Synonyms: 7-[(2Z)-2-{3-[(E)-(6,8-Disulfonaphthalen-2-yl)diazenyl]-4-hydroxy-6-oxocyclohexa-2,4-dien-1-ylidene}hydrazinyl]naphthalene-1,3-disulfonic acid - 1,2-bis(2-methylphenyl)guanidine (1:4);7,7'-[(4,6-Dihydroxy-1,3-phenylene)bis(2,1-diazenediyl)]bis-1,3-naphthalenedisulfonic acid N,N'-Bis(2-methylphenyl)guanidine;Solvent Brown 20;