A compound having an antiviral effect based on 2',3'-dideoxy-2',3'-dihydroadenosine derivatization

Abstract

The application discloses a compound with antiviral effect based on 2', 3'-dideoxy-2', 3'-dihydroadenosine derivative, and the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivative is shown as formula I. The application provides a series of nucleoside analogues (2', 3'-dideoxy-2', 3'-dihydroadenosine (beta-L-D4A) derivatives) with good antiviral effect, which are modified by taking 2', 3'-dideoxy-2', 3'-dihydroadenosine (beta-L-D4A) as a mother nucleus and being chemically modified.

Description

Technical Field

[0001] This invention relates to the field of biomedicine, specifically to a 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivative compound, its preparation method, and its application in the preparation of antiviral products. Background Technology

[0002] Viruses, as one of the major pathogens endangering human health, cause infectious diseases that seriously threaten human health. For example, infectious and difficult-to-cure viral diseases such as HIV / AIDS and viral hepatitis continue to spread globally. In recent years, the novel coronavirus and its variants have also constantly threatened human health. Developing safe and effective antiviral drugs is an important means of combating viral diseases. Currently, there are over a thousand viruses that cause disease in humans, but only a few viral infectious diseases can be treated with drug intervention. Among the antiviral drugs approved globally in recent years, those that combat viruses mainly include HIV, hepatitis B virus, hepatitis C virus, cytomegalovirus, and others. Exploring and discovering more types of antiviral drugs is a serious challenge facing the pharmaceutical field today.

[0003] Nucleosides, as one of the most important endogenous compounds in the human body, play a crucial role in metabolic processes. Nucleoside analogues have long been an important source of antiviral drugs, and currently available nucleoside antiviral drugs include zidovudine, lamivudine, abacavir, emtricitabine, tenofovir, and stavudine. Nucleoside compounds have become popular drugs against hepatitis B virus (HBV). Jan Balzarini's research group at KU Leuven studied the antiviral activity of 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) and its aryloxyaminophosphate derivatives against viruses such as human immunodeficiency virus (HIV), simian immunodeficiency virus (SIV), and hepatitis B virus (HBV) (FEBS Letters, 1997, 410, 324-32). The research group of Lin Jusheng at Tongji Hospital, Huazhong University of Science and Technology, demonstrated strong anti-hepatitis B virus replication activity and low toxicity by selectively targeting viral polymerase with 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) (World J Gastroenterol, 2003, 9, 1840-1843). The mechanism of action may lie in the irreversible inhibition of HBV DNA replication initiation or DNA chain elongation by β-L-D4A metabolites (Chinese Journal of Hepatology, 2003, 11, 268-270). 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivatives show broad research prospects in the field of antiviral therapy. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivative compound, its preparation method, and its application in the preparation of antiviral products.

[0005] Invention concept: Utilizing the good antiviral effect of 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A), a series of nucleoside analogs (2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivatives) with 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) as the parent nucleus are provided through chemical modification.

[0006] To solve the above-mentioned technical problems, the present invention discloses the following technical solution:

[0007] In a first aspect, the present invention discloses a 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) as shown in Formula I;

[0008]

[0009] in,

[0010] R1 is selected from hydrogen or... R 11 and R 12 Each group is independently selected from hydroxyl, C1-C6 alkoxy, amino, phenoxy, or any one of the amino acid groups or amino acid alkyl ester groups described in the following structural formulas;

[0011]

[0012] R2 is selected from amino or R 21 Selected from C1-C6 alkyl, C3-C7 cycloalkyl, furanyl, phenyl, pyridyl, or pyrimidinyl;

[0013] R3 is selected from hydrogen or isopropylamino;

[0014] R4 is selected from hydrogen, methyl, fluorine, or chlorine; and

[0015] There is no instance where R1, R3, and R4 are selected from hydrogen and R2 is selected from amino groups.

[0016] In some embodiments, the structure of the 2',3'-dideoxy-2',3'-dihydroadenosine derivative is shown in Formula II;

[0017]

[0018] in,

[0019] R 11 and R 12 Each group is independently selected from hydroxyl, C1-C6 alkoxy, amino, phenoxy, or any one of the amino acid groups or amino acid alkyl ester groups described in the following structural formulas;

[0020]

[0021] R 21 Selected from C1-C6 alkyl, C3-C7 cycloalkyl, furanyl, phenyl, pyridyl, or pyrimidinyl;

[0022] R3 is selected from hydrogen or isopropylamino;

[0023] R4 is selected from hydrogen, methyl, fluorine, or chlorine.

