120067-83-6Relevant articles and documents
Synthesis of fipronil sulfide, an active metabolite, from the parent insecticide fipronil
Beeler, Aaron B.,Schlenk, Daniel K.,Rimoldi, John M.
, p. 5371 - 5372 (2001)
A convenient procedure for the synthesis of fipronil sulfide, one of several active metabolites identified from the insecticide fipronil, has been developed. Reduction of fipronil with trifluoroacetic anhydride-sodium iodide in acetone, followed by flash chromatography afforded fipronil sulfide in 60% yield and >99.9 percent purity. This represents the first direct synthesis of this key metabolite from fipronil.
Mechanisms for selective toxicity of fipronil insecticide and its sulfone metabolite and desulfinyl photoproduct
Hainzl, Dominik,Cole, Loretta M.,Casida, John E.
, p. 1529 - 1535 (1998)
Fipronil, an N-phenylpyrazole with a trifluoromethylsulfinyl substituent, initiated the second generation of insecticides acting at the γ-aminobutyric acid (GABA) receptor to block the chloride channel. The first generation includes the polychlorocycloalkanes α-endosulfan and lindane. In this study, we examine the mechanisms for selective toxicity of the sulfoxide fipronil and its sulfone metabolite and desulfinyl photoproduct relative to their target site interactions in vitro and ex vivo and the importance in fipronil action of biooxidation to the sulfone. Differences in GABA receptor sensitivity, assayed by displacement of 4'-ethynyl-4-n-[2,3-3H2]- propylbicycloorthobenzoate ([3H]EBOB) from the noncompetitive blocker site, appear to be a major factor in fipronil being much more toxic to the insects (housefly and fruit fly) than to the vertebrates (humans, dogs, mice, chickens, quail, and salmon) examined; in insects, the IC50s range from 3 to 12 nM for fipronil and its sulfone and desulfinyl derivatives, while in vertebrates, the IC50 average values are 1103, 175, and 129 nM for fipronil, fipronil sulfone, and desulfinyl fipronil, respectively. The insect relative to the vertebrate specificity decreases in the following order: fipronil > lindane > desulfinyl fipronil > fipronil sulfone > α-endosulfan. Ex vivo inhibition of [3H]EBOB binding in mouse brain is similar for fipronil and its sulfone and desulfinyl derivatives at the LD50 dose, but surprisingly, at higher doses fipronil can be lethal without detectably blocking the [3H]EBOB site. The P45 inhibitor piperonyl butoxide, acting in houseflies, increases the metabolic stability and effectiveness of fipronil and the sulfone but not those of the desulfinyl compound, and in mice it completely blocks the sulfoxide to sulfone conversion without altering the poisoning. Thus, the selective toxicity of fipronil and fipronil-derived residues is due in part to the higher potency of the parent compound at the insect versus the mammalian GABA receptor but is also dependent on the relative rates of conversion to the more persistent and less selective sulfone metabolite and desulfinyl photoproduct.
A convenient conversion of pyrazolyl disulfide to sulfides by sodium dithionite and synthesis of sulfoxides
Tang, Ri-Yuan,Zhong, Ping,Lin, Qiu-Lian
, p. 948 - 953 (2006)
Indirectly introduce trifluoromethylthio-, alkylthio-, and trifluoromethylsulfinyl to pyrazole ring by a convenient reaction of a pyrazolyl disulfide with F3CBr and alkyl halides in the presence of sodium dithionite at room temperature. Followed by selective oxidation with H2O2 or trichloroisocyanuric acid (TCCA) to give trifluoromethylsulfenyl phenylpyrazole, alkylsulfenyl phenylpyazole, trifluoromethylsulfinyl phenylpyrazole 4a (a highly efficient insecticide named fipronil) and ethylsulfinyl phenylpyrazole 4c derivatives, respectively.
Chiral resolution of the insecticide fipronil enantiomers and the simultaneous determination of its major transformation products by high-performance liquid chromatography interfaced with mass spectrometry
Paolini, Léa,Hausser, Nicolas,Zhang, Tong
supporting information, p. 473 - 483 (2022/01/22)
A high-performance liquid chromatography–mass spectrometry (HPLC-MS) method was developed using a chiral column based on amylose tris(3-chloro-5-methylphenylcarbamate) for analysis of fipronil (a popular insecticidal nerve agent) and the related transformation products. The optimized method reached the goal of the simultaneous and complete separation of the multiple fiproles in a single run, including the chiral separation of fipronil enantiomers, fipronil metabolites, and photoproducts. The efficacy of such a method was demonstrated by its application in analyzing a series of fipronil samples exposed to sunlight conditions. In general terms, our study provided experimental approaches and an efficient analytical tool for monitoring the environmental fate of fipronil as well as its multitransformation products upon its applications either in agricultural or any other areas.
Method for preparing fipronil
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Paragraph 0007; 0008; 0009; 0010; 0011; 0012, (2019/01/23)
The invention relates to a method for preparing fipronil. The method comprises the following steps: taking 2-bromo-1,3-dichloro-5-(trifluoromethyl)benzene as an initial raw material, reacting the initial raw material with 5-amino-4-((trifluoromethyl)sulfenyl)-1H-pyrazol-3-formonitrile, wherein the product does not need to be treated; and further reacting to obtain the target product fipronil. Compared with the traditional synthetic method, the method disclosed by the invention takes Cu as a catalyst, and is more efficient and relatively high in yield. Moreover, the operating method is simple and convenient, and the reaction conditions are mild.
A kind of fipronil process for the preparation of intermediates
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Paragraph 0016; 0017, (2017/03/28)
The invention relates to a preparation method of a fipronil intermediate-5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazoles-3-nitrile. According to the invention, a brand new reaction mechanism is used for using 5-amino-3cyan-1-(2,6-dichloro4-(trifluoromethyl)phenyl)-pyrazolidine sulfenyl to prepare 5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazoles-3-nitrile. In the reaction process, usage of severe toxic substances such as PCI can be avoided, phosphorous oxychloride with little toxicity is taken as a chloridizing agent, security of the preparation process is greatly increased, and the purity of the products can reach more than 95%.
Preparation method of 5-amino-1-(2,6-dihydro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylmercapto)-1H-parazole-3-nitrile
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Paragraph 0028; 0029, (2016/12/07)
The invention discloses a preparation method of 5-amino-1-(2,6-dihydro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylmercapto)-1H-parazole-3-nitrile, which comprises the following steps: (1) adding 5-amino-3-cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-parazole, trifluoromethyl sulfinate, an organic solvent, and a phosphorus-containing iminazole liquid to a reactor, mixing under stirring, and cooling the mixture in an ice bath; and (2) dropwise adding phosphorus trihalide or an organic solution of phosphorus trihalide to the reactor under stirring, reacting at 30-60 DEG C for 1-5h under stirring, quenching the reaction with ice water, extracting with an extracting agent, washing, drying and concentrating to obtain 5-amino-1-(2,6-dihydro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylmercapto)-1H-parazole-3-nitrile. The method is simple and convenient to operate, and can obtain the effects of good yield and purity, etc.
PROCESS FOR THE PREPARATION OF N-SUBSTITUTED PYRAZOLE COMPOUNDS
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Paragraph 0070; 0071; 0072; 0073; 0074, (2014/12/09)
A process for the preparation of a compound of formula I: wherein, R1 represents hydrogen, cyano, nitro, halogen, or acyl; R2 represents aryl, alkenyl, alkynyl, halogen substituted alkyl, halogen substituted alkenyl, or halogen substituted alkynyl; R3 represents hydrogen or NR6R7 wherein R6 and R7 each independently represent hydrogen, alkyl, alkenylalkyl, alkynylalkyl, formyl, optionally halogen substituted alkanoyl, optionally halogen substituted alkoxycarbonyl, or alkoxymethyleneamino, halogen, or R6 and R7 together with, the N atom attached form a heterocycle; and R4 represents hydrogen, alkyl, aryl, or heteroaryl; the process including oxidizing a compound of formula II:
PROCESS FOR SYNTHESIS FIPRONIL
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, (2013/03/26)
The present disclosure relates to a process for trifluoromethylsulfinyl pyrazole compound of formula I, from a compound of formula III, wherein, R, R1 and R2 represent a group containing halogen group respectively and R3 represents a perhaloalkyl.
PROCESS FOR THE PREPARATION OF N-SUBSTITUTED PYRAZOLE COMPOUNDS
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Page/Page column 16; 17, (2013/03/28)
There is provided a process for preparing sulfinyl-pyrazole derivatives of formula (I) which comprises oxidizing substituted amino-4-mercapto-1H-pyrazole compound (II) with an oxidant in the absence of trifluoroperacetic acid. Hydrogen peroxide is a particularly preferred oxidant and is carried out in the presence of sodium tungstate and hydrochloric acid as catalyst.
