A kind of synthesis technique of 3,4-difluorobenzonitrile

A technology of difluorobenzonitrile and synthesis process, applied in 3, can solve the problems of complicated post-treatment, serious dehalogenation side reaction, long reaction time, etc., and achieve the effects of good thermal stability, less discharge of three wastes, and short reaction time

Active Publication Date: 2017-10-27
SHANGHAI HUAYI GRP CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method has a long reaction time of more than 20 hours, serious side reactions such as dehalogenation and coking, and complicated post-processing.

Method used

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  • A kind of synthesis technique of 3,4-difluorobenzonitrile

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Add 150g of 3,4-dichlorobenzonitrile, 450g of 1,3-dimethyl-2-imidazolidinone, 100g of cyclohexane into a 1000ml reactor with stirrer, reflux separator and thermometer, and heat up to 90°C. Reflux water diversion 1 hour, after treating that there is no water in the water separator, drop into 75g spray-dried potassium fluoride, two-(N-bis(dimethylamino)methylene)-imine chloride 10g, be warming up to 140°C, reflux and water separation for 3 hours to obtain the intermediate 3-chloro-4fluorobenzonitrile, continue to heat up to 180°C, and the reaction is over for 5h.

[0030] Dilute the obtained reaction solution with toluene and filter under reduced pressure to remove salt, wash the filter cake 3 times with toluene, transfer the filtrate to a rectification kettle for rectification under reduced pressure, control the vacuum degree to 0.08-0.09MPa, and collect The 105°C fraction was 79g, the GC purity was 99%, and the yield was 65%.

Embodiment 2

[0032] Add 150g of 3,4-dichlorobenzonitrile, 450g of 1,3-dimethyl-2-imidazolidinone, 100g of toluene into a 1000ml reaction kettle equipped with a stirrer, reflux separator, and thermometer, heat up to 120°C, and reflux Water for 2 hours, after no water comes out in the water separator, put in 150g of spray-dried potassium fluoride, 15g of bis-(N-bis(dimethylamino)methylene)-imide chloride, and heat up to 130°C , reflux and water separation reaction for 2 hours to obtain the intermediate 3-chloro-4fluorobenzonitrile, continue to heat up to 200 ° C, and the reaction is completed for 6 hours.

[0033] Dilute the obtained reaction liquid with toluene, then filter under reduced pressure, remove salt, wash the filter cake with toluene 3 times, transfer the filtrate to a rectification kettle for rectification under reduced pressure, control the vacuum degree to 0.08-0.09MPa, and collect at the top of the tower 84g fraction at 90-105°C, GC purity 99%, yield 70%.

Embodiment 3

[0035] Add 150g of 3,4-dichlorobenzonitrile, 300g of 1,3-dimethyl-2-imidazolidinone, 100g of toluene into a 1000ml reactor with stirrer, reflux separator, and thermometer, heat up to 120°C, reflux Water for 1.5 hours, after no water has come out in the water separator, put in 150g of spray-dried potassium fluoride, 15g of bis-(N-bis(dimethylamino)methylene)-imide chloride, and heat up to 150°C , refluxed and separated water for 2.5 hours to obtain the intermediate 3-chloro-4fluorobenzonitrile, and continued to heat up to 180°C, and the reaction was completed for 5 hours.

[0036] Dilute the obtained reaction liquid with toluene, then filter under reduced pressure, remove salt, wash the filter cake with toluene 3 times, transfer the filtrate to a rectification kettle for rectification under reduced pressure, control the vacuum degree to 0.08-0.09MPa, and collect at the top of the tower The fraction at 90-105°C was 87.3g, the GC purity was 99%, and the yield was 72%.

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Abstract

The present invention disclosed a synthetic process of 3,4‑ ylfluorophenpine, with 3,4‑ ‑ 腈 腈 as the raw material, potassium fluoride is a fluoride reagent, and 1,3‑ 甲 咪 咪 2‑ pyramoleAntinone is a response solvent. Double ‑ (N -two (diharamine) sore) chloride salt is catalyst. The reactor reacts from 130 to 150 ° C for 2 to 3h, and the reaction of 180 ° C ° C is 5 ~ 5 ~At the end of 6h, the reactive decompression and refined distillation of 3,4‑ ‑ylfluorophenillene, which was purified after filtering the reaction solution, reached 85%.Terminal liquid (including catalyst) is directly used for the next batch of reactions.The material raw materials of the present invention are easy to obtain, the response conditions are mild, the response time is short, the operation is simple, the yield is high, the reaction solvent (including catalyst) can be applied multiple times, the cost is low, the three waste discharge is small, and it is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of synthesis of 3,4-difluorobenzonitrile, a key intermediate of the rice herbicide cyhalofop-ethyl, in particular to a synthesis process of 3,4-difluorobenzonitrile. Background technique [0002] 3,4-Difluorobenzonitrile can be used as an intermediate for the synthesis of various medicines, dyes, and liquid crystal materials, and is also an important intermediate for the selective herbicide cyhalofop-ethyl. Cyhalofop-ethyl is a selective herbicide for rice, which is quite safe for transplanted and direct-seeded rice, and is internationally recognized as an excellent rice herbicide. With the rapid development of cyhalofop-ethyl, the market demand for 3,4-difluorobenzonitrile is great. [0003] There are many synthetic routes of 3,4-difluorobenzonitrile reported in the literature, and the most economical route is the direct fluorination synthesis of 3,4-dichlorobenzonitrile. Generally, potassium fluoride is ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C253/30C07C255/50
Inventor 杨伟领兰红丽宋芬施险峰赖春波廖本仁揭元萍
Owner SHANGHAI HUAYI GRP CO
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