[0024] In some embodiments, R 11 and R 12 Each group is independently selected from hydroxyl, C2-C3 alkoxy, amino, phenoxy, or any one of the amino acid groups or amino acid alkyl ester groups described in the following structural formulas.

[0025]

[0026] In some embodiments, R1 is selected from hydrogen, such as R1 1 -R1 8 The groups shown are phosphate group, diethyl phosphate group, dipropyl phosphate group, diisopropyl phosphate group, phosphorylaminoethyl phosphate group, phosphorylalanine isopropyl phenyl ester group, (R)-phosphoryl isoleucine methyl phenyl ester group, and (S)-phosphoryl isoleucine methyl phenyl ester group.

[0027]

[0028] In some embodiments, R 21 It is selected from C3-C4 alkyl, C5-C6 cycloalkyl, furanyl, phenyl, pyridyl, or pyrimidinyl.

[0029] In some embodiments, R2 is selected from amino groups, or such as R2 1 -R2 8 The groups shown are acetamide, isopropylamide, isobutyramide, cyclopentylformamide, furanamide, benzamide, and pyridineformamide.

[0030]

[0031] In some embodiments, the 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivative shown in Formula I is selected from any one of Compound 1 to Compound 20.

[0032]

[0033]

[0034] In a second aspect, the present invention discloses an antiviral composition, the active ingredient of which includes the 2',3'-dideoxy-2',3'-dihydroadenosine derivative described in the first aspect above.

[0035] The composition can be an antiviral pharmaceutical preparation, and in addition to the above-mentioned active ingredients, it also includes pharmaceutically acceptable excipients, including fillers, lubricants, etc. The content of the active ingredients in the composition is 1%-99%, such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.

[0036] Thirdly, the present invention discloses the use of the 2',3'-dideoxy-2',3'-dihydroadenosine derivative described in the first aspect and the composition described in the second aspect in the preparation of antiviral products.

[0037] The viruses mentioned include influenza A virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and EV71 enterovirus.

[0038] Thirdly, this invention discloses a method for preparing the 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivative described in the first aspect above. The preparation method is a synthetic approach corresponding to the modification method.

[0039] Specifically as follows:

[0040] A. Modify R1

[0041]

[0042] In formula IR-1, R2 to R4 are the same as R2 to R4 in formula I, or each can be a separate protecting group.

[0043] When R in formula I 11 and R 12 When the groups are independently selected from C1-C6 alkoxy, amino, phenyl, amino acid, or amino acid alkyl ester groups, the preparation method of the compound shown in Formula I includes: reacting compound IR-1 with a modified or unsubstituted p-toluenesulfonyloxymethyl phosphate in anhydrous N,N-dimethylformamide organic solvent, using NaH or tert-butylmagnesium chloride as a catalyst, wherein the substitution is any one or more functional groups selected from C1-C6 alkoxy, amino, phenyl, amino acid, or amino acid alkyl ester groups; preferably, when the catalyst is NaH, the molar ratio of compound IR-1, modified agent, catalyst, and organic solvent is 0.1 mol: 0.1–0.15 mol:

[0044] The reaction mixture consists of 0.2–0.03 mol: 100–200 mL, preferably 0.1 mol: 0.1–0.15 mol: 0.2–0.03 mol: 140–160 mL, at a temperature of -20–0 °C and a reaction time of 0.5–6 h. Preferably, when the catalyst is tert-butylmagnesium chloride, the ratio of compound IR-1, modifier, catalyst, and organic solvent is 0.1 mol:

[0045] 0.1–0.2 mol: 0.05–0.4 mol: 50–150 mL, the reaction temperature is room temperature, and the reaction time is 1–3 h;

[0046] When R in formula I 11 and R 12 When the hydroxyl group is selected, the preparation method of the compound shown in Formula I includes: in the organic solvent n-butyronitrile, R... 11 and R 12 Compound I, selected independently from C1-C6 alkoxy groups, reacts with trimethylchlorosilane, wherein R2-R4 in compound I are the same as R2-R4 in formula I, or each is selected as an independent protecting group; preferably, R... 11 and R 12 The ratio of compound I, trimethylchlorosilane, and organic solvent, each independently selected from C1-C6 alkoxy groups, is 1 mmol: 4-8 mmol: 1-3 mL; preferably, the reaction temperature is reflux temperature, and the reaction time is 12-36 h.

