Synthesis process of 2, 2 '-dichloroazobenzene

A technology of dichloroazobenzene and synthesis process, applied in the direction of organic chemistry, etc., can solve the problems of high labor intensity, large zinc powder consumption, complicated operation, etc., and achieve the goal of increasing production rate, improving production efficiency, and simple synthesis process Effect

Pending Publication Date: 2022-04-12
JIANGSU KANGHENG CHEM
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

Chemical reduction methods include: 1. The traditional zinc powder reduction method, which is backward in technology, consumes a lot of zinc powder, costs high, and is difficult to treat the three wastes, so it has basically been eliminated; 2. Glucose-zinc powder reduction method. It has been improved, but still has the problems of high cost, complicated aftertreatment, and serious pollution; 3, formaldehyde-hydrazine hydrate reduction method is the main industrial production method in China at present, and the raw material of this method is easy to get, and the productive rate is higher, but in A large amount of waste water is produced in the production process, and the intermediate product needs to be separated and purified. The operation is complicated, the labor intensity is high, and the price of hydrazine hydrate is high, the toxicity is high, and the environmental pollution is serious.

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  • Synthesis process of 2, 2 '-dichloroazobenzene

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A kind of 2,2'-dichloroazobenzene synthesis technique, concrete synthesis technique is as follows:

[0020] S1: Preparation of raw materials: using 2-chloronitrobenzene as raw material, mix 2-chloronitrobenzene and isopropanol solution to form a mixed solution, and the content of 2-chloronitrobenzene in the mixed solution is 25% ; With alumina as the adsorbent, the ruthenium catalyst is adsorbed by alumina;

[0021] S2: Preparation of 2,2'-dichloroazobenzene: Put the ruthenium catalyst adsorbed by 5kg alumina into the fixed bed reactor, and pass the booster pump to the fixed bed reactor at a rate of 10ml / min Continuously feed 100 kg of a mixed solution with a 25% 2-chloronitrobenzene content; at the same time, feed hydrogen gas into the solution in the fixed-bed reactor, and heat the fixed-bed reactor to 125°C;

[0022] S3: Distillation under reduced pressure: open the pressure relief valve of the fixed bed reactor to release the pressure of the fixed bed reactor, then...

Embodiment 2

[0025] A kind of 2,2'-dichloroazobenzene synthesis technique, concrete synthesis technique is as follows:

[0026] S1: Preparation of raw materials: using 2-chloronitrobenzene as raw material, mix 2-chloronitrobenzene and isopropanol solution to form a mixed solution, and the content of 2-chloronitrobenzene in the mixed solution is 25% ; With alumina as the adsorbent, the ruthenium catalyst is adsorbed by alumina;

[0027] S2: Preparation of 2,2'-dichloroazobenzene: Put the ruthenium catalyst adsorbed by 5kg alumina into the fixed bed reactor, and pass the booster pump to the fixed bed reactor at a rate of 10ml / min Continuously feed 100 kg of a mixed solution with a 2-chloronitrobenzene content of 30%; at the same time, feed hydrogen into the solution in the fixed-bed reactor, and heat the fixed-bed reactor to 125°C;

[0028] S3: Distillation under reduced pressure: open the pressure relief valve of the fixed bed reactor to release the pressure of the fixed bed reactor, then ...

Embodiment 3

[0031] A kind of 2,2'-dichloroazobenzene synthesis technique, concrete synthesis technique is as follows:

[0032] S1: Preparation of raw materials: using 2-chloronitrobenzene as raw material, mix 2-chloronitrobenzene and isopropanol solution to form a mixed solution, and the content of 2-chloronitrobenzene in the mixed solution is 25% ; With alumina as the adsorbent, the ruthenium catalyst is adsorbed by alumina;

[0033] S2: Preparation of 2,2'-dichloroazobenzene: Put the ruthenium catalyst adsorbed by 5kg alumina into the fixed bed reactor, and pass the booster pump to the fixed bed reactor at a rate of 10ml / min Continuously feed 100 kg of a mixed solution with a 2-chloronitrobenzene content of 35%; at the same time, feed hydrogen into the solution in the fixed-bed reactor, and heat the fixed-bed reactor to 125°C;

[0034] S3: Distillation under reduced pressure: open the pressure relief valve of the fixed bed reactor to release the pressure of the fixed bed reactor, then ...

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Abstract

The invention relates to a synthesis process of 2, 2 '-dichloroazobenzene, which is characterized in that the specific synthesis process comprises the following steps: S1, preparing raw materials; s2, preparation of 2, 2 '-dichloroazobenzene; s3, reduced pressure distillation; s4, cooling crystallization; 2, 2 '-dichloroazobenzene is continuously synthesized in the fixed bed reactor, and step-by-step molding and step-by-step molding by equipment are not needed; catalytic synthesis is carried out through the alumina-loaded ruthenium catalyst, and the production rate is increased by using the catalyst; according to the production process, 2-chloronitrobenzene and hydrogen are directly used as raw materials to directly synthesize 2, 2 '-dichloroazobenzene under the action of an aluminum oxide loaded ruthenium catalyst, the production efficiency is high, the synthesis process is simple, the production efficiency is improved, the yield of 2, 2'-dichloroazobenzene is 91%, and the liquid phase detection content is greater than 99%.

Description

technical field [0001] The invention relates to the field of 2,2'-dichloroazobenzene, in particular to a synthesis process of 2,2'-dichloroazobenzene. Background technique [0002] 2,2'-dichloroazobenzene is an important intermediate for the synthesis of DCB (3,3'-dichlorobenzidine), and DCB synthetic pigments account for more than 27% of the total pigments, so for 2,2'-dichlorobenzidine The research on the synthesis of azobenzene is of great significance; [0003] At present, its synthesis methods mainly include electrolytic reduction method, catalytic hydrogenation method and chemical reduction method, but chemical reduction method is still the main method in China. Chemical reduction methods include: 1. The traditional zinc powder reduction method, which is backward in technology, consumes a lot of zinc powder, costs high, and is difficult to treat the three wastes, so it has basically been eliminated; 2. Glucose-zinc powder reduction method. It has been improved, but s...

Claims

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Application Information

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IPC IPC(8): C07C245/08
Inventor 邱志刚窦清玉
Owner JIANGSU KANGHENG CHEM
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