Whitening compound containing picolinamide structure as well as preparation method and application of whitening compound

Abstract

The invention discloses a whitening compound containing a picolinamide structure as well as a preparation method and application thereof, and belongs to the technical field of medicine synthesis. The whitening compound containing the picolinamide structure provided by the invention has a structure as shown in a general formula (I), in the formula (I), a preparation method mainly comprises the step of contacting a compound with a structure as shown in a formula (II) in the presence of an alkaline solvent, and A, B and X are respectively defined as in the specification. The compound containing the picolinamide structure has an excellent effect on preventing and treating gramineous weeds or broadleaf weeds, the safety of crops is relatively high, and the effect is even superior to that of some commercial herbicides sold in the market. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of pharmaceutical synthesis, and particularly relates to an albinoid compound containing a pyridine amide structure, a preparation method thereof, and an application thereof. Background Art

[0002] Phytoene desaturase (EC 1.3.99.26, PDS) is the first rate-limiting enzyme in the biosynthesis of carotenoids in plants. Plant photosynthesis mainly depends on chlorophyll in chloroplasts, and at the same time, both photosystem I and II protein complexes in chloroplasts contain carotenoids. Carotenoids are key accessory pigments in plant photosynthesis and are also important precursors for the synthesis of the plant hormone abscisic acid. The biosynthesis process of carotenoids requires two key precursor substances: isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The mechanism of action of IPP in higher plants is generally formed through the methylerythritol pathway. In this process, glyceraldehyde 3-phosphate and pyruvate are precursor substances, and through a series of biochemical reactions, IPP is generated. Under the action of IPP isomerase, IPP is isomerized to generate DMAPP, and then DMAPP is condensed with three IPP molecules under the catalytic action of geranylgeranyl pyrophosphate synthase to form geranylgeranyl pyrophosphate (GGPP). Two GGPP molecules are catalyzed by phytoene synthase to form phytoene, and then PDS catalyzes the desaturation process of phytoene to generate ζ-carotene. Then, dehydrogenation occurs under the catalysis of ζ-carotene desaturase, and dehydrogenation is catalyzed by carotenoid isomerase to obtain trans-lycopene. Finally, through a series of cyclization reactions, various carotenoids are formed. Inhibition of PDS will hinder the biosynthesis of carotenoids in plants, making it impossible for plants to carry out normal photosynthesis, resulting in leaf whitening. Although the treated plants may grow temporarily, due to their inability to produce green leaf tissue for photosynthesis, their growth cannot continue, ultimately leading to growth stagnation and plant death.

[0003] At present, 7 commercial PDS inhibitors have entered development, application and the market in the world. The main varieties are: pyridazinone, norflurazon; phenylfuranone, flurtamone; pyridine, fluridone; pyrrolidone, flurochloridone; amide, flufenacet, flufenacet and fluthiacet-methyl. Among them, flufenacet can achieve the most ideal herbicidal effect when applied before and early after the germination of weeds. As the leaf age of weeds increases, its control effect will decrease. Mixing with some foliar herbicides can improve herbicidal activity and extend the drug efficacy period. Flufenacet is mainly used in wheat fields and paddy fields to control various annual gramineous weeds and some broad-leaved weeds. This variety has a relatively long residual period and is a "high-volume" variety occupying an important market position. Therefore, PDS-inhibiting herbicides are a type of herbicides with great research value and development prospects, and at the same time, they have attracted the R & D investment of many pesticide companies. Summary of the Invention

[0004] For the above reasons, in view of the problems or defects existing in the prior art, the purpose of the present invention is to provide a kind of albino compound containing a pyridine amide structure, its preparation method and application, aiming to solve a part of the problems in the prior art or at least alleviate a part of the problems in the prior art.

[0005] The present invention is realized as follows. The first object of the present invention is to provide an albino compound containing a pyridine amide structure, and the structural general formula of the albino compound containing a pyridine amide structure is shown as the following formula (I):

[0006]

[0007] A and B independently selected from halogen, cyano, hydroxyl, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl; wherein: the cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl is optionally substituted by one or more substituents selected from the following: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclic group, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl;

[0008] X is independently selected from -H and -C(O)R each time it appears; where: R is independently halogen, cyano, hydroxy, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl, where: the cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl is optionally substituted with one or more substituents selected from: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclic group, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl.

[0009] The second object of the present invention is to provide a method for preparing a depigmenting compound containing a pyridine amide structure as described above, by subjecting a compound having the structure shown in the following formula (II) to a nucleophilic addition reaction in the presence of a basic solvent.

