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

Synthetic method for preparing pyridine N-oxide

A technology of pyridine nitrogen oxide and synthesis method, which is applied in the direction of organic chemistry, can solve the problems of difficult post-processing, unsuitable industrial production, and high raw material prices, and achieve the effects of improving production safety factor, easy operation, and small environmental pollution

Inactive Publication Date: 2011-11-23
ASYMCHEM LAB TIANJIN
View PDF2 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method avoids the use of a large amount of solvent, the price of the raw material itself is very high and the post-processing is difficult
[0007] There are certain defects in the above three types of synthetic methods, which cannot meet the needs of industrialized production now.

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
  • Synthetic method for preparing pyridine N-oxide
  • Synthetic method for preparing pyridine N-oxide
  • Synthetic method for preparing pyridine N-oxide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] (1) Preparation of urea-hydrogen peroxide complex: add 708.2kg 30% hydrogen peroxide (3eq.), 12.5kg salicylic acid (0.1g / g) and 125kg urea (1.0eq.) to a 2000L enamel kettle, and heat Insulation reaction. After the reaction is complete, cool down to -10-0°C, heat and stir for 3 hours and then centrifuge. The centrifuged solid is rinsed with 375L of petroleum ether (3ml / g), and the filter cake is a urea-hydrogen peroxide complex with a yield of 80% and a purity of 98%.

[0030] (2) Preparation of product 2-chloropyridine-N-oxide The reaction process: 360L ethyl acetate (3ml / g), 155kg phthalic anhydride (1.0eq.), and 120kg dichloropyridine (1.0eq.) were added to a 2000L enamel kettle. After the feeding is complete, raise the temperature of the system to 90-110°C, add 200kg of urea-hydrogen peroxide compound (2.0eq) to the system, and keep it warm; The test paper no longer turns blue, and then adjust the pH of the system to 9-10 with 20% sodium hydroxide, centrifuge, ext...

Embodiment 2

[0035] (1) Preparation of urea-hydrogen peroxide compound: add 47.2kg 30% hydrogen peroxide (0.5eq.), 4.0kg ethylenediaminetetraacetic acid (0.08g / g) and 50kg urea (1.0eq.) in 300L enamel kettle, ~40°C heat preservation reaction. After the reaction is complete, lower the temperature to 5-15°C, keep stirring for 1 hour and then centrifuge. The centrifuged solid is rinsed with 25L isopropyl acetate (0.5ml / g), and the filter cake is urea-hydrogen peroxide complex, with a yield of 78% and a purity of 98%. ;

[0036] (2) Preparation of product 2-methoxypyridine-N-oxide The reaction process of: add 18L isopropyl acetate (15ml / g) in 72L reaction bottle, 3.3kg acetic anhydride (4eq.), 1.2kg 2-methoxypyridine (1.0eq), after feeding completes, system is warmed up to 30~40℃, add 2.8kg urea hydrogen peroxide compound (4.5eq) to the system, and keep warm for reaction; after the reaction is complete, lower the temperature to 0~10℃, add 0.12kg saturated sodium sulfite solution (until the ...

Embodiment 3

[0041] (1) Preparation of urea-hydrogen peroxide compound: add 75.6kg 30% hydrogen peroxide (0.8eq.), 0.05kg potassium dihydrogen phosphate (0.001g / g) and 50kg urea (1.0eq.) to a 200L enamel kettle, 40 ℃ insulation reaction. After the reaction is complete, lower the temperature to 0-5°C, heat and stir for 0.5 h, then centrifuge, and rinse the centrifuged solid with 100L ethyl acetate (2ml / g). The filter cake is the urea-hydrogen peroxide complex, with a yield of 79% and a purity of 97%;

[0042] (2) Preparation of product 2-chloro-3-picoline nitrogen oxide The reaction process: add 252L ethyl acetate (9ml / g) in the 500L enamel kettle, 45.7kg acetic anhydride (2.5eq.), 28kg 2-chloro-3-picoline (1.0eq.), after the addition is complete, the The temperature of the system is raised to 80-110°C, and 16.8kg of urea-hydrogen peroxide complex (1.0eq) is added to the system, and the reaction is carried out with heat preservation; after the reaction is complete, the temperature is lowe...

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

Provided is a synthetic method for preparing pyridine N-oxide. According to the method, raw materials which are commercialized on the market are selected, or pyridine, monosubstituted pyridine or polysubstituted pyridine derivatives which are easy to prepare are used as starting materials, and the materials are oxidized by urea-hydrogen peroxide compound so to prepare the final product. The advantages of the invention are as follows: 1, the raw materials used in the invention are easily available and cheap and are commercialized or easily preparable raw materials, meeting requirements for large scale production; 2, a safer oxidation method is employed in the invention, thereby avoiding condensation of acetate containing hydrogen peroxide and greatly improving safety factors of production; 3, chemical reaction conditions required in the invention are mild, the operation is simple, little pollution to environment is produced, and the method is technically mature for large scale production.

Description

(1) Technical field: [0001] The invention relates to a synthetic method of an important organic chemical intermediate, in particular to a synthetic method for preparing pyridine nitrogen oxide. (two) background technology: [0002] Pyridine nitrogen oxides are derivatives of pyridine, which are an important class of organic chemical intermediates, widely used in many chemical fields such as medicine, dyes, and catalysis. There are many types of new pesticides and medicines containing pyridine groups with strong physiological activity. These new pesticides are not only highly efficient, low-toxic, and broad-spectrum, but also have excellent environmental compatibility for humans and animals, which is in line with the development trend of pesticides today. In medicine, it is an important intermediate for the synthesis of 2-chloromethyl-4-methoxy-3,5-lutidine hydrochloride, and it is also an important intermediate for the preparation of cardiotonic agents, bactericides, antiar...

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): C07D213/89
Inventor 洪浩韦建陈元东
Owner ASYMCHEM LAB TIANJIN
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