New process for preparing p-xylylene dichloride by adopting novel reaction equipment

A technology of para-dichlorobenzyl and reaction equipment, applied in the field of preparing para-dichlorobenzyl, can solve the problems of low single-pass yield of dichlorobenzyl, low content of dichlorobenzyl, low reaction selectivity, etc., so as to reduce the generation of by-products , reduce the reaction temperature, the effect of high initiation efficiency

Pending Publication Date: 2018-08-17
青岛和兴精细化学有限公司
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The preparation process of p-dichlorobenzyl mentioned in previous literatures has the following problems in varying degrees: low reaction selectivity, resulting in the generat

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
  • New process for preparing p-xylylene dichloride by adopting novel reaction equipment
  • New process for preparing p-xylylene dichloride by adopting novel reaction equipment

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0042] Example one

[0043] A new type of reaction equipment for preparing p-dichlorobenzyl includes a reactor, a gas-liquid separator, a crystallizer, and an LED lamp;

[0044] An LED lamp 4 is fixedly arranged outside the reactor, and a chlorine gas inlet pipe 5 is sealed in the reactor;

[0045] The reactors are divided into three groups, namely one-stage reactor 1, two-stage reactor 2, and three-stage reactor 3;

[0046] The gas-liquid separator is divided into two groups, namely gas-liquid separator one 6 and gas-liquid separator two 7;

[0047] The gas-liquid separator 6 is arranged between the first-stage reactor 1 and the second-stage reactor 2, and is connected to the first-stage reactor 1 through the material pipeline 8 and the second-stage reactor 2 is sealed by the reaction liquid pipeline 9; The two-stage gas-liquid separator 7 is arranged between the second-stage reactor 2 and the third-stage reactor 3, and is connected to the second-stage reactor through the material pip...

Example Embodiment

[0058] Example two

[0059] The total amount of 1000G p-xylene and 1210G chlorine is continuously pumped into the chlorinator with a high-pressure pump, and the reaction is initiated by LED lights. The material after a period of chlorine reaction enters the gas-liquid separator to complete the reaction liquid and the hydrogen chloride gas produced by the reaction After the gas-liquid separation, the reaction liquid and chlorine gas were passed into the second-stage reactor, so that chlorine was passed through three stages. The final reaction liquid was sampled and tested (Table 1). The conversion rate of p-xylene was 97.75%, and the conversion of p-dichlorobenzyl was 97.75%. The total selectivity with p-methyl benzyl chloride is 99.01%, and the content of p-dichlorobenzyl is 74.65%. The third stage chlorinated material enters the crystallizer, and after gas-liquid separation and crystallization, it is filtered and separated to obtain the final product with a product content of 99...

Example Embodiment

[0060] Example three

[0061] The total amount of 1000G p-xylene and 1170G chlorine is continuously pumped into the chlorinator with a high-pressure pump, and the reaction is initiated by LED lights. The material after a period of chlorine reaction enters the gas-liquid separator to complete the reaction liquid and the hydrogen chloride gas produced by the reaction After the gas-liquid separation, the reaction liquid and chlorine gas were passed into the second-stage reactor, and the chlorine was divided into three sections. The final reaction liquid was sampled and tested (Table 1). The conversion rate of p-xylene was 96.49%, and the p-dichlorobenzyl The total selectivity with p-methyl benzyl chloride is 99.09%, and the content of p-dichlorobenzyl is 70.04%. The third stage chlorinated material enters the crystallizer, after gas-liquid separation and crystallization, the final product is obtained by filtration and separation, and the product content reaches 99.59%.

[0062] S...

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 new process for preparing p-xylylene dichloride by adopting novel reaction equipment. The novel reaction equipment comprises a chlorinator, a gas-liquid separator, a crystallizer and the like. The process for preparing the p-xylylene dichloride by adopting the novel reaction equipment comprises the following steps: (1) reaction; and (2) separation by crystallization. Theprocess has the beneficial effects that by adopting the novel reaction equipment, p-xylene and chlorine gas can be thoroughly and uniformly mixed, and excessive chlorination caused by high local chlorine concentration is avoided; chlorination is carried out in three stages, a reactant proportioning ratio of each stage is accurately controlled, the single-pass conversion ratio of p-xylene is higherthan 96%, the total selectivity of p-xylylene dichloride and p-methyl benzyl chloride in a chlorination solution reaches up to 98%, and the content of p-xylylene dichloride reaches up to 70% or more;a used LED lamp, as a light source, for initiating reaction is proper in wavelength and is high in initiating efficiency, the reaction temperature can be greatly lowered, and side reactions can be effectively reduced; and the chlorination solution is low in impurity content, the product is not required to be purified by a vacuum rectification process, and the product with the content of 99% or more can be obtained by once simple crystallization.

Description

technical field [0001] The invention relates to a new process for preparing p-dichlorobenzyl by adopting novel reaction equipment. Background technique [0002] p-Dichlorobenzyl is an important chemical raw material, its appearance is white flaky crystal, as an intermediate of organic synthesis, it is mainly used in the manufacture of p-xylylenedimethanol, p-xylylene dimethyl ether, terephthalaldehyde and other dyes. Can be used as pharmaceutical intermediates. [0003] The preparation process of p-dichlorobenzyl mentioned in previous literatures has the following problems in varying degrees: low reaction selectivity, resulting in the generation of a large number of by-products; The content of benzyl is low, and the one-pass yield to dichlorobenzyl is not high; the production cost caused by various reasons is high. Contents of the invention [0004] The technical problem to be solved by the present invention is to provide a new process for preparing p-dichlorobenzyl by a...

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): C07C22/04C07C17/14C07C17/38
CPCC07C17/14C07C17/38C07C22/04
Inventor 况宗盛孙晓伟张相荣
Owner 青岛和兴精细化学有限公司
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