sodium 2-[[[2,5-dichloro-4-[(2-phenyl-1H-indol-3-yl)azo]phenyl]sulphonyl]amino]ethanesulphonate

2-[2,5-Dichloro-4-(2-phenyl-1H-indol-3-ylazo)phenylsulfonylamino]ethanesulfonic acid sodium salt