[0047] B. Modify R2

[0048]

[0049] In formula IR-2, R1, R3 to R4 are the same as R1, R3 to R4 in formula I, or are independently selected from protecting groups;

[0050] In equation I, R2 is selected from... R 21 When the compounds are selected from C1-C6 alkyl, C3-C7 cycloalkyl, furanyl, phenyl, pyridyl, or pyrimidinyl, the preparation method of the compound shown in Formula I includes: reacting compound IR-2 with a substituted acyl chloride under anhydrous pyridine conditions, wherein the substitution is any one or more functional groups selected from C1-C6 alkyl, C3-C7 cycloalkyl, furanyl, phenyl, pyridyl, and pyrimidinyl; preferably, the ratio of compound IR-2, substituted acyl chloride, and anhydrous pyridine is 1 mmol: 1-3 mmol: 6-8 mL, the reaction temperature is 15-50 °C, and the reaction time is 3-12 h.

[0051] C. Modify R3

[0052]

[0053] In formula IR-3, R1~R2 and R4 are the same as R1~R2 and R4 in formula I, or are independently selected from protecting groups;

[0054] The preparation method of the compound shown in Formula I includes: replacing compound IR-3 with 2-propylamine in dioxane; preferably, the ratio of the amount of compound IR-3, 2-propylamine and dioxane is 1 mmol: 1-3 mmol: 5-15 mL, the reaction temperature is 80-120 °C and the reaction time is 15-30 h.

[0055] D. Modify R4

[0056]

[0057] In formulas IR-4 and IR-4a, R1 to R3 are the same as R1 to R3 in formula I, or are independently selected from protecting groups;

[0058] When R4 in Formula I is selected from methyl, the preparation method of the compound shown in Formula I includes: reacting compound IR-4, iodomethane, and potassium carbonate in dichloromethane solvent; preferably, the ratio of the amount of compound IR-4, iodomethane, potassium carbonate, and dichloromethane is 1 mmol: 1-4 mmol: 2-3 mmol: 6-10 mL, the reaction temperature is 30-40 °C, and the reaction time is 3-8 h.

[0059] When R4 in Formula I is selected from fluorine or chlorine, the preparation method of the compound shown in Formula I includes: nitrating compound IR-4 with tetrabutylamine nitrate in dichloromethane under the catalysis of trifluoroacetic anhydride to obtain nitrated intermediate IR-4a; then, in acetonitrile, nitrated intermediate IR-4a is substituted with tetrabutylammonium fluoride or tetrabutylammonium chloride; preferably, the ratio of the amount of compound IR-4, tetrabutylamine nitrate, trifluoroacetic acid and dichloromethane is 1 mmol: 1.4-2 mmol: 1-4 mmol: 15-40 mL; the ratio of the amount of nitrated intermediate IR-4a, tetrabutylammonium fluoride or tetrabutylammonium chloride and acetonitrile is 1 mmol: 1.2-1.6 mmol: 20-40 mL, the temperature of the nitration reaction is 0-40°C, and the time of the nitration reaction is 20 min-16 h.

[0060] Beneficial effects:

[0061] This invention provides a series of nucleoside analogs (2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) derivatives) that are chemically modified with 2',3'-dideoxy-2',3'-dihydroadenosine (β-L-D4A) as the parent nucleus, which have good antiviral effects. Detailed Implementation

[0062] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0063] Example 1: Preparation of compound 1

[0064]

[0065] Compound 2 (3.69 g, 10 mmol) was added to a 100 mL reaction flask, followed by 20 mL of n-butyronitrile. Trimethylchlorosilane (6.52 g, 60 mmol) was then added dropwise at room temperature. After the addition was complete, the reaction mixture was refluxed for 24 h. After the reaction was complete, the solvent was concentrated to dryness by vacuum distillation. 20 mL of water was added to the residue, and 2 M sodium hydroxide was added to adjust the pH to approximately 8. The mixture was then extracted three times with ethyl acetate (50 mL). The aqueous phase was neutralized to pH 3–4 with 1 M hydrochloric acid. The mixture was then heated to 70–80 °C for crystallization to obtain compound 1, weighing 2.2 g, with a yield of 69%. The detection results of the prepared compound 1 are as follows. 1 H NMR(400MHz,DMSO-d6)δ8.31(s,1H),8.17(s,1H),7.18(s,1H),6.66(dt,J=4.8,0.8Hz,1H),6.51(s,1H), 6.32(dd,J=9.0,3.1Hz,1H), 6.14(dd,J=9.0,4.8Hz,1H), 4.71(qd,J=2.7,1.0Hz,1H), 4.34–4.25(m,2H). 13 C NMR(100MHz,DMSO-d6)δ156.1,152.4,149.8,139.1,134.1,133.3,119.4,96.6,86.6,70.0.MSI-MS:314.2[M+H] + .

