8-Methyl-3-methyl-sulfanyl-8a,8b-di-hydro-5-1-oxa-2,4-di-aza-ace-naphthyl-ene.

In the tricyclic title compound, CHNOS, the 2,3,4,5-tetra-hydro-pyridine ring adopts a half-chair conformation. This ring makes dihedral angles of 27.72 (7) and 45.17 (7)°, respectively, with the isoxazole and the cyclo-hexa-1,3-diene rings while the isoxazole ring is oriented at an acute angle of 63.46 (7)° with respect to the cyclo-hexa-1,3-diene ring. In the crystal, mol-ecules associate C-H⋯N hydrogen bonds and C-H⋯π inter-actions, forming a three-dimensional network.