Ethyl 4-acetyl-3,5-di­methyl-1H-pyrrole-2-carboxyl­ate

In the title compound, C₁₁H₁₅NO₃, the mol­ecules are joined into dimers by a pair of strong hydrogen bonds between the pyrrole N atom and the carbonyl O atom of the carboxyl­ate substituent [N...O 2.861 (2) Å and N—H...O 168 (2)°]. A single C—H...π intermolecular interaction is observed, with an H...π distance of 3.04 Å, linking the dimers together.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.044
• wR factor = 0.144
• Data-to-parameter ratio = 15.1

checkCIF results

No syntax errors found



ADDSYM reports no extra symmetry

General Notes



ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      0.897
          Tmax scaled      0.880 Tmin scaled      0.808

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Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA (Spek, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Ethyl 4-acetyl-3,5-dimethyl-1H-pyrrole-2-carboxylate

Crystal data

C11H15NO3	F(000) = 448
Mr = 209.24	Dx = 1.258 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
a = 8.0985 (10) Å	Cell parameters from 25 reflections
b = 6.8757 (15) Å	θ = 21.0–35.3°
c = 20.406 (2) Å	µ = 0.76 mm^−1
β = 103.607 (8)°	T = 293 K
V = 1104.4 (3) Å^3	Prism, colourless
Z = 4	0.49 × 0.22 × 0.17 mm

Data collection

Enraf-Nonius MACH3 diffractometer	1678 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.013
Graphite monochromator	θmax = 72.4°, θmin = 4.5°
ω–2θ scans	h = 0→10
Absorption correction: ψ scan (North et al., 1968)	k = −8→0
Tmin = 0.90, Tmax = 0.98	l = −25→24
3600 measured reflections	3 standard reflections every 180 min
2187 independent reflections	intensity decay: 5%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.044	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.144	w = 1/[σ^2(Fo^2) + (0.0687P)^2 + 0.281P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
2187 reflections	Δρmax = 0.19 e Å^−3
145 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0204 (17)

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.8972 (2)	−0.0839 (2)	−0.07436 (7)	0.0737 (5)
O2	0.73325 (17)	−0.3164 (2)	−0.13193 (6)	0.0612 (4)
O3	0.7991 (3)	−0.6843 (4)	0.17562 (10)	0.1351 (10)
N1	0.9100 (2)	−0.2672 (3)	0.04547 (7)	0.0542 (4)
H1	0.969 (3)	−0.160 (4)	0.0481 (11)	0.073 (7)*
C2	0.8216 (2)	−0.3473 (3)	−0.01446 (8)	0.0502 (4)
C3	0.7497 (2)	−0.5198 (3)	−0.00037 (9)	0.0526 (4)
C4	0.7976 (2)	−0.5415 (3)	0.07151 (9)	0.0575 (5)
C5	0.8973 (2)	−0.3805 (3)	0.09743 (9)	0.0576 (5)
C10	0.7529 (3)	−0.6949 (4)	0.11427 (11)	0.0748 (6)
C11	0.6472 (3)	−0.8647 (4)	0.08397 (13)	0.0863 (7)
H11A	0.6362	−0.9534	0.1190	0.129*
H11B	0.7009	−0.9296	0.0528	0.129*
H11C	0.5367	−0.8201	0.0606	0.129*
C9	0.6448 (3)	−0.6542 (3)	−0.05197 (10)	0.0668 (5)
H9A	0.6401	−0.6046	−0.0964	0.100*
H9B	0.5319	−0.6625	−0.0450	0.100*
H9C	0.6956	−0.7811	−0.0475	0.100*
C12	0.9849 (3)	−0.3218 (4)	0.16754 (10)	0.0787 (7)
H12A	1.0828	−0.2444	0.1663	0.118*
H12B	1.0199	−0.4359	0.1943	0.118*
H12C	0.9084	−0.2473	0.1870	0.118*
C6	0.8225 (2)	−0.2377 (3)	−0.07523 (9)	0.0530 (5)
C7	0.7292 (3)	−0.2051 (3)	−0.19316 (9)	0.0724 (6)
H7A	0.8415	−0.1999	−0.2022	0.087*
H7B	0.6911	−0.0732	−0.1884	0.087*
C8	0.6080 (3)	−0.3071 (4)	−0.24911 (11)	0.0901 (8)
H8A	0.6498	−0.4352	−0.2546	0.135*
H8B	0.5973	−0.2351	−0.2902	0.135*
H8C	0.4989	−0.3165	−0.2385	0.135*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1012 (11)	0.0619 (9)	0.0505 (8)	−0.0132 (8)	0.0028 (7)	0.0004 (6)
O2	0.0705 (8)	0.0690 (9)	0.0393 (6)	−0.0048 (6)	0.0030 (5)	−0.0013 (6)
O3	0.1571 (19)	0.176 (2)	0.0636 (12)	−0.0557 (17)	0.0091 (11)	0.0372 (13)
N1	0.0593 (9)	0.0591 (9)	0.0425 (8)	0.0058 (8)	0.0089 (6)	−0.0047 (7)
C2	0.0508 (9)	0.0567 (10)	0.0414 (9)	0.0078 (8)	0.0074 (7)	−0.0035 (7)
C3	0.0448 (9)	0.0629 (11)	0.0499 (9)	0.0091 (8)	0.0109 (7)	0.0008 (8)
C4	0.0502 (9)	0.0718 (12)	0.0514 (10)	0.0091 (9)	0.0137 (7)	0.0078 (9)
C5	0.0573 (10)	0.0724 (12)	0.0433 (9)	0.0140 (9)	0.0125 (7)	0.0018 (8)
C10	0.0625 (12)	0.0986 (17)	0.0633 (13)	0.0037 (12)	0.0150 (9)	0.0227 (12)
C11	0.0895 (16)	0.0847 (16)	0.0881 (17)	−0.0026 (13)	0.0277 (13)	0.0219 (14)
C9	0.0650 (11)	0.0716 (13)	0.0605 (11)	−0.0069 (10)	0.0080 (9)	−0.0010 (10)
C12	0.0905 (15)	0.1009 (18)	0.0420 (10)	0.0078 (13)	0.0099 (10)	−0.0037 (11)
C6	0.0571 (10)	0.0550 (10)	0.0437 (9)	0.0059 (8)	0.0057 (7)	−0.0048 (8)
C7	0.0846 (14)	0.0821 (15)	0.0434 (10)	−0.0061 (12)	0.0007 (9)	0.0066 (10)
C8	0.1023 (18)	0.105 (2)	0.0504 (12)	−0.0077 (15)	−0.0076 (11)	−0.0024 (12)

