A coumarin derivative, its preparation method and application

Abstract

The present invention relates to the field of medicine, and particularly relates to a coumarin compound containing formula (I) and its application in the preparation of bacterial biofilm inhibitors. The coumarin compounds involved in the present invention have been verified for their pharmacodynamic effects in vitro and in vivo. Most of the obtained compounds have excellent bacterial biofilm inhibitory activities and can be used for the preparation of anti-biofilm agents, showing the potential for development into novel antibacterial drugs.

Description

Technical Field

[0001] The present invention belongs to the field of medicine, and particularly relates to a method for preparing coumarin derivatives and their application in the preparation of bacterial biofilm inhibitors. Background Art

[0002] In the 1940s, the discovery of antibiotics was undoubtedly a victory for humanity in the fight against pathogenic microorganisms, saving tens of thousands of lives. The excellent bactericidal efficacy and strong selectivity of antibiotics once made people think that infectious diseases would become a thing of the past. However, the abuse and overuse of antibiotics have exacerbated the mutation and evolution of pathogenic microorganisms, making their drug resistance continuously increase, thus emerging "super bacteria" with multidrug resistance. Their drug resistance is mainly manifested through the following mechanisms: (1) producing enzymes that destroy antibiotics, such as β-lactamases; (2) changing the chemical properties of antibiotic action targets; (3) adapting to the extracellular drug efflux mechanism; (4) preventing drug diffusion into cells by reducing the cell wall permeability; (5) bacteria forming biofilms to resist drugs. With the widespread use of antibiotics, we have witnessed the alarming phenomenon of treatment failure of infections caused by bacterial drug resistance in clinical practice, which poses a major threat to human health and survival. Therefore, there is an urgent need for new antibiotics and antibacterial strategies in clinical practice to solve the worldwide problem of bacterial drug resistance.

[0003] The problem of bacterial drug resistance is becoming increasingly prominent, and about 16 million patients die directly from bacterial infections every year. Research has found that more than 70% of these severe infections are related to the drug resistance of bacteria forming biofilms. In nature, most bacteria can attach to different surfaces and form biofilms. A biofilm is a complex bacterial aggregate, wrapped in its own matrix by extracellular polymeric substances (EPS), and affected by factors such as temperature and nutrient components. After bacteria form biofilms, the bacteria within the biofilm can evade the host's immune response, and their ability to resist antibacterial drug treatment is 1000 times that of planktonic bacteria. Bacteria forming biofilms is one of the important reasons for bacterial drug resistance. Developing bacterial biofilm inhibitors is one of the strategies to address the problem of bacterial antibiotic resistance. Unfortunately, currently, no bacterial biofilm inhibitor has been successfully applied clinically. Therefore, researching new biofilm inhibitors is expected to alleviate the problem of bacterial drug resistance and has important scientific significance. Coumarin is a class of natural products of benzopyranones, with various pharmacological properties, including antidepressant, antibacterial, anti-inflammatory, anticholinesterase, antithrombotic, and anticancer pharmacological activities. In order to overcome the above-mentioned disadvantages and deficiencies of the prior art, the primary object of the present invention is to provide a coumarin compound, which can overcome the drug resistance of bacteria to antibiotics by inhibiting the formation of bacterial biofilms and has the potential to be developed into an anti-biofilm drug. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a coumarin compound having the structure shown in formula (I), a preparation method and use thereof, and the compound can selectively act on Pseudomonas aeruginosa and inhibit the formation of Pseudomonas aeruginosa biofilm.

[0005] In a first aspect of the present invention, there is provided a compound of formula (I) or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof:

[0006]

[0007] n = 3, 4, 5, 6

[0008] R I = -H, 6'-F, 6'-Br, 6'-CH3, 7'-OCH3

[0009] In a second aspect of the present invention, there is provided a pharmaceutical composition comprising at least one of the compound of formula (I), or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof, and optionally a pharmaceutically acceptable excipient or carrier.

[0010] The compound of the present invention, or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof, or the pharmaceutical composition can be administered in unit dosage form, and the administration route can be oral, intramuscular, subcutaneous, nasal, oral mucosa, skin, peritoneal or rectal. The dosage forms can be tablets, capsules, dripping pills, aerosols, pills, powders, solutions, suspensions, emulsions, granules, liposomes, transdermal agents, buccal tablets, suppositories, or freeze-dried powder injections. It can be a conventional preparation, a sustained-release preparation, a controlled-release preparation and various particulate drug delivery systems.

[0011] Generally, the pharmaceutical composition of the present invention contains 0.1 to 99.9% by mass of the compound, or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof.

[0012] In some embodiments of the present invention, the administration form of the pharmaceutical composition includes administering the compound, or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof, simultaneously, separately or sequentially with other active pharmaceutical ingredients.

[0013] The present invention also provides a combined drug comprising at least one of the compound of formula (I) or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof, and ciprofloxacin.

[0014] Preferably, the mass ratio of the compound of formula (I) or a pharmaceutically acceptable salt, isomer, solvate or prodrug thereof to ciprofloxacin is 50:0.5 to 10, preferably 50:1 to 5.

[0015] The third aspect of the present invention provides the use of the compound shown in the above formula (I) or its pharmaceutically acceptable salt, isomer, solvate or prodrug, or the above-mentioned pharmaceutical composition in the preparation of an anti-biofilm agent.

[0016] Preferably, the biofilm is a bacterial biofilm. More preferably, the bacterium is Pseudomonas aeruginosa.

[0017] The present invention also provides the use of the compound shown in the above formula (I) or its pharmaceutically acceptable salt, isomer, solvate or prodrug, or the above-mentioned pharmaceutical composition in the preparation of an antibacterial drug.

[0018] Preferably, the bacterium is a bacterium, more preferably Pseudomonas aeruginosa.

[0019] The compound shown in the formula (I) of the present invention, especially the compound 7-((6-methylcoumarin-4-yl)oxy)-N-hydroxyheptanamide, has excellent biofilm inhibitory activity.

[0020] The coumarin derivative shown in the formula (I) of the present invention has the chemical structure shown in Table 1:

[0021] Table 1 Structures and names of compounds

[0022]

[0023]

[0024] The term "pharmaceutically acceptable salt" in the present application includes conventional salts formed with pharmaceutically acceptable inorganic acids or organic acids, or inorganic bases or organic bases.

[0025] "Pharmaceutical composition" includes a product containing a therapeutically effective amount of the compound of the present invention, and any product directly or indirectly produced by the combination of the compounds of the present application.

[0026] The fourth aspect of the present invention provides a preparation method of the coumarin derivative shown in the formula (I), which specifically includes the following steps:

[0027] (1.1) 2-Hydroxyacetophenone substituted with different groups, diethyl carbonate and NaH are placed in a solvent, and the reaction solution after the reaction is purified to obtain compounds 1a-1e;

[0028] (1.2) Compounds 1a-1e are combined with and K2CO3 are placed in a solvent, and the obtained reaction solution is purified to obtain compounds 2a-2q;

[0029] (1.3) Compound 2a - 2q, hydroxylamine hydrochloride, and potassium hydroxide were placed in a solvent, and the resulting reaction solution was purified to obtain compounds 3a - 3q.

[0030] The synthetic route at this time is as follows:

[0031]

[0032] The compounds according to the embodiments of the present invention have at least the following beneficial effects:

[0033] (1) The present invention provides a coumarin compound containing the structure shown in formula (I), among which compound 3p with the benzene ring of coumarin substituted by a methyl group at the 6th position has excellent antibacterial biofilm inhibitory activity and a low IC 50 value.

