Production technology for preparing p-chlorotoluene by methylbenzene directional chlorination

A p-chlorotoluene and production process technology, applied in the production process field of toluene directional chlorination to prepare p-chlorotoluene, can solve the problems of high cost, poor directional selectivity of toluene chlorination, etc., achieve low cost, improve overall utilization rate, reduce The effect of by-product formation

Pending Publication Date: 2019-05-10
JIANGSU QIHENG AGRI & CHEM TECHCO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art, to provide a production process for preparing p-chlorotoluene by directional chlorination of toluene, which solves the problems of poor directional selectivity and high cost of toluene chlorination in the prior art, and provides A production process with high p-chlorotoluene yield, high conversion rate, better selection of para-position orientation and reasonable process cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] A kind of production technology that the directional chlorination of toluene prepares p-chlorotoluene comprises the steps:

[0033] Step 1, chlorination: put the catalyst into the reaction container, then add toluene into the reaction container, pass inert gas to discharge the air in the reaction container, then put the reaction container into a constant temperature device after shading treatment, wherein the toluene and chlorine The molar ratio is 1:0.6, the mass ratio of catalyst to toluene is 1:120, the reaction temperature of the constant temperature device is 20°C, the chlorine gas dried by concentrated sulfuric acid is mixed with nitrogen to form chlorinated gas, and then passed into the constant temperature device for chlorination Reaction, wherein the feed rate of chlorinated gas is 0.5L / min, wherein the chlorinated gas is a mixture of chlorine and nitrogen according to the volume ratio of 1:0.8, the reaction tail gas is absorbed by purified water to form an aqueou...

Embodiment 2

[0039] A kind of production technology that the directional chlorination of toluene prepares p-chlorotoluene comprises the steps:

[0040] Step 1, chlorination: put the catalyst into the reaction container, then add toluene into the reaction container, pass inert gas to discharge the air in the reaction container, then put the reaction container into a constant temperature device after shading treatment, wherein the toluene and chlorine The molar ratio is 1:0.7, the mass ratio of catalyst to toluene is 1:130, the reaction temperature of the constant temperature device is 50°C, the chlorine gas dried by concentrated sulfuric acid is mixed with nitrogen to form chlorinated gas, and then passed into the constant temperature device for chlorination Reaction, wherein the feed rate of chlorinated gas is 0.6L / min, wherein the chlorinated gas is a mixture of chlorine gas and nitrogen gas at a volume ratio of 1:1.0, the reaction tail gas is absorbed by purified water to form an aqueous ...

Embodiment 3

[0046] A kind of production technology that the directional chlorination of toluene prepares p-chlorotoluene comprises the steps:

[0047] Step 1, chlorination: put the catalyst into the reaction container, then add toluene into the reaction container, pass inert gas to discharge the air in the reaction container, then put the reaction container into a constant temperature device after shading treatment, wherein the toluene and chlorine The molar ratio is 1:0.6, the mass ratio of catalyst to toluene is 1:123, the reaction temperature of the constant temperature device is 30°C, the chlorine gas dried by concentrated sulfuric acid is mixed with nitrogen to form chlorinated gas, and then passed into the constant temperature device for chlorination Reaction, wherein the feed rate of chlorinated gas is 0.6L / min, wherein the chlorinated gas is a mixture of chlorine gas and nitrogen gas at a volume ratio of 1:0.9, the reaction tail gas is absorbed by purified water to form an aqueous ...

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PUM

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Abstract

The invention relates to the technical field of chemical raw material preparation, in particular to a production technology for preparing p-chlorotoluene by methylbenzene directional chlorination. Theproduction technology includes the steps: chlorination: adding catalysts into a reaction vessel, adding methylbenzene into the reaction vessel, leading in inert gas, discharging air in the reaction vessel, placing the reaction vessel into a constant temperature device after shading treatment, leading chlorine into a constant temperature device, performing chlorination reaction and chromatographicanalysis and accordingly judging reaction endpoints to obtain chlorinated mixture for standby application; rectification: adjusting reflux ratio to be 10:1 and collecting fraction with the temperature of 158-162 DEG C to obtain o-chlorotoluene and p-chlorotoluene mixed solution for standby application; primary purification; secondary purification. The production technology solves the problems ofpoor methylbenzene chlorination directional selectivity and high cost in the prior art, and is high in p-chlorotoluene yield and conversion rate, good in para-position directional selectivity and reasonable in technological cost.

Description

technical field [0001] The invention relates to the technical field of chemical raw material preparation, in particular to a production process for preparing p-chlorotoluene by directional chlorination of toluene. Background technique [0002] P-chlorotoluene is an important raw material and intermediate of pesticides, medicines, dyes and other fine organic chemical products. A series of important fine chemical intermediates can be derived through chlorination, oxidation, ammoxidation on the side chain of p-chlorotoluene, chlorination, nitration, sulfonation, Friedel-Crafts reaction, chloromethylation and other reactions on the ring , more than 100 kinds of pesticides, medicines and dyes can be developed through these intermediates. Such as pesticides such as grass grass, paclobutrazol, trifluralin, and herbethrin insecticides; medicine indomethacin; dye water dyeing base, etc. p-Chlorotoluene is an important fine chemical raw material and an organic chemical intermediate ...

Claims

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Application Information

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IPC IPC(8): C07C17/12C07C17/392C07C25/02
Inventor 王健吴明俊
Owner JIANGSU QIHENG AGRI & CHEM TECHCO
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