A chrysenyl aryl hydrazide derivative, its preparation method and application

Abstract

The present application relates to the technical field of pesticides, and discloses a chromene aryl hydrazide derivative, a preparation method and application thereof, a structural general formula of the chromene aryl hyydrazide derivative is as formula (I); the preparation method is as follows: taking p-hydroxybenzaldehyde as raw material, and obtaining the chromene aryl hydrazide compound through substitution reaction, cyclization reaction, oxidation reaction, acylation reaction and hydrazinolysis reaction. The chromene aryl hydrazide compound is used for preparing an agricultural bacteriostatic agent. The present application combines aryl hydrazine and chromene skeleton by using the pharmacophore splicing principle in medicinal chemistry, and designs and synthesizes a series of chromene aryl hydrazide compounds. The bacteriostatic activity test result shows that the compounds have excellent bacteriostatic activity, and can be used as active ingredients for preparing a plant pathogenic fungus fungicide.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to a chromene aryl hydrazide derivative, its preparation method, and its application. Background Technology

[0002] Plant diseases caused by pathogenic fungi rank first among fungal diseases, bacterial diseases, and viral diseases, and are one of the main causes of agricultural losses. Currently, chemical agents are mainly used to control fungal diseases, but problems such as disease resistance, environmental pollution, pesticide residues, and food safety are becoming increasingly prominent with long-term use of these drugs. Therefore, there is an urgent need to research and develop novel green pesticides with unique mechanisms of action.

[0003] Natural products containing chromene skeletons are widely found in edible and medicinal plants, such as *Tea japonica*, *Eupatorium adenophorum*, *Ageratum macrocephalum*, and *Eupatorium spp.* Pharmacological activity studies have shown that compounds containing such skeletons possess a variety of biological activities, including anti-inflammatory, anticancer, antioxidant, antiviral, antibacterial, and insecticidal effects, making them a class of natural products with significant research value. However, there are currently few reports on structural modifications based on chromene skeletons as lead compounds for agricultural biological activities.

[0004] Jiang Shichun et al. disclosed the antibacterial activity of novel 4H-chromene-4-one derivatives containing dithiocarbamate. These derivatives can inhibit three bacterial diseases: rice bacterial blight, tobacco bacterial wilt, and citrus canker. However, these derivatives cannot inhibit other fungal pathogens. Therefore, it is urgent to develop a chromene derivative that can inhibit plant pathogenic fungi. Summary of the Invention

[0005] This invention provides a chromene arylhydrazide derivative, its preparation method, and its application, which solves the problem that existing chromene derivatives can only inhibit three bacterial diseases: rice bacterial blight, tobacco wilt, and citrus canker, and cannot inhibit other fungal diseases.

[0006] A chromene aryl hydrazide derivative, the general structural formula of which is shown in formula (I):

[0007]

[0008] Wherein, R is an aryl, substituted aryl, heteroaryl, substituted heteroaryl, or C1-C6 alkyl.

[0009] Preferably, the chromene arylhydrazide derivative includes any one of the following compounds:

[0010]

[0011] The second objective of this invention is to protect the method for preparing the aforementioned chromene aryl hydrazide compounds, which uses p-hydroxybenzaldehyde as a raw material to obtain chromene aryl hydrazide compounds through substitution reaction, cyclization reaction, oxidation reaction, acylation reaction and hydrazinolysis reaction.

[0012] Preferably, the substitution reaction and cyclization reaction are as follows:

[0013] p-hydroxybenzaldehyde was dissolved in acetonitrile, copper chloride was added, and the mixture was stirred in an ice bath for 5-15 min. Then, 1,8-diazabicyclo[5.4.0]undec-7-ene was added dropwise, followed by the addition of 3-chloro-3-methyl-1-butyne. The mixture was stirred in an ice bath for 9-11 h. After the reaction was completed, water was added and the product was purified to obtain the substitution reaction product.

[0014] The substitution reaction product was dissolved in N,N-diethylaniline and reacted at 150–170 °C for 3–5 h under argon protection. After the reaction was completed, hydrochloric acid was added and the product was purified to obtain the cyclization reaction product.

[0015] Preferably, the oxidation reaction is as follows: the obtained cyclization reaction product and 2-methyl-2-butene are dissolved, an aqueous solution of sodium dihydrogen phosphate is added, the mixture is stirred in an ice bath and an aqueous solution of sodium hypochlorite is added, the mixture is stirred at room temperature for 1-3 hours, after the reaction is complete, water is added, the mixture is extracted, dried and concentrated, and the oxidation reaction product is purified; wherein, the ratio of cyclization reaction product, 2-methyl-2-butene, sodium dihydrogen phosphate, water and sodium hypochlorite is 4.2 mmol: 11 mL: 34 mmol: 2 mL: 30 mmol.

