1-(3-chloro-4-fluorobenzyl) piperazine chromone derivative, preparation method and application of 1-(3-chloro-4-fluorobenzyl) piperazine chromone derivative as tyrosinase inhibitor

Abstract

The invention relates to the technical field of drug synthesis, in particular to a 1-(3-chloro-4-fluorobenzyl) piperazine chromone derivative, a preparation method and application of the 1-(3-chloro-4-fluorobenzyl) piperazine chromone derivative as a tyrosinase inhibitor, and the 1-(3-chloro-4-fluorobenzyl) piperazine chromone derivative has a structural formula shown in a formula (I). Wherein R is one or more substituent groups; r is independently selected from one or more of hydrogen, hydroxyl, halogen, alkyl and alkoxy and has a relatively strong tyrosinase inhibition effect, and compared with positive control kojic acid, the tyrosinase inhibition effect is maximally improved by 168 times; the compound has a reversible and mixed inhibition effect on tyrosinase; the influence on melanogenesis and tyrosinase activity of the B16F10 cells in vitro is carried out at the concentration of 3-90 mu M, and no cytotoxicity is caused to the B16F10 cells; under the same test concentration, the compound W2 has higher melanin inhibition activity than kojic acid, has excellent druggability, and has wide application prospects.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical synthesis technology, specifically to 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivatives, their preparation methods, and their application as tyrosinase inhibitors. Background Technology

[0002] Tyrosinase (TYR), also known as polyphenol oxidase, is a redox enzyme containing a binuclear copper ion active center and is a key rate-limiting enzyme in the melanin synthesis pathway in organisms. It possesses a unique dual catalytic function, catalyzing both the ortho-hydroxylation of monophenols and the further oxidation of diphenols to quinones, thereby initiating and driving a series of biochemical reactions that ultimately produce melanin. In mammals, melanin is mainly synthesized in the skin, eyes, hair, and brain, playing a crucial physiological protective role against ultraviolet radiation damage to the skin and eyes. However, when the activity of this enzyme is dysregulated, leading to abnormal and excessive melanin deposition in the skin, it can trigger a series of pigmentary disorders, such as melasma, freckles, post-inflammatory melanosis, pigmented acne scars, and even malignant melanoma, significantly impacting the physical and mental health and quality of life of patients.

[0003] Based on the function of tyrosinase in pathological pigmentation processes, the development of effective tyrosinase inhibitors has become an important research direction in the cosmetics, pharmaceutical, and food industries. Currently, various natural or synthetic small molecules are used as tyrosinase inhibitors, such as hydroquinone, arbutin, kojic acid, azelaic acid, L-ascorbic acid (vitamin C), ellagic acid, and tranexamic acid. These compounds, by inhibiting tyrosinase activity and reducing melanin production, are widely used in skin-whitening and pigmentation-reducing cosmetics and as adjunctive treatments for pigmentary disorders.

[0004] Although the above inhibitors have certain application effects, they generally have significant technical defects and safety hazards, which seriously limit their long-term and widespread application. The main issues are as follows: (1) Safety and toxicity problems are prominent: Although hydroquinone has a significant inhibitory effect, it has been proven to have potential gene mutagenicity and can cause serious adverse reactions such as contact dermatitis, skin irritation, vitiligo and even bone marrow toxicity. Its prodrug arbutin has the risk of decomposing and releasing hydroquinone in vivo, and its chemical properties are unstable, posing a safety hazard. Similarly, kojic acid is strictly limited in its application due to the reported potential carcinogenic risk. (2) Insufficient stability and bioavailability: L-ascorbic acid is easily oxidized and degraded by factors such as heat and light, losing its activity; ellagic acid has poor water solubility and bioavailability, resulting in poor transdermal absorption and in vivo efficacy; arbutin and kojic acid also have poor storage stability. (3) Unclear mechanism of action or limited activity: The melanin metabolism mechanism of tranexamic acid is not yet clear, which is not conducive to targeted structural optimization and the design of highly effective drugs. However, some relatively safe inhibitors often have insufficient activity, making it difficult to meet the needs of highly effective treatment.

[0005] The current commercially available inhibitors generally suffer from the technical problem of being "highly toxic due to high efficacy, and lowly or unstable due to safety." Developing novel tyrosinase inhibitors with novel structures, high inhibitory activity, low cytotoxicity, and stable physicochemical properties to overcome the bottlenecks of existing technologies and meet the urgent market demand for safe and effective products has become a crucial technical task and development direction in this field. Summary of the Invention

[0006] The first aspect of this invention provides 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives, the structural formula of which is shown in formula (I): ; (I) Wherein, R is one or more substituents; R is independently selected from one or more of hydrogen, hydroxyl, halogen, alkyl, and alkoxy groups.

[0007] Preferably, the 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative is selected from one of the following structures: .

[0008] A second aspect of the present invention provides a method for preparing the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative, wherein the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W1, comprising the following steps: (1) Synthesis of compound S3: Weigh out compound S1 Compound S2 HBTU was placed in a flask, dichloromethane solution was added, triethylamine was added dropwise, and the mixture was stirred overnight at room temperature. Extraction yielded compound S3. ; (2) Synthesis of compound S4: Weigh out compound S3 obtained in step (1). In a flask, dichloromethane was added in an ice bath, followed by acid. The mixture was stirred in the ice bath, then the ice bath was removed, and the mixture was stirred at room temperature. After the reaction was complete, excess trifluoroacetic acid was quenched with a saturated sodium bicarbonate solution, and the mixture was extracted with dichloromethane to obtain compound S4. ; (3) Synthesis of compound W1: Weigh out compound S4 In a pressure-resistant tube, 3-chloro-4-fluorobenzyl bromide was dissolved in dichloromethane, and then triethylamine was added dropwise. The mixture was stirred at room temperature, and dilute hydrochloric acid was added to remove excess triethylamine. Then, saturated sodium bicarbonate solution was used to remove excess dilute hydrochloric acid. The mixture was extracted 3 to 5 times and separated by column chromatography to finally obtain compound W1.

