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

Chandra Kumar, K.; Kokila, M.K.; Puttaraja; Saravanan, J.; Kulkarni, M.V.

doi:10.1107/S160053680801828X

organic compounds

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ISSN: 2056-9890

Volume 64| Part 7| July 2008| Page o1311

doi:10.1107/S160053680801828X

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

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

^aDepartment of Engineering Physics, HKBK College of Engineering, Nagawara, Bangalore 560 045, Karnataka, India, ^bDepartment of Physics, Bangalore University, Bangalore 560 056, Karnataka, India, ^cPES College of Pharmacy, Hanumanthanagar, Bangalore 560 050, Karnataka, India, and ^dDepartment of Chemistry, Karnatak University, Dharwad 580 003, Karnataka, India
^*Correspondence e-mail: prmkkgroup@gmail.com

(Received 5 June 2008; accepted 16 June 2008; online 21 June 2008)

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, P 2₁ /n
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[F² > 2σ(F²)] = 0.053
wR(F²) = 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

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
Symmetry code: (i) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

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 ).

Supporting information

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

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

checkCIF report

Comment top

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.

Related literature top

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 top

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%).

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SMART (Bruker, 1998); 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).

Figures top

	Fig. 1. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms.Dashed lines indicate intramolecular hydrogen bonds; H atoms not involved in hydrogen bonding have been omitted.
	Fig. 2. The packing of (I), viewed down the a axis shows molecules connected by N—H···O hydrogen bonds (dashedlines). H atoms not involved in hydrogen bonding have been omitted.

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

Crystal data top

C₁₄H₁₆N₂O₂S	F(000) = 584
M_r = 276.35	D_x = 1.355 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2yn	Cell parameters from 670 reflections
a = 8.606 (2) Å	θ = 2.0–28.5°
b = 7.5193 (19) Å	µ = 0.24 mm⁻¹
c = 21.297 (5) Å	T = 291 K
β = 100.599 (5)°	Block, yellow
V = 1354.7 (6) Å³	0.45 × 0.35 × 0.28 mm
Z = 4

Data collection top

Bruker SMART CCD area-detector diffractometer	2514 independent reflections
Radiation source: fine-focus sealed tube	1503 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.051
ψ and ω scans	θ_max = 25.5°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
T_min = 0.908, T_max = 0.937	k = −9→9
9834 measured reflections	l = −25→23

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.142	H-atom parameters constrained
S = 0.99	w = 1/[σ²(F_o²) + (0.0749P)²] where P = (F_o² + 2F_c²)/3
2514 reflections	(Δ/σ)_max = 0.001
175 parameters	Δρ_max = 0.25 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₁₄H₁₆N₂O₂S	V = 1354.7 (6) Å³
M_r = 276.35	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 8.606 (2) Å	µ = 0.24 mm⁻¹
b = 7.5193 (19) Å	T = 291 K
c = 21.297 (5) Å	0.45 × 0.35 × 0.28 mm
β = 100.599 (5)°

