Polysubstituted pyrrolidine derivative as well as preparation method and application thereof

Abstract

The invention discloses a compound shown in a general formula (I) or a general formula (II), a stereoisomer, a tautomer, a deuterated derivative or a pharmaceutically acceptable salt thereof, a preparation method and application of the compound, and a pharmaceutical composition containing the compound, the stereoisomer, the tautomer, the deuterated derivative or the pharmaceutically acceptable salt thereof, the compound can be used as a sodion channel subtype Nav1.8 inhibitor, and can be used as a medicine for treating and preventing pain-related diseases.

Description

[0001] Related applications

[0002] This application claims priority to Chinese invention patent application No. 202411664623.9, filed with the China National Intellectual Property Administration on November 20, 2024, entitled "Multi-substituted pyrrolidine derivatives, their preparation methods and uses", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of pharmaceutical synthesis, and more specifically, to a class of polysubstituted pyrrolidine derivatives, their stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts, as well as methods for preparing and using said compounds, and pharmaceutical compositions comprising these compounds, their stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts, said compounds being used as inhibitors of the sodium ion channel subtype Nav1.8, and their pharmaceutical use in the treatment and prevention of pain-related diseases. Background Technology

[0004] Pain is one of the most common clinical symptoms. The National Institutes of Health (NIH) estimates that 100 million people in the United States suffer from chronic pain, and global healthcare costs for pain treatment reach $75 billion annually. Currently, the most commonly used analgesics are nonsteroidal anti-inflammatory drugs (NSAIDs). However, NSAIDs have relatively weak analgesic effects and exhibit a ceiling effect. There is a significant unmet clinical need in the analgesic market.

[0005] Pain is an important protective mechanism for healthy organisms to prevent further tissue damage. However, the body sometimes experiences useless, long-term chronic, pathological pain, such as neuropathic pain. The main causes of neuropathic pain include physical and mechanical damage to neurons, metabolic or nutritional nerve changes, neuronal structural abnormalities, and neurotransmitter dysfunction. Herpes, diabetes, and medications can sometimes induce metabolic or nutritional nerve changes.

[0006] Pain perception is the process by which noxious stimuli are generated and transmitted between neurons. Sodium channel activity is a crucial factor in the conduction of excitatory stimuli by neurons. Voltage-gated sodium channels (VGSCs) are multi-subunit transmembrane glycoproteins expressed on the cell membrane, composed of α subunits (functional units) and β subunits. Based on the differences in the α subunits, they are divided into nine subtypes, namely the nine members of sodium channel 1 (Nav1) – Nav1.1 to 1.9. The α subunit of Nav1 consists of four homologous transmembrane domains (I-IV), each containing six transmembrane hydrophobic α-helices (S1-S6). The positively charged S4 segment functions as a voltage receptor, regulating the hydrophilic pore between S5 and S6 that allows sodium ions to pass through, causing cell depolarization or hyperpolarization, thus completing the transmembrane signal transmission. When a neuron is stimulated, the NaV1 channel opens, allowing positively charged sodium ions to cross the cell membrane and enter the previously negatively charged cell. Changes in the electrical charge on the cell membrane generate an electric current, increasing the excitability of neurons and initiating downstream signal transduction that leads to pain.

[0007] Different subtypes of Nav1 are expressed in different tissues and participate in different types of pain transmission. Some are expressed only in peripheral neurons, while others mediate signal transmission in both central and peripheral neurons. Based on channel sensitivity to tetrodotoxin (TTX), Nav1.1-1.4, Nav1.6, and Nav1.7 are TTX-sensitive channels (TTX-S), while Nav1.5, Nav1.8, and Nav1.9 are TTX-tolerant channels (TTX-R). Studies have shown that broad-spectrum sodium channel blockers produce severe side effects after blocking Nav1.4 (related to skeletal muscle) and Nav1.5 (related to cardiac muscle). Therefore, designing selective blockers for specific Nav channels is a direction for pain drug development. As an important ion channel in pain receptors, Nav1.8 is distributed only in peripheral neurons and plays a crucial role in pain signal transduction in the peripheral nervous system. It is a major pathogenic factor involved in neuropathic pain, chronic pruritus, inflammatory pain, atrial fibrillation, and Budd-Chiari syndrome. Currently, existing inhibitors targeting Nav1.8, such as WO2021113627A1, WO2022256622A1, WO2022256676A1, WO2022256679A1, WO2022256702A1, and WO2022256842A1, are all furan derivatives. There are currently no marketed drugs specifically targeting the Nav1.8 subtype. Clinical studies have shown that selective Nav1.8 blockers have good inhibitory effects on neuropathic pain; therefore, further designing highly active and specific Nav1.8 inhibitors holds promise for providing a highly effective treatment option in the field of pain management. Summary of the Invention

[0008] According to one aspect of the invention, an object of the invention is to provide a class of compounds represented by general formula (I) or general formula (II), their stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts:

[0009]

[0010] Among them, R1 is selected from hydrogen atom, C 1-6 Alkyl group; preferably hydrogen atom, C 1-4 Alkyl; more preferably hydrogen atom, methyl, ethyl, n-propyl, isopropyl; more preferably hydrogen atom, methyl, ethyl.

[0011] R2 is selected from C 1-6 Alkyl, C 1-6 Alkoxy, deuterated C 1-6 Alkyl, Halogenated C 1-6 Alkyl; preferably C 1-4 Alkyl, deuterated C 1-4 Alkyl, Halogenated C1-4 Alkyl; more preferably methyl, ethyl, n-propyl, isopropyl, deuterated methyl; more preferably methyl or ethyl.

[0012] R3 is selected from C 1-6 Alkyl, deuterated C 1-6 Alkyl, Halogenated C 1-6 Alkyl; preferably C 1-4 Alkyl, deuterated C 1-4 Alkyl, Halogenated C 1-4 Alkyl; more preferably methyl, ethyl, n-propyl, isopropyl, deuterated methyl; even more preferably methyl, ethyl, deuterated methyl.

[0013] R9 is selected from hydrogen atom, halogen atom, amino group, hydroxyl group, carbonyl group, cyano group, amide group (-CONH2), substituted or unsubstituted C atom. 1-6 Alkyl, wherein the substituted C 1-6 Alkyl refers to C 1-6 The alkyl group is substituted with one to three substituents selected from the following: halogen atom, nitro, amino, hydroxyl, cyano, formamido; preferably, R9 is selected from hydrogen atom, halogen atom, amino, hydroxyl, amide group (-CONH2), substituted or unsubstituted C. 1-4 Alkyl, wherein the substituted C 1-4 Alkyl refers to C 1-4 The alkyl group is substituted with one to three substituents selected from the following: halogen atom, hydroxyl group; more preferably, R9 is selected from hydrogen atom, halogen atom, amino group, hydroxyl group, amide group (-CONH2), substituted or unsubstituted C group. 1-4 Alkyl, wherein the substituted C 1-4 Alkyl refers to C 1-4 The alkyl group is substituted with one or two hydroxyl groups; more preferably, R9 is selected from hydrogen atom, halogen atom, hydroxyl group, amide group (-CONH2), trifluoromethyl, hydroxymethyl, 1,2-dihydroxyethyl, 1,2-dihydroxypropyl, 2,3-dihydroxypropyl.

[0014] In general formula (II), X1 and X2 are N or C, and at least one of them is an N atom.

[0015] n is an integer selected from 0, 1, 2, 3 or 4, preferably an integer of 0, 1 or 2; more preferably an integer of 0 or 1.

[0016] Preferably, the compound represented by general formula (II), its stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts according to the present invention are selected from the following compounds which can be represented by general formula (IIa) or general formula (IIb):

[0017]

[0018] The definitions of R1, R2, R3, and R9 are the same as in general formula (II).

[0019] Preferably, the compounds according to the present invention represented by general formula (I), general formula (II), general formula (IIa) or general formula (IIb), their stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts are selected from the following compounds:

[0020]

[0021]

[0022] According to another aspect of the invention, another object of the invention is to provide a method for preparing compounds represented by general formula (I), general formula (II), general formula (IIa) or general formula (IIb), their stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts, said method comprising the following steps:

[0023]

[0024] or:

[0025]

[0026] Step 1: Compound Ia, whose amino group is protected by an amino protecting group PG, where PG is Boc or Cbz, is electrophilically added to an alkyl metal reagent (such as alkyllithium, alkylGernig reagent, trimethylsilylmethyllithium, etc.) to obtain the compound shown in general formula Ib.

[0027] Step 2: Under strongly acidic conditions (such as hydrochloric acid / dioxane solution) or in a hydrogen atmosphere, remove the amino protecting group PG from Ib to obtain the compound represented by general formula Ic.

[0028] Step 3: Ic and phenylacetic acid compound Id are condensed with amide to obtain the compound shown in general formula Ie, wherein the substituent R3 in compound Id does not include a deuterated substituent;

[0029] Step 4: Under alkaline conditions (such as potassium hydroxide, sodium hydroxide, sodium hydrogen, etc.), Ie undergoes molecular ring closure and dehydration to obtain the compound shown in the general formula If;

[0030] Step 5: Reduce the double bond on the ring under catalytic hydrogenation conditions with sodium borohydride and nickel or palladium chloride to obtain the compound shown in general formula Ig;

[0031] Step 6: After reducing the lactam in Ig to an imine with Schwartz reagent, it undergoes an addition reaction with trimethylnitrile silane, or sodium cyanide or potassium cyanide to obtain a pyrrolidine compound with general formula Ih.

[0032] Step 7: Compound Ih hydrolyzes the cyano group to acid Ii under strongly acidic conditions (such as hydrochloric acid / dioxane) or strongly alkaline conditions (such as potassium hydroxide aqueous solution);

[0033] Step 8: In the presence of a Lewis acid, remove the Ii benzyl group to obtain the phenol compound Ij;

[0034] Step 9: Under alkaline conditions, Ij reacts with two molecules of deuterated iodomethane, and then the ester group is hydrolyzed into an acid under strong alkaline conditions to obtain the deuterated acid Ik.

[0035] Step 10: Ii reacts with an aldehyde under palladium-catalyzed hydrogenation conditions or in the presence of a borohydride reducing agent to alkylate pyrrolidine with NH to obtain the compound shown in general formula Im;

[0036] Step 101: Ik reacts with an aldehyde under palladium-catalyzed hydrogenation conditions or in the presence of a boron-hydrogen reducing agent to alkylate pyrrolidine NH to give the compound shown in general formula Im';

[0037] Step 11: React Im or Im' with aniline compound Il by amide condensation to obtain the final product shown in general formula I;

[0038] or

[0039] Step 12: React compound Im or Im' with aniline II-1 by amide condensation to obtain compound of general formula II-2, wherein the substituent R3 in compound of general formula II-2 includes deuterated substituents defined in general formula (I), general formula (II), general formula (IIa) or general formula (IIb).

[0040] Step 13: Convert compounds of general formula II-2 into compounds of general formula II thioamide by reacting with a thioreagent (such as phosphorus pentasulfide).

[0041] According to another aspect of the invention, the invention provides a pharmaceutical composition comprising a therapeutically effective amount of a compound according to formula (I), formula (II), formula (IIa) or formula (IIb), its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts as an active ingredient, and pharmaceutically acceptable excipients.

[0042] According to another aspect of the invention, the invention provides the use of compounds represented by general formula (I), general formula (II), general formula (IIa) or general formula (IIb), their stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts, or pharmaceutical compositions according to the invention, in the preparation of medicaments for treating acute and chronic pain.

[0043] According to another aspect of the invention, the invention provides a method for treating chronic pain, the method comprising providing a subject with a therapeutically effective amount of a compound according to formula (I), formula (II), formula (IIa) or formula (IIb), its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts, or the pharmaceutical composition according to the invention.

[0044] Beneficial effects

[0045] Compared to compounds in the prior art, the compounds according to the present invention exhibit high inhibitory activity against NaV1.8. They can be used to treat both acute and chronic pain. Attached Figure Description

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 The absolute configuration diagram is shown for the compound (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrole-2-one (1f) prepared in Example 1.

