1, 4-diazepane derivative compound and pet probe

Abstract

To provide a new compound capable of specifically detecting OX1R. To provide a compound usable for a OX1R specific PET probe.SOLUTION: A 1, 4-diazepane derivative compound represented by the following general formula (1): wherein R1 represents hydrogen, fluoro, or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with fluoro. R2 is hydrogen, fluoro or a C1-C5 alkyl group which may be substituted with fluoro. R3 represents hydrogen, an alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having 3 to 5 carbon atoms, and the alkyl group and the cycloalkyl group may be each independently substituted with at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and a cycloalkyl group having 3 to 5 carbon atoms. However, at least one of R1 and R2 contains a fluoride atom. ] SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to 1,4-diazepane derivative compounds and PET probes. [Background technology]

[0002] Orexin is a neuropeptide localized in the lateral hypothalamus and its vicinity, and orexin receptors (OXRs) are widely expressed in the brain. Two types of OXRs are known: orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R). OX1R is highly expressed in the locus coeruleus and hypothalamus and is involved in the reward system and autonomic nervous system, while OX2R plays a key role in regulating wakefulness, but the full extent of their physiological roles remains unknown.

[0003] The orexin receptor antagonists suvorexant, lemborexant, and daridorexant, which are dual antagonists of OX1R and OX2R, are used clinically to treat insomnia. On the other hand, although selective OX1R antagonists have been researched and developed, none have yet been used clinically.

[0004] PET (Positron Emission Tomography) is a diagnostic imaging method that uses a radioactive probe that specifically binds to a target substance to non-invasively and selectively image the inside of a living body. The probe is called a PET probe. For example, three types of compounds, namely [ 18 F]THIQ-1, [ 11 C]CW24,[ 18 F]PBC-1 is known (Non-Patent Documents 1 to 3, Figure 1). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Watanabe, H, et al. Synthesis and biological evaluation of F-18 labeled tetrahydroisoquinoline derivatives targeting orexin 1 receptor. Bioorg. Med. Chem. Lett. 2019, 29 (13), 1620-1623. DOI: 10.1016 / j.bmcl.2019.04.044. [Non-patent document 2] Bai, P, et al. A New Positron Emission Tomography Probe for Orexin Receptors Neuroimaging. Molecules 2020, 25 (5), 1018. DOI: 10.3390 / molecules25051018. [Non-patent document 3] Watanabe, H, et al, Synthesis and biological evaluation of novel 18F-labeled phenylbenzofuran-2-carboxamide derivative for detection of orexin 1 receptor in the brain. Bioorg. Med. Chem. Lett. 2021, 43, 128098. DOI: 10.1016 / j.bmcl.2021.128098. Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors believed that specific detection of OX1R would be useful for further clarifying the physiological role of OX1R and the relationship between OX1R and diseases. Furthermore, they believed that specific detection of OX1R in the brain using PET technology would be useful for further clarifying the role and relationship. Such elucidation may also contribute to the further development of drugs, such as drugs for treating insomnia, that target OX1R.

[0007] Therefore, an object of the present disclosure is to provide a novel compound capable of specifically detecting OX1R, and a compound that can be used for a selective PET probe targeting OX1R (OX1R-specific PET probe). [Means for solving the problem]

[0008] The present inventors have newly synthesized various 1,4-diazepane derivative compounds and conducted extensive research, and as a result, have found that a 1,4-diazepane derivative compound represented by the following general formula (1) can specifically bind to OX1R. The present inventors have also found that this compound can be used as an OX1R-specific PET probe. The present invention was completed through further research based on this finding, and the present disclosure encompasses, for example, the following representative inventions. Item 1. A 1,4-diazepane derivative compound represented by the following general formula (1): [ka] [In the formula, R1 represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom.] R2 represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom. R3 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having 3 to 5 carbon atoms, and the alkyl group and the cycloalkyl group may each independently be substituted with at least one group selected from the group consisting of alkyl groups having 1 to 5 carbon atoms and cycloalkyl groups having 3 to 5 carbon atoms. However, at least one of R1 and R2 contains a fluorine atom.] Item 2. The compound according to Item 1, wherein in the general formula, R3 has 1 to 5 carbon atoms in total. Item 3. The compound according to Item 1 or 2, wherein the compound represented by the general formula is a compound selected from the group consisting of the following formulae (1a) to (1g): (1a) A compound in which, in the above general formula, R1 represents a fluorine atom, R2 represents a hydrogen atom, and R3 represents a methyl group. [ka] (1b) A compound in which, in the above general formula, R1 represents a fluorine atom, R2 represents a fluorine atom, and R3 represents a methyl group. [ka] (1c) A compound in which, in the above general formula, R1 represents a hydrogen atom, R2 represents a fluorine atom, and R3 represents a methyl group. [ka] (1d) A compound in which, in the above general formula, R1 represents a methyl group, R2 represents a fluorine atom, and R3 represents a methyl group. [ka] (1e) A compound in which, in the above general formula, R1 represents a methyl group, R2 represents a fluorine atom, and R3 represents a methyl group. [ka] (1f) A compound in which, in the above general formula, R1 represents a methyl group substituted with three fluorine atoms, R2 represents a fluorine atom, and R3 represents a methyl group. [ka] (1g) A compound in which, in the above general formula, R1 represents a fluorine atom, R2 represents a methyl group, and R3 represents a methyl group. [ka] Item 4. Furthermore, at least one of R1 and R2 is a radioisotope 18 The compound according to any one of items 1 to 3, which contains F. Item 5. A composition for a PET probe, comprising the compound according to Item 4. Item 6. Use of the compound according to Item 4 as a PET probe. [Effects of the Invention]

[0009] A compound capable of specifically detecting OX1R can be provided. A compound usable for an OX1R-specific PET probe can be provided. An OX1R-specific PET probe, etc., can be provided using the compound. [Brief explanation of the drawings]

[0010] [Figure 1] The structures of known PET probes ([18F]THIQ-1, [11C]CW24, and [18F]PBC-1) are shown. [Figure 2] 1 shows the structures of Compound 1, Almorexant (negative control), and [ 125 I] 5 I BOM (competitive ligand) used in Test Example 1. [Figure 3] 1 shows the results of an experiment on the distribution of radioactivity in the body in Test Example 2 (Examples 1 and 2). [Figure 4] The structures of compounds 3 to 7 (labeled with 18F) produced in Test Example 4 are shown below. [Figure 5] 1 shows the results of an experiment on internal radioactivity distribution in Test Example 4 (Example 3). [Figure 6] 1 shows the results of an experiment on internal radioactivity distribution in Test Example 4 (Example 4). [Figure 7] 1 shows the results of an experiment on internal radioactivity distribution in Test Example 4 (Example 7). [Figure 8] 1 shows the results of an in vitro autoradiography experiment in Test Example 5 (Example 7). [Figure 9] 1 shows the results of an in vivo binding inhibition experiment in Test Example 5 (Example 7). [Figure 10] 1 shows PET / CT imaging in Test Example 5 (Example 7). [Figure 11] 1 shows the saturation curve of cell binding of [ 125 I]5IBOM. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments included in the present disclosure will be described in more detail. In the present disclosure, "comprise" also means "consist essentially of" or "consist of."

[0012] 1,4-diazepane derivative compounds represented by general formula (1) The present disclosure encompasses a 1,4-diazepane derivative compound represented by the following general formula (1): Hereinafter, such a compound may be referred to as the "compound of the present disclosure."

[0013] [ka] [In the formula, R1 represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom.] R2 represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom. R3 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having 3 to 5 carbon atoms, and the alkyl group and the cycloalkyl group may each independently be substituted with at least one group selected from the group consisting of alkyl groups having 1 to 5 carbon atoms and cycloalkyl groups having 3 to 5 carbon atoms. However, at least one of R1 and R2 contains a fluorine atom.]

