1-Naphthalenesulfonic acid, 7-(4,5-dihydro-3-methyl-5-oxo-4-(phenylazo)-1H-pyrazol-1-yl)-3-hydroxy- 68227-67-8 7-(4,5-Dihydro-3-methyl-5-oxo-4-(phenylazo)-1H-pyrazol-1-yl)-3-hydroxy-1-naphthalenesulfonic acid 7-(4,5-Dihydro-3-methyl-5-oxo-4-(phenylazo)-1H-pyrazol-1-yl)-3-hydroxynaphthalene-1-sulphonic acid EINECS 269-378-4