Method for producing p-chorotoluene by using element selenium as catalyst

A technology for p-chlorotoluene and a catalyst is applied in the field of producing p-chlorotoluene, can solve problems such as difficulty in industrial application, and achieve the effects of easy production process control, simple process flow and low production cost

Active Publication Date: 2014-03-05
ZHEJIANG WEIHUA NEW MATERIAL CO LTD
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are problems of difficulty in industrial application

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

[0028] Preparation of catalyst and chlorination reaction

[0029] In a four-necked flask equipped with a reflux condenser, a chlorine pipe, a stirring and a thermometer, 0.5 g of iron powder, 0.8 g of selenium powder and 0.7 ml of benzyl chloride were added, and then 400 ml of toluene was added. Begin to pass chlorine gas at room temperature, and control the temperature not to exceed 40 °C. The chlorine gas feeding rate is 150-160 ml / min, and the feeding time is about 6 hours. At this time, the iron powder and selenium powder are all dissolved, the conversion rate of toluene is between 60-70%, and there is a large amount of the reaction material system. of oil is produced. The catalyst prepared above was stored for later use.

[0030] Take 40 ml of the above uniformly mixed catalyst (should be quickly measured after full stirring to avoid catalyst sedimentation), add 400 ml of fresh toluene, and place it in a four-necked flask equipped with a reflux condenser, a chlorine pip...

Embodiment 2

[0036] Chlorination

[0037] According to the experimental method of Example 1, an appropriate amount of one of antimony trichloride, ferric chloride and zinc chloride is added in an amount of 0.05-0.1 g, and the time of the chlorination reaction can be shortened to 5 hours. After testing, its ratio to the adjacent position is similar to that of Example 1, and the number of applications can also reach 20-80 times.

Embodiment 3

[0039] Industrialized catalyst preparation and chlorination reaction

[0040] In a 3000L reaction kettle equipped with a reflux condenser, a chlorine pipe, stirring and a thermometer, 4.0Kg of iron powder, 6.4Kg of selenium powder and 6.5L of benzyl chloride were added, and then 1600L of toluene was added. The catalyst for the cyclic chlorination of toluene is prepared by introducing chlorine gas. The preparation method is controlled as in Example 1.

[0041] 10,000 L of dry toluene was put into a reaction tower with a diameter of 1.3 m and a height of 12 m, and then 250 L of the above-mentioned catalyst was put into the reaction tower, and the reaction was carried out with chlorine. The external circulation is cooled, the temperature is controlled not to exceed 55°C, and the reaction end point is detected by chromatography. The results are: the ratio of ortho-position is 57:43, the conversion rate is more than 99.0%, and the dichlorotoluene is less than 2.5%.

[0042] Af...

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 provides a method for producing p-chorotoluene by using the element selenium as a catalyst, comprising the following steps of: using a selenium-containing organic compound as a catalyst, performing a liquid phase ring chlorination reaction between toluene and chlorine, followed by aeration after the reaction, removing residual chlorine and hydrogen chloride gas in the reaction solution, rectifying to obtain o-chlorotoluene, and carrying out melt crystallization on the enriched p-chorotoluene to obtain the high-purity p-chorotoluene. By the adoption of the method, the yield of p-chorotoluene is raised; the catalyst with a stable structure can be repeatedly applied; the technology and equipment are simple; the production cost is low; and there is no pollution to the environment.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a method for producing p-chlorotoluene by using elemental selenium as a catalyst. Background technique [0002] Chlorotoluene, including p-chlorotoluene and o-chlorotoluene, is an important organic chemical raw material and is widely used in fine organic chemical products such as pesticides, medicines, and dyes. Among them, p-chlorotoluene is more widely used, and its price is much higher than that of o-chlorotoluene. [0003] Chlorotoluene is generally prepared by toluene ring chlorination, but using common Lewis acid as a catalyst, most of the monochlorotoluene obtained by toluene ring chlorination is o-chlorotoluene, and the content of p-chlorotoluene is only 30%. %-40%. Since the use of p-chlorotoluene is far more than that of o-chlorotoluene, a catalyst that can improve the ratio of cyclic chlorination must be selected to increase the ratio of p-chlorotoluene in the cyclic...

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 Patents(China)
IPC IPC(8): C07C25/02C07C17/12
Inventor 陈静华吴江伟张增兴张泉泉
Owner ZHEJIANG WEIHUA NEW MATERIAL CO LTD
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