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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 7| July 2010| Page o1655
doi:10.1107/S1600536810022051

Ethyl 3,4-di­methyl-5-[(E)-(phenyl­imino)­meth­yl]-1H-pyrrole-2-carboxyl­ate

Wei-Na Wu,a* Lei Yang,a Xiao-Xia Li,b Bao-Feng Qinc and Qiu-Fen Wanga

aDepartment of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000, People's Republic of China, bInstitute of Functional Materials, Jiangxi University of Finance & Economics, Nanchang330013, People's Republic of China, and cLanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
*Correspondence e-mail: wuwn08@hpu.edu.cn

(Received 12 April 2010; accepted 9 June 2010; online 16 June 2010)

In the title compound, C16H18N2O2, the mol­ecule adopts an E conformation about the C=N double bond. The dihedral angle between the pyrrole and phenyl rings is 41.55 (8)°. In the crystal structure, pairs of inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. In the dimer, the two pyrrole rings are almost coplanar and the two phenyl rings are parallel to each other.

Related literature

For the structure of 5-formyl-3,4-dimethyl-1H-pyrrole-2-carboxyl­ate, see Wu et al. (2009[Wu, W.-N., Wang, Y. & Wang, Q.-F. (2009). Acta Cryst. E65, o1661.]). For the similar structure of ethyl 5-[(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyra­zol-4-yl)imino­meth­yl]-3,4-dimethyl-1H-pyrrole-2-carboxyl­ate, see Wang et al. (2009[Wang, Y., Wu, W.-N. & Wang, Q.-F. (2009). Acta Cryst. E65, o1933.]). For the coordination abilities for metal ions of pyrrol-2-yl­methyl­ene­amine ligands, see: Wang et al. (2010[Wang, Y., Wu, W.-N., Wang, Q. & Yang, Z.-Y. (2010). J. Coord. Chem. 63, 147-155.]); Yang et al. (2003[Yang, L. Y., Chen, Q. Q., Yang, G. Q. & Ma, J. S. (2003). Tetrahedron, 59, 10037-10041.]).

[Scheme 1]

Experimental

Crystal data

  • C16H18N2O2

  • Mr = 270.32

  • Monoclinic, P 21 /c

  • a = 12.5463 (7) Å

  • b = 14.6525 (9) Å

  • c = 8.4490 (5) Å

  • β = 105.042 (3)°

  • V = 1500.00 (15) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 296 K

  • 0.35 × 0.26 × 0.18 mm
Data collection

  • Bruker SMART CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.975, Tmax = 0.986

  • 12405 measured reflections

  • 3413 independent reflections

  • 2078 reflections with I > 2σ(I)

  • Rint = 0.030
Refinement

  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.144

  • S = 1.01

  • 3413 reflections

  • 184 parameters

  • H-atom parameters constrained

  • Δρmax = 0.20 e Å−3

  • Δρmin = −0.16 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N2—H2A⋯O3i 0.86 2.06 2.8883 (18) 162
Symmetry code: (i) -x, -y, -z.

Data collection: SMART (Bruker, 1997[Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1997[Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810022051/gw2080sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810022051/gw2080Isup2.hkl

checkCIF report


Comment top

Pyrrol-2-ylmethyleneamine ligands have attracted much recent attention due to their excellent coordination abilities for metal ions (Yang et al., 2006 & Wang et al., 2010). As part of our ongoing search for a biologically active material, the title compound was synthesized and characterized by X-ray diffraction.

In the title compound, all the bond lengths are comparable with those observed in the other similar compound (Wang et al., 2009). The molecule adopts an E configuration at the C=N double bond. The dihedral angle between pyrrole ring (N2/C8–C11, r.m.s. deviation 0.0035 Å) and phenyl ring (C1–C6, r.m.s. deviation 0.0036 Å) is 41.55 (8)°. In the crystal, the molecules are linked into a centrosymmetric dimer by two intermolecular N—H···O hydrogen bonds, forming a R22(10) ring motif (Table1, Fig. 2). In the dimer, the two pyrrole rings are almost coplanar (r.m.s. deviation 0.028 Å) and the two phenyl rings are parallel with each other. The crystal packing is further stabilized by the stacking between the C=N with the adjacent pyrrole ring, with centroid–centroid distances of 3.642 Å.

Related literature top

For the structure of 5-formyl-3,4-dimethyl-1H-pyrrole-2-carboxylate, see Wu et al. (2009). For the similar structure of ethyl 5-[(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)iminomethyl]- 3,4-dimethyl-1H-pyrrole-2-carboxylate, see Wang et al. (2009). For the coordination abilities for metal ions of pyrrol-2-ylmethyleneamine ligands, see: Wang et al. (2010); Yang et al. (2003).

