Crystal structure of 4-bromo-N-(2-bromo-3-nitrobenzyl)-2-nitronaphthalen-1-amine

In the title compound, C17H11Br2N3O4, the dihedral angle between the planes of the naphthalene system and the benzene ring is 52.86 (8)°. The nitro substituent and the attached naphthalene system are almost coplanar [dihedral angle = 5.6 (4)°], probably as a consequence of an intramolecular N—H⋯O hydrogen bond with the amine group. The nitro substituent attached to the benzene ring is disordered over two sets of sites with occupancies of 0.694 (3) and 0.306 (3). The major component deviates significantly from the ring plane [dihedral angle = 53.6 (2)°]. In the crystal, the molecules are linked into a three-dimensional array by extensive π–π interactions involving both the naphthalene and benzene rings [range of centroid–centroid distances = 3.5295 (16)–3.9629 (18) Å] and C—H⋯O interactions involving the methylene H atoms and the phenyl-attached nitro group.


2000)
. Introduction of a second ortho-coordinating group towards selenium leads to interesting reactivity of the selenium derivatives and isolation of unusual species (Singh et al., 2010). Recently, we reported the isolation of novel photoluminescent selenospirocyclic compounds via intermolecular C-C bond formation (Singh et al., 2011). In continuation of this research, we attempted the synthesis of naphthylamine based spirocyclic compounds. However, the reaction led to the isolation of 4-bromo-N-(2-bromo-3-nitrobenzyl)-2-nitronaphthalen-1-amine (2) instead of the desired spiro-compound (3) (Fig. 1).
In the structure of the title compound, Fig. 2, the naphthyl nitro substituent is almost coplanar with the naphthyl ring (dihedral angle = 5.6 (4)°) probably as a consequence of an intramolecular hydrogen bond with the N-H moiety.

S2. Experimental
Referring to Fig. 1, to a stirred solution of selenide 1 (0.400 g 1 mmol in 3 mL CHCl 3 ) at 0° C, was added bromine (0.05 ml in 1 mL CHCl 3 ). After 30 mins a yellow precipitate was formed. Stirring was continued for further 30 mins, Et 3 N (0.140 ml) added and the stirring continued for an additional 6 h. After completion of the reaction, the reaction mixture was poured into water and extracted with CHCl 3 (2 × 30 mL

S2.1. Refinement
C-bound H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C-H distances of 0.95-0.99 Å, and with U iso (H) = 1.2-1.5U eq (C). The N-bound H atom was refined freely. One of the nitro groups was disordered over two conformations with occupancies of 0.694 (3)

Figure 1
The reaction scheme.

Figure 2
The molecular structure of C 17 H 11 Br 2 N 3 O 4 showing the numbering scheme and 30% probability displacement ellipsoids and the intramolecular N-H···O hydrogen bond (shown as a dashed bond).  The molecular packing for C 17 H 11 Br 2 N 3 O 4 viewed along the c axis showing the linking of the molecules into a threedimensional array by π-π interactions as well as a network of C-H···O interactions (shown as dashed bonds).

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