Locally acting quaternary ammonium salt-type sphingosine-1-phosphate receptor subtype 1 agonist

Abstract

The present invention belongs to the field of inflammatory bowel diseases, and relates to a locally acting quaternary ammonium salt-type sphingosine-1-phosphate receptor subtype 1 agonist. The compounds of the present application, and stereoisomers thereof and pharmaceutically acceptable salts thereof are locally acting S1PR1 agonists. The compounds exhibit a good agonistic activity against sphingosine-1-phosphate receptor subtype 1, are hardly absorbed upon oral administration, and have a low oral bioavailability, but still have a good in-vivo activity against ulcerative colitis. The compounds are capable of ameliorating intestinal inflammatory injuries in mice with ulcerative colitis, increasing mouse body weight, and increasing mouse colon length. Therefore, the compounds can reduce the risk of infection caused by systemic immunosuppression while maintaining an in-vivo anti-ulcerative colitis activity. The sphingosine-1-phosphate receptor subtype 1 agonist has a structural formula represented by formula (I).

Description

A quaternary ammonium salt-based locally acting sphingosine 1-phosphate receptor subtype 1 agonist Technical Field

[0001] This invention belongs to the field of inflammatory bowel disease and relates to a quaternary ammonium salt-based locally acting sphingosine 1-phosphate receptor subtype 1 agonist. Specifically, it relates to a quaternary ammonium salt compound as a locally acting S1PR1 modulator, and a pharmaceutical composition containing such a compound for the treatment of inflammatory bowel diseases, such as ulcerative colitis. Background Technology

[0002] Sphingosine 1-phosphate receptor subtype 1 (S1PR1) is a G-protein-coupled receptor (GPCR) and a member of the endothelial differentiation gene (EDG) receptor family. Endogenous ligands for the EDG receptor include lysophospholipids such as sphingosine 1-phosphate (S1P). Like all GPCRs, receptor ligation transmits second messenger signals via activation of G proteins (α, β, and γ).

[0003] The development of small-molecule S1PR1 agonists and antagonists has provided insights into the physiological role of the S1P1 / S1P-receptor signaling system. S1P1 receptor agonism interferes with lymphocyte trafficking, sequestering them in lymph nodes and other secondary lymphoid tissues. This leads to rapid and irreversible lymphopenia, likely due to receptor binding on lymphocyte endothelial cells and the lymphocytes themselves (Rosen et al., Immunol. Rev., 2003, 195:160-177). Clinically valuable outcomes of lymphocyte sequestration include reduced lymphocyte counts in surrounding inflamed tissues and suppression of the inflammatory response. Furthermore, S1P1R agonists inhibit dendritic cell migration, thereby suppressing antigen presentation, inhibiting lymphocyte activation, and ultimately suppressing the inflammatory response.

[0004] Although fingolimod, simpomod, bonesimod, and ozamod are currently available for the treatment of multiple sclerosis, these compounds still carry the risk of bradycardia. In fact, fingolimod, simpomod, and bonesimod require electrocardiographic monitoring during the initial dose, and all four drugs require dose-escalation regimens to reduce the incidence of bradycardia. Furthermore, because marketed S1PR1 agonists are administered orally, they can distribute systemically, systematically reducing peripheral lymphocyte counts, thus increasing the risk of severe infections while suppressing inflammation. Therefore, there is still a need in clinical practice for more effective and safer S1P1 receptor agonists. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a compound of formula (I), or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate or solvate thereof, in order to address the shortcomings of the prior art.

[0006] Furthermore, the technical problem to be solved by the present invention is to provide a method for preparing the compound shown in the above formula (I).

[0007] Furthermore, the technical problem to be solved by the present invention is to provide a composition containing a compound represented by the above formula (I), or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate or solvate thereof.

[0008] Furthermore, the technical problem to be solved by the present invention is to provide the compound shown in formula (I) above, or its stereoisomer, or its pharmaceutically acceptable salt, prodrug, hydrate or solvate, or the use of the above composition in the prevention and / or treatment of inflammatory bowel disease.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] This invention discloses a compound having the formula (I), or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof.

[0011] in,

[0012] R1 is selected from cyano, halogen, or methyl group substituted with one or more halogens;

[0013] R2 is selected from substituted or unsubstituted C1-C3 alkoxy or C3-C6 cycloalkyl; preferably, the substitution is selected from substitution by one or more halogens;

[0014] R3, R4, and R5 are independently selected from substituted or unsubstituted C1-C4 alkyl groups; preferably, the substituted C1-C4 alkyl groups are substituted with hydroxyl or C1-C3 alkoxy groups.

[0015] R3 and R4 can combine through carbon atoms or heteroatoms to form substituted or unsubstituted 5-6 membered heterocycles; preferably, the substituted 5-6 membered heterocycles are substituted with hydroxyl groups or hydroxyC1-C3 alkyl groups;

[0016] L represents a carbonyl group or -CH2-;

[0017] n is 1, 2, 3 or 4;

[0018] A is a halogen.

[0019] In some embodiments, preferably

[0020] R1 is selected from cyano, halogen, or methyl group substituted with one or more halogens; wherein the halogen is fluorine, chlorine, or bromine;

[0021] R2 is selected from substituted or unsubstituted C1-C3 alkoxy or C3-C6 cycloalkyl groups; preferably, the substitution is selected from substitution by one or more halogens; wherein the halogen is fluorine, chlorine or bromine;

[0022] R3, R4, and R5 are independently selected from substituted or unsubstituted C1-C4 alkyl groups; preferably, the substituted C1-C4 alkyl groups are substituted with hydroxyl or C1-C3 alkoxy groups.

[0023] R3 and R4 can combine through carbon atoms or heteroatoms to form substituted or unsubstituted 5-6 membered heterocycles; preferably, the substituted 5-6 membered heterocycles are substituted by hydroxyl groups or hydroxyC1-C3 alkyl groups; more preferably, the 5 membered heterocycle is a tetrahydropyrrole ring and the 6 membered heterocycle is a morpholine ring or a piperidine ring.

[0024] L represents a carbonyl group or -CH2-;

[0025] n is 1 or 2;

[0026] A is fluorine, chlorine, or bromine.

[0027] In some embodiments, preferably, R2 is selected from substituted or unsubstituted C1-C3 alkoxy or C3-C6 cycloalkyl; preferably, the substituted C1-C3 alkoxy is substituted by one or more halogens.

[0028] In some embodiments, preferably, the compound represented by formula (I) is selected from any of the following structures:

[0029] In some embodiments, preferably, R1 is selected from cyano, chloro, or trifluoromethyl; more preferably, R1 is selected from cyano or trifluoromethyl.

[0030] In some embodiments, preferably, R2 is selected from methoxy, ethoxy, trifluoroethoxy, isopropoxy, cyclopentyl, or cyclohexyl.

[0031] In some embodiments, more preferably, R2 is selected from trifluoroethoxy, isopropoxy, cyclopentyl, or cyclohexyl.

[0032] In some embodiments, more preferably, R2 is selected from isopropoxy or cyclopentyl.

[0033] In some embodiments, preferably, R3, R4, and R5 are independently selected from methyl, ethyl, isopropyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, methoxyethyl, or ethoxyethyl.

[0034] In some embodiments, more preferably, R3, R4, and R5 are independently selected from methyl, ethyl, isopropyl, hydroxyethyl, or methoxyethyl.

[0035] In some embodiments, preferably, R3 and R4 can form 5- to 6-membered heterocycles through carbon atoms or oxygen atoms.

[0036] In some embodiments, more preferably, R3 and R4 can form 5- to 6-membered heterocycles through carbon atoms or oxygen atoms, wherein the 5-membered heterocycle is a tetrahydropyrrole ring, and the 6-membered heterocycle is a morpholine ring or a piperidine ring.

[0037] In some embodiments, preferably, n is selected from 1 or 2.

[0038] In some embodiments, preferably, A is selected from chlorine, bromine, or iodine.

[0039] In some embodiments, more preferably, A is selected from bromine or chlorine.

[0040] In some embodiments, and more preferably, the compound is selected from any one of the following structures:

[0041] Preferably, the compound is selected from any one of the following structures:

[0042] In some embodiments, preferably, the pharmaceutically acceptable salt is a hydrochloride, hydrobromide, sulfate, phosphate, nitrate, acetate, maleate, fumarate, citrate, tartrate, methanesulfonate, p-toluenesulfonate, or benzenesulfonate.

[0043] In some embodiments, more preferably, the pharmaceutically acceptable salt is a hydrochloride salt.

[0044] Furthermore, the present invention provides a method for preparing the compound represented by formula (I) above, selected from one of the following synthetic routes:

[0045] Synthesis Route 1:

[0046] Compound Ia-1 undergoes a first substitution reaction with compound Ia-2 to give compound Ia-3; compound Ia-3 then undergoes a first quaternization reaction with compound Ia-4 to give compound Ia-5; compound Ia-5 undergoes a deprotection reaction to give compound Ia.

[0047] or,

[0048] Synthesis Route 2:

[0049] Compound Ib-1 undergoes a second substitution reaction with compound Ib-2 to give compound Ib-3; compound Ib-3 and compound Ib-4 then undergo a third substitution reaction to give compound Ib-5; compound Ib-5 and compound Ia-4 undergo a second quaternization reaction to give compound Ib.

[0050] in,

[0051] X1, X2, and X3 are independently selected from halogens;

[0052] R1 is selected from cyano, halogen, or methyl group substituted with one or more halogens;

[0053] R2 is selected from substituted or unsubstituted C1-C3 alkoxy or C3-C6 cycloalkyl; preferably, the substitution is selected from substitution by one or more halogens;

[0054] R3, R4, and R5 are independently selected from substituted or unsubstituted C1-C4 alkyl groups; preferably, the substituted C1-C4 alkyl groups are substituted with hydroxyl or C1-C3 alkoxy groups.

[0055] R3 and R4 can combine through carbon atoms or heteroatoms to form substituted or unsubstituted 5-6 membered heterocycles; preferably, the substituted 5-6 membered heterocycles are substituted with hydroxyl groups or hydroxyC1-C3 alkyl groups;

[0056] L represents a carbonyl group or -CH2-;

[0057] n is 1, 2, 3 or 4;

[0058] A is a halogen.

[0059] In some embodiments, in synthetic route one: in the first substitution reaction, a first base is used to catalyze the first substitution reaction; the first base is any one or a combination of several of sodium hydride, HDMSLi, and HDMSNa; the molar ratio of compound Ia-1 to compound Ia-2 and the first base is 1.0:1.0-3.0:1.0-6.0, preferably 1.0:2.2:5.8; the first substitution reaction is carried out under inert gas protection; the reaction temperature of the first substitution reaction is 50-80°C, preferably 60°C; wherein, the solvent used in the first substitution reaction is preferably any one or a combination of several of anhydrous tetrahydrofuran, anhydrous N,N-dimethylformamide, and anhydrous toluene, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0060] In some embodiments, in the first synthetic route: the first quaternization reaction is carried out at room temperature; in the first quaternization reaction, the amount of compound Ia-4 is in excess; the solvent used in the first quaternization reaction is preferably any one or a combination of acetone, acetonitrile and diethyl ether, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0061] In some embodiments, in synthetic route one: in the deprotection reaction, a first acid is used; the first acid is any one or a combination of two of hydrochloric acid and trifluoroacetic acid; the reaction temperature of the deprotection reaction is 20-40°C, preferably 40°C; in the deprotection reaction, the amount of the first acid is in excess; the solvent used in the deprotection reaction is preferably any one or a combination of methanol, dichloromethane and 1,4-dioxane, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0062] In some embodiments, in synthetic route two: in the second substitution reaction, a second base is used to catalyze the second substitution reaction; the second base is any one or a combination of potassium carbonate, cesium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate; the molar ratio of compound Ib-1 to compound Ib-2 and the second base is 1.0:1.0-2.0:0.5-2.0, preferably 1.0:1.25:1.35; the reaction temperature of the second substitution reaction is room temperature; the solvent used in the second substitution reaction is preferably any one or a combination of toluene, tetrahydrofuran, and acetonitrile, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0063] In some embodiments, in synthetic route two: in the third substitution reaction, a third base is used to catalyze the third substitution reaction; the third base is any one or a combination of several of potassium carbonate, cesium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate; the molar ratio of compound Ib-3 to compound Ib-4 and the third base is 1.0:1.0-5.0:0.5-2.5, preferably 1.0:2.0:2.0; the reaction temperature of the third substitution reaction is 30-70°C, preferably 50°C; the solvent used in the third substitution reaction is preferably any one or a combination of two of N,N-dimethylformamide and tetrahydrofuran, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0064] In some embodiments, in synthetic route two: the second quaternization reaction is carried out at room temperature; in the second quaternization reaction, the amount of compound Ia-4 is in excess; the solvent used in the second quaternization reaction is preferably any one or a combination of acetone, acetonitrile and diethyl ether, and the amount of solvent is not particularly required, as long as the raw materials are dissolved or dispersed evenly.

[0065] Furthermore, the present invention provides a pharmaceutical composition comprising (i) a compound of formula (I) above, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate or solvate thereof, and (ii) a pharmaceutically acceptable carrier, diluent or excipient.

[0066] The use of the compound represented by formula (I) above, or its stereoisomers, or its pharmaceutically acceptable salts, prodrugs, hydrates or solvates, or the pharmaceutical compositions described above in the preparation of sphingosine receptor subtype 1 agonists is also within the scope of protection of this invention.