[0014] When R1 is an alkyl group having 1 to 5 carbon atoms, examples of the alkyl group having 1 to 5 carbon atoms include linear or branched alkyl groups having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, and a neopentyl group. Preferred examples of the alkyl group include linear or branched alkyl groups having 1 to 4 carbon atoms, and more preferred examples include linear or branched alkyl groups having 1, 2, or 3 carbon atoms.

[0015] In R1, when the alkyl group is substituted with a fluorine atom, the number of the substituents is not limited, and preferably 1, 2 or 3 is exemplified.

[0016] Although not limiting the present disclosure, preferred examples of R1 include a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 3 carbon atoms which may be substituted with the above-mentioned substituents. More preferred examples of R1 include a hydrogen atom, a fluorine atom, or an alkyl group having 1 or 2 carbon atoms which may be substituted with the above-mentioned substituents.

[0017] When R2 is a fluorine atom, the fluorine atom may be present at any position, but is preferably present at the 5th or 6th position of the benzothiazole ring shown in general formula (1), as exemplified by formulas (1b) to (1g) described below.

[0018] When R2 is an alkyl group having 1 to 5 carbon atoms, examples of the alkyl group having 1 to 5 carbon atoms include linear or branched alkyl groups having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, and a neopentyl group. Preferred examples of the alkyl group include linear or branched alkyl groups having 1 to 4 carbon atoms, and more preferred examples include linear or branched alkyl groups having 1, 2, or 3 carbon atoms.

[0019] In R2, when the alkyl group is substituted with a fluorine atom, the number of the substituents is not limited, and preferably 1, 2 or 3 is exemplified.

[0020] Although not limiting the present disclosure, preferred examples of R2 include a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 3 carbon atoms which may be substituted with the above-mentioned substituents. More preferred examples of R2 include a hydrogen atom or a fluorine atom.

[0021] When R3 is an alkyl group having 1 to 5 carbon atoms, examples of the alkyl group having 1 to 5 carbon atoms include linear or branched alkyl groups having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, and a neopentyl group. Preferred examples of the alkyl group include linear or branched alkyl groups having 1 to 4 carbon atoms, and more preferred examples include linear or branched alkyl groups having 1, 2, or 3 carbon atoms.

[0022] When R3 is a cycloalkyl group having 3 to 5 carbon atoms, the cycloalkyl group may be a single ring or may have two rings, and is preferably a single ring. Preferred examples of the cycloalkyl group include cycloalkyl groups having 3 or 4 carbon atoms, and more preferably cycloalkyl groups having 3 carbon atoms.

[0023] In R3, when at least one of the alkyl group and the cycloalkyl group has a substituent, the substituent is independently at least one group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and a cycloalkyl group having 3 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms and the cycloalkyl group having 3 to 5 carbon atoms are as explained above.

[0024] Although not limiting the present disclosure, preferred examples of the number of carbon atoms constituting R3 are 1 to 7 in total, more preferably 1 to 6, even more preferably 1 to 5, and more preferably 1, 2, 3, or 4. Although not limiting the present disclosure, preferred examples of R3 are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, a cycloalkylmethyl group having 4 or 5 carbon atoms, and a cycloalkylethyl group having 5 carbon atoms.

[0025] The compound of the present disclosure contains a fluorine atom in at least one of R1 and R2 in general formula (1). Here, "contains" means "introduced." That is, a fluorine atom may be introduced into both R1 and R2, or into only one of R1 and R2.

[0026] As a preferred embodiment of the compound of the present disclosure, without limiting the present disclosure, in general formula (1), R1 represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 3 carbon atoms substituted with 1, 2, or 3 fluorine atoms; R2 represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 3 carbon atoms; and R3 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, a cycloalkylmethyl group having 4 or 5 carbon atoms, or a cycloalkylethyl group having 5 carbon atoms, and at least one of R1 and R2 contains a fluorine atom.

[0027] In addition, in the general formula (1), the fluorine atoms introduced into R1 and R2 are each independently a radioisotope. 18 F (hereinafter simply 18 F), or a non-radioactive fluorine atom F, preferably at least one of 18 In addition, when the compound of the present disclosure is used as a PET probe, at least one of R1 and R2 may have F introduced therein. 18 F is introduced, and preferably only one of R1 and R2 18 An example is where F is introduced into the compound of the present disclosure. 18 When the compound is labeled with F, it can be preferably used as a PET probe.

[0028] Although not limiting the present disclosure, preferred embodiments of the compounds of the present disclosure include, as compounds represented by general formula (1), 1,4-diazepane derivative compounds represented by the following formulas (1a) to (1g).

[0029] [ka]

[0030] The 1,4-diazepane derivative compound represented by formula (1a) is a compound in which R1 represents a fluorine atom, R2 represents a hydrogen atom, and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atom of R1 is 18 A preferred example is F.

[0031] [ka]

[0032] The 1,4-diazepane derivative compound represented by formula (1b) is a compound in which R1 represents a fluorine atom, R2 represents a fluorine atom, and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atoms of R1 and / or R2 are 18 A preferred example is F, and the fluorine atom of R1 is 18 A more preferred example is F.

[0033] [ka]

[0034] The 1,4-diazepane derivative compound represented by formula (1c) is a compound in which R1 represents a hydrogen atom, R2 represents a fluorine atom, and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atom of R2 is 18 A preferred example is F.

[0035] [ka]

[0036] The 1,4-diazepane derivative compound represented by formula (1d) is a compound in which R1 represents a methyl group, R2 represents a fluorine atom (5-position), and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atom of R2 is 18 A preferred example is F.

[0037] [ka]

[0038] The 1,4-diazepane derivative compound represented by formula (1e) is a compound in which R1 represents a methyl group, R2 represents a fluorine atom (6-position), and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atom of R2 is 18 A preferred example is F.

[0039] [ka]

[0040] The 1,4-diazepane derivative compound represented by formula (1f) is a compound in which, in general formula (1), R1 represents a methyl group substituted with three fluorine atoms, R2 represents a fluorine atom, and R3 represents a methyl group. When the compound is used as a PET probe, the fluorine atoms introduced into R1 and / or R2 are 18 A preferred example is F (wherein R1 is 18 When F is introduced, 1, 2 or 3 fluorine atoms constituting R1 18 F), and the fluorine atom of R2 is 18 A more preferred example is F.

[0041] [ka]

[0042] The 1,4-diazepane derivative compound represented by formula (1g) is a compound in which R1 represents a fluorine atom, R2 represents a methyl group, and R3 represents a methyl group in general formula (1). When the compound is used as a PET probe, the fluorine atom of R1 is 18 A preferred example is F.

[0043] Method for producing 1,4-diazepane derivative compound represented by general formula (1) The method for producing the compound of the present disclosure is not particularly limited. Examples of the method for producing the compound of the present disclosure include the following method.

[0044] The compounds of the present disclosure ( 18 As an example of a method for producing F-unlabeled 1,4-diazepane derivative compound, the following procedure according to Scheme A is preferably exemplified. Compound 4-1 is synthesized by condensation reaction of compound 2-1 with compound 3-1 in dichloromethane (DCM) in the presence of 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC-HCl) and triazolo[4,5-b]pyridin-3-ol (HOAt), and compound 5-1 is obtained by deprotection using trifluoroacetic acid (TFA) / HO (1:1). The final compound (1,4-diazepane derivative compound represented by the above general formula (1)) can be synthesized by SNAr reaction from compound 5-1 and compound 7-1. In Scheme A, R1, R2, and R3 are as defined above.

