2-Amino-N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]acetamide

In the title compound, C15H15ClN2O2S, the 2-aminoacetamide N—C(=O)—C—N unit is approximately planar, with an r.m.s. deviation of 0.020 (4) Å. The central thiophene ring makes dihedral angles of 7.84 (11) and 88.11 (11)°, respectively, with the 2-aminoacetamide unit and the 2-chlorophenyl ring. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked by an N—H⋯O hydrogen bond and weak C—H⋯O interactions into a chain along the c axis. A C—H⋯π interaction is also present.

In the title compound, C 15 H 15 ClN 2 O 2 S, the 2-aminoacetamide N-C( O)-C-N unit is approximately planar, with an r.m.s. deviation of 0.020 (4) Å . The central thiophene ring makes dihedral angles of 7.84 (11) and 88.11 (11) , respectively, with the 2-aminoacetamide unit and the 2-chlorophenyl ring. An intramolecular N-HÁ Á ÁO hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked by an N-HÁ Á ÁO hydrogen bond and weak C-HÁ Á ÁO interactions into a chain along the c axis. A C-HÁ Á Á interaction is also present.
Cg1 is the centroid of the thiophene C8/C9/S1/C10/C11 ring. Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  properties (Nakamura & Mukasa, 1992). Thiophenes and their biheterocycles have received considerable attention during last two decades as they are endowed with variety of biological activities and have wide range of therapeutic properties (Gewald & Schindler, 1990;Ramanathan & Namboothiri, 1978). Thiophene derivatives possess different pharmacological and biological properties, of which the more potent properties are the anticonvulsant, anti-inflammatory and antibacterial activities (Jagadees Babu et al., 2011;Shafeeque et al., 1999). In view of the importance of thiophenes, the crystal structure of the title compound (I) is reported.

Experimental
The title compound was synthesized by the literature method (Nakanishi et al., 1973). Yellow block-shaped single crystals of the title compound suitable for X-ray structure determination were recrystalized from C 2 H 5 OH/DMSO (1:1 v/v) by slow evaporation of the solvent at room temperature after several days (m.p. 417-419 K).

Refinement
All H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(N-H) = 0.83 Å for NH, 0.87 Å for NH 2 , and d(C-H) = 0.93 Å for aromatic, 0.97 Å for CH 2 and 0.96 Å for CH 3 groups. The U iso (H) values were constrained to be 1.5U eq of the carrier atom for methyl H atoms and 1.2U eq for the remaining H atoms. A rotating group model was used for the methyl groups.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound, showing 40% probability displacement ellipsoids and the atom-numbering scheme. The intramolecular N-H···O hydrogen bond is shown as a dash line.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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.