[0016] Preferably, the acylation and hydrazinolysis reactions are as follows:

[0017] The obtained oxidation reaction product was dissolved in thionyl chloride and reacted at 80-90°C for 1-3 hours under argon protection. After the reaction was completed, the reaction solution was removed, and substituted phenylhydrazine was added under alkaline conditions with stirring. The mixture was stirred at room temperature until the reaction was complete, and the chromene arylhydrazine compound was purified to obtain the compound.

[0018] A third objective of this invention is to protect the use of the aforementioned chromene arylhydrazide compounds in the preparation of agricultural antibacterial agents.

[0019] Preferably, the agricultural antibacterial agent is used to prevent and control plant diseases caused by plant pathogenic fungi.

[0020] Preferably, the plant pathogenic fungi include *Potato rot fungus*, *Watermelon wilt fungus*, *Phytophthora indicum*, *Wheat scab fungus*, *Sclerotinia sclerotiorum*, *Apple rot fungus*, *Tobacco scab fungus*, *Rice blast fungus*, *Chinese cabbage black spot fungus*, and *Tomato gray mold fungus*.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) This invention utilizes the pharmacophore combination principle in medicinal chemistry to combine it with the chromene skeleton, designing and synthesizing a series of chromene arylhydrazide compounds. Antibacterial activity tests show that these compounds possess excellent antibacterial activity and can be used as active ingredients in the preparation of fungicides for plant pathogenic fungi. These fungicides are used to control plant diseases caused by *Potato rot fungus*, *Fusarium wilt*, *Phytophthora indicum*, *Fusarium graminearum*, *Fusarium graminearum*, *Sclerotinia sclerotiorum*, *Pseudomonas chinensis*, *Fusarium graminearum*, *Sclerotinia sclerotiorum*, *Fungiella rotundifolia*, *Aureobasidium aureum*, *Aureobasidium rotundifolia*, *Aureobasidium spp.*, *Bacillus thuringiensis*, *Bacillus oryzae*, *Bacillus oryzae*, and *Gyromitra rotundifolia*.

[0023] (2) The compounds designed and synthesized in this invention are all derivatives of the chromene skeleton of natural products. Furthermore, some of these compounds exhibit potential low toxicity, high efficiency, and broad-spectrum activity against plant pathogenic fungi compared to commonly used commercial fungicides such as chlorothalonil and oxadixyl. This invention can provide candidate compounds for the development of plant-derived antifungal agents based on the chromene skeleton. Attached Figure Description

[0024] Figure 1 The graph shows the inhibitory effect of different concentrations of compound 6c prepared in Example 1 of this invention on tomato gray mold.

[0025] Figure 2 The graph shows the inhibitory effect of different concentrations of the compound prepared in Example 1 of this invention on apple rot pathogens over 6 hours.

[0026] Figure 3 Compound 6a prepared in Example 1 of this invention 1 HNMR spectrum;

[0027] Figure 4 Compound 6a prepared in Example 1 of this invention 13 C NMR spectrum;

[0028] Figure 5 Compound 6e prepared in Example 1 of this invention 1 H NMR spectrum;

[0029] Figure 6 Compound 6e prepared in Example 1 of this invention 13 C NMR spectrum. Detailed Implementation

[0030] The technical solutions of this invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] Unless otherwise specified, the methods described in the various embodiments of this invention are conventional methods. Unless otherwise specified, the materials and reagents used are commercially available.

[0032] This invention uses p-hydroxybenzaldehyde as a starting material to obtain chromene aryl hydrazides through substitution, cyclization, oxidation, acylation, and hydrazinolysis reactions. The specific synthetic route is as follows:

[0033]

[0034] Where R can be any of the following:

[0035]

[0036] Example 1:

[0037] Prepare 4-(2-methyl-3-yne-2-hydroxy)benzaldehyde, denoted as compound 2:

[0038] 2.0 g (16.4 mmol) of p-hydroxybenzaldehyde was dissolved in 15 mL of acetonitrile, and 4.0 mg (0.032 mmol) of copper chloride was added. After stirring in an ice bath for 10 minutes, 17.6 mmol of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was added dropwise, followed by 1.8 g (17.6 mol) of 3-chloro-3-methyl-1-butyne. The mixture was stirred in an ice bath for 10 hours. The reaction was confirmed by TLC. 20 mL of water was added to the reaction mixture, and the mixture was extracted three times with 30 mL of ethyl acetate each time. The combined organic phases were dried over anhydrous sodium sulfate and concentrated. The mixture was then purified by silica gel column chromatography to obtain 1.4 g of a pale yellow oily compound 2, which is the substitution reaction product with a yield of 45%. This product was used directly in the next step.

