2-Methyl-3-(10H-pheno­thia­zin-10-yl)buta-1,3-diene-1,1,4,4-tetra­carbo­nitrile

In the title compound, C₂₁H₁₁N₅S, the pheno­thia­zine unit has a butterfly structure, and the central six-membered ring adopts a boat conformation. The dihedral angle between the benzene rings is 127.64 (6)°, which is smaller than those reported for similar compounds because of the steric repulsion between the pheno­thia­zine and its tetra­cyano-1,3-butadiene substituent. The di­cyano­vinyl groups are almost orthogonal to one another, making a dihedral angle of 80.58 (6)°. In the crystal, the mol­ecules are aligned along the b axis. Four kinds of weak C—H...N inter­actions are recognized, one of which connects the mol­ecules into a one-dimensional array and the remaining three link these arrays.