- Development of an enzyme-linked immunosorbent assay for the insecticide thiamethoxam
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An enzyme-linked immunosorbent assay (ELISA) was developed for the neonicotinoid insecticide thiamethoxam, 3-(2-chlorothiazol-5-ylmethyl)-5-methyl-4-nitroimino-1,3,5-oxadiazinane. Three antisera were raised from rabbits immunized with the hapten - KLH conjugate. On the basis of the computational analysis of hapten candidates, the hapten with a spacer arm on the thiazolyl ring of thiamethoxam was synthesized to elicit thiamethoxam-specific antisera. The hapten was 3-[2-(2-carboxyethylthio)-5-ylmethyl]-5-methyl-4-nitroimino-1,3, 5-oxadiazinane. Antisera were characterized with indirect competitive ELISA. Cross-reactivity and effects of organic solvents, pH, and ionic strengths were evaluated. The antiserum was specific for thiamethoxam and tolerant of up to 5% acetonitrile and 5% acetone. Various ionic strengths and pH values in the tested ranges had negligible effect on the assay performance. Under the optimized conditions, the half-maximal inhibition concentration (IC50) and the limit of detection were approximately 9.0 and 0.1 μg/L of thiamethoxam, respectively. ELISA analysis of stream and tap water samples showed an excellent correlation with the fortification levels.
- Kim, Hee-Joo,Liu, Shangzhong,Keum, Young-Soo,Li, Qing X.
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- Synthesis and properties of thiamethoxam and related compounds
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The neonicotinoids are the most successful chemical class of insecticides reaching sales of more than $1 billion in 2003, mainly due to the excellent market performance of imidacloprid and thiamethoxam. This paper describes the discovery, the synthesis and the insecticidal activity of thiamethoxam and related compounds and reports the hydrolytic stability and the degradation pathways of thiamethoxam together with the synthesis of the degradation products.
- Maienfisch, Peter
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- Azido-neonicotinoids as candidate photoaffinity probes for insect nicotinic acetylcholine receptors [1]
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The neonicotinoids are the most successful chemical class of insecticides reaching sales of more than 630 Mio $ in 2001, mainly due to the excellent market performance of imidacloprid and thiamethoxam. The insect nicotinic acetylcholine receptors (nAChRs) are the targets for these compounds, which are highly effective against a variety of sucking and chewing insects. Compared with the other neonicotinoid sales products, thiamethoxam binds in a different way, possibly to a different site of nAChRs in aphids. To gain further insight into the different modes of binding, a research program applying the photoaffinity labeling technique was started. A series of novel candidate photoaffinity probes containing a 5-azido-6-chloropyridin-3-ylmethyl group were prepared from 5-azido-6-chloropyridin-3-ylmethyl chloride, which was obtained in three steps from 6-chloropyridin-3-ylmethyl chloride. These probes showed good to excellent contact/feeding and systemic activity against Myzus persicae, however, they were at least 4- to 16-fold less effective against Aphis craccivora, Nilaparvata lugens, Spodoptera littoralis, and Diabrotica balteata than the neonicotinoid sales products. In general, the introduction of an azide group at C(5) of the 6-chloropyridin-3-ylmethyl substituent resulted in reduced potency as well as in a narrower pest spectrum. In competition binding assays with [3H]imidacloprid, analogues of imidacloprid, clothianidin, thiacloprid and thiamethoxam containing a 5-azido-6-chloropyridin- 3-ylmethyl group showed high displacing potency with nAChRs from Aphis and Myzus (Ki values: 2 to 27 nM) suggesting that these compounds are valuable candidate photoaffinity probes. Taking into account the biological screening activity as well as the receptor binding potency, 1-(5-azido-6- chloropyridin-3-ylmethyl)-2-nitroimino-imidazolidine N-(5-azido-6-chloropyridin- 3-ylmethyl)-N′-methyl-N″-nitroguanidine and 3-(5-azido-6- chloropyridin-3-ylmethyl)-2-cyanoimino-thiazolidine were identified as the preferred candidate neonicotinoid photoaffinity probes to study the imidacloprid binding site.
- Maienfisch, Peter,Haettenschwiler, Joerg,Rindlisbacher, Alfred,Decock, Arnaud,Wellmann, Henning,Kayser, Hartmut
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- Mannich-type reaction for synthesis of 3-methyl-4-nitroimino-tetrahydro-1, 3,5-oxadiazine
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The reaction of N-methyl-N-nitroguanidine with 3-methyl-4-nitroimino- tetrahydro-1,3,5-oxadiazine is a Mannich-type reaction. The reaction was catalyzed by several organic and inorganic bases at different reaction times and temperatures. Three inorganic base catalysts [potassium carbonate (K 2CO3), sodium hydrogen carbonate (NaHCO3), and sodium hydroxide (NaOH)] and several organic bases (methylamine, ethamine, iso-propylamine, and n-butylamine) have been studied. The results showed that both the inorganic and organic base catalysts can be used as catalysts, with the organic bases performing better. N-Methyl-N′-nitroguanidine reacts to give the title compound 2 and is catalyzed by both acids and bases. The intensity of inorganic base catalysts, reaction temperature, and reaction time had significant effects on the products.
- Qu, Wen-Yan,She, Dong-Mei,Zhao, Jian,Lin, De-Jie,Huang, Qi-Liang,Li, Feng-Min
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- Thiamethoxam and uses thereof
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A crystalline form of 3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl 1,3,5-oxadiazinan-yledene (nitro)amine (thiamethoxam) is provided. The crystalline form exhibits an X-ray powder diffraction pattern having characteristic peaks (expressed in degrees 2?? +/- 0.2?° ??) at one or more of the following positions: 6.09, 15.37, 17.83, 18.43, 20.86, 22.01, 26.95 and 27.84, and an Infrared (IR) spectrum having characteristic peaks at about 2933.62, 2161.78 and 1593.88 cm-1. A method of preparing the crystalline form comprises crystallizing 3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan -4-yledene (nitro)amine (thiamethoxam) from a solvent system comprising a solvent selected from an alcohol, a glycol, an ether, a ketone, an ester, an amide, a nitrile, an aliphatic or aromatic hydrocarbon, or mixtures thereof; and isolating the resulting crystals. The exemplified solvents are methanol, ethanol, 1-propanol, ethylene glycol, toluene and xylene.
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Paragraph 0072-0076
(2020/02/17)
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- Thiamethoxam production method and extractant
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The invention provides a thiamethoxam production method and an extractant, belongs to the technical field of pesticides, particularly provides an extractant taking ethylene glycol salicylate as a complexing agent, and also provides a composite extractant. The extractant comprises a complexing agent and a diluent, and the complexing agent comprises the ethylene glycol salicylate and P204, wherein the extraction ratio of ethylene glycol salicylate to P204 is 1:1.5 to 1:2. The ethylene glycol salicylate used as the complexing agent and -N- of thiamethoxam have strong ion association to generate an ion extract with the same structure, so that the distribution ratio is increased; and when the extractant and the P204 are used for composite extraction, hydrogen bond association of the strong electron withdrawing group nitro -NO2 of thiamethoxam and -OH of P204 can be promoted, and when the extraction ratio of ethylene glycol salicylate to the P204 extractant is 1:(1.5-2), the distribution ratio can be synergistically increased, and the extraction rate is increased.
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Paragraph 0088-0089; 0096-0097
(2020/05/01)
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- PROCESS FOR THE PREPARATION OF THIAMETHOXAM
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There is disclosed the use of a solvent system comprising a C1 to C4 alcohol, a substituted benzene derivative bearing two or more C1 to C4 alkyl substituents, or a mixture thereof in the preparation of a crystalline form of 3-(2-chloro-1, 3-thiazol-5-yl methyl)-5-methyl-1, 3, 5-oxadiazinan-4-yledene (nitro) amine (thiamethoxam). Crystalline thiamethoxam prepared in this way exhibits a significantly improved stability, in particular a resistance to photolysis, compared with crystalline thiamethoxam prepared using other solvents.
