tetrasodium 7-[[6-[(5-chloro-2,6-difluoro-4-pyrimidinyl)amino]-1-hydroxy-3-sulphonato-2-naphthyl]azo]naphthalene-1,3,6-trisulphonate

7-[[6-[(5-Chloro-2,6-difluoro-4-pyrimidinyl)amino]-1-hydroxy-3-sodiooxysulfonyl-2-naphthalenyl]azo]-1,3,6-naphthalenetrisulfonic acid trisodium salt