Novel synthetic method of halogenated aromatic hydrocarbon

A technology of halogenated aromatic hydrocarbons and synthesis methods, which is applied in the field of preparation of pesticide chemical intermediate products, can solve the problems of low chlorine gas absorption utilization rate and low reaction yield, and achieve remarkable economic and social benefits, convenient operation, Effect of reduction of by-products and exhaust emissions

Inactive Publication Date: 2020-01-10
JIANGSU FENGHUA CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] (1) During the chlorination reaction, due to the failure to strictly control the occurrence of side reactions, the content of p-chlorobenzotrifluoride in the chlorination reaction can only reach about 90%, and the reaction yield is low;
[0007] (2) In the chlorination production process of this synthesis process, since the single-pot chlorination form is adopted, the absorption and utilization rate of chlorine gas in the chlorination process is too low, only about 75%

Method used

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  • Novel synthetic method of halogenated aromatic hydrocarbon

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Experimental program
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Effect test

Embodiment 1

[0026] (1) Chlorination step: put 630g of p-chlorotoluene into a dehydration kettle, heat to 80°C to remove water to obtain 629g of p-chlorobenzotrifluoride, put it into a 3L chlorination reaction kettle, heat up to 110°C, add 63g of chlorinated Copper catalyst (added in 4 batches, each batch 10-20g), start to pass dry chlorine gas, flow 40-80 m 3 / h, then add the catalyst every 30 minutes, control the temperature at 110-112°C, and the reaction time is 24 hours. After sampling and analyzing the chlorinated material as qualified, stop the chlorine flow. The p-chlorotrichlorotoluene produced by chlorination is pumped into the chlorination tank for use, and the tail gas generated by the reaction is sent to the tail gas absorption device.

[0027] (2) Fluorination step: Press 4 moles of p-chlorotrichlorotoluene and 12 moles of anhydrous hydrogen fluoride into a 3L fluorination reaction kettle, open the frozen brine system, press hydrogen fluoride into the fluorination kettle with...

Embodiment 2

[0031] (1) Chlorination step: put 630g of p-chlorotoluene into the dehydration kettle, heat to 80°C to remove water to obtain 629g of p-chlorobenzotrifluoride, put it into a 3L chlorination reaction kettle, raise the temperature to 110°C, add 60g of chlorinated Copper catalyst (added in 4 batches, 15g in each batch), and dry chlorine gas was introduced at the flow rate of 40-80 m 3 / h, then add the catalyst every 30 minutes, control the temperature at 110-112°C, and the reaction time is 22 hours. After sampling and analyzing the chlorinated material as qualified, stop the chlorine flow. The p-chlorotrichlorotoluene produced by chlorination is pumped into the chlorination tank for use, and the tail gas generated by the reaction is sent to the tail gas absorption device.

[0032] (2) Fluorination step: Press 4 moles of p-chlorotrichlorotoluene and 13 moles of anhydrous hydrogen fluoride into a 3L fluorination reaction kettle, open the frozen brine system, press hydrogen fluorid...

Embodiment 3

[0036] (1) Chlorination step: Put 470kg of p-chlorotoluene into the dehydration kettle and heat it to 80°C to remove water, then pump it into a 3000L chlorination kettle, raise the temperature to 110°C, add 30kg (add in 4 batches, 7-8kg per batch ) cuprous chloride catalyst, and start to feed the chlorine gas vaporized by the gasifier into the chlorination kettle with a flow rate of 40-80 m 3 / h, while cooling water is passed into the jacket of the chlorination kettle, and catalyst is added every half hour, the temperature is controlled at 110-112°C, and the reaction time is 24 hours. After sampling and analyzing the chlorinated material as qualified, stop the chlorine flow. The p-chlorotrichlorotoluene produced by chlorination is pumped into the chlorination tank for use, and the tail gas generated by the reaction is sent to the tail gas absorption device.

[0037] (2) Fluorination step: pump 690kg of p-chlorotrichlorotoluene into the high level tank for metering and put it i...

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Abstract

The invention discloses a novel synthetic method of halogenated aromatic hydrocarbon, wherein p-chlorotoluene is used as a raw material, copper chloride or cuprous chloride is used as a catalyst, andp-chlorobenzotrifluoride is synthesized through two steps of chlorination and fluorination. Compared with the method in the prior art, the method of the invention has the following characteristics that raw materials are subjected to heating dehydration treatment in a dehydration kettle, so that the chlorination side reactions are few, the product purity is high, the grading chlorination device does not need to be additionally arranged, the technological process is simple, and the operation is convenient; and by adding the catalyst in batches in the chlorination process, the use efficiency of the catalyst is improved, so that the emission of the byproducts and the waste gas generated by the chlorination reaction in production is greatly reduced, and the emission of pollutants in the production process is reduced.

Description

technical field [0001] The invention relates to a preparation method of a pesticide chemical intermediate product, in particular to a novel synthesis method of a halogenated aromatic hydrocarbon. This method is applicable to the occasion of synthesizing p-chlorobenzotrifluoride through two steps of chlorination and fluorination by using p-chlorotoluene as raw material. Background technique [0002] 4-Chlorobenzotrifluorotoluene (4-chlorobenzotrifluoride) is a colorless transparent liquid at room temperature with the smell of halogenated benzene. The compound is insoluble in water, but miscible with benzene, toluene, ethanol, ether, halogenated hydrocarbons, etc. p-Chlorobenzotrifluoride is an important intermediate in organic synthesis, the fluorine atom contained in it endows it with special activity, and it is widely used in fine organic synthesis fields such as medicine, pesticide and dyestuff. p-Chlorobenzotrifluoride is a key intermediate in the synthesis of various f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/20C07C25/13
CPCC07C17/14C07C17/206C07C25/13C07C25/02
Inventor 郑龙生方东张亮李付香
Owner JIANGSU FENGHUA CHEM IND
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