9,9'-Spirobi[9H-fluorene]-3,3',6,6'-tetracarboxylic acid, 2,2',7,7'-tetramethoxy-

9,9'-Spirobi[9H-fluorene]-3,3',6,6'-tetracarboxylic acid, 2,2',7,7'-tetramethoxy- · CAS 1801236-35-0