A radioactive isotope carbon-14 labeled metyridyl and its preparation method and application

Abstract

The application relates to the field of synthesis of radioactive compounds, in particular to a radioisotope carbon-14 labeled metyridyl and a preparation method and application thereof. 14 The [2- 14 C]metyridyl provided by the application is carbon-14 labeled on a stable parent nucleus, has high metabolic stability and pharmacokinetic equivalence, can be used as a key carbon-14 labeled synthesis block to prepare a metyridyl parent nucleus compound of a core parent nucleus, is used for metabolic tracing experiments, accurately traces the in-vivo metabolism and environmental migration rule of a tricyclic skeleton, and effectively overcomes the technical defects of carbon-14 side chain labeling. The application uses metyridyl as a starting material, uses carbon-14 labeled alkali metal / alkaline earth metal cyanide as an isotope raw material, realizes the positioning labeling of carbon-14 at the 2-position of the metyridyl parent nucleus through a labeling synthesis strategy of "carbon ring opening-ring closure of a carbon chain", solves the preparation difficulty of a non-radioactive key raw material, and also provides a complete process route for realizing carbon-14 labeling synthesis based on the key raw material.

Description

Technical Field

[0001] This application relates to the field of radiochemical synthesis, specifically to a radioisotope carbon-14 labeled mtiline, its preparation method, and its application. Background Technology

[0002] Pleuromutilin (CAS 125-65-5, as shown in formula A below) was discovered in the 1950s from higher fungi. Pleurotus mutilus (Fr.) Sacc. and Pleurotus passeckerianus The natural antibacterial substances isolated from Pilat belong to the tricyclic diterpenoids formed by the fusion of five-membered, six-membered, and eight-membered rings. Their molecular skeleton contains eight chiral carbon atoms, with a hydroxyacetic acid ester side chain attached to the 14-carbon position. (Absolute configuration of mutilin, 5-acetylmutilin and 5-bromoacetylmutilin [J],) Acta Cryst (1995, C51, 2676-2680). Naturally truncated pleurotin has shortcomings such as weak antibacterial activity and poor water solubility. However, due to its strong molecular structure plasticity, derivatives with strong inhibitory activity against multidrug-resistant Gram-positive bacteria can be obtained through directional modification and structural modification of the 14-position side chain. This makes it an important lead compound in the research and development of new antibacterial drugs for human use, veterinary use, and agriculture.

[0003]

[0004] Since the Swiss company Sandoz first synthesized and marketed tiamulin (a veterinary drug, as shown in formula B above), a truncated pleurotin derivative modified at the 14-position, in 1976, the research and development of truncated pleurotin drugs has continued to advance: Valnemulin (a veterinary drug, as shown in formula C above) was approved for marketing in the European Union in 1999; Retapamulin (a human drug, as shown in formula D above) was approved by the US FDA for the treatment of local infections in humans in 2007; and Lefamulin (a human drug, as shown in formula E above) was approved in the US and Europe in 2019-2020 for the treatment of community-acquired bacterial pneumonia in adults, realizing the leap from veterinary to human use of this class of drugs. Meanwhile, significant progress has also been made in related domestic research. For example, the candidate pesticide chlorpyrifos developed based on truncated pleurotin (Wang Shaobo, Design, Synthesis and Mechanism of Action of Truncated Pleurotin Derivatives with Resistance to Bacterial Leaf Streak of Rice [D], Guizhou University, 2024; ZL202410918527.6), as shown in Formula F above, has shown good application potential in the control of bacterial diseases in crops.

[0005] In the research and development and premarket registration of truncated pleurotin drugs (including human drugs, pesticides and veterinary drugs), systematically elucidating their metabolic behavior and assessing their safety are the core steps, and radioisotope tracing technology is the key means to achieve this goal and the internationally recognized gold standard (Lappin G, Temple S). Radiotracers in drugs development [M]. Florida: CRC Press, Taylor&Francis Group, 2006; Roberts D, Lockley W. Radiochemistry, a vital role supporting drug development[J]. Drug Discovery World (2004, Fall Issue: 59-64). Radiopharmacokinetics studies of truncated pleurotin derivatives for human use and metabolic tests for new pesticide registration (including truncated pleurotin derivatives registered for the first time in China) both rely on carbon-14 labeling tracer technology. Radioisotope carbon-14 labeled drugs of this class are essential tracers for conducting isotope tracer studies (drug metabolism studies, pesticide registration metabolic tests, etc.).

[0006] The selection of labeling sites is crucial in the study of radioisotope carbon-14 labeled tracer drugs, as it determines the pharmacokinetic equivalence, metabolic stability, synthetic feasibility, and economic viability of the labeled drug. Pharmacokinetic equivalence is the primary principle; the labeled compound must not alter the backbone, configuration, chirality, or physicochemical properties of the parent drug molecule, and must show no significant differences from the unlabeled prototype drug in terms of metabolic behavior, protein binding rate, and tissue distribution (with the isotope effect as small as possible). Additionally, the label needs to be firmly attached, not easily detached, and possess high metabolic stability, fully reflecting the drug's main metabolic transformation patterns. However, the in vivo metabolic pathways of drugs are often complex, and new metabolic pathways may exist, leading to the loss of labeled atoms at unexpected locations. The synthesis of radioisotope-labeled drugs also faces numerous challenges and difficulties. These include the difficulty of site-specific selective introduction, high technical barriers in synthesis, the difficulty in precisely introducing isotopes at single sites for complex molecules, and the tendency for multi-site secondary labeling; the difficulty in maintaining specific configurations, with racemization and epimerization easily occurring during drug labeling, leading to difficulties in maintaining chirality and configuration, affecting the consistency of efficacy and in vivo behavior; generally low synthetic yields, limited substrate activity in isotope synthesis, numerous side reactions, and purification and separation difficulties far exceeding those of conventional organic synthesis. These factors increase the difficulty of developing radioisotope-labeled tracer drugs. For a given drug molecule, it is often difficult to obtain a suitable isotope-labeled compound with a specific site label through a simple and economical synthetic route. The successful acquisition of tracer drugs with specific site labels is the result of long-term innovative research and development, comprehensively considering factors such as pharmacokinetic equivalence, metabolic stability, synthetic feasibility, and economy.

[0007] For truncated tiamulin drugs, currently, publicly reported methods only include carbon-14 labeling schemes targeting the 14-position side chain (such as the side chain labeling of tiamulin, see: Metabolism of tritium- and carbon-14-labeled tiamulin in dogs, rats, and pigs[J]. J Antibiot , 1979, 32 (5): 496-503).

[0008] In view of the above-mentioned prior art, the purpose of this application is to provide a practical solution for stable radioactive tracers required for the research of such derivative isotope tracing. Summary of the Invention

[0009] To achieve the purpose of this invention, the inventors previously discovered that in the existing technology, the carbon-14 labeling of truncated pleurotin drugs is concentrated on the 14-position side chain. Practice has proven that this type of labeling scheme has obvious defects: ① The 14-position side chain has poor metabolic stability in complex systems such as organisms and soil-water bodies, and is easily degraded and broken, causing the carbon-14 label to fall off. This makes it impossible to continuously track the metabolic trajectory of the drug matrix (tricyclic skeleton), thus affecting the accuracy of metabolic test data and even making it difficult to carry out key metabolic tests completely; ② The degraded side chain fragments are easily reused by organisms, inducing errors in tissue residue detection and distortion of material balance data. Moreover, the parent nucleus cannot be tracked by isotopes throughout the process, further limiting the integrity of metabolic research. Therefore, side chain labeling cannot meet the technical requirements for metabolic research for the registration of human drugs, pesticides, and veterinary drugs.

[0010] Mutilin (also known as dehydroxyacetylated truncated pleurotin, 14-dehydroxyacetylated truncated pleurotin, CAS 6040-37-5) is the core nucleus compound obtained by dehydroxyacetylation of the 14-position side chain of truncated pleurotin. It is the common core nucleus of tricyclic diterpenoids of various truncated pleurotin derivatives. Through preliminary research, the inventors discovered that the multeline molecule contains a fused ring system formed by the combination of five-membered, six-membered, and eight-membered rings, which is relatively stable in physicochemical structure and exhibits excellent metabolic stability. By site-specifically carbon-14 labeling on its stable carbon ring backbone, it can be used as a key marker building block for the preparation of radioactive tracers required for isotope tracing studies of this type of derivative. This method is expected to overcome the technical defects of existing 14-position side chain markers, which are prone to metabolic loss at radioactive sites and cannot truly and comprehensively reflect the metabolism and environmental fate of the tricyclic nucleus. It can firmly fix the isotope marker, avoid signal loss, and completely restore the in vivo metabolic behavior and environmental fate of the drug's main structure. It can be widely used in in vivo metabolic studies of human and veterinary drugs containing multeline nucleus (especially truncated pleurotins) and in new pesticide registration evaluation tests.

[0011]

[0012] Therefore, only by fixing carbon-14 labeling onto the truncated pleurotin stable tricyclic core can the stability and resistance to degradation of the labeling site be guaranteed, enabling true traceability of drug metabolism and accurate detection of residues throughout the entire process. However, there is currently no publicly available research on carbon-14 labeled compounds and synthetic processes for truncated pleurotin cores, leaving a technological gap in this field.

[0013] In view of the shortcomings of existing side chain labeling schemes and the aforementioned technological gaps, this application focuses on the carbon-14 labeling technology of multiline, seeking a stable carbon-14 labeled multiline for the parent nucleus and its preparation method.

[0014] The tricyclic diterpenoid skeleton of mustiline has 14 carbon atoms. In the early research, the inventors attempted to label the carbon atoms in the eight-membered ring using a total synthesis method. However, after reviewing the literature, they found that the labeling synthesis route was particularly long and the non-radioactive raw materials used in the labeling synthesis were not available. The self-synthesis technology route was also too long, so this approach was not feasible. The inventors also attempted to introduce carbon-14 into the 3-carbon of the moltiline molecular ring skeleton, but after multiple attempts, this technical route was found to be unfeasible. This route involves the halogenation reaction of 4-OH as shown below. Although theoretically, halogen nucleophilic substitution reactions of 4-OH are generally highly feasible, after multiple attempts with different reaction methods and conditions (covering conventional nucleophilic substitution reaction conditions), the target halogenated product was not successfully obtained. Analysis suggests that the 5-C and 9-C on both sides of 4-OH are quaternary carbons, and the large substituents significantly occupy space, directly hindering the nucleophile's attack on 4-OH, making it difficult to initiate the nucleophilic substitution reaction. At the same time, the six-membered ring has a chiral environment, and its rigid conformation further compresses the reaction site space of the 4-OH secondary alcohol, exacerbating the steric hindrance of the substitution reaction. Due to the steric hindrance of this six-membered ring skeleton, 4-OH cannot be halogenated. Based on previous research, the inventors further optimized and adjusted the labeling site and synthetic route, and finally successfully synthesized the 2-carbon-14 labeled moltiline described in this application.

[0015]

[0016] To achieve the objectives of this invention, this application provides a radioisotope carbon-14 labeled multeline, its preparation method, and its application. This labeling, achieved by carbon-14 labeling of the stable multeline core, exhibits high metabolic stability and pharmacokinetic equivalence. It can serve as a key carbon-14 labeled synthetic building block for preparing carbon-14 labeled multeline-containing core compounds. This can be used for metabolic tracing experiments of drugs containing the multeline core, especially truncated pleurotin drugs, accurately tracing the in vivo metabolism and environmental migration patterns of the tricyclic skeleton. This meets the isotope labeling technical specifications for metabolic experiments in the registration of new human, veterinary, and pesticide drugs both domestically and internationally. It effectively overcomes the technical deficiencies of existing carbon-14 side chain labeling for truncated pleurotin drugs, fills the technical gap in carbon-14 labeling of the main skeleton of truncated pleurotin drugs, and meets the needs of isotope tracing research for the preparation and application of such drug labeling.

[0017] In a first aspect, this application provides a carbon-14 labeled multiline, [2- 14 C]Mtiline, its structural formula is shown below:

[0018] The asterisk (*) indicates the carbon-14 labeled site.

[0019] This application uses multiline as the starting material and carbon-14 labeled alkali metal / alkaline earth metal cyanides as isotopic raw materials. Through a labeling synthesis strategy of "carbon ring opening—introduction of carbon-14—carbon chain closure," carbon-14 is precisely labeled at the 2-position of the multiline five-membered carbon ring core. This scheme not only solves the problem of preparing non-radioactive key raw materials in labeling synthesis but also provides a complete process route for carbon-14 labeled synthesis based on these key raw materials.

[0020] In a second aspect, this application provides a carbon-14 labeled multiline, [2- 14 The preparation method and synthetic route of C] methylphenidate are as follows: ; In this context, X1 and X2 are each independently selected from halogens, PG represents a silicon-based protecting group, and "RS-1" to "RS-6" represent suitable reaction conditions for each step of the reaction.

[0021] In some embodiments, X1 and X2 are each independently selected from Cl, F, Br, or I; PG is selected from tert-butyldimethylsilyl (TBS), triethylsilyl (TES), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), diethylisopropylsilyl (DESP), or diisopropylethylsilyl (DEIPS). Preferably, X1 and X2 are each independently Br or I, and PG is selected from tert-butyldimethylsilyl (TBS).

[0022] In some embodiments, the reaction conditions for the cyanidation reaction of the 11,14-dihydroxyprotected morteline ring-opening halogen (8) are as follows: RS-1: the isotopic raw material is selected from carbon-14 alkali metal cyanide or carbon-14 alkaline earth metal cyanide, such as Na 14 CN or K 14 CN, preferably Na 14 CN. The reaction is carried out in the presence of an iodide, such as KI or NaI; the molar amount of the iodide is 2-30% of compound (8), preferably 5-25%, more preferably 10-15%. An organic solvent system, such as DMSO, is used as the reaction solvent. N , N The reaction mixture uses dimethylformamide (DMF), acetonitrile (ACN), and their mixed solvents; or a low molecular weight alcohol-water binary mixture, such as an EtOH-H2O mixture, with an alcohol-water volume ratio of 9:1 to 1:1. Preferably, when using an alcohol-water binary mixture, a phase transfer catalyst, such as 18-crown-6 catalyst, is used. The reaction temperature is 0 to 150 °C, preferably 20 to 100 °C, and more preferably 50 to 80 °C.

[0023] In some embodiments, regarding the ring-opening of 11,14-dihydroxyprotected murtiline [cyano- 14Reduction hydrolysis reaction of cyano compound (9) under the following conditions: RS-2: The reaction is carried out in the presence of a reducing agent and a base. Preferably, the reducing agent is diisobutylaluminum hydride (DABAL-H), and the base is an organic base, such as morpholine. N Methylmorpholine, piperidine, or pyrrolidine, etc. The solvent used is an aprotic inert solvent, such as THF, DCM, PhMe, or hexane. The reaction temperature is -78 to 30 °C, preferably -50 to 10 °C, and more preferably -10 to 0 °C.

[0024] In some embodiments, regarding the ring-opening of 11,14-dihydroxyprotected murtiline [aldehyde-] 14 Reduction conditions for aldehyde (10) RS-3: The reaction is carried out in the presence of a reducing agent, preferably an alkali metal borohydride or an alkaline earth metal borohydride, such as sodium borohydride or potassium borohydride. The solvent is a low molecular weight alcohol, such as methanol or ethanol. The reaction temperature is 0~30 ℃, preferably 0~25 ℃.

[0025] In some embodiments, regarding the ring-opening of 11,14-dihydroxyprotected murtiline [2- 14 The reaction conditions for the halogenation of alcohol (11) are as follows: RS-4: The reaction is carried out in the presence of a halogenating agent, triphenylphosphine, and a base; the halogenating agent is NBS, NIS, Br2, or I2, preferably I2; the base is imidazole (Imid), diisopropylethylamine (DIPEA), or pyridine (Py). The solvent is THF, DCM, CCl4, DMF, PhMe, or ACN, preferably THF or DCM. The reaction temperature is 0~30 ℃, preferably 0~25 ℃.

[0026] In some embodiments, regarding the ring-opening of 11,14-dihydroxyprotected murtiline [2- 14 The reaction conditions for the cyclization reaction of the [C] haloester (12) are as follows: RS-5: The reaction is carried out in the presence of a reducing agent and a catalyst; the reducing agent is samarium iodide (SmI2); the catalyst is tris(dibenzoylmethyl)ferric (Fe(DBM)3, tris(acetylacetonyl)ferric (Fe(acac)3), nickel iodide, or hexamethylphosphoric triamine (HMPA). The solvent is an ether solvent, such as THF or 2-MeTHF; the reaction temperature is -5 to 35 °C, preferably 0 to 30 °C, and more preferably 15 to 25 °C.

[0027] In some embodiments, regarding the protection of 11,14-dihydroxyl groups [2- 14The deprotection reaction conditions for [C] methylphenidate (13) are as follows: The silicon-based protecting group is removed using a fluoride ion-containing reagent or under mild alkaline conditions, such as tetrabutylammonium fluoride (TBAF), hydrogen fluoride (HF), or a hydrogen fluoride-pyridine complex. The solvent used is THF, DCM, ACN, or DMF; the reaction temperature is 0–90 °C, preferably 20–80 °C, and more preferably 50–70 °C. All silicon-based protecting groups can be efficiently removed using fluoride ion-containing reagents, and triethylsilyl (TES) can also be selectively removed under mild alkaline conditions (such as a saturated potassium carbonate aqueous solution / methanol system).

[0028] In some embodiments, the carbon-14 labeled multiline described in this application, [2- 14 The preparation method of C] methyltetramine also includes the synthesis of 11,14-dihydroxyprotected methyltetramine ring-opening halogenated derivatives using methyltetramine as a reactant (8); the specific synthetic route is as follows: ; Where X1 represents halogen, PG represents silicon-based protecting group, R represents silicon-based protecting group, NPhth represents phthalimide group; "S-1" to "S-8" represent suitable reaction conditions for each step of the reaction.

[0029] In some embodiments, X1 is selected from Cl, F, Br, or I; PG is selected from tert-butyldimethylsilyl (TBS), triethylsilyl (TES), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), diethylisopropylsilyl (DESP), or diisopropylethylsilyl (DEIPS); and R is selected from triethylsilyl (TES) or trimethylsilyl (TMS). Preferably, X1 is selected from Br or I, PG is selected from tert-butyldimethylsilyl (TBS), and R is selected from trimethylsilyl (TMS).

[0030] In some embodiments, the reaction conditions S-1 for the silanization protection of 11,14-dihydroxyl groups in methylphenidate are as follows: the reaction is carried out in the presence of a silanizing agent corresponding to the silanizing protecting group and a base; the silanizing agent is selected from trifluoromethanesulfonate or chloride corresponding to the silanizing protecting group, preferably TBSOTf or TBSCl; the base is selected from pyridine (Py), imidazole (Imid), DIPEA, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 2,6-dimethylpyridine or triethylamine (TEA), preferably DIPEA or imidazole. The solvent is selected from aprotic solvents, such as tetrahydrofuran (THF), dichloromethane (DCM), ACN, DMF or pyridine (Py), etc., preferably DMF or ACN; the reaction temperature is selected from -5 to 110 °C, preferably 10 to 100 °C, more preferably 50 to 90 °C.

[0031] In some embodiments, regarding the enolization of the 3-carbonyl group of 11,14-dihydroxyprotected multiline (1) and O - Reaction conditions S-2 for silanization reaction: The reaction is carried out in the presence of a silanizing reagent corresponding to the silanizing protecting group and a base; the silanizing reagent is selected from trifluoromethanesulfonate or chloride corresponding to the silanizing protecting group, preferably trimethylchlorosilane (TMSCl), trimethylsilyl trifluoromethanesulfonate (TMSOTf), triethylsilyl trifluoromethanesulfonate (TESOTf), or triethylchlorosilane (TESCl), more preferably TMSCl or TMSOTf; the base is selected from lithium bis(trimethylsilyl)amino (LiHMDS), sodium bis(trimethylsilyl)amino (NaHMDS), potassium bis(trimethylsilyl)amino (KHMDS), or lithium diisopropylamino (LDA). The reaction solvent is selected from ether solvents (such as THF, 2-MeTHF, etc.), hexamethylphosphoric triamine (HMPA), or a mixture of the two; the reaction temperature is -70~10 ℃, preferably -50~0 ℃, more preferably -20~-10 ℃.

[0032] In some embodiments, the reaction conditions S-3 for the 2-position hydroxylation of 11,14-dihydroxyprotected mtiline-3-enol trialkylsilyl ether (2) are as follows: the reaction is carried out in the presence of an oxidant, with acid and base added sequentially. The oxidant is m-chloroperoxybenzoic acid (...). m The reaction solvents are CPBA, hydrogen peroxide, urea peroxide, or tert-butanol peroxide; the acid is an organic acid, such as HOAc, and the base is an organic or inorganic base, such as pyridine (Py) or sodium bicarbonate. The reaction solvent is DCM or 1,2-dichloroethane (DCE); the reaction temperature is -50~10 ℃, preferably -30~0 ℃, and more preferably -25~-10 ℃.

[0033] If trimethylsilyl (TMS) is used for PG, TMS will detach during the reaction, making the reaction system more complex.

[0034] In some embodiments, the reaction conditions S-4 for the ring-opening reaction of 11,14-dihydroxyprotected-2-hydroxymtiline (3) are as follows: the reaction is carried out in the presence of an oxidant, preferably sodium periodate. The solvent is a mixture of THF and water in a volume ratio of 2:1 to 6:1, preferably 3:1 to 4:1. The reaction temperature is 0 to 50 °C, preferably 10 to 40 °C, and more preferably 20 to 30 °C.

[0035] In some embodiments, the reaction conditions S-5 for the esterification reaction of the 11,14-dihydroxyprotected mtiline ring-opening product (4) are as follows: the reaction is carried out in the presence of a methylating agent; the methylating agent is selected from diazomethane, iodomethane, dimethyl sulfate, methyl trifluoromethanesulfonate (MeOTf), or methanol. When MeI, Me2SO4, or MeOTf is selected as the methylating agent, the acid produced by the reaction needs to be neutralized with a base. In this case, the base is selected from alkali metal carbonates or alkali metal bicarbonates, such as potassium carbonate or sodium carbonate. The solvent is selected from MeOH, DMF, DMSO, THF, DCM, ACN, or acetone (ACE). The reaction temperature is 0~50 °C, preferably 10~40 °C, more preferably 20~30 °C.

[0036] In some embodiments, the reaction condition S-6 for the aldehyde oxidation of 11,14-dihydroxyprotected multiline ring-opening ester (5) is as follows: the reaction is carried out in the presence of an oxidizing agent. Specifically, the reaction can be carried out under the following two oxidation conditions: ① Pinnick oxidation: the oxidizing agent is sodium chlorite (0.8~2.5 equiv, preferably 1.0~2.0 equiv, more preferably 1.2~1.5 equiv), the buffer is sodium dihydrogen phosphate (0.5~3.0 equiv, preferably 0.8~2.0 equiv, more preferably 1.0~1.5 equiv), and the reaction aid is isopentenene (5~25 equiv, preferably 8-20 equiv, more preferably 10~15 equiv). The reaction is carried out in the presence of sodium chlorite, sodium dihydrogen phosphate, and isopentenylene; three types of solvents can be used: tert-butanol as a single solvent, a binary mixture of tetrahydrofuran and water (volume ratio of 3:1 to 6:1, preferably 4:1 to 5:1), a binary mixture of tetrahydrofuran and water (volume ratio of 3:1 to 6:1, preferably 4:1 to 5:1), or a ternary mixture of THF-water-tert-butanol (volume ratio of (2 to 5):1:(2 to 5), preferably (3 to 4):1:(3 to 4)); the reaction is carried out at room temperature; ② the oxidant is oxygen or air, the catalyst is Cu(NO3)2·3H2O and TEMPO in combination, the solvent is DCE, and the reaction is carried out at room temperature.

[0037] In some embodiments, the reaction conditions S-7 for the carboxyl activation reaction of the 11,14-dihydroxyprotected multiline ring-opening oxidation product (6) are as follows: the reaction is carried out in the presence of an activating agent, a condensing agent, and a base; the activating agent is selected from... N -Hydroxyphthalimide (NHPI, CAS 524-38-9) N1-Hydroxysuccinimide (NHS, CAS 6066-82-6), 1-hydroxybenzotriazole (HOBt, CAS 2592-95-2), 1-hydroxy-7-azabenzotriazole (HOAt, CAS 39968-33-7), or pentafluorophenol (PFP, CAS 771-61-9) are preferred, with NHPI being the preferred choice; condensing agent should be selected from... N , N ′-Dicyclohexylcarbodiimide (DCC, CAS 538-75-0), N , N ′-Diisopropylcarbodiimide (DIC, CAS 693-13-2), benzotriazole- N , N , N ′, N '-Tetramethylurea hexafluorophosphate (HBTU / HTAU, CAS 94790-37-1) N - (3-Dimethylaminopropyl)- N ′-Ethylcarbodiimide hydrochloride (EDCI·HCl, CAS 25952-53-8) or N -Cyclohexyl- N '-(2-morpholinoethyl)carbodiimide p-toluenesulfonate (CMC, CAS 2491-17-0), preferred N , N ′-Dicyclohexylcarbodiimide; base selection includes pyridine, 4-dimethylaminopyridine, DIPEA, NMM ( N (-methylmorpholine), triethylamine, preferably 4-dimethylaminopyridine. Solvents may include DCM, DMF, DMSO, THF, CHCl3, ethyl acetate (EA), or ACN. The reaction temperature is -10 to 50 °C, preferably -5 to 40 °C, more preferably 0 to 30 °C, and most preferably at room temperature.

[0038] In some embodiments, the reaction conditions S-8 for the decarboxylation halogenation reaction of 11,14-dihydroxyprotected mtiline ring-opening phthalimide active ester (7) are as follows: The photocatalytic reaction is carried out in the presence of a halogenating agent and a catalyst; the halogenating agent is selected from KI, LiI, KBr, LiBr or LiCl, preferably LiBr or KBr; the catalyst is selected from triphenylphosphine, diphenylcyclohexylphosphine, 4CzIPN (CAS 1416881-52-1), Ir[dF(CF3)ppy]2(dtbbpy)PF6 (CAS 870987-63-6) or Ir(ppy)3 (CAS 94928-86-6), preferably 4CzIPN; the light source is blue light, preferably a 40 W, 456 nm blue LED. The solvent is selected from ACN, ACE, N ,N - Dimethylacetamide (DMA), DMF, DMSO, THF or EA; the reaction temperature is 0~60 ℃, preferably 10~50 ℃, more preferably 20~35 ℃, and most preferably 25~33 ℃.

[0039] In a third aspect, this application provides a method for synthesizing carbon-14 labeled murtiline, [2- 14 The intermediate of C] emtelin has one of the following specific structures:

[0040] ; X1 and X2 are each independently selected from halogens, and PG represents a silicon-based protecting group.

[0041] In some embodiments, X1 and X2 are each independently selected from Cl, F, Br, or I; PG is selected from tert-butyldimethylsilyl (TBS), triethylsilyl (TES), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), diethylisopropylsilyl (DESP), or diisopropylethylsilyl (DEIPS). Preferably, X1 and X2 are each independently selected from Br or I; PG is selected from tert-butyldimethylsilyl (TBS).

[0042] In a fourth aspect, this application provides a method for synthesizing carbon-14 labeled murtiline, [2- 14 The preparation method of 11,14-dihydroxy-protected methyltetramine ring-opening halogenated derivative (8) of methyltetramine intermediate (C) is described, using methyltetramine as a reactant to synthesize compound (8); the specific synthetic route is as follows: ; Wherein, X1 is selected from halogens, PG represents a silicon-based protecting group, R represents a silicon-based protecting group, NPhth is a phthalimide group; "S-1" to "S-8" represent the appropriate reaction conditions for each step of the reaction.

[0043] In some embodiments, X1 is selected from Cl, F, Br, or I; PG is selected from tert-butyldimethylsilyl (TBS), triethylsilyl (TES), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), diethylisopropylsilyl (DESP), or diisopropylethylsilyl (DEIPS); and R is selected from triethylsilyl (TES) or trimethylsilyl (TMS). Preferably, X1 is selected from Br or I, PG is selected from tert-butyldimethylsilyl (TBS), and R is selected from trimethylsilyl (TMS).

[0044] In some implementations, the specific conditions for each reaction step, “S-1” to “S-8”, are as described above.

[0045] In the fifth aspect, this application provides carbon-14 labeled multiline, [2- 14 The application of [C] morteline in isotopic tracing studies of compounds containing the morteline core, among which, [2- 14 The structural formula of C] methyltetramine is shown below: The asterisk (*) indicates the carbon-14 labeled site.

[0046] In some embodiments, the compound containing the multiline nucleus is a compound containing the multiline nucleus with a side chain at position 14, or a compound containing the multiline nucleus with a side chain at position 11. Preferably, the compound containing the multiline nucleus is a truncated pleurotin derivative.

[0047] In some embodiments, the [2- 14 C] Mtilline is used in the preparation of 14 C-labeled compounds containing a morteline core.

[0048] In a sixth aspect, this application provides a [2- 14 C] compounds of the mustiline nucleus, wherein, [2- 14 The structural formula of C] methyltetramine is shown below: The asterisk (*) indicates the carbon-14 labeled site.

[0049] In some embodiments, the [2- 14 [C]Mtiline's parent compound is a compound containing a [2-] side chain at position 14. 14 Compounds containing the [2-] motiline core, or compounds with a side chain at the 11-position. 14 Compounds containing the [2-]mtiline nucleus. Preferably, the compound containing [2- 14 The compounds in the C] mtiline nucleus are truncated pleurotin derivatives.

[0050] The beneficial effects achieved by this application are as follows: 1. Achieving carbon-14 localization labeling of the carbon ring skeleton of the methyltetramine molecule. Literature review revealed no publicly available reports on the synthesis of mteline tricyclic diterpenoid core carbon-14 labeling. The synthesis of mteline core carbon-14 labeling presents significant technical difficulties and challenges, and this application can fill a gap in this field.

[0051] twenty two- 14 C] Advantages and application value of marker sites for methylphenidate Mtiracene is the core structural framework of truncated pleurotin derivatives. This application focuses on carbon-14 localization labeling of the carbon ring of the core nucleus of multiracene, preparing the key [2-] required for the isotopically labeled synthesis of this type of compound. 14 [C]Mtielline Synthetic Building Block. The carbon-14 isotope of this building block is located in the physicochemically stable core region, which has the advantages of strong labeling site, strong metabolic stability and isotope is not easy to fall off, and it is also pharmacokinetic equivalent to non-isotope labeled compounds.

[0052] This application provides [2- 14 [C] Mtilimene synthetic building blocks can serve as key isotope-labeled synthetic building blocks, widely used in the preparation of carbon-14 labeled core nucleus compounds containing mtilimene, especially truncated pleurotin derivatives, for metabolic tracing assays of these drugs. This allows for the early identification of metabolic risks in the development of new drugs with mtilimene as the core nucleus (especially truncated pleurotin derivatives), significantly reducing the failure rate and development costs of new drug development.

[0053] [2- 14 [C] Mtilimane synthetic building blocks, as an indispensable key carbon-14 synthetic building block, have been used in the domestically developed novel fungicide chlorpyrifos with mtilimane as the core for carbon-14 labeling synthesis. The results show that the quality indicators of this label meet the requirements of pesticide registration metabolic tests (including label site stability, specific activity, radiochemical purity, chemical purity, etc.), supporting the smooth conduct of subsequent pesticide registration metabolic tests.

