disodium 7-[[4-[[4-[[4-(benzoylamino)benzoyl]amino]-o-tolyl]azo]phenyl]azo]naphthalene-1,3-disulphonate

7-[[4-[[4-[[4-(Benzoylamino)benzoyl]amino]-2-methylphenyl]azo]phenyl]azo]-1,3-naphthalenedisulfonic acid disodium salt