organic compounds
Dimethyl (E)-2-(N-phenylacetamido)but-2-enedioate
aDepartment of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, People's Republic of China
*Correspondence e-mail: chem826@hotmail.com
The title compound, C14H15NO5, was obtained from the reaction of acetanilide with dimethyl acetylenedicarboxylate in the presence of potassium carbonate. The C=C double bond adopts an E configuration and the geometry around the amide N atom is almost planar rather than pyramidal (mean deviation of 0.0032 Å from the C3N plane). The packing of the molecules in the is stabilized by intermolecular C—H⋯O hydrogen bonds.
Related literature
For background to the hydroamidation of ; Goossen et al. (2005); Cacchi & Fabrizi (2005); For structurally related compounds, see: Kawahara et al. (1989); Penney et al. (1995); Yet et al. (2003); Hua et al. (2003).
see: Severin & Doye (2007)Experimental
Crystal data
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Refinement
|
Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED; 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.
Supporting information
https://doi.org/10.1107/S1600536810050890/zl2334sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810050890/zl2334Isup2.hkl
To a solution of acetanilide (0.27 g, 2.00 mmol) and dimethyl acetylenedicarboxylate (0.29 g, 2.04 mmol) in toluene (10 ml), potassium carbonate (0.57 g, 4.13 mmol) was added at room temperature. The mixture was then refluxed for 12 h under an atmosphere of dinitrogen. After concentration, the residue was purified by flash δ 7.60-7.24 (m, 5 H, Ar), 5 .85 (s, 1 H, CH), 3.79 (s, 3 H, OCH3), 3.58 (s, 3 H, OCH3), 1.96 (s, 3 H, CH3) ppm; 13C NMR (101 MHz, CDCl3): δ 168.6, 166.4, 166.1, 152.3, 135.9, 129.6, 123.2, 121.5, 107.5, 52.8, 52.0, 20.8 ppm. ESI-MS: 300.3 [M+Na]+. Single crystals were obtained by slow evaporation of a solution in dichloromethane/hexane.
(ethyl acetate/petroleum = 1:2) to give the product as a white solid. Yield: 0.37 g, 67.2%. 1H NMR (400 MHz, CDCl3):One of the reflections, (-5 3 5), was found to be inconsistent with an I(obs) value more that 10 times SigmaW diffeent from I(calc). Inspection of the frame showed that the reflection was located at the frame edge and it was thus omitted from the refinement.
All non-hydrogen atoms were refined anisotropically. The hydrogen atoms were positioned geometrically (C—H = 0.93, 0.93 or 0.96Å for phenyl, methylene or methyl H atoms respectively) and included in the
in the riding model approximation. The displacement parameters of vinyl and phenyl H atoms were set to 1.2Ueq(C), while those of methyl H atoms were set to 1.5Ueq(C). In the final Fourier map the highest peak is 0.72 Å from atom H8A and the deepest hole is 0.59 Å from atom C8.Hydroamidation of
has proved to be an effective approach to construct enamides (Severin & Doye, 2007; Goossen et al. 2005; Cacchi & Fabrizi 2005), which are important substructures often found in natural products and synthetic drugs (Yet et al. 2003). In our studies on the reaction of dimethyl acetylenedicarboxylate with acetanilide in the presence of potassium carbonate, the title compound was formed via base mediated hydroamidation.An X-ray diffraction study has been carried out to determine the structure (Fig. 1). The C=C double bond adopts an E configuration. The geometry around the amide N atom is planar rather than pyramidal, as reflected by the small mean deviation of 0.0032 Å from the least-squares plane defined by the four constituent atoms N1, C2, C7 and C11, which is probably due to the large degree of conjugation between the amide N atom and the adjacent acetyl group (the maximium deviation from the least-squares plane defined by N1, C2, C7, C11 and O5 is 0.0956 (9) Å for N1) (Penney, et al. 1995). The C1-C2 double bond is slightly tilted against one ester group with a dihedral angle of only 9.10 (21)° between the (C2, C1, C3) plane and the (C1, C3, O1, O2) plane, but it is tilted against the other ester group with a dihedral angle of 80.25 (4)° between the (C1, C2, C5) plane and the (C2, C5, O3, O4) plane. The dihedral angle of the double bond plane (C1, C2, N1) with respect to the amide group plane (C2, N1, C7, C11) is 23.97 (18) °. The structural features of the title compound agree well with that of similar compounds reported in literature (Kawahara et al. 1989; Hua et al. 2003).
