Heterocyclic compounds as AT2R antagonists and uses thereof

Abstract

The invention provides a compound as shown in a formula I, and a tautomer, a stereoisomer, a hydrate, a solvate, a pharmaceutically acceptable salt or a prodrug thereof. These compounds useful as antagonists of AT2R, # imgabs0

Description

[0001] The present invention claims:

[0002] Priority to the prior application, patent application number 202310724422.2, filed with the State Intellectual Property Office of China on June 16, 2023, entitled “Heterocyclic compounds as AT2R antagonists and their uses”;

[0003] Priority to the prior application, patent application number 202311331793.0, filed with the State Intellectual Property Office of China on October 13, 2023, entitled “Heterocyclic compounds as AT2R antagonists and their uses”;

[0004] Priority to the prior application, patent application number 202410010872.X, entitled “Heterocyclic compounds as AT2R antagonists and their uses”, filed with the State Intellectual Property Office of China on January 3, 2024;

[0005] Priority to the prior application, patent application number 202410669486.1, filed with the State Intellectual Property Office of China on May 27, 2024, entitled “Heterocyclic compounds as AT2R antagonists and their uses”;

[0006] The entirety of said prior application is incorporated herein by reference. Technical Field

[0007] The present invention belongs to the field of medicine, and in particular, relates to a heterocyclic compound as an angiotensin II (Ang II) type 2 receptor (AT2R) antagonist and its use. Background Art

[0008] Neuropathic pain is a chronic pain disease caused by primary damage or dysfunction of the nervous system. It can be divided into peripheral neuropathic pain and central neuropathic pain according to the location of the lesion. Trauma, inflammation, infection or compression can cause neuropathic pain, such as diabetic neuropathy (DNP), postherpetic neuralgia (PHN), primary neuropathy, secondary neuropathy, peripheral neuropathy, and neuropathy caused by mechanical nerve damage or biochemical nerve damage. At present, the drugs used in clinical treatment of neuropathic pain mainly include antiepileptic drugs, antidepressants and narcotic analgesics, such as gabapentin, pregabalin, tricyclic antidepressants, etc. However, these drugs are not targeted, the therapeutic effect is very limited, and there are serious side effects, including cognitive changes, sedation, nausea, tolerance and dependence, which are far from meeting the clinical drug needs. Therefore, it is necessary to study the pathogenesis of neuropathic pain, find clear targets for drug action, and develop new drugs that can effectively treat neuropathic pain with fewer adverse reactions.

[0009] In humans, two major types of angiotensin II (Ang II) receptors have been identified, named Ang II type 1 receptor (AT1R) and Ang II type 2 receptor (AT2R). Ang II has been shown to regulate blood pressure, body fluid and electrolyte homeostasis in many organs, including the kidneys, adrenal glands, heart, blood vessels, brain, gastrointestinal tract and reproductive organs. The effects of Ang II are regulated by the balance of expression of two G protein-coupled receptors (GPCRs), AT1R and AT2R. AT1R is expressed throughout the life cycle and is mainly responsible for regulating blood pressure. Its blockers are widely used as antihypertensive drugs in clinical practice. AT1R controls most of the physiological effects of Ang II. AT2R is mainly expressed in embryonic tissues and is related to blood pressure regulation, nerve growth, pain control and myocardial regeneration. Drugs targeting AT2R can improve cardiovascular function and relieve neuropathic pain. AT2R is related to pain mechanisms in the nervous system and is mainly expressed in dorsal root ganglia and trigeminal ganglia. Compared with normal nerves, damaged nerves and painful neuromas have higher AT2R expression. After AT2R activation, the second messenger pathway activated by G protein-coupled receptors can sensitize ion channels in neurons. Sensitization leads to ion channel activation, which in turn excites neurons. AT2R antagonists have been proven to be useful for pain relief through animal and clinical trials.

[0010] Although some progress has been made in the research and application of AT2R antagonists, there is still huge room for improvement, and it is still necessary to continue researching and developing new AT2R antagonists. Summary of the invention

[0011] The object of the present invention is to provide a compound as an AT2R antagonist and its use. The compound has a structure as shown in the first aspect of the present invention, and the compound can be used to prepare a drug, a pharmaceutical composition or a preparation for treating and / or preventing a disease or condition associated with AT2R; or to treat and / or prevent a disease or condition associated with AT2R.

[0012] In the first aspect of the present invention, there is provided a compound of formula I, a tautomer, a stereoisomer, a hydrate, a solvate, a pharmaceutically acceptable salt or a prodrug thereof:

[0013]

[0014] wherein Ring A is selected from a 5-6 membered heteroaromatic ring;

[0015] R1 is selected from halogen, hydroxyl, amino, cyano, oxo (=O), C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, amino, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl, oxo;

[0016] m is selected from 0, 1, 2, 3 or 4; when there are multiple substituents R1, the R1 are the same or different;

[0017] L is absent or selected from C0-C6 alkylene-O-C0-C6 alkylene, C1-C6 alkylene; the C1-C6 alkylene-O-C1-C6 alkylene or C1-C6 alkylene is optionally substituted by 1-4 substituents selected from the following groups: deuterium, oxo (=O), methyl, ethyl, halomethyl, haloethyl;

[0018] R2 is selected from C1-C6 alkyl, C3-C7 cycloalkyl, 5-10 membered heterocyclic ring, 6-10 membered aromatic ring; the C1-C6 alkyl, C3-C6 cycloalkyl, 5-10 membered heterocyclic ring, 6-10 membered aromatic ring is optionally substituted by 1, 2, 3, 4 substituents selected from the following groups: halogen, hydroxyl, cyano, amino, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; and R2 is not methyl, ethyl, isopropyl, -CF3;

[0019] n is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; when there are multiple substituents R2, the R2 are the same or different;

[0020] Ring E is selected from a benzene ring or a 6-membered heteroaromatic ring;

[0021] R3 is selected from halogen, hydroxyl, cyano, dimethylamino, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl;

[0022] p is selected from 0, 1, 2, 3 or 4; when there are multiple substituents R3, the R3 are the same or different;

[0023] M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole or tetrazole bioisostere; the bioisostere includes but is not limited to phosphoric acid,

[0024] R5 is selected from H, OH, NH2, ONa, OK (potassium ion), C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle; the C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle are optionally substituted by 1-4 substituents selected from the following groups: halogen, amino, C3-C7 heterocycloalkyl, C1-C3 alkyl, C3-C6 cycloalkyl, and C1-C3 alkoxy.

[0025] In a preferred embodiment of the present invention, the ring A is a 5-6 membered heteroaromatic ring, and the 5-6 membered heteroaromatic ring contains 1, 2, or 3 heteroatoms;

[0026] The heteroatom is selected from N, O, and S; more preferably, the heteroatom is N.

[0027] In a preferred embodiment of the present invention, the ring A is selected from the group consisting of furan, pyrrole, thiophene, oxazole, oxadiazole, thiazole, pyrazole, imidazole, triazole, tetrazole, pyridine, pyrimidine, pyridazine, triazine;

[0028] In a preferred embodiment of the present invention, the ring A is selected from: pyridine, pyrimidine, pyridazine, pyrazine.

[0029] In a preferred embodiment of the present invention, the ring A is selected from

[0030] In a preferred embodiment of the present invention, the ring E is a benzene ring or a 6-membered heteroaromatic ring;

[0031] The 6-membered heteroaromatic ring contains 1, 2, or 3 heteroatoms;

[0032] The heteroatom is selected from N, O and S.

[0033] In a preferred embodiment of the present invention, the ring E is selected from benzene ring, pyridine, pyrimidine, and pyridazine.

[0034] In a preferred embodiment of the present invention, the ring E is selected from a benzene ring.

[0035] In a preferred embodiment of the present invention, R1 is selected from halogen, hydroxyl, amino, cyano, oxo (=O), C1-C3 alkyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C3-C7 cycloalkyl, C1-C3 alkyl-C1-C3 alkoxy, C1-C3 alkyl-C3-C7 cycloalkyl;

[0036] m is selected from 0, 1, 2, 3 or 4.

[0037] In a preferred embodiment of the present invention, R1 is selected from halogen, methyl, halomethyl, methoxy; and m is selected from 0.

[0038] In a preferred embodiment of the present invention, the compound is selected from the following structures:

[0039]

[0040] Ring A, M, L, R1, R3, m and p are as defined in the first aspect of the present invention.

[0041] In a preferred embodiment of the present invention, the compound is selected from the following structures:

[0042]

[0043]

[0044] The definitions of ring A, M, L, R1, R3, m and p are as described in the first aspect of the present invention. In a preferred embodiment of the present invention, the compound is selected from the following structures:

[0045]

[0046] M and R2 are as defined in the first aspect of the present invention;

[0047] Preferably, the compound of formula IV has structure IVa, IVb:

[0048]

[0049] In a preferred embodiment of the present invention, the compound is selected from the following structures:

[0050]

[0051] Preferably, it has structure IIa or IIb:

[0052]

[0053] In a preferred embodiment of the present invention, the compound is selected from the following structures:

[0054]

[0055] Preferably, it has structure IV-2a, IV-2b, IV-3a or IV-3b:

[0056]

[0057] In a preferred embodiment of the present invention, R2 is selected from C1-C3 alkyl, C3-C6 cycloalkyl, 5-6 membered heterocycle, 5-6 membered heteroaromatic ring, benzene ring; the C1-C3 alkyl, C3-C6 cycloalkyl, 5-6 membered heterocycle, benzene ring are optionally substituted with 1, 2, 3, 4 substituents selected from the following groups: halogen, hydroxyl, cyano, amino, C1-C3 alkyl, C1-C3 alkoxy, C3-C6 cycloalkyl; and R2 is not methyl, ethyl, isopropyl, -CF3.

[0058] In a preferred embodiment of the present invention, n is selected from 1, 2, and 3.

[0059] In a preferred embodiment of the present invention, n is 1.

[0060] In a preferred embodiment of the present invention, the R2 is selected from CH2F, CHF2, C1-C3 alkyl-C1-C6 alkoxy, C3-C7 cycloalkyl, C1-C3 alkyl-C3-C7 cycloalkyl;

[0061] n is selected from 1, 2, 3, 4, 5, 6, 7 or 8.

[0062] In a preferred embodiment of the present invention, R2 is selected from CH2F, CHF2, C1-C3 alkyl-C1-C6 alkoxy, C3-C7 cycloalkyl, C1-C3 alkyl-C3-C7 cycloalkyl.

[0063] In a preferred embodiment of the present invention, R2 is selected from CH2F, CHF2, C1-C3 alkyl-C1-C3 alkoxy, C3-C4 cycloalkyl, C1-C3 alkyl-C3-C4 cycloalkyl; n is selected from 1, 2, 3.