[0045] [ka]

[0046] The compounds of the present disclosure ( 18 As an example of the method for producing the F-labeled compound, the procedure according to the following scheme B is preferably exemplified. 18 Boronate ester (compound 2-2 or 2-3) was used as a precursor for the F labeling reaction. The precursor was dissolved in N,N-dimethylformamide and [ 18[F]KF and kriptofix2.2.2 were added, and the mixture was heated at 130°C for 20 minutes in the presence of tetrakis(pyridine)copper(II) triflate to give the 1,4-diazepane derivative compound ( 18 F-labeled compound) was synthesized. In Scheme B, R1, R2, and R3 are as defined above.

[0047] [ka]

[0048] Thus, according to the present disclosure, a compound represented by general formula (1) can be provided. 18 It is possible to provide a compound represented by general formula (1) labeled with F.

[0049] A more preferred example of the compound represented by general formula (1) is a compound represented by formula (1h).

[0050] [ka]

[0051] In formula (1h), R1, R2, and R3 are as described above. Preferably, in formula (1h), R1, R2, and R3 are exemplified by the combinations shown in formulas (1a) to (1g).

[0052] The compounds of the present disclosure can specifically bind to OX1R. In the present disclosure, "specifically bind to OX1R" means that, of the two types of receptors known as OXR, OX1R and OX2R, the compound preferentially binds to OX1R over OX2R.

[0053] Whether or not a compound preferentially binds to OX1R over OX2R can be confirmed according to the test examples described below. Specifically, it can be confirmed by the ratio of the Ki value for OX2R to the Ki value for OX1R (hereinafter, sometimes referred to as the "OX2R / OX1R ratio"). While not limiting the present disclosure, preferred examples of compounds of the present disclosure include compounds with an OX2R / OX1R ratio of 2 or more. Examples of OX2R / OX1R ratios include more preferably 3 or more, more preferably 4 or more, 5 or more, 6 or more, 7 or more, 7.5 or more, 8 or more, or 8.5 or more. The upper limit of the OX2R / OX1R ratio is not limited, and it is most preferable that the compound of the present disclosure does not bind to OX2R. That is, it is most preferable that the Ki value for OX2R cannot be calculated due to the compound of the present disclosure not binding to OX2R. In this respect, the upper limit of the OX2R / OX1R ratio is not limited, and examples of the ratio include 1000 or less, 500 or less, 100 or less, 50 or less, or 20 or less. Therefore, the ratio is preferably 2 to 1000, more preferably 3 to 100, even more preferably 4 to 50, and particularly preferably 4 to 20. The higher the ratio, the more preferentially the antibody binds to OX1R over OX2R, i.e., the higher the OX1R specificity. The ratio is determined according to the procedure in the test example described below, specifically, according to the following procedure.

[0054] Ovarian cells (CHO-K1 cells) stably expressing human OX1R (CHO-OX1R) or OX2R (CHO-OX2R) were seeded onto well plates and cultured at 5% CO2 and 37°C for 24 hours. After removing the medium, the cells were cultured in Ham's F-12 medium containing 1% bovine serum albumin (BSA) and 2% dimethyl sulfoxide (DMSO). 125A mixture of [I]5IBOM (compound 14 in the test example described below) and a compound of the present disclosure (test compound) was added to each well and incubated at 37°C for 1.5 hours. The medium was then replaced with Ham's F-12 medium and incubated for another hour. The wells were then washed with phosphate-buffered saline (NaCl 8000 mg / L, KCl 200 mg / L, NaHPO 1150 mg / L, KHPO 200 mg / L, pH(-)7.4) containing 1% BSA and 1% DMSO, and the mixture was dissolved in 1N NaOH. The resulting cell lysate was poured into tubes, and the radioactivity in each tube was measured using an automatic gamma counter (Wallac 2470 Wizard; PerkinElmer, Massachusetts, USA). The competitive ligand ([ 125 The concentration at which 50% of the total binding of [I]IBOM is displaced is determined as the IC50 value, and the Ki value is calculated using GraphPad Prism software (version 6.0; GraphPad Software, CA, USA). The Ki value is calculated using the following formula: Ki = IC50 / (1+[L] / Kd) Here, [L] is [ 125 I]5IBOM concentration, Kd for each receptor [ 125 I]5IBOM Kd values ​​(OX1R: 173 nM, OX2R: 179 nM).

[0055] Further, as the compound of the present disclosure, a compound having a Ki value of 100 nM or less for OX1R is more preferably exemplified. Although not limiting the present disclosure, as the affinity of the compound of the present disclosure, a compound having a Ki value of 50 nM or less is more preferably exemplified. As the Ki value, 20 nM or less, 10 nM or less, etc. are more preferably exemplified. There is no lower limit in these. Although not limiting the present disclosure, if a lower limit of the Ki value is set, a value greater than 0 nM is exemplified, and further examples of the lower limit of the Ki value include 0.001 nM or more, 0.01 nM or more, 0.05 nM or more, or 0.1 nM or more. Therefore, the Ki value is preferably exemplified as a value greater than 0 nM to 100 nM, more preferably 0 nM or more to 50 nM, and even more preferably 0 nM or more to 20 nM. The lower the Ki value, the higher the binding affinity of the compound to OX1R, i.e., the more efficiently it can bind. The Ki value is determined by the procedure according to the test example described below, and specifically, it is the Ki value measured and determined in the calculation of the OX2R / OX1R ratio described above.

[0056] More preferred examples of the compounds of the present disclosure include compounds having an OX2R / OX1R ratio of 2 to 1000 and a Ki value of greater than 0 nM to 100 nM, and more preferred examples include compounds having an OX2R / OX1R ratio of 3 to 100 and a Ki value of greater than 0 nM to 50 nM. Compounds that can specifically bind to OX1R and efficiently bind to OX1R allow for more efficient detection of OX1R, even when smaller amounts of the compound are used. Furthermore, because the compounds of the present disclosure can specifically bind to OX1R, they may be useful as antagonists for OX1R, and may contribute to the development of new antagonists that target OX1R.

[0057] As described above, orexin is a neuropeptide localized in the lateral hypothalamus and its vicinity, and orexin receptors (OXRs) are expressed widely in the brain. Thus, OX1R and OX2R are publicly known, and their amino acid sequences can be found from publicly known databases. For example, in the Protein Data Bank (PDB), the amino acid sequence of human OX1R is registered as a co-crystal structure with an orexin antagonist, e.g., 4ZJ8. The amino acid sequence of human OX2R is also registered as a co-crystal structure with an orexin antagonist, e.g., 4SOV. Furthermore, as shown in the Examples below, Chinese hamster ovary cells (CHO-K1 cells, GenScript (New Jersey, USA)) stably expressing human OX1R (CHO-OX1R) or OX2R (CHO-OX2R) are commercially available, and thus OX1R and OX2R are publicly known.

[0058] In addition, the compounds of the present disclosure 18 F was introduced 18 When the compound is an F-labeled compound, the compound can be used as a PET probe. 18 When using F-labeled PET probes, defluorination 18 It is known that F tends to accumulate in bones. When the compound of the present disclosure is used as a PET probe, 18 From the viewpoint of suppressing F accumulation, at least R1 18 A preferred example is a compound into which F is introduced.

[0059] For this reason, the present disclosure further provides: 18 It can also be said that a composition for a PET probe containing a compound of the present disclosure into which F has been introduced (hereinafter, sometimes referred to as the "composition of the present disclosure") is provided. The composition comprises: 18 There is no particular limitation as long as the composition contains the compound of the present disclosure into which F has been introduced. The content of the compound in the composition is not limited. For example, when the composition is liquid, the content of the compound in the composition is 1×10 -13 % by mass to 99.9% by mass, and more preferably 1×10 -13The form of the composition of the present disclosure is not limited, and even in the case of a solid or semi-solid form, the content of the compound in the composition may be appropriately determined with reference to the content.

