Preparation method and use of myocardial metabolism PET imaging agent

Abstract

The application provides a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro 18 The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro 18 The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application provides a preparation method and application of the myocardial metabolism PET imaging agent trans-2-(2-(5-(fluoro The application discloses a preparation method and application of a myocardial metabolism PET imaging agent trans-2-(2-(

Description

[0001] This application is a divisional application of the patent application filed on June 14, 2022, with application number 202210666003.3 and titled "A method for preparing a myocardial metabolism PET imaging agent and its use". Technical Field

[0002] This application belongs to the field of chemical pharmaceutical technology, and in particular relates to a... 18 Preparation method and applications of F-labeled myocardial metabolism PET imaging agent. Background Technology

[0003] As the most advanced imaging technology in the field of biomedical engineering today, molecular medical imaging technology applies imaging methods to conduct qualitative and quantitative studies of biological processes at the cellular and molecular levels in living organisms. It provides real-time, dynamic, in vivo, and non-invasive imaging of physiological and pathological changes at the molecular level. It is a key and core technology for researching targeted and specific molecular probes and therapeutic drugs. Multimodal molecular imaging technology allows for the complementary advantages of different imaging devices, resulting in more accurate and reliable imaging results. Clinical practice has proven that multimodal molecular medical imaging equipment plays a crucial role in the early diagnosis and treatment of major diseases, the development of treatment plans, and the verification and evaluation of treatment effects.

[0004] Positron emission tomography (PET) is primarily a functional imaging technique. It consists of a PET imaging unit and a radioactive tracer injected into the patient's bloodstream. One commonly used radioactive tracer is fluorodeoxyglucose (FDG), a compound synthesized from a simple sugar and a small amount of radioactive fluorine. [The text abruptly ends here, so the translation also ends here.] 18 After FDG is administered, it accumulates in the body's tissues and organs. 18 F decays, emitting a positron. The positron annihilates, producing a pair of photons moving in opposite directions with an energy of 511 keV. PET scanners can detect these photons and record their information. Using this information, the location of the positron's annihilation within the body can be reconstructed, thus obtaining […]. 18 Distribution map of FDG in the human body.

[0005] However 18 F-FDG still has some limitations in clinical applications such as brain tumor imaging that uses glucose metabolism as an energy substrate and differential diagnosis between tumors and inflammation. Summary of the Invention

[0006] This application provides a method for preparing compound I, which can be used in cardiac imaging, and its application therein.

[0007] The technical solution of this application is as follows: 1. A method for preparing compound I, comprising: Nucleophilic substitution reaction: The activated nucleophilic substitution reaction... 18 F ions are mixed with a solution containing the precursor of compound I tert-butyl ester to undergo a nucleophilic substitution reaction, yielding an intermediate product solution containing compound I tert-butyl ester; Detert-butyl ester reaction: An acidic solvent is added to the intermediate product solution of tert-butyl ester of the above compound I to carry out the detert-butyl ester reaction, and a product containing compound I is obtained.

[0008] Among them, compound I is trans-2-(2-(5-(fluorine[ 18 [F])tridecyl)cyclopropyl)acetic acid; The precursor of compound I, tert-butyl ester, is trans-2-(2-(5-(methanesulfonyloxy)tridecyl)cyclopropyl)tert-butyl acetate; Compound I, tert-butyl ester, is trans-2-(2-(5-fluoro[ 18 F] Tridecyl)cyclopropyl)tert-butyl acetate.

[0009] 2. The preparation method according to item 1, In nucleophilic substitution reactions, Compound I tert-butyl ester precursor (mg) / 18 The ratio of F ion activity (Ci) ranges from (0.2 to 5):1; Preferably, the reaction solvent is an aprotic polar solvent; More preferably, the aprotic polar solvent is one or more of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and 2-methyl-2-butanol.

[0010] 3. The preparation method according to item 1, In the detert-butyl ester reaction The acidic solvent is selected from one of the following: a mixture of trifluoroacetic acid and dichloromethane, hydrochloric acid, and formic acid, preferably a mixture of trifluoroacetic acid and dichloromethane. Preferably, in a mixed solvent of trifluoroacetic acid and dichloromethane, The amount of trifluoroacetic acid is 0.1-1 parts by volume relative to 1 part by volume of dichloromethane; More preferably, the amount of trifluoroacetic acid is 0.5-1 parts by volume relative to 1 part by volume of dichloromethane. 4. The preparation method according to item 1, In the detert-butyl ester reaction The reaction temperature is 30℃-100℃, preferably 40℃-80℃.

[0011] 5. The preparation method according to item 1, In the detert-butyl ester reaction The reaction time is 1 min to 30 min, preferably 1 min to 15 min.

[0012] 6. The preparation method according to item 1, Prior to the nucleophilic substitution reaction, it also includes 18 F ion preparation steps; Preferably, 18 The F ion preparation steps also include... 18 Preparation of F ion solution 18 F ion enrichment and elution 18 F ion activation; More preferably, 18 F-ion solution preparation: Accelerator preparation 18 F ion solution; 18 F ion enrichment: The above-prepared 18 F ion solution was enriched by anion exchange column; 18 F-ion elution: elution was performed using a solution of silane and alkali metal salt catalyst. 18 F ions; 18 F-ion activation: Activation is achieved by controlling the temperature and using a nitrogen or inert gas stream to dry the solvent. 18 F ions were obtained after activation. 18 F ions.

