Boron carrying agent for tumor diagnosis and treatment integration, preparation method and use thereof

Abstract

The present invention relates to boron carrying agents for tumor diagnosis and therapy integration, methods of preparation and uses thereof. Provided are compounds of Formula I: wherein the R group is hydrogen or alkyl. The boron atom attached to the benzene ring can be 10 B or natural boron. At least one of the fluorine atoms in ‑ may be radiolabeled. The present invention generally relates to the field of radiopharmaceuticals and nuclear medicine. The compounds of the present invention can be used as diagnosis and therapy integration agents for tumor diagnosis and BNCT therapy, providing reliable in vivo distribution results of the drug through their identical chemical structure.

Description

Technical Field

[0001] This invention generally relates to the fields of radiopharmaceuticals and nuclear medicine, and specifically to a boron carrier for integrated tumor diagnosis and treatment, used for boron neutron capture therapy and tumor diagnosis. Background Technology

[0002] Boron neutron capture therapy (BNCT) is a binary targeted radiotherapy precision medicine technique. First, a boron-carrying drug that accumulates within tumor cells is administered to the patient, followed by irradiation with thermal or ultrathermal neutrons. The principle is that a highly targeted boron-containing drug is applied to the patient and accumulates within cancer cells. The thermal neutron capture cross-section of 10B is very high compared to normal elements in the human body. Utilizing the capture reaction between thermal neutrons and 10B atoms, the resulting high-energy alpha particles and Li particles act only within approximately 10 μm of cancer cells, causing irreversible damage to the cell structure, leading to apoptosis. Using this therapy for malignant tumor treatment can kill tumor tissue while preserving the surrounding normal tissue and function to the greatest extent possible, thus improving the patient's post-treatment quality of life and survival time. 4-Borate-L-phenylalanine (BPA) is the most commonly used boron-carrying drug approved by the FDA for clinical application in BNCT. However, since BNCT requires the planning of treatment strategies based on the pharmacokinetic results of boron carriers, how to effectively obtain the concentration of BPA in tumors and other tissues and organs has become one of the key issues in various studies.

[0003] Positron emission tomography (PET) is a molecular imaging technique based on radioactive molecular probes. It combines molecular probes with medical imaging technology to qualitatively and quantitatively study pathological and physiological processes in vivo at the cellular and molecular levels. Positrons emitted from isotopes such as 11C and 18F undergo annihilation by colliding with widely distributed negatively charged electrons, converting their energy into two photons with opposite energies of 511 keV. These two photons are simultaneously detected by two opposing probes of the instrument, indicating that annihilation has occurred along the line connecting the two probes. Thus, PET can accurately locate and quantify the distribution of radioactivity within the body. After computer reconstruction, a three-dimensional PET image of the human body can be obtained. PET is one of the most effective tools for studying drug distribution in vivo.

[0004] Integrating therapeutic components with PET imaging to achieve integrated tumor imaging and treatment is a direction for technological development. 2-fluoro-4-L-boronophenylalanine (FBPA) is a BPA with a fluorine atom substituted at position 2 of the benzene ring. This fluorine atom can be radioactive 18F, in which case the molecule can serve as a PET probe to simulate the distribution of BPA in vivo. 18 PET imaging technology using FBPA as a probe is now applied to the pre-treatment diagnosis of BNCT, helping to understand the dynamic distribution of BPA in the patient's body (Ishiwata K, et al. Melanoma Research, 1992. PMID: 1450671). However, FBPA and BPA differ in molecular structure, and the probe dose of FBPA cannot represent the distribution of the therapeutic dose of BPA in the body. FBPA-PET technology is not yet mature, so it is urgent to develop a new drug molecule that can achieve integrated diagnosis and treatment. Summary of the Invention

[0005] BNCT treatment relies on the high enrichment of boron carriers at the tumor site, and the treatment plan must be customized based on this enrichment. This necessitates real-time monitoring of the in vivo concentration distribution of boron carriers. As the only currently approved BNCT drug, studying the distribution of BPA in vivo is particularly important. A key method is PET molecular imaging, which involves introducing radioactive elements onto the benzene ring of BPA. 18 F obtained [ 18 F]FBPA. Through [ 18 F]FBPA simulates the distribution of BPA in vivo, thus enabling the planning of BNCT. However, from a chemical structure perspective, replacing the H atom on the benzene ring with an F atom cannot guarantee that its chemical and biological properties will remain the same as BPA. This difference will bring considerable uncertainty to BNCT.

[0006]

[0007] To address the problem that existing FBPA-PET methods cannot accurately and effectively reflect the distribution of BPA in vivo, thus hindering precise and efficient BNCT, this invention provides a novel therapeutic boron carrier, such as (S)-BBPA, which can be conveniently radiolabeled. The labeled and unlabeled versions have the same chemical structure, accurately reflecting the boron's distribution in vivo. This solves the problem of unclear real-time distribution prediction in vivo associated with classic boron carriers, providing more efficient BNCT planning. Furthermore, the use of two boron atoms within the molecule enables even more efficient BNCT.