[0067] The use of the compound represented by formula (I) above, or its stereoisomers, or its pharmaceutically acceptable salts, prodrugs, hydrates or solvates, or the pharmaceutical compositions described above in the preparation of medicaments for the prevention and / or treatment of inflammatory bowel disease is also within the scope of protection of this invention.

[0068] The use of the compound represented by formula (I) above, or its stereoisomers, or its pharmaceutically acceptable salts, prodrugs, hydrates or solvates, or the pharmaceutical compositions described above, in the preparation of medicaments for the prevention of inflammatory bowel disease, and / or the reduction of the progression of inflammatory bowel disease, and / or the treatment of inflammatory bowel disease or its symptoms is also within the scope of protection of this invention.

[0069] Specifically, preferably, the inflammatory bowel disease is selected from ulcerative colitis or Crohn's disease.

[0070] Unless otherwise stated, the following terms as used in this application shall have the following meanings. A particular term should not be considered uncertain or unclear unless specifically defined, but should be understood in accordance with its ordinary meaning in the art. When a trade name appears herein, it is intended to refer to the corresponding product or its active ingredient.

[0071] The term "substituted" refers to the substitution of one or more hydrogen atoms on a particular atom by a substituent, provided that the valence state of the particular atom is normal and the substituted compound is stable.

[0072] C in this article n ~C mThe term "C1-C6" indicates that the group has an integer number of carbon atoms within a given range. For example, "C1-C6" means that the group can have 1, 2, 3, 4, 5, or 6 carbon atoms. Similarly, "C1-C3" means that the group can have 1, 2, or 3 carbon atoms.

[0073] When any variable (e.g., R) appears more than once in the composition or structure of a compound, its definition is independent in each case. Therefore, for example, if a group is substituted by two Rs, each R has an independent option.

[0074] When the number of a linking group is 0, such as -(CH2)0-, it indicates that the linking group is a covalent bond.

[0075] When one of the variables is selected as a covalent bond, it means that the two groups it connects are directly connected. For example, when L in ALZ represents a covalent bond, it means that the structure is actually AZ.

[0076] The term "halogen" or "halogen" refers to fluorine, chlorine, bromine, and iodine.

[0077] The term "hydroxyl group" refers to the -OH group.

[0078] The term "cyano" refers to the -CN group.

[0079] The term "carboxyl group" refers to the -COOH group.

[0080] The term "alkyl" refers to a compound with the general formula C1. n H 2n+1 The alkyl group. This alkyl group can be straight-chain or branched. For example, the term "C 1- "C6 alkyl" refers to an alkyl group containing 1 to 6 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, hexyl, 2-methylpentyl, etc.). Similarly, the alkyl portion (i.e., alkyl) of alkoxy, alkylamino, dialkylamino, alkylsulfonyl, and alkylthio groups has the same definition. For example, the term "C6 alkyl"... 1- "C3 alkyl" refers to alkyl groups containing 1 to 3 carbon atoms (e.g., methyl, ethyl, propyl, and isopropyl).

[0081] The term "alkoxy" refers to the aforementioned alkyl group having a specific number of carbon atoms linked by an oxygen bridge. C1 to C6 alkoxy groups include C1, C2, C3, C4, C5, and C6 alkoxy groups. Examples of alkoxy groups include, but are not limited to: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, and S-pentoxy.

[0082] The term "treatment" means administering the compound or preparation described in this application to improve or eliminate a disease or one or more symptoms related to said disease, and includes:

[0083] i. To suppress a disease or disease state, that is, to curb its development;

[0084] ii. To alleviate a disease or disease state, even if the disease or disease state subsides.

[0085] The term "pharmaceutical acceptable" refers to compounds, materials, compositions, and / or dosage forms that, within the bounds of reliable medical judgment, are suitable for use in contact with human and animal tissues without excessive toxicity, irritation, allergic reactions, or other problems or complications, in proportion to a reasonable benefit / risk ratio.

[0086] The term "pharmaceutically acceptable salt" refers to the salt of the compounds in this application, prepared by reacting a compound with a relatively non-toxic acid or base, as discovered in this application, with a specific substituent. When the compounds in this application contain relatively acidic functional groups, a base addition salt can be obtained by contacting a suitable base with the neutral form of such a compound. When the compounds in this application contain relatively basic functional groups, an acid addition salt can be obtained by contacting a suitable acid with the neutral form of such a compound. Certain specific compounds in this application contain both basic and acidic functional groups, and thus can be converted into either a base or an acid addition salt.

[0087] The term "pharmaceutical composition" refers to a mixture of one or more compounds of this application or their salts with pharmaceutically acceptable excipients. The purpose of a pharmaceutical composition is to facilitate the administration of the compounds of this application to an organism.

[0088] The word “comprise” or “comprise” and its English variants such as comprises or comprising should be understood in an open, non-exclusive sense, meaning “including but not limited to”.

[0089] The compounds of this invention can exist in specific geometric or stereoisomeric forms. This invention contemplates all such compounds, including cis and trans isomers, (-)- and (+)- enantiomers, (R)- and (S)- enantiomers, diastereomers, (D)- isomers, (L)- isomers, and racemic mixtures thereof, as well as other mixtures, such as mixtures enriched with enantiomers or diastereomers, all of which are within the scope of this invention. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomers and mixtures thereof are included within the scope of this invention.

[0090] Unless otherwise stated, "(D)" or "(+)" indicates right-handed rotation, "(L)" or "(-)" indicates left-handed rotation, and "(DL)" or "(±)" indicates racemic rotation.

[0091] Unless otherwise specified, use wedge-shaped solid line keys. and wedge-shaped dashed key The absolute configuration of the center of a solid is represented by a straight solid line key. and straight dashed key The relative configuration of the center of a solid is indicated by a wavy line. Indicates wedge-shaped solid line key or wedge-shaped dashed key Or use wavy lines Indicates a straight solid line key and straight dashed key

[0092] Optically active (R)- and (S)- isomers, as well as D- and L- isomers, can be prepared by chiral synthesis, chiral reagents, or other conventional techniques. To obtain an enantiomer of a compound of the present invention, it can be prepared by asymmetric synthesis or derivatization with a chiral auxiliary, wherein the resulting diastereomeric mixture is separated, and the auxiliary group is cleaved to provide the desired enantiomer in pure form. Alternatively, when the molecule contains a basic functional group (such as an amino group) or an acidic functional group (such as a carboxyl group), a salt of the diastereomeric isomer is formed with a suitable optically active acid or base, followed by diastereomeric resolution using conventional methods known in the art, and then the pure enantiomer is recovered. Furthermore, the separation of enantiomers and diastereomeric isomers is typically accomplished by using chromatography employing a chiral stationary phase, optionally combined with chemical derivatization (e.g., from amines to carbamates).

[0093] The compounds of this invention may contain non-natural proportions of atomic isotopes on one or more of the atoms constituting the compound. For example, the compounds may be labeled with radioactive isotopes such as tritium (3H), iodine-125 (125I), or C-14 (14C). As another example, deuterated drugs may be formed by replacing hydrogen with deuterium; for instance, d3-methyl indicates that all three hydrogen atoms on the methyl group are replaced by deuterium atoms. The bond between deuterium and carbon is stronger than that between ordinary hydrogen and carbon. Compared to undeuterated drugs, deuterated drugs have advantages such as reduced toxicity, increased drug stability, enhanced efficacy, and prolonged biological half-life. All variations in the isotopic composition of the compounds of this invention, regardless of radioactivity, are included within the scope of this invention.

[0094] This application also includes compounds of this application that are identical to those described herein, but with one or more atoms replaced by isotopes of atomic weights or mass numbers different from those commonly found in nature. Examples of isotopes that can be incorporated into compounds of this application include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, iodine, and chlorine, such as 2H, 3H, 11C, 13C, 14C, 13N, 15N, 15O, 17O, 18O, 31P, 32P, 35S, 18F, 123I, 125I, and 36Cl, respectively.

[0095] Certain isotopically labeled compounds of this application (e.g., those labeled with 3H and 14C) can be used in compound and / or substrate tissue distribution analysis. Tritium (i.e., 3H) and carbon-14 (i.e., 14C) isotopes are particularly preferred due to their ease of preparation and detectability. Positron emission isotopes, such as 15O, 13N, 11C, and 18F, can be used in positron emission tomography (PET) studies to determine substrate occupancy. Isotopically labeled compounds of this application can generally be prepared by replacing unlabeled reagents with isotopically labeled reagents using a procedure similar to those disclosed in the schemes and / or examples below.

[0096] In addition, heavier isotopes (such as deuterium) are used. 2 H)) substitution can provide certain therapeutic advantages resulting from higher metabolic stability (e.g., increased in vivo half-life or reduced dose requirement), and may therefore be preferred in certain situations, wherein deuterium substitution can be partial or complete, with partial deuterium substitution referring to at least one hydrogen being replaced by at least one deuterium, and all such compounds are included within the scope of this application.

[0097] The compounds of this application may be asymmetric, for example, having one or more stereoisomers. Unless otherwise stated, all stereoisomers include, such as enantiomers and diastereomers. The compounds containing asymmetric carbon atoms of this application can be isolated in optically active pure form or in racemic form. The optically active pure form can be resolved from a racemic mixture or synthesized using chiral starting materials or chiral reagents.

[0098] The pharmaceutical compositions of this application can be prepared by combining the compounds of this application with suitable pharmaceutically acceptable excipients, for example, in solid, semi-solid, liquid or gaseous formulations, such as tablets, pills, capsules, powders, granules, ointments, emulsions, suspensions, suppositories, injections, inhalers, gels, microspheres and aerosols.

[0099] Typical routes of administration for the compounds of this application or their pharmaceutically acceptable salts or pharmaceutical compositions thereof include, but are not limited to, oral, rectal, topical, inhalation, parenteral, sublingual, vaginal, intranasal, intraocular, intraperitoneal, intramuscular, subcutaneous, and intravenous administration.

[0100] The pharmaceutical composition of this application can be manufactured using methods well known in the art, such as conventional mixing, dissolving, granulation, sugar-coated pill making, grinding, emulsification, freeze drying, etc.

[0101] The therapeutic dose of the compound may be determined based on factors such as the specific therapeutic purpose, the method of administration, the patient's health and condition, and the prescribing physician's judgment. The proportion or concentration of the compound in the pharmaceutical composition may not be fixed and depends on various factors, including dosage, chemical properties (e.g., hydrophobicity), and route of administration. For example, the compound may be provided in a physiologically buffered aqueous solution containing about 0.1–10% (g / mL) of the compound for parenteral administration. Some typical dosage ranges are from about 1 μg / kg to about 1 g / kg body weight / day. In some embodiments, the dosage range is from about 0.01 mg / kg to about 100 mg / kg body weight / day. The dosage is likely to depend on variables such as the type and severity of the disease or condition, the general health status of the specific patient, the relative biological potency of the selected compound, the excipient formulation, and the route of administration. The effective dose can be obtained by extrapolation from dose-response curves derived from in vitro or animal model testing systems.

[0102] The compounds of this application can be prepared by a variety of synthetic methods known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthetic methods, and equivalent substitutions known to those skilled in the art. Preferred embodiments include, but are not limited to, the embodiments of this application.

[0103] The chemical reactions in the specific embodiments of this application are carried out in a suitable solvent, which must be suitable for the chemical changes and the reagents and materials required in this application. In order to obtain the compounds of this application, it is sometimes necessary for those skilled in the art to modify or select the synthesis steps or reaction process based on existing embodiments.

[0104] The compounds of this application can be prepared by a variety of synthetic methods known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthetic methods, and equivalent substitutions known to those skilled in the art. Preferred embodiments include, but are not limited to, the embodiments of this application.

[0105] The chemical reactions in the specific embodiments of this application are carried out in a suitable solvent, which must be suitable for the chemical changes and the reagents and materials required in this application. In order to obtain the compounds of this application, it is sometimes necessary for those skilled in the art to modify or select the synthesis steps or reaction process based on existing embodiments. Beneficial effects:

[0106] Compared with the prior art, the present invention has the following advantages:

[0107] The compounds, their stereoisomers, and pharmaceutically acceptable salts of this application are locally acting S1PR1 agonists. These compounds exhibit good agonistic activity against sphingosine monophosphate receptor subtype 1, are almost entirely not absorbed orally, and have low oral bioavailability. However, they still possess good in vivo anti-ulcerative colitis activity, improving intestinal inflammatory damage in ulcerative colitis mice, increasing mouse body weight, and increasing colon length. Therefore, these compounds can reduce the risk of infection caused by systemic immunosuppression while maintaining in vivo anti-ulcerative colitis activity. Attached Figure Description

[0108] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0109] Figure 1 shows the DAI score curves of mice in each group; among them, compared with the blank group, ###P<0.00l; compared with the model group, *P<0.05, **P<0.0l, and ***P<0.00l.

[0110] Figure 2 shows the curves of the rate of change in body weight of mice in each group; among them, compared with the blank group, ###P<0.00l; compared with the model group, *P<0.05, **P<0.0l, and ***P<0.00l.

[0111] Figure 3 shows the colorectal length data of mice in each group; among them, compared with the blank group, ###P<0.00l; compared with the model group, *P<0.05, **P<0.0l, and ***P<0.00l.

[0112] Figure 4 shows the actual condition of the colon and rectum of mice in each group. Detailed Implementation

[0113] For clarity, the present invention is further illustrated by examples, but these examples are not intended to limit the scope of this application. It will be apparent to those skilled in the art that various changes and modifications can be made to specific embodiments of the invention without departing from the spirit and scope thereof. All reagents used in this application are commercially available and can be used without further purification.

[0114] All compound structural formulas in this invention were drawn using the software KingDraw.

[0115] Example 1: Synthesis of (2-(((1S)-4-(5-(3-cyano-4-(prop-2-yloxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)diethylmethylammonium bromide hydrochloride (compound I-1)

[0116] The structural formula of compound I-1 is shown below:

[0117] The synthesis route is shown below:

[0118] Step 1: Synthesis of methyl 3-bromo-4-isopropoxybenzoate (compound I-1-2)

[0119] In a three-necked round-bottom flask, compound I-1-1 (20 g, 0.087 mol), 2-bromopropane (34.2 g, 0.278 mol), potassium carbonate (38 g, 0.275 mol), and N,N-dimethylformamide (DMF, 150 mL) were added. The mixture was stirred at 110 °C for 15 h under nitrogen protection. The reaction solution was cooled to room temperature, filtered, and the filter cake was washed with ethyl acetate (EA, 150 mL). 1 L of aqueous phase was added to the organic phase, and the aqueous phase was extracted with EA. The organic phases were combined, washed with water (150 mL × 3), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to give 20.2 g of a pale yellow oily liquid, methyl 3-bromo-4-isopropoxybenzoate (compound I-1-2), with a yield of 83.9%.

[0120] 1 H NMR (400MHz, Chloroform-d) δ8.24-8.20(m,1H),7.94(dd,J=8.9,2.2Hz,1H),6.90(d,J=8.6Hz,1H),4.69-4.62(m,1H),3.89(s,3H),1.41(d,J=6.0Hz,6H).

[0121] Step 2: Synthesis of methyl 3-cyano-4-isopropoxybenzoate (compound I-1-3)

[0122] Compound I-1-2 (8 g, 29.30 mmol) was dissolved in DMF (50 mL), and cuprous cyanide (7.6 g, 84.92 mmol), cuprous iodide (0.5 g, 2.632 mmol), and 2-acetylcyclohexanone (0.03 g, 0.214 mmol) were added sequentially. The mixture was stirred at 120 °C for 16 h under nitrogen protection. The reaction solution was cooled to room temperature, diluted with EA (50 mL), filtered, and the filter cake was washed with EA (150 mL). Water (250 mL) was added to the filtrate, and the phases were separated. The aqueous phase was extracted with EA (50 mL × 3), and the organic phases were combined, washed with water (20 mL × 3), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to give 4.3 g of a yellow liquid, methyl 3-cyano-4-isopropoxybenzoate (denoted as compound I-1-3), with a yield of 67.2%.

[0123] Step 3: Synthesis of 3-cyano-4-isopropoxybenzoic acid (compound I-1-4)

[0124] Compound I-1-3 (4 g, 18.24 mmol) was dissolved in 1,4-dioxane (20 mL), and lithium hydroxide monohydrate (2.14 g, 51.06 mmol) was dissolved in 20 mL of water and slowly added dropwise to the reaction solution. The mixture was stirred at room temperature for 2 h. Under ice-water bath conditions, 1 N HCl was added dropwise to the reaction solution to adjust the pH to 1. The mixture was filtered to obtain 3.59 g of a white solid 3-cyano-4-isopropoxybenzoic acid (designated as compound I-1-4), with a yield of 95.9%.

[0125] 1 H NMR (400MHz, Chloroform-d) δ8.31(d,J=2.2Hz,1H),8.24(dd,J=9.0,2.2Hz,1H),7.02(d,J=9.0Hz,1H),4.83-4.70(m,1H),1.45(d,J=6.1Hz,6H).

[0126] Step 4: Synthesis of 4-cyano-1-indanone (compound I-1-6)

[0127] Compound I-1-5 (80 g, 0.379 mol) was dissolved in DMF (200 mL), and cuprous cyanide (102 g, 1.14 mol), cuprous iodide (7.2 g, 0.038 mol), and 2-acetylcyclohexanone (1.8 g, 0.013 mol) were added sequentially. The mixture was stirred at 120 °C for 21 h under nitrogen protection. The reaction solution was cooled to room temperature, diluted with dichloromethane (DCM, 250 mL), filtered, and the filter cake was washed with DCM (500 mL). The filtrate was separated by adding water (1.6 L). The aqueous phase was extracted with DCM (250 mL × 3). The organic phases were combined, washed with water (200 mL × 3), and concentrated under reduced pressure to obtain a green solid crude product. The crude product was heated to reflux with 150 mL (ethanol / methanol = 4 / 1) and stirred for 1 h. After cooling to room temperature, stirring was continued for 30 min. The mixture was filtered to obtain a yellow solid 4-cyano-1-indanone (denoted as compound I-1-6), 43.1 g, with a yield of 72.3%.

[0128] 1 H NMR (400MHz, Chloroform-d) δ7.97(d,J=7.7Hz,1H),7.88(d,J=7.2Hz,1H),7.52(t,J=7.6Hz,1H),3.37-3.29(m,2H),2.83-2.76(m,2H).

[0129] Step 5: Synthesis of N-[(1S)-4-cyano-2,3-dihydro-1H-inden-1-yl]-2-methylpropane-2-sulfinamide (compound I-1-7): Compound I-1-6 (52.9 g, 0.337 mol) was dissolved in toluene (250 mL), followed by the sequential addition of (s)-(-)-tert-butylsulfinamide (44.9 g, 0.370 mol) and tetraethyl titanate (115 g, 0.504 mol). The reaction mixture was stirred at 60 °C for 4 h under nitrogen protection. The reaction solution was diluted with tetrahydrofuran (THF, 400 mL) and cooled to -30 °C. Sodium borohydride (45.9 g, 1.21 mol) was added in portions, with the temperature not exceeding -25 °C. After stirring at this temperature for one hour, the reaction solution was slowly heated to 0 °C and stirred for 16 h. The reaction solution was quenched by adding saturated sodium potassium tartrate (400 mL) and saturated sodium chloride solution (100 mL) under an ice-water bath. A large amount of pale yellow solid precipitated. EA was added and stirred (550 mL) for 2 h. The mixture was filtered, and the filter cake was washed with EA (300 mL). The filtrate was separated, and the aqueous phase was extracted with EA (250 mL × 3). The organic phases were combined and washed once with saturated sodium bicarbonate (100 mL), then washed with saturated sodium chloride water (100 mL × 2). The mixture was concentrated to give 55.1 g of yellow solid N-[(1S)-4-cyano-2,3-dihydro-1H-inden-1-yl]-2-methylpropane-2-sulfinamide (compound I-1-7), with a yield of 62.5%. The crude product was used directly in the next reaction without further purification.

[0130] Step 6: Synthesis of (1S)-1-amino-2,3-dihydro-1H-indene-4-carbonitrile hydrochloride (compound I-1-8)

[0131] Compound I-1-7 (55.1 g, 0.193 mol) was dissolved in a methanol solution of HCl (w / w 10%, 90 mL) and 1,4-dioxane (60 mL), and the mixture was stirred at room temperature for about 3 h. The reaction solution was filtered, and the filter cake was washed with methanol (180 mL). The filtrate was concentrated under reduced pressure to give a green, viscous crude solid (38 g). The crude solid was added to acetonitrile (180 mL) and heated to reflux with stirring for 2 h. Then it was slowly cooled to room temperature, stirred in an ice-water bath for 10 min, and filtered to obtain a yellowish-brown solid (1S)-1-amino-2,3-dihydro-1H-inden-4-carbonitrile hydrochloride (denoted as compound I-1-8), 18.1 g, yield 44%.

[0132] 1H NMR(400MHz,DeuteriumOxide)δ7.79(dd,J=7.8,4.1Hz,2H),7.51(t,J=7.8Hz,1H),4.97(dd,J =8.1,5.0Hz,1H),3.40-3.28(m,1H),3.26-3.14(m,1H),2.80-2.66(m,1H),2.30-2.17(m,1H).

[0133] Step 7: Synthesis of tert-butyl N-[(1S)-4-cyano-2,3-dihydro-1H-indene-1-yl]carbamate (compound I-1-9) Compound I-1-8 (3.13 g, 0.016 mol) was dissolved in DCM (10 mL) and stirred. Triethylamine (3.33 g, 0.033 mol) was added dropwise under an ice-water bath. Ditert-butyl dicarbonate (3.91 g, 0.018 mol) was dissolved in DCM (10 mL) and slowly added dropwise to the reaction solution. The reaction was stirred at room temperature for 2 h. The reaction solution was diluted with DCM (30 mL), then washed with saturated sodium chloride solution (30 mL × 3), the organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated to give a yellow-green solid tert-butyl N-[(1S)-4-cyano-2,3-dihydro-1H-inden-1-yl]carbamate (denoted as compound I-1-9), 3.74 g, yield 93.5%. The crude product was used directly in the next reaction without further purification.

[0134] Step 8: Synthesis of N-[(1S)-4-(N-hydroxycarbamoyl)-2,3-dihydro-1H-inden-1-yl] tert-butyl carbamate (compound I-1-10)

[0135] Compound I-1-9 (2.6 g, 10.07 mmol) was dissolved in ethanol (25 mL), and hydroxylamine hydrochloride (2.08 g, 30.21 mmol) and triethylamine (3.05 g, 30.21 mmol) were added sequentially. The mixture was stirred under reflux for 2 h under nitrogen protection. The reaction solution was concentrated and redissolved with DCM (80 mL), washed with water (20 mL × 3), dried over anhydrous sodium sulfate, filtered, and concentrated to give 2.7 g of white solid N-[(1S)-4-(N-hydroxycarbamoyl)-2,3-dihydro-1H-inden-1-yl] tert-butyl carbamate (compound I-1-10), yield 92.1%.

[0136] 1H NMR(400MHz,Chloroform-d)δ7.36(t,J=8.2Hz,2H),7.22(t,J=7.8Hz,1H),5.16(d,J=8.4Hz,1H),4.98(d ,J=9.0Hz,1H),4.81(s,2H),3.16-3.10(m,1H),2.95-2.83(m,1H),2.52(s,1H),1.65(s,1H),1.50(s,9H).

[0137] Step 9: Synthesis of N-[(1S)-4-{5-[3-cyano-4-(prop-2-yloxy)phenyl]-1,2,4-oxadiazol-3-yl}-2,3-dihydro-1H-inden-1-yl] tert-butyl carbamate (compound I-1-11)

[0138] Compound I-1-4 (0.7 g, 3.41 mmol) was dissolved in DMF (8 mL), followed by the addition of 1-hydroxybenzotriazole (0.51 g, 3.76 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (1.44 g, 7.514 mmol), and triethylamine (0.79 g, 7.80 mmol). The mixture was stirred at room temperature for 0.5 h. Separately, compound I-1-10 (0.84 g, 2.89 mmol) was dissolved in DMF (10 mL) and added to the reaction mixture. The mixture was stirred at room temperature for 2 h. The reaction mixture was then heated to 95 °C and stirred overnight. After cooling to room temperature, the reaction mixture was diluted with water (100 mL) and extracted with EA (20 mL × 3). The combined organic phases were washed once with saturated sodium bicarbonate solution (20 mL) and then washed three times with saturated sodium chloride solution (20 mL × 3). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 1.31 g of crude N-[(1S)-4-{5-[3-cyano-4-(prop-2-yloxy)phenyl]-1,2,4-oxadiazol-3-yl}-2,3-dihydro-1H-indene-1-yl]carbamate (compound I-1-11), with a yield of 98.3%.

[0139] 1H NMR(400MHz,DMSO-d6)δ8.52(d,J=2.2Hz,1H),8.42(dd,J=9.0,2.3Hz,1H),8.03- 7.96(m,1H),7.56(d,J=9.1Hz,1H),7.44(d,J=6.4Hz,2H),7.36(d,J=8.5Hz,1H), 5.09(q,J=8.3Hz,1H),5.02-4.96(m,1H),3.37(dd,J=8.3,3.0Hz,1H),3.10-3.02 (m,1H),2.47-2.38(m,1H),1.94-1.84(m,1H),1.45(s,9H),1.39(d,J=6.0Hz,6H).

[0140] Step 10: Tert-butyl N-[(1S)-4-{5-[3-cyano-4-(prop-2-acyloxy)phenyl]-1,2,4-oxadiazol-3-yl}-2,3-dihydro-1H-inden-1-yl]-N-[2-(diethylamino)ethyl]carbamate (Compound I-1-12)

[0141] Compound I-1-11 (0.6 g, 1.3 mmol) was dissolved in anhydrous THF (10 mL) under nitrogen protection. 60% NaH (0.3 g, 7.5 mmol) was added in batches at 0 °C. The reaction was stirred for 1 h while maintaining the internal temperature at 0 °C. After 1 h, 2-diethylamino-1-bromoethane hydrobromide (0.75 g, 2.87 mmol) was added and stirred for 5 min. The reaction was then stirred at 60 °C for 12 h. After the reaction was completed, the reaction solution was quenched with saturated sodium bicarbonate solution until no bubbles were generated. Water (100 mL) was added for dilution, and the mixture was extracted with EA (30 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The phases were separated and dried with anhydrous sodium sulfate. The mixture was filtered and concentrated under reduced pressure to obtain a yellow oily crude product. The crude product was purified by column chromatography (DCM / MeOH = 25 / 1) to obtain a yellow oily compound tert-butyl N-[(1S)-4-{5-[3-cyano-4-(prop-2-acyloxy)phenyl]-1,2,4-oxadiazol-3-yl}-2,3-dihydro-1H-inden-1-yl]-N-[2-(diethylamino)ethyl]carbamate (denoted as compound I-1-12), 0.5 g, yield 68.5%.

