Chalcone compound suitable for antiviral effect as well as preparation method and application of chalcone compound

Abstract

The invention relates to the field of biological medicine, in particular to a chalcone compound suitable for antiviral action, the structure of the compound is shown in the following formula A, and each variable is defined in the specification. Through structural optimization and structure-function relationship research, the invention finds that the compound with a stronger SARS-CoV-2 3CL protease inhibition effect is found and provided, and the compound can inhibit novel coronavirus replication at a cellular level and has an anti-inflammatory effect. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of biomedicine, and in particular to a chalcone compound suitable for antiviral effect and a preparation method and application thereof. Background Art

[0002] Coronavirus Disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has killed millions of people worldwide and continues to be a global health problem. Although the new coronavirus vaccine can effectively prevent SARS-CoV-2 infection, reduce the spread of the new coronavirus, reduce the risk of morbidity, severe illness and death, and block the spread of the new coronavirus infection, studies have reported that the effectiveness of the new coronavirus infection vaccine has declined within a few months after vaccination, and the vaccination coverage of the population in some countries is still relatively low. Therefore, the risk of a global pandemic of the new coronavirus infection still exists.

[0003] To date, some small molecule antiviral drugs for the treatment of COVID-19 (such as nivolumab, remdesivir and monupiravir) have been launched on the market. Most of them need to be administered within 10 days of symptom onset. In addition, new variants such as the novel coronavirus BA.2.86 have appeared in many countries. Therefore, effective treatment strategies still need to be studied to deal with COVID-19.

[0004] The development of virus-targeted inhibitors aims to block different stages of the SARS-CoV-2 life cycle, such as entry (spike protein inhibitors), proteolytic processing (main protease, i.e. 3CL pro Inhibitors, papain-like inhibitors), RNA synthesis (NSP12-NSP16 inhibitors) and assembly (nucleocapsid inhibitors), etc. Among the SARS-CoV-2 targets, 3CL pro The active site is highly conserved and has low homology with the amino acid sequence of human proteases, making it one of the most effective targets for developing broad-spectrum antiviral drugs. Therefore, the development of a new type of 3CL pro The inhibitors have potential application prospects.

[0005] Chalcone is an aromatic ketone of an α,β-unsaturated carbonyl compound, which can be used as the core of various important biological compounds, collectively referred to as chalcone compounds. Benzylideneacetophenone is the skeleton of the chalcone series. Chalcone's potential anti-cancer, anti-inflammatory, antibacterial, antioxidant and anti-parasitic properties and its unique chemical structure characteristics have inspired the synthesis of many chalcone derivatives. Patent CN 115304513 A discloses chalcone derivatives with anti-inflammatory activity, their synthesis methods and applications. Some of the compounds prepared have strong anti-inflammatory activity and can be used to prepare anti-inflammatory drugs.

[0006] According to existing literature reports, the chalcone skeleton molecules shown below have a wide range of clinical activities. Compound a has anti-cancer effects; compound b (naringenin chalcone) has anti-inflammatory and anti-allergic effects; compound c has anti-malarial and other effects; compound d (citricarborin) has antihypertensive, myocardial protection, anti-diabetic, lipid-lowering, anti-inflammatory, antioxidant and other effects.

[0007]

[0008] Based on this, the present invention develops inhibitors suitable for fighting the new coronavirus based on chalcone compounds, and for the first time discovers that chalcone compounds with new structures, as SARS-CoV-23CL protease inhibitors, have strong anti-new coronavirus and anti-inflammatory activities. Summary of the invention

[0009] The present invention provides a chalcone compound suitable for antiviral effect and a preparation method and application thereof. The compound with a new structure has stronger activity as a covalent inhibitor of SARS-CoV-23CL protease and has potential application prospects in the preparation of drugs for treating COVID-19.

[0010] The present invention is achieved through the following technical solutions:

[0011] A chalcone compound suitable for antiviral effect, the structural formula of which is a compound shown in the following formula or a pharmaceutically acceptable salt thereof:

[0012]

[0013] In formula A,

[0014] R 1 is a mono- or poly-substituent of the following groups: halogen, alkoxy, alkyl, nitro, cyano, trifluoromethyl, phenyl, hydrogen, aryl, three-membered ring, isopropyl; preferably, the alkoxy is a C1-C10 alkoxy;

[0015] R 2is an alkoxy group, a hydroxyl group, an oxo group, a C1-C6 alkoxy group, or an aryl group; preferably, the alkoxy group is a C1-C6 alkoxy group;

[0016] R 3 It is alkyl, hydrogen, acetyl.

[0017] As a preferred technical solution of the present invention, the chalcone compounds used for antiviral effect are selected from one or more of the following structural formulas:

[0018] (1) Compound 1: (2) Compound 2: (3) Compound 3: (4) Compound 4: (5) Compound 5: (6) Compound 6: (7) Compound 7: (8) Compound 8: (9) Compound 9: (10) Compound 10: (11) Compound 11: (12) Compound 12: (13) Compound 13:

[0019] (14) Compound 14: (15) Compound 15: (16) Compound 16: (17) Compound 17: (18) Compound 18: (19) Compound 19

[0020] As a further preferred technical solution of the present invention, the chalcone compounds used for antiviral effect are selected from one or more of the following structural formulas:

[0021] Compound 3: Compound 4: Compound 6: Compound 7: Compound 12: Compound 15: Compound 18: Compound 19:

[0022] In a further preferred technical solution, the chalcone compound used for antiviral effect is selected from one or more of the following structural formulas:

[0023] Compound 3: Compound 4: Compound 6: Compound 7:

[0024] The above-mentioned compounds 1 and 2 are prepared by the following route:

[0025]

[0026] The specific steps include:

[0027] Step a: Dissolve compound 1a in a solvent (e.g., anhydrous dichloromethane, i.e., DCM), add a chlorinating agent (e.g., sulfonyl chloride SO 2 Cl 2 ), stirring for 1.5-2.5 (preferably 2 hours) hours, TLC detection, after the raw materials are completely reacted, the organic phase is added dropwise to an alkaline reagent (such as 10% sodium bicarbonate solution) until no gas is generated, and then extracted with an organic solvent (such as DCM), and the organic phase is washed with water (for example, washed 3 times with saturated brine), and after removing water, a solid compound 1b is obtained;

[0028] Step b: Dissolve compound 1b in a solvent (e.g. DCM, chloroform), add a chlorinating agent (e.g. SO 2 Cl 2 ) or a brominating agent (such as N-bromosuccinimide NBS), react at 65-75° C. (preferably 70° C.) under nitrogen conditions overnight, and detect by TLC that the raw materials are completely reacted, add water and DCM, collect the organic phase, wash the organic phase with water (preferably with saturated brine), and separate and purify by thin layer chromatography to obtain solid compound 1c;

[0029] Step c: adding methyl 2-(dimethoxyphosphoryl)acetate to a solution of sodium hydrogen in tetrahydrofuran at 0°C, stirring after the addition, then adding compound 1c dropwise, bringing the resulting mixture to room temperature and stirring for 12-20 hours (e.g., 16 hours), and detecting the reaction by LCMS. After the reaction is complete, adding water to quench the reaction, extracting with ethyl acetate, collecting the organic phase, concentrating, and separating and purifying by column chromatography to obtain methyl benzoate compound 1d;

[0030] Step d: Dissolve compound 1d in an organic solvent (such as anhydrous DCM), add boron tribromide (BBr 3 , 1M), the mixture is warmed to room temperature and stirred (for example, for 2 hours). After the reaction, the reaction solution is dropped into ice water to quench the reaction, the solvent is removed under reduced pressure, and the mixture is extracted with ethyl acetate. The organic phase is collected and dried to obtain a white solid, and the product is prepared by high performance liquid chromatography.

[0031] The above-mentioned compounds 3-6 and compounds 9-19 were prepared by the following route:

[0032]

[0033] The specific steps include:

[0034] Step a: dissolving compound 2a (e.g. 4-fluorobenzaldehyde) in a solvent (e.g. anhydrous tetrahydrofuran), adding a nucleophilic reagent (preferably methylmagnesium bromide) dropwise at 0°C under nitrogen, and then reacting at room temperature for 1.5-2.5 hours (preferably 2 hours). After the reaction is complete, adding an acidic reagent (e.g. 1M hydrochloric acid) to adjust the pH to neutral, and then extracting with an organic solvent (e.g. ethyl acetate), collecting the organic phase, drying, and concentrating, and purifying the residue to obtain compound 2b;

[0035] Step b: dissolving compound 2b in a solvent (such as ethyl acetate), adding 2-iodoacylbenzoic acid, reacting at 80-90° C. (preferably 85° C.) overnight, and checking by TLC, the raw material is completely reacted, the solid in the reaction is filtered to obtain a filtrate, and after vacuum distillation, wet loading and purification by chromatographic column to obtain compound 2c;

[0036] Step c: On an ice bath, a ketone compound (e.g., 2,6-dichloro-3,4,5-trimethoxybenzaldehyde) and compound 2c are dissolved in a solvent (e.g., methanol), a methanolic NaOH solution is added and stirred, and the reaction is stirred at room temperature overnight. The reaction solid is separated by filtration and washed with water to obtain a crude product 2d;

[0037] Step d: Dissolve compound 2d in a solvent (such as anhydrous DCM), add boron tribromide (BBr 3 , 1M), the mixture was warmed to room temperature and stirred. After the reaction, the reaction solution was dropped into ice water to quench the reaction, the solvent was removed under reduced pressure, extracted with ethyl acetate, the organic phase was collected and dried to obtain a white solid, and finally the product (Compound 3, Compound 5, Compound 6 and Compounds 9-19, etc.) was prepared by high performance liquid chromatography;

[0038] Step e: dissolving compound 3 in acetic anhydride, reacting at 60°C overnight, detecting by TLC, generating new spots, extracting with water and ethyl acetate, and performing column chromatography to obtain the final compound 4;

[0039] The ketone compound in step c is selected according to the target compound, specifically: Compound 3 and Compound 4 use 2,6-dichloro-3,4,5-trimethoxybenzaldehyde, Compound 5 uses 2-chloro-3,4,5-trimethoxybenzaldehyde, and Compound 6 uses 3,4,5-trimethoxybenzaldehyde; Compound 9 uses 4-chloroacetophenone, Compound 10 uses 4-bromoacetophenone, Compound 11 uses 4-nitroacetophenone, Compound 12 uses 4-trifluoromethylacetophenone, Compound 13 uses 2'-fluoroacetophenone, Compound 14 uses 1-(2,6-dichloro-4-fluorophenyl)ethane-1-one, Compound 15 uses acetophenone, Compound 16 uses 4-methoxyacetophenone, Compound 17 uses 2-acetylthiophene, Compound 18 uses 2-acetylfuran, and Compound 19 uses 1-(4'-fluoro-[1,1'-biphenyl]-4-yl)ethane-1-one.

[0040] The above compounds 7 to 8 were prepared by the following route:

[0041]

[0042] The specific steps include:

[0043] (1) CuI, Cs 2 CO 3 The mixture is mixed in a solvent (such as anhydrous THF), and the mixture is stirred at room temperature (preferably for 20 minutes), and then bis(pinacolato)diboron, compound 3a, and then methanol are added, stirred at room temperature, and reacted for 24-36 hours (preferably 30 hours), the mixture is extracted with ethyl acetate for several times, and the combined organic phases are washed with saline solution and washed with Na 2 SO 4 Drying, filtration, concentration and purification by flash chromatography gave solid compound 3b;

[0044] Alternatively, compound 3a is dissolved in methanol, and then a catalyst (such as 10% Pd / C) is added, and the reaction is carried out overnight at room temperature under hydrogen conditions. The reaction is monitored by TLC. When the raw material is completely reacted, the mixture is filtered through diatomaceous earth, dried by spin drying, and separated and purified by column chromatography to obtain the reduced hydroxy compound 4a;

[0045] (2) Dissolve compound 3b or compound 4a in a solvent (such as anhydrous DCM), add boron tribromide (BBr) at -60 °C. 3 , 1M), the mixture is slowly warmed to room temperature and stirred (preferably for 2 hours). After the reaction, the reaction solution is dropped into ice water to quench the reaction, the solvent is removed under reduced pressure, extracted with ethyl acetate, the organic phase is collected and dried to obtain a solid, and finally the product is prepared by high performance liquid chromatography.

[0046] An application of a chalcone compound suitable for antiviral effects, wherein the compound or a pharmaceutically acceptable salt thereof is used to prepare an anti-novel coronavirus drug;

[0047] And / or, the compound or a pharmaceutically acceptable salt thereof is used to prepare an anti-novel coronavirus inhibitor;

[0048] And / or, the compound or a pharmaceutically acceptable salt thereof exerts an antiviral effect by inhibiting 3CL protease;

[0049] And / or, use of the compound or a pharmaceutically acceptable salt thereof as an active ingredient in the preparation of a 3CL protease inhibitor;

[0050] And / or, the virus is selected from SARS-CoV-2.

[0051] Furthermore, an antiviral pharmaceutical preparation is provided, comprising a safe and effective dose of the above compound or a pharmaceutically acceptable salt thereof, with the remainder being a pharmaceutically acceptable carrier.

[0052] Pharmaceutically acceptable carriers are various commonly used auxiliary materials and / or excipients in pharmacy, including (but not limited to) sugars (such as lactose, glucose and sucrose), starches (such as corn starch and potato starch), cellulose and its derivatives (such as sodium carboxymethyl cellulose, ethyl cellulose and methyl cellulose), tragacanth powder, malt, gelatin, talc, solid lubricants (such as stearic acid and magnesium stearate), calcium sulfate, vegetable oils, such as peanut oil, cottonseed oil, sesame oil, olive oil, corn oil and cocoa butter, polyols (such as propylene glycol, glycerol, sorbitol, mannitol and polyethylene glycol), alginic acid, emulsifiers (such as Tween, polyoxyethylene castor oil), wetting agents (such as sodium lauryl sulfate), colorants, flavorings, tablets, stabilizers, antioxidants, preservatives, pyrogen-free water, isotonic saline solution and phosphate buffer, etc.; the carrier can improve the stability, activity and biological effectiveness of the formulation as needed.

