Novel sodium channel regulator

Abstract

Novel sodium channel modulator, in particular Nav1.8 channel modulator, sodium channel modulator having structure represented by formula I: # imgabs0 #

Description

[0001] This application claims the priority benefit of a prior application filed by the applicant with the State Intellectual Property Office of China on December 26, 2023, with the patent application number CN202311805889.6 and the title "A Novel Sodium Channel Modulator", and the full text of the prior application is incorporated into this application by reference. Technical Field

[0002] The present invention relates to a novel sodium channel modulator, particularly a Nav1.8 channel modulator. Background Art

[0003] Voltage-gated sodium channels (VGSCs) mediate the selective influx of sodium ions in excitable cells and play an important role in initiating and propagating action potentials. Voltage-gated sodium channels are ubiquitously present in the central and peripheral nervous systems and are also present in skeletal and cardiac muscles.

[0004] Nav’s form a subfamily of the voltage-gated ion channel superfamily and contain nine isoforms named Nav1.1-Nav1.9. The tissue localization of the nine isoforms is different. Nav1.4 is the main sodium channel in skeletal muscle, and Nav1.5 is the main sodium channel in cardiomyocytes. Nav1.7, 1.8, and 1.9 are mainly localized in the peripheral nervous system, while Nav1.1, 1.2, 1.3, and 1.6 are neuronal channels found in the central and peripheral nervous systems. The functional behaviors of the nine isoforms are similar but different in specific aspects of voltage dependence and kinetic behavior.

[0005] The Nav1.8 voltage-gated sodium channel is thought to play a role in various diseases, including neuropathic pain, chronic itch, and inflammatory pain sensation.

[0006] There is still a need for effective Nav1.8 sodium channel activity inhibitors with selective activity against the Nav1.8 sodium channel. Therefore, the compounds of the present invention can be used to treat and prevent diseases, disorders, and conditions involving the Nav1.8 receptor and the Nav1.8 voltage-gated sodium channel. Summary of the Invention

[0007] The present invention provides the following compounds for treating and preventing diseases, disorders, and conditions involving the Nav1.8 receptor and the Nav1.8 voltage-gated sodium channel.

[0008] On the one hand, this application provides a compound of Structural Formula I:

[0009]

[0010] Its isomers, racemates, pharmaceutically acceptable salts or prodrugs, wherein:

[0011] R1, R2, R3, R4, and R5 are each independently selected from H, deuterium, halogen, hydroxy, C 1-6 alkyl, C 1-6 alkoxy, -S-C 1-6 alkyl, C 1-6 alkylamino, -S-haloC 1-6 alkyl, deuteroC 1-6 alkyl, deuteroC 1-6 alkoxy, -S-deuteroC 1-6 alkyl, C 3-6 cycloalkyl, 3-7 membered heterocycloalkyl, C 3-6 cycloalkoxy, haloC 1-6 alkyl, haloC 1-6 alkoxy, haloC 3-6 cycloalkyl, halo 3-7 membered heterocycloalkyl, haloC 3-6 cycloalkoxy; wherein the C 1-6 alkyl, C 1-6 alkoxy, -S-C 1-6 alkyl, C 1-6 alkylamino, -S-haloC 1-6 alkyl, deuteroC 1-6 alkyl, deuteroC 1-6 alkoxy, -S-deuteroC 1-6 alkyl, C 3-6 cycloalkyl, 3-7 membered heterocycloalkyl, C 3-6 cycloalkoxy, haloC 1-6 alkyl, haloC 1-6 alkoxy, haloC 3-6 cycloalkyl, halo 3-7 membered heterocycloalkyl, haloC 3-6 cycloalkoxy may optionally be further substituted by one or more substituents independently selected from hydrogen, halogen, hydroxy, C 1-6 alkyl, C 1-6 alkoxy, C 3-6 cycloalkyl, 3-7 membered heterocycloalkyl;

[0012] R6 is selected from hydrogen, halogen, C 1-6 alkyl, C 1-6 alkoxy, C 3-6 cycloalkyl, 3-7 membered heterocycloalkyl, -S-C 1-6 alkyl, C 3-6 cycloalkoxy, haloC 1-6 alkyl, haloC 1-6 alkoxy, haloC 3-6 cycloalkyl, haloC 3-6 cycloalkoxy, halo 3-7 membered heterocycloalkyl;

[0013] R7 and R8 are each independently selected from H, halogen, hydroxy, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylamino, C 3-6 cycloalkyl, 3-7 membered heteroalkyl, halo-C 1-6 alkyl, halo-C 1-6 alkoxy, halo-C 3-6 cycloalkyl, halo-3-7 membered heteroalkyl;

[0014] R9, R 10 further cyclizes with the carbon atom to which they are attached to form a 5-10 membered heteroalkyl; the 5-10 membered heteroalkyl may be further substituted by one or more substituents independently selected from R 11 ; R 11 is selected from hydrogen, C 1-6 alkyl, halo-C 1-6 alkyl, -L1-OR 12 、-L1-NR 13 R 14 、C 3-6 cycloalkyl, 3-7 membered heteroalkyl, C 1-6 alkyleneC 3-6 cycloalkyl, C 1-6 alkylene3-7 membered heteroalkyl, 5-6 membered heteroaryl; wherein, the C 1-6 alkyl, halo-C 1-6 alkyl, -L1-OR 12 、-L1-NR 13 R 14 、C 3-6 cycloalkyl, 3-7 membered heteroalkyl, C 1-6 alkyleneC 3-6 cycloalkyl, C 1-6 alkylene3-7 membered heteroalkyl, 5-6 membered heteroaryl may be optionally substituted by one or more substituents independently selected from hydrogen, halogen, hydroxy, C 1-6 alkyl, halo-C 1-6 alkyl, C 3-6 cycloalkyl, 3-7 membered heteroalkyl;

[0015] L1 is selected from a bond, C 1-6 alkylene or C 3-6 subcycloalkyl;

[0016] R 12 is selected from hydrogen, C 1-6 alkyl, halo-C 1-6 alkyl;

[0017] R 13 、R 14 are each independently selected from hydrogen, C 1-6alkyl, 3- to 7-membered heterocycloalkyl.

[0018] In one embodiment of the present invention, in Formula I, selected from and the five-membered ring moiety thereof is optionally substituted with one or more substituents independently selected from R 11 .

[0019] In one embodiment of the present invention, in Formula I, selected from

[0020] In one embodiment of the present invention, R1, R2, R3, R4, R5 are each independently selected from H, FCH2O-, CH3O-, CH3S-, CH3CH2O-, CH3CH2S-, F,

[0021] In one embodiment of the present invention, Formula I has the structure of Formula II:

[0022]

[0023] wherein, R1, R2, R3, R4, R5, R6, R7, R8 are as defined in Formula I.

[0024] In one embodiment of the present invention, the H on 11 may optionally be further substituted with one or more substituents independently selected from R

[0025] In one embodiment of the present invention, selected from

[0026] In one embodiment of the present invention, selected from

[0027] In one embodiment of the present invention, Formula I has the structures of Formula IIa and Formula IIb:

[0028]

[0029] wherein, R1, R2, R3, R4, R5, R6, R7, R8, R 11 are as defined above.

[0030] In some embodiments of the present invention,

[0031] R 11 is selected from hydrogen, C 1-6 alkyl, halo C 1-6 alkyl, -L1-OR 12 , -L1-NR13 R 14 、 C 3-6 cycloalkyl, 3- to 7-membered heterocycloalkyl, C 1-6 alkylene C 3-6 cycloalkyl, C 1-6 alkylene 3- to 7-membered heterocycloalkyl, 5- to 6-membered heteroaryl; wherein the C 1-6 alkyl, halo C 1-6 alkyl, -L1-OR 12 、 -L1-NR 13 R 14 、 C 3-6 cycloalkyl, 3- to 7-membered heterocycloalkyl, C 1-6 alkylene C 3-6 cycloalkyl, C 1-6 alkylene 3- to 7-membered heterocycloalkyl, 5- to 6-membered heteroaryl may be optionally substituted by one or more substituents independently selected from hydrogen, halogen, hydroxy, C 1-6 alkyl, halo C 1-6 alkyl, C 3-6 cycloalkyl, 3- to 7-membered heterocycloalkyl;

[0032] L1 is selected from a bond, C 1-6 alkylene or C 3-6 subcycloalkylene;

[0033] R 12 is selected from hydrogen, C 1-6 alkyl, halo C 1-6 alkyl;

[0034] R 13 、 R 14 are each independently selected from hydrogen, hydroxy, C 1-6 alkyl, 3- to 7-membered heterocycloalkyl;

[0035] In one embodiment of the present invention, the isomer is the isomer shown by formula I-YG:

[0036]

[0037] In one embodiment of the present invention, formula I-YG has the structure of formula II-YG:

[0038]

[0039] In one embodiment of the present invention, formula I-YG has the structures of formula IIa-YG and IIb-YG:

[0040]

[0041] In one embodiment of the present invention, R6 is selected from halogen, C 1-6Alkyl, C 1-6 Alkoxy, C 3-6 Cycloalkyl.

[0042] In one embodiment of the present invention, Formula I has the structure of Formula III:

[0043]

[0044] In one embodiment of the present invention, Formula I has the structures of Formula IIIa and Formula IIIb:

[0045]

[0046] In one embodiment of the present invention, the Formula I-YG has the structure of Formula III-YG:

[0047]

[0048] In one embodiment of the present invention, the Formula I-YG has the structures of Formula IIIa-YG and IIIb-YG:

[0049]

[0050] In one embodiment of the present invention, R1, R2, R3, R4, and R5 are each independently selected from H, halogen, C 1-6 alkyl, C 1-6 alkoxy, halo C 1-6 alkoxy; wherein the C 1-6 alkyl, C 1-6 alkoxy, halo C 1-6 alkoxy may optionally be further substituted by one or more substituents independently selected from hydrogen, hydroxy, C 1-6 alkyl, C 1-6 alkoxy, C 3-6 cycloalkyl, 3-7 membered heterocycloalkyl.

[0051] In one embodiment of the present invention, R 11 is selected from H, C 1-6 alkyl, C 3-6 cycloalkyl, -L1-OR 12 、-L1-NR 13 R 14 、3-7 membered heterocycloalkyl; L1 is selected from a bond, C 1-6 alkylene or C 3-6 subcycloalkyl; R 12 is selected from hydrogen.

[0052] In one embodiment of the present invention, C 3-6 cycloalkyl, C 3-6 subcycloalkyl is a 3-6 membered monocyclic, spiro, or bridged cycloalkyl.

[0053] In one embodiment of the present invention, the 3- to 7-membered heterocycloalkyl is a 3- to 7-membered N-containing heterocycloalkyl.

[0054] In one embodiment of the present invention, the 3- to 7-membered heterocycloalkyl is a 3- to 7-membered monocyclic, spiro, or bridged N-containing heterocycloalkyl.

[0055] In one embodiment of the present invention, R 11 is selected from H, -CH3,

[0056]

[0057] In an optional embodiment of the present invention, the present invention also provides a compound of formula I, formula II, or formula III, its isomers, racemates, pharmaceutically acceptable salts or prodrugs, wherein the compound is selected from:

[0058]

[0059]

[0060] In some embodiments, according to the compounds of formula I, formula II, or formula III described above in the present invention, their isomers, racemates, or pharmaceutically acceptable salts or prodrugs, wherein the compound is selected from:

[0061]

[0062]

[0063] In some embodiments, according to the compounds of formula I, formula II, or formula III described above in the present invention, their isomers, racemates, or pharmaceutically acceptable salts or prodrugs, wherein the compound is selected from:

[0064]

[0065]

[0066] Term definition:

[0067] In the present invention, the term "C 1-6 alkyl" refers to a straight-chain or branched-chain alkyl group containing 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, neopentyl, pivalyl, or similar groups.

[0068] In the present invention, the term "C 1-6 alkylene" refers to the removal of C 1-6A divalent group formed by replacing another hydrogen of an alkyl group, and it can be substituted or unsubstituted. In some embodiments, C 1-4 alkylene, C 2-4 alkylene and C 1-3 alkylene are preferred. The unsubstituted alkylene includes but is not limited to: methylene, ethylene, propylene, butylene, pentylene, hexylene, and the like.

[0069] In the present invention, the term "C 1-6 alkoxy" refers to a straight-chain or branched-chain alkoxy group having 1-6 carbon atoms, including non-limitingly methoxy, ethoxy, propoxy, isopropoxy, butoxy, and the like. Preferably, it is C 1-4 alkoxy.

[0070] In the present invention, the term "C 1-6 alkylamino" refers to an alkyl group substituted with at least one amino group, including non-limitingly methylamino, ethylamino, propylamino, isopropylamino, n-butylamino, isobutylamino, 2-butylamino, tert-butylamino, n-pentylamino, 2-pentylamino, 3-pentylamino, n-hexylamino, and the like.

[0071] In the present invention, the term "C 3-6 cycloalkyl" refers to a cyclic alkyl group having 3-6 carbon atoms in the ring. C 3-6 cycloalkyl can be a 3-6 membered monocyclic, spiro, or bridged cycloalkane, including non-limitingly cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0072] The term "heterocycloalkyl" should be understood as a non-aromatic cyclic group containing heteroatoms, which can be a 5-10 membered, 3-7 membered, 3-8 membered, 5-6 membered heterocycloalkyl, etc. The heteroatoms in the "heterocycloalkyl" can be one, two, or more than three heteroatoms selected from the group consisting of N, O, and S. The term "5-10 membered heterocycloalkyl" is a 5-10 membered (5, 6, 7, 8, 9, 10 membered) heterocyclic group containing 1, 2, or 3 heteroatoms selected from N, O, and S, and can be monocyclic, spiro, or bridged. Preferably, the 5-10 membered heterocyclic group contains one or more groups selected from NH, CO, C 1-6 alkylene, O, or SO2.

[0073] In the present invention, the term "3-7 membered heterocycloalkyl" is a 3-7 membered heterocyclic group containing 1, 2, or 3 heteroatoms selected from N, O, and S. Preferably, the 3-7 membered heterocycloalkyl is a 3-7 membered N-containing heterocycloalkyl. Preferably, the 3-7 membered heterocycloalkyl is a 3-7 membered monocyclic, spiro, or bridged N-containing heterocycloalkyl, including but not limited to the following groups:

[0074] Those skilled in the art will understand that when a linking group is clearly required in the compound structure, the Markush variables listed for that group should be understood as linking groups. For example, if the structure requires a linking group and the Markush group definition for that variable lists "alkyl" or "cycloalkyl", it should be understood that the "alkyl" or "cycloalkyl" represents a linked alkylene group or arylene group, respectively. Therefore, when acting as a linking group, "*yl" and "sub-*ylene" have equivalent definitions. For example, "C 1-6 alkyl" and "C 1-6 alkylene" have equivalent definitions, "C 3-6 cycloalkyl" and "C 3-6 cycloalkylene" have equivalent definitions.