[0066] Example 2: Preparation of compound 2

[0067]

[0068] β-L-D4A (23.3 g, 100 mmol) was added to a 500 mL reaction flask, along with 150 mL of DMF as a solvent, and the mixture was heated to dissolve. After rapid cooling to room temperature, NaH (6.4 g, 267 mmol) was slowly added with stirring, and the mixture was kept at room temperature and stirred for 15 min. The reaction mixture was cooled to -10 °C in a cryogenic reactor, and diethyl p-toluenesulfonyloxymethyl phosphate (45.1 g, 140 mmol) was added dropwise. After the addition was complete, the mixture was stirred at this temperature for 1 h, and then gradually heated to room temperature and stirred for 4 h. After the reaction was complete, glacial acetic acid was added dropwise to adjust the pH to neutral. The reaction mixture was filtered, washed with dichloromethane, and the filtrate was extracted three times with water (60 mL). The dichloromethane phases were combined, the solvent was removed by vacuum distillation, and toluene was added to the residue for recrystallization. The mother liquor was filtered, and the filter cake was dried under reduced pressure at 50°C to obtain a white powdery solid compound 2, weighing 17.7 g, with a yield of 48%. The detection results of the prepared compound 2 are as follows. 1 H NMR (400MHz, DMSO-d6) δ8.31(s,1H),8.17(s,1H),7.18(s,3H),6.66(dt,J=4.8,0.8Hz,2H),6.32(dd,J=9.0,3.1Hz,2H),6 .14(dd,J=9.0,4.8Hz,2H),4.73(dd,J=2.0,1.0Hz,1H),4.42–4.23(m,4H),4.16(q,J=7.0Hz,7H),1.37(t,J=6.9Hz,12H). 13 C NMR(100MHz,DMSO-d6)δ156.1,152.4,149.8,139.1,134.1,133.4,119.4,96.6,86.6,70.6,64.4,16.3.MSI-MS:370.3[M+H] + .

[0069] Example 3: Preparation of compound 3

[0070]

[0071] Add 50 mL of toluene to a 150 mL reaction flask and cool the reaction solution to 0 °C in a cryogenic reactor. Add isopropanol (3.03 mL, 39 mmol), 4-nitrophenyl phosphorus dichloride (5 g, 19.5 mmol), and then triethylamine (5.42 mL, 39 mmol) to the reaction system sequentially. Stir the mixture overnight at room temperature. Filter the reaction solution, evaporate the solvent from the filtrate, and purify by column chromatography using hexane and ethyl acetate in a ratio of 80:20. The result is diisobutyl phosphate (4-nitrophenyl) (4.65 g, 14 mmol) in 72% yield. The analysis results of the prepared compound are as follows: 1 HNMR(400MHz,Chloroform-d)δ8.20(d,J=10Hz,2H),7.34(d,J=10Hz,2H),4.74(q,J=5Hz,2H),1.32(d,J=5Hz,12H). 13 C NMR(100MHz,Chloroform-d)δ156.4,144.6,125.7,120.6,74.4,14.3.MSI-MS:354.3[M+Na] + .

[0072] β-L-D4A (2.33 g, 10 mmol) was added to a 500 mL reaction flask and dissolved in 100 mL of anhydrous DMF. Diisobutyl phosphate (4-nitrophenyl) (4.96 g, 15 mmol) was also added. Tert-butylmagnesium chloride (1.17 g, 10 mmol) was dissolved in 20 mL of THF and slowly added dropwise to the above reaction solution. The reaction mixture was gradually heated to room temperature and reacted for 2 h, monitored by TLC. After the reaction was complete, the resulting mixture was allowed to stand, diluted with 100 mL of ethyl acetate, washed and extracted three times with 50 mL of saturated sodium bicarbonate solution each time, followed by extraction with 50 mL of saturated sodium chloride solution. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting oil was purified by silica gel column chromatography (eluent: dichloromethane: methanol = 10:1) to give compound 3, weighing 2.70 g, with a yield of 68%. The detection results of the prepared compound 3 are as follows. 1H NMR(400MHz,DMSO-d6)δ8.31(d,J=0.8Hz,1H),8.17(s,1H),7.18(s,2H),6.66(dt ,J=4.8,0.8Hz,1H),6.32(dd,J=9.0,3.1Hz,1H),6.14(dd,J=9.0,4.8Hz,1H),4.7 3(dtd,J=3.1,2.1,0.9Hz,1H),4.44(hept,J=6.3Hz,2H),4.33(dd,J=10.4,2.2Hz ,1H),4.28(dd,J=10.6,2.2Hz,1H),1.39(d,J=6.4Hz,6H),1.34(d,J=6.2Hz,6H). 13 C NMR(100MHz,DMSO-d6)δ156.1,152.4,149.8,139.1,134.1,133.4,119.4,96.6,86.6,71.7,70.6,24.7.MSI-MS:398.1[M+H] + .

