benzyl chloroformate (680 mg, 4 mmol) in ethyl acetate (15 mL), add cesium carbonate (1630 mg, 5 mmol), stir at room temperature for 10 minutes, then dropwise add tert-butyl 4-(4-amino-2-methoxyphenyl)piperazine-1-carboxylate (1228 mg, 4 mmol) dissolved in ethyl acetate (30 mL) to the above solution. The reaction solution is refluxed and stirred at 80 °C for 17 hours, filtered through diatomaceous earth, and evaporated under reduced pressure to remove the solvent. The residue is purified by silica gel column chromatography (dichloromethane / methanol = 20 / 1, v / v) to obtain a brown-yellow oily compound 1 (1320 mg, 2.99 mmol), with a yield of 74.8%;

[0055] Structure confirmation of Compound 1: HRMS C 24 H 32 N3O5[M+H] + Theoretical molecular weight 442.2336, measured molecular weight 442.2322, Δ=-3.2741 ppm;

[0056] (2) Synthesis of Compound 2:

[0057] Dissolve Compound 1 (1320 mg, 2.99 mmol) in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, rotary evaporate under reduced pressure to remove the solvent. Dissolve the residue in ethyl acetate (20 mL), add cesium carbonate (1304 mg, 4 mmol), and stir at room temperature for 10 minutes. Then, dropwise add tert-butyl (5-bromopentyl)carbamate (795 mg, 3 mmol) dissolved in ethyl acetate (30 mL) to the above solution. The reaction mixture is refluxed and stirred at 80 °C for 48 hours, filtered through diatomaceous earth, rotary evaporated under reduced pressure to remove the solvent, and the residue is purified by silica gel column chromatography (dichloromethane / methanol = 20 / 1, v / v) to obtain Compound 2 as a purple-red oil (1415 mg, 2.69 mmol), yield: 89.7%;

[0058] Structure confirmation of Compound 2: HRMS C 29 H 43 N4O5[M+H] + Theoretical molecular weight 527.3227, measured molecular weight 527.3211, Δ=-3.2188 ppm;

[0059] (3) Synthesis of Compound 3:

[0060] Compound 2 (38 mg, 0.072 mmol) was dissolved in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, the solvent was removed by rotary evaporation under reduced pressure to obtain a brown oil. 5-(tert-Butoxy)-5-oxo-4-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanoic acid (50 mg, 0.071 mmol) was dissolved in ultra-dry N,N-dimethylformamide (2 mL). The solution was stirred in an ice-water bath, and 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 66 mg, 0.17 mmol) was added. N,N'-Diisopropylethylamine (DIPEA, 54 mg, 0.42 mmol) was added dropwise. After stirring in the ice-water bath for 30 minutes, the above-mentioned brown oil dissolved in ultra-dry N,N-dimethylformamide (2 mL) was added dropwise. The reaction mixture was stirred in the ice-water bath for 3 hours, extracted with ethyl acetate (30 mL × 3), and the organic phase was collected. The organic phase was washed with saturated brine (30 mL × 2), and the organic phase was collected, dried over anhydrous sodium sulfate, filtered, and anhydrous sodium sulfate was removed. After the solvent was removed from the filtrate by rotary evaporation under reduced pressure, it was purified by silica gel column chromatography (dichloromethane / methanol = 40 / 1, v / v) to obtain yellow oily compound 3 (59.6 mg, 0.054 mmol), with a yield of 75.7%;

[0061] Structure confirmation of compound 3: HRMS C 59 H 97 N8O 12 [M+H] + Theoretical molecular weight 1109.722, measured molecular weight 1109.7197, Δ = -2.1158 ppm;

[0062] (4) Synthesis of the PDGFRβ inhibitor 1:

[0063] Compound 3 (10.2 mg, 0.0092 mmol) was dissolved in methanol (5 mL), palladium on carbon (0.5 mg, 0.0047 mmol) was added, and the mixture was stirred at room temperature for 1 hour under a hydrogen atmosphere. After filtration through diatomaceous earth, the solvent was removed by rotary evaporation under reduced pressure. The residue was dissolved in methanol (12 mL), N-(2-chloro-5-methylpyrimidin-4-yl)-1H-indazol-6-amine (30 mg, 0.116 mmol) and trifluoroacetic acid (0.48 mL) were added, and the mixture was refluxed and stirred at 80 °C for 60 hours under a nitrogen atmosphere. The solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (phase A: 0.1% trifluoroacetic acid in water, phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain a yellow floc. The yellow floc was dissolved in trifluoroacetic acid (5 mL), stirred at room temperature for 8 hours, and then the solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (phase A: 0.1% trifluoroacetic acid in water, phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain colorless flocculent inhibitor 1 (2.02 mg, 0.0021 mmol), with a yield of 22.6% and a purity of >95%;

[0064] Structural confirmation of the PDGFRβ inhibitor 1: HRMS C 47 H 68 N 13 O 10 [M + H] + Theoretical molecular weight 974.5206, measured molecular weight 974.5194, Δ = -1.2956 ppm;

[0065] As Figure 1-1 shown is the high-resolution mass spectrum of the PDGFRβ inhibitor 1;

[0066] Step 2: Preparation and characterization of the PDGFRβ inhibitor 2:

[0067] The synthetic route is as follows:

[0068]

[0069] Specifically, it includes the following steps:

[0070] (1) Synthesis of compound 4:

[0071] Compound 2 (275 mg, 0.65 mmol) was dissolved in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, the solvent was removed by rotary evaporation under reduced pressure to obtain a brown oil. 2,2-Dimethyl-4-oxo-3,8,11,14-tetraoxa-5-azaoctadecane-17-oic acid (208 mg, 0.65 mmol) was dissolved in ultradry N,N-dimethylformamide (2 mL). The solution was stirred in an ice-water bath, and 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 591 mg, 1.55 mmol) was added. N,N'-Diisopropylethylamine (DIPEA, 482 mg, 3.73 mmol) was added dropwise. After stirring in the ice-water bath for 30 minutes, the above-mentioned brown oil dissolved in ultradry N,N-dimethylformamide (2 mL) was added dropwise. The reaction mixture was stirred in the ice-water bath for 4 hours, extracted with ethyl acetate (30 mL × 3), and the organic phase was collected. The organic phase was washed with saturated brine (30 mL × 2), and the organic phase was collected, dried over anhydrous sodium sulfate, filtered, and anhydrous sodium sulfate was removed. After the solvent was removed from the filtrate by rotary evaporation under reduced pressure, it was purified by silica gel column chromatography (dichloromethane / methanol = 30 / 1, v / v) to obtain yellow oily compound 4 (303.6 mg, 0.416 mmol), yield: 64.0%;

[0072] Structure confirmation of compound 4: HRMS C 38 H 60 N5O9[M+H] + Theoretical molecular weight 730.4385, measured molecular weight 730.4369, Δ = -2.2666 ppm;

[0073] (2) Synthesis of compound 5:

[0074] Compound 4 (52 mg, 0.071 mmol) was dissolved in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, the solvent was removed by rotary evaporation under reduced pressure to obtain a brown oil. 5-(tert-Butoxy)-5-oxo-4-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanoic acid (50 mg, 0.071 mmol) was dissolved in ultradry N,N-dimethylformamide (2 mL). The solution was stirred in an ice-water bath, and 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 66 mg, 0.17 mmol) was added. N,N'-Diisopropylethylamine (DIPEA, 54 mg, 0.42 mmol) was added dropwise. After stirring in the ice-water bath for 30 minutes, the above-mentioned brown oil dissolved in ultradry N,N-dimethylformamide (2 mL) was added dropwise. The reaction mixture was stirred in the ice-water bath for 7.5 hours, extracted with ethyl acetate (30 mL × 3), and the organic phase was collected. The organic phase was washed with saturated brine (30 mL × 2), and the organic phase was collected, dried over anhydrous sodium sulfate, filtered, and the anhydrous sodium sulfate was removed. After the solvent was removed from the filtrate by rotary evaporation under reduced pressure, it was purified by silica gel column chromatography (dichloromethane / methanol = 30 / 1, v / v) to obtain yellow oily compound 5 (78.7 mg, 0.060 mmol), with a yield of 84.5%;

[0075] Structure confirmation of compound 5: HRMS C 68 H 114 N9O 16 [M+H] + Theoretical molecular weight 1312.8378, measured molecular weight 1312.8405, Δ = 2.0518 ppm;

