Fipronil, with the molecular formula C12H4Cl2F6N4OS, is a type of pesticide; it is useful for crustaceans, ants, termites, beetles, cockroaches, ticks, zooplankton, bees and other insects, so Fipronil is Punido is used as an insecticide for many common ants, termites, beetles, cockroaches, ticks and other insects or as a flea product for pets. [1] Pesticide products are mostly in the form of granules, gel bait or liquid products.
Some research experiments have confirmed that fipronil can cause harm to animals and the environment, and is also a carcinogen. Therefore, fipronil has been banned by many countries, including Italy, France, and mainland China; At present, the United Kingdom and Australia are also considering banning the use of this special pesticide. Basic introduction Chinese name: Fipronil Foreign name: Fipronil Molecular formula: C12H4Cl2F6N4OS Molecular weight: 437.2 CAS number: 120068-37-3 Introduction, chemical composition, review, physical and chemical properties, toxicity, application, usage, production method, prohibited, Introduction by Developed by the French company Rh?ne-Poulenc, it was granted a Chinese patent (CN86108643). The patent for this compound expired on December 19, 2006. At the same time, Bayer's preparation method for fipronil and its intermediates was also obtained in my country. Patent authorization (CN95100789.0), this patent will be valid until 2015. Chemical Ingredients Overview Fipronil, the English generic name is fipronil, the chemical name is fipronil, the trade name is Regent, and its alias is fipronil. Test code MB-46030, chemical name (RS)-5-amino-1-(2,6-dichloro-a,a,a-trifluoro-p-tolyl)-4-trifluoromethylsulfinyl Pyrazole-3-nitrile, English chemical name: (±)-5-amino-1-(2,6-dichloro-a,a,a,-trifluoro-P-tolyl)-4-frifluoromethylsulfinylpyrazole-3-Carbonitrile, Molecular formula: C12H4Cl2F6N4OS, molecular weight: 437.2 CAS number: 120068-37-3 Physical and chemical properties The pure product is a white solid, melting point 200~201℃, density 1.477~1.626 (20℃). Vapor pressure 3.7×10-7pa (20℃); distribution coefficient (25℃) logP=4.0. Solubility in water (20°C, mg/L) 1.9 (distilled water), 1.9 (PH=5), 2.4 (PH=9); solubility in other solvents (20°C, g/L): acetone 545.9, methylene chloride 22.3, Toluene 3.0, hexane lt; 0.028. It is stable in water with PH=5 and 7, and hydrolyzes slowly at PH=9. The DT50 is about 28 days. It degrades slowly under sunlight, but can be quickly decomposed by light in aqueous solution. Toxicity Rat acute oral LD50: 97mg/kg, mouse acute oral LD50: 95mg/kg; rat acute dermal LD50: gt; 2000mg/kg, rabbit acute dermal LD50: 354mg/kg, rat inhalation LC50 (4 hours): 0.682mg/L, this product is non-toxic to rabbit eyes and skin. There are no "three principles". Mallard LD50: gt; 2000mg/kg; Quail LD50: 11.3mg/kg; Quail LC50: 49mg/kg, Mallard LC50: 5000mg/kg. Rainbow trout and carp LC50 (96 hours): 248ppm. Daphnia LC50 (48 hours): 0.19mg/L. Highly toxic to fish, shrimp, bees, and silkworms.