[0034] (2) The preparation method of the compound shown in formula (I) of the present invention has the advantages of short route, high yield, convenient post - treatment, and good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the synergistic effect of compound 3p on CIP. (A) Bacterial plating results of the wound infection area of mice in the Control group, the group administered with CIP alone, and the group administered with 3p - CIP in combination. Each experiment was repeated 3 times. (B) Bacterial survival rate in the wound infection area of mice. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. (C) Photographic monitoring of the wound infection area of mice. (D) Monitoring of the wound area of mice, and the wound area was calculated using Image J. (E) Representative tissue immunofluorescence images of the heart, liver, spleen, lungs, and kidneys of mice in the Control group, the CIP group, and the 3p - CIP group. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be further described below in conjunction with specific embodiments.

[0037] Example 1: Preparation of 6 - fluoro - 4 - hydroxy - coumarin (1b).

[0038] The raw material 5 - fluoro - 2 - hydroxyacetophenone (1000.00 mg, 6.49 mmol) and NaH (778.50 mg, 32.44 mmol) were placed in a 250 - ml two - necked flask, 30 ml of toluene was added, and after stirring the reaction at 0 °C for 30 min, diethyl carbonate (1150.00 mg, 9.75 mmol) was added to the reaction flask, and the reaction was continued at 100 °C for 4 h. After the reaction was completed, the reaction was quenched with water, and the pH was adjusted to 2 with dilute hydrochloric acid. A solid precipitated, and the solid was filtered and washed with water to obtain 1b as a white solid of 1048.70 mg, with a yield of 89.71%. 11H NMR (400 MHz, DMSO) δ 12.72 (s, 1H), 7.61–7.47 (m, 2H), 7.47–7.36 (m, 1H), 5.63 (s, 1H). 13 13C NMR (101 MHz, DMSO) δ 165.25, 165.23, 162.11, 158.32 (d, 1 J C-F = 241.1 Hz), 150.26 (d, 4 J C-F = 1.5 Hz), 120.45 (d, 2 J C-F = 24.6 Hz), 118.95 (d, 3 J C-F = 8.6 Hz), 117.39 (d, 3 J C-F = 8.6 Hz), 109.10 (d, 2 J C-F = 25.0 Hz).

[0039] Example 2: Preparation of 6-bromo-4-hydroxy-coumarin (1c).

[0040] Using 5-bromo-2-hydroxyacetophenone (1000.00 mg, 4.65 mmol) and diethyl carbonate (824.00 mg, 6.98 mmol) as raw materials, the synthesis method was the same as that of compound 1b, and 1c was obtained as a white solid of 958.20 mg, yield: 85.49%. 1 1H NMR (400 MHz, DMSO) δ 7.88 (s, 1H), 7.77 (d, J = 8.7 Hz, 1H), 7.34 (d, J = 8.7 Hz, 1H), 5.62 (s, 1H). 13 13C NMR (101 MHz, DMSO) δ 165.08, 161.88, 153.00, 135.54, 125.81, 119.24, 118.35, 116.11, 92.06.

[0041] Example 3: Preparation of 6-methyl-4-hydroxy-coumarin (1d).

[0042] Using 5-methyl-2-hydroxyacetophenone (1000.00 mg, 6.66 mmol) and diethyl carbonate (1180.00 mg, 9.99 mmol) as raw materials, the synthesis method was the same as that of compound 1b, and 1d was obtained as a white solid of 1124.30 mg, yield: 95.82%. 1HNMR (400 MHz, DMSO) δ 12.44 (s, 1H), 7.59 (s, 1H), 7.43 (d, J = 7.3 Hz, 1H), 7.24 (d, J = 8.4 Hz, 1H), 5.57 (s, 1H), 2.36 (s, 3H). 13 C NMR (101 MHz, DMSO) δ 166.07, 162.49, 152.11, 133.91, 133.58, 123.21, 116.57, 115.91, 91.40, 20.78.

[0043] Example 4: Preparation of 7-methoxy-4-hydroxy-coumarin (1e).

[0044] Using 4-methoxy-2-hydroxyacetophenone (1000.00 mg, 6.02 mmol) and diethyl carbonate (1066.3 mg, 9.03 mmol) as raw materials, the synthesis method was the same as that of compound 1b, and 866.50 mg of 1e was obtained as a white solid, yield: 74.56%. 1 HNMR (400 MHz, DMSO) δ 12.77 (s, 1H), 8.13 (d, J = 8.4 Hz, 1H), 7.34 (d, J = 10.3 Hz, 2H), 5.86 (s, 1H), 4.27 (s, 3H). 13 C NMR (101 MHz, DMSO) δ 166.52, 163.37, 162.76, 155.87, 124.77, 112.27, 109.39, 100.95, 88.95, 56.32.

[0045] Example 5: Preparation of methyl 4-((coumarin-4-yl)oxy)butyrate (2a).

[0046] Put the raw material 1a, i.e., 4-hydroxycoumarin (500.00 mg, 3.08 mmol) and K2CO3 (1065.50 mg, 7.71 mmol) into a 25 ml two-necked flask, add 2 ml of DMF as the solvent, stir and react for 30 min, then add methyl 4-bromobutyrate (0.44 ml, 3.39 mmol) to the reaction flask, and continue to react at 80 °C for 4 h. After the reaction is completed, cool the reaction solution to room temperature, adjust the pH to 7 with dilute hydrochloric acid, extract the reaction solution with dichloromethane 2 times in sequence, wash it with water 2 times, dry the organic phase with anhydrous sodium sulfate and then filter by suction, concentrate the filtrate under reduced pressure, and recrystallize it in ethyl acetate and petroleum ether. After solid precipitation, filter by suction to obtain 638.40 mg of 2a as a white solid, yield: 79.03%. 11H NMR (400 MHz, CDCl3) δ 7.78 (dd, J = 7.9, 1.5 Hz, 1H), 7.54 (td, J = 8.0, 7.4, 1.6 Hz, 1H), 7.32–7.24 (m, 2H), 5.66 (s, 1H), 4.18 (t, J = 6.1 Hz, 2H), 3.69 (s, 3H), 2.57 (t, J = 7.2 Hz, 2H), 2.25 (p, J = 6.8 Hz, 2H). 13 13C NMR (101 MHz, CDCl3) δ

[0047] 173.02, 165.41, 162.78, 153.30, 132.42, 123.88, 122.93, 116.76, 115.60, 90.61, 68.21, 51.82, 30.33, 23.89.

[0048] Example 6: Preparation of methyl 5-((coumarin-4-yl)oxy)pentanoate (2b).

[0049] Using 1a (500.00 mg, 3.08 mmol) and methyl 5-bromopentanoate (0.47 ml, 3.39 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2b was obtained as a white solid (724.70 mg), yield: 85.14%. 1 1H NMR (400 MHz, CDCl3) δ 7.82 (dd, J = 7.9, 1.3 Hz, 1H), 7.59–7.51 (m, 1H), 7.35–7.23 (m, 2H), 5.67 (s, 1H), 4.15 (t, J = 6.0 Hz, 2H), 3.70 (s, 3H), 2.45 (t, J = 7.1 Hz, 2H), 2.03–1.93 (m, 2H), 1.93–1.84 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 173.53, 165.58, 162.92, 153.33, 132.39, 123.89, 123.00, 116.77, 115.70, 90.48, 68.85, 51.66, 33.44, 27.96, 21.48.

[0050] Example 7: Preparation of methyl 6-((coumarin-4-yl)oxy)hexanoate (2c).

