The title heterocyclic compound, C(14)H(15)N(3)O(3), is a new synthetic mol-ecule containing oxazolidine and quinoxaline rings. It is built up from two fused six-membered rings linked to a five-membered oxazolidin-2-one ring by a C(2) chain. Both ring systems are essentially planar [maximum deviation = 0.894 (3) Å, r.m.s. deviation = 0.0043 Å]. The structure is held together by van der Waals forces [electrostatic interactions between dipoles, O⋯C = 3.002 (2) Å] between mol-ecules and by weak π-π stacking between symmetry-related mol-ecules, with an inter-planar distance of 3.579 Å and a centroid-centroid distance of 3.800 (1) Å. Inter-molecular C-H⋯O hydrogen bonds are also observed in the crystal structure.