[0075] In the present invention, the term "halogen" includes fluorine, chlorine, bromine, and iodine.

[0076] In the present invention, the term "halo" means substituted by halogen. Halo C 1-6 alkyl, halo C 1-6 alkoxy, halo C 3-6 cycloalkyl, halo C 3-6 cycloalkoxy, halo 3-7-membered heterocycloalkyl means that one or more hydrogen atoms in C 1-6 alkyl, C 2-6 alkenyl, C 1-6 alkoxy, C 3-6 cycloalkyl, C 3-6 cycloalkoxy, 3-7-membered heterocycloalkyl are replaced by halogen groups.

[0077] In the present invention, the term "oxy" is O.

[0078] In the present invention, used to depict a chemical bond, which is the point where a partial or substituent is connected to the core structure or backbone structure.

[0079] In the present invention, the terms "aromatic heterocycle" or "heteroaryl" have the same meaning and refer to a heteroaromatic group containing one or more heteroatoms. For example, "heteroaryl" refers to an aromatic heterocycle containing 1 to 4 heteroatoms selected from oxygen, sulfur, and nitrogen and 3 to 10 carbon atoms. Non-limiting examples include: furyl, thienyl, pyridyl, pyrazolyl, pyrrolyl, N-alkylpyrrolyl, pyrimidinyl, pyrazinyl, imidazolyl, tetrazolyl, etc. The heteroaryl can be optionally substituted or unsubstituted.

[0080] In the present invention, the term "optionally substituted by one or more" or "optionally further substituted by one or more" means that one or more hydrogen atoms on a specific group are substituted by specific substituents. The specific substituents are the substituents described correspondingly in the foregoing, or the substituents appearing in each embodiment. Unless otherwise specified, a substituted group may have a substituent selected from a specific group at any substitutable site of the group, and the substituents may be the same or different at each position. Herein, "more than one" includes two or more, such as 2, 3, 4, 5, 6.

[0081] In the present invention, the term "1-6" means 1, 2, 3, 4, 5 or 6. Other similar terms each independently have a similar meaning.

[0082] In the present invention, the term "substituted" should be considered to include multiple degrees of substitution of the indicated substituents. When multiple substituent moieties are disclosed or claimed, the substituted compound may be independently mono- or multiply substituted by one or more of the disclosed or claimed substituent moieties. Independently substituted means that (two or more) substituents may be the same or different.

[0083] The compounds of the present invention may contain one or more asymmetric centers and thus may exist in the form of isomers, racemates, etc., wherein the racemate includes a racemic body and a racemic mixture; the isomers include a single enantiomer, a diastereomer mixture and a single diastereomer. The present invention is intended to include all such isomeric forms of the compounds of Formula I, II or III.

[0084] "Stereoisomers" refer to compounds having the same chemical structure but different arrangements of atoms or groups in space. Stereoisomers include enantiomers, diastereomers, conformational isomers (rotational isomers), geometric isomers (cis / trans) isomers, atropisomers, and so on.

[0085] "Enantiomers" refer to two isomers of a compound that cannot be overlapped but are mirror images of each other.

[0086] "Diastereomers" refer to stereoisomers having two or more chiral centers and whose molecules are not mirror images of each other. Diastereomers have different physical properties, such as melting point, boiling point, spectral properties and reactivity. Diastereomer mixtures can be separated by high-resolution analytical operations such as electrophoresis and chromatography, such as HPLC.

[0087] Any asymmetric atoms (e.g., carbon, etc.) of the compounds of the present invention can exist in racemic or enantiomerically enriched forms, such as in the form of (R)-, (S)-, or (R,S)-configurations. In certain embodiments, each asymmetric atom has at least 0% enantiomeric excess, at least 60% enantiomeric excess, at least 70% enantiomeric excess, at least 80% enantiomeric excess, at least 90% enantiomeric excess, at least 95% enantiomeric excess, or at least 99% enantiomeric excess in terms of the (R)- or (S)-configuration. The independent synthesis of optical isomers and diastereoisomers or their chromatographic separation can be achieved by appropriate modification of the methods disclosed herein as known in the art. Their absolute stereochemistry can be determined by X-ray crystallography of the crystalline product or crystalline intermediate, which, if necessary, is derivatized with a reagent containing an asymmetric center of known absolute configuration or a heavy enough atom for absolute assignment.

[0088] If desired, the racemic mixture of the compound can be separated to isolate the individual enantiomers. The separation can be carried out by methods well known in the art, such as coupling the racemic mixture of the compound to an enantiomerically pure compound to form a mixture of diastereoisomers, and then separating the individual diastereoisomers by standard methods (e.g., fractional crystallization or chromatography).

[0089] The racemic mixture of the compound can also be directly separated by chromatographic methods using a chiral stationary phase, which is well known in the art. Alternatively, any enantiomer of the compound can be obtained by stereoselective synthesis using optically pure starting materials or reagents of known configuration by methods well known in the art.

[0090] The term "prodrug" represents a structure that can be converted in vivo to the compound represented by formula (I). Such conversion is affected by the hydrolysis of the prodrug in the blood or enzymatic conversion in the blood or tissues to the parent structure.

[0091] In the compounds of structural formula I, II, or III, the atoms can exhibit their natural isotopic abundances, or one or more atoms can be artificially enriched with specific isotopes having the same atomic number but different atomic masses or mass numbers from those predominantly found in nature.

[0092] The present invention is intended to include all suitable isotopic variants of the compounds of structural formula I, II, or III. For example, different isotopic forms of hydrogen (H) include protium (1H), deuterium (2H), and tritium (3H).

[0093] Isotope-enriched compounds within structural formulas I, II, or III can be prepared by conventional techniques well-known to those skilled in the art or by methods similar to those described in the protocols and examples herein, using appropriate isotope-enriched reagents and / or intermediates, without undue experimentation.

[0094] In another aspect of the present invention, there is provided a pharmaceutical composition comprising a compound, an isomer, a racemate, or a pharmaceutically acceptable salt thereof as described in any one of the above, and a pharmaceutically acceptable carrier.

[0095] In another aspect of the present invention, there is also disclosed the use of a compound, an isomer, a racemate, or a pharmaceutically acceptable salt thereof as described in any one of the above, in the preparation of a medicament for treating a condition, disorder, or disease responsive to inhibition of Nav1.8 channel activity in a mammalian subject in need thereof. The ability of the compounds of the present invention to block, partially block, interfere with, reduce, or decrease the activity or expression of Nav1.8 in a subject, "inhibition" encompasses a complete and / or partial reduction of channel function, such as a reduction of at least 10%, in some embodiments at least 20%, 30%, 50%, 75%, 95%, 98%, and up to and including 100%.

[0096] More specifically, the IC 50 value or inhibitory activity of the compounds of the present invention against the Nav1.8 channel is less than 10 μM, more preferably less than 1 μM, more preferably less than 50 nM, and more preferably less than 10 nM.

[0097] In another aspect of the present invention, there is also disclosed the use of a compound, an isomer, a racemate, or a pharmaceutically acceptable salt thereof as described in any one of the above, in the preparation of a medicament for treating, preventing, or controlling pain conditions, cough disorders, acute pruritus disorders, or chronic pruritus disorders.

[0098] In one embodiment of the present invention, the conditions include chronic pain, visceral pain, neuropathic pain, musculoskeletal pain, acute pain, inflammatory pain, cancer pain, idiopathic pain, postoperative pain, visceral pain, multiple sclerosis, Charcot-Marie-Tooth syndrome, incontinence, pathological cough, or arrhythmia, or a method for reducing their severity.

[0099] In one embodiment of the present invention, the pain includes neuropathic pain, musculoskeletal pain (preferably osteoarthritis pain), acute pain (preferably acute postoperative pain), postoperative pain, or visceral pain.

[0100] In one embodiment of the present invention, the neuropathic pain includes postherpetic neuralgia, small fiber neuropathy, idiopathic small fiber neuropathy, or diabetic neuropathy, preferably one or more of diabetic peripheral neuropathy.

[0101] In one embodiment of the present invention, the postoperative pain includes one or more of bunionectomy pain, abdominoplasty pain, or hernia repair pain.

[0102] The present invention also discloses administering one or more additional therapeutic agents to the subject while, before, or after treating with any of the above-mentioned compounds, their isomers, racemates, or their pharmaceutically acceptable salts or pharmaceutical compositions.

[0103] Another aspect of the present invention discloses the compounds, their isomers, racemates, or their pharmaceutically acceptable salts described in any of the above; the use of any of the pharmaceutical compositions as a medicine.

[0104] Beneficial effects

[0105] The present invention provides a Nav1.8 selective inhibitor with novel structure, excellent pharmacokinetic properties, good efficacy and drug-likeness, which can be used for the treatment, prevention or control of Nav1.8-related pain conditions, cough disorders, acute pruritus disorders or chronic pruritus disorders, and has significant clinical application value. Detailed implementation manners

[0106] The present invention will be further described below in conjunction with examples. It should be noted that the following examples are provided for illustrative purposes only and do not constitute a limitation on the scope of the present invention claimed.

[0107] Unless otherwise specified, the raw materials, reagents, methods, etc. used in the examples are all conventional raw materials, reagents, methods in the art, and the experimental materials and reagents used can be obtained from commercial channels.

[0108] Experimental materials and analytical instruments:

[0109] The thin layer analysis (TLC) plate model is HSGF-254 (thickness 0.15 - 0.2 mm, produced by Yantai Chemical Industry Experimental Factory); the column chromatography silica gel is 200 - 300 mesh commercial silica gel produced by Qingdao Marine Chemical Factory;

[0110] 1 1H-NMR was recorded using a Bruker Avance III-400 nuclear magnetic resonance spectrometer, with tetramethylsilane (TMS) as the internal standard; the chemical shift is (ppm, δ:), and the proton coupling is labeled as singlet (s), doublet (d), triplet (t), quartet (q), multiplet (m);

[0111] Low-resolution mass spectrometry was recorded using an Agilent 6110 mass spectrometer.

[0112] Abbreviations and notes:

[0113] DMF: N,N-dimethylformamide; DMSO: dimethyl sulfoxide; psi: pounds per square inch; DIPEA: N,N-diisopropylethylamine; HATU: 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; CDI: N,N′-carbonyldiimidazole; MTBE: methyl tert-butyl ether; DIBAL-H: diisobutylaluminum hydride; DMAP: 4-dimethylaminopyridine; LiHMDS: lithium hexamethyldisilazide; DCC: 1,3-dicyclohexylcarbodiimide; CuCl: cuprous chloride; THF: tetrahydrofuran; DCM: dichloromethane; EtOAC: ethyl acetate.

[0114] Example 1: Preparation of Compound P-1

[0115] The synthetic route of Compound P-1 is as follows:

[0116]

[0117] Step 1: Preparation of (R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one

[0118] Dissolve 2-(3,4-difluoro-2-methoxyphenyl)acetic acid (Intermediate A, 10.00 g, 49.5 mmol) in an acetonitrile solution, then add CDI (9.22 g, 56.9 mmol), and activate and stir at 40 °C for 15 minutes. Add (R)-4,4,4-trifluoro-3-hydroxy-3-methylbutan-2-one (Intermediate B, 7.72 g, 59.4 mmol) and potassium carbonate (8.46 g, 61.9 mmol) thereto in sequence, and raise the temperature to 60 °C and continue stirring for 24 hours. Quench the reaction with water, and extract the aqueous phase with MTBE 2-3 times. Wash the organic phase with 2 M hydrochloric acid solution (2 × 50 mL), dry over anhydrous sodium sulfate, and concentrate under reduced pressure in vacuo. Purify by column chromatography to obtain 11.5 g of white solid compound (R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one, with a yield of 72.1%. MS m / z calculated value: 322.06; experimental value: 323.1 [M+H] + .

[0119] Step 2: Preparation of (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one

[0120] (R)-3-(3,4-Difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one (3.00 g, 9.3 mmol) was added to a high-pressure reactor and dissolved in absolute ethanol. Then palladium / carbon (10% wt, 0.99 g, 9.3 mmol) and palladium hydroxide / carbon (20% wt, 1.57 g, 11.16 mmol) were added successively. After gas displacement three times, hydrogen was charged until the pressure reached 50 psi. The mixture was heated to 80 °C and stirred for 40 hours. After the mixture was cooled to room temperature, the reactor was opened and TLC was used to monitor the complete reaction of the raw materials. The mixture was filtered under reduced pressure with diatomaceous earth filter aid, the filter cake was rinsed with absolute ethanol, and the filtrate was concentrated under reduced pressure to obtain 2.75 g of white solid compound (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one, with a yield of 91.1%. MS m / z calculated value: 324.07; experimental value: 325.08 [M+H] + .

[0121] Step 3: Preparation of (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol

[0122] Under nitrogen protection at -78 °C, DIBAL-H (2.30 g, 16.2 mmol) was slowly added dropwise to a dichloromethane solution containing compound (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one (2.50 g, 7.7 mmol), and TLC was used to monitor until the reaction was complete. Subsequently, saturated ammonium chloride solution was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate 2 - 3 times. The combined organic phases were washed with saturated brine and concentrated under reduced pressure to obtain 2.50 g of a crude product mainly composed of the diastereoisomer (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol, with a yield of 99.2%. MS m / z calculated value: 326.09; experimental value: 327.1 [M+H] + .