[0013] 7. The preparation method according to item 6, exist 18 In the preparation steps of F ion solution will contain 18 O-type water is transported to the accelerator target, and the accelerator is activated to generate a proton beam that bombards the target. 18 O-water, producing products containing 18 Solution of F ions; Preferably, the 18 The initial activity of F is 0.09 Ci to 4.4 Ci.

[0014] 8. The preparation method according to item 6, exist 18 F ion enrichment The anion exchange column is a QMA column, which is a tetraalkylammonium salt anion exchange column.

[0015] 9. The preparation method according to item 6, exist 18 In the F ion elution step The dosage of cryptane is 2mg-20mg, and the dosage of alkali metals is 0.5mg-10mg; Preferably, the cryptether is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane (Kryptofix-2.2.2, amino polyether), and the alkali metal salt is one or more of K2CO3, Na2CO3, Cs2CO3, KHCO3, and NaHCO3; More preferably, the catalyst solution is selected from an acetonitrile / water mixed solvent system, wherein the volume ratio of acetonitrile to water is (0.2-10):1.

[0016] 10. The preparation method according to item 6, exist 18 In the F ion activation step The activation temperature is 80℃-130℃; The programmed temperature control includes the following steps: 100-120℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20~-60mbar, evaporation 60-120s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20~-60mbar, evaporation 150-200s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -60~-100mbar, evaporation 10-30s; 100-120℃, nitrogen positive pressure 800-1200mbar, vacuum pressure -800~-1000mbar, evaporation 80-120s; 80-100℃, nitrogen positive pressure 400-600mbar, vacuum pressure -800~-1000mbar, evaporation 100-120s. 80-100℃, nitrogen positive pressure 600-900mbar, vacuum pressure -800~-1000mbar, evaporation 10-20s.

[0017] 11. The preparation method according to item 1, The product containing compound I was purified by high performance liquid chromatography, using a C18 OBD column and a mixed solvent system of acetonitrile and water as the mobile phase. The eluent containing compound I was collected. Preferably, the eluent containing compound I is diluted and then enriched by passing it through a Sep-Pak C18 column. The purified compound I is enriched on the C18 column. The C18 column is then washed with anhydrous ethanol into sodium chloride injection to obtain a liquid composition of compound I.

[0018] 12. The preparation method according to item 11, In the high-performance liquid chromatography purification step In the mobile phase, the volume ratio of acetonitrile to water is (3-6):1; Preferably, the chromatographic column is an XBridge BEH C18 OBD Prep column; More preferably, the flow rate is 3 mL / min to 6 mL / min.

[0019] 13. The use of compound I prepared according to any one of items 1-12 in a PET imaging agent for myocardial metabolism.

[0020] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application improves the initial efficiency by optimizing the experimental process scheme. 18 The reduced radioactivity of F ions decreased reaction time, improved labeling rate and yield, and yielded compound I. The process parameters and flow were clearly defined, suitable for large-scale activity production, and met automation requirements.

[0021] (2) Improve the efficiency of each reaction step and increase the yield.

[0022] (3) The preparation process was optimized, the time was simplified, and the radiochemical purity and stability of the product were improved. Detailed Implementation

[0023] Compound I, named trans-2-(2-(5-(fluorine) 18 F])tridecyl)cyclopropyl)acetic acid, with the following chemical structural formula: The chemical formula is: C 18 H 33 18 FO2 The molecular weight is 299.46. In this application, 18 F-labeled myocardial metabolism PET imaging agent refers to compound I.

[0024] Compound I, a precursor of tert-butyl ester, is chemically named trans-2-(2-(5-(methanesulfonyloxy)tridecyl)cyclopropyl)tert-butyl acetate, and its chemical structural formula is as follows: The chemical formula is: C 23 H 44 O5S The molecular weight is 432.66. Compound I, tert-butyl ester, chemically named trans-2-(2-(5-fluoro[ 18 F] Tridecyl)cyclopropyl)tert-butyl acetate, with the following chemical structural formula: The chemical formula is: C 22 H 41 18 FO2 The molecular weight is 355.57. The precursor of compound I, chemically named trans-2-(2-(5-(methanesulfonyloxy)tridecyl)cyclopropyl)acetate, has the following chemical structural formula: The chemical formula is: C 20 H 38 O5S The molecular weight is 390.58. Amino polyether (K) 222 ( ) is a tribridged crown ether molecule with cavitary cavitation, a typical nitrogen-containing cavitary ether, and a type of cavitary ether. Due to their unique coordination properties, nitrogen-containing cavitary ethers can effectively and selectively complex transition metal and heavy metal cations, resulting in more stable complexes. They also possess lipophilic and hydrophilic properties, thus showing promising research prospects.

