Synonyms: potassium 2-[[1-(2-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]naphthalene-1-sulphonate;1-Naphthalenesulfonic acid, 2-[[1-(2-chlorophenyl)-4, 5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]-, potassium salt;1-Naphthalenesulfonic acid, 2-(2-(1-(2-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)diazenyl)-, potassium salt (1:1);2-Pyrazolin-5-one, 1-(2-chlorophenyl)-3-methyl-4-((1-sulfo-2-naphthalenyl)azo)-, potassium salt;Einecs 267-526-2;Potassium 2-((1-(2-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)naphthalene-1-sulphonate