[0142] 1H NMR(400MHz,Chloroform-d)δ8.45(d,J=2.2Hz,1H),8.36(dd,J=8.9,2.2Hz,1H),8.11(dd,J=6.7,2.1Hz, 1H),7.44-7.35(m,2H),7.15(d,J=9.0Hz,1H),4.87-4.75(m,1H),3.63-3.47(m,1H),3.26-2.94(m,3H),2. 67-2.49(m,4H),2.40(s,3H),2.13(d,J=52.5Hz,1H),1.50(d,J=6.1Hz,6H),1.48-1.42(m,1H),1.37(s,3H ),1.31-1.20(m,1H),1.06(q,J=6.9Hz,1H),0.95(d,J=28.4Hz,6H),0.20-0.15(m,1H),0.14-0.08(m,3H).

[0143] Step 11: (S)-2-((tert-butoxycarbonyl)(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N,N-diethyl-N-methylammonium bromide (Compound I-1-13)

[0144] Compound I-1-12 (0.5 g, 0.894 mmol) was dissolved in acetone (10 mL), and excess methyl bromoethane was added and stirred at room temperature for 3 h. The reaction mixture was evaporated to dryness to give the crude product. The crude product was purified by column chromatography (DCM / MeOH = 15 / 1) to give a white solid (S)-2-((tert-butoxycarbonyl)(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N,N-diethyl-N-methylammonium bromide (designated as compound I-1-13), 0.27 g, yield 46.2%.

[0145] 1H NMR(400MHz,Chloroform-d)δ8.42(d,J=2.2Hz,1H),8.36(dd,J=8.9,2.2Hz,1H),8. 13(d,J=7.6Hz,1H),7.47(t,J=7.5Hz,1H),7.41(s,1H),7.16(d,J=9.0Hz,1H),5.60 (s,1H),5.32(s,1H),4.94-4.73(m,1H),3.81-3.52(m,8H),3.22(s,4H),2.84-2.48 (m,1H),2.33-1.98(m,1H),1.49(s,9H),1.44-1.40(m,6H),1.28(t,J=10.0Hz,6H).

[0146] Step 12: Synthesis of (2-(((1S)-4-(5-(3-cyano-4-(prop-2-yloxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)diethylmethylammonium bromide hydrochloride (compound I-1)

[0147] Compound I-1-13 (0.27 g, 0.413 mmol) was added to a methanol solution of HCl (w / w 13.5%, 10 mL), and the mixture was stirred at 40 °C for 3 h. After the reaction was complete, the reaction solution was concentrated under reduced pressure, then stirred with n-hexane (8 mL) for 1 h, and filtered to give a white solid (2-(((1S)-4-(5-(3-cyano-4-(prop-2-yloxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)diethylmethylammonium bromide hydrochloride (denoted as compound I-1), 0.15 g, yield 62.5%.

[0148] 1 H NMR (400MHz, DMSO-d6) δ10.16(d,J=71.2Hz,2H),8.52(q,J=2.2Hz,1H),8.41(dd, J=9.1,1.7Hz,1H),8.20-8.13(m,2H),7.57(d,J=8.9Hz,2H),5.02-4.96(m,1H),4. 93(s,1H),3.60-3.40(m,9H),3.34-3.25(m,1H),3.07(s,3H),2.56(dd,J=14.4,7. 7Hz,1H),2.44(s,1H),1.39(d,J=6.0Hz,6H),1.29(t,J=7.1Hz,6H).HRMS(ESI,[M] + )m / z:474.28400.

[0149] Example 2: Synthesis of (3-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)propyl)trimethylammonium bromide hydrochloride (compound I-2)

[0150] Referring to the preparation method of Example 1, except that 2-diethylamino-1-bromoethane hydrobromide in step 10 was replaced with 3-bromo-N,N-dimethyl-1-propylamine hydrobromide, finally yielding (3-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)propyl)trimethylammonium bromide hydrochloride (denoted as compound I-2). The NMR and mass spectrometry data of compound I-2 are as follows:

[0151] 1 H NMR (400MHz, DMSO-d6) δ9.94 (s, 1H), 9.79 (s, 1H), 8.52 (d, J = 2.3Hz, 1H), 8.41 (dd, J = 9.0 ,2.3Hz,1H),8.17(d,J=7.7Hz,1H),8.12(d,J=7.6Hz,1H),7.60-7.53(m,2H),5.02-4.96( m,1H),4.91(s,1H),3.59-3.46(m,3H),3.30-3.22(m,1H),3.10(s,9H),3.05(s,2H),2.60 -2.52(m,1H),2.39-2.32(m,1H),2.28-2.18(m,2H),1.39(d,J=6.0Hz,6H).HRMS(ESI,[M] + )m / z:460.26978.

[0152] Example 3: Synthesis of 4-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine ammonium bromide hydrochloride (compound I-3)

[0153] Referring to the preparation method of Example 1, except that 2-diethylamino-1-bromoethane hydrobromide in step 10 was replaced with 4-(2-bromoethyl)morpholine hydrobromide, finally yielding 4-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine ammonium bromide hydrochloride (denoted as compound I-3). The NMR and mass spectrometry data of compound I-3 are as follows:

[0154] 1 H NMR (400MHz, DMSO-d6) δ10.25(s,1H),10.04(s,1H),8.54(d,J=2.2Hz,1H),8.43( dd,J=9.0,2.3Hz,1H),8.19(d,J=7.7Hz,1H),8.14(d,J=7.6Hz,1H),7.66-7.52(m ,2H),5.02-4.96(m,1H),4.94(s,1H),3.99(t,J=4.6Hz,4H),3.67-3.48(m,8H),3 .29(s,4H),2.62-2.53(m,1H),2.44(s,1H),1.40(d,J=6.0Hz,6H).HRMS(ESI,[M] + )m / z:488.26501.

[0155] Example 4: Synthesis of 1-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-1-methyltetrahydropyrrole hydrochloride (compound I-4)

[0156] Referring to the preparation method of Example 1, except that 2-diethylamino-1-bromoethane hydrobromide in step 10 was replaced with 1-(2-bromoethyl)pyrrolidine hydrobromide, finally yielding 1-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-1-methyltetrahydropyrrole hydrochloride (denoted as compound I-4). The NMR and mass spectrometry data of compound I-4 are as follows:

[0157] 1H NMR (400MHz, Methanol-d4) δ8.37(d,J=8.9Hz,2H),8.22(d,J=7.6Hz,1H),8.04(d,J=7.5Hz, 1H),7.56(t,J=7.6Hz,1H),7.43(d,J=8.7Hz,1H),5.06(s,1H),4.96(q,J=6.0Hz,1H),4.04– 3.90(m,2H),3.89–3.80(m,2H),3.77(s,4H),3.68–3.59(m,1H),3.45–3.34(m,1H),3.28(s, 3H),2.79–2.65(m,1H),2.55(s,1H),2.38–2.29(m,4H),1.47(d,J=5.9Hz,6H).HRMS(ESI,[M] + )m / z:472.27049.

[0158] Example 5: Synthesis of 1-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-1-methylpiperidine bromide hydrochloride (compound I-5)

[0159] Referring to the preparation method of Example 1, except that 2-diethylamino-1-bromoethane hydrobromide in step 10 was replaced with 1-(2-bromoethyl)piperidine hydrobromide, finally yielding 1-(2-(((1S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-1-methylpiperidine bromide hydrochloride (denoted as compound I-5). The NMR and mass spectrometry data of compound I-5 are as follows:

[0160] 1H NMR (400MHz, DMSO-d6) δ8.54(d,J=2.3Hz,1H),8.43(dd,J=9.0,2.3Hz,1H),8.22–8.16(m,1H),8.10(d,J= 7.6Hz,1H),7.65–7.55(m,2H),5.02–4.97(m,1H),4.94(s,1H),3.86(q,J=11.1,10.1Hz,1H),3.82–3.70( m,1H),3.54(d,J=19.0Hz,3H),3.45(dd,J=11.8,6.0Hz,4H),3.32–3.26(m,1H),3.14(s,3H),2.61–2.52( m,1H),2.41(t,J=4.7Hz,1H),1.85(d,J=6.0Hz,4H),1.63–1.53(m,2H),1.40(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:486.23.

[0161] Example 6: Synthesis of (S)-N-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-N,N-dimethyl-N-isopropylammonium bromide (compound I-6)

[0162] The structure of compound I-6 is shown below:

[0163] The synthesis route is shown below:

[0164] Step 1: Synthesis of (S)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile hydrochloride (compound I-6-1)

[0165] Compound I-1-11 was prepared according to the preparation method in Example 1. Compound I-1-11 (1 g, 2.1 mmol) was dissolved in 10 mL of methanol, and 10 mL of 10% HCl-CH3OH was added. The mixture was stirred at 40 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure to give 0.86 g of a white solid (S)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile hydrochloride (denoted as compound I-6-1), yield 99.7%.

[0166] 1H NMR (600MHz, Methanol-d4) δ8.48–8.42(m,2H),8.26(d,J=7.7Hz,1H),7.75(d,J=7.6Hz,1H),7.57(t,J=7.7Hz,1H),7.46(d,J=9.0Hz,1H),4.99–4. 95(m,J=6.1Hz,1H),4.92(dd,J=8.1,4.9Hz,1H),3.65–3.57(m,1H),3.48– 3.40(m,1H),2.78–2.69(m,1H),2.26–2.18(m,1H),1.48(d,J=6.0Hz,6H).

[0167] Step 2: Synthesis of (S)-2-chloro-N-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)acetamide (compound I-6-2)

[0168] Compound I-6-1 (0.8 g, 2 mmol) was dissolved in 10 mL of toluene, and potassium carbonate solid (0.37 g, 2.7 mmol) was added. Then, chloroacetyl chloride (0.28 g, 2.5 mmol) was slowly added, and the reaction was stirred at room temperature. After the reaction was complete, 30 mL of cold water was added to the reaction solution, and the mixture was extracted with DCM (30 mL × 3). The organic phases were combined and washed with water (30 mL × 3). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give a white solid (S)-2-chloro-N-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)acetamide (denoted as compound I-6-2), 0.87 g, yield 98.7%.

[0169] 1 H NMR (600MHz, Methanol-d4) δ8.48(d,J=2.2Hz,1H),8.45(dd,J=8.9,2.3Hz,1H),8.12(d,J=7.6Hz,1H),7.51–7.41(m,3H),5.52(q,J=7.3Hz,1H),5 .02–4.92(m,1H),4.12(s,2H),3.58–3.50(m,1H),3.29–3.20(m,1H),2.6 8–2.59(m,1H),2.06–1.97(m,1H),1.48(d,J=6.0Hz,6H).MS(ESI,[M+Na] + )m / z:459.15.

[0170] Step 3: Synthesis of (S)-N-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)-2-(isopropyl(methyl)amino)acetamide (compound I-6-3)

[0171] Compound I-6-2 (0.46 g, 1.05 mmol) was dissolved in DMF (10 mL), followed by the addition of N-methylisopropylamine (0.15 g, 2.10 mmol) and potassium carbonate (0.29 g, 2.10 mmol). The mixture was stirred at 50 °C. After the reaction was complete, EA (10 mL) was added for dilution, followed by the addition of water (30 mL) for phase separation. The aqueous phase was extracted with EA (20 mL × 3), and the organic phases were combined. The organic phase was washed with water (20 mL × 3), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a yellow solid crude product. Column chromatography purification yielded a white solid (S)-N-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)-2-(isopropyl(methyl)amino)acetamide (designated as compound I-6-3), 205 mg, yield 41%.

[0172] 1 H NMR (600MHz, DMSO-d6) δ8.52(d,J=2.2Hz,1H),8.42(dd,J=9.0,2.3Hz,1H),8.03(dd,J=13.0,8.2 Hz,2H),7.56(d,J=9.1Hz,1H),7.48–7.37(m,2H),5.43(q,J=8.4Hz,1H),5.01–4.97(m,1H),3.46 –3.38(m,1H),3.15–3.08(m,1H),3.00(d,J=3.6Hz,2H),2.83–2.79(m,1H),2.49–2.47(m,1H),2. 20(s,3H),2.03–1.92(m,1H),1.39(d,J=6.0Hz,6H),0.97(dd,J=6.5,1.3Hz,6H).HRMS(ESI,[M+H] + )m / z:474.24988.

