Substituted naphthylmethyl oxadiazole-anilines and uses thereof

Abstract

The application belongs to the technical field of medicine, and discloses a substituted naphthalene methyl oxadiazole-aniline compound, a preparation method thereof, a pharmaceutical composition taking the compound as an active ingredient, and application of the compound in treatment and / or prevention of infectious diseases caused by a coronavirus. Specifically, the application relates to a compound shown in formula (I) and isomers thereof, or a pharmaceutically acceptable salt thereof and a pharmaceutical composition containing the compound, wherein R1, R2, R3, R4, m and n are as described in the specification. The application aims to prepare a new compound with anti-coronavirus activity, which can be used as a potential new drug for the treatment or preventive treatment of infectious diseases caused by a virus, in particular, diseases caused by a coronavirus.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology. In particular, it relates to substituted naphthylmethyloxadiazole-aniline compounds of general formula (I), their preparation methods, pharmaceutical compositions with the compounds as active ingredients, and their use in treating and / or preventing infectious diseases caused by coronaviruses, especially the novel coronavirus (SARS-CoV-2). Background Technology

[0002] Viral infections have consistently threatened human life and health, and currently, effective antiviral drugs are still lacking for most viruses. COVID-19, caused by the novel coronavirus SARS-CoV-2, is an infectious disease characterized by its high insidiousness and strong infectivity, posing a significant threat to public health and safety. The efficacy of existing antiviral drugs and traditional Chinese medicine is uncertain, and clinical treatment remains primarily supportive and symptomatic. Currently, there are no specific drugs targeting this virus. Therefore, based on the structure of coronaviruses, finding targeted, highly effective, and low-toxicity drugs to treat this virus is of great significance. SARS-CoV-2 encodes 16 non-structural proteins. As the protein structures have been elucidated one by one, drug development technologies based on the druggable target structures of coronaviruses have begun to be widely adopted. A representative advancement is the successful market launch of Paxlovid, an inhibitor targeting Mpro. Papain-like protease (PLpro) is a 300-amino acid non-structural protein responsible for the maturation and cleavage of viral precursor proteins, essential for viral replication in cells. Furthermore, PLpro is involved in key processes such as viral antagonism of the host's innate immunity. The multiple functions of PLpro in the viral life cycle make it an important research target for drugs against the novel coronavirus. GRL0617 is a lead compound discovered after screening and structural optimization of SARS-CoV PLpro. It has high inhibitory activity and affinity for the target enzyme. The three-dimensional structure of PLpro has been resolved, and the crystal structure of its complex with GRL0617 has also been reported. These research results lay the foundation for the development of novel PLpro inhibitors. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a novel substituted naphthylmethyloxadiazole-aniline compound with anti-coronavirus, especially SARS-CoV / SARS-CoV-2, and PLpro inhibitory activity. This invention discovers that substituted naphthylmethyloxadiazole-aniline compounds possess strong PLpro inhibitory activity and anti-SARS-CoV / SARS-CoV-2 activity, while exhibiting low cytotoxicity and superior metabolic stability compared to GRL0617. These compounds can be used for the treatment or prevention of infectious diseases caused by viruses, particularly those caused by the novel coronavirus. This invention is based on these findings. Invention Overview

[0005] Therefore, in a first aspect, the present invention provides compounds of general formula (I) and their isomers, or pharmaceutically acceptable salts thereof.

[0006]

[0007] in,

[0008] R1 can be hydrogen, methyl, ethyl, propyl, or isopropyl.

[0009] R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents.

[0010] R3 can be hydrogen, methyl, ethyl, or propyl.

[0011] m is 0 or 1;

[0012] R4 is a substituted or unsubstituted C3-C7 cycloalkyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted thiophene, a substituted or unsubstituted furanyl, or a substituted or unsubstituted spiro[3,3]heptyl;

[0013] The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

[0014] In a preferred embodiment, the compound has the structural formula shown in (II):

[0015]

[0016] in,

[0017] R1 is hydrogen or methyl;

[0018] R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents.

[0019] m is 0 or 1;

[0020] R4 is a substituted or unsubstituted C3-C7 cycloalkyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted thiophene, a substituted or unsubstituted furanyl, or a substituted or unsubstituted spiro[3,3]heptyl;

[0021] The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

[0022] In some respects, the compound of formula (II) wherein:

[0023] R1 is hydrogen or methyl;

[0024] R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents.

[0025] m is 0;

[0026] R4 is a substituted or unsubstituted C3-C7 cycloalkyl group or a substituted or unsubstituted spiro[3,3]heptyl group;

[0027] The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, hydroxymethyl, carboxyl, sulfonic acid, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl.

[0028] In other respects, the compound of formula (II) wherein:

[0029] R1 is hydrogen or methyl;

[0030] R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents.

[0031] m is 0 or 1;

[0032] R4 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted thiophene group, or a substituted or unsubstituted furanyl group;

[0033] The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

[0034] In another preferred embodiment, the compound has the structural formula shown in (III):

[0035]

[0036] in,

[0037] R1 is hydrogen or methyl;

[0038] R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents.

[0039] R3 represents hydrogen or methyl;

[0040] m is 0 or 1;

[0041] R4 is a substituted or unsubstituted phenyl group or a substituted or unsubstituted thiophene group;

[0042] The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, monofluoromethyl, difluoromethyl, trifluoromethyl, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

[0043] The pharmaceutically acceptable salts described in this invention are salts formed by the compounds of this invention with an acid selected from the following: hydrochloric acid, p-toluenesulfonic acid, tartaric acid, maleic acid, lactic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, citric acid, acetic acid, or trifluoroacetic acid. Hydrochloric acid, p-toluenesulfonic acid, or trifluoroacetic acid are preferred.

[0044] According to any one of the first aspects of the present invention, the target compound of the present invention (represented by a structural formula or described by a systematic name) prepared in the examples and its isomers, and pharmaceutically acceptable salts thereof.

[0045] According to any one of the first aspects of the present invention, the compound is selected from the following:

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] A second aspect of the present invention provides a method for preparing the compound according to any one of the first aspects of the present invention, comprising the following steps:

[0053]

[0054] Compound A is reacted with compound B in a suitable solvent (e.g., dichloromethane, tetrahydrofuran, acetonitrile, 1,4-dioxane, preferably 1,4-dioxane) under the action of reagents CDMT and NMM, in the presence of air or an inert gas (Ar or N2), at -10°C to 50°C for 1 to 24 hours, preferably at room temperature for 2 to 3 hours, followed by heating to reflux for 1 to 24 hours, preferably 6 to 12 hours, to obtain the compound shown in formula C; the compound shown in formula C is reacted with ammonium chloride and metal powder (zinc powder, iron powder, preferably zinc powder) in a suitable solvent (e.g., methanol, ethanol, methanol / water, ethanol / water, preferably methanol / water) at -10°C to 60°C for 1 to 24 hours, preferably at room temperature for 2 to 4 hours, in the presence of ammonium chloride and metal powder (zinc powder, iron powder, preferably zinc powder), to obtain the compound shown in formula D;

[0055]

[0056] The compound shown in Formula D is reacted with compound R4Br in a suitable solvent (e.g., DMF, DMSO, preferably DMF) under alkaline conditions (e.g., sodium carbonate, potassium carbonate, cesium carbonate, preferably potassium carbonate) and under the protection of air or an inert gas (Ar or N2) at -10°C to 120°C for 1 to 24 hours, preferably at 60°C to 90°C for 4 to 8 hours, to obtain the compound shown in Formula (I); or the compound shown in Formula D is reacted with compound R4Br in a suitable solvent (e.g., tetrahydrofuran, acetonitrile, 1,4-dioxane, toluene, preferably toluene) under the action of the reagents palladium acetate, BINAP, and cesium carbonate and under the protection of an inert gas (Ar or N2) at -10°C to 120°C for 1 to 24 hours, preferably at 90°C to 110°C for 4 to 8 hours, to obtain the compound shown in Formula (I);

[0057]

[0058] The compound shown in Formula D is reacted with compound R4CHO in a suitable solvent (e.g., dichloromethane, tetrahydrofuran, acetonitrile, 1,2-dichloroethane, preferably 1,2-dichloroethane) under acidic conditions (e.g., formic acid, acetic acid, preferably acetic acid) and a reducing agent (e.g., sodium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, preferably sodium triacetoxyborohydride) at -10°C to 50°C for 1 to 24 hours, wherein the reaction is preferably carried out at room temperature for 6 to 12 hours, to obtain the compound shown in Formula (I);

[0059]

[0060] The compound shown in Formula D is reacted with compound R3I in a suitable solvent (e.g., tetrahydrofuran, DMF, DMSO, acetone, preferably acetone) under alkaline conditions (e.g., sodium hydride, sodium carbonate, potassium carbonate, cesium carbonate, preferably potassium carbonate) under the protection of air or an inert gas (Ar or N2) at -10°C to 120°C for 1 to 24 hours, preferably at 0°C to 70°C for 4 to 8 hours, to obtain the compound shown in Formula E. The compound shown in Formula E is reacted with compound R4CHO in a suitable solvent (e.g., dichloromethane, tetrahydrofuran, acetonitrile, 1,2-dichloroethane, preferably 1,2-dichloroethane) under acidic conditions (e.g., formic acid, acetic acid, preferably acetic acid) and a reducing agent (e.g., sodium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, preferably sodium triacetoxyborohydride) at -10°C to 50°C for 1 to 24 hours, wherein the reaction is preferably carried out at room temperature for 6 to 12 hours, to obtain the compound shown in Formula (I);

[0061] The third aspect of the present invention provides the use of the compounds and isomers thereof, or pharmaceutically acceptable salts thereof, described in any of the first aspects of the present invention in the preparation of papain-like protease (PLpro) inhibitors.

[0062] A fourth aspect of the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of any of the compounds of the first aspect of the present invention and their isomers, or pharmaceutically acceptable salts thereof, and optionally one or more pharmaceutically acceptable excipients.

[0063] The fifth aspect of the present invention provides the use of any of the compounds and isomers thereof, or pharmaceutically acceptable salts thereof, as described in any of the first aspects of the present invention, or the pharmaceutical compositions described in any of the fourth aspects of the present invention, in the preparation of medicaments for treating and / or preventing infectious diseases caused by coronaviruses.

[0064] The foregoing description only outlines certain aspects of the invention, but is not limited to these aspects. These and other aspects will be described in more detail below. Invention Details

[0066] The various aspects and features of the present invention will be further described below.

[0067] The various terms and phrases used in this invention have their general meanings known to those skilled in the art. Nevertheless, this invention still aims to provide a more detailed explanation and interpretation of these terms and phrases. In the event of any inconsistency between the mentioned terms and their known meanings and the meanings expressed in this invention, the meanings shall prevail. Below are definitions of various terms used in this invention. These definitions apply to all terms used throughout this specification, unless otherwise specified in the specific context.

[0068] Generally, the term "substituted or unsubstituted" indicates that one or more hydrogen atoms in a given structure are substituted by a specific substituent. Unless otherwise indicated, an optional substituent may be substituted at each substituted position of the group. When the given structure is always capable of being substituted at more than one position by one or more substituents selected from a specific group, the substituents may be substituted at each position in the same or different manner.

[0069] C i -C j This indicates a portion having an integer number of carbon atoms from "i" (inclusive) to an integer number of carbon atoms from "i" (inclusive). Therefore, for example, C1-C3 alkyl refers to an alkyl group having 1 to 3 (inclusive) carbon atoms.

