organic compounds
(E)-3-Dimethylamino-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one
aMedicinal, Aromatic and Poisonous Plants Research Center (MAPPRC), College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia, bDepartment of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia, and cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my
In the title compound, C11H15NOS, the 3-(dimethylamino)prop-2-en-1-one unit is approximately planar [maximum deviation = 0.0975 (14) Å] and its mean plane of seven non-H atoms makes a dihedral angle of 6.96 (10)° with the thiophene ring. In the crystal, molecules are linked by pairs of C—H⋯O hydrogen bonds into inversion dimers with R22(14) ring motifs. The dimers are stacked along the c axis through C—H⋯π interactions. The two methyl groups, attached to the thiophene ring and the amino N atom, are each disordered over two orientations, with site-occupancy ratios of 0.59 (4):0.41 (4) and 0.74 (4):0.26 (4), respectively.
Related literature
For background to and the biological activity of thiophene derivatives, see: Ghorab et al. (2006); Al-Said et al. (2011); Shaaban et al. (2010); Krantz et al. (1990); Kikugawa & Ichino (1973); Gogte et al. (1967); Medower et al. (2008); Ghorab et al. (1998); Hassan et al. (1998). For hydrogen-bond motifs, see: Bernstein et al. (1995).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2009); cell SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).
Supporting information
10.1107/S1600536812021022/is5136sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812021022/is5136Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812021022/is5136Isup3.cml
A mixture of 1-(2,5-dimethylthiophen-3-yl)ethanone (1.54 g, 0.01 mole) and dimethylformamide-dimethylacetal (1.19 g, 0.01 mole) in dry N,N-dimethylformamide (20 ml) was heated under reflux for 5 h. The reaction mixture was cooled and poured into ice water. The solid obtained was then recrystallized from ethanol to give the title compound. Single crystals suitable for X-ray structural analysis were obtained by slow evaporation from an N,N-dimethylformamide solution at room temperature.
The major parts of disordered H atoms attached to atoms C5 and C11 [(H5A, H5B, H5C) and (H11A, H11B, H11C)] were positioned geometrically, whereas the corresponding minor parts, (H5X, H5Y, H5Z) and (H11X, H11Y, H11Z) were located in a difference Fourier map. A rotating group model was used for both major and minor parts of disorders and refined using a riding model with Uiso(H) = 1.5Ueq(C) (C—H distance = 0.96 Å). The refined site-occupancy ratios are (H5A, H5B, H5C):(H5X, H5Y, H5Z) = 0.59 (4):0.41 (4) and (H11A, H11B, H11C):(H11X, H11Y, H11Z) = 0.74 (4):0.26 (4). The remaining H atoms were positioned geometrically (C—H = 0.93 and 0.96 Å) and refined with Uiso(H) = 1.2 or 1.5Ueq(C). Rotating group model was also applied to the other methyl groups in the final refinement.
