140707-45-5

1,4-Benzenedisulfonic acid,2-[4-[5-[1-(2,5-disulfophenyl)-1,5-dihydro-5-oxo-4H-pyrazol-4-ylidene]-1,3-pentadienyl]-5-hydroxy-1H-pyrazol-1-yl]-, tetrapotassium salt