[0009] Preferably, the compound S1 described in step (1) and compound S2 The molar ratio is 1:(1~1.2).

[0010] Preferably, the molar ratio of compound S1, HBTU and triethylamine in step (1) is 1:(1.5~1.7):(3~3.2).

[0011] Preferably, the acid in step (2) is trifluoroacetic acid or hydrochloric acid.

[0012] Preferably, the volume ratio of dichloromethane and trifluoroacetic acid in step (2) is 2:(1~1.2).

[0013] Preferably, the molar ratio of compound S4 and 3-chloro-4-fluorobenzyl bromide in step (3) is 1:(1~1.2).

[0014] Preferably, the molar ratio of compound S4 and triethylamine in step (3) is 1:(1.5~1.7).

[0015] A third aspect of the present invention provides a method for preparing the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative, wherein the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W2, comprising the following steps: (1) Synthesis of compound S6: Weigh out compound S5 In a reaction flask, pyridine solution was added, and after vigorous stirring at 0–5 °C, ethyl oxaloyl chloride was added dropwise. The ice bath was removed, and the temperature was raised to room temperature. The reaction was then carried out at 55 °C for 5 hours. After the reaction was complete, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was collected and washed twice each with 10% dilute hydrochloric acid and water. The organic phase was dried and concentrated to obtain compound S6. ; (2) Synthesis of compound S7: Compound S6 obtained in step (1) was synthesized. The compound S7 was dissolved in ethanol and 5% sodium carbonate solution and refluxed. After the reaction was completed, the ethanol was evaporated under reduced pressure. The concentrated mixture was acidified with 10% hydrochloric acid, extracted with hot ethyl acetate, and the organic phase was collected, washed with water, dried and concentrated. The solid obtained was added with an appropriate amount of DCM, sonicated and filtered to obtain compound S7. ; (3) Synthesis of compound S10: Weigh out compound S9 In a reaction flask, add DCM and dissolve it completely to dissolve compound S8. After being mixed with DCM, the mixture was added dropwise to the reaction mixture under ice bath conditions, followed by the addition of alkali. The reaction was stirred at 0 °C. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with dichloromethane. The organic phase was collected, dried, and concentrated to obtain compound S10. ; (4) Synthesis of compound W2: Weigh out compound S7 Compound S10 Add pyridine to EDCI and react at room temperature. After the reaction is complete, add dilute hydrochloric acid to quench the reaction and adjust the pH to 4-6. Extract three times with dichloromethane, collect the organic phase, dry and concentrate it, and purify it by column chromatography to obtain compound W2.

[0016] Preferably, the molar ratio of compound S5 and oxaloyl chloride ethyl ester in step (1) is 1:(7~7.2).

[0017] Preferably, the volume ratio of ethanol to 5% sodium carbonate solution in step (2) is 1:(2~2.2).

[0018] Preferably, the molar ratio of compound S8 and compound S9 in step (3) is 1:(5~5.2).

[0019] Preferably, the alkali mentioned in step (3) is one of potassium carbonate and sodium carbonate.

[0020] Preferably, the molar ratio of compound S8 and base in step (3) is 1:(6~6.2).

[0021] A fourth aspect of the present invention provides a method for preparing the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative, wherein the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W3~W14, comprising the following steps: (1) Synthesis of compound S10: Weigh out compound S9 In a reaction flask, add DCM and dissolve it completely to dissolve compound S8. After being mixed with DCM, the mixture was added dropwise to the reaction mixture under ice bath conditions, followed by the addition of alkali. The reaction was stirred at 0 °C. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with dichloromethane. The organic phase was collected, dried, and concentrated to obtain compound S10. ; (2) Synthesis of compound S12: Weigh out compound S11 Add 1,4-dioxane to dissolve and replace N2. Add diethyl oxalate under ice bath conditions, followed by 30% sodium methoxide methanol solution. Stir thoroughly and allow the reaction to proceed. Then add HCl aqueous solution and continue stirring. After the reaction is complete, immerse the reactants in water and extract three times with ethyl acetate. Collect the organic phase, dry and concentrate to obtain compound S12. ; (3) Synthesis of compounds W3~W14: Weigh out compound S12 Compound S10 Add EDCI and pyridine, react at room temperature, and after the reaction is complete, add dilute hydrochloric acid to quench the reaction, adjust the pH to 4-6, extract three times with dichloromethane, collect the organic phase, dry and concentrate it, and purify it by column chromatography to obtain compounds W3-W14.

[0022] Preferably, the molar ratio of compound S12 and compound S10 in step (3) is 1:(1~1.2).

[0023] Preferably, the molar ratio of compound S12 and EDCI in step (3) is 1:(3~3.2).

[0024] A fifth aspect of the present invention provides a tyrosinase inhibitor comprising the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative thereof or a pharmaceutically acceptable salt thereof, or comprising the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative prepared by the preparation method thereof, and a pharmaceutically acceptable carrier or excipient.

[0025] Preferably, the tyrosinase inhibitor is incorporated into a pharmaceutically acceptable carrier or excipient in the form of tablets, capsules, oral liquids, injections, creams, emulsions, or gels.

[0026] The sixth aspect of the present invention provides the use of the 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative in the preparation of anti-pigmentation pharmaceuticals, health products, food or cosmetics.

[0027] The seventh aspect of the present invention provides the use of the 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative in the preparation of anti-melanoma pharmaceuticals or health products.

[0028] The eighth aspect of the present invention provides a whitening cosmetic comprising a 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative.

[0029] The beneficial effects of the present invention are: (1) The present invention provides 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives, the structural formula of which is shown in formula (I): ; (I) Wherein, R is one or more substituents; R is independently selected from one or more of hydrogen, hydroxyl, halogen, alkyl, and alkoxy groups.

[0030] (2) The 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivatives described above have strong tyrosinase inhibitory activity, and their IC50... 50 The values ​​ranged from 0.087 ± 0.004 µM to 1.77 ± 0.062 µM, compared to the positive control kojic acid (IC50). 50 =14.64 ± 0.65 μM), which increased by up to 168 times, and can be used as a tyrosinase inhibitor to regulate melanin production.

