A 2,3-disubstituted naphthoquinone compound and its uses and preparation method

Abstract

This invention belongs to the field of veterinary drug technology, specifically relating to a 2,3-disubstituted naphthoquinone compound, its uses, and a preparation method. The 2,3-disubstituted naphthoquinone compound has the general formula: where X is selected from C, NH, O, and S; where X is selected from C, the X-R1 substituent represents an aryl substituent; when X is selected from NH, R1 is selected from hydrogen atom, C1-6 alkyl, C3-6 cycloalkyl, substituted aryl, substituted benzyl, or substituted acyl; when X is selected from O, R1 is selected from hydrogen atom, C1-6 alkyl, C3-6 cycloalkyl, C4-6 cycloalkyl, C5-6 cycloalkyl, C6-6 cyclo ... 3-6 cycloalkyl, substituted benzyl, substituted acyl; when X is selected from S, R1 is selected from C1-6 alkyl, substituted aryl, substituted benzyl; R2 is selected from C1-16 alkyl, substituted aryl, Ra-(CH2)n-, Ra-CO-(CH2)n-; This series of compounds has novel structures, excellent antiparasitic activity, and has been successfully applied in the field of veterinary drugs, solving long-standing safety and toxicity problems; its synthesis process is simple, the conditions are mild, and it can efficiently prepare a variety of 2,3-disubstituted naphthoquinone compounds.

Description

Technical Field

[0001] This invention belongs to the field of veterinary drug technology, specifically relating to a 2,3-disubstituted naphthoquinone compound and its uses and preparation method. Background Technology

[0002] Ectoparasites are common parasitic diseases in livestock and pets, causing symptoms such as intense itching, hair loss, and eczematous dermatitis, leading to emaciation, weakness, anemia, and even death. Therefore, ectoparasites severely impact the production of meat, milk, and eggs, as well as the quality of fur and the working capacity of draft animals. This not only directly harms the healthy development and production efficiency of animal husbandry but also affects related industries such as leather processing, causing significant economic losses. Furthermore, some ectoparasites, such as ticks, are vectors for zoonotic infectious diseases (such as viruses, bacteria, fungi, and protozoa), directly endangering human health. Therefore, ectoparasitic diseases not only hinder the development of animal husbandry and cause huge economic losses but are also one of the most widespread and serious public health problems.

[0003] Currently, chemical drugs remain the dominant method for controlling ectoparasitic diseases in animals, mainly including organophosphates, organochlorines, macrolides, pyrethroids, and pyrethroids. These drugs are widely used due to their high efficacy, rapid action, and ease of use. However, long-term and irrational use has led to increasingly poor clinical efficacy, resulting in the "3R" problems of residues, drug resistance, and resurgence, posing potential threats to ecological environmental protection, public health, and food safety. Furthermore, in the past decade or so, there have been virtually no major breakthroughs or innovations in ectoparasitic disease control technologies and products. Therefore, the discovery of a novel, safe, and highly effective acaricide compound is of great significance for the control of ectoparasitic diseases in animals.

[0004] Naphthoquinones are widely found in nature and are the main active ingredients in many important traditional Chinese medicines. They possess a wide range of biological activities and have been extensively studied in areas such as antibacterial, antifungal, anticancer, antiparasitic, anti-inflammatory, and antiviral activity. For example, natural products such as scotin, scotin, juglone, and shikonin have all demonstrated good antiparasitic activity. Furthermore, antiparasitic drugs developed based on naphthoquinone structures are already widely used, such as the broad-spectrum antiparasitic drug atovaquinone, and bupavaquinone, which is currently the most effective drug for treating bovine babesiosis. In addition, naphthoquinones have also been researched and applied in the field of plant insecticides, such as the acaricide fennecone, which is widely used abroad for the control of pests in fruit trees and vegetables. However, how to introduce them into the field of live veterinary drugs, with safety and toxicity remaining technical challenges that have plagued those skilled in the art for many years. Therefore, the structure of naphthoquinones has significant research value in the development of new animal-specific antiparasitic veterinary drugs.

[0005] Currently, with the rapid development of my country's livestock industry and the steady increase in pet ownership, existing drugs for the prevention and treatment of animal ectoparasites (ticks, mites) are insufficient to meet the increasingly demanding requirements. Therefore, there is an urgent need to develop a new veterinary drug with better activity and higher safety for treating animal ectoparasites. Summary of the Invention

[0006] This invention aims to provide a novel 2,3-disubstituted naphthoquinone compound with a novel structure, good insecticidal effect, and safety, along with its preparation method and application. It can be used to prepare drugs for the prevention and control of ectoparasites (ticks, mites) in animals in the veterinary field to meet the growing demand.

[0007] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0008] A 2,3-disubstituted naphthoquinone compound,

[0009] The general formula of the compound is shown in Formula I.

[0010] Wherein, X is selected from C, NH, O, S; wherein, when X is selected from C, the X-R1 substituent represents an aryl substituent; wherein, the aryl substituent is 3-monosubstituted, 4-monosubstituted, 3,4-disubstituted, or 3,5-disubstituted; wherein, the substituent on the aryl group is one or two of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I.

[0011] When X is selected from NH, R1 is selected from hydrogen atom, C1-6 alkyl, C3-6 cycloalkyl, substituted aryl, substituted benzyl, substituted acyl;

[0012] When X is selected from O, R1 is selected from hydrogen atom, C1-6 alkyl, C3-6 cycloalkyl, substituted benzyl, substituted acyl;

[0013] When X is selected from S, R1 is selected from C1-6 alkyl, substituted aryl, or substituted benzyl;

[0014] The R2 is selected from C1-16 alkyl, substituted aryl, Ra-(CH2)n-, Ra-CO-(CH2)n-.

[0015] Furthermore, the C1-6 alkyl group mentioned in R1 is an alkyl substituent with 1-6 carbon atoms, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, and alkyl derivatives with different functional groups, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, and amino.

[0016] Wherein, the C3-6 cycloalkyl group mentioned in R1 is cyclopropane, cyclobutane, cyclopentane and cyclohexane, and derivatives with different functional groups substituted, wherein the functional group is selected from cyano, halogroup, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, amino and substituted aryl.

[0017] Wherein, the substituted aryl group in R1 is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0018] Wherein, the substituted benzyl group in R1 is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0019] Wherein, the substituted acyl group in R1 is a C1-6 alkyl-substituted acyl group, a C3-6 cycloalkyl-substituted acyl group, an aryl-substituted benzoyl group, a Ph-(CH2)n-substituted acyl group (n=1-4), or a tert-butyloxy-substituted acyl group; wherein, the C1-6 alkyl group is an alkyl substituent with 1-6 carbon atoms, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, and alkyl derivatives with different functional groups, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, and amino; wherein The cycloalkyl group is cyclopropane, cyclobutane, cyclopentane, and cyclohexane, and derivatives with different functional group substitutions, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, amino, and substituted aryl; wherein the aryl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I.

[0020] Wherein, the C1-16 alkyl group is an alkyl group having 1-16 carbon atoms, an alkyl group containing one or more double bonds, and an alkyl derivative with different functional groups substituted.

[0021] The aryl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; and the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I.

[0022] Wherein, Ra is a substituted aryl, 5-6 membered heterocyclic molecule; wherein, the heterocyclic molecule is a monocyclic or fused cyclic molecule containing one or two of the three heteroatoms: nitrogen, sulfur, and oxygen; wherein, the number n of CH2 is n = 1-10.

[0023] Furthermore, both substituents cannot be aryl at the same time.

[0024] Furthermore, the compound is one of the following compounds: Naph-01 to Naph-80:

[0025]

[0026] The present invention also discloses the use of the above-mentioned 2,3-disubstituted naphthoquinone compound, which is applied in the field of veterinary drugs for the prevention and treatment of ectoparasites in animals; the ectoparasites include arthropod parasites such as itch mites, scabies mites, demodicosis mites and ticks; the animals are one of the common livestock such as cattle, sheep, pigs, rabbits, cats and dogs.

[0027] This invention also discloses a method for preparing the above-mentioned 2,3-disubstituted naphthoquinone compound.

[0028] The preparation method includes the following steps:

[0029] When X is C, the general structural formula of 2,3-disubstituted naphthoquinone compounds is: Prepared via the following chemical reaction equation:

[0030]

[0031] The specific preparation steps for the above reaction equation are as follows:

[0032] S1, Arylization:

[0033] 1,4-Naphthoquinone and substituted phenol or substituted arylboronic acid are dissolved in a solvent in a certain proportion, and the reaction is carried out under the catalysis of metal catalyst and additives. After purification, 2-arylnaphthoquinone is obtained.

[0034] S2, Decarboxylation and Alkylation:

[0035] Under the catalysis of metal catalysts and additives, 2-arylnaphthoquinone and the corresponding carboxylic acid are dissolved in a solvent in a certain proportion for decarboxylation and alkylation. After the reaction is kept at a certain temperature and purified, the target compound is obtained.

[0036] Wherein, the aryl substituent R is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0037] The substituent Rb is a C1-16 alkyl group, Ra-(CH2)n-, or Ra-CO-(CH2)n-; wherein the C1-16 alkyl group is an alkyl group with 1-16 carbon atoms, an alkyl group containing one or more double bonds, or an alkyl derivative with different functional groups substituted.

[0038] In reaction step S1, the molar ratio of 1,4-naphthoquinone to substituted phenol or substituted arylboronic acid is 1:1.5-3.0.

[0039] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 1-10:1;

[0040] The ratio of 1,4-naphthoquinone to solvent or mixed solvent is 1 mol: 1.5-1.8 L;

[0041] The metal catalyst is one or two of FeCl3, FeNO2, FeSO4|, Pd(acac)2, Pd(OAc)2, Cu(BF4)2, Cu(OTf)2, and [Cp*RhCl2]2, and the molar ratio of its dosage to 1,4-naphthoquinone is 0.1-3.0:1.