[0070] As described herein, the term "alkyl" refers to an alkyl group having a specified number of carbon atoms, which is a straight-chain or branched alkyl group, and may include its daughter groups, for example, when referring to "C1-C3 alkyl", it may also include groups in the subrange of C1-C2 alkyl, as well as specific groups such as methyl, ethyl, n-propyl, isopropyl.

[0071] As described herein, the terms “alkoxy” and “alkylamine” are conventional expressions referring to alkyl groups, which are respectively attached to the remainder of a molecule by an oxygen atom or an amino group, wherein the alkyl group is as described in this invention.

[0072] As described herein, the term "halogenated alkyl" means that the hydrogen atom in an alkyl group is replaced by one or more halogen atoms, and such examples include, but are not limited to, monofluoromethyl, monofluoromethoxy, etc.

[0073] As described herein, the term "cycloalkyl" refers to a cyclic alkyl group having a specified number of cyclic carbon atoms, and may include its subgroups, such as when referring to "C3-C7 cycloalkyl", it may also include subranges such as C3-C5 cycloalkyl, C4-C7 cycloalkyl, and specific groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0074] As described herein, the term "ring" refers to a substituted or unsubstituted cycloalkyl group. So-called rings include fused rings. The number of atoms on a ring is generally defined as the ring number; for example, a "C3-C6 ring" refers to 3-6 atoms arranged in a ring.

[0075] As described in this article, the terms “halogen”, “halogenated”, etc., refer to fluorine (F), chlorine (Cl), or bromine (Br).

[0076] In this invention, "room temperature" refers to a temperature ranging from 10°C to 40°C. In some embodiments, "room temperature" refers to a temperature ranging from 20°C to 30°C; in other embodiments, room temperature refers to 25°C.

[0077] As described herein, the term "effective amount" refers to a dosage of medicine that can achieve the desired therapeutic effect on the disease or condition described in this invention in a subject.

[0078] As described herein, the term "pharmaceutically acceptable," for example, when describing "pharmaceutically acceptable salt," indicates that the salt is not only physiologically acceptable to the subject but can also refer to a synthetic substance that has pharmaceutical value.

[0079] As described herein, the term "pharmaceutical composition" can also refer to a "composition" which can be used to treat the disease or condition described in this invention in subjects, particularly mammals.

[0080] The “treatment” of the disease includes:

[0081] (1) Prevention of the disease, that is, preventing the development of clinical symptoms of the disease in mammals that are exposed to or susceptible to the disease but do not experience or show symptoms of the disease.

[0082] (2) Inhibit the disease, that is, stop or reduce the progression of the disease or its clinical symptoms.

[0083] (3) To alleviate the disease, that is, to restore the disease or its clinical symptoms.

[0084] "Therapeutic effective amount" refers to the amount of a compound sufficient to treat a disease when administered to a mammal. Therapeutic effective amount will vary depending on the compound, the disease to be treated and its severity, and factors such as the mammal's age, weight, and sex. Therapeutic effective amount can also refer to any amount of a compound sufficient to achieve the desired beneficial effect, including disease prevention, disease inhibition, or disease ablation as described in (1)-(3) above. For example, the amount of the compound may be between 0.1-250 mg / kg, or preferably, 0.5-100 mg / kg, or more preferably, 1-50 mg / kg, or even more preferably, 2-20 mg / kg. Preferably, the amount of the compound is administered to the mammal twice daily. More preferably, the amount of the compound is administered to the mammal once daily.

[0085] As described herein, the term "disease and / or symptom" refers to a physical condition of the subject that relates to the disease and / or symptom described in this invention. For example, the disease and / or symptom described in this invention refers to a tuberculosis infection.

[0086] As described herein, the term "subject" may refer to a patient or other animal, particularly a mammal, such as a human or monkey, that receives a compound of Formula I of the present invention or a pharmaceutical composition thereof to treat the disease or condition described herein.

[0087] Another aspect of the invention relates to pharmaceutical compositions using compounds of the invention as active ingredients. These pharmaceutical compositions can be prepared according to methods known in the art. They can be formulated into any dosage form suitable for human or animal use by combining the compounds of the invention with one or more pharmaceutically acceptable solid or liquid excipients and / or adjuvants.

[0088] The compounds or pharmaceutical compositions containing them in this invention can be administered in unit dose form via enteral or non-enteric routes, such as oral, intravenous, intramuscular, subcutaneous, nasal, oral mucosa, eye, lung and respiratory tract, skin, vagina, rectum, etc.

[0089] Dosage forms can be liquid, solid, or semi-solid. Liquid dosage forms can include solutions (including true solutions and colloidal solutions), emulsions (including o / w, w / o, and double emulsions), suspensions, injections (including aqueous injections, powder injections, and infusions), eye drops, nasal drops, lotions, and liniments, etc.; solid dosage forms can include tablets (including regular tablets, enteric-coated tablets, lozenges, dispersible tablets, chewable tablets, effervescent tablets, and orally disintegrating tablets), capsules (including hard capsules, soft capsules, and enteric-coated capsules), granules, powders, microcapsules, pellets, suppositories, films, patches, aerosols, and sprays, etc.; semi-solid dosage forms can include ointments, gels, and pastes, etc.

[0090] The compounds of this invention can be formulated into conventional formulations, sustained-release formulations, controlled-release formulations, targeted formulations, and various microparticle delivery systems.

[0091] To formulate the compounds of the present invention into tablets, a wide variety of excipients known in the art can be used, including diluents, binders, wetting agents, disintegrants, lubricants, and solubilizers. Diluents can be starch, dextrin, sucrose, glucose, lactose, mannitol, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, dicalcium phosphate, calcium carbonate, etc.; wetting agents can be water, ethanol, isopropanol, etc.; binders can be starch paste, dextrin, syrup, honey, glucose solution, microcrystalline cellulose, gum arabic paste, gelatin paste, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, acrylic resin, carbomer, polyvinylpyrrolidone, polyethylene glycol, etc.; disintegrants can be dry starch, microcrystalline cellulose, low-substituted hydroxypropyl cellulose, croscarmellose, croscarmellose sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate and citric acid, polyoxyethylene sorbitol fatty acid ester, sodium dodecyl sulfonate, etc.; lubricants and cosolvents can be talc, silica, stearate, tartaric acid, liquid paraffin, polyethylene glycol, etc.

[0092] Tablets can also be further processed into coated tablets, such as sugar-coated tablets, film-coated tablets, enteric-coated tablets, or bilayer and multilayer tablets.

[0093] To formulate the drug delivery unit into capsules, the active ingredient, the compound of the present invention, can be mixed with a diluent and a solubilizer, and the mixture can be placed directly into hard or soft capsules. Alternatively, the active ingredient, the compound of the present invention, can be first formed into granules or microspheres with a diluent, binder, and disintegrant, and then placed into hard or soft capsules. The diluents, binders, wetting agents, disintegrants, and solubilizers used to prepare tablets of the compound of the present invention can also be used to prepare capsules of the compound of the present invention.

[0094] To prepare the compounds of this invention into injectable formulations, water, ethanol, isopropanol, propylene glycol, or mixtures thereof can be used as solvents, and appropriate amounts of commonly used solubilizers, co-solvents, pH adjusters, and osmotic pressure adjusters can be added. Solubilizers or co-solvents can be poloxamer, lecithin, hydroxypropyl-β-cyclodextrin, etc.; pH adjusters can be phosphates, acetates, hydrochloric acid, sodium hydroxide, etc.; osmotic pressure adjusters can be sodium chloride, mannitol, glucose, phosphates, acetates, etc. If preparing lyophilized powder injections, mannitol, glucose, etc., can also be added as supporting agents.

[0095] In addition, colorants, preservatives, flavorings, tasters or other additives may be added to pharmaceutical preparations if necessary.

[0096] To achieve the purpose of medication and enhance the therapeutic effect, the drug or drug composition of the present invention can be administered using any known method of administration.

[0097] The compounds or compositions of the present invention can be taken alone or in combination with other therapeutic or symptomatic drugs. When the compounds of the present invention have a synergistic effect with other therapeutic drugs, their dosage should be adjusted according to the actual situation.

[0098] Beneficial technical effects

[0099] The compounds in this invention exhibit strong PLpro inhibitory activity; the inhibitory effect of 30 compounds (IC50) is shown to be significant. 50 The PLpro inhibitory activity of 14 compounds was less than 50 μM, with an IC50 value. 50 <10 μM. The three compounds exhibited superior antiviral activity compared to the PLpro inhibitor GRL0617, demonstrating strong anti-coronavirus activity. Furthermore, these compounds showed low cytotoxicity to Vero E6 cells (IC50). 50 The concentration of the active ingredient (>50 μM) indicates that this class of compounds has good safety. Human and mouse liver microsomal metabolic stability tests show that the compounds of this invention have good metabolic stability. This invention provides a class of novel compounds with strong in vitro PLpro inhibitory activity and low cytotoxicity, which can be used in drugs that inhibit PLpro activity, and particularly as therapeutic agents for diseases related to coronavirus infection. Detailed Implementation

[0100] The present invention will be described in detail through the following embodiments, but this does not imply any adverse limitation on the invention. The present invention has been described in detail, and specific embodiments thereof have also been disclosed. It will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the present invention without departing from the spirit and scope thereof.

[0101] For all the following embodiments, standard operating and purification methods known to those skilled in the art can be used. 1 It was determined by H NMR.

[0102] Preparation Examples

[0103] The structure of the compound was determined by 1H NMR spectroscopy (NMR spectroscopy). 1 The NMR spectrum was determined by 1H NMR. The 1H NMR shift (δ) is given in parts per million (ppm). The coupling constant (J) is in Hertz (Hz). The NMR spectra were measured using a 400 Hz, 500 Hz, or 700 Hz NMR spectra, with deuterated dimethyl sulfoxide (DMSO-d6) or deuterated chloroform (CDCl3) as solvents and tetramethylsilane (TMS) as an internal standard.

[0104] Example 1

[0105] N-Cyclohexyl-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0106]

[0107] Synthesis route:

[0108]

[0109] Experimental steps:

[0110] Step 1: Preparation of 3-(2-methyl-5-nitrophenyl)-5-(1-(naphth-2-yl)ethyl)-1,2,4-oxadiazole C-1

[0111] In a 100 mL reaction flask, 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT, 878 mg, 5.0 mmol) and N-methylmorpholine (NMM, 1517 mg, 15.0 mmol) were dissolved in 1,4-dioxane (50 mL). The mixture was stirred at room temperature for 15 minutes, then 2-(naphthyl-2-yl)propionic acid (A-1, 1000 mg, 5.0 mmol) was added, and the mixture was stirred at room temperature for 30 minutes. Then (Z)-N'-hydroxy-2-methyl-5-nitrobenzamide (B-1, 976 mg, 5.0 mmol) was added, and the mixture was stirred at room temperature for 2 hours. The mixture was then heated to reflux for 6 hours. The solution was concentrated under reduced pressure and separated by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether (V:V = 0–5:100) mixture as eluent. Intermediate C-1 was given as 1.18 g of a pale yellow solid, in 66% yield.

[0112] 1H NMR (400MHz, CDCl3) δ8.94(d,J=2.5Hz,1H),8.21(dd,J=8.5,2.5Hz,1H),8.16(d,J=8.3Hz,1H),7.90(d,J=8.8Hz,1H),7.82(d,J =8.9Hz,1H),7.61–7.56(m,1H),7.55–7.51(m,1H),7.51–7.45(m,3H),5.31(q,J=7.2Hz,1H),2.73(s,3H),2.00(d,J=7.2Hz,3H).

