Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for preparing p-phenylenediamine

A technology for p-phenylenediamine and p-dinitrobenzene is applied in the field of preparing p-phenylenediamine and can solve problems such as high cost and high price

Inactive Publication Date: 2016-03-23
王晓伟
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process effectively solves the problem of environmental pollution, but the biggest disadvantage of this process is the use of expensive noble metal catalysts, which are very expensive

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

[0016] Add 16.8g (0.1mol) of p-dinitrobenzene, 0.64g (8mmol) of Se, 40mL (2.2mol) of water, 10.6g (0.1mol) of sodium carbonate and 300mL of solvent methanol into a 1000mL autoclave. After closing the autoclave and checking the airtightness, nitrogen gas was introduced to a pressure of 1 MPa, and then released. Replace 5 times in order to remove the oxygen in the autoclave, feed carbon monoxide to a pressure of 3Mpa, then deflate, and then feed carbon monoxide to a pressure of 5Mpa. Heating to 100°C for reaction for 4 hours, cooling to room temperature, deflation, passing through oxygen or air and stirring for 1-2 hours, filtering, cooling and crystallizing the filtrate, suction filtration, and drying the filter cake in vacuum to obtain the finished p-phenylenediamine product with a yield of 96.7% with a purity of 99.6%.

Embodiment 2

[0018] Add 16.8g (0.1mol) of p-dinitrobenzene, 0.64g (8mmol) of Se, 40mL (2.2mol) of water, 10.6g (0.1mol) of sodium carbonate and 300mL of solvent methanol into a 1000mL autoclave. After closing the autoclave and checking the airtightness, nitrogen gas was introduced to a pressure of 1 MPa, and then released. Replace 5 times in order to remove the oxygen in the autoclave, feed carbon monoxide to a pressure of 3Mpa, then deflate, and then feed carbon monoxide to a pressure of 5Mpa. Heat to 150°C to react for 2 hours, cool to room temperature, let oxygen or air in and stir for 1-2 hours after degassing, filter, the filtrate is cooled and crystallized, filtered with suction, and the filter cake is vacuum-dried to obtain the finished p-phenylenediamine product with a yield of 95.1% with a purity of 99.7%.

Embodiment 3

[0020] Add 16.8g (0.1mol) of p-dinitrobenzene, 0.64g (8mmol) of Se, 40mL (2.2mol) of water, 10.2g (0.1mol) of triethylamine and 300mL of solvent methanol in a 1000mL autoclave. After closing the autoclave and checking the airtightness, nitrogen gas was introduced to a pressure of 1 MPa, and then released. Substitute 5 times in order to remove the oxygen in the autoclave, feed carbon monoxide to a pressure of 5Mpa, then deflate, and then feed carbon monoxide to a pressure of 5Mpa. Heating to 120°C to react for 3 hours, cooling to room temperature, deflated, passing through oxygen or air and stirring for 1-2 hours, filtering, cooling and crystallizing the filtrate, suction filtering, and drying the filter cake in vacuum to obtain the finished product of p-phenylenediamine, the yield is 94.3% with a purity of 99.4%.

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 belongs to the technical field of fine chemical engineering, and mainly relates to a preparation method for p-phenylenediamine. The preparation method for the high-purity p-phenylenediamine comprises the steps that a nitro selection reduction reaction is performed in organic solvent under high pressure by taking p-dinitrobenzene as a raw material, taking selenium as a catalyst and taking alkali as a catalyst promoter, wherein the reaction temperature ranges from 80 DEG C to 150 DEG C, the reaction pressure ranges from 1 MPa to 10 MPa, and the reaction time ranges from 2 hours to 10 hours; cooling is performed until the room temperature is achieved, after degassing is performed, oxygen or air is introduced, stirring is performed for 1-2 hours, filtering is performed, cooling crystallization is performed on filtrate, suction filtration is performed, and after vacuum drying is performed on filter cakes, the finished p-phenylenediamine is obtained.

Description

technical field [0001] The invention belongs to the field of fine chemicals and relates to a method for preparing p-phenylenediamine from p-dinitrobenzene. More specifically, it relates to a method for preparing p-phenylenediamine by using p-dinitrobenzene as a raw material and selenium as a catalyst in the presence of carbon monoxide and water. Background technique [0002] P-phenylenediamine is an important organic chemical raw material, which is generally used in the production of dyes, rubber antioxidants, etc. The traditional production method of p-phenylenediamine is to use p-nitrochlorobenzene as raw material, react with ammonia water (or ammonia gas) under high temperature and high pressure conditions to prepare p-nitroaniline, and p-nitroaniline is then reduced to produce p-nitroaniline by alkali sulfide or iron powder The crude p-phenylenediamine is purified by recrystallization to prepare high-purity p-phenylenediamine. The biggest defect of this process is that...

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): C07C211/51C07C209/36
CPCC07C209/325
Inventor 王晓伟
Owner 王晓伟
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com