4-Formyl-2-nitrophenyl 2-chlorobenzoate

In the title compound, C14H8ClNO5, the benzene rings form a dihedral angle of 19.55 (9)°. The mean plane of the central ester group [r.m.s. deviation = 0.024 Å] forms dihedral angles of 53.28 (13) and 36.93 (16)°, respectively, with the nitro- and chloro-substituted rings. The nitro group forms a dihedral angle of 19.24 (19)° with the benzene ring to which it is attached. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds, forming C(7) chains, which run along [100].

In the title compound, C 14 H 8 ClNO 5 , the benzene rings form a dihedral angle of 19.55 (9) . The mean plane of the central ester group [r.m.s. deviation = 0.024 Å ] forms dihedral angles of 53.28 (13) and 36.93 (16) , respectively, with the nitro-and chloro-substituted rings. The nitro group forms a dihedral angle of 19.24 (19) with the benzene ring to which it is attached. In the crystal, molecules are linked by weak C-HÁ Á ÁO hydrogen bonds, forming C(7) chains, which run along [100].

Comment
The title compound (I) is part of a series of studies on the structural properties of formyl nitro aryl benzoates, and extends from earlier work from our research group with the synthesis of 4-formyl-2-nitrophenyl 4-bromo benzoate (FBrB) (Moreno-Fuquen et al., 2013a). The nitroaromatic compounds and their derivatives constitute a main class of industrial chemicals and are widely used as intermediates in the synthesis of many varied products, ranging from drugs, pigments, pesticides and plant growth regulators to the explosives (Ju & Parales, 2010). The molecular structure of (I) is shown in forming C(7) chains (Etter, 1990) along [100] (see Fig. 2). The C14 atom of the aldehyde group at (x,y,z) acts as hydrogen-bond donor to O4 atom at (x-1/2,-y+1/2,+z) (see Table 1; Nardelli, 1995). This interaction probably helps to reinforce the separation between nitro and chlorine groups, which are in different rings of the molecule. In the title structure, halogen···halogen interactions are not observed.

Experimental
The reagents and solvents for the synthesis were obtained from the Aldrich Chemical Co., and were used without additional purification. The title compound was obtained through a two-step reaction. First, 2-chlorobenzoic acid (0.200 g, 1.278 mmol) was placed in reflux with thionyl chloride (5 mL) in chloroform for an hour. Then, the excess of thionyl chloride was distilled to purify the 2-chlorobenzoyl chloride obtained as a pale-yellow translucent liquid. The same reaction flask was rearranged and an equimolar solution (0.213 g) of 4-hydroxy-3-nitrobenzaldehyde in acetonitrile was dropped inside it with 0.1 mL of pyridine. The reaction mixture was taken to room temperature with constant stirring for about an hour. A colorless solid was obtained after leaving the solvent to evaporate. After some difficulties in the crystallization process giving poor quality of crystals grown in different solvents (acetonitrile, dichloromethane, acetone), a colorless crystal of good quality (with some remnant amorphous solid) was obtained from a solution of the title compound in chloroform. IR spectra were recorded on a FT-IR SHIMADZU IR-Affinity-1 spectrophotometer. Colourless crystals; m.p 386 (1)

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.

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.