Preparation method of thiamethazide

A technology of thiamethoxam and oxadiazine, which is applied in the field of preparation of thiamethoxam, can solve the problems of increased work, low yield of waste water, etc., and achieve the effects of reducing waste water, less three wastes, and saving unit consumption

Inactive Publication Date: 2018-11-16
湖北犇星农化有限责任公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the existing process of generating thiamethoxam with 2-chloro-5-chloromethylthiazole and 3-methyl-4-nitroimino-1,3,5-oxadiazine, the temperature is too high when the solvent used is distilled. High results in too low yield and a large amount of waste water, and increases follow-up work

Method used

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  • Preparation method of thiamethazide
  • Preparation method of thiamethazide
  • Preparation method of thiamethazide

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preparation example Construction

[0020] Please refer to figure 1 , the embodiment of the present invention provides a kind of preparation method of thiamethoxam, comprises the following steps:

[0021] S1. Add metered solvent, 3-methyl-4-nitroimino-1,3,5-oxadiazine, potassium carbonate and catalyst in sequence in the reactor, solvent, potassium carbonate and 3-methyl-4 - The mass ratio of nitroimino-1,3,5-oxadiazine is preferably 20-40:10:8, stirring to make the materials evenly mixed, and raising the temperature to 25-35°C;

[0022] S2. Add dropwise the mixture of 2-chloro-5-chloromethylthiazole and solvent in the above reaction system at a rate of 40-60ml / h, control the temperature not higher than 35°C, 2-chloro-5-chloromethylthiazole After the mixture with the solvent is added dropwise, stir and react for 8-16 hours, and check whether the reaction is complete by thin-layer chromatography. If the reaction is not complete, continue the reaction. After the reaction is completed, proceed to step S3;

[0023]...

Embodiment 1

[0028] Complete the continuous application of the mother liquor for 2 times

[0029] Small test A: Add metered 300g N,N-dimethylformamide (DMF), 117.5g 3-methyl-4-nitroimino-1,3,5-oxadiazine, 116g carbonic acid in a three-necked flask Potassium, 3g catalyst, then dropwise add the mixed solution of 148g 2-chloro-5-chloromethylthiazole and 30g DMF, control the temperature at 30-35°C, stir and react for 8h, thin layer chromatography (TLC) detects that the reaction is complete, the reaction Incomplete, continue the reaction, the reaction is complete, the reaction system remains in a yellow suspension state, heat to 65-70°C, filter the coarse salt while it is hot, rinse the coarse salt with 100g DMF to obtain DMF eluent A and granular wet product A107g (collected and processed), cooled to 0-5°C for crystallization and filtration, 551g of the filtrate (mother liquor A) was used as a solvent, and the filter cake was rinsed twice with 100g*2 methanol, and the obtained methanol lotion ...

Embodiment 2

[0036] Complete the continuous application of the mother liquor for 2 times, verify Example 1:

[0037] Small test E: Add metered 300g N,N-dimethylformamide, 117.5g 3-methyl-4-nitroimino-1,3,5-oxadiazine, 116g potassium carbonate, 3g of catalyst, then dropwise add a mixed solution of 148g 2-chloro-5-chloromethylthiazole and 30gDMF, control the temperature at 30-35°C, stir for 8h, TLC detects that the reaction is complete, and the reaction system remains in a yellow suspension state. to 65-70°C, filter while hot, and rinse the filter cake with 100g DMF to obtain DMF eluent E and granular wet product Eg (collected and processed), the filtrate is cooled to 0-5°C and filtered, and the filtrate is 552g (mother liquor E) Used as solvent, the filter cake was rinsed with 100g*2 methanol, the resulting methanol lotion was E1, E2, the obtained wet product thiamethoxam was 36g, dried to obtain 22.5g of light yellow powdered thiamethoxam, and the detected content was 98.69%. The yield wa...

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Abstract

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.

Description

technical field [0001] The invention relates to the technical field of pesticide preparation, in particular to a preparation method of thiamethoxam. Background technique [0002] Thiamethoxam is a new generation of high-efficiency, low-toxicity thionicotinoid insecticides, the trade name is actety, it has excellent biological activity and field control effect on greenhouse whitefly and type B whitefly adults. Thiamethoxam is applied at the early stage of pest occurrence, and its quick-acting effect is relatively good, and its lasting effect period is more than 10 days, which has a prospect of popularization and application. Judging from the current situation of the development of the domestic planting industry, especially in the process of large-scale grain production, due to the frequent breeding of various diseases and insect pests, it is necessary to rely heavily on pesticides, especially the use of chemical pesticides, in order to truly effectively maximize the Recover ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D417/06
CPCC07D417/06
Inventor 戴百雄白伟卢威贺从国张建广连建军何小明马立涛罗斌
Owner 湖北犇星农化有限责任公司
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