Data collection top

Bruker SMART CCD area-detector diffractometer	2514 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1503 reflections with I > 2σ(I)
T_min = 0.908, T_max = 0.937	R_int = 0.051
9834 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	0 restraints
wR(F²) = 0.142	H-atom parameters constrained
S = 0.99	Δρ_max = 0.25 e Å⁻³
2514 reflections	Δρ_min = −0.18 e Å⁻³
175 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.2740 (3)	0.5092 (4)	0.74695 (12)	0.0593 (8)
H1A	0.2056	0.5582	0.7662	0.071*
H1B	0.2436	0.4570	0.7109	0.071*
N2	0.4683 (3)	0.6863 (3)	0.93475 (11)	0.0480 (7)
H2	0.5646	0.6512	0.9455	0.058*
O1	0.2675 (3)	0.7169 (3)	0.85124 (9)	0.0630 (7)
O2	0.6570 (3)	0.7367 (3)	1.04138 (10)	0.0676 (7)
S1	0.56490 (10)	0.41424 (12)	0.73395 (4)	0.0535 (3)
C2	0.4302 (3)	0.5144 (4)	0.77352 (13)	0.0420 (7)
C3	0.5040 (3)	0.5902 (4)	0.83034 (12)	0.0377 (7)
C4	0.6745 (3)	0.5669 (4)	0.84070 (13)	0.0398 (7)
C5	0.7229 (3)	0.4775 (4)	0.79298 (15)	0.0467 (7)
C6	0.4057 (3)	0.6700 (4)	0.87196 (14)	0.0420 (7)
C7	0.3992 (4)	0.7521 (4)	0.98507 (14)	0.0473 (8)
C8	0.2397 (4)	0.7879 (4)	0.98133 (16)	0.0627 (9)
H8	0.1694	0.7726	0.9430	0.075*
C9	0.1854 (5)	0.8470 (5)	1.0354 (2)	0.0760 (11)
H9	0.0784	0.8705	1.0332	0.091*
C10	0.2894 (6)	0.8706 (5)	1.09189 (19)	0.0783 (12)
H10	0.2519	0.9096	1.1278	0.094*
C11	0.4478 (5)	0.8375 (4)	1.09617 (16)	0.0681 (11)
H11	0.5174	0.8549	1.1346	0.082*
C12	0.5028 (4)	0.7782 (4)	1.04318 (14)	0.0528 (8)
C13	0.7904 (4)	0.6333 (4)	0.89802 (14)	0.0574 (9)
H13A	0.7849	0.5590	0.9342	0.086*
H13B	0.7642	0.7534	0.9074	0.086*
H13C	0.8955	0.6298	0.8889	0.086*
C14	0.8866 (4)	0.4251 (5)	0.78467 (17)	0.0650 (9)
H14A	0.9630	0.4970	0.8119	0.097*
H14B	0.8970	0.4428	0.7410	0.097*
H14C	0.9043	0.3021	0.7958	0.097*
C15	0.7716 (5)	0.7639 (6)	1.09758 (16)	0.0876 (13)
H15A	0.7754	0.8879	1.1086	0.131*
H15B	0.8733	0.7265	1.0902	0.131*
H15C	0.7435	0.6959	1.1320	0.131*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0488 (17)	0.082 (2)	0.0435 (15)	−0.0024 (14)	−0.0015 (13)	−0.0087 (14)
N2	0.0424 (14)	0.0643 (17)	0.0367 (14)	0.0069 (12)	0.0056 (12)	−0.0021 (12)
O1	0.0517 (14)	0.0900 (18)	0.0449 (13)	0.0223 (12)	0.0019 (11)	0.0006 (12)
O2	0.0649 (16)	0.0908 (18)	0.0437 (13)	−0.0020 (14)	0.0012 (12)	−0.0051 (12)
S1	0.0587 (6)	0.0575 (5)	0.0451 (5)	−0.0032 (4)	0.0117 (4)	−0.0088 (4)
C2	0.0434 (17)	0.0445 (16)	0.0374 (16)	−0.0041 (14)	0.0055 (14)	0.0028 (13)
C3	0.0402 (17)	0.0392 (15)	0.0327 (15)	0.0016 (13)	0.0043 (13)	0.0021 (13)
C4	0.0418 (17)	0.0356 (15)	0.0410 (17)	−0.0004 (13)	0.0051 (13)	0.0033 (13)
C5	0.0457 (18)	0.0442 (17)	0.0508 (18)	0.0008 (14)	0.0106 (15)	0.0013 (14)
C6	0.0418 (18)	0.0429 (17)	0.0395 (17)	0.0021 (14)	0.0031 (14)	0.0067 (13)
C7	0.058 (2)	0.0443 (18)	0.0433 (18)	0.0022 (15)	0.0187 (16)	0.0033 (14)
C8	0.067 (2)	0.070 (2)	0.055 (2)	0.0124 (18)	0.0222 (18)	0.0090 (18)
C9	0.083 (3)	0.075 (3)	0.081 (3)	0.024 (2)	0.044 (2)	0.020 (2)
C10	0.126 (4)	0.061 (2)	0.060 (3)	0.019 (2)	0.046 (3)	0.0082 (19)
C11	0.109 (3)	0.055 (2)	0.044 (2)	0.002 (2)	0.023 (2)	0.0019 (16)
C12	0.075 (2)	0.0466 (18)	0.0370 (18)	−0.0016 (17)	0.0123 (17)	0.0028 (14)
C13	0.0458 (19)	0.068 (2)	0.055 (2)	0.0007 (16)	0.0024 (16)	−0.0063 (17)
C14	0.056 (2)	0.066 (2)	0.075 (2)	0.0058 (18)	0.0185 (19)	−0.0091 (19)
C15	0.088 (3)	0.123 (3)	0.044 (2)	−0.026 (3)	−0.010 (2)	0.007 (2)

Geometric parameters (Å, º) top

N1—C2	1.360 (3)	C7—C8	1.387 (5)
N1—H1A	0.8600	C8—C9	1.392 (5)
N1—H1B	0.8600	C8—H8	0.9300
N2—C6	1.352 (3)	C9—C10	1.373 (5)
N2—C7	1.407 (4)	C9—H9	0.9300
N2—H2	0.8600	C10—C11	1.373 (5)
O1—C6	1.241 (3)	C10—H10	0.9300
O2—C12	1.370 (4)	C11—C12	1.376 (4)
O2—C15	1.419 (4)	C11—H11	0.9300
S1—C2	1.727 (3)	C13—H13A	0.9600
S1—C5	1.740 (3)	C13—H13B	0.9600
C2—C3	1.382 (4)	C13—H13C	0.9600
C3—C4	1.454 (4)	C14—H14A	0.9600
C3—C6	1.462 (4)	C14—H14B	0.9600
C4—C5	1.347 (4)	C14—H14C	0.9600
C4—C13	1.512 (4)	C15—H15A	0.9600
C5—C14	1.504 (4)	C15—H15B	0.9600
C7—C12	1.399 (4)	C15—H15C	0.9600