Geometric parameters (Å, º)

O1—C6	1.216 (2)	C11—H11A	0.9600
O2—C6	1.327 (2)	C11—H11B	0.9600
O2—C7	1.459 (2)	C11—H11C	0.9600
O3—C10	1.221 (3)	C9—H9A	0.9600
N1—C5	1.339 (2)	C9—H9B	0.9600
N1—C2	1.378 (2)	C9—H9C	0.9600
N1—H1	0.88 (2)	C12—H12A	0.9600
C2—C3	1.381 (3)	C12—H12B	0.9600
C2—C6	1.453 (3)	C12—H12C	0.9600
C3—C4	1.434 (2)	C7—C8	1.494 (3)
C3—C9	1.504 (3)	C7—H7A	0.9700
C4—C5	1.399 (3)	C7—H7B	0.9700
C4—C10	1.467 (3)	C8—H8A	0.9600
C5—C12	1.495 (3)	C8—H8B	0.9600
C10—C11	1.493 (4)	C8—H8C	0.9600
C6—O2—C7	115.52 (16)	C3—C9—H9B	109.5
C5—N1—C2	110.48 (18)	H9A—C9—H9B	109.5
C5—N1—H1	125.9 (15)	C3—C9—H9C	109.5
C2—N1—H1	123.6 (15)	H9A—C9—H9C	109.5
N1—C2—C3	108.34 (16)	H9B—C9—H9C	109.5
N1—C2—C6	116.38 (17)	C5—C12—H12A	109.5
C3—C2—C6	135.27 (16)	C5—C12—H12B	109.5
C2—C3—C4	106.06 (16)	H12A—C12—H12B	109.5
C2—C3—C9	125.30 (17)	C5—C12—H12C	109.5
C4—C3—C9	128.63 (18)	H12A—C12—H12C	109.5
C5—C4—C3	107.31 (16)	H12B—C12—H12C	109.5
C5—C4—C10	123.03 (18)	O1—C6—O2	122.29 (17)
C3—C4—C10	129.6 (2)	O1—C6—C2	122.76 (16)
N1—C5—C4	107.81 (16)	O2—C6—C2	114.94 (17)
N1—C5—C12	119.5 (2)	O2—C7—C8	106.65 (19)
C4—C5—C12	132.64 (19)	O2—C7—H7A	110.4
O3—C10—C4	120.5 (2)	C8—C7—H7A	110.4
O3—C10—C11	118.6 (2)	O2—C7—H7B	110.4
C4—C10—C11	120.9 (2)	C8—C7—H7B	110.4
C10—C11—H11A	109.5	H7A—C7—H7B	108.6
C10—C11—H11B	109.5	C7—C8—H8A	109.5
H11A—C11—H11B	109.5	C7—C8—H8B	109.5
C10—C11—H11C	109.5	H8A—C8—H8B	109.5
H11A—C11—H11C	109.5	C7—C8—H8C	109.5
H11B—C11—H11C	109.5	H8A—C8—H8C	109.5
C3—C9—H9A	109.5	H8B—C8—H8C	109.5
C5—N1—C2—C3	−0.2 (2)	C3—C4—C5—C12	−179.3 (2)
C5—N1—C2—C6	179.15 (15)	C10—C4—C5—C12	2.1 (3)
N1—C2—C3—C4	0.29 (18)	C5—C4—C10—O3	1.9 (3)
C6—C2—C3—C4	−178.91 (19)	C3—C4—C10—O3	−176.3 (2)
N1—C2—C3—C9	−179.06 (16)	C5—C4—C10—C11	−179.5 (2)
C6—C2—C3—C9	1.7 (3)	C3—C4—C10—C11	2.3 (3)
C2—C3—C4—C5	−0.25 (19)	C7—O2—C6—O1	−0.6 (3)
C9—C3—C4—C5	179.06 (17)	C7—O2—C6—C2	178.37 (16)
C2—C3—C4—C10	178.16 (19)	N1—C2—C6—O1	0.4 (3)
C9—C3—C4—C10	−2.5 (3)	C3—C2—C6—O1	179.55 (19)
C2—N1—C5—C4	0.1 (2)	N1—C2—C6—O2	−178.54 (15)
C2—N1—C5—C12	179.58 (16)	C3—C2—C6—O2	0.6 (3)
C3—C4—C5—N1	0.1 (2)	C6—O2—C7—C8	−173.90 (18)
C10—C4—C5—N1	−178.42 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.88 (2)	2.00 (2)	2.861 (2)	168 (2)

Symmetry code: (i) −x+2, −y, −z.