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Acta Crystallogr Sect E Struct Rep Online. 2010 September 1; 66(Pt 9): o2309.
Published online 2010 August 18. doi:  10.1107/S160053681003179X
PMCID: PMC3008020

Ethyl 3,4-dimethyl-1H-pyrrole-2-carboxyl­ate

Abstract

The non-H atoms of the title compound, C9H13NO2, are almost coplanar (r.m.s. deviation = 0.0358 Å). Weak inter­molecular N—H(...)O hydrogen bonds link the mol­ecules into zigzag chains along the b axis with graph-set motif C(5). The chains are further linked into a three-dimensional network by C—H(...)O hydrogen bonds and C—H(...)π inter­actions.

Related literature

Schiff bases containing pyrrole units have been extensively investigated due to their excellent coordination abilities, see: Wu et al. (2003 [triangle]). For our studies on bis­(pyrrol-2-yl-methyl­ene­amine) ligands, see: Wang et al., (2008 [triangle]). For a similar structure, 5-formyl-3,4-dimethyl-1H-pyrrole-2-carboxyl­ate, see Wu et al. (2009 [triangle]). For the preparation, see: Helms et al. (1992 [triangle]). For graph-set motifs, see: Etter et al. (1990 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o2309-scheme1.jpg

Experimental

Crystal data

  • C9H13NO2
  • M r = 167.20
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2309-efi1.jpg
  • a = 7.7485 (2) Å
  • b = 7.0611 (2) Å
  • c = 17.2167 (5) Å
  • β = 95.103 (2)°
  • V = 938.24 (5) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.08 mm−1
  • T = 296 K
  • 0.28 × 0.26 × 0.18 mm

Data collection

  • Bruker SMART APEX CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2007 [triangle]) T min = 0.977, T max = 0.985
  • 8174 measured reflections
  • 2146 independent reflections
  • 1579 reflections with I > 2σ(I)
  • R int = 0.019

Refinement

  • R[F 2 > 2σ(F 2)] = 0.044
  • wR(F 2) = 0.136
  • S = 1.04
  • 2146 reflections
  • 112 parameters
  • H-atom parameters constrained
  • Δρmax = 0.21 e Å−3
  • Δρmin = −0.17 e Å−3

Data collection: APEX2 (Bruker, 2007 [triangle]); cell refinement: SAINT (Bruker, 2007 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681003179X/fb2205sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053681003179X/fb2205Isup2.hkl

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

Acknowledgments

The authors are grateful for financial support by the Doctoral Foundation of Henan Polytechnic University (B2009–70 648364).

supplementary crystallographic information

Comment

Schiff bases containing pyrrole units have been extensively investigated due to their excellent coordination abilities (Wu et al., 2003). As a part of our studies on bis(pyrrol-2-yl-methyleneamine) ligands (Wang et al., 2008), the crystal structure of the title compound is reported here.

The non-hydrogen atoms of the title molecule (Fig. 1) are situated in a fair plane (r.m.s. deviation of the non-hydrogen atoms being 0.0358 Å). In the crystal structure, the molecules are linked by weak intermolecular N—H···O hydrogen bonds, forming zig-zag chains with the graph-set motifs C(5) (Etter & MacDonald, 1990). The chains are extended along the b axis (Tab. 1, Fig. 2, Fig. 3). The structure is also stabilized by the C—H···O hydrogen bonds (Tab. 1) and C—H···π-electron ring interactions (Tab. 1).

Experimental

The title compound was prepared according to Helms et al. (1992). Acetic acid (114 ml) was placed in a 1-L round-bottom flask and heated to 85 °C. Sodium acetate (31.09 g), 27.54 g of sodium 2-methyl-3-oxo-l-butene-1-oxide, 37.20 g of diethyl 2-(hydroxyimino)malonate, and a solution of 47 ml of acetic acid in 19.6 ml of H2O were then added in the respective order. The reaction temperature was raised to 95 °C, and 43.26 g of Zn-dust was added over 45 min while maintaining the temperature between 95 and 110 °C. After the addition of Zn-dust had been completed, the mixture was stirred while keeping its temperature at 110 °C for further 45 min. The reaction mixture was then poured into 500 ml of ice water. The obtained solid was filtered, washed with water and subsequently dissolved in dichloromethane. The solution was washed with saturated sodium hydrogencarbonate, dried with anhydrous sodium sulfate and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography on a silica gel [Rf = 0.68, petroleum ether-ethyl acetate (100:1) as an eluent] to yield 4.82 g (13%) of the title compound. Colourless block crystals [average size: 0.25× 0.25 × 0.20 mm] were obtained by slow evaporation of the ethyl acetate solution at room temperature.

