Synthesis of (<I>E</I>)-1-benzyl-4-benzylidenepyrrolidine-2, 3-dione: Spectroscopic Characterization and X-ray Structure Determination

Abstract

The compound (<I>E</I>)-1-benzyl-4-benzylidenepyrrolidine-2,3-dione was synthetized using Ethyl 1-benzyl-4,5-dioxopyrrolidine-3-carboxylate, and benzaldehyde in Ethanol/HCl medium. The isolated compound was characterized by elemental analyses, ¹H and ¹³C NMR and FTIR spectroscopy. Suitable crystal for X-ray diffraction was obtained from slow evaporation of a solution of the compound in ethyl acetate. The compound crystallizes in the centrosymmetric space group P-1 of the triclinic system with the following unit cell parameters <i>a</i> = 6.4367 (4) Å, <i>b</i> = 7.4998 (5) Å, <i>c</i> = 15.3455 (5) Å, <i></i> = 86.448 (4)°, <i>β</i> = 78.732 (4)°, <i></i> = 83.943 (5)°, <I>V</I> = 721.80 (7) ų, <I>Z</I> = 2, <I>R</I>₁ = 0.049 and <i>wR</i>₂ = 0.135. In the title molecule, C₁₈H₁₅NO₂, the pyrrolidine-2,3-dione ring is almost planar (r.m.s. deviation = 0.0081 Å). The pyrrolidine ring has an envelope conformation with a methylene carbon as the flap. The two phenyl rings are severely twisted with dihedral angle of 72.234 (5)°. The pyrrolidine ring is quite coplanar with the C13-C18 phenyl ring and severely twisted from the C1-C6 phenyl ring with dihedral angles of 0.762 (5)° and 72.750 (5)°. The molecule adopts an <I>E</I> configuration with respect to the ethylenic moiety. Unclassical C—H•••O hydrogen bonding link the molecules, forming layers in the <i>bc</i> plane.