[0060] The composition of the present disclosure also comprises: 18 In addition to the compound of the present disclosure into which F has been introduced, other components may be contained as needed, as long as they do not impair the effect of the compound as a PET probe. Examples of such other components include buffers, solvents, solubilizers, surfactants, dispersants, thickeners, etc. The other components may be used alone or in combination of two or more, and the content thereof is not limited. The composition comprises: 18 The compound of the present disclosure into which F has been introduced can be produced by mixing the compound with the other components according to a conventional method.

[0061] Also, 18 The compound of the present disclosure into which F has been introduced and the composition of the present disclosure may be provided in the form of a kit in combination with instructions for use, etc. The instructions for use may include a webpage URL, a readable code, etc., and instructions for use, etc. may be accessible via the URL, readable code, etc.

[0062] The compounds of the present disclosure are useful for the specific detection of OX1R. Furthermore, by using the compounds of the present disclosure as PET probes, OX1R can be specifically detected in the brain noninvasively using PET. The specific detection of OX1R is useful for further clarifying the physiological role of OX1R, the relationship between OX1R and diseases, etc., and such elucidation can contribute to the further development of drugs targeting OX1R, such as drugs for treating insomnia, bulimia, panic syndrome, and drug addiction. [Example]

[0063] Hereinafter, the embodiments of the present disclosure will be described more specifically with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

[0064] In the synthesis of the following compounds, compounds 2, 3, 7, 9, 15, 16, 21, 22, 23, 33, and 34 were commercially available. The preparative liquid chromatography system used was a Yamazen Corporation automatic setting medium-pressure preparative liquid chromatograph system (EPCLC W-Prep 2XY; No. 580D pump (with built-in mixer), prep UV-254W fixed-wavelength detector, and FR-260 fraction collector), equipped with a HI-FLASH column (packing material: silica gel SiOH, pore size: 60 Å, particle size: 50 μm, column size: L or 2 L) and an INJECT column (packing material: silica gel SiOH, pore size: 60 Å, particle size: 40 μm, column size: M or L). Nuclear magnetic resonance spectroscopy (NMR) was performed at 500 MHz using a JEOL JNM-ECS500 instrument with tetramethylsilane as an internal standard and deuterated chloroform as the solvent. Electrospray ionization mass spectrometry (ESI-MS) or electron ionization high-resolution mass spectrometry (ESI-HRMS) was performed using a Shimadzu LCMS-2020 high-performance chromatograph mass spectrometer or a liquid chromatography / mass spectrometry ion trap time-of-flight (LCMS-IT-TOF) mass spectrometer. High-performance liquid chromatography (HPLC) was performed using a Shimadzu LC-20AD column and a Shimadzu SPD-20A ultraviolet spectrometer and a Universal Giken US-3000T detector. The reversed-phase HPLC column was Cosmosil 5C manufactured by Nacalai Tesque, Inc. 18 -MS-II (4.6 mm ID × 150 mm) was used.

[0065] Test Example 1 1-1. Test procedure Synthesis of Compounds (Examples 1 and 2) As shown in Scheme 1, two 1,4-diazepane derivative compounds (11 and 13) were synthesized. Compound 11 (5FBTM) was used in Example 1, and compound 13 (6FBTM) was used in Example 2. Commercially available starting materials (compounds 2 and 3) and compounds 7 and 9 were used. Compound 4 was synthesized by the condensation reaction of compounds 2 and 3, followed by deprotection using trifluoroacetic acid (TFA) / HO (1:1) to obtain compound 5. The final compounds (compound 11 in Example 1 and compound 13 in Example 2) were synthesized by the SNAr reaction of compound 5 and compound 7 or 9. The total yields were 1.27-29.7%. For more details on the production and properties of the compounds used in this experiment, please also refer to the "Synthesis and Properties of Compounds" section below.

[0066] [ka]

[0067] The reagents and conditions in Scheme 1 are as follows: (a) 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl), triazolo[4,5-b]pyridin-3-ol (HOAt), dichloromethane (DCM), room temperature (25 °C) (rt); (b) TFA, HO, rt; (c) compound 7, 9, 33, or 34, triethylamine (EtN), N,N-dimethylformamide (DMF), 75 °C

[0068] Cell binding inhibition experiment procedure 1 To examine the binding affinity of each compound (Examples 1 and 2) to OX1R and OX2R, cell binding inhibition experiments were performed according to the following procedure. Chinese hamster ovary cells (CHO-K1 cells) stably expressing human OX1R (CHO-OX1R) or OX2R (CHO-OX2R) were purchased from GenScript (New Jersey, USA). The cells were maintained in Ham's F-12 medium (Nacalai Tesque) supplemented with 10% heat-inactivated fetal bovine serum (Thermo Fisher Scientific; MA, USA) and 50 μg / mL G418 at 37°C under a 5% CO atmosphere.

[0069] The cells (CHO-OX1R or CHO-OX2R cells) were seeded into a 12-well plate (4.0 to 7.5 × 10 cells per well). 5 The cells were cultured at 37°C in a 5% CO2 atmosphere for 24 hours. After removing the medium, the cells were replaced with Ham's F-12 medium containing 1% bovine serum albumin (BSA) and 2% dimethyl sulfoxide (DMSO). 125 I]IBOM (compound 14) (4.9–15.4 kBq / mL) and the test compound (10 -4 ~10 3 A mixture (0.6 mL) of 1000 nM β-lactam HCl (NaCl) and 100 nM β-lactam HCl (NaHPO4) was added to each well and incubated at 37°C for 1.5 hours. The mixture was then replaced with 0.6 mL of Ham's F-12 medium and incubated for another hour. The wells were then washed twice with 0.6 mL of phosphate-buffered saline (NaCl 8000 mg / L, KCl 200 mg / L, NaHPO4 1150 mg / L, KHPO4 200 mg / L, pH 7.4) containing 1% BSA and 1% DMSO, and the cells were dissolved in 0.6 mL of 1N NaOH. The resulting cell lysate was poured into a tube. Radioactivity in each tube was measured using an automatic γ counter (Wallac 2470 Wizard; PerkinElmer, Massachusetts, USA). In this test, the competitive ligand ([ 125The IC50 value was determined when 50% of the total binding of [I]IBOM was displaced, and the Ki value was calculated using GraphPad Prism software (version 6.0; GraphPad Software, CA, USA). The Ki value was calculated using the following formula: Ki = IC50 / (1 + [L] / Kd) Here, [L] is [ 125 I]5IBOM concentration, Kd for each receptor [ 125 I]5IBOM Kd values ​​(OX1R: 173 nM, OX2R: 179 nM).

[0070] In this test example, the compounds of Example 1, Example 2, and Compound 1 (Figure 2), which is known to selectively bind to OX1R, were used as test compounds, and Almorexant (Figure 2), a known non-selective OXR antagonist, was used as a negative control. Furthermore, in conducting the test, the compound [I]5IBOM was synthesized (see the "Compound Synthesis and Properties" section below) and used as a competitive ligand with equivalent affinity for OX1R and OX2R.

[0071] 1-2.Results The results (OX2R / OX1R ratio and Ki value) are shown in Table 1.

