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

Abstract

The mol­ecule of the title compound, C₁₀H₁₃NO₃, is approximately planar (maximum deviation 0.1424 Å). In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds, and the dimeric units are linked by non-classical C—H⋯O hydrogen bonds, forming a layered structure.

Related literature

For a related structure, see: Kang et al. (2008 ▶). For our studies of bis­(pyrrol-2-yl-methyl­eneamine) ligands, see: Wang et al. (2008 ▶, 2009 ▶). For the synthesis, see: Wang et al. (2008 ▶).

Experimental

Crystal data

• C₁₀H₁₃NO₃

• M _r = 195.21

• Triclinic,

• a = 7.2223 (12) Å

• b = 7.4347 (12) Å

• c = 10.0488 (17) Å

• α = 78.412 (2)°

• β = 84.191 (2)°

• γ = 79.051 (2)°

• V = 517.84 (15) ų

• Z = 2

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 296 K

• 0.30 × 0.18 × 0.15 mm

Data collection

• Bruker SMART CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.980, T _max = 0.986

• 6232 measured reflections

• 2416 independent reflections

• 1692 reflections with I > 2σ(I)

• R _int = 0.017

Refinement

• R[F ² > 2σ(F ²)] = 0.060

• wR(F ²) = 0.212

• S = 1.07

• 2416 reflections

• 129 parameters

• H-atom parameters constrained

• Δρ_max = 0.29 e Å⁻³

• Δρ_min = −0.29 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXL97 (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

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—H1A⋯O2i	0.86	2.07	2.919 (2)	169
C5—H5A⋯O1ii	0.93	2.54	3.347 (3)	145

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

Schiff Base bearing pyrrole units have been extensively investigated for a long time because they could stabilize mono- or binuclear metal complexes which have various structures and special properties. As part of our owning studies of bis(pyrrol-2-yl-methyleneamine) ligands (Wang et al., 2008), we report here the crystal structure of the title compound, (I), (Fig. 1), which is approximately planar.

The molecules are joined to dimers via intermolecular N—H···O hydrogen bonds (Table 1), and the dimeric units are linked with each other by nonclassical C—H···O hydrogen bonds (Table 1) to form a layered geometry (Fig. 2).

Experimental

A quantity of POCl₃ (2.30 g, 0.015 mol) was added dropwise to DMF (1.10 g, 0.015 mol) under stirring on an ice-water bath, then a CH₂Cl₂ solution (30 ml) containing 3,4-dimethyl-2-ethoxycarbonyl-pyrrole (2.51 g, 0.015 mol) was added. After stirring at room temperature for 4 h, a 10% Na₂CO₃ solution (80 ml) was added. The reaction mixture was refluxing for 0.5 h, then cooled to room temperature, extracted with CH₂Cl₂ (3×10 ml), and dried with anhydrous Na₂CO₃. The solvent was evaporated under reduced pressure. The crude product was treated with column chromatography on silica gel [petroleum ether-ethyl acetate (100:1)] to yield (I) 2.25 g (77%). Colorless prisms of (I) were obtained by slow evaporation of an ethanol solution.

Refinement

(type here to add refinement details)

Figures

Fig. 1.

The molecular structure of the title compound shown with 50% probability displacement ellipsoids.

Fig. 2.

Layered structure of the title compound. Hydrogen-bonding interactions are shown as dashed lines.

Crystal data

C10H13NO3	Z = 2
Mr = 195.21	F(000) = 208
Triclinic, P1	Dx = 1.252 Mg m−3
a = 7.2223 (12) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.4347 (12) Å	Cell parameters from 2123 reflections
c = 10.0488 (17) Å	θ = 2.1–27.7°
α = 78.412 (2)°	µ = 0.09 mm−1
β = 84.191 (2)°	T = 296 K
γ = 79.051 (2)°	Prism, colorless
V = 517.84 (15) Å3	0.30 × 0.18 × 0.15 mm

Data collection

Bruker SMART CCD diffractometer	2416 independent reflections
Radiation source: fine-focus sealed tube	1692 reflections with I > 2σ(I)
graphite	Rint = 0.017
φ and ω scans	θmax = 27.7°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.980, Tmax = 0.986	k = −9→9
6232 measured reflections	l = −13→13

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.212	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.1226P)2 + 0.0669P] where P = (Fo2 + 2Fc2)/3
2416 reflections	(Δ/σ)max < 0.001
129 parameters	Δρmax = 0.29 e Å−3
0 restraints	Δρmin = −0.29 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
C4	0.3634 (3)	0.8003 (2)	1.03572 (18)	0.0519 (5)
C8	0.2197 (3)	0.8074 (3)	1.1488 (2)	0.0593 (5)
C3	0.5533 (3)	0.7196 (2)	1.0262 (2)	0.0556 (5)
C1	0.4613 (3)	0.8683 (3)	0.8185 (2)	0.0585 (5)
C2	0.6149 (3)	0.7620 (3)	0.8883 (2)	0.0605 (5)
C5	0.4495 (4)	0.9519 (4)	0.6766 (2)	0.0780 (7)
H5A	0.5582	0.9328	0.6195	0.094*
C7	0.6715 (3)	0.6084 (3)	1.1392 (2)	0.0720 (6)
H7A	0.7978	0.5703	1.1030	0.108*
H7B	0.6181	0.5001	1.1808	0.108*
H7C	0.6741	0.6836	1.2060	0.108*
C9	0.1496 (4)	0.7387 (5)	1.3863 (3)	0.1023 (10)
H9A	0.1126	0.8660	1.4008	0.123*
H9B	0.0375	0.6948	1.3693	0.123*
C10	0.2342 (5)	0.6221 (6)	1.5051 (3)	0.1191 (12)
H10A	0.1453	0.6265	1.5826	0.179*
H10B	0.3450	0.6663	1.5212	0.179*
H10C	0.2687	0.4960	1.4906	0.179*
C6	0.8106 (3)	0.7039 (4)	0.8285 (3)	0.0872 (8)
H6A	0.8884	0.6318	0.8993	0.131*
H6B	0.8631	0.8128	0.7869	0.131*
H6C	0.8059	0.6301	0.7612	0.131*
O3	0.2874 (2)	0.7315 (2)	1.26943 (15)	0.0771 (5)
O2	0.0572 (2)	0.8726 (3)	1.13418 (17)	0.0899 (6)
O1	0.3095 (3)	1.0448 (3)	0.62612 (17)	0.1053 (7)
N1	0.3105 (2)	0.8889 (2)	0.90931 (15)	0.0539 (4)
H1A	0.1993	0.9484	0.8903	0.065*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C4	0.0506 (9)	0.0554 (9)	0.0481 (10)	−0.0087 (7)	−0.0052 (7)	−0.0051 (7)
C8	0.0550 (11)	0.0682 (11)	0.0493 (10)	−0.0082 (8)	−0.0053 (8)	0.0004 (8)
C3	0.0517 (10)	0.0526 (9)	0.0619 (11)	−0.0072 (7)	−0.0068 (8)	−0.0095 (8)
C1	0.0601 (11)	0.0638 (11)	0.0518 (11)	−0.0101 (8)	0.0033 (8)	−0.0155 (8)
C2	0.0555 (11)	0.0608 (10)	0.0652 (12)	−0.0072 (8)	0.0024 (9)	−0.0180 (9)
C5	0.0779 (15)	0.1027 (17)	0.0473 (12)	−0.0053 (13)	0.0084 (11)	−0.0156 (11)
C7	0.0584 (12)	0.0679 (12)	0.0837 (15)	0.0005 (9)	−0.0165 (10)	−0.0048 (10)
C9	0.0778 (16)	0.148 (3)	0.0571 (14)	−0.0005 (16)	0.0093 (12)	0.0119 (14)
C10	0.108 (2)	0.161 (3)	0.0668 (17)	−0.010 (2)	0.0026 (16)	0.0126 (18)
C6	0.0651 (14)	0.0912 (16)	0.0983 (19)	−0.0010 (12)	0.0157 (13)	−0.0233 (14)
O3	0.0625 (9)	0.1094 (12)	0.0475 (8)	−0.0070 (8)	−0.0043 (7)	0.0061 (7)
O2	0.0552 (9)	0.1288 (15)	0.0616 (10)	0.0092 (9)	0.0013 (7)	0.0126 (9)
O1	0.0927 (14)	0.1528 (19)	0.0505 (10)	0.0128 (12)	−0.0006 (9)	−0.0065 (10)
N1	0.0507 (8)	0.0637 (9)	0.0445 (8)	−0.0055 (7)	−0.0028 (6)	−0.0083 (6)

