Crystal structure of 2-amino-N-(2-fluorophenyl)-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide

In the title compound, C15H15FN2OS, the dihedral angle between the planes of the benzothiophene ring system and the fluorobenzene ring is 3.74 (14)°. The six-membered ring of the benzothiophene moiety adopts a half-chair conformation. The molecular conformation is consolidated by intramolecular N—H⋯F and N—H⋯O hydrogen bonds. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, generating C(6) [001] chains.


S1. Comment
Thiophene nucleus has been established as a potential entity in the largely growing chemical world of heterocyclic compounds possessing promising pharmacological characteristics such as anti-HIV PR inhibitors (Bonini et al., 2005) and anti-breast cancer (Brault et al., 2005) activities. Particularly, benzothiophene derivative shows significant antimicrobial and anti-inflammatory activities (Isloora et al., 2010). In addition structures containing fluorine atoms plays a major role in intermolecular interactions (Choudhury et al., 2004). The title compound was prepared and characterized by single-crystal X-ray diffraction studies.

S2. Experimental
Cyclohexanone (1 equiv.), 2-cyano-N-(2-fluorophenyl) acetamide (1.1 equiv.), elemental sulfur (1.2 equiv.), diethylamine (0.8 equiv.) was taken in ethanol and mixed thoroughly in a microwave tube. The tube was sealed and irradiated at 325 K for 15 min. After cooling ethyl acetate was added to the reaction mixture and solid residue was removed by filtration. The filtrate was concentrated under reduced pressure and purified by column chromatography to obtain yellow block shaped crystals.

S3. Refinement
H atoms were placed at idealized positions and allowed to ride on their parent atoms with N-H distance is equal to 0.86 and C-H distances in the range of 0.93 to 0.97 Å; U iso (H) = 1.2-1.5U eq (carrier atom) for all H atoms.

Figure 1
Perspective diagram of the molecule with 50% probability displacement ellipsoids.

Special details
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.