organic compounds
of ethyl 5-acetyl-2-{[(dimethylamino)methylidene]amino}-4-methylthiophene-3-carboxylate
aDepartment of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, Karnataka, India
*Correspondence e-mail: noorsb@rediffmail.com
In the title thiophene derivative, C13H18N2O3S, the dihedral angles between the thiophene ring and the [(dimethylamino)methylidene]amino side chain (r.m.s. deviation = 0.009 Å) and the –CO2 ester group are 3.01 (16) and 59.9 (3)°, respectively. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds generate R22(16) loops. The dimers are linked by another weak C—H⋯O interaction, forming chains along [001]. In addition, weak C—H⋯π interactions are observed, which link the chains into (001) layers.
CCDC reference: 1421360
1. Related literature
For background to the applications of thiophene derivatives, see: Sabnis et al. (1999). For a related structure, see: Mukhtar et al. (2010). For further synthetic details, see: Gewald et al. (1966).
2. Experimental
2.1. Crystal data
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2.3. Refinement
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Data collection: SMART (Bruker, 1998); cell SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus; 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, 2012) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 2012).
Supporting information
CCDC reference: 1421360
10.1107/S2056989015016217/hb7483sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S2056989015016217/hb7483Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989015016217/hb7483Isup3.cml
Step-1: 3.3 g of cyano ethyl acetate was weighed and transferred to RB flask and 5 g of acetyl acetone and 10 to 15 ml of ethanol were added to it. The whole mixture was stirred for 10 min. After stirring 1.6 g of elemental sulfur was added to the mixture and cold condition was maintained by using crushed ice. Later 5 ml of diethyl amine was added drop by drop the solution changes its color to red. After the completion of addition the solution was again kept for stirring (10 min). Ice pack was removed and stirring was continued for about an hour. The precipitated product (1) was filtered, dried and recrystallized from ethanol (yield: 68%, m.p. 430 K)
Step-2: A mixture of compound 1 (10 mmol) and DMF—DMA (5 ml) was stirred at room temperature for 30 minutes. To this was added ethanol and kept in room temperature to give a solid product (title compound) that was collected by filtration. The compound was recrystallized by slow evaporation from ethanol, yielding single crystals suitable for X-ray diffraction studies.
The H atoms were placed at calculated positions in the riding-model approximation with C—H = 0.96° A, 0.97 ° A and 0.93 ° A for methyl, methylene and methyne H-atoms respectively, with Uiso(H) = 1.5Ueq(C) for methyl H atoms and Uiso(H) = 1.2Ueq(C) for other hydrogen atoms.
