No abstract

View of the molecule of compound (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are represented by circles of arbitrary size.

Key indicatorsSingle-crystal X-ray study T = 293 K Mean '(C±C) = 0.008 A Ê R factor = 0.078 wR factor = 0.190 Data-to-parameter ratio = 13.3For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. # 2004 International Union of Crystallography Printed in Great Britain ± all rights reservedThe molecule of the title compound, C 10 H 13 NO 2 S, is planar. The crystal structure is stabilized by intra-and intermolecular NÐHÁ Á ÁO hydrogen bonds. Comment2-Aminothiophenes are a useful class of compounds because they display different biological properties, such as antitubercular, bacteriostatic and antifungal activities (Nakanishi et al., 1970). The structure of the title compound, (I), is composed of a thiophene ring substituted by a 2-amino group and a 3-methyl ester group. The molecule is planar (Fig. 1). The terminal ester group lies in the plane of the thiophene ring system, the torsion angle C10ÐO2ÐC9ÐC2 being 178.0 (4) .The carbonyl group has a cis orientation with respect to the C2 C3 double bond. This leads to a strong intramolecular hydrogen bond (Table 1) between one of the H atoms, viz. H2N of the amino group, and the O atom of the carbonyl group. The other H atom, H1N, is involved in molecular chains along the c axis (Fig. 2). ExperimentalThe title compound, (I), was synthesized by the Gewald reaction (Gewald et al., 1966) by mixing cyclohexanone (0.04 mol), ethyl cyanoacetate (0.04 mol), sulfur (0.04 mol) and 40 ml of ethanol and stirring the mixture at 325 K for 1 h, with dropwise addition of 4 ml of dimethylamine to yield the ester, followed by alkaline hydrolysis View of the molecule of (I), drawn with 50% probability displacement ellipsoids. The hydrogen bond is shown as dashed lines.

The compounds 2-{[(E)-(4-methoxyphenyl)methylene]amino}-N-(3-methylphenyl)-4,5,6,7-tetrahydro-1-benzothiophene-3carboxamide, C 24 H 24 N 2 O 2 S, (I), and N-(4-methylphenyl)-2-{[(E)-(4-methylphenyl)methylene]amino}-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide, C 24 H 24 N 2 OS, (II), show antibacterial and antifungal activities. The m-toluidine ring in (I) and the p-toluidine ring in (II) are coplanar with their respective thiophene rings. In (I), an intermolecular CÐ HÁ Á ÁO hydrogen bond is present, whereas (II) does not exhibit any signi®cant intermolecular interactions. However, in both compounds, an intramolecular NÐHÁ Á ÁN hydrogen bond forms a pseudo-six-membered ring, thus locking the molecular conformation and eliminating conformational¯exibility. Comment The design of compounds that possess important pharmacological properties, such as antibacterial, anticancer, anti-in¯amatory and antitoxic activities, is an important area of research, and Schiff bases (

In the current study, two novel Knoevenagel condensation products of substituted napthofuran-2-carbaldehydes were designed, synthesized and characterized. In order to study the intermolecular interactions of title compounds, single crystals were grown by slow evaporation solution growth technique at room temperature and crystal structure has been determined by single crystal X-ray diffraction technique. Both the molecules crystallize in the monoclinic centrosymmetric space group P2 1 /c with one molecule in the asymmetric unit. In compound [4] the molecules are connected via bifurcated C-H•••O=C and C-H•••N=C H-bonds and van der Waals interactions forming a layered structure, whereas in compound [5a] the molecular conformation is stabilized via intramolecular C-H•••O H-bond and molecule interacts with other molecule generated via 2 1-screw via bifurcated C-H•••O=C along with C-H•••N=C H-bonds, which are interacting with nitro-of other molecule generated via same symmetry operation, forming bifurcated C-H•••O-N H-bonds, which helps in formation of molecular sheet-like structure. Further, in order to understand the various types and nature of intermolecular interactions in the supramolecular structure Hirshfeld surface analysis and fingerprint plot analysis was carried out.