Experimental top

A quantity of aniline (0.186 g, 2 mmol) was dissolved in ethanol (10 ml), then an ethanol solution (10 ml) containing ethyl 5-formyl-3,4-dimethyl-1H-pyrrole-2-carboxylate (0.39 g, 2 mmol) was added dropwise at room temperature. After stirring for 4 h, the mixture was filtered and set aside to crystallize at room temperature for several days, giving yellow block crystals.

Refinement top

All H atoms were placed in calculated positions, with C—H = 0.93–0.97 Å and N—H = 0.86 Å, and were thereafter treated as riding, with Uiso(H) values of 1.5Ueq(C) for methyl groups and 1.2Ueq(C,N) for others.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure shown with 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. Crystal packing of the title compound showing the dimers formed by hydrogen bonds (dashed lines).
Ethyl 3,4-dimethyl-5-[(E)-(phenylimino)methyl]-1H-pyrrole-2-carboxylate top
Crystal data top
C16H18N2O2F(000) = 576
Mr = 270.32Dx = 1.197 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 5515 reflections
a = 12.5463 (7) Åθ = 2.2–26.2°
b = 14.6525 (9) ŵ = 0.08 mm−1
c = 8.4490 (5) ÅT = 296 K
β = 105.042 (3)°Block, yellow
V = 1500.00 (15) Å30.35 × 0.26 × 0.18 mm
Z = 4
Data collection top
Bruker SMART CCD
diffractometer		3413 independent reflections
Radiation source: fine-focus sealed tube2078 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.030
phi and ω scansθmax = 27.6°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −14→16
Tmin = 0.975, Tmax = 0.986k = −14→19
12405 measured reflectionsl = −10→8
Refinement top
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: inferred from neighbouring sites
wR(F2) = 0.144H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.0645P)2 + 0.3198P]
where P = (Fo2 + 2Fc2)/3
3413 reflections(Δ/σ)max = 0.007
184 parametersΔρmax = 0.20 e Å−3
0 restraintsΔρmin = −0.16 e Å−3
Crystal data top
C16H18N2O2V = 1500.00 (15) Å3
Mr = 270.32Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.5463 (7) ŵ = 0.08 mm−1
b = 14.6525 (9) ÅT = 296 K
c = 8.4490 (5) Å0.35 × 0.26 × 0.18 mm
β = 105.042 (3)°
Data collection top
Bruker SMART CCD
diffractometer		3413 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		2078 reflections with I > 2σ(I)
Tmin = 0.975, Tmax = 0.986Rint = 0.030
12405 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.144H-atom parameters constrained
S = 1.01Δρmax = 0.20 e Å−3
3413 reflectionsΔρmin = −0.16 e Å−3
184 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
xyzUiso*/Ueq
N20.02009 (11)0.14614 (9)0.03549 (16)0.0474 (3)
H2A−0.01300.0983−0.01250.057*
O20.24807 (9)0.06709 (8)0.35169 (14)0.0576 (3)
O30.12317 (10)−0.01491 (9)0.17093 (15)0.0612 (4)
C140.15990 (13)0.05888 (12)0.22476 (19)0.0462 (4)
C110.11351 (13)0.14570 (11)0.16129 (19)0.0444 (4)
N1−0.15004 (12)0.33049 (10)−0.16873 (18)0.0545 (4)
C8−0.01284 (13)0.23366 (11)−0.0027 (2)0.0466 (4)
C100.14228 (13)0.23604 (11)0.20337 (19)0.0458 (4)
C4−0.25266 (15)0.33933 (12)−0.2860 (2)0.0543 (5)
C7−0.11212 (14)0.25067 (12)−0.1305 (2)0.0514 (4)
H7−0.15000.2012−0.18740.062*
C90.06264 (13)0.29161 (11)0.1002 (2)0.0465 (4)
