Ethyl 5-methyl-1H-pyrrole-2-carboxyl­ate

Abstract

In the title mol­ecule, C₈H₁₁NO₂, the r.m.s. deviation of non-H atoms from their best plane is 0.031 Å. Mol­ecules are connected via a pair of N—H⋯O hydrogen bonds into a centrosymmetric dimer.

Related literature

For the crystal structure of the 5-cyano analogue of the title compound, see: Zhang et al. (2003 ▶). For the synthesis of the title compound, see: Motekaitis et al. (1970 ▶).

Experimental

Crystal data

• C₈H₁₁NO₂

• M _r = 153.18

• Monoclinic,

• a = 7.0759 (3) Å

• b = 18.0705 (9) Å

• c = 6.6606 (3) Å

• β = 101.349 (3)°

• V = 835.01 (7) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 296 K

• 0.20 × 0.15 × 0.13 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.984, T _max = 0.989

• 7496 measured reflections

• 1991 independent reflections

• 1157 reflections with I > 2σ(I)

• R _int = 0.029

Refinement

• R[F ² > 2σ(F ²)] = 0.045

• wR(F ²) = 0.143

• S = 1.02

• 1991 reflections

• 102 parameters

• H-atom parameters constrained

• Δρ_max = 0.16 e Å⁻³

• Δρ_min = −0.16 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811021180/gk2381Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1i	0.86	1.99	2.8363 (19)	167

Symmetry code: (i) .

supplementary crystallographic information

Comment

As part of our studies on hydrazone ligands bearing pyrrole unit the title compound was synthesized and characterized by X-ray diffraction.

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 0.0306 Å). 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 (Table 1, Fig. 2).

Experimental

The title compound was synthesized according to the literature procedure (Motekaitis et al., 1970). The crude orange solid was washed well with ice water and dried in air. Colorless plates of the title compound were obtained by slow evaporation of petroleum ether/ethyl acetate (100:1) solution.

Refinement

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 U_iso(H) values of 1.5Ueq(C) for methyl groups and 1.2Ueq(C,N) for others.

Figures

Fig. 1.

The title compound with the displacement ellipsoids shown at the 50% probability level.

Fig. 2.

The centrosymmetric dimer via N-H···O hydrogen bonds of the title compound (hydrogen bonds shown as dashed lines, symmetry code:: 1 - x, 1 - y, 2 - z).

Crystal data

C8H11NO2	F(000) = 328
Mr = 153.18	Dx = 1.218 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2070 reflections
a = 7.0759 (3) Å	θ = 2.3–24.2°
b = 18.0705 (9) Å	µ = 0.09 mm−1
c = 6.6606 (3) Å	T = 296 K
β = 101.349 (3)°	Plate, colorless
V = 835.01 (7) Å3	0.20 × 0.15 × 0.13 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	1991 independent reflections
Radiation source: fine-focus sealed tube	1157 reflections with I > 2σ(I)
graphite	Rint = 0.029
φ and ω scans	θmax = 27.9°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −9→9
Tmin = 0.984, Tmax = 0.989	k = −23→23
7496 measured reflections	l = −8→8

Refinement

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.143	H-atom parameters constrained
S = 1.02	w = 1/[σ2(Fo2) + (0.0683P)2 + 0.0738P] where P = (Fo2 + 2Fc2)/3
1991 reflections	(Δ/σ)max < 0.001
102 parameters	Δρmax = 0.16 e Å−3
0 restraints	Δρmin = −0.16 e Å−3

