PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 March 1; 66(Pt 3): o711.
Published online 2010 February 27. doi:  10.1107/S1600536810006951
PMCID: PMC2983595

3-Methyl-1H-pyrrolo[2,1-c][1,4]oxazin-1-one

Abstract

In the title mol­ecule, C8H7NO2, all the non-H atoms lie essentially in the same plane (r.m.s. deviation = 0.019 Å) In the crystal structure, weak inter­molecular C—H(...)O inter­actions link mol­ecules into chains along [100]. In addition, there are π–π stacking inter­actions between mol­ecules related by the c-glide plane, with alternating centroid–centroid distances of 3.434 (2) and 3.639 (2) Å.

Related literature

For the synthesis and applications of the title compound, see: Dumas et al. (1988 [triangle]); Micheli et al. (2008 [triangle]). For standard bond-length data, see: Allen et al. (1987 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0o711-scheme1.jpg

Experimental

Crystal data

  • C8H7NO2
  • M r = 149.15
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o711-efi1.jpg
  • a = 6.915 (4) Å
  • b = 15.502 (8) Å
  • c = 7.024 (4) Å
  • β = 112.866 (8)°
  • V = 693.8 (6) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.10 mm−1
  • T = 113 K
  • 0.32 × 0.28 × 0.08 mm

Data collection

  • Rigaku Saturn CCD area-detector diffractometer
  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 [triangle]) T min = 0.967, T max = 0.992
  • 4630 measured reflections
  • 1223 independent reflections
  • 957 reflections with I > 2σ(I)
  • R int = 0.044

Refinement

  • R[F 2 > 2σ(F 2)] = 0.035
  • wR(F 2) = 0.091
  • S = 1.01
  • 1223 reflections
  • 102 parameters
  • H-atom parameters constrained
  • Δρmax = 0.23 e Å−3
  • Δρmin = −0.19 e Å−3

Data collection: CrystalClear (Rigaku, 2005 [triangle]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: PLATON (Spek, 2009 [triangle]); software used to prepare material for publication: CrystalClear.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810006951/pv2260sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810006951/pv2260Isup2.hkl

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

Acknowledgments

STK acknowledges funding from the Industrial Linkage Programme of Pakistan Council of Scientific and Industrial Research (PCSIR) Laboratories, Pakistan. He also thanks Dr Alan J. Lough (Department of Chemistry, University of Toronto, Canada) for his help in preparing the manuscript. PY is grateful to Tianjin University of Science & Technology for research funding (research grant No. 2009 0431). The authors also thankful to Dr Song Haibin (Nankai University) for the X-ray crystallographic data collection.

supplementary crystallographic information

Comment

The preparation of the title compound was originally reported by Dumas (1988) as an intermediate in the synthesis of peramine. Recently, Micheli et al. (2008) used various analogues of this compound to synthesize a new series of pyrrolo[1,2-a]pyrazine compounds that are potent and selective non-competitive mGluR5 antagonists.

The crystal structure of the title compound is shown in Fig. 1. The bond lengths are as expected (Allen et al., 1987). All the non-hydrogen atoms are essentially in the same plane (r.m.s. deviation = 0.019 Å). In the crystal structure, weak intermolecular C—H···O interactions link molecules into chains along [100] (Fig. 2). In addition, there are π–π stacking interactions with Cg1···Cg2(x,3/2-y,-1/2+z) = 3.434 (2) and Cg1···Cg2(x,3/2-y,1/2+z) = 3.639 (2) Å, where Cg1 and Cg2 are the centroids defined by rings atoms N1/C1—C4 and O1/C5/C4/N1/C7/C6, respectively.

Experimental

A solution of 1-chloropropan-2-one (7.56 mL, 90 mmol) in acetone (50 ml) was dropwise added through a dropping funnel to a slurry of 2,2,2-trichloro-1-(lH-pyrrol-2-yl)ethanone (12.72 g, 60 mmol), potassium carbonate (24.84 g, 180 mmol) and acetone (150 ml) at room temperature in a 250 ml round-bottom flask. The reaction mixture was stirred at room temperature. After 24 h, the solid was removed by filtration and washed with acetone. The filtrate was concentrated under reduced pressure by rotary evaporator, the residue was partitioned between water and ethyl acetate (200 ml each) in a separatory funnel (500 ml). The organic layer was separated and the aqueous phase was washed with ethyl acetate (100 ml x 2). The combined organic layers were washed successively with water (100 ml x 3) and brine solution and dried over anhydrous MgSO4. After filtration, the solvent was removed by rotary evaporator to obtain the oily brown solid residue (13.0 g) which was purified by flash column chromatography (Petroleum ether: Ethyl acetate; 2:1) to afford the desired compound as pale yellow solid (5.1 g, 57%). The product was recrystallized in a mixture of petroleum ether and ethyl acetate (5:1). The colorless needles of the title compound were obtained by slow evaporation of solvent at room temperature. Melting point and NMR spectral data were consistent with the reported values (Dumas, 1988).

Refinement

H atoms were placed in calculated positions with C—H = 0.95Å or C—H = 0.98Å for methyl H atoms and were included in the refinement in a riding-model approximation with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(Cmethyl).

Figures

Fig. 1.
The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
Fig. 2.
Part of the crystal structure of the title compound with weak C—H···O hydrogen bonds drawn as dashed lines.

Crystal data

C8H7NO2F(000) = 312
Mr = 149.15Dx = 1.428 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2364 reflections
a = 6.915 (4) Åθ = 3.1–27.9°
b = 15.502 (8) ŵ = 0.10 mm1
c = 7.024 (4) ÅT = 113 K
β = 112.866 (8)°Prism, colorless
V = 693.8 (6) Å30.32 × 0.28 × 0.08 mm
Z = 4

Data collection

Rigaku Saturn CCD area-detector diffractometer1223 independent reflections
Radiation source: rotating anode957 reflections with I > 2σ(I)
multilayerRint = 0.044
Detector resolution: 14.63 pixels mm-1θmax = 25.0°, θmin = 3.4°
ω and [var phi] scansh = −8→8
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)k = −12→18
Tmin = 0.967, Tmax = 0.992l = −8→8
4630 measured reflections

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.091w = 1/[σ2(Fo2) + (0.0505P)2] where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max = 0.002
1223 reflectionsΔρmax = 0.23 e Å3
102 parametersΔρmin = −0.19 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.025 (6)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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)

xyzUiso*/Ueq
O10.45807 (13)0.61029 (5)0.34499 (13)0.0259 (3)
O20.78058 (13)0.65952 (7)0.42312 (15)0.0384 (3)
N10.29846 (17)0.77385 (7)0.30630 (16)0.0221 (3)
C10.2544 (2)0.85965 (8)0.2913 (2)0.0287 (4)
H10.12040.88470.26150.034*
C20.4378 (2)0.90383 (9)0.32687 (19)0.0323 (4)
H20.45250.96470.32520.039*
C30.5987 (2)0.84336 (9)0.3659 (2)0.0304 (4)
H30.74230.85550.39600.037*
C40.5104 (2)0.76289 (8)0.35257 (18)0.0237 (4)
C50.5972 (2)0.67754 (8)0.3770 (2)0.0250 (4)
C60.24605 (19)0.62433 (8)0.30253 (19)0.0228 (3)
C70.1665 (2)0.70294 (8)0.28336 (19)0.0235 (3)
H70.02160.71110.25440.028*
C80.1316 (2)0.54197 (8)0.2877 (2)0.0316 (4)
H8A−0.01470.55420.26540.047*
H8B0.19810.50930.41620.047*
H8C0.13570.50800.17160.047*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0236 (5)0.0252 (5)0.0306 (5)0.0023 (4)0.0125 (4)0.0013 (4)
O20.0227 (6)0.0449 (7)0.0502 (7)0.0045 (4)0.0170 (5)0.0071 (5)
N10.0238 (6)0.0216 (6)0.0213 (6)0.0004 (4)0.0093 (4)0.0011 (4)
C10.0359 (8)0.0227 (7)0.0276 (7)0.0059 (6)0.0123 (6)0.0015 (6)
C20.0449 (10)0.0223 (7)0.0268 (8)−0.0076 (7)0.0110 (7)−0.0004 (6)
C30.0296 (8)0.0338 (8)0.0265 (7)−0.0083 (6)0.0093 (6)0.0009 (6)
C40.0212 (7)0.0299 (8)0.0197 (7)−0.0018 (6)0.0076 (5)0.0018 (6)
C50.0225 (8)0.0307 (8)0.0235 (7)−0.0006 (6)0.0108 (6)0.0024 (6)
C60.0187 (7)0.0289 (8)0.0212 (7)−0.0003 (6)0.0081 (5)−0.0003 (6)
C70.0197 (7)0.0258 (7)0.0254 (7)−0.0008 (6)0.0091 (5)0.0006 (6)
C80.0307 (8)0.0250 (7)0.0375 (8)−0.0026 (6)0.0114 (7)−0.0009 (6)