C2—N1—H1A	120.0	C8—C9—H9	119.9
C2—N1—H1B	120.0	C10—C9—H9	119.9
H1A—N1—H1B	120.0	C11—C10—C9	120.9 (4)
C6—N2—C7	129.6 (3)	C11—C10—H10	119.5
C6—N2—H2	115.2	C9—C10—H10	119.5
C7—N2—H2	115.2	C10—C11—C12	119.5 (4)
C12—O2—C15	118.0 (3)	C10—C11—H11	120.3
C2—S1—C5	91.95 (14)	C12—C11—H11	120.3
N1—C2—C3	129.5 (3)	O2—C12—C11	125.3 (3)
N1—C2—S1	119.1 (2)	O2—C12—C7	114.0 (3)
C3—C2—S1	111.4 (2)	C11—C12—C7	120.8 (3)
C2—C3—C4	111.8 (3)	C4—C13—H13A	109.5
C2—C3—C6	118.4 (2)	C4—C13—H13B	109.5
C4—C3—C6	129.6 (2)	H13A—C13—H13B	109.5
C5—C4—C3	112.9 (3)	C4—C13—H13C	109.5
C5—C4—C13	121.6 (3)	H13A—C13—H13C	109.5
C3—C4—C13	125.4 (3)	H13B—C13—H13C	109.5
C4—C5—C14	130.2 (3)	C5—C14—H14A	109.5
C4—C5—S1	111.9 (2)	C5—C14—H14B	109.5
C14—C5—S1	117.9 (2)	H14A—C14—H14B	109.5
O1—C6—N2	120.5 (3)	C5—C14—H14C	109.5
O1—C6—C3	121.6 (3)	H14A—C14—H14C	109.5
N2—C6—C3	117.9 (2)	H14B—C14—H14C	109.5
C12—C7—N2	115.7 (3)	O2—C15—H15A	109.5
C12—C7—C8	119.1 (3)	O2—C15—H15B	109.5
N2—C7—C8	125.2 (3)	H15A—C15—H15B	109.5
C9—C8—C7	119.6 (4)	O2—C15—H15C	109.5
C9—C8—H8	120.2	H15A—C15—H15C	109.5
C7—C8—H8	120.2	H15B—C15—H15C	109.5
C8—C9—C10	120.2 (4)

C5—S1—C2—N1	179.1 (2)	C4—C3—C6—O1	163.3 (3)
C5—S1—C2—C3	−1.1 (2)	C2—C3—C6—N2	157.1 (3)
N1—C2—C3—C4	−179.5 (3)	C4—C3—C6—N2	−18.8 (4)
S1—C2—C3—C4	0.8 (3)	C6—N2—C7—C12	−170.1 (3)
N1—C2—C3—C6	3.9 (5)	C6—N2—C7—C8	11.3 (5)
S1—C2—C3—C6	−175.8 (2)	C12—C7—C8—C9	−0.7 (5)
C2—C3—C4—C5	0.1 (3)	N2—C7—C8—C9	177.8 (3)
C6—C3—C4—C5	176.3 (3)	C7—C8—C9—C10	0.4 (5)
C2—C3—C4—C13	−179.9 (3)	C8—C9—C10—C11	0.3 (6)
C6—C3—C4—C13	−3.8 (5)	C9—C10—C11—C12	−0.6 (5)
C3—C4—C5—C14	−179.9 (3)	C15—O2—C12—C11	−3.0 (5)
C13—C4—C5—C14	0.1 (5)	C15—O2—C12—C7	178.2 (3)
C3—C4—C5—S1	−1.0 (3)	C10—C11—C12—O2	−178.6 (3)
C13—C4—C5—S1	179.1 (2)	C10—C11—C12—C7	0.3 (5)
C2—S1—C5—C4	1.2 (2)	N2—C7—C12—O2	0.7 (4)
C2—S1—C5—C14	−179.7 (3)	C8—C7—C12—O2	179.4 (3)
C7—N2—C6—O1	0.1 (5)	N2—C7—C12—C11	−178.3 (3)
C7—N2—C6—C3	−177.8 (3)	C8—C7—C12—C11	0.4 (5)
C2—C3—C6—O1	−20.8 (4)

Hydrogen-bond geometry (Å, º) top

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

Symmetry code: (i) −x+1/2, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₆N₂O₂S
M_r	276.35
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	291
a, b, c (Å)	8.606 (2), 7.5193 (19), 21.297 (5)
β (°)	100.599 (5)
V (Å³)	1354.7 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.24
Crystal size (mm)	0.45 × 0.35 × 0.28

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.908, 0.937
No. of measured, independent and observed [I > 2σ(I)] reflections	9834, 2514, 1503
R_int	0.051
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.142, 0.99
No. of reflections	2514
No. of parameters	175
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.18

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), PARST (Nardelli, 1995) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1	0.8600	2.1500	2.724 (3)	124.00
N1—H1B···O1ⁱ	0.8600	2.2300	3.009 (4)	151.00
N2—H2···O2	0.8600	2.1500	2.565 (3)	109.00
C8—H8···O1	0.9300	2.3000	2.874 (4)	119.00

Symmetry code: (i) −x+1/2, y−1/2, −z+3/2.

Acknowledgements

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.

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