[0042] The additive is at least one of DDQ, K2S2O8, (NH4)2S2O8, H2O2, TBHP, dppben, dppe, dppb, dppp, and dppethy, and the molar ratio of its dosage to that of 1,4-naphthoquinone is 0.1-5:1.

[0043] The heat preservation reaction temperature is 25-75℃, and the heat preservation reaction time is 10-24 hours;

[0044] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 64.0-1.0:1.

[0045] In reaction step S2, the molar ratio of 2-arylnaphthoquinone to the corresponding carboxylic acid is 1:3.0-5.0.

[0046] The metal catalyst is one of AgNO3, Ag2SO4, AgOAc, and AgOTf, and its molar ratio with 2-arylnaphthoquinone is 0.1-0.5:1.

[0047] The additive is at least one of DDQ, K2S2O8, (NH4)2S2O8, H2O2, and TBHP, and the molar ratio of its dosage to that of 2-arylnaphthoquinone is 1.2-2.5:1.

[0048] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0049] The ratio of 2-arylnaphthoquinone to solvent or mixed solvent is 1 mol: 1.0-1.3 L;

[0050] The heat preservation reaction temperature is 85-95℃, and the heat preservation reaction time is 5-24 hours;

[0051] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 64.0-1.0:1.

[0052] Furthermore, when X is NH, the general structural formula of 2,3-disubstituted naphthoquinone compounds is: Prepared via the following chemical reaction equation:

[0053]

[0054] The specific preparation steps for the above reaction equation are as follows:

[0055] A. Preparation of naphthoquinone derivatives, as shown in reaction equation a);

[0056] S1. Aminoation: 1,4-naphthoquinone or 2-arylnaphthoquinone and an amino derivative are dissolved in a solvent in a certain proportion, and the reaction is carried out under the catalysis of a catalyst. After purification, the naphthoquinone derivative is obtained.

[0057] S2, Boc protection: When Rd = H or BzO-, a 2-aminonaphthoquinone derivative with Re = H is obtained. After being dissolved with Boc2O in a certain proportion, the reaction is carried out under the action of a catalyst and kept at a constant temperature. After purification, the naphthoquinone derivative is obtained.

[0058] B. Preparation of 2-aminonaphthoquinone derivatives, as shown in reaction equation b);

[0059] S1. Decarboxylation and alkylation: Under the catalysis of metal catalysts and additives, amino-substituted naphthoquinone derivatives and corresponding carboxylic acids are dissolved in solvent in a certain proportion for decarboxylation and alkylation. The reaction is kept at a certain temperature and purified to obtain naphthoquinone derivatives.

[0060] S2, Deprotection: When Rf = Boc-, it reacts under the action of an acidic catalyst at a constant temperature, and after purification, a 2-aminonaphthoquinone derivative is obtained.

[0061] The preparation of C, 2,3-disubstituted naphthoquinone derivatives is shown in reaction equation c);

[0062] Acylation and alkylation: Under the catalysis of an alkaline catalyst, 2-amino-3-substituted naphthoquinone derivatives are acylated or alkylated with the corresponding acyl chlorides or haloalkanes in a certain proportion in a solvent. The reaction is carried out under heat and purified to obtain 2,3-disubstituted naphthoquinone derivatives.

[0063] Wherein, the substituent Rc is H or a substituted aryl group; the substituent Rd is H, a substituted aryl group, a substituted benzyl group, and BzO-; the substituent Re is H, a substituted aryl group, and a substituted benzyl group; the substituent Rf is Boc-, a substituted aryl group, and a substituted benzyl group; the substituent Rb is C1-16 alkyl, Ra-(CH2)n-, Ra-CO-(CH2)n-; the substituent Rg is C1-6 alkyl, C3-6 cycloalkyl, a substituted aryl group, Ph-(CH2)n- (n=1-4); and the substituent Rh is C1-6 alkyl and C3-6 cycloalkyl.

[0064] Wherein, the substituted aryl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0065] Wherein, the substituted benzyl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0066] Wherein, the C1-6 alkyl group is an alkyl substituent with 1-6 carbons, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, and alkyl derivatives substituted with different functional groups, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, and amino.

[0067] Wherein, the C3-6 cycloalkyl group is cyclopropane, cyclobutane, cyclopentane and cyclohexane, and derivatives with different functional groups substituted, wherein the functional group is selected from cyano, halogroup, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, amino and substituted aryl.

[0068] In reaction step S1.1, the molar ratio of 1,4-naphthoquinone or 2-arylnaphthoquinone to ammonia or amino derivative is 1:1.5-3.0.

[0069] The catalyst is one of BiCl3, Bi(OTf)3, BF3·OEt2, AcOH, AlCl3, Cu(OAc)2·H2O, CuI, t-BuOK, NaOH, K2CO3, Et3N, and iPr2EtN, and the molar ratio of its dosage to 1,4-naphthoquinone is 0.1-1.5:1.

[0070] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, EtOH, HFIP, EtOAc, CHCl3, DMF, DMAC, DMSO, toluene, H2O or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent: water = 2-10:1;

[0071] The ratio of 1,4-naphthoquinone or 2-arylnaphthoquinone to the solvent or mixed solvent is 1 mol: 0.85-1.0 L;

[0072] The heat preservation reaction temperature is 30-90℃, and the heat preservation reaction time is 10-24 hours;

[0073] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0074] In reaction step S1.2, the molar ratio of the 2-aminonaphthoquinone derivative to Boc2O is 1:1.5-3.0.

[0075] The catalyst is one of DMAP, Et3N, Pyridine, and iPr2EtN, and the molar ratio of its dosage to the 2-aminonaphthoquinone derivative is 0.1-1.5:1.

[0076] The solvent is one of CH3CN, DCM, THF, and CHCl3;

[0077] The heat preservation reaction temperature is 25-90℃, and the heat preservation reaction time is 5-12 hours;

[0078] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0079] In reaction step S2.1, the molar ratio of the amino-substituted naphthoquinone derivative to the corresponding carboxylic acid is 1:3.0-5.0.

[0080] The metal catalyst is one of AgNO3, Ag2SO4, AgOAc, and AgOTf, and the molar ratio of its amount to the amino-substituted naphthoquinone derivative is 0.1-0.5:1.

[0081] The additive is at least one of DDQ, K2S2O8, (NH4)2S2O8, H2O2, and TBHP, and the molar ratio of its dosage to that of the amino-substituted naphthoquinone derivative is 1.2-2.5:1.

[0082] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0083] The ratio of the amino-substituted naphthoquinone derivative to the solvent or mixed solvent is 1 mol: 1.0-1.3 L;

[0084] The heat preservation reaction temperature is 85-95℃, and the heat preservation reaction time is 5-24 hours;

[0085] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 64.0-1.0:1.

[0086] In reaction step S2.2, the acid catalyst is one of H2SO4, TFA, H3PO4, HCl, and acetic acid, and the molar ratio of its amount to the Boc-substituted aminonaphthoquinone derivative is 1.5-3.0:1.

[0087] The solvent is one of CH3CN, DCM, THF, CHCl3, H2O or a mixed solvent with water, and the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0088] The ratio of the Boc-substituted aminonaphthoquinone derivative to the solvent or mixed solvent is 1 mol: 1.5-1.8 L;

[0089] The heat preservation reaction temperature is 25-30℃, and the heat preservation reaction time is 1-6 hours;

[0090] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0091] In reaction step S3, the molar ratio of the 2-amino-3-substituted naphthoquinone derivative to the corresponding acyl chloride or haloalkane is 1:2.0-3.5.

[0092] The alkaline catalyst is one of Et3N, Pyridine, iPr2EtN, K2CO3, Na2CO3, NaHCO3, KHCO3, and KH2PO4, and the molar ratio of its amount to the 2-amino-3-substituted naphthoquinone derivative is 1.2-2.5:1.

[0093] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, DMF, DMAC, DMSO, and acetone.

[0094] The heat preservation reaction temperature is 30-120℃, and the heat preservation reaction time is 6-24 hours;

[0095] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0096] Furthermore, the preparation method includes the following steps:

[0097] When X is O, the general structural formula of 2,3-disubstituted naphthoquinone compounds is: Prepared via the following chemical reaction equation:

[0098]

[0099] The specific preparation steps for the above reaction equation are as follows:

[0100] A. The preparation of 2-hydroxynaphthoquinone is shown in reaction equation a);

[0101] S1, Acylation: 1,4-naphthoquinone and acetic anhydride are added in a certain proportion, a catalyst is added dropwise, the reaction is kept at a certain temperature, and the product is obtained by crystallization and filtration.

[0102] S2, hydrolysis and acidification: The acylate and the base are dissolved in a solvent in a certain proportion. After the reaction is kept at a certain temperature for a period of time, the solid generated is filtered and then added to hot water to dissolve. The mixture is filtered while hot, and after the filtrate is cooled, acid is added for acidification. The mixture is stirred under ice bath conditions, and the precipitated solid is filtered, washed with water until neutral, and dried to obtain 2-hydroxy-naphthoquinone.

[0103] B. Preparation of 2-hydroxy-3-substituted naphthoquinone derivatives, as shown in reaction equation b);

[0104] S1. Alkylation: 2-hydroxy-naphthoquinone, catalyst, additive and corresponding aldehyde are dissolved in solvent in a certain proportion, the reaction is kept at a certain temperature, water is added to quench after the reaction is completed, the organic phase is separated, concentrated and purified to obtain 2-hydroxy-3-substituted naphthoquinone derivative.

[0105] S2. When Ri = substituted aryl, the obtained 2-hydroxy-3-substituted benzyl naphthoquinone derivative is dissolved in a solvent. Under the action of oxidant and additive, the reaction is kept at a certain temperature and purified to obtain the 2-hydroxy-3-substituted aryl naphthoquinone derivative.