[0008]

[0009] The concept of this invention is as follows: Boronine is a class of amino acid derivatives developed by replacing the carboxyl group of natural amino acids with boron trifluoride. Through 18F-19F isotope exchange reactions, it can be used to construct radioactive probes using 18F radiolabeling, thereby achieving PET imaging. The inventors discovered in their research that the boron trifluoride group and the carboxyl group exhibit high similarity in electrical properties; therefore, boronine and its corresponding natural amino acid also exhibit similarities in biorecognition and transport. Based on this, the applicant discovered that by replacing the carboxyl group in BPA with a boron trifluoride group, BBPA can be constructed, in which the chiral carbon atoms have S and R configurations. The R-configured (R)-BBPA has the same chirality as the natural amino acid, while the S-configured (S)-BBPA has the opposite configuration. Both can be highly enriched in tumor regions, with (S)-BBPA exhibiting lower background uptake in normal tissue, demonstrating better clinical application value. On the one hand, (S)-BBPA can be labeled with F-18 to achieve molecular concentration distribution analysis in vivo; on the other hand, it can also be directly used as a boron carrier for BNCT. Because (S)-BBPA has a completely identical chemical structure before and after radiolabeling, it can be used to […]. 18 F](S)-BBPA can accurately reflect the distribution of (S)-BBPA in the body, providing an important basis for the implementation of BNCT treatment regimens. More importantly, (S)-BBPA contains two boron atoms, which has a stronger boron carrying capacity, enabling more efficient boron delivery.

[0010] In one aspect, the present invention provides compounds of formula I or pharmaceutically acceptable salts thereof:

[0011]

[0012] The R group is either hydrogen or alkyl.

[0013] In one embodiment, the compound is an S-type or R-type compound.

[0014] In one embodiment, the compound has the structure of Formula II:

[0015] The R group is either hydrogen or alkyl.

[0016] In one embodiment, the boron atom attached to the benzene ring is 10 B or native boron. In one embodiment, -BF3 - At least one fluorine atom in it is a radioactive fluorine atom, for example 18 F.

[0017] In one embodiment, the alkyl group is methyl.

[0018] In one implementation, -BF3 - The boron atoms in it are natural boron.

[0019] In another aspect, the present invention provides a method for preparing the compound of this application, comprising the following steps: by processing compound 6 Preferred Add KHF2 solution and hydrochloric acid until pH < 5 to produce compound 7. Preferred Then acid is added to obtain the compound.

[0020] In one implementation, the method includes one or more of the following steps:

[0021] (1) p-bromophenylethanol Transformed into compound 1

[0022] (2) Converting compound 1 into compound 2 with the addition of N-methyliminoacetic acid.

[0023] (3) Convert compound 2 into compound 3

[0024] (4) Convert compound 3 into compound 4

[0025] (5) Convert compound 4 into compound 5 Preferred

[0026] (6) Convert compound 5 into compound 6 Preferred as well as

[0027] (7) Convert compound 6 into compound 7 Preferred

[0028] (8) Convert compound 7 into compound 8 Preferred as well as

[0029] (9) Convert compound 8 to Preferred

[0030] In another aspect, the present invention provides boron carrier compositions comprising one or more compounds of Formula I of the present invention and a pharmaceutically acceptable carrier.

[0031] In one embodiment, the boron carrier composition further comprises one or more of fructose, disodium undecylmercaptododecyl and its dimer, boron dendritic polymer-EGF bioconjugate, EGFR monoclonal antibody-borate conjugate, FR-targeting boron-containing liposomes, FR-targeting boron-containing nanoparticles, and borate porphyrin.

[0032] In another aspect, the present invention provides the use of the compounds of the invention in the preparation of a medicament for the treatment or diagnosis of cancer. The compounds of the invention achieve a therapeutic purpose by being highly enriched in tumors via the LAT-1 transporter. The cancer can be a cancer that expresses or overexpresses the LAT-1 transporter.

[0033] In one implementation, the drug is a boron carrier for use in oncology-therapeutic integration or boron neutron capture therapy.

[0034] In one implementation, the cancer is selected from squamous cell carcinoma, lung cancer, peritoneal cancer, hepatocellular carcinoma, gastric cancer, melanoma, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, uterine cancer, salivary gland cancer, kidney cancer, liver cancer, prostate cancer, vulvar cancer, thyroid cancer, liver cancer, head and neck cancer, B-cell lymphoma, leukemia, or pituitary adenoma.

[0035] The advantages of this invention include:

[0036] (1) This invention uses 18 Compounds of formula I with the same chemical structure before and after the F label, such as (S)-BBPA and [ 18 F](S)-BBPA is a therapeutic drug that can be used for both tumor diagnosis and BNCT treatment, providing reliable in vivo drug distribution results through its identical chemical structure.

[0037]

[0038] (2) The structure contains two B atoms, which has higher B delivery efficiency.

[0039] (3) The method of the present invention achieves fluorination of a single boron.

[0040] (4) The compounds of the present invention have high uptake in tumors.

[0041] (5) The present invention provides a novel diagnostic and therapeutic boron carrier, such as (S)-BBPA, for obtaining the dynamic distribution of boron carriers, for treatment planning before BNCT, and can also be used directly for BNCT.

[0042] (6) This invention provides a new method for preparing the compounds of this invention.

[0043] (7) Compared with (R)-BBPA, (S)-BBPA has the same or better therapeutic effect in vivo, with fewer side effects and lower background uptake. Brief description of the attached diagram

[0044] Figure 1 Radio-HPLC chromatogram of the prepared [18F](S)-BBPA.