[0031] (3) The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives described above exhibit reversible, mixed-type inhibition of tyrosinase. In vitro studies on the effects on melanin production and tyrosinase activity in B16F10 cells were conducted at concentrations (3-90 μM), and no cytotoxicity was observed in B16F10 cells. At the same test concentration, compound W2 showed stronger melanin-inhibiting activity than kojic acid, demonstrating excellent drug-like properties and broad application prospects. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 The graph shows the half-maximal inhibitory concentration (IC50) of compound W2 as a tyrosinase inhibitor in vitro. Figure 2 The diagram shows the in vitro enzyme kinetics of compound W2 as a tyrosinase inhibitor. Figure 3 This is a diagram showing the substrate kinetics of compound W2 as a tyrosinase inhibitor in vitro. Figure 4 The cytotoxicity of compounds W2 and kojic acid on B16F10 cells was determined. Figure 5 The inhibitory effect of compounds W2 and kojic acid on melanin production in B16F10 cells; Figure 6 The inhibitory effects of compounds W2 and kojic acid on intracellular tyrosinase activity in B16F10 cells were investigated. Detailed Implementation

[0033] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0034] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0035] Substances considered "pharmaceutically acceptable excipients" include, but are not limited to: ion exchangers; aluminum; aluminum stearate; lecithin; serum proteins, such as human serum albumin; buffering substances such as phosphates; glycine; sorbic acid; potassium sorbate; mixtures of partial glycerides of saturated vegetable fatty acids; water (including pyrogen-free water); salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts; colloidal silica; magnesium trisilicate; polyvinylpyrrolidone; polyacrylates; waxes; polyethylene-polyoxypropylene-blocking polymers; lanolin; sugars, such as lactose, glucose, and sucrose; starches, such as corn starch and potato starch; cellulose and... Its derivatives include sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; gum powder; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols such as propylene glycol and polyethylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffers such as magnesium hydroxide and aluminum hydroxide; alginic acid; Ringer's solution; ethanol; phosphate buffer solution; and other non-toxic and suitable lubricants such as sodium lauryl sulfate and magnesium stearate; colorants; release agents; coatings; flavorings; fragrances; preservatives and antioxidants.

[0036] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0037] The reagents used in the embodiments of this invention are as follows: 4-Benzopyranone-2-carboxylic acid (Compound S1) CAS No.: 4940-39-0, Piperazine-1-carboxylic acid tert-butyl ester (Compound S2) CAS No.: 57260-72-7, HBTU CAS No.: 94790-37-1, TEA CAS No.: 121-44-8, TFA CAS No.: 76-05-1, 2,4,6-Trihydroxyacetophenone (Compound S5) CAS No.: 480-66-0, ethyl oxaloyl chloride CAS No.: 4755-77-5, pyridine CAS No.: 110-86-1, sodium carbonate CAS No.: 497-19-8, potassium carbonate CAS No.: 584-08-7, ethanol CAS No.: 64-17-5, diethyl oxalate CAS No.: 95-92-1, 3-chloro-4-fluorobromobenzyl CAS No.: 192702-01-5, piperazine CAS No.: 110-85-0, sodium methoxide CAS No.: 124-41-4, 1,4-dioxane CAS No.: 123-91-1, EDCI CAS No.: 7084-11-9; all are commercially available.

[0038] .

[0039] Example 1: Preparation method of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative W1 The reaction equations and steps are as follows: .

[0040] (1) Synthesis of compound S3: Accurately weigh 4-benzopyranone-2-carboxylic acid (S1, 2 g, 10.52 mmol), piperazine-1-carboxylic acid tert-butyl ester (S2, 1.959 g, 10.52 mmol), and HBTU (5.983 g, 15.78 mmol) into a clean, dry round-bottom flask. Add 40 ml of dichloromethane solution as a solvent to dissolve the solids. Then add 4.4 ml of triethylamine dropwise to the reaction flask and stir overnight at room temperature. Extract with water and dichloromethane to obtain compound S3.

[0041] (2) Synthesis of compound S4: Compound S3 (5 g, 13.96 mmol) was accurately weighed into a clean, dry round-bottom flask. 110 ml of dichloromethane was added in an ice bath as a solvent to dissolve the solid. Then, 110 ml of trifluoroacetic acid was slowly added to the reaction flask. The mixture was stirred in an ice bath for 5 min, then the ice bath was removed, and the mixture was stirred at room temperature for 12 hours. After the reaction was complete, excess trifluoroacetic acid was quenched with a saturated sodium bicarbonate solution, and compound S4 was obtained by extraction with dichloromethane.

[0042] (3) Synthesis of compound W1: Compound S4 (258.28 mg, 1 mmol) was weighed into a clean, dry pressure-resistant tube. 3-chloro-4-fluorobenzyl bromide (1 mmol) was dissolved in 5 ml of dichloromethane, and then triethylamine (208.5 μL, 1.5 mmol) was added dropwise. The mixture was stirred at room temperature for 3 hours. Dilute hydrochloric acid was added to remove excess triethylamine, and then saturated sodium bicarbonate solution was used to remove excess dilute hydrochloric acid. The mixture was then extracted 3 to 5 times with saturated sodium chloride and dichloromethane solution. Finally, the mixture was separated by column chromatography to obtain compound W1, whose structural formula is as follows; ; Its NMR data are as follows: 2-(4-(3-Chloro-4-fluorobenzyl)piperazine-1-carbonyl)-4H-chromen-4-one (W3). Yellow solid; yield 58%; mp 244.8–245.7 ℃; 1 H NMR (500 MHz, DMSO- d 6) δ 8.05 (dd, J = 7.9, 1.7 Hz, 1H), 7.86 – 7.83 (m, 1H), 7.69 (dd, J = 8.5, 1.0 Hz,1H), 7.56 – 7.51 (m, 2H), 7.39 – 7.31 (m, 2H), 6.54 (s, 1H), 3.64 – 3.54 (m,4H), 3.53 (s, 2H), 2.47 – 2.41 (dt, J = 16.2, 5.0 Hz, 4H); 13 C NMR (125 MHz, DMSO- d 6) δ 177.05, 160.55, 158.41, 156.79 (d, 1 J C-F = 245.5 Hz), 155.91, 136.26,135.24, 131.11, 129.86, 126.49, 125.39, 124.18, 119.67 (d, 2 J C-F = 17.6 Hz), 119.11, 117.12 (d, 2 J C-F= 20.7 Hz), 111.05, 60.48, 52.99, 52.10, 46.95, 42.14.