[0051] Using 1a (500.00 mg, 3.08 mmol) and methyl 6-bromohexanoate (0.55 ml, 3.39 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2c was obtained as a white solid (642.90 mg), yield: 71.91%. 11H NMR (400 MHz, CDCl3) δ 7.82 (dd, J = 7.9, 1.2 Hz, 1H), 7.58–7.52 (m, 1H), 7.34–7.27 (m, 2H), 5.67 (s, 1H), 4.14 (t, J = 6.3 Hz, 2H), 3.68 (s, 3H), 2.38 (t, J = 7.4 Hz, 2H), 1.94 (dt, J = 14.2, 6.4 Hz, 2H), 1.75 (dt, J = 15.2, 7.4 Hz, 2H), 1.62–1.52 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 173.83, 165.64, 162.96, 153.35, 132.36, 123.86, 122.99, 116.77, 115.76, 90.43, 69.07, 51.57, 33.84, 28.22, 25.56, 24.53.

[0052] Example 8: Preparation of methyl 7-((coumarin-4-yl)oxy)heptanoate (2d).

[0053] Using 1a (500.00 mg, 3.08 mmol) and methyl 7-bromoheptanoate (0.58 ml, 3.39 mmol) as starting materials, the synthesis method was the same as that of compound 2a. 777.00 mg of 2d was obtained as a white solid, yield: 82.91%. 1 1H NMR (400 MHz, CDCl3) δ 7.82 (d, J = 7.9 Hz, 1H), 7.55 (t, J = 7.8 Hz, 1H), 7.34–7.26 (m, 2H), 5.66 (s, 1H), 4.13 (t, J = 6.3 Hz, 2H), 3.67 (s, 3H), 2.35 (t, J = 7.4 Hz, 2H), 1.92 (p, J = 6.6 Hz, 2H), 1.69 (p, J = 7.4 Hz, 2H), 1.55 (dt, J = 14.9, 7.3 Hz, 2H), 1.44 (q, J = 7.9 Hz, 2H). 13 13C NMR (101 MHz, CDCl3) δ 174.04, 165.68, 162.99, 153.34, 132.34, 123.86, 123.00, 116.76, 115.79, 90.39, 69.24, 51.52, 33.89, 28.73, 28.31, 25.68, 24.74.

[0054] Example 9: Preparation of methyl 4-(6-fluorocoumarin-4-yl)oxy)butanoate (2e).

[0055] Using 1b (300.00 mg, 1.67 mmol) and methyl 4-bromobutyrate (0.24 ml, 1.83 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2e was obtained as a white solid (318.10 mg), with a yield of 67.96%. 1 H NMR (400 MHz, CDCl3) δ 7.46 (dd, J = 8.3, 2.6 Hz, 1H), 7.31–7.26 (m, 2H), 5.72 (s, 1H), 4.21 (t, J = 6.1 Hz, 2H), 3.73 (s, 3H), 2.59 (t, J = 7.1 Hz, 2H), 2.27 (p, J = 6.6 Hz, 2H). 13 C NMR (101 MHz, CDCl3) δ 172.94, 164.53 (d, 4 J C-F = 2.7 Hz), 162.39, 158.62 (d, 1 J C-F = 243.9 Hz), 149.42 (d, 4 J C-F = 6.7 Hz), 119.91 (d, 2 J C-F = 24.4 Hz), 118.43 (d, 3 J C-F = 8.3 Hz), 116.59, 108.76 (d, 2 J C-F = 25.3 Hz), 91.37, 68.47, 51.87, 30.27, 23.81.

[0056] Example 10: Preparation of methyl 5-(6-fluorocoumarin-4-yl)oxy)pentanoate (2f).

[0057] Using 1b (300.00 mg, 1.67 mmol) and methyl 5-bromovalerate (0.20 ml, 1.83 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2f was obtained as a white solid (350.00 mg), with a yield of 71.22%. 1 H NMR (400 MHz, CDCl3) δ 7.48 (dd, J = 8.4, 2.7 Hz, 1H), 7.31–7.26 (m, 2H), 5.71 (s, 1H), 4.16 (t, J = 6.0 Hz, 2H), 3.71 (s, 3H), 2.46 (t, J = 7.1 Hz, 2H), 2.03–1.93 (m, 2H), 1.93–1.83 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.45, 164.69 (d, 4 JC-F = 2.7 Hz), 162.49, 158.63 (d, 1 J C-F = 243.8 Hz), 149.43 (d, 4 J C-F = 2.0 Hz), 119.87 (d, 2 J C-F = 24.5 Hz), 118.40 (d, 3 J C-F = 8.2 Hz), 116.62 (d, 3 J C-F = 9.0 Hz), 108.82 (d, 2 J C-F = 25.4 Hz), 91.20, 69.12, 51.68, 33.38, 27.88, 21.44.

[0058] Example 11: Preparation of methyl 6-(6-fluorocoumarin-4-yl)oxy)hexanoate (2 g).

[0059] Using 1b (300.00 mg, 1.67 mmol) and methyl 6-bromohexanoate (0.29 ml, 1.83 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2 g was obtained as 305.90 mg of a pale yellow solid, yield: 59.41%. 1 H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 8.4 Hz, 1H), 7.29 (t, J = 6.5 Hz, 2H), 5.71 (s, 1H), 4.15 (t, J = 6.0 Hz, 2H), 3.69 (s, 3H), 2.40 (t, J = 7.2 Hz, 2H), 1.95 (p, J = 6.6 Hz, 2H), 1.76 (p, J = 8.4, 7.9 Hz, 2H), 1.57 (p, J = 7.8, 7.3 Hz, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.78, 164.75 (d, 4 J C-F = 2.3 Hz), 162.54, 158.62 (d, 1 J C-F = 243.5 Hz), 149.43 (d, 4 J C-F = 1.8 Hz), 119.84 (d, 2 J C-F = 24.2 Hz), 118.39 (d, 3 J C-F = 8.3 Hz), 116.69 (d, 3 JC-F = 9.0 Hz), 108.80 (d, 2 J C-F = 25.3 Hz), 91.14, 69.28, 51.58, 33.80, 28.17, 25.51, 24.50.

[0060] Example 12: Preparation of methyl 7-(6-fluorocoumarin-4-yl)oxy)heptanoate (2h).

[0061] Using 1b (300.00 mg, 1.67 mmol) and methyl 7-bromoheptanoate (0.31 ml, 1.83 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2h was obtained as a pale yellow solid (365.60 mg), yield: 67.92%. 1 H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 8.3 Hz, 1H), 7.28 (d, J = 7.4 Hz, 2H), 5.71 (s, 1H), 4.14 (td, J = 6.7, 2.1 Hz, 2H), 3.69 (d, J = 2.5 Hz, 3H), 2.36 (td, J = 7.5, 2.3 Hz, 2H), 2.00–1.87 (m, 2H), 1.77–1.63 (m, 2H), 1.60–1.50 (m, 2H), 1.49–1.40 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 174.01, 164.79 (d, 4 J C-F = 2.2 Hz), 162.58, 158.62 (d, 1 J C-F = 243.7 Hz), 149.44 (d, 4 J C-F = 2.0 Hz), 119.82 (d, 2 J C-F = 24.5 Hz), 118.39 (d, 3 J C-F = 8.4 Hz), 116.68, 108.81 (d, 2 J C-F = 25.3 Hz), 91.11, 69.49, 51.53, 33.87, 28.71, 28.26, 25.65, 24.71.

[0062] Example 13: Preparation of methyl 4-(6-bromocoumarin-4-yl)oxy)butanoate (2i).

