Method for reducing using amount of catalyst in production of difluorobenzonitrile

A technology of difluorobenzonitrile and catalyst, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve problems such as different effects, different purposes, and large differences, and achieve the effect of reducing the amount of use

Active Publication Date: 2015-03-04
天津河清化学工业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical solutions disclosed in the above patent documents are quite different from the present application, with different purposes, different realized solutions, and different obtained effects

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] A method for reducing the amount of catalyst used in the production of difluorobenzonitrile, the feeding method of allowing dichlorobenzonitrile and potassium fluoride to double in excess alternately can ensure complete reaction and obtain relatively pure difluorobenzonitrile, the following fluorine The chemical reaction is at 160-170 degrees. After the reaction, cool down to 40-50 degrees and then filter.

[0016] (1) First add catalyst, solvent DMF, dichlorobenzonitrile, potassium fluoride and polymerization inhibitor, so that the molar ratio of dichlorobenzonitrile is doubled. At this time, potassium fluoride can react completely, and the remaining input amount of dichlorobenzonitrile Half, produced potassium chloride solid simultaneously, removed by the method for filtering; Filtrate is the mixed solution of dichlorobenzonitrile and difluorobenzonitrile;

[0017] Wherein: the mass ratio of solvent and dichlorobenzonitrile is 2:1, and the mass ratio of catalyst and d...

Embodiment 2

[0022] The invention discloses a method for reducing the amount of catalyst used in the production of difluorobenzonitrile. The method of feeding dichlorobenzonitrile and potassium fluoride alternately doubles the excess, which can not only ensure the complete reaction, but also obtain relatively pure difluorobenzonitrile. The following fluorination reaction is at 160-170 degrees, after the reaction, cool down to 40-50 degrees and then filter;

[0023] (1) First add catalyst, solvent DMF, dichlorobenzonitrile, potassium fluoride and polymerization inhibitor, so that the molar ratio of potassium fluoride is doubled. At this time, dichlorobenzonitrile can react completely, and half of the remaining input amount of potassium fluoride , generated potassium chloride solid simultaneously; Filtrate, and filtrate is collected, prepares to go rectifying;

[0024] (2) Collect the solid again, and then add catalyst, solvent DMF, dichlorobenzonitrile, and polymerization inhibitor. At this...

Embodiment 3

[0030] A method for reducing catalyst consumption in the production of difluorobenzonitrile, the steps are as follows:

[0031] (1) When feeding for the first time, 100g dichlorobenzonitrile, 135g dry potassium fluoride, 200gDMF, 5g catalyst and 0.5g polymerization inhibitor, react at 165 degrees for 4 hours, cool down to 45 degrees, filter, put the filtrate in two Fluorobenzonitrile collection tank, retaining solids;

[0032] (2) Put 200g of dichlorobenzonitrile into the filtrate, the same reaction temperature and reaction time, then cool down to 45 degrees to filter, filter out the filter residue, and keep the filtrate.

[0033] (3) Add dry potassium fluoride, catalyzer and polymerization inhibitor identical with the first charging amount in the filtrate again, same temperature of reaction and reaction time, then cool down and filter, filtrate is put into difluorobenzonitrile collecting tank, retain solid, Repeat this operation.

[0034] It is stipulated to throw dichlorob...

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PUM

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Abstract

The invention relates to a method for reducing using amount of a catalyst in production of difluorobenzonitrile. By adopting a feeding method that dichlorobenzonitrile and potassium fluoride are alternately excessive by one time, the complete reaction can be ensured, and relatively pure difluorobenzonitrile can be also obtained. The molar quantity of potassium fluoride in the previous reaction needs to be excessive by about 50%; and by using the operation steps of the method provided by the invention, from the point of view of charging in a relatively long period, potassium fluoride only needs to be excessive by about 5%, so that the using amount of potassium fluoride is greatly reduced.

Description

technical field [0001] The invention belongs to the field of fine chemical synthesis and relates to a method for reducing the amount of catalyst used in the production of difluorobenzonitrile. Background technique [0002] Difluorobenzonitrile is obtained by the reaction of dichlorobenzonitrile and potassium fluoride. In order to make the reaction complete, one side must be in excess. In order to obtain relatively pure difluorobenzonitrile, potassium fluoride is usually in excess. However, the price of potassium fluoride is very high, and a large excess will inevitably cause too much cost investment. Therefore need to develop a kind of method that can guarantee that reaction is complete, can obtain purer difluorobenzonitrile again, and greatly reduce the input of cost. [0003] According to the search, the following patent documents are found, and the specific disclosure content is as follows: [0004] 1, CN103539699A a kind of 3, the synthetic technique of 4-difluorobenzo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/30C07C255/50
Inventor 刘国平赵娜常娜刘乾威李维魏
Owner 天津河清化学工业有限公司
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