[0113] Step 2: Preparation of 4-methyl-3-(5-(1-(naphthyl-2-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline D-1

[0114] In a 25 mL reaction flask, 3-(2-methyl-5-nitrophenyl)-5-(1-(naphthyl-2-yl)ethyl)-1,2,4-oxadiazole (C-1, 719 mg, 2.0 mmol) was dissolved in 10 mL of ethanol. A saturated ammonium chloride aqueous solution (2 mL) was added, and the mixture was stirred until homogeneous. Zinc powder (A-1, 650 mg, 10.0 mmol) was added, and the mixture was stirred at room temperature for 3 hours. The mixture was filtered, concentrated under reduced pressure, and separated by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether (V:V = 0–30:100) mixture as the eluent. Intermediate D-1 was obtained as a white solid, 470 mg, in 71% yield.

[0115] 1 H NMR (500MHz, CDCl3) δ8.15(d,J=8.5Hz,1H),7.89(d,J=8.1Hz,1H),7.81(d,J=9.3Hz,1H),7.57(t,J=7.7Hz,1H),7.51(t,J=7.4Hz,1H),7. 47(d,J=7.0Hz,2H),7.38(s,1H),7.09(d,J=8.1Hz,1H),6.73(d,J=8.2Hz,1H),5.27(q,J=7.3Hz,1H),2.49(s,3H),1.97(d,J=7.2Hz,3H).

[0116] Step 3: Preparation of N-cyclohexyl-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline I-1

[0117] In a 25 mL reaction flask, 4-methyl-3-(5-(1-(naphthyl-2-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline (D-1, 165 mg, 0.5 mmol), bromocyclohexane (98 mg, 0.6 mmol), and potassium carbonate (83 mg, 0.6 mmol) were dissolved in DMF (2 mL), and the mixture was heated to 70 °C and reacted for 4 hours. The solution was concentrated under reduced pressure, and separated by silica gel (200-300 mesh) column chromatography using an ethyl acetate-petroleum ether (V:V = 0–10:100) mixture as eluent. Compound I-1 (compound 1) was given as a white solid, 138 mg, yield 67%.

[0118] 1 H NMR (400MHz, CDCl3) δ8.16(d,J=8.5Hz,1H),7.89(d,J=8.9Hz,1H),7.80(dd,J=7.4,2 .1Hz,1H),7.59–7.43(m,4H),7.25(d,J=2.8Hz,1H),7.07(d,J=8.2Hz,1H),6.65(dd,J =8.4,2.6Hz,1H),5.27(q,J=7.2Hz,1H),3.32–3.23(m,1H),2.46(s,3H),2.10–2.01(m ,2H),1.96(d,J=7.2Hz,3H),1.79–1.70(m,2H),1.40–1.30(m,2H),1.28–1.09(m,4H).

[0119] Example 2

[0120] N-(4,4-dimethylcyclohexyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0121]

[0122] Using 4-bromo-1,1-dimethylcyclohexane (115 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-2 (compound 2), 126 mg of off-white solid, with a yield of 57%.

[0123] 1H NMR (400MHz, CDCl3) δ8.16 (d, J=8.5Hz, 1H), 7.89 (d, J=8.7Hz, 1H), 7.80 (dd, J= 7.3,2.5Hz,1H),7.62–7.40(m,4H),7.28(s,1H),7.08(d,J=8.3Hz,1H),6.68(d ,J=8.2Hz,1H),5.27(q,J=7.2Hz,1H),3.28–3.18(m,1H),2.46(s,3H),1.96(d, J=7.2Hz,3H),1.93–1.84(m,2H),1.38–1.23(m,6H),0.94(s,3H),0.93(s,3H).

[0124] Example 3

[0125] N-(4-cyanocyclohexyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0126]

[0127] Using 1-bromo-4-cyanocyclohexane (113 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-4 (compound 4), 155 mg of off-white solid, in a yield of 71%.

[0128] 1 H NMR (500MHz, CDCl3) δ8.16(d,J=8.5Hz,1H),7.89(d,J=8.1Hz,1H),7.81(d,J=7.6Hz,1 H),7.56(t,J=8.4Hz,1H),7.54–7.41(m,3H),7.25(s,1H),7.09(d,J=8.3Hz,1H),6.65( d,J=8.3Hz,1H),5.27(q,J=7.1Hz,1H),3.40–3.28(m,1H),2.89(t,J=4.3Hz,1H),2.47( s,3H),2.12–2.01(m,4H),1.97(d,J=7.2Hz,3H),1.76–1.66(m,2H),1.61–1.54(m,2H).

[0129] Example 4

[0130] N-(4-methoxycyclohexyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0131]

[0132] Using 1-bromo-4-methoxycyclohexane (116 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-4 (compound 4), 140 mg of off-white solid, in a yield of 63%.

[0133] 1 H NMR (400MHz, CDCl3) δ8.16(d,J=8.4Hz,1H),7.89(dd,J=7.9,1.9Hz,1H),7.80(dd,J=7.3,2.1Hz,1H),7.60–7.42(m,4H),7.30(s,1H),7.08(d,J=8.2H z,1H),6.70(s,1H),5.27(q,J=7.2Hz,1H),3.42–3.34(m,2H),3.31(s,3H) ,2.46(s,3H),1.96(d,J=7.2Hz,3H),1.89–1.75(m,4H),1.64–1.52(m,4H).

[0134] Example 5

[0135] 4-((4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclohexane-1-carboxylic acid

[0136]

[0137] Preparation of intermediate 4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-2

[0138]

[0139] Using 1-naphthacetic acid as the starting material, and following similar steps to the first and second steps in Example 1, intermediate D-2 was obtained.

[0140] 1 H NMR (400MHz, CDCl3) δ8.11(d,J=8.4Hz,1H),7.88(d,J=7.8Hz,1H),7.83(d,J=8.1Hz,1H),7.59–7.42(m, 4H),7.36(d,J=2.6Hz,1H),7.07(d,J=8.1Hz,1H),6.75(dd,J=8.1,2.6Hz,1H),4.72(s,2H),2.46(s,3H).

[0141] Preparation of 4-((4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclohexane-1-carboxylic acid I-5

[0142] Using 4-bromocyclohexane-1-carboxylic acid (124 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-2 to give compound I-5 (compound 5), 105 mg of off-white solid, in a yield of 48%.

[0143] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.3Hz,1H),7.88(d,J=8.5Hz,1H),7.83(d,J=8.1 Hz,1H),7.59–7.42(m,4H),7.23(d,J=2.9Hz,1H),7.07(d,J=8.3Hz,1H),6.66(d, J=8.3Hz,1H),4.72(s,2H),3.31–3.21(m,1H),2.44(s,3H),2.32(q,J=4.8,4.2Hz ,1H),2.25–2.13(m,2H),2.13–2.04(m,2H),1.84–1.64(m,2H),1.64–1.50(m,2H).

[0144] Example 6

[0145] 4-((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclohexane-1-carboxylic acid

[0146]

[0147] Using 4-bromocyclohexane-1-carboxylic acid (124 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-6 (compound 6), 98 mg of off-white solid, in a yield of 43%.

[0148] 1H NMR (500MHz, CDCl3) δ8.15(d,J=8.5Hz,1H),7.88(d,J=8.1Hz,1H),7.80(d,J=7.6Hz,1H),7.56(t,J =7.6Hz,1H),7.53–7.42(m,3H),7.23(d,J=2.6Hz,1H),7.08(d,J=8.2Hz,1H),6.67–6.58(m,1H),5.2 7(q,J=7.2Hz,1H),3.28(t,J=11.0Hz,1H),2.46(s,3H),2.38–2.27(m,1H),2.20(d,J=12.0Hz,2H), 2.09(d,J=12.0Hz,2H), 1.96(d,J=7.2Hz,3H), 1.59(q,J=13.0Hz,2H), 1.14(q,J=13.4,12.6Hz,2H).

[0149] Example 7

[0150] 3-((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclohexane-1-carboxylic acid

[0151]

[0152] Using 3-bromocyclohexane-1-carboxylic acid (124 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-7 (compound 7), 135 mg of off-white solid, in a yield of 59%.

[0153] 1 H NMR (500MHz, CDCl3) δ8.14(d,J=8.5Hz,1H),7.88(d,J=8.0Hz,1H),7.80(d,J=7.7Hz,1 H),7.55(t,J=6.9Hz,1H),7.52–7.43(m,3H),7.30(s,1H),7.09(d,J=8.2Hz,1H),6.70 (d,J=8.2Hz,1H),5.26(q,J=7.2Hz,1H),3.69–3.62(m,1H),2.79–2.70(m,1H),2.47(s ,3H),2.22–2.11(m,1H),1.96(d,J=7.2Hz,3H),1.87–1.78(m,2H),1.77–1.55(m,5H).

[0154] Example 8

[0155] 3-((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclobutane-1-carboxylic acid

[0156]

[0157] Using 4-bromocyclobutane-1-carboxylic acid (107 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-8 (compound 8), 120 mg of off-white solid, yield 56%.

[0158] 1 H NMR (400MHz, CDCl3) δ8.15(d,J=8.5Hz,1H),7.87(d,J=8.0Hz,1H),7.79(d,J=7.6Hz,1H),7.60–7.39(m,5H),7.10(d,J=8.2Hz,1H),6.63(d,J=5. 4Hz,1H),5.27(q,J=7.1Hz,1H),4.24–4.13(m,1H),3.22–3.12(m,1H),2 .79–2.69(m,2H),2.47(s,3H),2.25–2.14(m,2H),1.96(d,J=7.2Hz,3H).

[0159] Example 9

[0160]

[0161] Using methyl 4-bromocyclobutane-1-carboxylic acid (116 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-9 (compound 9), 113 mg of off-white solid, in a yield of 51%.

[0162] 1H NMR (400MHz, CDCl3) δ8.16(d,J=7.9Hz,1H),7.89(d,J=7.8Hz,1H),7.81(dd,J=7.0,2.5Hz,1H ),7.60–7.54(m,1H),7.54–7.50(m,1H),7.50–7.43(m,2H),7.24(d,J=2.6Hz,1H),7.09(d,J=8 .3Hz,1H),6.62(dd,J=8.3,2.6Hz,1H),5.27(q,J=7.2Hz,1H),4.00–3.85(m,1H),3.69(s,3H) ,2.95–2.80(m,1H),2.78–2.63(m,2H),2.47(s,3H),2.18–2.06(m,2H),1.97(d,J=7.2Hz,3H).

[0163] Example 10

[0164] 3-((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)cyclopentane-1-carboxylic acid methyl ester

[0165]

[0166] Using methyl 3-bromocyclopentane-1-carboxylic acid (124 mg, 0.6 mmol) as a starting material, and following a similar procedure to step 3 in Example 1, the mixture was reacted with intermediate D-1 to give compound I-10 (compound 10), 110 mg of off-white solid, in a yield of 48%.

[0167] 1 H NMR (400MHz, CDCl3) δ8.16(d,J=8.5Hz,1H),7.89(d,J=9.8Hz,1H),7.80(dd,J=7.2,2.3Hz,1H) ,7.59–7.54(m,1H),7.54–7.43(m,3H),7.29(d,J=2.6Hz,1H),7.10(dd,J=8.3,3.9Hz,1H),6.69 (dd,J=8.2,2.7Hz,1H),5.27(q,J=7.2Hz,1H),4.01–3.89(m,1H),3.68(s,3H),2.93–2.82(m,1H ),2.47(s,3H),2.38–2.05(m,3H),2.02–1.98(m,2H),1.97(d,J=7.3Hz,3H),1.89–1.78(m,1H).

[0168] Example 11

[0169] 6-((4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)spiro[3.3]heptane-2-carboxylic acid

[0170]

[0171] Using 6-bromospiro[3.3]heptane-2-carboxylic acid (131 mg, 0.6 mmol) as the starting material, and following a similar procedure to the third step in Example 1, the mixture was reacted with intermediate D-2 to give compound I-11 (compound 11), 100 mg of off-white solid, yield 44%.

[0172] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.3Hz,1H),7.88(d,J=7.7Hz,1H),7.84(d,J=8.1H z,1H),7.59–7.43(m,4H),7.15(s,1H),7.07(d,J=8.2Hz,1H),6.59(dd,J=8.3,2.6H z,1H),4.73(s,2H),3.86–3.72(m,1H),3.10–3.01(m,1H),2.61–2.54(m,1H),2.51– 2.46(m,1H),2.44(s,3H),2.42–2.28(m,3H),2.26–2.16(m,1H),1.93–1.78(m,2H).

[0173] Example 12

[0174] 6-((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)spiro[3.3]heptane-2-carboxylic acid

[0175]

[0176] Using 6-bromospiro[3.3]heptane-2-carboxylic acid (131 mg, 0.6 mmol) as the starting material, and following a similar procedure to the third step in Example 1, the mixture was reacted with intermediate D-1 to give compound I-12 (compound 12), 110 mg of off-white solid, with a yield of 47%.

[0177] 1H NMR (400MHz, CDCl3) δ8.15(d,J=8.4Hz,1H),7.89(d,J=9.6Hz,1H),7.80(d,J=9.6Hz,1H),7. 62–7.40(m,4H),7.22(d,J=2.6Hz,1H),7.09(d,J=8.3Hz,1H),6.61(dd,J=8.2,2.6Hz,1H),5. 31–5.22(m,1H),3.86–3.76(m,1H),3.12–3.00(m,1H),2.61–2.54(m,1H),2.51–2.48(m,1H), 2.47(s,3H),2.40–2.29(m,3H),2.25–2.17(m,1H),1.96(d,J=7.2Hz,3H),1.94–1.80(m,2H).

[0178] Example 13

[0179] N-Benzyl-4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline

[0180]

[0181] Experimental steps:

[0182]

[0183] In a 25 mL reaction flask, 4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline (D-2, 126 mg, 0.4 mmol), benzaldehyde (85 mg, 0.8 mmol), and glacial acetic acid (144 mg, 2.4 mmol) were dissolved in 1,2-dichloroethane (10 mL). Sodium triacetoxyborohydride (506 mg, 2.4 mmol) was added, and the mixture was stirred at room temperature for 3 hours. The solution was concentrated under reduced pressure and separated by silica gel column chromatography (200-300 mesh), using an ethyl acetate-petroleum ether mixture (V:V = 0–10:100) as the eluent. Compound I-13 (compound 13) was given as a white solid, 121 mg, in 75% yield.

[0184] 1H NMR (400MHz, CDCl3) δ8.12(d,J=8.3Hz,1H),7.91–7.86(m,1H),7.83(d,J=8.2Hz,1H),7.58–7.40(m,5H),7. 38–7.25(m,5H),7.06(d,J=8.2Hz,1H),6.64(dd,J=8.2,2.7Hz,1H),4.71(s,2H),4.33(s,2H),2.44(s,3H).

[0185] Example 14

[0186] N-(4-Bromobenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0187]

[0188] Using 4-bromobenzaldehyde (148 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-14 (compound 14), 140 mg of off-white solid, with a yield of 70%.

[0189] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),7.89(d,J=8.8Hz,1H),7.80(dd,J=6.2,3.3Hz,1H),7.59–7.48(m,2H),7.48–7.40(m,4H),7.33(d,J=2.6Hz ,1H),7.23(d,J=8.2Hz,2H),7.08(d,J=8.2Hz,1H),6.63(dd,J=8.2,2.6Hz, 1H), 5.26 (q, J = 7.2Hz, 1H), 4.30 (s, 2H), 2.47 (s, 3H), 1.95 (d, J = 7.2Hz, 3H).

[0190] Example 15

[0191] N-(4-cyanobenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0192]

[0193] Using 4-cyanobenzaldehyde (105 mg, 0.8 mmol) as a raw material, and following a similar procedure to the third step in Example 13, the mixture was reacted with intermediate D-1 to give compound I-15 (compound 15), 124 mg of off-white solid, with a yield of 70%.

[0194] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.89(d,J=8.0Hz,1H),7.84–7.78(m,1H),7.58(d,J=8.4Hz,2H),7.56–7.50(m,2H),7.47–7.42(m,4H) ,7.28(d,J=2.7Hz,1H),7.07(d,J=8.3Hz,1H),6.58(dd,J=8.3,2.7Hz,1H ),5.25(q,J=7.2Hz,1H),4.41(s,2H),2.47(s,3H),1.95(d,J=7.2Hz,3H).

[0195] Example 16

[0196] N-(4-hydroxybenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0197]

[0198] Using 4-hydroxybenzaldehyde (98 mg, 0.8 mmol) as a starting material, and following a similar procedure to the third step in Example 13, the mixture was reacted with intermediate D-1 to give compound I-16 (compound 16), 130 mg of off-white solid, with a yield of 75%.

[0199] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.4Hz,1H),7.87(d,J=6.0Hz,1H),7.78(d,J=7.8Hz,1H),7.56–7.40(m,4H),7.27(d,J=2.6Hz,1H),7.13(d,J=8.4Hz, 2H),7.07(d,J=8.2Hz,1H),6.71(d,J=8.5Hz,2H),6.63(dd,J=8.2,2.6Hz,1 H),5.27(q,J=7.2Hz,1H),4.14(s,2H),2.47(s,3H),1.95(d,J=7.2Hz,3H).

[0200] Example 17

[0201] N-(benzo[d][1,3]dioxolane-5-ylmethyl)-4-methyl-3-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline

[0202]

[0203] Using benzo[d][1,3]dioxolane-5-carboxaldehyde (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-2 to give compound I-17 (compound 17), 121 mg of off-white solid, yield 67%.

[0204] 1 H NMR (400MHz, CDCl3) δ8.11(d,J=8.3Hz,1H),7.88(d,J=7.9Hz,1H),7.83(d,J=8.1Hz,1H),7.59–7.41(m,4H),7.27(s,1H),7.0 6(d,J=8.3Hz,1H),6.83(s,1H),6.82–6.69(m,2H),6.63(d,J=5.4Hz,1H),5.92(s,2H),4.71(s,2H),4.22(s,2H),2.44(s,3H).

[0205] Example 18

[0206] N-(4-methoxycarbonylbenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0207]

[0208] Using methyl paraformylbenzoate (131 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-18 (compound 18), 160 mg of off-white solid, yield 84%.

[0209] 1H NMR (400MHz, CDCl3) δ8.14(d,J=8.5Hz,1H),8.01–7.95(m,2H),7.89(d,J=7.6Hz,1H),7.84–7.76(m,1H),7.60–7.29(m,7H),7.0 8(d,J=8.2Hz,1H),6.65(d,J=11.1Hz,1H),5.26(q,J=7.3Hz,1H),4.42(s,2H),3.90(s,3H),2.47(s,3H),1.95(d,J=7.2Hz,3H).

[0210] Example 19

[0211] N-(4-Carboxybenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0212]

[0213] Using p-formylbenzoic acid (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-19 (compound 19), 143 mg of off-white solid, with a yield of 77%.

[0214] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),8.05(d,J=8.4Hz,2H),7.88(d,J=7.7Hz,1H),7.83–7.77(m,1H),7.59–7.49(m,2H),7.49–7.43 (m,4H),7.39(s,1H),7.09(d,J=8.2Hz,1H),6.68(d,J=8.3Hz,1H),5.26(q,J=7.1Hz,1H),4.45(s,2H),2.48(s,3H),1.96(d,J=7.2Hz,3H).

[0215] Example 20

[0216] N-(4-Methanesulfonylbenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0217]

[0218] Using p-formylbenzylsulfonic acid (149 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-20 (compound 20), 162 mg of off-white solid, with a yield of 81%.

[0219] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),7.93–7.83(m,3H),7.83–7.76(m,1H),7.59–7.49(m,4H),7.46(d,J=5.7Hz,2H),7.29(d,J=2.7Hz ,1H),7.08(d,J=8.2Hz,1H),6.59(dd,J=8.3,2.7Hz,1H),5.26(q,J=7.2Hz,1H),4.45(s,2H),3.01(s,3H),2.47(s,3H),1.95(d,J=7.2Hz,3H).

[0220] Example 21

[0221] N-(3-Carboxybenzyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0222]

[0223] Using m-formylbenzoic acid (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to the third step in Example 13, it was reacted with intermediate D-1 to give compound I-21 (compound 21), 125 mg of off-white solid, yield 67%.

[0224] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),8.10(s,1H),7.99(d,J=7.7Hz,1H) ,7.87(d,J=7.2Hz,1H),7.79(dd,J=6.9,2.5Hz,1H),7.60(d,J=7.7Hz,1H),7.57 –7.38(m,5H),7.35(d,J=2.6Hz,1H),7.08(d,J=8.3Hz,1H),6.64(dd,J=8.2,2.6 Hz,1H),5.26(q,J=7.2Hz,1H),4.41(s,2H),2.47(s,3H),1.95(d,J=7.3Hz,3H).

[0225] Example 22

[0226] N-(4-Carboxybenzyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0227]

[0228] Preparation of intermediate 2-(5-(1-(naphth-2-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline D-3

[0229]

[0230] Using (Z)-N'-hydroxy-3-nitrobenzoamidine as the starting material, intermediate D-3 was obtained by following similar steps to the first and second steps in Example 1.

[0231] 1 H NMR(400MHz, CDCl3)δ8.12(d,J=8.4Hz,1H),7.88(d,J=8.1Hz,1H),7.80(s,1H),7.60–7.38(m ,6H),7.28–7.21(m,1H),6.80(d,J=7.5Hz,1H),5.25(q,J=7.6Hz,1H),1.95(d,J=7.3Hz,3H).

[0232] Preparation of N-(4-carboxybenzyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0233] Using p-formylbenzoic acid (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-3 to give compound I-22 (compound 22), 133 mg of off-white solid, with a yield of 74%.

[0234] 1 H NMR (400MHz, CDCl3) δ8.11(d,J=8.4Hz,1H),8.04(d,J=7.8Hz,2H),7.86(d,J=8.0Hz,1H),7.81–7.74(m,1H),7.53(t,J=7.5Hz,1H),7.49(d,J=7.6 Hz,1H),7.47–7.39(m,5H),7.36(s,1H),7.23(t,J=8.0Hz,1H),6.67(d,J =10.5Hz,1H),5.24(q,J=7.2Hz,1H),4.42(s,2H),1.93(d,J=7.2Hz,3H).

