Method for preparing 2,6-difluorobenzonitrile by using 2,6-dichlorobenzonitrile fluoro

A technology of dichlorobenzonitrile and difluorobenzonitrile, applied in 2, can solve the problems of cumbersome reaction operation, long reaction cycle, and large amount of solvent used, and achieve good technical effect, easy operation, and less solvent amount

Inactive Publication Date: 2003-09-24
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to overcome the problems in the previous literature that only high-content 2,6-DCBN can be used as raw materials, the amount of solvent used in the

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0013] Specific implementing manner [Example 1]

[0017] Add 27.3 grams of crude dichlorobenzonitrile (mass fraction of 75.1%) and 50.0 grams of toluene into a 250 ml three-necked flask equipped with a stirrer, condenser and thermometer. Heat to reflux until there are no obvious water droplets. Toluene was removed by pressure distillation (the amount of water was measured to be 4.4 g), and then 2,6-dichlorotoluene was distilled off at 130°C / 13kPa (this is the starting material for preparing 2,6-dichlorobenzonitrile). Cool, add 70.0 ml of sulfolane, 17.4 g (0.30 mol) of anhydrous potassium fluoride and C m H 2m+1 O(C n H 2n+1 O) x C m H 2m+1 (n=2, m=1, average molecular weight M: 600) 0.5 g, the temperature is raised to 250° C. with rapid stirring, and the reaction is maintained at this temperature for 3.5 hours. After the reaction is completed, vacuum distillation is performed to collect 12.7 g of 92-98°C / 2.5kPa product, with a 2,6-DFBN yield of 91.5% and...

Example Embodiment

[0013] Specific implementing manner [Example 1]

[0018] Add 21.3 grams of crude dichlorobenzonitrile (96.0% by mass) and 50.0 grams of toluene into a 250 ml three-necked flask with a stirrer, condenser, and thermometer. Heat to reflux until there are no obvious droplets. Toluene was removed by pressure distillation (the amount of water was measured to be 3.4 g), and then 2,6-dichlorotoluene was distilled off at 130°C / 13kPa (this is the starting material for preparing 2,6-dichlorobenzonitrile). Cool, add 85.7 ml of sulfolane, 29.0 g (0.50 mol) of anhydrous potassium fluoride and C m H 2m+1 O(C n H 2n+1 O) x C m H 2m+1 (n=3, m=2, average molecular weight M: 1200) 1.2 grams, the temperature was raised to 230° C. with rapid stirring, and the reaction was maintained at this temperature for 5.0 hours. After the reaction, vacuum distillation was performed to collect 12.2 g of the product at 92-98°C / 2.5kPa, the yield of 2,6-DFBN was 87.7%, and the mass fraction ...

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Abstract

The present invention adopts 2,6-dichlorobenzonitrile crude product as raw material, uses sulfolane as solvent and uses low-grade polyaliphatic alcohol ether compound as catalyst, under the conditions of that its reaction temp. is 170-250 deg.C and reaction pressure is normal pressure make the above-mentioned materials produce reaction for 2-5 hr, so as to obtain the invented product 2,6-difluorobenzonitrile.

Description

technical field [0001] The invention relates to a method for preparing 2,6-difluorobenzonitrile by fluorinating 2,6-dichlorobenzonitrile. Background technique [0002] 2,6-Difluorobenzonitrile (2,6-Difluorobenzonitrile, 2,6-DFBN for short) is an important intermediate for the synthesis of benzoylurea insecticides. Benzoylurea compounds have a unique insecticidal mechanism, are highly selective, use less, and are environmentally friendly. They are known as green pesticides in the 21st century and are valued by pesticide synthesis and plant workers. The development of this The production technology of quasi-intermediates is becoming more and more important. [0003] The method of the synthetic fluorobenzonitrile of domestic and foreign reports mainly contains following several: (1) take 2,6-dichlorobenzonitrile (2,6-DCBN) as raw material fluorination synthetic 2,6-DFBN; ( 2) Using 2,3,6-trichlorobenzonitrile as a raw material to synthesize DFBN...

Claims

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Application Information

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IPC IPC(8): C07C253/14C07C253/30C07C255/50
Inventor 陈金华沈之芹金文清胡永君杨霞琴
Owner CHINA PETROLEUM & CHEM CORP
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