[0106] S3. Decarboxylation and alkylation: Under the catalysis of metal catalyst and additives, 2-hydroxy-naphthoquinone and the corresponding carboxylic acid are dissolved in a solvent in a certain proportion for decarboxylation and alkylation. The reaction is kept at a certain temperature and purified to obtain 2-hydroxy-3-substituted naphthoquinone derivatives.

[0107] The preparation of C, 2,3-disubstituted naphthoquinone derivatives is shown in reaction equation c);

[0108] Acylation and alkylation: Under the catalysis of an alkaline catalyst, 2-hydroxy-3-substituted naphthoquinone derivatives are acylated or alkylated with the corresponding acyl chlorides or haloalkanes in a certain proportion in a solvent. The reaction is carried out under heat and purified to obtain 2,3-disubstituted naphthoquinone derivatives.

[0109] Wherein, the substituent Ri is a substituted aryl, a substituted benzyl, or a C1-16 alkyl; the substituent Rb is a C1-16 alkyl, Ra-(CH2)n-, or Ra-CO-(CH2)n-; the substituent Rg is a C1-6 alkyl, C3-6 cycloalkyl, a substituted aryl, or Ph-(CH2)n- (n = 1-4); and the substituent Rh is a C1-6 alkyl or a C3-6 cycloalkyl.

[0110] Wherein, the substituted aryl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0111] Wherein, the substituted benzyl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0112] Wherein, the C1-16 alkyl group is an alkyl group having 1-16 carbon atoms, an alkyl group containing one or more double bonds, and an alkyl derivative with different functional groups substituted.

[0113] Wherein, the C1-6 alkyl group is an alkyl substituent with 1-6 carbons, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, and alkyl derivatives substituted with different functional groups, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, and amino.

[0114] Wherein, the C3-6 cycloalkyl group is cyclopropane, cyclobutane, cyclopentane and cyclohexane, and derivatives with different functional groups substituted, wherein the functional group is selected from cyano, halogroup, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, amino and substituted aryl.

[0115] In step A, the molar ratio of 1,4-naphthoquinone to acetic anhydride in reaction step S1 is 1:6.0-10.0.

[0116] The catalyst is at least one selected from protic acid sulfuric acid, trifluoroacetic acid, acetic acid, formic acid, perchloric acid, phosphoric acid, and nitric acid, and the molar ratio of its dosage to that of 1,4-naphthoquinone is 0.3-1.0:1.

[0117] The dripping temperature is 10-40℃, and the dripping method is to add the product drop by drop.

[0118] The heat preservation reaction temperature is 0-15℃, and the heat preservation reaction time is 1-2.5 hours;

[0119] The crystallization method involves adding 1-2 times the volume of cold water to the reaction system, cooling to allow crystals to precipitate, and then filtering to obtain the acylated derivative.

[0120] In step A, the molar ratio of the acylated derivative to the base in reaction step S2 is 1:1.2-3.0;

[0121] The alkali is at least one selected from potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, sodium methoxide, and sodium ethoxide.

[0122] The solvent is one of dioxane, THF, MeOH, EtOH, nBuOH, iPrOH, HFIP, DMF, and DMSO;

[0123] The heat preservation reaction temperature is 0-5℃, and the heat preservation reaction time is 0.5-4.5 hours;

[0124] The hot water temperature is 90-100℃, and the acid used for acidification is at least one of concentrated hydrochloric acid, acetic acid, formic acid, perchloric acid, and phosphoric acid, with an acidification degree of pH 1-2.

[0125] The purification method is as follows: filtration, followed by washing with water at a volume of 5-10 times that of the solvent, and vacuum drying at 65-75°C for 8-12 hours to obtain 2-hydroxy-naphthoquinone.

[0126] In step B, the molar ratio of 2-hydroxy-naphthoquinone to the corresponding aldehyde in reaction step S1 is 1:1.2-2.0;

[0127] The catalyst is at least one selected from L-alanine, L-lysine, L-leucine, L-phenylalanine, L-tryptophan, L-tyrosine, L-proline, L-arginine, L-histidine, and L-leucine, and the molar ratio of its amount to 2-hydroxynaphthoquinone is 0.2-0.5:1.

[0128] The additive is at least one of 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate dimethyl ester, 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate diethyl ester, and 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate didodecyl ester, and the molar ratio of its dosage to 2-hydroxy-naphthoquinone is 1-1.05:1.

[0129] The solvent is one of CH3CN, dioxane, THF, MeOH, EtOH, iPrOH, DCM, and CHCl3;

[0130] The heat preservation reaction temperature is 25-35℃, and the heat preservation reaction time is 6-8 hours;

[0131] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0132] In step B, the molar ratio of the 2-hydroxy-3-substituted benzylnaphthoquinone derivative to the oxidant in reaction step S2 is 1:1.5-2.5;

[0133] The oxidant is at least one selected from DDQ, K2S2O8, (NH4)2S2O8, H2O2, TBHP, and KMnO4;

[0134] The additive is at least one of NaOH, KOH, LiOH, CsOH, tBuOK, and tBuONa, and the molar ratio of its dosage to the 2-hydroxy-3-substituted benzylnaphthoquinone derivative is 8.0-16.0:1.

[0135] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent: water = 2-5:1;

[0136] The ratio of the 2-hydroxy-3-substituted benzylnaphthoquinone derivative to the solvent or mixed solvent is 1 mol: 1.0-1.2 L;

[0137] The heat preservation reaction temperature is 25-30℃, and the heat preservation reaction time is 10-24 hours;

[0138] The purification method is filtration, acidification of the filtrate with 10-20% HCl aqueous solution, extraction with ethyl acetate, drying with anhydrous sodium sulfate, concentration, column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0139] In step B, the molar ratio of 2-hydroxy-naphthoquinone to the corresponding carboxylic acid in reaction step S3 is 1:3.0-5.0.

[0140] The metal catalyst is one of AgNO3, Ag2SO4, AgOAc, and AgOTf, and the molar ratio of its dosage to 2-hydroxy-naphthoquinone is 0.1-0.5:1.

[0141] The additive is at least one of DDQ, K2S2O8, (NH4)2S2O8, H2O2, and TBHP, and the molar ratio of its dosage to that of 2-hydroxy-naphthoquinone is 1.2-2.5:1.

[0142] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0143] The ratio of 2-hydroxy-naphthoquinone to solvent or mixed solvent is 1 mol: 1.0-1.3 L;

[0144] The heat preservation reaction temperature is 85-95℃, and the heat preservation reaction time is 5-24 hours;

[0145] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 64.0-1.0:1.

[0146] In C, the molar ratio of the 2-hydroxy-3-substituted naphthoquinone derivative to the corresponding acyl chloride or haloalkane is 1:2.0-3.5;

[0147] The alkaline catalyst is one of Et3N, Pyridine, iPr2EtN, K2CO3, Na2CO3, NaHCO3, KHCO3, and KH2PO4, and the molar ratio of its amount to the 2-hydroxy-3-substituted naphthoquinone derivative is 1.2-2.5:1.

[0148] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, DMF, DMAC, DMSO, and acetone.

[0149] The heat preservation reaction temperature is 30-120℃, and the heat preservation reaction time is 6-24 hours;

[0150] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0151] Furthermore, the preparation method includes the following steps:

[0152] When X is S, the general structural formula of 2,3-disubstituted naphthoquinone compounds is: Prepared via the following chemical reaction equation:

[0153]

[0154] The specific preparation steps for the above reaction equation are as follows:

[0155] S1, sulfidation:

[0156] 1,4-naphthoquinone, a catalyst, and the corresponding arylthiophenol or thiol are dissolved in a solvent in a certain proportion, and the reaction is carried out under heat. After purification, a 2-substituted thioether naphthoquinone derivative is obtained.

[0157] S2, Arylization:

[0158] The 2-substituted thioether naphthoquinone derivative, the catalyst, and the corresponding arylhydrazine were dissolved in a solvent in a certain proportion, and the reaction was carried out under heat. After purification, the 2-substituted thioether-3-arylnaphthoquinone derivative was obtained.

[0159] S3, Decarboxylation and Alkylation:

[0160] Under the catalysis of metal catalysts and additives, 2-substituted thioether naphthoquinone derivatives and corresponding carboxylic acids are dissolved in solvent in a certain proportion for decarboxylation and alkylation. After the reaction is kept at a certain temperature and purified, 2-substituted thioether-3-substituted naphthoquinone derivatives are obtained.

[0161] Wherein, the substituent Rj is a C1-6 alkyl, a substituted aryl, or a substituted benzyl; the substituent Rb is a C1-16 alkyl, Ra-(CH2)n-, or Ra-CO-(CH2)n-.

[0162] Wherein, the C1-6 alkyl group is an alkyl substituent with 1-6 carbons, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, isohexyl, and alkyl derivatives substituted with different functional groups, wherein the functional group is selected from cyano, haloyl, alkenyl, alkynyl, trifluoromethyl, hydroxyl, carboxyl, and amino.

[0163] Wherein, the substituted aryl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0164] Wherein, the substituted benzyl group is 2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,4-disubstituted, 3,4-disubstituted, 3,5-disubstituted, 2,6-disubstituted, or 2,4,6-trisubstituted; wherein, the substituent on the aryl group is one or more of hydroxyl, methyl, methoxy, cyano, nitro, trifluoromethyl, halogen F, Cl, Br, and I;

[0165] Wherein, the C1-16 alkyl group is an alkyl group having 1-16 carbon atoms, an alkyl group containing one or more double bonds, and an alkyl derivative with different functional groups substituted.

[0166] In reaction step S1, the molar ratio of 1,4-naphthoquinone to the corresponding arylthiophenol or thiol is 1:1.2-2.5.