[0073] Example 4: Preparation of compound 4

[0074]

[0075] Benzene dichlorophosphate (6.00 g, 28.44 mmol) was dissolved in 10 mL of THF and cooled in an ice bath. Alanine isopropyl hydrochloride (4.77 g, 28.46 mmol) was rapidly added under N2. The mixture was cooled to -55 °C, and after 70 min, triethylamine (6.03 g, 59.60 mmol) was added. After 0.5 h, the mixture was heated to -5 °C, and a 20 mL DCM solution of pentafluorophenol (5.24 g, 28.47 mmol) and triethylamine (3.21 g, 31.72 mmol) was slowly added to the reaction solution. The mixture was stirred at 0 °C for 4 h, filtered, evaporated, and dissolved in 60 mL of ethyl acetate. The organic layer was washed with water, dried on Na2SO4, and evaporated to obtain a solid. The obtained solid was ground in ethyl acetate / n-hexane (20:80, V / V) for 1.5 h, and the resulting mixture was filtered to obtain a white solid. The remaining filtrate was concentrated under reduced pressure and then ground in ethyl acetate / n-hexane (20:80, V / V) for 20 h to obtain a white solid. The obtained solid was mixed and dissolved in ethyl acetate. The organic phase was washed with water, dried, and concentrated to obtain ((perfluorophenoxy)(phenoxy)phosphoryl)-L-alanine isopropyl ester (4.36 g, 9.62 mmol), with a yield of 28%. The results of the analysis of the prepared compound are as follows: 1H NMR(400MHz,Chloroform-d)δ7.45–7.34(m,2H),7.22–7.08(m,4H),5.73(d,J=9.3Hz,2H) ,5.10–4.92(m,1H),4.16(dd,J=9.3,7.0Hz,1H),1.34–1.27(m,6H),1.25(d,J=5.6Hz,3H). 13 C NMR(100MHz,Chloroform-d)δ171.50,151.55,140.55,138.90,138.40,138.01,13 6.84,135.99,129.49,125.58,120.67,68.39,51.60,22.02,18.73.MSI-MS:454.3

[0076] [M+H] + .

[0077] Add β-L-D4A (2.33 g, 10 mmol) to a 500 mL reaction flask, then add 100 mL of anhydrous THF and cool to 0 °C. Then add 23.7 mL (40.4 mmol) of 1.7 M tert-butylmagnesium chloride solution to the cooling solution, maintaining the internal temperature below 5 °C for 0.5 h. Stir the white suspension at this temperature for 0.5 h, then heat to ambient temperature (20 °C) and stir for 30 min. Cool the reaction mixture to 5 °C and add a 20 mL THF solution of ((perfluorophenoxy)(phenoxy)phosphoryl)-L-alanine isopropyl ester (9.67 g, 21.34 mmol) for 0.5 h. Heat the mixture to room temperature and stir for 10 h, then quench the reaction with ammonium chloride solution. Extract the solution with ethyl acetate, wash with 5% sodium carbonate solution and brine, dry with Na2SO4, and concentrate by filtration under reduced pressure. Compound 4 was obtained after column chromatography purification, weighing 3.61 g, with a yield of 72%. The detection results of the prepared compound 4 are as follows. 1 H NMR(400MHz,Chloroform-d)δ8.34(s,1H),8.01(s,1H),7.31–7.06(m,5H),6.52(s,2H),6.38(d,J=5.0Hz,1H),6.11(d,J=6.1Hz,1H),5.11(s,1H), 4.99–4.89(m,1H),4.55(d,J=10.8Hz,1H),4.26(s,1H),3.94(q,J=8.2Hz ,1H),3.72(d,J=8.7Hz,1H),1.30(d,J=7.0Hz,3H),1.16(d,J=6.1Hz,6H). 13C NMR (100MHz, CDCl3) δ173.07,155.78,153.24,150.54,149.69,138.89,133.27,129.21,126.37,124.92, 120.08,88.26,85.43,69.19,67.96,67.03,63.58,50.27,25.60,21.65,20.92,1.03.MSI-MS:501.2[M+H] + .