Geometric parameters (Å, °)

C4—N1	1.364 (2)	C7—H7B	0.9600
C4—C3	1.390 (3)	C7—H7C	0.9600
C4—C8	1.461 (3)	C9—C10	1.443 (4)
C8—O2	1.194 (2)	C9—O3	1.463 (3)
C8—O3	1.330 (2)	C9—H9A	0.9700
C3—C2	1.405 (3)	C9—H9B	0.9700
C3—C7	1.500 (3)	C10—H10A	0.9600
C1—N1	1.354 (2)	C10—H10B	0.9600
C1—C2	1.396 (3)	C10—H10C	0.9600
C1—C5	1.440 (3)	C6—H6A	0.9600
C2—C6	1.498 (3)	C6—H6B	0.9600
C5—O1	1.206 (3)	C6—H6C	0.9600
C5—H5A	0.9300	N1—H1A	0.8600
C7—H7A	0.9600
N1—C4—C3	108.93 (17)	H7B—C7—H7C	109.5
N1—C4—C8	117.47 (17)	C10—C9—O3	108.7 (3)
C3—C4—C8	133.61 (18)	C10—C9—H9A	109.9
O2—C8—O3	123.29 (19)	O3—C9—H9A	109.9
O2—C8—C4	123.38 (19)	C10—C9—H9B	109.9
O3—C8—C4	113.32 (17)	O3—C9—H9B	109.9
C4—C3—C2	106.33 (17)	H9A—C9—H9B	108.3
C4—C3—C7	127.64 (19)	C9—C10—H10A	109.5
C2—C3—C7	126.03 (19)	C9—C10—H10B	109.5
N1—C1—C2	108.25 (17)	H10A—C10—H10B	109.5
N1—C1—C5	121.70 (19)	C9—C10—H10C	109.5
C2—C1—C5	130.0 (2)	H10A—C10—H10C	109.5
C1—C2—C3	107.43 (18)	H10B—C10—H10C	109.5
C1—C2—C6	126.8 (2)	C2—C6—H6A	109.5
C3—C2—C6	125.8 (2)	C2—C6—H6B	109.5
O1—C5—C1	125.0 (2)	H6A—C6—H6B	109.5
O1—C5—H5A	117.5	C2—C6—H6C	109.5
C1—C5—H5A	117.5	H6A—C6—H6C	109.5
C3—C7—H7A	109.5	H6B—C6—H6C	109.5
C3—C7—H7B	109.5	C8—O3—C9	115.39 (18)
H7A—C7—H7B	109.5	C1—N1—C4	109.06 (16)
C3—C7—H7C	109.5	C1—N1—H1A	125.5
H7A—C7—H7C	109.5	C4—N1—H1A	125.5
N1—C4—C8—O2	6.4 (3)	C7—C3—C2—C1	−179.66 (18)
C3—C4—C8—O2	−173.7 (2)	C4—C3—C2—C6	−179.9 (2)
N1—C4—C8—O3	−174.52 (16)	C7—C3—C2—C6	−0.1 (3)
C3—C4—C8—O3	5.4 (3)	N1—C1—C5—O1	−0.2 (4)
N1—C4—C3—C2	−0.1 (2)	C2—C1—C5—O1	−178.7 (2)
C8—C4—C3—C2	179.9 (2)	O2—C8—O3—C9	−2.1 (4)
N1—C4—C3—C7	−179.99 (18)	C4—C8—O3—C9	178.8 (2)
C8—C4—C3—C7	0.1 (3)	C10—C9—O3—C8	169.4 (3)
N1—C1—C2—C3	−0.7 (2)	C2—C1—N1—C4	0.6 (2)
C5—C1—C2—C3	178.0 (2)	C5—C1—N1—C4	−178.23 (18)
N1—C1—C2—C6	179.8 (2)	C3—C4—N1—C1	−0.3 (2)
C5—C1—C2—C6	−1.5 (4)	C8—C4—N1—C1	179.68 (15)
C4—C3—C2—C1	0.5 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2i	0.86	2.07	2.919 (2)	169
C5—H5A···O1ii	0.93	2.54	3.347 (3)	145

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