[0123] Step 4: Preparation of (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate

[0124] Under normal temperature conditions, acetic anhydride (4.69 g, 46.2 mmol) was added to a mixed solution of (3S,4S,5R)-3-(3-fluoro-4-hydroxy-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol (2.50 g, 7.7 mmol) and DMAP (1.40 g, 11.6 mmol). TLC was monitored until the reaction was complete. After the reaction was completed, saturated sodium bicarbonate solution was added, and the reaction system was extracted with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 2.77 g of stereoisomers with (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate as the main diastereomer, with a yield of 98.5%. MS m / z calculated value: 368.10; experimental value: 369.1 [M+H] + 。

[0125] Step 5: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile

[0126] Under -78 °C conditions, trimethylsilyl cyanide (1.86 g, 18.8 mmol) and boron trifluoride diethyl etherate (3.20 g, 22.5 mmol) were successively added to a dichloromethane solution of (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate (2.77 g, 7.5 mmol). The reaction mixture was stirred for 30 minutes, and then the reaction was transferred to room temperature until the reaction was complete. The reaction was quenched with saturated sodium bicarbonate solution (60 mL), and then the mixture was extracted with dichloromethane. The organic phases were combined and dried, concentrated under reduced pressure, to obtain 2.48 g of stereoisomers with (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile as the main diastereoisomer, with a yield of 98.5%. MS m / z calculated value: 335.09; experimental value: 336.1 [M+H] + 。

[0127] Step 6: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid

[0128] To (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile (2.00 g, 5.9 mmol), 10 mL of sodium hydroxide (2 M) and 20 mL of methanol were added, and the mixture was heated to 60 °C. The reaction was monitored by TLC until completion. The reaction system was partitioned between ethyl acetate and 1 M hydrochloric acid, and the layers were separated. The organic layer was combined and concentrated under reduced pressure in vacuo to give 2.02 g of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid as a transparent oil, with a yield of 95.9%. MS m / z calculated value: 354.08; experimental value: 355.1 [M+H] + 。

[0129] Step 7: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-N-(7-oxo-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide

[0130] At 0 °C, (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid (0.1 g, 0.3 mmol) was dissolved in DMF (50 mL), and 4-amino-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Intermediate C, 0.11 g, 0.45 mmol), DIPEA (0.10 g, 0.9 mmol), and HATU (0.16 g, 0.45 mmol) were added respectively. The reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction system was diluted with ethyl acetate and then washed with saturated brine. The organic layer was dried, concentrated under reduced pressure, and purified by column chromatography to give 0.05 g of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-N-(7-oxo-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide as a white solid, with a yield of 36.5%.

[0131] 11H NMR (400 MHz, DMSO-d6) δ 10.35 (s, 1H), 8.95 (s, 1H), 8.60 (d, J = 5.4 Hz, 1H), 7.97 (d, J = 5.4 Hz, 1H), 7.18 (q, J = 3.3, 2.8 Hz, 2H), 5.28 (d, J = 10.2 Hz, 1H), 4.35 (d, J = 8.0 Hz, 2H), 3.95 (d, J = 2.2 Hz, 3H), 3.93 (d, J = 2.1 Hz, 1H), 1.99 (s, 1H), 1.61 (s, 3H), 0.77–0.71 (m, 3H).

[0132] Example 2: Preparation of Compound P-2

[0133] The synthetic route of Compound P-2 is as follows:

[0134]

[0135] Step 1: Preparation of (R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one

[0136] Dissolve 2-(3-fluoro-2,4-dimethoxyphenyl)acetic acid (Intermediate D, 30.00 g, 140.1 mmol) in an acetonitrile solution, and then add CDI (26.12 g, 161.1 mmol). Activate and stir at 40 °C for 15 minutes. Add (R)-4,4,4-trifluoro-3-hydroxy-3-methylbutan-2-one (Intermediate B, 40.11 g, 168.1 mmol) and potassium carbonate (19.35 g, 175.1 mmol) to it in sequence, and raise the temperature to 60 °C and continue stirring for 24 hours. Quench the reaction with water, and extract the aqueous phase with MTBE 2-3 times. Wash the organic phase with 2 M hydrochloric acid solution (2 × 50 mL), dry over anhydrous sodium sulfate, and concentrate under reduced pressure in vacuo. Purify by column chromatography to obtain 27.85 g of white solid compound (R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one, with a yield of 59.5%. MS m / z calculated value: 334.08; experimental value: 335.1 [M+H] + 。

[0137] Step 2: Preparation of (3S,4S,5R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one

[0138] (R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one (5.00 g, 14.9 mmol) was added to a high-pressure reactor and dissolved in absolute ethanol. Then palladium / carbon (10% wt, 1.58 g, 14.9 mmol) and palladium hydroxide / carbon (20% wt, 2.51 g, 17.8 mmol) were added successively. After gas displacement three times, hydrogen was charged until the pressure reached 50 psi. The mixture was heated to 80 °C and stirred for 36 hours. After the mixture was cooled to room temperature, the reactor was opened and TLC was used to monitor the complete reaction of the raw materials. The mixture was filtered under reduced pressure with diatomaceous earth filter aid, the filter cake was rinsed with absolute ethanol, and the filtrate was concentrated under reduced pressure to obtain 4.50 g of white solid compound (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one, with a yield of 89.3%. MS m / z calculated value: 336.09; experimental value: 337.1 [M+H] + .

[0139] Step 3: Preparation of (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol

[0140] Under nitrogen protection at -78 °C, DIBAL (6.34 g, 89.2 mmol) was slowly added dropwise to a dichloromethane solution containing compound (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)dihydrofuran-2(3H)-one (15.00 g, 44.6 mmol). TLC was used to monitor until the reaction was complete. Subsequently, saturated ammonium chloride solution was added to quench the reaction, and the reaction mixture was extracted with ethyl acetate 2-3 times. The combined organic phases were washed with saturated brine and concentrated under reduced pressure to obtain 13.50 g of a crude product mainly composed of the diastereoisomer (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol, with a yield of 89.5%. MS m / z calculated value: 338.11; experimental value: 339.1 [M+H] + .

[0141] Step 4: Preparation of (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate

[0142] Under normal temperature conditions, acetic anhydride (24.44 g, 239.4 mmol) was added to a mixed solution of (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-ol (13.50 g, 39.9 mmol) and DMAP (7.31 g, 59.8 mmol). TLC was monitored until the reaction was complete. After the reaction was completed, saturated sodium bicarbonate solution was added, and the reaction system was extracted with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 13.20 g of a stereoisomer with (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate as the main diastereomer, with a yield of 87.0%. MS m / z calculated value: 380.12; experimental value: 381.1 [M+H] + .

[0143] Step 5: Preparation of (2R,3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile

[0144] At -78 °C, trimethylsilyl cyanide (8.61 g, 86.7 mmol) and boron trifluoride diethyl etherate (14.77 g, 104.1 mmol) were successively added to a dichloromethane solution of (3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-yl acetate (13.20 g, 34.7 mmol). The reaction mixture was stirred for 30 minutes, and then the reaction was transferred to room temperature until the reaction was complete. The reaction was quenched with saturated sodium bicarbonate solution (60 mL), and then the mixture was extracted with dichloromethane. The organic phases were combined and dried, concentrated under reduced pressure, to obtain 11.50 g of a stereoisomer with (2R,3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile as the main diastereoisomer, with a yield of 95.4%. MS m / z calculated value: 347.11; experimental value: 348.1 [M+H] + .

[0145] Step 6: Preparation of (2R,3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid

[0146] (2R,3S,4S,5R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carbonitrile (11.50 g, 33.1 mmol) was added to 80 mL of sodium hydroxide (2 M) and 160 mL of methanol, and the mixture was heated to 60 °C. The reaction was monitored by TLC until completion. The reaction mixture was partitioned between ethyl acetate and 1 M hydrochloric acid. The layers were separated and the organic layer was combined and concentrated under reduced pressure in vacuo to give 10.10 g of (2R,3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid as a clear oil, with a yield of 83.3%. MS m / z calculated: 366.11; found: 367.0 [M+H] + .

[0147] Step 7: Preparation of (2R,3S,4S,5R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-N-(7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide

[0148] At 0 °C, (2R,3S,4S,5R)-3-(3-Fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid (0.2 g, 0.5 mmol) was dissolved in DMF (50 mL). 4-Amino-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Intermediate C, 0.11 g, 0.75 mmol), DIPEA (0.19 g, 1.5 mmol), and HATU (0.28 g, 0.75 mmol) were added respectively. The reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was diluted with ethyl acetate and then washed with saturated brine. The organic layer was dried, concentrated under reduced pressure and purified by column chromatography to give 0.08 g of (2R,3S,4S,5R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-N-(7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide as a white solid, with a yield of 32.2%.

[0149] 11H NMR (400 MHz, DMSO-d6) δ 9.73 (s, 1H), 8.89 (s, 1H), 8.52 (d, J = 5.4 Hz, 1H), 7.63 (d, J = 5.5 Hz, 1H), 6.95 (t, J = 9.9 Hz, 1H), 6.75 (t, J = 8.5 Hz, 1H), 5.01 (d, J = 9.2 Hz, 1H), 3.99 (t, J = 2.4 Hz, 2H), 3.96–3.92 (m, 3H), 3.87–3.82 (m, 1H), 3.73 (s, 3H), 3.22–3.13 (m, 1H), 1.44 (s, 3H), 0.95 (d, J = 12.9, 6.6 Hz, 3H).

[0150] Example 3: Preparation of Compound P-3:

[0151]

[0152] Step 1: Preparation of Methyl (R)-2-(2-(3,4-Difluoro-2-methoxyphenyl)acetoxy)-3,3,3-trifluoro-2-methylpropionate

[0153] At 0 °C, oxalyl chloride (6.00 mL, 68.8 mmol) was added dropwise to a solution of 2-(3,4-difluoro-2-methoxyphenyl)acetic acid (Intermediate A, 6.00 g, 29.9 mmol) and DMF (100.0 μL, 1.3 mmol) in DCM (100 mL), and the mixture was stirred at room temperature for 1 hour. After the reaction mixture was concentrated in vacuo, a solution of methyl (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionate (Intermediate F, 4.40 g, 25.6 mmol) and triethylamine (7.8 mL, 55.9 mmol) in DCM (10 mL) was added, and the mixture was stirred at room temperature overnight until the reaction was complete. The reaction was quenched by adding saturated ammonium chloride solution (50 mL). The aqueous phase was extracted with DCM (150 mL) 2 - 3 times. The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by column chromatography gave 4.30 g of a white solid product with a yield of 41.5%. MS m / z calculated value: 356.07; experimental value: 357.1 [M + H] + .

[0154] Step 2: Preparation of (R)-3-(3,4-Difluoro-2-methoxyphenyl)-4-hydroxy-5-methyl-5-(trifluoromethyl)furan-2(5H)-one

[0155] After dissolving methyl (R)-2-(2-(3,4-difluoro-2-methoxyphenyl)acetoxy)-3,3,3-trifluoro-2-methylpropionate (1.48 g, 4.2 mmol) in a THF (20 mL) solution, it was slowly added to a THF (20 mL) solution of LiHMDS (10 mL, 10.0 mmol) at -78 °C. The reaction mixture was continuously stirred at -78 °C for 5 h and monitored by TLC until the reaction was complete. The reaction was quenched by adding 2 M HCl, and the aqueous phase was extracted 2 - 3 times with EtOAC (150 mL). The combined organic phases were dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by column chromatography gave 0.80 g of a yellow oily product with a yield of 59.7%. MS m / z calculated value: 324.04; experimental value: 325.0 [M + H] + 。

[0156] Step 3: Preparation of (R)-3-(3,4-difluoro-2-methoxyphenyl)-4-methoxy-5-methyl-5-(trifluoromethyl)furan-2(5H)-one

[0157] Under nitrogen protection, methanol (4 mL, 68.5 mmol) was added dropwise to a mixture of DCC (2.71 g, 13.1 mmol) and CuCl (0.04 g, 0.4 mmol) at 0 °C. After continuous stirring for 1 h, the reaction was transferred to room temperature and continued overnight. The reaction mixture was concentrated in vacuo. Purification by column chromatography gave 2.1 g of 1,3-dicyclohexyl-2-methylisourea as a colorless oil. Subsequently, 1,3-dicyclohexyl-2-methyl-isourea (0.44 g, 1.7 mmol) was dissolved in a THF solution, and then slowly added dropwise to a THF solution of methyl (R)-2-(2-(3,4-difluoro-2-methoxyphenyl)acetoxy)-3,3,3-trifluoro-2-methylpropionate (0.28 g, 0.8 mmol). The reaction mixture was heated at 85 °C overnight. After the reaction was completed, the white precipitate in the reaction mixture was filtered. The mother liquor was collected and concentrated in vacuo. Purification by column chromatography gave 0.26 g of (R)-3-(3,4-difluoro-2-methoxyphenyl)-4-methoxy-5-methyl-5-(trifluoromethyl)furan-2(5H)-one with a yield of 86.4%. MS m / z calculated value: 338.06; experimental value: 339.1 [M + H] + 。

[0158] The series of reactions from step 4) to step 9) in this example are similar to the reaction process from step 2) to step 7) in Example 2, with the difference that the reaction raw material (R)-3-(3-fluoro-2,4-dimethoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)furan-2(5H)-one in step 2 of Example 2 is replaced by (R)-3-(3,4-difluoro-2-methoxyphenyl)-4-methoxy-5-methyl-5-(trifluoromethyl)furan-2(5H)-one. Subsequently, through a series of reactions, 82 mg of the target compound (2R,3R,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4-methoxy-5-methyl-N-(7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide was obtained, with a yield of 60.7%.

[0159] 1 H NMR(400MHz,DMSO-d6)δ10.40(s,1H),8.94(s,1H),8.59(d,J=5.5Hz,1H),7.95(d,J=5.5Hz,1H),7.30–7.19(m,2H),5.26(d,J=10.6Hz,1H),4.43–4.23(m,2H),4.10(d,J=4.8Hz,1H),3.96(s,3H),2.93(s,3H),2.00(q,J=7.2Hz,1H),1.55(s,3H).

[0160] Example 4: Preparation of Compound P-4

[0161]

[0162] In this reaction route, -PMB represents p-methoxybenzyl.

