2-Amino-N-(2-methoxy­phen­yl)-4,5-dimethyl­thio­phene-3-carboxamide

K Chandra Kumar; M K Kokila; Puttaraja; J Saravanan; Manohar V Kulkarni

doi:10.1107/S160053680801828X

. 2008 Jun 21;64(Pt 7):o1311. doi: 10.1107/S160053680801828X

2-Amino-N-(2-methoxyphenyl)-4,5-dimethylthiophene-3-carboxamide

K Chandra Kumar ^a, M K Kokila ^b,^*, Puttaraja ^b, J Saravanan ^c, Manohar V Kulkarni ^d

PMCID: PMC2961803 PMID: 21202939

Abstract

In the title compound, C₁₄H₁₆N₂O₂S, the two aromatic rings make a dihedral angle of 13.9 (1)°. The crystal structure is stabilized by both inter- and intramolecular N—H⋯O, C—H⋯O and C—H⋯N hydrogen bonds.

Related literature

For related literature, see: Gewald et al. (1966 ▶); Cohen et al. (1977 ▶); Csaszar & Morvay (1983 ▶); Lakshmi et al. (1985 ▶); Mohan & Saravanan (2003 ▶); Bruns et al. (1990 ▶).

Experimental

Crystal data

C₁₄H₁₆N₂O₂S
M _r = 276.35
Monoclinic,
a = 8.606 (2) Å
b = 7.5193 (19) Å
c = 21.297 (5) Å
β = 100.599 (5)°
V = 1354.7 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 291 (2) K
0.45 × 0.35 × 0.28 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.908, T _max = 0.937
9834 measured reflections
2514 independent reflections
1503 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.142
S = 0.99
2514 reflections
175 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SMART; data reduction: SAINT (Bruker, 1998 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: PARST (Nardelli, 1995 ▶) and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680801828X/bt2721sup1.cif

e-64-o1311-sup1.cif^{(18.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680801828X/bt2721Isup2.hkl

e-64-o1311-Isup2.hkl^{(121KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1	0.86	2.15	2.724 (3)	124
N1—H1B⋯O1ⁱ	0.86	2.23	3.009 (4)	151
N2—H2⋯O2	0.86	2.15	2.565 (3)	109
C8—H8⋯O1	0.93	2.30	2.874 (4)	119

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are grateful to Professor T. N. Guru Row, Indian Institute of Science, and the Department of Science and Technology, India, for the data collection using the CCD facility, and Bangalore University. CK thanks the Management, Administrator and Principal of HKBK College of Engineering for encouragement and support.

supplementary crystallographic information

Comment

Thiophene derivates containing amino and carboxyl functions have been found to exhibit anti-viral, antiinflamatory and antimicrobial activities (Mohan & Saravanan, 2003). Specifically the 2-amino-carboxylic acid esters were recognized as allosteric enhancers for A1 adenosine receptors (Bruns et al., 1990).

Interaction of 3-(2-thienyl alanine) with human phenyl alanine has been studied with a view to understand the mechanism of catalysis and substrate activation. Diffraction studies on bis 5-bromo-2-substituted thiophene derivatives have revealed the existence of S—S stacking interactions. Our earlier investigations on the structures of the biologically active thiophene carboxamide, has shown that the chloro substitution in the aryl amide group had a significant effect. The ortho-chloro group reversed the orientation of the amide linkage and favoured the formation of more intra molecular hydrogen bonds. The para-chloro substitution induces stabilizing effects via inter molecular hydrogen bonds. The compound in the present study bears a close structural relationship with the reported allosteric enhancers for adenosine and hence the structure has been investigated.

The molecular structure and the packing diagram are shown in Fig. 1 and 2, respectively. The molecular structure is stabilized by intra molecular C—H···O, N—H···O hydrogen bonds and intermolecular N—H···O interactions. (Table 2) The intra molecular C8 - H8···O1 and N1 - H1···O1 hydrogen bonds form pseudo- six membered rings and N2 - H2···O2 forms a pseudo five membered ring thus locking the molecular conformation and eliminating conformational flexibility.

Experimental

The title compound was synthesized by mixing of ethyl methyl ketone (0.72 g, 0.01 mol) and o-methoxycyanoacetanilide (1.94 g, 0.01 mol) and refluxing the mixture for 1 h (Gewald et al., 1966) in the presence of 4.0 ml of diethylamine. Sulfur powder (1.28 g, 0.04 mol) and 40 ml ethanol were then added and the resulting solution was heated for 2 h at 323 K. Crystals were grown by slow evaporation in a solution of isopropyl alcohol (yield 50%).