[0039] Prepare 2,2-dimethyl-2H-chromene-6-carboxaldehyde, denoted as compound 3:

[0040] 1.4 g (7.4 mmol) of the prepared compound 2 was dissolved in 3 mL of N,N-diethylaniline and reacted at 160 °C for 4 h under argon protection. The reaction was confirmed to be complete by TLC. 8 mL of 6 mol / L hydrochloric acid was added, and the mixture was extracted three times with 20 mL of ethyl acetate each time. The combined organic phases were washed with 20 mL of saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified to obtain 1.05 g of a yellow oily compound 3, the cyclization product, with a yield of 75%. The eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 30:1, V:V. 1HNMR (600MHz, CDCl3) δ9.82 (s, 1H, CHO), 7.64 (dd, 1H, J = 8.4, 1.8Hz), 7.51 (d, 1H, J = 1.8Hz) ,6.86(d,1H,J=7.8Hz),6.37(d,1H,J=10.2Hz),5.70(d,1H,J=10.2Hz),1.47(s,6H,2CH3); 13 C NMR(150MHz, CDCl3)δ190.7,158.6,131.9,131.4,129.9,127.7,121.3,121.1,116.7,77.9,28.4.HRMS(ESI)calcd for C 12 H 13 O2[M+H] + m / z:189.0916, found 189.0923.

[0041] Prepare 2,2-dimethyl-2H-chromene-6-carboxylic acid, denoted as compound 4:

[0042] 800 mg (4.2 mmol) of the prepared compound 3 and 11 mL (85.2 mmol) of 2-methyl-2-butene were dissolved in 7 mL of tert-butanol. 2 mL of an aqueous solution of sodium dihydrogen phosphate was added, and the mixture was stirred in an ice bath. 2.7 g (30 mmol) of sodium hypochlorite was then added, and the mixture was allowed to heat naturally and then stirred at room temperature for 2 h. The aqueous solution of sodium dihydrogen phosphate consisted of 4.06 g (34.0 mmol) of sodium dihydrogen phosphate dissolved in 2 mL of water. TLC analysis confirmed the reaction was complete. 10 mL of water was added to the reaction mixture, and the mixture was extracted three times with 20 mL of ethyl acetate each time. The combined organic phases were dried over anhydrous sodium sulfate and concentrated. The solution was purified by silica gel column chromatography to obtain 810 mg of a white solid, compound 4, which was the oxidation product, with a yield of 93%. The eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 4:1, V:V. Melting point: 155-158℃; 1H NMR (600MHz, DMSO-d6) δ 7.72 (dd, 1H, J=8.4, 1.8Hz), 7.67 (d, 1H, J=7.8Hz), 6.82 (d, 1H, J=8.4Hz), 6.51 (d, 1H, J=9.6Hz), 5.83 (d, 1H, J=10.2Hz), 1.40 (s, 6H, 2CH3); 13 C NMR (150MHz, DMSO-d6) δ166.8,156.2,131.4,130.7,127.7,122.9,121.0,120.4,115.8,77.2,27.8.

[0043] Preparation of chromene arylhydrazides 6a-r:

[0044] 85 mg (0.42 mmol) of the prepared compound 4 was dissolved in 2 mL of thionyl chloride and reacted at 80 °C for 2 h under argon protection. The reaction was confirmed to be complete by TLC. The reaction solution was removed to obtain compound 5, which was used directly in the next reaction without further purification. Compound 5 and 21 mg (0.57 mmol) of sodium hydroxide were dissolved in 2 mL of dichloromethane. 0.378 mmol of substituted phenylhydrazine was added with stirring, and the mixture was stirred at room temperature until the reaction was complete. The reaction solution was removed, and the mixture was purified by silica gel column chromatography to obtain the target compounds 6a-6r.

[0045] In some implementation schemes, the specific compound structures are shown in Table 1:

[0046]

[0047]

[0048]

[0049] The above embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0050] Table 1 shows the physicochemical properties and spectral data of the compounds:

[0051] Compound 6a, namely 2,2-dimethyl-N'-phenyl-2H-chromene-6-carboxyhydrazide: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 3:1, V:V, yield 52%, white solid, melting point: 95-97℃; 1 H NMR (600MHz, CDCl3) δ8.05 (s, 1H), 7.58 (dd, 1H, J = 8.4, 2.4Hz), 7.49 (d, 1H, J = 1.8Hz), 7.23 (t, 2H, J = 7.8Hz), 6.90-6.88(m,3H),6.79(d,1H,J=8.4Hz),6.31(d,1H,J=10.2Hz),5.67(d,1H,J=10.2Hz),1.45(s,6H,2CH3); see Figure 3 . 13 C NMR (150MHz, CDCl3) δ167.4,156.5,148.1,131.5,129.2,128.1,125.8,124.5,121.6,121.3,121.1,116.4,113.7,77.3,28.2.HRMS(ESI)calcd for C 18 H 19 N₂O₂[M+H] +m / z:295.1447, found 295.1449. See Figure 4 .

