trisodium 7-[[4-[(2,6-dichloro-4-pyrimidinyl)amino]phenyl]azo]naphthalene-1,3,5-trisulphonate

7-[[4-[(2,6-Dichloro-4-pyrimidinyl)amino]phenyl]azo]-1,3,5-naphthalenetrisulfonic acid trisodium salt