- Experimental and DFT studies on the vibrational, electronic spectra and NBO analysis of thiamethoxam
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Vibrational and electronic spectral measurements were performed for 3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene(nitro) amine (thiamethoxam). Optimized geometrical structure and harmonic vibrational frequencies were calculated
- Zhang, Fang,Zhang, Yu,Ni, Haiwei,Ma, Kuirong,Li, Rongqing
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Read Online
- 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; 0098-0099
(2020/05/01)
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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 0085-0095
(2020/02/17)
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- Preparation method of thiamethoxam
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The invention discloses a preparation method of thiamethoxam. The method comprises the following steps: reacting a raw material 2-chloro-5-chloromethylthiazole with 3-methyl-4-nitroiminoperhydro-1,3,5-oxadiazine, carrying out a reaction with dimethyl carbonate as a reaction solvent and N,N-diisopropylethylamine as an acid binding agent, decolorizing the obtained solution with ozone after the reaction is finished, adding water to cool and crystallize, and filtering and drying the obtained solution to obtain high-quality pure white thiamethoxam. The method of the invention has the advantages ofeasy availability of raw materials, mild reaction conditions, few three wastes, simplicity in operation, short time, and easiness in industrial production, and the finished product has the advantagesof high yield and high content.
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Paragraph 0006; 0049-0068
(2019/10/01)
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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 18
(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 0028; 0035; 0036; 0040-0042; 0049
(2018/04/02)
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- Synthesis method of thiamethoxam
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The invention relates to the field of compound synthesis, in particular to a synthesis method of an agricultural insecticide thiamethoxam. According to the preparation method of the thiamethoxam provided by the invention, through selecting appropriate reaction raw materials, a new synthetic route is designed, and an intermediate 2-chlorine-5-chloromethyl-thiazole can be prepared at room temperature, so that a cooling device is not needed, the energy is saved, and the reaction yield can be improved.
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Paragraph 0027; 0030; 0034; 0038
(2018/07/07)
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- Preparation method of thiamethazide
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The invention discloses a preparation method of thiamethazide. The preparation method comprises the following steps of sequentially adding the measured solvent, 3-methyl-4-nitrocarbamide-1,3,5-oxadiazine, potassium carbonate and catalyst, stirring, uniformly mixing, and heating to 25 to 35 DEG C; dripping a mixture of 2-chloro-5-chloromethylthiazole and solvent into a reaction system at the speedof 40 to 60ml/h, controlling the temperature to be lower than 35 DEG C, stirring to react for 8 to 16h after the mixture of 2-chloro-5-chloromethylthiazole and solvent is dripped, and completely reacting; heating to 65 to 70 DEG C, and filtering coarse salt under the heat condition; cooling to 0 to 5 DEG C, crystallizing, filtering to obtain filtrate and filter cake, treating the filtrate for recycling, spraying the filter cake by methanol twice, and drying under the vacuum condition, so as to obtain the crude drug of the thiamethazide. The preparation method has the advantages that a large amount of subsequent workload is reduced, the highest reaction yield rate of thiamethazide can reach 92% or above, the content is about 98%, and the production of a large amount of wastewater is reduced.
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Paragraph 0029-0032; 0035; 0036-0039; 0045-0048; 0053-0056;
(2018/11/27)
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- Preparation method for high-purity thiamethoxam
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The invention discloses a preparation method for high-purity thiamethoxam. Thiamethoxam has a structure shown as formula (I). The method comprises the following steps: reacting the compound with the structure as shown in a formula (II) with the compound with a structure as shown in a formula (III) in a polar aprotic solvent in the presence of a catalyst and inorganic base, and then filtering, decolorizing, desolventizing and crystallizing, thereby acquiring a thiamethoxam product with a purity above 99% and a yield of 90%. The method disclosed by the invention is short in reaction time, low in reaction temperature, easy to operate, environment-friendly, capable of increasing product purity and yield and suitable for industrial production.
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Paragraph 0052; 0064; 0066; 0067; 0070
(2018/01/11)
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- Thiamethoxam production method
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The invention provides a thiamethoxam production method. The thiamethoxam production method is used for producing thiamethoxam, and comprises a first-step reaction, a second-step reaction and crude product processing to obtain the end product of thiamethoxam, wherein 1-methyl-3-nitroguanidine and paraformaldehyde are taken as reaction raw materials to perform the first-step reaction under the condition that a mixed acid is a solvent; and an obtained competitive product (3-methyl-4-nitroimino-1,3,5-oxadiazine) and 2-chloro-5-chloromethylthiazole performs the second-step reaction to obtain a crude product (thiamethoxam). The thiamethoxam production method has the advantages of environmental friendliness and low production cost.
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Paragraph 0020; 0023; 0026
(2017/12/27)
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- Preparation method of thiamethoxam
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The invention relates to a preparation method of thiamethoxam. According to the preparation method, 2-chloro-5-chloromethylthiazole and 3-methyl-4-nitryl imino-1,3,5-oxadiazine are reacted; the preparation method comprises the following reaction steps: in the existence of a solvent, taking the 2-chloro-5-chloromethylthiazole, the 3-methyl-4-nitryl imino-1,3,5-oxadiazine and potassium carbonate to react at 50 DEG C for 16h, so as to obtain a product thiamethoxam; after the treatment, cooling, filtering, washing with water and drying to obtain a thiamethoxam solid. The preparation method of the thiamethoxam, provided by the invention, has the advantages that the generation of side reactions is controlled through controlling a dropwise adding speed of the 2-chloro-5-chloromethylthiazole, so that the reaction yield of the thiamethoxam can reach 98.0 percent or above at maximum; the amount of the used solvent is less and the recovery rate is high; when the preparation method is used, the prepared thiamethoxam is high in product purity, less in impurity content and high in molar yield, and good economic benefits are obtained; the preparation method is safe and environment-friendly and is applicable to industrial production.
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Paragraph 0017-0019
(2017/07/19)
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- A process for the preparation of thiamethoxam
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The invention relates to a preparation method of thiamethoxam. The preparation method comprises the following steps of with C2-C5 fatty alcohol and inorganic base as a solvent and an acid-binding agent, respectively, reacting 3-methyl-4-nitro-imino-1,3,5-oxadiazine with 2-chloro-5-chloromethyl thiazole in a high-pressure reaction kettle at 0.1-0.5MPa, carrying out filtering and desolventizing, dropwise adding the solvent, namely halogenated aliphatic hydrocarbon or aromatic hydrocarbon to regulate the acidity until the pH is 5-6, and carrying out cooling, crystallization, filtering and water washing, so as to obtain the thiamethoxam. The preparation method has the characteristics of safety in operation, high yield, standard products and environmental friendliness and is suitable for industrial production.
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Paragraph 0027-0029
(2017/03/18)
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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 13-18
(2015/12/18)
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- Process for the preparation of thiazole derivatives
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The Invention relates to a process for the preparation of a compound of the formula wherein Q, Y, Z, R1, R2, R3, R4and R5are as defined in the specification, which comprises a) reacting a compound of the formula ?with a halogenating agent to form a compound of the formula b) converting a compound of formula (II) by means of a halogenating agent into a compound of the formula ?optionally c) converting the compound of formula (IV) into a compound of formula (III); d) converting a compound of formula (III) by means of a compound of the formula e) converting a compound (IV) by means of a compound (V) into a compound (VI); and f) converting a compound (VI) by means of a chlorinating agent into a compound (I); a compound (IV); to a process for the preparation of a compound (III) and to a process for the preparation of a compound (IV).
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Page column 29
(2008/06/13)
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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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