Preparation method of 4,4'-(Hexafluoroisopropylidene) diphthalic anhydride

A technology of hexafluoroisopropenylene and diphthalic anhydride, applied in 4 fields, can solve the problems such as the lack of effective guarantee of production safety, high reaction temperature, high reaction pressure and the like

Active Publication Date: 2011-09-07
天津众泰材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But there are following defects in this preparation process: use strong corrosive reagent-hydrofluoric acid in the alkylation reaction, high reaction temperature (above 130 ℃), reaction pressure height (above 2Mpa), obtain 4,4 ' The yield of -(hexafluoroisopropenide) di-o-xylene is 67%; 4,4'-(hexafluoroisopropenide) di-o-xylene is oxidized with potassium permanganate under alkaline conditions to obtain The yield of 4,4'-(hexafluoroisopropenylidene)diphthalic acid is 66%; The yield of 6-FDA obtained by the dehydration reaction in the medium is 78%—the high reaction temperature and the reaction pressure make the production safety not effectively guaranteed, which makes it difficult to realize industrial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] 106g (1mol) o-xylene, 330g (1.5mol) 2,2-dichlorohexafluoropropane, AlCl 3 200g and 1300g 1-butyl-3-methylimidazoline tetrafluoroborate, heated to 85°C for 15 hours, cooled to 20°C, poured into 1500L water, extracted twice with 2000L toluene, dried with anhydrous magnesium sulfate, Filter, distill off the toluene, distill under a vacuum of 2 mmHg to obtain a crude product and recrystallize with isopropanol to obtain 150 g of 4,4'-(hexafluoroisopropenylene) di-o-xylene, with a yield of 83%. (Melting point: 78-80°C).

Embodiment 2

[0023] 106g (1mol) o-xylene, 330g (1.5mol) 2,2-dichlorohexafluoropropane, ZnCl 2 204g and 1300g 1-butyl-3-methylimidazoline tetrafluoroborate, heated to 85°C to react for 15 hours, cooled to 20°C, poured into 1500L water, extracted twice with 2000L toluene, dried with anhydrous magnesium sulfate, The toluene was distilled off by filtration, and the crude product was distilled under a vacuum of 2 mmHg to obtain 115 g of 4,4'-(hexafluoroisopropenylene) di-o-xylene by recrystallization from isopropanol, with a yield of 64%. (Melting point: 78-80°C).

Embodiment 3

[0025] 106g (1mol) o-xylene, 330g (1.5mol) 2,2-dichlorohexafluoropropane, AlCl 3 200g and 1300g of 1-butyl-3-methylimidazoline hexafluorophosphate, heated to 85°C for 15 hours, cooled to 20°C, poured into 1500L water, extracted twice with 2000L toluene, dried with anhydrous magnesium sulfate, filtered , The toluene was distilled off, and the crude product was distilled under a vacuum of 2 mmHg to obtain 61 g of 4,4′-(hexafluoroisopropenylene) di-o-xylene by recrystallization with isopropanol, with a yield of 34%. (Melting point: 78-80°C).

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Abstract

The invention discloses a preparation method of 4,4'-(Hexafluoroisopropylidene) diphthalic anhydride (6-FDA), belonging to the technical field of liquid crystal materials. The main technical scheme is achieved as follows: o-xylene and 2,2-dichloro-hexafluoropropane undergo alkylation reaction in an ionic liquid under the catalytic action of Lewis acids (AlCl3, ZnCl2) to obtain 4,4'-(Hexafluoroisopropylidene) di(2-xylene); then the 4,4'-(Hexafluoroisopropylidene) di(2-xylene) is oxidized by permanganic acid TEBA triethylbenzylammonium salts to obtain 4,4'-(Hexafluoroisopropylidene) diphthalandione; and finally, the 4,4'-(Hexafluoroisopropylidene) diphthalandione is dehydrated by acetic oxide to obtain the 4,4'-(Hexafluoroisopropylidene) diphthalicanhydride (6-FDA). The preparation method has the advantages of mild reaction condition, less three-waste emission and high yield.

Description

Technical field [0001] The present invention relates to the preparation of 4,4'-(hexafluoroisopropenylene) di-o-xylene and the preparation of 4,4'-(hexafluoroisopropenylene) which can be used as raw materials for liquid crystals through oxidation and dehydration reactions Diphthalic anhydride method. Background technique [0002] At present, the preparation method of 4,4'-(hexafluoroisopropenylene) diphthalic anhydride (6-FDA) is the alkylation reaction of o-xylene and hexafluoroacetone under the high temperature catalysis of hydrofluoric acid 4,4'-(hexafluoroisopropenylene) di-o-xylene is prepared, and then oxidized by potassium permanganate in sodium hydroxide solution to obtain 4,4'-(hexafluoroisopropenylene) di-o-xylene The phthalic acid is finally dehydrated in a xylene solution at high temperature to obtain the product (Journal of Fluorine Chemistry 2003, Volume 123, pages 221-225). However, this preparation process has the following defects: the alkylation reaction uses ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D307/89
Inventor 尚振华栗晓东楮吉成董传明何红军
Owner 天津众泰材料科技有限公司
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