Oxadiazole-substituted spirocyclic compounds and their applications

Abstract

Provided are a series of compounds represented by formula (I) or pharmaceutically acceptable salts thereof. These compounds can be used to prepare drugs for treating diseases associated with sphingosine 1-phosphate receptor 1, such as autoimmune diseases or inflammation. #imgabs0#

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application CN202110384689.2, filed on April 9, 2021, the entire text of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a series of oxadiazole-substituted spiro compounds and applications thereof, and particularly to compounds represented by formula (I) or pharmaceutically acceptable salts thereof. Background Art

[0004] Sphingosine-1-phosphate (S1P) is a pleiotropic lipid mediator with a broad spectrum of physiological activities, including cell proliferation, survival, lymphocyte trafficking, cytoskeletal organization, and morphogenesis. Sphingosine is released from ceramide by the enzyme ceramide kinase. Sphingosine undergoes phosphorylation by sphingosine kinase to produce sphingosine-1-phosphate (S1P), which interacts with the sphingosine-1-phosphate receptor (S1PR) to produce physiological activities.

[0005] Sphingosine-1-phosphate receptor 1 (S1PR1), also known as endothelial differentiation gene 1 (EDG1), is a G protein-coupled receptor that belongs to the endothelial differentiation gene (EDG) receptor family. The protein encoded by the S1PR1 gene. Sphingosine-1-phosphate receptors (S1PRs) include five subtypes (S1PR1-5), of which Sphingosine-1-phosphate receptor 1 (S1PR1) is abundant on the endothelial cell membrane. Like other G protein-coupled receptors, S1PR1 detects its ligand from outside the cell and activates intracellular signaling pathways, leading to cellular responses.

[0006] Sphingosine-1-phosphate (S1P) is crucial in the human body, primarily regulating the vascular system and immune system. Small molecule S1P1 agonists and inhibitors mimic the binding mechanism of S1P to its receptors and have been shown to play important physiological roles in these signaling systems. Sphingosine-1-phosphate receptor 1 (S1PR1) agonism disrupts lymphocyte trafficking, sequestering them in lymph nodes and other secondary lymphoid organs, leading to rapidly reversible lymphocytopenia. Clinical studies have demonstrated that lymphocyte sequestration reduces inflammatory or autoimmune responses and is crucial for immune regulation.

[0007] Currently, published in vivo efficacy studies of sphingosine-1-phosphate receptor 1 (S1PR1) agonists are used to treat or prevent autoimmune diseases. The discovery and application of new sphingosine-1-phosphate receptor 1 (S1PR1) agonists has broad prospects. Summary of the Invention

[0008] The present invention provides a compound represented by formula (I) or a pharmaceutically acceptable salt thereof,

[0009]

[0010] in,

[0011] R1 is selected from H, F, Cl, Br, I, OH, NH2, CN, C 1-3 Alkyl and C 1-3 Alkoxy, wherein the C 1-3 Alkyl and C 1-3 The alkoxy groups are each independently optionally substituted with 1, 2 or 3 R a replace;

[0012] R2 is selected from H, C 1-3 Alkyl and C 1-3 Alkoxy, wherein the C 1-3 Alkyl and C 1-3 The alkoxy groups are each independently optionally substituted with 1, 2 or 3 R b replace;

[0013] R3 are independently selected from C 1-3 Alkyl and C 1-3 Alkoxy, wherein the C 1-3 Alkyl and C 1-3 The alkoxy groups are each independently optionally substituted with 1, 2 or 3 R c replace;

[0014] Alternatively, R2, R3 and the carbon atom to which they are attached together form C 3-7 Cycloalkyl;

[0015] R a 、R b and R c Each is independently selected from F, Cl, Br, I, OH, NH2, CN and COOH.

[0016] In some embodiments of the present invention, the above R a 、R b and R c are independently selected from F, Cl and Br, and other variables are as defined in the present invention.

[0017] In some embodiments of the present invention, the above R1 is selected from H, F, Cl, Br, CN, -CH3 and - wherein -CH3 and -OCH3 are each independently optionally replaced by 1, 2 or 3 R a Replacement, R a and other variables are as defined in the present invention.

[0018] In some embodiments of the present invention, the above R1 are independently selected from H, F, Cl, Br, CN, -CH3, Other variables are as defined in the present invention.

