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

Method for preparing 2,6-dimethylnaphthalene through dismutation of beta methylnaphthalene under catalysis of ion liquid

A technology of ionic liquid and dimethylnaphthalene, which is applied in chemical instruments and methods, organic chemistry, hydrocarbons, etc., can solve the problems of environmental pollution, solid acid catalysts, difficult separation of products, difficult recycling, etc., and achieve good selectivity , not easy to lose, easy to operate

Inactive Publication Date: 2005-08-31
HEILONGJIANG INST OF PETROCHEM
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for preparing 2,6-dimethylnaphthalene by catalyzing the disproportionation of β-methylnaphthalene by ionic liquid, which uses ionic liquid as catalyst for the first time in the preparation of 2,6-dimethylnaphthalene , it not only overcomes the problems of difficult separation of products in liquid catalysts, serious equipment corrosion and environmental pollution, serious carbon deposition of solid acid catalysts and difficulty in recycling, but also the catalyst synthesis process used in the present invention is simple and convenient, effectively reducing industrial costs

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

specific Embodiment approach 1

[0008] Specific embodiment 1: In this embodiment, 2,6-dimethylnaphthalene is prepared in this way: β-methylnaphthalene and the solvent are mixed in a molar ratio of 1: (4~7), and the total amount of the mixed solution is added to the mixed solution The ionic liquid catalyst with a weight of 8-17% is used for the disproportionation reaction of β-methylnaphthalene under the protection of an inert gas at a temperature of 120-160° C., and the reaction ends after 2-4 hours to obtain 2,6-dimethylnaphthalene. The ionic liquid catalyst is a clear liquid that is liquid at room temperature or close to room temperature and is composed of metal halides and organic nitrogen-containing compounds. It is obtained by the following method: metal halides and organic nitrogen-containing compounds are The ratio of (1-5):1 is mechanically mixed at room temperature (this process is an exothermic reaction). The mixing process should be carried out slowly to avoid the formation of hot spots, which will...

specific Embodiment approach 2

[0009] Specific embodiment two: present embodiment is realized in this way; In the there-necked bottle of 250ml that has condensing tube, nitrogen protection device, thermometer and magnetic force stirring, add β-methylnaphthalene, mesitylene successively, account for total mass 8 ~17% ionic liquid catalyst, wherein the molar ratio of β-methylnaphthalene and mesitylene is 1: (4~7), seal, stir, be raised to temperature 120~160 ℃, react 2~4 hours, stop Heated, cooled to room temperature, and the supernatant was taken for qualitative and quantitative analysis by gas chromatography. Since the anti-product is immiscible with the ionic liquid, it naturally separates after cooling, and the ionic liquid is in the lower layer. After decanting the upper layer of the reaction solution, the remaining ionic liquid can be reused. After repeated use, the catalyst can be used in the At 80-100°C, evacuate the reactor for 30 minutes to remove unreacted substances and other organic matter, and r...

specific Embodiment approach 3

[0010] Specific embodiment three: this embodiment is achieved in this way: in the there-necked flask of 250ml that has condensing tube, nitrogen protection device, thermometer and magnetic force stirring, add successively 6 grams of β-methyl naphthalene, 30ml mesitylene, 14wt .% of chlorinated 1-methyl-3-butylimidazolium salt-aluminum trichloride ([Bmim]Cl-AlCl 3 ) ionic liquid catalyst, wherein the mol ratio of aluminum trichloride and chlorinated 1-methyl-3-butyl imidazolium salt is 4: 1, seal, stir, be raised to temperature 160 ℃, react 3 hours after, stop heating , cooled to room temperature, the supernatant was taken for qualitative and quantitative analysis by gas chromatography, and the conversion rate of β-methylnaphthalene and the selectivity of 2,6-dimethylnaphthalene were calculated by the area normalization method. The data are shown in Table 1.

[0011] Reaction conditions

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

An ionic liquid catalyzing process for preparing 2,6-dimethyl naphthalene by dismutating beta-methyl naphthalene includes proportionally mixing beta-methyl naphthalene with solvent, adding ionic liquid catalyst, and dismutation reaction at 120-160 deg.C for 2-4 hr under protection of inertial gas. Its advantages are high selectivity and no environmental pollution.

Description

Technical field: [0001] The invention relates to a method for preparing 2,6-dimethylnaphthalene, in particular to a method for preparing 2,6-dimethylnaphthalene by using ionic liquid to catalyze the disproportionation of β-methylnaphthalene. Background technique: [0002] 2,6-Dimethylnaphthalene (2,6-DMN) is an important fine chemical raw material for the synthesis of naphthalene-containing polymers, and 2,6-dimethylnaphthalene dicarboxylate obtained after oxidation and esterification of 2,6-DMN Naphthalene dicarboxylate (PEN) is obtained by polycondensation of ester (NDC) and ethylene glycol. PEN is a new type of high-performance polyester material. Compared with the currently commonly used polyethylene terephthalate (PET), it has better heat resistance, mechanical properties, gas barrier properties, chemical stability and radiation resistance. etc. are superior. The application prospect of PEN is very broad, and can be widely used in manufacturing industries such as inst...

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): C07C2/00C07C15/24
CPCY02P20/54
Inventor 白雪峰李艳伟刘宁生
Owner HEILONGJIANG INST OF PETROCHEM
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