[0064] In a preferred embodiment of the present invention, R2 is selected from CH2F, CHF2, methyl-methoxy, ethyl-methoxy, cyclopropyl, methyl-cyclopropyl; and n is selected from 1.

[0065] In a preferred embodiment of the present invention, said R2 is selected from CH2F, CHF2, methyl-methoxy, cyclopropyl.

[0066] In a preferred embodiment of the present invention, R2 is selected from CH2F, CHF2,

[0067] In a preferred embodiment of the present invention, R2 is selected from CH2F and CHF2.

[0068] In a preferred embodiment of the present invention, said R2 is selected from CHF2.

[0069] In a preferred embodiment of the present invention, the R3 is selected from halogen, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl;

[0070] p is selected from 0, 1, 2, 3 or 4.

[0071] In a preferred embodiment of the present invention, R3 is selected from F, C1-C5 alkyl, C1-C5 haloalkyl, methyl-cyclopropyl; p is selected from 1, 2, 3.

[0072] In a preferred embodiment of the present invention, R3 is selected from F, methyl, trifluoromethyl, isobutyl, isobutyl substituted with F, methyl-cyclopropyl; p is selected from 2.

[0073] In a preferred embodiment of the present invention, p is selected from 2, and R3 is selected from F and isobutyl.

[0074] In a preferred embodiment of the present invention, the M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole or tetrazole bioisostere.

[0075] In a preferred embodiment of the present invention, the tetrazole bioisostere is selected from -C(=O)-R5, -C(=O)NH-R5, -N(R5)C(=O)-R5, -ON(R5) e1 )C(=O)-R5, -S(=O)-R5, -S(=O)2-R5, -NH-S(=O)2-R5, -C(=O)-NH-S(=O)2-R5, -NH-C(=O)-NH-S(=O)2-R5, -NH-C(=O)-NH-C(=O)-R5, -P(=O)(-R5)2, 4-8 membered heterocycloalkyl substituted with 1, 2, 3 or 4 oxo (=O), wherein the R5 is selected from H, OH, NH2, ONa, OK (potassium ion), C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle; the C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle are optionally substituted by 1-4 substituents selected from the following groups: halogen, amino, C3-C7 heterocycloalkyl, C1-C3 alkyl, C3-C6 cycloalkyl, and C1-C3 alkoxy.

[0076] In a preferred embodiment of the present invention, the M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole; and the R5 is selected from C1-C3 alkyl, C3-C5 cycloalkyl.

[0077] In a preferred embodiment of the present invention, the M is selected from carboxylic acid, tetrazole, and -CONHSO2CH2CH3.

[0078] In a preferred embodiment of the present invention, the M is selected from carboxylic acid and tetrazole.

[0079] In a preferred embodiment of the present invention, the M is selected from tetrazole.

[0080] In a preferred embodiment of the present invention, the R2 is selected from CHF2, and the M is selected from tetrazole and carboxylic acid.

[0081] In a preferred embodiment of the present invention, the R2 is selected from CH2F, and the M is selected from carboxylic acid, tetrazole, -CONHSO2CH2CH3.

[0082] In a preferred embodiment of the present invention, the R2 is selected from CH2F, and the M is selected from carboxylic acid and tetrazole.

[0083] In a preferred embodiment of the present invention, the R2 is selected from CH2F, and the M is selected from tetrazole.

[0084] In a preferred embodiment of the present invention, said R2 is selected from CH2F, and said M is selected from carboxylic acid.

[0085] In a preferred embodiment of the present invention, said R2 is selected from CH2F, and said M is selected from -CONHSO2CH2CH3.

[0086] In a preferred embodiment of the present invention, the R2 is selected from cyclopropyl, and the M is selected from tetrazole.

[0087] In a preferred embodiment of the present invention, said R2 is selected from The M is selected from tetrazole.

[0088] In a preferred embodiment of the present invention, L is absent or selected from carbonyl, methylene, -CH2CH2-, -CH(CH3)-, -CH2CH2CH2-, -CH2CH(CH3)-, -O-CH2-.

[0089] In a preferred embodiment of the present invention, L is selected from methylene, -CH2CH2-, -CH(CH3)-, and -O-CH2-.

[0090] In a preferred embodiment of the present invention, said L is selected from methylene.

[0091] In a preferred embodiment of the present invention, the compound of formula I, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, is characterized in that the compound comprises:

[0092]

[0093] In a preferred embodiment of the present invention, the compound of formula I, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, is characterized in that the compound comprises:

[0094]

[0095]

[0096] In a second aspect, the present invention provides a pharmaceutical composition, comprising the compound of formula I as described in the first aspect, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug; and optionally a pharmaceutically acceptable carrier.

[0097] In a preferred embodiment of the present invention, the pharmaceutical composition comprises the compound of formula I as described in the first aspect, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug; and a pharmaceutically acceptable carrier

[0098] In a third aspect of the present invention, the use of the compound of formula I as described in the first aspect, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, or the pharmaceutical composition as described in the second aspect, the use comprising:

[0099] Acts as an AT2R antagonist;

[0100] and / or, preventing and / or treating AT2R-mediated diseases;

[0101] and / or, preventing and / or treating diseases in which a reduction in the action of Ang II is desired or required;

[0102] and / or, preparing a medicament, pharmaceutical composition or formulation as an AT2R antagonist;

[0103] And / or, preparing a medicament, pharmaceutical composition or formulation for preventing and / or treating a disease in which AT2R is expressed and its inhibition is desired or necessary.

[0104] Provided is a compound of formula I as described in the first aspect, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, or the pharmaceutical composition as described in the second aspect, which is expected to be used for treating neuropathy or neuropathic pain.

[0105] Neuropathies that should be mentioned include primary neuropathies, secondary neuropathies, peripheral neuropathies, neuropathies caused by mechanical or biochemical nerve damage or diabetic-related neuropathies.

[0106] Neuropathic pain that should be mentioned includes postherpetic neuralgia or diabetic neuropathy.

[0107] The compound of formula I described in the first aspect of the present invention, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, or the pharmaceutical composition described in the second aspect, is suitable for the treatment and / or preventive treatment of the above-mentioned diseases.

[0108] The fourth aspect of the present invention provides a method for treating a disease, wherein the disease is an AT2R-mediated disease, and / or a disease in which it is desired or necessary to reduce the effect of AngⅡ, and / or a disease in which AT2R is expressed and inhibition is desired or necessary, the method comprising administering a therapeutically effective amount of the compound of formula I described in the first aspect of the present invention, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, or the pharmaceutical composition described in the second aspect to a person suffering from or susceptible to the disease.

[0109] In a preferred embodiment of the present invention, the disease comprises an AT2R-mediated disease, a disease in which a reduction in the action of Ang II is desired or required.

[0110] In a preferred embodiment of the present invention, the disease comprises primary neuropathy, secondary neuropathy, peripheral neuropathy, neuropathy caused by mechanical nerve damage or biochemical nerve damage, or diabetic-related neuropathy.

[0111] In a preferred embodiment of the present invention, the disease comprises postherpetic neuralgia or diabetic neuropathy.

[0112] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

[0113] Terms and Definitions

[0114] Unless otherwise specified, the definitions of groups and terms recorded in the specification and claims of this application, including their definitions as examples, exemplary definitions, preferred definitions, definitions recorded in tables, definitions of specific compounds in examples, etc., can be arbitrarily combined and combined with each other. The group definitions and compound structures after such combination and combination shall fall within the scope recorded in the specification of this application.

[0115] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art to which the subject matter of the claims pertains. Unless otherwise indicated, all patents, patent applications, and publications cited herein are incorporated herein by reference in their entirety. If there are multiple definitions of a term herein, the definition in this chapter shall prevail.

[0116] It should be understood that the above brief description and the detailed description below are exemplary and are only used for explanation, and do not impose any restrictions on the subject matter of the present invention. In this application, unless otherwise specifically stated, the use of the singular also includes the plural. It must be noted that unless otherwise clearly stated in the text, the singular form used in this specification and claims includes the plural form of the referred thing. It should also be noted that unless otherwise stated, the "or" and "or" used mean "and / or". In addition, the term "including" and other forms, such as "including", "containing" and "containing" are not restrictive.

[0117] Definitions of standard chemical terms can be found in references (including Carey and Sundberg "ADVANCED ORGANIC CHEMISTRY 4 THE ED." Vols. A (2000) and B (2001), Plenum Press, New York). Unless otherwise stated, conventional methods within the technical scope of the art, such as mass spectrometry, NMR, IR and UV / VIS spectroscopy and pharmacological methods, are used. Unless specifically defined, the terms used herein in the relevant descriptions of analytical chemistry, organic synthetic chemistry, and drugs and medicinal chemistry are known in the art. Standard techniques can be used in chemical synthesis, chemical analysis, drug preparation, formulation and delivery, and in the treatment of patients. For example, the manufacturer's instructions for use of the kit can be used, or the reaction and purification can be carried out in a manner known in the art or in accordance with the description of the present invention. The above-mentioned techniques and methods can usually be implemented according to the descriptions in the multiple summaries and more specific documents cited and discussed in this specification, according to conventional methods well known in the art. In this specification, groups and substituents thereof can be selected by those skilled in the art to provide stable structural parts and compounds.

[0118] When a substituent is described by a conventional chemical formula written from left to right, the substituent also includes chemically equivalent substituents that would result if the formula were written from right to left. For example, CH2O is equivalent to OCH2. As used herein, As used herein, "R1", "R2" and "R 1 " have the same meaning and can be replaced with each other. For other symbols such as R2, similar definitions have the same meaning.

[0119] The section headings used herein are only for the purpose of organizing the article and should not be interpreted as limitations on the subject matter described. All documents or portions of documents cited in this application, including but not limited to patents, patent applications, articles, books, operating manuals and papers, are incorporated herein by reference in their entirety.

[0120] In addition to the foregoing, when used in the specification and claims of the present application, the following terms have the meanings indicated below unless otherwise specifically stated.

[0121] When the numerical range described in the specification and claims of this application is understood as an "integer", it should be understood that the two endpoints of the range and each integer in the range are recorded. For example, "an integer from 1 to 6" should be understood as recording each integer of 0, 1, 2, 3, 4, 5 and 6.

[0122] In the present application, when indicating the number of substituents, the term "one or more" refers to one substitution to the maximum possible number of substitutions, i.e., replacing one hydrogen to all hydrogens are replaced by substituents. When indicating the number of substituents, the term "1-4" refers to 1, 2, 3 or 4 substitutions, i.e., 1, 2, 3 or 4 hydrogens are replaced by substituents.

[0123] In the present application, "saturated, partially saturated or unsaturated" includes substituents saturated with hydrogen, substituents completely unsaturated with hydrogen and substituents partially saturated with hydrogen.