[0076] (3) Synthesis of the PDGFRβ inhibitor 2:

[0077] Compound 5 (63.5 mg, 0.048 mmol) was dissolved in methanol (5 mL), and palladium on carbon (2.55 mg, 0.024 mmol) was added. After stirring the reaction under a hydrogen atmosphere at room temperature for 1 hour, it was filtered through diatomaceous earth, and the solvent was removed by rotary evaporation under reduced pressure. The residue was dissolved in methanol (12 mL), N-(2-chloro-5-methylpyrimidin-4-yl)-1H-indazole-6-amine (30 mg, 0.116 mmol) and trifluoroacetic acid (0.48 mL) were added, and the reaction was refluxed and stirred under a nitrogen atmosphere at 80 °C for 60 hours. The solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (Phase A: 0.1% trifluoroacetic acid in water, Phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain a yellow floc. The yellow floc was dissolved in trifluoroacetic acid (5 mL), stirred at room temperature for 8 hours, and then the solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (Phase A: 0.1% trifluoroacetic acid in water, Phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain a colorless flocculent inhibitor 2 (17.1 mg, 0.0145 mmol), yield: 30.3%, purity: >95%;

[0078] Structure confirmation of the PDGFRβ inhibitor 2: HRMS C 56 H 84 N 14 O 14 [M+H] + Theoretical molecular weight 1177.6364, measured molecular weight 1177.6339, Δ = -2.1406 ppm;

[0079] As Figure 1-2 shown is the high-resolution mass spectrum of the PDGFRβ inhibitor 2;

[0080] Step 3: Preparation and characterization of the PDGFRβ inhibitor 3:

[0081] The synthetic route is as follows:

[0082]

[0083] Specifically, it includes the following steps:

[0084] (1) Synthesis of compound 6:

[0085] Compound 2 (158 mg, 0.3 mmol) was dissolved in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, the solvent was removed by rotary evaporation under reduced pressure to obtain a brown oil. 2,2-Dimethyl-4-oxo-3,8,11,14,17,20,23-heptaoxa-5-azapentacosanoic acid (136 mg, 0.3 mmol) was dissolved in ultradry N,N-dimethylformamide (2 mL), and the solution was stirred in an ice-water bath. 2-(7-Azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 273.6 mg, 0.72 mmol) was added, and N,N'-diisopropylethylamine (DIPEA, 223 mg, 1.725 mmol) was added dropwise. After stirring in an ice-water bath for 30 minutes, the above-mentioned brown oil dissolved in ultradry N,N-dimethylformamide (2 mL) was added dropwise. The reaction solution was stirred and reacted in an ice-water bath for 4 hours, extracted with ethyl acetate (30 mL × 3), and the organic phase was collected, washed with saturated brine (30 mL × 2), and the organic phase was collected, dried over anhydrous sodium sulfate, filtered, and anhydrous sodium sulfate was removed. After the solvent was removed from the filtrate by rotary evaporation under reduced pressure, it was purified by silica gel column chromatography (dichloromethane / methanol = 20 / 1, v / v) to obtain yellow oily compound 6 (221.6 mg, 0.257 mmol), yield: 85.7%;

[0086] Structure confirmation of compound 6: HRMS C 44 H 72 N5O 12 [M+H] + Theoretical molecular weight 862.5172, measured molecular weight 862.5151, Δ = -2.4347 ppm;

[0087] (2) Synthesis of compound 7:

[0088] Compound 6 (74 mg, 0.086 mmol) was dissolved in trifluoroacetic acid (5 mL). After stirring at room temperature for 30 minutes, the solvent was removed by rotary evaporation under reduced pressure to obtain a brown oil. 5-(tert-Butoxy)-5-oxo-4-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanoic acid (60 mg, 0.086 mmol) was dissolved in ultradry N,N-dimethylformamide (2 mL). The solution was stirred in an ice-water bath, and 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU, 98 mg, 0.26 mmol) was added. N,N'-Diisopropylethylamine (DIPEA, 90 mg, 0.70 mmol) was added dropwise. After stirring in the ice-water bath for 30 minutes, the above-mentioned brown oil dissolved in ultradry N,N-dimethylformamide (2 mL) was added dropwise. The reaction solution was stirred in the ice-water bath for 8.5 hours, extracted with ethyl acetate (30 mL × 3), and the organic phase was collected. The organic phase was washed with saturated brine (30 mL × 2), and the organic phase was collected, dried over anhydrous sodium sulfate, filtered, and anhydrous sodium sulfate was removed. After the solvent was removed by rotary evaporation under reduced pressure, the residue was purified by silica gel column chromatography (dichloromethane / methanol = 30 / 1, v / v) to obtain yellow oily compound 7 (83.9 mg, 0.058 mmol), with a yield of 67.6%;

