Process for the preparation of tetrafluorophthalic acid and/or tetrafluorophthalic anhydride

U.S. Patent Number: 5384413

Abstract: The present invention relates to a process for the preparation of tetrafluorophthalic acid and/or tetrafluorophthalic anhydride by reacting a compound of the formula ##STR1## in which X is a radical ##STR2## which is optionally mono- or polysubstituted on the aromatic nucleus by fluorine and/or chlorine and/or alkyl groups having 1 to 4 carbon atoms, or is a radical ##STR3## in which R.sub.1, R.sub.2 and R.sub.3 are as defined, with water, and subsequently removing the water still present by azeotropic distillation or extracting the tetrafluorophthalic acid and/or its anhydride with a water-insoluble solvent or solvent mixture.

Inventors: Pfirmann; Ralf (Griesheim, DE), Papenfuhs; Theodor (Frankfurt, DE)

Assignee: Hoechst Aktiengesellschaft (Frankfurt am Main, DE)

Application Number: 08/090,794

Issued: 1995-01-24

Expired: 2007-01-24

Classes: 549/246 ; 203/15; 203/67; 203/68; 203/69; 203/70; 549/247; 549/248; 562/483; 562/494

Field of search: 549/246,247,248 562/483,494 203/15

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