[0167] The catalyst is at most one of BiCl3, Bi(OTf)3, BF3·OEt2, AcOH, and AlCl3, and the molar ratio of its amount to 1,4-naphthoquinone is 0.05-0.3:1.

[0168] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, EtOH, iPrOH, nBuOH, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0169] The ratio of 1,4-naphthoquinone to solvent or mixed solvent is 1 mol: 0.85-1.0 L;

[0170] The heat preservation reaction temperature is 25-35℃, and the heat preservation reaction time is 10-24 hours;

[0171] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0172] In reaction step S2, the molar ratio of the 2-substituted thioether naphthoquinone derivative to the corresponding arylhydrazine is 1:2.0-3.5.

[0173] The catalyst is one of PIDA, PIFA, TBAI, I2, and pyridine, and the molar ratio of its dosage to the 2-substituted thioether naphthoquinone derivative is 0.05-0.5:1.

[0174] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, iPrOH, TFE, HFIP, and H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-5:1;

[0175] The ratio of the 2-substituted thioether naphthoquinone derivative to the solvent or mixed solvent is 1 mol: 1.5-1.8 L;

[0176] The heat preservation reaction temperature is 25-70℃, and the heat preservation reaction time is 15-36 hours;

[0177] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 16.0-1.0:1.

[0178] In reaction step S3, the molar ratio of the 2-substituted thioether naphthoquinone derivative to the corresponding carboxylic acid is 1:3.0-5.0.

[0179] The metal catalyst is one of AgNO3, Ag2SO4, AgOAc, and AgOTf, and the molar ratio of its dosage to the 2-substituted thioether naphthoquinone derivative is 0.1-0.5:1.

[0180] The additive is at least one of DDQ, K2S2O8, (NH4)2S2O8, H2O2, and TBHP, and the molar ratio of its dosage to the 2-substituted thioether naphthoquinone derivative is 1.2-2.5:1.

[0181] The solvent is one of CH3CN, DCM, dioxane, THF, MeOH, toluene, H2O, or a mixed solvent with water, wherein the ratio of the mixed solvent is organic solvent:water = 2-10:1;

[0182] The ratio of the 2-substituted thioether naphthoquinone derivative to the solvent or mixed solvent is 1 mol: 1.0-1.3 L;

[0183] The heat preservation reaction temperature is 85-95℃, and the heat preservation reaction time is 5-24 hours;

[0184] The purification method is column chromatography, and the eluent system is petroleum ether:ethyl acetate, with a volume ratio of 64.0-1.0:1.

[0185] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0186] This invention provides a 2,3-disubstituted naphthoquinone compound, its uses, and a preparation method. This series of compounds has a novel structure and good to excellent in vitro parasitic activity. It is particularly worth mentioning that this series of compounds has been introduced into the field of live veterinary drugs, overcoming a technical problem that has long plagued those skilled in the art—namely, the safety and toxicity of the compounds. Moreover, the synthesis process of this series of compounds is simple, the reaction conditions are mild, and a variety of 2,3-disubstituted naphthoquinone compounds can be prepared efficiently. Attached Figure Description

[0187] Figure 1 1H NMR spectrum of tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl)carbamate

[0188] Figure 2 1H NMR spectrum of Naph-13

[0189] Figure 3 1H NMR spectrum of Naph-14

[0190] Figure 4 1H NMR spectrum of Naph-16

[0191] Figure 5 1H NMR spectrum of Naph-17

[0192] Figure 6 1H NMR spectrum of Naph-19

[0193] Figure 7 1H NMR spectrum of Naph-20

[0194] Figure 8 1H NMR spectrum of Naph-21

[0195] Figure 9 1H NMR spectrum of Naph-44

[0196] Figure 10 1H NMR spectrum of Naph-45

[0197] Figure 11 1H NMR spectrum of Naph-46

[0198] Figure 12 1H NMR spectrum of Naph-48

[0199] Figure 13 1H NMR spectrum of Naph-51

[0200] Figure 14 1H NMR spectrum of Naph-52

[0201] Figure 15 1H NMR spectrum of Naph-58

[0202] Figure 16 1H NMR spectrum of Naph-59

[0203] Figure 17 1H NMR spectrum of Naph-60

[0204] Figure 18 1H NMR spectrum of Naph-62

[0205] Figure 19 1H NMR spectrum of Naph-63

[0206] Figure 20 1H NMR spectrum of Naph-70

[0207] Figure 21 1H NMR spectrum of Naph-71

[0208] Figure 22 1H NMR spectrum of Naph-73

[0209] Figure 23 1H NMR spectrum of Naph-74

[0210] Figure 24 1H NMR spectrum of Naph-75 Detailed Implementation

[0211] The following examples are intended to help those skilled in the art better understand the invention, but do not limit the invention in any way. All raw materials used in this invention are known compounds, commercially available, or prepared using methods known in the art.

[0212] Example 1: Preparation of compound Naph-01

[0213] Step 1: Preparation of 2-Phenynaphthoquinone

[0214] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh out potassium persulfate (100 mmol, 27.03 g) and ferric nitrate (2.5 mmol, 604.6 mg) and add them to the flask. Then add 1,4-naphthoquinone (25 mmol, 3.95 g) and phenylboronic acid (50 mmol, 6.09 g), dissolve them in 200 mL of a toluene:water (1:1) mixture, and gradually raise the temperature from room temperature to 70 °C. Maintain the temperature for 20 hours.

[0215] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 10:1). After evaporating the solvent, 4.45 g of a yellow solid was obtained, with a yield of 76%.

[0216] 1H NMR (400MHz, CDCl3) δ8.17-8.15(m,1H),8.13-8.11(m,1H),7.80-7.77(m,2H),7.59-7.55(m,2H),7.48-7.47(m.3H),7.06(s,1H).

[0217] Step 2: Preparation of Naph-01

[0218] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh 2-phenylnaphthoquinone (9 mmol, 2.10 g) and add it to the flask. Dissolve it in 100 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.35 mmol, 420.9 mg) and acetic acid (36 mmol, 2.16 g). Stir at room temperature for ten minutes. Then dissolve ammonium persulfate (22.5 mmol, 5.13 g) in 60 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat the system to 90 °C and keep it at that temperature for 18 hours.

[0219] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 10:1). After evaporating the solvent, 1.07 g of yellow solid was obtained, with a yield of 48%.

[0220] 1H NMR (400MHz, CDCl3) δ 8.16-8.10 (m, 2H), 7.75-7.70 (m, 2H), 7.50-7.39 (m, 3H), 7.23 (d, J = 8.3Hz, 2H), 2.08 (s, 3H).

[0221] Example 2: Preparation of compound Naph-02

[0222] Step 1: Preparation of 2-(4-hydroxyphenyl)naphthoquinone

[0223] In a 250 mL round-bottom flask, after adding a magnetic flask, weigh 1,4-naphthoquinone (25 mmol, 3.95 g) and phenol (50 mmol, 4.71 g) and add them to the flask. Dissolve them in 160 mL of dichloromethane, then add potassium persulfate (75 mmol, 20.27 g). Subsequently, add ferric chloride (62.5 mmol, 10.14 g) in five portions to the reaction system one by one, and react at room temperature for 18 hours.

[0224] After the TLC reaction was completed, the reaction was quenched with water, the organic phase was separated, the aqueous phase was extracted with dichloromethane, the combined organic phases were washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 9:1), and 4.56 g of yellow solid was obtained after evaporation of the solvent, with a yield of 73%.

[0225] 1H NMR (400MHz, CDCl3) δ9.00(brs,1H),8.13–8.11(m,1H),8.06–8.04(m,1H),7.73–7.70(m,2H),7.46(d,J=8.0,2H),6.98(s,1H),6.90(d,J=8.0,2H).

[0226] Step 2: Preparation of Naph-O2

[0227] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh 2-(4-hydroxyphenyl)naphthoquinone (9 mmol, 2.25 g) and add it to the flask. Dissolve it in 100 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver nitrate (1.8 mmol, 305.8 mg) and acetic acid (36 mmol, 2.16 g). Stir at room temperature for ten minutes. Then dissolve ammonium persulfate (22.5 mmol, 5.13 g) in 60 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat the system to 90 °C and keep it at that temperature for 18 hours.

[0228] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 9:1). After evaporating the solvent, 1.02 g of yellow solid was obtained, with a yield of 43%.

[0229] 1H NMR (400MHz, CDCl3) δ9.05 (brs, 1H), 8.15–8.03 (m, 2H), 7.76–7.71 (m, 2H), 7.48 (d, J = 8.0, 2H), 6.88 (d, J = 8.0, 2H), 2.10 (s, 3H).

[0230] Example 3: Preparation of compound Naph-03

[0231] Step 1: Preparation of 2-Phenynaphthoquinone

[0232] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh out ammonium persulfate (100 mmol, 22.82 g) and ferric sulfate (2.5 mmol, 429.8 mg) and add them to the flask. Then add 1,4-naphthoquinone (25 mmol, 3.95 g) and phenylboronic acid (50 mmol, 6.09 g), dissolve them in 200 mL of toluene:water (1:1) mixed solvent, and gradually raise the temperature from room temperature to 75 °C and keep the reaction at this temperature for 22 hours.

[0233] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 10:1). After evaporating the solvent, 4.15 g of a yellow solid was obtained, with a yield of 71%.

[0234] 1H NMR (400MHz, CDCl3) δ8.17-8.15(m,1H),8.13-8.11(m,1H),7.80-7.77(m,2H),7.59-7.55(m,2H),7.48-7.47(m.3H),7.06(s,1H).

[0235] Step 2: Preparation of Naph-O3

[0236] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh 2-phenylnaphthoquinone (9 mmol, 2.10 g) and add it to the flask. Dissolve it in 100 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver nitrate (1.35 mmol, 229.3 mg) and heptanoic acid (36 mmol, 4.69 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (22.5 mmol, 6.08 g) in 60 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat to 95 °C and keep the reaction at that temperature for 22 hours.

