Imidazothiadiazole compounds as well as preparation method therefor and use thereof

Abstract

The present invention relates to the technical fields of radiopharmaceutical chemistry and clinical nuclear medicine, in particular to imidazothiadiazole compounds as well as a preparation method therefor and the use thereof. The compounds are shown as general structural formula (I). After being labeled with a suitable radioisotope, the compounds and derivatives thereof can perform nuclear medicine imaging on α-synuclein aggregates in the brain, so as to assist in clinical diagnosis of synuclein diseases including Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, and some rare diseases.

Description

An imidazothiadiazole compound, its preparation method and application

[0001] Cross-referencing

[0002] This application claims priority to Chinese Patent Application No. 202410573725.3, filed on May 10, 2024, entitled “An imidazothiadiazole compound and its preparation method and application”, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to the fields of radiopharmaceutical chemistry and clinical nuclear medicine, specifically to a series of derivatives based on the imidazothiadiazole structure, their preparation methods, and applications. Background Technology

[0004] α-synuclein (α-syn) is a small protein composed of 140 amino acids. Under normal physiological conditions, it is widely distributed in the brain and peripheral nervous system in a random helical form, mainly at the synaptic terminals. Its main physiological function is to maintain the normal function and plasticity of synapses.

[0005] In certain specific diseases, soluble α-synucleinocytes abnormally fold to form highly ordered β-sheet structures, which further induce aggregation, forming oligomers and fibers, and ultimately insoluble cellular inclusion bodies. These diseases include Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and some rare diseases, collectively known as α-synucleinopathies. Due to the complex etiology of these diseases and the long time lag between the onset of the pathological process and the appearance of clinical symptoms, early and accurate diagnosis is extremely difficult.

[0006] In neurons of patients with Parkinson's disease (PD) and Dalbone-Lewy syndrome (DLB), α-synuclein is pathologically deposited as Lewy bodies (LBs) and Lewy neuritis (LNs), collectively known as Lewy pathology. In patients with schizophrenia (MSA), α-synuclein is pathologically deposited in oligodendrocytes as glial cytoplasmic inclusions (GCIs). The presence of pathological α-synuclein aggregates is closely related to disease progression, making α-synuclein a biomarker for these diseases and providing a window for further understanding and precise monitoring of disease status.

[0007] Nuclear medicine imaging techniques mainly include positron emission tomography (PET) and single-photon emission computed tomography (SPECT). In recent years, nuclear medicine imaging technology has matured, and many PET and SPECT probes have been developed for the specific biomarkers Aβ and Tau of Alzheimer's disease (AD). However, radionuclide-labeled probes targeting α-synuclein are still in the early stages of research, and no imaging agents are yet available for clinical use. Currently, the more extensively researched α-synuclein probes include […]. 11 C]MODAG-001, [ 18 F]SPAL-T-06 and [ 18 F]ACI-12589, etc., each has its own limitations. 11 C]MODAG-001 does not have good selectivity for Aβ, while [ 18 F]SPAL-T-06 and [ 18 The imaging capabilities of F]ACI-12589 for α-synuclein aggregates in the brains of PD patients still require further evaluation. In summary, the development of new α-synuclein probes is currently a research hotspot.

[0008] Summary of the Invention

[0009] This invention provides a method for preparing imidazothiadiazole compounds and their applications. These compounds have a certain affinity for α-synuclein aggregates in the human brain. By labeling them with appropriate radioisotopes, these compounds can be used for nuclear medicine imaging of α-synuclein in the human brain.

[0010] In a first aspect, the present invention provides imidazothiadiazole compounds as shown in general structural formula (I),

[0011] in,

[0012] R1 is selected from R3 is selected from 123 I, 124 I, 125 I, 127 I, 18 F, 19 F, (OCH2CH2) m 18 F, (OCH2CH2) m 19 F, m are integers between 1 and 6;

[0013] R2 is selected from Y independently represents N or CH, and R4 and R5 independently represent -H, -Cl, and -OCH3, respectively.

[0014] Specifically, R1 is selected from R3 is selected from 123 I, 124 I, 125 I, 127 I, 18 F, 19 F.

[0015] Specifically, R1 is selected from R3 is selected from 123 I, 124 I, 125 I, 127 I, 18 F, 19 F.

[0016] Specifically, R2 is selected from

[0017] Specifically, R2 is selected from Y independently represents N or CH, and R4 and R5 independently represent -H, -Cl, and -OCH3, respectively.

[0018] Specifically, m is 1, 2, 3, 4, 5, or 6.

[0019] The compound of general formula (I) provided by this invention, which is based on an imidazothiadiazole structure, can be used as a radiopharmaceutical with high affinity for α-synuclein aggregates (including Lewy bodies, Lewy neurites, glial cell inclusions, etc.). 18 F, 11 C or 123 / 125 I. For PET (positron emission tomography) or SPECT (single photon emission computed tomography) imaging, to achieve early diagnosis and disease monitoring of α-synucleinosis, including but not limited to Parkinson's disease, Lewy body dementia, multiple system atrophy and some rare diseases.

[0020] Preferably, the compound represented by general formula (I) is selected from any of the following compounds:

[0021] Preferably, I is 123 I, 124 I, 125 I or 127 I;F is 18 F or 19 F.

[0022] The aforementioned preferred compounds have a higher affinity for α-synuclein.

[0023] In a second aspect, the present invention provides a method for preparing the compound represented by the above general formula (I), comprising:

[0024] When I is 123 I, 124 I or 125 At step I, compound (I-1)-compound (I-11) is composed of a trialkyltin, trialkylsilane, boric acid or borate ester precursor compound and [ 123 / 124 / 125 The solution of I]NaI is obtained by reacting in the presence of an oxidizing agent;

[0025] When F is 18 At F, compound (I-12)-compound (I-22) is composed of p-toluenesulfonate, trimethyl quaternary ammonium salt, boric acid, borate ester or high-valent iodine cofactor precursor compound and [ 18 The F]F anion is obtained by reaction in the presence of a phase transfer catalyst.

[0026] [ 123 / 124 / 125 I]NaI indicates [ 123 I]NaI or [ 124 I]NaI or [ 125 I]NaI.

[0027] Thirdly, the present invention also provides derivatives of the compounds represented by the above general formula (I), which are pharmaceutically acceptable salts, esters or amides or prodrugs of the compounds represented by general formula (I).

[0028] Fourthly, the present invention also provides an α-synuclein diagnostic or detection reagent, the active ingredient of which is a compound of general formula (I) and / or its derivatives. The derivatives are pharmaceutically acceptable salts, esters, or amides or prodrugs of the compound of general formula (I). Specifically, the diagnostic or detection reagent is a diagnostic or detection reagent for α-synuclein diseases caused by abnormal aggregation of α-synuclein, including but not limited to Parkinson's disease, Lewy body dementia, multiple system atrophy, and other rare α-synuclein diseases.

[0029] Fifthly, the present invention further provides the use of the compound of general formula (I) and / or its derivatives in the preparation of nuclear medicine imaging agents. Specifically, the nuclear medicine imaging agent is a PET or SPECT imaging agent.

[0030] Compared with the prior art, the present invention has at least the following advantages:

[0031] The compound of general formula (I) provided by this invention has a high affinity for α-synuclein. After being labeled with a suitable radioisotope, it can be used for nuclear medicine imaging, and is particularly suitable for the diagnosis of patients with neurodegenerative diseases characterized by α-synuclein aggregates, including Parkinson's disease. Attached Figure Description

[0032] Figure 1 is a schematic diagram of the synthesis process of compounds in Examples 1-53 of the present invention, wherein the reaction reagents and conditions involved are as follows:

[0033] (a)(1) Thioaminourea, ethanol, reflux, 4 h; (2) Ferric chloride hexahydrate, ethanol, 100 °C, 12 h; (b) 2',4-dibromoacetophenone, n-butanol, 110 °C, 8 h; (c) 2'-bromo-4-iodoacetophenone, n-butanol, 110 °C, 8 h; (d) n-hexabutyltin, tetra(triphenylphosphine)palladium, 1,4-dioxane, 110 °C, 8 h; (e) For compounds 37-41 and 43-45, (1) [ 125 I] NaI, HCl (1M), H2O2 (3%), acetonitrile, room temperature, 15 min; (2) sodium bicarbonate, room temperature, 5 min; for compound 42, (1) [ 125 I] NaI, HCl (1M), H2O2 (3%), acetonitrile, room temperature, 15 min; (2) HCl (6M), 100℃, 10 min; (3) Sodium bicarbonate, room temperature, 5 min; (f)(1) Iodine, acetonitrile, room temperature, 15 min; (2) Saturated sodium thiosulfate solution, 5 min; (g) Piperazine-1-carboxylic acid tert-butyl ester, potassium carbonate, acetonitrile, 85℃, 12 h; (h) Anhydrous piperazine, potassium carbonate, acetonitrile, 85℃, 12 h; (i)(1) Hydrazine hydrate (85%), isopropanol, room temperature, 10 min; (2) Pyrazine-1-carboxaldehyde, ethanol, 100℃, 3 h; (j) Ferric chloride hexahydrate, ethanol, 100℃, 8 h.

[0034] Figure 2 is a schematic diagram of the synthesis process of compounds 21-30 in Examples of the present invention, wherein the reaction reagents and conditions involved are as follows:

[0035] (a) 2'-Bromo-4-iodoacetophenone, n-butanol, 110 °C, 4 h; (b) 2-Bromo-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)ethane-1-one, n-butanol, 110 °C, 8 h; (c) 18 F -(d) Tetrabutylammonium bicarbonate, Cu(OTf)2(pyr)4, n-butanol / N,N-dimethylformamide, 110℃, 20 min; (e) 3-(2-bromoacetyl)pyridine 1-oxide, n-butanol, 110℃, 8 h; (f) Trimethylamine (1M tetrahydrofuran solution), trifluoroacetic anhydride, dichloromethane, room temperature, 1 h; (c) Potassium fluoride, potassium carbonate, K 222 DMSO, 70℃, 2h; (g) 18 F - Potassium carbonate, K 222 (h) 2'-Bromo-4-hydroxyacetophenone, n-butanol, 110℃, 8h; (i) 2-Bromoethanol, sodium hydride, DMF, 90℃, 4h; (j) 4-Methylbenzylsulfonyl chloride, triethylamine, dichloromethane, room temperature, 12h; (k) 1-Fluoro-2-bromoethanol, potassium carbonate, potassium iodide, acetonitrile, 105℃, 12h; (l) 18 F - Potassium carbonate, K 222 , DMSO, 100℃, 10min; (m) For compounds 18, 69, 70, (1) thioaminourea, sodium acetate, ethanol, reflux, 4h; (2) iodine, potassium carbonate, 110℃, 24h; For compounds 71-73, thioaminourea, trifluoroacetic acid, 80℃, 4h; (n) boron tribromide (1M dichloromethane solution), dichloromethane, room temperature, 72h.