The packing of molecules in the
is stabilized by non-classical intermolecular C—H···O hydrogen bonds (Fig. 2, Table 1). The intermolecular hydrogen bonding interactions between O3 atom of the ester group and methyl C-H (C4—H4C···O3i) as well as the aromatic C-H (C14—H14A···O3ii) form a 2-D networks parallel to the ac plane, which is further cross-linked by a hydrogen bond between O5 of the other ester group and an aromatic C-H (C12—H12A···O5iii) to give a 3-D hydrogen bonding network (Symmetry codes: (i) x-1/2,-y+1/2,z-1/2; (ii) x+1/2,-y+1/2,z-1/2; (iii) -x+1,-y,-z).For background to the hydroamidation of
see: Severin & Doye (2007); Goossen et al. (2005); Cacchi & Fabrizi (2005); For structurally related compounds, see: Kawahara et al. (1989); Penney et al. (1995); Yet et al. (2003); Hua et al. (2003).Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell
CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); 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).C14H15NO5 | F(000) = 584 |
Mr = 277.27 | Dx = 1.367 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 4186 reflections |
a = 9.7920 (5) Å | θ = 2.8–29.0° |
b = 12.1917 (4) Å | µ = 0.11 mm−1 |
c = 12.2281 (6) Å | T = 173 K |
β = 112.629 (6)° | Block, colorless |
V = 1347.42 (11) Å3 | 0.15 × 0.12 × 0.10 mm |
Z = 4 |
Oxford Diffraction Gemini S Ultra diffractometer | 3009 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 2415 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
Detector resolution: 16.1930 pixels mm-1 | θmax = 27.5°, θmin = 2.8° |
ω scans | h = −12→12 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008) | k = −15→10 |
Tmin = 0.885, Tmax = 1.000 | l = −14→15 |
7263 measured reflections |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.091 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.058P)2] where P = (Fo2 + 2Fc2)/3 |
3009 reflections | (Δ/σ)max = 0.001 |
181 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C14H15NO5 | V = 1347.42 (11) Å3 |
Mr = 277.27 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 9.7920 (5) Å | µ = 0.11 mm−1 |
b = 12.1917 (4) Å | T = 173 K |
c = 12.2281 (6) Å | 0.15 × 0.12 × 0.10 mm |
β = 112.629 (6)° |
Oxford Diffraction Gemini S Ultra diffractometer | 3009 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008) | 2415 reflections with I > 2σ(I) |
Tmin = 0.885, Tmax = 1.000 | Rint = 0.029 |
7263 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.091 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.24 e Å−3 |
3009 reflections | Δρmin = −0.21 e Å−3 |
181 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | ||
O1 | 0.35048 (9) | 0.34762 (7) | 0.14129 (7) | 0.0233 (2) | |
N1 | 0.65965 (10) | 0.10602 (8) | 0.11896 (8) | 0.0173 (2) | |
C1 | 0.50153 (12) | 0.26233 (10) | 0.05139 (10) | 0.0184 (2) | |
H1A | 0.5426 | 0.2750 | −0.0045 | 0.022* | |
O2 | 0.36589 (9) | 0.41845 (7) | −0.02353 (7) | 0.0233 (2) | |
C2 | 0.54018 (12) | 0.17090 (9) | 0.11658 (10) | 0.0166 (2) | |
O3 | 0.53999 (10) | 0.14493 (7) | 0.30872 (7) | 0.0265 (2) | |