[0019] In some embodiments of the present invention, the above R2 is selected from H, -CH3, -CH2CH3, wherein -CH3, -CH2CH3, Each independently optionally substituted by 1, 2 or 3 R b Replacement, R b and other variables are as defined in the present invention.

[0020] In some embodiments of the present invention, the above R2 is selected from H, -CH3, -CH2CH3, Other variables are as defined in the present invention.

[0021] In some embodiments of the present invention, the above R3 is selected from -CH3, -CH2CH3, wherein -CH3, -CH2CH3, Each independently optionally replaced by 1, 2 or 3 R c Replacement, R c and other variables are as defined in the present invention.

[0022] In some embodiments of the present invention, the above R3 is selected from -CH3, -CH2CH3, Other variables are as defined in the present invention.

[0023] In some embodiments of the present invention, the above R2, R3 and the carbon atom to which they are attached together form Other variables are as defined in the present invention.

[0024] In some embodiments of the present invention, the above structural unit Selected from Other variables are as defined in the present invention.

[0025] In some embodiments of the present invention, the above structural unit Selected from Other variables are as defined in the present invention.

[0026] Some other solutions of the present invention are obtained by arbitrarily combining the above variables.

[0027] The present invention also provides a compound represented by the following formula or a pharmaceutically acceptable salt thereof:

[0028]

[0029]

[0030] The present invention also provides a compound represented by the following formula or a pharmaceutically acceptable salt thereof:

[0031]

[0032] The present invention also provides a compound or a pharmaceutically acceptable salt thereof, wherein the compound is mixtures (e.g., racemic mixtures).

[0033] The present invention also provides a pharmaceutical composition comprising the above compound or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier.

[0034] The present invention also provides the use of the above-mentioned compound or a pharmaceutically acceptable salt thereof or the above-mentioned pharmaceutical composition in the preparation of a drug for treating diseases related to sphingosine 1-phosphate receptor 1.

[0035] The present invention also provides use of the above-mentioned compound or a pharmaceutically acceptable salt thereof as a sphingosine 1-phosphate receptor 1 agonist.

[0036] In some embodiments of the present invention, the disease is an autoimmune disease or inflammation.

[0037] Technical Effects

[0038] The compound of the present invention has significant S1PR1 agonistic activity and good bioavailability.

[0039] Definition and Description

[0040] Unless otherwise indicated, the following terms and phrases used herein are intended to have the following meanings. A particular term or phrase should not be construed as indefinite or unclear unless specifically defined, but rather should be understood in accordance with its ordinary meaning. When a trade name appears in this document, it is intended to refer to the corresponding commercial product or its active ingredient.

[0041] The term "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions and / or dosage forms which, within the scope of sound medical judgment, are suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0042] The term "pharmaceutically acceptable salt" refers to salts of the compounds of the present invention, prepared by reacting the compounds of the present invention with relatively nontoxic acids or bases. When the compounds of the present invention contain relatively acidic functional groups, base addition salts can be obtained by contacting the compounds with a sufficient amount of base in neat solution or in a suitable inert solvent. Pharmaceutically acceptable base addition salts include sodium, potassium, calcium, ammonium, organic amine, or magnesium salts, or similar salts. When the compounds of the present invention contain relatively basic functional groups, acid addition salts can be obtained by contacting the compounds with a sufficient amount of acid in neat solution or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include inorganic acid salts such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, bicarbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, bisulfate, hydroiodic acid, phosphorous acid, and the like; and organic acid salts such as acetic acid, propionic acid, isobutyric acid, maleic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, and methanesulfonic acid; and salts of amino acids (such as arginine) and organic acids such as glucuronic acid. Certain specific compounds of the present invention contain both basic and acidic functional groups and can be converted into either base or acid addition salts.

[0043] Pharmaceutically acceptable salts of the present invention can be synthesized by conventional chemical methods from parent compounds containing acid radicals or bases. Generally, such salts are prepared by reacting these compounds in free acid or base form with a stoichiometric amount of a suitable base or acid in water or an organic solvent or a mixture of the two.

[0044] The compounds of the present invention may exist in specific geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis- and trans-isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, and racemic mixtures and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the present invention. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomers and mixtures thereof are encompassed within the scope of the present invention.

[0045] Unless otherwise indicated, the term "enantiomer" or "optical isomer" refers to stereoisomers that are mirror images of one another.

