Synthesis, crystal structure and Hirshfeld surface analysis of 1,7-dimethyl-5a,6,11a,12-tetrahydrobenzo[ b ]benzo[5,6][1,4]oxazino[2,3- e ][1,4]oxazine

Molecules of the title compound, C 16 H 16 N 2 O 2 , occupy special positions on the twofold rotation axes. The heterocyclic ring adopts a slightly twisted envelope conformation with one of the two junction carbon atoms as the flap. The mean planes through the two halves of the molecule form a dihedral angle of 72.01 (2)°. In the crystal, molecules are linked by pairs of C—H...O and N—H...C contacts into layers parallel to (100). H...H contacts make the largest contribution to the Hirshfeld surface (58.9%).