[0045] Figure 2 Radio-HPLC chromatogram of [18F](S)-BBPA shows that [18F](S)-BBPA remains adequately stable in a simulated in vivo environment over a 4-hour timescale (two 18F half-lives).

[0046] Figure 3 Image obtained by PET / CT of mice 15 minutes after tumor cell injection.

[0047] Figure 4 Figure: A comparison of imaging contrast between (S)-BBPA and (R)-BBPA.

[0048] Figure 5 : A graph showing the therapeutic effects of (S)-BBPA and (R)-BBPA on tumors in mice.

[0049] Figure 6 Figure: Effects of (S)-BBPA and (R)-BBPA on mouse body weight.

[0050] Figure 7 Graph showing the radioactivity intensity of cells measured using a gamma counter.

[0051] Figure 8A 1H-NMR and 19F-NMR spectra of -B:(S)-BBPA.

[0052] Figure 9 HPLC-MS results of (R)-BBPA. Detailed Implementation

[0053] This invention provides compounds of formula I or pharmaceutically acceptable salts thereof:

[0054]

[0055] The compounds of this invention can be L-type or S-type. These compounds can be used in positron emission tomography (PET) imaging or boron neutron capture therapy.

[0056] In formula (I), R is either hydrogen or alkyl. "alkyl" refers to a saturated linear hydrocarbon group. For example, alkyl can be methyl, ethyl, propyl, butyl, pentyl, etc. Preferably, the R group is methyl.

[0057] In equation (I), -BF3 - At least one fluorine atom in it is radioactively labeled. For example, 1, 2, or 3 fluorine atoms are radioactively labeled. 18 F. -BF3 - The boron atoms in it can be natural boron.

[0058] In formula (I), the boron atom bonded to the benzene ring is 10 B or natural boron.

[0059] The present invention also provides compounds of formula II or pharmaceutically acceptable salts thereof:

[0060] The R group is hydrogen or an alkyl group, preferably methyl.

[0061] The present invention also provides boron carrier compositions comprising the compounds of the present invention and a pharmaceutically acceptable carrier. The boron carrier compositions may also comprise fruit acids, or may comprise other boron carriers, such as one or more of the following: undecylmercaptododecyl disodium salt and its dimer, boron-derived dendritic polymer-EGF bioconjugates, EGFR monoclonal antibody-borate conjugates, FR-targeting boron-containing liposomes, FR-targeting boron-containing nanoparticles, and borate porphyrins.

[0062] The present invention also provides a method for preparing the compound. The method may include one or more of the following steps:

[0063] (1) p-bromophenylethanol Transformed into compound 1

[0064] (2) Converting compound 1 into compound 2 with the addition of N-methyliminoacetic acid.

[0065] (3) Convert compound 2 into compound 3

[0066] (4) Convert compound 3 into compound 4

[0067] (5) Convert compound 4 into compound 5 Preferred

[0068] (6) Convert compound 5 into compound 6 Preferred as well as

[0069] (7) Convert compound 6 into compound 7 Preferred

[0070] (8) Convert compound 7 into compound 8 Preferred as well as

[0071] (9) Convert compound 8 to Preferred

[0072] In step (1), p-bromophenylethanol can be dissolved in anhydrous tetrahydrofuran, cooled (e.g., -78°C), and a solution of n-butyllithium / hexane can be added. The solution gradually turns yellow and then becomes a creamy white paste. The mixture is stirred for 15 min (e.g., at -78°C). Triisopropyl borate is then added dropwise, and the solution becomes clear. The reaction is continued for 20 min (e.g., at -78°C). The mixture is then brought to room temperature, hydrochloric acid is added, and the mixture is stirred at room temperature. The liquid-liquid phase is separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, washed with saturated sodium chloride, dried over anhydrous sodium sulfate, and the solvent is removed under vacuum to obtain a white solid compound 1.

[0073] In step (2), compound 1 can be dissolved in toluene, and then reacted with DMSO and N-methyliminoacetic acid to obtain compound 2.

[0074] In step (3), compound 2 can be dissolved in a mixed solvent of anhydrous dichloromethane and anhydrous tetrahydrofuran, DMP oxidant is added, and then sodium bicarbonate powder is added to react. Then, saturated sodium thiosulfate solution and saturated sodium bicarbonate solution are added and stirred. The insoluble matter is removed by filtration, the organic phase is separated, the aqueous phase is extracted with ethyl acetate, the organic phases are combined, washed with saturated sodium chloride, dried with anhydrous sodium sulfate, and the solvent is removed under vacuum. The mixture can be separated by silica gel column chromatography to obtain a white solid compound 3.

[0075] In step (4), compound 3 can be dissolved in anhydrous tetrahydrofuran, (S)-tert-butylsulfinamide can be added, and tetraisopropyl titanate can be added dropwise while stirring at room temperature. The reaction is quenched with water and stirred, and the insoluble matter is removed by filtration to separate the organic phase. The aqueous phase is extracted with ethyl acetate, the organic phases are combined, washed with saturated sodium chloride, dried over anhydrous sodium sulfate, and the solvent is removed under vacuum. Compound 4, a yellow crystalline compound, can be obtained by silica gel column chromatography.

