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A kind of method for preparing n-alkyl-4-nitrophthalimide

A technology of alkylphthalimide and nitrophthalimide, which is applied in the field of low-temperature nitration reaction to prepare N-alkyl-4-nitrophthalimide series products, It can solve the problems of low yield of N-alkyl-4-nitrophthalimide, no N-alkylphthalimide has been seen, and difficulty in transferring heat of nitration reaction in time, so as to avoid the phenomenon of overheating , Reduce the amount of nitric acid and the discharge of three wastes, the effect of reducing the amount

Active Publication Date: 2020-07-28
ZHEJIANG WANFENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] (1) Using the method of reacting 4-nitrophthalic anhydride with methylamine, the disadvantage is that 4-nitrophthalic anhydride is an uncommon industrial product, and the preparation process is more complicated, with many by-products, it is difficult to achieve the purpose of purification, while 4-nitrophthalic anhydride When reacting with methylamine, the conversion rate of 4-nitrophthalic anhydride is low, resulting in low yield of N-alkyl-4-nitrophthalimide, therefore, this method is not suitable for industrialized production
[0008] At present, the traditional production process of preparing phthalimide azo dye intermediates at home and abroad is mainly based on the process of intermittent nitration with mixed acid, which has the following defects: the heat of nitration reaction is difficult to transfer in time, and it is easy to cause the temperature to run out of control and cause safety accidents; Poor mass transfer efficiency, easy to cause material accumulation, long reaction time
So far, there has been no process research and equipment technology report on the nitration reaction of N-alkylphthalimide in the continuous reaction mode of microchannels

Method used

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  • A kind of method for preparing n-alkyl-4-nitrophthalimide
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  • A kind of method for preparing n-alkyl-4-nitrophthalimide

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Effect test

Embodiment 1

[0047] (1) Refer to image 3 Determine the connection mode of the microchannel reactor, the channel type is a cylindrical straight channel combined with a diamond microchannel structure, the number of microchannel mixed reaction modules is determined according to the flow rate and residence time, and the heat transfer medium is heat transfer oil.

[0048] The N-methylphthalimide-concentrated sulfuric acid solution is regarded as raw material A, and the concentrated nitric acid solution is regarded as raw material B, and the two streams of materials are injected into the reactor through a metering pump at a flow rate of 5ml / min and 20ml / min respectively In the preheating module, after the two stocks of materials are fully preheated respectively, they enter the reaction zone for mixed reaction. At this time, the molar ratio of the concentrated nitric acid and the substrate is controlled to be 1:1, and the mass ratio of the substrate to the concentrated sulfuric acid is 1:1. 1. U...

Embodiment 2

[0050] (1) Refer to image 3 Determine the connection mode of the microchannel reactor and remove the preheating area module. The channel types are cylindrical straight channel and heart-shaped microchannel. The number of microchannel mixed reaction modules is determined according to the flow rate and residence time.

[0051] The N-ethylphthalimide-concentrated sulfuric acid solution is regarded as raw material A, and the concentrated nitric acid solution is regarded as raw material B, and the two materials are injected into the reaction zone through the metering pump at the flow rate of 8ml / min and 20ml / min respectively Carry out mixed residence reaction in, control the mol ratio of concentrated nitric acid and substrate at this moment to be 1.2:1, the mass ratio of substrate and the concentrated sulfuric acid is 1:2, adopt figure 2 In a microchannel reactor, the temperature is controlled at 50°C and the residence time is 150s. The reaction solution is collected quantitative...

Embodiment 3

[0053] (1) Refer to image 3 Determine the connection mode of the microchannel reactor, the channel type is cylindrical straight channel and triangular microchannel structure, the number of microchannel mixed reaction modules is determined according to the flow rate and residence time, and the heat transfer medium is heat transfer oil.

[0054] The N-n-butylphthalimide-concentrated sulfuric acid solution is regarded as raw material A, and the concentrated nitric acid solution is regarded as raw material B, and the two streams of materials are injected into the reactor through the metering pump at the flow rate of 15ml / min and 35ml / min respectively. In the thermal module, after the two streams of materials are fully preheated, they enter the reaction zone for mixed reaction. At this time, the molar ratio of concentrated nitric acid and substrate is controlled to be 1.3:1, and the mass ratio of substrate to concentrated sulfuric acid is 1:4. ,use figure 2 In a microchannel rea...

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Abstract

The invention belongs to the technical field of organic synthetic processes, and relates to a method for preparing N-alkyl-4-nitrophthalimide by adopting N-alkyl phthalimide as a raw material, nitricacid as a nitrating agent, and performing low-temperature nitration reaction by virtue of a continuous flow to prepare the series product of N-alkyl-4-nitrophthalimide. The method is short in reactiontime and short in production period, solves the problems produced by the accumulation of raw materials in an intermittent reaction kettle, is more stable in the reaction process, and can significantly improve the reaction efficiency. The mass transfer performance and heat conduction performance in a micro-channel reactor of different structures can be improved, the constant reaction temperature can be kept, the temperature runaway phenomenon can be avoided, the generation of byproducts can be reduced, and the safety of the reaction process can be improved. By adopting the high mass transfer effect in the micro-channel reactor, a liquid-liquid reaction solution is sufficiently mixed, in the reaction process, the consumption of concentrated sulfuric acid and nitric acid can be greatly reduced, and the generation of waste acid can be reduced.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis technology, and relates to a method for preparing N-alkyl-4-nitro-phthalimide by using N-alkyl phthalimide as raw material and nitric acid as nitrating agent through continuous flow for low-temperature nitration reaction. Method for phthalimide series products. Background technique [0002] Phthalimide is an important fine chemical intermediate, widely used in medicine, pesticide, dyestuff and other fields. With the advancement of science and technology, its new uses have been continuously developed in recent years, and many downstream products have high added value. Disperse dyes have become one of the most active dye categories in the world's dye market. Due to factors such as the industrialization of ultrafine polyester fibers, the growth of polyester fibers for tourism, and the increase in the use of polyester fabrics for sportswear and vehicles, the high Among the high-performance...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D209/48
CPCC07D209/48
Inventor 刘涛姚晨华俞杏英俞啸天
Owner ZHEJIANG WANFENG CHEM
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