[0046] Unless otherwise indicated, the term "cis-trans isomers" or "geometric isomers" arises from the inability to rotate freely about double bonds or single bonds forming ring carbon atoms.

[0047] Unless otherwise indicated, the term "diastereomer" refers to stereoisomers that have two or more chiral centers and that are not mirror images of each other.

[0048] Unless otherwise indicated, "(+)" indicates dextrorotatory, "(-)" indicates levorotatory, and "(±)" indicates racemic.

[0049] Unless otherwise specified, use a solid wedge key. and dotted wedge key To indicate the absolute configuration of a stereocenter, use a straight solid bond and straight dashed bond Indicate the relative configuration of stereocenters with a wavy line Indicates a wedge-shaped solid key or dotted wedge key Or use a wavy line Indicates a straight solid bond and straight dashed bond Unless otherwise indicated, the term "tautomer" or "tautomeric form" refers to isomers of different functional groups that are in dynamic equilibrium at room temperature and readily interconvert into each other. If tautomerism is possible (e.g., in solution), chemical equilibrium of the tautomers can be achieved. For example, proton tautomers (also called prototropic tautomers) include interconversions via proton migration, such as keto-enol isomerization and imine-enamine isomerization. Valence tautomers include interconversions via reorganization of some bonding electrons. A specific example of keto-enol tautomerization is the interconversion between pentane-2,4-dione and 4-hydroxypent-3-en-2-one.

[0050] Unless otherwise indicated, the terms "enriched in one isomer", "isomerically enriched", "enriched in one enantiomer" or "enantiomerically enriched" mean that the content of one isomer or enantiomer is less than 100%, and the content of that isomer or enantiomer is greater than or equal to 60%, or greater than or equal to 70%, or greater than or equal to 80%, or greater than or equal to 90%, or greater than or equal to 95%, or greater than or equal to 96%, or greater than or equal to 97%, or greater than or equal to 98%, or greater than or equal to 99%, or greater than or equal to 99.5%, or greater than or equal to 99.6%, or greater than or equal to 99.7%, or greater than or equal to 99.8%, or greater than or equal to 99.9%.

[0051] Unless otherwise indicated, the term "isomer excess" or "enantiomeric excess" refers to the difference between the relative percentages of two isomers or two enantiomers. For example, if the content of one isomer or enantiomer is 90% and the content of the other isomer or enantiomer is 10%, the isomer or enantiomeric excess (ee value) is 80%.

[0052] Optically active (R)- and (S)-isomers, as well as D and L isomers, can be prepared by chiral synthesis or chiral reagents or other conventional techniques. If one enantiomer of a compound of the present invention is desired, 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 pure desired enantiomer. 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 diastereomeric salt is formed with an appropriate optically active acid or base, and then the diastereoisomers are resolved by conventional methods known in the art, and then the pure enantiomer is recovered. In addition, the separation of enantiomers and diastereomers is typically accomplished by using chromatography, which employs a chiral stationary phase and is optionally combined with a chemical derivatization method (e.g., carbamate formation from an amine).

[0053] The compounds of the present invention may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute the compound. For example, the compounds may be labeled with radioactive isotopes, such as tritium ( 3 H), iodine-125( 125 I) or C-14( 14 C). For example, deuterated drugs can be formed by replacing hydrogen with heavy hydrogen. The bond between deuterium and carbon is stronger than the bond between ordinary hydrogen and carbon. Compared with non-deuterated drugs, deuterated drugs have advantages such as reduced toxic side effects, increased drug stability, enhanced efficacy, and prolonged drug biological half-life. All isotopic variations of the compounds of the present invention, whether radioactive or not, are included within the scope of this invention.

[0054] The terms "optional" or "optionally" mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0055] The term "substituted" means that any one or more hydrogen atoms on a particular atom are replaced by a substituent, which may include deuterium and hydrogen variants, as long as the valence state of the particular atom is normal and the substituted compound is stable. When the substituent is oxygen (i.e., =O), it means that two hydrogen atoms are replaced. Oxygen substitution does not occur on aromatic groups. The term "optionally substituted" means that it may be substituted or unsubstituted, and unless otherwise specified, the type and number of substituents can be any on the basis of chemical achievable.