[0048] Figure 2 The absolute configuration diagram is shown for the compound (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (4b) prepared in Example 4. Detailed Implementation

[0049] The present invention will now be described in detail. Before proceeding with the description, it should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the invention, based on the principle that the inventors are allowed to appropriately define the terms for the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention. It should be understood that other equivalents or modifications can be obtained from it without departing from the spirit and scope of the invention.

[0050] In this document, the terms “comprising,” “including,” “having,” “containing,” or any similar terms are open-ended transitional phrases intended to encompass non-exclusive inclusions. For example, a composition or article containing a plurality of elements is not limited to those listed herein but may also include other elements not explicitly listed but typically inherent to the composition or article. Furthermore, unless explicitly stated otherwise, the term “or” is inclusive, not exclusive. For example, the condition “A or B” is satisfied in any of the following cases: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); A and B are both true (or exist). Moreover, in this document, the terms “comprising,” “including,” “having,” and “containing” are interpreted as specifically disclosed and simultaneously encompassing closed or semi-closed transitional phrases such as “composed of” and “substantially composed of.”

[0051] In this document, all features or conditions defined in the form of numerical ranges or percentage ranges are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible secondary ranges and individual values ​​within those ranges, particularly integer values. For example, a range description of "1 to 8" should be considered as specifically disclosing all secondary ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., particularly secondary ranges defined by all integer values, and should be considered as specifically disclosing individual values ​​within those ranges such as 1, 2, 3, 4, 5, 6, 7, 8, etc. Unless otherwise specified, the foregoing interpretation applies to all content throughout this invention, regardless of its scope.

[0052] If a quantity or other numerical value or parameter is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that this document has specifically disclosed all ranges consisting of any upper or preferred value of that range and the lower or preferred value of that range, regardless of whether such ranges are separately disclosed. Furthermore, when a range of numerical values ​​is mentioned herein, unless otherwise stated, the range shall include its endpoints and all integers and fractions within the range.

[0053] In this document, numerical values ​​are to be understood as having a precision with significant digits, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover a range from 39.50 to 40.49.

[0054] In this document, when Markush groups or alternative terms are used to describe features or examples of the invention, those skilled in the art should understand that subgroups of all elements within a Markush group or option list, or any individual element, can also be used to describe the invention. For example, if X is described as "selected from the group consisting of X1, X2, and X3," it also indicates that the claim that X is X1 and the claim that X is X1 and / or X2 have been fully described. Furthermore, when Markush groups or alternative terms are used to describe features or examples of the invention, those skilled in the art should understand that any combination of subgroups of all elements within a Markush group or option list, or any combination of individual elements, can also be used to describe the invention. Accordingly, for example, if X is described as "selected from the group consisting of X1, X2, and X3," and Y is described as "selected from the group consisting of Y1, Y2, and Y3," it indicates that the claim that X is X1 or X2 or X3 and Y is Y1 or Y2 or Y3 has been fully described.

[0055] definition

[0056] The definitions of specific functional groups and chemical terms are described in more detail below. Chemical elements are determined according to the periodic table on the inner cover of the CAS edition of the *Handbook of Chemistry and Physics*, 75th edition, and specific functional groups are generally defined as described therein. This invention is not intended to be limited in any way by the exemplary list of substituents described herein.

[0057] The compounds described herein may contain one or more asymmetric centers and therefore may exist in a variety of isomeric forms, such as enantiomers and / or diastereomers. For example, the compounds described herein may be in the form of individual enantiomers, diastereomers, or geometric isomers, or may be in the form of mixtures of stereoisomers, including racemic mixtures and mixtures rich in one or more stereoisomers. Isomers can be separated from mixtures by methods known to those skilled in the art, including chiral high-performance liquid chromatography (HPLC) and the formation and crystallization of chiral salts; or preferably, isomers can be prepared by asymmetric synthesis. This disclosure further covers the compounds described herein as individual isomers substantially free of other isomers, or as mixtures of various isomers.

[0058] When listing a series of values, the intention is to cover every value within that range and every subrange. For example, "C 1-6 "Aims to cover C1, C2, C3, C4, C5, C6, C 1-6 C 1-5 C 1-4 C 1-3 C 1-2 C 2-6 C 2-5 C 2-4 C2-3 C 3-6 C 3-5 C 3-4 C 4-6 C 4-5 and C 5-6 .

[0059] The term "alkyl" refers to a straight-chain or branched saturated hydrocarbon group having 1 to 6 carbon atoms ("C..."). 1-6 Alkyl group). In some embodiments, the alkyl group has 1 to 5 carbon atoms (“C1”). 1-5 Alkyl group). In some embodiments, the alkyl group has 1 to 4 carbon atoms (“C1”). 1-4 Alkyl group). In some embodiments, the alkyl group has 1 to 3 carbon atoms (“C1”). 1-3 Alkyl group (“alkyl”). In some embodiments, the alkyl group has 1 to 2 carbon atoms (“C”). 1-2 Alkyl group (“C1 alkyl”). In some embodiments, the alkyl group has 1 carbon atom (“C1 alkyl”). In some embodiments, the alkyl group has 2 to 6 carbon atoms (“C1 alkyl”). 2-6 Alkyl group). C 1-6 Examples of alkyl groups include methyl (C1), ethyl (C2), propyl (C3) (e.g., n-propyl, isopropyl), butyl (C4) (e.g., n-butyl, tert-butyl, sec-butyl, isobutyl), pentyl (C5) (e.g., n-pentyl, 3-pentyl, neopentyl, 3-methyl-2-butyl, tert-pentyl), and hexyl (C6) (e.g., n-hexyl). Unless otherwise stated, each example of an alkyl group is independently unsubstituted or substituted with one or more substituents (e.g., halogens, such as F). In some embodiments, the alkyl group is an unsubstituted C1. 1-6 Alkyl groups, such as -CH3. In some embodiments, the alkyl group is a substituted C- group. 1-6 Alkyl groups, such as -CF3.

[0060] "Alkoxy" signifies a monovalent -O-alkyl group, wherein the alkyl moiety has a specified number of carbon atoms. In this disclosure, alkoxy groups typically contain 1-6 carbon atoms ("C1-6 alkoxy groups"), and include, for example, methoxy, ethoxy, isopropoxy, tert-butyloxy, etc. Unless otherwise stated, each instance of an alkoxy group may independently be optionally substituted, i.e., unsubstituted ("unsubstituted alkoxy group") or substituted with one or more substituents ("substituted alkoxy group"), said substituents being, for example, halogen atoms, nitro groups, amino groups, hydroxyl groups, cyano groups, amide groups, etc. In some embodiments, the alkoxy group is an unsubstituted C1-6 alkoxy group. 1-6 Alkyl group. In some embodiments, the alkoxy group is a substituted C- group. 1-6 Alkyl group.

[0061] Unless otherwise expressly provided, atoms, portions or groups described herein may be unsubstituted or substituted, provided that valence permits.

[0062] "Halogen" or "halogen" refers to fluorine (fluorinated, -F), chlorine (chlorinated, -Cl), bromine (brominated, -Br), or iodine (iodinated, -I).

[0063] The term "pharmaceutically acceptable salt" refers to those salts that, within reasonable medical judgment, are suitable for contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic reactions, etc., and in proportion to a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. Pharmaceutically acceptable salts of the compounds described herein include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable non-toxic acid addition salts are amino salts formed with inorganic acids (such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid) or with organic acids (acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid) or by using other methods known in the art (such as ion exchange). Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, hydrogen sulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentylpropionate, diglucuronate, dodecyl sulfate, ethanesulfonate, formate, fumarate, glucohepanoate, glyceryl phosphate, glucuronate, hemisulfate, heptahydrate, hydrogen iodide, 2-hydroxy-ethanesulfonate, lacturonate, lactate, laurate, dodecyl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, dihydroxynaphthalate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, neopentanoate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate, etc. Salts derived from suitable bases include alkali metals, alkaline earth metals, ammonium, and nitrogen. + (C 1-4 Alkyl)4-salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, etc. Where appropriate, other pharmaceutically acceptable salts include non-toxic ammonium, quaternary ammonium, and amine cations formed using balancing ions such as halide, hydroxide, carboxyl, sulfate, phosphate, nitrate, lower alkyl sulfonate, and aryl sulfonate.

[0064] The term "tautomer" or "tautomerizing" refers to a compound in which two or more interconvertions result from at least one formal migration of a hydrogen atom and at least one change in valence (e.g., a single bond becomes a double bond, a triple bond becomes a single bond, or vice versa). The exact proportions of tautomers depend on several factors, including temperature, solvent, and pH. Tautomerization reactions (i.e., reactions that provide tautomer pairs) can be catalyzed by acids or bases. Exemplary tautomerization reactions include keto-enol, amide-imide, lactam-lactamimide, enamine-imide, and enamine-(different enamines) tautomerization reactions.

[0065] It should also be understood that compounds with the same molecular formula but different properties, different atomic bonding sequences, or different spatial arrangements of atoms are called "isomers". Isomers with different atomic spatial arrangements are called "stereoisomers".

[0066] Stereoisomers that are not mirror images of each other are called "diastereomers," while stereoisomers that are not mirror images of each other are called "enantiomers." When a compound has an asymmetry center, for example, if it is bonded to four different groups, a pair of enantiomers may exist. Enantiomers can be characterized by the absolute configuration of their asymmetry center and are described by the R- and S-sequence rules of Cahn and Prelog or by rotating the molecular plane of polarization, and are represented as dextrorotatory or levorotatory (i.e., (+) or (-)- isomers, respectively). Chiral compounds can exist as individual enantiomers or as mixtures thereof. A mixture containing equal proportions of enantiomers is called a "racemic mixture."

[0067] The term “inhibition” or “inhibitor” refers to the ability of a compound to reduce, slow down, block, or prevent the activity of a particular biological process (such as the activity of Nav1.8 in tissues).

[0068] The term "subject" to be administered refers to a person (i.e., a male or female of any age group, such as a pediatric subject (e.g., an infant, child, or adolescent) or an adult subject (e.g., a young adult, middle-aged, or elderly person)). "Patient" refers to a human subject who requires treatment for a disease.

[0069] The term "biological sample" refers to any sample that includes tissue samples (e.g., tissue sections and needle biopsies); cell samples (e.g., cytological smears such as Pap smears or blood smears or cell samples obtained by microdissection); samples of whole organisms (e.g., yeast or bacterial samples); or any sample containing cellular parts, fragments, or organelles (e.g., obtained by lysing cells and separating their components by centrifugation or other methods). Other examples of biological samples include blood, serum, urine, semen, feces, cerebrospinal fluid, interstitial fluid, mucus, tears, sweat, pus, biopsy tissue (e.g., obtained by surgical or needle biopsy), nipple aspirate, milk, vaginal fluid, saliva, swabs (e.g., oral swabs), or any material containing biomolecules derived from the first biological sample.

[0070] The term “administration” means the implantation, absorption, ingestion, injection, inhalation or other introduction of the compound or a combination thereof described herein into or onto a subject.

[0071] The term "treatment" refers to reversing, alleviating, delaying the onset of the disease described herein, or inhibiting its development. In some embodiments, treatment may be administered after one or more signs or symptoms of the disease have developed or been observed. In other embodiments, treatment may be administered in the absence of signs or symptoms of the disease. For example, treatment may be administered to susceptible subjects before the onset of symptoms (e.g., based on a history of symptoms and / or based on exposure to a pathogen) to delay or prevent the occurrence of the disease. Treatment may also continue after symptoms have subsided, for example, to delay or prevent recurrence.

[0072] The "therapeuticly effective amount" of a compound described herein is an amount sufficient to provide therapeutic benefit in treating a condition or to delay or minimize one or more symptoms associated with said condition. Therapeuticly effective amount of a compound refers to the amount of a therapeutic agent, alone or in combination with other therapies, that provides therapeutic benefit in treating the condition. The term "therapeuticly effective amount" may include amounts that improve overall treatment, reduce or avoid symptoms, signs, or causes, and / or enhance the therapeutic efficacy of another therapeutic agent.

[0073] The pharmaceutical compositions described herein can be prepared by any method known in the field of pharmacology. Generally, such preparation methods involve conjugating the compound described herein (i.e., the “active ingredient”) with a carrier or excipient, and / or one or more other adjuvants, and then, if necessary and / or required, shaping and / or packaging the product into the desired single- or multi-dose units.