[0036] Figure 3 shows the probe in Embodiment 84 of the present invention. 125 I]37-45、[ 125 I]47 and [ 125 I]54 Autoradiography results on brain tissue sections of PD and AD patients (first row, PD, striatum, 73 years old, female; second row, AD, temporal lobe, 88 years old, female).

[0037] Figure 4 shows the probe in Embodiment 84 of the present invention. 18 F]55、[ 18 F]59、[ 18 F]92-99 Autoradiography results on brain tissue sections of PD and AD patients (first row, AD, temporal lobe, 88 years old, female; or frontal lobe, 97 years old, female; or temporal lobe, 91 years old, female; second row, PD, locus coeruleus in the midbrain, 73 years old, female).

[0038] Figure 5 shows the competitive binding curves of compounds 39, 55, and 59 on α-syn aggregates (AC) and Aβ aggregates (DF) on brain tissue sections of PD patients (73 years old, female) and AD patients (92 years old, female) in Examples 86 and 87 of the present invention.

[0039] Figure 6 shows the probe in Embodiment 88 of the present invention. 18 F]55 and [ 18 F]59 PET / CT imaging experiment in normal rats. (A) and (B) are respectively [ 18 F]55 and [ 18 The curves showing the change in brain volume of F]59 over time, (C) and (D) are respectively [ 18 F]55 and [ 18 PET image of F]59. Detailed Implementation

[0040] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0041] Example 1: Synthetic intermediate 6

[0042] Compound 6-chloronicotinaldehyde (495.5 mg, 3.5 mmol), piperazine-1-carboxylic acid tert-butyl ester (781.0 mg, 4.2 mmol), and DIPEA (680.0 mg, 5.3 mmol) were dissolved in 20 mL of acetonitrile. The mixture was heated in an oil bath at 80 °C for 24 hours. After the reaction was complete, the acetonitrile was removed by vacuum distillation, and the mixture was separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:1 to give 679.9 mg of a pale yellow solid, with a yield of 66.7%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ9.78(s,1H),8.55(s,1H),7.94(d,J=8.3Hz,1H),6.65(d,J=9.0Hz,1H),3.75(s,4H),3.55(s,4H),1.48(s,9H).

[0043] Example 2: Synthesis Intermediate 8

[0044] Compounds 6-chloronicotinaldehyde (1415.5 mg, 10.0 mmol), tetrahydropyrrole (853.5 mg, 12.0 mmol), and DIPEA (1935.0 mg, 15.0 mmol) were dissolved in 25 mL of acetonitrile. The mixture was heated in an oil bath at 90 °C for 4 hours. After the reaction was complete, the acetonitrile was removed by vacuum distillation, and the mixture was separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 2:1 to give 1407.9 mg of a pale yellow solid, with a yield of 79.9%. The structure is as follows: 1H NMR (600MHz, CDCl3) δ9.76(s,1H),8.55(d,J=2.1Hz,1H),7.91(dd,J=8.9,2.2Hz,1H),6.42(d,J=8.9Hz,1H),3.80–3.35(m,4H),2.06(s,4H).

[0045] Example 3: Synthetic intermediate 10

[0046] Compounds 3-pyridinecarboxaldehyde (1072.0 mg, 10.0 mmol) and thioaminourea (1069.8 mg, 11.7 mmol) were dissolved in 40 mL of ethanol and heated in an oil bath at 100 °C for 4 hours. After the reaction was complete, a white solid precipitated. The precipitate was filtered and washed with 10 mL of petroleum ether. The solid was then dispersed in 40 mL of ethanol, and ferric chloride hexahydrate (2730.0 mg, 10.1 mg) was added. The mixture was refluxed in an oil bath at 100 °C for 12 hours. Subsequently, the ethanol was removed by vacuum distillation, and a saturated sodium thiosulfate solution was added. The mixture was extracted four times with ethyl acetate. The combined organic phases were dried over anhydrous magnesium sulfate, concentrated by vacuum distillation, and separated by column chromatography with an eluent ratio of ethyl acetate:methanol = 10:1, yielding 166.2 mg of a pale yellow solid, with a yield of 9.3%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ8.95(dd,J=2.3,0.5Hz,1H),8.62(dd,J=4.8,1.5Hz,1H),8.15–8.13(m,1H),7.55(s,2H),7.51(dd,J=7.9,4.8Hz,1H).

[0047] Example 4: Synthetic intermediate 11

[0048] Following the method of Example 3, intermediate 11 was synthesized from 4-pyridinecarboxaldehyde to obtain 367.1 mg of a yellow solid, with a yield of 20.6%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ8.65 (dd, J=4.5, 1.7Hz, 2H), 7.71 (dd, J=4.5, 1.6Hz, 1H), 7.69 (s, 1H).

[0049] Example 5: Synthesis of intermediate 12

[0050] Method 1: Following the method in Example 3, intermediate 12 was synthesized from 2-pyrazinaldehyde to obtain 234.9 mg of a pale green solid, with a yield of 13.2%.

[0051] Method 2: 2-Cyanopyrazine (1045.1 mg, 9.9 mmol) and thioaminourea (998.9 mg, 11.0 mmol) were dissolved in 8 mL of trifluoroacetic acid. The mixture was heated in an oil bath at 80 °C for 4 hours. After the reaction was complete, 30 mL of water was added to the reaction system, and a light brown solid precipitated. The solid was filtered, dried, and yielded intermediate 12 in a total of 1699.5 mg, with a yield of 95.8%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ9.27 (d, J = 1.3Hz, 1H), 8.68–8.66 (m, 2H), 7.85 (br, 2H).

[0052] Example 6: Synthetic intermediate 13

[0053] Following the method of Example 3, intermediate 13 was synthesized from 6-methoxy-3-pyridinecarboxaldehyde to obtain 204.0 mg of a white solid, with a yield of 9.8%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ8.48(d,J=2.5Hz,1H),8.04(dd,J=8.7,2.5Hz,1H),7.37(s,2H),6.89(d,J=8.7Hz,1H),3.86(s,3H).

[0054] Example 7: Synthetic intermediate 14

[0055] Following the method of Example 3, intermediate 14 was synthesized from 6-chloronicotinaldehyde to obtain 495.5 mg of a light brown solid, with a yield of 23.3%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ8.78 (s, 1H), 8.21 (d, J = 8.3Hz, 1H), 7.67–7.55 (m, 3H).

[0056] Example 8: Synthetic intermediate 15

[0057] Following the method of Example 3, intermediate 15 was synthesized from intermediate 6 as a raw material, yielding 482.0 mg of a yellow solid with a yield of 13.3%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.44(d,J=2.4Hz,1H),7.90(dd,J=8.9,2.5Hz,1H),7.27( s,2H),6.92(d,J=9.0Hz,1H),3.60–3.57(m,4H),3.44–3.41(m,4H),1.43(s,9H).

[0058] Example 9: Synthetic Intermediate 16

[0059] Following the method of Example 3, intermediate 16 was synthesized from 4-morpholine benzaldehyde to obtain 154.6 mg of a yellow solid, with a yield of 5.9%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ7.60–7.58(m,2H),7.21(s,2H),7.01–6.98(m,2H),3.76–3.73(m,4H),3.20–3.17(m,4H).

[0060] Example 10: Synthetic Intermediate 17

[0061] Following the method of Example 3, intermediate 17 was synthesized from intermediate 8 as a raw material, yielding 42.0 mg of a yellow solid with a yield of 1.7%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ8.39(s,1H),7.84(d,J=8.8Hz,1H),7.20(s,2H),6.52(d,J=8.7Hz,1H),5.75(s,1H),3.43(s,4H),1.95(s,4H).

[0062] Example 11: Synthetic Intermediate 18

[0063] The compounds benzo[d][1,3]dioxane-5-carboxaldehyde (3017.4 mg, 20.0 mmol), thiourea (2852.8 mg, 31.0 mmol), and anhydrous sodium acetate (942.8 mg, 11.5 mmol) were dispersed in 50 mL of ethanol and heated in an oil bath at 100 °C for 4 hours. After the reaction was complete, a white solid precipitated. The precipitated product was filtered, and then the solid was dispersed in 40 mL of 1,4-dioxane and anhydrous potassium carbonate (8 mg, 11.5 mmol) was added. 281.5 mg (30.0 mmol) and iodine (6100 mg, 24.0 mmol) were added and refluxed in an oil bath at 110 °C for 24 h. Subsequently, 1,4-dioxane was removed by vacuum distillation. A saturated sodium thiosulfate solution was added, and the mixture was extracted four times with ethyl acetate. The combined organic phases were dried over anhydrous magnesium sulfate, and after concentration by vacuum distillation, separation was performed by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:1 to give 230.1 mg of a pale purple solid, with a yield of 5.2%. The structure is as follows: 1H NMR (400MHz, d6-DMSO) δ7.33(d,J=1.8Hz,1H),7.31(s,2H),7.20(dd,J=8.1,1.8Hz,1H),6.99(d,J=8.1Hz,1H),6.09(s,2H).

[0064] Example 12: Synthetic Intermediate 19

[0065] Intermediate 10 (78.8 mg, 0.44 mmol) and 2',4-dibromoacetophenone (202.5 mg, 0.73 mmol) were dissolved in n-butanol and heated in an oil bath at 110 °C for 8 h. After the reaction was complete, the mixture was cooled to room temperature, and a pale yellow solid precipitated. The crude product was obtained by filtration. After drying the crude product, it was separated by column chromatography using a dichloromethane:ethyl acetate eluent with a volume ratio of 1:1 to obtain a pale yellow intermediate 19, totaling 10.8 mg, with a yield of 6.9%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ9.14(d,J=2.0Hz,1H),8.78(dd,J=4.7,1.1Hz,1H),8.19(d,J=8.0Hz, 1H),8.09(s,1H),7.73(d,J=8.4Hz,2H),7.56(d,J=8.4Hz,2H),7.50(dd,J=7.9,4.9Hz,1H).

[0066] Example 13: Synthetic intermediate 20

[0067] Following the method of Example 12, intermediate 20 was synthesized from intermediate 11 to obtain 57.0 mg of a light yellow solid, with a yield of 16.0%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ8.90 (s, 1H), 8.82 (d, J = 4.4Hz, 2H), 7.92 (d, J = 4.6Hz, 2H), 7.87 (d, J = 8.0Hz, 2H), 7.63 (d, J = 7.9Hz, 2H).

[0068] Example 14: Synthetic intermediate 21

[0069] Following the method of Example 12, intermediate 21 was synthesized from intermediate 13 as a raw material, yielding 233.6 mg of a pale yellow solid with a yield of 89.3%. The structure is as follows: 1H NMR (600MHz, d6-DMSO) δ9.40(d,J=1.2Hz,1H),8.90(s,1H),8.88(d,J=2.3Hz,1H),8.84(d,J=1.4Hz,1H),7.87(d,J=8.4Hz,2H),7.64(d,J=8.5Hz,2H).

[0070] Example 15: Synthetic intermediate 22

[0071] Following the method of Example 12, intermediate 22 was synthesized from intermediate 14 to obtain 45.3 mg of a light pink solid, with a yield of 24.3%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.81(s,1H),8.77(d,J=2.5Hz,1H),8.25(dd,J=8.7,2.5 Hz,1H),7.77(s,2H),7.70(d,J=8.3Hz,2H),7.05(d,J=8.7Hz,2H),3.96(s,3H).

[0072] Example 16: Synthetic intermediate 23

[0073] Following the method of Example 12, intermediate 23 was synthesized from intermediate 15 to obtain 23.4 mg of a yellow solid, with a yield of 38.7%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ9.01(d,J=2.6Hz,1H),8.89(s,1H),8.42(dd,J=8.4,2 .6Hz,1H),7.87(d,J=8.5Hz,2H),7.79(d,J=8.3Hz,1H),7.64(d,J=8.6Hz,2H).

[0074] Example 17: Synthetic intermediate 24

[0075] Intermediate 15 (95.6 mg, 0.26 mmol) and 2',4-dibromoacetophenone (156.2 mg, 0.56 mmol) were dissolved in 10 mL of n-butanol and heated in an oil bath at 110 °C for 6 h. After the reaction was completed, the mixture was cooled to room temperature and a white solid precipitated. The mixture of intermediates 24(a) and (b) was obtained by filtration and directly used in Example 26 without purification.

[0076] Example 18: Synthetic intermediate 25

[0077] Following the method of Example 12, intermediate 25 was synthesized from intermediate 16 as a raw material, yielding 33.3 mg of a yellow solid with a yield of 44.7%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ8.70(s,1H),7.80(d,J=6.3Hz,2H),7.75(d,J=7.3Hz,2H), 7.57(d,J=8.4Hz,2H),7.07(d,J=9.4Hz,2H),3.73–3.70(m,4H),2.64–2.62(m,4H).

[0078] Example 19: Synthetic intermediate 26

[0079] Following the method of Example 12, intermediate 26 was synthesized from intermediate 17 as a raw material, yielding 26.3 mg of a gray solid with a yield of 44.2%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.72(s,1H),8.54(d,J=2.2Hz,1H),8.07(d,J=10.9Hz,1H),7.80(d,J=8 .5Hz,2H),7.58(d,J=8.5Hz,2H),6.80(d,J=11.1Hz,1H),3.52–3.49(m,4H),1.99–1.94(m,4H).

[0080] Example 20: Synthetic Intermediate 27

[0081] Following the method of Example 12, intermediate 27 was synthesized from intermediate 18 as a raw material, yielding 5.6 mg of a brown solid in a yield of 5.6%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ8.01(s,1H),7.71(d,J=8.5Hz,2H),7.54(d,J=6.9Hz,2H),7.4 0(d,J=1.8Hz,1H),7.35(dd,J=8.1,1.8Hz,1H),6.92(d,J=8.1Hz,1H),6.09(s,2H).

[0082] Example 21: Synthesis of labeled precursor compound 28

[0083] Intermediate 19 (53.4 mg, 0.15 mmol), n-hexabutylditin (191.4 mg, 0.33 mmol), and tetrakis(triphenylphosphine)palladium (30 mg, 0.025 mmol) were dissolved in 10 mL of 1,4-dioxane. The mixture was heated in an oil bath at 110 °C for 12 h. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed by vacuum distillation. The mixture was then separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:1 to give 18.6 mg of a pale yellow solid, with a yield of 21.9%. The structure is as follows: 1 H NMR(600MHz, CDCl3) δ9.13(d,J=2.0Hz,1H),8.77–8.75(m,1H),8.18–8.16(m,1H),8.09(d,J=3.1Hz,1H),7.79(d,J=7.7Hz,2H), 7.53(d,J=8.0Hz,2H),7.47(dd,J=7.9,4.9Hz,1H),1.58–1.54(m,6H),1.33–1.26(m,6H),1.12–1.05(m,6H),0.92–0.87(m,9H).

[0084] Example 22: Synthesis of labeled precursor compound 29

[0085] Following the method of Example 21, labeled precursor compound 29 was synthesized from intermediate 20, yielding 5.2 mg of a yellow amorphous solid in a yield of 8.1%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.81(d,J=5.8Hz,2H),8.10(s,1H),7.80(d,J=8.0Hz,2H),7.76(d,J=6.0Hz,2H ),7.54(d,J=8.0Hz,2H),1.63–1.50(m,6H),1.40–1.28(m,6H),1.11–1.05(m,6H),0.92–0.86(m,9H).

[0086] Example 23: Synthesis of labeled precursor compound 30

[0087] Following the method of Example 21, labeled precursor compound 30 was synthesized from intermediate 21, yielding 95.8 mg of a yellow-green solid with a yield of 26.9%. The structure is as follows: 1H NMR(600MHz, CDCl3)δ9.42(s,1H),8.71(d,J=2.1Hz,1H),8.66–8.65(m,1H),8.10(s,1H),7.81(d,J=7.9H z,2H),7.55(d,J=7.9Hz,2H),1.59–1.53(m,6H),1.36–1.30(m,6H),1.11–1.04(m,6H),0.94–0.89(m,9H).

[0088] Example 24: Synthesis of labeled precursor compound 31

[0089] Following the method of Example 21, labeled precursor compound 31 was synthesized from intermediate 22, yielding 8.6 mg of a white amorphous solid in a yield of 12.3%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.64(s,1H),8.07–8.02(m,2H),7.77(d,J=6.7Hz,2H),7.51(d,J=6.7Hz,2H),7.32(s,1H), 6.87(d,J=8.7Hz,1H),4.01(s,3H),1.59–1.51(m,6H),1.37–1.29(m,6H),1.09–1.02(m,6H),0.94–0.88(m,9H).

[0090] Example 25: Synthesis of labeled precursor compound 32

[0091] Following the method of Example 21, labeled precursor compound 32 was synthesized from intermediate 23, yielding 4.5 mg of a yellow amorphous solid in a yield of 12.2%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ8.88(s,1H),8.13(d,J=7.5Hz,1H),8.08(s,1H),7.78(d,J=6.1Hz,2H),7.52(d,J=6.3 Hz,2H),7.49(d,J=7.4Hz,1H),1.58–1.52(m,6H),1.36–1.32(m,7H),1.09–1.00(m,6H),0.90–0.86(m,9H).

[0092] Example 26: Synthesis of labeled precursor compound 33

[0093] Following the method of Example 21, labeled precursor compound 33 was synthesized from intermediate 24 to obtain 3.2 mg of a pale yellow solid, with a yield of 7.5%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.62(d,J=2.3Hz,1H),8.00(s,1H),7.94(dd,J=9.0,2.4Hz,1H),7.77(d,J=7.9Hz,2H),7.51(d,J=7.9Hz,2H),6.69(d,J =9.0Hz,1H),3.72–3.67(m,4H),3.59–3.55(m,4H),1.58–1.52(m,6H), 1.50(s,9H),1.10–1.04(m,6H),1.37–1.31(m,6H),0.93–0.89(m,9H).

[0094] Example 27: Synthesis of labeled precursor compound 34

[0095] Following the method of Example 21, labeled precursor compound 34 was synthesized from intermediate 25, yielding 8.6 mg of a white amorphous solid in a yield of 12.3%. The structure is as follows: 1 H NMR(400MHz, CDCl3)δ8.01(s,1H),7.80–7.75(m,4H),7.52(d,J=6.8Hz,2H),6.96(d,J=7.5Hz,2H),3.91–3 .86(m,4H),3.33–3.29(m,4H),1.57–1.53(m,6H),1.38–1.31(m,6H),1.13–1.02(m,6H),0.92–0.87(m,9H).

[0096] Example 28: Synthesis of labeled precursor compound 35

[0097] Following the method of Example 21, labeled precursor compound 35 was synthesized from intermediate 26, yielding 4.8 mg of a yellow solid in a yield of 10.8%. The structure is as follows: 1H NMR (400MHz, CDCl3) δ8.61(d,J=2.4Hz,1H),8.00(s,1H),7.92(dd,J=9.0,2.4Hz,1H),7.78(d,J=8.0Hz,2H),7.51(d,J=8.1Hz,2H),6.47( d,J=8.9Hz,1H),3.57(s,4H),2.06(t,J=6.6Hz,4H),1.59–1.51(m,6H),1.39–1.34(d,J=7.3Hz,6H),1.10–1.01(m,6H),0.92–0.89(m,9H).

[0098] Example 29: Synthesis of labeled precursor compound 36

[0099] Following the method of Example 21, labeled precursor compound 36 was synthesized from intermediate 27, yielding 5.6 mg of a pale yellow solid in a yield of 63.3%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.02(s,1H),7.79(d,J=7.3Hz,2H),7.52(d,J=7.3Hz,2H),7.41(s,1H),7.35(dd,J=8.1,1.7Hz, 1H), 6.91 (d, J = 8.1Hz, 1H), 6.08 (s, 2H), 1.60–1.50 (m, 6H), 1.38–1.31 (m, 6H), 1.15–0.98 (m, 6H), 0.92–0.84 (m, 9H).

[0100] Example 30: Synthesis of compound 37

[0101] Intermediate 10 (400.5 mg, 2.25 mmol) and 2'-bromo,4-iodoacetophenone (888.0 mg, 2.69 mmol) were dissolved in 20 mL of n-butanol and heated in an oil bath at 110 °C for 12 h. After the reaction was complete, the mixture was cooled to room temperature, and an orange solid precipitated. The crude product was obtained by filtration. After drying the crude product, column chromatography was performed using dichloromethane:ethyl acetate (v / v) as the eluent to give a pale yellow compound 37, totaling 142.3 mg, with a yield of 15.6%. The structure is as follows: 1H NMR (600MHz, CDCl3) δ9.13 (dd, J=2.3, 0.7Hz, 1H), 8.78 (dd, J=4.8, 1.6Hz, 1H), 8.18 (ddd, J=8.0, 2. 2,1.8Hz,1H),8.09(s,1H),7.77–7.75(m,2H),7.60–7.59(m,2H),7.48(ddd,J=8.1,4.8,0.7Hz,1H). 13 C NMR (151MHz, d6-DMSO) δ159.51,153.04,147.77,145.36,145.30,138.02,134.96,133.79,127.35,126.53,125.03,111.71,93.81.HRMS:m / z calcd for C 15 H 10 N4IS 404.96654; found 404.96652,M+H + .

[0102] Example 31: Synthesis of compound 38

[0103] Following the method of Example 30, compound 38 was synthesized from intermediate 11 to obtain 35.4 mg of a yellow solid, with a yield of 6.2%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.80(d,J=4.2Hz,2H),8.10(s,1H),7.80–7.72(m,4H),7.59(d,J=7.7Hz,2H). 13 C NMR (151MHz, CDCl3) δ150.87,146.64,144.70,137.98,137.59,133.06,127.02,122.55,120.39,116.19,109.80.HRMS:m / z calcd for C 15 H 10 N4IS 404.96654;found 404.96649,M+H + .

[0104] Example 32: Synthesis of compound 39

[0105] The labeled precursor compound 30 (40.5 mg, 0.07 mg) was dissolved in 10 mL of acetonitrile. Iodine (125.4 mg, 0.49 mmol) was added while stirring, and the mixture was stirred at room temperature for 30 min. Subsequently, a saturated sodium thiosulfate solution was added, at which point a white solid precipitated in the reaction system. The solid was filtered and washed with petroleum ether to give a white compound 39, totaling 20.6 mg, with a yield of 71.4%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ7.53 (s, 1H), 7.12 (d, J = 5.3Hz, 2H), 7.08 (s, 1H), 6.25 (d, J = 6.1Hz, 2H), 6.19 (d, J = 6.4Hz, 2H). 13 C NMR(151MHz,CF3COOD)δ165.10,148.66,145.86,145.44,141.03,140.03,139.05,135.75,126.81,123.75,111.07,97.12.HRMS:m / z calcd for C 14 H9N5IS 405.96179; found 405.96191,M+H + .

[0106] Example 33: Synthesis of compound 40

[0107] Following the method of Example 30, compound 40 was synthesized from intermediate 13, yielding 10.5 mg of a white solid in a yield of 13.8%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ8.66 (s, 1H), 8.09–8.04 (m, 2H), 7.75 (d, J = 7.8Hz, 2H), 7.59 (d, J = 7.7Hz, 2H), 6.89 (d, J = 8.7Hz, 1H), 4.03 (s, 3H). 13 C NMR (101MHz, CF3COOD) δ162.93,160.40,147.28,143.97,139.95,139.05,138.14,126.80,123.72,120.13,111.94,111.21,97.10,59.15.HRMS:m / z calcd for C 16 H 12 ON4IS 434.97710;found 434.97729,M+H + .

[0108] Example 34: Synthesis of compound 41

[0109] Following the method of Example 30, compound 41 was synthesized from intermediate 14 to obtain 96.5 mg of a yellow solid, with a yield of 42.9%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ9.00 (d, J = 2.2Hz, 1H), 8.87 (s, 1H), 8.40 (dd, J = 8.4, 2.3Hz, 1H), 7.78 (t, J = 7.5Hz, 3H), 7.71 (d, J = 8.2Hz, 2H). 13 C NMR (151MHz, d6-DMSO) δ158.31,153.38,148.20,145.47,145.36,138.23,138.01,133.71,127.36,126.05,125.68,111.70,93.86.HRMS:m / z calcd for C 15 H9N4ClIS 438.92756; found 438.92749,M+H + .

[0110] Example 35: Synthesis of compound 42

[0111] Following the method of Example 30, compound 42 was synthesized from intermediate 15, yielding 9.6 mg of a gray solid with a yield of 30.7%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ7.55(br,1H),7.51(s,1H),7.46(d,J=2.0Hz,1H),6.99(dd,J=7.2,2.0Hz,1H),6 .72(d,J=6.8Hz,2H),6.65(d,J=6.7Hz,2H),6.19(d,J=7.3Hz,1H),3.63–3.59(m,4H),3.09–3.05(m,4H). 13 C NMR(151MHz,CF3COOD)δ163.30,154.97,146.06,144.32,142.06,141.46,138 .94,129.12,126.17,118.28,116.49,113.55,99.43,45.82,45.49.HRMS:m / z calcd for C 19 H 18 N6IS 489.03528; found 489.03516,M+H + .

[0112] Example 36: Synthesis of compound 43

[0113] Following the method of Example 32, compound 43 was synthesized from labeled precursor compound 34, yielding 5.4 mg of a gray solid in a yield of 50.0%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.01(s,1H),7.83(d,J=8.5Hz,2H),7.78(d,J=8.9Hz,2H),7.61( d,J=8.5Hz,2H),7.00(d,J=8.8Hz,2H),3.91–3.89(m,4H),3.37–3.34(m,4H).HRMS:m / z calcd for C 19 H 18 N6IS 489.35492; found 489.02173,M+H + .

[0114] Example 37: Synthesis of compound 44

[0115] Following the method of Example 32, compound 44 was synthesized from labeled precursor compound 35, yielding 3.2 mg of a pale yellow solid in 95.2% yield. The structure is as follows: HRMS: m / z calcd for C 19 H 17 N5IS 474.02439; found 474.02432,M+H + .

[0116] Example 38: Synthesis of compound 45

[0117] Following the method of Example 32, compound 45 was synthesized from intermediate 36 to obtain 0.8 mg of a white solid, with a yield of 20.2%. The structure is as follows: 1 H NMR (400MHz, CDCl3) δ8.03 (s, 1H), 7.79 (d, J = 7.7Hz, 2H), 7.59 (d, J = 7.3Hz, 2H), 7.43–7.34 (m, 2H), 6.93 (d, J = 13.6Hz, 1H), 6.11 (s, 2H). 13C NMR (101MHz, CDCl3) δ164.26,151.67,148.98,146.52,144.71,138.39,132.2 3,129.61,127.12,122.79,109.75,109.24,106.76,102.36,29.82.HRMS:m / z calcd for C 17 H 11 O2N3IS 447.96112; found 447.96136,M+H + .

[0118] Example 39: Synthetic intermediate 46

[0119] Compound 5-bromo-1,3,4-thiadiazol-2-amine (198.3 mg, 1.10 mmol) and 2'-bromo,4-iodoacetophenone (324.6 mg, 1.0 mmol) were dissolved in 10 mL of n-butanol and heated in an oil bath at 110 °C for 2 h. After the reaction was complete, the mixture was cooled to room temperature, and a light brown solid precipitated. The solid was filtered to give intermediate 26, totaling 202.6 mg, with a yield of 50.0%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ8.03 (s, 1H), 7.74 (d, J = 8.4Hz, 2H), 7.54 (d, J = 8.3Hz, 2H).

[0120] Example 40: Synthesis of compound 47

[0121] Intermediate compound 46 (81.9 mg, 0.2 mmol), anhydrous piperazine (115.3 mg, 1.3 mmol), and anhydrous potassium carbonate (134.6 mg, 1.0 mmol) were dissolved in 10 mL of acetonitrile. The mixture was heated in an oil bath at 85 °C for 12 h. After the reaction was complete, the acetonitrile was removed by vacuum distillation. The mixture was then separated by column chromatography with an eluent ratio of ethyl acetate:methanol = 10:1 to give a white compound 47, totaling 8.9 mg, in a yield of 10.7%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ8.33(s,1H),7.67(d,J=8.5Hz,2H),7.55(d,J=8.4Hz,2H),3.36–3.33(d,J=4.8Hz,4H),2.82–2.80(m,4H). 13C NMR(151MHz,d6-DMSO)δ165.35,141.81,141.25,137.77,134.49,126.75,110.97,92.37,49.34,44.90.HRMS:m / z calcd for C 14 H 15 N5IS 412.00874; found 412.00873,M+H + .

[0122] Example 41: Synthetic intermediate 48

[0123] Compound 5-bromo-1,3,4-thiadiazol-2-amine (359.8 mg, 2.0 mmol), piperazine-1-carboxylic acid tert-butyl ester (457.5 mg, 2.5 mmol), and anhydrous potassium carbonate (678.0 mg, 4.9 mmol) were dissolved in 18 mL of acetonitrile. The mixture was heated in an oil bath at 85 °C for 12 h. After the reaction was complete, the acetonitrile was removed by vacuum distillation. Recrystallization from a mixed solution of ethanol and petroleum ether (volume ratio 1:1) yielded 301.1 mg of a white solid, with a yield of 43.1%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ6.52 (s, 2H), 3.41 (d, J = 3.5Hz, 4H), 3.21 (d, J = 3.7Hz, 4H), 1.41 (s, 9H).

[0124] Example 42: Synthetic intermediate 49

[0125] Following the method of Example 12, compound 49 was synthesized from intermediate 48 to obtain 51.3 mg of a white solid, with a yield of 10.8%, and its structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ8.40(s,1H),7.75–7.73(m,2H),7.56–7.54(m,2H),3.50–3.48(m,4H),3.47–3.45(m,4H),1.43(s,9H).

[0126] Example 43: Synthesis of labeled precursor compound 50

[0127] Following the method of Example 21, labeled precursor compound 50 was synthesized from intermediate 49, yielding 36.5 mg of a yellow solid in a yield of 57.4%. The structure is as follows: 1H NMR (600MHz, CDCl3) δ7.74(s,1H),7.70(d,J=8.1Hz,2H),7.48(d,J=8.0Hz,2H),3.61–3.58(m,4H),3.47 –3.45(m,4H),1.56–1.52(m,6H),1.49(s,9H),1.35–1.32(m,6H),1.07–1.04(m,6H),0.91–0.87(m,9H).

[0128] Example 44: Synthetic intermediate 51

[0129] Benzene 1-bromo-4-isothiocyanate (1755.3 mg, 8.2 mmol) was dissolved in isopropanol, and then 85% hydrazine hydrate aqueous solution (800 μL) was added dropwise with stirring. After reacting at room temperature for 10 minutes, a white precipitate was formed. The white precipitate was collected by vacuum filtration and washed with EtOH. The precipitate was then dissolved in EtOH again, and pyrazine-2-carboxaldehyde (768.7 mg, 7.05 mmol) was added. The mixture was heated in an oil bath at 100 °C for 3 hours. After the reaction was completed, the solvent was removed by vacuum distillation. The solid residue was dispersed in EtOAc, sonicated for 10 min, and filtered to obtain a beige intermediate compound of 2195.7 mg, with a yield of 92.6%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ12.19 (s, 1H), 10.32 (s, 1H), 9.63 (d, J = 1.4Hz, 1H), 8.5 9(dd,J=2.5,1.6Hz,1H),8.57(d,J=2.5Hz,1H),8.16(s,1H),7.56–7.49(m,4H).

