Preparation method of thiodicarb

A technology of thiodimethomyl and methomyl, which is applied in the field of preparation of thiodimethomyl to achieve the effects of reducing self-decomposition, reducing the possibility of high-temperature translocation, and reducing the probability of translocation

Active Publication Date: 2018-05-18
湖南海利常德农药化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Due to the increasingly severe situation of the global environment, in order to further reduce the impact of chemical pesticides on the environment, the production of high-quality pesticides and the reduction of the content of non-active ingredients in pesticides are also one of the current development directions of pesticides. Currently, non-sulfur impurities in thiodicarb The requirement is increased from the original 0.6% to 0.4%, but the traditional process cannot solve this problem

Method used

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  • Preparation method of thiodicarb

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Experimental program
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Effect test

Embodiment 1

[0026] Add 225g of pyridine and 1.62g of 4-dimethylaminopyridine (DMAP) into a 1000mL four-necked flask equipped with mechanical stirring, a thermometer and a constant pressure dropping funnel. Seal the reaction system, cool down to -5-5°C in an ice bath, first drop 1 / 3 of 74.5g of sulfur dichloride (calculated according to 83% mass content, the same below); then gradually increase the temperature to 20°C while simultaneously The pyridine solution of methomyl (162.2g methomyl dissolved in 250g pyridine) and the remaining sulfur dichloride were added dropwise, and the dropwise was completed within 4 hours. After the dropwise addition, the mixture was incubated and reacted at 20° C. for 4 hours. After completion of the reaction, it is detected that the content of methomyl in the reaction solution is 0.3%, and 285g of methanol is added in the reaction solution to quench, stirred and washed at room temperature for 30 minutes, filtered, and the resulting filter residue is dried at ...

Embodiment 2

[0029] Add 225g of pyridine and 1.62g of 4-dimethylaminopyridine (DMAP) into a 1000mL four-necked flask equipped with mechanical stirring, a thermometer, and a constant pressure dropping funnel, seal the reaction system, cool to -5 to 5°C in an ice bath, and drop Add 1 / 3 of 72.0g of sulfur dichloride, and then gradually add the pyridine solution of methomyl (162.2g of methomyl dissolved in 250g of pyridine) and the remaining sulfur dichloride , finished dripping within 4 hours. After the dropwise addition, the mixture was incubated and reacted at 20° C. for 4 hours. After completion of the reaction, it is detected that the methomyl content in the reaction solution is 0.29%. Add 285g of methanol to the reaction solution to quench, stir and wash at room temperature for 30 minutes, filter, and the resulting filter residue is dried at 50°C, which is thiodicarb product.

[0030] After testing, the product quality was 155.4g, the mass percentage of thiodicarb was 97.5%, the yield ...

Embodiment 3

[0032] Add 225g of pyridine and 1.62g of 4-dimethylaminopyridine (DMAP) into a 1000mL four-necked flask equipped with mechanical stirring, a thermometer, and a constant pressure dropping funnel, seal the reaction system, cool to -5 to 5°C in an ice bath, and drop Add 1 / 3 of 67.01g of sulfur dichloride, and then gradually add the pyridine solution of methomyl (162.2g of methomyl dissolved in 250g of pyridine) and the remaining sulfur dichloride , finished dripping within 4 hours. After the dropwise addition, the mixture was incubated and reacted at 20° C. for 4 hours. After completion of the reaction, it is detected that the content of methomyl in the reaction solution is 0.28%. In the reaction solution, 285g of methanol is added to quench, stirred and washed at room temperature for 30 minutes, filtered, and the resulting filter residue is dried at 50°C, which is thiodicarb product.

[0033] After testing, the product quality was 154.7g, the mass percentage of thiodicarb was ...

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Abstract

The invention discloses a preparation method of thiodicarb. The preparation method comprises the following steps: (1) dividing a solvent into two portions, dissolving methomyl in one of the two portions to obtain a methomyl solution, and dissolving 4-dimethylaminopyridine in the other portion to obtain a solvent which contains a catalyst; and (2) dividing sulfur dichloride into two portions, dropwise adding one portion of the sulfur dichloride in the solvent which contains the catalyst under a closed condition, meanwhile, dropwise adding the other portion of sulfur dichloride and carrying outdropwise adding reaction on the other portion of sulfur dichloride and the methomyl solution obtained in step (1), and carrying out insulating reaction after dropwise adding is finished to obtain thethiodicarb. The preparation method of the thiodicarb has the advantages that the reaction selectivity is high, the purity of the obtained product is high, the content of thiodicarb isomer is smaller than 0.4%, the yield is high and the like.

Description

technical field [0001] The invention belongs to the technical field of pesticide compound synthesis, and in particular relates to a preparation method of thiodicarb. Background technique [0002] Thiodicarb (thiodicarb for short), English common name thiodicarb, also known as Lavein, is a second-generation carbamate insecticide, which is further improved on the basis of methomyl and has a low One of the poisoned derivatives, that is, two methomyl molecules are connected through a thioether chain to form a biscarbamate, and the toxicity is only about one tenth of that of methomyl. It is a high-efficiency, broad-spectrum, low toxicity, Systemic stomach poisonous insecticide. The product was developed simultaneously by United Carbide and Ciba-Geigy in 1977 and put into production in 1984. So far, it has been registered in more than 30 countries in the world, with an annual sales volume of thousands of tons. The drug is widely used in crops such as cotton, vegetables, fruit t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C381/08
CPCC07C381/08
Inventor 徐建兵曾敬胡志彬曾雪云陈明刘伟王宇王胜得
Owner 湖南海利常德农药化工有限公司
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