Tracer precursor compound targeting FAP, preparation and application thereof

Abstract

The FAPI precursor compound with a brand new structure provided by the invention is prepared by adopting a batch of commercially available compound as an initial raw material, and the FAPI precursor compound provided by the invention is used for preparing an FAP tracer (such as 18F-NOTA-FAPI), so that commercialized expanded production of drugs and drug cost control can be realized, and clinical medication requirements can be better met.

Description

This application is a divisional application of the Chinese patent application with application number 2024112461337, application date September 6, 2024, and invention name “A tracer precursor compound targeting FAP, preparation and application thereof”. Technical Field

[0001] The present invention relates to the field of compound preparation, and in particular to a tracer precursor compound targeting FAP, and its preparation and application. Background Art

[0002] Fibroblast activating protein inhibitor (FAPI) is a small molecule enzyme activity inhibitor that has high affinity and specificity for FAP on the surface of tumor-associated fibroblasts (CAFs). 68 Ga labeled) can be used as a FAP tracer in the field of nuclear medicine for PET imaging, which has high sensitivity and is conducive to the non-invasive early diagnosis, staging, differential diagnosis and prognosis evaluation of FAP-positive diseases.

[0003] 18 F-NOTA-FAPI (clinical trial registration number CTR20230410) is a positron-emitting nuclide 18 The F-labeled FAP-targeted PET tracer has been approved for clinical PET studies of FAP solid tumors. 18 Preparation method of F-NOTA-FAPI tracer precursor compound NOTA-FAPI02 (see page 3 of its specification):

[0004] The process uses compound 1 as the starting compound, and compound 1, compound NOTA-NHS and N,N-diisopropylethylamine are added to N,N-dimethylformamide in sequence. The reaction system is stirred at room temperature and monitored by HPLC until the reaction is completed. The crude product is purified by reverse column and freeze-dried to obtain the purified compound NOTA-FAPI02. The commercial purchase and application of the raw material compound NOTA-NHS used in this process are greatly restricted, which is not conducive to the subsequent commercial expansion of drug production and drug cost control. Summary of the invention

[0005] In view of the above problems, the present invention provides a new structure 18 F-NOTA-FAPI tracer precursor compound, through which the precursor compound can be further obtained 18F-NOTA-FAPI tracer, the acquisition of this precursor compound can get rid of the limitations of commercial raw material sources and scale, and ultimately achieve 18 The invention also relates to a method for preparing the FAP-targeting tracer precursor compound, and the FAP-targeting tracer precursor compound in the preparation of the FAP-targeting tracer (such as 18 F-NOTA-FAPI).

[0006] Specifically, the present invention provides a tracer precursor compound targeting FAP, the structure of which is shown in formula (I):

[0007] The present invention also provides a method for preparing the above-mentioned tracer precursor compound targeting FAP, and the preparation method comprises the following preparation route:

[0008] The above preparation route is a multi-step continuous reaction, that is, the process of preparing intermediate B from compound A and further obtaining the compound of formula (I) is a continuous feeding process.

[0009] Furthermore, the preparation route comprises the following steps: S1, taking p-toluenesulfonic acid monohydrate and compound A and placing them in an appropriate amount of acetonitrile, after temperature control reaction, the reaction solution is subjected to reduced pressure rotary evaporation to remove the solvent to obtain intermediate B; S2, mixing NOTA-Bis(tBuEster) and HATU in an appropriate amount of DMF solution to obtain an active ester solution; S3, taking the intermediate B obtained in S1 and DIPEA, mixing them in an appropriate amount of DMF solution, adding the active ester solution, and reacting under controlled temperature; S4, adding an appropriate amount of purified water to the reaction system, adding an appropriate amount of DCM for extraction, collecting the organic phase, and performing rotary evaporation under reduced pressure to obtain a crude product of the compound of formula (I); S5. Continue to purify the crude compound of formula (I) by silica gel column chromatography to obtain the purified compound of formula (I).