[0054] 3. Core advantages and technological innovations of core carbon ring backbone labeling compared to side chain labeling Compared with traditional side-chain carbon-14 labeling of novel drugs with multeline as the parent structure, the core carbon ring labeling strategy of this application has irreplaceable core advantages. Practice has shown that side-chain labeling of truncated pleurotin derivatives is prone to loss of radioactive signal due to side-chain metabolic breakage, making it difficult to fully track the drug's fate; while carbon-14 labeling at a stable site in the core carbon ring of this type of novel drug can ensure that the signal is not lost throughout the metabolic process, and fully track the migration, distribution and metabolic changes of drugs containing multeline as the parent structure, especially truncated pleurotin drugs (including human drugs, veterinary drugs, and pesticides) in complex systems such as experimental animals, experimental plants, soil-water systems, humans and cells, fully revealing the drug's fate in organisms and the environment, and meeting the technical requirements of new drug pharmacokinetic studies. This strategy can meet the mandatory requirements for material balance (recovery rate ≥90%) for pesticide, veterinary drug and human drug registration, accurately quantify multi-media distribution, and provide compliant data for residue limits, safety intervals and risk assessments; it can cover unknown metabolites and non-extractable bound residues in complex matrices, achieve qualitative and quantitative unity, and complement mass spectrometry to build a complete chain of evidence.

[0055] 4. Technological and safety advantages of the labeling synthesis route The synthesis of carbon-14 labeling of the multiline core presents significant technical difficulties and challenges. Previous research by the inventors attempted a total synthesis approach to label the carbon atoms in the eight-membered ring, but literature review revealed that the labeling synthesis route was too long, and the non-radioactive raw materials required were unavailable. Furthermore, the in-house synthesis route was also too lengthy, rendering this approach unfeasible. The inventors also attempted to introduce carbon-14 into the 3-position carbon of the multiline molecular ring framework, but after multiple attempts, this route proved infeasible. Building upon previous research, the inventors further optimized and adjusted the labeling site and synthetic route, ultimately successfully synthesizing the [2-...] carbon described in this application. 14 [C] marked multiline.

[0056] This application uses multiline as the starting material and carbon-14 labeled alkali metal / alkaline earth metal cyanides as isotopic raw materials. Through a labeling synthesis strategy of "carbon ring opening—introduction of carbon-14—carbon chain closure," carbon-14 is precisely labeled at the 2-position of the multiline five-membered carbon ring core. This solves the problem of preparing non-radioactive key raw materials in labeling synthesis. The synthetic route provided in this application is characterized by easy preparation of non-radioactive raw materials, readily available carbon-14 isotope raw materials, and a concise labeling synthesis route. The reaction conditions are mild, the operation is simple, and harsh environments of high temperature and high pressure are not required. This synthetic route has few side reactions, high radiochemical yield of products, low preparation cost, and short synthesis cycle, making it particularly suitable for trace and semi-trace radioactive labeling synthesis scenarios. Furthermore, the experimental process of this scheme is safe and controllable, effectively reducing the risk of radioactive material leakage, minimizing environmental pollution, and avoiding internal radiation damage to experimental personnel, resulting in a higher overall process safety level. Attached Figure Description

[0057] Figure 1 and Figure 2 The images show the hydrogen and carbon NMR spectra of the intermediate of this invention: 11,14-dihydroxyTBS protecting multiline (1a).

[0058] Figure 3 The 1H NMR spectrum of 11,14-dihydroxyTBS protecting multeline-3-enol trimethylsilyl ether (2a), which is the intermediate of this invention.

[0059] Figure 4 and Figure 5 The images show the hydrogen and carbon NMR spectra of the intermediate of this invention: 11,14-dihydroxy-TBS-protected-2-hydroxymtiline (3a).

[0060] Figure 6 and Figure 7The images show the hydrogen and carbon NMR spectra of the intermediate of this invention: 11,14-dihydroxy-TBS-protected methyltetramine open ring ester (5a).

[0061] Figure 8 and Figure 9 The images show the 1H and 1C NMR spectra of the intermediate of this invention: 11,14-dihydroxyTBS protecting the ring-opening oxidation product of multiline (6a).

[0062] Figure 10 and Figure 11 The images show the 1H and 1C NMR spectra of the intermediate of this invention: 11,14-dihydroxyTBS-protected methyltetramine ring-opening phthalimide active ester (7a).

[0063] Figure 12 The 1H NMR spectrum of the intermediate of this invention: 11,14-dihydroxyTBS protecting the open-ring brominated methyltetramine (8a).

[0064] Figure 13 The radioactive intermediate of this invention: 11,14-dihydroxyTBS protecting murtiline ring-opening [cyano- 14 The proton NMR spectrum of cyano compound (9a) C.

[0065] Figure 14 The radioactive intermediate of this invention: 11,14-dihydroxyTBS protecting multeline ring-opening [aldehyde-] 14 The proton NMR spectrum of C] aldehyde (10a).

[0066] Figure 15 The radioactive intermediate of this invention: 11,14-dihydroxyTBS protects multiline ring-opening [2- 14 The proton NMR spectrum of C] alcohol (11a).

[0067] Figure 16 The radioactive intermediate of this invention: 11,14-dihydroxyTBS protects multiline ring-opening [2- 14 The proton NMR spectrum of iodinated ester (12a) C.

[0068] Figure 17 The radioactive intermediate of this invention: 11,14-dihydroxyTBS protects [2- 14 [C] The proton NMR spectrum of methyltrimethoprim (13a).

[0069] Figure 18 The target object obtained in this invention [2- 14 [C] The proton NMR spectrum of methyltrimethoprim.

[0070] Figure 19 The target object obtained in this invention [2- 14C] High performance liquid chromatogram of methyltetracycline (HPLC-CAD).

[0071] Figure 20 The target object obtained in this invention [2- 14 [C] Radioactive high-performance liquid chromatography (HPLC-FSA) of multiline. Detailed Implementation

[0072] Unless otherwise stated, all terms used in disclosing this application (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains, and the following definitions are provided for a better understanding of the teachings of this application. The explanations of the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of this application.

[0073] Features described or illustrated as part of one set of embodiments in this application may be used in another set of embodiments to produce further embodiments.

[0074] The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0075] The terms “containing,” “comprising,” and “including” as used in this application are synonyms and are inclusive or open-ended, and do not exclude additional, uncited members, elements, or method steps.

[0076] The range of values ​​represented by endpoints in this application includes all values ​​and fractions contained within that range, as well as the endpoints referenced.

[0077] In this application, concentration values ​​are defined as those within a certain range of fluctuation. For example, fluctuations are allowed within a corresponding precision range. For instance, 2% may fluctuate within ±0.1%. For larger values ​​or values ​​that do not require extremely fine control, even greater fluctuations are permitted. For example, 100mM may fluctuate within ranges of ±1%, ±2%, or ±5%. Regarding molecular weight, fluctuations of ±10% are allowed.

[0078] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity of 2 or more.

[0079] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0080] In this application, terms such as "preferred," "better," "more suitable," "specific," and "preferably" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. In this application, terms such as "optional," "optionally," "optional," and "optional" mean that something is optional, that is, selected from either "with" or "without" parallel solutions. If multiple "optional" options appear in a technical solution, unless otherwise specified and without contradiction or mutual constraint, each "optional" option is independent.

[0081] When the lower and upper limits of a numerical range are disclosed, any numerical value or subrange falling within that range is specifically disclosed. In particular, each numerical range of parameters disclosed herein (e.g., in the form of "about a to b", or equivalent "approximately a to b", or equivalent "about ab") should be understood to encompass every numerical value and subrange therein.

[0082] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art can make various modifications and changes to this application without departing from the scope or spirit of this application. For experimental methods in the following embodiments where specific conditions are not specified, the guidance given in this application should be used first, or experimental manuals or conventional conditions in the art can be followed, or other experimental methods known in the art can be referred to, or the conditions recommended by the manufacturer can be followed.

[0083] In the specific embodiments described below, the measurement parameters involving raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. Temperature and time parameters are subject to acceptable deviations due to instrument testing accuracy or operational precision.

[0084] In addition, this application may use protecting groups to protect certain functional groups from unwanted reactions. Protecting groups suitable for various functional groups and their protection or deprotection conditions are well known to those skilled in the art. For example, TW Greene and GM Wuts' "Protecting Groups in Organic Preparations" (3rd edition, Wiley, New York, 1999 and cited references in the book) describes in detail a large number of protecting or deprotecting groups.

[0085] The separation and purification of compounds and intermediates employ appropriate methods and procedures depending on specific needs, such as filtration, extraction, distillation, crystallization, column chromatography, preparative thin-layer chromatography, preparative high-performance liquid chromatography, or a combination of the above methods. Specific methods can be found in the examples described in this application. Of course, other similar separation and purification techniques can also be used. Conventional methods (including physical constants and spectroscopic data) can be used for characterization.

[0086] Example 1: TBS protection of 11,14-dihydroxyl group in methylphenidate

[0087] Under nitrogen protection at room temperature, TBSOTf (124 g, 459 mmol) was slowly infused dropwise into methyltetracycline (50.0 g, 156.3 mmol) and... N,N The solution of diisopropylethylamine (101 g, 781 mmol) in anhydrous DMF (400 mL) was heated to 90 °C and stirred for 3 h. TLC analysis was performed. R f (Mtiline) = 0.10, R f (1a) = 0.60, V EA : V PE The ratio was 1:5, and phosphomolybdic acid was used for color development (this method was used for all subsequent TLC color development). After the reaction was complete, the reaction was quenched in an ice-water bath; water (1000 mL) was added, and the mixture was extracted four times with ethyl acetate. The organic phases were combined and washed successively with dilute hydrochloric acid (1.0 mol / L, the same below) and saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was dissolved under reduced pressure. The residue was used directly in the next reaction step.