[0072] [Table 1]

[0073] As shown in Table 1, the compounds of Examples 1 and 2 exhibited selective binding affinity for OX1R over OX2R. Specifically, as shown in Table 1, the OX2R / OX1R ratio was 11.3 in Example 1, 9.63 in Example 2, 8.71 for Compound 1, which has previously been known to be able to selectively bind to OX1R, and 1.26 for the conventionally known non-selective OXR antagonist Almorexant. Thus, it was found that the ratio values ​​of the compounds of Examples 1 and 2 were higher than those of Compound 1 and Almorexant. From this, it was found that the compounds of Examples 1 and 2 have higher OX1R selectivity than Compound 1 and have much higher OX1R selectivity than non-selective OXR antagonists. In this test example, the OX2R / OX1R ratio is the value obtained by dividing the K value of OX2R by the K value of OX1R. A larger ratio means more selective binding to OX1R compared to OX2R, i.e., higher specificity for OX1R. Therefore, the compounds of Examples 1 and 2 were found to be useful compounds capable of specifically detecting OX1R.

[0074] Furthermore, the compounds of Examples 1 and 2 bound to OX1R with nanomolar affinity (Ki values ​​of 1.14 and 2.14 nM, respectively), comparable to Compound 1 (Ki = 1.12 nM) and a non-selective OXR antagonist (Ki = 2.67 nM). This indicates that both the compounds of Examples 1 and 2 can bind to OX1R efficiently. In this test example, a smaller Ki value indicates more efficient binding to OX1R.

[0075] Test Example 2 2-1. Test procedure Radioisotope labeling (Examples 1 and 2) 18 F sign included)) In Test Example 1, the compounds of Examples 1 and 2 (non-radioisotope labeled) were found to have the desired OX1R specificity. 18 F-labeled compounds of Examples 1 and 2 were prepared according to the following procedure. 18 Precursors for the F labeling reaction (19 and 20 in Scheme 2) and 18F-labeled compounds of Examples 1 and 2 (in Scheme 2, [ 18 F]11([ 18 F]5FBTM), [ 18 F]13([ 18 The synthetic route to [F]6FBTM) is shown in Scheme 2. Precursors (19, 20) were synthesized by replacing bromine with boronate ester following procedures known in the art in 5.45% and 4.58% yields, respectively. 18 F]5FBTM and [ 18 The radiochemical yields of [F]6FBTM were 6.06% and 1.82%, respectively, and the radiochemical purities were over 95%. They were identified by comparison of retention times with those of non-radioactive 5FBTM and 6FBTM in reverse-phase HPLC.

[0076] [ka]

[0077] The reagents and conditions in Scheme 2 are as follows: (a) Et3N, DMF, 75°C; (b) B2Pin2, KOAc, [1,1'-bis(diphenylphosphino)ferrocene]dichloro]palladium(II) (PdCl2·dppf), tetrahydrofuran (THF), 75°C; (c) [ 18 F]KF, Cu(OTf)2(py)4, DMF, 130℃

[0078] · Internal radioactivity distribution experiment (Examples 1 and 2) 18 F sign included)) The compounds of Examples 1 and 2 ( 18To evaluate the pharmacokinetics of F-labeled compounds, biodistribution studies using normal mice were performed according to the following procedure. All studies were conducted with approval from the Kyoto University Animal Experimentation Committee. A physiological saline solution (100 μL, 20-600 kBq) prepared by mixing ethanol (10 μL), Tween 80 (0.1 μL), and the compound of Example 1 or Example 2 was directly injected into the tail vein of ddY mice (5-week-old, male, purchased from Japan SLC, Inc., Shizuoka, Japan). Mice were sacrificed 2, 10, 30, and 60 minutes after injection (n=5 per time point), and the organs of interest were excised, weighed, and radioactivity measured using a gamma counter. For organs other than the stomach, the dose per gram of organ (% injected dose / gram) is shown, while for the stomach, the dose per organ is shown (the values ​​below are the mean (SD) of 5 mice).

[0079] 2-2.Results The results are shown in Figure 3. For both compounds of Examples 1 and 2, early brain uptake (3.81% and 2.42% ID / g, respectively, 2 minutes after intravenous injection) and rapid clearance (less than 0.5% ID / g 30 minutes after intravenous injection) were observed. Rapid blood clearance was also observed (2.20% and 1.44% ID / g, respectively, 30 minutes after intravenous injection). The compounds of Examples 1 and 2 showed significantly higher accumulation in the liver (30.6% and 26.9% ID / g, respectively, 10 minutes after intravenous injection), followed by the intestine (15.3% and 16.3% ID / g, respectively, 60 minutes after intravenous injection). Furthermore, the radioactivity accumulation in bone of the compounds of Examples 1 and 2 increased in a time-dependent manner, suggesting the occurrence of defluorination metabolism.

[0080] The results of this test example showed that the compounds were taken up into various organs, but were primarily taken up into the brain, indicating that Compounds 1 and 2 can be used as PET probes.

[0081] Test Example 3 3-1. Test procedure Compound Synthesis 2 (Examples 3 to 7) To reduce radioactivity accumulation in bone, five additional 1,4-diazepane derivative compounds (Examples 3 to 7) were synthesized according to the following procedure. The synthetic route for the compounds of Examples 3 to 7 is shown in Scheme 3. In Scheme 3, compounds 21, 33, and 34 were commercially available. Compound 2 was the same as described above. Compounds 22 and 23 were synthesized by the SNAr reaction from 1H-1,2,3-triazole and 5-fluoro-2-iodobenzoic acid or 2-iodo-5-(trifluoromethyl)benzoic acid. The final compounds (Compound 30 in Example 3, Compound 31 in Example 4, Compound 32 in Example 5, Compound 35 in Example 6, and Compound 36 in Example 7) were synthesized according to the methods described above for the aforementioned compounds, with total yields ranging from 0.603 to 6.55%. For more details on the production and properties of the compounds used in this experiment, please also refer to the "Synthesis and Properties of Compounds" section below.

[0082] [ka]

[0083] The reagents and conditions in Scheme 3 are as follows: (a) EDC·HCl, HOAt, DCM, rt; (b) TFA, H2O, rt; (c) Et3N, DMF, 75℃

[0084] Cell binding inhibition experiment 2 A cell binding inhibition experiment was carried out using the same procedure as in Test Example 1. The results are shown in Table 2.

[0085] 3-2.Results The results (Ki value and OX2R / OX1R ratio) are shown in Table 2.

[0086] [Table 2]

[0087] As shown in Table 2, the compounds of Examples 3 to 7 exhibited selective binding affinity to OX1R over OX2R. Furthermore, the compounds of Examples 3 to 7 were shown to be able to selectively bind to OX1R with Ki<10 nM.

[0088] Specifically, as shown in Table 2, the OX2R / OX1R ratios were 8.08 in Example 3, 8.19 in Example 4, 2.85 in Example 5, 3.50 in Example 6, and 26.9 in Example 7. All of these compounds had higher OX2R / OX1R ratios than the known non-selective OXR antagonist Almorexant (1.26) shown in Table 1. These results demonstrate that the compounds of Examples 3 to 7 have ratios more than twice as high as those of the non-selective OXR antagonist Almorexant, making them useful compounds capable of specifically detecting OX1R. Furthermore, all of the compounds of Examples 3 to 7 are excellent in that they can bind to OX1R with nanomolar affinity. In particular, the K values ​​of compounds 3, 4, and 7 were all very low (0.640 nM, 1.89 nM, and 2.33 nM, respectively), demonstrating their highly efficient binding to OX1R.

