Method for preparing p-xylylene dichloride through ultraviolet-induced catalysis

A technology of induced catalysis and p-dichlorobenzyl, applied in chemical instruments and methods, halogenated hydrocarbon preparation, organic chemistry, etc., can solve the problems of high environmental pressure and cost pressure, long process flow, high equipment requirements, and meet equipment requirements The effect of less, low process cost and simple equipment requirements

Pending Publication Date: 2020-12-29
ZHANGJIAGANG JIULI NEW MATERIAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above methods either use other solvents, or use p-xylene as a solvent, and are also chlorinated in the form of raw materials, which have problems such as low conversion rate and high cost; The crude product with low content can be obtained, and the final product must be rectified under high temperature and vacuum. The whole process is long and requires high equipment, so the pressure on environmental protection and cost are relatively high.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Add 430 kg of p-xylene (about 500 liters) and 800 ml of catalyst into a 0.5 cubic reaction kettle, and slowly heat to 80 degrees Celsius; turn on the ultraviolet lamp and the chlorine gas valve to feed chlorine gas, pay attention to the tail gas, and slightly bubble the recovered liquid It is appropriate. Continue to heat up to 100 degrees Celsius, and keep warm between 99-110 degrees Celsius, adjust the chlorine valve, continue to feed chlorine gas, after 5 hours, take a sample every half an hour, and monitor the content of trichloro compounds and tetrachloro compounds by gas chromatography; 9 After one hour, the total content of trichloro compounds, tetrachloro compounds and a very small amount of pentachloro compounds reached 3.3%, and the ventilation of chlorine gas was stopped.

[0037] Through the pipeline connected by the bottom valve, the above-mentioned high-temperature reaction solution is directly introduced into a stirred tank with 1.5 cubic meters of water,...

Embodiment 2

[0041] Add 430 kg of p-xylene (about 500 liters) and 600 ml of catalyst in a 0.5 cubic reaction kettle, and slowly heat to 80 degrees Celsius; turn on the ultraviolet lamp and the chlorine gas valve to feed chlorine gas, pay attention to the tail gas, and slightly bubble the recovery liquid It is appropriate. Continue to heat up to 100 degrees Celsius, and keep warm between 99-110 degrees Celsius, adjust the chlorine gas valve, continue to feed chlorine gas, after 5 hours, take a sample every half an hour, and monitor the content of trichloro compounds and tetrachloro compounds by gas chromatography; 10 After one hour, the total content of trichloro compounds, tetrachloro compounds and a very small amount of pentachloro compounds reached 2.8%, and the ventilation of chlorine gas was stopped.

[0042] Through the pipeline connected by the bottom valve, the above-mentioned high-temperature reaction solution is directly introduced into a stirred tank with 1.5 cubic meters of wate...

Embodiment 3

[0046] Add 400 kg of p-xylene and 30 kg of recovered p-xylene and p-methyl benzyl chloride mixture (about 500 liters in total) and 1000 ml of catalyst in a 0.5 cubic reaction kettle, slowly heat to 80 degrees Celsius; turn on the ultraviolet lamp and chlorine gas Chlorine gas is fed through the valve, pay attention to observe the exhaust gas, it is advisable to slightly bubble the recovery liquid. Continue to heat up to 100 degrees Celsius, and keep warm between 99-110 degrees Celsius, adjust the chlorine gas valve, continue to feed chlorine gas, after 5 hours, take a sample every half an hour, and monitor the content of trichloro compounds and tetrachloro compounds by gas chromatography; 8 After one hour, the total content of trichloride, tetrachloride and very small amount of pentachloride reached 3.0%, stop passing chlorine gas.

[0047] Through the pipeline connected by the bottom valve, the above-mentioned high-temperature reaction solution is directly introduced into a s...

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Abstract

The invention relates to a method for preparing p-xylylene dichloride by ultraviolet-induced catalysis, wherein the method comprises the following steps: step 1, adding p-xylene and a catalyst into areaction kettle, and slowly heating to a certain temperature; turning on an ultraviolet lamp, introducing chlorine gas from the bottom (or inserting a gas guide pipe into the bottom), and controllingthe introduction rate of the chlorine gas until a tail gas absorption liquid is slightly bubbled; when the temperature rises to 100 DEG C, heating is stopped, carrying out heat preservation, and introducing chlorine gas at the constant temperature for reaction; and after 5 hours, monitoring the reaction process by gas chromatography to obtain a high-temperature reaction solution; step 2, pre-adding a large amount of water into another kettle with strong stirring, and rapidly adding the reaction solution obtained in the step 1 into the water under strong stirring to form a large amount of whiteprecipitates; step 3, carrying out suction filtration, and rinsing the obtained white solid with water several times. and step 4, drying to obtain the target product p-xylylene dichloride.

Description

technical field [0001] The invention relates to the field of organic chemical synthesis, in particular to a method for synthesizing p-dichlorobenzyl. Background technique [0002] p-Dichlorobenzyl is an important chemical raw material, its appearance is white crystal or powder, and its melting point is 98-102 degrees Celsius. It can be used to produce terephthalamide; terephthalaldehyde; p-xylylene dimethyl ether and other downstream chemical raw materials; using p-dichlorobenzyl as a crosslinking agent can synthesize polysulfone hollow fiber nanofiltration composite membrane; it is also a Important pharmaceutical intermediates; in addition, it is also widely used in the synthesis of dyes and sewage treatment agents. [0003] There are many ways to also synthesize p-dichlorobenzyl, for example, using p-phenylenedimethanol as a raw material, using NMP as a solvent, chlorinating through benzoyl chloride (CN 106187674); or using dichloromethane as a solvent, using thionyl chlo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/14C07C17/38C07C22/04
CPCC07C17/14C07C17/38C07C22/04
Inventor 苏旭
Owner ZHANGJIAGANG JIULI NEW MATERIAL TECH CO LTD
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