[0237] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 10:1). After evaporating the solvent, 1.12 g of a yellow oily liquid was obtained, with a yield of 39%.

[0238] 1H NMR (400MHz, CDCl3) δ8.23-8.04(m,2H),7.86-7.68(m,2H),7.61-7.37(m,3H),7.35 -7.18(m,2H),2.59-2.37(m,2H),1.59-1.38(m,2H),1.37-1.08(m,6H),0.84(s,3H).

[0239] Example 4: Preparation of compound Naph-13

[0240] Step 1: Preparation of 2-aminonaphthoquinone

[0241] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh benzyloxyamine hydrochloride (37.5 mmol, 5.99 g) and add it to the round-bottom flask. Add 60 mL of anhydrous ethanol and Et3N (25 mmol, 2.53 g) to dissolve the compound. Place the round-bottom flask in an ice bath and stir for ten minutes. Then, dissolve 1,4-naphthoquinone (25 mmol, 3.95 g) in 50 mL of anhydrous ethanol and add it dropwise to the round-bottom flask in the ice bath. After the addition is complete, raise the temperature to room temperature and keep the reaction at this temperature for 10 hours.

[0242] After the TLC reaction was completed, the mixture was cooled to room temperature, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 2:1). After evaporating the solvent, 3.81 g of red solid was obtained, with a yield of 88%.

[0243] 1H NMR (400MHz, CDCl3) δ8.05 (d, J = 11.5, 2H), 7.71 (d, J = 7.6, 1H), 7.62 (d, J = 7.6, 1H), 6.00 (s, 1H), 5.31 (brs, 2H).

[0244] Step 2: Preparation of tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl)carbamate

[0245] In a 100 mL round-bottom flask, after adding a magnetic stir bar, weigh out 2-aminonaphthoquinone (9 mmol, 1.56 g), ditert-butyl dicarbonate (13.5 mmol, 2.95 g), and DMAP (0.9 mmol, 110.0 mg). Add 50 mL of THF to dissolve the ingredients, then heat to 75 °C and reflux for 8 hours.

[0246] After the TLC reaction was completed, the mixture was cooled to room temperature, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 10:1). After evaporating the solvent, 1.67 g of a yellow solid was obtained, with a yield of 68%.

[0247] ¹H NMR (400 MHz, CDCl₃) δ 8.17–8.05 (m, 2H), 7.80–7.67 (m, 3H), 7.48 (s, 1H), 1.54 (s, 9H). [The ¹H NMR spectrum of tert-butyl(1,4-dioxo-1,4-dihydronaphth-2-yl)carbamate is attached to the instruction manual.] Figure 1 】

[0248] Step 3: Preparation of Naph-13

[0249] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl) carbamate (5 mmol, 1.36 g) and add it to the flask. Dissolve it in 80 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.0 mmol, 311.8 mg) and nonanoic acid (15 mmol, 2.37 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (7.5 mmol, 2.03 g) in 40 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat to 95 °C and maintain the temperature for 20 hours.

[0250] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 16:1). After evaporating the solvent, 0.79 g of a yellow solid was obtained, with a yield of 41%.

[0251] ¹H NMR (400MHz, CDCl₃) δ 8.10–8.05 (m, 2H), 7.73–7.66 (m, 2H), 7.06 (brs, 1H), 2.78–2.60 (m, 2H), 1.51 (s, 9H), 1.44–1.07 (m, 14H), 0.86 (t, J = 6.8Hz, 3H). [See the attached manual for the ¹H NMR spectrum of Naph-13.] Figure 2 】

[0252] Example 5: Preparation of compound Naph-14

[0253] Steps: Preparation of Naph-14

[0254] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl) carbamate (5 mmol, 1.36 g) and add it to the flask. Dissolve it in 80 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.0 mmol, 311.8 mg) and dodecanoic acid (15 mmol, 3.00 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (7.5 mmol, 2.03 g) in 40 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat the system to 95 °C and maintain the temperature for 20 hours.

[0255] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 16:1). After evaporating the solvent, 0.75 g of a yellow solid was obtained, with a yield of 33%.

[0256] ¹H NMR (400MHz, CDCl₃) δ 8.10 (dt, J = 7.7, 1.0 Hz, 2H), 7.79–7.67 (m, 3H), 2.34 (t, J = 7.6 Hz, 2H), 1.71–1.61 (m, 2H), 1.54 (s, 9H), 1.49–1.10 (m, 16H), 0.88 (t, J = 6.8 Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-14.] Figure 3 】

[0257] Example 6: Preparation of compound Naph-16

[0258] Steps: Preparation of Naph-16

[0259] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl) carbamate (5 mmol, 1.36 g) and add it to the flask. Dissolve it in 80 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.0 mmol, 311.8 mg) and phenylbutyric acid (15 mmol, 2.46 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (7.5 mmol, 2.03 g) in 40 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat the mixture to 95 °C and maintain the temperature for 20 hours.

[0260] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 16:1). After evaporating the solvent, 0.99 g of a yellow solid was obtained, with a yield of 51%.

[0261] ¹H NMR (400MHz, CDCl₃) δ 8.09–8.04 (m, 2H), 7.73–7.66 (m, 2H), 7.27–7.10 (m, 5H), 7.08 (brs, 1H), 2.85–2.60 (m, 4H), 1.98–1.83 (m, 2H), 1.50 (s, 9H). [See the instruction manual for the ¹H NMR spectrum of Naph-16.] Figure 4 】

[0262] Example 7: Preparation of compound Naph-17

[0263] Step 1: Preparation of Naph-17

[0264] In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl)carbamate (5 mmol, 1.36 g) and add it to the flask. Dissolve it in 80 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.0 mmol, 311.8 mg) and 3-benzoylpropionic acid (15 mmol, 2.67 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (7.5 mmol, 2.03 g) in 40 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat the mixture to 95 °C and maintain the temperature for 20 hours.

[0265] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 16:1). After evaporating the solvent, 0.43 g of a yellow solid was obtained, with a yield of 21%.

[0266] ¹H NMR (400MHz, CDCl₃) δ 8.11–8.05 (m, 2H), 8.01–7.94 (m, 2H), 7.75–7.66 (m, 3H), 7.57–7.53 (m, 1H), 7.44 (dd, J = 8.3, 7.0Hz, 2H), 3.50 (t, J = 6.9Hz, 2H), 3.00 (t, J = 6.9Hz, 2H), 1.50 (s, 9H). [See the instruction manual for the ¹H NMR spectrum of Naph-17.] Figure 5 】

[0267] Example 8: Preparation of compound Naph-19

[0268] Steps: Preparation of Naph-19

[0269] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-13 (1 mmol, 399 mg) and add it to the flask. Add 10 mL of DCM to dissolve it, and then add TFA (3 mmol, 229.7 mg). Keep the reaction at room temperature.

[0270] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, and the organic phase was washed with saturated sodium bicarbonate and saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 4:1). After evaporating the solvent, 0.25 g of orange-red solid was obtained, with a yield of 84%.

[0271] ¹H NMR (400MHz, CDCl₃) δ 8.08 (d, J = 7.6Hz, ¹H), 8.02 (d, J = 7.6Hz, ¹H), 7.68 (t, J = 7.5Hz, ¹H), 7.59 (t, J = 7.5Hz, ¹H), 5.00 (brs, 2H), 2.52–2.43 (m, 2H), 1.50 (dd, J = 10.9, 5.1Hz, 2H), 1.38–1.24 (m, ¹²H), 0.87 (t, J = 6.8Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-19.] Figure 6 】

[0272] Example 9: Preparation of compound Naph-20

[0273] Step 1: In a 250 mL round-bottom flask, after adding a magnetic stir bar, weigh tert-butyl (1,4-dioxo-1,4-dihydronaphth-2-yl) carbamate (5 mmol, 1.36 g) and add it to the round-bottom flask. Dissolve it in 80 mL of a mixed solvent of acetonitrile:water (3:1). Then add silver sulfate (1.0 mmol, 311.8 mg) and tridecanoic acid (15 mmol, 3.21 g). Stir at room temperature for 10 minutes. Dissolve potassium persulfate (7.5 mmol, 2.03 g) in 40 mL of a mixed solvent of acetonitrile:water (3:1) and add it dropwise to the reaction system. Heat to 95 °C and maintain the temperature for 20 hours.

[0274] After the TLC reaction was completed, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was washed with saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 16:1). After evaporating the solvent, 0.73 g of a yellow solid was obtained, with a yield of 33%.

[0275] Step 2: Preparation of Naph-20

[0276] In a 50 mL round-bottom flask, after adding a magnetic ball, weigh the product obtained in step 1 (1 mmol, 441 mg) and add it to the round-bottom flask. Add 10 mL of DCM to dissolve it, and then add TFA (3 mmol, 229.7 mg). Keep the reaction at room temperature.

[0277] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, and the organic phase was washed with saturated sodium bicarbonate and saturated brine, dried, concentrated, and purified by column chromatography (petroleum ether: ethyl acetate = 4:1). After evaporating the solvent, 0.27 g of orange-red solid was obtained, with a yield of 79%.

[0278] ¹H NMR (400MHz, CDCl₃) δ 8.08 (d, J = 7.6Hz, ¹H), 8.02 (d, J = 7.6Hz, ¹H), 7.71–7.64 (m, ¹H), 7.61–7.58 (m, ¹H), 5.00 (brs, 2H), 2.57–2.39 (m, 2H), 1.52–1.23 (m, 20H), 0.87 (t, J = 5.6Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-20.] Figure 7 】

[0279] Example 10: Preparation of compound Naph-21

[0280] Steps: Preparation of Naph-21

[0281] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-20 (1 mmol, 341 mg) and K2CO3 (2 mmol, 276.4 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add iodomethane (2 mmol, 283.88 mg) to the reaction flask. Heat the flask to 60 °C and maintain the temperature for the reaction.

