3,3'-(Sulfonylbis(4,1-phenyleneazo(4,5-dihydro-5-imino-3-methyl-1H-pyrazole-4,1-diyl)))bisbenzenesulfonic acid, disodium salt 71033-19-7 Benzenesulfonic acid, 3,3'-(sulfonylbis(4,1-phenyleneazo(5-imino-3-methyl-1H-pyrazole-4,1-diyl)))bis-, disodium salt Disodium 3,3'-(sulphonylbis(p-phenyleneazo(5-imino-3-methyl-1H-pyrazole-4,1-diyl)))bis(benzenesulphonate) EINECS 275-148-4