[0078] Example 5: Preparation of compound 5

[0079]

[0080] Following the method in Example 2, compound 5a was prepared from β-L-D4A via phosphorylation. Compound 5a (3.97 g, 10 mmol) and butyryl chloride (1.07 g, 10 mmol) were reacted in an ice bath with 60 mL of anhydrous pyridine. The reaction was gradually heated to 40 °C and reacted for 10 h. The reaction was monitored by TLC. After the reaction was complete, water and ethyl acetate were added for extraction. The organic phase was back-extracted, collected, and rotary evaporated to obtain an oily liquid. After purification by column chromatography, compound 5 was obtained, weighing 3.27 g, with a yield of 70%. The detection results of the prepared compound 5 are as follows. 1 HNMR(400MHz, DMSO-d6)δ9.94(s,1H),8.34(s,1H),6.65(dt,J=4.7,0.8Hz,1H),6.32(dd,J=9.0,3.1Hz,1H),6.16–6.11(m,1H), 4.76–4.71(m,1H),4.37–4.26(m,2H),4.00–3.89(m,4H),2.39(t,J=6.2Hz,2H),1.70–1.55(m,4H),0.97(td,J=7.5,6.0Hz,9H). 13 C NMR(100MHz,DMSO-d6)δ171.6,152.4,151.8,149.8,139.1,134.1,133.4,12 3.5,96.6,86.6,70.6,66.6,39.9,26.6,19.0,13.1,9.9.MSI-MS:468.2[M+H] + .

[0081] Example 6: Preparation of compound 10

[0082]

[0083] Compound 10 was prepared from compound 2 via an acylation step according to the method of Example 5, wherein butyryl chloride was replaced with benzoyl chloride, with an overall yield of 69%. The detection results of the prepared compound 10 are as follows: 1 H NMR(500MHz,DMSO-d6)δ9.11(s,1H),8.34(s,1H),7.95(d,J=6.7Hz,1H),7.57–7.44(m,1H),6.32(dd,J=9.0,3.1Hz,1H),6.14(dd,J=9.0,4.8Hz, 1H), 4.73 (dtd, J = 3.1, 2.1, 0.9Hz, 1H), 4.34 (dd, J = 10.6, 2.2Hz, 1H), 4.28 (dd, J = 10.5, 2.1Hz, 1H), 4.16 (q, J = 6.9Hz, 4H), 1.37 (t, J = 6.9Hz, 6H). 13 C NMR(100MHz,DMSO-d6)δ164.7,152.4,151.8,149.8,139.1,134.1,133.4,13 2.1,128.8,127.5,123.5,96.6,86.6,70.6,64.4,16.3.MSI-MS:474.1[M+H] + .

[0084] Example 7: Preparation of compound 13

[0085]

[0086] 2.33 g (10 mmol) of β-L-D4A was added to 40.00 mL of anhydrous pyridine and 8.5 mL of acetic anhydride under ice bath conditions. The reaction was monitored by HPLC and ended after approximately 5 hours. The solvent was removed to obtain a viscous liquid 13a, weighing 2.23 g, with a yield of 82%. MSI-MS: 276.1 [M+H]. + .

[0087] Compound 13a (3.35 g, 10 mmol) and butyryl chloride (1.07 g, 10 mmol) were reacted in an ice bath with 60 mL of anhydrous pyridine. The reaction was gradually heated to 40 °C and carried out for 10 h. The reaction was monitored by TLC. After the reaction was completed, water and ethyl acetate were added for extraction. The organic phase was back-extracted, collected, and rotary evaporated to obtain an oily liquid. After purification by column chromatography, compound 13 was obtained, weighing 2.45 g, with a yield of 81%. The detection results of the prepared compound 13 are as follows. 1H NMR(400MHz, DMSO-d6)δ9.94(s,1H),8.35(d,J=10.5Hz,2H),6.39–6.33(m,1H),6.24(dd,J=9.2,4.8Hz,1H),4.57–4.52(m,1H),4.22(d,J=6.1H z,1H),3.97(ddd,J=11.2,6.2,2.6Hz,1H),3.90(ddd,J=11.0,6.0,2.5Hz,1H),2.39(t,J=6.2Hz,2H),1.65–1.55(m,1H),0.98(d,J=7.6Hz,2H). 13 C NMR (100MHz, DMSO-d6) δ171.6,152.4,151.8,149.8,139.1,134.1,133.4,123.5,96.9,89.2,64.2,39.9,19.0,13.1.MSI-MS:305.1[M+H] + .