[0173] Step 4: Synthesis of (S)-N-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-N,N-dimethyl-N-isopropylammonium bromide (compound I-6)

[0174] Using compound I-6-3 and methyl bromo as raw materials, and referring to step 11 of Example 1, (S)-N-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-N,N-dimethyl-N-isopropylammonium bromide (denoted as compound I-6) was finally prepared. The NMR and mass spectrometry data of compound I-6 are as follows:

[0175] 1 H NMR(400MHz, Methanol-d4)δ8.49–8.41(m,2H),8.14(d,J=7.6Hz,1H),7.55(d,J=7.5Hz, 1H),7.50–7.42(m,2H),5.54(dd,J=14.2,6.9Hz,1H),5.00–4.94(m,1H),4.19–4.13(m,1H ),4.11(s,2H),3.60–3.47(m,1H),3.31(s,3H),3.31(s,3H),3.30–3.24(m,1H),2.72–2. 59(m,1H),2.09–1.96(m,1H),1.49(d,J=2.3Hz,6H),1.47(d,J=1.7Hz,6H).HRMS(ESI,[M] + )m / z:488.26523.

[0176] Example 7: Synthesis of (S)-N-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-N-methyl-N-ethyl-N-isopropylammonium bromide (compound I-7)

[0177] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with N-ethylisopropylamine, the final product (S)-N-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-N-methyl-N-ethyl-N-isopropylammonium bromide (denoted as compound I-7) was prepared. The NMR and mass spectrometry data of compound I-7 are as follows:

[0178] 1H NMR (400MHz, Methanol-d4) δ8.50–8.41(m,2H),8.14(d,J=7.6Hz,1H),7.54(d,J=7.4Hz,1H),7.50–7.42(m,2 H),5.54(t,J=7.3Hz,1H),5.00–4.94(m,1H),4.26–4.15(m,1H),4.12(d,J=15.3Hz,1H),4.03(d,J=15.2Hz,1H ),3.89–3.75(m,1H),3.76–3.62(m,1H),3.60–3.47(m,1H),3.30–3.24(m,1H),3.22(d,J=1.9Hz,3H),2.72–2 .59(m,1H),2.09–1.96(m,1H),1.48(d,J=4.4Hz,6H),1.47(d,J=4.9Hz,6H),1.45–1.40(m,3H).HRMS(ESI,[M] + )m / z:502.28079.

[0179] Example 8: Synthesis of (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N,N-diethyl-N-methyl-2-oxoethylammonium bromide (compound I-8)

[0180] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with diethylamine, the final product (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N,N-diethyl-N-methyl-2-oxoethylammonium bromide (denoted as compound I-8) was prepared. The NMR and mass spectrometry data of compound I-8 are as follows:

[0181] 1H NMR (400MHz, Methanol-d4) δ8.45–8.38(m,2H),8.11(d,J=7.6Hz,1H),7.53(d,J =7.5Hz,1H),7.44(dd,J=8.6,6.6Hz,2H),5.52(t,J=7.3Hz,1H),4.99–4.93(m,1H ),4.10(s,2H),3.80–3.60(m,4H),3.56-3.47(m,1H),3.28(s,4H),2.69-2.59(m, 1H),2.09–1.95(m,1H),1.48(d,J=6.0Hz,6H),1.43(t,J=7.3Hz,6H).MS(ESI,[M] + )m / z:488.28.

[0182] Example 9: Synthesis of (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-ethyl-N,N-dimethyl-2-oxoethylammonium bromide (compound I-9)

[0183] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with N-methylethylamine, the final product (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-ethyl-N,N-dimethyl-2-oxoethylammonium bromide (denoted as compound I-9) was prepared. The NMR and mass spectrometry data of compound I-9 are as follows:

[0184] 1 H NMR(400MHz, Methanol-d4)δ8.46–8.38(m,2H),8.15–8.08(m,1H),7.54(d,J=7.5Hz,1H ),7.44(dd,J=8.3,6.9Hz,2H),5.51(s,1H),5.00–4.94(m,1H),4.14(d,J=1.2Hz,2H),3. 72(q,J=7.3Hz,2H),3.57–3.47(m,1H),3.35(d,J=1.2Hz,6H),3.30–3.22(m,1H),2.71–2 .58(m,1H),2.08–1.97(m,1H),1.48(d,J=6.0Hz,6H),1.44(d,J=7.3Hz,3H).MS(ESI,[M] + )m / z:474.17.

[0185] Example 10: Synthesis of (S)-4-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-4-methylmorpholine bromide (compound I-10)

[0186] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with a morpholine ring, the final product (S)-4-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-4-methylmorpholine bromide (denoted as compound I-10) was prepared. The NMR and mass spectrometry data of compound I-10 are as follows:

[0187] 1 H NMR(400MHz, Methanol-d4)δ8.49–8.40(m,2H),8.13(d,J=7.6Hz,1H),7.55(d,J=7.5Hz,1H), 7.49–7.41(m,2H),5.54(dd,J=14.4,7.1Hz,1H),5.04–4.90(m,1H),4.32(d,J=1.5Hz,2H),4.1 6–4.00(m,4H),3.90–3.81(m,2H),3.78–3.70(m,2H),3.53(s,3H),3.52–3.49(m,1H),3.27(dd ,J=17.2,8.3Hz,1H),2.72–2.59(m,1H),2.10–1.97(m,1H),1.48(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:502.25.

[0188] Example 11: Synthesis of (S)-1-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-4-(hydroxymethyl)-1-methylpiperidine bromide (compound I-11)

[0189] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with 4-hydroxymethylpiperidine, the final product (S)-1-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-4-(hydroxymethyl)-1-methylpiperidine bromide (denoted as compound I-11) was prepared. The NMR and mass spectrometry data of compound I-11 are as follows:

[0190] 1 H NMR(400MHz, Methanol-d4)δ8.48–8.40(m,2H),8.13(dd,J=7.7,1.4Hz,1H),7.58–7.51(m,1H),7.4 5(dd,J=8.8,6.4Hz,2H),5.54(t,J=7.3Hz,1H),5.02–4.93(m,1H),4.27–4.12(m,2H),3.88(d,J=12. 3Hz,1H),3.63(d,J=12.0Hz,1H),3.59–3.47(m,4H),3.45(s,1H),3.38(s,3H),3.26(dd,J=17.2,8.1 Hz,1H),2.71–2.58(m,1H),2.10–1.95(m,3H),1.90–1.74(m,3H),1.48(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:530.28.

[0191] Example 12: Synthesis of 1-(2-((S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-3-hydroxy-1-methylpyrrolidine bromide (compound I-12)

[0192] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with 3-hydroxypyrrolidine, the final product was 1-(2-((S)-4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-3-hydroxy-1-methylpyrrolidine bromide (denoted as compound I-12). The NMR and mass spectrometry data of compound I-12 are as follows:

[0193] 1H NMR (400MHz, Methanol-d4) δ8.417–8.37(m,2H),8.07(d,J=7.7Hz,1H),7.52(dd,J=7.4,4.8 Hz,1H),7.45–7.39(m,2H),5.55–5.47(m,1H),4.99–4.91(m,1H),4.72(d,J=5.9Hz,1H),4.42 (d,J=3.0Hz,1H),4.39–4.25(m,1H),4.15–3.76(m,4H),3.57–3.44(m,4H),3.27–3.17(m,1H) ,2.72–2.54(m,2H),2.29–2.15(m,1H),2.07–1.95(m,1H),1.47(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:502.16.

[0194] Example 13: Synthesis of (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-methoxyethyl)-N,N-dimethyl-2-oxoethylammonium bromide (compound I-13)

[0195] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with N-methyl-2-methoxyethylamine, the final product (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-methoxyethyl)-N,N-dimethyl-2-oxoethylammonium bromide (denoted as compound I-13) was prepared. The NMR and mass spectrometry data of compound I-13 are as follows:

[0196] 1H NMR (400MHz, Methanol-d4) δ8.49–8.40(m,2H),8.13(d,J=7.6Hz,1H),7.54(d,J=7.5Hz,1H ),7.45(t,J=7.7Hz,2H),5.53(t,J=7.4Hz,1H),5.02–4.92(m,1H),4.23(dd,J=9.0,1.7Hz, 2H),3.99–3.85(m,4H),3.59–3.47(m,1H),3.42(d,J=3.2Hz,6H),3.41(s,3H),3.26(dd,J= 17.2,8.2Hz,1H),2.70–2.57(m,1H),2.08–1.94(m,1H),1.48(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:504.20.

[0197] Example 14: Synthesis of (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-hydroxyethyl)-N,N-dimethyl-2-oxoethylammonium bromide (compound I-14)

[0198] Referring to the synthesis method of Example 6, except that N-methylisopropylamine was replaced with 2-(methylamino)ethanol, the final product (S)-2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-hydroxyethyl)-N,N-dimethyl-2-oxoethylammonium bromide (denoted as compound I-14) was prepared. The NMR and mass spectrometry data of compound I-14 are as follows:

[0199] 1H NMR (400MHz, Methanol-d4) δ8.41(d,J=7.8Hz,2H),8.10(d,J=7.6Hz,1H),7.53(d,J=7.5H z,1H),7.48–7.39(m,2H),5.52(t,J=7.5Hz,1H),5.00–4.92(m,1H),4.29(d,J=3.2Hz,2H) ,4.06(t,J=4.8Hz,2H),3.92–3.76(m,2H),3.55–3.47(m,1H),3.46(s,3H),3.45(s,3H),3 .29–3.19(m,1H),2.67–2.57(m,1H),2.06–1.96(m,1H),1.48(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:490.18.

[0200] Example 15: Synthesis of (S)-4-(2-((4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-15)

[0201] The synthesis route is shown below:

[0202] The synthesis steps are as follows:

[0203] Step 1: Synthesis of methyl 4-(cyclopent-1-en-1-yl)-3-(trifluoromethyl)benzoate (compound I-15-2)

[0204] Methyl 3-trifluoromethyl-4-bromobenzoate (5 g, 17.67 mmol) was dissolved in 1,4-dioxane (50 mL), followed by the addition of potassium carbonate (7.3 g, 53.00 mmol), tetrakis(triphenylphosphine)palladium (1.02 g, 0.88 mmol), cyclopenten-1-ylboronic acid (2.35 g, 21.02 mmol), and water (10 mL) to obtain the reaction solution. The reaction solution was stirred and refluxed at 110 °C for 1 h under nitrogen protection. After cooling to room temperature, the reaction solution was filtered. 100 mL of water was added to the reaction solution, and the mixture was extracted with ethyl acetate (20 mL × 3). The organic phases were combined and washed with saturated brine (20 mL × 3). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a crude black oily product. The crude product was purified by column chromatography (PE:EA = 80:1) to obtain a clear yellow oily product, methyl 4-(cyclopent-1-en-1-yl)-3-(trifluoromethyl)benzoate (denoted as compound I-15-2), 4.57 g, yield 96%.

[0205] 1 H NMR(400MHz,Chloroform-d)δ8.34(d,J=1.8Hz,1H),8.14(dd,J=8.1,1.8Hz,1H),7.39(d,J=8.0Hz ,1H),5.82(t,J=2.3Hz,1H),3.97(s,3H),2.74–2.65(m,2H),2.61–2.51(m,2H),2.10–2.00(m,2H).

[0206] Step 2: Synthesis of methyl 4-cyclopentyl-3-(trifluoromethyl)benzoate (compound I-15-3)

[0207] Compound I-15-2 (1 g, 3.7 mmol) was dissolved in methanol (10 mL), and palladium on carbon hydrogenation catalyst (0.2 g) was added. The mixture was placed in a hydrogen-filled balloon and stirred at 60 °C for 24 h under a hydrogen atmosphere. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure to obtain a dark yellow oil. Column chromatography purified the oil to methyl 4-cyclopentyl-3-(trifluoromethyl)benzoate (denoted as compound I-15-3), 0.89 g, yield 89%.

[0208] 1 H NMR(400MHz,Chloroform-d)δ8.29(d,J=1.8Hz,1H),8.16(dd,J=8.3,1.8Hz,1H),7.56(d,J=8.3Hz,1H),3. 96(s,3H),3.48–3.40(m,1H),2.18–2.08(m,2H),1.95–1.84(m,2H),1.82–1.72(m,2H),1.69–1.60(m,2H).

[0209] Step 3: Synthesis of 4-cyclopentyl-3-(trifluoromethyl)benzoic acid (compound I-15-4)

[0210] Compound I-15-3 (0.89 g, 3.27 mmol) was dissolved in 1,4-dioxane (8 mL), and 1M NaOH aqueous solution (5 mL, 5 mmol) was added. The mixture was stirred at 40 °C for 1 h. After the reaction was completed, the reaction solution was cooled to room temperature and placed in an ice bath. The pH was adjusted to 1 with 1M HCl, and a white solid precipitated. The reaction solution was filtered to obtain 0.81 g of a white powder solid 4-cyclopentyl-3-(trifluoromethyl)benzoic acid (designated as compound I-15-4), with a yield of 95%.

[0211] Step 4: Synthesis of (S)-(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)tert-butyl carbamate (compound I-15-5)

[0212] Following the synthesis method in step 9 of Example 1, (S)-(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl) tert-butyl carbamate (denoted as compound I-15-5) was prepared by coupling with compounds I-1-10 and I-15-4 as raw materials.

[0213] Step 5: Synthesis of (S)-(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)(2-morpholinoethyl)carbamate tert-butyl ester (compound I-15-6)

[0214] Referring to the synthesis method in step 10 of Example 1, except that 4-(2-bromoethyl)morpholine hydrobromide and compound I-15-5 were used as raw materials to prepare (S)-(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl)(2-morpholinoethyl) tert-butyl carbamate (denoted as compound I-15-6).