[0056] When any variable (e.g., R) occurs more than once in a compound's composition or structure, its definition at each occurrence is independent. Thus, for example, if a group is substituted with 0-2 Rs, the group may be optionally substituted with up to two Rs, with each occurrence of R being an independent choice. Furthermore, combinations of substituents and / or their variants are permissible only if such combinations result in stable compounds.

[0057] When the number of a linking group is 0, such as -(CRR)0-, it means that the linking group is a single bond.

[0058] When one of the variables is selected from a single bond, it means that the two groups it connects are directly connected. For example, when L in ALZ represents a single bond, it means that the structure is actually AZ.

[0059] When a substituent is vacant, it means that the substituent does not exist. For example, when X in AX is vacant, it means that the structure is actually A. When the substituent is listed without specifying which atom it is connected to the substituted group, the substituent can be bonded through any atom of the substituent. For example, a pyridyl substituent can be connected to the substituted group through any carbon atom on the pyridine ring.

[0060] When the linking group is listed without specifying its linking direction, its linking direction is arbitrary, for example, The connecting group L is -MW-, in which case -MW- can connect ring A and ring B in the same direction as the reading order from left to right to form You can also connect ring A and ring B in the opposite direction of reading from left to right to form Combinations of linkers, substituents, and / or variations thereof are permissible only if such combinations result in stable compounds.

[0061] Unless otherwise specified, when a group has one or more connectable sites, any one or more sites of the group can be connected to other groups through chemical bonds. When the chemical bond connection mode is non-positional and there are H atoms at the connectable sites, when the chemical bond is connected, the number of H atoms at the site will decrease accordingly with the number of connected chemical bonds, and become a group with a corresponding valence. The chemical bond connecting the site to other groups can be a straight solid bond. Straight dotted key or wavy lines For example, the straight solid bond in -OCH3 indicates that it is connected to other groups through the oxygen atom in the group; The straight dashed bond in the group indicates that the two ends of the nitrogen atom in the group are connected to other groups; The wavy line in the phenyl group indicates that it is connected to other groups through the carbon atoms at positions 1 and 2 in the phenyl group; Indicates that any linkable site on the piperidinyl group can be connected to other groups through a chemical bond, including at least In these four connection methods, even if an H atom is drawn on -N-, Still includes For groups connected in this way, when one chemical bond is connected, the H at that site will be reduced by one and become a corresponding monovalent piperidine group.

[0062] Unless otherwise specified, when a compound contains a double bond structure, such as a carbon-carbon double bond, a carbon-nitrogen double bond, and a nitrogen-nitrogen double bond, and each atom on the double bond is connected to two different substituents (in a double bond containing a nitrogen atom, a lone pair of electrons on the nitrogen atom is regarded as a substituent to which it is connected), if the atoms on the double bond in the compound and their substituents are separated by a denoted by , it represents the (Z) isomer, (E) isomer or a mixture of both isomers of the compound.

[0063] Unless otherwise specified, the term “C 1-3 "Alkyl" is used to represent a straight or branched chain saturated hydrocarbon group consisting of 1 to 3 carbon atoms. 1-3 Alkyl groups include C 1-2 and C 2-3 Alkyl, etc.; it can be monovalent (such as methyl), divalent (such as methylene) or polyvalent (such as methine). 1-3 Examples of alkyl groups include, but are not limited to, methyl (Me), ethyl (Et), propyl (including n-propyl and isopropyl), and the like.

[0064] Unless otherwise specified, the term “C 1-3 "Alkoxy" refers to those alkyl groups containing 1 to 3 carbon atoms which are attached to the rest of the molecule via an oxygen atom. The C 1-3 Alkoxy groups include C 1-2 、C 2-3 , C3 and C2 alkoxy, etc. 1-3 Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy (including n-propoxy and isopropoxy), and the like.

[0065] Unless otherwise specified, “C 3-7 "Cycloalkyl" refers to a saturated cyclic hydrocarbon group consisting of 3 to 7 carbon atoms, including monocyclic and bicyclic systems, wherein the bicyclic system includes spirocyclic, fused and bridged rings. 3-7 Cycloalkyl groups include C 3-6 、C 3-5 、C 4-7 、C4-6 、C 4-5 、C 5-7 or C 5-6 Cycloalkyl, etc.; it may be monovalent, divalent or polyvalent. 3-7 Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, norbornyl, spiroheptane, and the like.