[0025] In the prior art, amino polyether (K) 222 The classic synthetic method for α-aminopolyether (K) is the highly diluted method proposed by Lehn et al., which is a typical non-template ion synthesis method. The specific steps are as follows: 1,8-diamino-3,6-dioxane and 1,8-diacyl chloride-3,6-dioxane are dissolved in a large amount of benzene solvent and heated for 8 hours. Then, a reduction reaction with lithium aluminum hydride is carried out for 24 hours. Finally, the mixture is separated by column chromatography and recrystallized to obtain the aminopolyether (K). 222 This method requires large amounts of solvent, such as benzene, has a long synthetic route, is complex to operate, has low yield, and is not economically efficient. Besides the highly diluted method, amino polyethers (K...) 222 Another classic synthetic method is proposed by Kulstad and Malmsten, which uses Na2CO3 as a template to obtain amino polyethers (K) in acetonitrile. 222 The sodium iodide complex of ) is then decomplexed using a resin to obtain amino polyether (K) 222 The synthesis method of ) is as follows. The specific steps are: 1,2-bis(2-iodoethoxy)ethane and benzylamine are refluxed in acetonitrile solution for 3 days. Then, an intermediate is obtained through post-treatment. This intermediate is recrystallized from acetone, filtered, and a NaI complex is obtained. This complex is then decomplexed under acidic conditions using cation exchange resin and anion exchange resin, respectively, to prepare amino polyether (K). 222 This method uses simple equipment, requires little solvent, and operates under relatively mild reaction conditions. However, the applicant discovered through research that the decomplexing method using ion exchange resins fails to proceed when the sodium ion content decreases to a certain level, resulting in a low yield.

[0026] This application provides a method for preparing chemical I, the synthetic route of which is as follows: Compound I tert-butyl ester precursor Compound I tert-butyl ester Compound I Reactions involving protecting groups (such as tert-butyl ester protecting carboxyl groups, tert-butyloxycarbonyl protecting amino groups, etc.) are all carried out in a two-step process.

[0027] This application provides a method for preparing compound I, comprising: Nucleophilic substitution reaction: The activated nucleophilic substitution reaction... 18 F ions are mixed with a solution containing the precursor of compound I tert-butyl ester to undergo a nucleophilic substitution reaction, yielding an intermediate product solution containing compound I tert-butyl ester; Detert-butyl ester reaction: An acidic solvent is added to the intermediate product solution of tert-butyl ester of the above compound I to carry out the detert-butyl ester reaction, and a product containing compound I is obtained.

[0028] In some embodiments of this application, in the nucleophilic substitution reaction, compound I tert-butyl ester precursor (mg) / 18 The F ion activity (Ci) ratio ranges from (0.2-5):1. Among them, the precursor of compound I tert-butyl ester (mg) / 18 The F ion activity (Ci) ratio can be 0.2:1, 0.3:1, 0.5:1, 0.7:1, 1:1, 2:1, 3:1, 4:1, 5:1 or any range thereof.

[0029] In some embodiments of this application, in the nucleophilic substitution reaction, the reaction solvent is an aprotic polar solvent; more preferably, the aprotic polar solvent is one or more of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and 2-methyl-2-butanol.

[0030] In some embodiments of this application, in the detert-butyl ester reaction, the acidic solvent is selected from a mixture of trifluoroacetic acid and dichloromethane, hydrochloric acid, and formic acid, preferably a mixture of trifluoroacetic acid and dichloromethane.

[0031] In some embodiments of this application, in the mixed solvent of trifluoroacetic acid and dichloromethane, the amount of trifluoroacetic acid is 0.1-1 parts by volume relative to 1 part by volume of dichloromethane; preferably, the amount of trifluoroacetic acid is 0.5-1 parts by volume relative to 1 part by volume of dichloromethane. For example, relative to 1 part by volume of dichloromethane, trifluoroacetic acid can be 0.1 parts by volume, 0.2 parts by volume, 0.3 parts by volume, 0.4 parts by volume, 0.5 parts by volume, 0.6 parts by volume, 0.7 parts by volume, 0.8 parts by volume, 0.9 parts by volume, 1 part by volume, or any range thereof.

[0032] In some embodiments of this application, the reaction temperature in the detert-butyl ester removal reaction is 30°C-100°C, preferably 40°C-80°C; In the detert-butyl ester reaction, the reaction temperature can be 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃ or any range thereof.

[0033] In some embodiments of this application, the reaction time in the detert-butyl ester removal reaction is 1 min to 30 min, preferably 1 min to 15 min; In the detert-butyl ester reaction, the reaction time can be any range from 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, or any time range thereof.

[0034] In some embodiments of this application, prior to the nucleophilic substitution reaction, it also includes... 18 F ion preparation steps; preferably, 18 The F ion preparation steps also include... 18 Preparation of F ion solution 18 F ion enrichment and elution 18 F ion activation.

[0035] In some embodiments of this application, 18 F-ion solution preparation: Accelerator preparation 18 F ion solution; 18 F ion enrichment: The above-prepared 18 F ion solution was enriched by anion exchange column; 18 F-ion elution: elution was performed using a solution of silane and alkali metal salt catalyst. 18 F ions; 18 F-ion activation: Activation is achieved by controlling the temperature and using a nitrogen or inert gas stream to dry the solvent. 18 F ions were obtained after activation. 18 F ions.

