Synthesis method of paranitroaniline

A technology for p-nitroaniline and a synthesis method, which is applied in the field of synthesis of p-nitroaniline, can solve problems such as low production efficiency, unstable product quality, poor equipment amplification reliability, etc., so as to improve production efficiency, improve technical economy, The effect of compressing the recycling cost

Active Publication Date: 2019-10-25
ZHEJIANG DIBANG CHEM +1
View PDF5 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a safe, efficient and green synthetic method of p-nitroaniline, which solves the problems of low production efficiency, unstable product quality, and poor reliability of equipment amplification in the existing p-nitroaniline preparation process. question

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Synthesis method of paranitroaniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] The ammonia water preparation unit prepares the ammonia water with a concentration of 25wt%, and the p-nitrochlorobenzene that melts at 120° C. is transported into the feed mixing unit respectively, and the molar ratio of ammonia water and p-nitrochlorobenzene is 4; the feed mix unit uses column Tubular heat exchanger and static mixer, exchange the heat of the materials to be mixed to 190°C for mixing, the pressure is 6.2MPa; the temperature of the reaction unit is 190°C, the pressure is 6.0MPa, and the residence time is 4h; the circulation ratio of the split circulation unit is 10. The circulating material enters the feed mixing unit, and is mixed with ammonia water and p-nitrochlorobenzene in sequence. The effluent material is flashed to recover unreacted ammonia, and the p-nitroaniline is obtained through cooling and crystallization, and the by-product ammonium chloride is obtained through evaporation and crystallization. , the mother liquor enters the ammonia water p...

Embodiment 2

[0030] The ammonia water preparation unit prepares the ammonia water with a concentration of 34wt%, and the p-nitrochlorobenzene melted at 120°C is transported into the feed mixing unit respectively, and the molar ratio of the ammonia water and p-nitrochlorobenzene is 20; the feed mixing unit uses Tube-and-tube heat exchanger and static mixer, heat exchange the materials to be mixed to 200°C and mix at a pressure of 7.8MPa; the temperature of the reaction unit is 200°C, the pressure is 7.6MPa, and the residence time is 1.0h; the circulation of the split circulation unit The ratio is 10, the circulating material enters the feed mixing unit, and is sequentially mixed with ammonia water and p-nitrochlorobenzene, and the effluent material is flashed to recover unreacted ammonia, and the p-nitroaniline is obtained through cooling and crystallization, and the by-product chlorine is obtained through evaporation and crystallization. ammonium chloride, and the mother liquor enters the a...

Embodiment 3

[0032] The ammonia water preparation unit prepares the ammonia water with a concentration of 20wt%, and the p-nitrochlorobenzene melted at 120°C is transported into the feed mixing unit respectively, and the molar ratio of the ammonia water and p-nitrochlorobenzene is 18; the feed mixing unit uses Tube-and-tube heat exchanger static mixer, heat exchange the materials to be mixed to 175°C for mixing, the pressure is 3.4MPa; the temperature of the reaction unit is 175°C, the pressure is 3.2MPa, and the residence time is 5h; the circulation ratio of the split circulation unit is 12. The circulating material enters the feed mixing unit, and is mixed with ammonia water and p-nitrochlorobenzene in sequence. The effluent material is flashed to recover unreacted ammonia, and the p-nitroaniline is obtained through cooling and crystallization, and the by-product ammonium chloride is obtained through evaporation and crystallization. , the mother liquor enters the ammonia water preparation...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a continuous synthesis method of paranitroaniline. The continuous synthesis method comprises the following steps: 1) preparing ammonia water by using an ammonia water preparation unit, respectively and continuously inputting the prepared ammonia water and molten p-nitrochlorobenzene into a feeding and mixing unit, carrying out preheating to a reaction temperature, and then,mixing the materials; 2) making the mixed materials flow into a tubular reactor for a reaction, then, making the reacted materials flow into a shunt circulation unit, and dividing the materials intoa circulating material and an outflow material according to a certain recycle; and 3) returning the circulating material to the feeding and mixing unit, and sequentially carrying out continuous onlinemixing on the circulating material as well as the ammonia water and the p-nitrochlorobenzene preheated to the reaction temperature; and cooling the outflow material to crystallize to obtain paranitroaniline with the yield reaching up to 99% or above. The method disclosed by the invention simultaneously has the advantages such as high production efficiency, good safety, low equipment material requirement, flexible and easily-controlled production process and low comprehensive cost and meets the requirements for safety, greenness and high efficiency.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a synthesis method of p-nitroaniline. Background technique [0002] p-Nitroaniline is an extremely important intermediate in organic synthesis in the fields of dyes, pesticides, antioxidants, etc. It can directly synthesize o-chloro-p-nitroaniline, 2,6-dichloro-p-nitroaniline, p-phenylene Amines, etc., are further used in the manufacture of azo dyes, such as direct dark green B, acid medium brown G, acid black 10B, etc. [0003] At present, the domestic production method of p-nitroaniline is mainly the amination method of p-nitrochlorobenzene. p-Nitrochlorobenzene and concentrated ammonia water are reacted in a stirred tank at 140-180°C, 3.7-5.5MPa, and a large excess of ammonia water for 15-20 hours, and crystallized and filtered to obtain p-nitroaniline. The process mainly has problems such as low production efficiency, unstable product quality, and poor reliability ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/10C07C211/52
CPCC07C209/10C07C211/52Y02P20/584
Inventor 吕阳成徐万福兰洲傅伟松丁亚刚
Owner ZHEJIANG DIBANG CHEM
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap