N-(4-Bromophenyl)-2-(naphthalen-1-yl)acetamide

In the title compound, C18H14BrNO, the naphthalene ring system and the benzene ring form dihedral angles of 78.8 (2) and 19.7 (2)°, respectively, with the acetamide C—C(=O)—N plane. The naphthalene ring system forms a dihedral angle of 64.88 (19)° with the benzene ring. In the crystal, molecules are linked via intermolecular bifurcated (N,C)—H⋯O hydrogen bonds, generating an R 2 1(6) ring motif, forming chains along the b axis.

In the title compound, C 18 H 14 BrNO, the naphthalene ring system and the benzene ring form dihedral angles of 78.8 (2) and 19.7 (2) , respectively, with the acetamide C-C( O)-N plane. The naphthalene ring system forms a dihedral angle of 64.88 (19) with the benzene ring. In the crystal, molecules are linked via intermolecular bifurcated (N,C)-HÁ Á ÁO hydrogen bonds, generating an R 2 1 (6) ring motif, forming chains along the b axis.

Experimental
Naphthalen-1-acetic acid (0.186g, 1 mmol) and 4-bromoaniline (0.172g, 1 mmol) were dissolved in dichloromethane (20 ml). The mixture was stirred in presence of triethylamine at 273 K for about 3 h. The contents were poured into 100 ml of ice-cold aqueous hydrochloric acid with stirring, and was extracted thrice with dichloromethane. Organic layer was washed with saturated NaHCO 3 solution and brine solution, dried and concentrated under reduced pressure to give the title compound. Single crystals were grown from toluene and acetone mixture by the slow evaporation method (m.p.: 476-478 K).

Refinement
Atom H1N1 was located from the difference Fourier map and refined using a riding model, with N1-H1N1 = 0.80 Å, and with U iso (H) = 1.2U eq (N). The remaining H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 or 0.97 Å and U iso (H) = 1.2 U eq (C). The same U ij parameters were used for atom pair C4/C5. Fig. 1. The molecular structure of the title compound, showing 20% probability displacement ellipsoids for non-H atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq