4-Acetyl-1H-pyrrole-2-carbaldehyde.

The title compound, C(7)H(7)NO(2), was synthesized via a one-pot Vilsmeier-Haack and subsequent Friedel-Crafts reaction. The pyrazole ring makes dihedral angles of 4.50 (9) and 2.06 (8)°, respectively, with the aldehyde and acetyl groups. In the crystal, classical N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions assemble the mol-ecules into a chain along the b axis.

Related literature

For the synthetic procedure, see: Ge et al. (2009 ▶). For related structures, see: Ge et al. (2011 ▶); Hao et al. (2012 ▶).

Experimental

Crystal data

C7H7NO2

M = 137.14

Monoclinic,

a = 3.811 (5) Å

b = 13.219 (5) Å

c = 13.167 (5) Å

β = 95.602 (5)°

V = 660.2 (9) Å3

Z = 4

Mo Kα radiation

μ = 0.10 mm−1

T = 293 K

0.15 × 0.13 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.541, T max = 0.556

3752 measured reflections

1348 independent reflections

1010 reflections with I > 2σ(I)

R int = 0.056

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.128

S = 1.04

1348 reflections

93 parameters

H-atom parameters constrained

Δρmax = 0.20 e Å−3

Δρmin = −0.14 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812039153/im2396sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812039153/im2396Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812039153/im2396Isup3.cml

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

C7H7NO2	F(000) = 288
Mr = 137.14	Dx = 1.380 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2yn	Cell parameters from 1324 reflections
a = 3.811 (5) Å	θ = 3.1–25.7°
b = 13.219 (5) Å	µ = 0.10 mm−1
c = 13.167 (5) Å	T = 293 K
β = 95.602 (5)°	Block, colorless
V = 660.2 (9) Å3	0.15 × 0.13 × 0.10 mm
Z = 4

Bruker APEXII CCD area-detector diffractometer	1348 independent reflections
Radiation source: fine-focus sealed tube	1010 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
phi and ω scans	θmax = 26.4°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −4→4
Tmin = 0.541, Tmax = 0.556	k = −15→16
3752 measured reflections	l = −12→16

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042	H-atom parameters constrained
wR(F2) = 0.128	w = 1/[σ2(Fo2) + (0.0703P)2] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
1348 reflections	Δρmax = 0.20 e Å−3
93 parameters	Δρmin = −0.14 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.031 (9)

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.

	x	y	z	Uiso*/Ueq
N1	0.4828 (4)	0.16971 (9)	0.21257 (10)	0.0472 (4)
H1A	0.4131	0.1739	0.2726	0.057*
O2	0.7983 (4)	0.23425 (9)	−0.10389 (9)	0.0634 (4)
C4	0.5018 (4)	0.24663 (12)	0.14876 (11)	0.0448 (4)
H4	0.4423	0.3133	0.1619	0.054*
C6	0.6799 (4)	0.27169 (12)	−0.02967 (12)	0.0459 (4)
C2	0.5910 (4)	0.08234 (11)	0.16858 (11)	0.0452 (4)
O1	0.4742 (4)	−0.03023 (10)	0.29831 (10)	0.0777 (5)
C3	0.6811 (4)	0.10776 (11)	0.07349 (12)	0.0437 (4)
H3	0.7652	0.0638	0.0264	0.052*
C5	0.6236 (4)	0.21205 (11)	0.05991 (11)	0.0413 (4)
C7	0.5885 (6)	0.38131 (13)	−0.02795 (14)	0.0606 (5)
H7A	0.6548	0.4132	−0.0887	0.091*
H7B	0.7126	0.4126	0.0308	0.091*
H7C	0.3392	0.3887	−0.0248	0.091*
C1	0.5825 (5)	−0.01457 (13)	0.21628 (14)	0.0582 (5)
H1	0.6661	−0.0696	0.1819	0.070*