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Page/Page column 15; 16
(2019/05/22)
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- Preparation method of thiamethoxam
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The invention discloses a preparation method of thiamethoxam. The preparation method of the thiamethoxam comprises the following steps: taking methylnitroguanidine as a starting material, preparing 3-methyl-4-nitroimine-1,3,5-oxadiazine (compound II), and then preparing the thiamethoxam. The method provided by the invention is simple in process, the finally synthesized thiamethoxam does not need recrystallization, the content of the final product is up to 98% or above, and the yield reaches 84% or above.
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Paragraph 0025; 0032; 0036-0039; 0046
(2018/04/02)
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- 3-methyl-4-nitro imine base entire hydrogen -1, 3, 5- [...] method for the synthesis of (by machine translation)
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The invention discloses 3-methyl-4-nitro imine base entire hydrogen -1, 3, 5- [...] (abbrebyted [...] ) synthesis method, characterized in that to methyl nitroguanideine with poly formaldehyde as the starting material, the formic acid and dilute sulfuric acid in the mixed acid system, direct ring adnation into 3-methyl-4-nitro imine base entire hydrogen -1, 3, 5- [...]. Reaction of this invention is the principle is simple, the process route is scientific and reasonable design, using formic acid and dilute sulfuric acid mixed reaction system, improves the conversion rate of the reaction. Initial easy availability of raw materials, intermediate stable performance, production cost saving, high product yield, high purity, strong competition product market. Easy to control in the production process, small pollution to the environment. With great market and social development value. (by machine translation)
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Paragraph 0018; 0019; 0020; 0021
(2016/11/28)
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- METHOD OF PRODUCING THIAMETHOXAM
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A process for the preparation of thiamethoxam: is provided, which process comprises reacting 3-methyl-N-nitro- 1,3,5,oxadiazinan-4-imine: with 2-chloro-5-chloromethyl thiazole: in the presence of a solvent system comprising dimethylformamide (DMF), a phase transfer catalyst and a base.
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Page/Page column 10; 11
(2015/12/18)
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- Design, synthesis, and insecticidal activity of 1,5-diphenyl-1-pentanone analogues
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Three series of novel 1,5-diphenyl-1-pentanone derivatives were designed and synthesized. Their structures were characterized by IR, 1H NMR techniques, and elemental analysis. The insecticidal activities of the new compounds were preliminarily evaluated. The bioassay results indicated that the compounds X11-X30 displayed better aphicidal activity against Aphis gossypii than compounds X1-X10 and the lead compound (E)-1,5-diphenyl-1-penten-1-one (A). The inhibitory rates of compounds X6 and X29 were 100% against Plutella xylostella (L.) at 600 mg·L-1. Compounds X12, X13, X19, X24, X25, X26 and X27 showed higher insecticidal activity against Tetranychus cinnabarinus (Boisduval) at 600 mg·L-1 than the lead compound (A).
- Yang, Shaoxiang,Kang, Tieniu,Rui, Changhui,Yang, Xinling,Sun, Yufeng,Cui, Zining,Ling, Yun
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experimental part
p. 2394 - 2400
(2012/02/04)
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- 2-nitroguanidine derivatives: X. Synthesis and nitration of 4-nitriminotetrahydro-1,3,5-oxadiazine and 2-nitriminohexahydro-1,3,5-triazine and their substituted derivatives
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A new synthetic procedure was developed to obtain 1-hydroxymethyl-2- nitroguanidine from 2-nitroguanidine and formaldehyde without catalyst. Reactions of 2-nitroguanidine and its 1-methyl-and 1-phenylsubstituted derivatives with formaldehyde and urotropin under acid catalysis resulted in 4-nitriminotetrahydro-1,3,5-oxadiazine and 2-nitriminohexahydro-1,3,5-triazine and their methyl-and phenyl-substituted derivatives, whose nitration with concn. HNO3 in the presence of acetic anhydride and concn. H 2SO4 depending on the temperature conditions led to the formation of 4-nitrimino-3,5-dinitrotetrahydro-1,3,5-oxadiazine, 3-methyl-4-nitrimino-5-nitrotetrahydro-1,3,5-oxadiazine, 2-nitrimino-5- nitrohexahydro-1,3,5-triazine, and 1,3,5-trinitro-hexahydro-1,3,5-triazine-2- one.