[0089] Structure confirmation of compound 7: HRMS C 74 H 125 N9O 19 [M+H] + Theoretical molecular weight 1444.9164, measured molecular weight 1444.9158, Δ = -0.4503 ppm;

[0090] (3) Synthesis of the PDGFRβ inhibitor 3:

[0091] Compound 7 (69.5 mg, 0.048 mmol) was dissolved in methanol (5 mL), and palladium on carbon (2.55 mg, 0.024 mmol) was added. After stirring the reaction under a hydrogen atmosphere at room temperature for 1 hour, it was filtered through diatomaceous earth, and the solvent was removed by rotary evaporation under reduced pressure. The residue was dissolved in methanol (12 mL), N-(2-chloro-5-methylpyrimidin-4-yl)-1H-indazol-6-amine (30 mg, 0.116 mmol) and trifluoroacetic acid (0.48 mL) were added, and the mixture was refluxed and stirred under a nitrogen atmosphere at 80 °C for 60 hours. The solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (Phase A: 0.1% trifluoroacetic acid in water, Phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain a yellow floc. The yellow floc was dissolved in trifluoroacetic acid (5 mL), stirred at room temperature for 8 hours, and then the solvent was removed by rotary evaporation under reduced pressure. The residue was purified by high performance liquid chromatography (Phase A: 0.1% trifluoroacetic acid in water, Phase B: 0.1% trifluoroacetic acid in acetonitrile, 0 - 15 minutes: 0% - 30% B, 15 - 17 minutes: 30% - 0% B; 17 - 20 minutes: 0% B) to obtain colorless flocculent inhibitor 3 (8.89 mg, 0.0068 mmol), yield: 14.2%, purity: >95%;

[0092] Structure confirmation of the PDGFRβ inhibitor 3: HRMS C 62 H 97 N 14 O 17 [M+H] + Theoretical molecular weight 1309.715, measured molecular weight 1309.7174, Δ = 1.7826 ppm;

[0093] As Figure 1-3 shown is the high-resolution mass spectrum of the PDGFRβ inhibitor 3.

[0094] Example 2: PDGFRβ-targeted radioactive probe 68 Ga]Ga-1, 177 Lu]Lu-1 preparation and quality control Step 1: PDGFRβ-targeted radioactive probe 68 Preparation and quality control of

[0095] 68 The Ga radioactive labeling route is as follows:

[0096]

[0097] Specifically, it includes the following steps:

[0098] Dissolve inhibitor 1 in dimethyl sulfoxide to prepare a labeled precursor solution at 1 μg / μL. Take the labeled precursor solution (14 μL, 14 μg, 14 nmol) and place it in a 10 mL vial, then add sodium acetate buffer solution (80 μL); use high-purity hydrochloric acid solution (6 mL, 0.6 M) to wash the germanium-68 / gallium-68 generator (iThemba) to obtain 68 Ga]GaCl3 hydrochloric acid solution, and take 68 Ga]GaCl3 hydrochloric acid solution (0.3 mL, 2.5 mCi) and add it to the above mixture. Mix the reaction solution evenly, heat it at 95 °C for 20 min and then cool it to room temperature. Use a high-performance liquid chromatograph with a radioactive detector and a TLC scanner to measure the radiochemical purity of the product, and obtain 68 Ga]Ga-1 with a radiochemical yield greater than 95%;

[0099] As Figure 2-1 shown, it is the radioactive HPLC chromatogram of the labeling reaction solution of 68 Ga]Ga-1 prepared in Example 2 of the present invention. The chromatogram shows that 68 the retention time of

