ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, vol.60, 2004 (SCI-Expanded)
The title compound, C18H18N2O2, was synthesized by heating 2,4-dioxo-1,3-diphenyl-7,8-benzo-6-ethyl-9-(2-phenylethyl)-1,3,6,9- tetrazaspiro[4.4] nonane in toluene. The quinoxaline ring system is planar and the dihedral angle between the phenyl and piperazine rings is 28.6 (1) degrees. The crystal structure is stabilized by intermolecular C - H...O hydrogen bonds.