[0036] In some embodiments of this application, in 18 In the preparation step of F ion solution, the F ion solution containing 18 O-type water is transported to the accelerator target, and the accelerator is activated to generate a proton beam that bombards the target. 18 O-water, producing products containing 18 A solution of F ions.

[0037] In some embodiments of this application, in 18 The F ion is enriched, and the anion exchange column is a QMA column, that is, a tetraalkylammonium salt anion exchange column.

[0038] In some embodiments of this application, in 18 In the F ion elution step, the amount of cryptane used is 2mg-20mg, and the amount of alkali metal used is 0.5mg-10mg.

[0039] In some embodiments of this application, in 18 In the F ion elution step, the cryptether is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane (Kryptofix-2.2.2, amino polyether), and the alkali metal salt is one or more of K2CO3, Na2CO3, Cs2CO3, KHCO3, and NaHCO3.

[0040] In some embodiments of this application, the catalyst solution is selected from an acetonitrile / water mixed solvent system, wherein the volume ratio of acetonitrile to water is (0.2-10):1.

[0041] In some embodiments of this application, in 18 In the F ion activation step, the activation temperature is 80-130℃; the programmed temperature control includes the following steps: 100-120℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20 to -60mbar, evaporation 60-120s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20 to -60mbar, evaporation 150-200s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -60 to -100mbar, evaporation 10-30s; 100-120℃, nitrogen positive pressure 800-1200mbar, vacuum pressure -800 to -1000mbar, evaporation 80-120s. At 80-100℃, with a nitrogen positive pressure of 400-600 mbar and a vacuum pressure of -800 to -1000 mbar, evaporation takes 100-120 seconds; at 80-100℃, with a nitrogen positive pressure of 600-900 mbar and a vacuum pressure of -800 to -1000 mbar, evaporation takes 10-20 seconds.

[0042] In some embodiments of this application, the product containing compound I is purified by high performance liquid chromatography, wherein the chromatographic column is a C18 OBD column, the mobile phase is a mixed solvent system of acetonitrile and water, and the eluent containing compound I is collected. In some embodiments of this application, the eluent of compound I is diluted and then enriched by passing it through a Sep-Pak C18 column, and the purified compound I is enriched in the C18 column.

[0043] In some embodiments of this application, anhydrous ethanol is used to rinse a C18 column into sodium chloride injection to obtain a liquid composition of compound I.

[0044] In some embodiments of this application, in the high performance liquid chromatography purification step, the volume ratio of acetonitrile to water in the mobile phase is (3-6):1; The volume ratio of acetonitrile to water can be 3:1, 4:1, 5:1, 6:1 or any range thereof.

[0045] In some embodiments of this application, the chromatographic column used in the high-performance liquid chromatography purification step is an XBridgeBEH C18 OBD Prep column.

[0046] In some embodiments of this application, the flow rate in the high performance liquid chromatography purification step is 3 mL / min-6 mL / min; The flow rate can be 3 mL / min, 4 mL / min, 5 mL / min, 6 mL / min or any range thereof.

[0047] This application also provides the application of the above-mentioned compound I in a PET imaging agent for myocardial metabolism. This application uses compound I tert-butyl ester as a precursor, increasing the yield to over 15% and reducing the production time from approximately 100 minutes to approximately 80 minutes. In this preparation method, replacing compound I methyl ester precursor with compound I tert-butyl ester precursor improves the labeling rate of the nucleophilic substitution reaction; the process is shortened by directly performing the detert-butyl ester removal reaction after the nucleophilic substitution reaction without prior purification, simplifying the purification time. The detert-butyl ester removal reaction uses a trifluoroacetic acid / dichloromethane system instead of a LiOH / methanol system, improving the conversion rate of the detert-butyl ester removal reaction; after the detert-butyl ester removal reaction, the solvent is directly dried, eliminating the need for acid neutralization and subsequent ether extraction steps, all of which save production time. In this application, the tert-butyl ester precursor is used in the nucleophilic substitution reaction. Compared to the methyl ester precursor, the tert-butyl ester precursor has greater steric hindrance in its structure, better stability to bases, and is less prone to deprotection during the labeling reaction. Subsequent deprotection can be quickly completed through acid hydrolysis, thus achieving a higher yield.

[0048] Fluorine in this application 18 The amount of F ions used was increased from the 100 mCi level to the 4 Ci level. The preparation method described in this application is applicable to higher concentrations. 18 Starting quantity of F ions.

[0049] In the existing technology, the preparation method of compound I uses a LiOH / methanol system. After the deprotection reaction, hydrochloric acid is added for neutralization, followed by ether extraction, which greatly increases the preparation time. However, by using a trifluoroacetic acid / dichloromethane mixed solvent system, the reaction can be directly dried with nitrogen after the detert-butyl group removal reaction, which can then be used for the next purification step, thus shortening the reaction time.

[0050] Due to the improvement 18 Once the initial amount of F is determined, manual labeling is not possible; automated synthesis equipment is required. The ether extraction step used in the deprotection process described above is difficult to implement with automated synthesis equipment, limiting its practical application.