[0089] Test Example 4 4-1. Test procedure · Radioisotope-labeled 2 (compounds of Examples 3, 4 and 7) 18 F sign included)) In Test Example 3, compounds 3, 4, and 7 (non-radioisotope labeled) were found to have particularly high affinity for OX1R. 18 F-labeled compounds of Examples 3, 4 and 7 were prepared according to the following procedure. 18 Precursors for the F labeling reaction (38, 42, and 43 in Scheme 4) and 18 F-labeled compounds of Examples 3, 4 and 7 (in Scheme 4, [ 18 F]30([ 18 F]6FBTH), [ 18 F]31([ 18 F]6FBTF), [ 18 F]36([ 18 The synthetic route of [F]BTF) is shown in Scheme 4. Compound 39 was synthesized in three steps from 5-bromo-2-iodobenzoic acid. 18The F-labeled precursors were synthesized in yields of 0.619–1.23%. 18 F]6FBTH,[ 18 F]6FBTF,[ 18 The radiochemical yields of [F]BTF were 1.11, 2.08, and 4.19%, respectively, and the radiochemical purities were over 95%. They were identified by comparison of retention times with their respective cold counterparts.

[0090] [ka]

[0091] The reagents and conditions in Scheme 4 are as follows: (a) Et3N, DMF, 75℃; (b) B2Pin2, KOAc, PdCl2·dppf, THF, 75℃; (c) [ 18 F]KF, Cu(OTf)2(py)4, DMF, 130℃.

[0092] Further, according to the above scheme, 18 F-labeled compounds 5 and 6 were also synthesized. 18 The structure and clogP value of the α-glucanase (labeled with F) are shown in Figure 4.

[0093] · Internal radioactivity distribution experiments (Examples 3, 4 and 7) 18 F sign included)) The compounds of Examples 3, 4 and 7 ( 18 Using F-labeled compound, an experiment on the distribution of radioactivity in the body was carried out in the same manner as in Test Example 2. The results are shown in Figures 5 to 7.

[0094] 4-2.Results When the compound of Example 3 was used (FIG. 5), radioactivity was detected in the brain, as in the cases of using the compounds of Examples 1 and 2. This indicates that the compound of Example 3 was also taken up into the brain, and therefore it was found that the compound of Example 3 can be used as a PET probe.

[0095] When the compound of Example 4 was used (FIG. 6), radioactivity was detected in the brain, as in the cases where the compounds of Examples 1 and 2 were used. This indicates that the compound of Example 3 was also taken up into the brain, and that the compound of Example 4 can be used as a PET probe. In particular, when the compound of Example 4 was used, the radioactivity measurement value in the bones was significantly reduced, that is, it was found that the accumulation of radioactivity in the bones was suppressed. When used as a PET probe, 18 It was suggested that changing the F-introduction position is effective in reducing defluorination metabolism. In this respect, the compound of Example 4 was found to be more useful as a PET probe than the compound of Example 3.

[0096] When the compound of Example 7 was used (FIG. 7), radioactivity was detected in the brain, as with the compounds of Examples 1 and 2. This indicates that the compound of Example 7 can also be taken up into the brain, and therefore it can be used as a PET probe. In particular, when the compound of Example 7 was used, it was shown to have brain penetration while suppressing radioactivity accumulation in bone, as with the compound of Example 4 (2 minutes after administration: 2.98% ID / g). This indicates that the compound of Example 7 is also more useful as a central PET probe than the compound of Example 3.

[0097] Test Example 5 5-1. Test procedure The following test was carried out using the compound of Example 7 used in the above Test Example 3. · In vitro autoradiography Brain slices (30 μm thick) from CD Sprague-Dawley rats (male, 10 weeks old, purchased from Japan SLC, Inc., Shizuoka, Japan) were used. Each slice was pre-incubated in a buffer (50 mM Tris, 10 mM MgCl, 2.5 mM ethylenediaminetetraacetic acid (EDTA), pH 7.4) for 30 minutes at room temperature. Then, the slices were pre-incubated in the same manner as in Example 7. 18The sections were incubated in a buffer containing F-labeled compounds (10.8 to 40.1 kBq / mL) at room temperature for 1 hour. For blocking experiments, adjacent sections were incubated with the same buffer as in Example 7 in the presence of BTF (100 nM). 18 The sections were incubated in a buffer solution containing F-labeled compound (40.1 kBq / mL). After washing with the buffer solution (5 min × 2) and drying, the sections were placed on a BAS imaging plate (FUJIFILM, Tokyo, Japan) and autoradiographic images were obtained using an Amersham Typhoon Scanner (GE Health Life Sciences, IL, USA). The results are shown in Figure 8.

[0098] · In vivo binding inhibition experiments DMSO (10 μL), Tween 80 (0.1 μL), and the compound of Example 7 ([ 18 Physiological saline (100 μL, 41 kBq) containing [F]BTF) was directly injected into the tail vein of ddY mice (5 weeks old, male) (n = 5). A blocking group of mice (n = 4) was administered the compound of Example 7 ([ 18 Ten minutes before the injection of [F]BTF, a blocking agent containing BTF (100 μL, 2 mg / kg) was injected via the tail vein. Ten minutes after injection, the mice were sacrificed. Organs were removed, weighed, and radioactivity was measured using a γ counter. The results are shown in Figure 9 (mean ± SD).

[0099] · PET / CT(Positron Emission Tomography / computed tomography) imaging DMSO (20 μL), Tween 80 (0.20 μL), and the compound of Example 7 ([ 18 Saline (200 μL, 407 kBq) containing [F]BTF was directly injected into the tail vein of ddY mice (male, 5 weeks old). Mice were anesthetized (isoflurane) to minimize discomfort, and PET / CT was performed using a G8 small animal PET / CT scanner (PerkinElmer). Dynamic PET imaging was performed for 60 minutes, followed by CT imaging. Image reconstruction for both PET and CT was performed in DICOM format.

[0100] 5-2.Results The results of the in vitro autoradiography are shown in FIG. 8, the results of the in vivo binding inhibition experiment in FIG. 9, and the results of PET / CT imaging in FIG.

[0101] Regarding the results of in vitro autoradiography (Fig. 8), the left photograph (A) shows the results of in vitro autoradiography of rat brain sections (Ctx-int: Internal Layer of Cortex, Hy: Hypothalamus, Amg: Amygdala). The right graph (B) shows the quantification results of the autoradiography (n = 3 in the absence of BTF, n = 6 in the presence of BTF, mean ± SD. *P < 0.005, **P < 0.001).

[0102] In Figure 8, radioactivity accumulation was observed throughout the brain, particularly in the inner cortex (Ctx-int), hypothalamus (Hy), and amygdala (Amg), where OX1R expression is known. Radioactivity accumulation in these regions was significantly reduced in the presence of BTF. It has been suggested that OX2R is also expressed in these regions, and therefore, the accumulation may be due to the compound of Example 7 ([ 18 However, since the radioactivity accumulation was reduced in the binding inhibition assay in the presence of BTF, it was considered that the detected radioactivity accumulation was mainly due to the compound of Example 7 ([F]BTF) bound to OX1R, taking into account the affinity and selectivity.

[0103] FIG. 9 shows the results of an in vivo binding inhibition experiment, showing the effect of the compound of Example 7 ([ 18 The binding of [F]BTF is shown (n=3 in the absence of BTF (-), n=4 in the presence of BTF (+), mean ± SD. *P<0.05). As shown in Figure 9, the radioactivity in the brain was significantly reduced by 12.9% in the presence of 2 mg / kg of non-radioactive BTF. This indicates that the compound of Example 7 ([F]BTF) was effective in the brain of normal mice. 18It was found that [F]BTF) specifically binds to OX1R. In this assay, increased brain uptake following administration of unlabeled compounds is sometimes observed, and this is thought to be largely due to efflux transporters such as P-gp (P-glycoprotein). In this study, no increase in radioactivity accumulation was observed following administration of unlabeled compounds, suggesting that the compound of Example 7 does not interact with P-gp.

