4-({4-[Bis(2-cyanoethyl)amino]phenyl}diazenyl)benzenesulfonamide

In the title compound, C18H16N6O2S, which belongs to the family of azo dyes, the dihedral angle between the benzene rings is 26.16 (7)°. In the crystal, molecules are joined by N—H⋯N and C—H⋯N hydrogen bonds into double chains parallel to the a axis.