Methyl N-(4-chlorophenyl)succinamate

In the structure of the title compound {systematic name: methyl 3-[(4-chlorophenyl)aminocarbonyl]propionate}, C11H12ClNO3, the conformations of the N—H and C=O bonds in the amide fragment are trans to each other and the conformations of the amide O atom and the carbonyl O atom of the ester fragment are also trans to the H atoms attached to the adjacent C atoms. Molecules are linked into a centrosymmetric R 2 2(14) dimer by simple N—H⋯O interactions. Furthermore, a short intramolecular C—H⋯O contact may stabilize the conformation adopted by the molecule in the crystal.

In the structure of the title compound {systematic name: methyl 3-[(4-chlorophenyl)aminocarbonyl]propionate}, C 11 H 12 ClNO 3 , the conformations of the N-H and C O bonds in the amide fragment are trans to each other and the conformations of the amide O atom and the carbonyl O atom of the ester fragment are also trans to the H atoms attached to the adjacent C atoms. Molecules are linked into a centrosymmetric R 2 2 (14) dimer by simple N-HÁ Á ÁO interactions. Furthermore, a short intramolecular C-HÁ Á ÁO contact may stabilize the conformation adopted by the molecule in the crystal.

Comment
Amides are of interest as conjugation between the nitrogen lone pair electrons and the carbonyl pi-bond results in distinct physical and chemical properties. The amide moiety is also an important constituent of many biologically significant compounds. Thus, the structural studies of amides are of interest (see Gowda et al., 2007 and references therein;Gowda, Foro & Fuess, 2008;Gowda, Foro, Sowmya et al., 2008;Jones et al., 1990;Wan et al., 2006 as representative examples). As a part of studying the effect of ring and side-chain substitutions on the solid state geometry of this class of compounds, we report herein the crystal structure of N-(4-chlorophenyl)methylsuccinamate (N4CPMSA). The conformations of N-H and C=O bonds in the amide fragment are trans to each other and the conformations of the amide oxygen and the carbonyl oxygen of the ester segment are also trans to the H-atoms attached to the adjacent carbons ( Fig. 1). The succinamido group and the benzene ring lie in the same plane with the Rms deviation of fitted atoms equal to 0.0720 Å. The molecules are linked into centrosymmetric R~2~^2^(14) dimer by simple N-H···O interactions (Bernstein et al., 1995). Furthermore, a short intramolecular C-H···.O contact may stabilize the conformation adopted by the molecule in the solid state (Table 1) is shown in Fig.2.

Experimental
The solution of succinic anhydride (0.025 mole) in toluene (25 cc) was treated dropwise with the solution of 4-chloroaniline (0.025 mole) 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. The slow crystallization of N-(4-chlorophenyl)-succinamic acid in hot methanol resulted in N-(4-chlorophenyl)-methylsuccinamate. It was further recrystallized to constant melting point from methanol. The purity of the compound was checked by elemental analysis and characterized by recording its infrared and NMR spectra. The single crystals used in X-ray diffraction studies were grown in methanolic solution by slow evaporation at room temperature.

Refinement
The H atoms of the methyl group were positioned with idealized geometry using a riding model with C-H = 0.96 Å.
The other H atoms were located in difference map, and their positional parameters were refined freely [N-H = 0.82 (3) Å, C-H = 0.90 (3)-1.01 (3) Å]. All H atoms were refined with isotropic displacement parameters with U iso (H) = 1.2 U eq (C-aromatic,N) or 1.5 U eq (C-methyl).   as those based on F, and R-factors based on ALL data will be even larger.