Cotton defoliating agent containing fluthidiazuron-containing derivative and application of cotton defoliating agent

Abstract

The invention provides a cotton defoliating agent containing a fluthidiazuron-containing derivative, and belongs to the technical field of plant growth regulators, the fluthidiazuron-containing derivative has the following structural formula: # imgabs0 #, and R is 0-5 fluorine atoms at any position of a benzene ring. According to the defoliating agent, the use temperature of the defoliating agent can be effectively reduced, the phenomenon that the defoliating agent is withered but does not fall after being applied is eliminated, and the yield and quality of cotton are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of plant growth regulators, in particular to a cotton defoliant containing a fluthiadiazuron derivative and application thereof. Background Art

[0002] Cotton is one of the most important cash crops in my country. In recent years, with the change of labor structure and the increase of labor cost in major cotton-producing areas, machine-picked cotton has been rapidly promoted. Chemical defoliation is the key to mechanical harvesting of cotton. Unsatisfactory defoliation effect and high impurity rate will affect the quality of machine-picked cotton.

[0003] Thidiazuron is a new and highly effective plant growth regulator with strong cell division activity. It can promote plant photosynthesis, improve fruit quality, and increase fruit storage resistance. When used as a defoliant in cotton planting, it can promote the natural formation of separation tissue between petioles and stems and cause leaf fall early, which is conducive to mechanical cotton harvesting and helps to improve cotton grades. However, when using thiazuron, there is no obvious defoliation effect when the daily minimum temperature is below 12°C, which means that thiazuron should not be used too late. If a product that can defoliate at low temperatures can be found, the application time of the defoliant can be postponed, so that more cotton bolls can be opened, and cotton yield and quality can be increased.

[0004] The invention aims to design and synthesize new fluorine-containing thiadiazole derivatives, study their properties, and contribute to the development of new cotton defoliants to increase cotton yield and quality. Summary of the invention

[0005] The invention provides a cotton defoliant containing a fluorinated thidiazuron derivative and application thereof, which solves the problem that the existing cotton defoliant containing thidiazuron is sensitive to temperature and has no obvious defoliation effect when the daily minimum temperature is lower than 12°C.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A cotton defoliant containing a fluorinated thiadipyridinium derivative, wherein the structural formula of the fluorinated thiadipyridinium derivative is as follows:

[0008]

[0009] Wherein, R is a benzene ring containing 0 to 5 fluorine atoms at any position.

[0010] Wherein, abscisic acid is also contained, and the mass ratio of the abscisic acid to the fluorinated thiadiazole derivative is 1:

[0011] (1-30).

[0012] Wherein, the mass ratio of the abscisic acid to the fluorine-containing thiadiazole derivative is 1:(1-20).

[0013] Wherein, the mass ratio of the abscisic acid to the fluorinated thiadiazole derivative is 1:(1-10).

[0014] Wherein, the dosage form of the defoliant is selected from one of wettable powder injection, dispersible suspension, solution and microemulsion.

[0015] The application of the above cotton defoliant in cotton defoliation.

[0016] The synthetic route of the fluorine-containing thiadiazole derivative is as follows:

[0017]

[0018] The preparation method of the fluorine-containing thiadiazole derivative comprises the following steps:

[0019] Step 1, using 5-amino-1,2,3-thiadiazole as a raw material, reacting with di-tert-butyl dicarbonate to obtain an amino-protected intermediate;

[0020] Step 2, fluorinating the reaction intermediate obtained in step 1 with a fluorinating agent to obtain a 4-fluoro intermediate;

[0021] Step 3, removing the amino protection to obtain 5-amino-4-fluoro-1,2,3-thiadiazole;

[0022] Step 4, 5-amino-4-fluoro-1,2,3-thiadiazole is reacted with different fluorinated phenyl isocyanates, and filtered to obtain different fluorine-containing thiadiazole derivatives.

[0023] Wherein, in step 1, the molar ratio of 5-amino-1,2,3-thiadiazole to di-tert-butyl dicarbonate is 1:1 to 1.5.

[0024] Wherein, in step 2, the fluorination reagents used include Selectfluor, Accufluor, NFSI, and AgF2 reagents, and the molar ratio of the amino-protected intermediate to the fluorination reagent is 1:1.5-3.

[0025] Wherein, in step 2, the solvent used is tetrahydrofuran, acetonitrile, DMF, acetone or dichloromethane.

[0026] Wherein, in step 2, the reaction temperature is between 25°C and 80°C, and the reaction time is between 2 and 8 hours.

[0027] Wherein, in step 3, the amino protection removal reagent used includes trimethylchlorosilane, hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, and trifluoroacetic acid.

[0028] Wherein, in step 4, the different fluorinated phenyl isocyanates include phenyl isocyanate, 2-fluorophenyl isocyanate, 3-fluorophenyl isocyanate, 4-fluorophenyl isocyanate, 2,3-difluorophenyl isocyanate, 2,4-difluorophenyl isocyanate, 3,4-difluorophenyl isocyanate, 2,5-difluorophenyl isocyanate, 2,6-difluorophenyl isocyanate, 2,3,4,-trifluorophenyl isocyanate, 2,3,5-trifluorophenyl isocyanate, and 3,4,5-trifluorophenyl isocyanate.

[0029] Wherein, in step 4, the molar ratio of 5-amino-4-fluoro-1,2,3-thiadiazole to different fluorinated phenyl isocyanate isocyanates is 1:1.01-1.2.

[0030] Wherein, in step 4, the reaction solvent is dichloromethane, tetrahydrofuran, acetonitrile or DMF.

[0031] Wherein, in step 4, the reaction temperature is 25°C to 50°C, and the reaction time is 1 to 24 hours.

[0032] Compared with the prior art, the present invention has the following beneficial technical effects:

[0033] 1. The defoliant of the present invention can effectively reduce the use temperature of the defoliant, eliminate the phenomenon of withering but not falling after the defoliant is applied, and ensure the yield and quality of cotton.

[0034] 2. The defoliant components of the present invention are reasonably compounded, showing a certain synergistic defoliation effect, effectively reducing the application temperature of the defoliant, and being beneficial to improving the quality of machine-picked cotton. At the same time, the defoliant does not contain herbicides and ethephon components, reducing soil environmental pollution and residues caused by chemical defoliation. DETAILED DESCRIPTION

[0035] The following embodiments are provided for a better understanding of the present invention, but are not limited to the best mode of implementation, and do not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0036] Example 1

[0037] The present embodiment provides a method for preparing a fluorine-containing thiadiazole derivative, comprising the following steps:

[0038] Step 1: Synthesis of 1-(4-fluoro-1,2,3-thiadiazol-5-yl)-3-phenylurea (R=H)

[0039] Weigh 15 g (150 mmol) of 5-amino-1,2,3-thiadiazole into a 250 ml round-bottom flask, add 150 ml of dichloromethane, 42.5 ml (180 mmol) of di-tert-butyl dicarbonate, 42.5 ml (300 mmol) of triethylamine, and 1.8 g (15 mmol) of 4-dimethylaminopyridine. The reaction mixture is stirred at 30°C for 2 h, then concentrated, and the residue is purified by silica gel chromatography to obtain 18.5 g (92 mmol) of tert-butyl N-(thiadiazole-5-yl)carbamate as a white solid, with a yield of 62%. 1 H NMR (DMSO, 400MHz) δ: 11.73 (s, 1H), 8.42 (s, 1H), 1.50 (s, 9H). 13 C NMRδ: 153.71, 153.19, 133.96, 82.33, 27.72.

