Trimethylamine → 1,4-Bis(3,4-dicyanotrifluorophenoxy)tetrafluorobenzene

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Reaction Steps

More specifically, in Reaction Scheme-7, tetrafluorophthalonitrile and tetrafluorohydroquinone (or its metal salts, e.g., disodium salt) are reacted usually in the presence of a base (for example, trimethylamine, etc.) in a polar solvent at 0° to 5° C. for 30 minutes to obtain 1,4-bis(3,4-dicyanotrifluorophenoxy)tetrafluorobenzene, which is then hydrolyzed, for example, in an aqueous 60% sulfuric acid solution at 150° C. for 15 hours to obtain 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene. Refluxing the product in acetic anhydride for 2 hours results in dehydration to give 1,4-bis(3,4-dicarboxytrifluorophenoxytetrafluorobenzene dianhydride. Also, 1,4-bis(3,4-dicyanotrifluorophenoxy)tetrafluorobenzene may be heated, for example, in an aqueous 80% sulfuric acid solution at 200° C. for 2 hours to effect hydrolysis and dehydration in one step to obtain 1,4-bis(3,4-dicarboxytrifluorophenoxytetrafluorobenzene dianhydride.

Provenance & Evidence