[0100] As Figure 2-2 shown, it is the radioactive TLC chromatogram of the labeling reaction solution of 68 Ga]Ga-1 prepared in Example 2 of the present invention. The chromatogram shows that 68 the R f of

[0101] Step 2: Preparation and quality control of the targeted PDGFRβ radioactive probe 177 Lu]Lu-1

[0102] 177 The Lu radioactive labeling route is as follows:

[0103]

[0104] Specifically, it includes the following steps:

[0105] Dissolve inhibitor 1 in dimethyl sulfoxide to prepare a labeled precursor solution at 1 μg / μL. Take the labeled precursor solution (14 μL, 14 μg, 14 nmol) and place it in a 10 mL vial, then add sodium acetate buffer solution (15 μL) and 177Lu]LuCl3 hydrochloric acid solution (0.4 mL, 1 mCi, 0.04 M hydrochloric acid). The reaction solution was mixed evenly, heated at 95 °C for 20 min and then cooled to room temperature. The radiochemical purity of the product was determined using a high-performance liquid chromatograph with a radioactive detector and a TLC scanner, and a radiochemical yield greater than 95% of 177 Lu]Lu-1;

[0106] As Figure 2-3 shown, it is the radioactive HPLC chart of the labeling reaction solution of 177 Lu]Lu-1 prepared in Example 2 of the present invention. The chart shows that 177 the retention time of 177 Lu]Lu-1 is 9.45 minutes, and the radiochemical purity ≥ 95%, being 96.0%;

[0107] As Figure 2-4 shown, it is the radioactive TLC chart of the labeling reaction solution of 177 Lu]Lu-1 prepared in Example 2 of the present invention. The chart shows that f the R 68 177 Example 3: Targeted PDGFRβ radioactive probe 68 Ga]Ga-2, 68 Lu]Lu-2 Preparation and Quality Control Step 1: Preparation and Quality Control of Targeted PDGFRβ Radioactive Probe 68 Preparation and Quality Control of

[0109] 68 The Ga radioactive labeling route is as follows:

[0110]

[0111] Specifically, it includes the following steps:

[0112] Dissolve inhibitor 2 in dimethyl sulfoxide to prepare a labeling precursor solution with a concentration of 1 μg / μL. Take the labeling precursor solution (17 μL, 17 μg, 14 nmol) into a 10 mL vial, and add sodium acetate buffer solution (80 μL); Use high-purity hydrochloric acid solution (6 mL, 0.6 M) to wash the germanium-68 / gallium-68 generator (iThemba) to obtain 68 Ga]GaCl3 hydrochloric acid solution, take 68The Ga]GaCl3 hydrochloric acid solution (0.3 mL, 2.5 mCi) was added to the above-mentioned mixed solution. The reaction solution was mixed evenly, heated at 95 °C for 20 min and then cooled to room temperature. The radiochemical purity of the product was determined using a high-performance liquid chromatograph equipped with a radioactive detector and a TLC scanner, and 68 Ga]Ga-2 with a radiochemical yield greater than 95% was obtained;

[0113] As Figure 3-1 shown, it is the radioactive HPLC chromatogram of the labeling reaction solution of 68 Ga]Ga-2 prepared in Example 3 of the present invention. The chromatogram shows that 68 the retention time of

[0114] As Figure 3-2 shown, it is the radioactive TLC chromatogram of the labeling reaction solution of 68 Ga]Ga-2 prepared in Example 3 of the present invention. The chromatogram shows that 68 the R f of

[0115] Step 2: Preparation and quality control of the radioactive probe 177 Lu]Lu-2 targeting PDGFRβ

[0116] 177 The Lu radioactive labeling route is as follows:

[0117]

[0118] Specifically, it includes the following steps:

[0119] The inhibitor 2 was dissolved in dimethyl sulfoxide to prepare a labeling precursor solution with a concentration of 1 μg / μL. Take the labeling precursor solution (17 μL, 17 μg, 14 nmol) in a 10 mL vial, add sodium acetate buffer solution (15 μL) and 177 Lu]LuCl3 hydrochloric acid solution (0.4 mL, 1 mCi, 0.04 M hydrochloric acid). The reaction solution was mixed evenly, heated at 95 °C for 20 min and then cooled to room temperature. The radiochemical purity of the product was determined using a high-performance liquid chromatograph equipped with a radioactive detector and a TLC scanner, and 177 Lu]Lu-2 with a radiochemical yield greater than 95% was obtained;

