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

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ISSN: 2056-9890

3-Phenyl-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, bCrystal Materials Research Unit, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, and cPharmaceutical Research Centre, PCSIR Labs Complex, Karachi 75280, Pakistan
*Correspondence e-mail: yupeng@tust.edu.cn

(Received 10 May 2010; accepted 14 May 2010; online 26 May 2010)

The mol­ecule of the title compound, C13H9NO2, is slightly twisted with a dihedral angle of 4.85 (9)° between the nine-membered ring system and the phenyl ring. The nine non-H atoms of the 1H-pyrrolo[2,1-c][1,4]oxazin-1-one system are coplanar [r.m.s. deviation = 0.0122 (2) Å]. In the crystal, weak inter­molecular C—H⋯O inter­actions link mol­ecules into chains along [1[\overline{1}]0]. The crystal studied was an inversion twin with a 0.48624 (9):0.51376 (9) domain ratio.

Related literature

For the biological activity and applications of pyrrolo[1,2-a]pyrazine derivatives, see: Bélanger et al. (1983[Bélanger, P. C., Atkinson, J. G., Rooney, C. S., Britcher, S. F. & Remy, D. C. (1983). J. Org. Chem. 48, 3234-3241.]); Fu et al. (2002[Fu, D.-C., Yu, H. & Zhang, S.-F. (2002). Chin. Chem. Lett. 13, 1051-1054.]); 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 a related structure, see: Khan et al. (2010[Khan, S. T., Yu, P., Hua, E., Ali, S. N. & Nisa, M. (2010). Acta Cryst. E66, o711.]). 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
  • C13H9NO2

  • Mr = 211.21

  • Monoclinic, P 21

  • a = 5.870 (1) Å

  • b = 3.8345 (7) Å

  • c = 21.733 (4) Å

  • β = 91.059 (7)°

  • V = 489.09 (15) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 113 K

  • 0.22 × 0.18 × 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 = 0.979, Tmax = 0.992

  • 4358 measured reflections

  • 1222 independent reflections

  • 1092 reflections with I > 2σ(I)

  • Rint = 0.032

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.085

  • S = 1.10

  • 1222 reflections

  • 147 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.20 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 2.27 3.109 (2) 147
Symmetry code: (i) x-1, y-1, 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

A series of pyrrolo[1,2-a]pyrazine compounds show potent and selective non-competitive mGluR5 antagonists properties (Micheli et al., 2008). We previously reported the synthesis and crystal structure of 3-methyl-1H-pyrrolo[2,1-c][1,4]oxazin-1-one (I) (Khan et al., 2010). The title compound (II), which was designed by changing the methyl substituent in (I) to phenyl, is a new key intermediate which can be used as a precursor for the syntheses of muscle relaxant agents (Bélanger et al., 1983) and other biological active compounds (Fu et al., 2002).

The molecule of title compound (Fig. 1) is slightly twisted, the dihedral angle between this nine membered ring system and phenyl ring being 4.85 (9)° and the O1–C6–C8–C9 torsion angle 5.0 (3)°. The nine non-hydrogen atoms of the 1H-pyrrolo[2,1-c][1,4]oxazin-1-one ring system are coplanar with a r.m.s. of 0.0122 (2) Å. The bond lengths are in normal ranges (Allen et al., 1987) and comparable with the related structure (Khan et al., 2010). In the crystal structure (Fig. 2), weak intermolecular C—H···O interactions (Table 1) link the molecules into chains along [110]. These chains are stacked along the b axis.

Related literature top

For the biological activity and applications of pyrrolo[1,2-a]pyrazine derivatives, see: Bélanger et al. (1983); Fu et al. (2002); Micheli et al. (2008). For a related structure, see: Khan et al. (2010). For standard bond-length data, see: Allen et al. (1987).