Data collection: APEX2 (Bruker, 2009); cell
SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).C11H15NOS | Z = 2 |
Mr = 209.30 | F(000) = 224 |
Triclinic, P1 | Dx = 1.207 Mg m−3 |
Hall symbol: -P 1 | Cu Kα radiation, λ = 1.54178 Å |
a = 5.9114 (2) Å | Cell parameters from 967 reflections |
b = 7.5424 (2) Å | θ = 3.2–67.4° |
c = 13.9940 (4) Å | µ = 2.24 mm−1 |
α = 81.274 (2)° | T = 296 K |
β = 88.828 (3)° | Plate, pink |
γ = 69.119 (3)° | 0.82 × 0.15 × 0.07 mm |
V = 575.83 (3) Å3 |
Bruker SMART APEXII CCD area-detector diffractometer | 1897 independent reflections |
Radiation source: fine-focus sealed tube | 1650 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.034 |
ϕ and ω scans | θmax = 65.0°, θmin = 3.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −6→5 |
Tmin = 0.260, Tmax = 0.859 | k = −8→8 |
7188 measured reflections | l = −16→16 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.039 | H-atom parameters constrained |
wR(F2) = 0.114 | w = 1/[σ2(Fo2) + (0.0443P)2 + 0.1016P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max < 0.001 |
1897 reflections | Δρmax = 0.16 e Å−3 |
134 parameters | Δρmin = −0.18 e Å−3 |
0 restraints | Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.010 (2) |
C11H15NOS | γ = 69.119 (3)° |
Mr = 209.30 | V = 575.83 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 5.9114 (2) Å | Cu Kα radiation |
b = 7.5424 (2) Å | µ = 2.24 mm−1 |
c = 13.9940 (4) Å | T = 296 K |
α = 81.274 (2)° | 0.82 × 0.15 × 0.07 mm |
β = 88.828 (3)° |
Bruker SMART APEXII CCD area-detector diffractometer | 1897 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 1650 reflections with I > 2σ(I) |
Tmin = 0.260, Tmax = 0.859 | Rint = 0.034 |
7188 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.16 e Å−3 |
1897 reflections | Δρmin = −0.18 e Å−3 |
134 parameters |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
S1 | 0.02985 (11) | 0.64848 (8) | 0.08507 (4) | 0.0778 (3) | |
O1 | 0.0467 (3) | 0.8400 (2) | 0.37669 (10) | 0.0842 (5) | |
N1 | 0.3675 (3) | 1.2353 (2) | 0.39674 (11) | 0.0645 (4) | |
C1 | −0.0007 (3) | 0.7081 (3) | 0.19944 (13) | 0.0608 (5) | |
C2 | 0.1315 (3) | 0.8191 (3) | 0.21208 (12) | 0.0572 (4) | |
C3 | 0.2590 (4) | 0.8516 (3) | 0.12684 (14) | 0.0665 (5) | |
H3A | 0.3579 | 0.9244 | 0.1232 | 0.080* | |
C4 | 0.2241 (4) | 0.7685 (3) | 0.05249 (15) | 0.0722 (5) | |
C5 | 0.3269 (5) | 0.7734 (4) | −0.04686 (17) | 0.0935 (8) | |
H5A | 0.4761 | 0.7964 | −0.0444 | 0.140* | 0.59 (4) |
H5B | 0.2134 | 0.8744 | −0.0910 | 0.140* | 0.59 (4) |
H5C | 0.3567 | 0.6526 | −0.0686 | 0.140* | 0.59 (4) |
H5X | 0.4875 | 0.6789 | −0.0443 | 0.140* | 0.41 (4) |
H5Y | 0.3329 | 0.8986 | −0.0688 | 0.140* | 0.41 (4) |
H5Z | 0.2258 | 0.7459 | −0.0909 | 0.140* | 0.41 (4) |
C6 | −0.1564 (4) | 0.6318 (3) | 0.26736 (16) | 0.0741 (6) | |