[0124] In this application, "AT2 receptor" and "AT2R" have the same definition.

[0125] In this application, the term "bioisostere" has the usual meaning in the art when used alone or as part of other substituents, and refers to a group or substituent with similar physical or chemical properties and has similar biological activity as the group or substituent. Bioisosteres are usually obtained by replacing one atom or group with another substantially similar atom or group, and may have one or more enhanced properties compared to the original compound, group or substituent (e.g., reduced toxicity, increased bioavailability, altered or increased activity, or improved metabolism). The term "tetrazole and its bioisostere" refers to tetrazole, and a substance with substantially similar or related biological activity produced by a group or substituent with similar physical and chemical properties in a biological sense to tetrazole. In some embodiments, the term "tetrazole and its bioisostere" includes but is not limited to -C(=O)-R5, -C(=O)NH-R5, -N(R5)C(=O)-R5, -ON(R5) e1)C(=O)-R5, -S(=O)-R5, -S(=O)2-R5, -NH-S(=O)2-R5, -C(=O)-NH-S(=O)2-R5, -NH-C(=O)-NH-S(=O)2-R5, -NH-C(=O)-NH-C(=O)-R5, -P(=O)(-R5)2, 4-8 membered heterocycloalkyl substituted with 1, 2, 3 or 4 oxo (=O), wherein the R5 is selected from H, OH, NH2, ONa, OK (potassium ion), C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, 5-6 membered heterocycle; the C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, 5-6 membered heterocycle is optionally substituted by 1-4 substituents selected from the following groups: halogen, amino, C3-C7 heterocycloalkyl, C1-C3 alkyl, C3-C6 cycloalkyl, C1-C3 alkoxy. The 4-8 membered heterocycloalkyl has the definition of the term "heterocycloalkyl" below. For example, the term "tetrazolyl and its bioisostere" includes but is not limited to carboxylic acid, phosphoric acid,

[0126] As used herein, the term "halogen" by itself or as part of another substituent refers to fluorine, chlorine, bromine, iodine.

[0127] As used herein, the term "amino" by itself or as part of another substituent refers to -NH2.

[0128] As used herein, the term "hydroxy" by itself or as part of another substituent refers to -OH.

[0129] As used herein, the term "cyano" by itself or as part of another substituent refers to -CN.

[0130] In the present application, when alone or as part of other substituents, the term "alkyl" means a straight or branched hydrocarbon chain group consisting only of carbon atoms and hydrogen atoms, free of unsaturated bonds, having, for example, 1 to 6 carbon atoms and connected to the rest of the molecule by a single bond. Examples of alkyls include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl and hexyl. Alkyl can be unsubstituted or substituted with one or more suitable substituents. Alkyl can also be an isotope isomer of a natural abundance alkyl rich in isotopes of carbon and / or hydrogen (i.e., deuterium or tritium). As used herein, the term "alkenyl" means an unbranched or branched monovalent hydrocarbon chain containing one or more carbon-carbon double bonds. As used herein, the term "alkynyl" refers to an unbranched or branched monovalent hydrocarbon chain containing one or more carbon-carbon triple bonds.

[0131] In the present application, the term "C1-C6 alkyl" alone or as part of another substituent is understood to mean a straight-chain or branched saturated hydrocarbon radical having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl radical is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, or the like or isomers thereof. In particular, such radicals have 1, 2 or 3 carbon atoms ("C1-C3 alkyl"), for example methyl, methylene, ethyl, n-propyl or isopropyl.

[0132] In the present application, the term "alkylene" is understood to mean a straight-chain divalent hydrocarbon group having 1 to 6 carbon atoms or a branched divalent hydrocarbon group having 3 to 6 carbon atoms, unless otherwise specified, such as methylene, ethylene, propylene, 1-methylpropylene, butylene, etc.

[0133] In the present application, when alone or as part of other substituents, the term "C1-C6 alkoxy" should be understood to mean a straight or branched saturated hydrocarbon group having 1, 2, 3, 4, 5 or 6 carbon atoms and an oxygen atom, or represented by C1-C6 alkyl-O-C1-C6 alkyl. The definition of alkyl is as described in this specification, and the oxygen atom can be connected to any carbon atom of the straight or branched C1-C6 alkyl. Including but not limited to: methoxy (CH3-O-), ethoxy (C2H5-O-), propoxy (C3H7-O-), butoxy (C4H9-O-).

[0134] As used herein, "haloalkoxy" alone or as part of another substituent refers to an alkoxy group as described above, wherein any number (at least one) of the hydrogen atoms attached to the alkoxy group are replaced by fluorine, chlorine, bromine or iodine.

[0135] In the present application, the term "oxo" alone or as part of other substituents refers to the replacement of two hydrogen atoms on a methylene group by oxygen, that is, the methylene group is replaced by a carbonyl group, representing =0.

[0136] In the present application, "haloalkyl" refers to saturated aliphatic hydrocarbon groups including branched and straight chains having a specific number of carbon atoms, substituted by one or more halogens (such as -CvFw, where v = 1 to 3, w = 1 to (2v+1)) when used alone or as part of other substituents. Examples of haloalkyl include, but are not limited to, trifluoromethyl, trichloromethyl, pentafluoroethyl, pentachloroethyl, 2,2,2-trifluoroethyl, heptafluoropropyl, and heptachloropropyl.

[0137] In this application, the term "aryl" or "aromatic ring" when used alone or as part of another substituent refers to a monocyclic or polycyclic carbon ring having 6 to 20 carbon atoms, at least one of which is aromatic. When one of the rings is non-aromatic, the group may be attached via the aromatic ring or via the non-aromatic ring. Examples of aryl include, but are not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthrenyl, anthracenyl, and acenaphthenyl.

[0138] In the present application, when alone or as part of other substituents, the term "heteroaromatic ring" refers to a monocyclic or polycyclic carbocyclic ring, wherein at least one ring atom is a heteroatom independently selected from oxygen, sulfur and nitrogen, and the remaining ring atoms are C, wherein at least one ring is an aromatic ring. The group may be a carbon group or a heteroatom group (i.e., it may be C-connected or N-connected, as long as it is possible). When one of the rings is a non-aromatic ring, the group may be connected by an aromatic ring or by a non-aromatic ring. Examples of heteroaryl include, but are not limited to, imidazolyl, acridinyl, carbazolyl, cinnolinyl, quinoxalinyl, pyrazolyl, indolyl, benzotriazolyl, furanyl, thienyl, benzothienyl, benzofuranyl, quinolyl, isoquinolyl, oxazolyl, isoxazolyl, indolyl, pyrazinyl, pyridazinyl, pyridyl, pyrimidinyl, pyrrolyl, N-methylpyrrolyl and tetrahydroquinoline. The term "heteroaromatic ring" can be used interchangeably with the term "heteroaromatic ring", "heteroaryl" or "heteroaromatic ring group". In the present application, when alone or as part of other substituents, the term "5-10 membered heteroaromatic ring" can be used interchangeably with "5-10 membered heteroaryl", and should be understood as an aromatic ring group having 5-10 ring atoms and containing 1-5 heteroatoms independently selected from N, O and S. The term "5-6 membered heteroaromatic ring" should be understood as an aromatic ring group having 5 or 6 ring atoms - and it contains 1-3 - heteroatoms independently selected from N, O and S. In particular, the heteroaryl group is selected from thienyl, furanyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl; or pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl.

[0139] As used herein, the term "cycloalkyl" or "carbocyclyl" when used alone or as part of another substituent refers to a cyclic alkyl group. m -C n"Cycloalkyl" is understood to mean a saturated, unsaturated or partially saturated carbon ring having m to n atoms. For example, "3-15 membered cycloalkyl" or "C3-C 15 "Cycloalkyl" refers to a cyclic alkyl group containing 3 to 15, 3 to 9, 3 to 6 or 3 to 5 carbon atoms, which may contain 1 to 4 rings. "5-8 membered cycloalkyl" contains 5-8 carbon atoms. It includes monocyclic, bicyclic, tricyclic, spirocyclic or bridged rings. Examples of unsubstituted cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and adamantyl, or a bicyclic hydrocarbon group such as a decalin ring. The cycloalkyl group may be substituted with one or more substituents. In some embodiments, the cycloalkyl group may be a cycloalkyl group fused to an aryl or heteroaryl group.

[0140] As used herein, "halocycloalkyl" by itself or as part of another substituent refers to a cycloalkyl as described above, wherein any number (at least one) of the hydrogen atoms attached to the cycloalkyl are replaced by fluorine, chlorine, bromine or iodine.

[0141] In the present application, when alone or as part of other substituents, the term "heterocycloalkyl" refers to a cycloalkyl group in which one or more (in some embodiments, 1 to 3) carbon atoms are replaced by heteroatoms, such as but not limited to N, O, S and P. "Heterocycloalkyl" can be saturated or unsaturated, but not aromatic. "Heterocycloalkyl" can also contain 1, 2 or 3 rings, including bridged rings and spirocyclic structures. The term "3-8 membered heterocycloalkyl" should be understood to mean a monocyclic, bicyclic or tricyclic ring with 3 to 8 atoms, wherein the heteroatoms are preferably selected from N, O and S, and it should be understood that when the total number of S atoms and O atoms in the heterocyclic group exceeds 1, these heteroatoms are not adjacent to each other. Examples of heterocycloalkyl include, but are not limited to, tetrahydroisoquinolyl, tetrahydroquinolyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl.

[0142] In the present application, the term "monocyclic" when alone or as part of other substituents means a group having only one ring, which may be saturated, unsaturated or partially saturated, and may be a carbocyclic ring (all ring atoms are carbon atoms) or a heterocyclic ring (in addition to carbon atoms, the ring atoms include, for example, 1, 2 or 3 heteroatoms, such as N, O or S).

[0143] As used herein, the term "heterocycle" includes "heterocycloalkyl" and "heteroaryl" when used alone or as part of other substituents, and refers to a cycloalkyl or aromatic ring group in which one or more (in some embodiments, 1 to 3) carbon atoms are replaced by heteroatoms, such as, but not limited to, N, O, S and P.

[0144] In the present application, the term "inert solvent" includes, but is not limited to: toluene, benzene, water, methanol, ethanol, isopropanol, ethylene glycol, N-methylpyrrolidone, dimethyl sulfoxide, tetrahydrofuran, dichloromethane, chloroform, 1,2-dichloroethane, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dioxane, or a combination thereof.