[0053] The pharmaceutical preparation of the present invention can be prepared into any conventional preparation form according to the general method of pharmacy.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] Prior to the present invention, there were no reports on the evaluation of the anti-SARS-CoV-2 3CL protease activity test for the compounds provided by the present invention. The inventors have discovered and proposed that the skeleton compound produces a series of new compound molecules with more meaningful structure and activity. The IC values ​​of compounds 1-19 were 50All of them were less than 5 μM, indicating that these compounds have a very good inhibitory effect on SARS-CoV-2 3CL protease. At a concentration of 50 μM, compounds 3, 4, 6, 7, 12, 15, 18 and 19 can inhibit SARS-CoV-2 replication by more than 50%. Compounds 3, 4, 6 and 7 were tested for EC 50 The results showed that the activities of SARS-CoV-2 in the replicon model were 19.91, 40.29, 11.65 and 32.10 μM, respectively, which is expected to provide a new source of compounds for biological activity screening and has potential application prospects in the preparation of drugs for the treatment of COVID-19. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1-2 The product 1 obtained in Example 1 of the present invention 1 HNMR and 13 Schematic diagram of C NMR.

[0057] Figure 3-4 The product 2 obtained in Example 2 of the present invention 1 HNMR and 13 Schematic diagram of C NMR.

[0058] Figure 5-7 The product 3 obtained in Example 3 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0059] Figure 8-10 The product 4 obtained in Example 4 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0060] Figure 11-13 The product 5 obtained in Example 5 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0061] Figure 14-16 The product 6 obtained in Example 6 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0062] Figure 17-19 The product 7 obtained in Example 7 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0063] Figure 20-22 The product 8 obtained in Example 8 of the present invention 1 HNMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0064] Figure 23-24 The product 9 obtained in Example 9 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0065] Figure 25-26 The product 10 obtained in Example 10 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0066] Figure 27-28 The product 11 obtained in Example 11 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0067] Figure 29-31 The product 12 obtained in Example 12 of the present invention 1 H NMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0068] Figure 32-34 The product 13 obtained in Example 13 of the present invention 1 H NMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0069] Figure 35-37 The product 14 obtained in Example 14 of the present invention 1 H NMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0070] Figure 38-39 The product 15 obtained in Example 15 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0071] Figure 40-41 The product 16 obtained in Example 16 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0072] Figure 42-43 The product 17 obtained in Example 17 of the present invention 1 H NMR and 13Schematic diagram of C NMR.

[0073] Figure 44-45 The product 18 obtained in Example 18 of the present invention 1 H NMR and 13 Schematic diagram of C NMR.

[0074] Figures 46-48 Example 19 of the present invention obtains product 19 1 H NMR, 13 C NMR and 19 Schematic diagram of FNMR.

[0075] Fig.49 The 19 compounds of the present invention are shown to be effective against SARS-CoV-23CL at different concentrations. pro Inhibitory effect.

[0076] Fig.50 The 12 embodiments of the present invention inhibit the SARS-CoV-2 replicon model.

[0077] Fig.51 The toxicity of the 12 compounds of the present invention to Huh7 cells.

[0078] Fig.52 This is an experiment to explore the inhibition mechanism of Examples 3 and 6 of the present invention.

[0079] Fig.53 This is the anti-inflammatory effect of Examples 3 and 17 of the present invention. DETAILED DESCRIPTION

[0080] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0081] The determination method of the compounds in the examples was confirmed by low-resolution mass spectrometry (molecular weight) and nuclear magnetic resonance (NMR) instrumentation (H spectrum, C spectrum or F spectrum).

[0082] Example 1

[0083]

[0084] The preparation method comprises the following steps:

[0085]

[0086] Steps a and b: Dissolve compound 1a (3,4,5-trimethoxybenzaldehyde) (10 g, 51 mmol) in anhydrous dichloromethane (100 mL, DCM) and add sulfonyl chloride (SO 2 Cl 2 )(17.2 g, 127.4 mmol), stirred for 16 hours. TLC detection showed that the raw material was completely reacted, and the organic phase was dripped into 10% sodium bicarbonate solution until no gas was generated, and then extracted with DCM, and the organic phase was washed with saturated brine for 3 times, the organic phase was spin-dried, and wet-loaded to obtain a white solid compound 2,6-dichloro-3,4,5-trimethoxybenzaldehyde 1c (12 g, 45.27 mmol).

[0087] Step c: At 0°C, slowly add methyl 2-(dimethoxyphosphoryl)acetate (1.03 g, 5.66 mmol) to a tetrahydrofuran solution of sodium hydrogen sulfide (226 mg, 5.66 mmol). After the addition is complete, stir for 30 minutes. Subsequently, compound 1c (1 g, 3.77 mmol) is added dropwise. The resulting mixture is moved to room temperature and stirred for 16 hours. Subsequently, LCMS is used to detect the reaction. After the reaction is complete, water is added to quench the reaction, and the mixture is extracted with ethyl acetate. The organic phase is collected, concentrated, and purified by column chromatography to obtain a methyl benzoate compound (trans)-3-(2,6-dichloro-3,4,5-trimethoxyphenyl)acrylate 1d (1.1 g, 3.43 mmol).

[0088] Step d: Compound 1d (200 mg, 0.62 mmol) was dissolved in anhydrous DCM, and boron tribromide (BBr) was slowly added at -60 °C. 3 (5mL, 1M in DCM), the mixture was slowly heated to room temperature and stirred for 2 hours. After the reaction, the reaction solution was dropped into ice water at zero degrees to quench the reaction, the solvent was removed under reduced pressure, extracted with ethyl acetate, the organic phase was collected and dried to obtain a white solid, and finally the white target compound (trans)-3-(2,6-dichloro-3,4,5-trihydroxyphenyl)acrylic acid I (80mg, 0.30mmol) was prepared by high performance liquid chromatography.

[0089] The obtained measurement results are as follows Figure 1 , 2 shown.

[0090] 1 H NMR (400MHz, CD 3 OD)δ7.80(d,J=16.0Hz,1H),6.54(d,J=16.0Hz,1H); 13 C NMR (100MHz, CD 3OD)δ170.2,142.8,140.8,137.9,125.4,122.7,114.4.LC-MS ESI(m / z):265.02[M+H] + .

[0091] Example 2

[0092]

[0093] The preparation method is basically the same as that in Example 1, except that: in step b, DCM is replaced by chloroform, SO 2 Cl 2 The reaction mixture was replaced by N-bromosuccinimide (NBS), and the rest were the same.

[0094] The obtained measurement results are as follows Figure 3 , 4 shown.

