1-Naphthalenesulfonic acid, 2-((1-(2,5-dichloro-4-sulfophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)-, disodium salt 12220-64-3 2-((1-(2,5-Dichloro-4-sulfophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)-1-naphthalenesulfonic acid, disodium salt 2-((1-(2,5-Dichloro-4-sulfophenyl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl)azo)-1-naphthalenesulfonic acid, disodium salt 66556-82-9 70865-22-4 Disodium 2-((1-(2,5-dichloro-4-sulphonatophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)naphthalene-1-sulphonate EINECS 235-409-5