[0040] Step 2: Synthesis of tert-butyl N-(4-fluoro-thiadiazole-5-yl)carbamate

[0041] Weigh 10g (50mmol) of tert-butyl N-(thiadiazole-5-yl)carbamate, add 100ml of anhydrous acetonitrile, 35g (100mmol) of fluorination reagent Selectfluor, replace with nitrogen 3 times, heat to 60°C for 4h, after the reaction, concentrate the reaction solution, add 150ml of ethyl acetate to dissolve, add 150ml of water to extract, extract the aqueous phase with 150ml of ethyl acetate twice, combine the organic phases, add anhydrous sodium sulfate to dry. Filter and evaporate the organic phase, purify by silica gel chromatography to obtain 3.5g (16mmol) of tert-butyl N-(4-fluoro-thiadiazole-5-yl)carbamate as a white solid, with a yield of 31.8%. 1 H NMR (CDCl3, 400MHz) δ: 7.58 (s, 1H), 1.55 (s, 9H). 13 C NMRδ: 158.65, 156.17, 151.99, 132.62, 132.41, 84.55, 27.99.

[0042] Step 3: Synthesis of 4-fluoro-1,2,3-thiadiazole

[0043] Weigh 3 g (13.7 mmol) of tert-butyl N-(4-fluoro-thiadiazole-5-yl)carbamate, add 30 ml of trifluoroethanol and 2 ml (15.7 mmol) of trimethylsilyl chloride, stir at 25 °C for 1 h, monitor the disappearance of the reaction raw materials by TLC, evaporate the solvent, and purify by silica gel chromatography to obtain 1.4 g (11.76 mmol) of 4-fluoro-1,2,3-thiadiazole in a yield of 85.9%. 1 H NMR (DMSO, 400MHz) δ: 7.16 (s, 2H).13 C NMRδ: 156.73, 154.33, 146.45, 146.21.

[0044] Step 4: Synthesis of 1-(4-fluoro-1,2,3-thiadiazol-5-yl)-3-phenylurea

[0045] Weigh 2g (16.8mmol) of 4-fluoro-1,2,3-thiadiazole, add 20ml of THF to dissolve, replace with nitrogen and seal. Weigh 2.1g (17.65mmol) of phenyl isocyanate, dilute with 20ml of THF, slowly add to the reaction bottle with a syringe, replace with nitrogen 3 times, stir at 25℃ for 1h, filter the precipitated solid, wash with THF and dry to obtain 2g (8.4mmol) of 1-(4-fluoro-1,2,3-thiadiazole-5-yl)-3-phenylurea, with a yield of 50%. 1 H NMR (DMSO, 400MHz) δ: 10.82 (s, 1H), 9.18 (s, 1H), 7.49 (d, 2H), 7.35 (d, 2H), 7.08 (t, 1H), 13 C NMRδ: 158.57, 156.12, 151.47, 146.45, 146.21.

[0046] The results of different reaction conditions in step 1 are shown in Table 1.

[0047] Table 1 Different reaction conditions and reaction results of step 1

[0048] Reaction conditions 1 Reaction Condition 2 Reaction conditions 3 Reaction Conditions 4 Reaction conditions 5 5-Amino-1,2,3-thiadiazole dosage (mmol) 150 150 150 150 150 Di-tert-butyl dicarbonate dosage (mmol) 180 150 225 195 165 Dichloromethane dosage (ml) 150 150 150 150 150 Triethylamine dosage (mmol) 300 300 300 300 300 4-Dimethylaminopyridine dosage 15 15 15 15 15 Temperature(℃) 30 30 30 30 30 Time (h) 2 2 2 2 2 Yield (%) 62 58 66 63 60

[0049] The results of different reaction conditions in step 2 are shown in Table 2.

[0050] Table 2 Different reaction conditions and reaction results of step 2

[0051]

[0052] The results of different reaction conditions in step 3 are shown in Table 3.

[0053] Table 3 Different reaction conditions and reaction results of step 3

[0054]

[0055]

[0056] The results of different reaction conditions in step 4 are shown in Table 4.

[0057] Table 4 Different reaction conditions and reaction results of step 4

[0058]

[0059] The operations of each embodiment (2-11) are basically the same as those of embodiment 1, and the differences are shown in Table 5 below.