Experimental top

A solution of α-bromo acetophenone (2.37 g, 11.91 mmol) in acetone (25 ml) was dropwise added through a dropping funnel to a slurry of 2,2,2-trichloro-1-(lH-pyrrol-2-yl)ethanone (1.69 g, 7.95 mmol), potassium carbonate (1.98 g, 14.31 mmol) and acetone (20 ml) at room temperature in a 100 ml reaction flask. The reaction mixture was refluxed for 4 h. The solid was then removed by filtration and washed with acetone. The filtrate was concentrated under reduced pressure by rotary evaporator, the residue was partitioned between water (20 ml) and ethyl acetate (40 ml) in a separatory funnel (100 ml). The organic layer was separated and the aqueous phase was washed with ethyl acetate (30 ml x 2). The combined organic layers were washed successively with water (20 ml x 3) and brine solution and dried over anhydrous MgSO4. After filtration, the solvent was removed by rotary evaporator to obtain the oily residue (1.90 g) which was purified by flash column chromatography (petroleum ether:ethyl acetate, 4:1 v/v) to afford the desired compound as white solid (1.05 g, yield 62.5 %). Colourless needle-shaped single crystals of the title compound suitable for X-ray structure determination were recrystalized from ethyl acetate by slow evaporation of the solvent at room temperature after several days.

Refinement top

H atoms were placed in calculated positions with C—H = 0.95 Å, and were included in the refinement in a riding-model approximation, with Uiso(H) = 1.2 Ueq(C). The highest residual electron density peak and the deepest hole are located at 0.69 Å and 0.93 Å from atom C4. The crystal studied was an inversion twin, with a refined BASF ratio of 0.48624 (9)/0.51376 (9). The final refinement was carried out with Friedel pairs merged.

