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

Preparation method of 2-chloro-3-aminopyridine

A technology of aminopyridine and nitropyridine, which is applied in the field of preparation of 2-chloro-3-aminopyridine, can solve the problems of difficult refining and decolorization, high price, and low product yield, so as to achieve cheap and easy-to-obtain raw materials and reduce production The effect of high cost and product yield

Inactive Publication Date: 2011-08-17
UNIV OF JINAN
View PDF1 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Among the above several methods for preparing 2-chloro-3-aminopyridine, the disadvantage of method (1) is that the chlorination of 3-aminopyridine obtains a certain amount of by-product 2,5-dichloro-3-aminopyridine, This by-product leads to a darker color of the product, making it difficult to refine and decolorize
Although multiple extractions with organic solvents can be used to remove the by-product 2,5-dichloro-3-aminopyridine, multiple extractions with organic solvents will lead to low product yields
To convert the by-product 2,5-dichloro-3-aminopyridine into the raw material 3-aminopyridine, the by-product 2,5-dichloro-3-aminopyridine needs to be separated from the product, and the by-product The product 2, 5-dichloro-3-aminopyridine is reduced to 3-aminopyridine, and the operation is more complicated
In addition, the raw material 3-aminopyridine source that this method adopts is limited, expensive
In method (2), the source of raw material 2-chloronicotinamide is limited, expensive and cumbersome to operate
In method (3), noble metal catalysts need to be used, which increases the preparation cost

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-aminopyridine
  • Preparation method of 2-chloro-3-aminopyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] In a four-neck flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, add 1.0L of water, 158.5g (1.0mol) of 2-chloro-3-nitropyridine, and 360g (6.7mol) of ammonium chloride , 60mL of concentrated ammonia water, heated to 80°C, 1250mL (3.5mol) of 20% sodium sulfide solution was added dropwise, the temperature was kept between 75-80°C during the dropwise addition process, and the addition was completed within 1h. After adding the sodium sulfide solution, continue the heat preservation reaction for 15 minutes, filter while it is hot, and cool the filtrate to precipitate a solid. Add 5% dilute hydrochloric acid to the solid until the solid is no longer dissolved. After filtration, the filtrate was adjusted to pH 9 with 15% NaOH solution, and crystals were precipitated. Suction filtration, washing with water, and vacuum drying yielded 110.6 g of 2-chloro-3-aminopyridine, with a yield of 86.1% and a content of 98.7% (results obtained by liquid chro...

Embodiment 2

[0017] In a four-neck flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, add 1.0L of water, 158.5g (1.0mol) of 2-chloro-3-nitropyridine, and 268.0g (5mol) of ammonium chloride , 60mL of concentrated ammonia water, heated to 75°C, 1250mL (3.5mol) of 20% sodium sulfide solution was added dropwise, the temperature was kept between 70-80°C during the dropwise addition process, and the addition was completed within 1h. After adding the sodium sulfide solution, continue the heat preservation reaction for 15 minutes, filter while it is hot, and cool the filtrate to precipitate a solid. Add 5% dilute hydrochloric acid to the solid until the solid is no longer dissolved. After filtering, the filtrate was adjusted to pH 10 with 15% NaOH solution, and crystals were precipitated. Suction filtration, washing with water, and vacuum drying gave 95.4 g of 2-chloro-3-aminopyridine, yield 74.2%, content 96.2%, m.p.79-81°C. The NMR data of the product obtained: ...

Embodiment 3

[0019] In a four-neck flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, add 1.0L of water, 158.5g (1.0mol) of 2-chloro-3-nitropyridine, 360.0g (6.7mol) of ammonium chloride ), concentrated ammonia water 60mL, heated to 80°C, and 1000mL (2.8mol) of 20% sodium sulfide solution was added dropwise, keeping the temperature between 75-80°C during the dropwise addition process, and the addition was completed within 1h. After adding the sodium sulfide solution, continue the heat preservation reaction for 15 minutes, filter while it is hot, and cool the filtrate to precipitate a solid. Add 5% dilute hydrochloric acid to the solid until the solid is no longer dissolved. Filter and adjust the pH value of the filtrate to 9-10 with 15% NaOH solution to precipitate crystals. Suction filtration, washing with water, and vacuum drying gave 102.2 g of 2-chloro-3-aminopyridine, yield 79.5%, content 97.6%, m.p.79-81°C. The NMR data of the product obtained: 1 HNM...

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 belongs to the field of fine chemical industry, and particularly relates to a preparation method of 2-chloro-3-aminopyridine. The method comprises the following steps: adding 2-chloro-3-nitropyridine into water, and dropwisely adding a sodium sulfide water solution to carry out reaction; after the reaction finishes, cooling to precipitate a solid, adding dilute hydrochloric acid to dissolve the solid, filtering, regulating the pH value of the filtrate to 9-10 with an NaOH water solution, and precipitating crystals, thereby obtaining the 2-chloro-3-aminopyridine. The preparation method of 2-chloro-3-aminopyridine has the advantages of mild reaction, high product yield and the like, is simple to operate, and is suitable for industrial production; no organic solvent is used in the reaction process, thereby being beneficial to clean production; and the raw materials are cheap and accessible, thereby lowering the production cost.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of 2-chloro-3-aminopyridine. Background technique [0002] 2-Chloro-3-aminopyridine is an important pharmaceutical and pesticide intermediate, which can be used in the synthesis of anti-peptic ulcer drugs, anti-AIDS drugs and insecticides. Its preparation method usually has the following several kinds: (1) Yin Xiangxiang and others disclosed a kind of production method of 2-chloro-3-aminopyridine in ZL2009101151690, and this method is to use 3-aminopyridine as raw material, through the following two It is prepared by two steps: ① 3-aminopyridine is chlorinated under the action of hydrogen peroxide and hydrochloric acid to obtain the main product 2-chloro-3-aminopyridine and by-product 2,6-dichloro-3-aminopyridine; ② making The by-product 2,6-dichloro-3-aminopyridine undergoes catalytic hydrogenation reaction to produce 3-aminopyridine which can be u...

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
IPC IPC(8): C07D213/73
Inventor 谭晓军杨秀利王国荣刘善奎
Owner UNIV OF JINAN
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