[0145] Compounds provided herein include intermediates that can be used to prepare compounds provided herein, which contain reactive functional groups (such as but not limited to carboxyl, hydroxyl and amino moieties), and also include protected derivatives thereof. "Protected derivatives" are those compounds in which one or more reactive sites are blocked by one or more protecting groups (also referred to as protecting groups). Suitable carboxyl moiety protecting groups include benzyl, tert-butyl, etc., and isotopes, etc. Suitable amino and amido protecting groups include acetyl, trifluoroacetyl, tert-butyloxycarbonyl, benzyloxycarbonyl, etc. Suitable hydroxyl protecting groups include benzyl, etc. Other suitable protecting groups are well known to those of ordinary skill in the art.

[0146] In the present application, the term "substituted" means that any one or more hydrogen atoms on a particular atom are replaced by a substituent, including deuterium and hydrogen variants, as long as the valence state of the particular atom is normal and the substituted compound is stable.

[0147] In the present application, the term "optional" or "optionally" means that the event or situation described later may or may not occur, and the description includes both the occurrence and non-occurrence of the event or situation. For example, "optionally substituted aryl" means that aryl is substituted or unsubstituted, and the description includes both substituted aryl and unsubstituted aryl.

[0148] In the present application, the term "optionally substituted by" or "optionally substituted by" means that the specified group is unsubstituted or substituted by one or more substituents independently selected from possible substituents. For example, "aryl is optionally substituted by 1-4 substituents independently selected from the following groups: halogen, cyano, hydroxyl, C 1-6 "Alkyl" means that the aryl group is unsubstituted or substituted by 1, 2, 3 or 4 substituents independently selected from the following groups: halogen, cyano, hydroxyl, C 1-6 The term "alkyl" refers to an alkyl group, and the description includes both substituted and unsubstituted aryl groups.

[0149] In the present application, the term "salt" or "pharmaceutically acceptable salt" includes pharmaceutically acceptable acid addition salts and pharmaceutically acceptable base addition salts. The term "pharmaceutically acceptable" refers to those compounds, materials, compositions and / or dosage forms that are suitable for use in contact with human and animal tissues within the scope of sound medical judgment without excessive toxicity, irritation, allergic reactions or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0150] In this application, the term "pharmaceutically acceptable acid addition salt" refers to a salt formed with an inorganic acid or organic acid that retains the biological effectiveness of the free base without other side effects. "Pharmaceutically acceptable base addition salt" refers to a salt formed with an inorganic base or organic base that retains the biological effectiveness of the free acid without other side effects. In addition to pharmaceutically acceptable salts, other salts are contemplated by the present invention. They can serve as intermediates in the purification of compounds or in the preparation of other pharmaceutically acceptable salts or can be used for the identification, characterization or purification of the compounds of the present invention.

[0151] In the present application, the term "amine salt" refers to the product obtained by neutralizing an alkyl primary amine, a secondary amine or a tertiary amine with an acid. The acid includes the inorganic acid or organic acid described in the present application.

[0152] In the present application, the term "stereoisomer" refers to isomers resulting from different spatial arrangements of atoms in molecules, including cis-trans isomers, enantiomers, diastereomers and conformational isomers.

[0153] Depending on the choice of starting materials and methods, the compounds of the invention may exist in the form of one of the possible isomers or a mixture thereof, for example as a pure optical isomer, or as a mixture of isomers, such as a racemic and diastereomeric mixture, depending on the number of asymmetric carbon atoms. When describing optically active compounds, the prefixes D and L or R and S are used to indicate the absolute configuration of the molecule with respect to the chiral center (or multiple chiral centers) in the molecule. The prefixes D and L or (+) and (–) are the symbols used to specify the rotation of plane polarized light caused by the compound, where (–) or L indicates that the compound is levorotatory. Compounds prefixed with (+) or D are dextrorotatory.

[0154] When the bonds to the chiral carbon in the formula of the present invention are depicted as straight lines, it should be understood that both the (R) and (S) configurations of the chiral carbon and the enantiomerically pure compounds and mixtures thereof produced therefrom are included within the scope of the general formula. The graphic representation of racemates or enantiomerically pure compounds herein is from Maehr, J. Chem. Ed. 1985, 62: 114-120. The absolute configuration of a stereocenter is indicated by a wedge-shaped bond and a dashed bond.

[0155] In the present application, the term "tautomer" refers to a functional group isomer resulting from the rapid movement of an atom in two positions in a molecule. The compounds of the present invention may exhibit tautomerism. Tautomeric compounds may exist in two or more interconvertible species. Prototropic tautomers arise from the migration of a covalently bonded hydrogen atom between two atoms. Tautomers generally exist in equilibrium, and attempts to separate a single tautomer generally produce a mixture whose physicochemical properties are consistent with a mixture of compounds. The position of equilibrium depends on the chemical properties within the molecule. For example, in many aliphatic aldehydes and ketones such as acetaldehyde, the keto form is predominant; whereas in phenols, the enol form is predominant. The present invention encompasses all tautomeric forms of the compounds.

[0156] In this application, the term "pharmaceutical composition" refers to a preparation of a compound of the present invention and a medium generally accepted in the art for delivering a biologically active compound to a mammal (e.g., a human). The medium includes a pharmaceutically acceptable carrier. The purpose of the pharmaceutical composition is to promote administration of an organism, facilitate the absorption of the active ingredient, and thus exert biological activity.

[0157] In this application, the term "pharmaceutically acceptable carrier" includes, but is not limited to, any adjuvant, carrier, excipient, glidant, sweetener, diluent, preservative, dye / colorant, flavoring agent, surfactant, wetting agent, dispersant, suspending agent, stabilizer, isotonic agent, solvent or emulsifier approved by the relevant governmental regulatory authorities as acceptable for human or livestock use.

[0158] In the present application, the term "solvate" means that the compound of the present invention or a salt thereof includes a stoichiometric or non-stoichiometric amount of a solvent bound by non-covalent forces between molecules. When the solvent is water, it is a hydrate.

[0159] In the present application, the term "prodrug" refers to a compound of the present invention that can be converted into a biologically active compound under physiological conditions or by solvolysis. The prodrug of the present invention is prepared by modifying the functional groups in the compound, and the modification can be removed by conventional operations or in vivo to obtain the parent compound. The prodrug includes a compound formed by connecting a hydroxyl or amino group in the compound of the present invention to any group. When the prodrug of the compound of the present invention is administered to a mammalian individual, the prodrug is cleaved to form a free hydroxyl group and a free amino group, respectively.

[0160] The compounds of the invention may contain unnatural proportions of atomic isotopes on one or more of the atoms that make up the compound. For example, the compounds may be labeled with radioactive isotopes, such as deuterium ( 2 H), tritium ( 3 H), iodine-125( 125 I) or C-14( 14C) All isotopic variations of the compounds of the present invention, whether radioactive or not, are included within the scope of the present invention.

[0161] In this application, the term "excipient" refers to a pharmaceutically acceptable inert ingredient. Examples of the type of the term "excipient" include, but are not limited to, binders, disintegrants, lubricants, glidants, stabilizers, fillers, and diluents. Excipients can enhance the handling characteristics of a pharmaceutical formulation, i.e., make the formulation more suitable for direct compression by increasing fluidity and / or adhesion.

[0162] As used herein, the term "treatment" and other similar synonyms include the following meanings:

[0163] (i) preventing a disease or condition from occurring in a mammal, particularly where such mammal is susceptible to the disease or condition but has not yet been diagnosed as having the disease or condition;

[0164] (ii) inhibiting a disease or condition, i.e. arresting its development;

[0165] (iii) alleviate the disease or condition, that is, cause regression of the disease or condition; or

[0166] (iv) alleviating the symptoms caused by the disease or condition.

[0167] Beneficial Effects

[0168] After extensive and in-depth research, the inventors unexpectedly developed a compound as an AT2R antagonist, the compound having the structure shown in the present invention. The compound of the present invention can prevent or treat diseases or conditions related to AT2 receptors, exhibits excellent pharmacokinetic properties, and has high safety and drug properties. DETAILED DESCRIPTION

[0169] The present invention is further described below in conjunction with specific examples. It should be understood that the following description is only the most preferred embodiment of the present invention and should not be considered as limiting the scope of protection of the present invention. On the basis of a full understanding of the present invention, the experimental methods in the following examples that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. Those skilled in the art may make non-essential changes to the technical solution of the present invention, and such changes should be deemed to be included in the scope of protection of the present invention.

[0170] This application has the following definitions:

[0171] Symbol or unit:

[0172] IC 50 : Half inhibitory concentration, which refers to the concentration at which half of the maximum inhibitory effect is achieved

[0173] M: mol / L, for example, n-butyllithium (14.56 mL, 29.1 mmol, 2.5 M n-hexane solution) means a n-butyllithium n-hexane solution with a molar concentration of 2.5 mol / L

[0174] N: equivalent concentration, for example, 2N hydrochloric acid means 2 mol / L hydrochloric acid solution

[0175] RT: retention time

[0176] Reagents:

[0177] DMF: N,N-dimethylformamide

[0178] DCM: dichloromethane

[0179] DIPEA: N,N-diisopropylethylamine

[0180] MeOH: Methanol

[0181] EA: Ethyl acetate

[0182] PE: Petroleum ether

[0183] HATU: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate

[0184] XPhos Pd G4: (SP-4-3)-[dicyclohexyl[2',4',6'-tri(isopropyl)[1,1'-biphenyl]-2-yl]phosphine](methanesulfonate)[2'-(methylamino)[1,1'-biphenyl]-2-yl]palladium

[0185] Test method:

[0186] LCMS: Liquid chromatography-mass spectrometry

[0187] TLC: Thin layer chromatography

[0188] Intermediate A1: Preparation of Intermediate A1

[0189] Synthesis of 2,6-difluoro-4-isobutylbenzonitrile

[0190]

[0191] The synthetic route of intermediate A1 is as follows:

[0192]

[0193] Isobutylboric acid (7.01 g, 68.81 mmol), 1,1-bis(diphenylphosphine)dichloropalladium iron (3.36 g, 4.59 mmol) and potassium carbonate (19.02 g, 137.61 mmol) were added to a solution of 4-bromo-2,6-difluorobenzonitrile (10 g, 45.87 mmol) in dioxane (150 mL), and the reaction solution was reacted at 115 ° C for 16 h. After the reaction was completed, the mixture was filtered with diatomaceous earth and concentrated to obtain a crude product. The crude product was purified by column chromatography (pure petroleum ether) to obtain the product 2,6-difluoro-4-isobutylbenzonitrile (7 g, yield 78.71%).