[0010] Further, the equivalent ratio of compound A and p-toluenesulfonic acid monohydrate in S1 is about 1:2-4; preferably, the equivalent ratio of compound A and p-toluenesulfonic acid monohydrate in S1 is about 1:2, 1:2.5, 1:3, 1:3.5, or 1.4; more preferably, the equivalent ratio of compound A and p-toluenesulfonic acid monohydrate in S1 is 1:3.

[0011] Further, the mass volume ratio of compound A and acetonitrile in S1 is about 1:8-15; preferably, the mass volume ratio of compound A and acetonitrile in S1 is about 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, or 1:15; more preferably, the mass volume ratio of compound A and acetonitrile in S1 is 1:10.

[0012] Furthermore, the temperature of the temperature-controlled reaction in S1 is about 50-80°C; preferably, the temperature of the temperature-controlled reaction in S1 is 60-70°C.

[0013] Furthermore, the vacuum rotary evaporation temperature in S1 is about 30-50°C; preferably, the vacuum rotary evaporation temperature in S1 is 35-45°C.

[0014] Further, the equivalent ratio of the compound A in S1 and the NOTA-Bis(tBuEster) in S2 is about 1:0.5-2; preferably, the equivalent ratio of the compound A in S1 and the NOTA-Bis(tBuEster) in S2 is about 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2; more preferably, the equivalent ratio of the compound A in S1 and the NOTA-Bis(tBuEster) in S2 is 1:1.

[0015] Further, the equivalent ratio of NOTA-Bis(tBuEster) and HATU in S2 is about 1:0.5-2; preferably, the equivalent ratio of NOTA-Bis(tBuEster) and HATU in S2 is about 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2; more preferably, the equivalent ratio of NOTA-Bis(tBuEster) and HATU in S2 is 1:1.2.

[0016] Further, the equivalent ratio of compound A in S1 to DIPEA in S3 is about 1:4-6; preferably, the equivalent ratio of compound A in S1 to DIPEA in S3 is about 1:4.1, 1:4.2, 1:4.3, 1:4.4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, 1:5.5, 1:5.6, 1:5.7, 1:5.8, 1:5.9, or 1:6; more preferably, the equivalent ratio of compound A in S1 to DIPEA in S3 is 1:5.2.

[0017] Furthermore, the temperature of the temperature-controlled reaction in S3 is about 10-40°C; preferably, the temperature of the temperature-controlled reaction in S3 is 20-30°C.

[0018] Further, the mass volume ratio of the compound A described in S1 to the purified water described in S4 is about 1:10-30; preferably, the mass volume ratio of the compound A described in S1 to the purified water described in S4 is about 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, or 1:30; more preferably, the mass volume ratio of the compound A described in S1 to the purified water described in S4 is 1:20.

[0019] Further, the mass volume ratio of the compound A described in S1 to the DCM described in S4 is about 1:10-30; preferably, the mass volume ratio of the compound A described in S1 to the DCM described in S4 is about 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, or 1:30; more preferably, the mass volume ratio of the compound A described in S1 to the DCM described in S4 is 1:20.

[0020] Furthermore, the elution system of the silica gel column chromatography purification in S5 is DCM:MeOH=50:1-10:1.

[0021] Furthermore, S4 also includes the following steps: washing the organic phase with an appropriate amount of purified water and an appropriate amount of saturated sodium chloride solution in sequence, adjusting the system pH to 7-8 during the purified water washing, and drying the washed organic phase over anhydrous sodium sulfate and then performing reduced pressure rotary evaporation to obtain a crude compound of formula (I).

[0022] In some specific embodiments, S4 comprises the following steps: adding an appropriate amount of purified water to the reaction system, adding an appropriate amount of DCM for extraction, collecting the organic phase, washing the organic phase with an appropriate amount of purified water and an appropriate amount of saturated sodium chloride solution in sequence, adjusting the system pH to 7-8 during the purified water washing, and drying the washed organic phase over anhydrous sodium sulfate and then performing reduced pressure rotary evaporation to obtain a crude compound of formula (I).

