Preparation for 2,6-diamino-3, 5-di nitryl pyridine

A technology of dinitropyridine and diaminopyridine, which is applied in the field of preparation of nitropyridine, can solve the problems of low yield, difficult industrial production, and low product purity, and achieve the effects of less by-products, less oxidation resistance, and high purity

Inactive Publication Date: 2008-12-03
HARBIN INST OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of low product purity, low yield and difficulty in industrial production in the...

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  • Preparation for 2,6-diamino-3, 5-di nitryl pyridine
  • Preparation for 2,6-diamino-3, 5-di nitryl pyridine

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specific Embodiment approach 1

[0010] Specific embodiment one: present embodiment 2,6-diamino-3, the preparation method of 5-dinitropyridine is realized according to the following steps: one, 2,6-diaminopyridine and the concentrated sulfuric acid mass concentration that mass concentration is 98% Add mole ratio 1~2:1 to absolute ethanol in order to mix and stir, the pH value is 3~5, vacuum filter after cooling to room temperature, and then dry the solid phase under vacuum condition of 40~60℃ for 22~ 26h, the sulfate salt of 2,6-diaminopyridine was obtained; the sulfate salt of 2,2,6-diaminopyridine was added to oleum at 0°C in a molar ratio of 1:2, and the temperature was kept <30°C, and then dripped Add fuming nitric acid with a mass concentration of 95%, keep the temperature <15°C, and react for 3 to 6 hours to obtain the mixture; 3. Stir the mixture at a rate of 600 to 800 r / min under ice quenching until it forms a Foamy yellow liquid, then carry out vacuum filtration, and then dry the solid phase under v...

specific Embodiment approach 2

[0011] Specific embodiment two: the difference between this embodiment and specific embodiment one is that in step one, 2,6-diaminopyridine and concentrated sulfuric acid with a mass concentration of 98% are sequentially added to absolute ethanol in a molar ratio of 1.5:1 and mixed and stirred , the pH value was 4, vacuum filtration was performed after cooling to room temperature, and then the solid phase was dried at 50° C. for 24 hours under vacuum conditions. Other steps and parameters are the same as those in Embodiment 1.

specific Embodiment approach 3

[0012] Embodiment 3: The difference between this embodiment and Embodiment 1 is that the oleum at 0° C. in step 2 is cooled in an ice-salt bath. Other steps and parameters are the same as those in Embodiment 1.

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Abstract

A method for preparing 2,6-diamino-3,5-dinitropyridine relates to a preparation method of nitropyridine, and solves the problems of low product purity, low yield and difficulty in industrialized production in the method for preparing 2,6-diamino-3,5-dinitropyridine by adopting the prior art. The first method comprises the steps as follows: preparing the sulfate of 2,6-diaminopyridine; mixing with fuming sulfuric acid and fuming nitric acid; and quenching, stirring, vacuum-filtering and drying to obtain 2,6-diamino-3,5-dinitropyridine. The second method comprises the steps as follows: mixing 2,6-diaminopyridine with fuming sulfuric acid and fuming nitric acid; and ice-quenching, vacuum-filtering and drying to obtain 2,6-diamino-3,5-dinitropyridin. The third method comprises the steps as follows: preparing the sulfate of 2,6-diaminopyridine; adding fuming sulfuric acid; and stirring, quenching and filtering to obtain 2,6-diamino-3,5-dinitropyridin. The methods have the advantages of high purity and high yield, and is suitable for the industrial production.

Description

technical field [0001] The present invention relates to the preparation method of nitropyridine. Background technique [0002] Nitropyridine is an indispensable and important intermediate in the production of medicines, pesticides, dyes, additives, etc. It can also be used as raw materials for food additives, ultra-efficient acylation catalysts, etc., and can also be directly used as drugs and analytical reagents. The nitro group on the pyridine ring has halogen-like properties, is easily replaced by a nucleophile, and can also be reduced to an aminopyridine. 2,3,5,6-tetraaminopyridine prepared from 2,6-diamino-3,5-dinitropyridine is a nitrogen-containing heterocyclic rigid rod-type organic fiber poly[2,5-dihydroxy -1,4 phenylenepyridodiimidazole]-PIPD (M5) is one of the monomers, and now the key technology for making M5 fibers is the preparation of the monomers. [0003] At present, the method for preparing 2,6-diamino-3,5-dinitropyridine generally has many by-products an...

Claims

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Application Information

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IPC IPC(8): C07D213/73
Inventor 黄玉东王艳红王保启宋元军
Owner HARBIN INST OF TECH
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