[0051] In the existing process, Sep-Pak normal-phase silica gel columns are used for purification. However, these columns are short, have a small theoretical plate number, and poor separation, making it impossible to separate impurities with similar polarity to compound I.

[0052] In this application, a C18 bonded silica reversed-phase column is selected in the high-performance liquid chromatography purification step, preferably the XBridge BEH C18 OBD Prep column, which has a high theoretical plate number. The separation effect can be adjusted by changing the type of stationary phase, the type or ratio of mobile phase, the flow rate, etc., and the separation effect is good.

[0053] In this application, the mobile phase used in the high-performance liquid chromatography (HPLC) purification step is a mixture of acetonitrile and water, with the following advantages: 1. Acetonitrile and water are miscible; 2. Acetonitrile has much lower polarity than water, and the separation effect can be improved by adjusting the ratio of acetonitrile; 3. Acetonitrile has excellent solubility; 4. Acetonitrile is non-corrosive to the HPLC system; 5. Acetonitrile has a low ultraviolet absorption wavelength, which provides a smoother baseline and better quantitative results in low-wavelength detection; 6. Acetonitrile has low viscosity, requiring less pressure from the HPLC system, making it suitable for rapid and efficient HPLC analysis, etc.

[0054] In this application, 18 F initial activity is also known as 18 F ion activity refers to the activity of protons generated by starting an accelerator to bombard oxygen-containing [ 18 After O] water, it produces products containing 18 The activity of the F ion solution was measured using a activity meter. 18 F ion activity.

[0055] In this application, 18 F-initial activity refers to the amount of oxygen-containing protons generated by the accelerator and bombarded with proton beams. 18 After O] water, it produces products containing 18 The concentration of F ions that can be detected immediately after solution formation is defined as a reasonable detection time that can be controlled by someone skilled in the art, such as within 10 minutes after production. Furthermore, those skilled in the art will understand that the concentration will vary with the time elapsed after production. 18 The initial activity of F may vary to some extent, but the error range is usually within ±10%.

[0056] In some embodiments of this application, the... 18 The initial activity of F is 0.09 Ci to 4.4 Ci; Among them, the 18 The initial activity of F can be 0.09Ci, 0.1Ci, 0.5Ci, 1Ci, 1.5Ci, 2Ci, 2.5Ci, 3Ci, 3.5Ci, 4Ci, 4.4Ci or any range thereof.

[0057] In this application, "high volume" refers to products with high total activity, which generally refers to products with a total activity exceeding 1 Ci, i.e., 37 GBq. High activity concentration products generally refer to products with an activity concentration exceeding 50 mCi / mL, or 1850 MBq / mL.

[0058] In this application, the labeling rate refers to 18 F undergoes a labeling reaction with the reaction precursor. 18 F replaces the leaving group in the precursor, converting it into the final labeled product, which contains... 18F, therefore, the labeling rate is defined as the ratio of the activity of the labeled product to the total activity of the reactants. 18 F activity.

[0059] In this application, yield refers to the ratio of the activity of the final product compound I liquid composition to... 18 The ratio of initial F activity.

[0060] The improved purification method for preparing compound I provided in this application is a semi-preparative HPLC separation and purification method. Semi-preparative HPLC uses columns with high theoretical plate numbers, and the separation effect can be adjusted by changing the type or ratio of the stationary phase, the flow rate, etc. Therefore, semi-preparative HPLC has a good separation effect, can separate most radiochemical impurities, and thus improves the radiochemical purity of compound I.

[0061] This application provides a general and / or specific description of the materials and test methods used in the experiments. In the following examples, unless otherwise specified, % represents wt%, i.e., weight percentage. Reagents or instruments used, unless otherwise specified, are all commercially available conventional reagent products. Table 1 shows the sources of the raw materials used in the examples.

[0062] Table 1. Sources of raw materials used in the examples

[0063] Example The automated equipment selected is the AllinOne model from Trasis. The equipment's power unit is a high-purity nitrogen generator with an electric rotor for the syringe, providing a vacuum system and equipped with an HPLC purification system. Because this process utilizes automated equipment housed in a radiation shielding chamber, it protects operators from radiation damage, increases the operating dose, and, due to computer control, allows for more precise control of process steps, higher repeatability, and reduced human error.

[0064] Example 1: Preparation of Compound I 1) 18 Preparation of F ion solution oxygen-containing 18 2g of water (O) is transported to the accelerator target, and the accelerator is activated to generate a proton beam to bombard the oxygen-containing [O]. 18 Water containing O] produces products containing 18 Solution of F ions 18 F initial activity 4Ci.

[0065] 2) 18 F ion enrichment The above-prepared 18The F ion solution was processed using an anion exchange solid-phase extraction column (Waters QMA column; the QMA column was preferably first rinsed with 5 mL of 0.5 mol / L K2CO3, then rinsed with 10 mL of water to complete the activation). 18 F ions are enriched on the QMA column.