C3 | 0.39784 (12) | 0.34379 (9) | 0.06335 (10) | 0.0184 (2) | |
O4 | 0.33137 (9) | 0.10799 (7) | 0.15035 (7) | 0.0211 (2) | |
C4 | 0.27339 (14) | 0.50801 (10) | −0.01660 (12) | 0.0268 (3) | |
H4A | 0.2562 | 0.5569 | −0.0821 | 0.040* | |
H4B | 0.3218 | 0.5470 | 0.0563 | 0.040* | |
H4C | 0.1806 | 0.4797 | −0.0194 | 0.040* | |
O5 | 0.56257 (9) | −0.04796 (7) | 0.16290 (8) | 0.0233 (2) | |
C5 | 0.47167 (13) | 0.13911 (9) | 0.20343 (10) | 0.0185 (3) | |
C6 | 0.26254 (15) | 0.07359 (11) | 0.22997 (12) | 0.0295 (3) | |
H6A | 0.1618 | 0.0529 | 0.1850 | 0.044* | |
H6B | 0.2646 | 0.1330 | 0.2821 | 0.044* | |
H6C | 0.3154 | 0.0120 | 0.2757 | 0.044* | |
C7 | 0.66568 (12) | −0.00447 (9) | 0.14735 (10) | 0.0179 (2) | |
C8 | 0.80390 (13) | −0.06526 (11) | 0.15872 (11) | 0.0251 (3) | |
H8A | 0.7954 | −0.1405 | 0.1783 | 0.038* | |
H8B | 0.8875 | −0.0324 | 0.2201 | 0.038* | |
H8C | 0.8171 | −0.0617 | 0.0850 | 0.038* | |
C11 | 0.77404 (12) | 0.15731 (9) | 0.08915 (10) | 0.0167 (2) | |
C12 | 0.77754 (13) | 0.14120 (10) | −0.02186 (10) | 0.0195 (3) | |
H12A | 0.7062 | 0.0980 | −0.0778 | 0.023* | |
C13 | 0.88875 (13) | 0.19028 (10) | −0.04866 (11) | 0.0224 (3) | |
H13A | 0.8931 | 0.1790 | −0.1225 | 0.027* | |
C14 | 0.99298 (13) | 0.25583 (10) | 0.03413 (11) | 0.0247 (3) | |
H14A | 1.0673 | 0.2887 | 0.0159 | 0.030* | |
C15 | 0.98695 (13) | 0.27261 (10) | 0.14413 (11) | 0.0240 (3) | |
H15A | 1.0568 | 0.3173 | 0.1993 | 0.029* | |
C16 | 0.87727 (13) | 0.22307 (10) | 0.17251 (11) | 0.0208 (3) | |
H16A | 0.8733 | 0.2339 | 0.2465 | 0.025* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0234 (5) | 0.0234 (5) | 0.0264 (5) | 0.0029 (4) | 0.0133 (4) | −0.0002 (4) |
N1 | 0.0167 (5) | 0.0172 (5) | 0.0206 (5) | 0.0008 (4) | 0.0101 (4) | 0.0014 (4) |
C1 | 0.0176 (5) | 0.0211 (6) | 0.0188 (6) | −0.0008 (5) | 0.0094 (5) | −0.0001 (5) |
O2 | 0.0258 (5) | 0.0194 (4) | 0.0259 (5) | 0.0052 (4) | 0.0112 (4) | 0.0038 (4) |
C2 | 0.0147 (5) | 0.0190 (6) | 0.0166 (6) | −0.0013 (4) | 0.0065 (4) | −0.0031 (4) |
O3 | 0.0285 (5) | 0.0340 (5) | 0.0187 (4) | 0.0051 (4) | 0.0111 (4) | −0.0002 (4) |
C3 | 0.0147 (5) | 0.0179 (6) | 0.0209 (6) | −0.0038 (4) | 0.0049 (5) | −0.0015 (5) |
O4 | 0.0193 (4) | 0.0218 (4) | 0.0269 (5) | −0.0009 (3) | 0.0140 (4) | 0.0020 (3) |
C4 | 0.0282 (7) | 0.0187 (6) | 0.0326 (7) | 0.0055 (5) | 0.0106 (5) | 0.0020 (5) |
O5 | 0.0236 (4) | 0.0204 (4) | 0.0297 (5) | −0.0009 (4) | 0.0145 (4) | 0.0033 (4) |
C5 | 0.0195 (6) | 0.0160 (6) | 0.0228 (6) | 0.0032 (4) | 0.0113 (5) | 0.0002 (5) |
C6 | 0.0331 (7) | 0.0262 (7) | 0.0417 (8) | 0.0001 (6) | 0.0284 (6) | 0.0036 (6) |
C7 | 0.0207 (6) | 0.0190 (6) | 0.0147 (5) | 0.0009 (5) | 0.0077 (4) | 0.0009 (4) |
C8 | 0.0245 (6) | 0.0220 (6) | 0.0308 (7) | 0.0055 (5) | 0.0130 (5) | 0.0076 (5) |
C11 | 0.0161 (6) | 0.0156 (5) | 0.0207 (6) | 0.0033 (4) | 0.0097 (5) | 0.0032 (5) |
C12 | 0.0185 (6) | 0.0200 (6) | 0.0204 (6) | −0.0011 (5) | 0.0079 (5) | −0.0011 (5) |
C13 | 0.0234 (6) | 0.0258 (6) | 0.0222 (6) | 0.0001 (5) | 0.0134 (5) | 0.0024 (5) |