[0052] Compound 6b, namely N'-(2-fluorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 45%, white solid, melting point: 116-118℃; 1 H NMR (600MHz, DMSO-d6) δ7.71 (dd, 1H, J = 8.4, 2.4Hz), 7.66 (d, 1H, J = 2.4Hz), 7.12-7.08 (m, 1H), 7.10 (t, 1H, J = 8. 4Hz),6.85-6.80(m,2H),6.76-6.75(m,1H),6.49(d,1H,J=10.2Hz),5.85(d,1H,J=10.2Hz),1.41(s,6H,2CH3); 13 CNMR(150MHz,DMSO-d6)δ166.3,155.8,151.5,149.9,137.5,132.2,129.1,126.2,1 25.5,125.0,121.6,121.0,119.4,116.2,115.4,114.2,77.5,28.2.HRMS(ESI)calcd for C 18 H 17 N₂O₂FNa[M+Na] + m / z:335.1172, found 335.1171.

[0053] Compound 6c, namely N'-(3-fluorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 35%, white solid, melting point: 110-112℃; 1 H NMR (600MHz, CDCl3) δ8.00(s,1H),7.59(dd,1H,J=8.4,2.4Hz),7.49(d,1H,J=2.4Hz),7.16-7.12(m,1H),6.80(d,1H,J=8.4H z),6.65(d,1H,J=8.4Hz),6.58-6.55(m,2H),6.43(s,1H),6.32(d,1H,J=10.2Hz),5.68(d,1H,J=10.2Hz),1.45(s,6H,2CH3); 13C NMR (150MHz, CDCl3) δ167.4,164.5,162.9,156.7,150.2,131.6,130.4,128.1,125 .7,124.1,121.4,121.2,116.4,109.2,107.8,100.9,77.4,28.26.HRMS(ESI)calcd forC 18 H 18 N₂O₂F[M+H] + m / z:313.1352, found 313.1358.

[0054] Compound 6d, namely N'-(4-fluorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 43%, white solid, melting point: 176-178℃; 1 H NMR (600MHz, CDCl3) δ10.24(s,1H),7.85(s,1H),7.74(dd,1H,J=8.4,1.8Hz),7.69(d,1H,J=1.8Hz),7.03(t,1H,J=8 .4Hz), 6.86 (d, 1H, J = 8.4Hz), 6.82-6.80 (m, 2H), 6.51 (d, 1H, J = 10.2Hz), 5.86 (d, 1H, J = 10.2Hz), 1.44 (s, 6H, 2CH3); 13 C NMR (150MHz, CDCl3) δ167.4,164.5,162.9,156.7,150.2,131.6,130.4,128.1,125 .7,124.1,121.4,121.2,116.4,109.2,107.8,100.9,77.4,28.2.HRMS(ESI)calcd for C 18 H 18 N₂O₂F[M+H] + m / z:313.1352,found313.1357.

[0055] Compound 6e, namely N'-(2,4-difluorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 51%, white solid, melting point: 106-108℃; 1H NMR (600MHz, DMSO-d6) δ10.25(s,1H),7.70-7.68(m,2H),7.66(s,1H),7.17-7.14(m,1H),6.89-6. 86(m,1H),6.83-6.80(m,2H),6.48(d,1H,J=10.2Hz),5.86(d,1H,J=10.2Hz),1.40(s,6H,2CH3); see Figure 5 . 13 C NMR(150MHz,DMSO-d6)δ166.3,155.8,154.4,150.91,149.30,134.4,132.1,129.0,1 26.3,125.6,121.7,120.9,116.1,114.6,111.3,104.2,77.5,28.3.HRMS(ESI)calcd for C 18 H 17 N₂O₂F₂[M+H] + m / z:331.1258, found 331.1263. See Figure 6 .

[0056] Compound 6f, namely N'-(pentafluorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 4:1, V:V, yield 57%, white solid, melting point: 113-115℃; 1 H NMR (600MHz, DMSO-d6) δ10.26(s,1H),8.16(s,1H),7.63(dd,1H,J=8.4,1.8Hz),7.59(d,1H,J=1 .8Hz), 6.82 (d, 1H, J = 8.4Hz), 6.46 (d, 1H, J = 10.2Hz), 5.83 (d, 1H, J = 9.6Hz), 1.40 (s, 6H, 2CH3); 13 CNMR(150MHz,DMSO-d6)δ166.4,155.9,138.7,137.0,132.1,129.0,126.3,125.1,121.6,120.9,116.2,77.5,28.3.HRMS(ESI)calcd for C 18 H 14 N₂O₂F₅[M+H] + m / z:385.0975,found385.0974.