[0074] Pharmaceutical compositions may be prepared, packaged, and / or sold in batches, as single-unit doses, and / or in multiple single-unit doses. The relative amounts of the active ingredient, pharmaceutically acceptable excipients, and / or any additional ingredients in the pharmaceutical compositions described herein will vary depending on the individual, size, and / or condition of the subject to be treated, and also on the route of administration of the composition. The compositions may contain from 0.1% to 100% (w / w) of the active ingredient.

[0075] Pharmaceutically acceptable excipients used in the preparation of the provided pharmaceutical compositions include inert diluents, dispersants and / or granulators, surfactants and / or emulsifiers, disintegrants, binders, preservatives, buffers, lubricants and / or oils. Excipients such as cocoa butter and suppository waxes, colorants, coating agents, sweeteners, flavorings and spices may also be present in the compositions.

[0076] Liquid dosage forms for oral and parenteral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups, and elixirs. In addition to the active ingredient, liquid dosage forms may contain inert diluents commonly used in the art, such as water or other solvents, solubilizers, and emulsifiers, such as ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butanediol, dimethylformamide, oils (e.g., cottonseed oil, peanut oil, corn oil, germ oil, olive oil, castor oil, and sesame oil), glycerin, tetrahydrofurfuryl alcohol, fatty acid esters of propylene glycol and sorbitol, and mixtures thereof. In addition to inert diluents, oral compositions may include adjuvants, such as wetting agents, emulsifiers and suspending agents, sweeteners, flavorings, and fragrances. In some embodiments for parenteral administration, the combinations described herein are mixed with solubilizers such as alcohols, oils, modified oils, glycols, polysorbates, cyclodextrins, polymers, and mixtures thereof.

[0077] Injectable formulations, such as sterile injectable aqueous or oily suspensions, can be formulated using suitable dispersants or wetting agents and suspending agents according to known techniques. Sterile injectable formulations can be sterile injectable solutions, suspensions, or emulsions in non-toxic, non-enteric-acceptable diluents or solvents, such as solutions of 1,3-butanediol. Acceptable carriers and solvents that can be used are water, Ringer's solution, USP, and physiological saline solutions. Furthermore, sterile, fixed oils are commonly used as solvents or suspension media. For this purpose, any mild fixed oil that can be used includes synthetic monoglycerides or diglycerides. In addition, fatty acids (such as oleic acid) are used in the preparation of injectable formulations.

[0078] To prolong the effect of a drug, it is generally desirable to reduce absorption from subcutaneous or intramuscular injections. This can be achieved by using liquid suspensions of crystals or amorphous materials with poor water solubility. The absorption rate of the drug depends on the dissolution rate, which in turn depends on crystal size and crystal form. Alternatively, delayed absorption of parenteral drug forms can be achieved by dissolving or suspending the drug in an oily carrier.

[0079] Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In this solid dosage form, the active ingredient is mixed with at least one inert, pharmaceutically acceptable mixture of the following: excipients or carriers, such as sodium citrate or dicalcium phosphate and / or (a) fillers or extenders, such as starch, lactose, sucrose, glucose, mannitol, and silica; (b) binders, such as, for example, carboxymethyl cellulose, alginate, gelatin, polyvinylpyrrolidone, sucrose, and gum arabic; (c) humectants, such as glycerin; (d) disintegrants, such as agar, calcium carbonate, potato or cassava starch, alginic acid, certain silicates, and sodium carbonate; (e) solution inhibitors, such as petrolatum; (f) absorption enhancers, such as quaternary ammonium compounds; (g) wetting agents, such as, for example, cetyl alcohol and glyceryl monostearate; (h) absorbents, such as kaolin and bentonite; and (i) lubricants, such as talc, calcium stearate, magnesium stearate, solid polyethylene glycol, sodium dodecyl sulfate, and mixtures thereof. In the case of capsules, tablets, or pills, the dosage form may contain a buffer.

[0080] The active ingredient can be in the form of microcapsules having one or more of the excipients described above. Tablets, sugar-coated pills, capsules, pellets, and granules in solid dosage forms can be prepared using coatings and shells (such as enteric coatings, release-controlling agent coatings, and other coatings known in the pharmaceutical formulation field). In such solid dosage forms, the active ingredient can be mixed with at least one inert diluent (e.g., sucrose, lactose, or starch). Conventionally, such dosage forms can contain substances other than inert diluents, such as tableting lubricants and other tableting aids, such as magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets, or pellets, the dosage form can contain a buffer. They may optionally contain a light-blocking agent and can be compositions having the property that they release the active ingredient only, or preferably, in a delayed manner, in certain portions of the intestine. Examples of encapsulants that can be used include polymers and waxes.

[0081] Although the description of the pharmaceutical compositions provided herein is primarily directed toward pharmaceutical compositions suitable for administration to humans, such compositions are generally suitable for administration to all types of animals. Modification of pharmaceutical compositions suitable for human administration to make the compositions suitable for administration to a variety of animals is readily understood, and such modifications can be designed and / or carried out by those skilled in the art using conventional experimental methods.

[0082] The compounds described herein are typically formulated in dosing units for ease of administration and uniformity of dosage. However, it is understood that the full routine use of the compositions described herein should be determined by a physician using reasonable medical judgment. The specific therapeutically effective dose level for any particular subject or organism depends on a range of factors including: the severity of the disease and condition being treated; the activity of the specific active ingredient used; the specific composition used; the subject's age, weight, health status, sex, and diet; the timing, route of administration, and excretion rate of the specific active ingredient; the duration of treatment; the combination with or consistency with the specific active ingredient used; and other factors known in the medical field.

[0083] The compounds and compositions provided herein can be administered via conventional routes, including enteral (e.g., oral), parenteral, intravenous, intramuscular, intra-arterial, intramedullary, intracapsular, subcutaneous, intraventricular, transdermal, subcutaneous, rectal, vaginal, intraperitoneal, and topical (e.g., via powder, ointment, cream, and / or droplets). Particularly anticipated routes are oral administration, intravenous administration (e.g., systemic intravenous injection), topical administration via blood and / or lymphatic supply, and / or direct administration to the intended site. Generally, the most suitable route of administration will depend on a range of factors, including the nature of the agent (e.g., stability in the gastrointestinal environment) and / or the condition of the subject (e.g., whether oral administration is permissible).

[0084] The exact amount of compound required to achieve an effective dose will vary depending on the subject, taking into account factors such as the subject's race, age, and general condition, the severity of side effects or illness, confirmation of the specific compound, and the mode of administration. An effective dose may be included in a single dose (e.g., a single oral dose) or multiple doses (e.g., multiple oral doses). In some embodiments, when multiple doses are administered to a subject or applied to a biological sample, tissue, or cell, any two doses of the multiple doses contain different or substantially the same compound described herein. In some embodiments, when multiple doses are administered to a subject or applied to a biological sample, tissue, or cell, the frequency of administration of multiple doses to the subject or to the tissue or cell may be three doses per day, two doses per day, one dose per day, one dose every two days, one dose every three days, or one dose per week. In some embodiments, the frequency of administration of multiple doses to a subject or to the tissue or cell is one dose per day. In some embodiments, the frequency of administration of multiple doses to a subject or to the tissue or cell is two doses per day. In some embodiments, when multiple doses are administered to a subject or applied to a biological sample, tissue, or cell, the duration between the first and last doses of the multiple doses is one day, two days, four days, one week, two weeks, three weeks, one month, two months, three months, four months, six months, nine months, one year, two years, three years, four years, five years, seven years, ten years, fifteen years, twenty years, or the lifespan of the subject, biological sample, tissue, or cell. In some embodiments, the duration between the first and last doses of the multiple doses is three months, six months, or one year. In some embodiments, the duration between the first and last doses of the multiple doses is the lifespan of the subject, biological sample, tissue, or cell. In some embodiments, the doses described herein (e.g., any single or multiple doses) independently comprise 1 mg to 3 mg, 3 mg to 10 mg, 10 mg to 30 mg, 30 mg to 100 mg, 100 mg to 300 mg, 300 mg to 1,000 mg, or 1 g to 10 g of the compound described herein. In some embodiments, the doses described herein independently comprise 3 mg to 10 mg of the compound described herein. In some embodiments, the dosage described herein independently comprises 10 mg to 30 mg of the compound described herein. In some embodiments, the dosage described herein independently comprises 30 mg to 100 mg of the compound described herein. In some embodiments, the dosage described herein independently comprises 100 mg to 300 mg of the compound described herein. In some embodiments, the dosage described herein independently comprises 300 mg to 1000 mg of the compound described herein.

[0085] The following embodiments are merely examples illustrating implementations of the present invention and do not constitute any limitation on the present invention. Those skilled in the art will understand that modifications made without departing from the spirit and concept of the present invention fall within the protection scope of the present invention. Unless otherwise specified, the reagents and instruments used in the following embodiments are commercially available products.

[0086] 1 The 1H NMR spectra were obtained using a Bruker instrument (400 MHz), and chemical shifts are expressed in ppm. Tetramethylsilane internal standard (0.00 ppm) was used. 1 H NMR representation: s = singlet, d = doublet, t = triplet, m = multiplet, br = broadened, dd = doublet of doublet, dt = doublet of triplet. If the coupling constant is provided, the unit is Hz.

[0087] Mass spectrometry is performed using an LC / MS instrument, and the ionization method can be ESI or APCI.

[0088] Thin-layer chromatography silica gel plates are Yantai Huanghai HSGF254 or Qingdao GF254. The silica gel plates used in thin-layer chromatography (TLC) are 0.15mm to 0.2mm in diameter, and the silica gel plates used for thin-layer chromatography separation and purification are 0.4mm to 0.5mm in diameter.

[0089] Column chromatography typically uses Yantai Huanghai silica gel with a mesh size of 200-300 as the carrier.

[0090] In the following examples, all temperatures are in Celsius unless otherwise specified. Unless otherwise specified, all starting materials and reagents are commercially available or synthesized according to known methods. Commercially available materials and reagents are used directly without further purification. Unless otherwise specified, they are purchased from manufacturers including but not limited to Aldrich Chemical Company, ABCR GmbH & Co. KG, Acros Organics, Shanghai Bid Pharmaceutical Technology Co., Ltd., and Shanghai Titan Technology Co., Ltd.

[0091] Unless otherwise stated or indicated by the context, the following abbreviations shall be understood to have the following meanings:

[0092] CD3OD: Deuterated methanol.

[0093] CDCl3: Deuterated chloroform.

[0094] DMSO-d6: Deuterated dimethyl sulfoxide.

[0095] D2O: Heavy water.

[0096] NMR: Nuclear Magnetic Resonance

[0097] ESI-MS: Electroinjection mass spectrometry analysis

[0098] LCMS: Liquid Chromatography-Mass Spectrometry

[0099] TLC: Thin-layer chromatography

[0100] HPLC: High Performance Liquid Chromatography

[0101] prep-HPLC: Preparative high-performance liquid chromatography

[0102] SFC: Supercritical Fluid Chromatography

[0103] g: gram

[0104] mg: milligram

[0105] L: Rise

[0106] mL: milliliters

[0107] μL: microliter

[0108] mmol: millimole

[0109] hr, h: hours

[0110] min: minutes

[0111] mm: millimeter

[0112] μm: micrometer

[0113] MHz: Megahertz

[0114] Hz: Hertz

[0115] eq.: equivalent

[0116] M: Moles per liter (concentration)

[0117] DCM: Dichloromethane

[0118] DMF: N,N-Dimethylformamide

[0119] DMSO: Dimethyl sulfoxide

[0120] EtOH: Ethanol

[0121] EtOAc, EA: Ethyl acetate

[0122] NMI: N-methylimidazole

[0123] TCFH: N,N,N',N'-Tetramethylchloromethylammonium hexafluorophosphate

[0124] MeOH: Methanol

[0125] MTBE: Methyl tert-butyl ether

[0126] THF: Tetrahydrofuran

[0127] ACN: Acetonitrile

[0128] TEA: Triethylamine

[0129] TGA: Thioglycolic Acid

[0130] RT, rt: Room temperature

[0131] MeMgBr: Methylmagnesium bromide

[0132] Schwartz's reagent: bis(cyclopentadienyl)zirconium hydrochloride (IV)

[0133] An argon atmosphere can be achieved by connecting an argon balloon to the reaction flask.

