6548-24-9 Benzenesulfonic acid, 4,4'-((phenylmethylene)bis(4,1-phenyleneazo(4,5-dihydro-3-methyl-5-oxo-1H-pyrazole-4,1-diyl)))bis(3-chloro-5-methyl-, disodium salt Disodium 4,4'-((phenylmethylene)bis(4,1-phenyleneazo(4,5-dihydro-3-methyl-5-oxo-1H-pyrazole-4,1-diyl)))bis(3-chloro-5-methylbenzenesulphonate) EINECS 229-467-0