[0235] Example 23

[0236] N-(4-Carboxybenzyl)-3-trifluoromethyl-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0237]

[0238] Preparation of intermediate 3-trifluoromethyl-5-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-4

[0239]

[0240] Using (Z)-N'-hydroxy-3-trifluoromethyl-5-nitrobenzamide as the starting material, intermediate D-4 was obtained by following similar steps to the first and second steps in Example 1.

[0241] 1 H NMR (400MHz, CDCl3) δ8.11(d,J=8.4Hz,1H),7.89(d,J=8.1Hz,1H),7.83–7.78(m,1H),7.74(s,1H) ,7.61–7.48(m,3H),7.47–7.44(m,2H),7.01(s,1H),5.26(q,J=6.7Hz,1H),1.96(d,J=7.2Hz,3H).

[0242] Preparation of N-(4-carboxybenzyl)-3-trifluoromethyl-5-(5-(1-(naphth-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0243] Using p-formylbenzoic acid (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-4 to give compound I-23 (compound 23), 162 mg of off-white solid, with a yield of 78%.

[0244] 1 H NMR (400MHz, CDCl3) δ8.10(d,J=8.5Hz,1H),8.06(d,J=7.8Hz,2H),7.87(d,J=8.0Hz,1H),7.84–7.75(m,1H),7.69(s,1H),7.55(t ,J=7.6Hz,1H),7.50(d,J=7.7Hz,1H),7.48–7.39(m,5H),6.90(s,1H),5.26(q,J=7.1Hz,1H),4.45(s,2H),1.95(d,J=7.1Hz,3H).

[0245] Example 24

[0246] 5-(((3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)furan-2-carboxylic acid

[0247]

[0248] Using 5-formyl-2-furanic acid (112 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-3 to give compound I-24 (compound 24), 123 mg of off-white solid, with a yield of 70%.

[0249] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.4Hz,1H),7.90(d,J=8.0Hz,1H),7.85–7.77(m,1H),7.61–7.48(m,2H),7.48–7.42(m,3H),7.42–7.37( m,1H),7.24(t,J=8.0Hz,1H),6.87(s,1H),6.80(d,J=8.1Hz,1H),6.28(s,1H),5.28(d,J=7.3Hz,1H),4.35(s,2H),1.96(d,J=7.2Hz,3H).

[0250] Example 25

[0251] 5-(((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)furan-2-carboxylic acid

[0252]

[0253] Using 5-formyl-2-furanic acid (112 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-25 (compound 25), 137 mg of off-white solid, with a yield of 76%.

[0254] 1H NMR (400MHz, CDCl3) δ8.13(d,J=5.4Hz,1H),7.88(d,J=5.4Hz,1H),7.84–7.74(m,1H),7.60–7.48(m,2H),7.48–7.43(m,2H),7.36(d,J=3.0Hz,1H) ,7.04(dd,J=8.4,3.0Hz,1H),6.83(s,1H),6.67(d,J=8.5Hz,1H),6.20(s ,1H),5.31–5.20(m,1H),4.26(s,2H),2.44(s,3H),1.95(d,J=3.7Hz,3H).

[0255] Example 26

[0256] 5-(((3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0257]

[0258] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-3 to give compound I-26 (compound 26), 105 mg of off-white solid, with a yield of 58%.

[0259] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.3Hz,1H),7.88(d,J=8.0Hz,1H),7.80(t,J=5.1Hz,1H),7.75–7.67(m,1H),7.63–7.36( m,6H),7.26(d,J=7.4Hz,1H),7.03(s,1H),6.77(d,J=8.1Hz,1H),5.32–5.21(m,1H),4.60(s,2H),1.95(d,J=7.2Hz,3H).

[0260] Example 27

[0261] 5-(((4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0262]

[0263] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-27 (compound 27), 121 mg of off-white solid, with a yield of 64%.

[0264] 1 H NMR (400MHz, CDCl3) δ8.15(d,J=8.4Hz,1H),7.89(d,J=8.9Hz,1H),7.80(dd,J=6.7,2.9 Hz,1H),7.72(d,J=3.8Hz,1H),7.56(t,J=6.8Hz,1H),7.52(d,J=7.0Hz,1H),7.50–7.45( m,2H),7.37(d,J=2.7Hz,1H),7.11(d,J=8.3Hz,1H),7.02(d,J=3.8Hz,1H),6.70(dd,J= 8.2, 2.7Hz, 1H), 5.27 (q, J = 7.1Hz, 1H), 4.57 (s, 2H), 2.49 (s, 3H), 1.96 (d, J = 7.3Hz, 3H).

[0265] Example 28

[0266] 5-(((2-methyl-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0267]

[0268] Preparation of intermediate 2-methyl-5-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-5

[0269]

[0270] Using (Z)-N'-hydroxy-4-methyl-3-nitrobenzomidine as the starting material, intermediate D-5 was obtained by following similar steps to the first and second steps in Example 1.

[0271] 1H NMR (400MHz, CDCl3) δ8.13(d,J=8.5Hz,1H),7.88(d,J=8.0Hz,1H),7.82–7.77(m,1H),7.60–7.47(m,2H),7.4 7–7.43(m,3H),7.42(s,1H),7.14(d,J=7.7Hz,1H),5.25(q,J=7.2Hz,1H),2.22(s,3H),1.95(d,J=7.2Hz,3H).

[0272] Preparation of 5-(((2-methyl-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid I-28

[0273] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-5 to give compound I-28 (compound 28), 110 mg of off-white solid, yield 59%.

[0274] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.3Hz,1H),7.88(d,J=8.2Hz,1H),7.84–7.76(m,1H),7.73(d,J=4.0Hz,1H),7.60–7.42(m,5 H),7.36(s,1H),7.18(d,J=7.7Hz,1H),7.07(s,1H),5.26(q,J=7.1Hz,1H),4.67(s,2H),2.23(s,3H),1.95(d,J=7.2Hz,3H).

[0275] Example 29

[0276] 5-(((3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)-5-(trifluoromethyl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0277]

[0278] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-4 to give compound I-29 (compound 29), 132 mg of off-white solid, with a yield of 63%.

[0279] 1H NMR (400MHz, CDCl3) δ8.11(d,J=8.5Hz,1H),7.89(d,J=8.0Hz,1H),7.81(t,J=5.0Hz,1H),7.74(s,2H), 7.62–7.43(m,5H),7.05(s,1H),6.96(s,1H),5.27(q,J=7.2Hz,1H),4.63(s,2H),1.96(d,J=7.1Hz,3H).

[0280] Example 30

[0281] 5-(((2-methoxy-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0282]

[0283] Preparation of intermediate 2-methoxy-5-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-6

[0284]

[0285] Using (Z)-N'-hydroxy-4-methoxy-3-nitrobenzomidine as the starting material, intermediate D-6 was obtained by following similar steps to the first and second steps in Example 1.

[0286] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.3Hz,1H),7.88(d,J=7.9Hz,1H),7.84–7.77(m,1H),7.61–7 .42(m,6H),6.84(d,J=8.4Hz,1H),5.24(q,J=7.3Hz,1H),3.90(s,3H),1.94(d,J=7.2Hz,3H).

[0287] Preparation of 5-(((2-methoxy-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0288] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-6 to give compound I-30 (compound 30), 120 mg of off-white solid, in a yield of 62%.

[0289] 1H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.88(d,J=8.0Hz,1H),7.82–7.76(m,1H),7.72(d,J=3.6Hz,1H),7.59–7.47(m,3H),7.47–7.43 (m,2H),7.36(s,1H),7.07(d,J=3.7Hz,1H),6.85(d,J=8.3Hz,1H),5.24(q,J=7.1Hz,1H),4.65(s,2H),3.91(s,3H),1.94(d,J=7.2Hz,3H).

[0290] Example 31

[0291] N-((5-chlorothiophene-2-yl)methyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-4-methyl-1,2,4-oxadiazol-3-yl)aniline

[0292]

[0293] Using 5-chlorothiophene-2-carboxaldehyde (117 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-31 (compound 31), 110 mg of off-white solid, in a yield of 60%.

[0294] 1 H NMR (400MHz, CDCl3) δ8.15(d,J=8.5Hz,1H),7.89(d,J=8.0Hz,1H),7.81(d,J=7.0Hz,1H),7.61–7.43(m,4H),7.38(s, 1H),7.12(d,J=8.3Hz,1H),6.79–6.68(m,3H),5.27(q,J=7.3Hz,1H),4.44(s,2H),2.49(s,3H),1.96(d,J=7.2Hz,3H).

[0295] Example 32

[0296] N-((5-bromothiophene-2-yl)methyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)-5-(trifluoromethyl)aniline

[0297]

[0298] Using 5-bromothiophene-2-carboxaldehyde (153 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-4 to give compound I-32 (compound 32), 150 mg of off-white solid, in a yield of 67%.

[0299] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.5Hz,1H),7.90(d,J=8.0Hz,1H),7.84–7.78(m,1H),7.73(s,1H),7.57(t,J=7.7Hz,1H),7.58–7 .54(m,2H),7.48–7.43(m,2H),6.96(s,1H),6.90(s,1H),6.79(s,1H),5.27(q,J=7.8Hz,1H),4.51(s,2H),1.96(d,J=5.0Hz,3H).

[0300] Example 33

[0301] N-((5-nitrothiophen-2-yl)methyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-4-methyl-1,2,4-oxadiazol-3-yl)aniline

[0302]

[0303] Using 5-nitrothiophene-2-carboxaldehyde (126 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-1 to give compound I-33 (compound 33), 130 mg of yellow solid, with a yield of 69%.

[0304] 1 H NMR(400MHz, CDCl3)δ8.13(d,J=8.4Hz,1H),7.89(d,J=6.9Hz,1H),7.85–7.73(m,2H),7.60–7.40(m,4H),7.32(s,1H),7.1 1(d,J=8.3Hz,1H),6.92(s,1H),6.66(d,J=8.3Hz,1H),5.31–5.22(m,1H),4.54(s,2H),2.49(s,3H),1.96(d,J=7.2Hz,3H).

[0305] Example 34

[0306] N-((5-methoxythiophene-2-yl)methyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)-5-(trifluoromethyl)aniline

[0307]

[0308] Using 5-methoxythiophene-2-carboxaldehyde (114 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-4 to give compound I-34 (compound 34), 144 mg of off-white solid, with a yield of 71%.

[0309] 1 H NMR(400MHz, CDCl3)δ8.12(d,J=8.3Hz,1H),7.90(d,J=8.0Hz,1H),7.86–7.76 (m,1H),7.75–7.69(m,1H),7.57(t,J=7.6Hz,1H),7.55–7.48(m,2H),7.48–7.4 4(m,2H),6.96(s,1H),6.66–6.55(m,1H),6.04–5.98(m,1H),5.27(q,J=7.2Hz ,1H),4.59(s,1H),4.41(s,1H),3.84(d,J=10.5Hz,3H),1.96(d,J=7.2Hz,3H).

[0310] Example 35

[0311] N-((5-methoxycarbonylthiophene-2-yl)methyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)-5-(trifluoromethyl)aniline

[0312]

[0313] Using methyl 5-aldehydethiophene-2-carboxylate (136 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-4 to give compound I-35 (compound 35), 113 mg of off-white solid, yield 53%.

[0314] 1H NMR (400MHz, CDCl3) δ8.19–8.04(m,1H),7.90(t,J=6.7Hz,1H),7.82(s,1H),7.74(d,J=5.3Hz,1H),7.67(t,J=4. 3Hz,1H),7.63–7.39(m,5H),7.08–6.85(m,2H),5.36–5.16(m,1H),4.61(s,2H),3.87(s,3H),2.01–1.90(m,3H).