[0095] 1 H NMR (400MHz, CD 3 OD)δ7.73(d,J=16.0Hz,1H),6.42(d,J=16.4Hz,1H); 13 CNMR (100MHz, CD 3 OD)δ169.9,143.9,143.3,143.1,137.4,125.9,124.5,114.0,104.4.LC-MSESI(m / z):308.92[M+H] + .

[0096] Example 3

[0097]

[0098] The preparation method comprises the following steps:

[0099]

[0100] Step a: dissolve the compound p-fluorobenzaldehyde (1 g, 8.06 mmol) in a solvent, add methylmagnesium bromide (5 mL, 2 M in THF) dropwise at 0 ° C. under nitrogen, and then react at room temperature for 2 hours. After the reaction is complete, add 1 M hydrochloric acid to adjust the pH to neutral, then extract with ethyl acetate, collect the organic phase, dry and concentrate, and purify the residue to obtain the compound 1-(4-fluorophenyl)ethane-1-ol (1 g, 7.13 mmol);

[0101] Step b: Dissolve the compound 1-(4-fluorophenyl)ethane-1-ol (1 g, 7.13 mmol) in ethyl acetate, add 2-iodoacylbenzoic acid (2.4 g, 8.56 mmol), react at 85°C overnight, the raw materials react completely, the solid in the reaction is filtered, and the filtrate is obtained. After vacuum distillation, wet loading, and purification by chromatographic column, the compound 4-fluoroacetophenone (0.95 g, 6.88 mmol) is obtained;

[0102] Step c: On an ice bath, 2,6-dichloro-3,4,5-trimethoxybenzaldehyde (384 mg, 1.45 mmol) and compound 4-fluoroacetophenone (200 mg, 1.45 mmol) were dissolved in a solvent, and methanolic NaOH (4.4 mL, 1 M in H 2 O) solution and stirred, and stirred at room temperature for overnight reaction, the reaction solid was separated by filtration, and washed with water to obtain the product trans-3-(2,6-dichloro-3,4,5-trimethoxyphenyl)-1-(4-fluorophenyl)prop-2-en-1-one (350 mg, 0.91 mmol);

[0103] Step d: The compound trans-3-(2,6-dichloro-3,4,5-trimethoxyphenyl)-1-(4-fluorophenyl)prop-2-en-1-one (200 mg, 0.52 mmol) was dissolved in anhydrous dichloromethane, and boron tribromide (3.2 mL, 1 Min DCM) was added at -60 ° C. The mixture was warmed to room temperature and stirred. After the reaction, the reaction solution was dropped into ice water to quench the reaction, the solvent was removed under reduced pressure, and the mixture was extracted with ethyl acetate. The organic phase was collected and dried to obtain a white solid, and finally the product III (130 mg, 0.38 mmol) was prepared by high performance liquid chromatography;

[0104] The obtained measurement results are as follows Figure 5 , 6 , as shown in 7.

[0105] 1 H NMR (400MHz, CD 3 OD)δ8.10(dd,J=8.8,5.6Hz,2H),7.92(d,J=16.0Hz,1H),7.78(d,J=16.0Hz,1H),7.27(t,J=8.6Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ190.7,167.2(J=251.8Hz),142.8,140.7,138.2,135.6(J=2.9Hz),132.4(J=9.4Hz),128.3,122.9,116.8(d,J=22.1Hz),114.9;19 F NMR (376MHz, CD 3 OD)δ-107.62.LC-MS ESI(m / z):342.94[M+H] + .

[0106] Example 4

[0107]

[0108] The preparation method of this embodiment comprises the following steps:

[0109] Based on Example 3, step e is further performed.

[0110] Step e: Dissolve compound III (100 mg, 0.29 mmol) in 10 mL of acetic anhydride, react at 60 ° C overnight, detect by TLC, generate new spots, extract with water and ethyl acetate, and perform column chromatography to obtain the final compound IV (trans)-4,6-dichloro-5-(3-(4-fluorophenyl)-3-oxoprop-1-en-1-yl)benzene-1,2,3-triacetate (110 mg, 0.23 mmol).

[0111] The obtained measurement results are as follows Figure 8 , 9 , as shown in 10.

[0112] 1 HNMR (400MHz, CDCl 3 )δ8.04(dd,J 1 =8.4Hz,J 2 =5.6Hz,2H),7.74(d,J=16.0Hz,1H),7.56(d,J=16.0Hz,1H),7.18(t,J=8.4Hz,2H),2.36(s,6H),2.32(s,3H); 13 C NMR (100 MHz, CDCl 3 )δ188.1,166.7,166.5,166.1(J=253.8Hz),140.3,137.7,136.8,133.9(J=3 .1Hz),132.2,131.6(J=9.4Hz),131.4,126.5,116.2(J=21.8Hz),20.3,20.2; 19 F NMR (376 MHz, CDCl 3 )δ–104.41.LC-MS ESI(m / z):468.76[M+H] + .

[0113] Example 5

[0114]

[0115] The preparation method is similar to that of Example 3, except that in step c, the raw material used is 2-chloro-3,4,5-trihydroxybenzaldehyde.

[0116] The obtained measurement results are as follows Figures 11 to 13 shown.

[0117] 1 H NMR (400MHz, CD 3 OD)δ8.16(d,J=16.0Hz,1H),8.11(dd,J 1 =8.0Hz,J 2 =6.0Hz,2H),7.47(d,J=15.6Hz,1H),7.26(t,J=8.6Hz,2H),7.00(s,1H); 13 C NMR (100MHz, CD 3 OD)δ190.7,167.1(J=250.3Hz),145.8,143.7,143.1,139.2,136.06(J=2.9Hz),132.4(J=9.3Hz),124.3,121.7,116.7(J=22.0Hz)116.2,106.5; 19 F NMR (376MHz, CD 3 OD)δ–108.03.LC-MS ESI(m / z):309.39[M+H] + .

[0118] Example 6

[0119]

[0120] The preparation method is similar to that of Example 3, except that in step c, the raw material used is 3,4,5-trimethoxybenzaldehyde.

[0121] The obtained measurement results are as follows Figures 14 to 16 shown.

[0122] 1 H NMR (400MHz, CD 3 OD)δ8.10(dd,J 1 =8.4Hz,J 2 =5.6Hz,2H),7.60(d,J=15.2Hz,1H),7.42(d,J=15.6Hz,1H),7.24(t,J=8.6Hz,2H),6.76(s,2H);13 C NMR (100MHz, CD 3 OD) δ 190.9, 167.0 (J = 251.1Hz), 147.9, 147.2, 138.3, 136.2 (J = 2.9Hz), 132.2 (J = 9.2Hz), 127.1, 119.4, 116.6 (J = 22.0Hz), 109.3; 19 F NMR (376MHz, CD 3 OD)δ–108.36.LC-MS ESI(m / z):275.14[M+H] + .