C120.05849 (16)0.39340 (12)0.1001 (2)0.0619 (5)
H12A0.03080.4150−0.01020.093*
H12B0.13130.41720.14520.093*
H12C0.01060.41350.16520.093*
C3−0.26627 (17)0.41010 (14)−0.3976 (2)0.0634 (5)
H3−0.20720.4482−0.39850.076*
C130.24063 (14)0.26959 (13)0.3311 (2)0.0606 (5)
H13A0.23670.33470.33990.091*
H13B0.30670.25330.30060.091*
H13C0.24160.24220.43470.091*
C2−0.3674 (2)0.42436 (17)−0.5076 (3)0.0782 (7)
H2−0.37560.4714−0.58380.094*
C150.29547 (16)−0.01538 (14)0.4354 (2)0.0635 (5)
H15A0.3295−0.05150.36560.076*
H15B0.2388−0.05190.46440.076*
C160.37962 (17)0.01386 (17)0.5854 (3)0.0793 (6)
H16A0.43270.05280.55530.119*
H16B0.4163−0.03890.64160.119*
H16C0.34420.04650.65620.119*
C5−0.34233 (16)0.28429 (15)−0.2859 (3)0.0727 (6)
H5−0.33480.2364−0.21160.087*
C1−0.4555 (2)0.37029 (19)−0.5058 (3)0.0869 (7)
H1−0.52380.3809−0.57890.104*
C6−0.44248 (18)0.30041 (18)−0.3958 (3)0.0893 (7)
H6−0.50230.2631−0.39500.107*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N20.0494 (8)0.0418 (8)0.0461 (8)0.0011 (6)0.0038 (6)−0.0006 (6)
O20.0557 (7)0.0545 (8)0.0523 (7)0.0022 (6)−0.0044 (6)0.0051 (6)
O30.0666 (8)0.0467 (8)0.0594 (8)0.0035 (6)−0.0030 (6)−0.0027 (6)
C140.0456 (9)0.0511 (11)0.0405 (9)0.0002 (8)0.0086 (7)−0.0011 (7)
C110.0459 (9)0.0457 (9)0.0396 (9)−0.0005 (7)0.0075 (7)0.0011 (7)
N10.0567 (9)0.0494 (9)0.0542 (9)0.0074 (7)0.0083 (7)0.0051 (7)
C80.0506 (9)0.0433 (9)0.0460 (9)0.0041 (7)0.0128 (7)0.0036 (7)
C100.0492 (9)0.0479 (10)0.0420 (9)−0.0043 (7)0.0149 (7)−0.0020 (7)
C40.0579 (10)0.0494 (10)0.0528 (11)0.0119 (8)0.0092 (8)0.0005 (8)
C70.0540 (10)0.0481 (10)0.0496 (10)0.0036 (8)0.0089 (8)0.0022 (8)
C90.0512 (9)0.0446 (9)0.0465 (9)−0.0008 (7)0.0176 (8)0.0013 (7)
C120.0680 (12)0.0455 (10)0.0714 (13)−0.0028 (9)0.0164 (10)−0.0009 (9)
C30.0763 (13)0.0590 (12)0.0550 (11)0.0166 (10)0.0170 (10)0.0081 (9)
C130.0593 (11)0.0601 (12)0.0583 (12)−0.0110 (9)0.0079 (9)−0.0053 (9)
C20.0990 (17)0.0783 (15)0.0530 (12)0.0344 (14)0.0118 (12)0.0095 (11)
C150.0636 (11)0.0639 (12)0.0568 (11)0.0111 (9)0.0046 (9)0.0116 (9)
C160.0634 (12)0.1025 (18)0.0616 (13)0.0050 (12)−0.0025 (10)0.0135 (12)
C50.0632 (12)0.0629 (13)0.0847 (15)0.0045 (10)0.0058 (11)0.0142 (10)
C10.0742 (15)0.0951 (19)0.0755 (16)0.0244 (14)−0.0093 (12)−0.0066 (13)
C60.0633 (13)0.0848 (17)0.106 (2)0.0012 (12)−0.0026 (13)−0.0002 (15)
Geometric parameters (Å, º) top
N2—C81.360 (2)C12—H12C0.9600
N2—C111.363 (2)C3—C21.381 (3)
N2—H2A0.8600C3—H30.9300
O2—C141.3313 (18)C13—H13A0.9600
O2—C151.448 (2)C13—H13B0.9600
O3—C141.216 (2)C13—H13C0.9600
C14—C111.443 (2)C2—C11.363 (3)
C11—C101.394 (2)C2—H20.9300
N1—C71.272 (2)C15—C161.487 (3)
N1—C41.412 (2)C15—H15A0.9700
C8—C91.395 (2)C15—H15B0.9700
C8—C71.443 (2)C16—H16A0.9600
C10—C91.403 (2)C16—H16B0.9600
C10—C131.496 (2)C16—H16C0.9600
C4—C31.382 (2)C5—C61.375 (3)
C4—C51.384 (3)C5—H50.9300
C7—H70.9300C1—C61.364 (3)
C9—C121.492 (2)C1—H10.9300
C12—H12A0.9600C6—H60.9300
C12—H12B0.9600
C8—N2—C11109.65 (13)C4—C3—H3119.9
C8—N2—H2A125.2C2—C3—H3119.9
C11—N2—H2A125.2C10—C13—H13A109.5
C14—O2—C15117.92 (14)C10—C13—H13B109.5
O3—C14—O2122.44 (15)H13A—C13—H13B109.5
O3—C14—C11124.58 (15)C10—C13—H13C109.5