[0076] In step (5), PCy3·HBF4 is added to 1 mL of toluene, followed by CuSO4·5H2O and 110 μL of deionized water, and the mixture is stirred vigorously at room temperature for 10 minutes. Then, benzylamine is added under nitrogen protection, immediately forming a deep blue catalyst. The reaction system is maintained at a low temperature (e.g., 0-40 °C, e.g., 0 °C), and compound 4 and B2pin2 are added. The reaction system is then brought back to room temperature, and the reaction proceeds until TLC shows complete disappearance of the reactants. The reaction mixture is washed with saturated EDTA, followed by washing with saturated brine. The organic phases are combined and dried over Na2SO4-free conditions, and the organic solvent is removed under vacuum to give a yellow oily liquid compound 5.

[0077] In step 6, compound 5 can be dissolved in methanol, and NaOH solution is added, with stirring at room temperature. HPLC analysis confirms the disappearance of compound 5 and the formation of compound 6. Subsequently, KHF2 solution is added dropwise to the reaction mixture, the pH of the solution is measured, and an appropriate amount of hydrochloric acid is added (e.g., until pH < 5), with stirring at room temperature. HPLC confirms the disappearance of the starting material and the formation of compound 7. Compound 7 can be purified using preparative HPLC to obtain a white powder.

[0078] In step 7, HCl can be added dropwise to the compound 7 powder, followed by stirring at room temperature (e.g., for 1 hour). HPLC confirms the disappearance of the starting material and the formation of BBPA, and preparative HPLC yields a white powder BBPA (e.g., (S)-BBPA).

[0079] In step (8), BBPA (e.g., (S)-BBPA) can be dissolved in water, then pyridazine-HCl buffer can be added, followed by water. 18 F-aqueous solution. The reaction mixture was reacted (e.g., at 85°C for 15 min), followed by quenching with physiological saline and removal of free fluoride ions with a Sep-Pak Alumina Light cartridge to obtain the final product.

[0080] This invention provides a method for treating or diagnosing cancer using a boron carrier composition. This invention also provides the use of the boron carrier composition in the preparation of a medicament for treating or diagnosing cancer. The medicament may be a boron carrier for therapeutic or boron neutron capture therapy. This invention further provides a boron carrier composition for treating or diagnosing cancer.

[0081] The terms “cancer” and “cancerous” refer to or describe a physiological condition in mammals characterized by unregulated cell growth. Examples of cancer include, but are not limited to, carcinomas, lymphomas, blastomas, sarcomas, and leukemias. More specific examples of such cancers include squamous cell carcinoma, lung cancer (including small cell lung cancer, non-small cell lung cancer, lung adenocarcinoma, and lung squamous cell carcinoma), peritoneal cancer, hepatocellular carcinoma, gastric cancer (including gastrointestinal cancer), melanoma, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine cancer, salivary gland cancer, kidney cancer, liver cancer, prostate cancer, vulvar cancer, thyroid cancer, liver cancer, and various types of head and neck cancers, as well as B-cell lymphomas (including low-grade / follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate-grade...). Follicular NHL; intermediate diffuse NHL; advanced immunoblastic NHL; advanced lymphoblastic NHL; advanced small aneuploid NHL; storage disease NHL; mantle cell lymphoma; AIDS-associated lymphoma; and Waldenström's macroglobulinemia); chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); hairy cell leukemia; chronic myeloid leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal angiogenesis associated with congenital melanocytic leukemia, edema (such as that associated with brain tumors), and Meigs syndrome.

[0082] The following exemplary embodiments are provided to further illustrate the invention. It should be understood that these embodiments are merely exemplary and not limiting, and the invention is defined only by the appended claims.

[0083] Example

[0084] Example 1: Preparation of the compound

[0085] Preparation of (S)-BBPA

[0086] Synthesis scheme

[0087]

[0088] 5 mmol of p-bromophenylethanol (0.7 mL) was dissolved in 50 mL of anhydrous tetrahydrofuran and cooled to -78 °C. A solution of n-butyllithium / hexane (12 mmol, 2.4 eq) was added dropwise; the solution gradually turned yellow and then became a creamy white paste. The mixture was stirred at -78 °C for 15 min. Triisopropyl borate (15 mol, 3.5 mL, 3 eq) was then added dropwise; the solution became clear, and the reaction was continued at -78 °C for 20 min. The mixture was then brought to room temperature, and 50 mL of 10% hydrochloric acid was added. The mixture was stirred at room temperature for 15 min. The aqueous phase was extracted with ethyl acetate (20 mL × 3). The organic phases were combined, washed with saturated sodium chloride (30 mL × 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum to give compound 1 (0.66 g, 80%) as a white solid. The compound did not require further purification and was used directly in the next reaction. 1H NMR (400MHz, Methanol-d4) δ7.60–6.94 (m, 4H), 3.75 (t, J = 7.1Hz, 2H), 2.82 (t, J = 7.1Hz, 2H).