[0010]

[0011] Wherein, A is independently selected from halogen, cyano, hydroxy, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl; the cycloalkyl, cycloalkenyl, heterocyclic group, aryl or heteroaryl is optionally substituted with one or more substituents selected from: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclic group, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl.

[0012] Furthermore, the synthetic route of the depigmenting compound containing a pyridine amide structure is as follows:

[0013]

[0014] Wherein compound 3 is the compound shown in the above formula (II).

[0015] Furthermore, the synthetic method for obtaining compound 3 from compound 1 can be: under basic conditions, subjecting compound 1 and compound 2 to an addition reaction in the presence of a palladium catalyst to obtain compound 3.

[0016] The base used in the above reaction can be various acid-binding agents well known in the art. For example, sodium hydroxide, potassium carbonate, triethylamine, diethylamine, pyridine and cesium carbonate can be used alone or in combination, and potassium carbonate is preferably used. The dosage of the above acid-binding agent, relative to the dosage of compound 1, is preferably 1.1 - 1.5 equivalents, and more preferably 1.2 - 1.4 equivalents.

[0017] The palladium catalysts used in the above reaction can be one or more of palladium acetate, palladium chloride, tetrakis(triphenylphosphine)palladium, bis(tri-tert-butylphosphine)palladium, and palladium on carbon, preferably tetrakis(triphenylphosphine)palladium. The dosage of the above palladium catalyst, relative to the dosage of compound 1, is preferably 5:1 - 15:1 equivalents, more preferably 10:1 equivalents.

[0018] The solvents required in the above reaction can be 95% ethanol; tetrahydrofuran; isopropanol:water (V:V) = 1:1; ethanol:water (V:V) = 1:1; toluene:water (V:V) = 1:1 and toluene:ethanol:water (V:V:V) = 3:2:1, more preferably toluene:ethanol:water (V:V:V) = 3:2:1.

[0019] The temperature of the addition reaction in the above reaction is preferably 85 - 100 °C, more preferably 95 °C. The reaction time is preferably 12 - 20 hours, more preferably 15 - 17 hours.

[0020] Furthermore, the synthetic method for obtaining compound (I) from compound 3 can be: under alkaline conditions, using a catalyst, subjecting compound 3 to an addition reaction with a nucleophile to obtain compound (I).

[0021] The above-mentioned nucleophile can be various substituted acyl chlorides well-known in the art. The dosage of the nucleophile, relative to the dosage of compound 3, is preferably 1 - 2 equivalents, more preferably 1.4 - 1.6 equivalents.

[0022] The base used in the above-mentioned addition reaction can be various acid-binding agents well-known in the art. For example, one or more of sodium hydroxide, potassium carbonate, triethylamine, diethylamine, pyridine, and cesium carbonate can be used, preferably triethylamine. The dosage of the above acid-binding agent, relative to the dosage of compound 3, is preferably 1.2 - 1.8 equivalents, more preferably 1.5 - 1.7 equivalents.

[0023] The catalyst used in the above-mentioned addition reaction can be one or more of 1-hydroxybenzotriazole, 1-hydroxy-7-azabenzotriazole, 4-dimethylaminopyridine, preferably 4-dimethylaminopyridine. The dosage of the catalyst used in the reaction is preferably 5:1 - 15:1 equivalents, more preferably 10:1 equivalents. The solvent used in the reaction can be dichloromethane, chloroform, N,N-dimethylformamide, or dimethyl sulfoxide, etc., preferably dichloromethane. The reaction temperature is 25 °C - 35 °C, preferably 20 °C - 25 °C. The reaction time is preferably 20 - 30 hours, more preferably completed within 23 - 25 hours.

[0024] The third object of the present invention is to provide the application of the above-mentioned albino compounds containing a pyridine amide structure in controlling weeds or in the preparation of herbicidal preparations.

[0025] Further, the weeds are at least one of broad-leaved weeds and gramineous weeds.

[0026] The fourth object of the present invention is to provide the application of the albino compound containing a pyridine amide structure as described above in the use as a PDS inhibitory herbicide.

[0027] The fifth object of the present invention is to provide the application of the albino compound containing a pyridine amide structure as described above in crop safety.

[0028] Further, the crops are at least one of soybean, rice, cotton, peanut, wheat, and corn.

[0029] In summary, the advantages and positive effects of the present invention are as follows:

[0030] The present invention provides an albino compound containing a pyridine amide structure and a preparation method thereof. The compound of the present invention has high safety activity for soybean, rice, and cotton while maintaining excellent herbicidal activity.