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
O2	0.12507 (16)	0.64959 (6)	0.92921 (18)	0.0629 (4)
N1	0.52408 (19)	0.57393 (7)	0.7402 (2)	0.0581 (4)
H1	0.5637	0.5360	0.8146	0.087*
C6	0.2631 (2)	0.60036 (9)	0.9187 (3)	0.0585 (4)
O1	0.2888 (2)	0.54602 (8)	1.0272 (2)	0.0861 (5)
C5	0.3729 (2)	0.61798 (9)	0.7644 (2)	0.0548 (4)
C2	0.6023 (2)	0.59835 (10)	0.5831 (3)	0.0600 (5)
C8	−0.1423 (3)	0.69326 (11)	1.0591 (3)	0.0768 (6)
H8A	−0.0794	0.7400	1.0916	0.115*
H8B	−0.2268	0.6837	1.1527	0.115*
H8C	−0.2159	0.6946	0.9217	0.115*
C4	0.3561 (2)	0.67196 (10)	0.6178 (3)	0.0651 (5)
H4	0.2658	0.7100	0.5976	0.078*
C7	0.0051 (3)	0.63353 (10)	1.0768 (3)	0.0691 (5)
H7A	0.0825	0.6324	1.2142	0.083*
H7B	−0.0569	0.5858	1.0480	0.083*
C1	0.7719 (3)	0.56133 (11)	0.5261 (3)	0.0780 (6)
H1A	0.8862	0.5893	0.5791	0.117*
H1B	0.7543	0.5585	0.3796	0.117*
H1C	0.7847	0.5123	0.5827	0.117*
C3	0.4987 (3)	0.65956 (10)	0.5044 (3)	0.0712 (5)
H3	0.5200	0.6879	0.3944	0.085*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O2	0.0581 (7)	0.0624 (7)	0.0748 (8)	0.0073 (5)	0.0294 (6)	0.0035 (6)
N1	0.0533 (8)	0.0560 (8)	0.0691 (9)	0.0001 (6)	0.0221 (7)	0.0000 (6)
C6	0.0519 (9)	0.0563 (9)	0.0698 (11)	0.0019 (8)	0.0182 (8)	−0.0026 (9)
O1	0.0847 (10)	0.0820 (9)	0.1032 (11)	0.0273 (8)	0.0467 (8)	0.0332 (8)
C5	0.0486 (9)	0.0532 (9)	0.0649 (11)	−0.0015 (7)	0.0165 (8)	−0.0035 (8)
C2	0.0539 (9)	0.0652 (10)	0.0644 (11)	−0.0091 (8)	0.0202 (8)	−0.0063 (8)
C8	0.0689 (12)	0.0819 (13)	0.0884 (15)	0.0074 (10)	0.0373 (11)	−0.0054 (10)
C4	0.0587 (10)	0.0616 (10)	0.0766 (12)	0.0036 (8)	0.0172 (9)	0.0060 (9)
C7	0.0635 (11)	0.0788 (12)	0.0716 (12)	0.0050 (9)	0.0293 (9)	0.0048 (9)
C1	0.0664 (12)	0.0894 (14)	0.0867 (14)	−0.0022 (10)	0.0360 (10)	−0.0094 (11)
C3	0.0683 (11)	0.0781 (12)	0.0715 (12)	−0.0023 (10)	0.0246 (10)	0.0107 (10)

Geometric parameters (Å, °)

C2—C1	1.487 (2)	C1—H1A	0.9600
C2—C3	1.373 (3)	C1—H1B	0.9600
C4—C3	1.392 (2)	C1—H1C	0.9600
C5—C4	1.369 (2)	C3—H3	0.9300
N1—C2	1.351 (2)	C4—H4	0.9300
N1—C5	1.368 (2)	C7—H7A	0.9700
C6—C5	1.440 (2)	C7—H7B	0.9700
C6—O1	1.212 (2)	C8—H8A	0.9600
O2—C6	1.3333 (19)	C8—H8B	0.9600
O2—C7	1.4490 (19)	C8—H8C	0.9600
C8—C7	1.490 (2)	N1—H1	0.8600
C6—O2—C7	115.81 (13)	C5—C4—C3	107.57 (16)
C2—N1—C5	110.53 (14)	C5—C4—H4	126.2
C2—N1—H1	124.7	C3—C4—H4	126.2
C5—N1—H1	124.7	O2—C7—C8	107.22 (15)
O1—C6—O2	122.31 (15)	O2—C7—H7A	110.3
O1—C6—C5	124.50 (15)	C8—C7—H7A	110.3
O2—C6—C5	113.19 (15)	O2—C7—H7B	110.3
C4—C5—N1	106.89 (14)	C8—C7—H7B	110.3
C4—C5—C6	133.09 (16)	H7A—C7—H7B	108.5
N1—C5—C6	119.97 (15)	C2—C1—H1A	109.5
N1—C2—C3	106.81 (15)	C2—C1—H1B	109.5
N1—C2—C1	121.69 (16)	H1A—C1—H1B	109.5
C3—C2—C1	131.48 (17)	C2—C1—H1C	109.5
C7—C8—H8A	109.5	H1A—C1—H1C	109.5
C7—C8—H8B	109.5	H1B—C1—H1C	109.5
H8A—C8—H8B	109.5	C2—C3—C4	108.20 (16)
C7—C8—H8C	109.5	C2—C3—H3	125.9
H8A—C8—H8C	109.5	C4—C3—H3	125.9
H8B—C8—H8C	109.5
C7—O2—C6—O1	−0.9 (2)	C5—N1—C2—C3	−0.1 (2)
C7—O2—C6—C5	177.93 (14)	C5—N1—C2—C1	178.73 (15)
C2—N1—C5—C4	−0.12 (19)	N1—C5—C4—C3	0.26 (19)
C2—N1—C5—C6	177.58 (14)	C6—C5—C4—C3	−177.02 (18)
O1—C6—C5—C4	173.57 (18)	C6—O2—C7—C8	−178.10 (14)
O2—C6—C5—C4	−5.3 (3)	N1—C2—C3—C4	0.2 (2)
O1—C6—C5—N1	−3.4 (3)	C1—C2—C3—C4	−178.40 (18)
O2—C6—C5—N1	177.75 (13)	C5—C4—C3—C2	−0.3 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.86	1.99	2.8363 (19)	167.

Symmetry codes: (i) −x+1, −y+1, −z+2.