Computing details top

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

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.
[Figure 2] Fig. 2. The crystal packing of the title compound viewd along the b axis. Intermoilecular C—H···O interactions are drawn as dashed lines.
3-Phenyl-1H-pyrrolo[2,1-c][1,4]oxazin-1-one top
Crystal data top
C13H9NO2F(000) = 220
Mr = 211.21Dx = 1.434 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybCell parameters from 1222 reflections
a = 5.870 (1) Åθ = 2.8–27.0°
b = 3.8345 (7) ŵ = 0.10 mm1
c = 21.733 (4) ÅT = 113 K
β = 91.059 (7)°Needle, colourless
V = 489.09 (15) Å30.22 × 0.18 × 0.08 mm
Z = 2
Data collection top
Rigaku Saturn CCD area-detector
diffractometer
1222 independent reflections
Radiation source: rotating anode1092 reflections with I > 2σ(I)
Multilayer monochromatorRint = 0.032
Detector resolution: 14.63 pixels mm-1θmax = 27.0°, θmin = 2.8°
ω and ϕ scansh = 77
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 44
Tmin = 0.979, Tmax = 0.992l = 2627
4358 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)] = 0.031H-atom parameters constrained
wR(F2) = 0.085 w = 1/[σ2(Fo2) + (0.050P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1222 reflectionsΔρmax = 0.20 e Å3
147 parametersΔρmin = 0.19 e Å3
1 restraintExtinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.037 (9)
Crystal data top
C13H9NO2V = 489.09 (15) Å3
Mr = 211.21Z = 2
Monoclinic, P21Mo Kα radiation
a = 5.870 (1) ŵ = 0.10 mm1
b = 3.8345 (7) ÅT = 113 K
c = 21.733 (4) Å0.22 × 0.18 × 0.08 mm
β = 91.059 (7)°
Data collection top
Rigaku Saturn CCD area-detector
diffractometer
1222 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
1092 reflections with I > 2σ(I)
Tmin = 0.979, Tmax = 0.992Rint = 0.032
4358 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0311 restraint
wR(F2) = 0.085H-atom parameters constrained
S = 1.10Δρmax = 0.20 e Å3
1222 reflectionsΔρmin = 0.19 e Å3
147 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
O10.4797 (2)0.4846 (4)0.25405 (5)0.0201 (4)
O20.7147 (2)0.7726 (4)0.31664 (6)0.0273 (4)
N10.1877 (2)0.3508 (4)0.34783 (7)0.0181 (4)
C10.0686 (3)0.3143 (6)0.40070 (8)0.0219 (5)
H10.07630.20670.40440.026*
C20.1959 (3)0.4614 (6)0.44782 (8)0.0232 (5)
H20.15460.47000.48990.028*
C30.3965 (3)0.5960 (6)0.42329 (9)0.0230 (5)
H30.51480.71400.44530.028*
C40.3895 (3)0.5244 (5)0.36106 (8)0.0186 (4)
C50.5406 (3)0.6064 (6)0.31182 (8)0.0198 (4)
C60.2775 (3)0.3039 (6)0.24323 (8)0.0177 (4)
C70.1330 (3)0.2396 (6)0.28844 (8)0.0189 (4)
H70.00570.11920.28020.023*
C80.2448 (3)0.1991 (6)0.17857 (8)0.0186 (4)
C90.4150 (3)0.2573 (6)0.13567 (8)0.0223 (5)
H90.55400.36510.14830.027*
C100.3819 (4)0.1584 (6)0.07468 (9)0.0258 (5)
H100.49870.19920.04590.031*
C110.1813 (4)0.0015 (6)0.05544 (8)0.0242 (5)
H110.15960.06510.01360.029*
C120.0115 (3)0.0580 (6)0.09787 (8)0.0248 (5)
H120.12730.16510.08490.030*
C130.0429 (3)0.0377 (6)0.15879 (8)0.0220 (5)
H130.07380.00680.18750.026*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0165 (7)0.0229 (8)0.0210 (6)0.0045 (6)0.0017 (5)0.0005 (7)
O20.0190 (7)0.0308 (9)0.0321 (8)0.0093 (7)0.0014 (5)0.0000 (7)
N10.0163 (8)0.0198 (10)0.0183 (8)0.0017 (7)0.0007 (6)0.0014 (7)
C10.0206 (10)0.0251 (12)0.0202 (9)0.0008 (9)0.0047 (7)0.0043 (9)
C20.0263 (10)0.0249 (12)0.0185 (9)0.0048 (10)0.0025 (7)0.0021 (9)
C30.0233 (10)0.0222 (12)0.0234 (9)0.0015 (9)0.0033 (7)0.0017 (9)
C40.0161 (9)0.0173 (12)0.0224 (9)0.0000 (8)0.0019 (7)0.0001 (9)
C50.0183 (10)0.0170 (11)0.0240 (9)0.0002 (9)0.0017 (7)0.0007 (9)
C60.0146 (9)0.0166 (11)0.0220 (9)0.0019 (8)0.0010 (7)0.0017 (8)
C70.0172 (9)0.0207 (11)0.0187 (8)0.0025 (8)0.0012 (7)0.0002 (9)
C80.0193 (9)0.0168 (11)0.0197 (9)0.0027 (8)0.0009 (7)0.0020 (8)
C90.0202 (10)0.0237 (12)0.0229 (9)0.0017 (9)0.0011 (7)0.0015 (10)
C100.0289 (11)0.0275 (13)0.0211 (9)0.0049 (10)0.0064 (8)0.0034 (9)
C110.0310 (11)0.0237 (12)0.0178 (9)0.0066 (9)0.0020 (7)0.0001 (9)
C120.0239 (10)0.0248 (12)0.0255 (10)0.0016 (10)0.0042 (7)0.0020 (10)
C130.0199 (10)0.0243 (13)0.0219 (9)0.0000 (9)0.0030 (7)0.0003 (10)
Geometric parameters (Å, º) top
O1—C51.380 (2)C6—C81.471 (2)
O1—C61.391 (2)C7—H70.9500
O2—C51.207 (2)C8—C91.397 (2)
N1—C11.363 (2)C8—C131.397 (3)
N1—C41.384 (2)C9—C101.389 (3)
N1—C71.391 (2)C9—H90.9500
C1—C21.377 (3)C10—C111.380 (3)
C1—H10.9500C10—H100.9500
C2—C31.400 (3)C11—C121.389 (3)
C2—H20.9500C11—H110.9500
C3—C41.380 (3)C12—C131.383 (3)
C3—H30.9500C12—H120.9500
C4—C51.438 (2)C13—H130.9500
C6—C71.333 (2)
C5—O1—C6121.88 (14)C6—C7—N1119.21 (18)
C1—N1—C4108.95 (15)C6—C7—H7120.4
C1—N1—C7129.57 (17)N1—C7—H7120.4
C4—N1—C7121.48 (15)C9—C8—C13118.58 (17)
N1—C1—C2107.74 (17)C9—C8—C6120.77 (17)
N1—C1—H1126.1C13—C8—C6120.65 (16)
C2—C1—H1126.1C10—C9—C8120.26 (19)
C1—C2—C3108.45 (17)C10—C9—H9119.9
C1—C2—H2125.8C8—C9—H9119.9
C3—C2—H2125.8C11—C10—C9120.78 (17)
C4—C3—C2106.83 (18)C11—C10—H10119.6
C4—C3—H3126.6C9—C10—H10119.6
C2—C3—H3126.6C10—C11—C12119.29 (18)
C3—C4—N1108.03 (16)C10—C11—H11120.4
C3—C4—C5132.71 (19)C12—C11—H11120.4
N1—C4—C5119.21 (16)C13—C12—C11120.47 (19)
O2—C5—O1117.52 (16)C13—C12—H12119.8
O2—C5—C4125.73 (18)C11—C12—H12119.8
O1—C5—C4116.75 (16)C12—C13—C8120.62 (17)
C7—C6—O1121.35 (17)C12—C13—H13119.7
C7—C6—C8125.48 (18)C8—C13—H13119.7
O1—C6—C8113.17 (15)
C4—N1—C1—C20.7 (2)C5—O1—C6—C8179.70 (17)
C7—N1—C1—C2178.7 (2)O1—C6—C7—N11.1 (3)
N1—C1—C2—C30.9 (2)C8—C6—C7—N1179.16 (18)
C1—C2—C3—C40.7 (2)C1—N1—C7—C6179.8 (2)
C2—C3—C4—N10.3 (2)C4—N1—C7—C60.5 (3)
C2—C3—C4—C5177.6 (2)C7—C6—C8—C9175.2 (2)
C1—N1—C4—C30.2 (2)O1—C6—C8—C95.0 (3)
C7—N1—C4—C3179.20 (19)C7—C6—C8—C134.5 (3)
C1—N1—C4—C5177.49 (18)O1—C6—C8—C13175.29 (19)
C7—N1—C4—C53.1 (3)C13—C8—C9—C100.5 (3)
C6—O1—C5—O2177.16 (18)C6—C8—C9—C10179.8 (2)
C6—O1—C5—C42.6 (3)C8—C9—C10—C110.0 (3)
C3—C4—C5—O21.3 (4)C9—C10—C11—C120.1 (4)
N1—C4—C5—O2175.7 (2)C10—C11—C12—C130.2 (4)
C3—C4—C5—O1178.9 (2)C11—C12—C13—C80.7 (4)
N1—C4—C5—O14.0 (3)C9—C8—C13—C120.8 (3)
C5—O1—C6—C70.1 (3)C6—C8—C13—C12179.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7···O2i0.952.273.109 (2)147
Symmetry code: (i) x1, y1, z.

