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

Khan, S.T.; Yu, P.; Hua, E.; Ali, S.N.; Nisa, M.

doi:10.1107/S1600536810006951

organic compounds

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Volume 66| Part 3| March 2010| Page o711

doi:10.1107/S1600536810006951

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

Salman Tariq Khan,^a Peng Yu,^a ^* Erbin Hua,^a Syed Nawazish Ali ^b and Mehrun Nisa ^a

^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 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 ); Micheli et al. (2008 ). For standard bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₈H₇NO₂
M_r = 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 ) 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[F² > 2σ(F²)] = 0.035
wR(F²) = 0.091
S = 1.01
1223 reflections
102 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supporting information

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

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

checkCIF report

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 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.

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).

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

	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.

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

Crystal data top

C₈H₇NO₂	F(000) = 312
M_r = 149.15	D_x = 1.428 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2364 reflections
a = 6.915 (4) Å	θ = 3.1–27.9°
b = 15.502 (8) Å	µ = 0.10 mm⁻¹
c = 7.024 (4) Å	T = 113 K
β = 112.866 (8)°	Prism, colorless
V = 693.8 (6) Å³	0.32 × 0.28 × 0.08 mm
Z = 4

Data collection top

Rigaku Saturn CCD area-detector diffractometer	1223 independent reflections
Radiation source: rotating anode	957 reflections with I > 2σ(I)
Multilayer monochromator	R_int = 0.044
Detector resolution: 14.63 pixels mm^-1	θ_max = 25.0°, θ_min = 3.4°
ω and ϕ scans	h = −8→8
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −12→18
T_min = 0.967, T_max = 0.992	l = −8→8
4630 measured reflections

Refinement top

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)] = 0.035	H-atom parameters constrained
wR(F²) = 0.091	w = 1/[σ²(F_o²) + (0.0505P)²] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max = 0.002
1223 reflections	Δρ_max = 0.23 e Å⁻³
102 parameters	Δρ_min = −0.19 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: 0.025 (6)

Crystal data top

C₈H₇NO₂	V = 693.8 (6) Å³
M_r = 149.15	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 6.915 (4) Å	µ = 0.10 mm⁻¹
b = 15.502 (8) Å	T = 113 K
c = 7.024 (4) Å	0.32 × 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)
T_min = 0.967, T_max = 0.992	R_int = 0.044
4630 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.091	H-atom parameters constrained
S = 1.01	Δρ_max = 0.23 e Å⁻³
1223 reflections	Δρ_min = −0.19 e Å⁻³
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

	x	y	z	U_iso*/U_eq
O1	0.45807 (13)	0.61029 (5)	0.34499 (13)	0.0259 (3)
O2	0.78058 (13)	0.65952 (7)	0.42312 (15)	0.0384 (3)
N1	0.29846 (17)	0.77385 (7)	0.30630 (16)	0.0221 (3)
C1	0.2544 (2)	0.85965 (8)	0.2913 (2)	0.0287 (4)
H1	0.1204	0.8847	0.2615	0.034*
C2	0.4378 (2)	0.90383 (9)	0.32687 (19)	0.0323 (4)
H2	0.4525	0.9647	0.3252	0.039*
C3	0.5987 (2)	0.84336 (9)	0.3659 (2)	0.0304 (4)
H3	0.7423	0.8555	0.3960	0.037*
C4	0.5104 (2)	0.76289 (8)	0.35257 (18)	0.0237 (4)
C5	0.5972 (2)	0.67754 (8)	0.3770 (2)	0.0250 (4)
C6	0.24605 (19)	0.62433 (8)	0.30253 (19)	0.0228 (3)
C7	0.1665 (2)	0.70294 (8)	0.28336 (19)	0.0235 (3)
H7	0.0216	0.7111	0.2544	0.028*
C8	0.1316 (2)	0.54197 (8)	0.2877 (2)	0.0316 (4)
H8A	−0.0147	0.5542	0.2654	0.047*
H8B	0.1981	0.5093	0.4162	0.047*
H8C	0.1357	0.5080	0.1716	0.047*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0236 (5)	0.0252 (5)	0.0306 (5)	0.0023 (4)	0.0125 (4)	0.0013 (4)
O2	0.0227 (6)	0.0449 (7)	0.0502 (7)	0.0045 (4)	0.0170 (5)	0.0071 (5)
N1	0.0238 (6)	0.0216 (6)	0.0213 (6)	0.0004 (4)	0.0093 (4)	0.0011 (4)
C1	0.0359 (8)	0.0227 (7)	0.0276 (7)	0.0059 (6)	0.0123 (6)	0.0015 (6)
C2	0.0449 (10)	0.0223 (7)	0.0268 (8)	−0.0076 (7)	0.0110 (7)	−0.0004 (6)
C3	0.0296 (8)	0.0338 (8)	0.0265 (7)	−0.0083 (6)	0.0093 (6)	0.0009 (6)
C4	0.0212 (7)	0.0299 (8)	0.0197 (7)	−0.0018 (6)	0.0076 (5)	0.0018 (6)
C5	0.0225 (8)	0.0307 (8)	0.0235 (7)	−0.0006 (6)	0.0108 (6)	0.0024 (6)
C6	0.0187 (7)	0.0289 (8)	0.0212 (7)	−0.0003 (6)	0.0081 (5)	−0.0003 (6)
C7	0.0197 (7)	0.0258 (7)	0.0254 (7)	−0.0008 (6)	0.0091 (5)	0.0006 (6)
C8	0.0307 (8)	0.0250 (7)	0.0375 (8)	−0.0026 (6)	0.0114 (7)	−0.0009 (6)