[0120] As Figure 3-3 shown, it is the radioactive HPLC chromatogram of the labeling reaction solution of 177 Lu]Lu-2 prepared in Example 3 of the present invention. The chromatogram shows that 177The retention time of Lu-2 is 9.55 minutes, and its radiochemical purity is ≥95%, being 95.9%;

[0121] As Figure 3-4 shown, it is the radioactive TLC map of the labeling reaction solution of Lu-2 prepared in Example 3 of the present invention. The map shows that 177 the Rf value of Lu-2 is 0.6 - 1.0, and its radiochemical purity is ≥95%, being 97.6%. 177 The Rf value of Lu-2 f is 0.6 - 1.0, and its radiochemical purity is ≥95%, being 97.6%.

[0122] Example 4: Targeted PDGFRβ radioactive probe 68 The preparation and quality control of Ga-3, 177 Lu-3: The preparation and quality control of the targeted PDGFRβ radioactive probe 68 The preparation and quality control of Ga-3

[0123] 68 The Ga radioactive labeling route is as follows:

[0124]

[0125] Specifically, it includes the following steps:

[0126] Dissolve inhibitor 3 in dimethyl sulfoxide to prepare a labeling precursor solution with a concentration of 1 μg / μL. Take the labeling precursor solution (19 μL, 19 μg, 14 nmol) and place it in a 10 mL vial, then add sodium acetate buffer solution (80 μL); use high-purity hydrochloric acid solution (6 mL, 0.6 M) to wash the germanium-68 / gallium-68 generator (iThemba) to obtain 68 GaCl3 hydrochloric acid solution. Take 68 GaCl3 hydrochloric acid solution (0.3 mL, 2.5 mCi) and add it to the above mixture. Mix the reaction solution evenly, heat it at 95 °C for 20 min and then cool it to room temperature. Use a high-performance liquid chromatograph with a radioactive detector and a TLC scanner to measure the radiochemical purity of the product, and obtain Ga-3 with a radiochemical yield greater than 95%; 68 Ga-3;

[0127] As Figure 4-1 shown, it is the radioactive HPLC map of the labeling reaction solution of Ga-3 prepared in Example 4 of the present invention. The map shows that 68 the retention time of Ga-3 is 9.54 minutes, and its radiochemical purity is ≥95%, being 96.9%; 68 Ga-3's retention time is 9.54 minutes, and its radiochemical purity is ≥95%, being 96.9%;

[0128] As Figure 4-2 shown, it is the 68Radioactive TLC map of the labeling reaction solution of [Ga]Ga-3. The map shows that 68 [Ga]Ga-3 has an R f value of 0.6 - 1.0, and the radiochemical purity is ≥95%, being 97.7%;

[0129] Step 2: Preparation and quality control of the radioactive probe targeting PDGFRβ 177 [Lu]Lu-3

[0130] 177 The Lu radioactive labeling route is as follows:

[0131]

[0132] Specifically, it includes the following steps:

[0133] Dissolve inhibitor 3 in dimethyl sulfoxide to prepare a labeling precursor solution with a concentration of 1 μg / μL. Take the labeling precursor solution (19 μL, 19 μg, 14 nmol) into a 10 mL vial, add sodium acetate buffer solution (15 μL) and 177 [Lu]LuCl3 hydrochloric acid solution (0.4 mL, 1 mCi, 0.04 M hydrochloric acid). Mix the reaction solution evenly, heat it at 95 °C for 20 min and then cool it to room temperature. Use a high-performance liquid chromatograph with a radioactive detector and a TLC scanner to measure the radiochemical purity of the product, and obtain [Lu]Lu-3 with a radiochemical yield greater than 95%; 177 [Lu]Lu-3

[0134] As Figure 4-3 shown, it is the radioactive HPLC map of the labeling reaction solution of [Lu]Lu-3 prepared in Example 4 of the present invention. The map shows that 177 [Lu]Lu-3 has a retention time of 9.74 minutes, and the radiochemical purity is ≥95%, being 97.8%; 177

[0135] Figure 4-4 As Figure 4-4 shown, it is the radioactive TLC map of the labeling reaction solution of [Lu]Lu-3 prepared in Example 4 of the present invention. The map shows that 177 [Lu]Lu-3 177 [Lu]Lu-3 has an R f value of 0.6 - 1.0, and the radiochemical purity is ≥95%, being 98.4%.

