Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method of 2-chloro-3-cyanopyridine

A cyanopyridine, phosphorus oxychloride technology, applied in the direction of organic chemistry and the like, can solve the problems of poor selectivity, inability to prepare 2-chloro-3-cyanopyridine with high selectivity, and low yield, etc., and achieve high selectivity High performance, high yield and simple operation

Pending Publication Date: 2022-05-03
黑龙江立科新材料有限公司
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The preparation of 2-chloro-3-cyanopyridine is usually based on 3-cyanopyridine as starting raw material at present, and 3-cyanopyridine N-oxide is obtained by oxidation reaction, and 3-cyanopyridine N-oxide is carried out Chlorination to obtain 2-chloro-3-cyanopyridine, but the existing chlorination process has the problems of low yield and poor selectivity, and it is still impossible to prepare 2-chloro-3-cyano with high yield and high selectivity pyridine

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of 2-chloro-3-cyanopyridine
  • Preparation method of 2-chloro-3-cyanopyridine
  • Preparation method of 2-chloro-3-cyanopyridine

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0028] The invention provides a preparation method of 2- chloro-3-cyanopyridine, which comprises the following steps:

[0029] Dissolve 3-cyanopyridine N- oxide in phosphorus oxychloride, drip organic alkali at 0-5℃ and control the pH of the system to 9.5-10.5, and then heat up the system to obtain 2- chloro-3-cyanopyridine.

[0030] The above preparation method can be represented by the following reaction formula:

[0031]

[0032] According to the invention, 3-cyanopyridine N- oxide is used as a raw material and phosphorus oxychloride is used as a chlorinating agent, so that 3-cyanopyridine N- oxide is directly dissolved in excessive phosphorus oxychloride for chlorination reaction without using a solvent; and organic alkali is added into the reaction system to neutralize the acid generated in the chlorination reaction, and the organic alkali is dripped at a low temperature to control the reaction speed and avoid the generation of excessive by-products.

[0033]The inventor fo...

Embodiment 1

[0060] The preparation method of 2- chloro-3-cyanopyridine in this example is as follows:

[0061] 1) preparation of 3-cyanopyridine N- oxide

[0062] Add 500 g (4.80 mol) of 3-cyanopyridine and 1600g of concentrated sulfuric acid into a 3,000 ml four-necked flask, raise the temperature to 90℃ to reflux, slowly drop 400mL of 30% hydrogen peroxide into the reaction system in the reflux state, and continue the reflux reaction for 2 hours after dropping, so as to detect that the raw material 3-cyanopyridine has been completely converted;

[0063] The reaction solution was cooled to room temperature and filtered to obtain a solid product, which was dried and weighed at 50℃ to obtain 548g of 3-cyanopyridine N- oxide with a yield of 95%.

[0064] 2) Preparation of 2-chloro-3-cyanopyridine

[0065] Add 500 g (4.16 mol) of 3-cyanopyridine N- oxide and 2000g(13.04mol) of phosphorus oxychloride into a 3000mL four-necked flask, stir, and drop 3 mol equivalents of cyclohexylamine at 200g per ...

Embodiment 2

[0071] The preparation method of 2- chloro-3-cyanopyridine in this example is as follows:

[0072] 1) preparation of 3-cyanopyridine N- oxide

[0073] Add 500 g (4.80 mol) of 3-cyanopyridine and 1600g of concentrated sulfuric acid into a 3,000 ml four-necked flask, raise the temperature to 90℃ to reflux, slowly drop 400mL of 30% hydrogen peroxide into the reaction system in the reflux state, and continue the reflux reaction for 2 hours after dropping, so as to detect that the raw material 3-cyanopyridine has been completely converted;

[0074] The reaction solution was cooled to room temperature and filtered to obtain a solid product, which was dried and weighed at 50℃ to obtain 548g of 3-cyanopyridine N- oxide with a yield of 95%.

[0075] 2) Preparation of 2-chloro-3-cyanopyridine

[0076] Add 500g(4.16mol) of 3-cyanopyridine N- oxide and 2000g(13.04mol) of phosphorus oxychloride into a 3000mL four-necked flask, stir, and drop 3 mol equivalents of pyridine at 200g per hour in an...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a preparation method of 2-chloro-3-cyanopyridine, which comprises the following steps: dissolving 3-cyanopyridine N-oxide in phosphorus oxychloride, dropwise adding organic alkali at 0-5 DEG C, controlling the pH value of the system to 9.5-10.5, and heating the system after dropwise adding to obtain the 2-chloro-3-cyanopyridine. According to the method, by controlling the pH value of a chlorination reaction system, the 2-chloro-3-cyanopyridine can be prepared with high selectivity and high yield, and the method has the advantages of simplicity in operation and mild conditions.

Description

Technical field [0001] The invention belongs to the field of organic synthesis and relates to a preparation method of 2-chloro-3-cyanopyridine. Background technique [0002] The pyridine ring is one of the most important nitrogen-containing heterocyclic rings. The pyridine ring is very different from the benzene ring in many properties and characteristics, especially in hydrophobicity. Therefore, new pesticide compounds obtained by replacing the benzene ring with a pyridine ring often have higher biological activity, systemic properties, selectivity and more Low toxicity, which is why the research, development and application of pyridine heterocyclic pesticides in various categories of pesticides such as insecticides, herbicides, fungicides, etc. have greatly developed. [0003] The earliest pyridine-containing pesticide was tobacco extract, a plant pesticide used in Europe from the late 17th to the early 18th century. In 1690, it was used in Europe to control pear oysters....

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/85
CPCC07D213/85
Inventor 洪杰
Owner 黑龙江立科新材料有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com