[0057] Compound 6g, namely N'-(2-dichlorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazide: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 61%, white solid, melting point: 178-179℃; 1 H NMR (600MHz, DMSO-d6) δ7.72(dd,1H,J=8.4,1.8Hz),7.67(d,1H,J=2.4Hz),7.32(dd,1H,J=7.8,1.8Hz),7.17-7.14(m,1H),6.85(d ,1H,J=8.4Hz),6.83(dd,1H,J=7.8,1.8Hz),6.79-6.77(m,1H),6.49(d,1H,J=10.2Hz),5.85(d,1H,J=10.2Hz),1.41(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ13C NMR(151MHz,DMSO)δ166.2,155.9,145.3,132.2,129.6,129.1,128.2,126.3, 125.4,121.6,121.0,120.2,117.8,116.2,113.5,77.6,28.2.HRMS(ESI)calcd forC 18 H 17 N₂O₂ClNa[M+Na] + m / z:351.0876, found 351.0878.

[0058] Compound 6h, namely N'-(3-chlorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine, was 67% yielded as a white solid with a melting point of 201-203℃ when eluted by silica gel column chromatography with petroleum ether:ethyl acetate = 2:1, V:V. 1 H NMR (600MHz, DMSO-d6) δ7.71(dd,1H,J=8.4,1.8Hz),7.65(d,1H,J=1.8Hz),7.19(t,1H,J=8.4Hz),6.8 5(d,1H,J=8.4Hz),6.75-6.72(m,3H),6.49(d,1H,J=9.6Hz),5.85(d,1H,J=9.6Hz),1.41(s,6H,2CH3); 13C NMR(150MHz,DMSO-d6)δ166.3,155.9,151.5,133.9,132.2,130.9,129.0,126.2 ,125.4,121.6,121.0,118.6,116.2,111.9,111.4,77.6,28.2.HRMS(ESI)calcd for C 18 H 18 N₂O₂Cl[M+H] + m / z:329.1057, found 329.1061.

[0059] Compound 6i, namely N'-(2,4-dichlorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 1:1, V:V, yield 47%, white solid, melting point: 155-157℃; 1 H NMR (600MHz, CDCl3) δ8.03(s,1H,NH),7.59(dd,1H,J=8.4,2.4Hz),7.48(d,1H,J=2.4Hz),7.28(d,1H,J=1.8Hz),7.08(dd,1H,J=8.4,2.4H z), 6.87 (d, 1H, J = 9.0Hz), 6.79 (d, 1H, J = 8.4Hz), 6.55 (d, 1H, J = 3.0Hz), 6.30 (d, 1H, J = 10.2Hz), 5.68 (d, 1H, J = 9.6Hz), 1.46 (s, 6H, 2CH3); 13 C NMR (150MHz, CDCl3) δ167.2,156.8,142.9,131.6,129.1,128.1,127.6,125.8, 125.5,123.8,121.4,121.1,120.1,116.4,114.4,77.4,28.2.HRMS(ESI)calcd forC 18 H 17 N₂O₂Cl₂[M+H] + m / z:363.0667, found 363.0675.

[0060] Compound 6j, namely N'-(3-fluoro-2-chlorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 4:1, V:V, yield 41%, white solid, melting point: 98-100℃; 1H NMR (600MHz, DMSO-d6) δ10.37(s,1H,NH),7.90(s,1H),7.71(dd,1H,J=8.4,1.8Hz),7.67(s,1H),7.17-7.13(m,1H),6.85(d, 1H,J=7.8Hz),6.74(t,1H,J=9.0Hz),6.63(d,1H,J=8.4Hz),6.49(d,1H,J=10.2Hz),5.84(d,1H,J=9.6Hz),1.41(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.2,159.2,157.6,155.9,147.4,132.1,129.1,128.6,12 6.4,125.5,121.7,121.0,116.2,108.7,106.1,104.4,77.5,28.3.HRMS(ESI)calcd forC 18 H 16 N₂O₂ClFNa[M+Na] + m / z:369.0782, found 369.0783.

[0061] Compound 6k, namely N'-(4-methyl-3-chlorophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 4:1, V:V, yield 75%, white solid, melting point: 207-208℃; 1 H NMR (600MHz, DMSO-d6) δ10.21(d,1H,J=2.4Hz,NH),7.96(d,1H,J=1.8Hz,NH),7.70(dd,1H,J=8.4,1.2Hz),7.66(s,1H),7.10(d,1H,J=8.4Hz), 6.83(d,1H,J=7.8Hz),6.76(s,1H),6.67(d,1H,J=8.4Hz),6.48(d,1H,J=10.2Hz),5.83(d,1H,J=9.6Hz),2.19(s,3H,CH3),1.40(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.2,155.8,149.6,133.7,132.1,131.7,129.0,126.3,1 25.7,124.9,121.7,121.0,116.1,112.7,111.8,77.5,28.3,19.0.HRMS(ESI)calcd for C 19 H19 N₂O₂NaCl[M+Na] + m / z:365.1033, found 365.1037.