[0163] Step 1: Preparation of methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate

[0164] Potassium carbonate (1.16 g, 8.5 mmol) was added to a solution of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid (1.0 g, 2.8 mmol) in N,N-dimethylformamide (50 mL). Then, methyl iodide (0.59 g, 4.2 mmol) was added dropwise to the solution. After the addition was complete, the temperature was raised to 70 °C. The reaction was monitored by TLC. After the reaction was completed and cooled to room temperature naturally, ethyl acetate (200 mL) was added to the reaction system for dilution, and the mixture was washed with saturated brine (300 mL) 3 - 5 times. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to obtain 0.92 g of crude product of methyl (2R,3S,4S,5R))-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate, with a yield of 88.5%. Calculated MS m / z value: 368.10; experimental value: 369.1 [M+H] + 。

[0165] Step 2: Preparation of methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-hydroxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate

[0166] At 0 °C, boron tribromide (1.87 g, 7.5 mmol) was slowly added dropwise to a solution of methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate (0.92 g, 2.5 mmol) in dichloromethane (100 mL). After the reaction was monitored by TLC and completed, the reaction system was slowly added dropwise to ice water for quenching, and the pH of the solution was adjusted to 7 - 8 using saturated sodium bicarbonate solution. The layers were separated, and the aqueous phase was extracted with dichloromethane (200 mL) 2 - 3 times. The combined organic phases were washed with saturated brine (300 mL) 2 - 3 times, dried over anhydrous sodium sulfate, concentrated in vacuo, and purified by column chromatography to obtain 0.71 g of a yellow oily liquid, with a yield of 80.2%. Calculated MS m / z value: 354.08; experimental value: 355.1 [M+H] + 。

[0167] Step 3: Preparation of methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate

[0168] Cesium carbonate (1.95 g, 6.0 mmol) was added to a solution of methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-hydroxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate (0.71 g, 2.0 mmol) in N,N-dimethylformamide (50 mL). Then, 2-bromoethyl methyl ether (0.42 g, 3.0 mmol) was added dropwise to the solution. After the addition was complete, the temperature was raised to 100 °C. The reaction was monitored by TLC. After cooling to room temperature naturally, the reaction system was diluted with ethyl acetate (200 mL) and washed 3 - 5 times with saturated brine (300 mL). The organic phase was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. After column chromatography, 0.53 g of a pale yellow oily liquid was obtained with a yield of 65.2%. MS m / z calculated value: 412.13; experimental value: 413.1 [M + H] + 。

[0169] Step 4: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide

[0170] Methyl (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate (0.53 g, 1.3 mmol) was dissolved in a 7 M ammonia in methanol solution (10 mL). After stirring for 6 h, the reaction was monitored by TLC. After concentration in vacuo, 0.47 g of the crude product of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide was obtained with a yield of 92.3%. MS m / z calculated value: 397.13; experimental value: 398.1 [M + H] + 。

[0171] Step 5: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-N-(6-(4-methoxybenzyl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide

[0172] Under nitrogen conditions, (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide (0.15 g, 0.38 mmol), 4-bromo-6-(4-methoxybenzyl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (0.14 g, 0.42 mmol), tris(dibenzylideneacetone)dipalladium (0.035 g, 0.038 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.044 g, 0.076 mmol), and cesium carbonate (0.25 g, 0.76 mmol) were added to a Schlenk tube. After purging the system with nitrogen three times, toluene (20 mL) was added to the system. The temperature was raised to 100 °C and the reaction was carried out overnight. After monitoring the reaction to completion by TLC, the reaction mixture was allowed to cool to room temperature naturally. Ethyl acetate (30 mL) was added to the reaction system for dilution, and the mixture was washed 3 - 5 times with saturated brine (40 mL). The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. After column chromatography, 0.11 g of a white solid was obtained with a yield of 44.9%. MS m / z calculated value: 649.22; experimental value: 650.2 [M+H] + 。

[0173] Step 6: Preparation of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-4,5-dimethyl-N-(7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide

[0174] (2R,3S,4S,5R)-3-(3,4-difluoro-2-(2-methoxyethoxy)phenyl)-N-(6-(4-methoxybenzyl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide (0.11 g, 0.19 mmol) and acetonitrile (10 mL) were added to a 50 mL round-bottom flask. Under an ice bath, an aqueous solution (5 mL) of ammonium cerium(IV) nitrate (0.37 g, 0.67 mmol) was added to the system in batches. After adding all the batches, the system was warmed to room temperature and reacted for 6 hours. After monitoring the reaction to completion by TLC, the system was transferred to a 250 mL beaker, saturated sodium bicarbonate solution (15 mL) was added, and the mixture was filtered under reduced pressure. The filtrate was extracted 3 times with dichloromethane (30 mL). The organic phase was washed three times with saturated brine (50 mL), dried over anhydrous sodium sulfate, concentrated under reduced pressure, and 0.08 g of a white solid was obtained after column chromatography with a yield of 89.2%.

[0175] 11H NMR (400 MHz, DMSO-d6) δ 10.53 (s, 1H), 8.13 (d, J = 2.0 Hz, 1H), 7.85 (t, J = 4.9 Hz, 1H), 7.78 (dd, J = 8.4, 2.0 Hz, 1H), 7.51 (d, J = 8.4 Hz, 1H), 7.17 (d, J = 6.7 Hz, 2H), 5.11 (d, J = 10.7 Hz, 1H), 4.35 (dd, J = 9.5, 6.1 Hz, 3H), 4.31–4.13 (m, 2H), 3.61 (q, J = 4.5 Hz, 2H), 3.27 (s, 3H), 2.83 (t, J = 7.3 Hz, 1H), 1.61 (s, 3H), 0.74–0.67 (m, 3H).

[0176] Example 5: Preparation of Compound P-5

[0177]

[0178] The preparation method of the compound was similar to that of Example 4, except that: 2-bromoethyl methyl ether in step 3) was replaced with an equimolar amount of fluoromethane iodide to obtain 0.10 g of a white solid compound with a yield of 82.6%.

[0179] 1 1H NMR (400 MHz, DMSO-d6) δ 10.51 (s, 1H), 8.11 (d, J = 1.9 Hz, 1H), 7.85 (t, J = 4.9 Hz, 1H), 7.77 (dd, J = 8.5, 2.0 Hz, 1H), 7.50 (d, J = 8.4 Hz, 1H), 7.41–7.22 (m, 2H), 5.93–5.86 (m, 1H), 5.76 (dt, J = 5.3, 2.6 Hz, 1H), 5.11 (d, J = 10.3 Hz, 1H), 4.33 (dd, J = 11.4, 6.9 Hz, 3H), 2.79 (p, J = 7.5 Hz, 1H), 1.61 (s, 3H), 0.78–0.71 (m, 3H).

[0180] Example 6: Preparation of Compound P-6

[0181]

[0182] The preparation method was similar to that of Example 4, except that: 2-bromoethyl methyl ether in step 3) was replaced with 3-(iodomethyl)oxetane to obtain 0.09 g of a white solid compound with a yield of 89.2%.

[0183] 11H NMR (400 MHz, DMSO-d6) δ 10.32 (s, 1H), 8.94 (s, 1H), 8.60 (d, J = 5.5 Hz, 1H), 7.98 (s, 1H), 7.25–7.16 (m, 2H), 5.29 (d, J = 10.4 Hz, 1H), 4.73 (ddd, J = 8.0, 6.0, 2.0 Hz, 2H), 4.52–4.41 (m, 3H), 4.37–4.25 (m, 4H), 3.43–3.37 (m, 1H), 2.77 (t, J = 7.3 Hz, 1H), 1.60 (s, 3H), 0.73 (d, J = 7.2 Hz, 3H).

[0184] Example 7: Preparation of Compound P-7:

[0185] The synthetic route of Compound P-7 is as follows:

[0186]

[0187] Step 1: Preparation of methyl 4-bromo-3-methylpyridine-2-carboxylate

[0188] To a 500 mL round-bottom flask, add 4-bromo-3-methylpyridine-2-carboxylic acid (5.00 g, 23.2 mmol), methyl iodide (6.50 g, 46.5 mmol), potassium carbonate (9.50 g, 69.7 mmol), and N,N-dimethylformamide (250 mL). Heat the resulting solution to 80 °C and react overnight. Monitor the reaction by TLC until completion. Transfer the reaction mixture to a separatory funnel, add ethyl acetate (500 mL), and wash three times with saturated brine (500 mL). Dry over anhydrous sodium sulfate and concentrate under reduced pressure. Purify the residue by column chromatography to obtain 4.56 g of a pale yellow oily product with a yield of 85.8%. MS m / z calculated value: 228.97; experimental value: 230.9 [M+H] + .

[0189] Step 2: Preparation of 4-bromo-3-(bromomethyl)pyridine-2-carboxylic acid

[0190] Methyl 4-bromo-3-methylpicolinate (4.56 g, 19.9 mmol), N-bromophthalimide (4.80 g, 29.8 mmol), 2,2'-azobis(2-methylpropionitrile) (0.30 g, 2.0 mmol), and carbon tetrachloride (150 mL) were added to a 500 mL round-bottom flask. The mixture was heated to 80 °C and stirred overnight. The reaction was monitored by TLC until completion. The reaction mixture was transferred to a beaker, and saturated sodium sulfite solution (100 mL) was added. The mixture was stirred for 1 h, then transferred to a separatory funnel. Dichloromethane (200 mL) was added, and the mixture was washed with saturated brine (500 mL) three times. The organic layer was concentrated under reduced pressure, and the residue was purified by column chromatography to obtain 5.15 g of the target compound as a yellow oil, with a yield of 86.9%. MS m / z calculated value: 294.86; experimental value: 295.7 [M+H] + 。

[0191] Step 3: Preparation of tert-butyl 3-(4-bromo-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)azetidine-1-carboxylate

[0192] 4-Bromo-3-(bromomethyl)picolonic acid (5.06 g, 17.3 mmol) and tetrahydrofuran (200 mL) were added to a 500 mL round-bottom flask. Then tert-butyl 3-aminoazetidine-1-carboxylate (4.57 g, 26.6 mmol) was added to the system. The temperature was raised to 80 °C and stirred for 3 h. The reaction was monitored by TLC until completion. The reaction mixture was concentrated under reduced pressure to obtain a crude product, which was slurried with n-hexane to obtain 4.57 g of the target compound as an off-white solid, with a yield of 72.2%. MS m / z calculated value: 367.05; experimental value: 368.09 [M+H] + 。

[0193] Step 4: Preparation of tert-butyl 3-(4-((2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamido)-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)azetidine-1-carboxylate

[0194] Under nitrogen atmosphere, (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide (0.20 g, 0.56 mmol), tert-butyl 3-(4-bromo-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)azetidine-1-carboxylate (0.24 g, 0.67 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.051 g, 0.056 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.065 g, 0.112 mmol), and cesium carbonate (0.36 g, 1.12 mmol) were added to a Schlenk tube. After purging the system with nitrogen three times, toluene (50 mL) was added, and the mixture was heated to 100 °C and stirred overnight. After the reaction was completed as monitored by TLC, the reaction mixture was allowed to cool to room temperature naturally. Then, ethyl acetate (200 mL) was added to dilute the reaction mixture, and the mixture was washed with saturated brine (300 mL) 3 - 5 times. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. After column chromatography, tert-butyl 3-(4-((2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamido)-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)azetidine-1-carboxylate (0.18 g) was obtained as a white oil with a yield of 50.2%. MS m / z calculated value: 640.23; experimental value: 641.2 [M+H] + 。

[0195] Step 5: Preparation of (2R,3S,4S,5R)-N-(6-(azetidin-3-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide (hydrochloride)

[0196] tert-Butyl 3-(4-((2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamido)-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)azetidine-1-carboxylate (0.18 g, 0.28 mmol) was dissolved in ethyl acetate (5 mL) with hydrochloric acid. After the reaction was monitored by TLC and concentrated in vacuo, (2R,3S,4S,5R)-N-(6-(azetidin-3-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide (hydrochloride) 0.13 g was obtained with a yield of 81.6%. MS m / z calculated value: 576.15; experimental value: 577.17 [M+H] + 。

[0197] 1 1H NMR (400 MHz, DMSO-d6) δ 10.48 (s, 1H), 8.75 (s, 2H), 8.60 (d, J = 5.5 Hz, 1H), 8.06 (d, J = 5.5 Hz, 1H), 7.17 (dd, J = 8.4, 4.9 Hz, 2H), 5.28 (d, J = 10.1 Hz, 1H), 5.16–5.05 (m, 1H), 4.80–4.59 (m, 2H), 4.30 (dd, J = 10.1, 7.5 Hz, 1H), 4.25–4.03 (m, 4H), 3.96 (d, J = 2.1 Hz, 3H), 2.85–2.75 (m, 1H), 1.61 (s, 3H), 0.79–0.72 (m, 3H).

[0198] Example 8: Preparation of Compound P-8:

[0199]

[0200] This preparation method is similar to that of Example 7, except that: tert-Butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with tert-Butyl 4-amino-2-azabicyclo[2.1.1]hexane-2-carboxylate, and 0.13 g of a white solid compound was obtained with a yield of 81.6%.

[0201] 11H NMR (400 MHz, DMSO-d6) δ 10.80 (s, 1H), 9.50 (s, 2H), 8.62 (d, J = 5.5 Hz, 1H), 8.01 (d, J = 5.5 Hz, 1H), 7.22–7.09 (m, 2H), 5.40 (d, J = 10.3 Hz, 1H), 4.62 (d, J = 8.7 Hz, 2H), 4.28 (dd, J = 10.3, 7.4 Hz, 1H), 3.96 (d, J = 2.1 Hz, 3H), 3.50 (t, J = 5.2 Hz, 2H), 2.78 (q, J = 7.2 Hz, 1H), 2.73–2.63 (m, 1H), 2.38 (s, 2H), 2.11 (ddd, J = 9.4, 5.3, 1.9 Hz, 2H), 1.61 (s, 3H), 0.81–0.72 (m, 3H).

[0202] Example 9: Preparation of Compound P-9:

[0203]

[0204] The preparation method was similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with tert-butyl (2-aminoethyl)carbamate, and 0.12 g of a white solid compound was obtained with a yield of 78.1%.

[0205] 1 1H NMR (400 MHz, DMSO-d6) δ 11.23–11.07 (m, 1H), 8.64 (d, J = 5.6 Hz, 1H), 8.09 (s, 3H), 8.06 (d, J = 5.6 Hz, 1H), 7.39 (ddd, J = 8.5, 5.9, 1.8 Hz, 1H), 7.28–7.16 (m, 1H), 5.53 (d, J = 10.4 Hz, 1H), 4.74–4.52 (m, 2H), 4.28 (dd, J = 10.4, 7.4 Hz, 1H), 3.98 (d, J = 2.1 Hz, 3H), 3.85 (t, J = 6.0 Hz, 2H), 3.13 (q, J = 5.9 Hz, 2H), 2.80 (p, J = 7.4 Hz, 1H), 1.62 (s, 3H), 0.81–0.72 (m, 3H).

[0206] Example 10: Preparation of Compound P-10:

[0207]

[0208] The preparation method was similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with tert-butyl (2-aminoethyl)(methyl)carbamate, and 0.13 g of a white solid compound was obtained with a yield of 83.2%.

[0209] 1 H NMR(400MHz,DMSO-d6)δ10.97(s,1H),8.76(s,2H),8.63(d,J=5.6Hz,1H),8.00(d,J=5.5Hz,1H),7.45–7.14(m,2H),5.45(d,J=10.3Hz,1H),4.62–4.51(m,2H),4.28(dd,J=10.4,7.4Hz,1H),3.97(d,J=2.0Hz,3H),3.89(s,2H),3.23(t,J=6.0Hz,2H),2.80(p,J=7.5Hz,1H),2.58(q,J=5.3Hz,3H),1.62(s,3H),0.80–0.71(m,3H).

[0210] Example 11: Preparation of Compound P-11:

[0211]

[0212] The preparation method was similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with tert-butyl 3-aminobicyclo[1.1.1]pentanecarboxylate, and 0.16 g of a white solid compound was obtained with a yield of 85.3%.