	U11	U22	U33	U12	U13	U23
N1	0.0623 (9)	0.0475 (8)	0.0331 (7)	−0.0014 (6)	0.0119 (6)	−0.0040 (6)
O2	0.0926 (10)	0.0596 (8)	0.0412 (7)	−0.0007 (6)	0.0225 (6)	−0.0005 (6)
C4	0.0576 (10)	0.0385 (8)	0.0390 (9)	0.0007 (7)	0.0082 (7)	−0.0040 (7)
C6	0.0535 (9)	0.0477 (9)	0.0366 (9)	−0.0042 (7)	0.0046 (7)	−0.0013 (7)
C2	0.0538 (10)	0.0432 (9)	0.0383 (9)	−0.0001 (7)	0.0026 (7)	−0.0017 (7)
O1	0.1213 (12)	0.0589 (9)	0.0546 (9)	−0.0035 (7)	0.0173 (8)	0.0133 (7)
C3	0.0503 (9)	0.0423 (9)	0.0389 (9)	0.0017 (7)	0.0065 (7)	−0.0067 (7)
C5	0.0467 (9)	0.0420 (9)	0.0356 (8)	−0.0020 (6)	0.0053 (6)	−0.0024 (6)
C7	0.0764 (12)	0.0480 (10)	0.0585 (11)	0.0044 (9)	0.0112 (9)	0.0073 (8)
C1	0.0797 (13)	0.0467 (10)	0.0480 (10)	−0.0001 (8)	0.0052 (9)	0.0011 (8)

N1—C4	1.325 (2)	C2—C1	1.429 (2)
N1—C2	1.373 (2)	O1—C1	1.211 (2)
N1—H1A	0.8600	C3—C5	1.405 (2)
O2—C6	1.2207 (18)	C3—H3	0.9300
C4—C5	1.378 (2)	C7—H7A	0.9600
C4—H4	0.9300	C7—H7B	0.9600
C6—C5	1.452 (2)	C7—H7C	0.9600
C6—C7	1.491 (2)	C1—H1	0.9300
C2—C3	1.372 (2)
C4—N1—C2	109.91 (13)	C5—C3—H3	126.1
C4—N1—H1A	125.0	C4—C5—C3	106.19 (13)
C2—N1—H1A	125.0	C4—C5—C6	126.74 (14)
N1—C4—C5	109.11 (13)	C3—C5—C6	127.07 (13)
N1—C4—H4	125.4	C6—C7—H7A	109.5
C5—C4—H4	125.4	C6—C7—H7B	109.5
O2—C6—C5	121.72 (16)	H7A—C7—H7B	109.5
O2—C6—C7	120.76 (14)	C6—C7—H7C	109.5
C5—C6—C7	117.52 (14)	H7A—C7—H7C	109.5
C3—C2—N1	106.92 (14)	H7B—C7—H7C	109.5
C3—C2—C1	129.75 (15)	O1—C1—C2	124.74 (17)
N1—C2—C1	123.23 (15)	O1—C1—H1	117.6
C2—C3—C5	107.87 (13)	C2—C1—H1	117.6
C2—C3—H3	126.1
C2—N1—C4—C5	0.08 (18)	C2—C3—C5—C6	−179.38 (15)
C4—N1—C2—C3	0.20 (18)	O2—C6—C5—C4	177.98 (16)
C4—N1—C2—C1	−176.51 (16)	C7—C6—C5—C4	−1.8 (2)
N1—C2—C3—C5	−0.40 (17)	O2—C6—C5—C3	−2.2 (2)
C1—C2—C3—C5	176.02 (16)	C7—C6—C5—C3	177.96 (15)
N1—C4—C5—C3	−0.33 (17)	C3—C2—C1—O1	−174.36 (18)
N1—C4—C5—C6	179.50 (14)	N1—C2—C1—O1	1.5 (3)
C2—C3—C5—C4	0.45 (17)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2i	0.86	2.11	2.876 (2)	148
C7—H7A···O1ii	0.96	2.54	3.453 (5)	159

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O2i	0.86	2.11	2.876 (2)	148
C7—H7A⋯O1ii	0.96	2.54	3.453 (5)	159

Symmetry codes: (i) ; (ii) .