[0062] Compound 6l, namely N'-(4-bromophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 73%, white solid, melting point: 116-118℃; 1 H NMR (600MHz, DMSO-d6) δ7.70(dd,1H,J=8.4,1.2Hz),7.65(d,1H,J=1.8Hz),7.31(d,2H,J=9.0Hz),6.84( d,1H,J=8.4Hz),6.74(d,2H,J=9.0Hz),6.48(d,1H,J=9.6Hz),5.84(d,1H,J=10.2Hz),1.40(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.3,155.8,149.3,132.2,131.8,129.0,126.2,125.5,121.7,121.0,116.2,114.8,109.9,77.5,28.2.HRMS(ESI)calcd forC 18 H 18 N₂O₂Br[M+H] + m / z:373.0552, found 373.0553.

[0063] Compound 6m, namely N'-(4-cyanophenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 49%, white solid, melting point: 195-196℃; 1 H NMR (600MHz, CDCl3) δ8.04 (s, 1H), 7.60 (dd, 1H, J = 8.4, 1.8Hz), 7.49 (d, 1H, J = 1.8Hz), 7.44 (d, 2H, J = 8.4Hz), 7 .86(d,2H,J=8.4Hz), 6.81(d,1H,J=8.4Hz), 6.31(d,1H,J=10.2Hz), 5.69(d,1H,J=10.2Hz), 1.46(s,6H,2CH3); 13CNMR(150MHz, CDCl3)δ167.4,156.9,151.9,133.5,131.7,128.2,125.8,123.6,121.3,121.2,119.6,116.5,113.1,103.1,77.5,28.2.HRMS(ESI)calcd for C 19 H 18 N3O2[M+H] + m / z:320.1399, found 320.1396.

[0064] Compound 6n, namely 2,2-dimethyl-N'-(pyridin-3-yl)-2H-chromene-6-carboxyhydrazide: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 1:1, V:V, yield 39%, white solid, melting point: 164-166℃; 1 H NMR (600MHz, DMSO-d6) δ8.05(d,1H,J=4.8Hz),7.71(d,1H,J=8.4Hz),7.66(s,1H),7.53-7.50(m,1H),6.83(d,1H,J= 8.4Hz),6.70-6.69(m,1H),6.62(d,1H,J=8.4Hz),6.48(d,1H,J=10.2Hz),5.84(d,1H,J=9.6Hz),1.40(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.2,160.5,155.7,147.9,137.9,132.1,129.1,126.4 ,125.7,121.7,120.9,116.1,115.0,106.9,106.9,77.5,28.2.HRMS(ESI)calcd for C 17 H 18 N3O2[M+H] + m / z:296.1399,found296.1400.

[0065] Compound 6o, namely N'-(4-methoxyphenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 2:1, V:V, yield 42%, white solid, melting point: 100-102℃; 1HNMR(600MHz,DMSO-d6)δ10.17(d,1H,J=3.0Hz,NH),7.69(d,1H,J=8.4Hz),7.64(d,1H,J=1.2Hz),7.53(d,1H,J=3.0Hz,NH), 6.82(d,1H,J=8.4Hz),6.77-6.73(m,4H),6.47(d,1H,J=10.2Hz),5.83(d,1H,J=9.6Hz),3.65(s,3H,℃CH3),1.40(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.2,155.6,153.1,143.9,132.0,128.9,126.3,126.0,121.8,120.9,116.1,114.6,114.2,77.4,55.7,28.3.HRMS(ESI)calcd for C 19 H 21 N₂O₃[M+H] + m / z:325.1552,found325.1550.

[0066] Compound 6p, namely N'-(2-methylphenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 3:1, V:V, yield 44%, white solid, melting point: 103-105℃; 1 H NMR (600MHz, DMSO-d6) δ10.21(d,1H,J=1.8Hz,NH),7.72(dd,1H,J=8.4,2.4Hz),7.67(d,1H,J=1.8Hz),7.20(s,1H),7.03-6.99 (m,2H),6.84(d,1H,J=8.4Hz),6.69(m,2H),6.48(d,1H,J=9.6Hz),5.83(d,1H,J=9.6Hz),2.20(s,3H,CH3),1.41(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.1,155.7,147.4,132.1,130.4,128.9,126.8,126.3,1 25.9,122.3,121.7,120.9,119.1,116.1,111.5,77.5,28.3,17.7.HRMS(ESI)calcd for C 19 H 21 N₂O₂[M+H] +m / z:309.1603,found309.1602.

[0067] Compound 6q, namely N'-(3-methylphenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 3:1, V:V, yield 46%, white solid, melting point: 122-124℃; 1 H NMR (600MHz, DMSO-d6) δ7.75(d,1H,J=2.4Hz),7.71(dd,1H,J=8.4,2.4Hz),7.66(d,1H,J=1.8Hz),7.03(t,1H,J=7.8Hz),6.83(d,1H,J= 8.4Hz),6.58-6.56(m,2H),6.53(d,1H,J=7.2Hz),6.48(d,1H,J=10.2Hz),5.83(d,1H,J=10.2Hz),2.20(s,3H,CH3),1.40(s,6H,2CH3); 13 C NMR(150MHz,DMSO-d6)δ166.2,155.7,150.1,138.2,132.0,129.0,128.9,126.3,1 25.9,121.8,120.9,119.8,116.1,113.2,110.1,77.4,28.3,21.7.HRMS(ESI)calcd forC 19 H 21 N₂O₂[M+H] + m / z:309.1603, found 309.1610.

