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Method for preparing 2,2,4-trimethyl-1,2-dihydroquinoline by using ionic liquid

A technology of ionic liquid and dihydroquinoline, which is applied in chemical recovery, organic chemistry, etc., can solve the problems of many by-products, low reaction yield, unfriendly, etc., and achieve simple operation, high yield, and simple reaction process Effect

Active Publication Date: 2021-09-28
HIGH & NEW TECH RES CENT OF HENAN ACAD OF SCI +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems in the prior art that the reaction yield is low, the by-products are more, the catalyst is difficult to recycle and is not friendly to the environment, the purpose of the present invention is to provide a method for preparing 2,2,4-trimethyl-1 , A new method for 2-dihydroquinolines

Method used

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  • Method for preparing 2,2,4-trimethyl-1,2-dihydroquinoline by using ionic liquid
  • Method for preparing 2,2,4-trimethyl-1,2-dihydroquinoline by using ionic liquid

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Effect test

Embodiment 1

[0018] Put 0.1 mole of aniline, 0.15 mole of 4-methyl-2,3-pentanedione and 0.3 mole of [NMPH]HSO into the reaction vessel 4 Ionic liquid, stirred and reacted at 60°C for 10 hours. Ethyl acetate was added for extraction, the organic layers were combined, and the solvent was removed by rotary evaporation to obtain a crude product, which was then separated by column chromatography to obtain 2,2,4-trimethyl-1,2-dihydroquinoline, and the yield of the reaction was 75 %; The ionic liquid was used for the next experiment after simple treatment.

[0019] 1 H NMR (400MHz, CDCl 3 ):δ=1.28(s,6H),1.99(s,3H),5.31(s,1H),6.43-6.45(d,1H),6.61-6.65(t,1H),6.98-7.07(m,2H ). 13 C NMR (100MHz, CDCl 3 ): δ=18.62, 31.05, 51.80, 112.93, 117.13, 121.53, 123.63, 128.36, 128.54, 143.29.

Embodiment 2

[0021] 0.6 moles of aniline, 0.6 moles of 4-methyl-2,3-pentanedione and 0.7 moles of [Me 3 NH]HSO 4 Ionic liquid, stirred and reacted at 80°C for 12 hours. Ethyl acetate was added for extraction, the organic layers were combined, and the solvent was removed by rotary evaporation to obtain a crude product, which was then separated by column chromatography to obtain 2,2,4-trimethyl-1,2-dihydroquinoline, and the yield of the reaction was 79 %; The ionic liquid was used for the next experiment after simple treatment.

Embodiment 3

[0023] 1.2 moles of aniline, 1.5 moles of 4-methyl-2,3-pentanedione and 0.8 moles of [Et 3 NH]HSO 4 Ionic liquid, stirred and reacted at 120°C for 8 hours. Ethyl acetate was added for extraction, the organic layers were combined, and the solvent was removed by rotary evaporation to obtain a crude product, which was then separated by column chromatography to obtain 2,2,4-trimethyl-1,2-dihydroquinoline, and the yield of the reaction was 80 %; The ionic liquid was used for the next experiment after simple treatment.

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Abstract

The invention discloses a method for preparing 2,2,4-trimethyl-1,2-dihydroquinoline by using ionic liquid, belonging to the field of organic chemical synthesis. According to the method, 2,2,4-trimethyl-1,2-dihydroquinoline is prepared by taking aniline and 4-methyl-2,3-pentanedione as raw materials and taking ionic liquid which is good in thermal stability, difficult to volatilize and recyclable as a catalyst and a solvent. The method does not use any toxic and harmful catalyst, is simple and convenient to operate, simple in post-treatment, mild in reaction conditions and high in yield, and is a novel green method for synthesizing the 2,2,4-trimethyl-1,2-dihydroquinoline.

Description

technical field [0001] The invention relates to a method for preparing 2,2,4-trimethyl-1,2-dihydroquinoline by using ionic liquid, belonging to the field of organic chemical synthesis. Background technique [0002] 2,2,4-Trimethyl-1,2-dihydroquinoline is an important class of nitrogen-containing heterocyclic compounds, which are widely used in medicinal chemistry, dyes and other fields; in addition, it can also be widely used as an intermediate Used in the production of tires, rubber shoes, hoses and other rubber products. [0003] Due to the important application of 2,2,4-trimethyl-1,2-dihydroquinoline in chemical engineering and other fields, the research on its synthesis method has always been a focus of attention. The traditional method is to take aniline and acetone (precursor chemicals) as raw materials, and the condensation reaction takes place in toluene solvent to synthesize this type of compound, usually selecting hydrochloric acid, p-toluenesulfonic acid or zinc ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D215/06
CPCC07D215/06Y02P20/584
Inventor 郭辉常莎王作堯田之涯张国宝曹健
Owner HIGH & NEW TECH RES CENT OF HENAN ACAD OF SCI