[0134] Unless otherwise specified in the examples, the solution in the reaction refers to an aqueous solution.

[0135] The compound was purified using a C18 reversed-phase column for preparative or semi-preparative purification, silica gel column chromatography eluent system, and thin-layer chromatography. The eluent system was selected from: A: petroleum ether and tetrahydrofuran system; B: acetonitrile and water system; C: petroleum ether and ethyl acetate system. The volume ratio of the solvent varied depending on the polarity of the compound and could be adjusted by adding a small amount of acidic or basic reagents, such as trifluoroacetic acid, acetic acid, or triethylamine.

[0136] Preparation of Intermediate 1: Synthesis of Intermediate 2-(3,4-difluoro-2-methoxyphenyl)acetyl chloride (Int1):

[0137]

[0138] Step 1: Synthesis of 3,4-difluoro-2-methoxybenzyl alcohol (Int1a):

[0139] Under ice bath conditions, a 1M tetrahydrofuran solution of borane (213 mL) was slowly added dropwise to an anhydrous tetrahydrofuran solution of 3,4-difluoro-2-methoxybenzoic acid (20.0 g, 106 mmol) (240 mL). After the addition was complete, the temperature was raised to 25 °C and stirred for 2 hours. The reaction was quenched by slow addition of methanol. After concentration, a colorless oily compound, 3,4-difluoro-2-methoxybenzyl alcohol Int1a (18.0 g, crude product), was obtained.

[0140] Step 2: Synthesis of 3,4-difluoro-2-methoxybenzyl methanesulfonate (Int1b):

[0141] Under ice bath conditions, methanesulfonyl chloride (14.0 g, 124 mmol) was slowly added dropwise to a solution of 3,4-difluoro-2-methoxybenzyl alcohol Int1a (18.0 g, crude) and diisopropylethylamine (40.0 g, 310 mmol) in anhydrous dichloromethane (128 mL). After the addition was complete, the mixture was stirred in an ice bath for 30 minutes. Hydrochloric acid aqueous solution (1 M, 60 mL) was then added, and the mixture was separated. The aqueous phase was treated with dichloromethane (60 mL). × 3) Extract, combine the organic phases, dry with anhydrous sodium sulfate, filter and concentrate to obtain brown oily compound 3,4-difluoro-2-methoxybenzyl methanesulfonic acid Int1b (20.0 g, crude product).

[0142] Step 3: Synthesis of 2-(3,4-difluoro-2-methoxyphenyl)acetonitrile (Int1c):

[0143] Sodium cyanide (6.61 g, 134.80 mmol) was added to a solution of 3,4-difluoro-2-methoxybenzyl methanesulfonate Int1b (crude product, 17.0 g, 67.40 mmol) in N,N-dimethylformamide (150 mL). After stirring at 25 °C for 1 hour, ethyl acetate (150 mL) and water (150 mL) were added sequentially. The mixture was separated, and the aqueous phase was treated with ethyl acetate (100 mL). × 3) Extract, combine the organic phases, dry with anhydrous sodium sulfate, filter and concentrate, and purify by silica gel column chromatography (PE:THF = 1:0 to 3:1) to give a yellow oily compound 2-(3,4-difluoro-2-methoxyphenyl)acetonitrile Int1c (9.30 g, 71.57% yield).

[0144] 1 H NMR(400MHz, CDCl3)δ:7.25-7.03(m,1H),6.90-6.83(m,1H),4.07(d,J=2.8H Z ,3H),3.65(s,2H).

[0145] Step 4: Synthesis of 2-(3,4-difluoro-2-methoxyphenyl)acetic acid (Int1d):

[0146] Add NaOH (15.5 g, 387 mmol) to a mixture of 2-(3,4-difluoro-2-methoxyphenyl)acetonitrile Int1c (9.3 g, 50.78 mmol) and water (350 mL), heat under reflux for 16 hours, cool, adjust the pH to 4 with hydrochloric acid aqueous solution (4 M), and then thaw the mixture with ethyl acetate (200 mL). ×3) After three extractions, the organic phases were combined, dried with anhydrous sodium sulfate, filtered, and concentrated to give a pale yellow solid compound 2-(3,4-difluoro-2-methoxyphenyl)acetic acid Int1d (10.2 g, 94.4% yield).

[0147] 1 H NMR (400MHz, DMSO-d6) δ: 12.41 (s, 1H), 7.13-7.05 (m, 2H), 3.86 (d, J = 2.0H Z ,3H),3.56(s,2H).

[0148] Step 5: Synthesis of 2-(3,4-difluoro-2-methoxyphenyl)acetyl chloride (Int1):

[0149] 2-(3,4-difluoro-2-methoxyphenyl)acetic acid Int1d (500 mg, 2.47 mmol, 1 equivalent) was dissolved in thionyl chloride (5.0 mL) and stirred at room temperature for 16 hours. The reaction was confirmed by LCMS (the reaction solution was concentrated to dryness and then a tetrahydrofuran solution of dimethylamine was added), indicating the reaction was complete. The reaction solution was concentrated to dryness under vacuum, and anhydrous dichloromethane (5.0 mL) was added to the residue. After evaporation to dryness again under vacuum, a yellow oily compound, 2-(3,4-difluoro-2-methoxyphenyl)acetyl chloride Int1 (540 mg, crude product), was obtained and used directly in the next reaction step.

[0150] Preparation of Intermediate 2: Synthesis of Intermediate 2-((tert-Butoxycarbonyl)amino)-3,3,3-trifluoro-2-methylpropionate (Int2):

[0151]

[0152] Step 1: Synthesis of methyl 2-((tert-butyloxycarbonyl)imine)-3,3,3-trifluoropropionate (Int2a):

[0153] To a solution of tert-butyl triphenylphosphinoiminocarbamate (23.1 g, 61.19 mmol, 1 equivalent) in tetrahydrofuran (200 mL), methyl trifluoropyruvate (10.0 g, 64.08 mmol, 1.05 equivalent) was added. After the addition was complete, the reaction system was protected under nitrogen atmosphere and stirred at 50 °C for 10 minutes, then cooled to 20 °C and stirred for another 2 hours. TLC (petroleum ether:ethyl acetate = 5:1, R0) was performed. f =0.6) The disappearance of the raw material was detected. After the reaction solution was concentrated to dryness, a mixed solvent (petroleum ether: diethyl ether = 1:1) was added and the mixture was stirred, filtered, and the filtrate was concentrated under vacuum to obtain a colorless oily compound methyl 2-((tert-butyloxycarbonyl)imine)-3,3,3-trifluoropropionate Int2a (16.8 g, crude product, 100% yield).

[0154] 1 H NMR (400MHz, CDCl3), δ: 3.95 (s, 3H), 1.58 (s, 9H).

[0155] Step 2: Synthesis of methyl rac-2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-methylpropionate (Int2):

[0156] 2-((tert-Butoxycarbonyl)imine)-3,3,3-trifluoropropionate methyl ester Int2a (6.0 g, 23.51 mmol, 1 equivalent) was dissolved in tetrahydrofuran (60.0 mL), cooled to -70 °C, and methyl magnesium bromide (7.84 mL, 23.51 mmol, 3 mol / L 2-methyltetrahydrofuran solution, 1 equivalent) was slowly added dropwise. After the addition was complete, the mixture was stirred at -70 °C for 1 hour, then heated to 20 °C and stirred for 30 minutes. TLC (petroleum ether:ethyl acetate = 5:1, R0) was performed. f =0.5) The reaction was detected as the starting material disappeared. Under ice bath conditions, a saturated aqueous solution of ammonium chloride (200 mL) was added to quench the reaction, followed by extraction three times with ethyl acetate (200 mL). The organic phases were combined, washed with saturated brine, dried, concentrated, and purified by normal-phase silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) to give a white solid compound rac-2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-methylpropionate methyl ester Int2 (5.2 g, crude product, 81.54% yield).

[0157] 1 H NMR (400MHz, CDCl3), δ: 5.13 (s, 1H), 3.83 (s, 3H), 1.74 (s, 3H), 1.44 (s, 9H).

[0158] Example 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (1):

[0159]

[0160] Step 1: Synthesis of rac-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)carbamate tert-butyl ester (1a):

[0161] At -70°C, trimethylsilylmethyllithium (408.2 mL, 228.6 mmol, 0.56 mol / L n-hexane solution, 3.1 equivalents) was slowly added dropwise to a tetrahydrofuran (400 mL) solution of methyl rac-2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-methylpropionate Int2 (20.0 g, 73.75 mmol, 1.0 equivalent) at -70°C. After the addition was complete, the mixture was stirred at -70°C for 40 minutes. TLC (petroleum ether:ethyl acetate = 5:1, R0) was performed. f =0.3) Most of the raw materials disappeared. The reaction solution was raised to 0°C, quenched with anhydrous methanol (20.0 mL) and stirred for 30 minutes, then saturated ammonium chloride solution (1000 mL) was added, and the mixture was extracted three times with ethyl acetate (400 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under vacuum to obtain a pale yellow oily compound rac-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)carbamate tert-butyl ester 1a (20.1 g crude product).

[0162] 1 H NMR (400MHz, CDCl3), δ: 5.15 (m, 1H), 2.21 (s, 3H), 1.53 (s, 3H), 1.35 (s, 9H).

[0163] Step 2: Synthesis of rac-3-amino-4,4,4-trifluoro-3-methylbutane-2-one (1b):

[0164] Compound rac-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)carbamate tert-butyl ester 1a (19.1 g crude, 74.83 mmol, 1.0 equivalent) was dissolved in 4 M hydrochloric acid / dioxane solution (191.0 mL) and stirred at room temperature for 2 hours. The starting material disappeared as detected by TLC. The reaction solution was concentrated to dryness, slurried with diethyl ether, filtered, and the filter cake was dried under vacuum to obtain a white solid compound rac-3-amino-4,4,4-trifluoro-3-methylbutane-2-one hydrochloride 1b (9.64 g crude).

[0165] 1 H NMR (400MHz, DMSO-d6), δ: 2.45 (s, 3H), 1.70 (s, 3H).

[0166] Step 3: Synthesis of rac-2-(3,4-difluoro-2-methoxyphenyl)-N-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)acetamide (1c):

[0167] At -10°C, pyridine (39.3 g, 496.86 mmol, 10.0 equivalent) was added to a dichloromethane (90 mL) suspension of compound rac-3-amino-4,4,4-trifluoro-3-methylbutane-2-one hydrochloride 1b (9.52 g crude, 49.69 mmol, 1.0 equivalent). Then, a dichloromethane (40 mL) solution of 2-(3,4-difluoro-2-methoxyphenyl)acetyl chloride Int1 (12.06 g, 54.65 mmol, 1.1 equivalent) was slowly added dropwise to the reaction mixture. The reaction mixture was allowed to warm naturally to room temperature and stirred for 16 hours. LC / MS analysis showed the reaction was complete. 1 mol / L hydrochloric acid (1000 mL) was added to the reaction mixture, and the mixture was extracted three times with dichloromethane (300 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under vacuum to give a yellow solid compound rac-2-(3,4-difluoro-2-methoxyphenyl)-N-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)acetamide 1c (11.7 g, 69.4% yield).

[0168] MS(ESI): m / z calculated value [M+H] + ]:340.09, Measured value:340.2

[0169] 1 H NMR (400MHz, DMSO-d6), δ: 9.15 (s, 1H), 7.13-7.04 (m, 2H), 3.86-3.84 (m, 3H), 3.62-3.53 (m, 2H), 2.05 (s, 3H), 1.49 (s, 3H).