[0123] Examples 7 and 8

[0124]

[0125] The preparation method comprises the following steps:

[0126]

[0127] Step a: Add CuI (6 mg, 0.03 mmol) and Cs into a round-bottom flask. 2 CO 3 (514mg, 1.58mmol) was then replaced with nitrogen, and then anhydrous THF was added, and the mixture was stirred at room temperature for 20 minutes. Then bis(pinacolato)diboron (193mg, 0.76mmol) was added. After 5 minutes, compound 3a (200mg, 0.63mmol) in anhydrous THF was added, and then MeOH (0.1mL) was added. The mixture was stirred at room temperature for 30 hours. After the reaction, the mixture was extracted three times with ethyl acetate. The combined organic phase was washed with brine solution and washed with Na 2 SO 4 Drying, filtration, concentration and purification by flash chromatography afforded 3b (136 mg, 0.43 mmol) as a white solid.

[0128] Step b: Compound 3a (150 mg, 0.47 mmol) was dissolved in methanol, and then 10% Pd / C (20 mg) was added. The mixture was reacted overnight at room temperature under hydrogen. The reaction was monitored by TLC. The raw material was completely reacted. The mixture was filtered through celite, dried by spin drying, and purified by column chromatography to obtain the reduced compound 4a (82 mg, 0.27 mmol).

[0129] Step c: Dissolve compound 4a (82 mg, 0.27 mmol) in anhydrous DCM and slowly add boron tribromide (BBr) at -60 °C. 3(1.6mL, 1M in DCM), the mixture was slowly warmed to room temperature and stirred for 2 hours. After the reaction, the reaction solution was dropped into ice water at zero degrees to quench the reaction, the solvent was removed under reduced pressure, extracted with ethyl acetate, the organic phase was collected and dried to obtain a white solid, and finally the white target compound VIII (54mg, 0.21mmol) was prepared by high performance liquid chromatography. Similarly, the target compound VII was obtained using raw material 3b.

[0130] The assay results of compound 7 are as follows: Figures 17 to 19 shown.

[0131] 1 HNMR (400MHz, CD 3 OD)δ8.01(dd,J 1 =8.4Hz,J 2 =5.6Hz,2H),7.18(t,J=8.6Hz,2H),6.23(s,2H),3.21(t,J=7.4Hz,2H),2.79(t,J=7.7Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ200.4,168.37(J=251.3Hz),147.0,134.9(J=3.0Hz),133.5,132.3,132.0(J=9.4Hz),116.5(J=22.0Hz),108.30,41.5,31.0; 19 F NMR(376MHz,CD3OD)δ–107.93.LC-MS ESI(m / z):277.32[M+H] + .

[0132] The assay results of compound 8 are as follows: Figures 20-22 shown.

[0133] 1 HNMR (400MHz, CD 3 OD)δ7.15–7.11(m,2H),6.95(t,J=8.8Hz,2H),6.19(s,2H),2.55(t,J=7.6Hz,2H),2.39(t,J=7.6Hz,2H),1.81(p,J=7.6Hz,2H); 13 C NMR (100MHz, CD 3 OD) δ 162.6 (J = 240.2Hz), 146.8, 139.6 (J = 3.2Hz), 134.6, 132.0, 130.9 (J = 7.9Hz), 115.7 (J = 21.1Hz), 108.3, 35.8, 35.4, 34.6;19 F NMR(376MHz,CD3OD)δ–120.20.LC-MS ESI(m / z):263.37[M+H] + .

[0134] The preparation methods of Examples 9 to 19 refer to Example 3, except that in step c, different acetophenones are used as raw materials. Example 9 uses 4-chloroacetophenone, Example 10 uses 4-bromoacetophenone, Example 11 uses 4-nitroacetophenone, Example 12 uses 4-trifluoromethylacetophenone, Example 13 uses 2'-fluoroacetophenone, Example 14 uses 1-(2,6-dichloro-4-fluorophenyl)ethane-1-one, Example 15 uses acetophenone, Example 16 uses 4-methoxyacetophenone, Example 17 uses 2-acetylthiophene, Example 18 uses 2-acetylfuran, and Example 19 uses 1-(4'-fluoro-[1,1'-biphenyl]-4-yl)ethane-1-one.

[0135] Example 9

[0136]

[0137] The obtained measurement results are as follows Figures 23-24 shown.

[0138] 1 HNMR (400MHz, CD 3 OD)δ8.01(d,J=8.0Hz,2H),7.94(d,J=16.0Hz,1H),7.77(d,J=16.0Hz,1H),7.56(d,J=8.0Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ191.0,142.9,141.1,140.5,138.5,137.8,131.3,130.1,128.3,122.9,115.0.LC-MS ESI(m / z):359.14[M+H] + .

[0139] Example 10

[0140]

[0141] The obtained measurement results are as follows Figures 25-26 shown.

[0142] 1 H NMR (400MHz, CD 3OD)δ7.92(d,J=16.0Hz,1H),7.91(d,J=8.0Hz,2H),7.75(d,J=16.0Hz,1H),7.70(d,J=8.0Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ191.2,142.9,141.1,138.4,138.1,133.2,131.3,129.1,128.2,122.9,115.0.LC-MS ESI(m / z):403.09[M+H] + .

[0143] Embodiment 11

[0144]

[0145] The obtained measurement results are as follows Figures 27-28 shown.

[0146] 1 H NMR (400 MHz, DMSO-d 6 )δ9.88(s,1H),9.60(s,2H),8.38(d,J=8.0Hz,2H),8.25(d,J=8.4Hz,2H),7.87(d,J=16.0Hz,1H),7.81(d,J=16.0Hz,1H); 13 C NMR (100 MHz, DMSO-d 6 )δ188.6,149.9,142.2,141.9,139.9,137.8,129.8,127.0,124.0,120.9,113.8.LC-MSESI(m / z):370.17[M+H] + .

[0147] Example 12

[0148]

[0149] The obtained measurement results are as follows Figures 29 to 31 shown.

[0150] 1 HNMR (400MHz, CD 3 OD)δ8.14(d,J=8.0Hz,2H),7.95(d,J=16.0Hz,1H),7.82(d,J=8.0Hz,2H),7.77(d,J=16.0Hz,1H); δ 13 C NMR (100MHz, CD 3OD)δ191.3,142.8,142.3,141.6,138.5,135.0(J=32.4Hz),130.1,128.2,126.7(J=3.7Hz),125.2(J=270.2Hz),122.7,115.1; 19 F NMR (376MHz, CD 3 OD)δ–64.47; LC-MS(ESI)m / z:393.00[M+H] + .

[0151] Embodiment 13

[0152]

[0153] The obtained measurement results are as follows Figures 32-34 shown.

[0154] 1 H NMR (400MHz, CD 3 OD)δ7.87(d,J=16.0Hz,1H),7.77(t,J=7.6Hz,1H),7.63-7.55(m,2H),7.32(t,J=7.4Hz,1H),7.24(t,J=9.6Hz,1H); δ 13 C NMR (100MHz, CD 3 OD)191.2,162.5(J=250.9Hz),142.9,141.1,138.5,135.5(J=8.9Hz),131.9,131. 7(J=2.5Hz), 128.1(J=13.2Hz), 125.8(J=3.5Hz), 122.6, 117.6(J=22.8Hz), 115.0; 19 F NMR (376MHz, CD 3 OD)δ–113.33; LC-MS(ESI)m / z:342.93[M+H] + .