[0213] 1 H NMR(400MHz,DMSO-d6)δ10.95(s,1H),9.11(s,3H),8.63(d,J=5.6Hz,1H),8.06(d,J=5.6Hz,1H),7.33(ddd,J=8.1,5.8,1.9Hz,1H),7.25–7.11(m,1H),5.46(d,J=10.4Hz,1H),4.55(d,J=5.7Hz,2H),4.29(dd,J=10.3,7.4Hz,1H),3.97(d,J=2.0Hz,3H),2.79(t,J=7.4Hz,1H),2.47(s,6H),1.62(s,3H),0.81–0.71(m,3H).

[0214] Example 12: Preparation of Compound P-12

[0215]

[0216] The preparation method is similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) is replaced with methylamine, and 0.13 g of a white solid compound is obtained, with a yield of 81.6%.

[0217] 1 H NMR(400MHz,DMSO-d6)δ10.45(s,1H),8.58(d,J=5.5Hz,1H),7.92(d,J=5.5Hz,1H),7.21–7.15(m,2H),5.28(d,J=10.3Hz,1H),4.45(d,J=7.3Hz,2H),4.26(dd,J=10.2,7.4Hz,1H),3.96(d,J=2.2Hz,3H),3.11(s,3H),2.78(h,J=7.9Hz,1H),1.61(s,3H),0.76(t,J=8.6Hz,3H).

[0218] Example 13: Preparation of Compound P-13

[0219] The synthetic route of Compound P-13 is as follows:

[0220]

[0221] Step 1: Preparation of ethyl rac-(4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)-4,5-dihydrofuran-2-carboxylate

[0222] Ethyl rac-(4R,5R)-4,5-dimethyl-5-(trifluoromethyl)-3-(((trifluoromethyl)sulfonyl)oxy)-4,5-dihydrofuran-2-carboxylate (Intermediate E, 10.2 g, 26.3 mmol) and (3,4-difluoro-2-(methylthio)phenyl)boronic acid (Intermediate F, 8 g, 39.4 mmol) were dissolved in a solution of toluene (90 mL) and water (10 mL). Potassium phosphate (11.17 g, 52.6 mmol) and tetrakis(triphenylphosphine)palladium(0) (3.04 g, 2.63 mmol) were added thereto. The mixture was purged with nitrogen three times and stirred at 100 °C for 1 hour. TLC monitoring showed that the raw materials had completely reacted. After cooling to room temperature, water (200 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (100 mL × 2). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 8.6 g of the yellow solid compound ethyl rac-(4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)-4,5-dihydrofuran-2-carboxylate, with a yield of 78.0%. Calculated MS m / z: 396.08; Experimental value: 397.1 [M+H] + 。

[0223] Step 2: Preparation of ethyl rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate

[0224] Ethyl rac-(4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)-4,5-dihydrofuran-2-carboxylate (5 g, 12.6 mmol) was dissolved in methanol (50 mL). Magnesium chips (1.53 mL, 63 mmol) and 1,2-dibromoethane (2.37 g, 12.6 mmol) were added thereto. The mixture was stirred at 70 °C for 3 days, filtered, and the filter cake was washed with methanol. The filtrate was concentrated under reduced pressure and purified by column chromatography and HPLC successively to obtain 0.5 g of the yellow solid compound ethyl rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate, with a yield of 9.52%. Calculated MS m / z: 398.10; Experimental value: 399.1 [M+H] + 。

[0225] Step 3: Preparation of rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid

[0226] Dissolve ethyl rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate (500 mg, 1.30 mmol) in a solution of tetrahydrofuran (9 mL) and water (3 mL). Add lithium hydroxide monohydrate (2.18 g, 5.19 mmol) thereto and stir at room temperature for 2 hours. Then add water (10 mL) to the reaction solution, adjust the pH value to ~2 with 1 M dilute hydrochloric acid, extract with ethyl acetate (10 mL × 3), combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate the filtrate under reduced pressure to obtain 480 mg of pale yellow solid rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid with a yield of 92%. Calculated MS m / z: 370.07; Experimental value: 371.1 [M+H] + 。

[0227] Step 4: Resolution of chiral isomers

[0228] Resolve rac-(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid (480 mg) by SFC column chromatography using the eluent [40% IPA (NH4OH 0.2%): 60% CO2] to obtain two single isomers: The first eluted isomer P1 (RT = 2.18 min): 116.48 mg of white solid (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid with a yield of 24.2%. Calculated MS m / z: 370.07; Experimental value: 371.1 [M+H] + 。The second eluted isomer P2 (RT = 2.37 min): 166.73 mg of white solid (2S,3R,4R,5S)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid with a yield of 34.7%. Calculated MS m / z: 370.07; Experimental value: 371.1 [M+H] + 。

[0229] Step 5: Preparation of tert-butyl 3-(5-((2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamido)-1-oxoisoindolin-2-yl)azetidine-1-carboxylate

[0230] At 0 °C, (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid (0.1 g, 0.3 mmol) was dissolved in DMF (50 mL). 4-Amino-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Intermediate C, 0.11 g, 0.45 mmol), DIPEA (0.10 g, 0.9 mmol), and HATU (0.16 g, 0.45 mmol) were added respectively. The reaction mixture was brought to room temperature and stirred overnight. The reaction system was diluted with ethyl acetate and then washed with saturated brine. The organic layer was dried, concentrated under reduced pressure, and purified by column chromatography to obtain 0.04 g of white solid (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methylthio)phenyl)-4,5-dimethyl-N-(7-oxo-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-4-yl)-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide, with a yield of 29.6%. MS m / z calculated value: 501.47; experimental value: 502.4 [M+H] + 。

[0231] 1 1H NMR (400 MHz, DMSO-d6) δ 10.35 (s, 1H), 8.90 (s, 1H), 8.53 (d, J = 5.4 Hz, 1H), 7.92 (d, J = 5.4 Hz, 1H), 7.18 (q, J = 3.3, 2.8 Hz, 2H), 5.28 (d, J = 10.2 Hz, 1H), 4.35 (d, J = 8.0 Hz, 2H), 3.93 (d, J = 2.1 Hz, 1H), 2.48 (d, J = 2.2 Hz, 3H), 1.99 (s, 1H), 1.61 (s, 3H), 0.77–0.71 (m, 3H).

[0232] Example 14: Preparation of Compound P-14:

[0233]

[0234] The preparation method was similar to that of Example 7, except that tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with an equimolar amount of 3-aminooxetane and step 5) was not performed, to obtain 0.15 g of a white solid compound with a yield of 0.1%.

[0235] 11H NMR (400 MHz, DMSO-d6) δ 10.77 (s, 1H), 8.60 (d, J = 5.4 Hz, 1H), 7.96 (d, J = 5.6 Hz, 1H), 7.22–7.14 (m, 2H), 5.40 (d, J = 10.4 Hz, 1H), 4.64 (s, 1H), 4.46 (m, 2H), 4.28 (d, J = 12.1 Hz, 1H), 3.96 (m, 2H), 3.85 (s, 3H), 3.73–3.43 (m, 2H), 2.70–2.53 (m, 1H), 1.60 (d, J = 23.5 Hz, 3H), 0.80 (d, J = 7.3 Hz, 3H).

[0236] Example 15: Preparation of Compound P-15:

[0237]

[0238] The preparation method was similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with an equimolar amount of 2-(tert-butyldimethylsilyloxy)ethylamine, and 0.10 g of a white solid compound was obtained with a yield of 79.4%.

[0239] 1 1H NMR (400 MHz, DMSO-d6) δ 10.80 (s, 1H), 8.62 (d, J = 5.5 Hz, 1H), 8.07 (d, J = 5.6 Hz, 1H), 7.54 - 7.16 (m, 2H), 5.53 (d, J = 10.3 Hz, 1H), 4.80 (t, J = 5.9 Hz, 1H), 4.66–4.54 (m, 2H), 4.29 (dd, J = 10.4, 7.4 Hz, 1H), 3.98 (d, J = 2.0 Hz, 3H), 3.64 - 3.49 (m, 4H), 2.79 (t, J = 7.4 Hz, 1H), 1.60 (s, 3H), 0.80–0.72 (m, 3H).

[0240] Example 16: Preparation of Compound P-16:

[0241]

[0242] The preparation method was similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) was replaced with an equimolar amount of 2-((tert-butyldimethylsilyloxy)-2-methylaziridine, and 0.14 g of a white solid compound was obtained with a yield of 82.3%.

[0243] 11H NMR (400 MHz, DMSO-d6) δ 10.95 (s, 1H), 8.65 (d, J = 5.6 Hz, 1H), 8.01 (d, J = 5.6 Hz, 1H), 7.48 (ddd, J = 8.5, 5.8, 1.9 Hz, 1H), 7.27–7.16 (m, 1H), 5.44 (d, J = 10.4 Hz, 1H), 4.76 (t, J = 5.7 Hz, 1H), 4.54 (d, J = 7.1 Hz, 2H), 4.27 (dd, J = 10.2, 7.4 Hz, 1H), 3.98 (d, J = 2.1 Hz, 3H), 3.54 (s, 2H), 2.79 (t, J = 7.4 Hz, 1H), 1.61 (s, 3H), 1.18 (s, 6H), 0.80 (m, 3H).

[0244] Example 17: Preparation of Compound P-17:

[0245]

[0246] This preparation method is similar to that of Example 7, except that: tert-butyl 3-aminoazetidine-1-carboxylate in step 3) is replaced with tert-butyl N-methyl-N-(trans-3-aminocyclobutyl)carbamate, and 0.16 g of a white solid compound is obtained, with a yield of 85.4%.

[0247] 1 1H NMR (400 MHz, DMSO) δ 10.87 (s, 1H), 9.29 (s, 2H), 8.60 (d, J = 5.5 Hz, 1H), 8.05 (d, J = 5.5 Hz, 1H), 7.32 (t, J = 7.5 Hz, 1H), 5.45 (d, J = 10.3 Hz, 1H), 5.08 (p, J = 8.0 Hz, 1H), 4.76–4.60 (m, 2H), 4.29 (dd, J = 10.4, 7.4 Hz, 1H), 3.96 (d, J = 2.1 Hz, 3H), 3.76 (s, 1H), 2.80 (q, J = 7.5 Hz, 1H), 2.76–2.65 (m, 2H), 2.63–2.56 (m, 2H), 2.53 (t, J = 5.5 Hz, 3H), 1.61 (s, 3H), 0.75 (d, J = 5.5 Hz, 3H).

[0248] Example 18: Preparation of Compound P-18:

[0249]

[0250] This preparation method is similar to Example 7, except that: tert-butyl ((1R,2R)-2-aminocyclopropyl)carbamate is used to replace tert-butyl 3-aminoazetidine-1-carboxylate in step 3), and 0.03 g of a white solid compound is obtained with a yield of 23.0%.

[0251] 1 H NMR(400MHz,DMSO)δ11.07(s,1H),8.87–8.73(m,3H),8.59(d,J=5.4Hz,1H),7.99(d,J=5.2Hz,1H),7.40(d,J=9.5Hz,1H),7.19(d,J=9.2Hz,1H),5.52(d,J=10.4Hz,1H),4.52(s,2H),4.32–4.22(m,1H),3.96(s,3H),2.99(s,1H),2.82–2.73(m,1H),2.09(s,1H),1.61(s,3H),0.85(d,J=9.1Hz,2H),0.75(d,J=7.3Hz,3H).

[0252] Comparative Example 1

[0253]

[0254] The preparation method of Comparative Example 1 is similar to Example 1, except that: 4-aminoisoindol-1-one in an equimolar amount is used to replace 4-amino-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one in step 7), and 0.04 g of a white solid compound is obtained with a yield of 30.0%.

[0255] 1 H NMR(400MHz,DMSO-d6)δ10.04(s,1H),8.55(s,1H),7.76(d,J=7.4Hz,1H),7.53–7.42(m,2H),7.20(t,J=8.1Hz,2H),5.19(d,J=10.4Hz,1H),4.20(s,2H),3.95(d,J=2.7Hz,3H),2.75(q,J=7.4Hz,1H),1.62(s,3H),1.23(s,1H),0.74(d,J=7.3Hz,3H).

[0256] Preparation of Intermediate A

[0257] The synthetic route of Intermediate A is as follows:

[0258]

[0259] Step 1: Preparation of Ethyl 2-(3,4-difluoro-2-methoxyphenyl)acetate

[0260] Ethyl 2-bromoacetate (23.12 g, 127.7 mmol), potassium carbonate (44.12 g, 319.2 mmol), tetrakis(triphenylphosphine)palladium(0) (0.26 g, 0.2 mmol), and copper(I) oxide (0.46 g, 3.2 mmol) were added to a reaction tube. The tube was purged with nitrogen three times, and then a toluene solution containing (3,4-difluoro-2-methoxyphenyl)boronic acid (20.00 g, 106.4 mmol) was added. The reaction was carried out overnight at 100 °C, and the completion of the reaction was monitored by TLC. The reaction was cooled to room temperature, and the reaction mixture was diluted with ethyl acetate solution. The mixture was washed with saturated brine 2 - 3 times, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 18.49 g of ethyl 2-(3,4-difluoro-2-methoxyphenyl)acetate with a yield of 75.5%. MS m / z calculated value: 230.07; experimental value: 231.1 [M+H] + 。

[0261] Step 2: Preparation of 2-(3,4-difluoro-2-methoxyphenyl)acetic Acid

[0262] At room temperature, lithium aluminum hydride (2.08 g, 52.2 mmol) was added to a solution of ethyl 2-(3,4-difluoro-2-methoxyphenyl)acetate (4.00 g, 17.4 mmol) in THF (50 mL). Then the temperature was raised to 50 °C and monitored until the reaction was completed. Hydrochloric acid solution (1 M) was added to the reaction mixture to adjust the pH = 2, and the mixture was extracted with ethyl acetate 2 - 3 times. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 3.54 g of crude product of 2-(3,4-difluoro-2-methoxyphenyl)acetic acid as a white solid with a yield of 99.6%. MS m / z calculated value: 202.04; experimental value: 203.2 [M+H] + 。

[0263] Preparation of Intermediate B

[0264] The synthetic route of Intermediate B is as follows:

[0265]

[0266] Step 1: Preparation of (R)-4,4,4-Trifluoro-3-hydroxy-3-methylbutan-2-one

[0267] (R)-3,3,3-Trifluoro-2-hydroxy-2-methylpropanoic acid (50.00 g, 316.3 mmol) and diethyl ether (10 L) were charged into a dry reaction flask under nitrogen. Under an ice bath, methyllithium lithium bromide complex (27.54 g, 253.04 mmol) was slowly added, and then the reaction mixture was stirred overnight at room temperature. The mixture was neutralized by adding citric acid (121.53 g, 632.6 mmol) and stirred for 30 minutes. The aqueous phase was separated and extracted with diethyl ether 2 - 3 times. The combined organic phases were distilled under reduced pressure (200 mbar, 70 °C). The distillate was a colorless oil. By adding solid potassium carbonate pellets, the product was dried and allowed to stand for 6 hours and then filtered through a glass filter to obtain 32.24 g of the colorless oil compound (R)-4,4,4-trifluoro-3-hydroxy-3-methylbutan-2-one, with a yield of 65.3%. MS m / z calculated value: 156.03; experimental value: 157.1 [M+H] + 。

[0268] Preparation of Intermediate C

[0269] The synthetic route of Intermediate C is as follows:

[0270]

[0271] In this reaction route, Boc- represents tert-butoxycarbonyl and PMB- represents p-methoxybenzyl.