[0043] Example 2: Preparation method of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative W2 .

[0044] (1) Synthesis of compound S6: Compound S5 (541.4 mg, 3.22 mmol) was accurately weighed into a reaction flask, and 10 mL of pyridine solution was added. After vigorous stirring at 0-5 °C, 2.25 mL of oxaloyl chloride ethyl ester was added dropwise. The ice bath was removed and the temperature was raised to room temperature. The reaction was then carried out at 55 °C for 5 h. After the reaction was completed, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was collected and washed twice each with 10% dilute hydrochloric acid and water. The organic phase was dried and concentrated to obtain compound S6.

[0045] (2) Synthesis of compound S7: The compound S6 obtained in the previous step was dissolved in 15 mL of ethanol solution and 30 mL of 5% sodium carbonate solution, and the mixture was refluxed for 3 h. After the reaction was completed, the ethanol was evaporated under reduced pressure, the concentrated mixture was acidified with 10% hydrochloric acid, extracted twice with hot ethyl acetate, the organic phase was collected, washed with water, dried and concentrated, and the solid obtained was added with an appropriate amount of DCM, sonicated and filtered to obtain compound S7.

[0046] (3) Synthesis of compound S10: Compound S9 (1.2921 g, 15 mmol) was accurately weighed into a reaction flask and dissolved completely in 3 mL of DCM. Compound S8 (405 μL, 3 mmol) was mixed with 1.5 mL of DCM and added dropwise to the reaction mixture under ice bath conditions. K2CO3 (2.4878 g, 6 mmol) was then added, and the mixture was stirred at 0 °C for 2 h. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with dichloromethane. The organic phase was collected, dried, and concentrated to obtain compound S10.

[0047] (4) Synthesis of compound W4: Compound S7 (1 mmol), compound S10 (1 mmol) and EDCI (3 mmol) were weighed and 1 mL of pyridine was added. The reaction was carried out at room temperature. After the reaction was completed, dilute hydrochloric acid was added to quench the reaction, the pH was adjusted to 4-6, and the mixture was extracted three times with dichloromethane. The organic phase was collected, dried and concentrated, and purified by column chromatography to obtain 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative W2, the structural formula of which is as follows; ; It was prepared using the above-described preparation method.

[0048] Its NMR data are as follows: 2- (4-(3-chloro-4-fluorobenzyl)piperazine-1-carbonyl)-5,7-dihydroxy- 4H-chromen-4-one (10). Yellow solid; yield 45%; mp 266.1–267.1 ℃; 1 H NMR (400 MHz, DMSO-) d 6) δ 12.49 (s, 1H), 11.03 (s, 1H), 7.52 (d, J = 7.3 Hz, 1H),7.40 – 7.31 (m, 2H), 6.47 (s, 1H), 6.40 (s, 1H), 6.24 (s, 1H), 3.61 – 3.52(m, 6H), 2.45 – 2.40 (m, 4H); 13 C NMR (100 MHz, DMSO- d 6) δ 181.27, 164.82,161.47, 159.66, 158.16, 157.21, 156.34 (d, 1 J C-F = 245.5 Hz), 135.79, 130.66,129.41, 119.21 (d, 2 J C-F = 17.6 Hz), 116.66 (d, 2 J C-F = 20.6 Hz), 109.08, 104.52, 99.39, 94.26, 60.00, 52.48, 51.59, 46.45, 41.69.

[0049] Example 3: Preparation method of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivatives W3~W14 .

[0050] (1) Synthesis of compound S10: Compound S9 (1.2921 g, 15 mmol) was accurately weighed into a reaction flask and dissolved completely in 3 mL of DCM. Compound S8 (405 μL, 3 mmol) was mixed with 1.5 mL of DCM and added dropwise to the reaction mixture under ice bath conditions. K2CO3 (2.4878 g, 6 mmol) was then added and the mixture was stirred at 0 °C for 2 h. After the reaction was completed, water was added to quench the reaction mixture, and the mixture was extracted with dichloromethane. The organic phase was collected, dried, and concentrated to obtain compound S10.

[0051] (2) Synthesis of compound S12: Weigh 1 mmol of compound S11, dissolve it in 2 mL of 1,4-dioxane to replace N2, add diethyl oxalate (407.4 μL, 3 mmol) under ice bath conditions, and then add 455.3 μL of 30% sodium methoxide methanol solution. After stirring thoroughly, react at 120 °C for 20 min. Then add 3 mL of 6M HCl aqueous solution and continue stirring for 40 min. After the reaction is complete, put the reactants into water, extract three times with ethyl acetate, collect the organic phase, dry and concentrate to obtain compound S12.

[0052] (3) Synthesis of compounds W3~W14: Weigh out compound S12 (1 mmol), compound S10 (1 mmol) and EDCI (3 mmol), add 1 mL of pyridine, and react at room temperature. After the reaction is complete, add dilute hydrochloric acid to quench the reaction, adjust the pH to 4~6, extract three times with dichloromethane, collect the organic phase, dry and concentrate it, and purify it by column chromatography to obtain compounds W3~W14.