[0215] Step 6: Synthesis of (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (compound I-15-7)

[0216] Referring to the synthesis method in step 11 of Example 1, except that methyl bromide and compound I-15-6 were used as raw materials to prepare (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (denoted as compound I-15-7).

[0217] Step 7: Synthesis of (S)-4-(2-((4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-15)

[0218] Referring to the synthesis method in step 12 of Example 1, except that (S)-4-(2-((4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-15) was prepared using compound I-15-7 and hydrochloric acid as raw materials. The NMR and mass spectrometry data of compound I-15 are as follows:

[0219] 1 H NMR (400MHz, Methanol-d4) δ9.01(s,1H),8.88(d,J=8.3Hz,1H),8.65(d,J=7.5Hz,1H),8.52(s,1H),8.3 2(d,J=8.3Hz,1H),8.07(t,J=7.3Hz,1H),5.76(s,1H),4.98–4.62(m,6H),4.58–4.48(m,2H),4.42(d,J=1 5.5Hz,2H),4.21(d,J=12.8Hz,3H),4.06(t,J=8.5Hz,1H),3.99(s,4H),3.24(s,1H),2.70(d,J=11.6Hz,2 H),2.43(d,J=8.4Hz,2H),2.35–2.26(m,2H),2.19(q,J=10.2,9.2Hz,2H),2.04–1.92(m,1H).MS(ESI,[M] + )m / z:541.33.

[0220] Example 16: Synthesis of (S)-4-(2-((4-(5-(4-cyclohexyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-16)

[0221] Referring to the synthesis method of Example 15, except that 4-cyclopentyl-3-(trifluoromethyl)benzoic acid (compound I-15-4) in step 4 was replaced with 4-cyclohexyl-3-trifluoromethylbenzoic acid, finally preparing (S)-4-(2-((4-(5-(4-cyclohexyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-16). The NMR and mass spectrometry data of compound I-16 are as follows:

[0222] 1H NMR (400MHz, Methanol-d4) δ8.50–8.35(m,2H),8.31(d,J=7.7Hz,1H),8.03(d,J=7.6Hz,1H),7.87(d,J=8.2Hz,1H),7. 60(t,J=7.8Hz,1H),5.05(dd,J=8.2,3.9Hz,1H),4.10(dd,J=5.6,3.5Hz,4H),4.07–4.00(m,1H),3.90–3.83(m,1H),3. 82–3.75(m,2H),3.75–3.70(m,2H),3.70–3.62(m,3H),3.53–3.45(m,1H),3.43(s,3H),3.05(t,J=11.8Hz,1H),2.79–2 .68(m,1H),2.58–2.48(m,1H),1.97–1.90(m,2H),1.89–1.81(m,3H),1.70–1.58(m,2H),1.54–1.38(m,3H).MS(ESI,[M] + )m / z:555.70.

[0223] Example 17: Synthesis of (S)-2-((4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-hydroxyethyl)-N,N-dimethylethylammonium chloride hydrochloride (compound I-17)

[0224] Referring to the synthesis method of Example 15, except that 4-(2-bromoethyl)morpholine hydrobromide in step 5 was replaced with N,N-dimethylaminobromoethane hydrobromide, and bromomethane in step 6 was replaced with ethylene oxide, to prepare (S)-2-((4-(5-(4-cyclopentyl-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-N-(2-hydroxyethyl)-N,N-dimethylethylammonium chloride hydrochloride (denoted as compound I-17). The NMR and mass spectrometry data of compound I-17 are as follows:

[0225] 1H NMR (400MHz, Methanol-d4) δ8.48–8.40(m,2H),8.37–8.30(m,1H),7.98(dd,J=7.7,4.5Hz,1H),7.89(d,J=8.3Hz, 1H),7.62(t,J=7.7Hz,1H),5.06–5.00(m,1H),4.08(t,J=4.5Hz,1H),4.00(t,J=4.5Hz,1H),3.96–3.85(m,5.3Hz,2 H),3.81(dd,J=14.7,5.6Hz,2H),3.73–3.66(m,2H),3.64–3.60(m,1H),3.55–3.45(m,2H),3.36(s,3H),3.35(s,3 H),2.79–2.67(m,1H),2.54–2.44(m,1H),2.16(d,J=9.9Hz,2H),2.03–1.92(m,2H),1.88–1.69(m,4H).MS(ESI,[M] + )m / z:529.29.

[0226] Example 18: Synthesis of (S)-4-(2-((4-(5-(3-chloro-4-cyclopentylphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-18)

[0227] The synthesis route is shown below:

[0228] The synthesis steps are as follows:

[0229] Step 1: Synthesis of methyl 4-trifluoromethanesulfonyloxy-3-chlorobenzoate (compound I-18-2)

[0230] Methyl 3-chloro-4-hydroxybenzoate (3 g, 16.13 mmol) was dissolved in DCM (50 mL). Under ice bath conditions, pyridine (0.127 g, 1.6 mmol) was added, followed by the slow addition of Tf₂O (9.1 g, 32.3 mmol). The reaction mixture was then magnetically stirred at room temperature. After the reaction was complete, the reaction solution was washed with pure water (50 mL × 3). The organic phase was then dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a black oily crude product. Column chromatography purification yielded a clear, yellow oily product, methyl 4-trifluoromethanesulfonyloxy-3-chlorobenzoate (designated as compound I-18-2), 3.2 g, yield 62.5%.

[0231] Step 2: Synthesis of methyl 4-(cyclopenten-1-yl)-3-chlorobenzoate (compound I-18-3)

[0232] Compound I-18-2 (3.2 g, 10.04 mmol) was dissolved in 1,4-dioxane (50 mL), followed by the addition of potassium carbonate (4.16 g, 30.12 mmol), tetrakis(triphenylphosphine)palladium (0.581 g, 0.5 mmol), cyclopenten-1-ylboronic acid (1.34 g, 11.95 mmol), and water (10 mL). The reaction mixture was stirred and refluxed at 110 °C for 1 h under nitrogen protection. After cooling to room temperature, the reaction mixture was filtered. 100 mL of water was added to the reaction mixture, and the mixture was extracted with ethyl acetate (20 mL × 3). The organic phases were combined and washed with saturated brine (20 mL × 3). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a crude black oily product. The crude product was purified by column chromatography to obtain a clear yellow oily product, methyl 4-(cyclopenten-1-yl)-3-chlorobenzoate (denoted as compound I-18-3), 1.89 g, with a yield of 79%.

[0233] 1 H NMR (400MHz, DMSO-d6) δ7.94(d,J=1.8Hz,1H),7.87(dd,J=8.1,1.8Hz,1H),7.53(d,J=8.1Hz,1H ), 6.32(t,J=2.2Hz,1H),3.87(s,3H),2.79–2.70(m,2H),2.57–2.52(m,,2H),2.01–1.92(m,2H).

[0234] Step 3: Synthesis of methyl 4-cyclopentenyl-3-chlorobenzoate (compound I-18-4)

[0235] Compound I-18-3 (1.89 g, 7.98 mmol) was dissolved in methanol (20 mL), and palladium on carbon hydrogenation catalyst (0.19 g) was added. The mixture was placed in a hydrogen-filled balloon and stirred at 60 °C for 24 h under a hydrogen atmosphere. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure to obtain a pale yellow oil. Column chromatography purified the oil to methyl 4-cyclopentenyl-3-chlorobenzoate (designated as compound I-18-4), 1.89 g, with a yield of 99%.

[0236] 1H NMR(400MHz,Chloroform-d)δ8.03(d,J=1.8Hz,1H),7.88(dd,J=8.1,1.8Hz,1H),7.39(d,J=8.2Hz,1H),3. 93(s,3H),3.54–3.46(m,1H),2.17–2.05(m,2H),1.91–1.79(m,2H),1.81–1.70(m,2H),1.66–1.58(m,2H).

[0237] Step 4: Synthesis of 4-cyclopentenyl-3-chlorobenzoic acid (compound I-18-5)

[0238] Compound I-18-4 (1.89 g, 7.92 mmol) was dissolved in 1,4-dioxane (10 mL), and 1M NaOH aqueous solution (15 mL, 15 mmol) was added. The mixture was stirred at 40 °C for 1 h. After the reaction was complete, the reaction solution was cooled to room temperature and placed in an ice bath. The pH was adjusted to 1 with 1M HCl, and a white solid precipitated. The reaction solution was filtered to obtain 1.75 g of a white powder solid 4-cyclopentenyl-3-chlorobenzoic acid (designated as compound I-18-5), with a yield of 98%.

[0239] Step 5: Synthesis of (S)-(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)tert-butyl carbamate (compound I-18-6)

[0240] Referring to the synthesis method in step 9 of Example 1, except that compounds I-1-10 and I-18-5 were used as raw materials to couple (S)-(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl) tert-butyl carbamate (denoted as compound I-18-6).

[0241] Step 5: Synthesis of (S)-(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)(2-morpholinoethyl) tert-butyl carbamate (compound I-18-7)

[0242] Referring to the synthesis method in step 10 of Example 1, except that 4-(2-bromoethyl)morpholine hydrobromide and compound 18-6 were used as raw materials to prepare (S)-(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl)(2-morpholinoethyl) tert-butyl carbamate (denoted as compound I-18-7).

[0243] Step 6: Synthesis of (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (compound I-18-8)

[0244] Referring to the synthesis method in step 11 of Example 1, except that methyl bromide and compound I-18-7 were used as raw materials to prepare (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(4-cyclopentyl-3-chlorophenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (denoted as compound I-18-8).

[0245] Step 7: Synthesis of (S)-4-(2-((4-(5-(3-chloro-4-cyclopentylphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-18)

[0246] Referring to the synthesis method in step 12 of Example 1, except that (S)-4-(2-((4-(5-(3-chloro-4-cyclopentylphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-18) was prepared using compound I-18-8 and hydrochloric acid as raw materials. The NMR and mass spectrometry data of compound I-18 are as follows:

[0247] 1 H NMR(400MHz, Methanol-d4)δ8.20(d,J=1.8Hz,1H),8.14–8.07(m,2H),7.63(dd,J=11.9 ,7.8Hz,2H),7.44(t,J=7.7Hz,1H),4.04(q,J=4.5Hz,4H),3.70–3.63(m,4H),3.58–3.46 (m,4H),3.34(s,3H),3.28–3.18(m,3H),2.54(q,J=12.0,8.7Hz,1H),2.23–2.14(m,2H), 2.04–1.96(m,1H),1.96–1.86(m,2H),1.86–1.76(m,2H),1.75-1.61(m,3H).MS(ESI,[M] + )m / z:507.36.

[0248] Example 19: Synthesis of (S)-4-(2-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-19)

[0249] The synthesis route is shown below:

[0250] Synthesis method:

[0251] Step 1: Synthesis of methyl 3-chloro-4-isopropoxybenzoate (compound I-19-2)

[0252] Methyl 3-chloro-4-hydroxybenzoate (5 g, 26.8 mmol) was dissolved in DMF (50 mL), followed by the addition of 2-bromopropane (6.54 g, 53.6 mmol) and potassium carbonate (7.4 g, 53.6 mmol). The mixture was heated and stirred at 70 °C. After the reaction was complete, 150 mL of water was added to the reaction solution, resulting in the precipitation of a solid. The reaction solution was filtered under reduced pressure to obtain 6.1 g of a white solid, methyl 3-chloro-4-isopropoxybenzoate (designated as compound I-19-2), with a yield of 99.5%.

[0253] Step 2: Synthesis of 3-chloro-4-isopropoxybenzoic acid (compound I-19-3)

[0254] Compound I-19-2 (6.1 g, 26.68 mmol) was dissolved in 1,4-dioxane (60 mL), and 1M NaOH aqueous solution (41 mL, 41 mmol) was added. The mixture was stirred at 40 °C for 1 h. After the reaction was complete, the reaction solution was cooled to room temperature and placed in an ice bath. The pH was adjusted to 1 with 1M HCl, and a white solid precipitated. The reaction solution was filtered to obtain 5.65 g of a white powder solid 3-chloro-4-isopropoxybenzoic acid (designated as compound I-19-3), with a yield of 98.6%.

[0255] 1 H NMR (400MHz, DMSO-d6) δ7.92–7.82(m,2H),7.26(d,J=8.7Hz,1H),4.84-4.75(mp,1H),1.32(d,J=6.0Hz,6H).

[0256] Step 3: Synthesis of (S)-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl) tert-butyl carbamate (compound I-19-4)

[0257] Referring to the synthesis method in step 9 of Example 1, except that compounds I-1-10 and I-19-3 were used as raw materials to couple (S)-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl) tert-butyl carbamate (denoted as compound I-19-4).

[0258] Step 4: Synthesis of (S)-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)(2-morpholinoethyl) tert-butyl carbamate (compound I-19-5)

[0259] Referring to the synthesis method in step 10 of Example 1, except that 4-(2-bromoethyl)morpholine hydrobromide and compound I-19-4 were used as raw materials to prepare (S)-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl)(2-morpholinoethyl) tert-butyl carbamate (denoted as compound I-19-5).

[0260] Step 5: Synthesis of (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (compound I-19-6)

[0261] Referring to the synthesis method in step 11 of Example 1, except that methyl bromide and compound I-19-5 were used as raw materials to prepare (S)-4-(2-(tert-butoxycarbonyl)(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide (denoted as compound I-19-6).