[0031] The albino compound containing a pyridine amide structure provided by the present invention has good inhibitory activity against phytoene desaturase. The albino herbicide containing a pyridine amide structure provided by the present invention has excellent herbicidal activity against weeds such as barnyard grass, redroot amaranth, abutilon theophrasti, and morning glory. The compound containing a pyridine amide structure of the present invention has high herbicidal activity, especially has excellent effects on controlling broad-leaved weeds and / or gramineous weeds, and has high safety for crops, and the effect is even better than some commercially available herbicides. Specific Embodiments

[0032] In order to make the objects, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to embodiments. The equipment and reagents used in each embodiment and test example can be obtained from commercial channels without special instructions. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The present invention discloses an albino compound containing a pyridine amide structure, a preparation method thereof, and an application thereof. In the following embodiments, the nuclear magnetic data is measured by using an Avance 600 nuclear magnetic resonance instrument, and the mass spectrometry data is measured by using a Waters UPLC / Xevo G2-XS Q-TOF LC / MS high-resolution mass spectrometer.

[0034] Example 1 Preparation of N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0035] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0036] 4.8 mmol of 3-(trifluoromethyl)phenylboronic acid was reacted with 4.3 mmol of 2-bromo-3-aminopyridine at 95 °C in the presence of 17.4 mmol of potassium carbonate as an acid scavenger and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and a solid precipitated at this time. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0037] Step B: Preparation of N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0038] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of benzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid scavenger. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 138.6-138.8 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.30(s,1H),8.64(dd,J=4.7,1.6Hz,1H),8.02(d,J=1.9Hz,1H),7.99(d,J=7.8Hz,1H),7.96(dd,J=8.0,1.6Hz,1H),7.85-7.80(m,2H),7.75-7.70(m,1H),7.65(t,J=7.8Hz,1H),7.60-7.55(m,1H),7.53(dd,J=8.0,4.7Hz,1H),7.49(t,J=7.7Hz,2H);HRMS(ES+)C 19 H 13 F 3 N 2 O[M+H] + , calculated value: 343.1058; measured value 343.1056. The structural formula is as follows:

[0039]

[0040] Example 2 Preparation of 3-Fluoro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0041] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0042] 4.8 mmol of 3-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0043] Step B: Preparation of 3-Fluoro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0044] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of m-fluorobenzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid-binding agent, and the reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 140.6 - 140.8 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.40(s,1H),8.65(dd,J=4.7,1.6Hz,1H),8.02-7.96(m,2H),7.96(dd,J=8.0,1.6Hz,1H),7.74(dd,J=7.7,1.8Hz,1H),7.70-7.64(m,2H),7.61(dt,J=9.8,2.1Hz,1H),7.55(ddd,J=14.6,8.0,5.2Hz,2H),7.47-7.40(m,1H);HRMS(ES+)C 19 H 12 F 4 N 2 O[M+H] + , calculated value: 361.0964; measured value: 361.0961. The structural formula is as follows:

[0045]

[0046] Example 3 Preparation of 3-chloro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0047] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0048] 4.8 mmol of 3-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0049] Step B: Preparation of 3-chloro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0050] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of m-chlorobenzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as a solvent, 1.5 mmol of 4-dimethylaminopyridine was used as a catalyst, and 11.0 mmol of triethylamine was used as an acid-binding agent. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 142.3 - 142.9 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.43(s,1H),8.65(dd,J=4.7,1.6Hz,1H),8.02-7.96(dd,J=8.0,1.6Hz,3H),7.85(d,J=2.4Hz,1H),7.78(d,J=7.8Hz,1H),7.73(d,J=7.8Hz,1H),7.69-7.63(m,2H),7.53(ddd,J=8.0,6.3,1.6Hz,2H);HRMS(ES+)C 19 H 12 ClF 3 N 2 O[M+H] +, Calculated value: 377.0669; Measured value: 377.0663. The structural formula is as follows:

[0051]

[0052] Example 4 Preparation of 3-Bromo-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0053] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0054] 4.8 mmol of 3-trifluoromethylphenylboronic acid was reacted with 4.3 mmol of 2-bromo-3-aminopyridine at 95 °C in the presence of 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0055] Step B: Preparation of 3-Bromo-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0056] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of 3-bromobenzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid-binding agent. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 146.5 - 146.9 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.43(s,1H),8.64(dd,J=4.7,1.6Hz,1H),7.99(dd,J=8.7,5.4Hz,3H),7.96(dd,J=8.0,1.6Hz,1H),7.83 - 7.76(m,2H),7.76 - 7.71(m,1H),7.66(t,J=7.8Hz,1H),7.53(dd,J=8.0,4.6Hz,1H),7.47(t,J=7.9Hz,1H);HRMS(ES+)C 19 H 12BrF 3 N 2 O[M+H] + , Calculated value: 421.0163; Measured value: 421.0158. The structural formula is as follows:

[0057]

[0058] Example 5 Preparation of 3-(trifluoromethyl)-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0059] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0060] 4.8 mmol of 3-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether: ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0061] Step B: Preparation of 3-(trifluoromethyl)-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0062] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of 3-trifluoromethylbenzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid-binding agent. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether: ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 170.6-170.8 °C. 1 H NMR(600MHz,DMSO-d 6)δ 10.58 (s, 1H), 8.66 (dd, J = 4.7, 1.6 Hz, 1H), 8.15 - 8.09 (m, 2H), 8.01 (d, J = 8.8 Hz, 2H), 7.98 (dd, J = 8.0, 1.5 Hz, 1H), 7.96 (d, J = 7.9 Hz, 1H), 7.78 - 7.71 (m, 2H), 7.67 (t, J = 7.7 Hz, 1H), 7.55 (dd, J = 8.0, 4.7 Hz, 1H); HRMS(ES+) C 20 H 12 F 6 N 2 O[M + H] + , calculated value: 411.0932; measured value: 411.0932. The structural formula is as follows:

[0063]

[0064] Example 6 Preparation of 3 - methyl - N - (2 - (3 - (trifluoromethyl)phenyl)pyridin - 3 - yl)benzamide

[0065] Step A: Preparation of 2 - (3 - (trifluoromethyl)phenyl)pyridin - 3 - amine

[0066] 4.8 mmol of 3 - trifluoromethylphenylboronic acid and 4.3 mmol of 2 - bromo - 3 - aminopyridine were reacted at 95 °C for 16 h with 17.4 mmol of potassium carbonate as an acid scavenger and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) after distillation under reduced pressure to obtain a yellow solid.

[0067] Step B: Preparation of 3 - methyl - N - (2 - (3 - (trifluoromethyl)phenyl)pyridin - 3 - yl)benzamide

[0068] 4.9 mmol of 2 - (3 - (trifluoromethyl)phenyl)pyridin - 3 - amine and 5.4 mmol of m - methylbenzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4 - dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid scavenger. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 156.4 - 156.8 °C.1 H NMR (600 MHz, DMSO-d 6 ) δ 10.25 (s, 1H), 8.63 (dd, J = 4.6, 1.6 Hz, 1H), 8.03 (d, J = 2.1 Hz, 1H), 7.99 (d, J = 7.7 Hz, 1H), 7.95 (dd, J = 8.0, 1.6 Hz, 1H), 7.73 (d, J = 7.8 Hz, 1H), 7.66 (t, J = 7.8 Hz, 1H), 7.65 - 7.58 (m, 2H), 7.52 (dd, J = 8.0, 4.7 Hz, 1H), 7.41 - 7.34 (m, 2H), 2.35 (s, 3H); HRMS (ES+) C 20 H 15 F 3 N 2 O [M + H] + , calculated value: 357.1215; found value: 357.1212. The structural formula is as follows:

[0069]

[0070] Example 7 Preparation of 2,4-bis(trifluoromethyl)-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0071] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0072] 4.8 mmol of 3-trifluoromethylphenylboronic acid was reacted with 4.3 mmol of 2-bromo-3-aminopyridine at 95 °C in the presence of 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and distilled under reduced pressure to obtain a brown mixture, which was purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0073] Step B: Preparation of 2,4-bis(trifluoromethyl)-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0074] Using 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of 2,4-bis(trifluoromethyl)benzoyl chloride as raw materials, dichloromethane with relatively low toxicity as the solvent, 1.5 mmol of 4-dimethylaminopyridine as the catalyst, and 11.0 mmol of triethylamine as the acid-binding agent, the reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) was used for separation to obtain a white solid. m.p. 184.6-185.0 °C. 1H NMR (600 MHz, DMSO-d 6 ) δ 10.22 (s, 1H), 8.62 (dd, J = 4.7, 1.6 Hz, 1H), 8.03 (d, J = 2.3 Hz, 1H), 7.98 (d, J = 7.7 Hz, 1H), 7.93 (dd, J = 8.0, 1.6 Hz, 1H), 7.76 - 7.71 (m, 1H), 7.66 (t, J = 7.8 Hz, 1H), 7.52 (dd, J = 8.0, 4.6 Hz, 1H), 7.41 (s, 2H), 7.20 (s, 1H); HRMS (ES+) C 21 H 11 F 9 N 2 O[M+H] + , calculated value: 479.0807; measured value: 479.0804. The structural formula is as follows:

[0075]

[0076] Example 8 Preparation of 2-chloro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)acetamide

[0077] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0078] 4.8 mmol of 3-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as the acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as the catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and at this time, the solid dissolved. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) after vacuum distillation to obtain a yellow solid.

