Method for preparing 2-nitro-m-trimethylbenzene by utilizing dynamic tubular reactor and application of 2-nitro-m-trimethylbenzene

A technology of nitro-m-trimethylbenzene and tubular reactor, which is applied in chemical instruments and methods, preparation of amino compounds, preparation of nitro compounds, etc., can solve the problems of dinitrogen by-products and oxidized impurities, and low purity, and achieve Avoid high energy consumption process, improve purity, process convenience and energy saving effect

Pending Publication Date: 2022-04-29
内蒙古鼎利科技有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The invention provides a method for preparing 2-nitro-meta-methylbenzene by using a dynamic tubular reactor, so as to solve the problem that the 2-nitro-meta-methylbenzene dinitrate by-products and oxidized impurities produced in the prior art are more and less pure. Not advanced question

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Mix concentrated sulfuric acid, fuming nitric acid and water in a ratio of 1:0.8:0.6 to prepare 1000g of mixed acid, stir for 0.5h, add 10g of stannous chloride, stir until dissolved and set aside.

[0030] Pass mesitylene and mixed acid into the metering pump, and pump them into the dynamic tubular reactor at a flow ratio of 1:1. The temperature of the dynamic tubular reactor is controlled at 10-20°C, and the stirring of the dynamic tubular reactor is started. Adjust the rotation speed to 200r / min, and the residence time of the reaction solution to 40min. After the reaction solution comes out of the outlet, it directly enters the automatic stratifier to separate the mixed acid from the organic layer. Organic layer chromatography 2-nitro-m-trimethylbenzene 93.23%, dinitrogen by-product 4.02%.

[0031] After collecting for 15 minutes, add 100.0 g of water to the organic layer, adjust the pH to 7-8 with 30% liquid caustic soda, add 80.0 g of water and obtain 2-nitro mesit...

Embodiment 2

[0033] Mix concentrated sulfuric acid, fuming nitric acid and water in a ratio of 1:0.8:0.6 to prepare 1000g of mixed acid, stir for 0.5h, add 15g of sodium fluoroborate, stir until dissolved and set aside.

[0034] Pass mesitylene and mixed acid into the metering pump, and pump them into the dynamic tubular reactor at a flow ratio of 1:0.5. The temperature of the dynamic tubular reactor is controlled at 5-10°C, and the stirring of the dynamic tubular reactor is started. Adjust the rotation speed to 200r / min, and the residence time of the reaction solution to 40min. After the reaction solution comes out of the outlet, it directly enters the automatic stratifier to separate the mixed acid from the organic layer. Organic layer chromatography 2-nitro m-trimethylbenzene 95.70%, dinitrogen by-product 1.72%.

[0035] After collecting for 15 minutes, add 100.0 g of water to the organic layer, adjust the pH to 7-8 with 30% liquid caustic soda, add 80.0 g of water and obtain 2-nitro me...

Embodiment 3

[0037] Mix concentrated sulfuric acid, fuming nitric acid and water in a ratio of 1:0.8:0.6 to prepare 1000g of mixed acid, stir for 0.5h, add 10g of urea, stir until dissolved and set aside.

[0038] Pass mesitylene and mixed acid into the metering pump, and pump them into the dynamic tubular reactor at a flow ratio of 1:1. The temperature of the dynamic tubular reactor is controlled at 0-5°C, and the stirring of the dynamic tubular reactor is started. Adjust the rotation speed to 200r / min, and the residence time of the reaction solution to 40min. After the reaction solution comes out of the outlet, it directly enters the automatic stratifier to separate the mixed acid from the organic layer. Organic layer chromatography 2-nitro-m-trimethylbenzene 94.20%, dinitrogen by-product 3.05%.

[0039] After collecting for 15 minutes, add 100.0 g of water to the organic layer, adjust the pH to 7-8 with 30% liquid caustic soda, add 80.0 g of water and obtain 2-nitro mesitylene liquid th...

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PUM

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Abstract

The invention relates to a method for preparing 2-nitro-m-trimethylbenzene by utilizing a dynamic tubular reactor and application of the 2-nitro-m-trimethylbenzene, and the method comprises the following steps: (1) preparing mixed acid: mixing concentrated sulfuric acid, nitric acid, water and an oxidation inhibitor to prepare the mixed acid according to the weight percentage ratio of 1: (0.5-2): (0.2-1.0): (0.005-0.05); (2) nitration reaction: respectively adding mesitylene and mixed acid into the dynamic tubular reactor according to a flow ratio of 1: (0.5-2), reacting at-10 to 50 DEG C to obtain a 2-nitro-m-trimethylbenzene organic layer, and separating the organic layer from the mixed acid; and (3) separating and refining: carrying out post-treatment on an organic layer to obtain the 2-nitro-m-trimethylbenzene with the purity of more than 99.5%. By utilizing the method disclosed by the invention, the 2-nitro-m-trimethylbenzene with the purity of more than 99.5% can be obtained, the yield of the 2-nitro-m-trimethylbenzene is more than 85%, oxidation impurities and dinitrate byproducts in the product are reduced, and the preparation purity is improved; through the oxidation inhibitor, generation of oxidation impurities is reduced, the reaction process is continuous and safe, and the method is suitable for industrial preparation.

Description

technical field [0001] The invention relates to the technical field of 2-nitro-meta-methylbenzene preparation, in particular to a method for preparing 2-nitro-meta-methylbenzene by using a dynamic tubular reactor and an application thereof. Background technique [0002] Trimethylaniline is an important acid dye intermediate, which can synthesize dyes such as weakly acidic brilliant blue RAW, reactive emerald green, and reactive brilliant blue. The purity of nitro-m-trimethylbenzene directly affects the finished product quality of mesitylene. [0003] At present, there are two main routes for the preparation of 2-nitro-m-trimethylbenzene: [0004] 1. The nitration reaction is carried out by mesitylene and nitric acid in the system of acetic anhydride and acetic acid. The nitration ability of this system is weak, so the selectivity of single nitration is good, but there will be oxidation by-products, and it is not conducive to the application of mixed acids. [0005] 2. The ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/06C07C201/08C07C209/36C07C211/47
CPCC07C201/08C07C209/36C07C205/06C07C211/47
Inventor 吴昊吴锋夏杰郭志超戴学明
Owner 内蒙古鼎利科技有限公司
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