[0155] Embodiment 14

[0156]

[0157] The obtained measurement results are as follows Figures 35-37 shown.

[0158] 1 H NMR (400MHz, CD 3OD)δ7.48(d,J=16.8Hz,1H),7.38(d,J=8.4Hz,2H),7.10(d,J=16.8Hz,1H); 13 C NMR (100MHz, CD 3 OD) δ 194.1, 163.6 (d, J = 252.0Hz), 145.1, 142.9, 139.1, 135.3 (d, J = 4.3Hz), 133.9 (d, J = 11.8Hz), 132.6, 121.7, 117.3 (d, J = 25.2Hz), 115.0; 19 F NMR (376MHz, CD 3 OD)δ–109.53; LC-MS ESI(m / z):411.04[M+H] + .

[0159] Embodiment 15

[0160]

[0161] The obtained measurement results are as follows Figures 38-39 shown.

[0162] 1 H NMR (400MHz, CD 3 OD)δ8.02(d,J=7.6Hz,2H),7.92(d,J=16.0Hz,1H),7.77(d,J=16.0Hz,1H),7.64(t,J=7.4Hz,1H),7.55(t,J=7.6Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ191.5,142.9,140.7,139.3,138.3,134.3,129.9,129.6,128.9,123.1,114.9.LC-MS ESI(m / z):325.10[M+H] + .

[0163] Example 16

[0164]

[0165] The obtained measurement results are as follows Figures 40-41 shown.

[0166] 1 H NMR (400MHz, CD 3OD) δ7.96(d,J=8.4Hz,2H),7.87(d,J=16.0Hz,1H),7.77(d,J=16.0Hz,1H),6.90(d,J=8.4Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ190.8,164.1,142.9,139.5,138.1,132.4,130.8,128.9,123.3,116.5,114.7.LC-MS ESI(m / z):341.15[M+H] + .

[0167] Embodiment 17

[0168]

[0169] The obtained measurement results are as follows Figures 42-43 shown.

[0170] 1 H NMR (400MHz, CD 3 OD) δ7.95(d,J=3.6Hz,1H), δ7.94(d,J=15.6Hz,1H),7.88(d,J=4.8Hz,1H),7.73(d,J=16.0Hz,1H),7.24(t,J=4.4Hz,1H); 13 C NMR (100MHz, CD 3 OD)δ184.1,146.4,142.8,139.7,138.3,136.1,134.2,129.7,128.3,122.8,115.0.LC-MS ESI(m / z):331.10[M+H] + .

[0171] Embodiment 18

[0172]

[0173] The obtained measurement results are as follows Figures 44-45 shown.

[0174] 1 H NMR (400MHz, CD 3 OD)δ8.00(d,J=16.0Hz,1H),δ7.86(s,1H),7.88(d,J=4.8Hz,1H),7.70(d,J=16.4Hz,1H),7.47(d,J=3.6Hz,1H),6.70(dd,J 1 =3.6Hz,J 2=1.2 Hz, 1H); 13 C NMR (100MHz, CD 3 OD)δ179.6,154.8,149.2,142.9,139.8,138.4,127.7,122.7,120.0,115.1,113.9.LC-MS ESI(m / z):315.20[M+H] + .

[0175] Embodiment 19

[0176]

[0177] The obtained measurement results are as follows Figures 46-48 shown.

[0178] 1 HNMR (400MHz, CD 3 OD)δ8.08(d,J=8.4Hz,2H),7.94(d,J=16.0Hz,1H),7.81(d,J=16.0Hz,1H),7.75(d,J=8.4Hz,2H),7.71(dd,J 1 =8.0,J 2 =5.6Hz,2H),7.19(t,J=8.6Hz,2H); 13 C NMR (100MHz, CD 3 OD)δ 13 C NMR (100MHz, Methanol-d 4 )δ191.7,164.5(J=245.3Hz),146.0,142.9,140.6,138.3,137.9,137.3(J=3. 2Hz), 130.4, 130.2 (J = 8.2Hz), 128.7, 128.2, 123.1, 116.8 (J = 21.6Hz), 114.9; 19 F NMR(376MHz,CD3OD)δ–116.27.LC-MSESI(m / z):418.99[M+H] + .

[0179]

Protease activity test

[0180] The compounds obtained in Examples 1-19 were subjected to SARS-CoV-23CL protease activity test and replicon model test.

[0181] 1. Materials and methods

[0182] 1.1 Materials

[0183] SARS-CoV-2 3CL protease was expressed and purified by the research group of Chen Lili from Shanghai University of Traditional Chinese Medicine and used as the enzyme source for in vitro 3CL protease inhibition experiments; the substrate Dabcyl-KNSTLQSGLRKE-Edans was synthesized by Nanjing GenScript; NaCl, KCl, Na 2 HPO 4 , KH 2 PO 4 , EDTA were purchased from the Discovery Platform (purity>98%); Milli-Q Direct 8 pure water / ultrapure water integrated system (USA); pipette; black 96-well plate; vortexer; microplate constant temperature oscillator (Hangzhou Ruicheng); BioTek multi-mode microplate reader (USA).

[0184] 1.2 Methods

[0185] 1.2.1 SARS-CoV-2 3CL protease activity test experiment

[0186] The fluorescent substrate Dabcyl-KNSTLQSGLRKE-Edans was prepared with DMSO, the stock solution concentration was 10 mM, and it was divided into small portions and frozen at -20°C for later use. 2 HPO 4 ,1.8mM KH 2 PO 4 ,1mM EDTA, pH7.4) for dilution.

[0187] The enzyme activity reaction system was 100 μL, including the compound, SARS-CoV-23CL protease and substrate Dabcyl-KNSTLQSGLRKE-Edans. The reaction was set up in duplicate wells. After SARS-CoV-23CL protease (final concentration 120 nM) and the compound were incubated at 37 ° C for 30 min, the fluorescent substrate (final concentration 20 μM) was added to start the reaction, and the multi-mode microplate reader was used to continuously detect at λex = 340 nm, λem = 490 nm for 20 min, with an interval of 2 min. The enzyme activity plus solvent group was set to 100%, and the inhibition of enzyme activity in the presence of the test compound was calculated as the inhibition rate of the compound. The inhibition curve was drawn with the logarithm of the inhibitor concentration as the horizontal axis and the inhibition rate as the vertical axis, and the data was processed by Graph PadPrism 8.0 software.

[0188] The calculation formula of the inhibition rate of the compound on 3CL protease is:

[0189] Inhibition rate (%) = 100-F 1 / F 0 ×100%

[0190] F 0 F is the fluorescence intensity value measured when 3CL protease is incubated with substrate without adding inhibitor. 1 is the fluorescence intensity value measured when adding inhibitors at different concentrations.

[0191] 1.2.2 Time-dose-dependent inhibition experiment

[0192] The time-dose-dependent inhibition experiment of the compound was carried out according to the above 3CL protease activity test experimental conditions. The compound was incubated with 3CL protease for 3 minutes and 60 minutes respectively to determine the inhibition rate.

