title: 1-{3-[(4-Oxopiperidin-1-yl)carbon-yl]benzoyl}piperidin-4-one.
abstract: Two independent mol-ecules comprise the asymmetric unit in the title compound, C(18)H(20)N(2)O(4). One of the mol-ecules exhibits disorder in one of its 4-piperidone rings, which is disposed over two orientations [site occupancy of the major component = 0.651 (5)]. The first independent mol-ecule and the minor component of the second disordered mol-ecule are virtually superimposable. The central four C atoms in the major component of the disordered mol-ecule have an opposite orientation. All the 4-piperidone rings have a chair conformation. The carbonyl groups in each mol-ecule have approximate anti conformations [O=C⋯C=O = 146.2 (2) and -159.9 (2)°]. The 4-piperidone rings lie to opposite sides of the central benzene ring in both mol-ecules. In the crystal, mol-ecules are linked by C-H⋯O inter-actions. The crystal studied was found to be a non-merohedral twin (twin law -1 0 0, 0 1 0, 0 - 1/2 - 1), the fractional contribution of the minor component being approximately 11%.
authors: K
authors: K
authors: Rajesh
authors: V
authors: V
authors: Vijayakumar
authors: S
authors: S
authors: Sarveswari
authors: T
authors: T
authors: Narasimhamurthy
authors: Edward R T
authors: ER
authors: Tiekink
references: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references: 18156677
references: Acta Crystallogr D Biol Crystallogr. 2009 Feb;65(Pt 2):148-55
references: 19171970
references: Acta Crystallogr Sect E Struct Rep Online. 2010 May 12;66(Pt 6):o1306-7
references: 21579402
references: Acta Crystallogr Sect E Struct Rep Online. 2009 Dec 16;66(Pt 1):o170
references: 21580057