[0066] 3) 18 F ion elution Eluting was performed using a solution of silane and alkali metal salt catalyst. 18 F ions are added to the reaction flask; specifically, K ions are added. 222 8 mg of K₂CO₃ (dissolved in 0.5 mL of acetonitrile) and 4 mg of K₂CO₃ (dissolved in 0.1 mL of water) were mixed to prepare a mixed solution of acetonitrile and water (acetonitrile to water volume ratio 5:1). This solution was used to elute the above QMA column. 18 F / K 222 The complex was eluted into the reaction flask.

[0067] 4) 18 F ion activation The eluted material from step 3) 18 F ions were activated by drying the solvent after being heated under a nitrogen stream at 95°C-125°C. 18 F ions.

[0068] 5) 18 F ion nucleophilic substitution reaction An acetonitrile solution containing the precursor of compound I tert-butyl ester was added to the reaction flask. The amount of the precursor of compound I tert-butyl ester was 1 mg. The amount of the precursor of compound I tert-butyl ester (mg) / 18 The initial activity (Ci) of F was 1 mg / 4 Ci (i.e., 0.25:1). The reaction was carried out under sealed conditions at 120°C for 10 min. Compound I, the tert-butyl ester precursor, reacted with K... 18 F / K 222 A nucleophilic substitution reaction was carried out to obtain an intermediate product containing compound I tert-butyl ester. After the substitution reaction was completed, the product was heated to 100°C under a nitrogen stream to remove acetonitrile.

[0069] 6) Determination of tert-butyl ester group Add 1 mL of a mixture of trifluoroacetic acid and dichloromethane (volume ratio of trifluoroacetic acid to dichloromethane is 0.43:1) to the above intermediate product containing tert-butyl ester (compound I). The reaction temperature is 40 °C and the reaction time is 15 min. Remove the tert-butyl ester protecting group to obtain the crude product containing compound I. After the reaction is completed, heat at 100 °C under a nitrogen stream to remove the solvent.

[0070] 7) Purification by high performance liquid chromatography The crude product containing compound I was loaded into the injection loop and purified under the following chromatographic conditions to obtain the HPLC eluent. Column 1: XBridge BEH C18 OBD Prep column, 130A, 5μm, 10×250mm; Mobile phase: a mixture of acetonitrile and water, wherein the volume ratio of acetonitrile to water is 4:1; Flow rate: 5 mL / min Detector: Radioactive detector Monitor and track radioactive signals, and collect the main radioactive peak of CardioPET into transfer bottle 1.

[0071] 8) C18 column purification Add 30 mL of sterile water for injection to the transfer bottle in step 7) to dilute the HPLC eluent, then pass it through a Sep-Pak C18 column for enrichment. Rinse the C18 column with 20 mL of sterile water for injection. The purified compound I is enriched in the C18 column. Rinse the C18 column with 2 mL of anhydrous ethanol and then into 18 mL of sodium chloride injection to obtain the compound I product.

[0072] Example 2 The only difference between Example 2 and Example 1 is that: 18 In the F-ion nucleophilic substitution reaction, the amount of tert-butyl ester precursor of compound I used was 3 mg. The amount of tert-butyl ester precursor of compound I (mg) / 18 The initial activity (Ci) was 3 mg / 4 Ci (i.e., 0.75:1), and all other conditions were the same.

[0073] Example 3 The only difference between Example 3 and Example 2 is that in the detert-butyl ester reaction, 1 mL of a mixture of trifluoroacetic acid and dichloromethane (volume ratio of trifluoroacetic acid to dichloromethane is 0.67:1) was added to the above intermediate product containing compound I tert-butyl ester. All other conditions were the same.

[0074] Example 4 The only difference between Example 4 and Example 2 is that in the detert-butyl ester reaction, 1 mL of a mixture of trifluoroacetic acid and dichloromethane (the volume ratio of trifluoroacetic acid to dichloromethane is 1:1) was added to the intermediate product containing compound I tert-butyl ester. All other conditions were the same.

[0075] Example 5 The only difference between Example 5 and Example 2 is that the reaction temperature in the detert-butyl ester removal reaction is 50°C, while all other conditions are the same.

[0076] Example 6 The only difference between Example 6 and Example 2 is that the reaction temperature in the detert-butyl ester removal reaction is 60°C, while all other conditions are the same.

[0077] Example 7 The only difference between Example 7 and Example 2 is that the reaction temperature in the detert-butyl ester removal reaction is 70°C, while all other conditions are the same.

[0078] Example 8 The only difference between Example 8 and Example 2 is that the reaction temperature in the detert-butyl ester removal reaction is 80°C, while all other conditions are the same.

[0079] Example 9 The only difference between Example 9 and Example 2 is that the reaction temperature in the detert-butyl ester removal reaction is 100°C, while all other conditions are the same.

[0080] Example 10 The only difference between Example 10 and Example 2 is that the reaction time for the removal of tert-butyl ester is 10 min, while all other conditions are the same.

[0081] Example 11 The only difference between Example 11 and Example 2 is that the reaction time for the removal of tert-butyl ester is 5 minutes, while all other conditions are the same.

[0082] Example 12 The only difference between Example 12 and Example 2 is that the reaction time for the removal of tert-butyl ester is 2 minutes, while all other conditions are the same.