[0066] The term "leaving group" refers to a functional group or atom that can be replaced by another functional group or atom through a substitution reaction (e.g., a nucleophilic substitution reaction). For example, representative leaving groups include trifluoromethanesulfonate; chlorine, bromine, iodine; sulfonate groups such as methanesulfonate, toluenesulfonate, p-bromobenzenesulfonate, p-toluenesulfonate, etc.; acyloxy groups such as acetoxy and trifluoroacetoxy, etc.

[0067] The term "protecting group" includes, but is not limited to, an "amino protecting group," a "hydroxy protecting group," or a "thiol protecting group." The term "amino protecting group" refers to a protecting group suitable for preventing side reactions at the amino nitrogen position. Representative amino protecting groups include, but are not limited to, formyl; acyl, such as alkanoyl (e.g., acetyl, trichloroacetyl, or trifluoroacetyl); alkoxycarbonyl, such as tert-butyloxycarbonyl (Boc); arylmethoxycarbonyl, such as benzyloxycarbonyl (Cbz) and 9-fluorenylmethoxycarbonyl (Fmoc); arylmethyl, such as benzyl (Bn), trityl (Tr), 1,1-bis-(4'-methoxyphenyl)methyl; silyl, such as trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS), and the like. The term "hydroxy protecting group" refers to a protecting group suitable for preventing side reactions at the hydroxyl group. Representative hydroxy protecting groups include, but are not limited to, alkyl groups such as methyl, ethyl and tert-butyl; acyl groups such as alkanoyl (e.g., acetyl); arylmethyl groups such as benzyl (Bn), p-methoxybenzyl (PMB), 9-fluorenylmethyl (Fm) and diphenylmethyl (diphenylmethyl, DPM); silyl groups such as trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS), and the like.

[0068] The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthesis methods, and equivalent substitutions well known to those skilled in the art. Preferred embodiments include but are not limited to the examples of the present invention.

[0069] The structures of the compounds of the present invention can be confirmed by conventional methods well known to those skilled in the art. If the present invention relates to the absolute configuration of the compounds, the absolute configuration can be confirmed by conventional techniques in the art. For example, single crystal X-ray diffraction (SXRD) is used to collect diffraction intensity data on the cultured single crystal using a Bruker D8 venture diffractometer, using CuKα radiation as the light source and scanning mode: After scanning and collecting relevant data, the crystal structure is further analyzed using the direct method (Shelxs97) to confirm the absolute configuration.

[0070] Compounds are named according to the conventional nomenclature in the art or using Software naming, commercially available compounds use supplier catalog names. DETAILED DESCRIPTION

[0071] The present invention is described in detail below by examples, but it is not intended to limit the present invention in any way. The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, the embodiments formed by combining them with other chemical synthesis methods, and equivalent replacement modes well known to those skilled in the art. Preferred embodiments include but are not limited to the embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications will be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention.

[0072] Example 1

[0073]

[0074]

[0075] first step

[0076] Compound 1a (2 g, 9.75 mmol) was dissolved in dichloromethane (20 mL). Oxalyl chloride (3.71 g, 29.24 mmol) and N,N-dimethylformamide (71.24 mg, 974.61 μmol) were added sequentially at 0°C. The reaction mixture was stirred at 20°C for 0.5 hours. The solvent was removed by concentration under reduced pressure. The resulting crude product 1b was used directly in subsequent reactions.

[0077] Step 2

[0078] Compound 1d (280.43 g, 1.54 mol) was dissolved in N,N-dimethylformamide (100 mL). Potassium tert-butoxide (166.15 g, 1.48 mol) was added portionwise at 25°C. After stirring the reaction at 25°C for 3 hours, 1c (250 g, 1.18 mol) was slowly added portionwise. The reaction was stirred at 25°C for 13 hours. Other parallel batches (840 g for 1d) were combined for post-processing. Water (1600 mL) was added to the reaction solution, and the solution was extracted with ethyl acetate (6 L x 5). The combined organic phases were washed with saturated brine (1.6 L x 1), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was separated by neutral alumina column chromatography (petroleum ether / ethyl acetate, 2 / 1 to 1 / 1, v / v) to obtain compound 1e. MS-ESI calculated value [M+H] + 267 and 269, measured values ​​267 and 269.

