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

Kang, S.-S.; Li, H.-L.; Zeng, H.-S.; Wang, H.-B.

doi:10.1107/S1600536808014542

organic compounds

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ISSN: 2056-9890

Volume 64| Part 6| June 2008| Page o1125

doi:10.1107/S1600536808014542

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

Si-Shun Kang,^a Hai-Lin Li,^a Hai-Su Zeng ^a and Hai-Bo Wang ^a ^*

^aCollege of Science, Nanjing University of Technolgy, Xinmofan Road No.5, Nanjing 210009, People's Republic of China
^*Correspondence e-mail: wanghaibo@njut.edu.cn

(Received 12 May 2008; accepted 14 May 2008; online 21 May 2008)

The molecule of the title compound, C₁₀H₁₃NO₃, is approximately planar. A network of N—H⋯O and weak C—H⋯O hydrogen bonds helps to consolidate the crystal structure.

Related literature

For related literature, see: Sun et al. (2002 ). For details of the synthesis, see: Tang et al. (1999 ).

Experimental

Crystal data

C₁₀H₁₃NO₃
M_r = 195.21
Monoclinic, P 2₁ /n
a = 3.9830 (8) Å
b = 15.572 (3) Å
c = 16.213 (3) Å
β = 96.96 (3)°
V = 998.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 (2) K
0.20 × 0.05 × 0.05 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.981, T_max = 0.995
2069 measured reflections
1798 independent reflections
935 reflections with I > 2σ(I)
R_int = 0.021
3 standard reflections every 200 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.083
wR(F²) = 0.190
S = 1.03
1798 reflections
127 parameters
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N—H0A⋯O1ⁱ	0.86	2.04	2.864 (5)	159
C1—H1A⋯O3	0.96	2.16	2.882 (5)	131
C6—H6A⋯O1ⁱ	0.96	2.58	3.401 (6)	143
C7—H7A⋯O2ⁱⁱ	0.93	2.60	3.525 (6)	176
Symmetry codes: (i) -x, -y, -z+1; (ii) $[-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); 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: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808014542/hb2732sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808014542/hb2732Isup2.hkl

checkCIF report

Comment top

As part of our owning studies of pyrrole derivatives (Sun et al., 2002), we report here the crystal structure of the title compound, (I), (Fig. 1), which is approximately planar (for the non-hydrogen atoms, r.m.s. deviation from the mean plane = 0.038Å).

A network of N—H···O and C—H···O hydrogen bonds (Table 1) helps to establish the crystal packing in (I). A short intramolecular C—H···O contact also occurs, based on the geometrically positioned H1A atom, which lies on the mirror plane.

Related literature top

For related literature, see: Sun et al. (2002). For details of the synthesis, see: Tang et al. (1999).

Experimental top

A mixture of 2-tert-butyl 4-ethyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate (30 mmol) in trifluoroacetic acid (40 ml) was stirred for 5 minutes and warmed to 313 K. The mixture was then cooled to 268 K and triethyl orthoformate (45 mmol) was added all at once. The mixture was stirred for about 1 minute, removed from the cold bath and then stirred for 1 h. The trifluoroacetic acid was removed by rotary evaporation and the residue was put into 200 g of ice. The gray floating precipitate was collected by vacuum filtration and washed with 40 ml water then recrystallized twice from ethyl acetate containing Darco carbon black to give 3.7 g of the title compound (Tang et al.,1999). Colourless needles of (I) were obtained by slow evaporation of an ethanol solution.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of (I), with displacement ellipsoids for the non-H atoms drawn at the 30% probability level. The short intramolecular C—H···O interaction is shown as dashed line.

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

Crystal data top

C₁₀H₁₃NO₃	F(000) = 416
M_r = 195.21	D_x = 1.299 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 25 reflections
a = 3.9830 (8) Å	θ = 9–12°
b = 15.572 (3) Å	µ = 0.10 mm⁻¹
c = 16.213 (3) Å	T = 293 K
β = 96.96 (3)°	Needle, colourless
V = 998.2 (3) Å³	0.20 × 0.05 × 0.05 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	935 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.021
Graphite monochromator	θ_max = 25.2°, θ_min = 1.8°
ω/2θ scans	h = −4→4
Absorption correction: ψ scan (North et al., 1968)	k = 0→18
T_min = 0.981, T_max = 0.995	l = 0→19
2069 measured reflections	3 standard reflections every 200 reflections
1798 independent reflections	intensity decay: none

