21493-04-9 6-Methyl-2-(p-((3-methyl-5-oxo-2-pyrazolin-4-yl)azo)phenyl)-7-benzothiazolesulfonic acid, sodium salt 7-Benzothiazolesulfonic acid, 2-(4-((4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl)azo)phenyl)-6-methyl-, monosodium salt 71598-21-5