Preparations SC, GR, FS, EC, WG, UL use fipronil as a GABA-chloride channel inhibitor, which has no interactive resistance with existing pesticides and is resistant to organophosphorus, organochlorine, carbamate, and pyrethroid. Pesticides such as esters have good control effects on pests that have developed resistance or are sensitive. Suitable crops include rice, corn, cotton, banana, sugar beet, potato, peanut, etc. It has no phytotoxicity to the crops at the recommended dosage. At the same time, it also has extraordinary effects on cockroach control of sanitary pests, such as 2 Shennong Cockroach Killing Bait and 1.1 Haiyun Cockroach Killing Bait. Instructions for use: Fenpunil has a broad insecticidal spectrum and has contact, stomach poisoning and moderate systemic effects. It can control both underground pests and above-ground pests. It can be used for stem and leaf treatment, soil treatment, and seed treatment. Foliage spraying of 25~50g active ingredient/hectare can effectively control potato leaf beetle, diamondback moth, pink moth, Mexican boll weevil and flower thrips. Using 50~100g of active ingredients/hectare in rice fields can effectively control borers, brown planthoppers and other pests. Foliar spraying of 6~15g active ingredients/hectare can control locust and desert locust pests in grasslands. When 100~150g of active ingredients/hectare is applied to the soil, it can effectively control corn root leaf beetles, wireworms and cutworms. Treating corn seeds with 250~650g of active ingredients/100kg of seeds can effectively control corn wireworms and cutworms. The main control targets of this product include aphids, leafhoppers, lepidopteran larvae, flies, coleoptera and other pests. It is recommended by many pesticide experts as one of the first choices to replace highly toxic organophosphorus pesticides. Production methods There are currently two main synthetic routes for the industrial production of fipronil. One is to use 2,6-dichloro-4-trifluoromethylaniline as the raw material, and obtain the diazonium salt through diazotization, which is then combined with 2,3- The second product is obtained by reacting ethyl dicyanopropionate; the second product is obtained by reacting 2,6-dichloro-4-trifluoromethylphenylhydrazine as raw material with fumaronitrile and then oxidizing it. 1.1 2,6-Dichloro-4-trifluoromethylaniline There are three main synthesis routes for 2,6-dichloro-4-trifluoromethylaniline: ① p-trifluoromethylaniline method. Direct chlorination of p-trifluoromethylaniline in a solvent gives 2,6-dichloro-4-trifluoromethylaniline. This method is simple and convenient, but trifluoromethylaniline is relatively expensive and the production cost is relatively high. This method is mainly used in foreign countries. ② p-Chlorotrifluorotoluene method. p-Chlorotrifluorotoluene reacts with dimethylformamide and NaNH2 at a certain temperature and pressure to obtain N, N-dimethyl p-trifluoromethylaniline, which is then chlorinated under light, demethylated and ring chlorinated Obtain the target product. This method has longer steps and a larger amount of "three wastes". ③3,4-Dichlorotrifluorotoluene method. 3,4-Dichlorotrifluoromethylaniline is used as raw material, reacted with dimethylformamide and sodium hydroxide in a pressure kettle, and chlorinated, demethylated and ring chlorinated under light conditions to obtain the product. At present, many domestic scientific research institutions are researching and developing this route. This route is more reasonable, the product quality is high, and the amount of "three wastes" is reduced to a certain extent. 1.2 The main direction of current research on 2,6-dichloro-4-trifluoromethylphenylhydrazine is to use p-chlorotrifluoromethylbenzene as raw material and undergo deep chlorination in the presence of ferric chloride to obtain 3,4,5-trifluoromethylphenylhydrazine. Chlorotrifluorotoluene is then reacted with hydrazine hydrate to obtain 2,6-dichloro-4-trifluoromethylphenylhydrazine. 1.3 Ethyl 2,3-dicyanopropionate There are two main methods for synthesizing ethyl 2,3-dicyanopropionate: step-by-step method and one-step method. The production process of the step-by-step method is relatively cumbersome. During the production process, highly toxic substances harmful to the human body are produced and the amount of "three wastes" is relatively large. Therefore, the one-step method is currently mainly used for production. The one-step synthesis process is as follows: Mix sodium cyanide and the solvent absolute ethanol. After fully dissolving, add paraformaldehyde. After dissolving, add ethyl cyanoacetate. The feeding ratio of sodium cyanide, paraformaldehyde, and ethyl cyanoacetate is: 1:1:0.91(m:m). Then use hydrochloric acid to acidify, then extract and wash with water to obtain the crude product, and finally distill to remove the solvent to obtain the product. At present, several domestic companies such as Taizhou Tianyuan Chemical Co., Ltd. use this method to produce ethyl 2,3-dicyanopropionate. Banned: Fapronil will be banned in my country starting from October 1, 2009.
Although fipronil is very effective in controlling rice stem borer and leaf roller, it is extremely unfriendly to the environment, so the country is still determined to ban it.