10-(Prop-1-yn-1-yl)-10H-phenothia­zine

In the title compound, C₁₅H₁₁NS, the asymmetric unit comprises one half-mol­ecule; a mirror plane passes through the S atom, the ynamine fragment, the methyl C atom and one methyl H atom. The phenothia­zine moiety has a butterfly conformation and the central six-membered ring has a boat conformation. The dihedral angle between the benzene rings is 149.40 (4)°. The crystal structure is stabilized by van der Waals inter­actions.