[0079] Step 3

[0080] Compound 1e (767 g, 2.87 mol) was dissolved in dimethyl sulfoxide (3000 mL). Cesium carbonate (748.44 g, 2.30 mol) was added to the mixture at 25°C. The reaction mixture was heated to 70°C and nitromethane (525.81 g, 8.61 mol) was slowly added dropwise. The reaction mixture was stirred at 70°C for 12 hours. Other parallel batches (1e, 767 g) were combined for post-processing. Water (2400 mL) was added to the reaction mixture, and the mixture was extracted with ethyl acetate (10 L x 1 and 5 L x 1). The combined organic phases were washed with saturated brine (5 L x 2), dried over anhydrous sodium sulfate (2 kg), filtered, and concentrated to obtain the crude product. The crude product was separated by neutral alumina column chromatography (petroleum ether / ethyl acetate, 1 / 1, v / v) to obtain compound 1f.

[0081] Step 4

[0082] Compound 1f (725 g, 2.21 mol) was dissolved in ethanol (2175 mL) and water (725 mL). Ammonium chloride (354.54 g, 6.63 mol) was added to the mixture at 25°C. The reaction mixture was heated to 80°C and iron powder (370.14 g, 6.63 mol) was slowly added in batches. The reaction mixture was stirred at 80°C for 12 hours. Other parallel batches (1f, 725 g) were combined for post-processing. The reaction mixture was filtered, and the filter cake was rinsed with ethyl acetate (8 L) and water (4 L) in sequence. The filtrate was concentrated to remove some of the solvent, and water (4 L) was added to the mixture. The mixture was extracted with ethyl acetate (4 L x 2). The combined organic phases were washed with saturated brine (3 L x 2), dried over anhydrous sodium sulfate (2 kg), filtered, and concentrated to obtain the crude product. The crude product was stirred in a mixed solvent (n-heptane / ethyl acetate, 1 / 1, V / V) at 25°C for 12 hours, filtered and dried to obtain 1 g of compound. MS-ESI calculated value [M+H] + 266 and 268, measured values ​​266 and 268.

[0083] Step 5

[0084] Compound 1g (50g, 178.06mmol) was dissolved in tetrahydrofuran (350mL). Borane-dimethyl sulfide solution (10M, 35.61mL) was added dropwise to the system at 20°C. The temperature was then raised to 70°C and stirred at 70°C for 12 hours. Other parallel batches (1g was added in 50g quantities) were combined for post-treatment. The reaction solution was poured into aqueous hydrochloric acid (1M, 400mL) at 80°C and extracted with ethyl acetate (200mL×3). The resulting aqueous phase was adjusted to a pH of approximately 9 with saturated aqueous sodium carbonate solution. The aqueous phase was extracted with dichloromethane (300mL×3). The combined organic phases were dried over anhydrous sodium sulfate (100g), filtered, and concentrated to obtain the crude product. The crude product 1h was used directly in the next reaction without further purification. MS-ESI calculated value [M+H] + 252 and 254, measured values ​​252 and 254.

[0085] Step 6

[0086] Compound 1h (22 g, 87.25 mmol) was dissolved in dichloromethane (130 mL). Triethylamine (21.19 g, 209.40 mmol) and di-tert-butyl dicarbonate (22.85 g, 104.70 mmol) were added to the system, and the reaction solution was stirred at 20°C for 12 hours. Other parallel batches (22 g for 1h) were combined for post-processing. Water (800 mL) was added to the system, and the reaction solution was extracted with dichloromethane (500 mL x 2). The combined organic phases were dried over anhydrous sodium sulfate (100 g), filtered, and concentrated to obtain the crude product. The crude product was separated by silica gel column chromatography (petroleum ether / ethyl acetate, 100 / 1 to 10 / 1, v / v) to obtain compound 1i. MS-ESI calculated value [M-tBu+H] + 296 and 298, measured values ​​296 and 298.

[0087] Step 7

[0088] Compound 1i (42.9 g, 121.78 mmol), tris(dibenzylideneacetone) (4.46 g, 4.87 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (4.64 g, 9.74 mmol), and zinc cyanide were added sequentially to N,N-dimethylformamide (400 mL). The reaction system was replaced with nitrogen and stirred at 90°C for 12 hours. Water (1000 mL) was added to the system and filtered. The filter cake was washed with ethyl acetate (200 mL × 2). The aqueous phase was extracted with ethyl acetate (300 mL × 2). The combined organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was separated by silica gel column chromatography (petroleum ether / ethyl acetate, 50 / 1 to 10 / 1, v / v) to obtain compound 1j. MS-ESI calculated value [M-tBu+H] + 243, measured value 243.

