title: 1,3-Dicyclo-hexyl-imidazolidine-2,4,5-trione: a second polymorph.
abstract: The title compound, C(15)H(22)N(2)O(3), was obtained as a by-product of oxidative cleavage of 1,3-dicyclo-hexyl-(3-oxo-2,3-dihydro-benzofuran-2-yl)imidazolidine-2,4-dione. Herein, we report the crystal structure of a second polymorph, which was obtained by crystallization from an ethanol solution at 253 K, instead of slow evaporation of the same solvent at room temperature. While the first polymorph [Talhi et al. (2011). Acta Cryst. E67, o3243] crystallized in the non-centrosymmetric space group P2(1)2(1)2(1), this second polymorph crystallizes in the centrosymmetric space group P2(1)/n. Compared to the first polymorph, in the crystal no C=O⋯C=O inter-actions were found (C⋯O inter-molecular distance longer than 3.15 Å) and instead, close packing of individual mol-ecular units is mediated by C-H⋯π and weak C-H⋯O inter-actions.
authors.affiliation: Department of Chemistry, University of Aveiro, QOPNA, 3810-193 Aveiro,  Portugal.
authors.forename: Oualid
authors.initials: O
authors.lastname: Talhi
authors.forename: José A
authors.initials: JA
authors.lastname: Fernandes
authors.forename: Diana C G A
authors.initials: DC
authors.lastname: Pinto
authors.forename: Artur M S
authors.initials: AM
authors.lastname: Silva
authors.forename: Filipe A
authors.initials: FA
authors.lastname: Almeida Paz