[0088] At room temperature, the above residue was dissolved in tetrahydrofuran (600 mL), and tetrabutylammonium fluoride (46.9 mL, 46.9 mmol, 1.0 mol / L THF solution) was slowly added under stirring for 20 min. After the reaction was complete, the reaction was quenched with ice water; the reaction solution was extracted with ethyl acetate (1000 mL × 3), the organic phases were combined, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure; the crude product was separated by silica gel rapid column chromatography (…). V EA : V PE =1:10, where PE is petroleum ether), to obtain white solid 1a (70.0 g, yield 82%): mp 88.6~90.4 ℃; 1 H NMR (500 MHz, CDCl3) δ 6.18 (dd, J = 17.3, 11.3 Hz, 1H), 5.30 – 5.25 (m, 1H), 5.24 (s, 1H), 4.49 (d, J =8.2 Hz, 1H), 3.45 (d, J = 5.7 Hz, 1H), 2.40 – 2.27 (m, 1H), 2.27 – 2.14 (m,2H), 2.07 (d, J = 2.7 Hz, 1H), 1.91 – 1.80 (m, 1H), 1.80 – 1.71 (m, 1H), 1.62 –1.50 (m, 3H), 1.50 – 1.42 (m, 3H), 1.36 (s, 3H), 1.34 – 1.29 (m, 1H), 1.09(s, 3H), 0.90 (d, J = 3.7 Hz, 9H), 0.89 (s, 3H), 0.86 (s, 9H), 0.84 (d, J = 7.3Hz, 3H), 0.10 (d, J = 2.9 Hz, 6H), 0.08 (d, J = 6.5 Hz, 6H); 13 C NMR (101 MHz, CDCl3) δ217.95, 139.90, 116.62, 77.32, 77.20, 77.00, 76.68, 76.46, 67.44, 59.55, 46.63, 45.73, 44.99, 43.93, 37.54, 35.91, 34.89, 30.64, 28.30, 27.19, 26.52, 26.47, 26.34, 25.69, 25.64, 25.31, 19.24, 18.85, 18.52, 14.35, 11.49, -1.63, -2.12, -2.96, -4.02, -4.08; APCI-HRMS: m / z 549.4159 [M+H] + (Theoretical calculated value: 549.4154).

[0089] The purpose of this step is as follows: In the first step reaction system, excess TBSOTf reacts with the 3-carbonyl enolization product of multiline to generate a small amount of trihydroxy TBS to protect multiline; the second step reaction aims to remove the silyl ether protecting group at the 3-hydroxy site, thereby improving the reaction yield of the target compound (1a).

[0090] Example 2 Enolization of 11,14-dihydroxy TBS protecting the 3-carbonyl group of multiline (1a) and O -Trimethylsilylation reaction

[0091] Under nitrogen protection, bis(trimethylsilylaminolithium) (265 mL, 265 mmol, 1.0 M inTHF) was slowly added dropwise to a solution of 1a (75.0 g, 136.6 mmol) and trimethylchlorosilane (29.5 g, 273.2 mmol) in anhydrous tetrahydrofuran (400 mL). After the addition was complete, the reaction system was slowly heated to -10 °C and stirred for 30 min. TLC analysis: R f (1a) = 0.50, R f (2a) = 0.80, V EA : V PE=1:20. After the reaction was complete, the reaction was quenched with saturated sodium bicarbonate solution; the reaction mixture was extracted with ethyl acetate (800 mL × 4), the organic phases were combined, and washed successively with saturated sodium bicarbonate solution (1000 mL) and saturated sodium chloride aqueous solution (800 mL × 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The resulting white solid 2a was directly used in the next reaction. White solid 2a: mp 58.8~60.2 ℃; 1 H NMR (500 MHz, CDCl3) δ 6.24 – 6.05(m, 1H), 5.23 – 5.19 (m, 1H), 5.18 (s, 1H), 4.32 (d, J = 8.0 Hz, 1H), 3.19 (d, J = 5.4 Hz, 1H), 2.37 – 2.26 (m, 2H), 2.21 – 2.14 (m, 1H), 2.02 – 1.89 (m, 2H),1.86 – 1.77 (m, 1H), 1.42 (d, J = 22.1 Hz, 2H), 1.37 (d, J = 2.2 Hz, 1H), 1.31(d, J = 3.6 Hz, 1H), 1.28 (s, 3H), 1.22 – 1.15 (m, 2H), 1.03 (s, 3H), 0.94 –0.91 (m, 3H), 0.90 (s, 9H), 0.86 (s, 9H), 0.76 (d, J = 7.2 Hz, 3H), 0.23 (s, 6H), 0.17 (d, J = 9.8 Hz, 4H), 0.10 – 0.06 (m, 9H), 0.04 (s, 2H); APCI-HRMS: m / z 621.4555 [M+H] + (Theoretical calculated value: 621.4549).

[0092] Example 3: 2-hydroxylation of 11,14-dihydroxytBS-protected morteline-3-enol trimethylsilyl ether (2a) at the 2-position.

[0093] At -20 to -25 °C, acetic acid (188 g, 3142 mmol) and anhydrous pyridine (59.0 g, 715 mmol) were added sequentially to a solution of m-chloroperoxybenzoic acid (41.6 g, 205 mmol, 85%) in anhydrous dichloromethane (400 mL); while maintaining this temperature, a 2a solution of dichloromethane (125 mL) was slowly added dropwise; after the addition was complete, the system was slowly raised to -10 °C and stirred for 30 min. TLC analysis: R f (2a) = 0.80, R f (3a) = 0.30, V EA : V PE =1:3. After the reaction was complete, the reaction was quenched with saturated sodium thiosulfate solution; water (200 mL) was added to the reaction solution, and extraction was performed with dichloromethane (600 mL × 3). The organic phases were combined and washed successively with saturated sodium bicarbonate solution (400 mL) and saturated sodium chloride solution (400 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure; the crude product was separated by silica gel rapid column chromatography (…). V EA : V PE =1:3), to obtain white solid 3a (60.0 g, yield 78%): mp 85.3~87.2 ℃; 1 H NMR (400 MHz, CDCl3) δ 6.17 (dd, J = 17.5, 11.3 Hz, 1H), 5.32 –5.24 (m, 1H), 5.27 – 5.20 (m, 1H), 4.48 (d, J = 8.2 Hz, 1H), 4.01 (t, J = 8.8 Hz, 1H), 3.39 (d, J = 5.5 Hz, 1H), 2.29 (q, J = 6.9 Hz, 1H), 2.21 (s, 1H), 2.06 (dd, J = 12.9, 8.8 Hz, 1H), 1.97 – 1.83 (m, 2H), 1.67 (d, J = 49.4 Hz, 1H), 1.50 (d, J=15.6 Hz, 2H), 1.38 (s, 4H), 1.36 – 1.25 (m, 3H), 1.09 (s, 3H), 1.08 – 0.99(m, 1H), 1.00 – 0.77 (m, 23H), 0.15 – 0.03 (m, 12H); 13 C NMR (101 MHz, CDCl3) δ219.35, 139.83, 116.71, 77.32, 77.20, 77.00, 76.68, 76.00, 72.73, 67.51,57.78, 46.85, 45.18, 44.46, 42.13, 39.09, 36.02, 35.06, 32.86, 28.33, 26.97,26.49, 26.33, 19.10, 18.80, 18.50, 14.87, 11.80, -1.68, -2.12, -4.00, -4.03;APCI-HRMS: m / z 565.4098 [M+H] + (Theoretical calculated value: 565.4103).

[0094] Example 4 Ring-opening reaction of 11,14-dihydroxytBS protecting 2-hydroxymtiline (3a)

[0095] Sodium periodate (66.8 g, 312 mmol) was added in portions to a mixture of 3a (80.0 g, 142 mmol), tetrahydrofuran (500 mL), and water (125 mL) at room temperature; the mixture was stirred for 48 h after the addition was complete. TLC analysis: R f (3a) = 0.60, R f (4a) = 0.30, V EA : V PE =1:2. After the reaction was complete, the reaction was quenched with a water-ethyl acetate mixture; the reaction solution was extracted with ethyl acetate (2000 mL × 3), the organic phases were combined, washed with saturated sodium chloride solution (2000 mL × 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure; the crude product was subjected to silica gel rapid column chromatography (…). V EA : V PE=1:2), yielding white solid 4a (80 g, 97% yield): mp 106.5~109.1℃; APCI-HRMS: m / z 579.3862 [MH] - (Theoretical calculated value: 579.3907).

[0096] Example 5 Esterification of 11,14-dihydroxytBS-protected morteline ring-opening product (4a)

[0097] At room temperature, iodomethane (29.0 g, 204 mmol) was added dropwise to a suspension of 4a (78.9 g, 136 mmol) and potassium carbonate (18.8 g, 136 mmol) in acetone (400 mL); the mixture was stirred for 30 h after the addition was complete. TLC analysis: R f (4a) = 0.30, R f (5a) = 0.80, V EA : V PE =1:2. After the reaction was complete, water (500 mL) was added to quench the reaction; the reaction mixture was extracted with ethyl acetate (250 mL × 4), the organic phases were combined, washed with saturated sodium chloride solution (300 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure; the crude product was subjected to silica gel rapid column chromatography (… V EA : V PE =1:10), to obtain white solid 5a: (57.1 g, yield 70%): mp 115.4~117.0 ℃; 1 H NMR (500 MHz, CDCl3) δ 9.65 (dd, J = 5.0, 1.5 Hz, 1H), 6.16 (dd, J = 17.4, 11.1 Hz, 1H), 5.26 (dd, J = 11.1, 1.5 Hz, 1H), 5.20 (dd, J = 17.4, 1.5 Hz, 1H), 4.48 (d, J = 9.2 Hz, 1H), 3.57 (s, 3H), 3.45 (d, J= 4.4Hz, 1H), 2.73 (s, 1H), 2.59 – 2.44 (m, 1H), 2.29 (dd, J = 15.4, 1.5 Hz, 1H),2.25 – 2.17 (m, 1H), 2.15 – 2.06 (m, 1H), 2.03 (dd, J = 15.4, 4.9 Hz, 1H), 1.95(dd, J = 16.2, 9.3 Hz, 1H), 1.85 – 1.73 (m, 1H), 1.54 (d, J = 16.1 Hz, 1H), 1.50– 1.38 (m, 2H), 1.25 (s, 1H), 1.12 (s, 3H), 0.90 (d, J = 7.1 Hz, 5H), 0.87 (s,9H), 0.84 (s, 9H), 0.82 (d, J = 7.1 Hz, 3H), 0.11 – 0.00 (m, 12H); 13 C NMR (126MHz, CDCl3) δ 201.93, 139.29, 116.56, 77.25, 77.00, 76.75, 75.64, 68.92,51.00, 48.14, 46.72, 46.07, 43.70, 41.95, 37.07, 34.83, 27.50, 27.27, 26.73,26.40, 26.30, 19.01, 18.89, 18.72, 18.49, 11.04, -1.82, -2.36, -3.95, -4.26; APCI-HRMS: m / z 593.4053 [MH] - (Theoretical calculated value: 593.4063).