C14 | 0.0194 (6) | 0.0241 (6) | 0.0336 (7) | −0.0012 (5) | 0.0135 (5) | 0.0070 (5) |
C15 | 0.0187 (6) | 0.0211 (6) | 0.0292 (7) | −0.0029 (5) | 0.0059 (5) | −0.0017 (5) |
C16 | 0.0204 (6) | 0.0212 (6) | 0.0207 (6) | 0.0021 (5) | 0.0078 (5) | −0.0006 (5) |
O1—C3 | 1.2106 (14) | C6—H6B | 0.9600 |
N1—C7 | 1.3867 (15) | C6—H6C | 0.9600 |
N1—C2 | 1.4031 (14) | C7—C8 | 1.5019 (16) |
N1—C11 | 1.4466 (14) | C8—H8A | 0.9600 |
C1—C2 | 1.3376 (16) | C8—H8B | 0.9600 |
C1—C3 | 1.4672 (16) | C8—H8C | 0.9600 |
C1—H1A | 0.9300 | C11—C16 | 1.3823 (16) |
O2—C3 | 1.3413 (14) | C11—C12 | 1.3849 (16) |
O2—C4 | 1.4418 (14) | C12—C13 | 1.3878 (15) |
C2—C5 | 1.5088 (15) | C12—H12A | 0.9300 |
O3—C5 | 1.2030 (14) | C13—C14 | 1.3820 (18) |
O4—C5 | 1.3290 (14) | C13—H13A | 0.9300 |
O4—C6 | 1.4432 (13) | C14—C15 | 1.3841 (18) |
C4—H4A | 0.9600 | C14—H14A | 0.9300 |
C4—H4B | 0.9600 | C15—C16 | 1.3876 (16) |
C4—H4C | 0.9600 | C15—H15A | 0.9300 |
O5—C7 | 1.2183 (14) | C16—H16A | 0.9300 |
C6—H6A | 0.9600 | ||
C7—N1—C2 | 120.51 (9) | H6B—C6—H6C | 109.5 |
C7—N1—C11 | 121.36 (9) | O5—C7—N1 | 120.25 (10) |
C2—N1—C11 | 118.12 (9) | O5—C7—C8 | 122.84 (11) |
C2—C1—C3 | 123.55 (10) | N1—C7—C8 | 116.91 (10) |
C2—C1—H1A | 118.2 | C7—C8—H8A | 109.5 |
C3—C1—H1A | 118.2 | C7—C8—H8B | 109.5 |
C3—O2—C4 | 115.32 (9) | H8A—C8—H8B | 109.5 |
C1—C2—N1 | 121.65 (10) | C7—C8—H8C | 109.5 |
C1—C2—C5 | 122.21 (10) | H8A—C8—H8C | 109.5 |
N1—C2—C5 | 115.69 (9) | H8B—C8—H8C | 109.5 |
O1—C3—O2 | 123.64 (10) | C16—C11—C12 | 121.21 (10) |
O1—C3—C1 | 126.44 (11) | C16—C11—N1 | 118.84 (10) |
O2—C3—C1 | 109.87 (10) | C12—C11—N1 | 119.95 (10) |
C5—O4—C6 | 114.63 (10) | C11—C12—C13 | 119.20 (11) |
O2—C4—H4A | 109.5 | C11—C12—H12A | 120.4 |
O2—C4—H4B | 109.5 | C13—C12—H12A | 120.4 |
H4A—C4—H4B | 109.5 | C14—C13—C12 | 120.11 (11) |
O2—C4—H4C | 109.5 | C14—C13—H13A | 119.9 |
H4A—C4—H4C | 109.5 | C12—C13—H13A | 119.9 |
H4B—C4—H4C | 109.5 | C13—C14—C15 | 120.12 (11) |
O3—C5—O4 | 125.75 (11) | C13—C14—H14A | 119.9 |
O3—C5—C2 | 121.56 (11) | C15—C14—H14A | 119.9 |
O4—C5—C2 | 112.68 (10) | C14—C15—C16 | 120.35 (11) |
O4—C6—H6A | 109.5 | C14—C15—H15A | 119.8 |
O4—C6—H6B | 109.5 | C16—C15—H15A | 119.8 |
H6A—C6—H6B | 109.5 | C11—C16—C15 | 119.00 (11) |
O4—C6—H6C | 109.5 | C11—C16—H16A | 120.5 |
H6A—C6—H6C | 109.5 | C15—C16—H16A | 120.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4C···O3i | 0.96 | 2.53 | 3.0831 (16) | 117 |
C14—H14A···O3ii | 0.93 | 2.57 | 3.2016 (15) | 125 |
C12—H12A···O5iii | 0.93 | 2.51 | 3.3073 (15) | 145 |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x+1/2, −y+1/2, z−1/2; (iii) −x+1, −y, −z. |
Experimental details
Crystal data | |
Chemical formula | C14H15NO5 |
Mr | 277.27 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 9.7920 (5), 12.1917 (4), 12.2281 (6) |
β (°) | 112.629 (6) |
V (Å3) | 1347.42 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.15 × 0.12 × 0.10 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini S Ultra |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2008) |
