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Preparation method of 5-chiorine-2-nitroaniline

A technology of nitroaniline and nitroacetaniline, which is applied in the field of preparation of 5-chloro-2-nitroaniline, can solve problems such as industrialization difficulties, preparation hazards, and production safety cannot be effectively guaranteed

Inactive Publication Date: 2011-05-25
天津均凯农业科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0002] The preparation method of 5-chloro-2-nitroaniline is at present: (1) patent DE3431827 reports 2 in 1986, and 4-dichloronitrobenzene is obtained by reacting with ammonia in a high-pressure vessel, and reaction temperature and pressure are all higher, make Production safety cannot be effectively guaranteed, and it is difficult to realize industrialized production
However, the preparation of its raw material 3,4-dinitrochlorobenzene is very dangerous, so there are certain difficulties in industrialization

Method used

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preparation example Construction

[0020] The preparation method of 5-chloro-2-nitroaniline of the present invention, the method is characterized in that:

[0021] (1) In an aprotic solvent, m-chloroaniline reacts with acetyl chloride at low temperature to obtain m-chloroacetanilide, where the aprotic solvent is preferably toluene. Heating temperature -5°C-30°C, preferably 5°C-20°C;

[0022] (2) In the mixture of nitric acid and acetic anhydride, m-chloroacetanilide is nitrated at low temperature to obtain 5-chloro-2-nitroacetanilide. The reaction temperature range is -5°C-10°C.

[0023] (3) In Claisen base, 5-chloro-2-nitroacetanilide is deacetylated by heating to obtain 5-chloro-2-nitroaniline, where the heating temperature is 50°C-90°C, preferably 60°C-80°C .

[0024] In the industrial field, m-chloroacetanilide can be obtained by reacting m-chloroacetaniline with acetyl chloride in an aprotic solvent according to the method developed by the inventor at low temperature. To describe the method in detail, ...

Embodiment 1

[0033] 1.9 kg of m-chloroaniline was dissolved in 2L of toluene, the temperature was controlled at 0°C, and 1.4 kg of acetyl chloride was added dropwise. After the dropwise addition, the temperature was raised to 20°C for 2 hours of reaction. Add 2L of water, stir at room temperature for 1 hour, separate the water layer, recover the toluene layer by distillation, add 3L of water to the residue, stir for 1 hour, stand still for 2 hours, and filter to obtain 2.3 kg of m-chloroacetanilide as a white powder with a yield of 91%. (Melting point: 78-80°C).

Embodiment 2

[0035] Dissolve 1.9 kg of m-chloroaniline in 2L of chlorobenzene, control the temperature at 0°C, add 1.4 kg of acetyl chloride dropwise, and then raise the temperature to 20°C for 2 hours to react. Add 2L of water, stir at room temperature for 1 hour, separate the water layer, recover the chlorobenzene layer by distillation, add 3L of water to the residue, stir for 1 hour, stand still for 2 hours, filter to obtain 2.1 kg of m-chloroacetanilide, white powder, yield 84% . (melting point: °C). (Melting point: 78-80°C).

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Abstract

The invention relates to a preparation method of 5-chiorine-2-nitroaniline. The preparation method is as follows: obtaining m-chloroacetanilide by acylation reaction of m-chloroaniline and acetylcjloride in aprotic solvent under a relative mild condition; then nitrating the m-chloroacetanilide so as to obtain 5-chiorine-2- nitracetanilide in the presence of nitric acid and anhydro; and finally, removing acetyl in the presence of Claisen alkaline so as to obtain the 5-chiorine-2-nitroaniline. By using the preparation method of the 5-chiorine-2-nitroaniline, the reaction yield is improved, the reaction danger is reduced, and the production danger is reduced, thus the safe production is ensured.

Description

technical field [0001] The invention belongs to the production of chemical and pharmaceutical raw materials. In particular, it relates to a preparation method of 5-chloro-2-nitroaniline which can be used as a fenbendazole intermediate. This 5-chloro-2-nitroaniline can also be used in the production of high-end dye red 11 and pharmaceutical products Background technique [0002] The preparation method of 5-chloro-2-nitroaniline is at present: (1) patent DE3431827 reports 2 in 1986, and 4-dichloronitrobenzene is obtained by reacting with ammonia in a high-pressure vessel, and reaction temperature and pressure are all higher, make Production safety cannot be effectively guaranteed, and it is difficult to realize industrialized production. (2) In 2006, it was reported in the literature that 3,4-dinitrochlorobenzene was used in the isopropanol solution of ammonia water to obtain 5-chloro-2-nitroaniline through reduction ("Fine and Specialty Chemicals", 2006, 14(7), 22-23). Ho...

Claims

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Application Information

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IPC IPC(8): C07C211/52C07C209/62C07C233/15C07C231/02
Inventor 尚振华栗晓东
Owner 天津均凯农业科技有限公司
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