3,5-Pyrazolidinedione, 4-n-butyl-1,2-di(4'-carboxyphenyl)- Benzoic acid, p-(4-butyl-3,5-dioxopyrazolidine-1,2-diyl)bis- DG4923500 p-(4-Butyl-3,5-dioxopyrazolidine-1,2-diyl)bisbenzoic acid