[0282] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to give 0.245 g of orange-red solid, with a yield of 69%.

[0283] ¹H NMR (400MHz, CDCl₃) δ 8.07 (d, J = 7.7Hz, ¹H), 7.98 (d, J = 7.6Hz, ¹H), 7.67 (t, J = 7.5Hz, ¹H), 7.56 (t, J = 7.5Hz, ¹H), 5.91 (brs, ¹H), 3.22 (d, J = 5.5Hz, 3H), 2.78–2.68 (m, 2H), 1.53–1.25 (m, 20H), 0.87 (d, J = 7.0Hz, 3H). [The ¹H NMR spectrum of Naph-21 is attached to the instruction manual.] Figure 8 】

[0284] Example 11: Preparation of compound Naph-44

[0285] Step 1: Preparation of 2-hydroxynaphthoquinone

[0286] Acylation: In a 100 mL round-bottom flask, after adding a magnetic flask, weigh naphthoquinone (20 mmol, 3.16 g) and add it to the round-bottom flask. Dissolve it in 15 mL of acetic anhydride. Place the round-bottom flask in an ice bath and stir for 10 minutes. Then, add sulfuric acid (7.5 mmol, 735.6 mg) dropwise to the round-bottom flask and keep the reaction in an ice bath for 2 hours.

[0287] After the TLC reaction was completed, 30 mL of cold water was added to quench the reaction, and the mixture was cooled to allow crystals to precipitate. The crystals were then filtered, washed with petroleum ether, and dried to obtain 5.43 g of a brown solid acylate, with a yield of 90%.

[0288] Hydrolysis and acidification: In a 100 mL round-bottom flask, after adding a magnetic flask, weigh out sodium methoxide (30 mmol, 1.62 g) and add it to the round-bottom flask. Add 50 mL of anhydrous methanol to dissolve the sodium methoxide and stir in an ice bath for 10 minutes. Then, add the acylated compound (15 mmol, 4.53 g) dropwise to the round-bottom flask and keep the mixture in an ice bath for 4 hours.

[0289] The resulting solid was filtered, washed with methanol, dissolved in hot water at 90°C, filtered while hot, acidified with concentrated hydrochloric acid to pH 1, cooled, and crystallized under ice bath conditions. The crystals were then filtered, washed with water until neutral, and dried under vacuum at 70°C for 8 hours to obtain 2.14 g of yellow solid 2-hydroxy-naphthoquinone, with a yield of 82%.

[0290] 1H NMR (400MHz, DMSO-d6) δ11.69(s,1H,OH),8.02–7.97(m,1H),7.96–7.92(m,1H),7.89–7.75(m,2H),6.17(s,1H).

[0291] Step 2: Preparation of Naph-44

[0292] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add n-butyraldehyde (10 mmol, 721.1 mg) to the round-bottom flask. Keep the mixture at room temperature for 6 hours.

[0293] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to give 0.876 g of yellow solid, yield 76%.

[0294] ¹H NMR (400MHz, CDCl₃) δ 8.11 (dt, J = 7.6, 2.0Hz, 1H), 8.06 (dt, J = 7.6, 2.0Hz, 1H), 7.76–7.71 (m, 1H), 7.68–7.65 (m, 1H), 7.33 (brs, 1H), 2.62–2.57 (m, 2H), 1.51 (qd, J = 8.0, 6.9, 4.1Hz, 2H), 1.40 (qd, J = 7.4, 2.7Hz, 2H), 0.93 (t, J = 7.3Hz, 3H). [The ¹H NMR spectrum of Naph-44 is attached in the instruction manual.] Figure 9 】

[0295] Example 12: Preparation of compound Naph-45

[0296] Steps: Preparation of Naph-45

[0297] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add hexanal (10 mmol, 1.0 g) to the round-bottom flask. Keep the mixture at room temperature for 6 hours.

[0298] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to obtain 0.94 g of yellow solid, yield 73%.

[0299] ¹H NMR (400MHz, CDCl₃) δ 8.11 (dd, J = 7.6, 1.3Hz, 1H), 8.06 (dd, J = 7.5, 1.4Hz, 1H), 7.74 (td, J = 7.6, 1.4Hz, 1H), 7.67 (td, J = 7.5, 1.3Hz, 1H), 7.32 (brs, 1H), 2.62–2.56 (m, 2H), 1.52 (td, J = 7.5, 7.0, 2.4Hz, 2H), 1.39–1.28 (m, 6H), 0.89–0.84 (m, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-45.] Figure 10 】

[0300] Example 13: Preparation of compound Naph-46

[0301] Steps: Preparation of Naph-46

[0302] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add n-octanal (10 mmol, 1.28 g) to the round-bottom flask. Keep the mixture at room temperature for 6 hours.

[0303] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to obtain 1.02 g of yellow solid, yield 71%.

[0304] ¹H NMR (400MHz, CDCl₃) δ 8.11 (d, J = 7.6Hz, ¹H), 8.07 (d, J = 7.6Hz, ¹H), 7.74 (t, J = 7.5Hz, ¹H), 7.67 (t, J = 7.5Hz, ¹H), 7.32 (s, ¹H), 2.59 (t, J = 7.8Hz, 2H), 1.53 (t, J = 7.7Hz, 2H), 1.38–1.25 (m, ¹⁰H), 0.86 (t, J = 6.7Hz, ³H). [See the instruction manual for the ¹H NMR spectrum of Naph-46.] Figure 11 】

[0305] Example 14: Preparation of compound Naph-48

[0306] Steps: Preparation of Naph-48

[0307] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add dodecyl aldehyde (10 mmol, 1.84 g) to the round-bottom flask. Keep the mixture at room temperature for 7 hours.

[0308] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to obtain 1.45 g of yellow solid, yield 85%.

[0309] ¹H NMR (400MHz, CDCl₃) δ 8.11 (dd, J = 7.8, 1.2Hz, 1H), 8.07 (dd, J = 7.6, 1.3Hz, 1H), 7.74 (td, J = 7.5, 1.4Hz, 1H), 7.67 (td, J = 7.5, 1.4Hz, 1H), 7.31 (s, 1H), 2.61–2.57 (m, 2H), 1.53 (t, J = 7.9Hz, 2H), 1.37–1.24 (m, 18H), 0.87 (t, J = 6.9Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-48.] Figure 12 】

[0310] Example 15: Preparation of compound Naph-51

[0311] Steps: Preparation of Naph-51

[0312] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add citronellol (10 mmol, 1.54 g) to the round-bottom flask. Keep the mixture at room temperature for 8 hours.

[0313] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to obtain 0.936 g of yellow solid, yield 60%.

[0314] 1H NMR (400MHz, CDCl3) δ8.11 (dd, J=7.7, 1.3Hz, 1H), 8.07 (dd, J=7.6, 1.4Hz, 1H), 7. 74(td,J=7.6,1.4Hz,1H),7.67(td,J=7.5,1.4Hz,1H),7.31(brs,1H),5.12–5.08( m,1H),2.65–2.54m,2H),2.06–1.91(m,2H),1.66(s,3H),1.59(s,3H),1.54–1.48 (m,2H),1.43–1.33(m,2H),1.22–1.16(m,1H),0.97(d,J=6.5Hz,3H).[1H of Naph-51 NMR spectra are attached to the instruction manual. Figure 13 】

[0315] Example 16: Preparation of compound Naph-52

[0316] Steps: Preparation of Naph-52

[0317] In a 100 mL round-bottom flask, after adding a magnetic flask, weigh 2-hydroxynaphthoquinone (5 mmol, 870.8 mg), L-proline (1 mmol, 115.1 mg), and dihydropyridine (5.25 mmol, 1.33 g) and add them to the round-bottom flask. Dissolve them in 50 mL of DCM, and then add undecenal (10 mmol, 1.68 g) to the round-bottom flask. Incubate the reaction at room temperature for 8 hours.

[0318] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to obtain 1.40 g of yellow solid, with a yield of 86%.

[0319] ¹H NMR (400MHz, CDCl₃) δ 8.11 (d, J = 7.6Hz, ¹H), 8.07 (d, J = 7.6Hz, ¹H), 7.76–7.72 (m, ¹H), 7.69–7.64 (m, ¹H), 7.31 (s, ¹H), 5.84–5.76 (m, ¹H), 5.00–4.96 (m, ¹H), 4.93–4.90 (m, ¹H), 2.62–2.56 (m, 2H), 2.02 (q, J = 7.1Hz, 2H), 1.56–1.50 (m, 2H), 1.38–1.25 (m, ¹²H). [The ¹H NMR spectrum of Naph-52 is attached to the instruction manual.] Figure 14 】

[0320] Example 17: Preparation of compound Naph-58

[0321] Steps: Preparation of Naph-58

[0322] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-46 (1 mmol, 286.1 mg) and add it to the flask. Add 25 mL of DCM to dissolve it. Then add propionyl chloride (2 mmol, 185.0 mg) and Et3N (2 mmol, 202.4 mg) to the reaction system and keep the reaction at room temperature for 8 hours.

[0323] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to obtain 256.6 mg of a pale yellow liquid, with a yield of 75%.

[0324] ¹H NMR (400MHz, CDCl₃) δ 8.11–8.06 (m, 2H), 7.88–7.55 (m, 2H), 2.71 (q, J = 7.5Hz, 2H), 2.54 (t, J = 7.8Hz, 2H), 1.53–1.22 (m, 15H), 0.87 (t, J = 6.8Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-58.] Figure 15 】

[0325] Example 18: Preparation of compound Naph-59

[0326] Steps: Preparation of Naph-59

[0327] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-46 (1 mmol, 286.1 mg) and add it to the flask. Add 25 mL of DCM to dissolve it. Then add butyryl chloride (2 mmol, 201.1 mg) and Et3N (2 mmol, 202.4 mg) to the reaction system and keep the reaction at room temperature for 8 hours.