[0136] Example 5: In vitro stability study of the radioactive probes labeled with [Ga]Ga targeting PDGFRβ 68 [Ga]Ga-1, 68 [Ga]Ga-2, 68 [Ga]Ga-3 68 ​

[0137] Separate 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 (100 μL) were added to normal saline (900 μL), incubated at 37 °C, samples were taken at 1 hour and 2 hours respectively, and the radiochemical purity was detected using a high performance liquid chromatograph with a radioactive detector; separate 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 (150 μL) were added to mouse serum (450 μL), incubated at 37 °C, samples (100 μL) were taken at 1 hour and 2 hours respectively, acetonitrile (200 μL) was added to precipitate proteins, centrifuged at 14000 rpm for 5 minutes in a centrifuge, the supernatant was taken, and the radiochemical purity was detected using a high performance liquid chromatograph with a radioactive detector;

[0138] As Figure 5 shown, in Example 5 of the present invention, 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 in normal saline or mouse serum incubated at 37 °C for different times, the radioactive HPLC chromatograms are shown, and the chromatograms show that 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 in normal saline or mouse serum incubated at 37 °C for 2 hours, the retention time did not change, and the radiochemical purity remained ≥95%, indicating that 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 all have excellent in vitro stability.

[0139] Example 6: Specific binding force study of 68 Ga-labeled radioactive probe 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 with PDGFRβ protein

[0140] Separate 68 Ga]Ga-1 or 68 Ga]Ga-2 or 68Ga]Ga-3 was added to serum-free DMEM culture medium to prepare a drug incubation solution of 28 pmol / 1.5 μCi / mL. Glioblastoma cells (U87MG cells, PDGFRβ-positive) were prepared into a cell suspension of 10 6 cells / mL using serum-free DMEM culture medium; for the uptake group, 1 mL of the drug incubation solution and 1 mL of the cell suspension were mixed in an EP tube and incubated at 37 °C for 30 minutes; for the inhibition group, 1 mL of the drug incubation solution (containing 8.4 μM PDGFRβ inhibitor (PDGFR-IN-1 or CP-673451)) and 1 mL of the cell suspension were mixed in an EP tube and incubated at 37 °C for 30 minutes; after incubation, the EP tube was centrifuged at 1000 rpm / min for 4 minutes, the liquid was discarded, 1 mL of ice-cold PBS was added, vortexed and mixed evenly, centrifuged at 1000 rpm / min for 4 minutes, the liquid was discarded, and the washing was repeated again; the EP tube was inserted into a soft tube, and the radioactivity count of the soft tube was measured using a γ counter; the total uptake of the drug by the cells was calculated as: radioactivity count of the soft tube / radioactivity count of 1 mL of the drug incubation solution per tube × 100%, with the unit of %ID / 10 6 cells;

[0141] As Figure 6 shown, in Example 6 of the present invention, in the absence / presence of different PDGFRβ inhibitors, the uptake of 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 by U87MG cells (PDGFRβ-positive) in vitro (n = 4). It can be seen from the figure that in the absence of PDGFRβ inhibitor, after incubation for 30 minutes, the uptake of 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 by U87MG cells with high expression of PDGFRβ was high, indicating that 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 all had excellent binding affinity with PDGFRβ protein; in the presence of an excessive amount of PDGFRβ inhibitor (PDGFR-IN-1 or CP-673451), the uptake of 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 by U87MG cells was significantly inhibited (P < 0.001), indicating that 68 Ga]Ga-1, 68 Ga]Ga-2, 68The binding of Ga]Ga-3 to U87MG cells is its specific binding to the PDGFRβ protein. 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 all have good specific binding affinity to the PDGFRβ protein.