[0194] Example 1: Preparation of target compound I-3

[0195] (R)-3-((4-(3-fluoro-5-isobutyl-2-(2H-tetrazol-5-yl)phenyl)-2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine

[0196]

[0197] The synthetic route of the target compound I-3 is as follows:

[0198]

[0199] Step 1: Synthesis of tert-butyl (R)-4-acetyl-3-(hydroxymethyl)piperazine-1-carboxylate

[0200]

[0201] Triethylamine (1.4 g, 13.8 mmol) and acetyl chloride (542 mg, 6.9 mmol) were added to a solution of (R)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (1 g, 4.6 mmol) in dichloromethane (10 mL), and then stirred at room temperature for 2 h. The reaction solution was poured into water (50 mL) and extracted three times with dichloromethane (20 mL). The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated to give a crude product. The crude product was purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 0-1 / 1) to give the product (R)-4-acetyl-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (800 mg, 67% yield).

[0202] Step 2: Synthesis of tert-butyl (R)-4-acetyl-3-(methoxymethyl)piperazine-1-carboxylate

[0203]

[0204] At 0°C, sodium hydrogen (144 mg, 6 mmol, 60% purity) was added to a solution of (R)-4-acetyl-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (400 mg, 1.5 mmol) in tetrahydrofuran (4 mL) and stirred for 0.5 h. Then iodomethane (284 mg, 2 mmol) was slowly dripped into the reaction solution and stirred at 25°C for 5 h. The reaction solution was slowly dripped into a saturated ammonium chloride solution (20 mL) and extracted three times with ethyl acetate (10 mL). The organic phase was washed twice with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 0-0 / 1) to obtain the product (R)-4-acetyl-3-(methoxymethyl)piperazine-1-carboxylic acid tert-butyl ester (350 mg, yield 83%).

[0205] Step 3: Synthesis of tert-butyl (R)-3-(methoxymethyl)piperazine-1-carboxylate

[0206]

[0207] To a solution of (R)-4-acetyl-3-(methoxymethyl)piperazine-1-carboxylic acid tert-butyl ester (350 mg, 1.3 mmol) in methanol (3.5 mL) was added 10 M aqueous sodium hydroxide solution (1.3 mL, 13 mmol) and stirred at 90°C for 18 h. The reaction solution was poured into water (50 mL) and extracted three times with ethyl acetate (20 mL). The organic phase was washed twice with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was purified by column chromatography (dichloromethane / methanol (V / V) = 1 / 0-10 / 1) to obtain the product (R)-3-(methoxymethyl)piperazine-1-carboxylic acid tert-butyl ester (130 mg, yield 43.9%).

[0208] Step 4: Synthesis of tert-butyl (R)-3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylate

[0209]

[0210] Triethylamine (182 mg, 1.8 mmol) and (R)-3-(methoxymethyl)piperazine-1-carboxylic acid tert-butyl ester (130 mg, 0.6 mmol) were added to a solution of 3-(chloromethyl)pyridazine (116 mg, 0.9 mmol) in N,N-dimethylformamide (1.3 mL), and then stirred at 50 ° C for 18 h. The reaction solution was poured into water (50 mL) and washed three times with ethyl acetate (20 mL). The organic phase was washed twice with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 0-0 / 1) to obtain the product (R)-3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylic acid tert-butyl ester (120 mg, yield 65.9%).

[0211] LC-MS, M / Z(ESI):323.3[M+H] +

[0212] Step 5: Synthesis of (R)-3-((2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine

[0213]

[0214] To a solution of (R)-tert-butyl 3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylate (120 mg, 0.4 mmol) in dioxane (1.2 mL) was added hydrochloric acid / 1,4-dioxane solution (1.2 mL, 4 M) and reacted at room temperature for 2 h. The reaction solution was concentrated to obtain the product (R)-3-((2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine (hydrochloride, 100 mg).

[0215] LC-MS, M / Z(ESI):223.3[M+H] +

[0216] Step 6: Synthesis of (R)-2-fluoro-4-isobutyl-6-(3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzonitrile

[0217]

[0218] To a solution of 2,6-difluoro-4-isobutylbenzonitrile (intermediate A1, 80 mg, 0.4 mmol) in N,N-dimethylformamide (1 mL) was added (R)-3-((2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine (89 mg, 0.4 mmol) and N,N-diisopropylethylamine (146 mg, 1.2 mmol), and then stirred at 80 ° C for 18 h. The reaction solution was poured into water (50 mL) and extracted three times with ethyl acetate (20 mL). The organic phase was washed five times with water (10 mL), washed twice with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was purified by column chromatography (dichloromethane / methanol (V / V) = 1 / 0-10 / 1) to give the product (R)-2-fluoro-4-isobutyl-6-(3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzonitrile (80 mg, yield 49.1%).

[0219] LC-MS, M / Z(ESI):398.3[M+H] +

[0220] Step 7: Synthesis of (R)-3-((4-(3-fluoro-5-isobutyl-2-(2H-tetrazolyl-5-yl)phenyl)-2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine

[0221]

[0222] (R)-2-Fluoro-4-isobutyl-6-(3-(methoxymethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzonitrile (80 mg, 0.8 mmol), sodium azide (104 mg, 1.6 mmol) and tributyltin chloride (521 mg, 1.6 mmol) were dissolved in toluene (1.2 mL), the solution was poured into a stainless steel can, sealed, and reacted at 140°C for 12 h. The reaction solution was slowly poured into water (50 mL) and extracted three times with ethyl acetate (20 mL). The organic phase was washed twice with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was subjected to reverse phase preparative chromatography (chromatographic column: Phenomenex Synergi C18100*25mm*4um; solvent: A=water+0.1 volume % formic acid (99%), B=acetonitrile; gradient: 5%-95%, 7 minutes) to obtain the product (R)-3-((4-(3-fluoro-5-isobutyl-2-(2H-tetrazol-5-yl)phenyl)-2-(methoxymethyl)piperazin-1-yl)methyl)pyridazine (21.3 mg, purity 99.42%, yield 24%).

[0223] 1H NMR(400MHz,DMSO)δ9.10(dd,1H),7.66(qd,2H),6.92–6.83(m,2H),4.14(d,1H),3.73(d,1H),3.47(dd,2H) ,3.17(dd,1H),3.12(s,3H),2.89(d,1H),2.76–2.51(m,6H),2.22–2.15(m,1H),1.90(dq,1H),0.89(d,6H).

[0224] LC-MS, M / Z(ESI):441.1[M+H] +

[0225] Example 2: Preparation of target compound I-5

[0226] (R)-2-Fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid

[0227]

[0228] The synthetic route of the target compound I-5 is as follows:

[0229]

[0230] Step 1: Synthesis of tert-butyl (R)-3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylate

[0231]

[0232] 3-(Chloromethyl)pyridazine (1 g, 7.5 mmol) and triethylamine (2 g, 15 mmol) were added to a solution of (R)-3-(fluoromethyl)piperazine-1-carboxylic acid tert-butyl ester (1.2 g, 5.5 mmol) in N,N-dimethylformamide (20 mL), and the mixture was stirred at 60 ° C for 18 hours. The reaction solution was directly concentrated to obtain a crude product. The crude product was purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 1) to obtain (R)-3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylic acid tert-butyl ester (500 mg, yield 29%).

[0233] LC-MS, M / Z(ESI):311.2[M+H] +

[0234] Step 2: Synthesis of (R)-3-((2-(fluoromethyl)piperazin-1-yl)methyl)pyridazine

[0235]

[0236] (R)-tert-butyl 3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazine-1-carboxylate (500 mg, 1.6 mmol) was dissolved in dichloromethane (10 mL), and then 5 mL of 4M hydrochloric acid dioxane solution was added and stirred at room temperature for 1 h. The product (R)-3-((2-(fluoromethyl)piperazin-1-yl)methyl)pyridazine (500 mg, yield 100%) was obtained by direct concentration.

[0237] LC-MS, M / Z(ESI):211.2[M+H] +

[0238] Step 3: Synthesis of (R)-methyl 4-bromo-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzoate

[0239]

[0240] A solution of methyl 4-bromo-2,6-difluorobenzoate (575 mg, 2.3 mmol), (R)-3-((2-(fluoromethyl)piperazine-1-yl)methyl)pyridazine (500 mg, 2.3 mol) and potassium carbonate (950 mg, 6.9 mmol) in dimethyl sulfoxide (5 mL) was placed in an oil bath at 100 ° C and reacted for 15 h. The reaction solution was added dropwise to a saturated aqueous sodium chloride solution (50 mL), and then extracted three times with ethyl acetate (20 mL). Washed five times with water (10 mL), washed twice with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. The crude product was purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 1) to give the product (R)-methyl 4-bromo-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzoate (150 mg, yield 15%).

[0241] LC-MS,M / Z(ESI):441.20 / 443.2[M+H] +

[0242] Step 4: Synthesis of (R)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid methyl ester

[0243]

[0244] Under nitrogen protection, (R)-methyl 4-bromo-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)benzoate (150 mg, 0.34 mmol), potassium carbonate (94 mg, 0.68 mmol), (SP-4-3)-[dicyclohexyl[2',4',6'-tri(isopropyl)[1,1'-biphenyl]-2-yl]phosphine](methanesulfonic acid)[2'-(methylamino)[1,1'-biphenyl]-2-yl]palladium (34 mg, 0.04 mmol) and isobutylboric acid (1.7 g, 1.7 mmol) were added to anhydrous dioxane (5 mL) and reacted at 90°C for 2 h. The crude product was directly concentrated and purified by column chromatography (petroleum ether / ethyl acetate (V / V) = 1 / 1) to give the product (R)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid methyl ester (120 mg, yield 84%).

[0245] LC-MS, M / Z(ESI):419.20[M+H] +

[0246] Step 5: Synthesis of (R)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid

[0247]

[0248] (R)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid methyl ester (120 mg, 0.29 mmol) was dissolved in methanol (4 mL) and water (1 mL), and then lithium hydroxide (21 mg, 0.87 mmol) was added and reacted at room temperature for 18 h. The reaction solution was concentrated to obtain a crude product, which was subjected to reverse phase preparative chromatography (chromatographic column: Phenomenex Synergi C18 100*25mm*4μm; solvent: A=water+0.1 volume % formic acid (99%), B=acetonitrile; gradient: 5%-95%, 7 minutes) to obtain the product (R)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid (80 mg, yield 68%).

[0249] 1H NMR(400MHz,dmso)δ13.50(s,1H),9.12(d,1H),7.74-7.65(m,2H),6.74-6.71(m,2H),4.87-4. 59(m,3H),4.20-3.94(m,3H),3.19-2.87(m,5H),2.44-2.40(m,2H),1.82(m,1H),0.84(d,6H).