H6A | −0.2750 | 0.7362 | 0.2930 | 0.111* | |
H6B | −0.0568 | 0.5417 | 0.3194 | 0.111* | |
H6C | −0.2368 | 0.5689 | 0.2330 | 0.111* | |
C7 | 0.1383 (3) | 0.8968 (3) | 0.30347 (13) | 0.0591 (5) | |
C8 | 0.2539 (3) | 1.0343 (3) | 0.30342 (13) | 0.0594 (5) | |
H8A | 0.3279 | 1.0684 | 0.2480 | 0.071* | |
C9 | 0.2569 (3) | 1.1156 (3) | 0.38331 (13) | 0.0580 (4) | |
H9A | 0.1705 | 1.0833 | 0.4351 | 0.070* | |
C10 | 0.3421 (4) | 1.3206 (3) | 0.48415 (16) | 0.0786 (6) | |
H10A | 0.2444 | 1.2712 | 0.5282 | 0.118* | |
H10B | 0.2658 | 1.4575 | 0.4684 | 0.118* | |
H10C | 0.4992 | 1.2896 | 0.5139 | 0.118* | |
C11 | 0.5161 (5) | 1.2903 (4) | 0.3226 (2) | 0.0893 (7) | |
H11A | 0.6385 | 1.1771 | 0.3058 | 0.134* | 0.74 (4) |
H11B | 0.5917 | 1.3690 | 0.3467 | 0.134* | 0.74 (4) |
H11C | 0.4161 | 1.3613 | 0.2663 | 0.134* | 0.74 (4) |
H11X | 0.6789 | 1.2527 | 0.3480 | 0.134* | 0.26 (4) |
H11Y | 0.4512 | 1.4270 | 0.3030 | 0.134* | 0.26 (4) |
H11Z | 0.5163 | 1.2276 | 0.2678 | 0.134* | 0.26 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0865 (4) | 0.0846 (4) | 0.0703 (4) | −0.0331 (3) | 0.0027 (3) | −0.0296 (3) |
O1 | 0.1196 (13) | 0.1037 (12) | 0.0637 (8) | −0.0794 (10) | 0.0170 (8) | −0.0201 (7) |
N1 | 0.0697 (10) | 0.0645 (9) | 0.0719 (10) | −0.0393 (8) | 0.0060 (7) | −0.0110 (7) |
C1 | 0.0613 (10) | 0.0593 (10) | 0.0623 (10) | −0.0210 (8) | −0.0024 (8) | −0.0123 (8) |
C2 | 0.0598 (10) | 0.0558 (10) | 0.0570 (10) | −0.0220 (8) | −0.0008 (7) | −0.0079 (8) |
C3 | 0.0681 (12) | 0.0701 (12) | 0.0638 (11) | −0.0280 (10) | 0.0062 (9) | −0.0105 (9) |
C4 | 0.0711 (12) | 0.0748 (13) | 0.0616 (11) | −0.0145 (10) | 0.0038 (9) | −0.0119 (9) |
C5 | 0.1003 (18) | 0.1024 (19) | 0.0662 (13) | −0.0218 (14) | 0.0163 (12) | −0.0163 (12) |
C6 | 0.0784 (14) | 0.0821 (14) | 0.0782 (13) | −0.0463 (11) | 0.0042 (10) | −0.0184 (10) |
C7 | 0.0625 (11) | 0.0611 (11) | 0.0599 (10) | −0.0301 (9) | 0.0011 (8) | −0.0078 (8) |
C8 | 0.0635 (11) | 0.0600 (11) | 0.0603 (10) | −0.0294 (8) | 0.0065 (8) | −0.0084 (8) |
C9 | 0.0583 (10) | 0.0559 (10) | 0.0653 (10) | −0.0289 (8) | 0.0025 (8) | −0.0050 (8) |
C10 | 0.0951 (16) | 0.0787 (14) | 0.0786 (13) | −0.0489 (12) | −0.0018 (11) | −0.0164 (11) |
C11 | 0.0905 (16) | 0.0933 (16) | 0.1066 (17) | −0.0600 (14) | 0.0237 (13) | −0.0189 (13) |
S1—C4 | 1.715 (2) | C5—H5Z | 0.9600 |
S1—C1 | 1.7161 (19) | C6—H6A | 0.9600 |
O1—C7 | 1.239 (2) | C6—H6B | 0.9600 |
N1—C9 | 1.325 (2) | C6—H6C | 0.9600 |
N1—C10 | 1.447 (3) | C7—C8 | 1.431 (3) |
N1—C11 | 1.453 (3) | C8—C9 | 1.357 (3) |
C1—C2 | 1.364 (3) | C8—H8A | 0.9300 |
C1—C6 | 1.502 (3) | C9—H9A | 0.9300 |
C2—C3 | 1.434 (3) | C10—H10A | 0.9600 |
C2—C7 | 1.492 (3) | C10—H10B | 0.9600 |
C3—C4 | 1.348 (3) | C10—H10C | 0.9600 |
C3—H3A | 0.9300 | C11—H11A | 0.9600 |
C4—C5 | 1.506 (3) | C11—H11B | 0.9600 |
C5—H5A | 0.9600 | C11—H11C | 0.9600 |