Experimental details

Crystal data
Chemical formulaC13H9NO2
Mr211.21
Crystal system, space groupMonoclinic, P21
Temperature (K)113
a, b, c (Å)5.870 (1), 3.8345 (7), 21.733 (4)
β (°) 91.059 (7)
V3)489.09 (15)
Z2
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.22 × 0.18 × 0.08
Data collection
DiffractometerRigaku Saturn CCD area-detector
diffractometer
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.979, 0.992
No. of measured, independent and
observed [I > 2σ(I)] reflections
4358, 1222, 1092
Rint0.032
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.085, 1.10
No. of reflections1222
No. of parameters147
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.20, 0.19

Computer programs: CrystalClear (Rigaku, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C7—H7···O2i0.952.273.109 (2)147
Symmetry code: (i) x1, y1, z.
 

Footnotes

Additional correspondence author, e-mail: salmankhann@hotmail.com.

§Thomson Reuters ResearcherID: A-5085-2009.

Acknowledgements

STK acknowledges funding from the Industrial Linkage Programme of Pakistan Council of Scientific and Industrial Research (PCSIR) Laboratories, Pakistan. He also thanks Dr Song Haibin of the State Key Laboratory of Elemento-Organic Chemistry, Nankai University, for the X-ray data collection. PY is grateful to Tianjin University of Science & Technology for a research grant (No. 2009 0431).

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 Web of Science
First citationBélanger, P. C., Atkinson, J. G., Rooney, C. S., Britcher, S. F. & Remy, D. C. (1983). J. Org. Chem. 48, 3234–3241.
First citationFu, D.-C., Yu, H. & Zhang, S.-F. (2002). Chin. Chem. Lett. 13, 1051–1054.  CAS
First citationKhan, S. T., Yu, P., Hua, E., Ali, S. N. & Nisa, M. (2010). Acta Cryst. E66, o711.  Web of Science CSD CrossRef IUCr Journals
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
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals

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