71422-67-8 Usage
Description
Chlorfluazuron is a benzoylurea fluorinated nitrogen heterocyclic pesticide with a unique mechanism of action, high efficiency, low toxicity, and environmentally friendly properties. It is characterized by its white or yellowish-white tasteless crystalline powder appearance and a melting point of 226.5°C (decomposition). Chlorfluazuron is sparingly soluble in water but readily dissolves in ketones, aromatic hydrocarbons, and alcohols. It remains stable under light and heat, as well as in neutral and weak acid conditions, but is prone to decomposition under alkaline treatment.
Uses
Used in Agriculture:
Chlorfluazuron is used as an insect growth regulator for controlling major insect pests in crops. It is particularly effective against Heliothis, Spodoptera, Bemisia tabaci, and other chewing insects on cotton, as well as Plutella and Thrips on vegetables. Additionally, it is utilized on fruit, potatoes, ornamentals, and tea.
Used in Insect Pest Control:
Chlorfluazuron is employed as a chitin synthesis inhibitor, acting through stomach poisoning and strong contact action. It permeates poorly and lacks endosuction effects. The insecticidal mechanism involves inhibiting the formation of chitin, which disrupts the normal molting process, leading to egg hatching, larvae molting, kidney malformations, adult emergence obstruction, and egg obstruction. This results in the insecticidal effect against a broad spectrum of pests, including various Lepidoptera, Diptera, Orthoptera, and Hymenoptera. It is particularly effective on insects found on vegetables and can also be used to control a variety of pests on cabbage, cotton, tea trees, and fruit trees.
Chemical Properties:
The pure product of Chlorfluazuron appears as a white, odor-free crystal with a melting point of 232-233.5°C and a relative density of 1.4977 (20°C). Its vapor pressure is less than 1 x 10^-10 Pa (20°C). The solubility of Chlorfluazuron in various solvents is as follows: cyclohexanone (110g/L), acetone (52.1g/L), ethyl acetate (45.7g/L), ethylene dichloride (22g/L), toluene (6.5g/L), xylene (3g/L), methanol (2.5 (2.2) g/L), ethanol (2.0 g/L), n-octanol (1 g/L), hexane (10 mg/L), and water (0.016 mg/L). The proto-drug is a yellow-brown crystal with a melting point of 220-223.9°C. Chlorfluazuron is stable at room temperature and resistant to light.
Characteristics
It is of gastric poisoning, contact kill (inhibition of chitin synthesis) effect with high efficacy against pests, but the efficacy is slow. The mechanism of action is through inhibition of chitin synthesis, hindering insect normal molting, egg hatching, larvae molting and pupal developmental deformity and block of adult feather.
An overview of chlorfluazuron, physical and chemical properties, characteristics, synthesis, precautions, etc. are edited by Shi Yan, lookchem. (2015-11-17)
Synthesis
Have 2, 6-dichloro-4-aminophenol and 2, 3-dichloro-5-trifluoromethylpyridine subject to etherification to give 3, 5-dichloro-4- (3- -trifluoromethyl-2-pyridyloxy) aniline, followed by reaction with 2, 6-difluorobenzoyl isocyanate (the reaction product of 2, 6-difluorobenzamide and solid phosgene) to obtain the target product Chlorfluazuron through condensation reaction; confirm its structure at the total yield of 95%.
Synthesis of 1, 3, 5-dichloro-4- (3-chloro-5-trifluoromethyl-2-pyridyloxy) aniline (4)
18.2g (0.10 mol) of 2,6-dichloro-4-aminophenol, 21.6 g (0.10 mol) of 2,3- dichloro-5-trifluoromethylpyridine Potassium and 0.5 g of catalyst were dissolved in 120 mL of DMF and reacted at 110-115 ° C; apply chromatography monitoring, when the raw material 2,3-dichloro-5-trifluoromethylpyridine has a content ≤ 0.5%, stop the reaction for about 6h. After the completion of the reaction, the residue was removed by filtration and the solvent was removed under reduced pressure. The residue was further extracted with 3 × 100 mL of dichloroethane, washed with 3 × 150 mL of water until neutral and dried by anhydrous magnesium sulfate overnight to give the dichloroethane solution of 3,5-dichloro-4- (3-chloro-5-trifluoromethyl-2-pyridyloxy) aniline (4) (to be used).
