Synthesis and structural characterization of 1,4-di(2-methoxyphenyl)-2,5-piperazinedione

A new derivative of 2,5-piperazinedione, 1,4-di(2-methoxyphenyl)-2,5-piperazinedione (1), was synthesized by the cyclocondensation reaction of N-2-methoxyphenyl chloroacetamide, and its structure was characterized by elemental analysis, IR, H-1 NMR and single crystal X-ray diffraction method. The crystal belongs to monoclinic system, space group P2(1)/c with unit cell dimensions a=0.56934(10) nm, b=1.3880(2) mn, c=1.00329(17) nm, beta=90.376(3)degrees, V=0.7928(2) nm(3), Z=2, D-c = 1.367 g center dot cm(-3), mu=0.98 cm(-1), R and wR being 0.0606 and 0.1564 respectively for 1549 unique reflections with 1247 observed reflections [I>2 sigma(I)]. The molecule has a crystallographically imposed symmetry center. The three rings in the molecule are each coplanar with their attached groups, excluding methyl H atoms and the H atoms attached to the piperazinedione ring, while the whole molecule is not planar, with dihedral angles of 74.7(1)degrees between the piperazinedione and each of the two aromatic rings. The crystal structure is stabilized by van der Waals and dipole-dipole forces.