Ethyl 2-(2-hydroxy-5-nitrophenyl)acetate

In the crystal structure of the title compound, C10H11NO5, intermolecular O—H⋯O hydrogen bonds link the molecules into chains along the b-axis direction. Weak C—H.·O hydrogen bonds also occur.

In the crystal structure of the title compound, C 10 H 11 NO 5 , intermolecular O-HÁ Á ÁO hydrogen bonds link the molecules into chains along the b-axis direction. Weak C-H.ÁO hydrogen bonds also occur.

Related literature
For the use of the title compound as a pharmaceutical intermediate and for the preparation, see: Omar et al. (2003). For bond-length data, see: Allen et al. (1987).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BQ2266).
In the molecule of the title compound ( Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges.
In the crystal structure, intermolecular O-H···O hydrogen bonds (Table 1.) link the molecules forming a stable structure and the other weak C-H···O hydrogen bonds reinforced the packing (Fig. 2).

Experimental
The title compound I was prepared by the literature method (Omar et al., 2003). To a 100 mL flask provided with Dean-Stark tramp and magnetic stirrer was added (2-hydroxy-phenyl)-acetic acid (4.4 g, 29 mmol) in 60 mL of toluene and catalytic amounts of p-TsOH. The mixture was refluxed for 4 h with removal of water and then the residual solvent was removed at reduced pressure to give 3H-benzofuran-2-one in quantitative yield (3.9 g), mp 325K. Then, a mixture of concentrated nitric acid (4 ml) and glacial acetic acid (4 ml) was added drop wise to a solution of 3H-benzofuran-2-one (3.9 g) in acetic anhydride (25 ml) while the temperature was maintained below 293 K. The mixture was stirred and refluxed for 1 hour in ethanol (30 ml). The precipitate (the desired anthranilic acid esters ethyl 2-(2-hydroxy-5-nitrophenyl) acetate) was filtered off and washed with water, yield 80%. Crystals suitable for x-ray analysis were obtained by slow evaporation of an methanol solution.

Refinement
H atoms were positioned geometrically, with O-H =1.92 Å (for OH) and C-H =0.93, 0.98 and 0.96 Å for aromatic, methine and methyl, respectively, and constrained to ride on their parent atoms, with U iso (H) = xU eq (C,N), where x = 1.5 for methyl H and x = 1.2 for all other H atoms. Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

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.