Synthesis of 2, 2, 6-difluorobenzoyl isocyanate (3)
15.7 g (0.10 mol) of 2, 6-difluorobenzamide (2) was dissolved in 150 mL of dichloroethane and 15.0 g (0.05 mol) of solid phosgene was added at -5 ° C. After holding for 1 hour, the mixture was heated to reflux 5h; the exhaust gas was absorbed by 5% sodium hydroxide solution. Apply chromatographic monitoring, when 2,6 - difluorobenzamide content ≤ 0.5%, cooled to room temperature for stand-by.
Synthesis of chlorfluazuron (1).
The dichloroethane solution of 3,5-dichloro-4- (3-chloro-5-trifluoromethyl-2-pyridyloxy) aniline (4) was slowly added dropwise at 80 to 85 ?C to the dichloroethane solution of 2,6-difluorobenzoyl isocyanate (3); the dropwise addition time is controlled at about 30min; incubate for 2h, then apply sampling control; when the etherate content ≤ 0.5%, apply atmospheric recovery of the solvent dichloroethane, filtered, and dried to give 47.0 g of off-white to white chlorfluazuron product.
Figure 1 shows the synthesis of chlorfluazuron
Controlling objects and synthesis methods
It is of high activity against Lepidoptera, Coleoptera, Orthoptera, Hymenoptera and Diptera with no effects on aphids, leafhoppers and planthoppers.
Control Pieris rapae and diamondback moth; during 1 to 3 instar larvae stage, apply 1 000 ~ 4 000 times 5% EC times for spray. Make appropriate adjustment in the above concentration range according to the severity of the pest and the size of insect instar.
Control Eucalyptus ladybugs, potato ladybugs, Spodoptera litura and cutworm; during the larval hatch stage, use 2000~3000 times 5% EC for spray.
Prevention and control of pod borer, use 1 000 ~ 2 000 times liquid to administrate once in both the crop flowering stage and pest egg stage.
Production
Preparation of 2, 6 - difluorobenzonitrile
2, 6-dichlorobenzonitrile can be made through single-step method using ammonia oxidation of 2, 6-dichlorotoluene. Take 2,6-dichlorobenzonitrile as raw material, potassium fluoride as fluorinating agent and DMF, DMSO or sulfolane as solvent, the reaction temperature is 200-250 ℃.
Synthesis method of 2,6-difluorobenzonitrile has the following improvements, such as: ① use phase transfer catalysts such as quaternary ammonium salt, crown ether and polyether for synthesis, if polyether is used as the catalyst, the reaction temperature is 210 ~ 230 ℃, the time is 8 ~ 10h, the yield is 86%; ② Owing to the strong electron-withdrawing group -CN, under normal fluorination condition, the halogen of the ortho-aryl group will be lost. After adding dinitrobenzene, the above phenomenon was obviously inhibited, thereby increasing the yield; ③ Japanese patent reports, the above reaction uses segmented insulation method (170 ℃, 0.5h, 175 ℃, 2h, 220 ℃, 4h) with the yield being 95.6%; Increase the surface area of KF, use spray drying method to produce ultra-fine anhydrous KF, yield up to 80%.
Preparation of 2, 6-difluorobenzamide
Use sulfuric acid as a catalyst, apply 2, 6-difluorobenzonitrile and water to have nucleophilic addition reaction to obtain the corresponding sulfate. Use alkali to neutralize to pH 6 to give 2, 6-difluorobenzamide.
Synthesis of chlorfluazuron
2,6-Difluorobenzamide was reacted with phosgene in dichloroethane solvent at 50 ° C for 1 h to yield 2,6-difluorobenzoyl isocyanate, which was then reacted with 4- (3-chloro-5-trifluoromethylpyridin-2-yloxy) -3,5-dichloroaniline to give chlorfluazuron.
Attention
Its application period is generally 3 days earlier than normal organophosphate, pyrethrins insecticide; in the best case, spray during the young larvae stage; for boring pests, it should be applied during the peak stage of egging.