[0272] Step 1: Preparation of methyl 4-bromo-3-methylpyridine-2-carboxylate

[0273] 4-Bromo-3-methylpyridine-2-carboxylic acid (5.00 g, 23.2 mmol), iodomethane (6.50 g, 46.5 mmol), potassium carbonate (9.50 g, 69.7 mmol), and N,N-dimethylformamide (250 mL) were added to a 500 mL round-bottom flask. The resulting solution was heated to 80 °C and reacted overnight. The reaction was monitored by TLC until completion. The reaction system was transferred to a separatory funnel, ethyl acetate (500 mL) was added, and it was washed three times with saturated brine (500 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by column chromatography to obtain 4.56 g of a pale yellow oily product, with a yield of 85.8%. MS m / z calculated value: 228.97; experimental value: 230.9 [M+H] + 。

[0274] Step 2: Preparation of 4-bromo-3-(bromomethyl)pyridine-2-carboxylic acid

[0275] Methyl 4-bromo-3-methylpicolinate (4.56 g, 19.9 mmol), N-bromophthalimide (4.80 g, 29.8 mmol), 2,2'-azobis(2-methylpropionitrile) (0.30 g, 2.0 mmol), and carbon tetrachloride (150 mL) were added to a 500 mL round-bottom flask. The mixture was heated to 80 °C and stirred overnight. The reaction was monitored by TLC until completion. The reaction mixture was transferred to a beaker, and saturated sodium sulfite solution (100 mL) was added and stirred for 1 hour. The reaction mixture was transferred to a separatory funnel, and dichloromethane (200 mL) was added. The organic layer was washed with saturated brine (500 mL) three times. The organic phase was concentrated under reduced pressure, and the residue was purified by column chromatography to obtain 5.15 g of the target compound as a yellow oil, with a yield of 86.9%. MS m / z calculated value: 294.86; experimental value: 295.7 [M+H] + 。

[0276] Step 3: Preparation of 4-bromo-6-(4-methoxybenzyl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one

[0277] 4-Bromo-3-(bromomethyl)picolonic acid (5.06 g, 17.3 mmol) and tetrahydrofuran (200 mL) were added to a 500 mL round-bottom flask. Then, 4-methoxybenzylamine (3.55 g, 26.6 mmol) was added to the system. The temperature was raised to 80 °C and stirred for 3 hours. The reaction was monitored by TLC until completion. The reaction mixture was concentrated under reduced pressure to obtain a crude product, which was triturated with n-hexane to obtain 4.14 g of the target compound as an off-white solid, with a yield of 72.2%. MS m / z calculated value: 332.01; experimental value: 334.1 [M+H] + 。

[0278] Step 4: Preparation of tert-butyl (6-(4-methoxybenzyl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)carbamate

[0279] 4-Bromo-6-(4-methoxybenzyl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (4.14 g, 12.5 mmol), tert-butoxycarbonylamine (2.20 g, 18.70 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.14 g, 1.2 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (1.44 g, 2.5 mmol), and cesium carbonate (6.09 g, 18.7 mmol) were added to a 500 mL three-necked flask. After the addition was complete, the flask was purged with argon three times, and then toluene (200 mL) was added. The reaction mixture was heated to 100 °C and stirred overnight. After monitoring the reaction by TLC and confirming its completion, the reaction mixture was filtered under reduced pressure. The filter cake was washed with ethyl acetate, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography to afford 1.88 g of a yellow oil, with a yield of 41.2%. MS m / z calculated value: 369.16; experimental value: 370.1 [M+H]. + Step 5: Preparation of tert-butyl (7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)carbamate

[0280] tert-Butyl (6-(4-methoxybenzyl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)carbamate (1.88 g, 5.1 mmol) was added to a 250 mL round-bottom flask, and the mixture was stirred at room temperature in acetonitrile (100 mL). Cerium(IV) ammonium nitrate (8.12 g, 20.5 mmol) was dissolved in water (50 mL), and the resulting solution was added to the reaction mixture at room temperature. The reaction mixture was stirred overnight. After monitoring the reaction by TLC and confirming its completion, the reaction mixture was transferred to a 1000 mL beaker, and saturated sodium bicarbonate solution (200 mL) was added. The mixture was filtered under reduced pressure. The filtrate was extracted with dichloromethane (500 mL) three times. The organic phase was washed with saturated brine (300 mL) three times, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford 0.92 g of a yellow crude product, with a yield of 41.5%. MS m / z calculated value: 249.11; experimental value: 250.3 [M+H]. + Step 6: Preparation of 4-amino-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one

[0281] tert-Butyl (7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-4-yl)carbamate (0.92 g, 3.7 mmol) was added to a 100 mL round-bottom flask, and ethanolic hydrochloric acid solution (40 mL) was added. The mixture was stirred at room temperature for 2 h. After monitoring the reaction by TLC and confirming its completion, the reaction mixture was concentrated under reduced pressure. The resulting crude product was triturated with dichloromethane to afford 0.61 g of a pale yellow solid compound, with a yield of 65.1%.

[0282] 11H NMR (400 MHz, DMSO-d6) δ 9.50 (s, 1H), 8.63 (s, 2H), 8.20 (d, J = 6.9 Hz, 1H), 6.95 (dd, J = 6.8, 1.5 Hz, 1H), 4.35 (s, 2H).

[0283] Preparation of Intermediate D

[0284] The synthetic route of Intermediate D is as follows:

[0285]

[0286] Step 1: Preparation of Ethyl 2-(3-fluoro-2,4-dimethoxyphenyl)acetate

[0287] Ethyl 2-bromoacetate (21.72 g, 120.0 mmol), potassium carbonate (41.46 g, 300.0 mmol), tetrakis(triphenylphosphine)palladium(0) (0.12 g, 0.1 mmol), and copper(I) oxide (0.43 g, 3.0 mmol) were added to a reaction tube. The tube was purged with nitrogen three times, and then a toluene solution containing (3-fluoro-2,4-dimethoxyphenyl)boronic acid (20.00 g, 100.0 mmol) was added. The reaction was carried out at 100 °C overnight, and the reaction completion was monitored by TLC. The reaction was cooled to room temperature, and the reaction mixture was diluted with ethyl acetate. The mixture was washed with saturated brine 2 - 3 times, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 15.58 g of ethyl 2-(3-fluoro-2,4-dimethoxyphenyl)acetate with a yield of 64.3%. MS m / z calculated value: 242.09; experimental value: 243.1 [M + H]. + 。

[0288] Step 2: Preparation of 2-(3-fluoro-2,4-dimethoxyphenyl)acetic acid

[0289] At room temperature, lithium aluminum hydride (2.34 g, 61.8 mmol) was added to a solution of ethyl 2-(3-fluoro-2,4-dimethoxyphenyl)acetate (5.00 g, 20.6 mmol) in THF (50 mL). Subsequently, the temperature was raised to 50 °C, and the reaction was monitored until completion. Hydrochloric acid solution (1 M) was added to the reaction mixture to adjust the pH to acidic, and the mixture was extracted with ethyl acetate 2 - 3 times. The combined organic phases were washed with saturated brine and dried over anhydrous sodium sulfate. After concentration under reduced pressure, 4.05 g of crude product of 2-(3-fluoro-2,4-dimethoxyphenyl)acetic acid as a white solid was obtained with a yield of 91.8%. MS m / z calculated value: 214.06; experimental value: 215.0 [M + H]. + 。

[0290] Preparation of Intermediate E

[0291] The synthetic route of intermediate E is as follows:

[0292]

[0293] Step 1: Preparation of ethyl 2-diazo-3-oxopentanoate

[0294] Dissolve ethyl propionylacetate (28.8 g, 200 mmol) in dichloromethane (250 mL) solution. Replace the gas with nitrogen three times. Cool the reaction solution to 0 °C. Add TEA (60.6 g, 600 mmol) to it. Stir at 0 °C for 5 minutes. Add 4-methylbenzenesulfonyl azide (47.3 g, 240 mmol). Slowly return to room temperature and stir for 6 h. Quench the reaction with water (300 mL), dichloromethane (1000 mL). Combine the organic phases, wash with saturated brine, dry over anhydrous sodium sulfate, concentrate under reduced pressure, and purify by column chromatography to obtain 17.3 g of ethyl 2-diazo-3-oxopentanoate as a colorless oily compound, with a yield of 51%. MS m / z calculated value: 170.17; experimental value: 171.1 [M+H] + .

[0295] Step 2: Preparation of ethyl (Z)-2-diazo-3-((trimethylsilyl)oxy)penta-3-enoate

[0296] Dissolve ethyl 2-diazo-3-oxopentanoate (60.0 g, 353 mmol) in dichloromethane (720 mL). Cool the temperature to -10 °C - 0 °C. Add TEA (57.0 g, 79.4 mL, 564 mmol). Slowly add trimethylsilyl trifluoromethanesulfonate TMSOTf (102.0 g, 82.8 mL, 458 mmol), and stir the reaction mixture at 0 °C for 60 minutes. Detect by TLC that the reaction is basically complete. Wash the reaction mixture with saturated sodium bicarbonate solution (1000 mL), separate the organic layer, wash with water (500 mL), dry over anhydrous sodium sulfate, filter and concentrate in vacuo to obtain 72 g of crude ethyl (Z)-2-diazo-3-((trimethylsilyl)oxy)penta-3-enoate, with a yield of 67%. Without further purification, directly use it in the next step of the reaction.

[0297] Step 3: Preparation of ethyl rac-(4R,5R)-2-diazo-6,6,6-trifluoro-5-hydroxy-4,5-dimethyl-3-oxohexanoate

[0298] A solution of trifluoroacetone (47.0 g, 37.5 mL, 416 mmol) in dichloromethane (300 mL) was cooled to -78 °C. A solution of titanium tetrachloride (78.9 g, 416 mmol) in dichloromethane (340 mL) was added dropwise to the stirred reaction mixture. The reaction solution was stirred at -78 °C for 10 minutes, and then a solution of ethyl (Z)-2-diazo-3-((trimethylsilyl)oxy)pent-3-enoate (72.0 g, 297 mmol) in dichloromethane (300 mL) was added dropwise. The reaction solution was stirred at -78 °C for 2 hours. Saturated aqueous sodium bicarbonate solution (1000 mL) was added, and the aqueous phase was extracted with dichloromethane (300 mL x 2). The organic layer was separated, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 51 g of pale yellow liquid ethyl rac-(4R,5R)-2-diazo-6,6,6-trifluoro-5-hydroxy-4,5-dimethyl-3-oxohexanoate, with a yield of 57.6%. MS m / z calculated value: 282.08; experimental value: 283.1 [M+H] + .

[0299] Step 4: Preparation of ethyl rac-(4R,5R)-4,5-dimethyl-3-oxo-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate

[0300] Ethyl rac-(4R,5R)-2-diazo-6,6,6-trifluoro-5-hydroxy-4,5-dimethyl-3-oxohexanoate (20.0 g, 70.9 mmol, 1.00 eq) was dissolved in toluene (100 mL), and rhodium(II) acetate dimer (470 mg, 1.06 mmol, 0.015 eq) was added. The reaction mixture was stirred at 100 °C for 2 hours. The solvent in the mixture was removed under vacuum to obtain 18.0 g of crude product ethyl rac-(4R,5R)-4,5-dimethyl-3-oxo-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate as a green oil, which was directly used in the next step.

[0301] Step 5: Preparation of ethyl rac-(4R,5R)-4,5-dimethyl-5-(trifluoromethyl)-3-(((trifluoromethyl)sulfonyl)oxy)-4,5-dihydrofuran-2-carboxylate

[0302] Ethyl rac-(4R,5R)-4,5-dimethyl-3-oxo-5-(trifluoromethyl)tetrahydrofuran-2-carboxylate (18.0 g crude, 70.5 mmol) was dissolved in anhydrous dichloromethane (200 mL). The reaction solution was purged with nitrogen three times and cooled to -78 °C. Diisopropylethylamine (10.9 g, 84.6 mmol) and a solution of trifluoromethanesulfonic anhydride (23.9 g, 84.6 mmol) in anhydrous dichloromethane (50 mL) were added thereto, and the mixture was stirred at this temperature for 1 hour. The reaction was gradually warmed to 0 °C and stirred for 0.5 hour. The reaction was quenched with saturated sodium bicarbonate solution (100 mL), and the mixture was extracted with dichloromethane (150 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 15 g of ethyl rac-(4R,5R)-4,5-dimethyl-5-(trifluoromethyl)-3-(((trifluoromethyl)sulfonyl)oxy)-4,5-dihydrofuran-2-carboxylate as a colorless oil, with a yield of 54.6%. MS m / z calculated value: 386.03; experimental value: 387.1 [M+H] + 。

[0303] Preparation of Intermediate F

[0304] The synthetic route of Intermediate F is as follows:

[0305]

[0306] Step 1: Preparation of (6-bromo-2,3-difluorophenyl)(methyl)sulfane

[0307] 4-Bromo-1,2-difluorobenzene (20 g, 103.6 mmol) was dissolved in tetrahydrofuran (200 mL). The reaction solution was purged with nitrogen three times and cooled to -78 °C. LDA (62 mL, 124 mmol, 2 M) was added thereto, and the mixture was stirred at this temperature for half an hour. Dimethyldisulfide (11.7 g, 124 mmol) was added. The reaction was gradually warmed to room temperature and stirred for 2.5 hours. The reaction was quenched with saturated ammonium chloride solution (400 mL), and the mixture was extracted with ethyl acetate (150 mL × 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 12 g of (6-bromo-2,3-difluorophenyl)(methyl)sulfane as a colorless oil, with a yield of 46%. MS m / z calculated value: 239.92; experimental value: 238.9 [M-H] - 。

