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Process for preparing cis-halochrysanthemic acid

A production method, the technology of halochrysanthemic acid, which is applied in the production field of cis-halogenated chrysanthemic acid, can solve the problems of high energy consumption, long production cycle, and long reaction steps, etc.

Inactive Publication Date: 2003-01-15
SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

An intractable problem encountered at present is that the purification of tetrachlorobutanone is technically difficult to solve, and further work is in progress
[0012] The product cis / trans=9:1 that the Grignard reagent method shown in the 3rd method obtains, but its major shortcoming is to have used Grignard reagent, and 1,4 addition product is subject to the competition of 1,2 addition reaction, obtains The rate stability is not good, and the reaction steps are long, and its practical value remains to be studied
Because in the cyclization reaction, sodium tert-butoxide with higher purity is required to ensure a relatively high cis-trans ratio, and if excessive tert-butanol is to be separated in this production method, it needs to be repeatedly azeotropically distilled with a large amount of inert aromatic solvent, The production cycle is long, the energy consumption is large, and the cost is high.

Method used

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  • Process for preparing cis-halochrysanthemic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Preparation of Methyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate

[0023] Under nitrogen protection, add 155 kg of methyl benicate, 400 kg of F113A and 900 kg of tert-butanol into a 2000-liter enamel reaction kettle, add 1.1 kg of cuprous chloride and 33 kg of ethanolamine in turn under stirring, and heat to reflux for 15 hours. The excess F113A and tert-butanol were recovered under normal pressure, and the fraction at 136-142° C. / 15 mmHg was collected by vacuum distillation, totaling 323.1 kg (content 92.24%), with a yield of 83%.

Embodiment 2

[0025] Preparation of Methyl cis, trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethylCyclopropanecarboxylate

[0026] In a 500-liter enamel reaction kettle, under nitrogen protection, sequentially add petroleum ether, 6 kg of sodium amide and 13.7 kg of tert-butanol, and slowly heat up to reflux according to the gas release rate. GC traces that the content of tert-butanol no longer declines, about It takes 3-5 hours. Cool to -15°C, add 36.8kg of fluorochloroethene at one time, slowly heat up to -5°C, GC tracking (sampling 1ml, adding 1ml of water, sending organic layer sample) until the content of fluorochlorofluoroester is less than 2% (deducting solvent), Add 110 kg of saturated ammonium chloride solution, separate the organic layer, extract the water layer twice with 100 kg of petroleum ether, combine the organic layers, dry, and concentrate to obtain 29.6 kg of crude product (cis:trans=9:1), which is directly used in the next step hydrolysis.

Embodiment 3

[0028] Preparation of Methyl,trans-3-(2-chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcyclopropanecarboxylate

[0029] In 500 liters of stainless steel reactors, add 50kg chlorofluorocyclic esters, 24kg potassium carbonate and 150kgDMF, heat up to 125 ℃ and react for 5 hours, GC tracks to raw material content

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Abstract

A process for preparing cis-halochrysanthemic acid includes such steps as the addition reaction of raw material (sodium tert-butyl alkoxide), reaction for removing hydrogen chloride and hydrolysis, reflux with excess sodium hydroxide in the mixed solvent of methanol or ethanol and water to obtain cyclocompound, and acidation. Its advantages are simple process, high output rate, low cost and less pollution.

Description

technical field [0001] The invention relates to a novel and practical improved production method of cis-halochrysanthemic acid, which includes permethrin, dibromochrysanthemic acid, kungfu chrysanthemic acid and the like. The method has the advantages of simple operation, high yield, low cost and less waste, and is an ideal method for producing halochrysanthemic acid. Background technique [0002] The development trend of new pesticides is: efficient, safe and economical. Pyrethroids are a class of biomimetic drugs developed on the basis of the chemical structure of natural pyrethroids. They are characterized by fast knockdown, strong insecticidal activity, broad spectrum, low toxicity, low residue and easy degradation. Low toxicity to animals and birds, safe to use, and does not pollute the environment. Since the late 1960s, especially in the 1970s, the development of pyrethroids has entered a period of great development. Due to the good insecticidal activity and photosta...

Claims

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Application Information

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IPC IPC(8): C07C51/09C07C61/10
Inventor 姜标张小兵魏慧玲高红兰
Owner SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI
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