[0170] Step 4: Synthesis of rac-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)-1,5-dihydro-2H-pyrrole-2-one (1d):

[0171] Compound rac-2-(3,4-difluoro-2-methoxyphenyl)-N-(1,1,1-trifluoro-2-methyl-3-oxobutane-2-yl)acetamide 1c (11.7 g, 4.72 mmol, 1.0 equivalent) was dissolved in hot ethanol (120.0 mL), followed by the addition of potassium hydroxide (1.94 g, 34.49 mmol, 1.0 equivalent). The reaction mixture was heated to 80 °C and stirred for 20 minutes. LC / MS analysis showed that the reaction was complete. The reaction mixture was cooled to room temperature and poured into water (1000 mL), then extracted three times with dichloromethane (400.0 mL). The organic phases were combined, washed with saturated brine, dried with anhydrous sodium sulfate, and concentrated under vacuum to give a pale yellow solid compound rac-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)-1,5-dihydro-2H-pyrrole-2-one 1d (8.8 g, 79.4% yield).

[0172] MS(ESI): m / z calculated value [M+H] + ]:322.08, Measured value:322.2

[0173] 1 H NMR (400MHz, DMSO-d6), δ: 9.13 (s, 1H), 7.27-7.21 (m, 1H), 7.04-6.99 (m, 1H), 3.75 (d, J = 1.2Hz, 3H), 1.88 (s, 3H), 1.56 (s, 3H).

[0174] Step 5: Synthesis of rac-(3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-one (1e):

[0175] Compound rac-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)-1,5-dihydro-2H-pyrrole-2-one 1d (14.63 g, 45.54 mmol, 1.0 equivalent) was dissolved in a mixed solvent (tetrahydrofuran:methanol = 1:5, 540.0 mL), cooled to -40 °C, and nickel chloride hexahydrate (10.82 g, 45.54 mmol, 1.0 equivalent) and sodium borohydride (5.17 g, 136.62 mmol, 3.0 equivalent) were added sequentially. After stirring the reaction mixture for 1 hour, equal amounts of nickel chloride hexahydrate and sodium borohydride were added at -40 °C until the starting material was consumed as indicated by LC / MS. The reaction solution was filtered, the filtrate was concentrated, and saturated ammonium chloride solution (1000 mL) was added. The mixture was extracted three times with dichloromethane (300.0 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under vacuum. A mixed solvent (100.0 mL, petroleum ether: ethyl acetate = 20:1) was added to the residue and stirred for 1 hour. The residue was filtered, and the filter cake was dried to obtain a white solid compound rac-(3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-one 1e (11.17 g, 75.9% yield).

[0176] MS(ESI): m / z calculated value [M+H] + ]:324.09, Measured value:324.2;

[0177] 1 H NMR(400MHz,DMSO-d6),δ:8.90(s,1H),7.16-7.09(m,1H),6.85-6.83(m,1H),4.22(d, J=10.4Hz,1H),3.92(d,J=1.6Hz,3H),2.85(m,1H),1.48(s,3H),0.68(d,J=6.0Hz,3H).

[0178] Step Six: Synthesis of (3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrole-2-one (1f):

[0179] 2.0 g of racemic compound 1e was subjected to chiral resolution using an SFC column (ChiralPak AD-H column from Daicel Chemical Industries, 5 μm particle size, 250 × 30 mm; mobile phase: supercritical carbon dioxide for solvent A, HPLC-grade ethanol containing 0.1% ammonia for solvent B, A:B = 90:10; flow rate: 60 mL / min; injection pressure: 100 bar; column temperature: 38 °C; detection wavelength: 220 nm) to obtain compound 1f (first eluted isomer, 940 mg) with a single configuration. Its absolute configuration was characterized by single-crystal X-ray diffraction. The absolute configuration of compound 1f is shown below. Figure 1 As shown, and the cell parameters are listed in Table 1 below:

[0180] MS(ESI): m / z calculated value [M+H] + [Value: 324.09, Measured value: 324.2]

[0181] 1 H NMR(400MHz, DMSO-d6)δ8.90(s,1H),7.13(ddd,J=10.3,8.9,7.8Hz,1H),6.91–6.74(m,1H),4.22 (d,J=10.5Hz,1H),3.92(d,J=2.4Hz,3H),2.84(q,J=8.4Hz,1H),1.48(s,3H),0.70-0.67(m,3H).

[0182] Table 1

[0183]

[0184] Step 7: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-onitrile (1g):

[0185] At -30°C, a solution of compound 1f (790 mg, 2.44 mmol, 1.0 equivalent) in THF (5.0 mL) was added to a nitrogen-protected suspension of dicyclopentadienylzirconium hydrogen chloride (Schwartz reagent) (3.15 g, 12.22 mmol, 5.0 equivalent) in THF (15.0 mL). After stirring for 0.25 hours, the reaction mixture was naturally heated to 20°C and stirred for another 16 hours. LCMS analysis showed that the starting material was completely converted to imine. The mixture was then filtered, and the filtrate was concentrated under vacuum to obtain crude imine intermediate. The prepared crude imine was dissolved in dichloromethane (10.0 mL) and cooled to 5°C. TMSCN (3.64 g, 36.66 mmol, 15.0 equivalent) was added, and the mixture was naturally heated to 20°C and stirred for 4 days. LCMS analysis showed that the imine was completely converted. Saturated sodium bicarbonate solution (100.0 mL) was added, and the mixture was extracted three times with dichloromethane (50 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under vacuum, and the residue was purified by normal-phase silica gel column chromatography (petroleum ether: ethyl acetate = 20:1) to give 1 g (430.0 mg, 52.63% yield) of a colorless oily compound.

[0186] MS(ESI): m / z calculated value [M+H+]: 335.11, measured value: 335.1;

[0187] 1H NMR (400MHz, DMSO-d6) δ7.28–7.09(m,2H),4.53(dd,J=7.0,4.6Hz,1H),4.12(d,J=4.7Hz,1H),3 .96(d,J=2.4Hz,3H),3.95–3.88(m,1H),2.67(q,J=7.6Hz,1H),1.48(s,3H),0.70-0.68(m,3H).

[0188] Step 8: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxylic acid (1h):

[0189] Concentrated hydrochloric acid (10.0 mL) was added to a 1 g (430.0 mg, 1.29 mmol, 1.0 equivalent) solution of 1,4-dioxane (2.0 mL), and the reaction mixture was stirred at 55 °C for 16 hours. LC-MS analysis showed that the reaction was complete. The reaction mixture was concentrated to dryness under vacuum, and the residue was dissolved in a mixture of water (20.0 mL) and ethyl acetate (10.0 mL). The pH was adjusted to 5 with sodium bicarbonate, and the mixture was extracted three times with ethyl acetate (5.0 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under vacuum to give a pale yellow solid compound 1 h (410.0 mg, 90.22% yield).

[0190] MS(ESI): m / z calculated value [M+H] + ]:354.11, Measured value:354.1;

[0191] 1 HNMR (400MHz, DMSO-d6) δ12.81(s,1H),7.23(ddd,J=8.3,6.0,2.0Hz,1H),7.13(td,J=9.6,7.6Hz,1H),4.12(d,J=8.9 Hz,1H),3.90(d,J=2.0Hz,3H),3.88–3.82(m,1H),2.80(s,1H),2.46(d,J=7.6Hz,1H),1.47(s,3H),0.68-0.65(m,3H).

[0192] Step Nine: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-hydroxyphenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxylic acid (1i):

[0193] At 0 °C, boron tribromide (0.42 mL, 424.58 μmol, 3.0 equivalent, 1 mol / L dichloromethane solution) was added dropwise to a 0.2 mL solution of compound 1 h (50.0 mg, 141.53 μmol, 1.0 equivalent). The reaction mixture was naturally heated to 20 °C and stirred for 16 hours. LC-MS analysis showed product formation. The reaction solution was concentrated to dryness under vacuum, and the residue was purified by prep-HPLC (column: Synergi Max-RP 250*40 mm*10 μm; mobile phase: water (0.05% HCl)-ACN; gradient: 30%-60%, 15 min; flow rate: 60 mL / min) to give a white solid compound 1i (25.0 mg, 52.07% yield).

[0194] MS(ESI): m / z calculated value [M+H] +]:340.09, Measured value:340.2;

[0195] Step 10: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxylic acid (1j):

[0196] Compound 1i (25.0 mg, 73.69 μmol, 1.0 equivalent) and potassium carbonate (30.6 mg, 221.07 μmol, 3.0 equivalent) were stirred in N,N-dimethylformamide (0.3 mL) at room temperature for 30 minutes. Then, deuterated iodomethane (26.7 mg, 184.22 μmol, 2.5 equivalent) was added, and stirring continued at room temperature for 3 hours. LCMS analysis showed complete consumption of the starting material. Potassium hydroxide (0.37 mL, 1.11 mmol, 15.0 equivalent, 3 mol / L aqueous solution) was added to the reaction mixture, and the temperature was raised to 50 °C with stirring for 2 hours. LCMS analysis showed complete hydrolysis. The reaction solution was cooled to 5°C, the pH was adjusted to 2 with dilute hydrochloric acid, and then extracted three times with ethyl acetate (5.0 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under vacuum. The residue was purified by prep-HPLC (column type: Welch Xtimate C18 250*30mm*10um; mobile phase: water (0.05% HCl)-ACN; gradient: 30%-60%, 15 min; flow rate: 40 mL / min) to give a white solid compound 1j (15.0 mg, 57.13% yield).

[0197] MS(ESI): m / z calculated value [M+H] + [Value: 357.12, Measured value: 357.2]

[0198] 1 H NMR (400MHz, DMSO-d6) δ7.26-7.21(m,1H),7.19-7.08(m,1H),4.26(d,J=9.3Hz ,1H),3.93(t,J=8.6Hz,1H),2.55-2.51(m,1H),1.51(s,3H),0.79-0.57(m,3H).

[0199] Step 11: Synthesis of 2,5-dioxopyrrolidine-1-yl(2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-4,5-dimethyl-5-(trifluoromethoxy)pyrrolidine-2-carboxamide (1k):

[0200] Under ice bath conditions, N,N,N',N'-tetramethylchloroformamidin hexafluorophosphate (9.64 g, 1.5 equivalences) was added in portions to an acetonitrile (120.0 mL) solution containing N-hydroxysuccinimide (3.96 g, 33.68 mmol, 1.5 equivalences), compound 1j (8.0 g, 22.45 μmol, 1.0 equivalences), and N-methylimidazole (5.64 g, 67.36 mmol, 3.0 equivalences).

[0201] 33.68 μmol (1.5 equivalents, Bittern reagent) was added, and the process was exothermic. After the addition was complete, the reaction mixture was stirred at room temperature for 2 hours. LCMS analysis showed that the starting material was completely consumed. 500.0 mL of water was added to the reaction mixture, and the mixture was extracted three times with ethyl acetate (150.0 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated to dryness under vacuum, and the residue was purified by normal-phase silica gel column chromatography (petroleum ether: ethyl acetate = 5:1) to give a white solid compound 1k (8.6 g, 84.48% yield).

[0202] MS(ESI):m / z[M+H + Calculated value: 454.14, measured value: 454.2;

[0203] Step Twelve: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (1m):

[0204] Compound 1l (34.18 mg, 176.00 μmol, 2.0 equivalent; preparation of compound 1l is described in WO2022256842A1, pages 110-113, Intermediates B, the first eluted isomer) and compound 1k (40.0 mg, 88.23 μmol, 1.0 equivalent) were dissolved in anhydrous tetrahydrofuran (2 mL). The reaction mixture was stirred at 70 °C for 9 days. LC-MS analysis showed product formation. The reaction mixture was concentrated under vacuum, and the residue was purified by normal-phase silica gel column chromatography (petroleum ether: ethyl acetate, 5:1 to 2:1) to give a white solid compound 1m (30.0 mg, 63.85% yield).

[0205] MS(ESI):m / z[M+H + Calculated value: 533.22, measured value: 533.3;

[0206] Step Thirteen: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (1):

[0207] At room temperature, TFA (614 mg, 5.38 μmol, 57.3 equivalents) was added to a 1 M (50.0 mg, 93.89 μmol, 1.0 equivalent) solution of compound in 2.0 mL of dichloromethane. The reaction mixture was stirred at room temperature for 1 hour. LC-MS analysis showed that the reaction was complete. The reaction solution was concentrated to dryness under vacuum. The residue was purified by prep-HPLC (column: WATERS XBridge C18, 19*150 mm, 5 μm; mobile phase: Water (0.1% FA)-ACN; gradient: 40%-60%, 13 min; flow rate: 15 mL / min) to give compound 1 (6.17 mg, 12.93% yield) as a white solid.

