1-Ethyl-4-Phenyl­ethyl-1,4-Di­hydro­Quinoxaline-2,3-Dione

Abstract

The title compound, C<inf>18</inf>H<inf>18</inf>N<inf>2</inf>O<inf>2</inf>, 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)°. The crystal structure is stabilized by intermolecular C-H⋯O hydrogen bonds. © 2004 International Union of Crystallography Printed in Great Britain - all rights reserved.