[0063] Using 1c (300.00 mg, 1.24 mmol) and methyl 4-bromobutyrate (0.18 ml, 1.37 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2i was obtained as a white solid, 292.90 mg, yield: 69.24%. 1 H NMR (400 MHz, CDCl3) δ 7.94–7.86 (m, 1H), 7.64 (ddd, J = 8.6, 4.6, 2.3 Hz, 1H), 7.21 (dd, J = 8.8, 4.6 Hz, 1H), 5.70 (d, J = 4.5 Hz, 1H), 4.21 (q, J = 5.9 Hz, 2H), 3.74 (d, J = 4.6 Hz, 3H), 2.59 (td, J = 7.0, 4.6 Hz, 2H), 2.28 (dq, J = 11.0, 6.4 Hz, 2H). 13 C NMR (101 MHz, CDCl3) δ 172.95, 164.22, 162.05, 152.18, 135.27, 125.58, 118.60, 117.21, 116.75, 91.37, 68.59, 51.92, 30.33, 23.79.

[0064] Example 14: Preparation of methyl 5-(6-bromocoumarin-4-yl)oxy)pentanoate (2j).

[0065] Using 1c (300.00 mg, 1.24 mmol) and methyl 5-bromovalerate (0.19 ml, 1.37 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2j was obtained as a white solid, 351.70 mg, yield: 79.85%. 1 H NMR (400 MHz, CDCl3) δ 7.93 (d, J = 2.3 Hz, 1H), 7.64 (dd, J = 8.8, 2.4 Hz, 1H), 7.21 (d, J = 8.8 Hz, 1H), 5.69 (s, 1H), 4.16 (t, J = 6.1 Hz, 2H), 3.72 (s, 3H), 2.46 (t, J = 7.1 Hz, 2H), 1.98 (dq, J = 11.2, 6.2 Hz, 2H), 1.93–1.85 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.48, 164.37, 162.17, 152.19, 135.24, 125.65, 118.59, 117.29, 116.74, 91.21, 69.23, 51.72, 33.39, 27.87, 21.43.

[0066] Example 15: Preparation of methyl 6-(6-bromocoumarin-4-yl)oxy)hexanoate (2k).

[0067] Using 1c (300.00 mg, 1.24 mmol) and methyl 6-bromohexanoate (0.22 ml, 1.37 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2k was obtained as a white solid (326.10 mg), with a yield of 71.23%. 1 1H NMR (400 MHz, CDCl3) δ 7.91 (s, 1H), 7.64 (d, J = 8.7 Hz, 1H), 7.21 (d, J = 8.6 Hz, 1H), 5.68 (s, 1H), 4.14 (t, J = 5.7 Hz, 2H), 3.70 (s, 3H), 2.40 (t, J = 6.9 Hz, 2H), 2.02–1.89 (m, 2H), 1.81–1.73 (m, 2H), 1.64–1.51 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 173.80, 164.42, 162.19, 152.19, 135.19, 125.64, 118.58, 117.34, 116.70, 91.15, 69.41, 51.62, 33.80, 28.17, 25.49, 24.49.

[0068] Example 16: Preparation of methyl 7-(6-bromocoumarin-4-yl)oxy)heptanoate (2l).

[0069] Using 1c (300.00 mg, 1.24 mmol) and methyl 7-bromoheptanoate (0.24 ml, 1.37 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2l was obtained as a white solid (410.60 mg), with a yield of 86.40%. 1 1H NMR (400 MHz, CDCl3) δ 7.92 (d, J = 2.3 Hz, 1H), 7.68–7.60 (m, 1H), 7.25–7.16 (m, 1H), 5.69 (s, 1H), 4.14 (t, J = 6.4 Hz, 2H), 3.69 (s, 3H), 2.36 (t, J = 7.4 Hz, 2H), 1.93 (p, J = 6.7 Hz, 2H), 1.78–1.65 (m, 2H), 1.55 (p, J = 7.2 Hz, 2H), 1.45 (p, J = 7.4, 6.7 Hz, 2H). 13 13C NMR (101 MHz, CDCl3) δ 174.04, 164.47, 162.24, 152.20, 135.18, 125.66, 118.58, 117.38, 116.71, 91.12, 69.61, 51.55, 33.89, 28.72, 28.26, 25.65, 24.72.

[0070] Example 17: Preparation of methyl 4-(6-methylcoumarin-4-yl)oxy)butyrate (2m).

[0071] Using 1d (300.00 mg, 1.70 mmol) and methyl 4-bromobutyrate (0.25 ml, 1.87 mmol) as starting materials, the synthesis method was the same as that of compound 2a. 2m was obtained as a white solid, 312.90 mg, yield: 66.62%. 1 H NMR (400 MHz, CDCl3) δ 7.59–7.54 (m, 1H), 7.36 (dd, J = 8.4, 1.9 Hz, 1H), 7.21 (d, J = 8.4 Hz, 1H), 5.66 (s, 1H), 4.19 (t, J = 6.1 Hz, 2H), 3.72 (s, 3H), 2.60 (t, J = 7.2 Hz, 2H), 2.42 (s, 3H), 2.27 (p, J = 6.6 Hz, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.05, 165.45, 163.06, 151.49, 133.62, 133.43, 122.55, 116.56, 115.25, 90.57, 68.16, 51.84, 30.41, 23.92, 20.91.

[0072] Example 18: Preparation of methyl 5-(6-methylcoumarin-4-yl)oxy)valerate (2n).

[0073] Using 1d (300.00 mg, 1.70 mmol) and methyl 5-bromovalerate (0.27 ml, 1.87 mmol) as starting materials, the synthesis method was the same as that of compound 2a. 2n was obtained as a white solid, 342.10 mg, yield: 69.31%. 1 H NMR (400 MHz, CDCl3) δ 7.59 (s, 1H), 7.36 (d, J = 8.4 Hz, 1H), 7.22 (d, J = 8.4 Hz, 1H), 5.65 (s, 1H), 4.15 (t, J = 5.9 Hz, 2H), 3.71 (s, 3H), 2.46 (t, J = 7.1 Hz, 2H), 2.43 (s, 3H), 1.98 (dt, J = 12.7, 6.2 Hz, 2H), 1.90 (d, J = 7.2 Hz, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.54, 165.59, 163.15, 151.49, 133.59, 133.38, 122.61, 116.53, 115.32, 90.41, 68.79, 51.67, 33.45, 27.96, 21.49, 20.92.

[0074] Example 19: Preparation of methyl 6-(6-methylcoumarin-4-yl)oxy)hexanoate (2o).

[0075] Using 1d (300.00 mg, 1.70 mmol) and methyl 6-bromohexanoate (0.30 ml, 1.87 mmol) as starting materials, the synthesis method was the same as that of compound 2a. 2o was obtained as a white solid (380.70 mg), and the yield was 73.58%. 1 H NMR (400 MHz, CDCl3) δ 7.62–7.55 (m, 1H), 7.36 (dd, J = 8.5, 1.9 Hz, 1H), 7.21 (d, J = 8.4 Hz, 1H), 5.65 (s, 1H), 4.13 (t, J = 6.4 Hz, 2H), 3.69 (s, 3H), 2.43 (s, 3H), 2.40 (t, J = 7.4 Hz, 2H), 2.00–1.89 (m, 2H), 1.83–

[0076] 1.74 (m, 2H), 1.63–1.53 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 173.84, 165.66, 163.21, 151.51, 133.59, 133.36, 122.61, 116.54, 115.39, 90.37, 69.02, 51.58, 33.85, 28.24, 25.56, 24.55, 20.92.

[0077] Example 20: Preparation of methyl 7-(6-methylcoumarin-4-yl)oxy)heptanoate (2p).