[0068] Compound 6r, namely N'-(4-methylphenyl)-2,2-dimethyl-2H-chromene-6-carbamoylhydrazine: eluent for silica gel column chromatography was petroleum ether:ethyl acetate = 3:1, V:V, yield 37%, white solid, melting point: 190-192℃; 1 H NMR (600MHz, CDCl3) δ8.01(s,1H),7.57(dd,1H,J=8.4,2.4Hz),7.47(d,1H,J=2.4Hz),7.03(t,2H,J=7.8Hz),6.81(d,2 H,J=8.4Hz),6.79(d,1H,J=8.4Hz),6.31(d,1H,J=10.2Hz),5.67(d,1H,J=9.6Hz),2.25(s,3H,CH3),1.45(s,6H,2CH3); 13C NMR(150MHz, CDCl3)δ167.3,156.4,145.8,131.4,130.7,129.7,128.1,125.7,124.5,121.6,121.1,116.4,114.0,77.3,28.2,20.5.HRMS(ESI)calcd for C 19 H 20 N₂O₂Na[M+Na] + m / z:331.1422,found 331.1423.

[0069] Examples of compound bioactivity assays

[0070] The growth rate method was used to determine the inhibitory activity of the compounds against ten plant pathogenic fungi: *Fusarium sulphureum* (MG), *Fusarium oxysporum* f.sp. *Niveum* (XK), *Phytophthora capsici* (LY), *Fusarium graminearum* (XC), *Sclerotinia sclerotiorum* (YJ), *Valsa mali* (PF), *Altenaria alternariae* (YC), *Pyricularia oryzae* (SD), *Alternaria brassicae* (BH), and *Botrytis cinerea* (FH). Acetone solution was used as a blank solvent control; hymexazol and chlorothalonil technical grade were used as positive control agents.

[0071] Dissolve the test drug in acetone, accurately transfer a measured amount of the solution into potato dextrose agar (PDA) medium to prepare a 50 μg / mL drug-containing medium, and then pour the medium into sterilized petri dishes and cool. Then, inoculate different test bacterial colonies with a diameter of 4 mm, with three replicates per group. A blank control, a chlorothalonil control group, and a hymexazol control group are also included. The cultures are incubated for 96 hours at T = 26 ± 1℃, RH = 70-80%, and L / D = 12h / 12h. Colony diameter is measured using the cross-sectional method, and the inhibition rate of each agent on mycelial growth is calculated using the following formula.

[0072]

[0073] The results of the activity test are shown in Table 2:

[0074] Table 2. Inhibitory activity of compounds against ten plant pathogenic fungi at a concentration of 50 μg / mL.

[0075]

[0076]

[0077] Note: "-" in the table indicates no activity.

[0078] Table 2 shows that the 18 synthesized target compounds all exhibited certain inhibitory effects against various plant pathogenic fungi at a concentration of 50 μg / mL. Among them, compounds 6a, 6c, 6d, 6e, and 6h showed excellent and broad-spectrum inhibitory effects against all ten tested plant pathogenic fungi, with inhibition rates of 58.8-98.7%, which were superior to the commercial fungicides hymexazol (26.8-72.7%) and chlorothalonil (47.7-97.7%). Compounds 6b, 6l, and 6p showed good inhibitory activity against nine pathogenic fungi other than Fusarium wilt of watermelon, with inhibition rates of 62.5-98.7%. Compounds 6g, 6i, 6m, 6q, and 6r showed significantly better antibacterial effects against some strains than the two positive control drugs hymexazol and chlorothalonil. However, the remaining compounds 6f, 6j, 6k, 6n, and 6o showed low inhibitory activity against the ten tested plant pathogenic fungi. Preliminary structure-activity relationship studies show that: (1) When the benzene ring is monosubstituted, compounds containing halogen electron-withdrawing groups are more active than compounds containing electron-donating groups, for example: 6b-d and 6o-r; (2) The more substitutions on the benzene ring, the lower the antibacterial activity, such as 6f and 6b-c, 6h and 6i-k; (3) Compounds containing pyridine rings are less active than compounds substituted with benzene rings, such as 6n and 6a.

