The mol-ecule of the title compound, C16H17N5O3, is build up from two fused six-membered rings linked to a 1,2,3-triazole ring, which is attached to an ethyl azido-acetate group. The di-hydro-qinoxalinone portion is planar to within 0.0512 (12) Å and is oriented at a dihedral angle of 87.83 (5)° with respect to the pendant triazole ring. In the crystal, a combination of inter-molecular C-H⋯O and C-H⋯N hydrogen bonds together with slipped π-stacking [centroid-centroid distance = 3.7772 (12) Å] and C-H⋯π (ring) inter-actions lead to the formation of chains extending along the c-axis direction. Additional C-H⋯O hydrogen bonds link these chains into layers parallel to the bc plane and the layers are tied together by complementary π-stacking [centroid-centroid distance = 3.5444 (12) Å] inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (44.5%), H⋯O/O⋯H (18.8%), H⋯N/N⋯H (17.0%) and H⋯C/C⋯H (10.4%) inter-actions.
Keywords: Hirshfeld surface; crystal structure; dihydroquinoxaline; hydrogen bond; π-stacking.