[0078] Using 1d (300.00 mg, 1.70 mmol) and methyl 7-bromoheptanoate (0.33 ml, 1.87 mmol) as starting materials, the synthesis method was the same as that of compound 2a. 2p was obtained as a white solid (416.40 mg), and the yield was 76.94%. 1 H NMR (400 MHz, CDCl3) δ 7.58 (s, 1H), 7.35 (d, J = 8.4 Hz, 1H), 7.21 (d, J = 8.4 Hz, 1H), 5.64 (s, 1H), 4.12 (t, J = 6.3 Hz, 2H), 3.68 (s, 3H), 2.42 (s, 3H), 2.36 (d, J = 7.3 Hz, 2H), 1.93 (s, 2H), 1.70 (s, 2H), 1.61–1.51 (m, 2H), 1.46 (q, J = 6.4, 5.5 Hz, 2H). 1313C NMR (101 MHz, CDCl3) δ 174.04, 165.68, 163.22, 151.49, 133.56, 133.32, 122.60, 116.51, 115.41, 90.32, 69.19, 51.52, 33.90, 28.74, 28.31, 25.69, 24.74, 20.91.

[0079] Example 21: Preparation of methyl 5-((7-methoxycoumarin-4-yl)oxy)pentanoate (2r).

[0080] Using 1e (300.00 mg, 1.55 mmol) and methyl 5-bromopentanoate (0.24 ml, 1.71 mmol) as starting materials, the synthesis method was the same as that of compound 2a, and 2r was obtained as a white solid, 283.70 mg, yield: 59.75%. 1 1H NMR (400 MHz, CDCl3) δ 7.71 (d, J = 8.8 Hz, 1H), 6.84 (dd, J = 8.8, 2.4 Hz, 1H), 6.79 (d, J = 2.4 Hz, 1H), 5.54 (s, 1H), 4.13 (t, J = 5.9 Hz, 2H), 3.87 (s, 3H), 3.70 (s, 3H), 2.44 (t, J = 7.1 Hz, 2H), 2.00–1.92 (m, 2H), 1.91–1.84 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 173.55, 165.99, 163.44, 163.22, 155.16, 124.05, 112.20, 108.93, 100.43, 87.99, 68.67, 55.73, 51.66, 33.45, 27.98, 21.48.

[0081] Example 22: Preparation of N-hydroxy-4-((coumarin-4-yl)oxy)butanamide (3a).

[0082] Hydroxylamine hydrochloride (738.00 mg, 11.44 mmol) and potassium hydroxide (1283.60 mg, 22.88 mmol) were first reacted in methanol solvent for 30 min, then filtered to obtain the filtrate. Reactant 2a (300.00 mg, 1.14 mmol) was added and the reaction continued for 30 min. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with dilute hydrochloric acid, and ice water was added to the reaction solution to precipitate a solid. If no solid was precipitated, the reaction solution was concentrated under reduced pressure until a solid was precipitated. The precipitated solid was filtered and washed with water to obtain 3a as a white solid, 184.30 mg, yield: 61.41%. 11H NMR (400 MHz, DMSO) δ 10.47 (s, 1H), 8.76 (s, 1H), 7.82 (d, J = 7.7 Hz, 1H), 7.65 (t, J = 8.3 Hz, 1H), 7.36 (dd, J = 13.8, 7.7 Hz, 2H), 5.86 (s, 1H), 4.20 (t, J = 6.0 Hz, 2H), 2.21 (t, J = 7.2 Hz, 2H), 2.06 (p, J = 6.5 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 168.93, 165.38, 162.11, 153.20, 133.17, 124.58, 123.50, 116.83, 115.67, 90.89, 69.29, 29.12, 24.61. HRMS (ESI) of compound 3a: calcd. for C 13 H 13 NO5 [M + H] + = 264.0866, found [M + H] + = 264.0874.

[0083] Example 23: Preparation of N-Hydroxy-5-((coumarin-4-yl)oxy)pentanamide (3b).

[0084] Using 2b (200.00 mg, 0.72 mmol) and hydroxylamine hydrochloride (467.00 mg, 7.24 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3b was obtained as a white solid (115.50 mg, yield: 57.85%). 1 1H NMR (400 MHz, DMSO) δ 10.40 (s, 1H), 8.72 (s, 1H), 7.80 (d, J = 7.8 Hz, 1H), 7.66 (t, J = 7.8 Hz, 1H), 7.43–7.33 (m, 2H), 5.88 (s, 1H), 4.22 (t, J = 6.0 Hz, 2H), 2.06 (t, J = 7.1 Hz, 2H), 1.81 (dt, J = 13.2, 6.0 Hz, 2H), 1.71 (p, J = 6.6, 6.1 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 169.31, 165.40, 162.14, 153.22, 133.19, 124.66, 123.25, 116.92, 115.72, 90.95, 69.52, 32.20, 27.92, 22.09. HRMS (ESI) of compound 3b: calcd. for C 14 H 15 NO5 [M + H] += 278.1023, found [M+H] + = 278.1016.

[0085] Example 24: Preparation of N-hydroxy-6-((coumarin-4-yl)oxy)hexanamide (3c).

[0086] Using 2c (300.00 mg, 1.03 mmol) and hydroxylamine hydrochloride (666.00 mg, 10.33 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3c was obtained as a white solid (287.00 mg), yield: 95.65%. 1 H NMR (400 MHz, DMSO) δ 10.42 (s, 1H), 8.69 (s, 1H), 7.80 (d, J = 7.8 Hz, 1H), 7.66 (t, J = 8.4 Hz, 1H), 7.44–7.32 (m, 2H), 5.88 (s, 1H), 4.20 (t, J = 6.1 Hz, 2H), 2.00 (t, J = 7.2 Hz, 2H), 1.82 (p, J = 6.2 Hz, 2H), 1.59 (p, J = 7.3 Hz, 2H), 1.52–1.36 (m, 2H). 13 C NMR (101 MHz, DMSO) δ 169.44, 165.43, 162.15, 153.23, 133.19, 124.67, 123.28, 116.92, 115.73, 90.94, 69.86, 32.61, 28.15, 25.50, 25.24. HRMS (ESI) of compound 3c: calcd. for C 15 H 17 NO5 [M+H] + = 292.1179, found [M+H] + = 292.1178

[0087] Example 25: Preparation of N-hydroxy-7-((coumarin-4-yl)oxy)heptanamide (3d).

[0088] Using 2d (200.00 mg, 0.66 mmol) and hydroxylamine hydrochloride (424.00 mg, 6.57 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3d was obtained as a white solid (158.90 mg), yield: 78.83%. 1HNMR(400MHz, DMSO) δ 10.27 (s, 1H), 8.79 (s, 1H), 7.80 (d, J = 7.6 Hz, 1H), 7.65 (t, J = 7.5 Hz, 1H), 7.48–7.20 (m, 2H), 5.87 (s, 1H), 4.19 (s, 2H), 1.96 (t, J = 6.8 Hz, 2H), 1.87–1.74 (m, 2H), 1.62–1.50 (m, 2H), 1.50–1.40 (m, 2H), 1.38–1.27 (m, 2H). 13 C NMR(101MHz, DMSO) δ 169.51, 165.44, 162.14, 153.22, 133.17, 124.67, 123.27, 116.90, 115.73, 90.91, 69.90, 32.66, 28.70, 28.31, 25.60,

[0089] 25.48. HRMS(ESI) of compound 3d: calcd. for C 16 H 19 NO5[M + H] + = 306.1336, found [M + H] + = 306.1331.

[0090] Example 26: Preparation of 4 - ((6 - fluorocoumarin - 4 - yl)oxy)-N - hydroxybutanamide (3e).