- Metelkina
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p. 1437 - 1440
(2008/09/16)
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- Synthesis and insecticidal activity of neonicotinoids derivatives
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A new class of compounds- neonicotinoids containing oxadiazole -were synthesized and characterized by using 1H NMR, IR, MS and Elemental Analysis. Their insecticidal activities were tested against Mythimna separata Walker and Aphis rumicis Linnaeus, some of them showed some insecticidal activity.
- Chai, Bing,Cao, Song,Liu, Haidong,Song, Gonghua,Qian, Xuhong
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p. 601 - 606
(2007/10/03)
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- The discovery of thiamethoxam: A second-generation neonicotinoid
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Neonicotinoids represent a novel and distinct chemical class of insecticides with remarkable chemical and biological properties. In 1985, a research programme was started in this field, in which novel nitroimino heterocycles were designed, prepared and assayed for insecticidal activity. The methodology for the synthesis of 2-nitroimino-hexahydro-1,3,5-triazines, 4-nitroimino-1,3,5-oxadiazinanes and 4-nitroimino-1,3,5-thiadiazinanes is outlined. Bioassays demonstrated that 3-(6-chloropyridin-3-ylmethyl)-4-nitroimino-1,3,5-oxadiazinane exhibited better insecticidal activity than the corresponding 2-nitroimino-hexahydro-1,3,5-triazine and 4-nitroimino-1,3,5-thiadiazinane. In most tests, this compound was equally or only slightly less active than imidacloprid. A series of structural modifications on this lead structure revealed that replacement of the 6-chloro-3-pyridyl group by a 2-chloro-5-thiazolyl moiety resulted in a strong increase of activity against chewing insects, whereas the introduction of a methyl group as pharmacophore substituent increased activity against sucking pests. The combination of these two favourable modifications led to thiamethoxam (CGA 293 343). Thiamethoxam is the first commercially available second-generation neonicotinoid and belongs to the thianicotinyl sub-class. It is marketed under the trademarks Actara for foliar and soil treatment and Cruiser for seed treatment. The compound has broad-spectrum insecticidal activity and offers excellent control of a wide variety of commercially important pests in many crops. Low use rates, flexible application methods, excellent efficacy and the favourable safety profile make this new insecticide well-suited for modern integrated pest management programmes in many cropping systems.
- Maienfisch, Peter,Huerlimann, Hanspeter,Rindlisbacher, Alfred,Gsell, Laurenz,Dettwiler, Hansruedi,Haettenschwiler, Joerg,Sieger, Evelyne,Walti, Markus
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p. 165 - 176
(2007/10/03)
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- Oxadiazine derivatives
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Compounds of the formula STR1 in which A is an unsubstituted or mono- to tetrasubstituted, aromatic or non-aromatic, monocyclic or bicyclic heterocyclic radical, where one to two of the substituents of A can be selected from the group consisting of halo-C1 -C3 alkyl, cyclopropyl, halocyclopropyl, C2 -C3 alkenyl, C2 -C3 alkynyl, halo-C2 -C3 alkenyl, halo-C2 -C3 alkynyl, halo-C1 -C3 alkoxy, C1 -C3 alkylthio, halo-C1 -C3 alkylthio, allyloxy, propargyloxy, allylthio, propargylthio, haloallyloxy, haloallylthio, cyano and nitro, and one to four of the substituents of A can be selected from the group consisting of C1 -C3 alkyl, C1 -C3 alkoxy and halogen; R is hydrogen, C1 -C6 alkyl, phenyl-C1 -C4 alkyl, C3 -C6 cycloalkyl, C2 -C6 alkenyl or C2 -C6 alkynyl; and X is N--NO2 or N--CN, and, if appropriate, tautomers thereof, in each case in free form or in salt form, can be used as insecticidal active ingredients and can be prepared in a manner known per se.
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