[0130] Example 45: Synthetic intermediate 52

[0131] Intermediate compound 51 (1937.6 mmol, 5.76 mmol) and ferric chloride hexahydrate (6736.5 mg, 25.0 mmol) were dissolved in 40 mL of anhydrous ethanol and heated in an oil bath at 100 °C for 8 hours. After the reaction was complete, the ethanol was removed by vacuum distillation, and a saturated sodium thiosulfate solution was added. The mixture was then extracted four times with dichloromethane. The combined organic phases were dried over anhydrous magnesium sulfate, and after concentration by vacuum distillation, the mixture was separated by column chromatography with a dichloromethane:ethyl acetate volume ratio of 1:2 to give 58.9 mg of a light green solid in a yield of 3.0%. The structure is as follows: 1H NMR (400MHz, d6-DMSO) δ10.91(s,1H),9.36(d,J=1.3Hz,1H),8.75(dd,J=2.7,2.0Hz,2H),7.68(d,J=9.0Hz,2H),7.57(d,J=9.0Hz,2H).

[0132] Example 46: Synthesis of labeled precursor compound 53

[0133] Following the method of Example 21, labeled precursor compound 53 was synthesized from intermediate 52 to obtain 23.8 mg of a yellow amorphous solid, with a yield of 26.3%, and its structure is as follows: 1 H NMR (400MHz, CDCl3) δ9.53(d,J=1.3Hz,1H),8.59(d,J=2.6Hz,1H),8.56(dd,J=2.6,1.6Hz,1H),7.55–7.5 0(m,2H),7.47–7.44(m,2H),1.66–1.55(m,6H),1.38–1.30(m,6H),1.10–1.05(m,6H),0.92–0.88(m,9H).

[0134] Example 47: Synthesis of compound 54

[0135] Following the method of Example 32, compound 54 was synthesized from intermediate 53 to obtain 6.8 mg of a white solid, with a yield of 90.5%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ10.89(s,1H),9.36(s,1H),8.74–8.72(m,2H),7.71(d,J=8.6Hz,2H),7.54(d,J=8.6Hz,2H).

[0136] Example 48: Synthesis of compound 55

[0137] Intermediate 12 (60.9 mg, 0.34 mmol) and 2'-bromo-4-fluoroacetophenone (112.8 mg, 0.52 mmol) were dissolved in n-butanol and heated in an oil bath at 110 °C for 4 h. After the reaction was complete, the mixture was cooled to room temperature, and a pale yellow solid precipitated. The crude product was obtained by filtration. After drying, the crude product was subjected to column chromatography with a dichloromethane:ethyl acetate ratio of 1:1 to obtain a pale yellow compound 55, totaling 29.1 mg, with a yield of 28.8%. The structure is as follows: HRMS: m / z calcd for C 14H9N5FS298.05572; found 298.05576,M+H + .

[0138] Example 49: Synthesis of labeled precursor compound 56

[0139] Intermediate 12 (73.3 mg, 0.41 mmol) and 2-bromo-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)ethane-1-one (346.6 mg, 1.1 mmol) were dissolved in 10 mL of n-butanol and heated in an oil bath at 110 °C for 8 h. After the reaction was complete, the mixture was cooled to room temperature, and a white solid precipitated. Filtering yielded labeled precursor compound 56, totaling 84.5 mg, with a yield of 50.8%. The structure is as follows: 1 HNMR(600MHz,d6-DMSO)δ9.41(s,1H),8.92–8.84(m,4H),8.06(s,1H),7.94(d,J=7.8Hz ,1H),7.89(d,J=7.8Hz,1H),7.84(d,J=7.8Hz,1H),7.73(d,J=7.7Hz,1H),1.31(s,12H).

[0140] Example 50: Synthetic Intermediate 57

[0141] Intermediate 12 (121.0 mg, 0.68 mmol) and 3-(2-bromoacetyl)pyridine 1-oxide (324.9 mg, 1.50 mmol) were dissolved in n-butanol and heated in an oil bath at 110 °C for 8 h. After the reaction was complete, the mixture was cooled to room temperature, and a light brown solid precipitated. The solid was filtered to give intermediate 57, totaling 124.3 mg, with a yield of 61.7%. The structure of the solid is as follows: 1 H NMR(600MHz,d6-DMSO)δ9.42(d,J=0.9Hz,1H),9.12(s,1H),8.73(d,J=2.3Hz,1H),8.67–8.65( m,1H),8.58(d,J=3.0Hz,1H),8.28(d,J=7.9Hz,1H),8.20(s,1H),7.46(dd,J=7.5,5.1Hz,1H).

[0142] Example 51: Synthesis of labeled precursor compound 58

[0143] Intermediate 57 (124.3 mg, 0.42 mmol) was dissolved in 10 mL of dichloromethane. At 0 °C, 6 mL of a 2 M solution of trimethylamine in tetrahydrofuran and 3 mL of trifluoroacetic anhydride were slowly added dropwise. The reaction was carried out at room temperature for 1 h. After the reaction was complete, 5 mL of water was added to the reaction system. Subsequently, dichloromethane was removed by vacuum distillation, followed by extraction with ethyl acetate (10 mL × 2). The organic phases were combined, concentrated by vacuum distillation, and then 30 mL of diethyl ether was added. The mixture was ultrasonically washed, centrifuged, and the lower precipitate was collected as labeled precursor compound 58, a light brown solid, totaling 59.4 mg, with a yield of 27.1%. Its structure is as follows: 1 H NMR(600MHz,CF3COOD)δ7.81(s,1H),7.47(s,1H),7.34(s,1H),7.30(s,1H),7. 01(s,1H),6.92(d,J=6.6Hz,1H),6.52(d,J=6.8Hz,1H),3.05(s,9H).HRMS:m / z calcd for C 16 H 16 N7S 338.11824;found 338.11777,M + .

[0144] Example 52: Synthesis of compound 59

[0145] The labeled precursor compounds 58 (12.1 mg, 0.027 mmol), K2CO3 (4.0 mg, 0.029 mmol), and K were used. 222 (22.4 mg, 0.059 mmol) and KF·2H2O (65.6 mg, 0.70 mmol) were dissolved in 5 mL of anhydrous DMSO and heated in an oil bath at 70 °C for 2 h. After the reaction was complete, deionized water was added, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, and the solvent was removed by vacuum distillation. The mixture was then separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:1 to give 4.5 mg of a yellow solid, with a yield of 55.9%. The structure is as follows: 1 H NMR (600MHz, CF3COOD) δ7.81(s,1H),7.47(s,1H),7.34(s,1H),7.30(s,1H),7.01(s,1H),6.92(d,J=6.6Hz,1H),6.52(d,J=6.8Hz,1H).HRMS:m / z calcd for C 13 H8N6FS 299.05097; found 299.05112,M+H + .

[0146] Example 53: Synthetic intermediate 60

[0147] Intermediate 12 (124.5 mg, 0.69 mmol) and 2'-bromo-4-hydroxyacetophenone (201.9 mg, 0.94 mmol) were dissolved in n-butanol and heated in an oil bath at 110 °C for 8 h. After the reaction was complete, the mixture was cooled to room temperature, and a pale yellow solid precipitated. This solid was filtered to give intermediate 60, totaling 176.5 mg, with a yield of 59.7%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ9.39(dd,J=4.1,1.4Hz,1H),8.87(d,J=2.5Hz,1H),8.83(dd ,J=2.5,1.6Hz,1H),8.65(s,1H),7.72(dd,J=8.6,3.6Hz,2H),6.83(d,J=8.7Hz,2H).

[0148] Example 54: Synthetic intermediate 61

[0149] Intermediate 60 (35.0 mg, 0.12 mmol) and 2-bromoethanol (1.0 g, 8.0 mmol) were dissolved in 5 mL of anhydrous DMF. 180.5 mg of NaH (containing 40% paraffin, 4.5 mmol) was slowly added to the solution with stirring. The mixture was heated in an oil bath at 90 °C for 4 h. After the reaction was complete, water was added to quench the reaction. The mixture was then extracted with ethyl acetate. The organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The mixture was then separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:2, yielding 7.8 mg of a yellow solid in 19.1% of the product. The structure of the solid is as follows: 1 H NMR(600MHz, CDCl3)δ9.44(s,1H),8.79(d,J=2.3Hz,1H),8.72–8.70(m,1H),8.03(s,1 H),7.85(d,J=8.7Hz,2H),7.05(d,J=8.7Hz,2H),4.17–4.14(m,2H),4.02–4.00(m,2H).

[0150] Example 55: Synthesis of labeled precursor compound 62

[0151] Intermediate 61 (26.3 mg, 0.078 mmol) and 4-methylbenzenesulfonyl chloride (206.5 mg, 1.08 mmol) were dissolved in 10 mL of dichloromethane. 500 μL of triethylamine was added with stirring, and the reaction was continued at room temperature for 12 h. After the reaction was complete, the solvent was removed by vacuum distillation, and the mixture was separated by column chromatography with a petroleum ether:ethyl acetate volume ratio of 1:1 to give a yellow labeled precursor compound 62, totaling 10.0 mg, in a yield of 26.0%. The structure is as follows: 1 H NMR(600MHz,)δ9.40(s,1H),8.70(d,J=2.4Hz,1H),8.66–8.63(m,1H),8.00(s,1H),7.83(d,J=8.2Hz,2H),7.75( d,J=8.7Hz,2H),7.35(d,J=4.8Hz,2H),6.85(d,J=8.7Hz,2H),4.41–4.39(m,2H),4.21–4.18(m,2H),2.45(s,3H).

[0152] Example 56: Synthesis of compound 63

[0153] Intermediate 60 (170.0 mg, 0.57 mmol), 1-fluoro-2-bromoethanol (1027.0 mg, 8.08 mmol), K₂CO₃ (156.0 mg, 1.13 mmol), and KI (116.4 mg, 0.70 mmol) were dissolved in 15 mL of acetonitrile. The mixture was heated in an oil bath at 105 °C for 12 h. After the reaction was complete, a saturated ammonium chloride solution was added, and the mixture was extracted with dichloromethane. The organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The mixture was then separated by column chromatography with a dichloromethane:ethyl acetate volume ratio of 1:1 to give a yellow compound 63, totaling 17.7 mg, in a yield of 8.9%. The structure is as follows: 1 H NMR (600MHz, CDCl3) δ9.15 (s, 1H), 8.78 (s, 1H), 8.21 (d, J = 5.8Hz, 1H), 8.05 (s, 1H), 7.83 (s, 2H), 7.52 (s, 1H), 7.13 (t, J = 8.1Hz, 2H).