[0079] Step B: Preparation of 2-chloro-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)acetamide

[0080] Using 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of chloroacetyl chloride as raw materials, dichloromethane with lower toxicity as the solvent, 1.5 mmol of 4-dimethylaminopyridine as the catalyst, and 11.0 mmol of triethylamine as the acid-binding agent, the reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether: ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 170.2 - 170.8 °C. 1H NMR (600 MHz, DMSO-d 6 ) δ 10.11 (s, 1H), 8.59 (dd, J = 4.6, 1.6 Hz, 1H), 7.98 - 7.92 (m, 1H), 7.95 - 7.91 (m, 1H), 7.79 (ddt, J = 7.7, 1.9, 1.0 Hz, 1H), 7.74 - 7.68 (m, 1H), 7.71–7.64 (m, 1H), 7.49 (dd, J = 8.1, 4.6 Hz, 1H), 4.22 (t, J = 6.6 Hz, 1H), 4.17 (s, 2H); HRMS (ES+) C 14 H 10 ClF 3 N 2 O[M + H] + , calculated value: 315.0513; measured value: 315.0510. The structural formula is as follows:

[0081]

[0082] Example 9 Preparation of N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)thiophene-2-carboxamide

[0083] Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0084] 4.8 mmol of 3-(trifluoromethyl)phenylboronic acid was reacted with 4.3 mmol of 2-bromo-3-aminopyridine at 95 °C in the presence of 17.4 mmol of potassium carbonate as an acid scavenger and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and a solid precipitated at this time. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) after distillation under reduced pressure to obtain a brown mixture, and a yellow solid was obtained.

[0085] Step B: Preparation of N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)thiophene-2-carboxamide

[0086] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of 2-thiophenecarbonyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid scavenger. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 180.6 - 181.2 °C. 1H NMR (600 MHz, DMSO-d 6 ) δ 10.32 (s, 1H), 8.65 (dd, J = 4.7, 1.6 Hz, 1H), 8.02 (dt, J = 2.6, 1.2 Hz, 1H), 7.99 (dd, J = 8.1, 1.6 Hz, 2H), 7.86 - 7.80 (m, 2H), 7.74 (ddd, J = 7.8, 2.1, 1.1 Hz, 1H), 7.69 - 7.63 (m, 1H), 7.55 (dd, J = 8.0, 4.7 Hz, 1H), 7.19 (dd, J = 5.0, 3.7 Hz, 1H); HRMS (ES+) C 17 H 11 F 3 N 2 OS[M + H] + , calculated value: 349.0623; measured value: 349.0627. The structural formula is as follows:

[0087]

[0088] Example 10 Preparation of N-(2-(4-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0089] Step A: Preparation of 2-(4-(trifluoromethyl)phenyl)pyridin-3-amine

[0090] 4.8 mmol of 4-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and a solid precipitated at this time. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0091] Step B: Preparation of N-(2-(4-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0092] 4.9 mmol of 2-(4-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of benzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid-binding agent, and the reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separated by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 172.4 - 172.8 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.40(s,1H),8.64(dd,J=4.7,1.5Hz,1H),8.00 - 7.96(m,2H),7.95(dd,J=8.0,1.5Hz,1H),7.77(d,J=8.3Hz,2H),7.73(q,J=3.7Hz,4H),7.65(t,J=7.7Hz,1H),7.53(dd,J=8.0,4.6Hz,1H);HRMS(ES+)C 19 H 13 F 3 N 2 O[M+H] + , calculated value: 343.1058; measured value: 343.1059. The structural formula is as follows:

[0093]

[0094] Example 11 Preparation of N-(2-(2,4-dichlorophenyl)pyridin-3-yl)benzamide

[0095] Step A: Preparation of 2-(2,4-dichlorophenyl)pyridin-3-amine

[0096] 4.8 mmol of 2,4-dichlorophenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and at this time, a solid precipitated. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0097] Step B: Preparation of N-(2-(2,4-dichlorophenyl)pyridin-3-yl)benzamide