C5—H5B | 0.9600 | C11—H11X | 0.9600 |
C5—H5C | 0.9600 | C11—H11Y | 0.9600 |
C5—H5X | 0.9600 | C11—H11Z | 0.9600 |
C5—H5Y | 0.9600 | ||
C4—S1—C1 | 93.45 (9) | C1—C6—H6C | 109.5 |
C9—N1—C10 | 121.97 (16) | H6A—C6—H6C | 109.5 |
C9—N1—C11 | 121.03 (18) | H6B—C6—H6C | 109.5 |
C10—N1—C11 | 116.98 (17) | O1—C7—C8 | 122.18 (17) |
C2—C1—C6 | 131.23 (18) | O1—C7—C2 | 119.57 (17) |
C2—C1—S1 | 110.76 (14) | C8—C7—C2 | 118.26 (16) |
C6—C1—S1 | 118.00 (14) | C9—C8—C7 | 120.80 (17) |
C1—C2—C3 | 111.44 (17) | C9—C8—H8A | 119.6 |
C1—C2—C7 | 123.46 (16) | C7—C8—H8A | 119.6 |
C3—C2—C7 | 125.09 (17) | N1—C9—C8 | 128.09 (17) |
C4—C3—C2 | 114.75 (19) | N1—C9—H9A | 116.0 |
C4—C3—H3A | 122.6 | C8—C9—H9A | 116.0 |
C2—C3—H3A | 122.6 | N1—C10—H10A | 109.5 |
C3—C4—C5 | 129.0 (2) | N1—C10—H10B | 109.5 |
C3—C4—S1 | 109.58 (15) | H10A—C10—H10B | 109.5 |
C5—C4—S1 | 121.38 (19) | N1—C10—H10C | 109.5 |
C4—C5—H5A | 109.5 | H10A—C10—H10C | 109.5 |
C4—C5—H5B | 109.5 | H10B—C10—H10C | 109.5 |
C4—C5—H5C | 109.5 | N1—C11—H11A | 109.5 |
C4—C5—H5X | 109.5 | N1—C11—H11B | 109.5 |
C4—C5—H5Y | 109.5 | N1—C11—H11C | 109.5 |
H5X—C5—H5Y | 109.5 | N1—C11—H11X | 109.5 |
C4—C5—H5Z | 109.5 | N1—C11—H11Y | 109.5 |
H5X—C5—H5Z | 109.5 | H11X—C11—H11Y | 109.5 |
H5Y—C5—H5Z | 109.5 | N1—C11—H11Z | 109.5 |
C1—C6—H6A | 109.5 | H11X—C11—H11Z | 109.5 |
C1—C6—H6B | 109.5 | H11Y—C11—H11Z | 109.5 |
H6A—C6—H6B | 109.5 | ||
C4—S1—C1—C2 | 0.81 (15) | C1—S1—C4—C5 | −179.91 (19) |
C4—S1—C1—C6 | −178.17 (16) | C1—C2—C7—O1 | 9.8 (3) |
C6—C1—C2—C3 | 178.17 (19) | C3—C2—C7—O1 | −170.80 (19) |
S1—C1—C2—C3 | −0.6 (2) | C1—C2—C7—C8 | −170.86 (17) |
C6—C1—C2—C7 | −2.3 (3) | C3—C2—C7—C8 | 8.6 (3) |
S1—C1—C2—C7 | 178.87 (14) | O1—C7—C8—C9 | −3.3 (3) |
C1—C2—C3—C4 | 0.1 (2) | C2—C7—C8—C9 | 177.32 (17) |
C7—C2—C3—C4 | −179.42 (18) | C10—N1—C9—C8 | 176.0 (2) |
C2—C3—C4—C5 | 179.6 (2) | C11—N1—C9—C8 | −2.5 (3) |
C2—C3—C4—S1 | 0.5 (2) | C7—C8—C9—N1 | 175.62 (18) |
C1—S1—C4—C3 | −0.76 (17) |
Cg1 is the centroid of the S1/C1–C4 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C10—H10A···O1i | 0.96 | 2.46 | 3.410 (3) | 172 |
C5—H5B···Cg1ii | 0.96 | 2.77 | 3.641 (3) | 152 |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) −x, −y+2, −z. |
Experimental details
Crystal data | |
Chemical formula | C11H15NOS |
Mr | 209.30 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 5.9114 (2), 7.5424 (2), 13.9940 (4) |
α, β, γ (°) | 81.274 (2), 88.828 (3), 69.119 (3) |
V (Å3) | 575.83 (3) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 2.24 |
Crystal size (mm) | 0.82 × 0.15 × 0.07 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.260, 0.859 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7188, 1897, 1650 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.588 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.114, 1.08 |
No. of reflections | 1897 |
No. of parameters | 134 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.16, −0.18 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
Cg1 is the centroid of the S1/C1–C4 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C10—H10A···O1i | 0.96 | 2.46 | 3.410 (3) | 172 |
C5—H5B···Cg1ii | 0.96 | 2.77 | 3.641 (3) | 152 |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) −x, −y+2, −z. |
Footnotes
‡Thomson Reuters ResearcherID: A-3561-2009.
Acknowledgements
MMG, MSAS and HAG acknowledge the sponsorship of the Research Center, College of Pharmacy and the Deanship of Scientific Research, King Saud University, Riyadh, Saudi Arabia. HKF and TSC thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSC also thanks the Malaysian Government and USM for the award of a research fellowship.
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
As part of a program designed to investigate the biological activity of tricyclic and tetracyclic heterocyclic systems containing a thiophene ring as the central nucleus (Ghorab et al., 2006), recently we have put forward a convenient way to synthesize thiophene derivatives as anticancer agents (Al-Said et al., 2011; Shaaban et al., 2010). A survey of the literature showed that thiophene derivatives possess antihypertensive action (Krantz et al., 1990), platelet aggregation inhibition (Kikugawa & Ichino, 1973) and antineoplastic activities (Gogte et al., 1967; Medower et al., 2008). In addition, several nitrogen, oxygen and sulfur-containing heterocyclic compounds incorporating thiophene residues were found to possess interesting biological properties (Ghorab et al., 1998; Hassan et al., 1998). In continuation of our work on the synthesis of a novel thiophene derivative which might show significant anticancer activity, the title compound was prepared and its crystal structure is now reported.
The molecular structure of the title compound is shown in Fig. 1. The mean plane of dimethylthiophene ring [S1/C1–C6; maximum deviation = 0.0180 (12) Å at atom C6] forms a dihedral angle of 6.63 (12)° with the mean plane of the rest non-H atoms [O1/N1/C7–C11; maximum deviation = 0.0975 (14) Å at atom O1]. In the molecule, the hydrogen atoms attached to atoms C5 and C11 are each disordered over two positions with site-occupancy ratios of (H5A, H5B, H5C):(H5X, H5Y, H5Z) = 0.59 (4):0.41 (4) and (H11A, H11B, H11C):(H11X, H11Y, H11Z) = 0.74 (4):0.26 (4), respectively.
In the crystal (Fig. 2), molecules are linked by pairs of intermolecular C10—H10A···O1 hydrogen bonds into inversion dimers with an R22(14) ring motif (Bernstein et al., 1995) and are further stacked parallel to the a axis. The crystal packing is further stabilized by C—H···π interaction (Table 1), involving Cg1 which is the centroid of S1/C1–C4 ring.