O2—C14—C11112.98 (14)H13A—C13—H13C109.5
N2—C11—C10107.94 (14)H13B—C13—H13C109.5
N2—C11—C14118.44 (14)C1—C2—C3120.7 (2)
C10—C11—C14133.60 (15)C1—C2—H2119.6
C7—N1—C4118.36 (15)C3—C2—H2119.6
N2—C8—C9108.10 (14)O2—C15—C16106.66 (17)
N2—C8—C7119.37 (15)O2—C15—H15A110.4
C9—C8—C7132.53 (16)C16—C15—H15A110.4
C11—C10—C9107.29 (14)O2—C15—H15B110.4
C11—C10—C13127.36 (15)C16—C15—H15B110.4
C9—C10—C13125.34 (16)H15A—C15—H15B108.6
C3—C4—C5118.75 (18)C15—C16—H16A109.5
C3—C4—N1118.45 (17)C15—C16—H16B109.5
C5—C4—N1122.62 (17)H16A—C16—H16B109.5
N1—C7—C8122.82 (16)C15—C16—H16C109.5
N1—C7—H7118.6H16A—C16—H16C109.5
C8—C7—H7118.6H16B—C16—H16C109.5
C8—C9—C10107.02 (14)C6—C5—C4120.0 (2)
C8—C9—C12126.15 (15)C6—C5—H5120.0
C10—C9—C12126.84 (15)C4—C5—H5120.0
C9—C12—H12A109.5C2—C1—C6119.4 (2)
C9—C12—H12B109.5C2—C1—H1120.3
H12A—C12—H12B109.5C6—C1—H1120.3
C9—C12—H12C109.5C1—C6—C5121.0 (2)
H12A—C12—H12C109.5C1—C6—H6119.5
H12B—C12—H12C109.5C5—C6—H6119.5
C4—C3—C2120.1 (2)
C15—O2—C14—O3−5.1 (2)C9—C8—C7—N1−1.8 (3)
C15—O2—C14—C11174.30 (15)N2—C8—C9—C10−0.44 (18)
C8—N2—C11—C10−0.93 (18)C7—C8—C9—C10178.79 (17)
C8—N2—C11—C14177.75 (15)N2—C8—C9—C12179.75 (15)
O3—C14—C11—N22.1 (3)C7—C8—C9—C12−1.0 (3)
O2—C14—C11—N2−177.28 (13)C11—C10—C9—C8−0.12 (18)
O3—C14—C11—C10−179.64 (17)C13—C10—C9—C8178.52 (15)
O2—C14—C11—C101.0 (3)C11—C10—C9—C12179.69 (16)
C11—N2—C8—C90.85 (18)C13—C10—C9—C12−1.7 (3)
C11—N2—C8—C7−178.50 (14)C5—C4—C3—C2−0.8 (3)
N2—C11—C10—C90.63 (18)N1—C4—C3—C2−176.03 (17)
C14—C11—C10—C9−177.76 (18)C4—C3—C2—C11.3 (3)
N2—C11—C10—C13−177.97 (15)C14—O2—C15—C16−171.10 (15)
C14—C11—C10—C133.6 (3)C3—C4—C5—C60.2 (3)
C7—N1—C4—C3−141.86 (17)N1—C4—C5—C6175.21 (19)
C7—N1—C4—C543.1 (3)C3—C2—C1—C6−1.2 (3)
C4—N1—C7—C8−174.75 (16)C2—C1—C6—C50.6 (4)
N2—C8—C7—N1177.38 (16)C4—C5—C6—C1−0.1 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O3i0.862.062.8883 (18)162
Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formulaC16H18N2O2
Mr270.32
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)12.5463 (7), 14.6525 (9), 8.4490 (5)
β (°) 105.042 (3)
V (Å3)1500.00 (15)
Z4
Radiation typeMo Kα
µ (mm−1)0.08
Crystal size (mm)0.35 × 0.26 × 0.18
Data collection
DiffractometerBruker SMART CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.975, 0.986
No. of measured, independent and
observed [I > 2σ(I)] reflections		12405, 3413, 2078
Rint0.030
(sin θ/λ)max (Å−1)0.651
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.144, 1.01
No. of reflections3413
No. of parameters184
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.20, −0.16

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O3i0.862.062.8883 (18)161.9
Symmetry code: (i) −x, −y, −z.
 

Acknowledgements

The authors are grateful for financial support from the Doctoral Foundation of Henan Polytechnic University (B2009–65 648359 and B2009–70 648364).

References

First citationBruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
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ISSN: 2056-9890
Volume 66| Part 7| July 2010| Page o1655
doi:10.1107/S1600536810022051
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