[0089] Step 8

[0090] Compound 1j (12.5 g, 41.89 mmol) was dissolved in ethanol (120 mL). Hydroxylamine hydrochloride (4.64 g, 9.74 mmol) and triethylamine (4.64 g, 9.74 mmol) were added sequentially to the system. The reaction solution was stirred at 80°C for 5 hours. After the reaction solution was concentrated, water (200 mL) was added to the system. The aqueous phase was extracted with ethyl acetate (150 mL × 2). The combined organic phases were washed with water (100 mL × 3), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product 1k was used directly in the next reaction without further purification. MS-ESI calculated value [M-tBu+H] + 276, measured value 276.

[0091] Step 9

[0092] Compound 1k (2.7 g, 7.14 mmol) and compound 1b (2.08 g, 9.28 mmol) were dissolved in dichloromethane (30 mL). N,N-diisopropylethylamine (2.77 g, 21.41 mmol) was added dropwise to the system. The reaction solution was stirred at 20°C for 12 hours. After the reaction solution was concentrated, water (80 mL) was added to the system. The aqueous phase was extracted with dichloromethane (40 mL × 2). The combined organic phases were dried over anhydrous sodium sulfate (10 g), filtered, and concentrated to obtain the crude product. The crude product 1l was used directly in the next reaction without further purification. MS-ESI calculated value [M-tBu+H] + 463, measured value 463.

[0093] Step 10

[0094] Compound 1l (5 g, 9.64 mmol) was dissolved in acetonitrile (50 mL). Sodium hydroxide (1.54 g, 38.57 mmol) was added, and the reaction mixture was stirred at 27°C for 12 hours. Water (80 mL) was added, and the aqueous phase was extracted with ethyl acetate (40 mL x 2). The combined organic phases were dried over anhydrous sodium sulfate (5 g), filtered, and concentrated to obtain the crude product. The crude product was separated by silica gel column chromatography (petroleum ether / ethyl acetate, 3 / 1, v / v) to obtain compound 1m. MS-ESI calculated value [M-tBu+H] + 445, measured value 445.

[0095] Step 11

[0096] Compound 1m (2.1 g, 4.20 mmol) was dissolved in ethyl acetate (20 mL). A 4 M solution of hydrogen chloride in ethyl acetate (20 mL) was added to the mixture, and the reaction mixture was stirred at 20°C for 0.5 h. The reaction mixture was concentrated under reduced pressure to obtain the crude product. The hydrochloride salt of the crude product 1n was used directly in the next reaction without further purification. MS-ESI calculated value [M+H] + 401, measured value 401.

[0097] Step 12

[0098] The hydrochloride salt of compound 1n (1 g, 2.29 mmol) was dissolved in acetonitrile (15 mL). Potassium iodide (189.96 mg, 1.14 mmol), potassium carbonate (948.93 mg, 6.87 mmol), and compound 1o (621.47 mg, 3.43 mmol) were added sequentially. The reaction mixture was stirred at 85°C for 12 hours. Water (30 mL) was added to the system, and the aqueous phase was extracted with ethyl acetate (20 mL x 2). The combined organic phases were dried over anhydrous sodium sulfate (5 g), filtered, and concentrated to obtain the crude product. The crude product was separated by silica gel column chromatography (petroleum ether / ethyl acetate, 5 / 1 to 3 / 1, V / V) to obtain compound 1p. MS-ESI calculated value [M+H] + 501, measured value 501.