[0088] Example 8: Preparation of compound 14

[0089]

[0090] Compound 14 was prepared from β-L-D4A via an acylation step according to the method of Example 7, wherein butyryl chloride was replaced with cyclopentylformyl chloride, with an overall yield of 74%. The detection results of the prepared compound 14 are as follows: 1 H NMR(400MHz,DMSO-d6)δ9.86(s,1H),8.36(s,1H),8.34(s,1H),6.62(d,J=4.8Hz,1 H),6.37(dd,J=9.2,3.8Hz,1H),6.24(dd,J=9.2,4.8Hz,1H),4.57–4.52(m,1H),4.2 2(d,J=6.1Hz,1H),3.97(ddd,J=11.2,6.2,2.6Hz,1H),3.90(ddd,J=11.0,6.0,2.5H z,1H),2.89–2.80(m,1H),2.01–1.90(m,2H),1.79–1.70(m,4H),1.69–1.61(m,1H). 13 C NMR(100MHz,DMSO-d6)δ164.7,152.4,151.8,149.8,139.1,134.2,134.1,133.4,132.1,128.8,127.5,123.5,96.9,89.2,64.2.MSI-MS:330.3[M+H]+ .

[0091] Example 9: Preparation of compound 15

[0092]

[0093] Compound 15 was prepared from β-L-D4A via an acylation step according to the method of Example 7, wherein butyryl chloride was replaced with furanoyl chloride, with an overall yield of 78%. The detection results of the prepared compound 15 are as follows: 1 H NMR (400MHz, DMSO-d6) δ8.36(s,1H),8.34(s,1H),7.77(s,1H),7.32(dd,J=5. 1,1.6Hz,1H),6.62(d,J=4.8Hz,1H),6.56(dd,J=5.1,1.6Hz,1H),6.37(dd,J=9 .2,3.8Hz,1H),6.24(dd,J=9.2,4.8Hz,1H),4.57–4.52(m,1H),4.22(d,J=6.1H z,1H),3.97(ddd,J=11.2,6.2,2.6Hz,1H),3.90(ddd,J=11.0,6.0,2.5Hz,1H). 13 C NMR(100MHz,DMSO-d6)δ163.8,152.4,151.8,149.8,148.2,143.8,139.1,134.1,133.4,123.5,115.3,111.7,96.9,89.2,64.2.MSI-MS:328.1[M+H] + .

[0094] Example 10: Preparation of compound 19

[0095]

[0096] A nitration mixture was prepared by adding 193 μL (1.39 mmol) of 2,2,2-trifluoroacetic anhydride to a solution of 428 mg (1.40 mmol) of tetrabutylamine nitrate in 15 mL of dry dichloromethane at 0 °C. After reacting at 0 °C for 45 min, the solution was slowly added to 369 mg (1 mmol) of compound 2 in 15 mL of dry dichloromethane. After reacting at room temperature in the dark for 14 h, the reaction mixture was extracted by pouring it into a cold mixture of H2O (50 mL), saturated NaHCO3 (35 mL), and CH2Cl2:Et2O (1:2, 30 mL). Extraction was performed twice with CH2Cl2:Et2O (1:2, 30 mL). The organic extract was washed with brine, dried over anhydrous Na2SO4, and then dried under vacuum (keeping the temperature below 50 °C). Compound 19a was purified by column chromatography, eluted with CH2Cl2, and then reacted with CH2Cl2:acetone (99:1 to 95:5) to give 199 mg, yielding 48% (MSI-MS: 415.1 [M+H]). + .

[0097] At 0 °C, TBAF (600 μL, 0.6 mmol) was added dropwise over 1 minute to a suspension of 19a (207 mg, 0.5 mmol) in dry acetonitrile (15 mL). The mixture was stirred for 20 minutes, and the resulting solution was evaporated under vacuum without heating. The crude product was purified by column chromatography, eluting with dichloromethane:acetone (100:0 to 90:10) to give compound 19, weighing 58 mg, in a yield of 30%. The detection results of the prepared compound 19 are as follows: 1 H NMR (500MHz, DMSO-d6) δ8.33(s,1H),7.27(s,1H),6.97(s,1H),6.55(d,J=4.8Hz,1H),6.32(dd,J=9.1,3.0Hz,2H),6. 17–6.12(m,1H),4.73(dtd,J=3.1,2.1,0.9Hz,2H),4.36–4.25(m,4H),4.16(q,J=7.0Hz,7H),1.37(d,J=13.9Hz,6H). 13 C NMR(100MHz,DMSO-d6)δ158.7,157.3,149.8,139.1,134.1,133.4,119.4,96.6,86.6,70.6,64.4,16.3.MSI-MS:388.1[M+H] + .

[0098] Antiviral inhibition tests were conducted on the above compounds according to Chinese invention patents CN202210357818.3 and CN202210355300.6. The results are shown in the table below (inhibitory effect of each compound against HBV and EV71 enterovirus / IC50). 50 Each compound can effectively inhibit HBV and EV71 enterovirus.

