Patent number: 5194633
Abstract: A process for preparing 1,1,1,3,3,3-hexafluoro-2,2-di(3,4-dicarboxyphenyl) propane anhydride is disclosed. 1,1,1,3,3,3-hexafluoro-2,2-di(3,4 -dimethylphenyl) propane is oxidized under liquid phase conditions in the presence of an oxygen-containing gas, bromine and heavy metal catalyst components to 1,1,1,3,3,3-hexafluoro-2,2-di(3,4-dicarboxyphenyl) propane in high yield. Addition of an anhydride of a low molecular weight carboxylic acid to the oxidation reaction mixture converts the 1,1,1-hexafluoro-2,2-di(3,4-dicarboxyphenyl)propane to 1,1,1,3,3,3-hexafluoro-2,2-di(3,4-dicarboxyphenyl) propane anhydride.
Type:
Grant
Filed:
November 26, 1991
Date of Patent:
March 16, 1993
Assignee:
Amoco Corporation
Inventors:
Walter Partenheimer, Douglas E. Fjare, Gayle G. Chany