Refinement

All the H atoms were located in the difference electron density map. The H atoms were situated into the idealized positions with the carrier atom-H distances = 0.93 Å for aryl, 0.97 for methylene, 0.96 Å for the methyl and 0.86 Å for the secondary amine hydrogens. The Uiso values were constrained to be 1.5Ueq of the carrier atom for the methyl H atoms and 1.2Ueq for the remaining H atoms.

Figures

Fig. 1.
The title molecule with the displacement ellipsoids shown at the 50% probability level.
Fig. 2.
The crystal packing for the title compound via N—H···O hydrogen bonds shown as the dashed lines.
Fig. 3.
A view showing zig-zag chains with the graph-set motifs C(5) pertinent to the N—H···O hydrogen bonds (the dashed lines) in the title structure. The atoms not involved in this motif have been omitted for clarity.

Crystal data

C9H13NO2F(000) = 360
Mr = 167.20Dx = 1.184 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3131 reflections
a = 7.7485 (2) Åθ = 2.4–24.8°
b = 7.0611 (2) ŵ = 0.08 mm1
c = 17.2167 (5) ÅT = 296 K
β = 95.103 (2)°Block, colourless
V = 938.24 (5) Å30.28 × 0.26 × 0.18 mm
Z = 4

Data collection

Bruker SMART APEX CCD diffractometer2146 independent reflections
Radiation source: fine-focus sealed tube1579 reflections with I > 2σ(I)
graphiteRint = 0.019
[var phi] and ω scansθmax = 27.5°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2007)h = −9→10
Tmin = 0.977, Tmax = 0.985k = −9→9
8174 measured reflectionsl = −22→22

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: difference Fourier map
wR(F2) = 0.136H-atom parameters constrained
S = 1.04w = 1/[σ2(Fo2) + (0.0691P)2 + 0.1432P] where P = (Fo2 + 2Fc2)/3
2146 reflections(Δ/σ)max < 0.001
112 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = −0.17 e Å3
49 constraints

Special details

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)

xyzUiso*/Ueq
O20.14704 (13)0.48430 (14)0.11453 (6)0.0534 (3)
O1−0.00527 (14)0.33077 (15)0.19987 (7)0.0615 (3)
N10.24389 (16)0.04205 (17)0.20998 (7)0.0498 (3)
H10.15970.01680.23770.060*
C20.41028 (18)0.1886 (2)0.12961 (8)0.0463 (4)
C70.12075 (18)0.34064 (19)0.16247 (8)0.0445 (3)
C10.25621 (17)0.20054 (19)0.16438 (8)0.0422 (3)
C80.0178 (2)0.6323 (2)0.10833 (10)0.0582 (4)
H8A0.01250.69460.15830.070*
H8B−0.09530.57960.09230.070*
C40.3843 (2)−0.0672 (2)0.20438 (10)0.0561 (4)
H40.4060−0.18200.22990.067*
C30.49035 (19)0.0178 (2)0.15508 (9)0.0521 (4)
C90.0697 (3)0.7705 (3)0.04886 (11)0.0686 (5)
H9A0.18370.81790.06440.103*
H9B−0.01110.87380.04470.103*
H9C0.06990.7085−0.00070.103*
C50.4845 (2)0.3287 (3)0.07667 (11)0.0702 (5)
H5A0.39730.36500.03630.105*
H5B0.58060.27250.05360.105*
H5C0.52340.43860.10600.105*
C60.6620 (2)−0.0563 (3)0.13353 (13)0.0784 (6)
H6A0.75280.02780.15330.118*
H6B0.6604−0.06400.07780.118*
H6C0.6820−0.17990.15570.118*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O20.0535 (6)0.0449 (6)0.0639 (7)0.0109 (4)0.0178 (5)0.0096 (5)
O10.0585 (7)0.0564 (7)0.0742 (8)0.0072 (5)0.0314 (6)0.0035 (5)
N10.0523 (7)0.0466 (7)0.0523 (7)0.0007 (5)0.0151 (6)0.0061 (5)
C20.0450 (7)0.0479 (8)0.0469 (8)0.0013 (6)0.0092 (6)0.0019 (6)
C70.0464 (7)0.0416 (7)0.0467 (8)−0.0002 (6)0.0107 (6)−0.0038 (6)
C10.0433 (7)0.0403 (7)0.0440 (7)0.0001 (5)0.0091 (6)0.0021 (6)
C80.0595 (9)0.0451 (8)0.0711 (10)0.0133 (7)0.0119 (8)0.0018 (8)
C40.0615 (9)0.0468 (8)0.0595 (9)0.0088 (7)0.0025 (7)0.0079 (7)
C30.0462 (8)0.0545 (9)0.0560 (9)0.0084 (6)0.0059 (7)−0.0004 (7)
C90.0832 (12)0.0541 (10)0.0685 (11)0.0128 (9)0.0066 (9)0.0102 (9)
C50.0643 (10)0.0732 (12)0.0775 (12)0.0024 (9)0.0302 (9)0.0191 (9)
C60.0571 (10)0.0842 (13)0.0950 (14)0.0260 (9)0.0134 (10)0.0026 (11)

