1-Naphthalenesulfonic acid, 2-((1-(2,5-dichloro-4-sulfophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)-, sodium salt 2-((1-(2,5-Dichloro-4-sulphophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)naphthalene-1-sulphonic acid, sodium salt 68966-45-0 EINECS 273-435-9