Synonyms: 2,7-Naphthalenedisulfonic acid, 4-hydroxy-5-(2-(4-(phenylamino)-5-sulfo-1-naphthalenyl)diazenyl)-, compds. with N,N'-di(phenyl, tolyl and xylyl)guanidine (1:3);2,7-Naphthalenedisulfonic acid, 5-((4-anilino-5-sulfo-1-naphthyl)azo)-4-hydroxy-, compd. with 1,3-di(phenyl, tolyl, and xylyl)guanidine (1:3);2,7-Naphthalenedisulfonic acid, 4-hydroxy-5-((4-(phenylamino)-5-sulfo-1-naphthalenyl)azo)-, compds. with N,N'-di(phenyl, tolyl and xylyl)guanidine (1:3);2,7-Naphthalenedisulfonic acid, 4-hydroxy-5-((4-(phenylamino)-5-sulfo-1-naphthalenyl)azo)-, compds. with N,N'-di(phenyl, tolyl and xylyl)guanidine(1:3);4-hydroxy-5-{(E)-[4-(phenylamino)-5-sulfonaphthalen-1-yl]diazenyl}naphthalene-2,7-disulfonic acid - guanidine (1:3)