4-(4,5-Dihydro-4-((4-methoxy-3-((2-sulfooxyethyl)sulfonyl)phenyl)azo)-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulfonic acid disodium salt 72121-81-4 Benzenesulfonic acid, 4-(4,5-dihydro-4-((4-methoxy-3-((2-(sulfooxy)ethyl)sulfonyl)phenyl)azo)-3-methyl-5-oxo-1H-pyrazol-1-yl)-, disodium salt Disodium p-(4,5-dihydro-4-((4-methoxy-3-((2-(sulphonatooxy)ethyl)sulphonyl)phenyl)azo)-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonate EINECS 276-353-1