Data collection: SMART (Bruker, 1998); cell
SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus (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, 2012) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 2012).Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius. | |
Fig. 2. Unit cell packing of the title compound showing intermolecular C—H···O interactions with dotted lines. H-atoms not involved in hydrogen bonding have been excluded. | |
Fig. 3. Unit cell packing depicting C—H···π interactions with dotted lines. |
C13H18N2O3S | F(000) = 1200 |
Mr = 282.35 | Dx = 1.354 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 3012 reflections |
a = 12.218 (3) Å | θ = 2.1–27.0° |
b = 7.332 (2) Å | µ = 0.24 mm−1 |
c = 30.923 (8) Å | T = 100 K |
V = 2769.9 (13) Å3 | Block, colorless |
Z = 8 | 0.29 × 0.26 × 0.10 mm |
Bruker SMART APEX CCD diffractometer | 3012 independent reflections |
Radiation source: fine-focus sealed tube | 2140 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.076 |
ω scans | θmax = 27.0°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −14→15 |
Tmin = 0.958, Tmax = 0.963 | k = −9→9 |
15478 measured reflections | l = −39→35 |
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)] = 0.058 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.173 | H-atom parameters constrained |
S = 1.19 | w = 1/[σ2(Fo2) + (0.0811P)2 + 0.3374P] where P = (Fo2 + 2Fc2)/3 |
3012 reflections | (Δ/σ)max < 0.001 |
177 parameters | Δρmax = 0.52 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
C13H18N2O3S | V = 2769.9 (13) Å3 |
Mr = 282.35 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 12.218 (3) Å | µ = 0.24 mm−1 |
b = 7.332 (2) Å | T = 100 K |
c = 30.923 (8) Å | 0.29 × 0.26 × 0.10 mm |
Bruker SMART APEX CCD diffractometer | 3012 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 2140 reflections with I > 2σ(I) |
Tmin = 0.958, Tmax = 0.963 | Rint = 0.076 |
15478 measured reflections |
R[F2 > 2σ(F2)] = 0.058 | 0 restraints |
wR(F2) = 0.173 | H-atom parameters constrained |
S = 1.19 | Δρmax = 0.52 e Å−3 |
3012 reflections | Δρmin = −0.33 e Å−3 |
177 parameters |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.8067 (2) | 0.2414 (4) | 0.37436 (9) | 0.0219 (6) | |
H1A | 0.8527 | 0.3124 | 0.3942 | 0.033* | |
H1B | 0.7973 | 0.3089 | 0.3473 | 0.033* | |
H1C | 0.8419 | 0.1240 | 0.3684 | 0.033* | |
C2 | 0.5031 (2) | 0.1973 (4) | 0.39447 (9) | 0.0194 (6) | |
C3 | 0.5979 (2) | 0.2312 (4) | 0.37104 (9) | 0.0193 (6) | |
C4 | 0.6967 (2) | 0.2091 (4) | 0.39477 (9) | 0.0196 (6) | |
C5 | 0.6764 (2) | 0.1574 (4) | 0.43709 (9) | 0.0190 (6) | |
C6 | 0.7476 (2) | 0.1108 (4) | 0.47350 (9) | 0.0211 (6) | |
C7 | 0.8697 (2) | 0.1198 (4) | 0.46853 (9) | 0.0252 (7) | |
H7A | 0.9048 | 0.0694 | 0.4944 | 0.038* | |
H7B | 0.8923 | 0.2471 | 0.4648 | 0.038* | |
H7C | 0.8919 | 0.0488 | 0.4431 | 0.038* | |