[0250] LC-MS, M / Z(ESI):405.2[M+H] +

[0251] Example 3: Preparation of target compound I-6

[0252] (R)-N-(Ethylsulfonyl)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzamide

[0253]

[0254] The synthetic route of the target compound I-6 is as follows:

[0255]

[0256] Step 1: Synthesis of (R)-N-(ethylsulfonyl)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzamide

[0257]

[0258] (R)-2-Fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzoic acid (80 mg, 0.19 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (380 mg, 1.98 mmol) and 4-dimethylaminopyridine (435 mg, 3.56 mmol) were dissolved in dichloroethane (3 mL), and then the nitrogen atmosphere was replaced. The reaction solution was stirred at room temperature for 10 min, and then ethylsulfonamide (324 mg, 2.98 mmol) was added, and the reaction solution was reacted at 50 ° C for 3 h. The reaction solution was concentrated to obtain a crude product, which was subjected to reverse phase preparative chromatography (chromatographic column: Phenomenex Synergi C18100*25mm*4um; solvent: A=water+0.1 volume % formic acid (99%), B=acetonitrile; gradient: 5%-95%, 7 minutes) to obtain the product (R)-N-(ethylsulfonyl)-2-fluoro-6-(3-(fluoromethyl)-4-(pyridazin-3-ylmethyl)piperazin-1-yl)-4-isobutylbenzamide (8 mg, yield 8%).

[0259] 1 H NMR(400MHz,DMSO)δ9.13(d,1H),7.75-7.73(m,2H),7.69-7.67(m,2H),6.73-6.71(m,2H),4.83- 4.74(m,3H),4.20-3.93(m,2H),3.21-2.43(m,8H),1.82(m,1H),1.24-1.23(m,3H),0.84(d,6H).

[0260] LC-MS, M / Z(ESI):496.2[M+H] +

[0261] Example 4: Preparation of target compound I-1

[0262] 3-(((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazol-5-yl)-5-isobutylphenyl)piperazin-1-yl)methyl)pyridazine

[0263]

[0264] The synthetic route of the target compound I-1 is as follows:

[0265]

[0266] Step 1: Synthesis of 6-((3R)-3-(difluoromethyl)piperazin-1-yl)-2-fluoro-4-isobutylbenzonitrile

[0267]

[0268] Under nitrogen protection, (2R)-2-(difluoromethyl)piperazine dihydrochloride (1.00 g, 4.81 mmol) and triethylamine (1.46 g, 14.43 mmol) were dissolved in DMF (20 mL), 2,6-difluoro-4-isobutylbenzonitrile (Intermediate A1, 940 mg, 4.81 mmol) was added thereto, and stirred at 80°C for 16 h. After the reaction was completed, it was diluted with water (50 mL), extracted three times with ethyl acetate (20 mL), the organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography to obtain 6-((3R)-3-(difluoromethyl)piperazine-1-yl)-2-fluoro-4-isobutylbenzonitrile (710 mg, yield 47%).

[0269] LC-MS, M / Z(ESI):312.1[M+H] +

[0270] Step 2: Synthesis of 6-((3R)-4-(pyridazine-3-ylcarbonyl)-3-(difluoromethyl)piperazine-1-yl)-2-fluoro-4-isobutylbenzonitrile

[0271]

[0272] 6-((3R)-3-(difluoromethyl)piperazin-1-yl)-2-fluoro-4-isobutylbenzonitrile (700 mg, 2.25 mmol), HATU (1.076 g, 2.70 mmol), 3-carboxypyridazine (308 mg, 2.48 mmol) and DIPEA (582 mg, 4.50 mmol) were dissolved in DMF (10 mL) and reacted at 25°C for 16 h. After the reaction was completed, it was diluted with water (50 mL) and extracted three times with ethyl acetate (20 mL). The organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography to obtain 6-((3R)-4-(pyridazin-3-ylcarbonyl)-3-(difluoromethyl)piperazin-1-yl)-2-fluoro-4-isobutylbenzonitrile (415 mg, yield 44%).

[0273] LC-MS, M / Z (ESI): 418.1 [M+H) +

[0274] Step 3: Synthesis of ((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazolyl-5-yl)-5-isobutylphenyl)piperazin-1-yl)(pyridazine-3-yl)methanone

[0275]

[0276] 6-((3R)-4-(pyridazine-3-ylcarbonyl)-3-(difluoromethyl)piperazine-1-yl)-2-fluoro-4-isobutylbenzonitrile (400 mg, 0.96 mmol), sodium azide (624 mg, 9.60 mmol) and tributyltin chloride (3.12 g, 9.60 mmol) were dissolved in toluene (2 mL), heated to 140°C in a sealed pot and stirred for 12 h. After the reaction was completed, it was diluted with water (20 mL), extracted three times with dichloromethane (20 mL), the organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography to give ((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazol-5-yl)-5-isobutylphenyl)piperazin-1-yl)(pyridazin-3-yl)methanone (233 mg, yield 53%).

[0277] LC-MS, M / Z(ESI):461.1[M+H] +

[0278] Step 4: Synthesis of 3-(((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazolyl-5-yl)-5-isobutylphenyl)piperazin-1-yl)methyl)pyridazine

[0279]

[0280] ((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazolyl-5-yl)-5-isobutylphenyl)piperazin-1-yl)(pyridazin-3-yl)methanone (200 mg, 0.43 mmol) was dissolved in tetrahydrofuran (5 mL), and a tetrahydrofuran solution of borane (3.44 mL, 4.30 mmol, 1 mol / L) was added thereto at 0°C. After the addition was complete, the mixture was stirred at room temperature for 6 h. After the reaction was completed, water (10 mL) was added thereto at 0°C, and the mixture was extracted three times with dichloromethane (10 mL). The organic phases were combined, washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography to give 3-(((2R)-2-(difluoromethyl)-4-(3-fluoro-2-(1H-1,2,3,4-tetrazol-5-yl)-5-isobutylphenyl)piperazin-1-yl)methyl)pyridazine (30 mg, yield 15%).

[0281] LC-MS, M / Z(ESI):447.1[M+H] +

[0282] 1H NMR (400MHz, DMSO) δ9.05 (s, 1H), 7.61 (s, 2H), 6.88 (d, J = 7.8Hz, 2H), 6.20 (td, J =55.7,4.1Hz,1H),4.02(dd,J=38.7,14.7Hz,2H),2.95(d,J=10.7Hz,1H),2.91–2 .83(m,1H),2.82–2.75(m,1H),2.70(d,J=8.0Hz,1H),2.66–2.53(m,2H),2.43(s, 2H), 2.24(d,J=10.9Hz,1H), 1.84(dt,J=12.8,6.5Hz,1H), 0.82(d,J=6.2Hz,6H).

[0283] Example 5: Preparation of target compound I-7

[0284] 2-((3R)-3-(difluoromethyl)-4-((pyridazin-3-yl)methyl)piperazin-1-yl)-6-fluoro-4-(2-methylpropanoic acid)benzoic acid

[0285]

[0286] The synthetic route of the target compound I-7 is as follows:

[0287]

[0288] Step 1: Synthesis of tert-butyl (3R)-3-(difluoromethyl)piperazine-1-carboxylate

[0289]

[0290] (2R)-2-(Difluoromethyl)piperazine dihydrochloride (1.00 g, 4.81 mmol) and triethylamine (1.46 g, 14.43 mmol) were dissolved in DCM (20 mL), and di-tert-butyl dicarbonate (1.05 g, 4.81 mmol) was added thereto at 0°C, and stirred at this temperature for 16 h. After the reaction was completed, it was diluted with water (50 mL), extracted three times with ethyl acetate (20 mL), and the organic phases were combined, washed with saturated brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography (PE / EA (v / v) = 2 / 1) to obtain (3R)-3-(difluoromethyl)piperazine-1-carboxylic acid tert-butyl ester (920 mg, yield 81%).

[0291] LC-MS, M / Z(ESI):237.1[M+H] +

[0292] Step 2: Synthesis of tert-butyl (3R)-3-(difluoromethyl)-4-(pyridazine-3-carbonyl)piperazine-1-carboxylate

[0293]

[0294] Dissolve (3R)-3-(difluoromethyl)piperazine-1-carboxylic acid tert-butyl ester (900 mg, 3.81 mmol), HATU (1.82 g, 4.57 mmol), 3-carboxypyridazine (473 mg, 3.81 mmol) and N,N-diisopropylethylamine (1.18 g, 9.14 mmol) in DMF (10 mL) and react at 25°C for 16 h. After the reaction is completed, dilute with water (50 mL), extract three times with ethyl acetate (20 mL), combine the organic phases, wash with saturated brine (30 mL), dry over anhydrous sodium sulfate, filter, and concentrate to obtain a crude product. The crude product is purified by column chromatography (PE / EA (v / v) = 1 / 1) to obtain (3R)-3-(difluoromethyl)-4-(pyridazine-3-carbonyl)piperazine-1-carboxylic acid tert-butyl ester (977 mg, yield 75%).

[0295] LC-MS, M / Z(ESI):343.1[M+H] +

[0296] Step 3: Synthesis of tert-butyl (3R)-3-(difluoromethyl)-4-((pyridazin-3-yl)methyl)piperazine-1-carboxylate

[0297]

[0298] Dissolve (3R)-3-(difluoromethyl)-4-(pyridazine-3-carbonyl)piperazine-1-carboxylic acid tert-butyl ester (950 mg, 2.78 mmol) in tetrahydrofuran (10 mL), add borane tetrahydrofuran solution (27.8 mL, 27.8 mmol, 1 mol / L) at 0°C, and stir at room temperature for 6 hours after the addition is complete. After the reaction is completed, water (10 mL) is added at 0°C to quench the reaction, and the mixture is extracted three times with ethyl acetate (10 mL). The organic phases are combined, washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product is purified by column chromatography (PE / EA (v / v) = 1 / 1) to obtain (3R)-3-(difluoromethyl)-4-((pyridazine-3-yl)methyl)piperazine-1-carboxylic acid tert-butyl ester (170 mg, yield 19%).

[0299] LC-MS, M / Z(ESI):329.1[M+H] +

[0300] Step 4: Synthesis of 3-(((2R)-2-(difluoromethyl)piperazin-1-yl)methyl)pyridazine

[0301]

[0302] Dissolve (3R)-3-(difluoromethyl)-4-((pyridazin-3-yl)methyl)piperazine-1-carboxylic acid tert-butyl ester (170 mg, 0.52 mmol) in dioxane (2 mL), add a solution of hydrogen chloride in dioxane (5 mL, 20 mmol, 4 mol / L), and stir at room temperature for 2 h. After the reaction is complete, concentrate to obtain 3-(((2R)-2-(difluoromethyl)piperazin-1-yl)methyl)pyridazine (118 mg, yield 99%).