[0091] Using 2e (200.00 mg, 0.71 mmol) and hydroxylamine hydrochloride (460.00 mg, 7.14 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3e was obtained as a white solid, 169.60 mg, yield: 84.94%. 1 HNMR(400MHz, DMSO) δ 10.45 (s, 1H), 8.74 (s, 1H), 7.62–7.49 (m, 2H), 7.46 (s, 1H), 5.93 (s, 1H), 4.20 (s, 2H), 2.20 (s, 2H), 2.05 (s, 1H). 13 C NMR(101MHz, DMSO) δ 168.95, 164.54 (d, 4 J C-F = 2.4 Hz), 161.87, 158.47 (d, 1 J C-F = 240.9 Hz), 149.52, 120.51 (d, 2 J C-F = 24.3 Hz), 118.97 (d, 3 JC-F = 8.6 Hz), 116.75 (d, 3 J C-F = 8.9 Hz), 109.19 (d, 2 J C-F = 25.8 Hz), 91.62, 69.58, 29.19, 24.56. HRMS(ESI) of compound 3e: calcd. for C 13 H 12 FNO5 [M + H] + = 282.0772, found [M + H] + = 282.0788.

[0092] Example 27: Preparation of 5 - ((6 - fluorocoumarin - 4 - yl)oxy)-N - hydroxypentanamide (3f).

[0093] Using 2f (200.00 mg, 0.68 mmol) and hydroxylamine hydrochloride (438.00 mg, 6.80 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3f was obtained as a white solid (155.40 mg, yield: 77.40%). 1 1H NMR (400 MHz, DMSO) δ 10.40 (s, 1H), 8.71 (s, 1H), 7.63–7.36 (m, 3H), 5.95 (s, 1H), 4.21 (s, 2H), 2.05 (s, 2H), 1.80 (s, 2H), 1.70 (s, 2H). 13 13C NMR (101 MHz, DMSO) δ 169.30, 164.53 (d, 4 J C-F = 2.3 Hz), 161.90, 158.46 (d, 1 J C-F = 241.0 Hz), 149.54 (d, 4 J C-F = 1.4 Hz), 120.53 (d, 2 J C-F = 24.3 Hz), 119.10 (d, 3 J C-F = 8.9 Hz), 116.80 (d, 3 J C-F = 9.3 Hz), 108.84 (d, 2 J C-F = 25.5 Hz), 91.70, 69.78, 32.19, 27.83, 22.03. HRMS(ESI) of compound 3f: calcd. for C 14 H14 FNO5 [M+H] + = 296.0929, found [M+H] + = 296.0938.

[0094] Example 28: Preparation of 6-((6-Fluorocoumarin-4-yl)oxy)-N-hydroxyhexanamide (3 g).

[0095] Using 2 g (100.00 mg, 0.32 mmol) and hydroxylamine hydrochloride (209.00 mg, 3.24 mmol) as raw materials, the synthesis method was the same as that of compound 3a, and 3 g of white solid 82.50 mg was obtained, yield: 83.36%. 1 H NMR (400 MHz, DMSO) δ 10.36 (s, 1H), 8.68 (s, 1H), 7.62–7.35 (m, 3H), 5.95 (s, 1H), 4.19 (s, 2H), 2.00 (s, 2H), 1.82 (s, 2H), 1.68–1.53 (m, 2H), 1.50–1.35 (m, 2H). 13 C NMR (101 MHz, DMSO) δ 169.44, 164.55 (d, 4 J C-F = 1.8 Hz), 161.89, 158.45 (d, 1 J C-F = 240.9 Hz), 149.55 (d, 4 J C-F = 2.0 Hz), 120.52 (d, 2 J C-F = 24.9 Hz), 119.09 (d, 3 J C-F = 8.3 Hz), 116.78 (d, 3 J C-F = 8.8 Hz), 108.83 (d, 2 J C-F = 25.1 Hz), 91.69, 70.10, 32.60, 28.07, 25.45, 25.23. HRMS (ESI) of compound 3g: calcd. for C 15 H 16 FNO5 [M+H] +

[0096] = 310.1085, found [M+H] + = 310.1089.

[0097] Example 29: Preparation of 7-((6-Fluorocoumarin-4-yl)oxy)-N-hydroxyheptanamide (3h).

[0098] Using 2h (100.00 mg, 0.31 mmol) and hydroxylamine hydrochloride (200.00 mg, 3.10 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3h was obtained as a white solid (73.90 mg), with a yield of 73.76%. 1 H NMR (400 MHz, DMSO) δ 10.34 (s, 1H), 8.66 (s, 1H), 7.61–7.42 (m, 3H), 5.94 (s, 1H), 4.19 (s, 2H), 1.96 (t, J = 6.7 Hz, 2H), 1.81 (s, 2H), 1.60–1.49 (m, 2H), 1.49–1.41 (m, 2H), 1.40–1.27 (m, 2H). 13 C NMR (101 MHz, DMSO) δ 169.52, 164.57 (d, 4 J C-F = 2.0 Hz), 161.89, 158.45 (d, 1 J C-F = 241.2 Hz), 149.53, 120.51 (d, 2 J C-F = 24.4 Hz), 119.09 (d, 3 J C-F = 8.5 Hz), 116.79 (d, 3 J C-F = 9.0 Hz), 108.83 (d, 2 J C-F = 25.3 Hz), 91.66, 70.15, 32.66, 28.69, 28.24, 25.51, 25.46. HRMS (ESI) of compound 3h: calcd. for C 16 H 18 FNO5 [M + H] + = 324.1242, found [M + H] + = 324.1247.

[0099] Example 30: Preparation of 4-((6-Bromocoumarin-4-yl)oxy)-N-hydroxybutanamide (3i).

[0100] Using 2i (200.00 mg, 0.59 mmol) and hydroxylamine hydrochloride (378.00 mg, 5.86 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3i was obtained as a white solid (188.90 mg), with a yield of 93.59%.1 1H NMR (400 MHz, DMSO) δ 10.51 (s, 1H), 8.74 (s, 1H), 7.91 (d, J = 2.2 Hz, 1H), 7.81 (d, J = 11.2 Hz, 1H), 7.37 (d, J = 8.8 Hz, 1H), 5.94 (s, 1H), 4.21 (t, J = 6.0 Hz, 2H), 2.20 (t, J = 7.2 Hz, 2H), 2.05 (p, J = 6.2 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 168.90, 164.20, 161.59, 152.27, 135.72, 125.61, 119.28, 117.56, 116.51, 91.74, 69.67, 29.14, 24.55. HRMS (ESI) of compound 3i: calcd. for C 13 H 12 BrNO5 [M + H] + = 341.9972, found [M + H] + = 341.9965.

[0101] Example 31: Preparation of 5 - ((6 - bromocoumarin - 4 - yl)oxy)-N - hydroxypentanamide (3j).

[0102] Using 2j (200.00 mg, 0.56 mmol) and hydroxylamine hydrochloride (363.00 mg, 5.63 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3j was obtained as a white solid (167.60 mg), yield: 84.03%. 1 1H NMR (400 MHz, DMSO) δ 10.43 (s, 1H), 8.71 (s, 1H), 7.87 – 7.76 (m, 2H), 7.37 (d, J = 8.6 Hz, 1H), 5.94 (s, 1H), 4.21 (s, 2H), 2.06 (t, J = 6.7 Hz, 2H), 1.88 – 1.76 (m, 2H), 1.75 – 1.64 (m, 2H). 13 13C NMR (101 MHz, DMSO) δ 169.30, 164.15, 161.60, 152.27, 135.68, 125.31, 119.36, 117.59, 116.45, 91.79, 69.87, 32.18, 27.85, 22.06. HRMS (ESI) of compound 3j: calcd. for C 14 H 14 BrNO5 [M + H] + = 356.0128, found [M + H]+ = 356.0129.

[0103] Example 32: Preparation of 6-((6-bromocoumarin-4-yl)oxy)-N-hydroxyhexanamide (3k).