[0083] Example 13 The only difference between Example 13 and Example 2 is that the purification step is replaced by high performance liquid chromatography, and Sep-Pak normal phase silica gel column is used for purification. The eluent is ethanol and dichloromethane in a volume ratio of 0.05:1. After elution, the solvent is dried to obtain compound I. All other conditions are the same.

[0084] Example 14 The only difference between Example 14 and Example 2 is that in the high performance liquid chromatography purification, the mobile phase is a mixture of acetonitrile and water, wherein the volume ratio of acetonitrile to water is 3:1; all other conditions are the same.

[0085] Example 15 The only difference between Example 15 and Example 2 is that in the high performance liquid chromatography purification, the mobile phase is a mixture of acetonitrile and water, wherein the volume ratio of acetonitrile to water is 1:1; all other conditions are the same.

[0086] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is: 18 In the F-ion nucleophilic substitution reaction, an acetonitrile solution containing the precursor of compound I methyl ester was added to the reaction flask. The amount of the precursor of compound I methyl ester was 3 mg, and all other conditions were the same.

[0087] Comparative Example 2 The only difference between Comparative Example 1 and Example 2 is that in the detert-butyl ester reaction, 1 mL of a mixture of LiOH and methanol (1 M LiOH and methanol volume ratio of 0.43:1) was added to the above intermediate product containing compound I tert-butyl ester, and then 0.3 mL of 1 M HCl was added to neutralize the reaction solution. All other conditions were the same.

[0088] Table 2 Parameters of Examples 1-15 and Comparative Examples 1-2

[0089] In Table 2, column 1 is an XBridge BEH C18 OBD Prep column, 130A, 5μm, 10×250mm. Additionally, Table 2 shows... 18 F-initial activity data refers to data that can be detected immediately after production, but those skilled in the art will understand that it is usually... 18 The initial activity of F changes with storage time and usage conditions; therefore, in Examples 1-15 and Comparative Examples 1-2... 18 The initial activity data for F is usually for this target. 18 The range of F initial activity data within ±10% is considered acceptable to those skilled in the art; for example, 4Ci is the target. 18 The initial activity (F) can be 3.6 Ci to 4.4 Ci in actual testing.

[0090] Verification Example The labeling rate was determined by: after the labeling reaction was completed, high performance liquid chromatography (HPLC) was used for injection analysis, and the ratio of the area of ​​the target product's radioactive peak to the area of ​​all radioactive peaks in the liquid chromatogram was used.

[0091] The method for determining the uncorrected yield is as follows: the activity of the final liquid composition product, measured using an activity meter, is compared with the initial yield. 18 The ratio of F activity.

[0092] The method for determining radiochemical purity 0h is as follows: using HPLC injection analysis, the ratio of the area of ​​the product's radioactive peak to the area of ​​all radioactive peaks is used.

[0093] The method for determining 6-hour stability (radiochemical purity index) is as follows: after the final product is placed at room temperature for 6 hours, HPLC analysis is performed to determine the ratio of the area of ​​the product's radioactive peak to the area of ​​all radioactive peaks.

[0094] Table 3 Experimental results data of Examples 1-15 and Comparative Examples 1-2

[0095] Compared to Example 1, Example 2 increased the amount of the precursor, which promotes... 18 The conversion of F will improve the yield and labeling rate. The radiochemical purity remains largely unchanged.

[0096] Compared to Example 2, Examples 3 and 4 changed the volume ratio of trifluoroacetic acid and dichloromethane. With the increase in the proportion of trifluoroacetic acid, the detert-butyl ester reaction was promoted, resulting in improved yield and labeling rate. The radiochemical purity remained largely unchanged.

[0097] Compared to Example 2, Examples 5-9 varied the temperature of the detert-butyl ester removal reaction. The yields and labeling rates of Examples 2 and 5-8 were superior to those of Example 9. The radiochemical purity remained largely unchanged. The highest yields and labeling rates were achieved at a temperature of 70°C, which was superior to temperatures of 40°C or 100°C.

[0098] Compared to Example 2, Examples 10-12 varied the reaction time; with a shorter reaction time, the yield and labeling rate increased. The radiochemical purity remained largely unchanged.

[0099] Compared to Example 2, Example 13 used Sep-Pak normal-phase silica gel columns, which significantly reduced the yield and labeling rate, and also significantly reduced the radiochemical purity.

[0100] Compared with Example 2, Examples 14 and 15 changed the volume ratio of acetonitrile to water in the mobile phase of high performance liquid chromatography purification, increasing the water content in the mobile phase. This resulted in a longer product elution time, increased the total preparation time, and a significant decrease in yield and labeling rate.

[0101] Compared to Example 2, Comparative Example 1 used the methyl ester precursor of compound I, resulting in a decrease in both labeling rate and yield.

[0102] Compared with Example 2, Comparative Example 2 used a LiOH and methanol mixture as the deprotection system, with a LiOH to methanol volume ratio of 0.43:1, resulting in a decrease in both the labeling rate and yield.

[0103] For Compound I, the radiochemical purity needs to be ≥90%; <90% is unsuitable and cannot be used.

