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Method for preparing N substituted o-phenylenediamine

A technology of o-phenylenediamine and nitroaniline, which is applied in the field of N-substituted o-phenylenediamine, can solve the problems that high-purity products cannot be separated, cannot be synthesized as intermediates, and products cannot be precipitated, etc., so as to suppress side reactions , low cost, and the effect of improving the conversion rate

Inactive Publication Date: 2009-12-23
沈阳感光化工研究院有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the raw materials used in this method have basically no safety and toxicity problems, and the pollution to the environment is small, but this common catalytic hydrogenation reduction method is used to prepare N-substituted o-phenylenediamine, and there are still serious side reactions The problem
If there is no ammonia or amine exists, using the usual catalytic hydrogenation method to prepare N-substituted o-phenylenediamine will produce a large number of by-products, and the product content in the reaction solution is only about 50%. Due to the interference of impurities produced by the side reaction, the product cannot be obtained from Precipitated in the reaction solution, unable to separate the high-purity product, it can only exist in the state of oil together with other impurities, and basically cannot be used as an intermediate for the synthesis of other compounds

Method used

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  • Method for preparing N substituted o-phenylenediamine
  • Method for preparing N substituted o-phenylenediamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] N 1 - Preparation of methyl-4-methoxy-1,2-phenylenediamine

[0015] In a 1-liter stainless steel autoclave, add 250 milliliters of methanol solution with a mass concentration of 25% ammonia, 2.0 grams of Ranery nickel catalyst, 40 grams of N 1 -Methyl-4-methoxy-2-nitroaniline. Replace the air in the kettle with nitrogen, and then fill the kettle with hydrogen to 15Mpa. Heat to 40-45°C under stirring, and react until no hydrogen is absorbed. Cool down to room temperature, let off the remaining hydrogen in the kettle, and replace the hydrogen in the kettle with nitrogen, filter and recover the Ranery nickel catalyst, add concentrated hydrochloric acid to the filtrate to adjust the pH to 6-7, cool to 0-5°C to precipitate. The product was collected by filtration, the purity by HPIC analysis was 97%, and the yield was 85%.

Embodiment 2

[0017] N 1 -Preparation of Methyl-4-Methyl-Phenyl-1,2-Phenenediamine

[0018] In a 1-liter stainless steel autoclave, add 250 milliliters of ethanol, 40 grams of N 1 -Methyl-4-methylpyrrole-2-nitroaniline, 60 grams of mass concentration 20% methylamine aqueous solution, 2.0 grams of Ranery nickel catalyst. After replacing the air in the kettle with nitrogen, fill it with hydrogen to 20-25Mpa. Heat to 40-45°C under stirring, and react until no hydrogen is absorbed. Let off the remaining hydrogen in the kettle, filter and recover the catalyst. About 180 ml of ethanol was evaporated from the filtrate, and the residue was adjusted to pH 6-7 by adding concentrated hydrochloric acid, and cooled to 0-5°C to precipitate the product. The product was collected by filtration, the purity by HPIC analysis was 97.5%, and the yield was 87.2%.

Embodiment 3

[0020] N 1 -Preparation of methyl-4-propyl-1.2-phenylenediamine

[0021] In a 1-liter stainless steel autoclave, add 250 milliliters of methanol solution with a mass concentration of 25% ammonia, 2.0 grams of Ranery nickel catalyst, 40 grams of N 1 -Methyl-4-propyl-2-nitroaniline. Replace the air in the kettle with nitrogen, and then fill the kettle with hydrogen to 5Mpa. Heat to 40-45°C under stirring, and react until no hydrogen is absorbed. Cool down to room temperature, let off the remaining hydrogen in the kettle, and replace the hydrogen in the kettle with nitrogen, filter and recover the Ranery nickel catalyst, add concentrated hydrochloric acid to the filtrate to adjust the pH to 6-7, cool to 0-5°C to precipitate. The product was collected by filtration, the purity by HPIC analysis was 97%, and the yield was 80%.

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Abstract

The invention provides a method for preparing N substituted o-phenylenediamine with the general formula (1), wherein R represents H, C1-C4 alkyl, C1-C4 alkoxyl and C1-C4 alkyl sulphonyl, and R1represents C1-C4 alkyl and phenyl. The method takes water, alcohol and other alkanes as solvent, and uses Ranery nickel to catalyse, hydrogenate and deoxidize N substituted o-nitroaniline with the general formula 2 into N substituted o-phenylenediamine in the presence of ammonia or amine. The method has the advantages of high purity, high yield, easy industrialization, no solid waste discharge and no environment pollution.

Description

technical field [0001] The invention relates to N-substituted o-phenylenediamine, specifically a method for catalytic hydrogenation reduction of N-substituted o-nitroaniline to N-substituted o-phenylenediamine by using Ranery nickel in the presence of ammonia or amine. Background technique [0002] N-substituted o-phenylenediamine is an important intermediate compound for the synthesis of pesticides and dyes, and can also be directly used as a metal treatment agent (acid corrosion inhibitor). [0003] The preparation of N-substituted o-phenylenediamine is to reduce the corresponding N-substituted o-nitroaniline to N-substituted o-phenylenediamine. In the past, most of these compounds were prepared by chemical reducing agent reduction method and metal (such as iron powder) reduction method. For example: N with sodium dithionite 1 -Methyl-4-methyl-2-nitroaniline is reduced to N 1 -Methyl-4-methanyl-1,2-phenylenediamine (Dyes and Pigments (1989), 11(2), 147-161), the product...

Claims

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Application Information

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IPC IPC(8): C07C209/36C07C213/02C07C315/04C07C217/84C07C317/36C07C211/51C07C211/55
Inventor 张秀岩祁咏梅
Owner 沈阳感光化工研究院有限公司
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