[0208] MS(ESI):m / z[M+H + Calculated value: 493.19, measured value: 493.30;

[0209] 1 H NMR (400MHz, DMSO-d6) δ10.32(s,1H),8.64(d,J=2.4Hz,1H),7.94(dd,J=8.6,2.4Hz,1H),7 .40(d,J=8.4Hz,1H),7.25–7.10(m,2H),5.31(d,J=4.8Hz,1H),4.63(t,J=5.6Hz,1H),4.55 –4.48(m,1H),4.23(dd,J=8.8,6.4Hz,1H),3.94(t,J=8.4Hz,1H),3.64-3.59(m,1H),3.47– 3.38(m,1H),3.08(d,J=6.0Hz,1H),2.57(t,J=7.6Hz,1H),1.52(s,3H),0.74–0.63(m,3H).

[0210] Example 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (2):

[0211]

[0212] Step 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((S)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (2a):

[0213] To a solution of compound 1l (110.0 mg, 566.11 μmol, 10.0 equivalent; preparation of compound 1l is described in WO2022256842A1, pages 110-113, Intermediates B, the first eluted isomer), compound 1h (20.0 mg, 56.61 μmol, 1.0 equivalent), and N-methylimidazole (46.5 mg, 566.11 μmol, 10.0 equivalent) in acetonitrile (4.0 mL), N,N,N',N'-tetramethylchloromethanemidazone hexafluorophosphate (31.8 mg, 113.22 μmol, 2.0 equivalent) was added in portions. The reaction mixture was stirred at 20 °C for 16 hours. LC-MS analysis showed product formation. Then, 50.0 mL of water was added to the reaction mixture, the pH was adjusted to 7-8 with dilute hydrochloric acid, and the mixture was extracted three times with ethyl acetate (100 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under vacuum. The residue was purified by prep-HPLC (column type: Welch Xtimate C18 250*30mm*10um; mobile phase: water (0.05% HCl)-ACN; gradient: 50%-80%, 15 min; flow rate: 40 mL / min) to obtain a white solid compound 2a (20.0 mg, 66.7% yield).

[0214] MS(ESI): m / z calculated value [M+H] + ]:530.20, Measured value:530.2;

[0215] Step 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (2):

[0216] At 20 °C, TFA (84.4 mg, 740.31 μmol, 20 equivalents) was added to a solution of compound 2a (20.0 mg, 37.02 μmol, 1.0 equivalent) in dichloromethane (1.0 mL), and the reaction mixture was stirred at 20 °C for 16 hours. LCMS analysis showed that the reaction was complete, and the reaction solution was concentrated to dryness under vacuum. A small amount of methanol was added to the residue to dissolve it, and the pH was adjusted to 8 with saturated sodium bicarbonate solution. The resulting solution was purified by RP-TLC (reversed-phase thin-layer chromatography using Silica gel 60RP-18F254s, ACN:H2O = 3:1) to give compound 2 (5.0 mg, 27.6% yield) as a white solid.

[0217] MS(ESI): m / z calculated value [M+H] + ]:490.17, Measured value:490.2;

[0218] 1 H NMR (400MHz, chloroform-d) δ9.06 (s, 1H), 8.55 (d, J = 2.4Hz, 1H), 8.11 (dd, J = 8.5, 2.4Hz, 1H), 7.3 1(d,J=8.5Hz,1H),7.11(t,J=7.3Hz,1H),6.90(q,J=8.8Hz,1H),4.79(t,J=4.8Hz,1H),4. 41(d,J=10.5Hz,1H),4.07-3.99(m,1H),3.95(d,J=2.6Hz,3H),3.89(dd,J=11.4,3.8Hz, 1H), 3.73 (dd, J=11.3, 5.6Hz, 1H), 2.60 (d, J=7.8Hz, 1H), 1.59 (s, 3H), 0.79-0.68 (m, 3H).

[0219] Example 3: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (3):

[0220]

[0221] Step 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((R)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (3a):

[0222] To a solution of compound 1l-1 (110.0 mg, 566.11 μmol, 10.0 equivalent; the preparation method of compound 1l-1 is as described in WO2022256842A1, pages 110-113, Intermediates C, the second eluted isomer), compound 1h (20.0 mg, 56.61 μmol, 1.0 equivalent), and N-methylimidazole (46.5 mg, 566.11 μmol, 10.0 equivalent) in acetonitrile (4.0 mL), N,N,N',N'-tetramethylchloromethanemidazone hexafluorophosphate (31.8 mg, 113.22 μmol, 2.0 equivalent) was added in portions. The reaction mixture was stirred at 20 °C for 16 hours. LC-MS analysis showed product formation. Then, 50.0 mL of water was added to the reaction mixture, the pH was adjusted to 7-8 with dilute hydrochloric acid, and the mixture was extracted three times with ethyl acetate (100 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under vacuum. The residue was purified by prep-HPLC (column type: Welch Xtimate C18 250*30mm*10um; mobile phase: water (0.05% HCl)-ACN; gradient: 50%-80%, 15 min; flow rate: 40 mL / min) to obtain a white solid compound 3a (14.2 mg, 47.3% yield).

[0223] MS(ESI): m / z calculated value [M+H] + ]:530.20, Measured value:530.2;

[0224] Step 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (3):

[0225] At 20 °C, TFA (61.2 mg, 536.34 μmol, 20 equivalents) was added to a solution of compound 3a (14.2 mg, 26.82 μmol, 1.0 equivalent) in dichloromethane (0.7 mL), and the reaction mixture was stirred at 20 °C for 16 hours. LCMS analysis showed that the reaction was complete, and the reaction solution was concentrated to dryness under vacuum. A small amount of methanol was added to the residue to dissolve it, and the pH was adjusted to 8 with saturated sodium bicarbonate solution. The resulting solution was purified by RP-TLC (reversed-phase thin-layer chromatography using Silica gel 60RP-18F254s, ACN:H2O = 3:1) to give a white solid compound 3 (3.5 mg, 26.7% yield).

[0226] MS(ESI): m / z calculated value [M+H] +]:490.17, Measured value:490.2;

[0227] 1 H NMR (400MHz, chloroform-d) δ9.03 (s, 1H), 8.55 (d, J = 2.5Hz, 1H), 8.12 (dd, J = 8.6, 2.5Hz, 1H), 7.31 ( d,J=8.6Hz,1H),7.11(t,J=7.3Hz,1H),6.91(q,J=8.8Hz,1H),4.79(t,J=4.7Hz,1H),4.41( d,J=10.5Hz,1H),4.02(t,J=9.5Hz,1H),3.95(d,J=2.6Hz,3H),3.90(dd,J=11.3,3.8Hz,1H ),3.74(dd,J=11.3,5.6Hz,1H),2.59(t,J=7.9Hz,1H),1.59(s,3H),0.74(d,J=6.7Hz,3H).

[0228] Example 4: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (4):

[0229]

[0230] Step 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxylic acid (4a):

[0231] Intermediate 1j (300 mg, 0.84 mmol, 1.0 equivalent) was dissolved in methanol (15.0 mL), and 40% formaldehyde aqueous solution (1302.84 mg, 16.8 mmol, 40% by mass, 20.0 equivalent) and palladium on carbon (178.79 mg, 0.084 μmol, 0.1 equivalent, 10% palladium catalyst loading, 50% water content) were added sequentially. The reaction mixture was stirred at room temperature for 16 hours under a hydrogen atmosphere (4.0 MPa). LCMS analysis showed that the starting material was completely consumed. The reaction solution was filtered, and the filtrate was concentrated to dryness under vacuum to give a pale yellow solid compound 4a (330 mg, crude product).

[0232] MS(ESI): m / z Calcd.for[M+H + ]:371.14,found:370.9;

[0233] 1 H NMR (400MHz, DMSO-d6) δ12.99(s,1H),7.20(t,J=7.8Hz,1H),7.10(td,J=9.5,7.6Hz,1H),3.92(d,J=3.1Hz,1 H),3.66(dd,J=8.8,3.1Hz,1H),2.73(p,J=7.8Hz,1H),2.51(s,3H),1.45(s,3H),0.75(dd,J=7.6,2.4Hz,3H).

[0234] Step 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (4b):

[0235] At room temperature, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (126.26 mg, 0.45 mmol, 1.5 equivalent) was added to a 2.0 mL solution of acetonitrile containing compound 4a (110.00 mg, 0.30 mmol, 1.0 equivalent), compound 1l (69.96 mg, 0.36 mmol, 1.2 equivalent), and N-methylimidazole (73.89 mg, 0.90 mmol, 3.0 equivalent). The reaction mixture was stirred at room temperature for 16 hours. LC-MS analysis showed the reaction was complete. Then, 1.0 mL of water was added to the reaction mixture and stirred for 10 minutes to quench the reaction. 1 g of silica gel was then added and stirred. The residue was purified by normal silica gel column chromatography (PE:EA = 5:1) to give a white compound 4b (138.00 mg, 85.01% yield).

[0236] MS(ESI): m / z Calcd.for[M+H + ]:547.23,found:546.8;

[0237] Preparation of compound 4b single crystals: 20.00 mg of compound 4b was dissolved in 0.3 mL of MTBE, and 0.1 mL of n-heptane was added. The mixture was heated to 50 °C and filtered while hot. The filtrate was allowed to evaporate naturally at room temperature to obtain needle-shaped, colorless, transparent crystals. SC-XRD analysis revealed its absolute configuration as shown below. Figure 2 As shown, and the cell parameters are listed in Table 2 below:

[0238] Table 2

[0239]

[0240] Step 3: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (4):

[0241] Compound 4b (118.00 mg, 0.22 mmol, 1.0 equivalent) was dissolved in a mixed solvent of THF (1.0 mL) and water (0.18 mL), and TFA (55.19 mg, 484.00 μmol, 2.2 equivalent) was added. The mixture was stirred at 60 °C for 16 hours. LCMS analysis showed that the reaction was complete. The reaction solution was concentrated to dryness under vacuum, and the residue was purified by prep-HPLC (column type: Welch Ultimate C18 50*21.2 mm*5 μm; mobile phase: NH4HCO3 aqueous solution-ACN; gradient: 45%-55%, 13 min; flow rate: 15 mL / min) to obtain the compound of Example 4 (31.58 mg, 27.98% yield, 96.89% purity).

[0242] MS(ESI): m / z Calcd.for[M+H + ]:507.20,found:507.37;

[0243] 1 H NMR (400MHz, DMSO-d6) δ10.34(s,1H),8.63(d,J=2.5Hz,1H),8.03(dt,J=8.6,2.6Hz,1H) ,7.42(dd,J=8.4,2.3Hz,1H),7.31-7.13(m,2H),5.33(dd,J=5.1,2.3Hz,1H),4.64(t,J= 6.3Hz,1H),4.54(d,J=5.4Hz,1H),4.15(d,J=2.8Hz,1H),3.74(d,J=9.1Hz,1H),3.62(s, 1H),3.44(dd,J=11.7,6.0Hz,1H),2.94-2.85(m,1H),1.52(s,3H),0.77(d,J=7.4Hz,3H).

[0244] Example 5: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (5):

[0245]

[0246] Step 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (4):

[0247] At room temperature, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (126.26 mg, 0.45 mmol, 1.5 equivalent) was added to a 2.0 mL solution of acetonitrile containing compound 4a (110.00 mg, 0.30 mmol, 1.0 equivalent), compound 1l-1 (69.96 mg, 0.36 mmol, 1.2 equivalent), and N-methylimidazole (73.89 mg, 0.90 mmol, 3.0 equivalent). The reaction mixture was stirred at room temperature for 16 hours. LC-MS analysis showed the reaction was complete. Then, 1.0 mL of water was added to the reaction mixture and stirred for 10 minutes to quench the reaction. 1 g of silica gel was then added and stirred. The residue was purified by normal silica gel column chromatography (PE:EA = 5:1) to give a white compound 5a (128.00 mg, 78.85% yield).