[0098] Example 6 Aldehyde oxidation of 11,14-dihydroxy-TBS-protected methyltetramine ring-opening ester (5a)

[0099] Under atmospheric pressure and nitrogen protection, 5a (30.1 g, 50.40 mmol) was added to a solution of tert-butanol (400 mL) and isopentenene (35.37 g, 504.0 mmol). The system was cooled to -5 to 0 °C, and a solution of sodium chlorite (7.99 g, 70.50 mmol, 80%) and sodium dihydrogen phosphate (6.10 g, 50.4 mmol) in water (90 mL) was added dropwise to the reaction system. After the addition was complete, the mixture was stirred for 50 min. The system was then brought to room temperature and stirred until the reaction was complete. TLC analysis: R f (5a) = 0.90, R f (6a) = 0.10, V EA : V PE =1:3. After the reaction was complete, the reaction solution was diluted with saturated saline and ethyl acetate; the aqueous phase was adjusted to pH 3 with dilute hydrochloric acid (1.0 mol / L), extracted with ethyl acetate (400 mL × 3), the organic phases were combined, washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure; the crude product was subjected to silica gel rapid column chromatography (…). V EA : V PE =1:3), to obtain white solid 6a (34.2 g, yield 97%): mp 169.3~171.1 ℃; 1 H NMR (500 MHz, CDCl3) δ 6.15 (dd, J = 17.4, 11.1 Hz, 1H),5.25 (dd, J = 11.0, 1.6 Hz, 1H), 5.19 (dd, J = 17.3, 1.6 Hz, 1H), 4.48 (d, J = 9.1Hz, 1H), 3.63 (s, 3H), 3.53 (d, J = 4.1 Hz, 1H), 2.77 (s, 1H), 2.39 (d, J = 14.1Hz, 1H), 2.31 (d, J = 13.6 Hz, 1H), 2.24 – 2.16 (m, 1H), 2.13 (d, J = 14.1 Hz,1H), 2.09 (s, 1H), 1.97 (dd, J= 16.0, 9.2 Hz, 1H), 1.74 – 1.62 (m, 1H), 1.57 –1.49 (m, 1H), 1.47 – 1.39 (m, 1H), 1.39 – 1.31 (m, 1H), 1.29 (d, J = 13.7 Hz,1H), 1.27 – 1.24 (m, 1H), 1.12 (s, 3H), 0.90 – 0.88 (m, 5H), 0.87 (s, 9H), 0.84 (s, 9H), 0.83 – 0.80 (m, 3H), 0.09 – 0.03 (m, 12H); 13 C NMR (101 MHz, CDCl3) δ 177.31, 173.90, 139.45, 116.42, 77.32, 77.20, 77.00, 76.68, 75.84, 69.05, 50.92, 46.70, 46.07, 43.99, 40.87, 38.91, 37.55, 34.65, 27.42, 27.19,26.95, 26.40, 26.33, 19.03, 18.94, 18.76, 18.50, 11.02, -0.02, -1.82, -2.44,-3.97, -4.21; APCI-HRMS: m / z 609.3963[M+H] + (Theoretical calculated value: 609.4012).

[0100] Example 7: Activation of the carboxyl group of 11,14-dihydroxytBS-protected morteline ring-opening oxidation product (6a)

[0101] Under room temperature and nitrogen protection, 6a (24.0 g, 39.3 mmol) was... N 4-Hydroxyphthalimide (9.61 g, 58.9 mmol) and 4-dimethylaminopyridine (0.48 g, 3.93 mmol) were dissolved in anhydrous DCM (300 mL); the system was cooled to -5 to 0 °C, and then added to the reaction system. N,N' - Anhydrous DCM (30 mL) solution of dicyclohexylcarbodiimide (5.28 g, 43.2 mmol); after addition, the system was brought to room temperature and stirred for 2 h. TLC analysis: R f (6a) = 0.20, Rf (7a) = 0.70, V EA : V PE =1:5. After the reaction was complete, water (200 mL) was added to the reaction system, and the mixture was extracted with DCM (250 mL × 3). The organic phases were combined, washed with saturated sodium chloride solution (300 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The crude product was subjected to silica gel rapid column chromatography (…). V EA : V PE =1:5), to obtain white solid 7a (26.0 g, yield 86%): mp 186.3~186.6 ℃; 1 H NMR (500MHz, CDCl3) δ 7.88 – 7.84 (m, 2H), 7.79 – 7.75 (m, 2H), 6.17 (dd, J = 17.4,11.1 Hz, 1H), 5.26 (dd, J = 11.1, 1.5 Hz, 1H), 5.21 (dd, J = 17.4, 1.6 Hz, 1H), 4.49 (d, J = 9.1 Hz, 1H), 3.71 (s, 3H), 3.56 (d, J = 4.3 Hz, 1H), 2.85 (s, 1H), 2.76 (d, J = 15.0 Hz, 1H), 2.49 – 2.39 (m, 2H), 2.31 – 2.24 (m, 1H), 2.20 (s,1H), 1.99 (dd, J = 16.1, 9.2 Hz, 1H), 1.87 – 1.80 (m, 1H), 1.59 – 1.48 (m, 2H), 1.45 – 1.34 (m, 1H), 1.14 (s, 3H), 0.94 – 0.90 (m, 9H), 0.89 (s, 9H), 0.85(s, 9H), 0.11 (d, J = 20.5 Hz, 6H), 0.09 (d, J = 1.8 Hz, 6H); 13C NMR (101 MHz, CDCl3) δ 173.45, 167.35, 161.75, 139.43, 134.62, 128.96, 123.83, 116.51,77.32, 77.21, 77.00, 76.68, 76.10, 68.97, 51.38, 46.69, 46.09, 43.98, 40.96,37.94, 36.02, 34.45, 27.46, 27.18, 26.99, 26.41, 26.35, 19.10, 18.98, 18.74,18.50, 11.35, -0.02, -1.80, -2.35, -3.96, -4.15; APCI-HRMS: m / z 756.4321[M+H] + (Theoretical calculated value: 756.4322).

[0102] Example 8: Decarboxylation and bromination reaction of 11,14-dihydroxy-TBS-protected methyltetramine ring-opening phthalimide active ester (7a)

[0103] Under nitrogen protection, compound 7a (1.0 g, 1.32 mmol), lithium bromide (0.23 g, 2.64 mmol), and 4CzIPN (52.2 mg, 0.07 mmol) were added to the reaction tube and dissolved in anhydrous acetonitrile (8 mL). The reaction tube was then placed in a photoreactor and stirred for 24 h under 40 W, 456 nm blue LED irradiation until the reaction was complete. The reaction temperature was controlled at 25–33 °C. TLC analysis: R f (7a) = 0.20, R f (8a) = 0.80, V EA : V PE =1:10. Eight parallel reactions were carried out in the photoreactor. After the reaction was completed, all reaction solutions were combined and subjected to unified post-processing. The reaction solution was desolvated under reduced pressure, and the residue was mixed with water (200 mL) and extracted with ethyl acetate (150 mL × 4). The organic phases were combined, washed with saturated sodium chloride solution (250 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The crude product was subjected to silica gel rapid column chromatography (…). V EA : V PE=1:100), to obtain white solid 8a (4.94 g, yield 72%): mp 52.4~54.1 ℃; 1 H NMR (400 MHz, CDCl3) δ 6.15 (dd, J = 17.4, 11.2 Hz, 1H), 5.26 (d, J = 11.1 Hz, 1H), 5.21 (d, J = 17.4 Hz, 1H), 4.46 (d, J = 9.0 Hz,1H), 4.05 (s, 1H), 3.67 (s, 3H), 3.43 – 3.26 (m, 2H), 2.85 (s, 1H), 2.29 –2.09 (m, 2H), 2.07 – 1.93 (m, 2H), 1.57 – 1.50 (m, 2H), 1.46 – 1.25 (m, 3H), 1.14 (s, 3H), 0.93 – 0.80 (m, 27H), 0.20 – 0.04 (m, 12H); APCI-HRMS: m / z 645.3360[M+H] + (Theoretical calculated value: 645.3365).

[0104] Example 9 Cyanolation reaction of 11,14-dihydroxy-TBS protecting the open-ring brominated methyl methacrylate (8a)

[0105] Compound 8a (646 mg, 1.0 mmol) was added under argon protection and at room temperature. 14 [C] Sodium cyanide (51.0 mg, 2109 MBq / mmol) and potassium iodide (16.6 mg, 0.1 mmol) were reacted in a mixture of DMF (1.0 mL) and DMSO (4.6 mL) to a solvent. The mixture was heated to 80 °C and stirred for 16 h until the reaction was complete. TLC analysis: R f (8a) = 0.8, R f (9a) = 0.5, V EA : V PE=1:10. Add water (50 mL) to the reaction solution and mix well. Extract with ethyl acetate (50 mL × 5). Combine the organic phases and wash successively with water (80 mL) and saturated sodium chloride aqueous solution (80 mL). Dry with anhydrous sodium sulfate, filter, and desolvate the filtrate under reduced pressure. The crude product is subjected to silica gel rapid column chromatography (…). V EA : V PE =1:20) Purification. The experiment was repeated 3 times to obtain a white solid labeled compound 9a (2152 mg, 7677.5 MBq, radiochemical yield 91%): 1 H NMR (400 MHz, CDCl3) δ 6.14 (dd, J = 17.4, 11.0 Hz, 1H),5.35 – 5.15 (m, 2H), 4.45 (d, J = 9.1 Hz, 1H), 3.72 (s, 3H), 3.68 (s, 1H), 2.85 (s, 1H), 2.31 – 2.06 (m, 5H), 1.97 (dd, J = 16.3, 9.1 Hz, 1H), 1.68 (d, J = 14.1Hz, 1H), 1.62 – 1.43 (m, 3H), 1.36 (d, J = 13.5 Hz, 1H), 1.31 – 1.22 (m, 1H), 1.14 (s, 3H), 0.91 – 0.80 (m, 24H), 0.17 – 0.05 (m, 12H).

[0106] Unlabeled analytes corresponding to 9a: mp 128.7~130.5 ℃; APCI-HRMS: m / z 592.4224[M+H] + (Theoretical calculated value: 592.4212).

[0107] Example 10 11,14-Dihydroxy TBS protects multiline ring-opening [cyano- 14 Reductive hydrolysis of cyano compound (9a)

[0108] Under argon protection and at -5 to 0 °C, a hexane solution of diisobutylaluminum hydride (4.22 mL, 4.22 mmol, 1.0 M) was added dropwise to a THF solution of morpholine (364 mg, 4.30 mmol) (0.5 mL), and the mixture was stirred for 30 min after the addition was complete. A tetrahydrofuran solution of compound 9a (500 mg, 1783.4 MBq) (8.0 mL) was then added dropwise, and the mixture was stirred at room temperature for 5 h. After the reaction was complete, a saturated ammonium chloride aqueous solution (50 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (50 mL × 4). The combined organic phases were washed successively with water (80 mL) and a saturated sodium chloride aqueous solution (80 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure and then subjected to silica gel rapid column chromatography (…). V EA : V PE Purification was performed at a ratio of 1:20. The experiment was repeated three times to obtain a white solid labeled compound 10a (1306 mg, 4636.1 MBq, radiochemical yield 65%). 1 H NMR (500 MHz, CDCl3) δ 6.15 (ddd, J = 17.9, 11.2, 0.9Hz, 1H), 5.37 (dd, J = 17.8, 1.4 Hz, 1H), 5.29 (dd, J = 11.1, 1.4 Hz, 1H), 4.35(d, J = 7.6 Hz, 1H), 3.41(d, J = 6.4 Hz, 1H), 2.28 – 2.15 (m, 3H), 2.07 – 2.04(m, 1H), 1.91 (dd, J = 15.9, 7.7 Hz, 1H), 1.74 (dt, J = 14.7, 3.3 Hz, 1H), 1.68(ddd, J = 12.3, 7.1, 3.8 Hz, 1H), 1.64 – 1.55 (m, 3H), 1.55 – 1.42 (m, 4H), 1.42 – 1.38 (m, 1H), 1.36 (s, 3H), 1.16 (s, 3H), 1.11 (dd, J = 14.0, 4.5 Hz, 1H), 0.97 (d, J = 7.1 Hz, 3H), 0.92 (d, J = 7.1 Hz, 3H).

[0109] Unlabeled molecule corresponding to 10a: mp 115.5~117.0 ℃; APCI-HRMS: m / z 593.4053 [MH] - (Theoretical calculated value: 593.4063).

[0110] Example 11 11,14-Dihydroxy TBS protects multiline ring-opening [aldehyde- 14 Reduction reaction of aldehyde (10a)

[0111] Sodium borohydride (76.1 mg, 2.01 mmol) was slowly added to a 12 mL solution of 10a (400 mg, 1420.8 MBq) in anhydrous methanol at 0–5 °C, and stirred at room temperature for 30 min. TLC analysis: R f (10a) = 0.70, R f (11a) = 0.30, V EA : V PE =1:2. The reaction was quenched slowly with water under ice bath cooling, and extracted with ethyl acetate (60 mL × 4). The organic phases were combined, washed with saturated sodium chloride solution (80 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The residue was subjected to rapid silica gel column chromatography (…). V EA : V PE Purification was performed using a 1:5 ratio. The experiment was repeated twice to obtain a white solid, 11a (1168 mg, 4092.2 MBq, radiochemical yield 97%). 1 H NMR (400 MHz, CDCl3) δ 6.16 (dd, J = 17.4, 11.3 Hz, 1H), 5.23 (d, J = 11.0 Hz, 1H), 5.18 (d, J = 17.4 Hz, 1H), 4.48 (d, J= 9.0 Hz, 1H), 3.65 (s,3H), 3.63 – 3.51 (m, 2H), 3.48 (s, 1H), 2.67 (s, 1H), 2.22 – 2.02 (m, 3H),2.02 – 1.87 (m, 1H), 1.81 – 1.63 (m, 1H), 1.50 (d, J = 14.2 Hz, 2H), 1.44 –1.22 (m, 5H), 1.12 (s, 3H), 0.92 – 0.82 (m, 22H), 0.79 (d, J = 7.0 Hz, 3H), 0.14 – 0.01 (m, 12H).

[0112] The unlabeled molecule mp for 11a was 66.2–68.6 °C; APCI-HRMS: m / z 595.4173 [MH] - (Theoretical calculated value: 595.4220).

[0113] Example 12 11,14-Dihydroxy TBS protects methylphenidate ring-opening [2- 14 Iodination of C] alcohol (11a)

[0114] Under argon protection and at room temperature, compound 11a (500 mg, 1750.1 MBq), imidazole (284 mg, 4.18 mmol), and triphenylphosphine (416 mg, 1.59 mmol) were dissolved in anhydrous THF (5 mL). The system was cooled to 0–5 °C, and then elemental iodine (424 mg, 1.67 mmol) was added. The mixture was stirred at constant temperature for 30 min, then heated to room temperature and stirred for 1 h. Triphenylphosphine (416 mg, 1.59 mmol) and elemental iodine (424 mg, 1.67 mmol) were then added, and the mixture was stirred at room temperature for 2 h. TLC analysis: R f (11a) = 0.2, R f (12a) = 0.8, V PE : V EA =5:1. After the reaction was complete, water (60 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (60 mL × 4). The organic phases were combined and washed successively with water (60 mL) and saturated sodium chloride aqueous solution (80 mL). The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The crude product was subjected to silica gel rapid column chromatography (…).V EA : V PE Purification was performed at a ratio of 1:50. The experiment was repeated once, yielding a total of 12a white solid (1030 mg, 3045.1 MBq, radiochemical yield 87%). 1 H NMR (400 MHz, CDCl3) δ 6.07 (dd, J =17.6, 11.4 Hz, 1H), 5.17 (d, J = 10.9 Hz, 1H), 5.11 (d, J = 17.4 Hz, 1H), 4.37(d, J = 8.8 Hz, 1H), 3.63 (s, 3H), 3.41 (s, 1H), 3.17 – 2.86 (m, 2H), 2.59 (s,1H), 2.13 – 1.92 (m, 4H), 1.91 – 1.80 (m, 1H), 1.72 (d, J = 12.5 Hz, 1H), 1.54– 1.39 (m, 2H), 1.35 (d, J = 12.3 Hz, 2H), 1.30 – 1.14 (m, 2H), 1.06 (s, 3H), 0.84 – 0.69 (m, 25H), 0.15 – -0.06 (m, 12H).

[0115] The unlabeled molecule mp for 12a was 160.7–162.7 °C; APCI-HRMS: m / z 707.3388[M+H] + (Theoretical calculated value: 707.3372).

[0116] Example 13 11,14-Dihydroxy TBS protects multiline ring-opening [2- 14 Cyclization reaction of C] iodide (12a)

[0117] Under argon protection and at room temperature, an anhydrous THF solution of iron triacetylacetone (12.5 mg, 0.035 mmol) in 0.5 mL was mixed with an anhydrous tetrahydrofuran solution of samarium diiodide (28.3 mL, 2.82 mmol, 0.1 mol / L). Then, an anhydrous tetrahydrofuran solution of compound 12a (500 mg, 1480.0 MBq) in 15 mL was slowly added dropwise over a time not less than 1 h. After the addition was complete, the mixture was stirred at room temperature for 2 h. TLC analysis: R f (12a) = 0.70, R f (13a) = 0.50, V PE : V EA =30 : 1. After the reaction was complete, dilute hydrochloric acid (80 mL) was added to the reaction solution and stirred for 1 h; the mixture was extracted with ethyl acetate (80 mL × 3), the organic phases were combined, washed successively with water (60 mL) and saturated sodium chloride solution (80 mL), dried over anhydrous sodium sulfate, filtered, the filtrate was desolvated under reduced pressure, and then subjected to silica gel rapid column chromatography (…). V EA : V PE Purification was performed at a ratio of 1:100. The experiment was repeated once, yielding a total of 13a white solid (311 mg, 1184.0 MBq, radiochemical yield 40%). 1 H NMR (400 MHz, CDCl3) δ 6.18 (dd, J = 17.4, 11.3 Hz, 1H), 5.27 (d, J = 6.2 Hz, 1H), 5.23 (s, 1H), 4.49 (d, J = 8.2 Hz, 1H), 3.45 (d, J = 5.6 Hz, 1H), 2.37 – 2.28 (m, 1H), 2.28 – 2.14 (m, 2H), 2.07 (s,1H), 1.85 (dd, J = 16.4, 8.3 Hz, 1H), 1.77 – 1.69 (m, 1H), 1.62 – 1.50 (m, 2H), 1.47 (d, J= 15.6 Hz, 2H), 1.36 (s, 3H), 1.17 – 1.11 (m, 1H), 1.09 (s, 3H), 0.95 – 0.81 (m, 26H), 0.13 – 0.02 (m, 12H).

[0118] Unlabeled molecule mp for 13a: 88.6–90.5 °C; APCI-HRMS: m / z 549.4159[M+H] + (Theoretical calculated value: 549.4154).

[0119] Example 14 11,14-Dihydroxy TBS protection [2- 14 Deprotective reaction of C]mteline (13a)

[0120] Under argon protection and at room temperature, tetrabutylammonium fluoride (2.2 mL, 2.2 mmol, 1.0 mol / L tetrahydrofuran solution) was added to an anhydrous tetrahydrofuran (5.0 mL) solution of compound 13a (300 mg, 1143.3 MBq). The system was heated to 70 °C and stirred for 5 h. TLC analysis: R f ([2- 14 C]Mtiline)=0.50, V EA : V PE =1:3. After the reaction was complete, the system was cooled to room temperature, and water (40 mL) was added to the reaction solution. Extraction was performed with ethyl acetate (30 mL × 4). The organic phases were combined and washed successively with water (30 mL) and saturated sodium chloride aqueous solution (50 mL). The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was desolvated under reduced pressure. The crude product was subjected to rapid silica gel column chromatography (…). V EA : V PE Purification with a ratio of 1:4 yielded a white solid [2- 14 C] Mtilim (131 mg, 858.4 MBq, radiochemical yield 75%): 1 HNMR (500 MHz, CDCl3) δ 6.15 (ddd, J = 17.8, 11.1, 0.8 Hz, 1H), 5.41 – 5.24 (m,2H), 4.35 (d, J = 7.6 Hz, 1H), 3.41 (d, J= 6.4 Hz, 1H), 2.28 – 2.14 (m, 3H), 2.05 (d, J = 2.9 Hz, 1H), 1.91 (dd, J = 15.9, 7.7 Hz, 1H), 1.78 – 1.72 (m, 1H), 1.70 – 1.65 (m, 1H), 1.63 – 1.54 (m, 3H), 1.52 – 1.39 (m, 5H), 1.36 (s, 3H), 1.15 (s, 3H), 0.96 (d, J = 7.0 Hz, 3H), 0.92 (d, J = 7.2 Hz, 3H); ESI-MS m / z 319 [MH] - , 321 [M+2-H] - .

[0121] HPLC-CAD analysis conditions: Agilent Poroshell 120 EC-C18 (3.0 mm × 150 mm, 2.7 μm) column; flow rate 0.60 mL / min; column temperature 30 ℃; injection volume 10 µL; gradient elution (min / %B) control: 0 / 25, 1 / 25, 20 / 100, 25 / 100; A is a solution containing 0.05% formic acid, and B is acetonitrile. Retention time R t ([2- 14 C]Mtiline) = 12.826min.