[0154] Example 57: Synthetic intermediate 69

[0155] Following the method of Example 11, intermediate 69 was synthesized from 3,4-dimethoxybenzaldehyde to obtain 625.4 mg of a yellow solid, with a yield of 51.1%. The structure is as follows: 1H NMR (600MHz, d6-DMSO) δ7.36(d,J=1.8Hz,1H),7.30(s,2H),7.20(dd,J=8.3,1.9Hz,1H),7.01(d,J=8.4Hz,1H),3.82(s,3H),3.80(s,3H).

[0156] Example 58: Synthetic intermediate 70

[0157] Following the method of Example 11, intermediate 70 was synthesized from 3,5-dimethoxybenzaldehyde to obtain 106.5 mg of a yellow solid, with a yield of 8.5%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ7.42(s,2H),6.86(s,2H),6.57(s,1H),3.79(s,6H).

[0158] Example 59: Synthetic Intermediate 71

[0159] 4-Chloro-3-hydroxybenzonitrile (998.4 mg, 6.5 mmol) and thioaminourea (938.9 mg, 10.3 mmol) were dissolved in 6 mL of trifluoroacetic acid and heated in an oil bath at 80 °C for 4 h. After the reaction was complete, 50 mL of water was added to the reaction system, and the pH of the solution was adjusted to neutral with sodium bicarbonate. A white solid precipitated, which was filtered to give intermediate 71, totaling 1345.1 mg, with a yield of 90.9%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ10.52(s,1H),7.42(s,2H),7.40(dd,J=7.0,5.2Hz,2H),7.14(dd,J=8.2,2.0Hz,1H).

[0160] Example 60: Synthetic Intermediate 72

[0161] Following the method of Example 59, intermediate 72 was synthesized from 3-chloro-4-hydroxybenzonitrile to obtain 1125.9 mg of gray solid, with a yield of 76.3%. The structure is as follows: ¹H NMR (600 MHz, d6-DMSO) δ 10.66 (s, 1H), 7.66 (d, J = 2.2 Hz, 1H), 7.48 (dd, J = 8.5, 2.2 Hz, 1H), 7.31 (s, 2H), 7.00 (d, J = 8.5 Hz, 1H).

[0162] Example 61: Synthetic intermediate 73

[0163] Following the method of Example 59, intermediate 73 was synthesized from 6-hydroxynicotinic acid nitrile to obtain 923.8 mg of off-white solid, with a yield of 57.1%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ11.95(s,1H),7.86(dd,J=9.6,2.7Hz,1H),7.74(d,J=2.5Hz,1H),7.29(s,2H),6.43(d,J=9.6Hz,1H).

[0164] Example 62: Synthetic Intermediate 74

[0165] Intermediate 69 (405.6 mg, 1.7 mmol) was dissolved in 20 mL of dichloromethane and placed in an ice-water bath. 2.5 mL of boron tribromide solution (1 M in DCM) was slowly added dropwise at 0 °C, followed by a reaction at room temperature for 72 h. After the reaction was complete, 20 mL of water was added to dilute the reaction system, and the pH of the solution was adjusted to 7 with saturated sodium bicarbonate solution. A white solid was formed. The solid was filtered, collected, and dried to obtain intermediate 74, totaling 256.8 mg, with a yield of 71.8%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ9.36 (s, 1H), 9.27 (s, 1H), 7.18 (d, J = 2.1Hz, 3H), 6.98 (dd, J = 8.2, 2.1Hz, 1H), 6.78 (d, J = 8.2Hz, 1H).

[0166] Example 63: Synthetic intermediate 75

[0167] Following the method of Example 62, intermediate 73 was synthesized from intermediate 70, yielding 156.8 mg of a off-white solid with a yield of 71.4%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ9.53 (s, 2H), 7.32 (s, 2H), 6.60 (d, J = 2.1Hz, 2H), 6.25 (t, J = 2.2Hz, 1H).

[0168] Example 64: Synthetic Intermediate 76

[0169] Intermediate 18 (221.5 mg, 1.0 mmol), 3-(2-bromoacetyl)pyridine 1-oxide (267.8 mg, 1.2 mmol), and sodium bicarbonate (122.4 mg, 1.4 mmol) were dissolved in ethanol and heated in an oil bath at 90 °C for 4 h. After the reaction was complete, the mixture was cooled to room temperature, and a white solid precipitated out. Filtering yielded intermediate compound 76, totaling 158.7 mg, with a yield of 47.0%. The structure is as follows: 1 H NMR (400MHz, CF3COOD) δ9.47 (s, 1H), 8.93 (d, J = 6.4Hz, 1H), 8.80–8.75 (m, 2H), 8. 19(dd,J=7.9,6.8Hz,1H),7.57–7.53(m,2H),7.05(d,J=8.0Hz,1H),6.15(s,2H).

[0170] Example 65: Synthetic Intermediate 77

[0171] Following the method of Example 64, intermediate 77 was synthesized from intermediate 69 as a raw material, yielding 60.0 mg of a off-white solid with a yield of 31.8%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.92(s,1H),8.75(d,J=1.4Hz,1H),8.16–8.14(m,1H),7.84–7.81(m,1H),7.53– 7.52(m,1H),7.51–7.49(m,1H),7.48(d,J=2.2Hz,1H),7.16(d,J=8.5Hz,1H),3.89(s,3H),3.87(s,3H).

[0172] Example 66: Synthetic Intermediate 78

[0173] Following the method of Example 65, intermediate 78 was synthesized from intermediate 70, yielding 51.3 mg of a off-white solid with a yield of 32.2%. The structure is as follows: 1 H NMR (400MHz, d6-DMSO) δ8.98 (s, 1H), 8.81 (s, 1H), 8.24 (d, J = 5.7Hz, 1H), 7.92 (d, J = 8. 1Hz,1H),7.59–7.55(m,1H),7.06(d,J=2.1Hz,2H),6.77(d,J=4.1Hz,1H),3.86(s,6H).

[0174] Example 67: Synthetic Intermediate 79

[0175] Following the method of Example 50, intermediate 79 was synthesized from intermediate 71 to obtain 16.1 mg of a white solid, with a yield of 9.7%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.76(s,1H),8.45(d,J=6.4Hz,1H),8.21(d,J=7.0Hz,1H),8.12(s,1H), 7.92(s,1H),7.87–7.84(m,1H),7.59(t,J=5.4Hz,1H),7.48–7.45(m,1H),7.33(d,J=8.0Hz,1H).

[0176] Example 68: Synthetic intermediate 80

[0177] Following the method of Example 50, intermediate 80 was synthesized from intermediate 72, yielding 56.4 mg of a white solid with a yield of 30.8%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ9.00–8.99(m,1H),8.73(t,J=1.5Hz,1H),8.16(ddd,J=6.3,1.7,0.9Hz,1H),7.83–7.81 (m,1H),7.59(d,J=8.3Hz,1H),7.56(d,J=2.1Hz,1H),7.49(dd,J=7.9,6.4Hz,1H),7.40(dd,J=8.2,2.1Hz,1H).

[0178] Example 69: Synthetic Intermediate 81

[0179] Intermediate 73 (413.4 mg, 2.1 mmol), 3-(2-bromoacetyl)pyridine-1-oxide (515.6 mg, 2.38 mmol), and sodium bicarbonate (184.5 mg, 2.20 mmol) were dissolved in 10 mL of anhydrous DMF. The mixture was heated in an oil bath at 110 °C for 6 h. After the reaction was complete, the mixture was cooled to room temperature, and a brown solid precipitated. Filtering yielded intermediate compound 81, totaling 249.5 mg, with a yield of 37.8%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ8.90(s,1H),8.72(s,1H),8.16(d,J=2.7Hz,1H),8.14(d,J=6.5Hz,1H),7.9 6(dd,J=7.0,2.6Hz,1H),7.79(d,J=8.1Hz,1H),7.47(dd,J=7.9,6.5Hz,1H),6.53(d,J=9.7Hz,1H).

[0180] Example 70: Synthetic Intermediate 82

[0181] Intermediate 74 (205.8 mg, 0.98 mmol), 3-(2-bromoacetyl)pyridine-1-oxide (243.4 mg, 1.1 mmol), and sodium bicarbonate (138.3 mg, 1.0 mmol) were dissolved in 10 mL of anhydrous ethanol. The mixture was heated in an oil bath at 90 °C for 6 h. After the reaction was complete, the mixture was cooled to room temperature, and a yellow solid precipitated. The solid was filtered to give intermediate compound 82, totaling 256.8 mg, with a yield of 80.3%. The structure is as follows: 1 HNMR(400MHz,d6-DMSO)δ9.93(s,1H),9.61(s,1H),8.90(s,1H),8.70(s,1H),8.13(d,J=6.2Hz,1H),7.79(d ,J=7.9Hz,1H),7.50–7.44(m,1H),7.34(d,J=1.5Hz,1H),7.25(dd,J=8.1,1.5Hz,1H),6.91(d,J=8.2Hz,1H).

[0182] Example 71: Synthetic intermediate 83

[0183] Following the method of Example 70, intermediate 83 was synthesized from intermediate compound 75 to obtain 228.4 mg of beige solid, with a yield of 97.2%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ8.96(s,1H),8.72(s,1H),8.15(d,J=6.9Hz,1H),7.81(d,J=8 .0Hz,1H),7.49(dd,J=7.9,6.5Hz,1H),6.80(d,J=2.1Hz,2H),6.45(t,J=2.1Hz,1H).

[0184] Example 72: Synthesis of labeled precursor compound 84

[0185] Following the method of Example 51, labeled precursor compound 84 was synthesized from intermediate 76, yielding 128.2 mg of a off-white solid, with a yield of 70.4%. The structure is as follows: 1H NMR(600MHz,CD3OD)δ9.09(t,J=2.4Hz,1H),8.63(s,1H),8.55–8.52(m,1H),8.01(d,J =8.8Hz,1H),7.49–7.45(m,2H),6.99(dd,J=8.6,4.1Hz,1H),6.10(s,2H),3.68(s,9H).