Refinement top

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)] = 0.083	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.190	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.06P)² + 0.5P] where P = (F_o² + 2F_c²)/3
1798 reflections	(Δ/σ)_max < 0.001
127 parameters	Δρ_max = 0.16 e Å⁻³
0 restraints	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₁₀H₁₃NO₃	V = 998.2 (3) Å³
M_r = 195.21	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 3.9830 (8) Å	µ = 0.10 mm⁻¹
b = 15.572 (3) Å	T = 293 K
c = 16.213 (3) Å	0.20 × 0.05 × 0.05 mm
β = 96.96 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	935 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.021
T_min = 0.981, T_max = 0.995	3 standard reflections every 200 reflections
2069 measured reflections	intensity decay: none
1798 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.083	0 restraints
wR(F²) = 0.190	H-atom parameters constrained
S = 1.03	Δρ_max = 0.16 e Å⁻³
1798 reflections	Δρ_min = −0.17 e Å⁻³
127 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

	x	y	z	U_iso*/U_eq
N	0.3042 (9)	−0.0589 (2)	0.60096 (19)	0.0712 (11)
H0A	0.1844	−0.0604	0.5531	0.085*
O1	0.0871 (10)	0.11115 (17)	0.55062 (19)	0.0982 (12)
C1	0.7132 (14)	0.0521 (3)	0.7869 (3)	0.0900 (16)
H1A	0.8505	0.0210	0.8296	0.135*
H1B	0.5247	0.0773	0.8096	0.135*
H1C	0.8459	0.0965	0.7656	0.135*
O2	0.8180 (10)	−0.23224 (19)	0.76904 (18)	0.0989 (12)
C2	0.5870 (11)	−0.0078 (3)	0.7184 (2)	0.0619 (11)
O3	0.9364 (8)	−0.11553 (16)	0.84573 (16)	0.0802 (10)
C3	0.6177 (10)	−0.0982 (2)	0.7165 (2)	0.0575 (10)
C4	0.4352 (13)	−0.1260 (3)	0.6409 (3)	0.0781 (14)
C5	0.3840 (12)	0.0144 (2)	0.6459 (2)	0.0719 (13)
C6	0.3837 (13)	−0.2149 (3)	0.6079 (3)	0.0840 (15)
H6A	0.2464	−0.2132	0.5550	0.126*
H6B	0.2725	−0.2487	0.6460	0.126*
H6C	0.5989	−0.2401	0.6015	0.126*
C7	0.2893 (14)	0.0965 (3)	0.6142 (3)	0.0825 (15)
H7A	0.3857	0.1437	0.6432	0.099*
C8	0.7874 (12)	−0.1552 (3)	0.7771 (2)	0.0656 (11)
C9	1.1202 (13)	−0.1682 (3)	0.9080 (2)	0.0797 (14)
H9A	1.3017	−0.1981	0.8852	0.096*
H9B	0.9713	−0.2105	0.9283	0.096*
C10	1.2602 (13)	−0.1105 (3)	0.9765 (3)	0.0888 (15)
H10A	1.3865	−0.1437	1.0195	0.133*
H10B	1.0782	−0.0815	0.9988	0.133*
H10C	1.4063	−0.0688	0.9556	0.133*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N	0.073 (3)	0.071 (2)	0.0652 (18)	0.004 (2)	−0.0076 (18)	0.0032 (16)
O1	0.125 (3)	0.0727 (18)	0.0864 (19)	0.006 (2)	−0.029 (2)	0.0039 (15)
C1	0.110 (5)	0.072 (3)	0.086 (3)	−0.002 (3)	0.001 (3)	−0.004 (2)
O2	0.130 (4)	0.0705 (19)	0.092 (2)	0.009 (2)	−0.004 (2)	−0.0027 (15)
C2	0.053 (3)	0.076 (3)	0.0595 (19)	0.001 (2)	0.0175 (18)	0.0012 (18)
O3	0.094 (3)	0.0629 (16)	0.0791 (18)	0.0052 (19)	−0.0082 (17)	0.0004 (14)
C3	0.047 (3)	0.069 (2)	0.060 (2)	−0.007 (2)	0.0210 (18)	0.0007 (17)
C4	0.088 (4)	0.069 (3)	0.077 (3)	−0.020 (3)	0.007 (2)	0.002 (2)
C5	0.071 (3)	0.055 (2)	0.083 (3)	0.010 (2)	−0.017 (2)	−0.002 (2)
C6	0.094 (4)	0.071 (3)	0.086 (3)	−0.011 (3)	0.003 (3)	−0.017 (2)
C7	0.101 (4)	0.075 (3)	0.069 (2)	−0.009 (3)	0.001 (3)	0.003 (2)
C8	0.061 (3)	0.065 (2)	0.074 (2)	0.002 (3)	0.020 (2)	−0.002 (2)
C9	0.090 (4)	0.068 (2)	0.077 (3)	0.012 (3)	−0.003 (3)	0.003 (2)
C10	0.084 (4)	0.089 (3)	0.091 (3)	0.012 (3)	−0.003 (3)	0.007 (2)

Geometric parameters (Å, º) top

N—C4	1.304 (5)	C3—C8	1.432 (5)
N—C5	1.370 (5)	C4—C6	1.489 (5)
N—H0A	0.8600	C5—C7	1.412 (5)
O1—C7	1.250 (5)	C6—H6A	0.9600
C1—C2	1.490 (5)	C6—H6B	0.9600
C1—H1A	0.9600	C6—H6C	0.9600
C1—H1B	0.9600	C7—H7A	0.9300
C1—H1C	0.9600	C9—C10	1.484 (5)
O2—C8	1.214 (4)	C9—H9A	0.9700
C2—C5	1.388 (5)	C9—H9B	0.9700
C2—C3	1.414 (5)	C10—H10A	0.9600
O3—C8	1.346 (4)	C10—H10B	0.9600
O3—C9	1.431 (4)	C10—H10C	0.9600
C3—C4	1.415 (5)

