Crystal structure of N-benzyl-N-1,3,4-tetramethyl- 2,5-dioxo-4-imidazolidinecarboxamide, C15H19N3O3

C15H19N3O3, monoclinic, P\2\!c\ (no. 14), a = 16.837(8) A, b = 7.368(4) A, c = 13.070(7) Ks=\ 11.005(4)°, V= 1513.7 A, Z = 4, Rgt(F) = 0.050, wRnf(r) = 0.120, T= 295 K. Source of material Reaction of diethyl 2-acetylamino-2-methylmalonate with benzylurea and sodium ethoxide in ethanol at 120 °C over 4 h according to [1] and purification of the crude product by column chromatography yielded N-benzyl-4-methyl-2,5-dioxo-4imidazolidinecarboxamide. Following alkylation with an excess of methyl iodide and sodium hydride in dry dimethylformamide for4h at 78 °C gave A^-benzyl-A/-l,3,4-tetramethyl-2,5-dioxo-4imidazolidinecarboxamide as an oil. Crystals were obtained by dissolution in dimethyl sulfoxide and slow evaporation of the solvent over a period of several months. Experimental details All hydrogen positions were localized by Fourier difference calculations and individually refined with respect to positions and isotropic thermal displacement parameters. Discussion The structure contains one molecule per asymmetric unit and is held together by Van der Waals forces. All intramolecular bond lengths are normal. The shortest intermolecular distances are d(07-• H093-C9) = 2.576(1) A and benzyl group (C14 C20) with r.m.s. = 0.009 A, is tilted by 66.8(1)° against the first mentioned plane. Both planes are connected by C10 and Ν12, which form together with (C4, C9, Ol 1, C13, C14) an almost planar third plane with r.m.s. = 0.07 A, tilted by 85.2(1)° against the first one and by 63.4(1)° against the second one. Table 1. Data collection and handling.