(2E)-1-(6-Chloro-2-methyl-4-phenylquinolin-3-yl)-3-(4-chlorophenyl)prop-2-en-1-one

Two independent molecules comprise the asymmetric unit of the title chalcone, C25H17Cl2NO, and while each has an E configuration about the ethylene double bond, they differ in the relative orientations of the carbonyl and ethylene double bonds within the prop-2-en-1-one residues, i.e. anti and syn. For each molecule, the benzene [dihedral angles = 71.04 (9) and 73.34 (12)°] and prop-2-en-1-one [C—C—C—O = 91.2 (2) and −119.1 (3)°] substituents are twisted out of the plane of the quinoline moiety to which they are attached. The crystal structure is stabilized by C—H⋯π and π–π [Cg(quinoline)⋯Cg(quinoline) = 3.7809 (12) and 3.8446 (11) Å] interactions.

Two independent molecules comprise the asymmetric unit of the title chalcone, C 25 H 17 Cl 2 NO, and while each has an E configuration about the ethylene double bond, they differ in the relative orientations of the carbonyl and ethylene double bonds within the prop-2-en-1-one residues, i.e. anti and syn. For each molecule, the benzene [dihedral angles = 71.04 (9) and 73.34 (12) ] and prop-2-en-1-one [C-C-C-O = 91.2 (2) and À119.1 (3) ] substituents are twisted out of the plane of the quinoline moiety to which they are attached. The crystal structure is stabilized by C-HÁ Á Á and -[Cg(quinoli-(quinoline)Á Á ÁCg(quinoline) = 3.7809 (12) and 3.8446 (11) Å ] interactions.
VV is grateful to the DST, India, for funding through the Young Scientist Scheme (Fast Track Proposal). The authors are also grateful to the University of Malaya for support of the crystallographic facility.

Comment
Chalcones and its analogs are valuable intermediates in organic synthesis and exhibit a multitude of biological activities.
From a chemical point of view, an important feature of chalcones and their heteroanalogs is the ability to act as activated unsaturated systems in conjugated addition reactions of carbanions in the presence of basic catalysts (Roman, 2004). The title compound, (I), was examined in continuation of our interest in the structural chemistry of chalcones (Prasath et al., 2010;Reddy et al., 2010).

Experimental
A mixture of 3-acetyl-6-chloro-2-methyl-4-phenylquinoline (3.1 g, 0.01 M) and 4-chlorobenzaldehyde (1.4 g, 0.01 M) and a catalytic amount of KOH in distilled ethanol (40 ml) was stirred for about 12 h. The resulting mixture was concentrated to remove ethanol, poured onto ice and neutralized with dilute acetic acid. The resultant solid was filtered, dried and purified by column chromatography using a 1:1 mixture of ethyl acetate and petroleum ether. Recrystallization was from acetone; Yield: 64% and m.pt: 397-399 K.

Refinement
Carbon-bound H-atoms were placed in calculated positions (C-H 0.93 to 0.96 Å) and were included in the refinement in the riding model approximation, with U iso (H) set to 1.2 to 1.5U equiv (C). Fig. 1. The molecular structure of the first independent molecule of (I), i.e. the anti form, showing the atom-labelling scheme and displacement ellipsoids at the 35% probability level. showing the atom-labelling scheme and displacement ellipsoids at the 35% probability level. Fig. 3. A view in projection down the c axis of the unit-cell contents of (I). The C-H···π, π-π, and C-Cl···π interactions are shown as purple, orange and green dashed lines, respectively.  Geometric parameters (Å, °)