C4—N—C5	110.5 (3)	C4—C6—H6B	109.5
C4—N—H0A	124.7	H6A—C6—H6B	109.5
C5—N—H0A	124.7	C4—C6—H6C	109.5
C2—C1—H1A	109.5	H6A—C6—H6C	109.5
C2—C1—H1B	109.5	H6B—C6—H6C	109.5
H1A—C1—H1B	109.5	O1—C7—C5	125.6 (4)
C2—C1—H1C	109.5	O1—C7—H7A	117.2
H1A—C1—H1C	109.5	C5—C7—H7A	117.2
H1B—C1—H1C	109.5	O2—C8—O3	120.2 (4)
C5—C2—C3	105.8 (3)	O2—C8—C3	125.7 (4)
C5—C2—C1	125.8 (4)	O3—C8—C3	114.0 (3)
C3—C2—C1	128.1 (4)	O3—C9—C10	107.2 (3)
C8—O3—C9	117.2 (3)	O3—C9—H9A	110.3
C2—C3—C4	106.7 (3)	C10—C9—H9A	110.3
C2—C3—C8	129.5 (4)	O3—C9—H9B	110.3
C4—C3—C8	123.7 (4)	C10—C9—H9B	110.3
N—C4—C3	108.5 (3)	H9A—C9—H9B	108.5
N—C4—C6	122.5 (4)	C9—C10—H10A	109.5
C3—C4—C6	129.0 (4)	C9—C10—H10B	109.5
N—C5—C2	108.5 (3)	H10A—C10—H10B	109.5
N—C5—C7	121.8 (3)	C9—C10—H10C	109.5
C2—C5—C7	129.5 (4)	H10A—C10—H10C	109.5
C4—C6—H6A	109.5	H10B—C10—H10C	109.5

C5—C2—C3—C4	1.3 (5)	C1—C2—C5—N	−176.2 (4)
C1—C2—C3—C4	175.6 (5)	C3—C2—C5—C7	−175.8 (5)
C5—C2—C3—C8	−177.2 (4)	C1—C2—C5—C7	9.7 (8)
C1—C2—C3—C8	−2.9 (8)	N—C5—C7—O1	11.4 (8)
C5—N—C4—C3	−0.7 (5)	C2—C5—C7—O1	−175.2 (5)
C5—N—C4—C6	178.6 (5)	C9—O3—C8—O2	−1.6 (7)
C2—C3—C4—N	−0.4 (5)	C9—O3—C8—C3	−178.1 (4)
C8—C3—C4—N	178.2 (4)	C2—C3—C8—O2	−175.8 (5)
C2—C3—C4—C6	−179.6 (5)	C4—C3—C8—O2	5.8 (8)
C8—C3—C4—C6	−0.9 (8)	C2—C3—C8—O3	0.4 (7)
C4—N—C5—C2	1.6 (5)	C4—C3—C8—O3	−177.9 (4)
C4—N—C5—C7	176.2 (5)	C8—O3—C9—C10	179.8 (4)
C3—C2—C5—N	−1.7 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N—H0A···O1ⁱ	0.86	2.04	2.864 (5)	159
C1—H1A···O3	0.96	2.16	2.882 (5)	131
C6—H6A···O1ⁱ	0.96	2.58	3.401 (6)	143
C7—H7A···O2ⁱⁱ	0.93	2.60	3.525 (6)	176

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+3/2, y+1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	C₁₀H₁₃NO₃
M_r	195.21
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	3.9830 (8), 15.572 (3), 16.213 (3)
β (°)	96.96 (3)
V (Å³)	998.2 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.05 × 0.05

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.981, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	2069, 1798, 935
R_int	0.021
(sin θ/λ)_max (Å⁻¹)	0.598

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.083, 0.190, 1.03
No. of reflections	1798
No. of parameters	127
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.17

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N—H0A···O1ⁱ	0.86	2.04	2.864 (5)	159
C1—H1A···O3	0.96	2.16	2.882 (5)	131
C6—H6A···O1ⁱ	0.96	2.58	3.401 (6)	143
C7—H7A···O2ⁱⁱ	0.93	2.60	3.525 (6)	176

Symmetry codes: (i) −x, −y, −z+1; (ii) −x+3/2, y+1/2, −z+3/2.

References

Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sun, L., Cui, J., Liang, C. & Zhou, Y. (2002). Bioorg. Med. Chem. Lett. 12, 2153–2157. Web of Science CrossRef PubMed CAS Google Scholar
Tang, P.-C., Sun, L. & McMahon, G. (1999). PCT Int. Appl. US 9 912 069. Google Scholar

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 6| June 2008| Page o1125

doi:10.1107/S1600536808014542

Open

access