[0315] Example 36

[0316] N-((5-methoxycarbonylthiophen-2-yl)methyl)-5-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)-2-methylaniline

[0317]

[0318] Using methyl 5-aldehydethiophene-2-carboxylate (136 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, it was reacted with intermediate D-5 to give compound I-36 (compound 36), 130 mg of off-white solid, yield 67%.

[0319] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.88(d,J=8.0Hz,1H),7.79(s,1H),7.66(s,1H),7.60–7.40(m,5H),7.34(s,1H) ),7.16(d,J=7.7Hz,1H),7.02(s,1H),5.24(d,J=7.1Hz,1H),4.63(s,2H),3.84(s,3H),2.21(s,3H),1.94(d,J=7.2Hz,3H).

[0320] Example 37

[0321] 5-(((3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-boronic acid

[0322]

[0323] Using 5-aldehyde-2-thiopheneboronic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-3 to give compound I-37 (compound 37), 110 mg of off-white solid, in a yield of 60%.

[0324] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.88(d,J=8.1Hz,1H),7.85–7.76(m,1H),7.60–7.43(m,4H),7.40(s,1H),7.31–7.24(m,1H) ,7.21(d,J=5.0Hz,1H),7.02(s,1H),6.95(t,J=4.4Hz,1H),6.78(d,J=8.2Hz,1H),5.29–5.20(m,1H),4.56(s,2H),1.95(d,J=7.2Hz,3H).

[0325] Example 38

[0326] N-(4-(methylsulfonyl)benzyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0327]

[0328] Preparation of intermediate 4-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-7

[0329]

[0330] Using (Z)-N'-hydroxy-4-nitrobenzoamidine as the starting material, intermediate D-7 was obtained by following similar steps to the first and second steps in Example 1.

[0331] 1 H NMR (400MHz, DMSO-d6) δ8.20(d,J=8.3Hz,1H),7.99(d,J=6.3Hz,1H),7.90(d,J=8.1Hz,1H),7.65(d,J=8.4Hz,2H),7.64–7.54(m,2H ),7.51(t,J=7.7Hz,1H),7.42(d,J=7.1Hz,1H),6.64(d,J=8.6Hz,2H),5.75(brs,2H),5.41(q,J=7.0Hz,1H),1.84(d,J=7.1Hz,3H).

[0332] Preparation of N-(4-(methylsulfonyl)benzyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0333] Using 4-methanesulfonylbenzaldehyde (147 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-7 to give compound I-38 (compound 38), 130 mg of off-white solid, in a yield of 67%.

[0334] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.4Hz,1H),7.94–7.86(m,5H),7.82–7.76(m,1H),7.56(d,J=7.6Hz,2H),7.54–7.48(m,2 H),7.44(d,J=4.8Hz,2H),6.72(d,J=8.2Hz,2H),5.23(q,J=7.2Hz,1H),4.52(s,2H),3.04(s,3H),1.93(d,J=7.2Hz,3H).

[0335] Example 39

[0336] 4-(((4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)benzoic acid

[0337]

[0338] Using p-formylbenzoic acid (120 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-7 to give compound I-39 (compound 39), 111 mg of off-white solid, with a yield of 62%.

[0339] 1 H NMR (400MHz, DMSO-d6) δ8.19(d,J=8.4Hz,1H),7.98(d,J=7.9Hz,1H),7.93–7. 87(m,3H),7.69(d,J=8.4Hz,2H),7.63–7.53(m,2H),7.50(t,J=7.7Hz,1H),7. 46(d,J=8.0Hz,2H),7.41(d,J=7.2Hz,1H),7.02(t,J=6.2Hz,1H),6.67(d,J=8 .5Hz,2H),5.40(q,J=7.0Hz,1H),4.43(d,J=6.0Hz,2H),1.83(d,J=7.0Hz,3H).

[0340] Example 40

[0341] 5-(((4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-boronic acid

[0342]

[0343] Using 5-aldehyde-2-thiopheneboronic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-7 to give compound I-40 (compound 40), 102 mg of off-white solid, yield 56%.

[0344] 1 H NMR (700MHz, CDCl3) δ8.13(d,J=8.5Hz,1H),7.96–7.87(m,2H),7.79(d,J=7.1Hz,1H),7.61–7.41(m,4H),7.23(s ,1H),7.02(s,1H),6.96(s,1H),6.70(d,J=8.3Hz,2H),5.23(d,J=7.1Hz,1H),4.56(s,2H),1.94(d,J=7.5Hz,3H).

[0345] Example 41

[0346] N-((5-nitrothiophen-2-yl)methyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0347]

[0348] Using 5-nitrothiophene-2-carboxaldehyde (126 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-7 to give compound I-41 (compound 41), 106 mg of yellow solid, with a yield of 57%.

[0349] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.92(d,J=8.3Hz,2H),7.88(d,J=8.0Hz,1H),7.81–7.78(m,2H),7.59–7.47(m,2H ),7.47–7.42(m,2H),6.97(d,J=4.1Hz,1H),6.70(d,J=8.2Hz,2H),5.24(q,J=7.1Hz,1H),4.60(s,2H),1.94(d,J=7.5Hz,3H).

[0350] Example 42

[0351] N-((5-methoxycarbonylthiophen-2-yl)methyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0352]

[0353] Using methyl 5-aldehydethiophene-2-carboxylate (136 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, it was reacted with intermediate D-7 to give compound I-42 (compound 42), 133 mg of off-white solid, yield 71%.

[0354] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.95–7.84(m,3H),7.82–7.76(m,1H),7.66(d,J=3.8Hz,1H),7.59–7.47(m,2H),7.47– 7.40(m,2H),6.99(d,J=3.7Hz,1H),6.68(d,J=8.3Hz,2H),5.23(q,J=7.2Hz,1H),4.58(s,2H),3.85(s,3H),1.94(d,J=7.2Hz,3H).

[0355] Example 43

[0356] 5-(((4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0357]

[0358] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-7 to give compound I-43 (compound 43), 110 mg of off-white solid, in a yield of 60%.

[0359] 1H NMR (400MHz, CDCl3) δ8.13(d,J=8.5Hz,1H),7.95–7.85(m,3H),7.82–7.75(m,1H),7.73(d,J=4.3Hz,1H),7.59–7.47(m,2H ),7.47–7.42(m,2H),7.02(d,J=3.8Hz,1H),6.79–6.65(m,2H),5.23(q,J=7.3Hz,1H),4.60(s,2H),1.94(d,J=7.2Hz,3H).

[0360] Example 44

[0361] 5-(((2-methyl-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0362]

[0363] Preparation of intermediate 2-methyl-4-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-8

[0364]

[0365] Using (Z)-N'-hydroxy-3-methyl-4-nitrobenzomidine as the starting material, intermediate D-8 was obtained by following similar steps to the first and second steps in Example 1.

[0366] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.88(d,J=7.5Hz,1H),7.82–7.75(m,3H),7.59–7.47(m,2H ),7.47–7.43(m,2H),6.74(d,J=8.2Hz,1H),5.24(q,J=7.2Hz,1H),2.22(s,3H),1.94(d,J=7.2Hz,3H).

[0367] Preparation of 5-(((2-methyl-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0368] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-8 to give compound I-44 (compound 44), 116 mg of off-white solid, with a yield of 62%.

[0369] 1 H NMR (700MHz, CDCl3) δ8.13(d,J=8.5Hz,1H),7.88(d,J=6.8Hz,1H),7.85–7.81( m,2H),7.79(dd,J=6.3,3.1Hz,1H),7.76(d,J=3.8Hz,1H),7.55(t,J=6.9Hz,1H) ,7.50(t,J=6.9Hz,1H),7.47–7.43(m,2H),7.05(d,J=3.8Hz,1H),6.65(d,J=8.3 Hz,1H),5.24(q,J=7.2Hz,1H),4.67(s,2H),2.23(s,3H),1.94(d,J=7.2Hz,3H).

[0370] Example 45

[0371] 5-(((2-Fluoro-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0372]

[0373] Preparation of intermediate 2-fluoro-4-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)aniline D-9

[0374]

[0375] Using (Z)-N'-hydroxy-3-fluoro-4-nitrobenzomidine as the starting material, intermediate D-9 was obtained by following similar steps to the first and second steps in Example 1.

[0376] 1 H NMR(400MHz, CDCl3)δ8.13(d,J=8.4Hz,1H),7.89(d,J=8.0Hz,1H),7.84–7.78(m,1H),7.77–7.69(m,2H), 7.60–7.48(m,2H),7.48–7.43(m,2H),6.87(t,J=8.5Hz,1H),5.24(q,J=7.2Hz,1H),1.94(d,J=7.2Hz,3H).

[0377] Preparation of 5-(((2-fluoro-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid

[0378] Using 5-formyl-2-thiophenecarboxylic acid (125 mg, 0.8 mmol) as a starting material, and following a similar procedure to step 3 in Example 13, the mixture was reacted with intermediate D-9 to give compound I-45 (compound 45), 130 mg of off-white solid, with a yield of 69%.

[0379] 1 H NMR (700MHz, CDCl3) δ8.12(d,J=8.5Hz,1H),7.88(d,J=8.1Hz,1H),7.80(t,J=4.8Hz,1H),7.78–7.72(m,2H),7.56(t,J=7.7Hz,1H),7.50(t,J=7.5H z,1H),7.45(d,J=4.8Hz,2H),7.26(s,1H),7.05(d,J=3.8Hz,1H),6.72(t ,J=8.4Hz,1H),5.24(q,J=7.2Hz,1H),4.65(s,2H),1.94(d,J=7.1Hz,3H).

[0380] Example 46

[0381] 5-((methyl(4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)amino)methyl)thiophene-2-carboxylic acid)

[0382]

[0383] Preparation of intermediate N-methyl-4-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)-aniline D-10

[0384]

[0385] In a 10 mL reaction flask, 4-(5-(naphth-1-ylmethyl)-1,2,4-oxadiazol-3-yl)-aniline D-9 (315 mg, 1.0 mmol) was dissolved in 5 mL of acetone, and potassium carbonate (138 mg, 1.0 mmol) and methyl iodoform (142 mg, 1.0 mmol) were added. The mixture was heated to reflux for 4 hours. The solution was concentrated under reduced pressure and separated by silica gel (200-300 mesh) column chromatography, using a methanol-dichloromethane (V:V = 0–5:100) mixture as the eluent. Intermediate D-10 was given as 227 mg of off-white solid, in 69% yield.

[0386] 1H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),7.92(d,J=8.6Hz,2H),7.88(d,J=8.1Hz,1H),7.79(d,J=6.5Hz,1H),7.59–7.53(m,1H), 7.51(d,J=7.6Hz,1H),7.49–7.40(m,2H),6.66(d,J=8.7Hz,2H),5.24(q,J=7.2Hz,1H),2.88(d,J=1.8Hz,3H),1.94(d,J=7.2Hz,3H).

[0387] Using 5-formyl-2-thiophenecarboxylic acid (126 mg, 0.8 mmol) and N-methyl-(4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline (132 mg, 0.4 mmol) as the starting material, the mixture was reacted with intermediate D-10 using a similar procedure to step 3 in Example 13 to give compound I-46 (compound 46), 117 mg of off-white solid, in a yield of 62%.

[0388] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.96(d,J=8.6Hz,2H),7.88(d,J=8. 0Hz,1H),7.79(dd,J=6.6,2.9Hz,1H),7.71(d,J=3.8Hz,1H),7.55(t,J=7.4Hz,1H ),7.51(d,J=7.6Hz,1H),7.49–7.42(m,2H),6.94(d,J=3.8Hz,1H),6.83(d,J=8. 6Hz, 2H), 5.24 (q, J = 7.2Hz, 1H), 4.75 (s, 2H), 3.11 (s, 3H), 1.94 (d, J = 7.2Hz, 3H).

[0389] Example 47

[0390] N-(4-methoxycarbonylphenyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0391]

[0392] route:

[0393]

[0394] Experimental steps:

[0395] In a 10 mL reaction flask, 3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline (D-2, 156 mg, 0.5 mmol), methyl p-bromobenzoate (129 mg, 0.6 mmol), palladium acetate (7 mg, 0.03 mmol), BINAP (25 mg, 0.04 mmol), and cesium carbonate (227 mg, 0.07 mmol) were added to 5 mL of anhydrous toluene and stirred until homogeneous. The mixture was heated to reflux for 8 hours under argon protection. The solution was concentrated under reduced pressure and separated by silica gel column chromatography (200-300 mesh) using an ethyl acetate-petroleum ether mixture (V:V = 0–10:100) as the eluent to give compound I-47 (compound 47), 144 mg of off-white solid, yield 64%.

[0396] 1 H NMR (400MHz, CDCl3) δ8.13 (d, J=8.3Hz, 1H), 7.97–7.73 (m, 6H), 7.60–7.39 (m, 5H), 7.30 (d, J= 8.2Hz, 1H), 7.02 (d, J = 8.3Hz, 2H), 5.27 (q, J = 7.1Hz, 1H), 3.88 (s, 3H), 1.96 (d, J = 7.2Hz, 3H).

[0397] Example 48

[0398] N-(4-methoxycarbonylphenyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0399]

[0400] Using methyl p-bromobenzoate (129 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-1 to give compound I-48 (compound 48), a white solid of 134 mg, in a yield of 58%.

[0401] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.4Hz,1H),7.94–7.86(m,3H),7.83–7.77(m,2H),7.56(t,J=7.6Hz,1H),7.52(d,J=7.5Hz,1H),7. 50–7.43(m,2H),7.27–7.19(m,2H),6.94(d,J=8.7Hz,2H),5.27(q,J=7.1Hz,1H),3.87(s,3H),2.58(s,3H),1.96(d,J=7.2Hz,3H).

[0402] Example 49

[0403] N-(4-methoxycarbonylphenyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)methyl)-1,2,4-oxadiazol-3-yl)aniline

[0404]

[0405] Using methyl p-bromobenzoate (129 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-2 to give compound I-49 (compound 49), 141 mg of off-white solid, in a yield of 63%.

[0406] 1 H NMR (400MHz, CDCl3) δ8.12(d,J=8.1Hz,1H),7.93–7.87(m,3H),7.84(d,J=8.1Hz,1H),7.76(s,1H),7.59–7.50(m,3H),7.4 6(t,J=7.6Hz,1H),7.24(d,J=7.5Hz,1H),7.21–7.15(m,1H),6.93(d,J=8.5Hz,2H),4.72(s,2H),3.88(s,3H),2.55(s,3H).

[0407] Example 50

[0408] N-(3-methoxycarbonylphenyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0409]

[0410] Using methyl m-bromobenzoate (129 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-3 to give compound I-50 (compound 50), 122 mg of off-white solid, in a yield of 52%.

[0411] 1H NMR (400MHz, CDCl3) δ8.13(d,J=8.5Hz,1H),7.89(d,J=8.0Hz,1H),7.83–7.78(m,1H),7.74(d,J=11.9Hz,2H),7.68(d,J=7.8H z,1H),7.61(d,J=7.4Hz,1H),7.59–7.42(m,4H),7.41–7.19(m,4H),5.26(q,J=7.1Hz,1H),3.89(s,3H),1.96(d,J=7.2Hz,3H).

[0412] Example 51

[0413] N-(4-Carboxyphenyl)-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0414]

[0415] Using p-bromobenzoic acid (121 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-3 to give compound I-51 (compound 51), 112 mg of off-white solid, yield 51%.

[0416] 1 H NMR (400MHz, DMSO-d6) δ8.98(brs,1H),8.22(d,J=8.4Hz,1H),8.00(d,J=9.7Hz,1H),7.91(d,J=8.1Hz,1H),7.83(d,J=8 .7Hz,2H),7.78(t,J=1.9Hz,1H),7.67–7.38(m,8H),7.12(d,J=8.7Hz,2H),5.50(q,J=7.1Hz,1H),1.88(d,J=7.1Hz,3H).

[0417] Example 52

[0418] N-(4-Carboxyphenyl)-4-methyl-3-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0419]

[0420] Using p-bromobenzoic acid (121 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-1 to give compound I-52 (compound 52), a white solid of 132 mg, in a yield of 59%.

[0421] 1 H NMR (400MHz, CDCl3) δ8.15(d,J=8.5Hz,1H),7.97(d,J=8.7Hz,2H),7.89(d,J=8.0Hz,1H),7.85–7.78(m,2H),7.60 –7.43(m,4H),7.31–7.21(m,2H),6.96(d,J=8.8Hz,2H),5.28(q,J=7.2Hz,1H),2.59(s,3H),1.97(d,J=7.2Hz,3H).

[0422] Example 53

[0423] N-(4-Carboxyphenyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0424]

[0425] Using p-bromobenzoic acid (121 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-7 to give compound I-53 (compound 53), 150 mg of off-white solid, in a yield of 69%.

[0426] 1 H NMR (400MHz, DMSO-d6) δ9.13(brs,1H),8.21(d,J=7.8Hz,1H),7.98(d,J=8.0Hz,1H),7.96–7.81(m,5H),7.67–7.47( m,3H),7.47–7.38(m,1H),7.30(d,J=5.7Hz,2H),7.20(d,J=6.0Hz,2H),5.45(q,J=6.7Hz,1H),1.86(d,J=4.4Hz,3H).

[0427] Example 54

[0428] N-(3-Carboxyphenyl)-4-(5-(1-(naphthyl-1-yl)ethyl)-1,2,4-oxadiazol-3-yl)aniline

[0429]

[0430] Using m-bromobenzoic acid (121 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, it was reacted with intermediate D-7 to give compound I-54 (compound 54), 127 mg of off-white solid, yield 58%.

[0431] 1 H NMR (400MHz, DMSO-d6) δ8.69(brs,1H),8.22(d,J=8.3Hz,1H),8.00(d,J=7.8Hz,1H),7.91(d,J=8. 1Hz,1H),7.71(d,J=10.8Hz,2H),7.66–7.29(m,10H),5.50(q,J=7.1Hz,1H),1.88(d,J=7.0Hz,3H).

[0432] Example 55

[0433] N-(3-methoxycarbonylphenyl)-4-(5-(1-(naphthyl-1-yl)methyl)-1,2,4-oxadiazol-3-yl)aniline

[0434]

[0435] Using methyl m-bromobenzoate (129 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-7 to give compound I-55 (compound 55), 150 mg of off-white solid, in a yield of 67%.

[0436] 1 H NMR (400MHz, CDCl3) δ8.13(d,J=8.4Hz,1H),7.89(d,J=8.0Hz,1H),7.80(s,1H),7.74(d,J=11.9Hz,2H),7.68(d,J=7.7Hz,1H),7. 61(d,J=7.3Hz,1H),7.59–7.48(m,2H),7.46(s,2H),7.41–7.18(m,4H),5.26(q,J=7.7Hz,1H),3.89(s,3H),1.96(d,J=7.2Hz,3H).

[0437] Example 56

[0438] N-(4-methoxycarbonylphenyl)-4-(5-(1-(naphthyl-1-yl)methyl)-1,2,4-oxadiazol-3-yl)aniline

[0439]

[0440] Using methyl p-bromobenzoate (129 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-7 to give compound I-56 (compound 56), 166 mg of off-white solid, in a yield of 74%.

[0441] 1H NMR (400MHz, CDCl3) δ8.14(d,J=8.6Hz,1H),8.03(d,J=8.0Hz,2H),7.96(d,J=7.7Hz,2H),7.89(d,J=8.2Hz,1H),7.80(d,J=6.9Hz,1H),7.60 –7.50(m,2H),7.46(d,J=7.1Hz,2H),7.20(d,J=7.8Hz,2H),7.09(d,J=7.8Hz,2H),5.26(q,J=7.5Hz,1H),3.89(s,3H),1.96(d,J=6.8Hz,3H).

[0442] Example 57

[0443] N-(4-cyanophenyl)-4-(5-(1-(naphthyl-1-yl)methyl)-1,2,4-oxadiazol-3-yl)aniline

[0444]

[0445] Using 4-bromobenzonitrile (109 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, it was reacted with intermediate D-7 to give compound I-57 (compound 57), 133 mg of off-white solid, yield 62%.

[0446] 1 H NMR (400MHz, DMSO-d6) δ9.28(brs,1H),8.22(d,J=8.3Hz,1H),8.00(d,J=8.0Hz,1H),7.97–7.88(m,3H),7.67(d,J=8.2Hz,2H),7. 65–7.49(m,3H),7.44(d,J=7.4Hz,1H),7.32(d,J=8.2Hz,2H),7.22(d,J=8.4Hz,2H),5.47(q,J=7.4Hz,1H),1.87(d,J=7.0Hz,3H).

[0447] Example 58

[0448] N-(3-cyanophenyl)-4-(5-(1-(naphthyl-1-yl)methyl)-1,2,4-oxadiazol-3-yl)aniline

[0449]

[0450] Using 3-bromobenzonitrile (109 mg, 0.6 mmol) as a starting material, and following similar procedures as in Example 47, the mixture was reacted with intermediate D-7 to give compound I-58 (compound 58), 140 mg of off-white solid, in a yield of 67%.

[0451] 1 H NMR (400MHz, CDCl3) δ8.14(d,J=8.6Hz,1H),8.02(d,J=8.3Hz,2H),7.89(d,J=8.2Hz,1H),7.81(s,1H),7.63–7. 41(m,4H),7.41–7.19(m,3H),7.12(d,J=8.3Hz,2H),6.06(s,1H),5.26(q,J=7.5Hz,1H),1.96(d,J=7.0Hz,3H).

[0452] Bioactivity test

[0453] 1. In vitro protease inhibitory activity test

[0454] Assay method: The half-maximal inhibitory concentration (IC50) of the compound against SARS-CoV-2PLpro was determined by fluorescence assay. 50 ).

[0455] Experimental Principle: Characteristic substrates of the PLpro protease are labeled with fluorescently quenched pairs. If the substrate is digested, it emits characteristic fluorescence; otherwise, it does not. The rate of substrate digestion by the protease is determined by detecting the fluorescence values ​​at different inhibitor concentrations. Based on the digestion rate at different inhibitor concentrations, the half-maximal inhibitory concentration (IC50) of the compound against PLpro can be calculated. 50 ).

[0456] Experimental methods:

[0457] (1) The compound was serially diluted with DMSO.

[0458] (2) In a 96-well transparent black plate (Greiner, 655096), reaction buffer, different concentrations of the test compound and PLpro protease were added in sequence according to the reaction system.

[0459] (3) After placing the reaction plate in a 37°C incubator for 8-10 minutes of enzymatic reaction, add the fluorescent substrate.