[0193] 1.2.3 Cytotoxicity assay

[0194] RAW 264.7 cells were collected at a rate of 2 × 10 4 Each well was inoculated in a 96-well plate, cultured at 37°C for 24 hours, and then the drug was administered after the cells adhered to the wall. The concentration of the compound group was set to 5, 50 μM (DMSO concentration was 0.5%), and an LPS group and a control group were set up at the same time. All the above groups except the LPS group and the control group were first pretreated with the corresponding drug for 1 hour, and then each group was added with LPS at a final concentration of 0.1 μg / mL, and the control group was added with 0.5% DMSO, placed in an incubator and cultured for 24 hours, the supernatant was discarded, 100 μL of 10% CCK-8 solution was added to each well, and after incubation for 60 minutes, the absorbance value (OD value) at 450nm was detected by an enzyme reader. The inhibition rate of the compound on cell proliferation was calculated according to 1-(OD value of the drug group-OD value of the blank) / (OD value of the control group-OD value of the blank).

[0195] 1.2.4 NO detection in cell culture supernatant

[0196] According to the above-mentioned cytotoxicity assay experiment, each group except the LPS group and the control group was first pretreated with the corresponding drug for 1 hour, and then LPS with a final concentration of 0.1 μg / mL was added to each group, and 0.5% DMSO was added to the control group. After culturing in an incubator for 24 hours, the cell culture supernatant was collected and operated according to the instructions of the NO detection kit. The OD value was measured at a wavelength of 540 nm, and the NO content in the sample was calculated based on the drawn standard curve.

[0197] 1.2.5 Mass spectrometry analysis

[0198] Mass spectrometry analysis was performed using a Waters H-class. SARS-CoV-23CL protease samples were washed with a reaction buffer (100 mM NaCl, 2.7 mM KCl, 10 mM Na 2 HPO 4 ,1.8mM KH 2 PO4 , 1mM EDTA, pH7.4) was diluted to 0.3mg / mL (8.59μM), and divided into two portions (100μL); 0.9μL of DMSO was added to one portion (as a control), and 60.9μL of the compound was added to the other portion (final concentration 90μM); after adding, the mixture was placed on a 37℃ metal bath shaker and incubated for 30min, and 2μg of each sample was separated on an ACQUITY UPLC Protein BEH C4 column (2.1×50mm, 1.7μm).

[0199] HPLC conditions: mobile phase A is an aqueous solution containing 0.1% formic acid, solvent B is an acetonitrile solution containing 0.1% formic acid; column temperature 80°C; flow rate 0.3 mL / min. Chromatographic gradient: 0-3 min: 98% mobile phase A, 2% mobile phase B; 3-5.5 min: 40% mobile phase A, 60% mobile phase B; 5.5-5.6 min: 95% mobile phase A, 5% mobile phase B; 5.6-7.0 min: 10% mobile phase A, 90% mobile phase B; 7.0-7.5 min: 98% mobile phase A, 2% mobile phase B; 7.5-10 min: 10% mobile phase A, 90% mobile phase B.

[0200] 2. Results

[0201] The inhibitory effect of the specific compounds of the present invention on SARS-CoV-23CL protease is shown in Fig.49 , further determined the IC 50 The values ​​are shown in Table 1 below.

[0202] Table 1

[0203]

[0204]

[0205] It can be seen from the data in Table 1 that the 19 compounds 1-19 discovered or prepared by the present invention have IC 50 All of them were less than 5 μM, indicating that the compounds discovered or prepared by the present invention have very good inhibitory effects on SARS-CoV-2 3CL protease. Among them, compound 3 showed the best inhibitory effect, with an IC 50 The value was 0.08 μM. 14 compounds with strong inhibitory activity were selected for testing based on the SARS-CoV-2 replicon model. It was found that at a concentration of 50 μM, compounds 3, 4, 6, 7, 12, 15, 18 and 19 could inhibit SARS-CoV-2 replication by more than 50% ( Fig.50 ), their toxicity to Huh7 cells is shown in Fig.51Considering the antiviral effects and cytotoxicity of the 19 compounds, compounds 3, 4, 6 and 7 were selected for EC 50 The values ​​were determined, and the results showed that their activities in inhibiting SARS-CoV-2 in the replicon model were 19.91, 40.29, 11.65 and 32.10 μM, respectively, as shown in Table 2 below.

[0206] Example Structural formula <![CDATA[CC 50 (μM)]]> <![CDATA[EC 50 (μM)]]> SI 3 Formula III 41.77 19.91 2.10 4 Formula IV ＞50 40.29 ＞1.24 6 Formula VI ＞50 11.65 ＞4.29 7 Formula VII ＞100 32.10 ＞3.12

[0207] Time-dependent inhibitory effect (TDI) experiments were conducted on compounds 3 and 6, which have stronger inhibitory effects on SARS-CoV-2 replication. It was found that compound 3 was non-covalently bound to SARS-CoV-2 3CL protease, and inhibition kinetic experiments were performed, indicating that compound 3 is a mixed non-covalent inhibitor. The TDI experiment confirmed that compound 6 was covalently bound to SARS-CoV-2 3CL protease, and mass spectrometry analysis confirmed that the compound had an addition reaction with SARS-CoV-2 3CL protease, further proving that the compound is a covalent inhibitor. The results are shown in Fig.52 .

[0208] The inhibition rates of compounds 3 and 17 of the present invention on the production of NO in RAW264.7 cells induced by LPS are as follows: Fig.53 As shown. The present invention found that compound 3 has significant cytotoxicity at 50 μM, and compound 17 has no cytotoxicity. Both compounds 3 and 17 can dose-dependently inhibit the production of NO in RAW264.7 cells induced by LPS, and the inhibition rate at 50 μM exceeds 95%, indicating that the compounds have good anti-inflammatory activity. Among them, the inhibition rate of compound 3 on NO production at 5 μM reaches 89.6%. Therefore, the compounds discovered or prepared by the present invention are antiviral and anti-inflammatory dual-functional molecules, among which compound 3 has the strongest antiviral and anti-inflammatory activity.

[0209] The above examples are for the purpose of illustrating the embodiments disclosed by the present invention and are not to be construed as limitations of the present invention. In addition, the various modifications listed herein and the variations of methods and compositions in the invention are obvious to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been specifically described in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. In fact, various modifications obvious to those skilled in the art as described above to obtain the invention should be included within the scope of the present invention.

Claims

1. A chalcone compound suitable for antiviral effect, It is characterized in that The structural formula is a compound shown below or a pharmaceutically acceptable salt thereof: In formula A, R 1 is a mono- or poly-substituent of the following groups: halogen, alkoxy, alkyl, nitro, cyano, trifluoromethyl, phenyl, hydrogen, aryl, three-membered ring, isopropyl; R 2 is alkoxy, hydroxy, sodium oxide, aryl; R 3 It is alkyl, hydrogen, acetyl.