[0303] LC-MS, M / Z(ESI):228.1[M+H] +

[0304] Step 5: Synthesis of methyl 4-bromo-2-((3R)-3-(difluoromethyl)-4-(((pyridazine-3-yl)methyl)piperazine-1-yl)-6-fluorobenzoate

[0305]

[0306] 3-(((2R)-2-(difluoromethyl)piperazin-1-yl)methyl)pyridazine (118 mg, 0.52 mmol), methyl 3,5-difluoro-4-bromobenzoate (144 mg, 0.57 mmol) and triethylamine (263 mg, 2.6 mmol) were dissolved in DMF (5 mL) and reacted at 80°C for 16 h. After the reaction was completed, it was diluted with water (10 mL) and extracted three times with ethyl acetate (10 mL). The organic phases were combined, washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography (PE / EA (v / v) = 1 / 1) to obtain methyl 4-bromo-2-((3R)-3-(difluoromethyl)-4-(((pyridazin-3-yl)methyl)piperazin-1-yl)-6-fluorobenzoate (167 mg, yield 70%).

[0307] LC-MS, M / Z(ESI):459.1[M+H] +

[0308] Step 6: Synthesis of methyl 2-((3R)-3-(difluoromethyl)-4-((pyridazine-3-yl)methyl)piperazine-1-yl)-6-fluoro-4-(2-methylpropyl)benzoate

[0309]

[0310] Methyl 4-bromo-2-((3R)-3-(difluoromethyl)-4-(((pyridazin-3-yl)methyl)piperazin-1-yl)-6-fluorobenzoate (160 mg, 0.35 mmol), isobutylboronic acid (72 mg, 0.70 mmol), potassium carbonate (145 mg, 1.05 mmol) and XPhos Pd G4 (30 mg, 0.035 mmol) was dissolved in dioxane (5 mL) and reacted at 90 ° C for 3 h. After the reaction was completed, it was diluted with water (10 mL), extracted three times with ethyl acetate (10 mL), and the organic phases were combined, washed with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography (PE / EA (v / v) = 1 / 3) to obtain methyl 2-((3R)-3-(difluoromethyl)-4-((pyridazine-3-yl)methyl)piperazine-1-yl)-6-fluoro-4-(2-methylpropyl)benzoate (99 mg, yield 65%).

[0311] LC-MS, M / Z(ESI):437.1[M+H] +

[0312] Step 7: Synthesis of 2-((3R)-3-(difluoromethyl)-4-((pyridazine-3-yl)methyl)piperazine-1-yl)-6-fluoro-4-(2-methylpropanoic acid)benzoic acid

[0313]

[0314] Methyl 2-((3R)-3-(difluoromethyl)-4-((pyridazin-3-yl)methyl)piperazin-1-yl)-6-fluoro-4-(2-methylpropyl)benzoate (99 mg, 0.23 mmol) and lithium hydroxide (83 mg, 3.45 mmol) were dissolved in a mixture of tetrahydrofuran (3 mL), methanol (3 mL) and water (1 mL) and reacted at 50°C for 32 h. After the reaction was completed, the mixture was diluted with water (10 mL), the pH was adjusted to about 3 with 1N hydrochloric acid, and the mixture was extracted three times with ethyl acetate (10 mL). The organic phases were combined, washed with saturated brine (10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by column chromatography (DCM / MeOH (v / v) = 10 / 1) to give 2-((3R)-3-(difluoromethyl)-4-((pyridazin-3-yl)methyl)piperazin-1-yl)-6-fluoro-4-(2-methylpropanoic acid)benzoic acid (45 mg, yield 47%).

[0315] LC-MS, M / Z(ESI):423.3[M+H] +

[0316] 1H NMR(400MHz,dmso)δ13.34(s,1H),9.12(dd,J=4.8,1.8Hz,1H),7.70(ddd,J=13.2,8 .4,3.3Hz,2H),6.81–6.70(m,2H),6.48(td,J=55.7,5.0Hz,1H),4.23–4.10(m,2H),3 .26–3.18(m,1H),3.15–3.01(m,2H),2.99–2.93(m,2H),2.94–2.83(m,1H),2.51–2.4 9(m,1H),2.42(d,J=7.2Hz,2H),1.84(td,J=13.3,6.6Hz,1H),0.83(d,J=6.6Hz,6H).

[0317] Example 6: The preparation of the following compounds can be obtained by referring to the preparation methods of the above compounds.

[0318]

[0319]

[0320] In the test example of the present invention, the preparation method of the reference compound I refers to patent WO2023006893A1, and the structure is shown below:

[0321]

[0322]

[0323] Biological Testing

[0324] The compounds prepared in the examples can be tested using the following test methods.

[0325] Test Example 1: Compound binding to AT2R

[0326] The experiment was performed according to the instruction manual of the Angiotensin AT2 Receptor Ligand Binding Assay Kit (#C1TT1AT2, Cisbio). First, the 10mM compound stock solution was serially diluted according to the dilution factor of 5× (including 10 concentrations, each concentration was repeated twice), and 160nL of the compound of different concentrations was added to a 384-well plate. 40μL 1×TLB was added to each well and shaken at room temperature for 15 minutes. A 15mL centrifuge tube with 5mL 1×TLB was prepared in advance for use. The frozen labeled cells were thawed in a 37℃ water bath (1-2 minutes), and the thawed cells were quickly transferred to the above 15mL centrifuge tube, mixed and centrifuged at 1000g for 5 minutes at room temperature. The supernatant was removed and 2.7mL 1×TLB was added to resuspend the cells. Take a new 384-well plate and add 10μL of the mixed cells to the corresponding wells according to the experimental design. 5 μL of 4× compound solution and 5 μL of 4× Tag-lite red fluorescent labeled ligand were added to each well. After incubation at room temperature for 1 hour, the data were read using the HTRF mode of EnVision. The excitation light intensity of 665nM and 615nM in each well was read respectively, and the ratio (Ratio = A665nM / B615nM) was calculated. IC was calculated using GraphPad Prism8 software. 50 Numerical values, X: logarithmic value of compound concentration; Y: ratio of A665nM / B615nM. The present invention exemplarily shows the results of some compounds, see Table 1 for details.

[0327] Table 1. IC values ​​of compounds tested for AT2R binding activity 50 value

[0328] Compound <![CDATA[IC 50 (nM)]]> I-1 1.7 I-3 59 I-5 6.2 1-7 5.6

[0329] The experimental results show that in the binding test of the test compound and AT2R, the test compound has a strong binding effect with AT2R.

[0330] Test Example 2: Pharmacokinetics test in rats

[0331] The pharmacokinetic test in rats was conducted using male SD rats, 3 in each group, 180-240g, fasted overnight, and each group was orally gavaged with 10 mg / kg. Blood was collected before administration and 15, 30 minutes, and 1, 2, 4, 6, 8, and 24 hours after administration. The blood sample was centrifuged at 8000 rpm and 4°C for 6 minutes, and the plasma was collected and stored at -20°C. The plasma at each time point was taken, 3-5 times the amount of acetonitrile solution containing the internal standard was added and mixed, vortexed for 1 minute, centrifuged at 13000 rpm and 4°C for 10 minutes, the supernatant was added with 3 times the amount of water and mixed, and an appropriate amount of the mixed solution was taken for LC-MS / MS analysis. The main pharmacokinetic parameters were analyzed by non-compartmental model using WinNonlin 7.0 software. The results of some compounds are shown in the present invention, see Table 2 for details.

[0332] Table 2: Results of pharmacokinetic studies in rats

[0333]

[0334] The experimental results show that the compound of the present invention has good pharmacokinetic properties in rats compared with the control compound I.

[0335] Test Example 3: Pharmacokinetics test in mice

[0336] Mouse pharmacokinetic test, using male ICR mice, 3 per group, 20-30g, fasting overnight, each group was orally gavaged 10mg / kg. Blood was collected before administration and 5, 15, 30 minutes and 1, 2, 4, 6, 8, 24 hours after administration. The blood sample was centrifuged at 6000g / min 2-8℃ for 3 minutes, and the plasma was collected and stored at -20℃. Take the plasma at each time point, add 10 times the amount of 50% methanol acetonitrile solution containing internal standard, mix, vortex mix for 5 minutes, centrifuge at 4000 rpm 4℃ for 10 minutes, take the supernatant and add 1 times the amount of water to mix, and take an appropriate amount of the mixed solution for LC-MS / MS analysis. The main pharmacokinetic parameters were analyzed by non-compartmental model using WinNonlin 7.0 software. The results of some compounds are shown in the present invention, see Table 3 for details.

[0337] Table 3: Results of pharmacokinetic studies in mice

[0338]

[0339] The experimental results show that the compound of the present invention has good pharmacokinetic properties in mice compared with the control compound I.

[0340] Test Example 4: Manual patch clamp technique to detect the effect of compounds on hERG channel current

[0341] Manual patch clamp experiments were performed using a HEK-293 cell line that stably expresses hERG potassium channels. hERG potassium channel cells were purchased from Creacell (Cat. No. A-0320). The final concentrations of the test compounds were prepared on the same day and dissolved in the extracellular solution. The extracellular solution (mM) was: 40mM NaCl, 3.5mM KCl, 1mM MgCl2·6H2O, 2mM CaCl2·2H2O, 10mM D-Glucose, 10mM HEPES, 1.25mM NaH2PO4·2H2O; pH 7.4 (NaOH titration). The intracellular solution (mM) was: 20mM KCl, 115mM K-Aspartic, 1mM MgCl2·6H2O, 5mM EGTA, 10mM HEPES, 2mM Na2-ATP; pH 7.4 (KOH titration).

[0342] Electrophysiological test: After whole-cell sealing, the cell membrane voltage was clamped at -80mV. The clamping voltage was depolarized from -80mV to -50mV for 0.5s (as leakage current detection), then stepped to 30mV for 2.5s, and then quickly restored to -50mV for 4s to stimulate the tail current of the hERG channel. Data were collected every 10s to observe the effect of drugs on the hERG tail current (Peak tailcurrent compound ) was used. A 0.5s stimulation of -50mV was used as the leakage current detection. The drug was administered after the hERG current recorded by the whole cell was stable. The next concentration was detected after each drug concentration was applied for 5min (or the current was stable). One or more concentrations were detected for each test compound. The peak tailcurrent (peak tailcurrent) of each cell detected in the external solution without the compound was Control ) as their own control group. Each concentration was tested twice independently using at least two cells. All electrophysiological experiments were performed at room temperature. The experimental data were collected by an IPA amplifier (Sutter Instrument) and stored in Sutter Patch software.

[0343] Data analysis: Calculate the inhibition rate (1-(Peak tail current compound / Peaktail current Control ), the concentration-effect curves were fitted nonlinearly in GraphPad Prism software, and the IC of each compound was calculated using the following equation: 50 Value: Y=1 / (1+10^((LogIC50-X)*HillSlope)). The present invention exemplarily shows the results of some compounds, see Table 4 for details.