[0104] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Anyone skilled in the art may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the appended patent application.

Claims

1. A method for preparing compound I, characterized in that, include: Nucleophilic substitution reaction: The activated nucleophilic substitution reaction... 18 F ions are mixed with a solution containing the precursor of compound I tert-butyl ester to undergo a nucleophilic substitution reaction, yielding an intermediate product solution containing compound I tert-butyl ester; Detert-butyl ester reaction: An acidic solvent was added to the intermediate product solution of tert-butyl ester of the above compound I to carry out the detert-butyl ester reaction, and a product containing compound I was obtained; Among them, compound I is trans-2-(2-(5-(fluorine[ 18 [F])tridecyl)cyclopropyl)acetic acid; The precursor of compound I, tert-butyl ester, is trans-2-(2-(5-(methanesulfonyloxy)tridecyl)cyclopropyl)tert-butyl acetate; Compound I, tert-butyl ester, is trans-2-(2-(5-fluoro[ 18 F] Tridecyl)cyclopropyl)tert-butyl acetate.

2. The preparation method according to claim 1, characterized in that, In nucleophilic substitution reactions, Compound I tert-butyl ester precursor (mg) / 18 The F ion activity (Ci) ratio ranges from (0.2 to 5):

1.

3. The preparation method according to claim 1, characterized in that, In the nucleophilic substitution reaction, the reaction solvent is selected from one or more of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and 2-methyl-2-butanol.

4. The preparation method according to claim 1, characterized in that, In the detert-butyl ester reaction The acidic solvent is selected from one of the following: a mixture of trifluoroacetic acid and dichloromethane, hydrochloric acid, and formic acid.

5. The preparation method according to claim 1, characterized in that, In the detert-butyl ester reaction The acidic solvent is a mixture of trifluoroacetic acid and dichloromethane.

6. The preparation method according to claim 5, characterized in that, In a mixed solvent of trifluoroacetic acid and dichloromethane, the amount of trifluoroacetic acid is 0.1-1 parts by volume relative to 1 part by volume of dichloromethane.

7. The preparation method according to claim 1, characterized in that, In the detert-butyl ester reaction The reaction temperature is 30℃-100℃; or The reaction time is 1 min to 30 min.

8. The preparation method according to claim 1, characterized in that, Prior to the nucleophilic substitution reaction, it also includes 18 F ion preparation steps; 18 The F ion preparation steps also include... 18 Preparation of F ion solution 18 F ion enrichment and elution 18 F ion activation; in, 18 F-ion solution preparation: Accelerator preparation 18 F ion solution; 18 F ion enrichment: The above-prepared 18 F ion solution was enriched by anion exchange column; 18 F-ion elution: elution was performed using a solution of silane and alkali metal salt catalyst. 18 F ions; 18 F-ion activation: Activation is achieved by controlling the temperature and using a nitrogen or inert gas stream to dry the solvent. 18 F ions were obtained after activation. 18 F ions.

9. The preparation method according to claim 8, characterized in that, exist 18 In the preparation steps of F ion solution will contain 18 The water containing O is transported to the accelerator target, and the accelerator is activated to generate a proton beam that bombards the target. 18 O-water, producing products containing 18 A solution of F ions.

10. The preparation method according to claim 8, characterized in that, exist 18 F ion enrichment The anion exchange column is a QMA column, i.e., a tetraalkylammonium salt anion exchange column; or exist 18 In the F ion elution step The dosage of cryptane is 2mg-20mg, and the dosage of alkali metals is 0.5mg-10mg.

11. The preparation method according to claim 8, characterized in that, exist 18 In the F ion activation step The activation temperature is 80℃-130℃; The programmed temperature control includes the following steps: 100-120℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20~-60mbar, evaporation 60-120s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -20~-60mbar, evaporation 150-200s; 120-130℃, nitrogen positive pressure 50-200mbar, vacuum pressure -60~-100mbar, evaporation 10-30s; 100-120℃, nitrogen positive pressure 800-1200mbar, vacuum pressure -800~-1000mbar, evaporation 80-120s; 80-100℃, nitrogen positive pressure 400-600mbar, vacuum pressure -800~-1000mbar, evaporation 100-120s. 80-100℃, nitrogen positive pressure 600-900mbar, vacuum pressure -800~-1000mbar, evaporation 10-20s.

12. The preparation method according to claim 1, characterized in that, The product containing compound I was purified by high performance liquid chromatography (HPLC) using a C18 OBD column and a mixed solvent system of acetonitrile and water as the mobile phase. The eluent containing compound I was collected.

13. The preparation method according to claim 12, characterized in that, The eluent containing compound I was diluted and then enriched by passing it through a Sep-Pak C18 column. The purified compound I was enriched in the C18 column, and the C18 column was washed with anhydrous ethanol into sodium chloride injection to obtain a liquid composition of compound I.

14. The preparation method according to claim 12, characterized in that, In the high-performance liquid chromatography purification step In the mobile phase, the volume ratio of acetonitrile to water is (3-6):

1.

15. The use of compound I prepared by the method according to any one of claims 1-14 in a PET imaging agent for myocardial metabolism.

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