[0104] Using 2k (200.00 mg, 0.54 mmol) and hydroxylamine hydrochloride (349.00 mg, 5.42 mmol) as starting materials, the synthesis method was the same as that of compound 3a. 174.50 mg of 3k was obtained as a white solid, with a yield of 87.30%. 1 HNMR (400 MHz, DMSO) δ 10.37 (s, 1H), 8.68 (s, 1H), 7.89–7.75 (m, 2H), 7.37 (d, J = 8.7 Hz, 1H), 5.94 (s, 1H), 4.19 (t, J = 6.2 Hz, 2H), 2.00 (t, J = 7.2 Hz, 2H), 1.83 (p, J = 6.4 Hz, 2H), 1.59 (p, J = 7.3 Hz, 2H), 1.43 (p, J = 7.9 Hz, 2H). 13 C NMR (101 MHz, DMSO) δ 169.45, 164.17, 161.61, 152.27, 135.67, 125.31, 119.36, 117.59, 116.44, 91.79, 70.20, 32.61, 28.09, 25.44, 25.24. HRMS (ESI) of compound 3k: calcd. for C 15 H 16 BrNO5 [M + H] + = 370.0285, found [M + H] + = 370.0272.

[0105] Example 33: Preparation of 7-((6-bromocoumarin-4-yl)oxy)-N-hydroxyheptanamide (3l).

[0106] Using 2l (200.00 mg, 0.52 mmol) and hydroxylamine hydrochloride (337.00 mg, 5.22 mmol) as starting materials, the synthesis method was the same as that of compound 3a. 193.10 mg of 3l was obtained as a white solid, with a yield of 96.65%. 11H NMR (400 MHz, DMSO) δ 10.40 (s, 1H), 8.78 (s, 1H), 7.94–7.74 (m, 2H), 7.38 (d, J = 8.8 Hz, 1H), 5.94 (s, 1H), 4.20 (t, J = 6.3 Hz, 23H), 1.97 (t, J = 7.3 Hz, 2H), 1.82 (p, J = 6.4 Hz, 2H), 1.53 (p, J = 7.4 Hz, 2H), 1.44 (dt, J = 14.6, 7.6 Hz, 2H), 1.33 (dt, J = 13.4, 7.0 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 169.48, 164.20, 161.62, 152.28, 135.68, 125.33, 119.38, 117.61, 116.45, 91.77, 70.27, 32.69, 28.69, 28.22, 25.53, 25.49. HRMS (ESI) of compound 3l: calcd. for C 16 H 18 BrNO5 [M + H] + = 384.0441, found [M +

[0107] H] + = 384.0455.

[0108] Example 34: Preparation of 4-((6-methylcoumarin-4-yl)oxy)-N-hydroxybutyramide (3m).

[0109] Using 2m (200.00 mg, 0.72 mmol) and hydroxylamine hydrochloride (467.00 mg, 7.20 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3m was obtained as a white solid (112.50 mg), with a yield of 56.35%. 1 1H NMR (400 MHz, DMSO) δ 10.43 (s, 1H), 8.83 (s, 1H), 7.60 (s, 1H), 7.45 (dd, J = 8.4, 1.6 Hz, 1H), 7.27 (d, J = 8.4 Hz, 1H), 5.83 (s, 1H), 4.19 (t, J = 6.0 Hz, 2H), 2.38 (s, 3H), 2.21 (t, J = 7.2 Hz, 2H), 2.05 (p, J = 6.5 Hz, 2H). 13CNMR(101MHz, DMSO) δ 168.90, 165.40, 162.26, 151.37, 133.99, 133.93, 123.02, 116.63, 115.35, 90.81, 69.28, 29.15, 24.59, 20.83. HRMS(ESI) of compound 3m: calcd.

[0110] for C 14 H 15 NO5[M + H] + =278.1023, found [M + H] + =278.1017.

[0111] Example 35: Preparation of 5 - ((6 - methylcoumarin - 4 - yl)oxy)-N - hydroxypentanamide (3n).

[0112] Using 2n (200.00 mg, 0.69 mmol) and hydroxylamine hydrochloride (444.00 mg, 6.90 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3n was obtained as a white solid, 157.40 mg, yield: 78.31%. 1 H NMR(400MHz, DMSO) δ 10.42(s, 1H), 8.73(s, 1H), 7.56(s, 1H), 7.45(d, J = 7.9Hz, 1H), 7.27(d, J = 8.2Hz, 1H), 5.84(s, 1H), 4.20(t, J = 6.1Hz, 2H), 2.37(s, 3H), 2.10–2.03(m, 2H), 1.84–1.77(m, 2H), 1.74–1.66(m, 2H). 13 CNMR(101MHz, DMSO) δ 169.29, 165.39, 162.28, 151.38, 133.99, 133.93, 122.73, 116.71, 115.39, 90.87, 69.48, 32.18, 27.91, 22.05, 20.85. HRMS(ESI) of compound 3n: calcd. for C 15 H 17 NO5[M + H] + =292.1179, found [M + H] + =292.1176.

[0113] Example 36: Preparation of 6 - ((6 - methylcoumarin - 4 - yl)oxy)-N - hydroxyhexanamide (3o).

[0114] Using 2o (200.00 mg, 0.66 mmol) and hydroxylamine hydrochloride (424.00 mg, 6.57 mmol) as raw materials, the synthesis method was the same as that of compound 3a, and 3o was obtained as a white solid of 158.60 mg, yield: 78.70%. 1 H NMR (400 MHz, DMSO) δ 10.31 (s, 1H), 8.78 (s, 1H), 7.56 (s, 1H), 7.45 (dd, J = 8.5, 1.8 Hz, 1H), 7.27 (d, J = 8.4 Hz, 1H), 5.84 (s, 1H), 4.18 (t, J = 6.3 Hz, 2H), 2.38 (s, 3H), 2.00 (t, J = 7.3 Hz, 2H), 1.82 (p, J = 6.5 Hz, 2H), 1.60 (p, J = 7.3 Hz, 2H), 1.44 (p, J = 7.4, 6.8 Hz, 2H). 13 C NMR (101 MHz, DMSO) δ 169.42, 165.42, 162.28, 151.38, 133.98, 133.96, 122.75, 116.71, 115.39, 90.86, 69.82, 32.60, 28.15, 25.47, 25.25, 20.85. HRMS (ESI) of compound 3o: calcd. for C 16 H 19 NO5 [M + H] + = 306.1336, found [M + H] + = 306.1341.

[0115] Example 37: Preparation of 7 - ((6 - methylcoumarin - 4 - yl)oxy)-N - hydroxyheptanamide (3p).

[0116] Using 2p (200.00 mg, 0.63 mmol) and hydroxylamine hydrochloride (405.00 mg, 6.28 mmol) as raw materials, the synthesis method was the same as that of compound 3a, and 3p was obtained as a white solid of 181.30 mg, yield: 90.11%. 11H NMR (400 MHz, DMSO) δ 10.35 (s, 1H), 8.68 (s, 1H), 7.55 (s, 1H), 7.45 (d, J = 8.4 Hz, 1H), 7.27 (d, J = 8.4 Hz, 1H), 5.83 (s, 1H), 4.18 (t, J = 6.3 Hz, 2H), 2.37 (s, 3H), 1.97 (d, J = 14.6 Hz, 2H), 1.81 (p, J = 6.5 Hz, 2H), 1.54 (p, J = 7.5 Hz, 2H), 1.44 (q, J = 7.2 Hz, 2H), 1.33 (p, J = 7.0, 6.2 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 169.56, 165.43, 162.28, 151.38, 133.98, 133.95, 122.73, 116.70, 115.39, 90.82, 69.86, 32.67, 28.70, 28.31, 25.56, 25.47, 20.85. HRMS (ESI) of compound 3p: calcd. for C 17 H 21 NO5 [M + H] +

[0117] = 320.1492, found [M + H] + = 320.1490.

[0118] Example 38: Preparation of 4 - ((7 - methoxycoumarin - 4 - yl)oxy)-N - hydroxybutanamide (3q).