Geometric parameters (Å, °)

O2—C71.3347 (17)C4—C31.371 (2)
O2—C81.4446 (17)C4—H40.9300
O1—C71.2186 (17)C3—C61.506 (2)
N1—C41.3440 (19)C9—H9A0.9600
N1—C11.3752 (17)C9—H9B0.9600
N1—H10.8600C9—H9C0.9600
C2—C11.3849 (19)C5—H5A0.9600
C2—C31.409 (2)C5—H5B0.9600
C2—C51.494 (2)C5—H5C0.9600
C7—C11.4406 (19)C6—H6A0.9600
C8—C91.495 (2)C6—H6B0.9600
C8—H8A0.9700C6—H6C0.9600
C8—H8B0.9700
C7—O2—C8116.91 (12)C4—C3—C2107.21 (13)
C4—N1—C1109.16 (12)C4—C3—C6126.27 (15)
C4—N1—H1125.4C2—C3—C6126.51 (15)
C1—N1—H1125.4C8—C9—H9A109.5
C1—C2—C3106.86 (12)C8—C9—H9B109.5
C1—C2—C5128.10 (13)H9A—C9—H9B109.5
C3—C2—C5125.02 (13)C8—C9—H9C109.5
O1—C7—O2122.94 (13)H9A—C9—H9C109.5
O1—C7—C1124.41 (14)H9B—C9—H9C109.5
O2—C7—C1112.65 (12)C2—C5—H5A109.5
N1—C1—C2107.69 (12)C2—C5—H5B109.5
N1—C1—C7118.98 (12)H5A—C5—H5B109.5
C2—C1—C7133.32 (13)C2—C5—H5C109.5
O2—C8—C9107.22 (13)H5A—C5—H5C109.5
O2—C8—H8A110.3H5B—C5—H5C109.5
C9—C8—H8A110.3C3—C6—H6A109.5
O2—C8—H8B110.3C3—C6—H6B109.5
C9—C8—H8B110.3H6A—C6—H6B109.5
H8A—C8—H8B108.5C3—C6—H6C109.5
N1—C4—C3109.09 (14)H6A—C6—H6C109.5
N1—C4—H4125.5H6B—C6—H6C109.5
C3—C4—H4125.5
C8—O2—C7—O10.1 (2)O1—C7—C1—C2−177.02 (15)
C8—O2—C7—C1179.83 (13)O2—C7—C1—C23.3 (2)
C4—N1—C1—C2−0.19 (16)C7—O2—C8—C9−177.04 (13)
C4—N1—C1—C7−178.84 (13)C1—N1—C4—C3−0.06 (18)
C3—C2—C1—N10.37 (16)N1—C4—C3—C20.29 (18)
C5—C2—C1—N1−178.16 (16)N1—C4—C3—C6179.24 (16)
C3—C2—C1—C7178.74 (16)C1—C2—C3—C4−0.40 (17)
C5—C2—C1—C70.2 (3)C5—C2—C3—C4178.18 (16)
O1—C7—C1—N11.2 (2)C1—C2—C3—C6−179.35 (16)
O2—C7—C1—N1−178.46 (12)C5—C2—C3—C6−0.8 (3)

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the N1,C1–C4 ring.
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.862.132.9264 (16)154.
C5—H5A···O20.962.602.962 (2)103.
C4—H4···Cg1ii0.932.923.7520 (17)149
C9—H9A···Cg1iii0.962.863.650 (2)141

Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x, y+1, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FB2205).

References

  • Bruker (2007). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA .
  • Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. [PubMed]
  • Helms, A., Heiler, D. & McLendon, G. (1992). J. Am. Chem. Soc.114, 6221–6238.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wang, Y., Yang, Z.-Y. & Chen, Z.-N. (2008). Bioorg. Med. Chem. Lett.18, 298–303. [PubMed]
  • Wu, Z. K., Chen, Q. Q., Xiong, S. X., Xin, B., Zhao, Z. W., Jiang, L. J. & Ma, J. S. (2003). Angew. Chem. Int. Ed.42, 3271–3274. [PubMed]
  • Wu, W.-N., Wang, Y. & Wang, Q.-F. (2009). Acta Cryst. E65, o1661. [PMC free article] [PubMed]

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