65294-20-4Relevant articles and documents
INVESTIGATION OF THE HF-CATALYZED CONDENSATION REACTION TO DIARYLHEXAFLUOROPROPANES
Appel, W. K.,Siegemund, G.,Stoebbe, M.
, p. 92 (1991)
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Preparation method of 4, 4 '-(hexafluoroisopropylidene) diphthalic anhydride
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Paragraph 0022, (2020/04/17)
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.
Preparation method of 2,2-bis(3,4-dimethylphenyl)hexafluoropropane
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Paragraph 0023; 0024; 0025; 0026; 0027; 0028-0038, (2017/07/21)
The invention discloses a method used for preparing 2,2-bis(3,4-dimethylphenyl)hexafluoropropane. According to the method, 2,2-bis(3,4-dimethylphenyl)hexafluoropropane is obtained via liquid phase reaction of o-xylene with hexafluoroacetone monohydrate under the action of hydrogen fluoride. The raw materials of the method are low in toxicity; reaction pressure is low; operation is convenient; reaction selectivity and yield are high; and the method is suitable for industrialized production. 2,2-bis(3,4-dimethylphenyl)hexafluoropropane prepared via the method can be taken as an intermediate to synthesize fluorine-containing polyimide.