(4-(4,5-Dihydro-4-((2-hydroxy-5-nitrophenyl)azo)-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonato(3-))iron 72479-34-6 EINECS 276-681-5 Iron, (4-(4,5-dihydro-4-((2-(hydroxy-kappaO)-5-nitrophenyl)azo-kappaN1)-3-methyl-5-(oxo-kappaO)-1H-pyrazol-1-yl)benzenesulfonato(3-))-