Two (E)-2-aryl-idene-1,4-di-p-tosyl-1,2,3,4-tetra-hydro-quinoxaline compounds: Supra-molecular frameworks built with C - H⋯O and C - H⋯π(arene) hydrogen bonds and π-π Stacking inter-actions

The pyrazine ring in two N-substituted quinoxaline derivatives, namely (E)-2-(2-methoxy-benzyl-idene)-1,4-di-p-tosyl-1,2,3,4-tetra-hydro-quin-oxaline, C30H28N2S2O5, (II), and (E)-methyl 2-[(1,4-di-p-tosyl-1,2,3,4-tetra-hydro- quinoxalin-2-yli-dene)methyl]benzoate, C31H28N2S2O6, (III), assumes a half-chair conformation and is shielded by the terminal tosyl groups. In the mol-ecular packing of the compounds, inter-molecular C - H⋯O hydrogen bonds between centrosymmetrically related mol-ecules generate dimeric rings, viz. R 2 2(22) in (II) and R 2 2(26) in (III), which are further connected through C - H⋯π(arene) hydrogen bonds and π-π stacking inter-actions into novel supra-molecular frameworks. © International Union of Crystallography 2007.