A method for preparing 2-amino-3-chloro-5-trifluoromethylpyridine

A technology of trifluoromethylpyridine and amino group, applied in the field of chemical raw material preparation, can solve the problems of high reaction temperature, high risk, unsuitability for use, etc., and achieves the effects of simple operation, low environmental pollution and good product quality

Active Publication Date: 2018-09-04
天津均凯农业科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the very active chemical properties and high reaction temperature of sodium amide, it is dangerous, so it is not suitable for industrial use.

Method used

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  • A method for preparing 2-amino-3-chloro-5-trifluoromethylpyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Add 51.5g (0.92mol) potassium hydroxide and 330ml (4mol) dimethyl sulfoxide to the reaction flask, stir and cool down to 20°C, slowly add 42.7g (0.7mol) acetamide, then dropwise add 100g (0.46mol) ) 2,3-dichloro-5-trifluoromethylpyridine (the molar ratio is: 2,3-dichloro-5-trifluoromethylpyridine: potassium hydroxide: acetamide: dimethyl sulfoxide=1: 2:1.5:10), after the dropwise addition, keep the reaction at this temperature. After the raw materials have reacted completely, add 500 ml of water to the reaction solution, adjust the pH to 1-2 with hydrochloric acid, and gradually precipitate solids. After stirring for 1 hour, Filtration, washing with water, and vacuum drying gave the product 3-chloro-2-acetylamino-5-trifluoromethylpyridine as a yellow powder, 108.5 g, with a yield of 98.63%.

[0023] 108.5g (0.45mol) 3-chloro-2-acetylamino-5-trifluoromethylpyridine, 273ml (6.8mol) methanol, 36g (0.9mol) sodium hydroxide (molar ratio: 3-chloro-2- Acetylamino-5-trifluorom...

Embodiment 2

[0025] Add 50.4g (0.9mol) potassium hydroxide and 360ml (4.1mol) N,N-dimethylacetamide to the reaction flask, stir and cool down to 35°C, slowly add 36.5g (0.6mol) acetamide, then drop Add 100g (0.46mol) 2,3-dichloro-5-trifluoromethylpyridine (the molar ratio is: 2,3-dichloro-5-trifluoromethylpyridine: potassium hydroxide: acetamide: N,N -Dimethylacetamide=1:2:1.3:9), keep the reaction at this temperature after the dropwise addition is completed, after the raw materials have reacted completely, add 500 ml of water to the reaction solution, adjust the pH to 1-2 with hydrochloric acid, Solids were gradually precipitated, and after stirring for 1 hour, filtered, washed with water, and dried in vacuo to obtain the product 3-chloro-2-acetylamino-5-trifluoromethylpyridine, a yellow powder, 103 g, with a yield of 93.71%.

[0026] 103g (0.43mol) 3-chloro-2-acetylamino-5-trifluoromethylpyridine, 300ml (6.45mol) ethanol, 51.6g (1.29mol) sodium hydroxide (molar ratio: 3-chloro-2- Acetyl...

Embodiment 3

[0028] Add 55.2g (1.4mol) sodium hydroxide and 360ml (4.1mol) N,N-dimethylformamide to the reaction flask, stir and cool down to 40°C, slowly add 47.4g (0.8mol) acetamide, then drop Add 100g (0.46mol) 2,3-dichloro-5-trifluoromethylpyridine (the molar ratio is: 2,3-dichloro-5-trifluoromethylpyridine: sodium hydroxide: acetamide: N,N -Dimethylformamide=1: 3: 1.7: 12), keep the reaction at this temperature after the dropwise addition is completed, after the raw materials have reacted completely, add 500 milliliters of water to the reaction solution, adjust the pH to 1-2 with hydrochloric acid, Solids were gradually precipitated, and after stirring for 1 hour, filtered, washed with water, and dried in vacuo to obtain the product 3-chloro-2-acetylamino-5-trifluoromethylpyridine, a yellow powder, 106 g, with a yield of 96.49%.

[0029] With 106g (0.44mol) 3-chloro-2-acetylamino-5-trifluoromethylpyridine, 264ml (4.4mol) ethanol, 49.3g (0.88mol) potassium hydroxide (molar ratio is: 3-...

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Abstract

The invention discloses a method for preparing 2-amino-3-chloro-5-(trifluoromethyl)pyridine. The method includes the following steps that 2,3-dichloro-5-(trifluoromethyl)pyridine or 2-fluoro-3-5-(trifluoromethyl)pyridine serves as the raw material, and 3-chloro-2-acetamido-5-(trifluoromethyl)pyridine is prepared through reaction of the raw material and acetamide in a polar solvent under the condition of adding alkaline matter; the 3-chloro-2-acetamido-5-(trifluoromethyl)pyridine is subjected to hydrolysis in the polar solvent under the condition of adding the alkaline matter to prepare 2-amino-3-chloro-5-(trifluoromethyl)pyridine. The method for preparing 2-amino-3-chloro-5-(trifluoromethyl)pyridine has the advantages that reaction is conducted under the normal pressure condition, so high-pressure reaction can be avoided, and production dangers are effectively reduced; operation is easy, and raw materials are easy to purchase; the yield is high, product quality is good, and environment pollution is little.

Description

technical field [0001] The invention belongs to the technical field of preparation of chemical raw materials, and in particular relates to a preparation method of 2-amino-3-chloro-5-trifluoromethylpyridine as an intermediate of the pesticide fungicide fluazinam. Background technique [0002] Fluazinam is a new type of substituted aniline and broad-spectrum fungicide developed by Ishihara Industrial Co., Ltd. in Japan. It has special effects on various gray molds caused by Botrytis cinerea. It is produced by 2,6-dinitro-4-tri Prepared from fluoromethyl-5-chloroaniline and key intermediate 2-amino-3-chloro-5-trifluoromethylpyridine. [0003] At present, Chinese patents CN102911115, WO2014198278, and WO2011092618 all disclose a preparation method of 2-amino-3-chloro-5-trifluoromethylpyridine, and these preparation methods are all under high pressure conditions (pressure range: 0.6~2.5 MPa) in the polar solvent by the reaction of intermediate 2,3-dichloro-5-trifluoromethylpyrid...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/73
CPCC07D213/73
Inventor 尚振华栗晓东张慧丽张文
Owner 天津均凯农业科技有限公司
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