[0023] The present invention also provides the use of the compound of formula (I) in the preparation of a FAP tracer drug targeting fibroblast activation protein.

[0024] The present invention also provides the use of any of the above-mentioned preparation methods, routes and steps in the preparation of a FAP tracer drug targeting fibroblast activation protein.

[0025] The preparation method of the FAPI precursor compound provided by the present invention uses a batch of commercially available compounds as starting materials, and uses the FAPI precursor compound provided by the present invention to prepare a FAP tracer (such as 18 F-NOTA-FAPI), can realize the commercial expansion of drug production and drug cost control, and better meet the clinical drug needs. In addition, the preparation method of the FAPI precursor compound provided by the present invention adopts a continuous investment route, which reduces the cumbersome processing process of the intermediate product while ensuring the high purity of the final product, not only reduces the demand for equipment and site in the preparation process, but also reduces the use of intermediate process processing and intermediate solvents, and reduces the risk of environmental pollution while controlling production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the mass spectrum of intermediate B; Figure 2 It is the mass spectrum of the compound of formula (I). DETAILED DESCRIPTION

[0027] Unless otherwise defined, technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art.

[0028] The "about" involved in the present invention generally refers to the approximate value of a number, or the result after some approximation. In actual calculations, if the mass of a certain compound is 5.7 grams, if a certain solvent with a mass-to-volume ratio of 1:3 needs to be added, for actual production and application, the actual amount is often measured by rounding, that is, 17 ml is actually measured according to the calculated value of 17.1 ml; similarly, if the mass of a certain compound is 6.8 grams, if a certain solvent with a mass-to-volume ratio of 1:7 needs to be added, for actual production and application, the actual amount is often measured by rounding, that is, 48 ​​ml is actually measured according to the calculated value of 47.6 ml. Therefore, it can be understood that the adjustment of the appropriate range for the convenience / controllability of actual production and application is still within the numerical range provided by the present invention.

[0029]

Abbreviations and compounds

[0030] The present invention is further described below in conjunction with examples. It should be understood that the examples are only used to further illustrate and explain the present invention, and are not intended to limit the present invention. Embodiment 1

[0031] Preparation of intermediate B

[0032] Weigh 23.8240g of p-toluenesulfonic acid monohydrate (3.0eq), add it to a reaction bottle, mix it with 22.9890g of compound A (1.0eq), add 230ml of acetonitrile (based on compound A, 10ml / g), start stirring, and react at 60-70℃. After reacting for 2h, the reaction solution was evaporated under reduced pressure at 35-45℃ to remove the solvent to obtain intermediate B (oil, its MS mass spectrum is shown in Figure 1 ). Embodiment 2

[0033] Preparation of compounds of formula (I)

[0034] 17.2417 g NOTA-Bis(tBuEster) (1.0 eq) and 19.0817 g HATU (1.2 eq) were weighed and added into a reaction bottle, and 69 ml DMF (based on compound A, 3 ml / g) was added and stirred for 30 min to prepare an active ester solution.

[0035] Measure 161 ml of DMF (based on compound A, 7 ml / g), add it to the reaction bottle, mix and stir with the whole batch of intermediate B, add 28.0465 g of DIPEA (5.2 eq), stir for 10 min, add the above prepared active ester solution, control the temperature at 20-30°C, and stir and react for 2 h.

[0036] 460 ml of purified water (based on compound A, 20 ml / g) was added to the system, stirred, and then 460 ml of DCM (based on compound A, 20 ml / g) was added each time for extraction, and extracted 3 times in total. After extraction, the organic phases were combined and washed once with 460 ml of purified water (based on compound A, 20 ml / g) and 460 ml of saturated sodium chloride solution (based on compound A, 20 ml / g) in sequence. When washing with purified water, an appropriate amount of 0.5 mol / L NaHCO3 solution (15 ml in this batch) was used to neutralize the excess acid in the system until the pH of the system was 7-8. The washed organic phase was dried with 206.90 g of anhydrous sodium sulfate, and then subjected to reduced pressure rotary evaporation at 35-45° C. to obtain 57.07 g of a crude compound of formula (I). The crude compound of formula (I) was purified by silica gel column chromatography (DCM:MeOH=50:1-10:1) to obtain 32.02 g of the purified compound of formula (I) (purity: 97.32%, yield: 90.4%, MS spectrum of which is shown in Figure 2 ). Embodiment 3