C8 | 0.5956 (2) | 0.2660 (4) | 0.32370 (9) | 0.0203 (6) | |
C9 | 0.5315 (2) | 0.4612 (4) | 0.26762 (9) | 0.0251 (7) | |
H9A | 0.4661 | 0.5384 | 0.2628 | 0.030* | |
H9B | 0.5215 | 0.3467 | 0.2511 | 0.030* | |
C10 | 0.6313 (2) | 0.5590 (5) | 0.25110 (10) | 0.0321 (7) | |
H10A | 0.6411 | 0.6730 | 0.2672 | 0.048* | |
H10B | 0.6219 | 0.5864 | 0.2203 | 0.048* | |
H10C | 0.6958 | 0.4814 | 0.2550 | 0.048* | |
C11 | 0.3149 (2) | 0.1822 (4) | 0.40202 (9) | 0.0216 (6) | |
H11 | 0.3262 | 0.1544 | 0.4317 | 0.026* | |
C13 | 0.1194 (2) | 0.1650 (4) | 0.41533 (10) | 0.0287 (7) | |
H13A | 0.1452 | 0.1305 | 0.4442 | 0.043* | |
H13B | 0.0736 | 0.0673 | 0.4035 | 0.043* | |
H13C | 0.0765 | 0.2776 | 0.4173 | 0.043* | |
C12 | 0.1888 (2) | 0.2409 (5) | 0.34251 (10) | 0.0323 (8) | |
H12A | 0.2567 | 0.2747 | 0.3277 | 0.048* | |
H12B | 0.1377 | 0.3439 | 0.3418 | 0.048* | |
H12C | 0.1558 | 0.1356 | 0.3280 | 0.048* | |
N1 | 0.40009 (18) | 0.2074 (3) | 0.37699 (7) | 0.0216 (5) | |
N2 | 0.21291 (18) | 0.1943 (3) | 0.38709 (7) | 0.0218 (5) | |
O1 | 0.70690 (16) | 0.0608 (3) | 0.50809 (6) | 0.0285 (5) | |
O2 | 0.63937 (18) | 0.1686 (3) | 0.29724 (6) | 0.0308 (5) | |
O3 | 0.54047 (16) | 0.4187 (3) | 0.31356 (6) | 0.0244 (5) | |
S1 | 0.53616 (5) | 0.13387 (10) | 0.44751 (2) | 0.0202 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0151 (15) | 0.0206 (15) | 0.0301 (16) | −0.0008 (11) | 0.0015 (11) | −0.0017 (12) |
C2 | 0.0147 (14) | 0.0169 (14) | 0.0267 (15) | 0.0005 (11) | −0.0003 (11) | −0.0026 (11) |
C3 | 0.0166 (15) | 0.0142 (14) | 0.0270 (15) | 0.0008 (10) | 0.0002 (11) | −0.0016 (11) |
C4 | 0.0154 (15) | 0.0127 (14) | 0.0308 (15) | −0.0002 (10) | −0.0009 (11) | −0.0039 (11) |
C5 | 0.0125 (14) | 0.0223 (15) | 0.0220 (14) | 0.0018 (11) | 0.0012 (11) | −0.0017 (11) |
C6 | 0.0176 (15) | 0.0189 (15) | 0.0268 (15) | 0.0001 (11) | −0.0015 (12) | −0.0001 (11) |
C7 | 0.0170 (15) | 0.0281 (16) | 0.0304 (16) | −0.0015 (12) | −0.0037 (12) | 0.0031 (12) |
C8 | 0.0133 (14) | 0.0197 (15) | 0.0278 (16) | −0.0041 (11) | −0.0025 (12) | −0.0015 (12) |
C9 | 0.0231 (16) | 0.0261 (16) | 0.0262 (15) | −0.0016 (12) | −0.0041 (12) | 0.0043 (12) |
C10 | 0.0262 (17) | 0.0424 (19) | 0.0276 (16) | −0.0008 (14) | −0.0002 (14) | 0.0053 (14) |
C11 | 0.0165 (15) | 0.0236 (15) | 0.0248 (15) | 0.0010 (11) | −0.0026 (12) | 0.0007 (12) |
C13 | 0.0131 (15) | 0.0363 (18) | 0.0368 (18) | −0.0005 (12) | 0.0015 (13) | 0.0009 (14) |
C12 | 0.0196 (16) | 0.043 (2) | 0.0341 (18) | 0.0057 (13) | −0.0040 (13) | −0.0024 (15) |
N1 | 0.0140 (13) | 0.0235 (13) | 0.0275 (13) | 0.0013 (10) | −0.0003 (10) | 0.0009 (10) |
N2 | 0.0130 (12) | 0.0285 (14) | 0.0240 (12) | 0.0006 (10) | 0.0000 (10) | 0.0005 (10) |
O1 | 0.0216 (11) | 0.0385 (13) | 0.0254 (11) | −0.0008 (9) | −0.0010 (9) | 0.0059 (9) |
O2 | 0.0307 (12) | 0.0372 (13) | 0.0245 (11) | 0.0088 (10) | −0.0012 (9) | −0.0060 (9) |