[0122] Online high-performance liquid chromatography-FSA (HPLC-FSA) analysis conditions: Diamonsil Plus C18 column (4.6 mm × 250 mm, 5 µm); flow rate 1.00 mL / min; column temperature 30 ℃; injection volume 10 µL; gradient elution (min / %B) control: 0 / 20, 1 / 20, 35 / 100, 40 / 100, A is a solution containing 0.01% formic acid, B is methanol. A PerkinElmer Radiomatic AIM ν.ARC was used with Optiphase HiSafe 3 scintillation fluid at a flow rate of 8.00 mL / min. Retention time R... t ([2- 14 C]Mtiline) = 28.23 min.

[0123] Analytical methods for quality indicators of isotope-labeled substances: Refer to the literature (Yu Zhiyang, Yang Zhengmin, Li Mengxue, et al. Radioactive isotopes).14 Synthesis of C-labeled remdesivir [J]. Nuclear Chemistry and Radiochemistry, 2025, 47(1): 93-102) The method for targeting [2- 14 Analysis was performed using C]mteline. The results showed that the target compound [2- 14 The total activity of C]mteline was 858.4 MBq, the specific activity was 2109.3 MBq / mmol, and the chemical purity and radiochemical purity were both greater than 98%.

[0124] In summary, with [ 14 [C] Sodium cyanide is used as an isotopic raw material, and the target compound [2-] is synthesized through a six-step radiolabeled synthesis reaction. 14 The total radiochemical yield of C]mteline was 15%.

Claims

1. A [2- 14 The preparation method of C] umteline is characterized by, Its synthetic route is as follows: In this context, the asterisk (*) indicates a carbon-14 labeled site; X1 and X2 are each independently selected from Cl, F, Br or I; PG is selected from tert-butyldimethylsilyl, triethylsilyl, tert-butyldiphenylsilyl, triisopropylsilyl, diethylisopropylsilyl or diisopropylethylsilyl. Regarding the cyanation reaction conditions for the 11,14-dihydroxyprotected mtiline ring-opening halogenated product (8), RS-1: The isotopic raw material is selected from carbon-14 alkali metal cyanide or carbon-14 alkaline earth metal cyanide, and the reaction is carried out in the presence of iodide, which is selected from KI and NaI. Regarding the ring-opening of 11,14-dihydroxyprotected morteline [cyano-] 14 Reduction hydrolysis reaction of cyano compound (9) under RS-2 conditions: The reaction is carried out in the presence of a reducing agent and a base. The reducing agent is diisobutylaluminum hydride, and the base is morpholine. N -Methylmorpholine, piperidine, or pyrrolidine; Reaction conditions RS-3 for the reduction reaction of the open ring [aldehyde group- 14 C] aldehyde (10) of 11,14-dihydroxy protected mutimerin: the reaction is carried out in the presence of a reducing agent, which is an alkali metal borohydride or an alkaline earth metal borohydride;​ Regarding the ring-opening of 11,14-dihydroxyprotective morteline [2- 14 The reaction conditions for the halogenation of C] alcohol (11) RS-4: The reaction is carried out in the presence of a halogenating agent, triphenylphosphine and a base. The halogenating agent is NBS, NIS, Br2 or I2; the base is imidazole, diisopropylethylamine or pyridine. Regarding the ring-opening of 11,14-dihydroxyprotective morteline [2- 14 The reaction conditions for the cyclization reaction of [C] haloesters (12) are RS-5: The reaction is carried out in the presence of a reducing agent and a catalyst. The reducing agent is samarium iodide; the catalyst is tris(dibenzoylmethyl)ferric, tris(acetylacetonyl)ferric, nickel iodide or hexamethylphosphoric triamine. Regarding the protection of 11,14-dihydroxyl groups [2- 14 The deprotection reaction conditions for C]mteline (13) RS-6: The silicon-based protecting group is removed using a fluoride ion reagent or under mild alkaline conditions. The fluoride ion reagent is selected from tetrabutylammonium fluoride, hydrogen fluoride or hydrogen fluoride-pyridine complex.

2. The preparation method according to claim 1, characterized in that, The reaction conditions for the cyanidation reaction of 11,14-dihydroxyprotected mtiline ring-opening halide (8) are as follows: RS-1: The isotopic raw material is Na. 14 CN, K 14 CN.

3. The preparation method according to claim 1 or 2, characterized in that, It also includes the step of using mtiline as a reactant to synthesize 11,14-dihydroxyprotected mtiline ring-opening halogenated derivatives (8).

4. The preparation method according to claim 3, characterized in that, The synthetic route for synthesizing 11,14-dihydroxyprotected mtiline ring-opening halide (8) using mtiline as the reactant is as follows: ； Wherein, X1 and PG are as described in claim 1, R represents a silicon-based protecting group, and NPhth is a phthalimide group; "S-1" to "S-8" represent suitable reaction conditions for each step of the reaction.

5. The preparation method according to claim 4, characterized in that, R is selected from triethylsilyl or trimethylsilyl.

6. The preparation method according to claim 4 or 5, characterized in that, It has one of the following characteristics: Regarding the reaction conditions for the silylation protection of 11,14-dihydroxyl groups in methylphenidate, S-1: the reaction is carried out in the presence of the silylating agent corresponding to the silyl protecting group and a base; or Regarding the enolization of the 3-carbonyl group of 11,14-dihydroxyprotected multiline (1) and O - Reaction conditions S-2 for silylation: The reaction is carried out in the presence of the silylating reagent corresponding to the silyl protecting group and a base; or Regarding the 2-hydroxylation reaction of 11,14-dihydroxyprotected mtiline-3-enol trialkylsilyl ether (2), the reaction conditions S-3 are as follows: the reaction is carried out in the presence of an oxidant, with acid and base added sequentially; or Regarding the ring-opening reaction of 11,14-dihydroxyprotected-2-hydroxymtiline (3), the reaction conditions S-4 are: the reaction is carried out in the presence of an oxidizing agent; or Regarding the esterification reaction of the 11,14-dihydroxyprotected morteline ring-opening product (4), the reaction conditions S-5 are: the reaction is carried out in the presence of a methylating agent; or Regarding the aldehyde oxidation reaction of 11,14-dihydroxyprotected morteline ring-opening ester (5), the reaction conditions S-6 are as follows: the reaction is carried out in the presence of an oxidizing agent; or The reaction conditions for the carboxyl activation reaction of the 11,14-dihydroxyprotected morteline ring-opening oxidation product (6) are as follows: S-7: The reaction is carried out in the presence of an activating agent, a condensing agent, and a base; or The reaction conditions for the decarboxylation halogenation of 11,14-dihydroxyprotected mtiline ring-opening phthalimide active ester (7) are as follows: S-8: photocatalytic reaction is carried out in the presence of halogenating reagent and catalyst.

7. The preparation method according to claim 6, characterized in that, Regarding the reaction conditions S-1 for the silanization protection of 11,14-dihydroxyl groups in methylphenidate: the silanizing agent is a trifluoromethanesulfonate or chloride corresponding to the silanizing protecting group; the base is pyridine, imidazole, diisopropylethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene or 2,6-dimethylpyridine and triethylamine; or Regarding the enolization of the 3-carbonyl group of 11,14-dihydroxyprotected multiline (1) and O - Reaction conditions S-2 for silanization: The silanizing agent is a trifluoromethanesulfonate or chloride corresponding to the silicon protecting group; the base is lithium bis(trimethylsilyl)amino, sodium bis(trimethylsilyl)amino, potassium bis(trimethylsilyl)amino, or lithium diisopropylamino; or The reaction conditions for the 2-position hydroxylation of 11,14-dihydroxyprotected mtiline-3-enol trialkylsilyl ether (2) are as follows: S-3: the oxidant is m-chloroperoxybenzoic acid, hydrogen peroxide, urea peroxide, or tert-butanol peroxide; the acid is an organic acid; the base is pyridine or sodium bicarbonate; or Regarding the ring-opening reaction of 11,14-dihydroxyprotected-2-hydroxymtiline (3), the reaction conditions S-4 are: sodium periodate as the oxidant; or Regarding the esterification reaction of the 11,14-dihydroxyprotected morteline ring-opening product (4), the reaction conditions S-5 are as follows: the methylating agent is selected from diazomethane, iodomethane, dimethyl sulfate, methyl trifluoromethanesulfonate, or methanol; or Regarding the aldehyde oxidation reaction of 11,14-dihydroxyprotected motiline ring open ester (5), the reaction conditions S-6 are as follows: One of the following two oxidation conditions is used: ① Pinnick oxidation: the reaction is carried out in the presence of sodium chlorite, sodium dihydrogen phosphate, and isopentenylene; ② Oxygen or air is used as the oxidant, and Cu(NO3)2·3H2O and TEMPO are used as the catalyst; or Reaction conditions S-7 for the carboxyl activation reaction of the 11,14-dihydroxyprotected morteline ring-opening oxidation product (6): Activating reagent selection N -Hydroxyphthalimide, N 1-Hydroxysuccinimide, 1-hydroxybenzotriazole, 1-hydroxy-7-azabenzotriazole, or pentafluorophenol; condensing agent selected. N , N ′-Dicyclohexylcarbodiimide, N , N ′-Diisopropylcarbodiimide, benzotriazole- N , N , N ′, N ′-Tetramethylurea hexafluorophosphate, N -(3-Dimethylaminopropyl)- N ′-Ethylcarbodiimide hydrochloride or N -Cyclohexyl- N '-(2-morpholinoethyl)carbodiimide p-toluenesulfonate; base selection: pyridine, 4-dimethylaminopyridine, DIPEA, N -Methylmorpholine, triethylamine; or The reaction conditions for the decarboxylation halogenation of 11,14-dihydroxyprotected methyl phthalimide active ester (7) are as follows: S-8: halogenating reagents are KI, LiI, KBr, LiBr or LiCl; catalysts are triphenylphosphine, diphenylcyclohexylphosphine, 4CzIPN, Ir[dF(CF3)ppy]2(dtbbpy)PF6 or Ir(ppy)3; light source is blue light.

8. The [2-] according to any one of claims 1-7 14 The application of the preparation method of [C] morteline in isotopic tracing studies of compounds containing the morteline core, among which, [2- 14 The structural formula of C] methyltetramine is shown below: The asterisk (*) indicates the carbon-14 labeled site; The [2- 14 C] Mtilline is used in the preparation of 14 C-labeled compounds containing the morteline core; The compound containing the tamsulene nucleus is either a compound containing the tamsulene nucleus with a side chain at the 14-position or a compound containing the tamsulene nucleus with a side chain at the 11-position.

Images