Catalytic hydrogenation method for preparing 3,4-dichloroaniline

A technology for dichloroaniline and catalytic hydrogenation, which is applied in 3 fields, can solve the problems of high price, difficult recovery of precious metals Ru and Pt, complicated preparation process, etc., achieves high reactivity and selectivity, and has obvious effects of inhibiting dechlorination.

Inactive Publication Date: 2007-05-16
ZHONGBEI UNIV
View PDF7 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] U.S. Patent US 4760187 has reported the method for preparing 3,4-dichloroaniline by catalytic hydrogenation of 3,4-dichloronitrobenzene using Ru-Pt-Ni-Cr/C as a catalyst, the method of 3,4-dichloroaniline The selectivity is 98%, but the patented technology uses a quaternary active component as a catalyst, the catalyst preparation process is complicated, and the recovery of precious metals Ru and Pt is very difficult
Chinese patent CN 200510050594 uses Ru-Fe/Al 2 o 3 As a catalyst, directly obtain hydrogen from the catalytic cracking of alcohol solution for the catalytic hydrogenation of 3,4-dichloronitrobenzene to prepare 3,4-dic

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 5 g of 3,4-dichloronitrobenzene and 25 mL of methanol into a 75 mL autoclave, add 0.5 g of W-4 ​​type Raney-Ni catalyst, and 0.1 g of dechlorination inhibitor ethanolamine at the same time, close the autoclave, and open the H 2 Valve to feed H into the autoclave 2 , adjust the kettle pressure to 0.9MPa, stir and heat up to 80°C, react for 50min, close the H 2 Valve, open the autoclave after cooling, discharge, add in the distillation bottle after filtering, add 50mL water and a small amount of gac, in N 2 The solvent methanol was recovered by atmospheric distillation under protection, and the remaining liquid was hot-filtered to remove activated carbon, then cooled to precipitate crystals, and vacuum-dried to obtain 3.50 g of 3,4-dichloroaniline, which was 99.93% by mass according to gas chromatography analysis.

Embodiment 2

[0022] Add 5 g of 3,4-dichloronitrobenzene and 30 mL of methanol into a 75 mL autoclave, add 0.6 g of W-4 ​​type Raney-Ni catalyst, and 0.1 g of dechlorination inhibitor ethanolamine at the same time, close the autoclave, and open the H 2 Valve to feed H into the autoclave 2 , adjust the kettle pressure to 1.0MPa, stir and heat up to 90°C, react for 60min, close the H 2 Valve, open the autoclave after cooling, discharge, add in the distillation bottle after filtering, add 50mL water and a small amount of gac, in N 2 The solvent methanol was recovered by atmospheric pressure distillation under protection, and the remaining liquid was hot filtered to remove activated carbon, then cooled to precipitate crystals, and dried in vacuum to obtain 3.47 g of 3,4-dichloroaniline, which was 99.36% by mass according to gas chromatography analysis.

Embodiment 3

[0024] Add 5 g of 3,4-dichloronitrobenzene and 30 mL of methanol into a 75 mL autoclave, add 0.8 g of W-4 ​​type Raney-Ni catalyst, and 0.2 g of dechlorination inhibitor ethanolamine at the same time, close the autoclave, and open the H 2 Valve to feed H into the autoclave 2 , adjust the kettle pressure to 1.3MPa, stir and heat up to 80°C, react for 70min, close the H 2 Valve, open the autoclave after cooling, discharge, add in the distillation bottle after filtering, add 50mL water and a small amount of gac, in N 2 The solvent methanol was recovered by atmospheric pressure distillation under protection, and the remaining liquid was hot-filtered to remove activated carbon, cooled to precipitate crystals, and vacuum-dried to obtain 3.51 g of 3,4-dichloroaniline, which was 99.36% by mass according to gas chromatography analysis.

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 preparing method of 3, 4-dichloroaniline, which is characterized by the following: adopting 3, 4-dichloronitrobenzene as raw material and alcohol solution as solvent system; aerating H2 under 0.5-1.5Mpa at 80-120 Deg C in the condition of Raney-Ni catalyst and dechlorination inhibitor; proceeding catalytic hydrogenating reducing reaction to produce the product. The selectivity of 3, 4-dichloroaniline is more than 99%, whose dechlorination quantity is less than 2%.

Description

technical field [0001] The present invention relates to a preparation method of 3,4-dichloroaniline, in particular to a method for preparing 3,4-dichloroaniline by catalytic hydrogenation reduction method using 3,4-dichloronitrobenzene as raw material . Background technique [0002] 3,4-Dichloroaniline is an important chemical intermediate for medicines, pesticides, dyes, spices, etc., and has a wide range of uses. The synthesis methods of 3,4-dichloroaniline usually include iron powder reduction method, alkali sulfide reduction method and catalytic hydrogenation reduction method, and 3,4-dichloroaniline is prepared by reduction of 3,4-dichloronitrobenzene. [0003] The chemical reduction methods such as the iron powder reduction method under acidic conditions or the alkali sulfide reduction method under alkaline conditions are used to prepare 3,4-dichloroaniline although the cost is low, but a large amount of amine-containing toxic metal residues or hydrochloric acid-conta...

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
IPC IPC(8): C07C211/52C07C209/36
Inventor 胡拖平陈宏博张学俊
Owner ZHONGBEI UNIV
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