5-(3,4-Dimeth­oxy­benzyl­idene)-1,3-dimethyl-1,3-diazinane-2,4,6-trione

In the title compound, C(15)H(16)N(2)O(5), the dihedral angle between 1,3-diazinane and benzene rings is only 4.27 (1)°. The essentially planar mol­ecular structure is characterized by a short intra­molecular C—H⋯O separation and by an exceptionally large bond angle of 138.25 (14)° at the bridging methine C atom. The meth­oxy groups deviate somewhat from the plane of the benzene ring, with C—C—O—C torsion angles of −15.6 (1) and 9.17 (6)°. In the crystal, mol­ecules form centrosymmetric dimers via donor–acceptor π–π inter­actions, with a centroid–centroid distance of 3.401 (1) Å.