[0098] 4.9 mmol of 2-(2,4-dichlorophenyl)pyridin-3-amine and 5.4 mmol of benzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as a solvent, 1.5 mmol of 4-dimethylaminopyridine was used as a catalyst, and 11.0 mmol of triethylamine was used as an acid-binding agent. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1-2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 163.2-163.8 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.05(s,1H),8.56(dd,J=4.7,1.6Hz,1H),8.00(dd,J=8.1,1.5Hz,1H),7.74-7.70(m,2H),7.65(d,J=2.0Hz,1H),7.58-7.52(m,2H),7.54-7.44(m,5H);HRMS(ES+)C 18 H 12 Cl 2 N 2 O[M+H] + , calculated value: 343.0405; measured value: 343.0402. The structural formula is as follows:

[0099]

[0100] Example 12 Preparation of N-benzoyl-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide Step A: Preparation of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine

[0101] 4.8 mmol of 3-(trifluoromethyl)phenylboronic acid was reacted with 4.3 mmol of 2-bromo-3-aminopyridine at 95 °C in the presence of 17.4 mmol of potassium carbonate as an acid scavenger and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst for 16 h. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and a solid precipitated at this time. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) after distillation under reduced pressure to obtain a yellow solid.

[0102] Step B: Preparation of N-benzoyl-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0103] 4.9 mmol of 2-(3-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of benzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as the solvent, 1.5 mmol of 4-dimethylaminopyridine was used as the catalyst, and 11.0 mmol of triethylamine was used as the acid scavenger. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 108.2 - 108.6 °C. 1H NMR (600 MHz, DMSO-d 6 ) δ 8.62 (dd, J = 4.8, 1.8 Hz, 1H), 7.94 (dd, J = 7.7, 1.8 Hz, 1H), 7.76 (d, J = 8.1 Hz, 2H), 7.58 (dd, J = 7.7, 4.8 Hz, 1H), 7.55 (d, J = 8.0 Hz, 2H), 7.50 - 7.44 (m, 2H), 7.46 - 7.41 (m, 4H), 7.36 - 7.30 (m, 4H); HRMS (ES+) C 26 H 17 F 3 N 2 O [M + H] + , calculated value: 447.1321; measured value: 447.1316. The structural formula is as follows:

[0104]

[0105] Example 13 Preparation of N-benzoyl-N-(2-(4-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0106] Step A: Preparation of 2-(4-(trifluoromethyl)phenyl)pyridin-3-amine

[0107] 4.8 mmol of 4-trifluoromethylphenylboronic acid and 4.3 mmol of 2-bromo-3-aminopyridine were reacted at 95 °C for 16 h with 17.4 mmol of potassium carbonate as an acid-binding agent and 0.4 mmol of tetrakis(triphenylphosphine)palladium as a catalyst. After the reaction was completed, it was cooled to room temperature, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The aqueous phase was separated, sodium bicarbonate was added to the aqueous phase, and a solid precipitated at this time. Ethyl acetate was added, and the solid dissolved at this time. The organic phase was extracted and purified by column chromatography (petroleum ether:ethyl acetate = 4:1, V:V) to obtain a yellow solid.

[0108] Step B: Preparation of N-benzoyl-N-(2-(3-(trifluoromethyl)phenyl)pyridin-3-yl)benzamide

[0109] 4.9 mmol of 2-(4-(trifluoromethyl)phenyl)pyridin-3-amine and 5.4 mmol of benzoyl chloride were used as raw materials, dichloromethane with low toxicity was used as a solvent, 1.5 mmol of 4-dimethylaminopyridine was used as a catalyst, and 11.0 mmol of triethylamine was used as an acid-binding agent. The reaction was carried out at 25 °C for 24 h. After the reaction was completed, 100 mL of water was added, and the pH was adjusted to 1 - 2 with 10% dilute hydrochloric acid while stirring. The organic phase was extracted, dichloromethane was removed by rotary evaporation, and separation was carried out by column chromatography (petroleum ether:ethyl acetate = 10:1, V:V) to obtain a white solid. m.p. 149.6 - 149.6 °C. 1 H NMR(600MHz,DMSO-d 6 )δ10.55(s,1H),8.66(dd,J=4.7,1.5Hz,1H),8.04 - 7.95(m,5H),7.89(d,J=8.0Hz,2H),7.75 - 7.71(m,1H),7.66(t,J=7.7Hz,1H),7.55(dd,J=8.0,4.7Hz,1H);HRMS(ES+)C 26 H 17 F 3 N 2 O 2 [M+H] + , calculated value: 447.1321; measured value: 447.1316. The structural formula is as follows:

[0110]

[0111] A series as shown in the following table was also synthesized by a similar method above, and all compounds were confirmed by NMR and high-resolution mass spectrometry.

