2,6-Dibenzyl-1,2,3,5,6,7-hexahydro-2,4,6,8-tetraaza-s-indacene and 2,6-bis(4-methoxybenzyl)-1,2,3,5,6,7-hexahydro-2,4,6,8-tetraaza-s-indacene.

The title compounds, C22H22N4 and C24H26N4O2 [alternative names: 2,6-dibenzyl-2,3,6,7-tetrahydro-1H,5H-dipyrrolo[3,4-b; 3',4'-e]pyrazine and 2,6-bis(4-methoxybenzyl)-2,3,6,7-tetrahydro-1H,5H-dipyrolo[3,4-b;3',4'-e]pyrazine], two 1,2,3,5,6,7-hexahydro-2,4,6,8-tetraaza-s-indacene derivatives, are both centrosymmetric and have similar S-shaped structures. In the former, there are two independent molecules (A and B), both of which possess Ci symmetry. These two molecules are arranged such that the benzene ring substituent of molecule B is directed towards the plane of the benzene ring substituent of molecule A, with a dihedral angle of 55.4 (2) degrees between their planes. The shortest C-H...C distance is, however, only 3.21 (1) A. In both compounds, the benzene ring substituents are almost perpendicular to the plane of the central pyrazine ring, and the pyrrolidine rings have perfect envelope conformations. In the crystal structures of both compounds, the molecules pack in a herring-bone arrangement.