[0308] Step 2: Preparation of (3,4-difluoro-2-(methylthio)phenyl)boronic acid

[0309] (6-Bromo-2,3-difluorophenyl)(methyl)sulfane (12 g, 50.2 mmol) was dissolved in tetrahydrofuran (120 mL) solution. After purging with nitrogen three times, the reaction solution was cooled to 0 °C, and i-PrMgBr·LiCl (30.1 mL, 60.2 mmol, 2 M) was added thereto. The mixture was stirred at 0 °C for half an hour, then triisopropyl borate (18.88 g, 100.4 mmol) was added, and the mixture was stirred at 0 °C for 2.5 hours. The reaction was quenched with saturated ammonium chloride solution (300 mL), and the mixture was extracted with ethyl acetate (100 mL × 3). The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by column chromatography to obtain 8 g of (3,4-difluoro-2-(methylthio)phenyl)boronic acid as a colorless oily compound, with a yield of 52%. MS m / z calculated value: 204.02; experimental value: 203.0 [M-H] - 。

[0310] Biological part test:

[0311] Test Example 1: Blocking activity of the compound of the present invention against sodium channel 1.8 (Nav1.8)

[0312] 1. Detection method: The whole-cell manual patch-clamp technique was used to detect the effect of the compound on the voltage-gated Nav1.8 channel current

[0313] 2. Preparation and analysis of the test compound

[0314] Blank control: An appropriate amount of DMSO was added to the extracellular fluid to obtain an extracellular fluid containing 0.1% DMSO as the blank control working solution

[0315] Test compound: An appropriate amount of the test substance was weighed and dissolved in DMSO to obtain a stock solution of the test compound, and then further diluted with extracellular fluid to working solutions of the test compound with final concentrations of 10 nM, 50 nM, 0.1 μM, 1 μM, and 10 μM (the DMSO concentration in the working solutions did not exceed 0.3%)

[0316] 3. Cell culture

[0317] The CHO cell line stably expressing Nav1.8 (gene information: SCN10A, NM_006514; SCN1B, NM_199037; SCN3B, NM_018400) was used. In a cell culture dish, cell culture and passage were carried out using HAM’S / F-12 medium (containing 10% fetal bovine serum, 10 μg / mL Blasticidin, 200 μg / mL Hygromycin B, and 100 μg / mL Zeocin). The temperature of the cell culture incubator was 37 °C, and the carbon dioxide concentration was 5%. To maintain the electrophysiological activity of the cells, the cell density in the culture dish should not exceed 80%

[0318] Before patch clamp detection, the cells were detached with 0.25%-Trypsin-EDTA, and 6.5×10 3 cells were seeded onto cover slips and cultured in 24-well plates (final volume: 500 μL). After adding tetracycline and inducing for 24 - 72 hours, the tests were conducted for detection.

[0319] 4. Electrophysiological experiments

[0320] (1) Liquids used in electrophysiological experiments

[0321] Extracellular solution: 140 mM NaCl, 3.5 mM KCl, 1 mM MgCl₂·6H₂O, 2 mM CaCl₂·2H₂O, 10 mM D-Glucose, 10 mM HEPES, 1.25 mM NaH₂PO₄·2H₂O, pH was adjusted to 7.4 with NaOH.

[0322] Intracellular solution: 50 mM CsCl, 10 mM NaCl, 10 mM HEPES, 60 mM CsF, 20 mM EGTA, pH was adjusted to 7.2 with CsOH.

[0323] (2) Patch clamp detection

[0324] The voltage stimulation protocol for whole-cell patch clamp recording of sodium current was as follows: After forming a whole-cell seal, the cell voltage was clamped at -120 mV. First, the voltage was stepped from -130 mV to -10 mV in 10-mV increments and maintained for 5 s, and then a 0-mV depolarizing pulse was given to obtain the half-inactivation voltage (Vhalf). The resting state and half-inactivated state of sodium current were detected using a double-pulse mode. First, a first depolarizing pulse (TP1) was given to 0 mV for 50 ms to detect the sodium current in the resting state. Then the voltage was adjusted to Vhalf and maintained for 5 s, then the voltage was restored to -120 mV and maintained for 20 ms, and then a second depolarizing pulse (TP2) was given to 0 mV for 50 ms to detect the sodium current in the half-inactivated state. Finally, it was restored to the clamped voltage of -120 mV. Data were collected every 20 s, and the effects of the drug on the peak sodium current values in the two different states were observed. The experimental data were collected by an EPC 10 amplifier (HEKA) and stored in the PatchMaster (HEKA) software.

[0325] For patch clamp operation, a glass capillary is first pulled into a recording electrode using a microelectrode puller. Then, the electrode filled with intracellular fluid is inserted into a microelectrode holder. Under an inverted microscope, the microelectrode manipulator is used to immerse the electrode in the extracellular fluid and record the electrode resistance (Rpip). Subsequently, the electrode is slowly brought into contact with the cell surface, and negative pressure aspiration is applied to form a GΩ high-resistance seal. At this time, fast capacitance compensation is performed, and negative pressure is continuously applied to rupture the cell membrane to form the whole-cell recording mode. Finally, slow capacitance compensation is carried out, and experimental parameters such as the series resistance (Rs) are recorded. Leakage compensation is not given.

[0326] After the sodium current in the whole-cell recording is stable, drug administration is initiated. Each drug concentration is allowed to act for 5 min (or until the current stabilizes), after which the next concentration is tested. The coverslip with cells is placed in a recording bath under an inverted microscope. The blank control extracellular solution and the working solution of the compound to be tested are perfused onto the cells in order of increasing concentration from low to high by gravity perfusion, and a peristaltic pump is used for liquid replacement during the recording. The current detected for each cell in the extracellular solution without the compound serves as its own control group. Each concentration is independently repeated and tested at least twice using two cells. All electrophysiological experiments are conducted at room temperature.

[0327] 5. Data analysis

[0328] First, the peak sodium current (Peak current compound ) after the action of each drug concentration and the peak current of the blank control (Peak current control ) are normalized. Then, the inhibition rate corresponding to each drug concentration in different states is calculated. And the average value of the inhibition rate for each concentration is taken.

[0329] The dose-effect curve is fitted using the Hill equation: Y = Bottom + (Top - Bottom) / (1 + 10^((LogIC 50 - X)*HillSlope)), where Bottom and Top represent the minimum and maximum values of inhibition, respectively, X represents the logarithm of the compound concentration, Y represents the Peak-current compound / Peak-current Control value, IC 50 represents the drug concentration that produces a 50% inhibitory effect, and HillSlope represents the Hill coefficient.

[0330] The percentage blockage activity results and the activity IC 50The values are shown in Table 1-3. TP1 is the Resting state and TP2 is the Half-inactivated state.

[0331] Table 1 Percentage blockage activities of some compounds of the present invention on Nav1.8 channels at a concentration of 100 nM

[0332]

[0333] The inhibition rates of P-1, P-3, P-4, P-5, P-6, P-7, P-8, P-9, P-10, P-11, P-12, P-13, P-17, P-18 on TP1 and TP2 at a concentration of 100 nM are > 50%.

[0334] Table 2 Percentage blockage activities of some compounds of the present invention on Nav1.8 channels at a concentration of 10 nM

[0335]

[0336] The inhibition rates of P-1, P-4, P-5, P-7, P-8, P-9, P-10, P-11 on TP1 and TP2 at a concentration of 10 nM are > 50%.

[0337] Table 3 Activity IC of representative compounds on Nav1.8 channels 50 Value (nM)

[0338]

[0339] Test Example 2 hERG Activity Test:

[0340] 1. Sample Preparation

[0341] Preparation of blank control: An appropriate amount of DMSO was added to the extracellular fluid to obtain an extracellular fluid containing 0.3% DMSO as the working solution of the blank control.

[0342] Preparation of positive control: An appropriate amount of Cisapride was weighed and dissolved in an appropriate amount of dimethyl sulfoxide (DMSO), and then diluted with extracellular fluid to prepare working solutions with concentrations of 1000 nM, 100 nM, 10 nM, 1 nM, and 0.1 nM (ensuring that the DMSO concentration was 0.3%).

[0343] Preparation of test substance: An appropriate mass of the test substance was weighed and dissolved in an appropriate amount of DMSO, and then diluted with extracellular fluid to prepare test substance working solutions with concentrations of 30 μM, 10 μM, 3 μM, 1 μM, and 0.3 μM, ensuring that the DMSO concentration in each working solution was 0.3%.

[0344] 2. Cell Culture

[0345] Using the HEK-293 cell line stably expressing the hERG potassium channel, the hERG potassium channel cells were purchased from Creacell (product number: A-0320). In the cell culture dish, they were cultured and passaged using DMEM medium containing 10% fetal bovine serum and 0.8 mg / mL G418. The temperature of the cell culture incubator was 37°C and the carbon dioxide concentration was 5%. To maintain the electrophysiological activity of the cells, the cell density must not exceed 80%.

[0346] Before patch clamp detection, the cells were separated with TrypLE TM Express, and 4×10 3 cells were plated onto cover slips and cultured in 24-well plates (final volume: 500 μL). After 18 hours, the tests were performed.

[0347] 3. Electrophysiological recording

[0348] Extracellular solution: K-007-1, 140 mM NaCl, 3.5 mM KCl, 1 mM MgCl2·6H2O, 2 mM CaCl2·2H2O, 10 mM D-Glucose, 10 mM HEPES, 1.25 mM NaH2PO4·2H2O, pH adjusted to 7.4 with NaOH.

[0349] Intracellular solution: K-002-2, 20 mM KCl, 115 mM K-Aspartic, 1 mM MgCl2·6H2O, 5 mM EGTA, 10 mM HEPES, 2 mM Na2-ATP, pH adjusted to 7.2 with KOH.

[0350] Patch clamp detection: The voltage stimulation protocol for recording hERG current by whole-cell patch clamp was as follows: When a whole-cell seal was formed, the cell membrane voltage was clamped at -80 mV. The clamped voltage was depolarized from -80 mV to -50 mV and maintained for 0.5 s (as leakage current detection), then stepped to 30 mV and maintained for 2.5 s, and then quickly restored to -50 mV and maintained for 4 s to elicit the tail current of the hERG channel. Data were collected every 10 s to observe the effect of the drug on the hERG tail current. The -50 mV stimulation for 0.5 s was used as leakage current detection. The experimental data were collected by an IPA amplifier (Sutter Instrument) and stored in the SutterPatch (with IgorPro) software.

[0351] Patch clamp operation: First, a glass capillary is pulled into a recording electrode using a microelectrode puller. Then, the electrode filled with intracellular solution is inserted into a microelectrode holder. Under an inverted microscope, the microelectrode manipulator is used to immerse the electrode into the extracellular solution and record the electrode resistance (Rpip). Next, the electrode is slowly brought into contact with the cell surface, and negative pressure aspiration is applied to form a GΩ high-resistance seal. At this time, fast capacitance compensation is performed, and negative pressure is continuously applied to rupture the cell membrane to form the whole-cell recording mode. Finally, slow capacitance compensation is carried out and experimental parameters such as series resistance (Rs) are recorded. Leakage compensation is not given.

[0352] After the hERG current in the whole-cell recording is stable, drug administration is started. Each drug concentration is allowed to act for 5 min (or until the current is stable), and then the next concentration is tested. Multiple concentrations are tested for each test compound. The coverslip with cells is placed in a recording bath under an inverted microscope. The blank control extracellular solution and the working solution of the test compound are perfused through the recording bath from low concentration to high concentration in sequence by gravity perfusion to act on the cells, and a peristaltic pump is used for liquid exchange during recording. The current detected in the extracellular solution without the compound for each cell is used as its own control group. Each concentration is independently repeated and tested at least three times using at least three cells. All electrophysiological experiments are carried out at room temperature.

[0353] 4. Data analysis

[0354] First, the tail current (Peak tail current compound ) after the action of each drug concentration and the blank control tail current (Peak tail current control ) are normalized, and then the inhibition rate corresponding to each drug concentration is calculated and the average value of the inhibition rate for each concentration is calculated.

[0355] The dose-effect curve is fitted using the Hill equation: Y = Bottom + (Top - Bottom) / (1 + 10^((LogIC 50 - X)*HillSlope)), where Bottom and Top represent the minimum and maximum values of inhibition respectively, X represents the logarithm of the compound concentration, Y represents the value of Peak tail current compound / Peak tail current Control , IC 50 represents the drug concentration that produces a half-maximal inhibitory effect, and HillSlope represents the Hill coefficient.

[0356] Table 4 Inhibitory activities of representative compounds on hERG

[0357] Compound number <![CDATA[hERG, IC 50 > P-1 >10 μM

[0358] Results show that the compound of the present invention has very weak inhibitory activity against hERG (potassium ion channel) and exhibits high ion channel selectivity.

[0359] Test Example 3 Liver microsome metabolic stability test:

[0360] 1. Sample preparation

[0361] Working solutions of the test compound and the positive control compound: The test compound and the positive control compound (dextromethorphan) were separately dissolved in DMSO to prepare 1 mM intermediate working solutions. Subsequently, the intermediate working solutions were diluted with acetonitrile (ACN) to 200 μM working solutions.

[0362] Phosphate buffer solution: Dissolve 8.709 g of dipotassium hydrogen phosphate (K2HPO4) in 950 mL of water, adjust the pH value of the solution to 7.4 with hydrochloric acid, and then add water to a final volume of 1000 mL. After filtering through a 0.22 μm filter membrane, store it in a refrigerator at 4 °C for later use.

[0363] Incubation matrix working solution: Liver microsomes of various species (protein concentration 20 mg / mL) were melted in a 37 °C water bath and then diluted with phosphate buffer solution to obtain liver microsome working solutions with a protein concentration of 0.629 mg / mL.

[0364] NADPH working solution: Prepare a 5 mM NADPH solution with the above phosphate buffer solution for later use.

[0365] Reaction termination solution: Prepare a stock solution of 1 mg / mL terfenadine / tolbutamide in DMSO, and then dilute it with a mixed solution of 50% methanol / 50% acetonitrile to obtain a reaction termination solution containing 5 / 10 ng / mL (terfenadine / tolbutamide) internal standard.

[0366] 2. Incubation and detection

[0367] Take 238.5 μL of liver microsome working solutions of different species and add them to 1.1 mL microtubes. Then add 1.5 μL of the test compound working solution or the positive control compound (dextromethorphan) working solution (200 μM). After mixing, pre-incubate in a 37 °C water bath for 5 min. Add 60 μL of NADPH solution to start the reaction. After thorough mixing, at the 0, 5, 15, 30, and 60 minute time points after the reaction, respectively transfer 30 μL of the reaction solution into 300 μL of the reaction termination solution. Vortex all the samples vigorously for 1 minute and then centrifuge at 4000 rpm at 4 °C for 15 minutes. Take the supernatant for LC-MS / MS analysis.