[0099] Virus types Compound 2 Compound 5 Compound 10 Compound 13 Compound 19 HBV b c b b e EV71 enterovirus b c d b d

[0100] Note: a is 200-300 μmol, b is 100-199 μmol, c is 10-99 μmol, d is 1-9 μmol, and e is 0.01-0.1 μmol.

[0101] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives as shown in formula I; I wherein, R1is selected from ; R 11 and R 12 are each independently selected from C1-C6alkoxy; R3 is selected from hydrogen; R2is selected from amino; R4is selected from fluoro or chloro; or, R2is selected from ; R 21 is selected from phenyl; R4is selected from fluoro or chloro.

2. The 2',3'-dideoxy-2',3'-dihydroadenosine derivative according to claim 1, characterized in that, The 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives are selected from any one of the following compounds: Compound 10 Compound 19.

3. An antiviral composition, characterized in that, The active ingredient of the composition comprises the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of any one of claims 1-2.

4. Use of the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of claim 1 or 2 or the composition of claim 3 in the preparation of an antiviral product.

5. Use according to claim 4, characterized in that, The virus is selected from influenza A virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus or EV71 enterovirus.

6. A preparation method of the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of claim 1 or 2, characterized in that, In formula I-R-1, R2~R4 are the same as R2~R4 in formula I; The preparation method of the compound shown in formula I comprises: in an organic solvent, anhydrous N, N-dimethylformamide, compound I-R-1 is reacted with modified or non-substituted p-toluenesulfonyloxymethyl phosphate with NaH or tert-butyl magnesium chloride as a catalyst, the substitution is C1-C6 alkoxy substitution; when the catalyst is NaH, the use amount ratio of the compound I-R-1, the modifier, the catalyst and the organic solvent is 0.1 mol: 0.1~0.15 mol: 0.2~0.03 mol: 100~200 mL, the reaction temperature is-20~0 ℃, and the reaction time is 0.5~6 h; when the catalyst is tert-butyl magnesium chloride, the use amount ratio of the compound I-R-1, the modifier, the catalyst and the organic solvent is 0.1 mol: 0.1~0.2 mol: 0.05~0.4 mol: 50~150 mL, the reaction temperature is room temperature, and the reaction time is 1~3 h.

7. A preparation method of the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of claim 1 or 2, characterized in that, In formula I-R-2, R1, R3~R4 are the same as R1, R3~R4 in formula I; When in formula I, R2is selected from ; R 21 When the substituent R is selected from phenyl, the method for preparing the compound of formula I comprises: reacting compound I-R-2 with a substituted acyl chloride, the substitution being phenyl substitution, in anhydrous pyridine, the amount ratio of compound I-R-2, substituted acyl chloride and anhydrous pyridine being 1 mmol: 1-3 mmol: 6-8 mL, the reaction temperature being 15-50 ℃, and the reaction time being 3-12 h.

8. A preparation method of the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of claim 1 or 2, characterized in that, In formula I-R-3, R1~R2, R4 are the same as R1~R2, R4 in formula I; The preparation method of the compound shown in formula I comprises: in dioxane, compound I-R-3 is subjected to 2-propylamine substitution reaction; the use amount ratio of the compound I-R-3, 2-propylamine and dioxane is 1 mmol: 1~3 mmol: 5~15 mL, the reaction temperature is 80~120 ℃, and the reaction time is 15~30 h.

9. A preparation method of the 2', 3'-dideoxy-2', 3'-dihydroadenosine derivatives of claim 1 or 2, characterized in that, In formula I-R-4 and I-R-4a, R1~R3 are the same as R1~R3 in formula I; When R4 in formula I is selected from fluorine or chlorine, the preparation method of the compound shown in formula I comprises: nitration of compound I-R-4 with tetrabutylammonium nitrate in dichloromethane under catalysis of trifluoroacetic anhydride to obtain a nitro-intermediate I-R-4a, and substitution reaction of the nitro-intermediate I-R-4a with tetrabutylammonium fluoride or tetrabutylammonium chloride in acetonitrile; the use amount ratio of the compound I-R-4, tetrabutylammonium nitrate, trifluoroacetic acid and dichloromethane is 1 mmol: 1.4-2 mmol: 1-4 mmol: 15-40 mL; the use amount ratio of the nitro-intermediate I-R-4a, tetrabutylammonium fluoride or tetrabutylammonium chloride and acetonitrile is 1 mmol: 1.2-1.6 mmol: 20-40 mL, the temperature of the nitration reaction is 0-40 ℃, and the time of the nitration reaction is 20 min-16 h.

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