[0104] Figure 10 shows a PET image (5-10 minutes after intravenous injection) obtained using the above procedure, overlaid on a CT image of the same mouse. Radioactive signals were observed in the hypothalamus and the locus coeruleus, areas of high OX1R expression.

[0105] Thus, in vitro autoradiography also demonstrated that the compound of Example 7 specifically binds to OX1R. Furthermore, in vivo binding inhibition experiments demonstrated that the compound of Example 7 binds to OX1R in vivo. Furthermore, PET / CT imaging revealed signals derived from the compound of Example 7 in areas with high OX1R expression.

[0106] [Synthesis and properties of compounds] (S)-2-Methyl-1-[5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]-4-tert-butoxycarbonyl-1,4-diazepan-1-yl methanone (4) To a solution of compound 3 (244 mg, 1.2 mmol) and triazolo[4,5-b]pyridin-3-ol (HOAt, 163 mg, 1.2 mmol) in anhydrous dichloromethane (9 mL), 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl, 288 mg, 1.5 mmol) was added. The reaction mixture was stirred at room temperature for 10 minutes, and then compound 2 (214 mg, 1.0 mmol) was added. The mixture was further stirred at room temperature for 20 hours. Saturated brine was added to the reaction mixture, which was then extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by silica gel chromatography using methanol / chloroform (8 / 92) as an eluent to give compound 4 (306 mg, 77% yield).

[0107] TIFF2026023237000026.tif20170

[0108] (S)-2-Methyl-1-[5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]-1,4-diazepan-1-yl methanone (5) Compound 4 (306 mg, 0.77 mmol) was dissolved in water (2.0 mL), TFA (2.0 mL) was added, and the mixture was stirred at room temperature for 19 hours. Saturated brine was added to the reaction mixture, and the mixture was extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give compound 5 in an amount of 218 mg (95%).

[0109] TIFF2026023237000027.tif27170

[0110] (S)-[4-(5-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (11: 5FBTM) Compound 7 (12.9 mg, 0.06 mmol) and triethylamine (7.7 μL, 0.06 mmol) were dissolved in anhydrous N,N'-dimethylformamide (DMF, 3 mL), and compound 5 (16.6 mg, 0.06 mmol) was added. The mixture was stirred at 75°C for 30 hours. Saturated brine was added to the reaction mixture, and the mixture was extracted with a mixture of ethyl acetate and hexane (1 / 4). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by reverse-phase liquid chromatography using acetonitrile and water (3 / 2) as the eluent to give compound 11 (10.2 mg, 40.8% yield).

[0111] TIFF2026023237000028.tif47170

[0112] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (13: 6FBTM) Compound 9 (19.1 mg, 0.10 mmol) was subjected to the same reaction as for Compound 11 to give Compound 13 (10.0 mg, 21.7% yield).

[0113] TIFF2026023237000029.tif47170

[0114] (S)-[4-(5-Bromobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (17) Compound 15 (108 mg, 0.37 mmol) was subjected to the same reaction as for Compound 11 to give Compound 17 (75.3 mg, 39.8% yield).

[0115] TIFF2026023237000030.tif27170

[0116] (S)-[4-(6-Bromobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (18) Compound 16 (124 mg, 0.50 mmol) was subjected to the same reaction as for Compound 11 to give Compound 18 (60.8 mg, 39.1% yield).

[0117] TIFF2026023237000031.tif20170

[0118] (S)-{4-[5-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzothiazol-2-yl]-2-methyl-1,4-diazepan-1-yl}[5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (19) Bis(pinacolato)diboron (38.1 mg, 0.15 mmol), potassium acetate (29.4 mg, 0.30 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (3.1 mg, 0.004 mmol) were dissolved in anhydrous tetrahydrofuran (1.0 mL), and compound 17 was added. The mixture was stirred at 75°C overnight. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by reversed-phase liquid chromatography using acetonitrile / water (3 / 1) as an eluent to give compound 19 in an amount of 15.3 mg (yield 18.8%).

[0119] TIFF2026023237000032.tif28170

[0120] (S)-{4-[6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzothiazol-2-yl]-2-methyl-1,4-diazepan-1-yl}[5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (20) Compound 18 (60.8 mg, 0.12 mmol) was subjected to the same reaction as for compound 19 to give compound 20 (10.5 mg, 16.1% yield).

[0121] TIFF2026023237000033.tif27170

[0122] (S)-2-Methyl-1-[2-(2H-1,2,3-triazol-2-yl)phenyl]-4-tert-butoxycarbonyl-1,4-diazepan-1-yl methanone (24) Compound 21 (42.9 mg, 0.20 mmol) was reacted in the same manner as for compound 4 to give compound 24 (41.8 mg, 54.2% yield).

[0123] TIFF2026023237000034.tif20170

[0124] (S)-2-Methyl-1-[5-fluoro-2-(2H-1,2,3-triazol-2-yl)phenyl]-4-tert-butoxycarbonyl-1,4-diazepan-1-yl methanone (25) Compound 22 (7.2 mg, 0.035 mmol) was subjected to the same reaction as for Compound 4 to give Compound 25 (8.0 mg, 67.8% yield).

[0125] TIFF2026023237000035.tif27170

[0126] (S)-2-Methyl-1-[5-trifluoromethyl-2-(2H-1,2,3-triazol-2-yl)phenyl]-4-tert-butoxycarbonyl-1,4-diazepan-1-yl methanone (26) Compound 23 (19.1 mg, 0.074 mmol) was subjected to the same reaction as for Compound 4 to give Compound 26 (20.1 mg, 71.5% yield).

[0127] TIFF2026023237000036.tif27170

[0128] (S)-2-Methyl-1-[2-(2H-1,2,3-triazol-2-yl)phenyl]-1,4-diazepan-1-yl methanone (27) Compound 24 (58.7 mg, 0.15 mmol) was subjected to the same reaction as for Compound 5 to give Compound 27 (20.3 mg, 46.7% yield).

[0129] TIFF2026023237000037.tif28170

[0130] (S)-2-Methyl-1-[5-fluoro-2-(2H-1,2,3-triazol-2-yl)phenyl]-1,4-diazepan-1-yl methanone (28) Compound 25 (131 mg, 0.33 mmol) was subjected to the same reaction as for Compound 5 to give Compound 28 (12.0 mg, yield 12.0%).

[0131] TIFF2026023237000038.tif27170

[0132] (S)-2-Methyl-1-[5-trifluoromethyl-2-(2H-1,2,3-triazol-2-yl)phenyl]-1,4-diazepan-1-yl methanone (29) Compound 26 (174 mg, 0.38 mmol) was subjected to the same reaction as for Compound 5 to give Compound 29 (58.1 mg, 42.8% yield).

[0133] TIFF2026023237000039.tif20170

[0134] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (30: 6FBTH) Compound 27 (10.3 mg, 0.04 mmol) was subjected to the same reaction as for Compound 11 to give Compound 30 (5.0 mg, 28.3% yield).

[0135] TIFF2026023237000040.tif46170

[0136] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-fluoro-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (31: 6FBTF) Compound 28 (12.0 mg, 0.04 mmol) was subjected to the same reaction as for Compound 11 to give 3.1 mg of Compound 31 (yield 17.1%).

[0137] TIFF2026023237000041.tif46170

[0138] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-trifluoromethyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (32: 6FBTCF3) Compound 29 (36.1 mg, 0.10 mmol) was subjected to the same reaction as for Compound 11 to give Compound 32 (15.9 mg, 30.8% yield).

[0139] TIFF2026023237000042.tif52170

[0140] (S)-[4-(6-Methylbenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-fluoro-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (35: 6MBTF) Compound 5 (106 mg, 0.35 mmol) was subjected to the same reaction as for Compound 11 to give Compound 35 (13.7 mg, 9.0% yield).