[0053] The structural formula of the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative W3 is as follows: ; Its NMR data are as follows: 2-(4-(3-Chloro-4-fluorobenzyl)piperazine-1-carbonyl)-5-hydroxy-4H- chromen-4-one (W5). White solid; yield 48%; mp 244.5–245.5 ℃; 1 H NMR (500MHz, DMSO- d 6) δ 12.32 (s, 1H), 7.70 (t, J = 8.4 Hz, 1H), 7.52 (dd, J = 7.4, 2.0Hz, 1H), 7.39 – 7.31 (m, 2H), 7.11 (dd, J = 8.6, 0.9 Hz, 1H), 6.86 (dd, J =8.2, 0.9 Hz, 1H), 6.62 (s, 1H), 3.63 – 3.61 (m, 2H), 3.56 – 3,54 (m, 2H), 3.53 (s, 2H), 2.45 – 2.40 (m, 4H); 13 C NMR (125 MHz, DMSO- d 6) δ182.92, 159.80,159.54, 156.34 (d, 1 J C-F = 245.4 Hz), 159.14, 155.74, 136.52, 135.83 (d, 3 J C-F = 3.7Hz), 130.66, 129.41 (d, 3 J C-F = 7.3 Hz), 119.21 (d, 2 J C-F = 17.5 Hz), 116.67 (d, 2 J C-F = 20.7 Hz), 111.53, 110.77, 109.48, 107.70, 60.01, 52.50, 51.58, 46.45, 41.72.

[0054] The structural formula of 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative W4 is as follows: ; Its NMR data are as follows: 2-(4-(3-Chloro-4-fluorobenzyl)piperazine-1-carbonyl)-7-hydroxy-4H- chromen-4-one (11a). Yellow solid; yield 47%; mp 259.9–262.0 ℃; 1 H NMR (400MHz, DMSO- d 6) δ 10.92 (s, 1H), 7.88 (d, J = 8.8 Hz, 1H), 7.52 (d, J = 7.3 Hz, 1H), 7.36 (dd, J = 18.4, 8.4 Hz, 2H), 7.02 – 6.84 (m, 2H), 6.39 (s, 1H), 3.65 – 3.52 (m, 6H), 2.46 – 2.33 (s, 4H); 13 C NMR (100 MHz, DMSO- d 6) δ 175.68,163.15, 160.20, 157.26, 157.23, 156.33 (d, 1J C-F = 245.9 Hz), 135.86, 130.64,129.39 (d, 3 J C-F = 7.4 Hz), 126.75, 119.21 (d, 2 J C-F = 18.0 Hz), 116.76, 116.52 (d, 3 J C-F = 7.6 Hz), 115.58, 110.38, 102.56, 60.04, 52.53, 51.67, 46.52, 41.68.

[0055] The structural formula of 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative W5 is as follows: ; Its NMR data are as follows: 2-(4-(3-Chloro-4-fluorobenzyl)piperazine-1-carbonyl)-5-fluoro-4H- chromen-4-one (W7). White solid; yield 51%; mp 232.6–233.5 ℃; 1 H NMR (500MHz, DMSO- d 6) δ 7.82 (td, J = 8.4, 5.5 Hz, 1H), 7.51 (t, J = 7.6 Hz, 2H), 7.39 –7.24 (m, 3H), 6.47 (s, 1H), 3.62 – 3.55 (m, 4H), 3.52 (s, 2H), 2.45 – 2.40(m, 4H); 13 C NMR (125 MHz, DMSO- d 6) δ 175.01, 159.75, 159.48 (d, 1 J C-F = 260.0 Hz),156.79, 156.40 (d, 3 J C-F = 3.6 Hz), 156.33 (d, 1 J C-F = 243.8 Hz), 135.83 (d,3 J C-F =3.7 Hz), 135.06 (d, 2 J C-F = 10.8 Hz), 130.64, 129.39 (d, 3 J C-F = 7.2 Hz), 119.20 (d, 2 J C-F = 17.7 Hz), 116.65 (d, 2 J C-F = 20.7 Hz), 114.74 (d, 3 J C-F = 4.3 Hz), 114.07 (d, 3 J C-F = 10.5 Hz), 112.55 (d, 2 J C-F = 20.2 Hz), 111.67, 60.01, 52.52, 51.61, 46.45, 41.69.

[0056] The structural formula of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative W6 is as follows; ; Its NMR data are as follows: 2-(4-(3-Chloro-4-fluorobenzyl)piperazine-1-carbonyl)-7-fluoro-4H- chromen-4-one(W7). Yellow solid; yield 56%; mp 261.4–262.5 ℃; 1 H NMR (500MHz, DMSO- d 6) δ 8.11 (dd, J = 8.9, 6.4 Hz, 1H), 7.69 (dd, J = 9.5, 2.4 Hz, 1H), 7.53 (dd, J = 7.4, 2.0 Hz, 1H), 7.43 – 7.32 (m, 3H), 6.55 (s, 1H), 3.62 (s,2H), 3.57 – 3.54 (m, 4H), 2.49 – 2.38 (m, 4H); 13C NMR (125 MHz, DMSO- d 6) δ 175.81, 165.21 (d, 1 J C-F = 252.6 Hz), 159.83, 158.09, 156.36 (d, 1 J C-F = 243.8 Hz), 156.55 (d, 3 J C-F = 14.0 Hz), 135.78, 130.69, 129.44 (d, 3 J C-F = 6.6 Hz), 127.82 (d, 3 J C-F = 11.0 Hz), 120.93 (d, 3 J C-F = 2.2 Hz), 119.21 (d, 2 J C-F = 17.6 Hz), 116.67 (d, 2 J C-F = 20.7 Hz), 114.61 (d, 2 J C-F = 23.1 Hz), 110.75, 105.57 (d, 2 J C-F = 26.0 Hz),59.98, 52.48, 51.59, 46.44, 41.66.

