organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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

aDepartment of Pharmaceutical Engineering, Biotechnology College, Tianjin University of Science & Technology (TUST), Tianjin 300457, People's Republic of China, and bDepartment of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, Republic of Korea
*Correspondence e-mail: yupeng@tust.edu.cn

(Received 7 February 2010; accepted 23 February 2010; online 27 February 2010)

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 ππ 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[Dumas, D. J. (1988). J. Org. Chem. 53, 4650-4653.]); Micheli et al. (2008[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.]). For standard bond-length data, see: Allen et al. (1987[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.]).

[Scheme 1]

Experimental

Crystal data
  • C8H7NO2

  • Mr = 149.15

  • Monoclinic, P 21 /c

  • 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[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.967, Tmax = 0.992

  • 4630 measured reflections

  • 1223 independent reflections

  • 957 reflections with I > 2σ(I)

  • Rint = 0.044

Refinement
  • R[F2 > 2σ(F2)] = 0.035

  • wR(F2) = 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

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C7—H7⋯O2i 0.95 2.52 3.252 (3) 134
Symmetry code: (i) x-1, y, z.

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: CrystalClear.

Supporting information


Comment top

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 ππ 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.

Related literature top

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

Experimental top

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 top

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).

Computing details top

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

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. Part of the crystal structure of the title compound with weak C—H···O hydrogen bonds drawn as dashed lines.
3-Methyl-1H-pyrrolo[2,1-c][1,4]oxazin-1-one top
Crystal data top
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 top
Rigaku Saturn CCD area-detector
diffractometer
1223 independent reflections
Radiation source: rotating anode957 reflections with I > 2σ(I)
Multilayer monochromatorRint = 0.044
Detector resolution: 14.63 pixels mm-1θmax = 25.0°, θmin = 3.4°
ω and ϕ scansh = 88
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 1218
Tmin = 0.967, Tmax = 0.992l = 88
4630 measured reflections
Refinement top
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) = 0.091 w = 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)
Crystal data top
C8H7NO2V = 693.8 (6) Å3
Mr = 149.15Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.915 (4) ŵ = 0.10 mm1
b = 15.502 (8) ÅT = 113 K
c = 7.024 (4) Å0.32 × 0.28 × 0.08 mm
β = 112.866 (8)°
Data collection top
Rigaku Saturn CCD area-detector
diffractometer
1223 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
957 reflections with I > 2σ(I)
Tmin = 0.967, Tmax = 0.992Rint = 0.044
4630 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.091H-atom parameters constrained
S = 1.01Δρmax = 0.23 e Å3
1223 reflectionsΔρmin = 0.19 e Å3
102 parameters
Special details top

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) top
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)
H8A0.01470.55420.26540.047*
H8B0.19810.50930.41620.047*
H8C0.13570.50800.17160.047*
Atomic displacement parameters (Å2) top
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, º) top
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—C43.46 (18)
C7—N1—C1—C2179.99 (12)C3—C4—C5—O22.3 (3)
N1—C1—C2—C30.36 (16)N1—C4—C5—O2177.76 (12)
C1—C2—C3—C40.26 (16)C3—C4—C5—O1177.79 (13)
C2—C3—C4—N10.07 (15)N1—C4—C5—O12.12 (18)
C2—C3—C4—C5179.84 (13)C5—O1—C6—C72.52 (18)
C1—N1—C4—C30.15 (14)C5—O1—C6—C8176.31 (11)
C7—N1—C4—C3179.86 (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—C61.32 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7···O2i0.952.523.252 (3)134
Symmetry code: (i) x1, y, z.

Experimental details

Crystal data
Chemical formulaC8H7NO2
Mr149.15
Crystal system, space groupMonoclinic, P21/c
Temperature (K)113
a, b, c (Å)6.915 (4), 15.502 (8), 7.024 (4)
β (°) 112.866 (8)
V3)693.8 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.32 × 0.28 × 0.08
Data collection
DiffractometerRigaku Saturn CCD area-detector
diffractometer
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.967, 0.992
No. of measured, independent and
observed [I > 2σ(I)] reflections
4630, 1223, 957
Rint0.044
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.091, 1.01
No. of reflections1223
No. of parameters102
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.23, 0.19

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7···O2i0.952.523.252 (3)134
Symmetry code: (i) x1, y, z.
 

Acknowledgements

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.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2. pp. S1–19.  CrossRef Google Scholar
First citationDumas, D. J. (1988). J. Org. Chem. 53, 4650–4653.  CrossRef CAS Web of Science Google Scholar
First citationMicheli, 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.  Web of Science CrossRef PubMed CAS Google Scholar
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
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