[0089] Compound 1 (0.66 g, 4 mmol) was dissolved in 16 mL of toluene, followed by the addition of 1.6 mL of DMSO and then N-methyliminoacetic acid (647 mg, 4.4 mmol, 1.1 eq.). The mixture was refluxed, and a separatory funnel filled with toluene was installed. The reaction was stopped after approximately 2 hours. The organic solvent was removed under vacuum, and the mixture was separated by silica gel column chromatography to give compound 2 (650 mg, 59%) as white crystals. ¹H NMR (400 MHz, Methanol-d⁴) δ 7.53–7.10 (m, 4H), 4.35–3.96 (m, 4H), 3.75 (t, J = 7.0 Hz, 2H), 3.31 (s, 3H), 2.82 (t, J = 7.1 Hz, 2H).

[0090] Compound 2 (1.1 g, 4 mmol) was dissolved in a mixed solvent of 40 mL anhydrous dichloromethane and 40 mL anhydrous tetrahydrofuran. DMP oxidant (1.7 g, 4 mmol, 1 eq.) was added, followed by sodium bicarbonate powder (3.36 g, 40 mmol, 10 eq.). The reaction was allowed to proceed at room temperature for 1 hour. Then, 40 mL of saturated sodium thiosulfate solution and 40 mL of saturated sodium bicarbonate solution were added, and the mixture was stirred for 15 minutes. The insoluble matter was removed by filtration, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (20 mL × 3). The organic phases were combined, washed with saturated sodium chloride (30 mL × 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. Separation by silica gel column chromatography yielded a white solid, compound 3 (541 mg, 49%). 1H NMR (400MHz, Acetone-d6) δ9.74 (s, 1H), 7.41 (dd, J = 100.7, 7.9Hz, 4H), 4.48–4.07 (m, 4H), 2.75 (s, 3H).

[0091] Compound 3 (541 mg, 1.97 mmol) was dissolved in 20 mL of anhydrous tetrahydrofuran, and (S)-tert-butylsulfinamide (477 mg, 3.94 mmol, 2 eq.) was added. Tetraisopropyl titanate (3.94 mmol, 1165 μL, 1.2 eq., possibly inconsistent with Ti(OPri)4 in the synthetic scheme) was added dropwise, and the mixture was stirred at room temperature for 2 hours. The reaction was quenched with 20 mL of water and stirred for 10 min. The insoluble matter was removed by filtration, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (20 mL × 3). The organic phases were combined, washed with saturated sodium chloride (30 mL × 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. Separation by silica gel column chromatography yielded yellow crystalline compound 4 (490 mg, 66%). 1H NMR (400MHz, Acetone-d6) δ 8.07 (s, 1H), 7.43 (dd, J = 83.2, 7.9Hz, 4H), 4.51–4.03 (m, 4H), 3.91 (d, J = 5.1Hz, 2H), 2.73 (s, 3H), 1.12 (s, 9H).

[0092] PCy3·HBF4 (2.4 mg, 6.6 μmol, 5 mol%) was added to 1 mL of toluene, followed by CuSO4·5H2O (1.65 mg, 6.6 μmol, 5 mol%) and 110 μL of deionized water. The mixture was stirred vigorously at room temperature for 10 minutes. Then, benzylamine (3 μL, 27 μmol, 20 mol%) was added under nitrogen protection, immediately forming a deep blue catalyst. The reaction mixture was maintained at 0 °C, and compound 4 (50 mg, 132 μmol, 1.0 eq.) and B2pin2 (67 mg, 264 μmol, 2.0 eq.) were added. The reaction mixture was then brought back to room temperature and reacted for 1 hour until TLC showed complete disappearance of the reactants. The reaction mixture was washed with saturated EDTA (2 × 5 mL) and then with saturated brine (5 mL). The organic phases were combined, dried over Na2SO4-free conditions, and the organic solvent was removed under vacuum to give a yellow oily liquid compound 5 (49 mg, 75%). The crude product can be used directly in the next reaction without purification.

[0093] Compound 5 (49 mg, 99 μmol, 1.0 eq.) was dissolved in 1 mL of methanol, and 1 mL of 1 M NaOH solution (1 mmol, 10 eq.) was added. The mixture was stirred at room temperature for one hour. HPLC analysis confirmed the disappearance of compound 5 and the formation of compound 6. Subsequently, 0.33 mL of 3 M KHF2 solution (10 eq.) was added dropwise to the reaction mixture, the pH of the solution was measured, and an appropriate amount of hydrochloric acid was added until the pH was <5. The mixture was stirred at room temperature for 4 hours. HPLC (C18, phase A: water / 0.1% TFA, phase B: acetonitrile, 0–15 min: 95% A–5% A, remainder B) confirmed the disappearance of the starting material and the formation of compound 7. The compound 7 (24 mg, 55%) was purified using preparative HPLC to obtain a white powder.

[0094] 1.1 mL of 1M HCl (1.1 mmol, 20 eq.) was added dropwise to compound 7 powder (24 mg, 54 μmol, 1.0 eq.), followed by stirring at room temperature for 1 hour. HPLC confirmed the disappearance of the starting material and the formation of BBPA. Preparative HPLC (C18, phase A: water / 0.1% TFA, phase B: acetonitrile, 0–15 min: 95% A–5% A, remainder B) yielded a white powder (S)-BBPA (9.3 mg, 74%). 19 FNMR(400MHz,D2O,ppm):147.65.LC-MS:Found:232.1(MS - ),Calculated:232.1.