[0248] MS(ESI): m / z Calcd.for[M+H + ]:547.23,found:546.8;

[0249] Step 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (5):

[0250] Compound 5a (109.31 mg, 0.20 mmol, 1.0 equivalent) was dissolved in a mixed solvent of THF (0.92 mL) and water (0.16 mL), and TFA (50.17 mg, 440.00 μmol, 2.2 equivalent) was added. The mixture was stirred at 60 °C for 16 hours. LCMS showed that the reaction was complete. The reaction solution was concentrated to dryness under vacuum, and the residue was purified by prep-HPLC (column type: Welch Ultimate C18 50*21.2 mm*5 μm; mobile phase: NH4HCO3 aqueous solution-ACN; gradient: 45%-55%, 13 min; flow rate: 15 mL / min) to obtain 5 (69.66 mg, 68.75% yield, 99.97% purity).

[0251] MS(ESI): m / z Calcd.for[M+H+ ]:507.20,found:507.37;

[0252] 1 H NMR (400MHz, DMSO-d6) δ10.34(s,1H),8.63(d,J=2.5Hz,1H),8.03(dt,J=8.6,2.6Hz,1H) ,7.42(dd,J=8.4,2.3Hz,1H),7.31-7.13(m,2H),5.33(dd,J=5.1,2.3Hz,1H),4.64(t,J= 6.3Hz,1H),4.54(d,J=5.4Hz,1H),4.15(d,J=2.8Hz,1H),3.74(d,J=9.1Hz,1H),3.62(s, 1H),3.44(dd,J=11.7,6.0Hz,1H),2.94-2.85(m,1H),1.52(s,3H),0.77(d,J=7.4Hz,3H).

[0253] Example 6: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (6):

[0254]

[0255] Step 1: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-2,2-dimethyl-1,3-dioxolane-4-yl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (6a):

[0256] Compound 1l-1 (34.18 mg, 176.00 μmol, 2.0 equivalent) and compound 1k (40.0 mg, 88.23 μmol, 1.0 equivalent) were dissolved in anhydrous tetrahydrofuran (2 mL), and the reaction mixture was stirred at 70 °C for 5 days. LCMS analysis showed product formation. The reaction solution was concentrated under vacuum, and the residue was purified by normal-phase silica gel column chromatography (petroleum ether: ethyl acetate = 5:1 to 2:1) to give a white solid compound 6a (30.0 mg, 63.85% yield).

[0257] MS(ESI): m / z Calcd.for[M+H + ]:533.20,found:532.8;

[0258] Step 2: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-(methoxy-d3)phenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (6):

[0259] At 25 °C, TFA (307 mg, 2.69 mmol, 57.3 equivalents) was added to a solution of compound 6a (25.0 mg, 46.95 μmol, 1.0 equivalent) in dichloromethane (2.0 mL). The reaction mixture was stirred at 20 °C for 3 hours. LCMS analysis showed that the reaction was complete. The reaction solution was concentrated to dryness under vacuum. A small amount of methanol was added to the residue to dissolve it, and the pH was adjusted to 8 with ammonia. The resulting solution was purified by prep-HPLC (column: Welch Xtimate C18150*21.2 mm*5 μm; mobile phase: NH4HCO3 aqueous solution-ACN; gradient: 45%-55%, 13 min; flow rate: 15 mL / min) to give a white solid compound 6 (9.30 mg, 40.23% yield).

[0260] MS(ESI): m / z Calcd.for[M+H + ]:492.29,found:493.47;

[0261] 1 H NMR (400MHz, DMSO-d6) δ10.32(s,1H),8.60(d,J=2.5Hz,1H),7.97(dd,J=8.5,2.6Hz,1H),7.4 0(d,J=8.5Hz,1H),7.26-7.11(m,2H),5.32(d,J=4.6Hz,1H),4.63(t,J=5.8Hz,1H),4.52(dt,J =7.8,4.2Hz,1H),4.23(dd,J=8.8,6.3Hz,1H),3.94(t,J=8.4Hz,1H),3.66-3.57(m,1H),3.47- 3.39(m,1H),3.07(d,J=6.3Hz,1H),2.57(t,J=7.7Hz,1H),1.52(s,3H),0.69(d,J=7.3Hz,3H).

[0262] Example 7: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((S)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (7):

[0263]

[0264] Referring to the synthesis method of compound 4 in Synthesis Example 4, compound 7 can be synthesized by replacing the starting intermediate 1j with intermediate 1h.

[0265] MS(ESI): m / z Calcd.for[M+H + ]:504.18,found:504.41;

[0266] 1 H NMR (400MHz, DMSO-d6) δ10.34(s,1H),8.63(dd,J=2.6,0.7Hz,1H),8.03(dd,J=8.6,2.5Hz,1H),7.42(d,J=8.5 Hz,1H),7.31–7.23(m,1H),7.18(td,J=9.5,7.6Hz,1H),5.32(d,J=4.9Hz,1H),4.64(t,J=5.9Hz,1H),4.53(dt ,J=6.8,4.5Hz,1H),4.15(d,J=3.5Hz,1H),3.88(d,J=2.3Hz,3H),3.74(dd,J=8.9,3.4Hz,1H),3.62(ddd,J=10 .5,6.0,4.2Hz,1H),3.43(ddd,J=10.9,6.9,5.8Hz,1H),2.89(p,J=7.7Hz,1H),1.52(s,3H),0.84–0.69(m,3H).

[0267] Example 8: Synthesis of (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-1,4,5-trimethyl-5-(trifluoromethyl)pyrrolidine-2-carboxamide (8):

[0268]

[0269] Referring to the synthesis method of compound 5 in Synthesis Example 5, compound 8 can be synthesized by replacing the starting intermediate 1j with intermediate 1h.

[0270] MS(ESI): m / z Calcd.for[M+H + ]:504.18,found:504.36;

[0271] 1H NMR (400MHz, DMSO-d6) δ10.34(s,1H),8.65–8.60(m,1H),8.03(dd,J=8.5,2.5Hz,1H),7.42(d,J=8.5Hz,1H), 7.27(t,J=7.8Hz,1H),7.18(td,J=9.5,7.5Hz,1H),5.32(d,J=4.9Hz,1H),4.64(t,J=5.9Hz,1H),4.54(dt,J= 6.8,4.5Hz,1H),4.15(d,J=3.4Hz,1H),3.88(d,J=2.2Hz,3H),3.73(dd,J=8.9,3.4Hz,1H),3.62(ddd,J=10.4 ,6.0,4.1Hz,1H),3.43(ddd,J=11.0,7.0,5.8Hz,1H),2.89(p,J=7.8Hz,1H),1.52(s,3H),0.83–0.70(m,3H).

[0272] Test Example 1:

[0273] 1. Restrictive activity of the test compound against human NaV1.8

[0274] The effect of the test substance on the channel current of stably overexpressed NaV1.8 was detected using manual patch-clamp technique to determine its blocking activity on NaV1.8.

[0275] 1.1. Cell Culture

[0276] The experiment used a CHO cell line that stably expresses the human Nav1.8 sodium channel. Gene information: Sodium channel, voltage-gated, type 8, alpha (SCN10A), cDNA strictly similar to GenBank accession number: NM_006514.

[0277] Cells were cultured in HAM'S / F-12 medium containing 10% fetal bovine serum and 10 μg / mL Blasticidin, 200 μg / mL Hygromycin B, and 100 μg / mL Zeocin at 37°C and 5% CO2. For expansion or maintenance culture, cells were treated with 0.25% Trypsin-EDTA, washed, centrifuged, and seeded into 6 cm cell culture dishes at a density of 2.5 × 10⁶ cells per dish. 5 100 cells (final volume: 5 mL). To maintain cell electrophysiological activity, cell density should not exceed 80%.

[0278] Prior to patch-clamp assay, cells were separated using 0.25% Trypsin-EDTA, and 6.5 × 10⁶ cells were collected. 3 The cells were seeded onto a coverslip and cultured in a 24-well plate (final volume: 500 μL) for 18 hours before being tested.

[0279] 1.2 Electrophysiological Recording

[0280] ●Extracellular fluid: K-007-1

[0281] 140mM NaCl, 3.5mM KCl, 1mM MgCl2·6H2O, 2mM CaCl2·2H2O, 10mM D-

[0282] Glucose, 10mM HEPES, 1.25mM NaH2PO4·2H2O, pH adjusted to 7.4 with NaOH.

[0283] ●Intracellular fluid: Nav-001-2

[0284] Adjust pH to 7.2 with 50mM CsCl, 10mM NaCl, 10mM HEPES, 60mM CsF, 20mM EGTA, and CsOH.

[0285] ●Instrument information is shown in Table 3 below:

[0286] Table 3: Instrument Information

[0287]

[0288] ● Patch clamp testing

[0289] Before the Nav1.8 channel current assay, the blank control stock solution (DMSO) was diluted in 10 ml of extracellular fluid to prepare the working solution. The positive control and test substance were diluted with different doses of DMSO according to their final concentrations, and then diluted with extracellular fluid to prepare the working solutions. 100 nM TTX was added to each working solution to block the TTX-S current. The working solutions were sonicated for 20 min before patch-clamp assays.

[0290] The patch-clamp procedure begins by drawing a capillary glass tube into a recording electrode using a microelectrode drawing device. The electrode, filled with intracellular fluid, is then inserted into the microelectrode holder. Under an inverted microscope, the microelectrode manipulator is used to immerse the electrode in the extracellular fluid, and the electrode resistance (Rpip) is recorded. Next, the electrode is slowly brought into contact with the cell surface, and negative pressure is applied to aspirate and form a GΩ seal. Fast capacitance compensation is then performed, and negative pressure is continued to rupture the cell membrane, establishing a whole-cell recording mode. Finally, slow capacitance compensation is performed, and experimental parameters such as series resistance (Rs) are recorded. No leakage compensation is applied.

[0291] Once the Nav1.8 current recorded in whole cells stabilized, drug administration began. Each drug concentration was administered for approximately 5 minutes (or until the current stabilized), followed by the next concentration. A coverslip containing cells was placed in a recording bath under an inverted microscope. Blank control solution and working solution of the test compound were sequentially flowed through the recording bath from low to high concentration using gravity perfusion, acting on the cells. A peristaltic pump was used for fluid exchange during recording. The current detected in the solution without the compound served as a control for each cell. Each concentration was independently replicated 2-3 times. All electrophysiological experiments were performed at room temperature.

[0292] The voltage stimulation protocol for whole-cell patch-clamp recording of Nav1.8 currents is as follows: After whole-cell sealing, the voltage is clamped at -120 mV. For recording the resting state of sodium current, the voltage is maintained for 5 seconds, then depolarized to 0 mV, followed by a depolarization pulse (TP1) to 0 mV for 50 ms to detect the resting sodium current. For recording the half-inactivated state, different voltage steps are first applied, maintained for 5 seconds, followed by a 0 mV depolarization pulse to obtain the half-inactivated voltage (Vhalf). Then, Vhalf is maintained for 5 seconds, followed by restoring the voltage to -120 mV for 20 ms, and then a depolarization pulse (TP2) to 0 mV for 50 ms to detect the half-inactivated sodium current. Experimental data were acquired using an EPC 10 amplifier (HEKA) and stored in PatchMaster (HEKA) software.

[0293] 1.3 Data Analysis

[0294] First, normalize the current and blank control current after each drug concentration. Then calculate the inhibition rate corresponding to each drug concentration. For each concentration inhibition rate, the mean (Mean), standard deviation (SD), and standard error (SE) were calculated, and the data are expressed as mean ± SE.

[0295] Y=Bottom+(Top-Bottom) / (1+10^((LogIC 50 -X)*HillSlope))

[0296] Calculate the IC for each compound using the above equations. 50 The values ​​were calculated, and a nonlinear fit was performed on the concentration-effect curve, where IC50 was used. 50 This is the half-inhibitory concentration (IC50). 50 The calculations and curve fitting were performed using GraphPad Prism software.