[0057] The structural formula of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative W7 is as follows; ; Its NMR data are as follows: 5-Chloro-2-(4-(3-chloro-4-fluorobenzyl)piperazine-1-carbonyl)-4H- chromen-4-one (W9). Yellow solid; yield 53%; mp 271.6–272.5 ℃; 1 H NMR (500MHz, DMSO- d 6) δ 7.75 (t,J = 8.2 Hz, 1H), 7.63 (d, J = 8.4 Hz, 1H), 7.55 – 7.50(m, 2H), 7.40 – 7.30 (m, 2H), 6.49 (s, 1H), 3.62 –3.56 (m, 4H), 3.52 (s, 2H),2.45 – 2.40 (m, 4H); 13 C NMR (125 MHz, DMSO- d 6) δ 175.55, 159.71, 157.17, 156.34(d, 1 J C-F = 245.6 Hz), 156.28, 135.83, 134.27, 131.58, 130.67, 129.43, 128.52,120.63, 119.22 (d, 2 J C-F = 17.6 Hz), 118.26, 116.68 (d, 2 J C-F = 20.7 Hz), 111.93, 60.02, 52.54, 51.63, 46.45, 41.71.

[0058] The structural formula of 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative W8 is as follows; ; Its NMR data are as follows: 7-Chloro-2-(4-(3-chloro-4-fluorobenzyl)piperazine-1-carbonyl)-4H- chromen-4-one (W10). Yellow solid; yield 55%; mp 247.2–248.2 ℃; 1 H NMR (500MHz, DMSO- d 6) δ 8.03 (d, J = 8.6 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.58 (dd, J =8.6, 2.0 Hz, 1H), 7.52 (dd, J= 7.4, 2.0 Hz, 1H), 7.39 – 7.31 (m, 2H), 6.57(s, 1H), 3.63 – 3.60 (m, 2H), 3.55 – 3.53 (m, 2H), 3.53 (s, 2H), 2.46 – 2.41(m, 4H); 13 C NMR (125 MHz, DMSO- d 6) δ 175.98, 159.78, 158.07, 156.32 (d, 1 J C-F =207.5 Hz), 155.72, 138.98, 135.83 (d, 3 J C-F = 3.7 Hz), 130.64, 129.40 (d, 3 J C-F =7.3 Hz), 126.79, 126.52, 122.63, 119.20 (d, 2 J C-F = 17.6 Hz), 118.68, 116.66 (d, 2 J C-F = 20.7 Hz), 110.94, 60.02, 52.51, 51.62, 46.45, 41.72.

[0059] Example 4: Tyrosinase Inhibition Activity Test The tyrosinase inhibitory activity of the synthesized compounds was evaluated using in vitro enzymatic experiments, as follows: Compound W1 prepared in Example 1 and compounds W2-W8 prepared in Example 2 were dissolved in dimethyl sulfoxide and diluted to different concentrations. 10 μL of tyrosinase (final concentration: 133.4 U / mL), 10 μL of the test compound, and 130 μL of PBS (50 mM, pH 6.8) were added to a 96-well plate, and the mixture was incubated at 25°C for 5 min. Then, 50 μL of L-DOPA solution (final concentration: 2 mM) was added. The absorbance change of the mixture at 475 nm was recorded, and the half-inhibition concentration (IC50) was calculated. 50 The value was determined by using kojic acid as a positive control, and each experiment was repeated four times.

[0060] The tyrosinase inhibitory activity of the synthesized compounds W1-W8 was tested using mushroom tyrosinase, and the results are shown in Table 1. The results indicate that compounds with tryptophan acid substituted with -OH, -F, or -Cl (W2-W8) exhibited better tyrosinase inhibitory activity than the unsubstituted tryptophan acid compound (W1). Among them, compound W2, substituted with two hydroxyl groups, showed the best tyrosinase inhibitory activity (IC50). 50 = 87.27 ± 4.21 nM), compared to the positive control kojic acid (IC50). 50 = 14.64 ± 0.65 μM) is about 168 times higher, and about 20 times higher than the unsubstituted chromoketo acid compound W1.

[0061] Table 1. Evaluation of the in vitro inhibitory activity of compounds W1-W8 against tyrosinase.

[0062] Note: 'a' indicates the IC50 difference between the compound and the positive control drug kojic acid. 50 The values ​​differed significantly ( P <0.0001) Example 5: Enzyme Kinetics Test The tyrosinase activity kinetics of the synthesized compounds were evaluated using in vitro enzyme kinetic experiments. The kinetic studies were conducted using the same experimental methods described above. For enzyme kinetics, the absorbance at 475 nm was recorded for mixtures containing different concentrations of tyrosinase (final concentration: 133.4 U / mL) and compound W2 (0, 62.5, 125, 250 nM).

[0063] The results of the enzyme kinetic inhibition type evaluation experiment are as follows: Figure 2 As shown, the inhibitor exhibits a reversible inhibitory effect.

[0064] Example 6: Substrate Dynamics Experiment The tyrosinase inhibitory activity of the synthesized active compounds was evaluated using in vitro substrate kinetic experiments. Compound W2, exhibiting the highest tyrosinase activity, was selected for kinetic experiments. Following the same method described above, the mixture was incubated with 10 µL of tyrosinase, 10 µL of the test compound, and 130 µL of PBS, followed by the addition of 50 µL of L-DOPA. Absorbance was then recorded. Data were processed using Lineweaver-Burk plots.

[0065] The experimental results for evaluating the type of substrate kinetic inhibition are as follows: Figure 3As shown, all the straight lines almost intersect in the second quadrant, indicating that compound W2 exhibits mixed inhibition, meaning that compound W2 binds not only to free tyrosinase but also to the tyrosinase-substrate complex. Therefore, the inhibition of tyrosinase by compound W2 is a mixed inhibition.

[0066] Example 7: B16F10 Cytotoxicity Assay To assess the potential toxicity of compound W2 and kojic acid reference standard to mouse melanoma B16F10 cells, we used the CCK-8 assay for cytotoxicity determination.

[0067] B16F10 cells in logarithmic growth phase were seeded at a density of 2000 cells per well in 96-well plates and pre-cultured at 37°C in a 5% CO2 incubator for 24 hours to ensure full cell adhesion. Then, the old culture medium was removed, and fresh culture medium containing a series of concentration gradients (3–90 µM) of compound W2, kojic acid, or an equal volume of solvent (as a blank control) was added to each well. Each concentration was used in 5–6 replicates. After culturing for another 48 hours, 10 µL of CCK-8 solution was added to each well, and the plates were incubated in the dark for 1–4 hours. Finally, the absorbance (OD value) of each well was measured using a microplate reader at 450 nm.

[0068] Cell viability is calculated using the following formula: Cell viability (%) = [(OD drug - OD blank) / (OD control - OD blank)] × 100% Among them, OD drug is the OD value of the drug-containing well, OD control is the OD value of the solvent control well, and OD blank is the OD value of the culture medium well without cells.

[0069] The results are as follows Figure 4 As shown, neither compound W2 nor kojic acid exhibited significant cytotoxicity at a concentration of 90 μM. Therefore, the effects of compound W2 on melanin production and tyrosinase activity in B16F10 cells in vitro were investigated at concentrations (3–90 μM), and no cytotoxicity was observed in B16F10 cells.

[0070] Example 8: Melanin Production Inhibition Experiment To investigate the inhibitory effect of compounds W2 and kojic acid on melanin synthesis in B16F10 cells, we established an α-melanocyte stimulating hormone (α-MSH) induced cell model.

[0071] B16F10 cells were seeded at an appropriate density in 6-well plates. After adhesion, the medium was replaced with medium containing 1 µM α-MSH (to stimulate melanin synthesis) and different concentrations of compound W2 or kojic acid. The following experimental groups were set up: ① Blank control group (without α-MSH and drug), ② Model control group (containing α-MSH, without drug), ③ Positive control group (containing α-MSH and different concentrations of kojic acid), ④ Experimental group (containing α-MSH and different concentrations of compound W2). Each group was divided into 3 replicates and cultured for 48-72 hours. After treatment, the culture supernatant was discarded, and the cells were gently washed twice with pre-cooled PBS. Subsequently, cell lysis buffer (PBS containing 1% Triton X-100) was added, and the cells were lysed on ice. The lysate was collected. A portion of the lysate was used to determine the total protein concentration using the BCA method to standardize melanin content. An equal volume of 1 M NaOH solution was added to another portion of the lysate, and the mixture was heated in an 80°C water bath for 1 hour to completely dissolve the melanin. Finally, the solution was transferred to a 96-well plate, and the absorbance was measured at a wavelength of 405 nm.

[0072] The melanin production inhibition rate is calculated using the following formula: Inhibition rate (%) = [1 - (OD experimental group / OD model control group)] × 100% The results are as follows Figure 5 As shown, the melanin-inhibiting effect of compound W2 was dose-dependent, at (19.71 ± 0.71)%, (27.83 ± 0.78)%, and (34.79 ± 0.57)%, respectively. Furthermore, at the same test concentration, compound W2 exhibited stronger melanin-inhibiting activity than kojic acid.

[0073] Example 9: Inhibition of Intracellular Tyrosinase Activity To evaluate the inhibitory effect of the compound on intracellular tyrosinase activity, the following methods were used for determination: B16F10 cells were loaded at a rate of 1 × 10⁻⁶. 5Cells were seeded at a density of 2 mL / well in 6-well plates and cultured at 37°C with 5% CO2 for 24 hours to allow adhesion. The original culture medium was discarded and replaced with fresh medium containing different concentrations of the test compounds, and cultured for another 48 hours. After treatment, the medium was discarded, and the cells were gently washed twice with pre-chilled phosphate-buffered saline (PBS). Then, 300 μL of pre-chilled cell lysis buffer (50 mM phosphate-buffered saline containing 1% Triton X-100, pH 6.8) was added to each well, and the cell culture plates were frozen at -80°C for 1 hour to achieve complete lysis. After removal, the cells were rapidly thawed in a 37°C water bath, and the cell lysis buffer was collected and centrifuged at 12,000 rpm for 5 minutes at 4°C. The supernatant was collected, and the total protein concentration was determined using a BCA protein quantification kit. All samples were then adjusted to a protein concentration of 0.8 mg / mL using the lysis buffer.

[0074] Take 80 μL of standardized protein sample and mix it with 20 μL of 10 mM L-DOPA solution in a 96-well plate. Immediately monitor the absorbance of the reaction mixture at 475 nm using a microplate reader for 1 hour, reading the data every 5 minutes. Calculate the tyrosinase activity based on the increase in absorbance within 10 minutes after the start of the reaction, and calculate the inhibition rate using the following formula: Inhibition rate (%) = [1 - (ΔA sample / ΔA control)] × 100% Here, ΔA sample and ΔA control represent the absorbance changes of the compound treatment group and the solvent control group within 10 minutes, respectively.

[0075] The results are as follows Figure 6 As shown, the inhibitory effect of compound W2 on intracellular tyrosinase activity was dose-dependent, with (6.12 ± 4.21)%, (22.61 ± 2.95)%, and (32.80 ± 3.63)%, respectively. Furthermore, at the same test concentration, compound W2 and kojic acid exhibited comparable intracellular tyrosinase inhibitory activity.

[0076] In summary, the present invention provides 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives, the structural formula of which is shown in formula (I): ; (I) Wherein, R is one or more substituents; R is independently selected from one or more of hydrogen, hydroxyl, halogen, alkyl, and alkoxy groups. The 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivatives described above exhibit strong tyrosinase inhibitory activity, with an IC50 value of [missing information]. 50The values ​​ranged from 0.087 ± 0.004 µM to 1.77 ± 0.062 µM, compared to the positive control kojic acid (IC50). 50 =14.64 ± 0.65 μM), with a maximum increase of 168-fold, enabling it to act as a tyrosinase inhibitor for regulating melanin production. The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative exhibits reversible, mixed-type inhibition of tyrosinase; its effects on melanin production and tyrosinase activity in B16F10 cells were tested in vitro at concentrations (3 ~ 90 μM), showing no cytotoxicity to B16F10 cells. At the same test concentrations, compound W2 exhibits stronger melanin-inhibiting activity than kojic acid, demonstrating excellent drug-like properties and broad application prospects.