[0095] Radiochemical labeling

[0096] Dissolve (S)-BBPA (0.3 mg) in 50 μL of water, then add 5 μL of pyridazine-HCl buffer (1.0 M, pH ~2.0), followed by water. 18 F-aqueous solution (30 μL, 370 MBq). The reaction mixture was reacted at 85 °C for 15 min, followed by quenching with 0.5 mL of physiological saline, and removal of free fluoride ions with a Sep-Pak Alumina Light cartridge to obtain the final product. 18 F](S)-BBPA (~148 MBq, RCY 40%). Radio-HPLC results are as follows: Figure 1 (HPLC method, Phase A: acetonitrile, Phase B: water / 0.1% TFA; 20% A, balance B).

[0097] Preparation of (R)-BBPA

[0098] Synthesis scheme

[0099]

[0100] As shown above, compounds 2 through 7 and (R)-BBPA were synthesized from commercially available p-bromophenylethanol (compound 1) as the starting compound.

[0101] 5 mmol of p-bromophenylethanol (0.7 mL, compound 1) was dissolved in 50 mL of anhydrous tetrahydrofuran and cooled to -78 °C. A solution of n-butyllithium / hexane (12 mmol, 2.4 eq) was added dropwise; the solution gradually turned yellow and then became a creamy white paste. The mixture was stirred at -78 °C for 15 min. Triisopropyl borate (15 mol, 3.5 mL, 3 eq) was then added dropwise; the solution became clear, and the reaction was continued at -78 °C for 20 min. The mixture was then brought to room temperature, and 50 mL of 10% hydrochloric acid was added. The mixture was stirred at room temperature for 15 min. The aqueous phase was extracted with ethyl acetate (20 mL x 3). The organic phases were combined, washed with saturated sodium chloride (30 mL x 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum to give a white solid, compound 2 (0.66 g, 80%). No further purification was required; the compound was used directly in the next reaction. Compound 2: 1H NMR (400MHz, Methanol-d4) δ 7.60–6.94 (m, 4H), 3.75 (t, J = 7.1Hz, 2H), 2.82 (t, J = 7.1Hz, 2H).

[0102] Compound 2 (0.66 g, 4 mmol) was dissolved in 16 mL of toluene, 1.6 mL of DMSO was added, followed by N-methyliminoacetic acid (647 mg, 4.4 mmol, 1.1 eq.). The mixture was refluxed, and a separatory funnel filled with toluene was installed. The reaction was stopped after approximately 2 hours. The organic solvent was removed under vacuum, and the mixture was separated by silica gel column chromatography to give compound 3 (650 mg, 59%) as white crystals. Compound 3: 1H NMR (400 MHz, Methanol-d4) δ 7.53–7.10 (m, 4H), 4.35–3.96 (m, 4H), 3.75 (t, J = 7.0 Hz, 2H), 3.31 (s, 3H), 2.82 (t, J = 7.1 Hz, 2H).

[0103] Compound 3 (1.1 g, 4 mmol) was dissolved in a mixed solvent of 40 mL anhydrous dichloromethane and 40 mL anhydrous tetrahydrofuran. DMP oxidant (1.7 g, 4 mmol, 1 eq.) was added, followed by sodium bicarbonate powder (3.36 g, 40 mmol, 10 eq.). The reaction was carried out at room temperature for 1 hour. Then, 40 mL of saturated sodium thiosulfate solution and 40 mL of saturated sodium bicarbonate solution were added, and the mixture was stirred for 15 minutes. The insoluble matter was removed by filtration, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (20 mL x 3). The organic phases were combined, washed with saturated sodium chloride (30 mL x 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. Separation by silica gel column chromatography yielded a white solid, compound 4 (541 mg, 49%). Compound 4: 1H NMR (400MHz, Acetone-d6) δ 9.74 (s, 1H), 7.41 (dd, J = 100.7, 7.9 Hz, 4H), 4.48–4.07 (m, 4H), 2.75 (s, 3H).

[0104] Compound 4 (541 mg, 1.97 mmol) was dissolved in 20 mL of anhydrous tetrahydrofuran, and tert-butylsulfinamide (477 mg, 3.94 mmol, 2 eq.) was added. Tetraisopropyl titanate (3.94 mmol, 1165 μl, 2 eq.) was added dropwise, and the mixture was stirred at room temperature for 2 hours. The reaction was quenched with 20 mL of water and stirred for 10 min. The insoluble matter was removed by filtration, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (20 mL x 3). The organic phases were combined, washed with saturated sodium chloride (30 mL x 2), dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. Separation by silica gel column chromatography yielded yellow crystalline compound 5 (490 mg, 66%). Compound 5: 1H NMR (400MHz, Acetone-d6) δ 8.07 (s, 1H), 7.43 (dd, J = 83.2, 7.9 Hz, 4H), 4.51–4.03 (m, 4H), 3.91 (d, J = 5.1 Hz, 2H), 2.73 (s, 3H), 1.12 (s, 9H).

