N-(1,4-Dioxo-1,4-dihydronaphthalen-2-yl)benzamide

The title compound, C17H11NO3, was an intermediate synthesized during bisacylation of 2-amino-1,4-naphthoquinone with benzoyl chloride. A mixture of block- and needle-shaped crystals were obtained after column chromatography. The block-shaped crystals were identified as the imide and the needles were the title amide. The naphthoquinone scaffold is roughly planar (r.m.s. deviation = 0.047 Å for the C atoms). The N—H and C=O bonds of the amide group are anti to each other. A dihedral angle between the naphthoquinone ring system and the amide group of 3.56 (3)°, accompanied by a dihedral angle between the amide group and the phenyl group of 9.51 (3)°, makes the naphthoquinone ring essentially coplanar with the phenyl ring [dihedral angle = 7.12 (1)°]. In the crystal, molecules are linked by a weak N—H⋯O hydrogen bond and by two weak C—H⋯O interactions leading to the formation of zigzag chains along [010].


Related literature
For similar crystal structures, see: Brandy et al. (2009Brandy et al. ( , 2012; Akinboye et al. (2009a,b). For the pharmacological properties of related compounds, see: Bakare et al. (2003); Berhe et al.  Table 1 Hydrogen-bond geometry (Å , ). RJB wishes to acknowledge the NSF-MRI program (grant CHE-0619278) for funds to purchase the diffractometer. We also acknowledge MRI grant No. CHE-1126533 from the National Science Foundation for the purchase of a TOF LC/ MS system used in this study and also funded in part by grant No. 5-U54-CA914-31 (Howard University/Johns Hopkins Cancer Center Partnership). This showed that the naphthoquinone scaffold was planar with N-H and C=O bonds anti to each other. A dihedral angle between the naphthoquinone ring and the amide group of -2.6 (3)°, accompanied with the dihedral angle between the amide group and the phenyl group of -8.8 (2)° makes the naphthoquinone ring coplanar to the phenyl group. The bond distances and angles are similar to those found in related structures (Brandy et al., 2009(Brandy et al., , 2012Akinboye et al., 2009aAkinboye et al., , 2009b. The crystal packing pattern results from N-H···O hydrogen bonds along with two weak intermolecular C-

H···O interactions.
Experimental 2-Amino-1,4-naphthoquinone (318 mg, 1.83 mmol) was dissolved in freshly distilled THF (15 ml). NaH (115 mg, 4.78 mmol) was added and the mixture was stirred at room temperature for 15 min. The appropriate benzoyl chloride (0.55 ml, 4.74 mmol) was added, drop wise, and the mixture was stirred for 24 h. THF was evaporated under vacuum and the mixture was washed with ice-water (10 g ice in 10 ml water). The ice-water mixture was extracted with CH 2 Cl 2 (30 ml, 20 ml consecutively) and the combined organic phase washed with water (3 x 20 ml), saturated NaCl solution (20 ml), then dried over anhydrous MgSO 4 . The crude was purified via triturating in ethanol (2 ml) and column chromatography with an eluent mixture of ethyl acetate and hexane to furnish the amide (39 mg, 7.7%). A mixure of block and needle crystals were obtained from column chromatography. The block crystals were identified as the imide (Brandy et al., 2012) and the needles were identified as the amide. The needle crystals were hand-picked from the mixture and analyzed by X-ray diffraction.

Refinement
H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with N-H = 0.88Å and C-H = 0.95Å and U iso (H) = 1.2U eq (C,N).

Figure 1
Diagram of C 17 H 11 NO 3 showing the atom labeling. Displacement ellipsoids are at the 30% probability level.

Figure 2
The molecular packing for C 17 H 11 NO 3 viewed along the a axis.

N-(1,4-Dioxo-1,4-dihydronaphthalen-2-yl)benzamide
Crystal data 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.