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Method for synthesizing aminopyridine and 4-aminopyridine in one step

An aminopyridine and cyanopyridine technology, applied in the field of chemical raw material synthesis, can solve the problems of high condition requirements, many three-waste pollution, complicated steps and the like, and achieve the effects of easy control of conditions, few side reactions and simple reaction steps

Active Publication Date: 2018-11-20
ANHUI XINGYU CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] Aiming at the problems in the existing preparation method of aminopyridine, such as high requirement of conditions, cumbersome steps, many pollutions of three wastes, low yield, etc., the present invention provides a method for synthesizing aminopyridine and 4-aminopyridine in one step. The present invention utilizes sodium tungstate as a catalyst, in Under the condition of sodium hypochlorite water solvent, cyanopyridine can be reacted in one step to generate aminopyridine, especially 4-cyanopyridine is reacted to generate 4-aminopyridine, and then extracted with chloroform, after distillation to remove the solvent, the aminopyridine product is obtained. The purity of the product is It can be as high as about 99.5%, and the yield of the reaction is increased from more than 50% in the prior art to 85%.

Method used

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  • Method for synthesizing aminopyridine and 4-aminopyridine in one step
  • Method for synthesizing aminopyridine and 4-aminopyridine in one step
  • Method for synthesizing aminopyridine and 4-aminopyridine in one step

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Embodiment 1

[0033] like figure 1 As shown, the present invention provides a method for synthesizing aminopyridine in one step. The main steps include: under low temperature conditions, using cyanopyridine as a raw material, using sodium tungstate as a catalyst, pre-reacting in an aqueous solution of sodium hypochlorite, and then heating up It is obtained by one-step Hoffman reaction. Compared with the prior art, the preparation method explored by the present invention has the advantages of easy control of reaction conditions, less by-products, less pollution of three wastes, etc., and is more suitable for industrial application. Taking 4-aminopyridine as an example, the above method is used to synthesize, and the main steps are:

[0034] (1) Prepare an aqueous solution of 4-cyanopyridine (in a reaction flask, dissolve 100 g of 4-cyanopyridine with 375 g of water to obtain an aqueous solution of 4-cyanopyridine), and cool the aqueous solution to below 0° C.;

[0035] (2) add catalyzer sod...

Embodiment 2

[0045] like figure 1 As shown, the method for the one-step synthesis of aminopyridine provided by the present invention, the main steps include: under low temperature conditions, using cyanopyridine as raw material, using sodium tungstate as catalyst (the addition of catalyst is 2% of the quality of raw material cyanopyridine ~5% or so), pre-reacted in sodium hypochlorite aqueous solution, and then heated up to carry out Hoffman one-step reaction to obtain. Taking 4-aminopyridine as an example, the above method is used to synthesize, and the main steps are:

[0046] (1) Prepare an aqueous solution of 4-cyanopyridine (dissolve 171 g of 4-cyanopyridine in a reaction flask with 400 g of water to obtain an aqueous solution of 4-cyanopyridine), and cool the aqueous solution to below 0° C.;

[0047] (2) add catalyzer sodium tungstate, add-on is 2% of 4-cyanopyridine quality, promptly adds 3.4g catalyzer;

[0048] (3) then slowly add sodium hypochlorite solution dropwise (the mass ...

Embodiment 3

[0055] like figure 1 As shown, a kind of one-step method for synthesizing aminopyridine provided by the present invention, main steps comprise: under low temperature condition, with cyanopyridine as raw material, with sodium tungstate as catalyst (the addition of catalyst is raw material cyanopyridine quality About 2% to 5% of the sodium hypochlorite solution), pre-reacted in an aqueous solution of sodium hypochlorite, and then heated up to perform a Hoffmann one-step reaction to obtain. Taking 4-aminopyridine as an example, the above method is used to synthesize, and the main steps are:

[0056] (1) Prepare an aqueous solution of 4-cyanopyridine (in a reaction flask, dissolve 100 g of 4-cyanopyridine with 300 g of water to obtain an aqueous solution of 4-cyanopyridine), and cool the aqueous solution to below 0° C.;

[0057] (2) add catalyzer sodium tungstate, add-on is 3% of 4-cyanopyridine quality, promptly adds 3g catalyzer;

[0058] (3) then slowly add sodium hypochlorit...

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Abstract

The invention discloses a method for synthesizing aminopyridine and 4-aminopyridine in one step and belongs to the technical field of chemical material synthesis. The method comprises the following steps: in a low temperature condition, carrying out a pre-reaction in a sodium hypochlorite aqueous solution by taking cyanopyridine as a raw material and sodium tungstate as a catalyst (the adding amount of the catalyst is about 2-5% by mass of the raw material cyanopyridine), wherein the reaction is stopped on formamide pyridine; and then raising the temperature for Hoffman one-step reaction to obtain aminopyridine. Taking synthesis of 4-aminopyridine as an example, the reaction condition is easy to control, the reaction step is simple, the product is convenient to operate, side reactions arefew, the product purity can reach 99.95%, and problems of severe pollution, low yield and the like in the prior art are solved.

Description

technical field [0001] The invention belongs to the technical field of chemical raw material synthesis, and more specifically relates to a method for synthesizing aminopyridine and 4-aminopyridine in one step. Background technique [0002] 4-Aminopyridine is an important pesticide, pharmaceutical and dye intermediate; it is also used as a chemical reagent. It is an intermediate for the synthesis of antibiotic drugs such as 4-acetamidopiperidine acetate, and is also a raw material for the preparation of cardiotonic agents, bactericides, antiarrhythmic drugs, antiulcer drugs, and antispasmodic drug Milverine; new antihypertensive drug pyridoxine An important raw material for Nadir. [0003] At present, the methods for preparing 4-aminopyridine include metal reduction method, catalyst hydrogenation method, electrochemical reduction method and so on. At present, most of the 4-aminopyridines are prepared by metal reduction method or acetic acid system to realize the reduction o...

Claims

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Application Information

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IPC IPC(8): C07D213/73
CPCC07D213/73
Inventor 张升张宽宇金文艺
Owner ANHUI XINGYU CHEM
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