Synthesis method of 2-cyano-4-nitroaniline

A synthetic method and technology of nitroaniline, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve problems such as not being environmentally friendly, affecting the purity of ammonolysis products, and being difficult to remove

Pending Publication Date: 2022-03-22
ZHEJIANG RUNTU +1
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Problems solved by technology

[0007] This technique mainly has the following two disadvantages: (1) in the nitration step, dissolving o-chlorobenzonitrile needs to consume a large amount of sulfuric acid, and the sulfuric acid in the nitration process is both used as a solvent and as a catalyst (to improve the dehydration value of the nitration reaction), and when the amount of sulfuric acid decreases , the material in the reaction system is very thick, and the mass transfer effect is very poor
(2) Ammonolysis step, it is divided into two kinds of chlorobenzene solvent method and ammonia water method, and wherein chlorobenzene solvent method makes the ammonolysis product monochlorobenzene a large amount of residues, is difficult to remove, not environmental protection, general ammonolysis product monochlorobenzene content Tens to hundreds of ppm; the nitration product 2-chloro-5-nitrobenzonitrile of the ammonia method will be hydrolyzed to varying degrees, which will affect the purity of the ammonolysis product
However, the method introduces the extractant chlorinated benzene, which will affect the purity of the ammonolysis product due to the introduction of new substances

Method used

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  • Synthesis method of 2-cyano-4-nitroaniline
  • Synthesis method of 2-cyano-4-nitroaniline

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preparation example Construction

[0045] The invention provides a kind of synthetic method of 2-cyano group-4-nitroaniline, it comprises the following steps:

[0046]Nitration step: dissolving o-chlorobenzonitrile in an organic solvent, and performing a nitration reaction in the presence of a mixed acid to obtain a nitration product, which contains 2-chloro-5-nitrobenzonitrile;

[0047] Mixing step: after mixing the nitrated product with an inorganic solvent, a mixed product is obtained;

[0048] Separation step: statically layering the mixed product to obtain an organic phase;

[0049] Ammonolysis step: passing liquid ammonia and / or ammonia gas into the organic phase to carry out ammonolysis reaction to obtain an ammonolysis product, which contains 2-cyano-4-nitroaniline.

[0050] The method for synthesizing 2-cyano-4-nitroaniline of the present invention saves acid, is environmentally friendly, simplifies operation, and saves costs, while simultaneously ensuring the purity and yield of the product 2-cyano-4...

Embodiment 1

[0079] Nitration reaction: Add 60g of 1,2-dichloroethane into a 250mL four-neck flask, start stirring, slowly drop in 25g of o-chlorobenzonitrile at room temperature, wait until the o-chlorobenzonitrile is completely dissolved, slowly drop in at 5°C Add a mixed acid made of 13g nitric acid and 25g sulfuric acid, drop it for about 1 hour; keep the temperature at 10°C for 2 hours, keep warm, add 90g water slowly, control the acidity value to 22%, then slowly raise the temperature to 45°C, stir 1 hour, and then stood at a temperature of 45°C to separate layers, the lower layer was the 1,2-dichloroethane organic phase, and the upper layer was the inorganic phase. The lower layer was washed with water until neutral (pH value was about 7), the water layer was separated and removed, and transferred to a 500mL autoclave for use.

[0080] Ammonolysis reaction: open the ammonia inlet valve, pour 8g of liquid ammonia into the autoclave, start stirring, raise the temperature to 150°C, con...

Embodiment 2

[0083]Nitration reaction: Add 65g of 1,3-dichloropropane into a 250mL four-necked flask, start stirring, slowly drop in 25g of o-chlorobenzonitrile at room temperature, wait until the o-chlorobenzonitrile is completely dissolved, slowly add Mixed acid made of 13.3g of nitric acid and 20g of sulfuric acid, drop it in about 1 hour; keep the temperature at 10°C for 2 hours, keep warm, add 80g of water slowly, control the acidity value to 20%, slowly raise the temperature to 40°C, stir for 1 hours, and then stood at a temperature of 40°C to separate layers, the lower layer was the 1,3-dichloropropane organic phase, and the upper layer was the inorganic phase. The lower layer was washed with water until neutral (pH value was about 7), the water layer was separated and removed, and transferred to a 500mL autoclave for use.

[0084] Ammonolysis reaction: open the ammonia inlet valve, pour 10g of liquid ammonia into the autoclave, start stirring, raise the temperature to 155°C, contro...

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Abstract

The invention provides a synthesis method of 2-cyano-4-nitroaniline. The synthesis method comprises the following steps of: synthesizing 2-cyano-4-nitroaniline; the synthesis method comprises the following steps: a nitration step: 2-chlorobenzonitrile is dissolved in an organic solvent, a nitration reaction is carried out in the presence of mixed acid, a nitration product is obtained, and the nitration product contains 2-chloro-5-nitrobenzonitrile; a mixing step: mixing the nitration product with an inorganic solvent to obtain a mixed product; a separation step: standing and layering the mixed product to obtain an organic phase; ammonia gas and/or ammonia gas are/is introduced into the organic phase, an ammonolysis reaction is carried out, an ammonolysis product is obtained, and the ammonolysis product contains the 2-cyano-4-nitroaniline. According to the synthesis method, a large amount of sulfuric acid can be saved, and the used organic solvent can be recycled after the reaction is finished. Furthermore, the synthetic method disclosed by the invention can ensure that the 2-chloro-5-nitrobenzonitrile does not carry water and the cyano group is not hydrolyzed in the ammonolysis reaction process.

Description

technical field [0001] The invention belongs to the field of synthesis of dye intermediates, in particular to a synthesis method of 2-cyano-4-nitroaniline. Background technique [0002] 2-cyano-4-nitroaniline (C 7 h 5 N 3 o 2 ), which is a light yellow powder at normal temperature and pressure, and is an important dye intermediate. As a diazo component, it can synthesize disperse ruby ​​SE-GFL, disperse bright red S-FL, disperse blue SE-2R, disperse brilliant purple S-R and other high-temperature or medium-temperature disperse dyes; as a raw material, it can synthesize 2-cyanide Base-4-nitro-6-bromoaniline, 3-amino-5-nitro-2,1-benzisothiazole and other important dye intermediates. [0003] At present, the method of industrial production of 2-cyano-4-nitroaniline is to use 2-chlorobenzonitrile (ortho-chlorobenzonitrile for short) as raw material to prepare 2-cyanobenzene through nitration reaction and ammoniation (ammonolysis) reaction. -4-Nitroaniline. It mainly inclu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/30C07C255/58C07C255/50
CPCC07C253/30C07C255/58C07C255/50
Inventor 何江伟丁兴成陈清陶彬彬秦汉锋陆皝明孟荣娟
Owner ZHEJIANG RUNTU
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