O3 | 0.0225 (11) | 0.0257 (11) | 0.0251 (11) | 0.0029 (8) | 0.0001 (8) | 0.0028 (9) |
S1 | 0.0121 (4) | 0.0250 (4) | 0.0237 (4) | −0.0003 (3) | 0.0004 (3) | 0.0017 (3) |
C1—C4 | 1.504 (4) | C9—O3 | 1.458 (3) |
C1—H1A | 0.9800 | C9—C10 | 1.504 (4) |
C1—H1B | 0.9800 | C9—H9A | 0.9900 |
C1—H1C | 0.9800 | C9—H9B | 0.9900 |
C2—N1 | 1.372 (3) | C10—H10A | 0.9800 |
C2—C3 | 1.388 (4) | C10—H10B | 0.9800 |
C2—S1 | 1.752 (3) | C10—H10C | 0.9800 |
C3—C4 | 1.422 (4) | C11—N1 | 1.310 (3) |
C3—C8 | 1.486 (4) | C11—N2 | 1.332 (3) |
C4—C5 | 1.385 (4) | C11—H11 | 0.9500 |
C5—C6 | 1.464 (4) | C13—N2 | 1.454 (4) |
C5—S1 | 1.752 (3) | C13—H13A | 0.9800 |
C6—O1 | 1.235 (3) | C13—H13B | 0.9800 |
C6—C7 | 1.501 (4) | C13—H13C | 0.9800 |
C7—H7A | 0.9800 | C12—N2 | 1.450 (4) |
C7—H7B | 0.9800 | C12—H12A | 0.9800 |
C7—H7C | 0.9800 | C12—H12B | 0.9800 |
C8—O2 | 1.210 (3) | C12—H12C | 0.9800 |
C8—O3 | 1.343 (3) | ||
C4—C1—H1A | 109.5 | C10—C9—H9A | 109.2 |
C4—C1—H1B | 109.5 | O3—C9—H9B | 109.2 |
H1A—C1—H1B | 109.5 | C10—C9—H9B | 109.2 |
C4—C1—H1C | 109.5 | H9A—C9—H9B | 107.9 |
H1A—C1—H1C | 109.5 | C9—C10—H10A | 109.5 |
H1B—C1—H1C | 109.5 | C9—C10—H10B | 109.5 |
N1—C2—C3 | 123.4 (3) | H10A—C10—H10B | 109.5 |
N1—C2—S1 | 126.5 (2) | C9—C10—H10C | 109.5 |
C3—C2—S1 | 110.1 (2) | H10A—C10—H10C | 109.5 |
C2—C3—C4 | 114.7 (3) | H10B—C10—H10C | 109.5 |
C2—C3—C8 | 122.0 (2) | N1—C11—N2 | 121.9 (3) |
C4—C3—C8 | 122.9 (2) | N1—C11—H11 | 119.0 |
C5—C4—C3 | 111.5 (2) | N2—C11—H11 | 119.0 |
C5—C4—C1 | 126.8 (2) | N2—C13—H13A | 109.5 |
C3—C4—C1 | 121.6 (3) | N2—C13—H13B | 109.5 |
C4—C5—C6 | 133.2 (3) | H13A—C13—H13B | 109.5 |
C4—C5—S1 | 112.1 (2) | N2—C13—H13C | 109.5 |
C6—C5—S1 | 114.7 (2) | H13A—C13—H13C | 109.5 |
O1—C6—C5 | 119.7 (3) | H13B—C13—H13C | 109.5 |
O1—C6—C7 | 120.2 (2) | N2—C12—H12A | 109.5 |
C5—C6—C7 | 120.1 (2) | N2—C12—H12B | 109.5 |
C6—C7—H7A | 109.5 | H12A—C12—H12B | 109.5 |
C6—C7—H7B | 109.5 | N2—C12—H12C | 109.5 |
H7A—C7—H7B | 109.5 | H12A—C12—H12C | 109.5 |
C6—C7—H7C | 109.5 | H12B—C12—H12C | 109.5 |
H7A—C7—H7C | 109.5 | C11—N1—C2 | 119.2 (2) |
H7B—C7—H7C | 109.5 | C11—N2—C12 | 122.3 (2) |
O2—C8—O3 | 123.7 (3) | C11—N2—C13 | 121.1 (2) |
O2—C8—C3 | 123.8 (3) | C12—N2—C13 | 116.5 (2) |
O3—C8—C3 | 112.5 (2) | C8—O3—C9 | 116.3 (2) |
O3—C9—C10 | 111.8 (2) | C2—S1—C5 | 91.56 (13) |
O3—C9—H9A | 109.2 | ||
N1—C2—C3—C4 | −178.5 (2) | C2—C3—C8—O2 | −117.1 (3) |
S1—C2—C3—C4 | −0.6 (3) | C4—C3—C8—O2 | 55.5 (4) |
N1—C2—C3—C8 | −5.4 (4) | C2—C3—C8—O3 | 63.5 (3) |
S1—C2—C3—C8 | 172.5 (2) | C4—C3—C8—O3 | −124.0 (3) |
C2—C3—C4—C5 | 0.0 (3) | N2—C11—N1—C2 | 178.5 (2) |
C8—C3—C4—C5 | −173.0 (2) | C3—C2—N1—C11 | −176.6 (3) |
C2—C3—C4—C1 | −179.7 (2) | S1—C2—N1—C11 | 5.8 (4) |
C8—C3—C4—C1 | 7.3 (4) | N1—C11—N2—C12 | −1.7 (4) |
C3—C4—C5—C6 | 177.1 (3) | N1—C11—N2—C13 | 179.7 (3) |
C1—C4—C5—C6 | −3.2 (5) | O2—C8—O3—C9 | 2.1 (4) |
C3—C4—C5—S1 | 0.6 (3) | C3—C8—O3—C9 | −178.4 (2) |
C1—C4—C5—S1 | −179.8 (2) | C10—C9—O3—C8 | −83.4 (3) |