[0060] Table 5 Different reaction conditions and reaction results of Examples 2-11

[0061]

[0062]

[0063] Example 12

[0064] The present embodiment provides a cotton defoliant containing a fluorinated thiadiazole derivative, which is a wettable powder defoliant (A). The preparation method is that the fluorinated thiadiazole derivative, abscisic acid and an auxiliary agent are fully mixed, and then crushed by a jet mill to obtain a wettable powder defoliant with different active ingredient contents. The abscisic acid raw material is purchased from the market with a purity of 95%. The fluorinated thiadiazole derivative is homemade (Example 1) with a purity of 99.0%. In the present embodiment, the auxiliary agent is sodium dodecyl sulfate, sodium lignin sulfonate, and kaolin. It should be noted that the percentages of the formulation formulas described in the present embodiment are all mass percentages.

[0065] Defoliant A-1: ​​contains 5% by mass of fluthiadiazuron derivative, 5% by mass of abscisic acid, 10% by mass of sodium dodecyl sulfate, 10% by mass of sodium lignin sulfonate, and the rest is kaolin.

[0066] Defoliant A-2: contains 10% by mass of fluthiadiazuron derivative, 2% by mass of abscisic acid, 10% by mass of sodium dodecyl sulfate, 10% by mass of sodium lignin sulfonate, and the rest is kaolin.

[0067] Defoliant A-3: contains 15% by mass of fluthiadiazuron derivative, 0.5% by mass of abscisic acid, 10% by mass of sodium dodecyl sulfate, 10% by mass of sodium lignin sulfonate, and the rest is kaolin.

[0068] Embodiment 13

[0069] The present embodiment provides a cotton defoliant containing a fluorinated thiadipyridinium derivative, which is an aqueous solution defoliant (B). The preparation method thereof is to fully mix the fluorinated thiadipyridinium derivative, abscisic acid and lauryl alcohol polyoxyethylene ether to obtain an aqueous solution defoliant. The abscisic acid raw material is purchased from the market with a purity of 95%. The fluorinated thiadipyridinium derivative is homemade with a purity of 99.1% (Example 2). Lauryl alcohol polyoxyethylene ether is purchased from the market with a purity of 99%. The percentages of the formulation formula described in this embodiment are all mass percentages.

[0070] Defoliant B-1: contains 2% by mass of fluthiadiazuron derivative, 2% by mass of abscisic acid, and the rest is lauryl alcohol polyoxyethylene ether.

[0071] Defoliant B-2: contains 2% by mass of fluthiadiazuron derivative, 0.5% by mass of abscisic acid, and the rest is lauryl alcohol polyoxyethylene ether.

[0072] Defoliant B-3: contains 4% by mass of fluthiadiazuron derivative, 0.2% by mass of abscisic acid, and the rest is lauryl alcohol polyoxyethylene ether.

[0073] Embodiment 14

[0074] The present embodiment provides a cotton defoliant containing a fluorinated thiadipyridinium derivative, which is a defoliant in the form of a water suspension (C). The preparation method is to fully mix the fluorinated thiadipyridinium derivative, abscisic acid and an auxiliary agent, grind them after being crushed by a jet mill, and then mix them with xanthan gum and shear them to obtain a water suspension defoliant. The abscisic acid raw material is purchased from the market with a purity of 95%. The fluorinated thiadipyridinium derivative is homemade with a purity of 99.1% (Example 3). The auxiliary agents are selected from pull-open powder, sodium lignin sulfonate, ethylene glycol, kason, silicone defoamer and kaolin. The percentages of the formulation formula described in this embodiment are all mass percentages.

[0075] Defoliant C-1: contains 1% by mass of a fluthiadiazuron derivative, 1% by mass of abscisic acid, 5% by mass of lakai powder, 5% by mass of sodium lignin sulfonate, 6% by mass of ethylene glycol, 0.5% by mass of kason, 0.5% by mass of silicone defoamer, 0.2% by mass of xanthan gum, and the rest is kaolin.

[0076] Defoliant C-2: contains 2% by mass of fluthiadiazuron derivative, 0.5% by mass of abscisic acid, 2% by mass of lakai powder, 8% by mass of sodium lignin sulfonate, 5% by mass of ethylene glycol, 0.5% by mass of kason, 0.5% by mass of organosilicon defoamer, 1% by mass of xanthan gum, and the rest is kaolin.

