N-(4-Chlorophenyl)succinamic acid

In the title compound, C10H10ClNO3, the conformation of the amide O atom and the carbonyl O atom of the acid segment are anti to each other and further, they are anti to the H atoms of their adjacent –CH2 groups. The C=O and O—H bonds of the acid group are in the syn position relative to each other. In the crystal, molecules are packed into infinite chains through intermolecular N—H⋯O and O—H⋯O hydrogen bonds.

In the title compound, C 10 H 10 ClNO 3 , the conformation of the amide O atom and the carbonyl O atom of the acid segment are anti to each other and further, they are anti to the H atoms of their adjacent -CH 2 groups. The C O and O-H bonds of the acid group are in the syn position relative to each other. In the crystal, molecules are packed into infinite chains through intermolecular N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds.

Related literature
For our study of the effect of ring and side-chain substitution on the solid-state geometry of anilides, see: Gowda et al. (2009a,b,c). For the modes of interlinking carboxylic acids by hydrogen bonds, see: Leiserowitz (1976). The packing of molecules involving dimeric hydrogen-bonded association of each carboxyl group with a centrosymmetrically related neighbor has also been observed, see: Jagannathan et al. (1994).  Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) x; y þ 1; z; (ii) Àx þ 2; Ày þ 1; Àz þ 3.

Comment
As a part of studying the effect of ring and side chain substitutions on the solid state geometry of anilides (Gowda et al., 2009a,b,c), we report herein the crystal structure of N-(4-chlorophenyl)succinamic acid (I). The conformations of N-H and C=O bonds in the amide segment are anti to each other and the conformation of the amide oxygen and the carbonyl oxygen of the acid segment are also anti to each other and further, they are anti to the H atoms of their adjacent -CH 2 groups ( Fig. 1), similar to that observed in N-(4-chlorophenyl)succinamate (Gowda et al., 2009a) and N-(2-chlorophenyl)succinamic acid (Gowda et al., 2009b). The C=O and O-H bonds of the acid group are in syn position to each other. The N-H···O and O-H···O intermolecular hydrogen bonds pack the mpolecules into infinite chains in the structure (Table 1, Fig.2).
The modes of interlinking carboxylic acids by hydrogen bonds is described elsewhere (Leiserowitz, 1976). The packing of molecules involving dimeric hydrogen bonded association of each carboxyl group with a centrosymmetrically related neighbor has also been observed (Jagannathan et al., 1994).

Experimental
The solution of succinic anhydride (2.5 g) in toluene (25 cc) was treated dropwise with the solution of 4-chloroaniline (2.5 g) also in toluene (20 cc) with constant stirring. The resulting mixture was stirred for about one hour and set aside for an additional hour at room temperature for completion of the reaction. The mixture was then treated with dilute hydrochloric acid to remove the unreacted 4-chloroaniline. The resultant solid N-(4-chlorophenyl)succinamic acid was filtered under suction and washed thoroughly with water to remove the unreacted succinic anhydride and succinic acid. It was recrystallized to constant melting point from ethanol. The purity of the compound was checked by elemental analysis and characterized by its infrared and NMR spectra. The single crystals used in X-ray diffraction studies were grown in ethanolic solution by slow evaporation at room temperature.

Refinement
The H atom of the OH group was located in a diffrerence map and its position refined   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 Rfactors(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.