Synonyms: Pyridinium,1-[2-[3,5-dichloro-4-[[p-[(2-cyanoethyl)methylamino]phenyl]azo]benzenesulfonamido]ethyl]-,chloride (8CI); Pyridinium,1-[2-[[[3,5-dichloro-4-[[4-[(2-cyanoethyl)methylamino]phenyl]azo]phenyl]sulfonyl]amino]ethyl]-,chloride (9CI); [2-[3,5-Dichloro-4-[4-[N-(2-cyanoethyl)-N-methylamino]phenylazo]benzenesulfonamido]ethyl]pyridiniumchloride