[0328] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to obtain 156.7 mg of pale yellow liquid, with a yield of 44%.

[0329] ¹H NMR (400MHz, CDCl₃) δ 8.11–8.06 (m, 2H), 7.75–7.69 (m, 2H), 2.65 (t, J = 7.4Hz, 2H), 2.53 (t, J = 7.8Hz, 2H), 1.87–1.80 (m, 2H), 1.50–1.24 (m, 12H), 1.09 (t, J = 7.4Hz, 3H), 0.87 (t, J = 6.8Hz, 3H). [The ¹H NMR spectrum of Naph-59 is attached to the instruction manual.] Figure 16 】

[0330] Example 19: Preparation of compound Naph-60

[0331] Steps: Preparation of Naph-60

[0332] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-46 (1 mmol, 286.1 mg) and add it to the flask. Add 25 mL of DCM to dissolve it. Then add isovaleryl chloride (2 mmol, 241.1 mg) and Et3N (2 mmol, 202.4 mg) to the reaction system and keep the reaction at room temperature for 7 hours.

[0333] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to obtain 251.7 mg of a pale yellow liquid, with a yield of 68%.

[0334] ¹H NMR (400MHz, CDCl₃) δ 8.12–8.06 (m, 2H), 7.75–7.69 (m, 2H), 2.55–2.52 (m, 4H), 2.32–2.24 (m, 1H), 1.49–1.24 (m, 12H), 1.11 (d, J = 6.7Hz, 6H), 0.87 (t, J = 6.8Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-60.] Figure 17 】

[0335] Example 20: Preparation of compound Naph-62

[0336] Steps: Preparation of Naph-62

[0337] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-46 (1 mmol, 286.1 mg) and add it to the flask. Dissolve it in 25 mL of DCM, then add 4-chlorobutyryl chloride (2 mmol, 282.0 mg) and Et3N (2 mmol, 202.4 mg) to the reaction system and keep the reaction at room temperature for 8 hours.

[0338] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to obtain 335.5 mg of pale yellow liquid, with a yield of 86%.

[0339] ¹H NMR (400MHz, CDCl₃) δ 8.18–8.00 (m, 2H), 7.75–7.70 (m, 2H), 3.72 (t, J = 6.2 Hz, 2H), 2.89 (t, J = 7.1 Hz, 2H), 2.54 (t, J = 7.8 Hz, 2H), 2.34–2.20 (m, 2H), 1.50–1.23 (m, 12H), 0.86 (t, J = 6.8 Hz, 3H). [The ¹H NMR spectrum of Naph-62 is attached to the instruction manual.] Figure 18 】

[0340] Example 21: Preparation of compound Naph-63

[0341] Steps: Preparation of Naph-63

[0342] In a 50 mL round-bottom flask, after adding a magnetic spool, weigh out Naph-46 (1 mmol, 286.1 mg) and add it to the flask. Add 25 mL of DCM to dissolve it. Then add trifluoropropionyl chloride (2 mmol, 293.0 mg) and Et3N (2 mmol, 202.4 mg) to the reaction system and keep the reaction at room temperature for 10 hours.

[0343] After the TLC reaction was completed, the mixture was quenched with water, extracted with dichloromethane, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to give 194.1 mg of yellow solid, yield 49%.

[0344] ¹H NMR (400MHz, CDCl₃) δ 8.15–8.08 (m, 2H), 7.78–7.73 (m, 2H), 3.56 (q, J = 9.8 Hz, 2H), 2.55 (t, J = 7.8 Hz, 2H), 1.49–1.25 (m, 12H), 0.87 (t, J = 6.8 Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-63.] Figure 19 】

[0345] Example 22: Preparation of compound Naph-70

[0346] Steps: Preparation of Naph-70

[0347] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-44 (1 mmol, 230.1 mg) and K2CO3 (2 mmol, 276.4 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add iodomethane (2 mmol, 283.88 mg) to the reaction flask. Heat the flask to 60 °C and maintain the temperature for the reaction.

[0348] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to give 202.6 mg of yellow solid, with a yield of 83%.

[0349] ¹H NMR (400MHz, CDCl₃) δ 8.07–8.00 (m, 2H), 7.70–7.65 (m, 2H), 4.11 (s, 3H), 2.60–2.55 (m, 2H), 1.47–1.36 (m, 4H), 0.94–0.91 (m, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-70.] Figure 20 】

[0350] Example 23: Preparation of compound Naph-71

[0351] Steps: Preparation of Naph-71

[0352] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-46 (1 mmol, 286.1 mg) and K2CO3 (2 mmol, 276.4 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add iodomethane (2 mmol, 283.88 mg) to the reaction flask. Heat the flask to 60 °C and maintain the temperature for the reaction.

[0353] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 16:1), and the solvent was evaporated to give 243 mg of yellow solid, yield 81%.

[0354] ¹H NMR (400MHz, CDCl₃) δ 8.08–8.00 (m, 2H), 7.70–7.65 (m, 2H), 4.11 (s, 3H), 2.60–2.53 (m, 2H), 1.45–1.25 (m, 12H), 0.86 (t, J = 6.7Hz, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-71.] Figure 21 】

[0355] Example 24: Preparation of compound Naph-73

[0356] Steps: Preparation of Naph-73

[0357] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-48 (1 mmol, 342.2 mg) and K2CO3 (1.2 mmol, 165.8 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add bromoamyl alcohol (2 mmol, 334.08 mg) to the reaction flask. Keep the reaction at room temperature for 12 hours.

[0358] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 4:1), and the solvent was evaporated to give 115.6 mg of yellow solid, yield 27%.

[0359] ¹H NMR (400MHz, CDCl₃) δ 8.07–8.02 (m, 2H), 7.71–7.66 (m, 2H), 4.35 (t, J = 6.4 Hz, 2H), 3.46–3.40 (m, 3H), 2.62–2.55 (m, 2H), 1.97–1.78 (m, 6H), 1.65–1.30 (m, 20H), 0.87 (t, J = 6.8 Hz, 3H). [The ¹H NMR spectrum of Naph-73 is attached in the instruction manual.] Figure 22 】

[0360] Example 25: Preparation of compound Naph-74

[0361] Steps: Preparation of Naph-74

[0362] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-46 (1 mmol, 286.1 mg) and K2CO3 (1.2 mmol, 165.8 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add ethyl bromoacetate (2 mmol, 334.08 mg) to the reaction flask. Keep the reaction at room temperature for 12 hours.

[0363] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to give 294.03 mg of yellow solid, with a yield of 79%.

[0364] ¹H NMR (400MHz, CDCl₃) δ 8.05 (dd, J = 7.3, 1.8Hz, ¹H), 7.99 (dd, J = 7.3, 1.9Hz, ¹H), 7.71–7.64 (m, 2H), 5.08 (s, 2H), 4.24 (q, J = 7.1Hz, 2H), 2.69–2.63 (m, 2H), 1.49 (dd, J = 10.7, 4.8Hz, 2H), 1.38–1.25 (m, ¹³H), 0.86 (t, J = 6.8Hz, ³H). [The ¹H NMR spectrum of Naph-74 is attached in the instruction manual.] Figure 23 】

[0365] Example 26: Preparation of compound Naph-75

[0366] Steps: Preparation of Naph-75

[0367] In a 50 mL round-bottom flask, after adding a magnetic flask, weigh out Naph-48 (1 mmol, 342.2 mg) and K2CO3 (1.2 mmol, 165.8 mg) and add them to the flask. Add 10 mL of DMF to dissolve them, and then add ethyl bromoacetate (2 mmol, 334.08 mg) to the reaction flask. Keep the reaction at room temperature for 12 hours.

[0368] After the TLC reaction was completed, the mixture was quenched with water, extracted with ethyl acetate, washed with saturated brine and dried, concentrated and purified by column chromatography (petroleum ether: ethyl acetate = 8:1), and the solvent was evaporated to give 355.5 mg of yellow solid, with a yield of 83%.

[0369] ¹H NMR (400MHz, CDCl₃) δ 8.06 (dd, J = 7.1, 1.9Hz, ¹H), 8.00 (dt, J = 7.3, 2.3Hz, ¹H), 7.72–7.63 (m, 2H), 5.08 (s, 2H), 4.24 (q, J = 7.1Hz, 2H), 2.71–2.63 (m, 2H), 1.51–1.47 (m, 2H), 1.36–1.24 (m, 2¹H), 0.89–0.85 (m, 3H). [See the instruction manual for the ¹H NMR spectrum of Naph-75.] Figure 24 】

[0370] This invention is not limited to the above embodiments. Any simple or equivalent changes or modifications made to the above embodiments based on the technical essence of this invention shall fall within the scope of this invention.

[0371] Method and results for determining the in vitro anti-rabbit pruritus activity of the compounds of this invention:

[0372] Parasite source: Natural mites were collected from the ears of New Zealand rabbits infected with mange as the test subject;

[0373] Compound sample preparation: Weigh the compound, prepare a stock solution of 1 mg / mL with DMSO, and then dilute it with distilled water to prepare solutions of 100 μg / mL, 50 μg / mL, 20 μg / mL, 10 μg / mL, 5 μg / mL, and 1 μg / mL.

[0374] The specific measurement method is as follows:

[0375] Place a 0.45μm microporous membrane with a diameter of 50mm in a 60mm petri dish and add 350μL of the drug solution;

[0376] Use a mites-picking needle to pick 20 mites from each dish, with 3 replicates per group. Place the mites in a petri dish containing the drug solution and incubate at 28°C for 24 hours. Record the number of mites that die in each dish and calculate the mortality rate.