Geometric parameters (Å, °)

O1—C51.3767 (16)C3—C41.3761 (19)
O1—C61.3950 (17)C3—H30.9500
O2—C51.2128 (16)C4—C51.4356 (19)
N1—C11.3596 (18)C6—C71.3223 (19)
N1—C41.3826 (19)C6—C81.4844 (18)
N1—C71.3976 (18)C7—H70.9500
C1—C21.376 (2)C8—H8A0.9800
C1—H10.9500C8—H8B0.9800
C2—C31.398 (2)C8—H8C0.9800
C2—H20.9500
C5—O1—C6121.78 (10)O2—C5—O1117.45 (12)
C1—N1—C4108.89 (11)O2—C5—C4126.13 (12)
C1—N1—C7130.07 (12)O1—C5—C4116.42 (12)
C4—N1—C7121.03 (11)C7—C6—O1121.79 (12)
N1—C1—C2108.03 (13)C7—C6—C8126.58 (13)
N1—C1—H1126.0O1—C6—C8111.61 (11)
C2—C1—H1126.0C6—C7—N1119.06 (13)
C1—C2—C3108.01 (13)C6—C7—H7120.5
C1—C2—H2126.0N1—C7—H7120.5
C3—C2—H2126.0C6—C8—H8A109.5
C4—C3—C2107.21 (13)C6—C8—H8B109.5
C4—C3—H3126.4H8A—C8—H8B109.5
C2—C3—H3126.4C6—C8—H8C109.5
C3—C4—N1107.85 (12)H8A—C8—H8C109.5
C3—C4—C5132.32 (14)H8B—C8—H8C109.5
N1—C4—C5119.83 (11)
C4—N1—C1—C20.31 (14)C6—O1—C5—C4−3.46 (18)
C7—N1—C1—C2179.99 (12)C3—C4—C5—O22.3 (3)
N1—C1—C2—C3−0.36 (16)N1—C4—C5—O2−177.76 (12)
C1—C2—C3—C40.26 (16)C3—C4—C5—O1−177.79 (13)
C2—C3—C4—N1−0.07 (15)N1—C4—C5—O12.12 (18)
C2—C3—C4—C5179.84 (13)C5—O1—C6—C72.52 (18)
C1—N1—C4—C3−0.15 (14)C5—O1—C6—C8−176.31 (11)
C7—N1—C4—C3−179.86 (11)O1—C6—C7—N10.00 (19)
C1—N1—C4—C5179.92 (12)C8—C6—C7—N1178.64 (12)
C7—N1—C4—C50.22 (18)C1—N1—C7—C6179.04 (12)
C6—O1—C5—O2176.42 (11)C4—N1—C7—C6−1.32 (18)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C7—H7···O2i0.952.523.252 (3)134

Symmetry codes: (i) x−1, y, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2260).

References

  • Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2 pp. S1–19.
  • Dumas, D. J. (1988). J. Org. Chem.53, 4650–4653.
  • Micheli, F., Bertani, B., Bozzoli, A., Crippa, L., Cavanni, P., Di Fabio, R., Donati, D., Marzorati, P., Merlo, G., Paio, A., Perugini, L. & Zarantonello, P. (2008). Bioorg. Med. Chem. Lett.18, 1804–1809. [PubMed]
  • Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography