Methyl N-phenylsuccinamate

In the structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide fragment are trans to each other. In the crystal, molecules are linked into a 21 helical chain that propagates along the c axis through N—H⋯O interactions.

In the structure of the title compound, C 11 H 13 NO 3 , the conformations of the N-H and C O bonds in the amide fragment are trans to each other. In the crystal, molecules are linked into a 2 1 helical chain that propagates along the c axis through N-HÁ Á ÁO interactions.

Comment
Amides are of interest as conjugation between the nitrogen lone pair electrons and the carbonyl π-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, andreferences therein, 2009a,b;Jones et al., 1990; 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-(phenyl)methylsuccinamate. The conformations of the N-H and C=O bonds in the amide fragment are trans to each other (Fig. 1). The side chain in the title compound is bent at C8 with C7-C8-C9-C10 torsional angle of 70.3 (4)°. The linking of molecules into a helical chain by N-H···O interactions (Table 1) is shown in Fig.2.

Experimental
A solution of succinic anhydride (0.025 mole) in toluene (25 ml) was treated dropwise with a solution of aniline (0.025 mole) in toluene (20 ml) with constant stirring. The resulting mixture was stirred for about 1 h 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 aniline. The resultant solid N-(phenyl)succinamic acid was filtered under suction and washed thoroughly with water to remove the unreacted succinic anhydride and succinic acid and was recrystallized from methanol. The recrystallized sample in methanol (20 ml) was treated with concentrated sulfuric acid (2 ml). The mixture was refluxed for 2 h and kept for slow evaporation at room temperature to obtain crystals of N-(phenyl)methylsuccinamate. The crystals were washed with water to remove sulfuric acid and dried. The purity of the compound was checked by elemental analysis and characterized by recording its infrared spectra. The single crystals used in X-ray diffraction studies were grown from methanolic solution by slow evaporation at room temperature.

Refinement
The H atom of the NH group was located in a difference map and its position refined with N-H = 0.85 (4) Å. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93-0.97 Å. Isotropic displacement parameters for the H atoms of the methyl group were set to 1.5 U eq (parent atom), for the other H atoms equal to 1.2 U eq (parent atom).
In the absence of significant anomalous dispersion effects, Friedel pairs were merged and the Δf" terms set to zero.  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 > 2σ(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.