[0186] Example 73: Synthesis of labeled precursor compound 85

[0187] Following the method of Example 51, labeled precursor compound 85 was synthesized from intermediate 77, yielding 17.8 mg of a off-white solid, with a yield of 22.2%. The structure is as follows: 1 H NMR (600MHz, d6-DMSO) δ9.07(d,J=2.1Hz,1H),8.97(s,1H),8.11(d,J=8.7Hz,1H),7.50(dd,J=8.3,2.0Hz,1H),7.43(d,J=2.0Hz,1H),7.13(d,J=0 8.4Hz,1H),3.85(s,3H),3.83(s,3H),3.57(s,9H).

[0188] Example 74: Synthesis of labeled precursor compound 86

[0189] Following the method of Example 51, labeled precursor compound 86 was synthesized from intermediate 78, yielding 13.2 mg of a brown solid in 18.4% yield. The structure is as follows: 1 H NMR (600MHz, CD3OD) δ9.12(s,1H),8.68(s,1H),8.57(d,J=7.8Hz,1H),8.02(d,J=8.5Hz,1H),7.10(s,2H),6.73(s,1H),3.88(s,6H),3.68(s,9H).

[0190] Example 75: Synthesis of labeled precursor compound 87

[0191] Following the method of Example 51, labeled precursor compound 87 was synthesized from intermediate 79, yielding 9.6 mg of a light brown solid with a yield of 18.4%. The structure is as follows: 1H NMR(400MHz,d6-DMSO)δ11.29(s,1H),9.11(d,J=2.0Hz,1H),9.02(s,1H),8.59(dd,J=8.7,2.1Hz,1H),8.1 5(d,J=8.7Hz,1H),7.95(d,J=2.1Hz,1H),7.78(dd,J=8.5,2.1Hz,1H),7.17(d,J=8.5Hz,1H),3.61(s,9H).

[0192] Example 76: Synthesis of labeled precursor compound 88

[0193] Following the method of Example 51, labeled precursor compound 88 was synthesized from intermediate 80, yielding 9.6 mg of a light brown solid in a yield of 11.0%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ10.93(s,1H),9.12(d,J=2.2Hz,1H),9.09(d,J=2.0Hz,1H),8.61(dd,J=8.7,2.3Hz,1H) ,8.17(d,J=8.7Hz,1H),7.60(d,J=8.3Hz,1H),7.57(d,J=2.1Hz,1H),7.40(dd,J=8.3,2.1Hz,1H),3.62(s,9H).

[0194] Example 77: Synthesis of labeled precursor compound 89

[0195] Following the method of Example 51, labeled precursor compound 89 was synthesized from intermediate 81, yielding 46.5 mg of a light brown solid in a yield of 12.4%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ12.35(s,1H),9.05(d,J=2.0Hz,1H),8.96(s,1H),8.54(dd,J=8.7,2.3 Hz,1H),8.11(t,J=6.4Hz,2H),7.91(dd,J=9.6,2.7Hz,1H),6.49(d,J=9.6Hz,1H),3.58(s,9H).

[0196] Example 78: Synthesis of labeled precursor compound 90

[0197] Following the method of Example 51, labeled precursor compound 90 was synthesized from intermediate 82, yielding 99.3 mg of a light brown solid in a yield of 33.5%. The structure is as follows: 1H NMR(400MHz,d6-DMSO)δ9.97(s,1H),9.63(s,1H),9.09(d,J=2.2Hz,1H),8.99(s,1H),8.57(dd,J=8.7,2.3Hz,1H ),8.14(d,J=8.7Hz,1H),7.35(d,J=2.2Hz,1H),7.26(dd,J=8.2,2.2Hz,1H),6.92(d,J=8.3Hz,1H),3.61(s,9H).

[0198] Example 79: Synthesis of labeled precursor compound 91

[0199] Following the method of Example 51, labeled precursor compound 91 was synthesized from intermediate 83, yielding 96.6 mg of a light brown solid in a yield of 25.0%. The structure is as follows: 1 H NMR(400MHz,d6-DMSO)δ9.91(s,2H),9.11(d,J=2.3Hz,1H),9.06(s,1H),8.59(dd,J=8.7,2 .3Hz,1H),8.16(d,J=8.7Hz,1H),6.80(d,J=2.1Hz,2H),6.47(t,J=2.1Hz,1H),3.62(s,9H).

[0200] Example 80: Synthesis of compound 92

[0201] Following the method of Example 52, compound 92 was synthesized from labeled precursor compound 84, yielding 10.3 mg of a white solid in a yield of 58.8%. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.82(s,1H),8.74(s,1H),8.40(dd,J=12.9,4.9Hz,1H),7.51(s,1 H),7.49(d,J=8.6Hz,1H),7.27(dd,J=8.5,1.7Hz,1H),7.13(d,J=8.1Hz,1H),6.18(s,2H).

[0202] Example 81: Synthetic intermediate 93

[0203] The labeled precursor compound 85 (12.0 mg, 0.024 mmol) was dissolved in 10 mL of anhydrous tetrahydrofuran. 100 μL of tetrabutylammonium fluoride solution (1 M tetrahydrofuran solution) was added dropwise with stirring. The mixture was then heated in an oil bath at 80 °C for 6 h. After the reaction was complete, the solvent was removed by vacuum distillation, and the mixture was separated by column chromatography with a petroleum ether:ethyl acetate ratio of 1:1, yielding 4.0 mg of a white solid in 47.7% yield. The structure is as follows: 1 H NMR(600MHz,d6-DMSO)δ8.81(s,1H),8.74(d,J=2.4Hz,1H),8.41(td,J=8.2,2.5Hz,1H),7.51(dd,J=8.4,2.2 Hz,1H),7.47(d,J=2.1Hz,1H),7.28(dd,J=8.6,2.6Hz,1H),7.16(d,J=8.5Hz,1H),3.89(s,3H),3.86(s,3H).

[0204] The following compounds were prepared according to the above examples:

[0205] Where F is 18 F or 19 F.

[0206] Example 82: 125 Preparation of I-labeled compounds

[0207] I. Experimental Procedure

[0208] (a) Compounds [ 125 I]37-41, [ 125 I]43-45 and [ 125 Preparation of I]54

[0209] 0.2 mg of the labeled precursor compounds (28-32, 34-36, and 53, respectively) were dissolved in 200 μL of acetonitrile, and Na was added sequentially. 125 The solution (100 μCi), 50 μL hydrochloric acid (1M) and 50 μL hydrogen peroxide solution (3%) were reacted at room temperature for 15 minutes. Then NaHCO3 solid was added to adjust the pH to neutral, and then the solution was separated and purified by HPLC.

[0210] (b) Compounds [ 125 I]42 and [ 125 Preparation of I]47

[0211] 0.2 mg of the labeled precursor compounds (33 and 50, respectively) were dissolved in 200 μL of acetonitrile, and Na was added sequentially. 125Solution I (100 μCi), 50 μL hydrochloric acid (1M), and 50 μL hydrogen peroxide solution (3%) were reacted at room temperature for 15 minutes. Then, 200 μL hydrochloric acid (6M) was added, and the reaction was heated at 110 °C for 10 minutes. After the reaction was complete, the mixture was cooled to room temperature, and the pH was adjusted to neutral with solid NaHCO3. After dilution with acetonitrile, the solution was purified by HPLC.

[0212] The separation conditions for the above radioactive iodine-labeled compounds were as follows: Venusil MP C18 column (5 μm, 4.6 mm × 250 mm), flow rate 1 mL / min. The eluent of the target product was collected, acetonitrile was removed by nitrogen, and the obtained product was prepared into the required solution.

[0213] II. Experimental Results

[0214] [ 125 I]37-45, [ 125 I]47, and [ 125 The labeling rate of I]54 and the HPLC separation conditions are as follows. After HPLC separation, 125 The radiochemical purity of the I-labeled probes is greater than 99%.

[0215] Table 1

[0216] a It contains 0.1% TFA. b Radiochemical yield.

[0217] Example 83: 18 Preparation of F-labeled compounds

[0218] I. Experimental Procedure

[0219] (a) Compounds [ 18 Preparation of F]55

[0220] [ 18 F]F - Ions were enriched on a QMA column and eluted with 1.0 mL of eluent (containing 6 mg TBAB, acetonitrile / water = 7 / 3) into a 10 mL vial. The column was heated in a 120 °C metal bath and dried by continuously passing N2 through it. Then, 1.0 mL of anhydrous acetonitrile was added in three portions and azeotropically dried to ensure that the reaction system was anhydrous.

[0221] 3.0 mg of the labeled precursor (56) and 7.0 mg of Cu(OTf)2(pyr)4 were dissolved in 100 μL of a mixture of n-butanol and 200 μL of DMA, and the solution was transferred to a solution containing [ 18 F]F -The reaction mixture was placed in a vial and reacted at 110°C for 20 minutes. After the reaction was complete, 10 mL of deionized water was added to dilute the reaction mixture. The mixture was then passed through a pretreated Light C18 column, and the column was eluted with 20 mL of deionized water to remove unreacted [products]. 18 F]F - Inorganic salts were also extracted. Subsequently, the column was washed with 1 mL of anhydrous ethanol to elute the organic compounds adsorbed on the column, and then purified by HPLC.

[0222] (b) Compounds [ 18 F]59 and [ 18 Preparation of F]92-99

[0223] [ 18 F]F - Ions were enriched on a QMA column and elute with 1.0 mL of elution buffer (containing 1.1 mg K₂CO₃, K₂O₃). 222 Elute 13 mg (acetonitrile / water = 8 / 2) into a 10 mL vial, heat in a 120 °C metal bath, continuously purge with N2 to dry, then add 1.0 mL of anhydrous acetonitrile in three portions and azeotropically dry to ensure the reaction system is anhydrous.

[0224] Dissolve 1.0 mg of the labeled precursor (58 or 84-91) in 300 μL of dry DMSO, and transfer the solution to a container containing [ 18 F]F - The reaction mixture was placed in a vial and reacted at 90°C for 10 minutes. After the reaction was complete, 150 μL of deionized water and 150 μL of acetonitrile were added to dilute the reaction mixture, and then the mixture was purified by HPLC.

[0225] The separation conditions were: Venusil MP C18 column (10 μm, 10 mm × 250 mm), flow rate 4 mL / min. The eluent of the target product was collected, acetonitrile was removed by nitrogen, and the obtained product was prepared into the required solution.

[0226] II. Experimental Results

[0227] [ 18 F]55,[ 18 F]59, and [ 18 The labeling rate of F]92-99 and the HPLC separation conditions are as follows. After HPLC separation... 18 The radiochemical purity of the F-labeled probes is greater than 99%.

[0228] Table 2

[0229] a It contains 0.1% TFA. b Radiochemical conversion rate.