[0037] 18 Preparation of F-NOTA-FAPI

[0038] 638 ml of TFA (based on the compound of formula I, 20 ml / g) was added to the reaction bottle, mixed with 32.0 g of the compound of formula I (1.0 eq), the temperature was controlled at 33-37° C., and the reaction was stirred for 20 min.

[0039] The reaction solution was added dropwise to 4469 ml MTBE (based on the compound of formula I, 140 ml / g), stirred while adding dropwise, solid was precipitated, and slurry was made. After the addition, suction filtration was performed, and the filter cake was rinsed with an appropriate amount of 638 ml MTBE (638 ml was used in this embodiment). During the rinsing, the MTBE on the filter cake should not be completely removed; after rinsing, the filter cake was transferred to a single-mouth bottle with an appropriate amount of MTBE (638 ml was used in this embodiment), and vacuum rotary evaporation at 35-45°C was performed to purify the NOTA-FAPI compound, and then a general 18 The NOTA-FAPI compound was labeled by F labeling method to obtain FAP tracer 18 F-NOTA-FAPI.

[0040] The above description is only a preferred embodiment, and various modifications and variations of the methods and compositions described in the present invention are obvious to those skilled in the art. Although the present invention is described by specific preferred embodiments, it should be understood that the present invention is not limited to the above specific embodiments. For those skilled in the relevant art, various variations of the modes described in the present invention are still within the scope of protection.

Claims

1. A tracer precursor compound targeting FAP, characterized in that The structure of the tracer precursor compound targeting FAP is shown in formula (I): The precursor compound of formula (I) is obtained by the following preparation method: The preparation method comprises a multi-step continuous reaction, and the preparation method comprises the following steps: S1, taking p-toluenesulfonic acid monohydrate and compound A and placing them in an appropriate amount of acetonitrile, after temperature control reaction, the reaction solution is subjected to reduced pressure rotary evaporation to remove the solvent to obtain intermediate B; S2, mixing NOTA-Bis(tBuEster) and HATU in an appropriate amount of DMF solution to obtain an active ester solution; S3, taking the intermediate B obtained in S1 and DIPEA, mixing them in an appropriate amount of DMF solution, adding the active ester solution, and reacting under controlled temperature; S4, adding an appropriate amount of purified water to the reaction system, adding an appropriate amount of DCM for extraction, collecting the organic phase, and performing rotary evaporation under reduced pressure to obtain a crude product of the compound of formula (I); S5. Continue to purify the crude compound of formula (I) by silica gel column chromatography to obtain the purified compound of formula (I).

2. The precursor compound according to claim 1, characterized in that The equivalent ratio of compound A and p-toluenesulfonic acid monohydrate described in step S1 is 1:2-4.

3. The precursor compound according to claim 1, characterized in that The equivalent ratio of the compound A described in step S1 and the NOTA-Bis(tBuEster) described in step S2 is 1:0.5-2.

4. The precursor compound according to claim 1, characterized in that The equivalent ratio of NOTA-Bis(tBuEster) and HATU described in step S2 is 1:0.5-2.

5. The precursor compound according to claim 1, characterized in that The equivalent ratio of the compound A described in step S1 and the DIPEA described in step S3 is 1:4-6.

6. The precursor compound according to claim 1, characterized in that The elution system of the silica gel column chromatography purification in step S5 is DCM:MeOH=50:1-10:

1.

7. The precursor compound according to claim 1, characterized in that The temperature of the temperature-controlled reaction in step S1 is 50-80°C; the temperature of the temperature-controlled reaction in step S3 is 10-40°C.

8. Use of the tracer precursor compound targeting FAP according to claim 1 in the preparation of a FAP tracer drug targeting fibroblast activation protein.

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