5-Chloro-2-hydroxy-3-[[3-methyl-5-oxo-1-(3-sulfophenyl)-2-pyrazolin-4-yl]azo]benzenesulfonic acid

5-chloro-2-hydroxy-3-[[3-methyl-5-oxo-1-(m-sulphophenyl)-2-pyrazolin-4-yl]azo]benzenesulphonic acid