[0230] Example 84: Radioactive Autoradiography Experiment

[0231] I. Experimental Procedure

[0232] (1) Comparing an 88-year-old female patient with an AD (Alzheimer's disease) and a 73-year-old female patient with PD (Parkinson's disease)

[0233] Paraffin sections of brain tissue were dewaxed by immersion in xylene for 5 minutes, followed by rinsing with anhydrous ethanol and pure water for 1 minute each.

[0234] stand-by;

[0235] (2) Cover the pretreated slices with 1 mL of [unspecified substance]. 125 I-labeled compound (5 μCi / mL) or 18 An aqueous solution of the F-labeled compound (20 μCi / mL) (containing 5% ethanol) was incubated at room temperature for 1.5 hours.

[0236] (3) After discarding the radioactive liquid on the surface, soak in 50% ethanol solution for 10 minutes, then rinse with 50% ethanol for 2 minutes. Repeat this step 3 times.

[0237] (4) After drying the sections, expose them to phosphorescent light under a phosphor screen. 125 Slices treated with I-labeled compounds should first be wrapped in plastic wrap and exposed to the light for 24 hours. 18 F-labeled compounds were exposed for 1.5 hours, and images were then acquired and analyzed using a phosphorus storage screen system.

[0238] II. Experimental Results

[0239] The experimental results are shown in Figures 3 and 4. Autoradiography results showed that these compounds can recognize α-syn aggregates on brain slices from PD patients and Aβ aggregates on brain slices from AD patients, indicating potential application value.

[0240] Example 85: Biodistribution experiment in normal mice

[0241] I. Experimental Procedure

[0242] Will 18 F-labeled compound (100 μL, 50-100 μCi / mL) or 125 I-labeled compound (100 μL, 10-20 μCi / mL) was injected intravenously into normal mice (ICR, male, 18-20 g, 3-4 weeks old) (n=3). Relevant organs were dissected at 2 minutes and 60 minutes post-injection to measure wet weight and radioactivity count. Data are expressed as percentage of radioactivity per gram of organ (%ID / g).

[0243] II. Experimental Results

[0244] The experimental results are shown in Table 3 below. The results show that the radioactivity... 125 I-labeled probe[ 125 I]37-39、[ 125 I]41 and radioactivity 18 F-labeled probe [ 18 F]55、[ 18 F]59、[ 18 The brain penetration rate of F]92-94 at 2 min was greater than 4% ID / g, indicating that these probes could cross the blood-brain barrier. At 60 min, all 125 The brain uptake of the I-labeled probe remained high, indicating that the clearance of the iodine-labeled compound was slow, while the modification to 18 After F-labeling the probe, the removal was significantly accelerated, meeting the requirements for subsequent imaging experiments.

[0245] Table 3. Animal distribution data of some compounds in normal mice.

[0246] a It is expressed as the percentage dose of radioactivity per gram of organ (%ID / g). b It is expressed as the percentage dose of radioactivity in an organ (%ID / organ). c Not measured.

[0247] Example 86: Assay of α-syn protein aggregate activity

[0248] I. Experimental Procedure

[0249] (1) Paraffin sections of brain tissue from a 73-year-old female PD patient were dewaxed by soaking in xylene for 5 minutes, and then rinsed with anhydrous ethanol and pure water for 1 minute respectively, and were ready for use.

[0250] (2) Cover the pretreated slice with 1 mL of the test compound at a concentration of 50 nM and [ 125 A mixed aqueous solution of I]39 (6 μCi / mL) (containing 10% ethanol) was incubated at room temperature for 1.5 h;

[0251] (3) After discarding the radioactive liquid on the surface, soak in 50% ethanol solution for 10 minutes, then rinse with 50% ethanol for 2 minutes. Repeat this step 3 times.

[0252] (4) After drying the sections, expose them to phosphorescent light for 24 hours. Analyze the images using a phosphorescent light storage system to obtain the quantified values ​​of Regions of Interests (ROIs) (Digital Light Unit / mm).2 DLU / mm 2 ), calculate the inhibition rate.

[0253] (5) For the dominant compounds 39, 55 and 59, the IC50 of the compounds was measured using the same method. 50 Value, cover the pretreated slice with 1 mL containing [ 125 I]39 was incubated with a mixed aqueous solution (containing 10% ethanol) of different concentrations of the test compound (compound 39, with final concentrations of 0M, 1nM, 5nM, 10nM, 50nM, 100nM and 500nM; compound 55, with final concentrations of 0M, 5nM, 10nM, 50nM, 100nM and 500nM; compound 59, with final concentrations of 0M, 10nM, 25nM, 50nM, 100nM, 500nM and 1000nM) at room temperature for 1.5 h. Then, following steps (3) and (4) above, the quantitative values ​​of Region of Interests (ROIs) (Digital Light Unit / mm) were obtained. 2 DLU / mm 2 Based on the numerical values ​​and the corresponding cold ligand concentration fitting curves, the data were analyzed and processed using GraphPad Prism 8 to obtain the IC50. 50 value.

[0254] II. Experimental Results

[0255] The α-syn aggregate activities of some of the test compounds are shown in Table 4 below. The IC50 values ​​of compounds 39, 55, and 59 for α-syn aggregates are also shown. 50 The values ​​are shown in Figures 5(A)-(C). Compounds 39 and 55 exhibit high α-syn activity, IC50... 50 The values ​​are 55 nM and 29 nM, respectively.

[0256] Table 4 shows the activity evaluation of some compounds on α-syn aggregates.

[0257] a No inhibitory effect was observed. b Not measured.

[0258] Example 87: Assay of Aβ protein aggregate activity

[0259] I. Experimental Procedure

[0260] (1) Paraffin sections of brain tissue from an AD patient (92 years old, female) were dewaxed by soaking in xylene for 5 minutes, and then rinsed with anhydrous ethanol and pure water for 1 minute respectively, and were ready for use.

[0261] (2) Perform the operation according to steps (2)(3)(4)(5) in Example 86.

[0262] II. Experimental Results

[0263] The Aβ aggregate activities of some of the test compounds are shown in Table 5 below. The IC50 values ​​of compounds 39, 55, and 59 for Aβ aggregates are also shown. 50 The values ​​are shown in Figures 5(D)-(F). Compounds 39, 55, and 59 all exhibit moderate Aβ activity, IC50... 50 The values ​​are 68 nM, 40 nM, and 26 nM, respectively.

[0264] Table 5. Activity evaluation of some compounds on Aβ aggregates

[0265] a No inhibitory effect was observed. b Not measured.

[0266] Example 88: PET / CT Imaging Experiment of Normal Rats

[0267] I. Experimental Procedure

[0268] Will[ 18 F]55 (464-472 μCi / mL, n=2) or [ 18 An aqueous solution of F]59 (464-564 μCi / mL, n=3) (containing 10% EtOH) was injected into normal rats via the tail vein, and dynamic PET imaging of their brains was performed using an IRIS PET / CT imaging system.

[0269] II. Experimental Results

[0270] The PET / CT images are shown in Figure 6, and the results indicate that [ 18 F]55 and [ 18 F]59 can cross the blood-brain barrier, and the initial brain uptake value is high 2 minutes after injection (SUV>2.5). 18 F]55 is cleared from the brain at a slow rate; even 60 minutes after injection, the brain still retains 1.93 SUV uptakes. 18 F]59 has a relatively fast brain clearance rate; 60 minutes after injection, the brain uptake SUV is 0.60, which meets the requirements for PET imaging.

[0271] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention. Industrial applicability

[0272] This invention provides an imidazothiadiazole compound, its preparation method, and its applications. The compound is shown in general structural formula (I). After labeling with a suitable radioisotope, this type of compound and its derivatives can be used for nuclear medicine imaging of α-synuclein aggregates in the brain, thereby aiding in the clinical diagnosis of synucleinosis, including Parkinson's disease, Lewy body dementia, multiple system atrophy, and some rare diseases, and possessing significant economic value and application prospects.

Claims

1. Imidazothiadiazole compounds represented by general structural formula (I), in, R1 is selected from R3 is selected from 123 I, 124 I, 125 I, 127 I, 18 F, 19 F, (OCH2CH2) m 18 F, (OCH2CH2) m 19 F, m are integers between 1 and 6; R2 is selected from Y independently represents N or CH, and R4 and R5 independently represent -H, -Cl, and -OCH3, respectively.

2. The imidazothiadiazole compound of general formula (I) according to claim 1, characterized in that, R1 is selected from R3 choice 123 I, 124 I, 125 I, 127 I, 18 F, 19 F.

3. The imidazothiadiazole compound of general formula (I) according to claim 1, characterized in that, R1 is selected from R3 choice 123 I, 124 I, 125 I, 127 I, 18 F, 19 F.

4. The imidazothiadiazole compound of general formula (I) according to claim 1, characterized in that, R2 is selected from 5. The imidazothiadiazole compound of general formula (I) according to claim 1, characterized in that, R2 is selected from Y independently represents N or CH, and R4 and R5 independently represent -H, -Cl, and -OCH3, respectively.

6. The imidazothiadiazole compound of general formula (I) according to claim 1, characterized in that, Selected from any of the following compounds: Preferably, I is 123 I, 124 I, 125 I or 127 I;F is 18 F or 19 F.

7. The method for preparing the imidazothiadiazole compound according to claim 6, characterized in that, When I is 123 I, 124 I or 125 At step I, compound (I-1)-compound (I-11) is composed of a trialkyltin, trialkylsilane, boric acid or borate ester precursor compound and [ 123 / 124 / 125 The solution of I]NaI is obtained by reacting in the presence of an oxidizing agent; When F is 18 At F, compound (I-12)-compound (I-22) is composed of p-toluenesulfonate, trimethyl quaternary ammonium salt, boric acid, borate ester or high-valent iodine cofactor precursor compound and [ 18 The F]F anion is obtained by reaction in the presence of a phase transfer catalyst.

8. A derivative of the imidazothiadiazole compound according to any one of claims 1-6, characterized in that, The derivatives include pharmaceutically acceptable salts, esters, amides, or prodrugs of compounds represented by general formula (I).

9. A diagnostic or detection reagent for α-synuclein, characterized in that, Its active ingredient is the imidazothiadiazole compound as described in any one of claims 1-6 and / or the derivative as described in claim 8; Optionally, the diseases detected include Parkinson's disease, Lewy body dementia, multiple system atrophy, and other rare alpha-synuclein diseases.

10. The use of the imidazothiadiazole compound according to any one of claims 1-6 or the derivative according to claim 8 in the preparation of a nuclear medicine imaging agent; optionally, the nuclear medicine imaging agent is a PET or SPECT imaging agent.

Images