The asymmetric unit of the title compound, C(18)H(21)N(3)S, contains five mol-ecules. The equivalent bond distances in the five mol-ecules are in excellent agreement, the r.m.s. fit being within 0.007 Å. The five mol-ecules are linked into a chain consisting of alternating pseudo-enanti-omers by N-H⋯S hydrogen bonds supplemented by weak C-H⋯π inter-actions. The action of a glide plane links the asymmetric unit into an extended chain. A polymorph of the title compound with one mol-ecule in the asymmetric unit was reported by Braun et al. [Cryst. Res. Technol. (1988), 23, 35-39].