[0141] TIFF2026023237000043.tif59170

[0142] (S)-[4-(Benzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-fluoro-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (36: BTF) Compound 5 (2.9 mg, 0.01 mmol) was subjected to the same reaction as for Compound 11 to give Compound 36 (0.26 mg, 6.0% yield).

[0143] TIFF2026023237000044.tif46170

[0144] (S)-[4-(6-Bromobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (37) Compound 27 (14.5 mg, 0.05 mmol) was subjected to the same reaction as for Compound 11 to give Compound 37 (6.8 mg, 26.9% yield).

[0145] TIFF2026023237000045.tif21170

[0146] (S)-{4-[6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzothiazol-2-yl]-2-methyl-1,4-diazepan-1-yl}[2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (38) Compound 37 (6.8 mg, 0.013 mmol) was subjected to the same reaction as for Compound 19 to give 0.5 mg of Compound 38 (yield 6.6%).

[0147] TIFF2026023237000046.tif21170

[0148] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-bromo-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (40) Compound 39 (120 mg, 0.33 mmol) was subjected to the same reaction as for Compound 11 to give Compound 40 (135 mg, 79.6% yield).

[0149] TIFF2026023237000047.tif21170

[0150] (S)-[4-(Benzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-bromo-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (41) Compound 39 (69.0 mg, 0.19 mmol) was subjected to the same reaction as for Compound 11 to give Compound 41 (32.6 mg, yield 34.6%).

[0151] TIFF2026023237000048.tif21170

[0152] (S)-[4-(6-Fluorobenzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (42) Compound 40 (66.0 mg, 0.26 mmol) was subjected to the same reaction as for compound 19 to give compound 42 (14.4 mg, 9.8% yield).

[0153] TIFF2026023237000049.tif21170

[0154] (S)-[4-(6-Benzothiazol-2-yl)-2-methyl-1,4-diazepan-1-yl][5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone (43) Compound 41 (47.2 mg, 0.09 mmol) was subjected to the same reaction as for Compound 19 to give Compound 43 (7.1 mg, 13.7% yield).

[0155] TIFF2026023237000050.tif27170

[0156] 18 F label 18 F was loaded onto an anion exchange column, Sep-Pak Accell Plus QMA Plus Light Cartridge (Waters Corporation, Massachusetts, USA), and then eluted into an amber vial with acetonitrile (1 mL) of Kryptofix 222 (10 mg / mL) / K2CO3 aqueous solution (34 mg / mL) at a ratio of 19:1. Acetonitrile (300 μL × 3) was added to the amber vial, and the mixture was heated to 120 °C under an argon stream for azeotropic dehydration. Precursors (19, 20, 38, 42, 43) (0.5–3.2 mg) were dissolved in DMF (200 μL) and heated at 130 °C for 20 min. The mixture was cooled to RT, water (1 mL) was added, and the mixture was extracted with ethyl acetate (500 μL × 3). The solvent was then dried over Na2SO4, filtered, and removed under an argon stream. The residue was purified by reverse-phase HPLC using a Cosmosil C18 column. The solvent was acetonitrile / HO = 40 / 60 (0 min) to 60 / 40 (30 min), and the flow rate was 1.0 mL / min.

[0157] [ 125 I] Synthesis and binding assay of 5IBOM([12I]14) ·[ 125I] Synthesis of 5IBOM([125I]14) [ 125 I]5IBOM precursor, 5IBOM and [ 125 The synthesis scheme of I]5IBOM is shown in Scheme 5. The reagents and conditions in Scheme 5 are as follows. (a) Et3N, DMF, 75℃; (b) EDC·HCl, HOAt, DCM, rt; (c) B2Pin2, CH3COOK, 1,3-Bis (2,6-diisopropylphenyl) imidazolium chloride, Pd[(OAc)2] n , THF, 75℃;(d)I2, DMAP, DCM, rt;(e)[ 125 I]NaI, Cu(OTf)2(py)4, MeOH, 20 min, rt.

[0158] [ka]

[0159] · Saturation binding assay Chinese hamster ovary cells (CHO-K1 cells) stably expressing human OX1R (CHO-OX1R) or OX2R (CHO-OX2R) were seeded into 12-well plates (5.0 × 10 cells per well). 5 The cells were cultured at 37°C for 24 hours in a 5% CO2 atmosphere. After removing the medium, the cells were transferred to Ham's F-12 medium containing 1% BSA and 2% DMSO. 125I-labeled IBOM or unlabeled IBOM (final concentrations of 6.25–800 nM and 0.23–59.5 kBq / mL, respectively) was mixed, and the resulting mixture (0.6 mL) was added to each well and incubated at 37°C for 1.5 hours. The wells were then washed twice with phosphate-buffered saline (0.6 mL) containing 1% BSA and 1% DMSO, and the cells were dissolved in 1N NaOH (0.6 mL). The resulting cell lysate was poured into a tube. Radioactivity in each tube was measured using an automatic γ counter (Wallac 2470 Wizard; PerkinElmer, Massachusetts, USA). The equilibrium dissociation constant (K d ) values ​​were calculated by Scatchard analysis using GraphPad Prism software (version 6.0; GraphPad Software, CA, USA). Figure 11 shows the [ 125 Figure 1 shows the saturation curve of I]5IBOM.

[0160] All data were analyzed using Microsoft Excel or GraphPad Prism software. 95-99.99% (P < 0.0001-0.05) confidence intervals were determined by Student's t-test or one-way analysis of variance (ANOVA) with Turkey's test.

Claims

1. A 1,4-diazepane derivative compound represented by the following general formula (1): 【Chemistry 1】 [In the formula, R １ represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom. R ２ represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and the alkyl group may be substituted with a fluorine atom. R ３ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having 3 to 5 carbon atoms, and the alkyl group and the cycloalkyl group may each independently be substituted with at least one group selected from the group consisting of alkyl groups having 1 to 5 carbon atoms and cycloalkyl groups having 3 to 5 carbon atoms. However, R １ and R ２ At least one of them contains a fluorine atom.]

2. In the general formula, R ３ The compound according to claim 1, wherein the total number of carbon atoms constituting the formula is 1 to 5.

3. The compound according to claim 1, wherein the compound represented by the general formula is a compound selected from the group consisting of the following formulas (1a) to (1g): (1a) In the general formula, R １ represents a fluorine atom, and R ２ represents a hydrogen atom, and R ３ is a compound that shows a methyl group 【Chemistry 2】 (1b) In the general formula, R １ represents a fluorine atom, and R ２ represents a fluorine atom, and R ３ is a compound that shows a methyl group 【Transformation 3】 (1c) In the general formula, R １ represents a hydrogen atom, and R ２ represents a fluorine atom, and R ３ is a compound that shows a methyl group 【Chemistry 4】 (1d) In the general formula, R １ represents a methyl group, and R ２ represents a fluorine atom, and R ３ is a compound that shows a methyl group 【Transformation 5】 (1e) In the general formula, R １ represents a methyl group, and R ２ represents a fluorine atom, and R ３ is a compound that shows a methyl group 【Transformation 6】 (1f) In the general formula, R １ represents a methyl group substituted with three fluorine atoms, and R ２ represents a fluorine atom, and R ３ is a compound that shows a methyl group 【Transformation 7】 (1g) In the general formula, R １ represents a fluorine atom, and R ２ represents a methyl group, and R ３ is a compound that shows a methyl group 【Transformation 8】

4. Furthermore, R １ and R ２ At least one of the following is a radioisotope １８ The compound according to any one of claims 1 to 3, comprising F.

5. A composition for a PET probe, comprising the compound according to claim 4.

6. Use of the compound according to claim 4 as a PET probe.

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