[0368] 3. Data analysis

[0369] The slope (ke) was measured by plotting the natural logarithm of the percentage of the remaining compound against time, and T was calculated according to the first-order kinetic formula 1 / 2 and the intrinsic clearance (CL int ):

[0370] The remaining rate of the compound was calculated as follows:

[0371]

[0372] C t = C0 * e -ke*t

[0373] lnC t = lnC o – ke * t

[0374] According to the above formula, when , the following can be obtained

[0375] The intrinsic clearance CL int (μL / min / mg protein) = 0.693 * 1000 / T 1 / 2 / protein concentration (0.5 mg protein / mL)

[0376] C t = C0 × e -ke·t ,

[0377]

[0378]

[0379] It is assumed that the unbound fraction (Fu) in the liver microsome mixture is 100%.

[0380]

[0381] The following physiological variables were used for predictive calculations:

[0382]

[0383] The test results of liver microsome stability are shown in Table 5.

[0384] Table 5 Liver microsomal stability of representative compounds against Nav1.8 channels

[0385]

[0386] The results showed that the compounds of the present invention exhibited good metabolic stability in human and rat liver microsomes.

[0387] Test Example 4 CYP450 Enzyme Inhibition Test

[0388] An in vitro test system was applied to evaluate the effects of the test substance on the activities of five isozymes of cytochrome P450 (CYP) in human liver microsomes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A). The specific probe substrates of CYP450 isozymes were incubated with human liver microsomes and different concentrations of the test substance, respectively. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) was added to initiate the reaction. After the reaction ended, the samples were processed and the metabolites produced by the specific substrates were quantitatively detected by liquid chromatography-tandem mass spectrometry (LC-MS / MS) method to determine the changes in CYP enzyme activity and calculate the IC 50 value to evaluate the inhibitory ability of the test substance on each CYP enzyme subtype.

[0389] The specific results are shown in Table 6.

[0390] Table 6 Results of CYP450 Enzyme Inhibition Test

[0391]

[0392] Test Example 5 Solubility Test:

[0393] Method for determining solubility in pH 7.4 phosphate buffer: Excessive DMSO stock solutions of the test compounds were separately placed in pH 7.4 phosphate buffer, shaken at 25°C - 350 rpm for 4 h, sampled, filtered through a 0.22 μm filter membrane, and the concentration of the continued filtrate was determined. The results are shown in the following table:

[0394] Table 7 Solubility of Representative Compounds

[0395] Compound number Solubility, μM (pH = 7.4) P-1 105 P-4 51.3 P-5 40.8 P-7 252

[0396] The results showed that the representative compounds exhibited good solubility.

[0397] Test Example 6 Spinal Nerve Ligation (SNL)-induced Mouse Neuropathic Pain Model

[0398] Female SPF-grade C57BL / 6J mice were adaptively fed for one week and then the model was established. The specific establishment method is as follows:

[0399] 1. Spinal Nerve Ligation (SNL) Modeling

[0400] (1) Disinfect surgical instruments;

[0401] (2) The experimental animals were anesthetized with isoflurane through a small animal gas anesthesia machine and placed prone on the operating table. The hair at the lumbar hip bone was shaved and prepared for skin disinfection;

[0402] (3) After disinfection with iodophor, make an opening about 2 cm along the spine near the hip bone, separate the fascia and muscles, and expose the transverse process of L5;

[0403] (4) Carefully bite off the transverse process of L5 with forceps to expose the L5 nerve;

[0404] (5) Separate the L5 nerve with a glass microprobe and ligate the nerve with a 5-0 ligature;

[0405] (6) Suture the muscles and skin and disinfect.

[0406] (7) Observe the overall recovery of the mice after surgery, as well as the gait, spontaneous pain, and weight-bearing preference of the mice, and pay attention to whether the back skin of the mice heals well.

[0407] 2. Observation of general clinical symptoms

[0408] Observe the movement of the right hind limb of the mice during locomotion after modeling. The mice with successful modeling show abnormal gait, manifested as mostly dragging or limping of the right hind limb; spontaneous pain behavior, manifested as licking or stroking the affected limb; weight-bearing preference, manifested as the mice tend to avoid placing weight on the affected hind limb.

[0409] 3. Measurement of mechanical pain

[0410] Use the classic up-down test method to detect the mechanical paw withdrawal threshold of the mice. The determination of the 50% paw withdrawal threshold refers to the mechanical force at which multiple mechanical stimulations can cause a 50% paw withdrawal response. Place an acrylic box on a metal screen. After the mice adapt to the acrylic box for 30 minutes, vertically stimulate the middle of the plantar surface of the hind limb of the mice with a Von Frey filament for a duration ≤ 4 s. The mice showing paw lifting or licking behavior are regarded as positive responses, and vice versa as negative responses.

[0411] Start stimulating with a force of 0.4. If there is no foot withdrawal response, select a force of 0.6 above it to stimulate the hind toe; if there is a foot withdrawal response, select a force of 0.16 below it to stimulate, and so on. When there is a different response from the previous one, from foot withdrawal response to no foot withdrawal response or from no foot withdrawal response to foot withdrawal response, continue to stimulate sequentially 4 times, for a total of 6 times, that is, the determination of the 50% foot withdrawal threshold is completed. If the force required exceeds 2.0 or is lower than 0.02, the threshold of this side is directly recorded as 2.0 or 0.02, and the interval between each stimulation is 30 s. Try to keep the measurement methods consistent in the experiment, such as the force direction, the force application speed, and the degree of filament bending, maintain the stability of the force, the force removal speed, etc. In addition, try to keep the response judgment criteria for mice consistent. The 50% foot withdrawal threshold is calculated using the formula 50% foot withdrawal threshold = 10log(X) + κδ (X is the force used in the last stimulation; κ is the coefficient for different stimulation methods, found in the coefficient table; δ is the average of the adjacent intervals of each stimulation force, here δ = 0.224).

[0412] Measure and record the 50% foot withdrawal threshold at 0.5 h, 1 h, 3 h, 6 h, and 8 h after iv administration.

[0413] 4. Data analysis

[0414] All experimental data were analyzed using GraphPad Prism 9 and IBM SPSS Statistics 19 software. The data were expressed as mean ± standard deviation (x ± s). The independent samples t-test was used for comparison between groups. p < 0.05, p < 0.01, and p < 0.001 indicated that the differences were statistically significant.

[0415] 5. Conclusion

[0416] The compounds of the present invention, such as the compounds in the examples, have significant analgesic effects. For example, compounds P-1, P-4, P-5, P-7, P-9, and P-10 all have significant analgesic effects at the administration doses of 15 mg / kg or 45 mg / kg.

[0417] For each of the above examples, the number and the corresponding structural formula shall prevail, and they are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that: within the scope not departing from the spirit and essence defined by the claims of the present invention, the technical solutions described in the foregoing examples can be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements are still within the scope defined by the claims of the present invention.

Claims

1. Compounds of formula I: Its isomers, racemates, pharmaceutically acceptable salts or prodrugs, wherein: R1, R2, R3, R4, and R5 are independently selected from H, deuterium, halogen, hydroxyl, C 1-6 Alkyl, C 1-6 Alkoxy, -SC 1-6 Alkyl, C 1-6 Alkylamino, -S-halogenated C 1-6 Alkyl, deuterated C 1-6 Alkyl, deuterated C 1-6 Alkoxy, -S-deuterated C 1-6 Alkyl, C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, C 3-6 Cycloalkyloxy, halogenated C 1-6 Alkyl, halogenated C 1-6 Alkoxy, halogenated C 3-6 Cycloalkyl, halogenated 3-7 membered heterocycloalkyl, halogenated C 3-6 Cycloalkyloxy; wherein the C 1-6 Alkyl, C 1-6 Alkoxy, -SC 1-6 Alkyl, C 1-6 Alkylamino, -S-halogenated C 1-6 Alkyl, deuterated C 1-6 Alkyl, deuterated C 1-6 Alkoxy, -S-deuterated C 1-6 Alkyl, C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, C 3-6 Cycloalkyloxy, halogenated C 1-6 Alkyl, halogenated C 1-6 Alkoxy, halogenated C 3-6 Cycloalkyl, halogenated 3-7 membered heterocycloalkyl, halogenated C 3-6 The cycloalkyloxy group may be further substituted by one or more independently selected from hydrogen, halogen, hydroxy, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-6 Substitution by a substituent of a cycloalkyl or 3-7 membered heterocycloalkyl; R6 is selected from hydrogen, halogen, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, -SC 1-6 Alkyl, C 3-6 Cycloalkyloxy, halogenated C 1-6 Alkyl, halogenated C 1-6 Alkoxy, halogenated C 3-6 Cycloalkyl, halogenated C 3-6 Cycloalkyloxy, halogenated 3-7 membered heterocycloalkyl; R7 and R8 are independently selected from H, halogen, hydroxyl, C 1-6 Alkyl, C 1-6 Alkoxy, C 1-6 Alkylamine, C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, halogenated C 1-6 Alkyl, halogenated C 1-6 Alkoxy, halogenated C 3-6 Cycloalkyl, halogenated 3-7 membered heterocycloalkyl; R9, R 10 Further cyclized with the carbon atoms to which they are attached to form a 5-10 membered heterocycloalkyl; the 5-10 membered heterocycloalkyl may be further substituted with one or more independently selected R 11 Substituents substituted; R 11 Selected from hydrogen, C 1-6 Alkyl, halogenated C 1-6 Alkyl, -L1-OR 12 、-L1-NR 13 R 14 , C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, C 1-6 Alkylene C 3-6 Cycloalkyl, C 1-6 Alkylene 3-7 membered heterocycloalkyl, 5-6 membered heteroaryl; wherein the C 1-6 Alkyl, halogenated C 1-6 Alkyl, -L1-OR 12 、-L1-NR 13 R 14 , C 3-6 Cycloalkyl, 3-7 membered heterocycloalkyl, C 1-6 Alkylene C 3-6 Cycloalkyl, C 1-6 Alkylene 3-7 membered heterocycloalkyl, 5-6 membered heteroaryl can be optionally substituted by one or more independently selected from hydrogen, halogen, hydroxyl, C 1-6 Alkyl, halogenated C 1-6 Alkyl, C 3-6 Substitution by a substituent of a cycloalkyl or 3-7 membered heterocycloalkyl; L1 is selected from a bond, C 1-6 Alkylene or C 3-6 Cycloalkylene; R 12 Selected from hydrogen, C 1-6 Alkyl, halogenated C 1-6 alkyl; R 13 , R 14 are independently selected from hydrogen, C 1-6 Alkyl, 3-7 membered heterocycloalkyl.

2. The compound of structural formula I according to claim 1, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, characterized in that: In the formula I, Selected from The five-membered ring portion is optionally substituted by one or more independently selected from R 11 Preferably, in the formula I, Selected from Preferably, the formula I has the structure of formula IIa or formula IIb: Among them, R1, R2, R3, R4, R5, R6, R7, R8, R 11 As defined in claim 1 or 2; Preferably, the formula I has the structure of formula IIa-YG, IIb-YG:

3. The compound according to claim 1 or 2, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, wherein: R6 is selected from halogen, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-6 Cycloalkyl; Preferably, the formula I has the structure of formula IIIa or IIIb: Preferably, the formula I has the structure of formula IIIa-YG, IIIb-YG:

4. The compound according to any one of claims 1 to 3, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, wherein: R1, R2, R3, R4, and R5 are independently selected from H, halogen, C 1-6 Alkyl, C 1-6 Alkoxy, halogenated C 1-6 Alkoxy; wherein the C 1-6 Alkyl, C 1-6 Alkoxy, halogenated C 1-6 The alkoxy group may be further substituted by one or more independently selected from hydrogen, hydroxy, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-6 substituted by cycloalkyl, 3-7 membered heterocycloalkyl; preferably, R1, R2, R3, R4, R5 are independently selected from H, FCH2O-, CH3O-、CH3S-、CH3 CH2O-、CH3 CH2S-、F、 5. The compound according to claim 1, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, wherein: R 11 Selected from H, C 1-6 Alkyl, C 3-6 Cycloalkyl, -L1-OR 12 、-L1-NR 13 R 14 , 3-7 membered heterocycloalkyl; L1 is selected from a bond, C 1-6 Alkylene or C 3-6 Cycloalkylene; R 12 Selected from hydrogen; Preferably, C 3-6 Cycloalkyl, C 3-6 Cycloalkylene is a 3-6 membered monocyclic, spirocyclic, or bridged cycloalkyl group; Preferably, the 3-7 membered heterocycloalkyl group is a 3-7 membered N-containing heterocycloalkyl group; Preferably, the 3-7 membered heterocycloalkyl is a 3-7 membered monocyclic, spirocyclic, or bridged ring N-containing heterocycloalkyl; Preferably, R 11 Selected from H, -CH3, 6. The compound of structural formula I according to any one of claims 1 to 5, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, wherein the compound of structural formula I is selected from:

7. A pharmaceutical composition comprising the compound according to any one of claims 1 to 6, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, and a pharmaceutically acceptable carrier.

8. Use of a compound according to any one of claims 1 to 6, an isomer, a racemate, a pharmaceutically acceptable salt or a prodrug thereof, or a pharmaceutical composition according to claim 7 in the preparation of a medicament for treating a disorder, condition or disease responsive to inhibition of Nav1.8 channel activity in a mammal in need thereof.

9. Use of the compound according to any one of claims 1 to 6, its isomer, racemate, pharmaceutically acceptable salt or prodrug thereof, or the pharmaceutical composition according to claim 7 in the preparation of a medicament, preferably, the medicament is used to treat, prevent or control pain symptoms, cough symptoms, acute pruritus symptoms or chronic pruritus symptoms.

10. The use according to claim 9, characterized in that: The condition comprises chronic pain, intestinal pain, neuropathic pain, musculoskeletal pain, acute pain, inflammatory pain, cancer pain, idiopathic pain, postoperative pain, visceral pain, multiple sclerosis, Charcot-Marie-Tooth syndrome, incontinence, pathological cough or cardiac arrhythmia or a method of reducing the severity thereof; Preferably, the pain comprises neuropathic pain, musculoskeletal pain (preferably osteoarthritis pain), acute pain (preferably acute postoperative pain), postoperative pain or visceral pain; Preferably, the neuropathic pain comprises one or more of postherpetic neuralgia, small fiber neuropathy, idiopathic small fiber neuropathy or diabetic neuropathy, preferably diabetic peripheral neuropathy; Preferably, the postoperative pain includes one or more of bunionectomy pain, abdominoplasty pain, or hernia repair pain; Preferably, the subject is treated with one or more additional therapeutic agents simultaneously, prior to or after treatment with the compound, its isomer, racemate, or pharmaceutically acceptable salt or pharmaceutical composition thereof.

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