[0460] (4) Real-time detection of fluorescence intensity was performed using an enzyme-linked immunosorbent assay (ELISA) reader.

[0461] (5) The obtained data were fitted using Origin and Graphpad to obtain the IC. 50 Numerical value.

[0462] Experimental results

[0463] Table 1. Results of the inhibitory effect of the compounds in the embodiments of the present invention on PLpro

[0464]

[0465]

[0466] As shown in Table 1, the compounds of this invention exhibit good PLpro inhibitory activity, with 14 compounds showing an IC50 inhibitory activity against PLpro. 50 <10μM.

[0467] 2. Cytotoxicity detection

[0468] Assay Method: MTT Assay Principle: Cell viability is determined by the reduction of oxidized 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide (trade name: thiazolyl) / MTT [3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide] to a poorly soluble blue formazan compound by mitochondrial dehydrogenases (such as succinate dehydrogenase). The formazan compound is dissolved in DMSO and then reacted with the formazan to determine its color. The amount of formazan is positively correlated with the number of viable cells.

[0469] Experimental methods:

[0470] (1) Digest VeroE6 cells cultured to the logarithmic growth phase with 0.25% trypsin for 2-3 minutes, discard the digestion solution, add an appropriate amount of culture medium, mix well, and take 20 μL for hemocytometer counting under a microscope to prepare a cell suspension of appropriate concentration for later use. Simultaneously prepare PBS (phosphate buffered solution) to...

[0471] Filter and sterilize a 5 g / L MTT solution for later use.

[0472] (2) Dissolve the test drug in DMSO, dilute it 50 times with culture medium to prepare the highest concentration of the test drug, and then use culture medium to perform serial dilution at 1:2 on a 96-well plate. Set 8 concentrations for each compound, with the highest concentration being 200 μM. Set 4 parallel wells for each concentration, 100 μL / well.

[0473] (3) The prepared cell suspension was seeded into 96-well plates at a density of 100 μL / well, with a cell concentration of 4 × 10⁻⁶ cells / well. 5Cells / mL. Control wells containing no drug and blank control wells containing culture medium were also included.

[0474] (4) After culturing for 48 hours, add 10 μL of MTT per well and continue culturing for another 4 hours. Remove the culture plate, carefully discard the culture medium in each well, add 100 μL of DMSO to each well, and shake until the formazan particles are completely dissolved. Then, measure the optical density (OD) at 570 nm using an enzyme-linked immunosorbent assay (ELISA) reader. 570 ).

[0475] (5) Data processing: Cell survival percentage (%) = [(cell control OD)] 570 Value - OD of the drug-treated group 570 (value) / (cell control OD) 570 Value - Blank OD 570 [Value] × 100%. The dose-response curve was fitted using Origin software to calculate the concentration (CC) of various compounds at 50% cell viability. 50 ).

[0476] Experimental results:

[0477] Table 2. Cytotoxicity results of the compounds of this invention

[0478]

[0479] As shown in Table 2, the compounds of this invention exhibit low cytotoxicity and demonstrate high safety.

[0480] 3. Antiviral activity detection

[0481] Assay Method: Quantitative Real-Time PCR (qPCR) for detecting total RNA in cell culture supernatant. Experimental Principle: During PCR amplification, a specific fluorescent probe is added simultaneously with a pair of primers. This probe is an oligonucleotide labeled with a reporter fluorescent group and a quencher fluorescent group at each end. When the probe is intact, the fluorescent signal emitted by the reporter group is absorbed by the quencher group. Initially, the probe binds to any single strand of DNA. During PCR amplification, the 5'-3' exonuclease activity of Taq polymerase cleaves and degrades the probe, separating the reporter and quencher fluorescent groups. This allows the fluorescence monitoring system to receive the fluorescent signal; that is, for each DNA strand amplified, one fluorescent molecule is formed, achieving complete synchronization between the accumulation of the fluorescence signal and the formation of the PCR product.

[0482] Experimental methods:

[0483] (1) Digest VeroE6 cells that have been cultured to the logarithmic growth phase with 0.25% trypsin for 2-3 minutes, discard the digestion solution, add an appropriate amount of culture medium, mix well, take 20 μL and count the cells under a microscope with a hemocytometer, and prepare a cell suspension of appropriate concentration for later use.

[0484] (2) Dissolve the test drug in DMSO, dilute it 50 times with culture medium to prepare the highest concentration of the test drug, and then use culture medium to perform serial dilution at 1:2 on a 96-well plate. Set 8 concentrations for each compound, with the highest concentration being 200 μM. Set 4 parallel wells for each concentration, 100 μL / well.

[0485] (3) The prepared cell suspension was seeded into 96-well plates at a density of 100 μL / well, with a cell concentration of 4 × 10⁻⁶ cells / well. 5 cell / mL.

[0486] (4) After incubating the cells with different dilutions of the drug working solution (200 μL) for 1 h, add 100 TCID45. 50 The 2019-Wuhan strain of virus was incubated for 2 hours.

[0487] (5) Remove the cell culture medium from the 96-well culture plate and add different concentrations of compound diluent, 200 μl per well, with 3 replicates per concentration. Also set up cell control wells without drug, blank control wells of culture medium, solvent control wells and virus control wells.

[0488] (6) After culturing for 48 hours, take the culture supernatant and add it to AVL lysis buffer. Repeatedly pipette for 15 seconds to ensure complete lysis. Then, extract RNA from the cell culture supernatant according to the RNA extraction kit steps.

[0489] (7) After the extracted RNA, fluorescent probe and polymerase are mixed evenly, the RNA in the supernatant is quantitatively detected by qPCR.

[0490] (8) Data Processing: Cellular antiviral activity = [(Ct value of drug-treated group - Ct value of virus control group / (Ct value of cell control group - Ct value of virus control group)] × 100%. GraphPad software was used to fit dose-response curves, and the concentrations (EC50) at which various compounds achieved 50% antiviral activity were calculated. 50 ).

[0491] Experimental results:

[0492] Table 3. Antiviral test results of the compounds

[0493]

[0494] As shown in Table 3, compounds 25, 43, and 46 of this invention exhibit superior antiviral activity compared to the PLpro inhibitor GRL0617, demonstrating a strong anti-coronavirus effect.

[0495] 4. Liver microsomal metabolic stability test

[0496] Experimental methods: The metabolic stability of target compounds in liver microsomes (mixed human bioreclamation) was studied. The specific method is as follows: 1 μM test solutions were prepared from the synthesized target compounds.

[0497] The microsomal protein concentration was 1 mg / mL. The reaction was initiated by adding NADPH (1 mM), and the sample was incubated in a shaking incubator at 37 °C for up to 60 min. The reaction was terminated at 0, 5, 15, and 30 min by adding ice-cold acetonitrile / methanol (50:50) containing an internal standard. Aliquots of the reaction mixture were collected at 0, 5, 15, 30, and 60 min, and then ice-cold acetonitrile / methanol (50:50, v / v) containing an internal standard were added. The sample was centrifuged at 4 °C for 15 min (4000 rpm), and the supernatant was analyzed by LC-MS / MS. Chromatographic conditions: Column: Kinetex C18 100A (30 mm × 3.0 mm, 2.6 μm); Column temperature: room temperature; Mobile phase: acetonitrile-water (containing 0.1% formic acid) gradient; Flow rate: 0.9 mL / min. The metabolic stability of a compound is assessed by measuring its residual amount with or without the NADPH cofactor.

[0498] Table 4. Metabolic stability data of some compounds in human and mouse liver microsomes of the present invention

[0499]

[0500] As shown in Table 4, compounds 29 and 43 of the present invention exhibit good metabolic stability in human and mouse liver microsomes.

Claims

1. A compound of formula (I) or a pharmaceutically acceptable salt thereof: in, R1 can be hydrogen, methyl, ethyl, propyl, or isopropyl. R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents; R3 can be hydrogen, methyl, ethyl, or propyl. m is 0 or 1; R4 is a substituted or unsubstituted C3-C7 cycloalkyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted thiophene, a substituted or unsubstituted furanyl, or a substituted or unsubstituted spiro[3,3]heptyl; The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, methanesulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

2. A compound of formula (II) or a pharmaceutically acceptable salt thereof: in, R1 is hydrogen or methyl; R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents; m is 0 or 1; R4 is a substituted or unsubstituted C3-C7 cycloalkyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted thiophene, a substituted or unsubstituted furanyl, or a substituted or unsubstituted spiro[3,3]heptyl; The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, methanesulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

3. The compound according to claim 2, or a pharmaceutically acceptable salt thereof: in, R1 is hydrogen or methyl; R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents; m is 0; R4 is a substituted or unsubstituted C3-C7 cycloalkyl group or a substituted or unsubstituted spiro[3,3]heptyl group; The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, hydroxymethyl, carboxyl, sulfonic acid, methanesulfonic acid, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl.

4. The compound according to claim 2, or a pharmaceutically acceptable salt thereof: in, R1 is hydrogen or methyl; R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents; m is 0 or 1; R4 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted thiophene group, or a substituted or unsubstituted furanyl group; The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, methanesulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

5. A compound of formula (III) or a pharmaceutically acceptable salt thereof: in, R1 is hydrogen or methyl; R2 is independently selected from hydrogen, F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, C1-C3 alkyl, halo-C1-C3 alkyl, C1-C3 alkoxy, and n represents 1, 2, 3 or 4 substituents; R3 represents hydrogen or methyl; m is 0 or 1; R4 is a substituted or unsubstituted phenyl group or a substituted or unsubstituted thiophene group; The substituents in R4 may be selected from the following groups: F, Cl, Br, hydroxyl, amino, nitro, cyano, trifluoromethoxy, vinyl, ethynyl, hydroxymethyl, carboxyl, sulfonic acid, methanesulfonic acid, boric acid, methylthio, C1-C4 alkyl, halo-C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxyformyl, C1-C4 alkoxysulfonyl, C1-C4 alkylamine.

6. The compound according to any one of claims 1 to 5 and its pharmaceutically acceptable salt, wherein the compound is selected from the following compounds:

7. A method for preparing the compound according to any one of claims 1 to 6, comprising the following steps: Compound A and compound B undergo condensation and cyclization to obtain compound C, which is then reduced to obtain intermediate D. When m = 0 and R4 is cycloalkyl, D reacts with R4Br under basic conditions to undergo a substitution reaction to obtain the compound shown in formula (I). When m = 0 and R4 is aryl, D reacts with R4Br via a CN coupling reaction to obtain the compound shown in formula (I). Compound D reacts with R4CHO via amination reduction to obtain the compound shown in formula (I). Compound D reacts with R3I via a substitution reaction to obtain compound E, which is then reacted with R4CHO via amination reduction to obtain the compound shown in formula (I). Wherein, R1, R2, R3, R4, m, and n are defined as in any one of claims 1-5.

8. Use of the compound of any one of claims 1 to 6 or a pharmaceutically acceptable salt thereof in the preparation of a papain-like protease PLpro inhibitor.

9. A pharmaceutical composition, characterized in that, The composition comprises a therapeutically and / or preventively effective amount of the compound of any one of claims 1 to 6 or a pharmaceutically acceptable salt thereof, and optionally one or more pharmaceutically acceptable carriers and excipients.

10. The use of the compound of any one of claims 1 to 6 and a pharmaceutically acceptable salt thereof or the composition of claim 9 in the preparation of a medicament for treating and / or preventing infectious diseases caused by coronaviruses.

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