Ethyl 5-bromo-3-ethoxycarbonylamino-1-benzofuran-2-carboxylate

In the title compound, C14H14BrNO5, the ester group is disordered [occupancy ratio 0.52 (2):0.48 (2)]. The major component is nearly coplanar with the benzofuran plane, subtending a dihedral angle of 7.84 (2)°, while the amide group is twisted out of the benzofuran plane making a dihedral angle of 39.69 (2)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, pairs of weak C—H⋯O hydrogen bonds link the molecules into inversion dimers, which are further linked via strong N—H⋯O hydrogen bonds, generating a zigzag chain extending along [100].

In the title compound, C 14 H 14 BrNO 5 , the ester group is disordered [occupancy ratio 0.52 (2):0.48 (2)]. The major component is nearly coplanar with the benzofuran plane, subtending a dihedral angle of 7.84 (2) , while the amide group is twisted out of the benzofuran plane making a dihedral angle of 39.69 (2) . An intramolecular N-HÁ Á ÁO hydrogen bond occurs. In the crystal, pairs of weak C-HÁ Á ÁO hydrogen bonds link the molecules into inversion dimers, which are further linked via strong N-HÁ Á ÁO hydrogen bonds, generating a zigzag chain extending along [100].
supplementary materials Acta Cryst. (2013). E69, o342 [doi:10.1107/S1600536813002997] properties. Substituted benzofurans also find their application in different field such as fluorescent sensor (Oter et al., 2007), antioxidants, brightening agents, a variety of drugs and agriculture (Habermann et al., 1999). In the title compound the ester group is nearly planar with the benzofuran plane with a dihedral angle of 7.84 (2)° while the amide group is twisted out of the benzofuran plane with a dihedral angle of 39.69 (2)°.
The crystal packing is mainly governed by intra-and inter-molecular interactions. An intra-molecular N1-H1···O4 hydrogen bond (Table 1, Figure 2) acting as conformational lock is found between carbonyl O4 and H1 atom of the amide group. The crystal structure is stabilized by inter-molecular interactions N1-H1···O2 (Table 1, Figure 3) resulting in molecular chains along a axis. The structure is further stabilised by inter-molecular C10-H10B···O4 interaction (Table 1, figure 3) resulting in the formation of centrosymmetric dimers about the inversion centers.

Refinement
All carbon-bound hydrogen atoms were placed in calculated positions with C-H distances of 0.95 -0.99 Å and refined as riding with U iso (H) =xU eq (C), where x = 1.5 for methyl and x = 1.2 for all other H-atoms. The N-bound H atom positions were determined from difference electron density map and refined freely. One of the ethoxy groups (O5, C10, and C11) was disordered. The disorder was resolved and the final occupancy factors of the components were in the ratio 51:49. The thermal parameters of the atoms of the disordered groups were restrained within an effective standard deviation of 0.02 Å 2.    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.

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