[0377] Meanwhile, a blank control group and a positive control group were set up, which were respectively supplemented with 1% DMSO and amitraz solution and ivermectin solution.

[0378] Mortality rate = (Number of dead mites / Total number of mites) × 100%;

[0379] Corrected mortality rate = (Mite mortality rate in compound group - Mite mortality rate in blank control group) / (1 - Mite mortality rate in blank control group) × 100%;

[0380] Test results: The partial test results for rabbit pruritus mites are as follows:

[0381] At a concentration of 100 μg / mL, after 24 hours of drug exposure, the lethality rates of Naph-05, Naph-11, Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, Naph-71, Naph-72, Naph-73, Naph-74, Naph-75, Naph-77, ivermectin, and amitraz were all above 90%.

[0382] At a concentration of 50 μg / mL, after 24 hours of drug exposure, the lethality of Naph-05, Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, Naph-71, Naph-72, Naph-73, Naph-74, Naph-75, and ivermectin was all above 90%.

[0383] At a concentration of 20 μg / mL, after 24 hours of drug exposure, the lethality of Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 90%.

[0384] At a concentration of 10 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 90%.

[0385] At a concentration of 5 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 85%.

[0386] At a concentration of 1 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 85%.

[0387] Method and results for determining the in vitro anti-canine scabies mite activity of the compounds of this invention:

[0388] Source of parasites: Dogs naturally infected with scabies mites were scraped off the affected area, and the scabies mites were detected under a microscope scraping microscope. The scraped skin tissue from the affected area was placed in a glass petri dish, the glass petri dish was covered, and the dish was placed on the surface of a 37°C water bath. After 1 hour, the petri dish was removed, and the scabies mites crawling out of the tissue were collected as test subjects.

[0389] Compound sample preparation: Weigh the compound, prepare a stock solution of 1 mg / mL with DMSO, and then dilute it with distilled water to prepare solutions of 100 μg / mL, 50 μg / mL, 20 μg / mL, 10 μg / mL, 5 μg / mL, and 1 μg / mL.

[0390] The specific measurement method is as follows:

[0391] Place a 0.45μm microporous organic filter membrane with a diameter of 50mm in a 60mm petri dish and add 350μL of the drug solution;

[0392] Ten mites were picked up with a mites picking needle in each dish, with three replicates per group. The mites were placed in a petri dish containing the drug solution and incubated in a 28°C incubator for 24 hours. The number of mites that died in each dish was recorded and the mortality rate was calculated.

[0393] Meanwhile, a blank control group and a positive control group were set up, which were treated with 1% DMSO and amitraz solution and ivermectin solution, respectively.

[0394] Mortality rate = (Number of dead mites / Total number of mites) × 100%;

[0395] Corrected mortality rate = (Mite mortality rate in compound group - Mite mortality rate in blank control group) / (1 - Mite mortality rate in blank control group) × 100%;

[0396] Test results: The partial test results for canine scabies mites are as follows:

[0397] At a concentration of 100 μg / mL, after 24 hours of drug exposure, the lethality rates of Naph-05, Naph-11, Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, Naph-71, Naph-72, Naph-73, Naph-74, Naph-75, Naph-77, ivermectin, and amitraz were all above 90%.

[0398] At a concentration of 50 μg / mL, after 24 hours of drug exposure, the lethality of Naph-05, Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, Naph-71, Naph-72, Naph-73, Naph-74, Naph-75, and ivermectin was all above 90%.

[0399] At a concentration of 20 μg / mL, after 24 hours of drug exposure, the lethality of Naph-13, Naph-14, Naph-17, Naph-19, Naph-20, Naph-21, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 90%.

[0400] At a concentration of 10 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 90%.

[0401] At a concentration of 5 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 85%.

[0402] At a concentration of 1 μg / mL, after 24 hours of drug exposure, the lethality of Naph-19, Naph-20, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 85%.

[0403] Method and results for determining the in vitro anti-Haemaphysalis activity of the compounds of this invention:

[0404] Parasite source: Haemaphysalis longicornis was cultured and fed on the back of rabbits during the parasitic period. During the non-parasitic period, it was cultured in an incubator with 70% humidity and 25°C. Saturated nymphs were used as test subjects.

[0405] Compound sample preparation: Weigh the compound, prepare a 1 mg / mL stock solution with DMSO, and then dilute it with distilled water to prepare solutions of 2500 μg / mL, 250 μg / mL, and 25 μg / mL.

[0406] The specific measurement method is as follows:

[0407] The drug was applied to the engorged nymphs of Haemaphysalis longicornis by immersion, with each tick being immersed for 5 minutes.

[0408] Each group contained 10-15 ticks, with 3 replicates per group. After incubation in a 70% relative humidity, 28℃ incubator for 48 hours, the number of tick deaths was recorded and the mortality rate was calculated.

[0409] At the same time, a blank control group and a positive control group were set up, which were treated with 10% DMSO and ivermectin solution, respectively.

[0410] Mortality rate = (Number of tick deaths / Total number of ticks) × 100%;

[0411] Corrected mortality rate = (mortality rate of ticks in the compound group - mortality rate of ticks in the blank control group) / (1 - mortality rate of ticks in the blank control group) × 100%;

[0412] Test results: The partial test results for Haemaphysalis longicornis are as follows:

[0413] At a concentration of 2500 μg / mL, after 48 hours of drug treatment, the lethality of Naph-05, Naph-19, Naph-20, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-58, Naph-60, Naph-63, and ivermectin was all above 90%.

[0414] At a concentration of 250 μg / mL, after 48 hours of drug treatment, the lethality of Naph-19, Naph-20, Naph-30, Naph-45, Naph-47, Naph-51, Naph-52, Naph-63, and ivermectin was all above 80%.

[0415] At a concentration of 25 μg / mL, after 48 hours of drug treatment, the lethality of Naph-19, Naph-20, Naph-47, Naph-51, Naph-52, Naph-63, and ivermectin was all above 60%.

[0416] Evaluation of the efficacy of the compound of this invention in treating clinical rabbit ear mite infestation and its implementation method:

[0417] Criteria for diagnosing diseased rabbits and scoring criteria for the degree of rabbit ear mite infection: Rabbits diagnosed with rabbit ear mite infection can be confirmed based on clinical symptoms, necropsy findings, and the presence of mites under a microscope. On days 0, 3, and 7 of the experiment, the ear inflammatory exudate and crusting were examined, and the presence of mites was assessed under a microscope. The degree of infection was scored as follows: no exudate or mites: 0 points; ear canal exudate but no mites: 0.5 points; ear canal with a small amount of crust and mites: 1 point; external ear canal filled with crust and mites: 2 points; ear canal and proximal 1 / 4 of the ear canal with crust and mites: 3 points; 1 / 2 of the ear canal filled with crust and mites: 4 points; 3 / 4 of the ear canal filled with crust and mites: 5 points; the entire ear canal filled with crust and mites: 6 points.

[0418] Clinical use plan of the compound of this invention:

[0419] The compounds Naph-19, Naph-51 and Naph-71 were prepared into a stock solution using DMSO and then diluted with distilled water to a concentration of 250 μg / mL for treatment.

[0420] Ivermectin was used as a positive control, and an aqueous solution containing 0.1% DMSO was used as a blank control.

[0421] Place the medication in a 50mL spray bottle and spray it evenly on the affected area every other day. Record the ear inflammation exudate and scab formation. After one week, examine under a microscope to check for mites.

[0422] Evaluation results: After 4 days of use, Naph-19, Naph-51 and Naph-71 greatly alleviated the clinical symptoms of the diseased rabbits, and some scabs fell off; after one week, all the scabs fell off, there was no inflammatory exudate in the ears, and no mites were found under microscopic examination. The ear mites in the clinically affected rabbits have been cured.

[0423] Evaluation of the efficacy of the compound of this invention in treating canine scabies and its implementation method:

[0424] The criteria for diagnosing canine scabies are as follows: use a blunt scalpel to scrape skin scrapings from the junction of the affected and normal skin until bleeding occurs, place the scrapings on a clean glass slide, and examine them under a low-power microscope. If live mites are found, the canine scabies can be confirmed.

[0425] Clinical use plan of the compound of this invention:

[0426] The compound Naph-51 was prepared into a stock solution using DMSO and then diluted with distilled water to a concentration of 2500 μg / mL for treatment.

[0427] Ivermectin was used as a positive control, and an aqueous solution containing 0.1% DMSO was used as a blank control.

[0428] Place the medication in a 50mL spray bottle and spray it evenly on the affected area every other day. Record the scab formation and hair growth. Examine under a microscope after 10 days to check for mites.

[0429] Evaluation results: After 5 days of use, Naph-51 significantly alleviated the clinical symptoms of the affected dogs, and some scabs fell off; after 10 days, all the scabs fell off, and no mites were found under microscopic examination; after two weeks, the dogs' hair growth returned to normal, and the canine scabies in the clinically affected dogs was cured.

[0430] In summary, this series of compounds, with their novel structures, exhibits antibody-specific in vitro parasitic activity ranging from good to excellent. Particularly noteworthy is that the introduction of this series of compounds into the field of live veterinary drugs has overcome a long-standing technical challenge for those skilled in the art—namely, how to ensure both high antiparasitic activity and a reasonable balance between safety and toxicity. Furthermore, the synthetic process for this series of compounds is simple, and the reaction conditions are mild, enabling the efficient preparation of a diverse range of 2,3-disubstituted naphthoquinone compounds.

Claims

1. Use of a 2,3-disubstituted naphthoquinone compound, characterized in that, This compound is used in the field of veterinary drugs for the prevention and treatment of ectoparasites in animals; the ectoparasites are one or more of the following: itch mites, scabies mites, demodicosis mites, and ticks; the animals are one or more of the following: cattle, sheep, pigs, rabbits, cats, and dogs. This compound is one of the compounds shown in the figure below:

Images