No suction conduction effect; the application must be uniform and thoughtful.
Avoid using it in the mulberry fields, fish ponds and other places.
For cotton and cabbage area, do not use more than 3 times for crops per season; for citrus, do not use more than 2 times. The safe interval is 21 days for cotton and citrus and 7 days for cabbage.
Toxicity
Rats acute oral LD50 8500mg / kg, mice 7000mg / kg, rat-acute percutaneous LD50 1000mg / kg; rat-acute inhalation LC50 1846mg / m3. No irritation effect on rabbit eyes and skin. Guinea pig sensitization test result is negative. The sub-acute oral no-effect dose for rat is 3mg / kg; rabbits subcutaneous sub-acute no-effect daily dose of rabbit is 1000mg / kg; chronic oral no-effect dose for rat is 50mg / kg. No teratogenic, carcinogenic, mutagenic effects were found. Carp LC50 300mg / L (96h); safe for birds and bees; sensitive to silkworms.
Toxicity classification
low toxicity
Acute Toxicity
Oral - Rat LD50:> 8500 mg / kg; Oral - Mouse LD50:> 8500 mg / kg
Flammability Hazard Characteristics
Combustion produces toxic nitrogen oxides, chlorides and fluoride gases.
Storage and transportation
warehouse ventilated, low temperature and drying; separate storage and transportation of food raw materials
Metabolic pathway
Only limited information is available in the open literature on the
metabolism of chlorfluazuron.
Degradation
Chlorfluazuron is reported to be hydrolytically stable (PM).
Check Digit Verification of cas no
The CAS Registry Mumber 71422-67-8 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 7,1,4,2 and 2 respectively; the second part has 2 digits, 6 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 71422-67:
(7*7)+(6*1)+(5*4)+(4*2)+(3*2)+(2*6)+(1*7)=108
108 % 10 = 8
So 71422-67-8 is a valid CAS Registry Number.
InChI:InChI=1/C20H9Cl3F5N3O3/c21-10-5-9(30-19(33)31-17(32)15-13(24)2-1-3-14(15)25)6-11(22)16(10)34-18-12(23)4-8(7-29-18)20(26,27)28/h1-7H,(H2,30,31,32,33)
71422-67-8Relevant articles and documents
Synthesis method of chlorfluazuron and application of chlorfluazuron in insecticide preparation
-
, (2017/07/21)
The invention belongs to the technical field of pesticide preparations, particularly relates to a synthesis method of chlorfluazuron and further discloses an application of chlorfluazuron in insecticide preparation. According to the synthesis method of chlorfluazuron, chlorfluazuron is prepared from 2,3-dichloro-5-(trifluoromethyl)pyridine, 2,6-dichloro-4-aminophenol and 2,6-difluorobenzoyl isocyanate as synthetic raw materials and N,N-dimethylacetamide as a reaction solvent on the basis of a conventional synthesis route in the prior art; under the action of a ZSM molecular sieve based catalyst, not only can synthesis of chlorfluazuron be realized, but also a reaction can be performed with the same reaction solvent, so that the problem of complicated process caused by the fact that solvents are required to be recovered step by step during two-step synthesis of chlorfluazuron in the prior art is solved; compared with the technology in the prior art, the synthesis method of chlorfluazuron has the advantages that the synthesis yield of products is further increased and product content is higher.
Insecticidal combination to control mammal fleas, in particular fleas on cats and dogs
-
, (2008/06/13)
Process and composition, in particular for controlling fleas on small mammals, characterized in that the composition includes, on the one hand, at least one insecticide of 1-N-arylpyrazole type, in particular fipronil, and, on the other hand, at least one compound of IGR (insect growth regulator) type, in doses and proportions which are parasiticidally effective on fleas, in a fluid vehicle which is acceptable for the animal and convenient for local application to the skin, preferably localized over a small surface area.
Use of acyl urea compounds for controlling endoparasites and ectoparasites of warm-blooded animals
-
, (2008/06/13)
A method of systemically controlling endoparasites and ectoparasites of warm-blooded animals by orally or percutaneously administering to the animal a parasiticidally effective amount of an acyl urea compound.
