High-efficiency and green method for preparing pymetrozine

A pymetrozine and green technology is applied in the field of high-efficiency and green pymetrozine preparation, which can solve the problems such as insufficient utilization of by-products, inability to recycle the solvent, influence on water yield, etc. The effect of reducing the overall production cost

Active Publication Date: 2014-04-16
JIANGSU ANPON ELECTROCHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] Purpose of the invention: Aiming at the problems existing in the prior art, provide an efficient and green preparation method of pymetrozine to overcome the fact that the solvent used in the existing process cannot be recycled, the by-products are not fully utilized, and the water in the synthesis process is harmful to the product. Disadvantages such as the influence of the rate and the large amount of waste water

Method used

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  • High-efficiency and green method for preparing pymetrozine
  • High-efficiency and green method for preparing pymetrozine
  • High-efficiency and green method for preparing pymetrozine

Examples

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Embodiment 1

[0030] The preparation of embodiment 1 pymetrozine.

[0031] (1) Preparation of acetylhydrazide: Put 1000g of methyl acetate (solvent) into a 3000ml three-necked bottle, and slowly add 500g of hydrazine hydrate dropwise to the three-necked bottle under stirring conditions, and control the dropping time to 2h. The temperature is 40-45°C. After the dropwise addition, the temperature was raised to 75° C. for 4 h. After cooling to room temperature, 725 g of solid acetylhydrazide was obtained after concentration and crystallization (cooling to below 0°C), yield: 98%.

[0032] (2) Preparation of oxadiazolone: ​​put 2000ml of methyl acetate into a 5000ml three-neck flask, add 740g of acetylhydrazide under stirring conditions, and when the temperature is cooled below 0°C, put in 1680g of sodium bicarbonate, and seal the reaction bottle. Continuously feed phosgene into the reaction bottle, the phosgene velocity is 15m 3 / h. After the reaction was completed, the solvent was distille...

Embodiment 2

[0036] The preparation of embodiment 2 acetylhydrazine.

[0037] Put 1,000 g of methyl acetate (solvent) into a 3,000 ml three-necked flask, and slowly add 500 g of hydrazine hydrate dropwise into the there-necked flask under stirring conditions, controlling the dropping time to 2 hours, and controlling the temperature of the reaction solution during the dropping to 40-45°C. After the dropwise addition, the temperature was raised to 60° C. for 5 h. Cool to room temperature, concentrate and crystallize at 0-5°C to obtain 706 g of solid acetylhydrazide, yield: 95%.

Embodiment 3

[0038] The preparation of embodiment 3 acetylhydrazine.

[0039] Put 1,000 g of methyl acetate (solvent) into a 3,000 ml three-necked flask, and slowly add 500 g of hydrazine hydrate dropwise into the there-necked flask under stirring conditions, controlling the dropping time to 2 hours, and controlling the temperature of the reaction solution during the dropping to 40-45°C. After the dropwise addition, the temperature was raised to 85° C. for 5 h. Cool to room temperature, concentrate and crystallize at 0-5°C to obtain 697 g of solid acetylhydrazide, yield: 94%.

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Abstract

The invention discloses a high-efficiency and green method for preparing pymetrozine. According to the method, a byproduct methyl acetate produced in a pymetrozine condensation step serves as a raw material and replaces ethyl acetate in a traditional process for synthesizing acethydrazide, and the produced byproduct methanol can serve as a solvent in a subsequent step, so that the byproduct is recycled, and the raw material utilization rate is improved. Hydrogen chloride or concentrated hydrochloric acid in a traditional process is replaced by adopting a saturated hydrogen chloride methanol solution in the condensation step, and moisture in the system is avoided, so that amino triazone is subjected to a hydrolysis reaction, and byproducts are basically eliminated. According to the method, the yield of the product and the utilization rate of the hydrogen chloride are improved, the reaction time is shortened, emission of wastewater and waste gas is reduced, the comprehensive production cost is reduced, and better conditions are created for industrial large-scale production of the product.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a high-efficiency and green preparation method of pymetrozine. Background technique [0002] Pymetrozine, chemical name: 4,5-dihydro-6-methyl-4-(3-pyridinemethyleneamino)-1,2,4-triazin-(2H)-one. It is a new type of iminopyridine insecticide developed by Ciba-Geigy in 1988. Because of its high selectivity, low toxicity to mammals, and safety to birds, fish, and non-target arthropods, this compound shows a very broad application prospect in integrated control. After many years of production practice, the synthesis process of pymetrozine is basically mature, but with people's emphasis on environmental protection and the country's policy of energy conservation and emission reduction, various environmental protection problems in the existing synthesis routes of pymetrozine have also emerged. According to literature reports, the currently commonly used method for synthes...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D401/12
CPCC07D401/12
Inventor 季玉祥姜育田姚修宇王俊生龙玺国郑辰谢俊
Owner JIANGSU ANPON ELECTROCHEM
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