Preparation methods of flonicamid and intermediate 4-(trifluoromethyl)nicotinic acid thereof

A technology of trifluoromethylnicotinic acid and flonicamid, which is applied in the field of flonicamid preparation, can solve the problems of huge production cost and high cost of raw materials, and achieve the effects of low equipment requirements, high total yield and low cost

Active Publication Date: 2018-06-22
SHANGHAI HETENG FINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But in this method, the ring-closing yield is only 45.3%, and its raw material cost is too high, and production cost is huge

Method used

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  • Preparation methods of flonicamid and intermediate 4-(trifluoromethyl)nicotinic acid thereof
  • Preparation methods of flonicamid and intermediate 4-(trifluoromethyl)nicotinic acid thereof
  • Preparation methods of flonicamid and intermediate 4-(trifluoromethyl)nicotinic acid thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Add cyanoacetamide and ethyl trifluoroacetoacetate to N-methylmorpholine, reflux for 12 hours, collect the obtained solid with a Buchner funnel, and purify it with ethanol to obtain 2,6-dihydroxy -3-cyano-4-trifluoromethylpyridine N-methylmorpholine salt. Add phosphorus oxychloride to the obtained 2,6-dihydroxy-3-cyano-4-trifluoromethylpyridine N-methylmorpholine salt, reflux reaction for 18 hours, and recover excess oxygen trichloride by distillation under reduced pressure. After phosphorus, the raffinate was poured into a mixture of ice and water and extracted with ethyl acetate, and the organic phase was collected and concentrated to directly obtain 2,6-dichloro-3-cyano-4-trifluoromethylpyridine with high purity and high yield. Add the 2,6-dichloro-3-cyano-4-trifluoromethylpyridine obtained in the previous step into the solvent THF, add 10% Pd / C and triethylamine to carry out atmospheric pressure hydrogenation, and complete within 4 hours For the reaction, the solid...

Embodiment 2

[0039] The preparation process of flonicamid is as follows:

[0040] 1) Weigh 10g (119mmol) of cyanoacetamide, add it to a 100mL three-necked reaction flask with a reflux condenser and a constant pressure dropping funnel, turn on the condensed water, and degas it with N 2 Protect. Add 30g (297mmol) N-methylmorpholine, stir well and add 20g (109mmol) ethyl trifluoroacetoacetate dropwise within 2h. Slowly raise the temperature to 78°C and keep the reaction for 12h. Afterwards, the reaction was cooled to -5°C, and the precipitated solid was filtered with a Buchner funnel, rinsed with 5g of ethanol, and the resulting product was dried at 70°C to obtain 27.6g (90.4mmol) of 2,6-dihydroxy-3-cyanide Base-4-trifluoromethylpyridinium N-methylmorpholine salt, yield 83.2%.

[0041] 2) Weigh 10g (32.8mmol) 2,6-dihydroxy-3-cyano-4-trifluoromethylpyridine N-methylmorpholine salt and 50g (326mmol) POCl 3 Add it to a 100mL three-neck reaction flask with a reflux condenser, and turn on the ...

Embodiment 3

[0046] The preparation process of flonicamid is as follows:

[0047] 1) Weigh 10g (119mmol) of cyanoacetamide, add it to a 100mL three-necked reaction flask with a reflux condenser and a constant pressure dropping funnel, turn on the condensed water, and degas it with N 2 Protect. Add 30g (297mmol) N-methylmorpholine, stir well and add 30g (163mmol) ethyl trifluoroacetoacetate dropwise within 2h. Slowly raise the temperature to 78°C and keep the reaction for 12h. Afterwards, the reaction was cooled to -5 °C, and the precipitated solid was filtered with a Buchner funnel, rinsed with 5 g of ethanol, and the resulting product was dried at 70 °C to obtain 33.2 g (109.1 mmol) of 2,6-dihydroxy-3-cyanide Base-4-trifluoromethylpyridinium N-methylmorpholine salt, yield 91.7%.

[0048] 2) Weigh 10g (32.8mmol) 2,6-dihydroxy-3-cyano-4-trifluoromethylpyridine N-methylmorpholine salt and 100g (326mmol) POCl 3 Add it to a 250mL three-neck reaction flask with a reflux condenser, and turn ...

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PUM

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Abstract

The invention relates to preparation methods of flonicamid and an intermediate 4-(trifluoromethyl)nicotinic acid thereof. The preparation method of 4-(trifluoromethyl)nicotinic acid comprises the steps that cyanoacetamide, ethyl 4,4,4-trifluoroacetoacetate and organic alkali serve as the raw materials, 2,6-dyhydroxy-3-cyano-4-tirfluoromethylpyridine N-methylmorpholine salt is prepared first, and then phosphorus oxychloride chlorination, catalytic hydrogenation and hydrolyzation are conducted in sequence to obtain 4-(trifluoromethyl)nicotinic acid; the preparation method of the flonicamid comprises the steps that 4-(trifluoromethyl)nicotinic acid is prepared and then mixed with glycinonitrile hydrochloride, and after an amidation reaction is conducted, the flonicamid is obtained. Compared with the prior art, the total recovery of the prepared flonicamid is high, the cost is low, operation is easy, the equipment requirement is low, and the requirement of industrial production can be met;the technological process is simple, separation and purification are easy, and the reaction condition is mild.

Description

technical field [0001] The invention belongs to the technical field of flonicamid preparation and relates to a preparation method of flonicamid and its intermediate 4-trifluoromethylnicotinic acid. Background technique [0002] Flunicamid is a low-toxic pyridine amide insect growth regulator insecticide. It obtained the temporary registration certificate of pesticide products in my country in 2007. The preparation is 10% water-dispersible granules. In addition to its contact and stomach poisoning effects, flonicamid also has a good nerve agent and rapid antifeedant effect. Aphids and other piercing-sucking mouthparts will be quickly prevented from sucking the juice after inhaling the plant juice with flonicamid. There will be no excrement at all within 1 hour, and eventually they will die of starvation. [0003] At present, the methods for synthesizing flonicamid basically start from 4-trifluoromethylnicotinic acid, mainly including the following: [0004] 1) U.S. Patent U...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/80C07D213/803C07D213/82
CPCC07D213/80C07D213/803C07D213/82
Inventor 陈盛施冠成孟海成
Owner SHANGHAI HETENG FINE CHEM
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