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

A technology of diphthalic anhydride and hexafluoroisopropylidene, which is applied in the field of organic synthesis, can solve the problems of reduced reaction risk, large environmental pollution, and hydrogen fluoride danger, and achieves reduced reaction risk, low environmental pollution, The effect of low reaction temperature

Active Publication Date: 2020-04-07
珠海派锐尔新材料有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems in the prior art of preparing 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, the catalyst hydrogen fluoride is dangerous, and the methyl oxidation step causes great environmental pollution, etc., the purpose of the present invention To provide a method for preparing 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, which uses concentrated sulfuric acid, concentrated hydrochloric acid, etc. as catalysts instead of hydrogen fluoride and normal pressure reaction without high pressure reaction, The danger of the reaction is reduced, the step of methyl oxidation in the traditional method is omitted, the use of metal oxides is avoided, and the environmental pollution is small; and the prepared 4,4'-(hexafluoroisopropylidene) di-ortho The purity of phthalic anhydride is high, and the yield is as high as 70% or more

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A preparation method of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, comprising the following steps:

[0025] a) Accurately weigh 37.8 g of N-propylphthalimide (0.2mol), place 40ml of concentrated sulfuric acid in a 500ml four-neck flask, stir and heat at 100°C to dissolve; slowly add 22.0g of hexafluoroacetone trihydrate dropwise (0.1mol), heated to 110°C and reacted for 24 hours while stirring, then poured into a large amount of water, filtered, neutralized sulfuric acid, washed, and filtered again to obtain 4,4-(hexafluoroisopropylidene)bis(N-propyl o- Phthalimide) powdered solid;

[0026] b) Add 160 g of 10% NaOH aqueous solution to the above solid and reflux at 95°C for 18 hours to hydrolyze to obtain the sodium salt of hexafluorotetraacid, then add dilute hydrochloric acid to the solution, adjust the pH value to neutral, and filter to obtain hexafluorotetrafluoride Four acids;

[0027] c) Reflux and dehydrate with 50ml acetic anhydride for 3h to obtain ...

Embodiment 2

[0029] A preparation method of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, comprising the following steps:

[0030] a) Accurately weigh 32.2 g of N-methylphthalimide (0.2mol), put 60ml of concentrated sulfuric acid in a 500ml four-necked flask, stir and heat at 110°C to dissolve; slowly add 33.0g of hexafluoroacetone trihydrate dropwise (0.15mol), heated to 130°C and stirred for 60h, then poured into a large amount of water, filtered, neutralized sulfuric acid, washed, and then filtered to obtain 4,4-(hexafluoroisopropylidene)bis(N-methyl-phthalate formimide) powdered solid;

[0031] b) Add 100 g of 20% NaOH aqueous solution to the above solid and reflux at 100°C for 10 hours to hydrolyze to obtain the sodium salt of hexafluorotetraacid, then add dilute sulfuric acid to the solution, adjust the pH value to neutral, and filter to obtain hexafluorotetraacid Fluorotetraic acid;

[0032] c) Heating and dehydrating at 280°C for 1 hour to obtain 4,4'-(hexafluoroisopropyl...

Embodiment 3

[0034] A preparation method of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, comprising the following steps:

[0035] a) Accurately weigh 40.6 g of N-butylphthalimide (0.2mol), place 40ml of concentrated sulfuric acid in a 500ml four-neck flask, stir and heat at 100°C to dissolve; slowly add 22.0g of dihydrate hexafluoroacetone (0.1 mol), then add 5 grams of anhydrous ferric chloride, heat to 100°C and react for 80 hours while stirring, then pour into a large amount of water, filter, neutralize sulfuric acid, wash, and then filter to obtain 4,4-(hexafluoroisopropylidene ) bis(N-butylphthalimide) powdered solid;

[0036] b) Add 135 grams of 25% KOH aqueous solution to the above solid and reflux at 95°C for 18 hours to hydrolyze to obtain the sodium salt of hexafluorotetraacid, then add dilute hydrochloric acid to the solution, adjust the pH value to neutral, filter to obtain Fluorotetraic acid;

[0037] c) Dehydration at 250°C for 3 hours to obtain 4,4'-(hexafluoroiso...

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PUM

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Abstract

The invention discloses a preparation method of 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride. The method comprises the following steps of (a) accurately weighing N-alkyl phthalimide and a catalyst, stirring and raising the temperature to 90-110 DEG C, and dissolving; slowly dropwise adding hexafluoroacetone hydrate, raising the temperature to 100 to 130 DEG C, reacting for 22 to 80 hourswhile stirring, and discharging to obtain 4, 4-(hexafluoroisopropyl) bis (N-alkyl phthalimide); (b) adding alkali to hydrolyze, and acidifying to obtain hexafluorotetracid; and (c) dehydrating to obtain the 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride. According to the preparation method, the hexafluoroacetone and specific N-alkyl phthalimide directly react under the action of a specific catalyst to prepare hexafluorodianhydride, the step of oxidizing methyl in a traditional method is omitted, the use of metal oxides is avoided, the environmental pollution is small, a normal-pressure reaction is adopted, a high-pressure reaction is not needed, the reaction risk is reduced, the purity of the prepared 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride is high, and the yield reaches 87% or above.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a preparation method of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Background technique [0002] Fluorine-containing polyimide has excellent comprehensive properties and is widely used in aerospace, microelectronics, electronic appliances, gas separation and other fields. The structural properties of fluoromonomers ultimately affect the performance of fluoropolyimides. The types of fluorine-containing monomers are limited, the preparation conditions are harsh, the process is complicated, and the cost is high, which limits the promotion and application of fluorine-containing polyimides. A 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) is the most widely used dianhydride monomer for the synthesis of fluorine-containing polyimides. With the development of microelectronics, OLED and other fields With the rapid growth of demand for fluorine-co...

Claims

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Application Information

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IPC IPC(8): C07D307/89
CPCC07D307/89
Inventor 饶先花王贤文黄华鹏
Owner 珠海派锐尔新材料有限公司
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