2. A chalcone compound suitable for antiviral effect according to claim 1, It is characterized in that One or more selected from the following structural formulas: (1) Compound 1: (2) Compound 2: (3) Compound 3: (4) Compound 4: (5) Compound 5: (6) Compound 6: (7) Compound 7: (8) Compound 8: (9) Compound 9: (10) Compound 10: (11) Compound 11: (12) Compound 12: (13) Compound 13: (14) Compound 14: (15) Compound 15: (16) Compound 16: (17) Compound 17: (18) Compound 18: (19) Compound 19 3. A chalcone compound suitable for antiviral effect according to claim 1, It is characterized in that One or more selected from the following structural formulas: Compound 3: Compound 4: Compound 6: Compound 7: Compound 12: Compound 15: Compound 18: Compound 19:

4. A method for preparing a chalcone compound suitable for antiviral effect as claimed in claim 2, It is characterized in that The compounds 1 and 2 were prepared by the following route:

5. A method for preparing a chalcone compound suitable for antiviral effect according to claim 4, It is characterized in that The specific steps include: Step a: dissolve compound 1a in a solvent, add a chlorinating agent at 0°C, and stir to react for 1.5-2.5 hours. After the raw materials are completely reacted, drop the organic phase into the alkaline reagent until no gas is generated, and then extract with an organic solvent. Wash the organic phase with water and remove the water to obtain a solid compound 1b; Step b: dissolving compound 1b in a solvent, adding a chlorinating agent or a brominating agent, reacting at 65-75° C. overnight under nitrogen, until the raw materials react completely, adding water and DCM, collecting the organic phase, washing the organic phase with water, and separating and purifying by a thin layer chromatography column to obtain a solid compound 1c; Step c: adding methyl 2-(dimethoxyphosphoryl)acetate to a solution of sodium hydrogen in tetrahydrofuran at 0°C, stirring after the addition, then adding compound 1c dropwise, bringing the resulting mixture to room temperature and stirring for 12-20 hours. After the reaction is complete, adding water to quench the reaction, extracting with ethyl acetate, collecting the organic phase, concentrating, and separating and purifying by column chromatography to obtain methyl benzoate compound 1d; Step d: Dissolve compound 1d in an organic solvent, add boron tribromide at -60°C, warm the mixture to room temperature and stir. After the reaction, drop the reaction solution into ice water to quench the reaction, remove the solvent under reduced pressure, extract with ethyl acetate, collect and dry the organic phase to obtain a white solid, and prepare the product by high performance liquid chromatography.

6. A method for preparing a chalcone compound suitable for antiviral effect as claimed in claim 2, It is characterized in that The compounds 3 to 6 and compounds 9 to 19 were prepared by the following route:

7. A method for preparing a chalcone compound suitable for antiviral effect according to claim 6, It is characterized in that The specific steps include: Step a: dissolving compound 2a in a solvent, adding a nucleophilic reagent dropwise at 0°C under nitrogen, and then reacting at room temperature for 1.5-2.5 hours. After the reaction is complete, adding an acidic reagent to adjust the pH to neutral, and then extracting with an organic solvent, collecting the organic phase, drying, and concentrating, and purifying the residue to obtain compound 2b; Step b: Compound 2b is dissolved in a solvent, 2-iodoacylbenzoic acid is added, and the reaction is carried out at 80-90° C. overnight. The raw materials are completely reacted, and the solid in the reaction is filtered to obtain a filtrate. After vacuum distillation, the filtrate is wet loaded and purified by a chromatographic column to obtain compound 2c; Step c: Under ice bath conditions, a ketone compound and compound 2c are dissolved in a solvent, a methanolic NaOH solution is added and stirred, and the reaction is stirred at room temperature overnight. The reaction solid is separated by filtration and washed with water to obtain a crude product 2d; Step d: Compound 2d was dissolved in a solvent, boron tribromide was added at -60°C, the mixture was warmed to room temperature and stirred, after the reaction, the reaction solution was dropped into ice water to quench the reaction, the solvent was removed under reduced pressure, extracted with ethyl acetate, the organic phase was collected and dried to obtain a white solid, and finally prepared by high performance liquid chromatography to obtain compounds 3, 5, 6 and 9-19; Step e: dissolving compound 3 in acetic anhydride, reacting at 60°C overnight, detecting by TLC, generating new spots, extracting with water and ethyl acetate, and performing column chromatography to obtain the final compound 4; The ketone compound in step c is selected from one of the following: 2,6-dichloro-3,4,5-trimethoxybenzaldehyde, 2-chloro-3,4,5-trimethoxybenzaldehyde, 3,4,5-trimethoxybenzaldehyde, 4-chloroacetophenone, 4-bromoacetophenone, 4-nitroacetophenone, 4-trifluoromethylacetophenone, 2'-fluoroacetophenone, 1-(2,6-dichloro-4-fluorophenyl)ethane-1-one, acetophenone, 4-methoxyacetophenone, 2-acetylthiophene, 2-acetylfuran, 1-(4'-fluoro-[1,1'-biphenyl]-4-yl)ethane-1-one.

8. A method for preparing a chalcone compound suitable for antiviral effect as claimed in claim 2, It is characterized in that The compounds 7 to 8 were prepared by the following route:

9. A method for preparing a chalcone compound suitable for antiviral effect according to claim 8, It is characterized in that The specific steps include: (1) CuI, Cs 2 CO 3 The mixture was mixed in a solvent and stirred at room temperature, then bis(pinacolato)diboron, compound 3a, and then methanol were added, stirred at room temperature, and reacted for 24-36 hours. The mixture was extracted with ethyl acetate several times, and the combined organic phases were washed with saline solution and washed with Na 2 SO 4 Drying, filtration, concentration and purification by flash chromatography gave solid compound 3b; Alternatively, compound 3a is dissolved in methanol, and then a catalyst is added, and the reaction is carried out overnight at room temperature under hydrogen conditions. The reaction is monitored by TLC. When the raw material is completely reacted, the product is filtered through diatomaceous earth, dried by spin drying, and separated and purified by column chromatography to obtain reduced hydroxy compound 4a; (2) Compound 3b or compound 4a is dissolved in a solvent, boron tribromide is added at -60°C, the mixture is slowly heated to room temperature and stirred, after the reaction, the reaction solution is dropped into ice water to quench the reaction, the solvent is removed under reduced pressure, extraction is performed with ethyl acetate, the organic phase is collected, and a solid is obtained by drying, and finally the product is obtained by high performance liquid chromatography.

10. Use of a chalcone compound suitable for antiviral effect as claimed in any one of claims 1 to 3, It is characterized in that The compound or a pharmaceutically acceptable salt thereof is used to prepare a drug against the new coronavirus; And / or, the compound or a pharmaceutically acceptable salt thereof is used to prepare anti-new coronavirus and anti-inflammatory drugs; And / or, the compound or a pharmaceutically acceptable salt thereof exerts an antiviral effect by inhibiting 3CL protease; And / or, use of the compound or a pharmaceutically acceptable salt thereof as an active ingredient in the preparation of a 3CL protease inhibitor; And / or, the virus is selected from SARS-CoV-2.

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