Preparation method of 4-n-propyl p-xylene cyclic dimer

A technology of p-xylene ring dimer and n-propyl group, applied in the field of preparation of 4-n-propyl p-xylene ring dimer, can solve problems such as rearrangement of carbon atoms, achieve short reaction time, high yield, The effect of avoiding isomerization

Inactive Publication Date: 2021-03-19
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] Purpose of the invention: The present invention aims at the problem that the carbon atom rearrangement easily occurs when the long-chain alkyl group is introduced into the p-xylene ring dimer by Friedel-Crafts alkylation in the prior art, and proposes a 4-n-propyl p-xylene ring The preparation method of the dimer, this method adopts Friedel-Crafts alkylation to introduce the long-chain alkyl group into the p-xylene ring dimer and then reduces it, so as to avoid the isomerization phenomenon of the long-chain alkyl group

Method used

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  • Preparation method of 4-n-propyl p-xylene cyclic dimer

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Embodiment 1

[0023] The present invention prepares the method for 4-n-propyl p-xylene ring dimer, specifically: under nitrogen atmosphere, add 50mL dichloromethane and 1.04g (5mmol) p-xylene ring dimer to 250mL four-necked flask, wait When the temperature drops to -15°C, add 50 mL of dichloromethane solution in which anhydrous aluminum trichloride and propionyl chloride have been dissolved (in the solution, 1.07 g (8 mmol) of anhydrous aluminum trichloride and 0.65 g (7mmol) propionyl chloride), start stirring; after continuous stirring for 30min, add 50mL 2mol / L glacial hydrochloric acid solution to the reaction system to quench, and stir for 30min, then leave to stand for layering, extract and separate the organic phase, and water and sodium bicarbonate solution were washed twice, dried, and the solvent was removed by rotary evaporation, and recrystallized with a mixed solvent of ethanol and tetrahydrofuran to obtain 0.95g 4-n-propionyl-[2,2]-p-xylene ring dimer, and the reaction yield wa...

Embodiment 2

[0031]The present invention prepares the method for 4-n-propyl p-xylene ring dimer, specifically: under nitrogen atmosphere, add 50mL dichloromethane and 1.04g (5mmol) p-xylene ring dimer to 250mL four-necked flask, wait When the temperature drops to -10°C, add 50mL of dichloromethane solution in which anhydrous aluminum trichloride and propionyl chloride have been dissolved (in the solution, 1.07g (8mmol) of anhydrous aluminum trichloride and 0.65g (7mmol) propionyl chloride), start stirring; after continuous stirring for 30min, add 50mL 2mol / L glacial hydrochloric acid solution to the reaction system to quench, and stir for 30min, then leave to stand for layering, extract and separate the organic phase, and water Wash twice with sodium bicarbonate solution, dry, remove the solvent by rotary evaporation, and recrystallize with a mixed solvent of ethanol and tetrahydrofuran to obtain 0.89g 4-n-propanoyl-[2,2]-p-xylene ring dimer, and the reaction yield The rate is 67.4%; Weigh...

Embodiment 3

[0039] The present invention prepares the method for 4-n-propyl p-xylene ring dimer, specifically: under nitrogen atmosphere, add 50mL dichloromethane and 1.04g (5mmol) p-xylene ring dimer to 250mL four-necked flask, wait When the temperature drops to 5°C, add 50mL of dichloromethane solution in which anhydrous aluminum trichloride and propionyl chloride have been dissolved (in the solution, 1.07g (8mmol) of anhydrous aluminum trichloride and 0.65g ( 7mmol) propionyl chloride), start stirring; after the continuous stirring reaction for 30min, add 50mL 2mol / L glacial hydrochloric acid solution to the reaction system to quench, and stir for 30min, then leave to stand for layering, extract and separate the organic phase, water and The sodium bicarbonate solution was washed twice, dried, and the solvent was removed by rotary evaporation, and recrystallized with a mixed solvent of ethanol and tetrahydrofuran to obtain 0.71 g of 4-n-propanoyl-[2,2]-p-xylene ring dimer. The reaction y...

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Abstract

The invention discloses a preparation method of 4-n-propyl p-xylene cyclic dimer. The preparation method specifically comprises the following steps: (1) adding p-xylene cyclic dimer and dichloromethane into a reaction device, adding a mixed solution of a catalyst and propionyl chloride dissolved by dichloromethane into the reaction device when the temperature is -25-5 DEG C, and reacting to obtaina crude product, recrystallizing with an organic solvent to obtain a 4-propionyl [2, 2]-p-xylene cyclic dimer; and (2) sequentially adding the 4-propionyl [2, 2]-p-xylene cyclic dimer obtained in thestep (1), potassium hydroxide and hydrazine hydrate into the reaction device, heating and refluxing for 1.5-3 hours, evaporating excessive hydrazine hydrate, heating to 195-215 DEG C, reacting for 2.5-3 hours, and extracting and recrystallizing the reacted crude product to obtain the 4-n-propyl p-xylene cyclic dimer.

Description

technical field [0001] The invention relates to a preparation method of a 4-n-propyl p-xylene ring dimer, belonging to the technical field of organic synthesis. Background technique [0002] Parylene series coating materials obtained by vacuum vapor deposition from p-xylene ring dimer and its derivatives, because Parylene series coating materials have excellent electrochemical properties, biocompatibility, moisture resistance, corrosion resistance, acid and alkali resistance And other characteristics, so it is widely used in military weapons, aerospace, biomedicine, microelectronic machinery and cultural relics document protection and other fields. [0003] The study found that by introducing long-chain alkyl groups to the benzene ring of the p-xylene ring dimer, the melting point of the Parylene film can be significantly reduced, and the flexibility of the film can be improved at the same time. It is very beneficial to certain fields that have high requirements on the flex...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C1/22C07C13/70C07C45/46C07C49/792
CPCC07C45/46C07C1/22C07C2603/92
Inventor 肖国民张曼玲高李璟
Owner SOUTHEAST UNIV
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