3-(4-Methoxyphenyl)-1-(2-pyrrolyl)prop-2-en-1-one

The title molecule, C14H13NO2, is almost flat with a dihedral angle of 8.0 (1)° between the pyrrole and benzene rings. The central C3O ketone unit has an s-cis conformation and is also coplanar with a torsion angle of −0.6 (3) °. An intramolecular C—H⋯O hydrogen bond generates an S(5) ring motif. In addition, the methoxy group is coplanar with the attached benzene ring. In the crystal structure, neighboring molecules are paired through N—H⋯O hydrogen bonds into centrosymmetric dimers with an R 2 2(10) motif.

The title molecule, C 14 H 13 NO 2 , is almost flat with a dihedral angle of 8.0 (1) between the pyrrole and benzene rings. The central C 3 O ketone unit has an s-cis conformation and is also coplanar with a torsion angle of À0.6 (3) . An intramolecular C-HÁ Á ÁO hydrogen bond generates an S(5) ring motif. In addition, the methoxy group is coplanar with the attached benzene ring. In the crystal structure, neighboring molecules are paired through N-HÁ Á ÁO hydrogen bonds into centrosymmetric dimers with an R 2 2 (10) motif.

3-(4-
Chalcone derivatives have recently attracted extensive interest due to possessing a wide variety of pharmaceutical (Lin et al., 2002;Modzelewska et al., 2006;Sogawa et al., 1994) and biological properties (Opletalova, 2000;Opletalova & Sedivy, 1999). Some substituted chalcones also exhibit the potential applications as non-linear optical materials (Agrinskaya et al., 1999;Indira et al., 2002). Considering the importance of these types of compounds, a new chalcone compound was synthesized and its crystal structure is reported here.
The molecular structure of the title molecule ( Fig. 1) is almost planar as indicated by a dihedral angle of 8.0 (1) ° between the pyrrole and benzene rings. The central O1/C5/C6/C7 ketone motif exhibits an s-cis conformation as usual in other related chalcone derivatives (Bukhari et al., 2008;Fun et al., 2008;Gong, et al., 2008;) and also coplanar with a torsion angle of -0.6 (3) °, meanwhile, O1 atom acts as an acceptor and is involved in an intramolecular C-H···O hydrogen bond (Table 1) to generate an S(5) ring motif. In the crystal packing, the compound can be stabilized by intermolecular N-H···O hydrogen bonds with -NH groups as donors to form centrosymmetric dimers with an R 2 2 (10) motif as shown in Fig. 2.

Experimental
The title compound was synthesized by the condensation of 2-acetylpyrrole (1.09 g, 10.0 mmol) and 4-methoxybenzaldehyde (1.06 g, 5.0 mmol) in methanol (30 ml) and ammonia (25%, 25 ml) in the presence of sodium hydroxide (0.56 g, 10 mmol). After refluxed at 358 K for 8 h, the contents of the flask were cooled to give a yellow crude precipitate which was separated by filtration, washed with water and iced ethanol. Recrystallization from ethanol afforded yellow prism-like crystals. Yield: 0.85 g (74.8%).

Refinement
All H-atoms were positioned geometrically and refined using a riding model with d(C-H) = 0.93 Å, U iso =1.2U eq (C) for aromatic and ethylene; 0.96 Å, U iso = 1.5U eq (C) for CH 3 atoms, and d(N-H) = 0.86 Å, U iso =1.2U eq (N) for pyrrole nitrogen atom. Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level and H atoms as spheres of arbitrary radius.