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

Method for preparing chlorophthalic anhydride through solvent-free liquid-phase catalytic oxidation

A chlorophthalic anhydride, liquid-phase catalysis technology, applied in the field of synthetic chemistry, can solve problems such as reducing investment in fixed assets, and achieve the effects of easy product separation and easy recovery

Pending Publication Date: 2021-12-03
HARBIN INST OF TECH AT WEIHAI
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the deficiencies in the preparation of the above-mentioned chlorinated phthalic anhydride, the present invention presents a new solution for the preparation of chlorinated phthalic anhydride by non-solvent catalytic oxidation of chlorinated o-xylene. Chlorinated phthalic acid above ℃ (melting point greater than ~130 ℃) is a solvent-free reaction system with additives, and the high-boiling point organic system meets the conditions for the formation of oxygen free radicals by the cobalt-manganese-bromine composite catalyst under normal pressure, and the by-products generated by the reaction Water can be diverted and removed in time without affecting the activity of the catalyst; and the reaction vessel does not need to be sealed, and the catalytic oxidation reaction can be realized by using a ceramic or glass reactor, avoiding the use of expensive titanium kettles, which can greatly reduce the investment in fixed assets. The present invention can use air and different concentrations of oxygen as the oxidizing agent, which is cheap and easy to obtain, and avoids the problem of using acetic acid as the solvent in the traditional liquid phase oxidation and being sensitive to the produced water

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
  • Method for preparing chlorophthalic anhydride through solvent-free liquid-phase catalytic oxidation
  • Method for preparing chlorophthalic anhydride through solvent-free liquid-phase catalytic oxidation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] In a 500mL glass reaction tube, add 140g 4-chloro-o-xylene (1moL), catalyst cobalt acetate 0.3g, manganese acetate 0.1g, tetrabromoethane 1g, 4-chlorophthalic acid 10g, mix, stir and heat To 150°C, start to feed oxygen with a purity of 100%, the flow rate is 360mL / min, and the temperature is controlled at 200°C for 10 hours. When the oxygen concentration in the tail gas is detected to be 95%, the reaction is stopped, and then distilled and dehydrated to obtain 4-chlorophthalic anhydride 182.3 g, yield 94%, melting point 96°C.

Embodiment 2

[0018] In a 500mL glass reaction tube, add 140g of 3-chloro-o-xylene (1moL), 0.4g of catalyst cobalt acetate, 0.15g of manganese acetate, 1.5g of tetrabromoethane, and 13g of 3-chlorophthalic acid, mix and stir Heat to 150°C, start to feed oxygen with a purity of 100%, flow rate 240mL / min, start the temperature, control the temperature at 210°C for 15 hours, stop the reaction when the concentration of oxygen in the tail gas is detected to be 95%, and then distill and dehydrate to obtain 3-chloro Phthalic anhydride 181.3g, yield 93%, melting point 125°C.

Embodiment 3

[0020] In a 500mL glass reaction tube, add 14g mixed 3-, 4-chloro-o-xylene mixture (0.1moL, 0.45 / 0.55), catalyst cobalt acetate 0.04g, manganese acetate 0.015g, sodium bromide 0.3g, 3-chloro Mix 1.3 g of substituted phthalic acid, stir and heat to 150°C, start to feed air at a flow rate of 240mL / min, gradually raise the temperature to 210°C, and react for 8 hours, stop the reaction when the concentration of oxygen in the tail gas is detected to be 20%, and then Distillation and dehydration gave 180.3 g of a mixture of 3- and 4-chlorophthalic anhydride, with a yield of 92% and a melting point of 98°C.

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 method for preparing chlorophthalic anhydride through solvent-free liquid phase catalytic oxidation. Chlorophthalic anhydride is prepared through catalytic oxidation under normal pressure by taking chloro-o-xylene as a raw material, cobalt, manganese and bromine as a composite catalyst, atomic oxygen as an oxidant and chlorophthalic acid as an additive. The method has the advantages that the normal-pressure solvent-free liquid-phase oxidation reaction avoids the problem that a large amount of acetic acid solvent is used traditionally, product separation is easy, and the catalyst is easy to recover.

Description

technical field [0001] The invention relates to a method for preparing chlorinated phthalic anhydride by catalytic oxidation in a solvent-free liquid phase, belonging to the category of synthetic chemistry. Background technique [0002] Chlorophthalic anhydride is currently the key raw material for preparing biphenyl dianhydride and various ether anhydrides. The existing preparation methods mainly include: 1) the method of passing chlorine gas through phthalic anhydride, but the product is mainly 4-chlorophthalic anhydride. There are a large amount of unreacted phthalic anhydride raw materials in the phthalic anhydride, and separation and purification are difficult; 2) by chlorinated o-xylene gas-phase oxidation method, but the method reaction temperature is high, carbonization corrosion is serious, and productive rate is only about about 70%, and atom economy is not good High, several times of industrialization all failed; 3) by the chlorinated o-xylene liquid-phase oxidati...

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): C07D307/89
CPCC07D307/89Y02P20/584
Inventor 高昌录孙秀花李大龙
Owner HARBIN INST OF TECH AT WEIHAI
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