Tmin, Tmax | 0.885, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7263, 3009, 2415 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.091, 1.00 |
No. of reflections | 3009 |
No. of parameters | 181 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.24, −0.21 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4C···O3i | 0.96 | 2.53 | 3.0831 (16) | 116.8 |
C14—H14A···O3ii | 0.93 | 2.57 | 3.2016 (15) | 125.2 |
C12—H12A···O5iii | 0.93 | 2.51 | 3.3073 (15) | 144.6 |
Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) x+1/2, −y+1/2, z−1/2; (iii) −x+1, −y, −z. |
Acknowledgements
The authors acknowledge the financial support from the Young Talent Project of the Department of Science & Technology of Fujian Province (grant No. 2007F3095).
References
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Hydroamidation of alkynes has proved to be an effective approach to construct enamides (Severin & Doye, 2007; Goossen et al. 2005; Cacchi & Fabrizi 2005), which are important substructures often found in natural products and synthetic drugs (Yet et al. 2003). In our studies on the reaction of dimethyl acetylenedicarboxylate with acetanilide in the presence of potassium carbonate, the title compound was formed via base mediated hydroamidation.
An X-ray diffraction study has been carried out to determine the structure (Fig. 1). The C=C double bond adopts an E configuration. The geometry around the amide N atom is planar rather than pyramidal, as reflected by the small mean deviation of 0.0032 Å from the least-squares plane defined by the four constituent atoms N1, C2, C7 and C11, which is probably due to the large degree of conjugation between the amide N atom and the adjacent acetyl group (the maximium deviation from the least-squares plane defined by N1, C2, C7, C11 and O5 is 0.0956 (9) Å for N1) (Penney, et al. 1995). The C1-C2 double bond is slightly tilted against one ester group with a dihedral angle of only 9.10 (21)° between the (C2, C1, C3) plane and the (C1, C3, O1, O2) plane, but it is tilted against the other ester group with a dihedral angle of 80.25 (4)° between the (C1, C2, C5) plane and the (C2, C5, O3, O4) plane. The dihedral angle of the double bond plane (C1, C2, N1) with respect to the amide group plane (C2, N1, C7, C11) is 23.97 (18) °. The structural features of the title compound agree well with that of similar compounds reported in literature (Kawahara et al. 1989; Hua et al. 2003).
The packing of molecules in the crystal structure is stabilized by non-classical intermolecular C—H···O hydrogen bonds (Fig. 2, Table 1). The intermolecular hydrogen bonding interactions between O3 atom of the ester group and methyl C-H (C4—H4C···O3i) as well as the aromatic C-H (C14—H14A···O3ii) form a 2-D networks parallel to the ac plane, which is further cross-linked by a hydrogen bond between O5 of the other ester group and an aromatic C-H (C12—H12A···O5iii) to give a 3-D hydrogen bonding network (Symmetry codes: (i) x-1/2,-y+1/2,z-1/2; (ii) x+1/2,-y+1/2,z-1/2; (iii) -x+1,-y,-z).