[0077] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives, characterized in that, The structural formula of the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is shown as formula (I): ； （Ⅰ） Wherein, R is one or more substituents; R is independently selected from one or more of hydrogen, hydroxyl, halogen, alkyl, alkoxy.

2. The 1-(3-chloro-4-fluorobenzyl)piperazinylchromone derivative as described in claim 1, characterized in that, The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is selected from one of the following structures: 。 3. The process for the preparation of 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivatives as claimed in claim 2, wherein, ###00002### is prepared by the reaction of ###00003### with ###00004### in presence of a base. The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W1, comprising the following steps: (1) Synthesis of compound S3: Compound S1 , compound S2 and HBTU were weighed into a flask, dichloromethane solution was added, triethylamine was added dropwise, and stirred at room temperature overnight. Extraction gave compound S3 ; (2) Synthesis of compound S4: Compound S3 obtained in step (1) was weighed In a flask, dichloromethane was added in an ice bath, the acid was added, after stirring in an ice bath, the ice bath was removed, and stirring was carried out at room temperature. After the reaction was completed, the excess trifluoroacetic acid was quenched with a saturated sodium bicarbonate solution, and dichloromethane was extracted to obtain compound S4 ; (3) Synthesis of compound Wl: Compound S4 In a pressure tube, 3-chloro-4-fluorobenzyl bromide was dissolved in dichloromethane, and triethylamine was added dropwise. The mixture was stirred at room temperature, and excess triethylamine was removed by adding dilute hydrochloric acid. Excess dilute hydrochloric acid was removed by adding a saturated sodium bicarbonate solution. The mixture was extracted 3-5 times, and the final compound Wl was isolated by column chromatography.

4. The method for preparing the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative as described in claim 2, characterized in that, The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W2, comprising the following steps: (1) Synthesis of compound S6: Compound S5 was weighed In a reaction flask, pyridine solution was added, after stirring vigorously at 0-5°C, oxalyl chloride ethyl ester was added drop by drop, the ice bath was removed to raise the temperature to room temperature, and then the reaction was carried out at 55°C for 5 hours. After the reaction was completed, the reaction mixture was poured into water, extracted with dichloromethane, and the organic phase was collected, washed with 10% dilute hydrochloric acid and water for 2 times respectively, and then dried and concentrated to obtain compound S6 ; (2) Synthesis of compound S7: Compound S6 obtained in step (1) was dissolved in ethanol solution and 5% sodium carbonate solution, and refluxed. After the reaction was completed, ethanol was evaporated under reduced pressure, and the concentrated mixture was acidified with 10% hydrochloric acid, extracted with hot ethyl acetate, washed with water, dried and concentrated to obtain a solid. The solid was dissolved in DCM, filtered after ultrasonic treatment to obtain compound S7 ; and (2) Synthesis of compound S7: Compound S6 obtained in step (1) was dissolved in ethanol solution and 5% sodium carbonate solution, and refluxed. After the reaction was completed, ethanol was evaporated under reduced pressure, and the concentrated mixture was acidified with 10% hydrochloric acid, extracted with hot ethyl acetate, washed with water, dried and concentrated to obtain a solid. The solid was dissolved in DCM, filtered after ultrasonic treatment to obtain compound S7 ; and (3) Synthesis of compound S10: Compound S9 was weighed in a reaction flask and dissolved in DCM. Compound S8 was added dropwise into the reaction under ice bath, and then a base was added. The reaction was stirred at 0 °C. After the reaction was completed, water was added for quenching. The organic phase was collected by extraction with dichloromethane, dried and concentrated to obtain compound S10 ; (4) Synthesis of compound W2: Compound S7 , compound S10 and EDCI, pyridine was added, and the reaction was carried out at room temperature. After the reaction was completed, dilute hydrochloric acid was added for quenching, the pH value was adjusted to 4-6, dichloromethane was added for extraction three times, the organic phase was collected and dried and concentrated, and column chromatography purification was carried out to obtain compound W2.

5. The method for preparing the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative as described in claim 2, characterized in that, The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative is compound W3-W14, comprising the following steps: (1) Synthesis of compound S10: Compound S9 was weighed in a reaction flask and dissolved in DCM. Compound S8 and DCM were mixed and added dropwise into the reaction under ice bath. Base was added and the reaction was stirred at 0 °C. After the reaction was completed, water was added for quenching. The organic phase was collected by extraction with dichloromethane and dried and concentrated to obtain compound S10 ; (2) Synthesis of compound S12: Weigh out compound S11 Add 1,4-dioxane to dissolve and replace N2. Add diethyl oxalate under ice bath conditions, followed by 30% sodium methoxide methanol solution. Stir thoroughly and allow the reaction to proceed. Then add HCl aqueous solution and continue stirring. After the reaction is complete, immerse the reactants in water and extract three times with ethyl acetate. Collect the organic phase, dry and concentrate to obtain compound S12. ; (3) Synthesis of compounds W3-W14: Compound S12 , S7 , compound S10 and EDCI, pyridine was added, and the reaction was carried out at room temperature. After the reaction was completed, dilute hydrochloric acid was added for quenching, the pH value was adjusted to 4-6, dichloromethane was added for extraction three times, the organic phase was collected and dried and concentrated, and column chromatography purification was carried out to obtain compounds W3-W14.

6. A tyrosinase inhibitor, characterized by, The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative of claim 1 or 2 or a pharmaceutically acceptable salt thereof, or the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative prepared by the preparation method of any one of claims 3-5, and a pharmaceutically acceptable carrier or excipient.

7. The tyrosinase inhibitor according to claim 6, wherein The tyrosinase inhibitor is added to a pharmaceutically acceptable carrier or excipient in the form of tablets, capsules, oral liquids, injections, creams, emulsions or gels.

8. Use of the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative of claim 1 or 2 in the preparation of an anti-pigmentation drug, health product, food or cosmetic.

9. Use of the 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative of claim 1 or 2 in the preparation of an anti-melanoma drug or health product.

10. A whitening cosmetic, characterized by, The 1-(3-chloro-4-fluorobenzyl)piperazinyl chromone derivative of claim 1 or 2.

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