(2E)-3-(4-Methylphenyl)-1-(pyridin-3-yl)prop-2-en-1-one

The title compound, C15H13NO, has two crystallographically independent molecules in the asymmetric unit which differ principally in the periplanar angle formed by the benzene and pyridine rings [41.41 (3) and 17.92 (5)°]. The molecules exhibit an E conformation between the keto group with respect to the olefin double bond.

The title compound, C 15 H 13 NO, has two crystallographically independent molecules in the asymmetric unit which differ principally in the periplanar angle formed by the benzene and pyridine rings [41.41 (3) and 17.92 (5) ]. The molecules exhibit an E conformation between the keto group with respect to the olefin double bond.
Natural chalcones appear mainly as petal pigments and in the heartwood, leaf, fruit and root of different kinds of flora.
A large number of chalcones and their corresponding heterocyclic analogues are a medicinally important class of compounds. It has been shown that chalcones exhibit biological activity against many diseases vectors. Currently, activities of natural and synthetic chalcones include: anticancer (Juvale et al. 2012), antioxidant (Sivakumar et al. 2011), analgesic (Viana et al. 2003), antileishmanial and antimalarial (Liu et al. 2003), antimicrobial (Bandgar et al. 2010) and antiviral (Trivedi et al. 2007) properties.
The pharmacological properties of chalcones are intrinsically linked to the substitution pattern of the two aromatic rings. Their versatility is attributed to the α,β-unsaturated ketene moiety, the conjugated double bonds and the completely delocalized π-electron system on both aromatic rings (Katsori & Hadjipavlou-Litina, 2011).

Experimental
(2E)-3-(4-Methylphenyl)-1-(pyridin-3-yl)prop-2-en-1-one was obtained using heterogeneous base catalysis. 3-acetyl pyridine 0.270 ml (2.47 mmol) was solubilized in 2 ml of methanol, to which was added 10 ml of 50% potassium hydroxide solution and 0.300 ml (2.47 mmol) of 3-methylbenzaldehyde, successively. The mixture was stirred at ambient conditions and the reaction progress monitored by TLC (Thin Layer Chromatography). Upon reaction completion the mixture was neutralized with a 10% HCl solution. The solid product was washed with water and filtered and subsequently recrystallized from ethanol. The reaction yield was 0.47 g (86%). Suitable crystals of (I) were grown by slow evaporation from a methanol solution..

Refinement
The hydrogen atoms were initially located from a difference Fourier map and subsequently refined in geometrically calculated positions with methyl C-H distances constrained to 0.98 Å and ethylene and aromatic C-H distances constrained to 0.95 Å. Methyl H atoms were allowed to rotate to minimize the electron density contribution. Thermal parameters of hydrogen atoms were tied to that of the atom to which they are bonded (1.5 × Ueq for methyl, 1.2 × Ueq for all others). All non-hydrogen atoms were refined with anisotropic displacement parameters.

Figure 1
The asymmetric unit of (I  An overlay diagram of the two independent molecules in the asymmetric unit of (I). Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.