C4—C5—C6—O1 | −176.9 (3) | N1—C2—S1—C5 | 178.6 (2) |
S1—C5—C6—O1 | −0.4 (3) | C3—C2—S1—C5 | 0.7 (2) |
C4—C5—C6—C7 | 1.8 (5) | C4—C5—S1—C2 | −0.8 (2) |
S1—C5—C6—C7 | 178.2 (2) | C6—C5—S1—C2 | −178.0 (2) |
Cg is the centroid of the C2/C3/C4/C5/S1 ring . |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···O2i | 0.99 | 2.45 | 3.270 (3) | 139 |
C11—H11···O1ii | 0.95 | 2.47 | 3.312 (4) | 147 |
C7—H7C···Cgiii | 0.98 | 2.86 | 3.693 (2) | 143 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, −y, −z+1; (iii) x+1/2, −y+3/2, −z. |
Cg is the centroid of the C2/C3/C4/C5/S1 ring . |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···O2i | 0.99 | 2.45 | 3.270 (3) | 139 |
C11—H11···O1ii | 0.95 | 2.47 | 3.312 (4) | 147 |
C7—H7C···Cgiii | 0.98 | 2.86 | 3.693 (2) | 143 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, −y, −z+1; (iii) x+1/2, −y+3/2, −z. |
Acknowledgements
NLP thanks the University Grants Commission (UGC), India for a CSIR–NET fellowship and MSK thanks the UGC for a UGC–BSR Meritorious fellowship.
References
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Thiophene belongs to a class of heterocyclic compounds containing a five membered ring made up of one sulfur as heteroatom, that are widely used as building blocks in many agrochemicals and pharmaceuticals. 2-Aminothiophenes attract special attention because of their applications in pharmaceuticals, agriculture, pesticides and dyes (Sabnis et al., 1999). The most convergent and well established classical approach for the preparation of 2-aminothiophenes is Gewald's method (Gewald et al., 1966), which involves the multicomponent condensation of a ketone with an activated nitrile and elemental sulfur in the presence of diethylamine as a catalyst. Herein, we report the structure of the title compound, (I).
The molecular structure of the compound is shown in Fig. 1. In the title compound, C13H18N2O3S, a thiophene derivative with dimethylamino- methyleneamino, acetyl, methyl and ethyl carboxylate substituents attached to a central thiophene ring. The thiophene ring and all the substituents are almost planar except the carboxyl group (C10/C9/O3/C8), it is slightly deviating from the plane at -83.474 (3)°. The carbonyl group of the exocyclic ester at C3 and acetyl at C5 adopts a trans orientation with C3=C2 and C5=C4 double bond respectively. The crystal structure features C—H···O interactions. The C11—H11···O1 hydrogen bonds resulting in a centrosymmetric head to head dimer with graph set R22(16) notation, which are in turn linked by another weak C9—H9A···O2 interactions to form chains of rings along [001] (Table.1; Fig. 2). In addition, weak C—H···π interactions of the type C7—H7C···Cg [Cg being the centroid of the thiophene ring (C2/C3/C4/C5/S1)] link the chains into layers parallel to (001) with a distance 2.864 Å is also observed (Fig. 3).