Synonyms: 5'-[(2,5-dichlorophenyl)azo]-1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-1,3'-bipyridinium malate;1,3'-Bipyridinium, 5'-((2,5-dichlorophenyl)azo)-1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-, salt with hydroxybutanedioic acid (1:1);1,3'-Bipyridinium, 5'-(2-(2,5-dichlorophenyl)diazenyl)-1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-, 2-hydroxybutanedioate (1:1);Einecs 269-303-5