Preparation method of aminobenzonitrile

A technology of aminobenzonitrile and aminobenzamide, which is applied in the field of preparation of aminobenzonitrile, can solve the problems of intractable waste water, low yield, short service life and the like, achieves improved yield and quality, and reduced reaction temperature , the effect of shortened response time

Pending Publication Date: 2020-06-12
新乡市锦源化工有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Halogenated aniline cyanation method requires the use of highly toxic cyanide, waste water is difficult to treat, and the yield is low, so it is not suitable for industrialization; halogenated benzonitrile amination method uses catalysts that are difficult to recycle, causing large pollution and high cost; Nitrobenzonitrile reduction method, the noble metal catalyst to be used has short service life, difficult recovery and activation, and high production cost; aminobenzamide dehydration method is a common method for domestic current industrial production. The main raw material is dehydrated under the action of phosphorus pentoxide, phosphorus oxychloride or phosphorus pentachloride. The raw materials used in this process are cheap and easy to obtain, and the production cost is low, but the post-reaction treatment is complicated, and a large amount of by-products containing Phosphorus wastewater is difficult to treat

Method used

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  • Preparation method of aminobenzonitrile

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Dehydration: Add 510 g of toluene and 102 g (0.75 mol) of 4-aminobenzamide into a 1000 ml reaction flask with a reflux device cooled by brine, raise the temperature to 90-100 ° C, slowly add 205 g (1.72 mol) of thionyl chloride dropwise, A large amount of tail gas is produced (HCl+SO 2 ), after the thionyl chloride has been dripped, continue to keep warm until all the materials are dissolved and no tail gas is emitted. Cool to 50-60°C, that is, dehydration liquid, keep warm for later use.

[0023] Hydrolysis: Add 102g of water into a 1000ml reaction bottle, stir and heat up to 50-60°C, add the above dehydration solution dropwise, at this time tail gas will be produced (SO 2 ), control the dropping speed, after the dropping is finished and stirred until no tail gas is released, adjust the pH of the water layer to 6.5-7.5 with 30% sodium hydroxide solution while hot. After standing for separation, the organic layer was slowly stirred and cooled to 0-5°C, filtered, washe...

Embodiment 2

[0025] Dehydration: Add 510g of toluene and 102g (0.75mol) of 3-aminobenzamide into a 1000ml reaction flask with a reflux device cooled by brine, raise the temperature to 90-100°C, slowly add 205g (1.72mol) of thionyl chloride dropwise, A large amount of tail gas is produced (HCl+SO 2 ), after the thionyl chloride has been dripped, continue to keep warm until all the materials are dissolved and no tail gas is released. Cool to 50-60°C, that is, dehydration liquid, keep warm for later use.

[0026] Hydrolysis: Add 102g of water into a 1000ml reaction bottle, stir and heat up to 50-60°C, add the above dehydration solution dropwise, at this time tail gas will be produced (SO 2 ), control the dropping speed, after the dropping is finished and stirred until no tail gas is released, adjust the pH of the water layer to 6.5-7.5 with 30% sodium hydroxide solution while hot. After static separation, the organic layer was slowly stirred and cooled to 0-5°C, filtered, washed with an app...

Embodiment 3

[0028] Dehydration: Add 510g of toluene and 102g (0.75mol) of 2-aminobenzamide into a 1000ml reaction flask with a reflux device cooled by brine, raise the temperature to 90-100°C, slowly add 205g (1.72mol) of thionyl chloride dropwise, A large amount of tail gas is produced (HCl+SO 2 ), after the thionyl chloride has been dripped, continue to keep warm until all the materials are dissolved and no tail gas is released. Cool to 50-60°C, that is, dehydration liquid, keep warm for later use.

[0029] Hydrolysis: Add 102g of water into a 1000ml reaction bottle, stir and heat up to 50-60°C, add the above dehydration solution dropwise, at this time tail gas will be produced (SO 2 ), control the dropping speed, after the dropping is finished and stirred until no tail gas is released, adjust the pH of the water layer to 6.5-7.5 with 30% sodium hydroxide solution while hot. After standing for separation, the organic layer was slowly stirred and cooled to 0-5°C, filtered, washed with ...

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Abstract

The invention relates to the technical field of fine chemical synthesis, and discloses a preparation method of aminobenzonitrile. Aminobenzamide is taken as a raw material, and aminobenzonitrile is obtained through a three-step reaction of amino protection, dehydration and hydrolysis by taking thionyl chloride as an amino protective agent and a dehydrating agent, The preparation method comprises the following steps: amino protection and dehydration are carried out on aminobenzamide by thionyl chloride in sequence to obtain an amino-protected nitrile organic matter, then water is added to carryout a hydrolysis reaction, and the protective agent on the amino group is removed to obtain the aminobenzonitrile product. The thionyl chloride is used, so the dehydration effect can be achieved, anda new group formed by a reaction of the thionyl chloride with the amino group can play a role in protecting the amino group in the reaction process, thereby the product yield and quality are obviously improved, the reaction temperature is greatly lower than that of a traditional process, the reaction time is obviously shortened, the safety is obviously improved, the operation is simple, the conditions are mild, the method is green and clean, aminobenzonitrile can be efficiently prepared at low cost, and the method is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of fine chemical synthesis, in particular to a preparation method of aminobenzonitrile. Background technique [0002] Aminobenzonitrile compounds are important intermediates in organic synthesis and are widely used in the production of medicines, pesticides, dyes, rubber and fine chemicals. For example, the condensation of m-aminobenzonitrile and cyclohexanone can directly synthesize tacrine, an effective drug for treating Alzheimer's disease; p-aminobenzonitrile can be used to synthesize bicalutamide (Zhaohui), etravirine and dabigatol Key intermediates of esters. [0003] At present, the methods for synthesizing aminobenzonitrile mainly include four methods such as cyanation of haloaniline, amination of halobenzonitrile, reduction of nitrobenzonitrile and dehydration of aminobenzamide. Halogenated aniline cyanation method requires the use of highly toxic cyanide, waste water is difficult to treat, and th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/30C07C255/58C07C253/20C07C255/60C07C231/12C07C237/42
CPCC07C253/30C07C253/20C07C231/12C07C237/42C07C255/60C07C255/58
Inventor 汪祝胜钟智奎赵维凯周明遥唐鹤
Owner 新乡市锦源化工有限公司
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