[0105] PCy3·HBF4 (124 mg, 6 mol%) was added to 10 mL of toluene, followed by CuSO4·5H2O solution (82 mg, 6 mol%) and deionized water (6 mL), and the mixture was stirred vigorously at room temperature for 10 min. Then, benzylamine (153 μL, 0.25 eq.) was added under nitrogen protection, immediately forming a deep blue catalyst. An additional 50 mL of toluene was added, maintaining the reaction system at 0 °C, and compound 5 (2.2 g, 5.7 mmol) and B2pin2 (2.8 g, 2.0 eq.) were added. The reaction system was then brought back to room temperature and reacted for 1 hour until TLC showed complete disappearance of the reactants. The reaction mixture was washed with saturated EDTA (2 x 50 mL), followed by washing with saturated brine (50 mL). The organic phases were combined and dried over Na2SO4-free conditions, and the organic solvent was removed under vacuum to give a yellow oily liquid compound 6 (3.0 g). The crude product was used directly in the next reaction without purification.

[0106] Compound 6 (3.0 g, 5.7 mmol) was dissolved in 50 mL of acetonitrile, and 57 mL of 1 M NaOH solution was added. The mixture was stirred at room temperature for half an hour. Then, 4.7 mL of concentrated hydrochloric acid was added to neutralize the reaction, yielding a reaction mixture containing compound 7, which was used directly in the next reaction step.

[0107] Add 14.25 mL of 3M KHF2 solution (10 eq.) to the reaction mixture containing compound 7, then add 4.7 mL of concentrated hydrochloric acid dropwise until pH < 0, and react at room temperature for 2 hours. Evaporate HCl under reduced pressure at 30 °C to lower the acidity to pH ~ 2, and react for 30 min. Add acetonitrile for azeotropic drying, wash the solid with acetonitrile, discard the insoluble matter, and purify the acetonitrile phase using pre-HPLC (phase A: acetonitrile, phase B: water / 0.1% TFA; 0–2 min: 5% A, 2–11 min: 5% A–50% A, remainder B) to obtain (R)-BBPA.

[0108] Example 2: Study on radioactivity stability

[0109] The [to be marked] 18 F](S)-BBPA was added to 50% fetal bovine serum and stored at 37°C. At specific times, a small amount was taken out and analyzed using Radio-HPLC (C18, phase A: water / 0.1% TFA, phase B: acetonitrile, 0-15 min: 80% + 20% B) to determine the radioactive composition. The signal was expressed as normalized intensity, i.e., the difference between the maximum and minimum signal values ​​was uniformly set to 1. The results showed that within a 4-hour timescale (two 18F half-lives), [ 18 F](S)-BBPA remains sufficiently stable in the simulated in vivo environment, as shown in the results. Figure 2 As shown.

[0110] Example 3: PET Animal Imaging

[0111] Establishment of animal tumor models: Tumor cells (BGC823 human gastric cancer cells, B16-F10 mouse melanoma, and GH3 rat pituitary adenoma) were cultured in a 5% CO2 incubator until confluence. Mice were selected at 4-6 weeks of age, with the right shoulder shaved, and approximately 10 [unclear text - possibly a number of cells] were [unclear text - possibly a number of cells]. 6 One tumor cell was suspended in 50 μL of PBS and injected into the right shoulder of a mouse. The mouse was then fed in a sterile environment for 1-2 weeks until the tumor volume reached 200-400 mm². 3 The tumor model has been established.

[0112] The labeled compound [ 18 F](S)-BBPA or [ 18 F](R)-BBPA was dissolved in 0.2 ml of physiological saline at a concentration of 200 μCi and injected via the tail vein into mice with tumors implanted in their shoulder. One hour after injection, a 15-minute PET / CT scan was performed to reconstruct the images. The results are as follows: Figure 3 As shown. 18 F](S)-BBPA or [ 18 F](R)-BBPA can both indicate the location of the tumor. 18 Although F](S)-BBPA has low tumor uptake, it also has low imaging background and muscle uptake, resulting in high actual imaging contrast, as shown in the quantitative analysis results. Figure 4 As shown.

[0113] Example 4: Low-dose boron neutron capture therapy experiment

[0114] BPA, (S)-BBPA, and (R)-BBPA containing natural boron were dissolved in physiological saline at a dose of 100 mg / kg and injected via the tail vein into mice with B16-F10 and melanoma implanted in their shoulders. BNCT treatment was performed 1 hour later, and tumor size was measured 21 days later and compared with groups that received the relevant drugs alone and groups that received neutron beam irradiation alone.

[0115] from Figure 5 and Figure 6As can be seen, (S)-BBPA and (R)-BBPA, with their two boron atoms, showed significant efficacy in combined neutron beam therapy, while BPA, with its lower boron concentration, was less effective than BBPA at low doses. It was also noted that while both (S)-BBPA and (R)-BBPA effectively inhibited tumor growth, (R)-BBPA significantly reduced body weight, possibly due to higher background uptake in muscle, leading to stronger side effects. In conclusion, both (S)-BBPA and (R)-BBPA, with their two boron atoms in their molecular structure, can serve as highly efficient boron carriers. However, the lower background uptake of (S)-BBPA results in better boron concentration differentiation and reduces the occurrence of side effects. This is significant for shortening treatment cycles, reducing drug dosage, lowering radiation dose and patient costs, and minimizing complications and side effects.

