Synonyms: 1,3-Isobenzofurandione, 4,4'-oxybis-, 4,4'-Oxybis[1,3-isobenzofurandione]; 2,2',3,3'-Diphenyl ether tetracarboxylic dianhydride; 2,2',3,3'-Tetracarboxydiphenyl oxidedianhydride; 3,3'-Oxydiphthalic anhydride; Bis(2,3-dicarboxyphenyl) ether dianhydride