[0077] Defoliant C-3: contains 5% by mass of fluthiadiazuron derivative, 1% by mass of abscisic acid, 10% by mass of lakai powder, 2% by mass of sodium lignin sulfonate, 4% by mass of ethylene glycol, 0.6% by mass of kason, 0.6% by mass of silicone defoamer, 1% by mass of xanthan gum, and the rest is kaolin.

[0078] Embodiment 15

[0079] The first defoliation test was conducted in Henan Modern Agricultural Development Base in 2024. The local temperature was about 20℃. 11 plots were randomly divided. Each plot was 3 meters long and 2 meters wide. Clean water control, 20g / mu of thidiazuron, defoliant A-1, defoliant A-2, defoliant A-3, defoliant B-1, defoliant B-2, defoliant B-3, defoliant C-1, defoliant C-2, defoliant C-3 were set. The amount of defoliant was calculated based on 20g / mu of fluorinated thidiazuron derivatives.

[0080] Table 6 Defoliation test results of the combination of fluthiadiazole derivatives and abscisic acid as cotton defoliants

[0081]

[0082] The second batch of defoliation tests was conducted in Henan Modern Agricultural Development Base in 2024. The local temperature was about 10℃. 13 plots were randomly divided, each plot was 3 meters long and 2 meters wide, and clear water control, 20g / mu of thiadiazole, 20g / mu of fluorine-containing thiadiazole derivatives, 2g / mu of abscisic acid (calculated as abscisic acid), defoliant A-1, defoliant A-2, defoliant A-3, defoliant B-1, defoliant B-2, defoliant B-3, defoliant C-1, defoliant C-2, defoliant C-3. The amount of defoliant was calculated based on 20g / mu of fluorine-containing thiadiazole derivatives.

[0083] Table 7 Defoliation test results of the combination of fluthiadiazole derivatives and abscisic acid as cotton defoliants

[0084]

[0085]

[0086] The fluorine-containing thiadiazole derivatives and abscisic acid used in the fluorine-containing thiadiazole derivative group and the abscisic acid group are the same as those in A-1.

[0087] The above data show that the prepared defoliant has a better defoliation effect than thidiazuron, can be used for defoliation before cotton harvest, and still has a good defoliation effect at low temperatures. In addition, fluthiazuron and abscisic acid have a synergistic effect, and the combination of the two is better than the effect of a single component.

[0088] In summary, the present invention provides a compound of fluorine-containing thidiazuron derivatives and abscisic acid as a cotton defoliant, which has a good defoliation effect. The defoliant provided by the present invention does not contain herbicides and ethephon components, is safer and more environmentally friendly, and has a better defoliation effect than thidiazuron. In addition, the defoliant of the present invention can overcome the influence of low temperature environment on the defoliation effect, delay the time of using the defoliant, make cotton bolls more, and increase cotton yield.

[0089] The present invention is described above in conjunction with the embodiments, but the present invention is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A cotton defoliant containing a fluthiadiazuron derivative, characterized in that The structural formula of the fluorinated thiadiazole derivative is as follows: Wherein, R is a benzene ring containing 0 to 5 fluorine atoms at any position.

2. The cotton defoliant containing a fluthiadiazuron derivative according to claim 1, characterized in that: It also contains abscisic acid, and the mass ratio of the abscisic acid to the fluorothiadiazole derivative is 1:(1-30).

3. A cotton defoliant containing a fluthiadiazuron derivative according to claim 2, characterized in that: The mass ratio of the abscisic acid to the fluorinated thiadiazole derivative is 1:(1-20).

4. The cotton defoliant containing a fluthiadiazuron derivative according to claim 2, characterized in that: The mass ratio of the abscisic acid to the fluorinated thiadiazole derivative is 1:(1-10).

5. The cotton defoliant containing a fluthiadiazuron derivative according to claim 1, characterized in that: The dosage form of the defoliant is selected from one of wettable powder injection, dispersible suspension, solution and microemulsion.

6. Use of the cotton defoliant according to any one of claims 1 to 5 in cotton defoliation.

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