Geometric parameters (Å, º) top

O1—C5	1.3767 (16)	C3—C4	1.3761 (19)
O1—C6	1.3950 (17)	C3—H3	0.9500
O2—C5	1.2128 (16)	C4—C5	1.4356 (19)
N1—C1	1.3596 (18)	C6—C7	1.3223 (19)
N1—C4	1.3826 (19)	C6—C8	1.4844 (18)
N1—C7	1.3976 (18)	C7—H7	0.9500
C1—C2	1.376 (2)	C8—H8A	0.9800
C1—H1	0.9500	C8—H8B	0.9800
C2—C3	1.398 (2)	C8—H8C	0.9800
C2—H2	0.9500

C5—O1—C6	121.78 (10)	O2—C5—O1	117.45 (12)
C1—N1—C4	108.89 (11)	O2—C5—C4	126.13 (12)
C1—N1—C7	130.07 (12)	O1—C5—C4	116.42 (12)
C4—N1—C7	121.03 (11)	C7—C6—O1	121.79 (12)
N1—C1—C2	108.03 (13)	C7—C6—C8	126.58 (13)
N1—C1—H1	126.0	O1—C6—C8	111.61 (11)
C2—C1—H1	126.0	C6—C7—N1	119.06 (13)
C1—C2—C3	108.01 (13)	C6—C7—H7	120.5
C1—C2—H2	126.0	N1—C7—H7	120.5
C3—C2—H2	126.0	C6—C8—H8A	109.5
C4—C3—C2	107.21 (13)	C6—C8—H8B	109.5
C4—C3—H3	126.4	H8A—C8—H8B	109.5
C2—C3—H3	126.4	C6—C8—H8C	109.5
C3—C4—N1	107.85 (12)	H8A—C8—H8C	109.5
C3—C4—C5	132.32 (14)	H8B—C8—H8C	109.5
N1—C4—C5	119.83 (11)

C4—N1—C1—C2	0.31 (14)	C6—O1—C5—C4	−3.46 (18)
C7—N1—C1—C2	179.99 (12)	C3—C4—C5—O2	2.3 (3)
N1—C1—C2—C3	−0.36 (16)	N1—C4—C5—O2	−177.76 (12)
C1—C2—C3—C4	0.26 (16)	C3—C4—C5—O1	−177.79 (13)
C2—C3—C4—N1	−0.07 (15)	N1—C4—C5—O1	2.12 (18)
C2—C3—C4—C5	179.84 (13)	C5—O1—C6—C7	2.52 (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—N1	0.00 (19)
C1—N1—C4—C5	179.92 (12)	C8—C6—C7—N1	178.64 (12)
C7—N1—C4—C5	0.22 (18)	C1—N1—C7—C6	179.04 (12)
C6—O1—C5—O2	176.42 (11)	C4—N1—C7—C6	−1.32 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O2ⁱ	0.95	2.52	3.252 (3)	134

Symmetry code: (i) x−1, y, z.

Experimental details

Crystal data
Chemical formula	C₈H₇NO₂
M_r	149.15
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	113
a, b, c (Å)	6.915 (4), 15.502 (8), 7.024 (4)
β (°)	112.866 (8)
V (Å³)	693.8 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.32 × 0.28 × 0.08

Data collection
Diffractometer	Rigaku Saturn CCD area-detector diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.967, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	4630, 1223, 957
R_int	0.044
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.091, 1.01
No. of reflections	1223
No. of parameters	102
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
C7—H7···O2ⁱ	0.95	2.52	3.252 (3)	134

Symmetry code: (i) x−1, 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

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. CrossRef Google Scholar
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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. Web of Science CrossRef PubMed CAS Google Scholar
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Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 3| March 2010| Page o711

doi:10.1107/S1600536810006951

Open

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