Production process of 3,5-dichloronitrobenzene

A technology of dichloronitrobenzene and production process, which is applied in the field of production technology of 3,5-dichloronitrobenzene, can solve the problems of pollution, low synthesis yield and the like, and achieves high yield, low cost and cost saving Effect

Pending Publication Date: 2021-03-16
德兴市德邦化工有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The purpose of this invention is to provide a kind of production technology of 3,5-dichloronitrobenzene, to solve the problem that the synthetic yield that adopts sodium sulfite as diazotization reagent is low in the traditional technology, serious pollution problem

Method used

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  • Production process of 3,5-dichloronitrobenzene
  • Production process of 3,5-dichloronitrobenzene
  • Production process of 3,5-dichloronitrobenzene

Examples

Experimental program
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Effect test

Embodiment 1

[0029] A kind of production technology of 3,5-dichloronitrobenzene, comprises the following steps:

[0030] (1) Diazotization: Add 2000kg of nitrosylsulfuric acid with a mass fraction of 42% into the reactor, cool down to 5°C, add 1000kg of 2,6-dichloro-p-nitroaniline, and control the temperature at 0- 5°C, react for 12h;

[0031] (2) Nitrogen removal: Add 3000kg of isopropanol to the reactor, control the temperature at 10-15°C, and react for 8 hours;

[0032] (3) Hydrolysis: Add 2400kg of desalted water to the reactor, control the temperature at 60°C, and react for 6 hours;

[0033] (4) Stripping: Water vapor is passed into the stripping tower, isopropanol and acetone are recovered by stripping, and isopropanol and acetone are obtained respectively through rectification. After water recovery, desalted water is prepared by R / O membrane separation, which is used in the step (3) During hydrolysis;

[0034] (5) Separation of acid: the bottom liquid after stripping is separated...

Embodiment 2

[0039] A kind of production technology of 3,5-dichloronitrobenzene, comprises the following steps:

[0040] (1) Diazotization: Add 1600kg of nitrosyl sulfuric acid with a mass fraction of 42% into the reactor, cool down to 5°C, add 1000kg of 2,6-dichloro-p-nitroaniline, and control the temperature at 45°C , reaction 18h;

[0041] (2) Nitrogen removal: add 1600kg of isopropanol to the reactor, control the temperature at 45°C, and react for 9 hours;

[0042] (3) Hydrolysis: Add 2400kg of desalted water to the reactor, control the temperature at 45°C, and react for 9 hours;

[0043] (4) Stripping: Water vapor is passed into the stripping tower, isopropanol and acetone are recovered by stripping, and isopropanol and acetone are obtained respectively through rectification. After water recovery, desalted water is prepared by R / O membrane separation, which is used in the step (3) During hydrolysis;

[0044] (5) Separation of acid: the bottom liquid after stripping is separated int...

Embodiment 3

[0047] A kind of production technology of 3,5-dichloronitrobenzene, comprises the following steps:

[0048] (1) Diazotization: 1700kg of nitrosyl sulfuric acid with a mass fraction of 42% was added to the reactor, the temperature was lowered to 5°C, 1000kg of 2,6-dichloro-p-nitroaniline was added, and the temperature was controlled at 45°C , react for 12h;

[0049] (2) Nitrogen removal: add 1700kg of isopropanol to the reactor, control the temperature at 0°C, and react for 6h;

[0050] (3) Hydrolysis: Add 2500kg of desalted water to the reactor, control the temperature at 0°C, and react for 6 hours;

[0051] (4) Stripping: Water vapor is passed into the stripping tower, isopropanol and acetone are recovered by stripping, and isopropanol and acetone are obtained respectively through rectification. After water recovery, desalted water is prepared by R / O membrane separation, which is used in the step (3) During hydrolysis;

[0052] (5) Separation of acid: the bottom liquid aft...

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Abstract

The invention provides a production process of 3,5- dichloronitrobenzene, and belongs to the field of preparation of pesticide intermediates. The method comprises the following steps: adding nitrosylsulfuric acid with the mass fraction of 42% into a reaction kettle, conducting cooling to 5 DEG C, sequentially adding 2,6-dichloro-4-nitroaniline or 4,6-dichloro-o-nitroaniline, isopropanol and desalted water to respectively complete diazotization, denitrification and hydrolysis processes, wherein the temperature of the whole process is not higher than 45 DEG C; conducting steam extraction with water vapor at 100 DEG C to recover isopropanol and acetone, separating diluted sulfuric acid and 3,5-dichloronitrobenzene from a reaction solution after steam extraction, washing 3,5-dichloronitrobenzene with water, carrying out hydrogenation reduction on the washed 3,5-dichloronitrobenzene to produce 3,5-dichloroaniline, carrying out vacuum concentration and high-temperature concentration on thediluted sulfuric acid to obtain 97% concentrated sulfuric acid to prepare nitrosyl sulfuric acid, and separating a sulfuric acid concentrated distillate through an R/O membrane to prepare desalted water, and recycling the desalted water in the process. The process provided by the invention has the advantages of high yield, no pollution and low cost, and is a green production process.

Description

technical field [0001] The invention relates to the field of preparation of pesticide intermediates, in particular to a production process of 3,5-dichloronitrobenzene. Background technique [0002] 3,5-Dichloroaniline is an important pesticide intermediate, which is generally prepared by hydrogenation reduction of 3,5-dichloronitrobenzene, and can be used to synthesize high-efficiency and low-toxic pesticide products, mainly used in the production of cyclic imides Pesticides. At the same time, it is widely used in the synthesis of medicine, fuel, pigment, etc. And adopt the diazotization deamination reduction method to produce 3,5-dichloronitrobenzene in industry and there are following problems at present: (1) synthesis yield is low; (2) pollution is serious. Contents of the invention [0003] The purpose of this invention is to provide a kind of production technique of 3,5-dichloronitrobenzene, to solve the low synthesis yield and serious pollution problems of using so...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/12C07C201/12C07C201/16C07C211/52C07C209/36
CPCC07C201/12C07C201/16C07C209/365C07C205/12C07C211/52
Inventor 蒋炎阳
Owner 德兴市德邦化工有限公司
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