[0262] Step 7: Synthesis of (S)-4-(2-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-19)

[0263] Referring to the synthesis method in step 12 of Example 1, except that (S)-4-(2-(4-(5-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-19) was prepared using compound I-19-6 and hydrochloric acid as raw materials. The NMR and mass spectrometry data of compound I-19 are as follows:

[0264] 1 H NMR(400MHz, Methanol-d4)δ8.29(d,J=7.7Hz,1H),8.21(d,J=2.2Hz,1H),8.12(dd,J=8.7,2.2Hz,1H), 8.02(d,J=7.6Hz,1H),7.60(t,J=7.6Hz,1H),7.32(d,J=8.7Hz,1H),5.06(d,J=6.7Hz,1H),4.86–4.82( m,1H),4.10(t,J=4.3Hz,5H),4.03–3.93(m,1H),3.92–3.78(m,2H),3.68(t,J=13.8Hz,5H),3.50(dd,J =8.7,4.4Hz,1H),3.42(s,3H),2.81–2.67(m,1H),2.58–2.49(m,1H),1.44(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:497.78.

[0265] Example 20: Synthesis of (S)-4-(2-(4-(5-(3-cyano-4-cyclohexylphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (compound I-20)

[0266] Referring to the synthesis method of Example 15, except that methyl 3-trifluoromethyl-4-bromobenzoate was replaced with methyl 3-cyano-4-bromobenzoate, and cyclopenten-1-ylboronic acid was replaced with cyclohexen-1-ylboronic acid to prepare methyl 4-(cyclohex-1-en-1-yl)-3-(cyano)benzoate; using methyl 4-(cyclohex-1-en-1-yl)-3-(cyano)benzoate as a starting material, (S)-4-(2-(4-(5-(3-cyano-4-cyclohexylphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-20) was finally synthesized. The NMR and mass spectrometry data of compound I-20 are as follows:

[0267] 1 H NMR (600MHz, Methanol-d4) δ8.51(d,J=1.9Hz,1H),8.44(dd,J=8.3,1.9Hz,1H),8.32(dd,J=7.8,1.1Hz,1H),8.04(d,J=7.6Hz, 1H),7.79(d,J=8.3Hz,1H),7.62(t,J=7.7Hz,1H),5.08(dd,J=7.9,3.9Hz,1H),4.13–4.07(m,4H),4.08–4.04(m,1H),4.01–3.94 (m,1H),3.91–3.84(m,1H),3.84–3.77(m,1H),3.77–3.63(m,5H),3.53–3.46(m,1H),3.43(s,3H),3.09(t,J=11.8Hz,1H),2.79– 2.70(m,1H),2.59–2.51(m,1H),2.00–1.93(m,4H),1.89–1.82(m,1H),1.68–1.50(m,4H),1.40(q,J=12.9Hz,1H).HRMS(ESI,[M] + )m / z:512.30145.

[0268] Example 21: Synthesis of (S)-4-methyl-4-(2-(4-(5-(4-(2,2,2-trifluoroethoxy)-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)morpholine bromide hydrochloride (compound I-21)

[0269] The synthesis method is the same as in Example 1, except that methyl 3-bromo-4-hydroxybenzoate (compound I-1-1) is replaced with methyl 3-(trifluoromethyl)-4-hydroxybenzoate, and 2-bromopropane is replaced with bromotrifluoroethane. This yields methyl 4-(2,2,2-trifluoroethoxy)-3-(trifluoromethyl)benzoate, which is then hydrolyzed to obtain 4-(2,2,2-trifluoroethoxy)-3-(trifluoromethyl)benzoic acid; 4-(2,2,2-trifluoroethoxy)-3-(trifluoromethyl)benzoic acid... After reacting formic acid with compound I-1-10, it is coupled with 4-(2-bromoethyl)morpholine hydrobromide, and finally quaternized and salted to obtain (S)-4-methyl-4-(2-(4-(5-(4-(2,2,2-trifluoroethoxy)-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)bromomorpholine hydrochloride (denoted as compound I-21). The NMR and mass spectrometry data of compound I-21 are as follows:

[0270] 1 H NMR(400MHz,CF3COOD)δ9.08(d,J=16.5Hz,2H),8.63(d,J=7.7Hz,1H),8.39(d,J=7.7Hz,1H ),8.11–8.02(m,1H),7.95(d,J=8.7Hz,1H),7.81(s,1H),5.71(s,1H),5.40(d,J=5.4Hz,2H ),4.89–4.73(m,7H),4.44(dd,J=13.7,5.9Hz,2H),4.30–4.21(m,2H),4.15(q,J=8.5,7.7H z,1H),4.03(s,3H),4.00–3.92(m,1H),3.41–3.22(m,1H),3.06–2.97(m,1H).HRMS(ESI,[M] + )m / z:571.2141.

[0271] Example 22: (S)-4-(2-((4-(5-(4-isopropoxy-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (Compound I-22)

[0272] The synthesis method is the same as in Example 1, except that methyl 3-bromo-4-hydroxybenzoate (compound I-1-1) is replaced with methyl 3-(trifluoromethyl)-4-hydroxybenzoate, which is then reacted with 2-bromopropane via a nucleophilic substitution reaction to prepare methyl 4-isopropoxy-3-(trifluoromethyl)benzoate, which is then hydrolyzed to give 4-isopropoxy-3-(trifluoromethyl)benzoic acid; methyl 4-isopropoxy-3-(trifluoromethyl)benzoate and compound I-1 After the reaction at -10, it is coupled with 4-(2-bromoethyl)morpholine hydrobromide, and finally quaternized and salted to obtain (S)-4-(2-((4-(5-(4-isopropoxy-3-(trifluoromethyl)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-22). The NMR and mass spectrometry data of compound I-22 are as follows:

[0273] 1H NMR (400MHz, DMSO-d6) δ8.42(dd,J=8.8,2.3Hz,1H),8.33(d,J=2.2Hz,1H),8.21(d,J= 7.7Hz,1H),8.07(d,J=7.6Hz,1H),7.64–7.57(m,2H),5.03–4.96(m,1H),4.94(s,1H),3 .98(d,J=5.7Hz,5H),3.90(s,1H),3.64–3.59(m,3H),3.59(s,4H),3.52(t,J=8.5Hz,1 H),3.28(s,3H),2.57(q,J=6.9Hz,1H),2.41(s,1H),1.37(d,J=6.0Hz,6H).MS(ESI,[M] + )m / z:531.20.

[0274] Example 23: (S)-4-(2-((4-(5-(3-cyano-4-methoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (Compound I-23)

[0275] Referring to the synthesis method of Example 1, except that methyl 3-bromo-4-hydroxybenzoate (compound I-1-1) was reacted with iodomethane via a nucleophilic substitution reaction to prepare methyl 3-bromo-4-methoxybenzoate, which was then reacted with cuprous cyanide via a Rosenmun-von-Braun reaction to prepare methyl 3-cyano-4-methoxybenzoate; methyl 3-cyano-4-methoxybenzoate was hydrolyzed to obtain 3-cyano-4-methoxybenzoic acid; 3-cyano-4 After reacting methoxybenzoic acid with compound I-1-10, it is coupled with 4-(2-bromoethyl)morpholine hydrobromide, and finally quaternized and salted to obtain (S)-4-(2-((4-(5-(3-cyano-4-methoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-23). ​​The NMR and mass spectrometry data of compound I-23 are as follows:

[0276] 1H NMR (400MHz, DMSO-d6) δ8.56(d,J=2.3Hz,1H),8.48(dd,J=8.9,2.2Hz,1H),8.20(d,J=7.6 Hz,1H),8.08(d,J=7.6Hz,1H),7.65–7.52(m,2H),4.93(s,1H),4.07(s,3H),3.98(d,J=6. 2Hz,5H),3.90(s,1H),3.65–3.59(m,2H),3.58(s,4H),3.55–3.50(m,2H),3.27(s,3H),2. 59(dd,J=14.6,8.0Hz,1H),2.53(d,J=1.9Hz,1H),2.40(s,1H).MS(ESI,[M]+)m / z:460.15.

[0277] Example 24: (S)-4-(2-((4-(5-(3-cyano-4-ethoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (Compound 24)

[0278] Referring to the synthesis method of Example 1, except that methyl 3-bromo-4-hydroxybenzoate (compound I-1-1) was reacted with iodoethane via a nucleophilic substitution reaction to prepare methyl 3-bromo-4-ethoxybenzoate, which was then reacted with cuprous cyanide via a Rosenmun-von-Braun reaction to prepare methyl 3-cyano-4-ethoxybenzoate; methyl 3-cyano-4-ethoxybenzoate was hydrolyzed to obtain 3-cyano-4-ethoxybenzoic acid; 3-cyano-4... After reacting ethoxybenzoic acid with compound I-1-10, it is coupled with 4-(2-bromoethyl)morpholine hydrobromide, and finally quaternized and salted to obtain (S)-4-(2-((4-(5-(3-cyano-4-ethoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (denoted as compound I-24). The NMR and mass spectrometry data of compound I-24 are as follows:

[0279] 1H NMR (400MHz, Methanol-d4) δ8.48–8.41(m,2H),8.30(dd,J=7.8,1.1Hz,1H),8.02(d,J=7.6Hz,1H) ,7.60(t,J=7.7Hz,1H),7.47–7.40(m,1H),5.05(dd,J=7.9,4.0Hz,1H),4.36(q,J=7.0Hz,2H),4.1 0(t,J=4.9Hz,4H),4.07–3.93(m,2H),3.90–3.73(m,3H),3.73–3.62(m,5H),3.52–3.44(m,1H),3. 42(s,3H),2.79–2.68(m,1H),2.58–2.48(m,1H),1.54(t,J=7.0Hz,3H).MS(ESI,[M]+)m / z:474.22.

[0280] Example 25: (R)-4-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylmorpholine bromide hydrochloride (Compound I-25)

[0281] Referring to the synthesis method of Example 1, except that (s)-(-)-tert-butylsulfinamide in step 5 was replaced with (R)-(-)-tert-butylsulfinamide, and compound I-1-6 underwent a reducing amine ring reaction with (R)-(-)-tert-butylsulfinamide. Subsequent steps were carried out in the same manner. Simultaneously, 2-diethylamino-1-bromoethane hydrobromide in step 10 was replaced with 4-(2-bromoethyl)morpholine hydrobromide, finally yielding (R)-4-(2-((4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)ethyl)-4-methylbromomorpholine hydrochloride (denoted as compound I-25), which has the opposite configuration to compound I-3. The NMR and mass spectrometry data of compound I-25 are as follows:

[0282] 1H NMR (400MHz, DMSO-d6) δ8.53(d,J=2.3Hz,1H),8.42(dd,J=9.0,2.3Hz,1H),8.19(d,J=7.7Hz,1H),8.11(d,J=7. 6Hz,1H),7.64–7.59(m,1H),7.58(d,J=6.7Hz,1H),5.04–4.95(m,1H),4.94(s,1H),4.00(d,J=2.8Hz,2H),3.98( d,J=4.4Hz,3H),3.96–3.89(m,1H),3.62(d,J=5.4Hz,2H),3.59(d,J=4.7Hz,3H),3.57–3.50(m,2H),3.34–3.30( m,1H),3.29(s,3H),2.62–2.53(m,1H),2.42(t,J=4.8Hz,1H),1.40(d,J=6.0Hz,6H).MS(ESI,[M]+)m / z:488.21.

[0283] Example 26: (S)-4-(2-((4-(5-(3-cyano-4-(2,2,2-trifluoroethoxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)amino)-2-oxoethyl)-4-methylmorpholine bromide (Compound I-26)

[0284] First, referring to the synthesis method of Example 1, 2-bromoethane was replaced with 1,1,1-trifluoro-2-iodoethane and reacted with compound I-1-1 to prepare methyl 3-bromo-4-(2,2,2-trifluoroethoxy)benzoate. Then, the reaction was carried out in the same manner to obtain 3-cyano-4-(2,2,2-trifluoroethoxy)benzoic acid. 3-cyano-4-(2,2,2-trifluoroethoxy)benzoic acid was reacted with compound I-1-10 to prepare N-[(1S)-4-{5-[3-cyano-4-(2,2,2-trifluoroethoxy)phenyl]-1,2,4-oxadiazol-3-yl}-2,3-dihydro-1H-inden-1-yl] tert-butyl carbamate. Then, referring to… According to the preparation method in Example 6, (S)-4-(2-((4-(5-(3-cyano-4-(2,2,2-trifluoroethoxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl)carbamate tert-butyl, hydrochloric acid, chloroacetyl chloride, morpholine, and bromomethane were sequentially used as raw materials to prepare (S)-4-(2-((4-(5-(3-cyano-4-(2,2,2-trifluoroethoxy)phenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-indene-1-yl)amino)-2-oxoethyl)-4-methylmorpholine bromide (denoted as compound I-26). The NMR and mass spectrometry data of compound I-26 are as follows:

[0285] 1 H NMR(400MHz, DMSO-d6)δ9.07(d,J=8.0Hz,1H),8.63(d,J=2.2Hz,1H),8.52(dd,J=9.0, 2.2Hz,1H),8.11–8.04(m,1H),7.67(d,J=9.0Hz,1H),7.56–7.46(m,2H),5.44(q,J=7. 7Hz,1H),5.18(q,J=8.6Hz,2H),4.31(s,2H),4.05–3.91(m,4H),3.76–3.61(m,4H),3. 48–3.42(m,1H),3.41(s,3H),3.24–3.14(m,1H),2.59–2.53(m,1H),1.99–1.88(m,1H) . .MS(ESI,[M]+)m / z:542.16.

