72139-21-0 Benzoic acid, 3,3'-((1,4-dioxo-2-butene-1,4-diyl)bis(imino-4,1-phenyleneazo))bis(6-hydroxy-, disodium salt Disodium 5,5'-((1,4-dioxobut-2-ene-1,4-diyl)bis(imino-p-phenyleneazo))disalicylate EINECS 276-377-2