[0297] The blocking rates of the compounds of the present invention against NaV1.8 are shown in Table 4 below:

[0298] Table 4

[0299] Compound numbering IC50(nM) 30 nM inhibition rate 1 10.37 2 14.26 3 46.55 4 55.35％ 5 56.13％ 6 46.50 7 59.22％ 8 15.66 75.02％

[0300] Test Example 2:

[0301] 2. Stability of the compound in liver microsomes:

[0302] 2.1 Preparation of intermediate storage solutions for test compounds:

[0303] 2.1.1. Working solution: Dilute 5 μL of the stock solution of the test compound or control compound (10 mM DMSO solution) with 495 μL of acetonitrile (ACN) to obtain an intermediate stock solution (100 μM, 99% ACN).

[0304] 2.2. Preparation of NADPH coenzyme working solution:

[0305] 2.2.1. Materials: Tetrasodium reduced coenzyme II (NADPH·4Na, supplier: BONTAC, Cat. No. BT04);

[0306] 2.2.2. Preparation process: Weigh an appropriate amount of NADPH powder and dilute it with 10mM MgCl2 buffer (working solution concentration: 10mM; final concentration of the reaction system: 1mM).

[0307] 2.3. Preparation of liver microsomal working solution:

[0308] 2.3.1. Materials: Rat liver microsomes (supplier: Xenotech, Cat No. R1000)

[0309] 2.3.2. Preparation process: Prepare an appropriate concentration of liver microsomal working solution in 100mM potassium phosphate buffer solution;

[0310] 2.4. Termination solution:

[0311] An acetonitrile (ACN) solution at 4°C containing 200 ng / mL tolbutamide and 200 ng / mL labetalol as internal standards.

[0312] 2.5. Operating Procedures:

[0313] 2.5.1. Preheat the empty incubation plates T60 and NCF60 for 10 minutes.

[0314] 2.5.2. Dilute liver microsomes to a concentration of 0.56 mg / mL with 100 mM potassium phosphate buffer.

[0315] 2.5.3. Transfer 445 μL of liver microsome working solution (0.56 mg / mL) to preheated T60 and NCF60 incubation plates, then preheat the plates at 37°C for 10 minutes while maintaining shaking. Transfer 54 μL of liver microsomes to each well of a blank plate, add 6 μL of NAPDH coenzyme solution to the blank plate, and finally transfer 180 μL of stop solution to the blank plate.

[0316] 2.5.4 Add 5 μL of the compound working solution (100 μM) to incubation plates T60 and NCF60 containing liver microsomes and mix three times.

[0317] 2.5.5. Add 50 μL of buffer to the NCF60 incubation plate and mix three times. Start timing and incubate at 37°C for 60 min while the incubation plate is shaking.

[0318] 2.5.6. Add 180 μL of quenching solution and 6 μL of NAPDH coenzyme working solution to the quenching plate T0 in sequence, ensuring that the plate is cold to prevent the incubation solution from evaporating.

[0319] 2.5.7. For T60 plates, after thoroughly mixing three times, immediately transfer 54 μL of the mixture (at time 0 min) to quenching plate T0, then add 44 μL of NAPDH coenzyme working solution to incubation plate T60. Start timing:

[0320] Table 5: Final concentrations of each component in the reaction solution

[0321]

[0322] 2.5.8. At time points of 5, 15, 30, 45 and 60 minutes, add 180 μL of quenching solution to the quenching plate, and at each time point transfer 60 μL of the reaction solution in the T60 plate to the quenching plate.

[0323] Table 6: Incubation time of reaction solution

[0324]

[0325] 2.5.9. For NCF60 plates, mix well, and at 60 minutes, transfer 60 μL of the reaction solution from the NCF60 incubation solution to a quenching plate containing 180 μL of quenching solution.

[0326] Table 7: NCF60 incubation

[0327]

[0328]

[0329] 2.5.10. All sample plates were mixed on a shaker for 10 min, and then centrifuged at 4000 rpm for 20 min at 4°C.

[0330] 2.5.11. Transfer 80 μL of supernatant to 240 μL of HPLC water and mix on a shaker for 10 minutes.

[0331] 2.5.12. Each sample to be analyzed should be sealed and mixed on a shaker for 10 minutes before being injected into the LC-MS / MS for analysis.

[0332] 2.6 Data Analysis:

[0333] 2.6.1. Calculate t based on first-order elimination kinetics 1 / 2 And Clint(mic) value:

[0334] The first-order elimination kinetic equation is:

[0335]

[0336] when

[0337]

[0338] Table 8: Liver microsomal stability results for some compounds:

[0339] Compound numbering <![CDATA[t 1 / 2 (min)]]> 1 >145 2 87.8 Reference compound 1 103.2

[0340] The structural formula of control compound 1 (referring to compound 1 in Example 1 of WO2022256622A1: (2R,3S,4S,5R)-3-(3,4-difluoro-2-methoxyphenyl)-N-(6-((R)-1,2-dihydroxyethyl)pyridin-3-yl)-4,5-dimethyl-5-(trifluoromethyl)tetrahydrofuran-2-carboxamide) is as follows:

[0341]

[0342] Test Example 3: Test of Free Drug Ratio in Human Plasma

[0343] On the day of the experiment, human plasma samples (purchased from Biomex) were thawed under running tap water, centrifuged at 3220g for 5 minutes, and blood clots were removed. The pH value of the obtained plasma was measured and adjusted to 7.4±0.1 using 1% phosphoric acid or 1N sodium hydroxide as needed.

[0344] Pre-treat the dialysis membrane according to the manufacturer's instructions: Soak the dialysis membrane strips in ultrapure water at room temperature for about 1 hour. Afterward, separate each strip containing two membrane layers and soak it in ethanol:water (20:80 v:v) for about 20 minutes. It is then ready for use or can be stored at 2-8℃ (can be stored for 1 month). Before the experiment, rinse the membrane in ultrapure water and soak it for 20 minutes.

[0345] Take 10 mM of the test compound or control warfarin in DMSO solution, dilute it to 400 μM with DMSO, then take 3 μL and add it to 597 μL of blank plasma matrix solution to obtain 2 μM compound solutions.

[0346] Transfer 50 μl of the test compound solution or control solution to a sample collection plate, three replicates per sample. Add 50 μl of blank PBS buffer to each well, followed by 500 μl of stop solution (acetonitrile containing 250 nmol / L toluidine and 250 nmol / L labetalol). Transfer 100 μl of the solution to the donor end of the dialysate well in each well, and add 100 μl of dialysate to the receiver end. Then incubate the plate at 37 ± 1 °C, 5% CO2, with shaking at approximately 100 rpm for 4 hours.

[0347] After dialysis, 50 μL of sample from both the buffer side and the plasma matrix side of the dialysis apparatus were placed into new 96-well sample collection plates. An equal volume of the opposite blank matrix (buffer or plasma matrix) was added to each sample, ensuring a plasma matrix to dialysis buffer volume ratio of 1:1 (v:v) in each well, for a final volume of 100 μL. All samples were then subjected to protein precipitation before LC-MS / MS analysis.

[0348] Unbound % , bound % , and recovered % are calculated using the following formula:

[0349] Unbound % = 100 × F / T

[0350] Bound % = 100 – Unbound %

[0351] Recovery rate % = 100 × (F + T) / T0

[0352] F = the peak area ratio of the test compound to the internal reference compound in the buffer solution after 4 hours of incubation.

[0353] T = After 4 hours of incubation, the peak area ratio of the test compound to the internal control compound on the plasma matrix side.

[0354] T0 = ​​the peak area ratio of the test compound to the internal reference compound at zero point.

[0355] Table 9: Percentage of free drugs in human plasma:

[0356] Compound numbering proportion of free drugs in human plasma 1 4.9％ 2 6.4％ 6 8.3％ 8 1.7％ Reference compound 1 5.6％

[0357] Conclusion: The data in Table 9 show that some of the compounds according to the present invention have a better proportion of free drug in human plasma, which can better exert the analgesic effect.

[0358] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A class of compounds represented by general formula (I) or general formula (II), their stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts: in, R1 is selected from hydrogen atom, C 1-6 Alkyl group; preferably hydrogen atom, C 1-4 alkyl; R2 is selected from C 1-6 Alkyl, C 1-6 Alkoxy, deuterated C 1-6 Alkyl, Halogenated C 1-6 alkyl; R3 is selected from C 1-6 Alkyl, deuterated C 1-6 Alkyl, Halogenated C 1-6 Alkyl; preferably C 1-4 Alkyl, deuterated C 1-4 Alkyl, Halogenated C 1-4 alkyl; R9 is selected from hydrogen atom, halogen atom, amino group, hydroxyl group, carbonyl group, cyano group, amide group (-CONH2), substituted or unsubstituted C atom. 1-6 Alkyl, wherein the substituted C 1-6 Alkyl refers to C 1-6 The alkyl group is substituted by one to three substituents selected from the following: halogen atom, nitro, amino, hydroxyl, cyano, formamido; In general formula (II), X1 and X2 are N or C, and at least one of them is an N atom; n is an integer selected from 0, 1, 2, 3 or 4.

2. The compound of general formula (I) or general formula (II), its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts according to claim 1, characterized in that, Preferably, R1 is selected from hydrogen atom, methyl, ethyl, n-propyl, and isopropyl; more preferably, it is hydrogen atom, methyl, or ethyl. Preferably, R2 is selected from C 1-4 Alkyl, deuterated C 1-4 Alkyl, Halogenated C 1-4 Alkyl; more preferably methyl, ethyl, n-propyl, isopropyl, deuterated methyl; more preferably methyl or ethyl; Preferably, R3 is selected from C 1-4 Alkyl, deuterated C 1-4 Alkyl, Halogenated C 1-4 Alkyl; more preferably methyl, ethyl, n-propyl, isopropyl, deuterated methyl; even more preferably methyl, ethyl, deuterated methyl; Preferably, R9 is selected from hydrogen atom, halogen atom, amino group, hydroxyl group, amide group (-CONH2), substituted or unsubstituted C atom. 1-4 Alkyl, wherein the substituted C 1-4 Alkyl refers to C 1-4 The alkyl group is substituted with one to three substituents selected from the following: halogen atom, hydroxyl group; more preferably, R9 is selected from hydrogen atom, halogen atom, amino group, hydroxyl group, amide group (-CONH2), substituted or unsubstituted C group. 1-4 Alkyl, wherein the substituted C 1-4 Alkyl refers to C 1-4 The alkyl group is substituted with one or two hydroxyl groups; more preferably, R9 is selected from hydrogen atom, halogen atom, hydroxyl group, amide group (-CONH2), trifluoromethyl, hydroxymethyl, 1,2-dihydroxyethyl, 1,2-dihydroxypropyl, 2,3-dihydroxypropyl; Preferably, n is an integer selected from 0, 1, or 2; more preferably, it is an integer selected from 0 or 1.

3. The compound of general formula (II), its stereoisomers, tautomers, deuterated derivatives, or pharmaceutically acceptable salts according to claim 1, characterized in that, It can be represented by the following general formula (IIa) or general formula (IIb): The definitions of R1, R2, R3, and R9 are the same as in general formula (II).

4. The compound of general formula (I), general formula (II), general formula (IIa) or general formula (IIb) according to claim 1, its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts are selected from the following compounds:

5. Use of the compound of any one of general formulas (I), (II), (IIa) or (IIb), its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts as a Nav1.8 inhibitor according to any one of claims 1 to 4.

6. A pharmaceutical composition comprising a therapeutically effective amount of a compound of any one of general formulas (I), (II), (IIa) or (IIb), its stereoisomers, tautomers, deuterated derivatives or pharmaceutically acceptable salts as an active ingredient, and pharmaceutically acceptable excipients, as claimed in any one of claims 1 to 4.

7. Use of the compound, stereoisomer, tautomer, deuterated derivative or pharmaceutically acceptable salt thereof, or the pharmaceutical composition according to any one of claims 1 to 4, of general formula (I), general formula (II), general formula (IIa) or general formula (IIb), or the pharmaceutical composition according to claim 6, in the preparation of a medicament for treating acute and chronic pain.

8. A method for treating chronic pain, the method comprising providing a subject with a therapeutically effective amount of a compound of any one of general formulas (I), (II), (IIa), or (IIb), a stereoisomer, tautomer, deuterated derivative, or pharmaceutically acceptable salt thereof, or a pharmaceutical composition according to claim 6, as described in any one of claims 1 to 4.

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