[0079] Next, to further determine the antibacterial efficacy of some compounds in the preliminary activity screening, we determined the half-maximal effect concentration (EC50) of compounds 6a, 6b, 6c, 6d, 6e, 6g, 6h, 6i, 6l, 6p, 6m, 6q, and 6r. 50 Tests were conducted. Table 3 shows that compounds 6b, 6c, 6d, 6e, 6h, 6i, and 6l are effective against the potato dry rot pathogen MG:EC. 50 The inhibitory activity of 0.32-8.84 μg / mL was superior to that of the positive control chlorothalonil EC. 50 =13.05 μg / mL; EC50 of compounds 6d, 6e, and 6h against *Fusarium wilt* var. *fusarium*. 50 The values ​​were 7.49 μg / mL, 6.42 μg / mL, and 8.14 μg / mL, respectively, which were similar to those of chlorothalonil EC. 50= 8.83 μg / mL equivalent; compounds 6a, 6b, 6c, 6d, 6e, 6h, 6i and 6l are effective against *Phytophthora capsici* LY: EC 50 =0.16-11.05 μg / mL and apple rot pathogen PF: EC 50 =0.03-3.46 μg / mL, the inhibitory activity was significantly higher than that of the positive control chlorothalonil LY:EC 50 =13.79 μg / mL, PF: EC 50 = 8.96 μg / mL; compounds 6b, 6c, 6d, 6e, 6h and 6l are effective against EC50 of Fusarium graminearum, the causal agent of wheat blight. 50 =0.17-2.35 μg / mL of inhibitory activity compared to chlorothalonil EC 50 =2.78 μg / mL strong; compounds 6a, 6b, 6c, 6d, 6e, 6h, 6l and 6m showed EC50 against *Sclerotinia sclerotinia* YJ, the causal agent of rapeseed infection. 50 The concentration ranged from 0.71 to 6.57 μg / mL, which is the concentration of the positive control drug chlorothalonil YJ:EC. 50 = 26.28-2.84 times that of 18.66 μg / mL; except for compound 6r against *Tobacco Acinarella* YC and compound 6m against *Cabbage Black Spot* BH, the other 12 compounds showed EC activity against these two bacteria YC: 50 =0.16-14.56 μg / mL, BH:EC 50 The inhibitory activity of 0.26-24.10 μg / mL was superior to that of the positive control oxadixyl YC:EC 50 =16.60 μg / mL, BH:EC 50 =33.80 μg / mL; Furthermore, all compounds showed efficacy against the rice blast fungus SD:EC 50 The inhibitory activity of 0.87-12.56 μg / mL was significantly better than that of chlorothalonil SD:EC. 50 = 37.15 μg / mL, but only the FH of compound 6e: EC 50 =0.34 μg / mL and 6 l of FH:EC 50 =0.31 μg / mL, the inhibitory activity against tomato gray mold is comparable to that of chlorothalonil. FH:EC 50 =0.45μg / mL.

[0080] Table 3 shows the EC50 inhibitory activity of compounds against plant pathogenic fungi. 50 (μg·mL -1 )value

[0081]

[0082]

[0083]

[0084]

[0085] Figure 1 The graph shows the inhibitory activity of compound 6c prepared in this invention against tomato gray mold FH at mass concentrations of 50 μg / mL, 12.5 μg / mL, 6.25 μg / mL, 3.125 μg / mL, and 1.5625 μg / mL. Figure 2 The inhibitory activity of compound 6h prepared in this invention against apple rot pathogen PF at mass concentrations of 50 μg / mL, 12.5 μg / mL, 6.25 μg / mL, 3.125 μg / mL and 1.5625 μg / mL is shown in the graph. Compared with the blank control (CK), the colony diameter of each pathogen decreased significantly with the increase of the mass concentration of compounds 6c and 6h, showing a dose-dependent effect.

[0086] In summary, this invention has prepared a series of chromene aryl hydrazide derivatives, and these compounds can be used to control plant diseases caused by plant pathogenic fungi. Antimicrobial activity tests show that some of the chromene aryl hydrazide compounds prepared in this invention exhibit superior and broader-spectrum antimicrobial activity compared to commercially available antimicrobial agents such as chlorothalonil and oxadixyl. In particular, compounds 6c, 6d, 6e, and 6h all showed excellent inhibitory activity against the ten tested plant pathogenic fungi, demonstrating significant development potential. Therefore, this invention provides a class of candidate compounds with novel skeletons, outstanding activity, and a broad antimicrobial spectrum for the research and development of plant-derived agricultural fungicides.

[0087] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0088] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A chromene arylhydrazide derivative, characterized in that, The chromene arylhydrazide derivatives include any one of the following compounds: 。 2. The application of the chromene arylhydrazide compound of claim 1 in the preparation of agricultural antibacterial agents, characterized in that, The agricultural antibacterial agent is used to prevent and control plant diseases caused by plant pathogenic fungi, which are selected from the following fungi: potato dry rot fungus, watermelon wilt fungus, pepper phytophthora fungus, wheat scab fungus, rapeseed sclerotium rot fungus, apple rot fungus, tobacco red spot fungus, rice blast fungus, Chinese cabbage black spot fungus, or tomato gray mold fungus.

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