[0112]

[0113] The yields of the group compounds represented by A, B, and X in the structural formula are shown in Table 1:

[0114] Table 1: Yields of the group compounds represented by A, B, and X in the structural formula

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] Note: The yield is the yield after the last step of purification.

[0121] Example 14: Inhibitory activity test of albino herbicides containing pyridine amide structure against PDS

[0122] In this example, the enzyme activity test was carried out according to the methods described in the literature "Ind. Crops Prod. 2019, 137, 566 - 575 and J. Agric. Food Chem. 2010, 58, 2643 - 2651" to obtain the inhibitory activity (half - inhibitory concentration IC 50 ) of the albino herbicides containing pyridine amide structure described in the present invention and the control requirements against PDS. The results are shown in Table 2.

[0123] Table 2: Comparative table of inhibitory activities of albino herbicides containing pyridine amide structure and control compounds against PDS

[0124]

[0125]

[0126] It can be seen from the results shown in Table 2 that the above - mentioned compounds have certain inhibitory activity against PDS. I - 12, I - 17, I - 29, I - 30, I - 31, I - 67 show excellent activity. In particular, the inhibitory activity of I - 31 is better than that of the commercially available control agent flufenacet.

[0127] From the above results, it can be known that when R and X are electron - withdrawing groups, it is beneficial to improve the inhibitory activity of the compound, and the stronger the electron - withdrawing ability of R and X, the higher the inhibitory activity of the compound; for the X - substituted compounds, the para - substituted compounds have higher activity than the ortho - and meta - substituted compounds.

[0128] Example 15 Herbicidal Activity Experiment

[0129] This example is used to illustrate the herbicidal activity inhibition rate (%) (dose is 300 g / ha) of the albino compounds containing pyridine amide structure described in the present invention.

[0130] Preliminary screening test: The test weeds are Pharbitis nil, Echinochloa crusgalli, Abutilon theophrasti, and Amaranthus retroflexus. Take a certain amount of soil passed through a 2-mm sieve, evenly sow the selected plump and peeled weed seeds on the soil, cover a layer of soil about 1 cm thick, water appropriately, and grow under room temperature and light irradiation conditions. Make up water every day to keep the soil humidity at about 80%, the growth temperature is 25 - 30 °C, and the air humidity is above 70%. Wait until the weeds grow to about the 3-leaf stage for standby. Each compound is evenly sprayed on the leaves with the prepared test solution at a dose of 300 g / ha. The weeds continue to grow under light irradiation conditions for 4 days and then the results are investigated. The inhibition rate (%) results are shown in Table 3.

[0131] Table 3 Comparison Table of Herbicidal Activity Inhibition Rates (%) of Different Compounds

[0132] Name Morning Glory Barnyard Grass Abutilon theophrasti Medic Redroot Amaranth Diflufenican 80 40 65 95 I-31 95 65 40 80 I-67 95 55 40 65

[0133] It can be seen from the results shown in Table 3 that the above compounds have generally higher activities against Pharbitis nil and Echinochloa crusgalli than the commercially available herbicide flufenacet.

[0134] Example 16 Safety Experiment

[0135] This example is used to illustrate the safety of the albino compounds containing pyridine amide structure described in the present invention as herbicides. Test crops: soybean, rice, cotton, peanut, wheat, corn.

[0136] Planting methods for rice, wheat, and corn: Soak the carefully selected plump seeds in warm water at about 40 °C for 1 h, sterilize them with 0.6% carbendazim for 30 min, then rinse them with distilled water. Put the treated seeds into a culture dish and place them in an incubator with the temperature set at 28 °C for 48 h of germination. Take residue-free soil and place it in a flower pot with a radius of 7 cm, then sow the germinated seeds with consistent germination into the soil (9 seeds per pot for corn, 25 seeds per pot for rice and wheat). Cover a thin layer of soil above the seeds, water them, and then put them into an artificial climate chamber at a temperature of 28 °C and a humidity of 80%. Cultivate them under the condition of 12 h light and 12 h dark cycle. When they grow to the 2-leaf stage, spray the stems and leaves of them with the solutions of Compound I-31 and flufenacet at 300 g ai / ha, and spray an equal amount of clear water as a blank control. After the liquid medicine dries, move them into the artificial climate chamber again, and measure the content of carotenoids in the leaves after 7 days.

