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Continuous diazotization reaction of pyridine compounds and its application

A technology for nitridation reaction and compound, applied in the direction of organic chemistry, etc., can solve the problems of high reaction energy consumption and low yield, and achieve the effects of simple equipment operation, reduced energy consumption, and improved yield

Active Publication Date: 2020-03-27
ASYMCHEM LAB TIANJIN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The main purpose of the present invention is to provide a continuous diazotization reaction of pyridine compounds and its application, so as to solve the problems of high energy consumption and low yield in the diazotization reaction of pyridine compounds in the prior art

Method used

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  • Continuous diazotization reaction of pyridine compounds and its application
  • Continuous diazotization reaction of pyridine compounds and its application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] Preparation of 2-bromopyridine

[0053] Control the temperature at 10~35℃, add 1.0 mol of pyridine compound I to the reaction flask A, and then add 11.33g / g hydrobromic acid dropwise. After TLC detects the salt formation is complete, the temperature will be reduced to 10~25℃, and then transferred to the feed bottle A. To be used, record it as raw material A; add 2.5 mol of 40% sodium nitrite aqueous solution to feed bottle B and record it as liquid B; the outlet of the coil reactor is connected to the receiving bottle, and the receiving pipeline is equipped with a back pressure valve. Connect the back pressure valve with the automatic control system; add 1.68 mol bromine to the receiving bottle; cool the outer bath of the coil reactor to -10~0℃, and lower the temperature of the outside bath of the receiving bottle to -10~0℃; The first automatic feed pump drives the raw material A from the feeder bottle A into the coil reactor, and the second automatic feed pump drives the ...

Embodiment 2

[0056] Preparation of 2-bromopyridine

[0057] Control the temperature at 10~35℃, add 1.0 mol of pyridine compound I to the reaction flask A, and then add 11.33g / g hydrobromic acid dropwise. After TLC detects the salt formation is complete, the temperature will be reduced to 10~25℃, and then transferred to the feed bottle A. To be used, record it as raw material A; add 2.5 mol of 40% sodium nitrite aqueous solution to feed bottle B and record it as liquid B; the outlet of the coil reactor is connected to the receiving bottle, and the receiving pipeline is equipped with a back pressure valve. Connect the back pressure valve to the automatic control system; add 3.0 mol bromine to the receiving bottle; cool the outer bath of the coil reactor to -10~0℃, and cool the outside bath of the receiving bottle to -10~0℃; The first automatic feed pump drives the raw material A from the feeder bottle A into the coil reactor, and the second automatic feed pump drives the liquid B from the feede...

Embodiment 3

[0060] Preparation of 2-bromopyridine

[0061] Control the temperature at 10~35℃, add 1.0 mol of pyridine compound I to the reaction flask A, and then add 11.33g / g hydrobromic acid dropwise. After TLC detects the salt formation is complete, the temperature will be reduced to 10~25℃, and then transferred to the feed bottle A. To be used, record it as raw material A; add 2.5 mol of 40% sodium nitrite aqueous solution to feed bottle B and record it as liquid B; the outlet of the coil reactor is connected to the receiving bottle, and the receiving pipeline is equipped with a back pressure valve. Connect the back pressure valve to the automatic control system; add 1.0 mol bromine to the receiving flask; cool the outer bath of the coil reactor to -10~0℃, and cool the outer bath of the receiving bottle to -10~0℃; The first automatic feed pump drives the raw material A from the feeder bottle A into the coil reactor, and the second automatic feed pump drives the liquid B from the feeder b...

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Abstract

The invention provides a continuous diazotization reaction of a pyridine compound and application thereof. The continuous diazotization reaction comprises the following steps: mixing an acid with the pyridine compound having a structural formula I as described in the specification so as to form a raw material A; continuously conveying an aqueous solution of sodium nitrite and the raw material A into a continuous reaction apparatus for a diazotization reaction so as to obtain diazosalt of pyridine, wherein the continuous reaction apparatus comprises a continuous coil reactor; and continuously conveying the diazosalt of pyridine to a receiving container from the continuous reaction apparatus, wherein R1 and R2 in the structural formula I are independently selected from H and C1-C5 alkyl groups, and the acid is hydrobromic acid, hydrochloric acid, sulfuric acid or nitric acid. According to the invention, the diazotization reaction is carried out in the continuous reaction apparatus including the continuous coil reactor, so the energy consumption of the diazotization reaction is reduced and the yield of a target product is improved to a certain extent; moreover, the continuous diazotization reaction provided by the invention has the advantages of simple operation of equipment, low labor intensity and high security.

Description

Technical field [0001] The invention relates to a diazotization reaction of a pyridine compound, in particular to a continuous diazotization reaction of a pyridine compound and its application. Background technique [0002] Diazotization reaction is a process in which aromatic amino compounds react with nitrous acid under acidic conditions to form diazonium salts. Diazonium salts have strong chemical activity and can undergo substitution, reduction, coupling, hydrolysis and other reactions to generate various types of compounds , It is widely used in dyes, photosensitive materials, medicine and pesticide industries. There are more and more reports of continuous diazotization reactions. Most of them are focused on the diazotization of benzene ring structures. There are few reports on the diazotization of pyridine compounds. [0003] Although the structure of pyridine is similar to benzene, it is aromatic, but because there is a SP2 hybrid orbital on the nitrogen atom that does not ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/76C07D213/61C07D213/64C07D213/16C07D213/127
CPCC07D213/127C07D213/16C07D213/61C07D213/64C07D213/76
Inventor 洪浩卢江平刘金光丰惜春
Owner ASYMCHEM LAB TIANJIN