[0116] Example 5: Study on (S)-BBPA uptake mechanism

[0117] In cellular uptake experiments, the mechanism of (S)-BBPA entry into cells can be studied through competitive inhibition by adding high concentrations of amino acid transporter substrates or inhibitors. In this study, alanine (Ala), glutamate (Glu), BCH (2-Aminobicyclo-(2,2,1)-heptane-2-carboxylicacid), BPA, and GPNA (L-γ-Glutamyl-p-nitroanilide) were selected as competitive substrates or inhibitors and compared with the control group.

[0118] B16-F10 mouse melanoma cells cultured under standard conditions were transferred to 1.5 ml EP tubes (4 × 10⁶ cells per tube). 5 Centrifuge at 150xg for 2 min and remove the supernatant. Prepare a series of PBS solutions containing natural amino acids (25 mM) or inhibitors (10 mM), and add them to the above-mentioned EP tubes containing cells (0.5 ml, n = 6), including a control group containing ordinary PBS. Then add 10 μl of [ 740 kBq] to each tube. 18 F](S)-BBPA in physiological saline. The cells were incubated at 37°C for 60 min, then centrifuged at 150 x g for 2 min, the supernatant was discarded, and the cells were washed with PBS (1 ml × 2). Finally, a gamma counter was used to measure the radioactivity intensity of the cells in each tube, and the ratio between each group and the control group was calculated. The results are as follows: Figure 7 As shown.

[0119] Ala is a substrate for both the ASC and A amino acid transport systems, while Glu is an X... c- The substrate of the transporter, neither of which can inhibit [ 18 F]BBPA uptake; while BCH is a specific inhibitor of the LAT-1 transporter, which significantly inhibits [ 18 The uptake of (S)-BBPA indicates that it enters tumor cells via LAT-1 transport. GPNA, a specific inhibitor of the ASCT2 transporter, cannot inhibit the uptake of (S)-BBPA. (S)-BBPA is a boronic acid derivative of BPA, and BPA significantly inhibits its uptake, with an inhibitory effect even superior to BCH. This demonstrates that although (S)-BBPA and BPA have different chirality, they share a high degree of biosimilarity in their transport pathways, exhibiting a completely identical biological pathway. Therefore, the basic conclusion is that (S)-BBPA is highly enriched in tumors via the LAT-1 transporter, which is consistent with the transport mechanism of BPA.

[0120] In summary, (S)-BBPA and BPA share high biosimilarity and primarily enter cells via LAT-1 transport. LAT-1 is an amino acid transporter highly expressed in tumor cells; therefore, (S)-BBPA can achieve high uptake in tumor tissue cells, which is beneficial for high-contrast imaging in PET and high-concentration boron enrichment for efficient BNCT.

[0121] While the invention has been described with reference to specific embodiments thereof, those skilled in the art will understand that various changes can be made and equivalents can be substituted without departing from the spirit and scope of the invention. Furthermore, numerous modifications can be made to adapt the specific circumstances, materials, compositions, methods, or one or more method steps to the purpose, spirit, and scope of the invention. All such modifications are intended within the scope of the appended claims.

Claims

1. A compound of formula I ###0001### wherein the R group is hydrogen, wherein the compound is in S configuration. Formula I, 6. A boron carrier composition comprising one or more compounds according to any one of claims 1 to 5 and a pharmaceutically acceptable carrier.

2. The compound according to claim 1, wherein the boron atom attached to the phenyl ring is 10 B or natural boron.

3. The compound according to claim 1 or 2, wherein at least one of the fluorine atoms in -BF3 - is a radioactive fluorine atom.

4. The compound according to claim 3, wherein the radioactive fluorine atom is 18 F.

5. The compound according to claim 1 or 2, wherein in -BF3 the boron atom is natural boron. - in which the boron atom is natural boron.

7. The boron carrier composition according to claim 6, further comprising one or more of fructose, disodium mercaptododecahydride borate and its dimer, boronated dendrimer-EGF bioconjugate, EGFR monoclonal antibody-borate conjugate, FR-targeted boron-containing liposome, FR-targeted boron-containing nanoparticle and borate porphyrin.

9. The method according to claim 8, comprising one or more of the following steps:

8. A process for the preparation of a compound according to any one of claims 1 to 5 comprising the steps of: by adding compound 6 Add KHF2 solution and add hydrochloric acid to pH < 5 to yield compound 7 and further acidification to give a compound according to any one of claims 1-5. and (1) converting p-bromophenethyl alcohol to compound 1 ; (2) Compound 1 is converted to Compound 2 in the presence of N-methyl imino acetic acid ; (3) converting compound 2 to compound 3 ; (4) converting compound 3 to compound 4 ; (5) converting compound 4 to compound 5 ; (6) converting compound 5 to compound 6 ; and (7) converting compound 6 to compound 7 ; (8) converting compound 7 to compound 8 ​ 10. Use of a compound according to any one of claims 1 to 5 or a boron carrier composition according to claim 6 or 7 for the manufacture of a medicament for the diagnosis of a cancer selected from gastric cancer, melanoma or pituitary tumor. (9) converting compound 8 to .

11. Use of a compound according to any one of claims 1 to 5 or a boron carrier composition according to claim 6 or 7 for the manufacture of a medicament for the treatment of melanoma.

12. Use according to claim 10 or 11, wherein the medicament is a boron carrier for tumor diagnosis and therapy integration or boron neutron capture therapy. ​

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