Synonyms: 1,5-Naphthalenedisulfonic acid, 2-(2-(4,5-dihydro-3-methyl-5-oxo-1-(4-((2-(sulfooxy)ethyl)sulfonyl)phenyl)-1H-pyrazol-4-yl)diazenyl)-;2-((4,5-Dihydro-3-methyl-5-oxo-1-(4-((2-(sulfooxy)ethyl)sulfonyl)phenyl)-1H-pyrazol-4-yl)azo)-1,5-naphthalenedisulfonic acid;1,5-Naphthalenedisulfonic acid, 2-((4,5-dihydro-3-methyl-5-oxo-1-(4-((2-(sulfooxy)ethyl)sulfonyl)phenyl)-1H-pyrazol-4-yl)azo)-;2-((4,5-Dihydro-3-methyl-5-oxo-1-(4-((2-(sulphooxy)ethyl)sulphonyl)phenyl)-1H-pyrazol-4-yl)azo)naphthalene-1,5-disulphonic acid;2-{(E)-[3-methyl-5-oxo-1-(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}naphthalene-1,5-disulfonic acid;2-[[3-methyl-5-oxo-1-[4-(2-sulfooxyethylsulfonyl)phenyl]-4H-pyrazol-4-yl]azo]naphthalene-1,5-disulfonic acid