804 https://doi.org/10.1107/S2056989017006272 Acta Cryst. (2017). E73, 804–808 research communications Received 28 February 2017 Accepted 25 April 2017 Edited by A. J. Lough, University of Toronto, Canada Keywords: crystal structure; quinoline; carbox- amide; acetophenone.. CCDC references: 1546038; 1546037; 1546036 Supporting information: this article has supporting information at journals.iucr.org/e Crystal structures of three N-(3-acetylphenyl)- quinoline-2-carboxamides Diana Pen ˜a-Solo ´ rzano, a Burkhard Ko ¨nig, b Cesar A. Sierra a and Cristian Ochoa- Puentes a * a Grupo de Investigacio ´ n en Macromole ´culas, Departamento de Quı ´mica, Universidad, Nacional de Colombia-Sede Bogota ´, Carrera 45 # 26-85, A.A. 5997, Bogota ´, Colombia, and b Institute of Organic Chemistry, University of Regensburg, 93040-Regensburg, Germany. *Correspondence e-mail: cochoapu@unal.edu.co In the title compounds, N-(5-acetyl-2-methylphenyl)quinoline-2-carboxamide [C 19 H 16 N 2 O 2 , (I)], N-(5-acetyl-2-bromophenyl)quinoline-2-carboxamide [C 18 H 13 BrN 2 O 2 , (II)] and N-(5-acetyl-2-ethynylphenyl)quinoline-2-carboxa- mide [C 20 H 14 N 2 O 2 , (III)], the quinoline ring system is essentially planar and forms a dihedral angles of 3.68 (5) (I), 5.59 (7) (II) and 1.87 (6) (III) with the acetyl-substituted ring. The molecular structures of (I) and (III) each feature an intramolecular N—HN hydrogen bond, forming an S(5) ring, while in (II) an intramolecular bifurcated N—H(N,Br) hydrogen bond forms two S(5) rings. In the crystals, weak C—HO hydrogen bonds link molecules of (I) into C(7) chains long [010], molecules of (II) into chains of R 2 2 (8) rings along [110] and molecules of (III) into C(8) chains along [010]. In (I), there are no significant – stacking interactions under 4 A ˚ , but in both (II) and (III), – interactions link the weak hydrogen-bonded chains into layers parallel to (001) [centroid– centroid disttances of 3.748 (1) A ˚ in (II) and 3.577 (1), 3.784 (1) and 3.780 (1) A ˚ in (III)]. 1. Chemical context Aminoacetophenones, quinolines and carboxamides have been reported to possess many interesting pharmacological activities and they are characteristic components of a large number of biologically active compounds. The wide spectrum of biological effects of these kind of compounds includes antimicrobial (Nawar & Hosny, 2000), anticonvulsant (Pandeya et al., 1998), cytotoxic (Zhao et al. , 2005), anti- malarial (Egan et al., 1994), antiproliferative (Chen et al., 2006), antituberculosis/antimycobacterial (Gonec et al., 2012) activities, radioligands (Matarrese et al. , 2001, Belloli et al., 2004), calpain inhibitors (Nam et al., 2008), TPSO ligand (Blair et al., 2013) and pharmaceutical medicaments (Weidmann et al., 2008), among others. 2. Structural commentary The molecular structure of title compounds (I), (II) and (III) are shown in Figs. 1, 2 and 3, respectively. The quinoline ring system [C1–C9/N1 in (I), C2–C10/N1 in (II) and C12–C20/N2 in (III)] in each compound is essentially planar with maximum deviations of 0.015 (1) A ˚ for C3 in (I), 0.017 (2) A ˚ for C3 in (II) and 0.013 (2) A ˚ for C17 in (III). The quinoline ring system forms dihedral angles of 3.68 (5) (I), 5.59 (7) (II) and 1.87 (6) (III) with the acetyl-substituted ring [C11–C16 in (I) ISSN 2056-9890