[0286] Example 27: S1PR1 agonist activity

[0287] 1. Experimental reagents and instruments:

[0288] The reagents and instruments used for the S1PR1 agonist activity assay are shown in Table 1.

[0289] Table 1. Reagents and Instruments

[0290] 2. Test methods

[0291] (1) Cell culture and solution preparation:

[0292] Cell line: Flpin-CHO-S1P1 (commercially purchased)

[0293] Complete culture medium: F12K (Hyclone) + 10% (v / v) fetal bovine serum (AUSGeneX) + 1× penicillin-streptomycin (Gibco)

[0294] Detection buffer: 1×Hanks' buffer (Gibco) + 20mM HEPES (Gibco) + 0.1% BSA (Perkin Elmer) + 500μM 3-isobutyl-1-methylxanthine (Sigma)

[0295] (2) Activity detection:

[0296] 1) Seed Flpin-CHO-S1P1 cells into 384-well plates at a density of 8000 cells / well;

[0297] 2) Prepare test compound solutions (final products obtained in Examples 1 to 26) with concentrations of 8000 nM, 2000 nM, 500 nM, 125 nM, 31.25 nM, 7.81 nM, 1.95 nM, 0.49 nM, 0.12 nM, and 0.03 nM using detection buffer.

[0298] 3) The solution of the test compound was added to the 384-well plate at a rate of 2.5 μL / well and incubated at 37°C for 10 min;

[0299] 4) Prepare an 8 μM Selleck solution using detection buffer, add 2.5 μL / well to a 384-well plate and incubate at 37°C for 30 min;

[0300] 5) Dilute the Eu-cAMP tracer in the LANCE Ultra cAMP Detection Kit (Perkin Elmer) to 50-fold with lysis buffer, and add 10 μL to each well;

[0301] 6) Dilute the Ulight-anti-cAMP in the LANCE Ultra cAMP Detection Kit (Perkin Elmer) to 150-fold with lysis buffer, and add 10 μL to each well;

[0302] 7) Incubate at room temperature for 1 hour;

[0303] 8) Detection was performed using an Envision 2105 microplate reader with an excitation wavelength of 340 nm and an emission wavelength of 665 nm;

[0304] 9) Graphpad was used for plotting to calculate EC 50 .

[0305] (3) Experimental results:

[0306] The S1PR1 EC of the target compound 50 As shown in Table 2. The results showed that the EC of most compounds of the present invention 50 < 10 nM, having good S1PR1 agonist activity.

[0307] Table 2. S1PR1 agonist activity of the target compound (EC 50 , nM)

[0308] Example 28: PK in mice

[0309] 1. Preparation of the test sample

[0310] Preparation method: Weigh an appropriate amount of the test compound and place it in a 5 mL centrifuge tube. Dissolve it with a mixed solvent of DMSO:Solutol:injection physiological saline = 1:2:17 to prepare a test sample of 1 mg / mL, and use this solution as the gavage administration preparation; Take 0.4 mL of the above gavage preparation and place it in a 5 mL centrifuge tube, and dilute it to 4 mL with a mixed solvent of DMSO:Solutol:injection physiological saline = 1:2:17 to prepare a test sample of 0.1 mg / mL, and use this solution as the intravenous injection preparation.

[0311] 2. PK detection

[0312] 1) 12 SPF-grade male ICR mice, 4 - 6 weeks old, weighing 18 - 22 g. The animals were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd., and the animal license number is: SCXK(Beijing)2021 - 0006; After the experimental animals were received, they were adaptively raised for one week, and then pharmacokinetic studies were carried out. The temperature of the animal room was 20 - 26 °C; the humidity was 40 - 70%; there was a 12-hour light-dark cycle; free access to water and food; the animals were fasted for 12 h before the start of the animal experiment.

[0313] 2) The compounds (the compound products prepared in Example 3, Example 15, and Example 17 respectively) were administered by gavage and intravenous injection. At 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, and 24 h after intravenous injection, and at 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, and 24 h after gavage, approximately 0.05 mL of blood samples were collected from the cheek.

[0314] 3) Heparin sodium anticoagulant tubes were used for blood collection and placed in a wet ice environment for more than 15 min, then centrifuged at 6000 r / min for 3 min to separate plasma, which was stored in a -20°C refrigerator for further testing.

[0315] 4) The LC-MS / MS method was used to determine the concentration of samples from each animal at each time point.

[0316] 5) WinNolin 8.2 software was used to calculate the pharmacokinetic parameters.

[0317] 3. Test Results [[ID=!13]]

[0318] As shown in Table 3, the oral bioavailability of the compound products prepared in Example 3, Example 15, and Example 17 were 0.82%, 2.76%, and 3.13% respectively. They were hardly absorbed orally, had little effect on the number of lymphocytes in the body, and could reduce the risk of systemic immunosuppression. Note: iv indicates intravenous injection; po indicates gavage.

[0319] Table 3. Mouse PK parameters using the compound products of Example 3, Example 15, and Example 17

[0320] Example 29: Evaluation of DSS-induced ulcerative colitis model in mice

[0321] 1. Experimental reagents and materials

[0322] 56 male C57BL / 6 mice, 6 - 8 weeks old, SPF grade, body weight (20 ± 2) g, were purchased from Henan Skebes Biotechnology Co., Ltd., production license number: SCXK Yu 2020 - 0005. All mice were housed separately in cages of 8 each, with free access to food and water. Housing environment: temperature 24°C, relative humidity 60%, 12 h / 12 h light / dark cycle. The research design and implementation process complied with animal welfare and ethical principles.

[0323] DSS was purchased from Nanjing Xinyi Biotechnology Co., Ltd.; Tween 80 was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0324] 2. Model construction and drug treatment

[0325] All mice were acclimatized for one week and then randomly divided into a blank control group, a model group, an ozamod group, a tofacitinib citrate group, a low-dose compound of Example 3 group, a medium-dose compound of Example 3 group, and a high-dose compound of Example 3 group, with 8 mice in each group.

[0326] The model group was given free access to 2.5% DSS solution for 7 days to induce colitis. When mice exhibited rough fur, reduced activity and food intake, weight loss, accompanied by diarrhea and visible bloody stools, showing significant differences compared to the control group, it indicated successful induction of colitis. The ozamod group was given free access to 2.5% DSS solution and simultaneously administered 1 mg / kg ozamod hydrochloride solution by gavage daily, followed by a blank solvent in the afternoon, for 7 consecutive days. In the tofacitinib citrate group, mice were given free access to 2.5% DSS solution and simultaneously administered tofacitinib citrate (30 mg / kg) daily, in the same manner as ozamod hydrochloride, for 7 consecutive days. In Example 3, the compound groups were given free access to 2.5% DSS solution and simultaneously administered 5 mg / kg, 10 mg / kg, and 25 mg / kg of the compound solution by gavage daily for 7 consecutive days. During administration to the drug groups, the control group and the model group were simultaneously administered the same volume of 95% saline + 5% Tween 80 by gavage.

[0327] Weigh and observe stool characteristics daily, and assign a DAI score to each group. The scoring criteria are shown in Table 4. DAI score = (weight change score + stool characteristics score + rectal bleeding score) / 3.

[0328] Table 4. DAI Scoring Criteria

[0329] Two hours after administration on day 7 of the experiment, mice in each group were euthanized by cervical dislocation, and the entire colon was quickly dissected and the length of the colon in each group was measured with a ruler.

[0330] 3. Test Results

[0331] As shown in Figures 1-4, compared with the control group, the model group had a significantly higher DAI score (0 vs 3.08, ###P<0.001), a significantly lower body weight (101.4% vs 86.7%, ###P<0.001), and a significantly shorter colon length (8.2cm vs 5.9cm, ###P<0.001), indicating that the ulcerative colitis model was successfully constructed.

[0332] This experiment used a double positive control group (ozamod hydrochloride and tofacitinib citrate). Compared with the model group, the positive control group ozamod significantly improved the DAI score (3.08 vs. 1.83, P<0.001), reduced weight loss (86.7% vs. 92.6%, P<0.05), and prolonged colon length (5.9cm vs. 6.6cm, P=0.09). Compared with the model group, the positive control group tofacitinib citrate significantly improved the DAI score (3.08 vs. 2.37, P<0.01), reduced weight loss (86.7% vs. 88.6%, P=0.19), and prolonged colon length (5.9cm vs. 6.6cm, P=0.19). Compared with the model group, the low-dose compound group of Example 3 significantly improved the DAI score (3.08 vs 1.92, P<0.001), reduced weight loss (86.7% vs 91.0%, P<0.05), and prolonged colon length (5.9cm vs 6.6cm, P=0.05); compared with the model group, the medium-dose compound group of Example 3 significantly improved the DAI score (3.08 vs 1.87, P<0.001), reduced weight loss (86.7% vs 90.4%, P<0.05), and prolonged colon length (5.9cm vs 6.5cm, P=0.10); compared with the model group, the high-dose compound group of Example 3 significantly improved the DAI score (3.08 vs 1.79, P<0.001), reduced weight loss (86.7% vs 90.4%, P<0.05), and prolonged colon length (5.9cm vs 6.5cm, P=0.10); compared with the model group, the high-dose compound group of Example 3 significantly improved the DAI score (3.08 vs 1.79, P<0.001), and reduced weight loss (86.7% vs 90.4%, P<0.05), and prolonged colon length (5.9cm vs 6.5cm, P=0.10). 92.8%, P<0.01), and colon length was increased (5.9cm vs 7.0cm, P<0.05); In summary, the compound prepared in Example 3 can improve the inflammatory damage of the intestine in mice with DSS-induced ulcerative colitis, increase body weight, and increase colon length.

[0333] This invention provides a concept and method for a quaternary ammonium salt-based locally acting sphingosine 1-phosphate receptor subtype 1 agonist. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A compound having the formula (I), or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, in, R1 is selected from cyano, halogen, or methyl group substituted with one or more halogens; R2 is selected from substituted or unsubstituted C1-C3 alkoxy or C3-C6 cycloalkyl; preferably, the substitution is selected from substitution by one or more halogens; R3, R4, and R5 are independently selected from substituted or unsubstituted C1-C4 alkyl groups; preferably, the substituted C1-C4 alkyl groups are substituted with hydroxyl or C1-C3 alkoxy groups. R3 and R4 can combine through carbon atoms or heteroatoms to form substituted or unsubstituted 5-6 membered heterocycles; preferably, the substituted 5-6 membered heterocycles are substituted with hydroxyl groups or hydroxyC1-C3 alkyl groups; L represents a carbonyl group or -CH2-; n is 1, 2, 3 or 4; A is a halogen.

2. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, The compound is selected from any of the following structures:

3. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, R1 is selected from cyano, chloro, or trifluoromethyl; preferably, R1 is selected from cyano or trifluoromethyl.

4. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, R2 is selected from methoxy, ethoxy, trifluoroethoxy, isopropoxy, cyclopentyl, or cyclohexyl; preferably, R2 is selected from trifluoroethoxy, isopropoxy, cyclopentyl, or cyclohexyl.

5. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, R3, R4, and R5 are independently selected from methyl, ethyl, isopropyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, methoxyethyl, or ethoxyethyl; preferably, R3, R4, and R5 are independently selected from methyl, ethyl, isopropyl, hydroxyethyl, or methoxyethyl.

6. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, R3 and R4 can form 5- to 6-membered heterocycles through carbon or oxygen atoms.

7. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, n is selected from 1 or 2.

8. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, A is selected from chlorine, bromine, or iodine; preferably, A is selected from bromine or chlorine.

9. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, The compound is selected from any one of the following structures: Preferably, the compound is selected from any one of the following structures:

10. The compound of formula (I) according to claim 1, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, characterized in that, The pharmaceutically acceptable salt is a hydrochloride, hydrobromide, sulfate, phosphate, nitrate, acetate, maleate, fumarate, citrate, tartrate, methanesulfonate, p-toluenesulfonate, or benzenesulfonate; preferably, the pharmaceutically acceptable salt is a hydrochloride.

11. A pharmaceutical composition, characterized in that, It includes (i) a compound of formula (I) as described in any one of claims 1 to 10, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate or solvate thereof, and (ii) a pharmaceutically acceptable carrier, diluent or excipient.

12. The use of the compound of formula (I) according to any one of claims 1 to 10, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate or solvate thereof, or the pharmaceutical composition according to claim 11 in the preparation of a sphingosine receptor subtype 1 agonist.

13. The use of the compound of formula (I) according to any one of claims 1 to 10, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, or the pharmaceutical composition according to claim 11, in the preparation of a medicament for the prevention and / or treatment of inflammatory bowel disease; preferably, the use of the compound of formula (I) according to any one of claims 1 to 10, or a stereoisomer thereof, or a pharmaceutically acceptable salt, prodrug, hydrate, or solvate thereof, or the pharmaceutical composition according to claim 11, in the preparation of a medicament for the prevention of inflammatory bowel disease, and / or the reduction of the progression of inflammatory bowel disease, and / or the treatment of inflammatory bowel disease or its symptoms; more preferably, the inflammatory bowel disease is selected from ulcerative colitis or Crohn's disease.

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