[0142] Example 7: 68 Ga-labeled radioactive probe 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Biodistribution study of Ga]Ga-3

[0143] Implant 10 6 U87MG cells (PDGFRβ positive) under the right axilla of the anterior right limb of female BALB / c nude mice (4 weeks old), and raise them in a specific pathogen-free environment for 4 - 5 weeks. After the tumor diameter reaches 8 - 10 mm, use them for experiments. Randomly divide the U87MG tumor-bearing nude mice into groups of 4; add 68 Ga]Ga-1 or 68 Ga]Ga-2 or 68 Ga]Ga-3 into physiological saline to prepare a radioactive preparation of 1.4 nmol / 75 μCi / 150 μL. Inject the radioactive preparation (150 μL) into the U87MG tumor-bearing nude mice via the tail vein. Anesthetize and sacrifice the nude mice at 10 minutes, 30 minutes, and 60 minutes, take out the tumor and other tissues of interest, weigh them, measure their radioactive counts using a γ counter, calculate the percentage of the injected dose per gram of tissue (%ID / g), and analyze the in vivo PDGFRβ targeting, tumor uptake, and tissue distribution and metabolism of the radioactive probe 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3;

[0144] As Figure 7 shown, in Example 7 of the present invention, 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 uptake maps in tumors and normal tissues of U87MG tumor-bearing (PDGFRβ positive) nude mice (n = 4). It can be seen from the figure that the radioactive probes 68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 all rapidly target tumors with high expression of PDGFRβ, have excellent tumor uptake, and except for the excretory organ (kidney), the tumor is the site with the highest radioactive concentration; the radioactive probe68 Ga]Ga-1, 68 Ga]Ga-2, 68 Ga]Ga-3 all have low uptake in normal tissues and are metabolized and excreted from the body relatively quickly through the kidneys.

[0145] The above experimental results show that the radioactive probe targeting PDGFRβ provided by the present invention can specifically target tumors with high expression of PDGFRβ, has good tumor uptake and rapid in vivo metabolism properties, can be rapidly metabolized and excreted from the body through the kidneys, and obtains a good tumor-to-background ratio.

[0146] As described above, it is only the preferred embodiment of the present invention, so the scope of implementation of the present invention cannot be limited thereby. That is, equivalent changes and modifications made according to the scope of the present invention patent and the content of the specification should still fall within the scope covered by the present invention.

Claims

1. An inhibitor targeting platelet-derived growth factor receptor β, characterized in that, The inhibitor is at least one of the compounds represented by Formula I: Formula I; Among them, the Chelator structure is: ； (A) does not exist, or (B) L1 is , and n1 is 1; L2 is , and n2 takes an integer from 0 to 8; L3 is or , where n3 is 1.

2. A radioactive probe targeting platelet-derived growth factor receptor β, characterized in that, The radioactive probe is at least one of the compounds represented by Formula II: Formula II; Among them, the Chelate portion is the structure formed by the chelation of a radionuclide and a bifunctional chelating agent, and is selected from any one of the following: , where M is a radionuclide; (A) does not exist, or (B) L1 is , and n1 is 1; L2 is , and n2 takes an integer from 0 to 8; L3 is or , where n3 is 1.

3. The radioactive probe targeting platelet-derived growth factor receptor β according to claim 2, wherein, M is a radionuclide, and the radionuclide is a diagnostic radionuclide or a therapeutic radionuclide; the diagnostic radionuclide is 68 Ga, and the therapeutic radionuclide is 177 Lu.

4. The inhibitor targeting platelet-derived growth factor receptor β according to claim 1, wherein the inhibitor is selected from one of the following inhibitors 1-3: 、 、 。 5. The radioactive probe targeting platelet-derived growth factor receptor β according to claim 2 or 3, wherein the radioactive probe is selected from one of the following radioactive probes 4-9: 、 、 、 、 、 。 6. Use of the radioactive probe according to any one of claims 2, 3 and 5 in the preparation of a radioactive imaging diagnostic reagent or a radionuclide therapy reagent, wherein the radioactive imaging diagnostic reagent is an early detection reagent, a therapeutic efficacy evaluation reagent, a prognosis judgment reagent or an anti-angiogenesis therapy benefit population screening reagent for tumors with high expression of platelet-derived growth factor receptor β; The radionuclide therapy reagent is a therapeutic reagent for tumors with high expression of platelet-derived growth factor receptor β; The tumor is a highly vascular tumor: liver cancer, glioblastoma, lung cancer, breast cancer, prostate cancer and colorectal cancer.

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