[0137] Planting methods for soybeans, cotton, and peanuts: Take soil without herbicide residues and place it in a circular flower pot with a radius of 7 cm. Then sow the untreated seeds into the soil (9 seeds of peanuts, soybeans, and cotton per pot each). Cover the seeds with approximately 2.5 cm of soil. After watering, place it in an artificial climate chamber (temperature 28°C, humidity 80%), and cultivate it under the condition of 12-hour cycles of light and darkness. When cotton and soybeans grow to the two-leaf stage and peanuts grow to the four-leaf stage, spray the compound I-31 and flufenacet solution at 300 g ai / ha on their stems and leaves, and spray an equal amount of clear water as a blank control. After the liquid medicine dries, move it back into the artificial climate chamber again. After 7 days, measure the contents of chlorophyll and carotenoids in the leaves.

[0138] Table 4 Comparison table of the chlorophyll content (mg / L) in the stems and leaves of different compounds for crops

[0139] Serial Number Dosage (g / ha) Soybean Rice Cotton Peanut Wheat Corn CK 300 8.82 4.74 5.10 7.44 6.32 7.00 Diflufenican 300 2.17 3.42 3.41 6.97 4.78 6.46 I-31 300 4.80 3.77 4.41 4.76 4.33 5.15 I-67 300 5.69 3.52 3.75 5.33 4.48 5.28

[0140] As can be seen from the results shown in Table 4, the above-mentioned compounds can all be used as herbicides, and the safety of compound I-31 at a dose of 300 g / ha for soybeans, rice, and cotton is significantly higher than that of the commercially available herbicide flufenacet.

[0141] From the above data, it can be known that the albino compounds containing pyridine amide fragments prepared in the present invention have excellent effects on controlling broad-leaved weeds or gramineous weeds, and the crop safety is relatively high.

[0142] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A whitening compound containing a pyridine amide structure, characterized in that: The general structural formula of the whitening compound containing a pyridine amide structure is shown in the following formula (I): A and B are independently selected from halogen, cyano, hydroxyl, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl; wherein: the cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl is optionally substituted with one or more substituents selected from the following: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl; X is independently selected at each occurrence from -H, -C(O)R; wherein: said R is independently halogen, cyano, hydroxyl, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl, wherein: said cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl is optionally substituted with one or more substituents selected from the following: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl.

2. The method for preparing the whitening compound containing a pyridine amide structure according to claim 1, characterized in that: The method specifically comprises subjecting a compound having a structure shown in the following formula (II) to a nucleophilic addition reaction in the presence of an alkaline solvent. wherein A is independently selected from halogen, cyano, hydroxyl, nitro, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl; and one or more of the cycloalkyl, cycloalkenyl, heterocyclyl, aryl or heteroaryl is optionally substituted by one or more substituents selected from the following: optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted aralkyl or optionally substituted heteroaralkyl, halogen, cyano, nitro, haloalkyl.

3. The method for preparing the whitening compound containing a pyridine amide structure according to claim 2, characterized in that: The synthetic route of the whitening compound containing pyridine amide structure is as follows: The compound 3 is the compound represented by formula (II) as claimed in claim 2.

4. The method for preparing the whitening compound containing a pyridine amide structure according to claim 3, characterized in that: The synthesis method for obtaining compound 3 from compound 1 is: under alkaline conditions, compound 1 and compound 2 are subjected to addition reaction in the presence of a palladium catalyst to obtain compound 3.

5. The method for preparing the whitening compound containing a pyridine amide structure according to claim 3, characterized in that: The synthesis method of compound (I) from compound 3 is: using a catalyst under alkaline conditions, compound 3 is subjected to an addition reaction with a nucleophilic reagent to obtain compound (I).

6. Use of the whitening compound containing a pyridine amide structure according to claim 1 as a PDS inhibitor.

7. Use of the albino compound containing a pyridine amide structure according to claim 1 in controlling weeds or in preparing herbicide preparations.

8. The use according to claim 7, characterized in that: The weeds are at least one of broadleaf weeds and grass weeds.

9. Use of the albino compound containing a pyridine amide structure according to claim 1 in crop safety.

10. The use according to claim 9, characterized in that: The crop is at least one of soybean, rice, cotton, peanut, wheat and corn.

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