Preparation method of N-methyl-4-nitroaniline

A technology of p-nitroaniline and p-nitrochlorobenzene, which is applied in the field of preparation of N-methyl-p-nitroaniline, can solve the problems of high toxicity of dimethyl sulfate, difficulty in product quality assurance, and high safety risks for operators, etc. problems, to achieve the effect of fewer raw material varieties, stable product quality, and less raw material residues

Inactive Publication Date: 2018-11-09
HAIMEN CITY CHEMGOO PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process route is very easy to produce N,N-dimethyl-p-nitroaniline, and the product quality is difficult to guarantee
[0004] Dimethyl sulfate is also used as an alkylating agent, but due to the high toxicity of dimethyl sulfate, there is a great safety risk for operators

Method used

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  • Preparation method of N-methyl-4-nitroaniline
  • Preparation method of N-methyl-4-nitroaniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 300g of p-nitrochlorobenzene and 700g of methylamine aqueous solution with a concentration of 40% to a 1L autoclave, add 2.0g of copper sulfate and 0.4g of cobalt sulfate, seal the autoclave, and replace the air in the autoclave with nitrogen gas. After the replacement, the temperature is raised, the temperature is 150°C, the temperature is kept at 1.4MPa for 2.8 hours, the temperature is lowered to 65°C and the pressure is released, and the discharged methylamine is absorbed through the absorption tower. Continue to cool down to normal temperature after depressurization, put the material in the autoclave into a filter and suction filter to obtain 280 g of N-methyl-p-nitroaniline crude product (calculated on dry basis).

[0021] Add 280g of crude N-methyl p-nitroaniline, 1100g of propylene glycol and 2g of sodium bisulfite into a three-necked flask, raise the temperature to 65°C and stir for half an hour, then cool down to 30°C, filter, wash, and dry to obtain N-meth...

Embodiment 2

[0023] Add 150g of p-nitrochlorobenzene and 450g of methylamine aqueous solution with a concentration of 40% to a 1L autoclave, add 1.4g of copper acetate and 0.3g of cobalt acetate, seal the autoclave, and replace the air in the autoclave with nitrogen gas to replace After the temperature is raised, the temperature is 150°C, and the pressure is about 1.4MPa, and the temperature is kept for 2.1hr. After cooling down to 65°C, the pressure is released, and the released free methylamine is absorbed through the absorption tower. Continue to cool down to 30° C., put the material in the autoclave into a filter for suction filtration, and obtain 138 g of crude N-methyl-p-nitroaniline (calculated on dry basis).

[0024] Add the crude product of N-methyl p-nitroaniline, 480g of butanol and 1.5g of sodium hydrosulfide into a three-necked flask, raise the temperature to 65°C and stir for half an hour, cool down to below 30°C, filter, wash, and dry to obtain N-methyl p-nitroaniline 135g o...

Embodiment 3

[0026] Add 200g of p-nitrochlorobenzene and 400g of methylamine aqueous solution with a concentration of 40% to a 1L autoclave, add 1.5g of copper acetate and 0.3 g of cobalt acetate, seal the autoclave, and pass nitrogen into the autoclave to replace the air in the autoclave. After the temperature rises, the temperature is 140°C, and the pressure is about 1.1MPa, and the temperature is kept for 2 hours. After cooling down to 40°C, the pressure is released, and the discharged free methylamine is absorbed through the absorption tower. Continue to cool down to 25° C., put the material in the autoclave into a filter for suction filtration, and obtain 185 g of crude N-methyl-p-nitroaniline (calculated on a dry basis).

[0027] Add the crude product of N-methyl p-nitroaniline, 555g of butanol and 0.18g of sodium hydrosulfide into a three-necked flask, raise the temperature to 60°C and stir for half an hour, then cool down to below 15°C, filter, wash, and dry to obtain N-methyl p-nit...

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Abstract

The invention discloses a preparation method of N-methyl-4-nitroaniline, comprising the following steps: firstly carrying out a reaction between para-nitrochlorobenzene and a methylamine water solution to obtain N-methyl-4-nitroaniline, filtering, dissolving N-methyl-4-nitroaniline in a solvent, adding a reducing protective agent, refining, filtering and drying to obtain high-purity N-methyl-4-nitroaniline. The preparation method has the following advantages: the reaction process is simple and there is hardly any by-product; the reaction is easy to operate, and the post-treatment is simple; overall yield reaches up to 92% and above; and purity of the product is greater than or equal to 99%.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a preparation method of N-methyl-p-nitroaniline. Background technique [0002] N-methyl-p-nitroaniline is an important chemical raw material. It is an intermediate used in the synthesis of nintedanib, a drug for the treatment of idiopathic pulmonary fibrosis. Idiopathic pulmonary fibrosis is a serious hazard to humans. patients with a fatal lung disease with a median survival of only 2 to 3 years after diagnosis. Nintedanib is the only tyrosine kinase inhibitor (TKI) approved for the treatment of idiopathic pulmonary fibrosis. In addition, it can be used as a stabilizer for gunpowder and a desensitizer for explosives, and is a widely used organic intermediate. [0003] At present, most N-methyl-p-nitroanilines use p-nitroaniline as a starting material, methyl iodide and methyl bromide as methylating reagents, and heat reflux in methanol to prepare the target product. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/48C07C209/10
CPCC07C209/10C07C211/48
Inventor 王力倪协屏孙乐达
Owner HAIMEN CITY CHEMGOO PHARMA
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