[0344] Table 4: Results of the inhibitory effects of the compounds on hERG

[0345] Compound IC50(μM) Comparative Compound I 2.5 I-1 6.8 I-5 >30 1-7 >30

[0346] The experimental results show that compared with the control compound I, the compound of the present invention has a lower risk of hERG inhibition in an in vitro system and a lower risk of cardiac safety.

[0347] Test Example 5: Rat Sciatic Nerve Chronic Constriction Injury (CCI) Model

[0348] Male SD rats weighing 200-250g were anesthetized and fixed in a prone position. The hair from the outer thigh to the femur area of ​​the animal was shaved and disinfected, and a 1.5cm incision was made on the thigh skin; the fascia was separated, and the biceps femoris was bluntly separated to expose the sciatic nerve. The nerve was freed about 7mm in the main trunk before the trifurcated branch of the sciatic nerve, and the sciatic nerve was gently separated; 2mm before the trifurcated branch, the sciatic nerve was ligated with 5-0 sutures 4 times, with a 1mm interval between each suture, so that the ligated nerve was about 4-5mm long. The tightness of the ligature was based on the visible slight twitching of the calf muscle or toes when the knot was tied; the muscles, subcutaneous tissues and skin were sutured in turn, the wound was cleaned and disinfected with iodine. The skin was sutured and disinfected. On the second day of modeling, the animals were randomly divided into groups, with 8 animals in each group, and the vehicle or the corresponding compound solution was orally gavaged. The mechanical pain threshold of the animals was tested with Von-Frey fibers before and after drug administration.

[0349] Mechanical pain threshold detection method: The test animal is continuously stimulated with Von-Frey fiber to make the fiber bend, and the animal's foot retraction reaction is observed. The test animals are stimulated one by one in the order of the fiber weight from small to large, and each fiber weight is stimulated 5 times continuously. If the positive reaction is less than 3 times, the larger fiber is used to repeat the above operation. When the positive reaction occurs 3 or more times for the first time, the fiber is the pain threshold of the animal (each animal is tested 3 times and the average value is taken). Fiber weight: 0.6, 1.0, 1.4, 2.0, 4.0, 6.0, 8.0, 10.0, 15.0; the cut-off value is 15.0g. GraphPad Prism 8.0 was used for data statistics of each group, and the statistical method was one-way ANOVA. The statistical differences between the groups were compared, and P<0.05 was considered statistically significant.

[0350] The experimental results show that the compounds of the present invention can significantly improve the reduction of the mechanical pain threshold of animals caused by the rat sciatic nerve modeling in the rat chronic constriction injury model, and have excellent analgesic effect.

[0351] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. The compound of formula I, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug: in, Ring A is selected from a 5-6 membered heteroaromatic ring; R1 is selected from halogen, hydroxyl, amino, cyano, oxo (=O), C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, amino, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl, oxo; m is selected from 0, 1, 2, 3 or 4; when there are multiple substituents R1, the R1 are the same or different; L is absent or selected from C0-C6 alkylene-O-C0-C6 alkylene, C1-C6 alkylene; the C1-C6 alkylene-O-C1-C6 alkylene or C1-C6 alkylene is optionally substituted by 1-4 substituents selected from the following groups: deuterium, oxo (=O), methyl, ethyl, halomethyl, haloethyl; R2 is selected from C1-C6 alkyl, C3-C7 cycloalkyl, 5-10 membered heterocyclic ring, 6-10 membered aromatic ring; the C1-C6 alkyl, C3-C6 cycloalkyl, 5-10 membered heterocyclic ring, 6-10 membered aromatic ring is optionally substituted by 1, 2, 3, 4 substituents selected from the following groups: halogen, hydroxyl, cyano, amino, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; and R2 is not methyl, ethyl, isopropyl, -CF3; n is selected from 1, 2, 3, 4, 5, 6, 7 or 8; when there are multiple substituents R2, the R2 are the same or different; Ring E is selected from a benzene ring or a 6-membered heteroaromatic ring; R3 is selected from halogen, hydroxyl, cyano, dimethylamino, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; p is selected from 0, 1, 2, 3 or 4; when there are multiple substituents R3, the R3 are the same or different; M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole or tetrazole bioisostere; the bioisostere includes but is not limited to phosphoric acid, R5 is selected from H, OH, NH2, ONa, OK (potassium ion), C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle; the C1-C8 alkyl, C3-C8 cycloalkyl, C1-C8 alkoxy, and 5-6 membered heterocycle are optionally substituted by 1-4 substituents selected from the following groups: halogen, amino, C3-C7 heterocycloalkyl, C1-C3 alkyl, C3-C6 cycloalkyl, and C1-C3 alkoxy.

2. The compound of formula (I) according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The ring A is a 5-6 membered heteroaromatic ring, and the 5-6 membered heteroaromatic ring contains 1, 2 or 3 heteroatoms; Preferably, the heteroatom is selected from N, O, S; More preferably, the heteroatom is N; Preferably, ring A is selected from the group consisting of furan, pyrrole, thiophene, oxazole, oxadiazole, thiazole, pyrazole, imidazole, triazole, tetrazole, pyridine, pyrimidine, pyridazine, and triazine; More preferably, ring A is selected from: pyridine, pyrimidine, pyridazine, pyrazine.

3. The compound of formula (I) as claimed in claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The ring E is a benzene ring or a 6-membered heteroaromatic ring; The 6-membered heteroaromatic ring contains 1, 2, or 3 heteroatoms; The heteroatom is selected from N, O, and S; Preferably, the ring E is selected from benzene ring, pyridine, pyrimidine, pyridazine; More preferably, the ring E is selected from a benzene ring.

4. The compound of formula (I) as claimed in claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: R1 is selected from halogen, hydroxyl, amino, cyano, oxo (=O), C1-C3 alkyl, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C3-C7 cycloalkyl, C1-C3 alkyl-C1-C3 alkoxy, C1-C3 alkyl-C3-C7 cycloalkyl; m is selected from 0, 1, 2, 3 or 4; Preferably, the R1 is selected from halogen, methyl, halomethyl, methoxy; m is selected from 0.

5. The compound of formula (I) according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The compound is selected from the following structures: Ring A, M, L, R1, R3, m and p have the meanings as defined in claim 1.

6. The compound of formula (I) according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The compound is selected from the following structures: Ring A, M, R1, R3, m and p have the same meanings as those defined in claim 1.

7. The compound of formula (I) according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The compound has the following structure: M and R2 have the definitions in claim 1; Preferably, it has structures IVa and IVb:

8. The compound according to claim 1 or claim 7, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The R2 is selected from C1-C3 alkyl, C3-C6 cycloalkyl, 5-6 membered heterocycle, benzene ring; the C1-C3 alkyl, C3-C6 cycloalkyl, 5-6 membered heterocycle, benzene ring is optionally substituted by 1, 2, 3, 4 substituents selected from the following groups: halogen, hydroxyl, cyano, amino, C1-C3 alkyl, C1-C6 alkoxy, C3-C6 cycloalkyl; and R2 is not methyl, ethyl, isopropyl, -CF3; and / or n is selected from 1, 2, 3; and / or n is 1.

9. The compound according to claim 1 or claim 7, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: R2 is selected from CH2F, CHF2, C1-C3 alkyl-C1-C6 alkoxy, C3-C7 cycloalkyl, C1-C3 alkyl-C3-C7 cycloalkyl; Preferably, R2 is selected from CH2F, CHF2, C1-C3 alkyl-C1-C3 alkoxy, C3-C4 cycloalkyl, C1-C3 alkyl-C3-C4 cycloalkyl; n is selected from 1, 2, 3; Preferably, R2 is selected from CH2F, CHF2, methyl-methoxy, ethyl-methoxy, cyclopropyl, methyl-cyclopropyl; n is selected from 1; Preferably, R2 is selected from CH2F, CHF2, Preferably, said R2 is selected from CH2F, CHF2; Preferably, said R2 is selected from CHF2.

10. The compound of formula (I) according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The R3 is selected from halogen, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; the C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl is optionally substituted by 1-4 substituents selected from the following groups: halogen, hydroxyl, cyano, C1-C6 alkyl, C1-C6 alkoxy, C3-C7 cycloalkyl; p is selected from 0, 1, 2, 3 or 4; Preferably, R3 is selected from F, C1-C5 alkyl, C1-C5 haloalkyl, methyl-cyclopropyl; p is selected from 1, 2, 3; More preferably, R3 is selected from F, methyl, trifluoromethyl, isobutyl, isobutyl substituted with F, methyl-cyclopropyl; and p is selected from 2.

11. The compound according to any one of claims 1 and 5 to 7, or its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole or tetrazole bioisostere; Preferably, M is selected from carboxylic acid, -CONHSO2R5, -SO2NHCOR5, tetrazole; said R5 is selected from C1-C3 alkyl, C3-C5 cycloalkyl; More preferably, M is selected from carboxylic acid, tetrazole, -CONHSO2CH2CH3; More preferably, M is selected from carboxylic acid and tetrazole; More preferably, M is selected from tetrazole.

12. The compound of formula (I) as claimed in claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: L is absent or selected from carbonyl, methylene, -CH2CH2-, -CH(CH3)-, -CH2CH2CH2-, -CH2CH(CH3)-, -O-CH2-; Preferably, L is selected from methylene, -CH2CH2-, -CH(CH3)-, -O-CH2-; More preferably, L is selected from methylene.

13. The compound according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The compounds include:

14. The compound according to claim 1, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug, characterized in that: The compounds include:

15. A pharmaceutical composition, characterized in that The pharmaceutical composition comprises: a compound according to any one of claims 1 to 14, a tautomer, a stereoisomer, a hydrate, a solvate, a pharmaceutically acceptable salt or a prodrug thereof; and optionally a pharmaceutically acceptable carrier.

16. Use of a compound according to any one of claims 1 to 14, its tautomer, stereoisomer, hydrate, solvate, pharmaceutically acceptable salt or prodrug or the pharmaceutical composition according to claim 15, comprising: Acts as an AT2R antagonist; and / or, preventing and / or treating AT2R-mediated diseases; and / or, preventing and / or treating diseases in which a reduction in the action of Ang II is desired or required; and / or, preparing a medicament, pharmaceutical composition or formulation as an AT2R antagonist; And / or, preparing a medicament, pharmaceutical composition or formulation for preventing and / or treating a disease in which AT2R is expressed and its inhibition is desired or necessary.

17. The use according to claim 16, characterized in that The disease is neuropathy or neuropathic pain.

18. The use according to claim 17, characterized in that The disease is primary neuropathy, secondary neuropathy, peripheral neuropathy, neuropathy caused by mechanical nerve damage or biochemical nerve damage, postherpetic neuralgia, diabetic neuropathy or diabetes-related neuropathies.

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