Method for preparing parachlorotoluene

A technology of p-chlorotoluene and toluene, which is applied in the field of preparation of p-chlorotoluene, can solve the problems of difficult industrial promotion and application, inactivation, etc., and achieve the effects of good industrial prospects, fast reaction rate and high catalytic activity

Inactive Publication Date: 2016-03-16
NANJING ZHONGTENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although the proportion of p-chlorotoluene has been significantly increased, thiazide compounds will decompose when encoun...

Method used

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Embodiment 1

[0017] The method for preparing p-chlorotoluene, the steps are as follows: N 2 Under protection, the AlCl 3 and L-type zeolite molecular sieves were added to distilled water, AlCl 3 The ratio of the amount to mass of the L-type zeolite molecular sieve is: 1mmol: 10g; the mass-volume ratio of the L-type zeolite molecular sieve to distilled water is: 1g: 15ml; at 40°C, reflux and stir for 2h. After the reaction, filter The final sample was dried at 80° C. for 12 h to obtain a catalyst for the chlorination reaction; the toluene raw material and the catalyst were added to the reactor, and the amount of the catalyst added was 0.1% of the toluene mass; chlorine gas was passed into the reactor to make the toluene Carry out liquid-phase ring chlorination reaction with chlorine gas, the chlorination reaction temperature is 50°C; the chlorination reaction time is 6h. The chlorination reaction is carried out by means of tower-type ring chlorination or kettle-type ring chlorination. The...

Embodiment 2

[0020] The method for preparing p-chlorotoluene, the steps are as follows: N 2 Under protection, the AlCl 3 and L-type zeolite molecular sieves were added to distilled water, AlCl 3 The ratio of the amount to mass of the L-type zeolite molecular sieve is: 3mmol:10g; the mass-volume ratio of the L-type zeolite molecular sieve to distilled water is: 1g:20ml; at 60°C, reflux and stir for 4h, after the reaction, filter The final sample was dried at 80°C for 12h to obtain a catalyst for the chlorination reaction; the toluene raw material and the catalyst were added to the reactor, and the amount of the catalyst added was 2% of the toluene mass; chlorine gas was passed into the reactor to make the toluene Carry out liquid-phase ring chlorination reaction with chlorine gas, the chlorination reaction temperature is 40°C; the chlorination reaction time is 12h. The chlorination reaction is carried out by means of tower-type ring chlorination or kettle-type ring chlorination. The mater...

Embodiment 3

[0023] The method for preparing p-chlorotoluene, the steps are as follows: N 2 Under protection, the AlCl 3 and L-type zeolite molecular sieves were added to distilled water, AlCl 3 The ratio of the amount to mass of the L-type zeolite molecular sieve is: 2mmol:10g; the mass-volume ratio of the L-type zeolite molecular sieve to distilled water is: 1g:18ml; at 50°C, reflux and stir for 3h. After the reaction is completed, filter The final sample was dried at 80° C. for 12 hours to obtain a catalyst for chlorination reaction; the toluene raw material and the catalyst were added to the reactor, and the amount of catalyst added was 1% of the toluene mass; chlorine gas was passed into the reactor to make the toluene Carry out liquid-phase ring chlorination reaction with chlorine gas, the chlorination reaction temperature is 40°C; the chlorination reaction time is 8h. The chlorination reaction is carried out by means of tower-type ring chlorination or kettle-type ring chlorination...

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Abstract

The invention provides a method for preparing parachlorotoluene. The method comprises the following steps of adding raw materials of methylbenzene and catalysts into a reaction kettle, and feeding chlorine into the reaction kettle to subject methylbenzene and chlorine to a liquid phase ring chlorination reaction; performing aeration after the reaction is completed, removing chlorine and hydrogen chloride remaining in reaction liquid, and rectifying the reaction liquid to separate out un-reacted methylbenzene and a small quantity of dichlorotoluene to obtain mixed chlorotoluene; separating mixed chlorotoluene through a melt crystallization method to obtain high-purity parachlorotoluene. According to the method, AlCl3 loaded L-shaped molecular sieve based catalysts are used for catalyzing methylbenzene for selective chlorination, the reaction rate is high, the catalytic activity is high, selectivity of parachlorotoluene is good, the requirement for process conditions is low, and the catalyst use amount is small; the catalyst is high in activity and capable of being recycled, and a good industrial prospect is achieved.

Description

technical field [0001] The invention belongs to the field of organic chemical industry, in particular to a method for preparing p-chlorotoluene. Background technique [0002] Toluene reacts with chlorine gas in the liquid phase under the action of Lewis acid catalysts such as iron trichloride, antimony trichloride, aluminum trichloride, etc., and the mono-substituted aromatic ring product monochlorotoluene is the mixture of o-chlorotoluene and p-chlorotoluene. mixture. If ferric chloride is used as catalyst, the ratio of p-chlorotoluene to o-chlorotoluene in the monochlorotoluene mixture is about 0.5-0.55:1. [0003] Among the toluene ring chlorination products, p-chlorotoluene is an important intermediate in the production of fine chemical products such as pesticides, medicines, and dyes, while o-chlorotoluene has much smaller uses, and a large part of it is used as a low-priced solvent. [0004] For a long time, people have been trying to find a way to increase the ratio...

Claims

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Application Information

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IPC IPC(8): C07C25/02C07C17/12
Inventor 钟华陆敏山陈秀珍蔡伟忠
Owner NANJING ZHONGTENG CHEM
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