Preparation method of pyrimethanil

A technology of pyrimethamine and aniline, which is applied in the field of preparation technology of fungicides, can solve the problems such as inability to remove water produced by reaction in time, low conversion rate of aniline, long reaction time, etc., and achieves shortened reaction period, high conversion rate, and reaction speed. quick effect

Inactive Publication Date: 2012-10-24
LIMIN CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] In order to solve the shortcomings of the prior art such as low conversion rate of aniline, long reaction time, inability to remove the reaction water in time, and low total yield, the invention provides a method for preparing pyrimethanil, which makes the product content reach more than 99%. At the same time, it ensures that the yield is higher than the existing production process level

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Add 385Kg (99%) aniline to the 3000L glass-lined airfoil stirred reactor, and stir, control the temperature below 60°C, add 450L (30%) hydrochloric acid dropwise, and keep the reaction for 30 minutes after the dropwise addition; turn on the steam, put Raise the temperature to 80-85°C, start to add 680Kg (30%) of cyanamide dropwise, and add it continuously and at a constant speed within 2 hours; After the end, cool to 40-45°C, add dropwise a solution made of 270Kg (96%) sodium carbonate and 450Kg water within 30 minutes, stir for 30 minutes, pass in 30°C circulating water to lower the temperature to 35°C, After cooling down, use the SGZ type three-legged automatic scraper lower discharge centrifuge to centrifuge and dry the mother liquor. After the mother liquor is dried, use 300 Kg of clean water to wash the material, and use a high-speed centrifuge to dry at a speed of 1200 rpm Material, obtain wet product phenylguanidine carbonate, and water content is 15%; Send wet p...

Embodiment 2

[0039] Put the phenylguanidine carbonate generated by the reaction in Example 1 into a 3000L stainless steel anchored stirring synthesis kettle, add 580Kg (99%) of acetylacetone, stir, evacuate to -0.098MPa, turn on the steam to raise the temperature to 75 ℃ for cyclization, reflux for 6 hours, add water, extract with dichloromethane, recrystallize with cyclohexane, then use 300 mesh SGZ type three-legged automatic scraper lower discharge centrifuge to filter, and finally use vacuum rake dryer to dry After 3.5 hours, pyrimethanil was obtained as a white powder.

[0040] The phenylguanidine carbonate with water content of 50%, 20%, 10%, 1%, 0.8% and 0.9% was tested, and the results are shown in Table 2.

[0041] Table 2 Experimental results of water content of phenylguanidine carbonate

[0042] batch Phenylguanidine Moisture Content Pyrimethanil weight Content of pyrimethanil Yield of pyrimethanil 1 50% 711 kg 91.2% 79.5% 2 20% 728 kg 93.5%...

Embodiment 3

[0049] Put the dried phenylguanidine carbonate in Example 1 into a 3000L stainless steel anchored stirring synthesis kettle, add 580Kg (99%) acetylacetone, stir and evacuate to -0.098MPa, turn on steam heating to raise the temperature to 75°C Carry out ring closure and reflux reaction for 6 hours. After the reaction, add solvent and stir to dissolve for 30 minutes, then cool to 0°C, use a 300-mesh SGZ type three-legged automatic scraper lower discharge centrifuge to filter, and use a vacuum rake dryer Drying for 3.5 hours gave pyrimethanil as a white powder. Experiments were carried out using cyclohexane, petroleum ether, and water+ethanol (85% ethanol) as solvents, and the results are shown in Table 4.

[0050] Table 4 Experimental results of different solvents

[0051] batch solvent Pyrimethanil weight Content of pyrimethanil Yield of pyrimethanil 1 Cyclohexane 775 kg 96.3% 91.5% 2 Cyclohexane 776 kg 96.0% 91.4% 3 petroleum ethe...

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PUM

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Abstract

The invention discloses a preparation method of pyrimethanil, which comprises the steps of: carrying out addition and salification reaction on aniline, hydrochloric acid, mono-cyanamide and sodium carbonate to generate aniline guanidine carbonate; carrying out cyclization reaction on aniline guanidine carbonate and acetyl benzophenone to generate pyrimethanil crude product; and directly adding water and alcohol mixed solvent to pyrimethanil crude product without separation, cooling, filtering and drying to obtain pyrimethanil. The content of pyrimethanil is more than 99%, and the total yield achieves more than 96% based on aniline. According to the invention, the process is simple and easy to operate, has the advantages of high product content, high yield, short reaction time, few side reactions and the like, and has significant economic benefit.

Description

technical field [0001] The invention relates to the field of pesticide preparation, in particular to a preparation process of a fungicide. Background technique [0002] Pyrimethanil is a pyrimidine amine fungicide developed by Germany Agford Company, chemical name N-(4,6-dimethylpyrimidine-ethyl) aniline, CA registration number: 533112-28-0, mainly used for the prevention and treatment of It is an excellent broad-spectrum, high-efficiency, low-toxicity, systemic fungicide, and has achieved remarkable results in crop sterilization and production increase. Therefore, countries around the world will Pyrimethanil was the fungicide of choice. Its physical and chemical properties are: the original drug is a colorless crystal or white crystal, soluble in organic solvents, slightly soluble in water, solubility in water at room temperature (25°C) is 0.12Kg / L, melting point at 25°C 96.3°C product), vapor pressure 2.2×10 -3 Pa (25°C), stable under weak acid and weak alkaline conditi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D239/42
Inventor 孙敬权尹拥军徐勤江卞继节孙丽梅陈婧
Owner LIMIN CHEM CO LTD
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