[0119] Using 2q (200.00 mg, 0.68 mmol) and hydroxylamine hydrochloride (440.00 mg, 6.82 mmol) as starting materials, the synthesis method was the same as that of compound 3a, and 3q was obtained as a white solid (107.50 mg), yield: 53.90%. 1 1H NMR (400 MHz, DMSO) δ 10.45 (s, 1H), 8.74 (s, 1H), 7.71 (d, J = 8.5 Hz, 1H), 7.02–6.87 (m, 2H), 5.70 (s, 1H), 4.18 (s, 2H), 3.85 (s, 3H), 2.19 (t, J = 6.2 Hz, 2H), 2.10–1.97 (m, 2H). 1313C NMR (101 MHz, DMSO) δ 168.91, 165.82, 163.36, 162.53, 155.09, 124.62, 112.58, 108.79, 100.91, 88.29, 69.12, 56.37, 29.10, 24.63. HRMS (ESI) of compound 3q: calcd. for C 14 H 15 NO6 [M + H] + = 294.0972, found [M + H] + = 294.0965.

[0120] Example 39: Crystal violet staining method was used to determine the biofilm inhibition rate of derivatives against Pseudomonas aeruginosa PAO1.

[0121] Experimental method: Single colony bacteria were picked on an LB agar plate and cultured overnight in LB medium. 100 μL of the bacterial solution was taken to measure OD 600 , and the bacteria were diluted to OD 600 = 0.01 with LB medium; the compound was formulated to the working concentration with the bacterial-containing medium, and 200 μL was taken and added to a 96-well plate. At the same time, a positive drug azithromycin group, a blank group (Control group, only bacteria), and a negative control group (Blank group, only medium) were set. The perimeter of the 96-well plate was sealed with 200 μL of LB medium to prevent edge effects caused by evaporation. Each set of data was set with 4 - 6 replicates. The 96-well plate was placed in a 37 °C incubator and statically cultured for 16 h; the bacterial solution was carefully aspirated, and washed 3 times with 200 μL of PBS solution; 200 μL of 0.1% crystal violet solution was added and stained for 30 min; the crystal violet was carefully aspirated, and then washed 3 times with 200 μL of PBS solution; after air drying, 200 μL of 30% glacial acetic acid solution was added to dissolve the crystal violet, and it was placed on a micro shaker and shaken well for 5 min and then OD 550 was measured; the biofilm inhibition rate was calculated as = [(Control OD值 - Blank OD值 ) - (drug-administered group OD值 - Blank OD值 )] / (Control OD值 - Blank OD值 ) × 100%. The IC 50 results of the coumarin derivatives determined by the crystal violet staining method are shown in Table 2:

[0122] Table 2 Inhibition rate of coumarin derivatives against the biofilm of Pseudomonas aeruginosa PAO1

[0123]

[0124] a. For all compounds, their IC 50 were all measured at a biofilm inhibition rate of >30% for the positive control drug azithromycin.

[0125] Experimental results: According to the experimental results in Table 2, it can be concluded that the introduction of bromine can slightly improve the activity of the compounds, and fluorine is the optimal electron-withdrawing substituent. Except for compound 3f with a carbon chain length of 4, which has the best biofilm inhibition activity among the compounds with electron-withdrawing substituents, its IC 50 is only 9.80 ± 9.91 μM. The introduction of fluorine increases the biofilm inhibition activity of the compounds as the carbon chain length increases. Subsequently, we also explored the effect of electron-donating substituents on the activity of the compounds. The results showed that the biofilm inhibition activity of compounds 3m - 3p with a methyl substitution at the 6th position was significantly improved, and the inhibitory effect increased significantly as the carbon chain length increased, which was basically consistent with the results obtained by fluorine substitution before. Among all the compounds, compound 3p with a methyl substitution at the 6th position and a carbon chain length of 6 carbons has the optimal biofilm inhibition activity, with an IC 50 = 3.66 ± 2.74 μM, and has the potential for further research as a lead compound. The above experimental results indicate that this series of derivatives has excellent biofilm inhibition activity.

[0126] Example 40: Synergistic study of compound 3p with ciprofloxacin (CIP) in a mouse wound infection model

[0127] Experimental method: This animal experiment was carried out in accordance with the relevant national regulations on animal experiments. The Pseudomonas aeruginosa PAO1 strain was used in this animal experiment. Female 5-week-old Babl / c mice were purchased from SPF(Beijing)Biotechnology.co.Ltd. The living environment of the mice was maintained at a constant temperature of 25 °C throughout the experiment, with a 12 h light / dark cycle, and sufficient food and water were provided. First, 20 mice were randomly divided into 4 groups, 5 mice per group. After anesthesia with 4% chloral hydrate, the hair on the backs of the mice was shaved off, and circular wounds of 4 - 5 mm were created on the backs of each mouse, and 5 × 10 8 CFU of PAO1 were inoculated on the wound surface to establish a wound infection model for 24 h. Then, different drugs were administered to different groups of mice for treatment (normal saline, 1 mg / ml CIP, 0.005 mg / ml CIP + 50 μM 3p, 0.001 mg / ml CIP + 50 μM 3p). After continuous drug administration for 3 days, the skin at the wound site of the mice was taken for CFU counting, and the wounds of the mice were photographed every day for monitoring to calculate the wound area.

[0128] Experimental results: As Figure 1As shown, after continuous administration to mice for 3 days, the bacteria at the wound site of the mice in the combination treatment group were significantly reduced compared to those treated with normal saline (Control). By calculating the bacterial survival rate at the wound site, the bacterial survival rate in the normal saline group was counted as 100%. After treatment with 1 mg / ml CIP for 3 days, almost all bacteria were cleared and the survival rate was 0%. After treatment with the combination of 0.005 mg / ml CIP + 50 μM 3p, very few bacteria survived and the survival rate approached 0%, indicating that the synergistic effect of 3p on CIP reached 200 times. In the combination treatment group of 0.001 mg / ml CIP + 50 μM 3p, the bacterial survival rate was also relatively low compared to the Control group, only about 5%. Subsequently, consistent experimental results were also obtained from the monitoring of the wound area of the mice. After 3 days of combined administration of 3p and diluted CIP, the wound area was basically the same as that of the group treated with CIP alone, and both were much smaller than the wound area of the Control group. On the 9th day, the wound healing degree reached about 80%. In addition, according to the histological H&E staining results of the mouse organs, compound 3p did not cause damage to the heart, liver, spleen, lungs, and kidneys of the mice. All of the above results indicate that as a biofilm inhibitor, 3p has a good synergistic effect on CIP, and its synergistic effect is 200 - 1000 times.

[0129] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A compound or a pharmaceutically acceptable salt thereof, characterized in that The compound has the chemical structure shown below:

2. A pharmaceutical composition, characterized in that, Comprising at least one of the compound according to claim 1 or a pharmaceutically acceptable salt thereof, and optionally a pharmaceutically acceptable excipient or carrier.

3. A combined medicine, comprising at least one of the compound according to claim 1 or a pharmaceutically acceptable salt thereof, and ciprofloxacin.

4. The combined medicine according to claim 3, wherein the mass ratio of the compound or its pharmaceutically acceptable salt to ciprofloxacin is 50:0.5 to 10.

5. The combined medicine according to claim 3, wherein the mass ratio of the compound or its pharmaceutically acceptable salt to ciprofloxacin is 50:1 to 5.

6. Use of the compound according to claim 1 or a pharmaceutically acceptable salt thereof in the preparation of an anti-biofilm agent.

7. Use of the compound according to claim 1 or a pharmaceutically acceptable salt thereof in the preparation of an antibacterial drug against Pseudomonas aeruginosa.

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