[0099] Step 13

[0100] Compound 1p (810 mg, 1.62 mmol) was dissolved in tetrahydrofuran (10 mL), and lithium borohydride (110 mg, 5.05 mmol) was added dropwise. The reaction mixture was stirred at 20°C for 0.5 hour, then heated to 70°C and stirred for 12 hours. Aqueous hydrochloric acid (1N, 30 mL) was added, and the aqueous phase was extracted with ethyl acetate (30 mL x 2). The combined organic phases were dried over anhydrous sodium sulfate (10 g), filtered, and concentrated to obtain the crude product. The crude product was separated by preparative HPLC (column: Waters Xbridge C18 150 × 50 mm × 10 μm; mobile phase: 10 mmol / L aqueous ammonium bicarbonate-acetonitrile; gradient: acetonitrile 62%-92% over 10 min) to obtain compound 1. MS-ESI calculated value [M+H] + 473, measured value 473. 1 H NMR (400MHz, CD3OD) δ=8.47-8.41(m,2H),8.01(d,J=7.6Hz,1H),7.54(d,J=7.4Hz,1H),7.48-7.37(m,2H),5.00-4.94(m,1H),3.47(s,2H),3.31- 3.27(m,2H),3.11-3.03(m,1H),3.03-2.95(m,3H),2.30-2.22(m,1H),2 .21-2.13(m,1H),2.11-1.96(m,2H),1.48(d,J=6.1Hz,6H),1.14(s,6H).

[0101] Biological activity evaluation

[0102] Test Example 1: In vitro evaluation of the S1PR1 agonist activity of the compounds of the present invention

[0103] Experimental purpose: To detect the agonist activity of compounds on S1PR1

[0104] 1. Cell Treatment

[0105] 1. Thaw the PathHunter cell line according to standard procedures;

[0106] 2. Inoculate cells into 20 μl of a 384-well microplate and incubate at 37°C for an appropriate time.

[0107] 2. Agonists

[0108] 1. For agonist assays, cells are incubated with the test sample to induce a response.

[0109] 2. Dilute the stock solution to be tested 5-fold into the buffer solution;

[0110] 3.5 μl of the 5-fold dilution was added to the cells and incubated at 37°C for 90-180 minutes. The vehicle concentration was 1%.

[0111] 3. Signal Detection

[0112] 1. Add 12.5 μl or 15 μl of 50% volume PathHunter detection reagent once, and then incubate at room temperature for 1 hour to generate detection signal;

[0113] 2. Read the microplate using a PerkinElmer Envision™ instrument for chemiluminescent signal detection.

[0114] 4. Data Analysis

[0115] 1. Use CBIS data analysis suite (ChemInnovation, CA) to analyze compound activity;

[0116] 2. Calculation formula:

[0117] % activity = 100% x (average test sample RLU - average vehicle RLU) / (average maximum control ligand - average vehicle RLU)

[0118] The experimental results are shown in Table 1:

[0119] Table 1 S1PR1 agonist activity test results

[0120]

[0121]

[0122] Conclusion: The compounds of the present invention all have significant and even unexpected S1PR1 agonist activity.

[0123] Test Example 2: Pharmacokinetic study of the compound of the present invention

[0124] Experimental purpose: To test the pharmacokinetics of the compound in SD rats

[0125] Experimental Materials:

[0126] Sprague Dawley rats (male, 200-300 g, 7-9 weeks old, Shanghai Slake)

[0127] Experimental operation:

[0128] The compound's pharmacokinetic characteristics in rodents were tested following intravenous and oral administration using a standard protocol. Rats were given a single intravenous and oral dose. The oral vehicle consisted of 0.5% methylcellulose and 0.2% Tween 80 in water, while the intravenous vehicle consisted of a 5:95 mixture of DMSO and 10% hydroxypropyl-β-cyclodextrin in water. Whole blood samples were collected within 48 hours and centrifuged at 3000 g for 15 minutes. The supernatant was separated to obtain plasma samples. Protein was precipitated by adding 4 volumes of acetonitrile containing an internal standard. The supernatant was centrifuged, added to an equal volume of water, and centrifuged again. The supernatant was injected. Plasma concentrations were quantified by LC-MS / MS analysis, and pharmacokinetic parameters such as peak concentration, time to peak concentration, clearance, half-life, area under the concentration-time curve, and bioavailability were calculated.

[0129] The experimental results are shown in Table 2:

[0130] Table 2 Pharmacokinetic test results

[0131]

[0132] Conclusion: The compound of the present invention showed good bioavailability, higher area under the concentration-time curve and longer half-life in the pharmacokinetics of SD rats.

Claims

1. A compound or a pharmaceutically acceptable salt thereof, wherein the compound is 2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein the compound is 3. A pharmaceutical composition comprising the compound according to claim 1 or 2 or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier.

4. Use of the compound according to claim 1 or 2 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition according to claim 3, in the preparation of a medicament as a sphingosine 1-phosphate receptor 1 agonist. The use according to claim 4 , wherein the drug is used to treat autoimmune diseases or inflammation.

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