1-Ethyl-3-methyl-quinoxalin-2(1H)-one.

The asymmetric unit of the title compound, C(11)H(12)N(2)O, contains two independent mol-ecules. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules. There are π-π contacts between the quinoxaline rings [centroid-centroid distances = 3.446 (2), 3.665 (2), 3.645 (3) and 3.815 (3) Å]. There also exist C-H⋯π contacts between the methyl groups and the quinoxaline rings.

Related literature

For general background, see: Amin (2003 ▶); Boutti & Lecolier (1975 ▶); Milos & John (1981 ▶); Rose et al. (1990 ▶); Salman et al. (2007 ▶); Kotharkar & Shinde (2006 ▶); Vishnu et al. (2006 ▶). For related literature, see: Nikolaenko & Munro (2004 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C11H12N2O

M = 188.23

Triclinic,

a = 7.4101 (6) Å

b = 9.1405 (8) Å

c = 14.2960 (12) Å

α = 84.976 (7)°

β = 78.717 (7)°

γ = 88.137 (7)°

V = 945.82 (14) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 180 K

0.18 × 0.13 × 0.07 mm

Data collection

Oxford Diffraction Xcalibur diffractometer

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007 ▶) T min = 0.988, T max = 0.991

7441 measured reflections

3865 independent reflections

2874 reflections with I > 2σ(I)

R int = 0.021

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.111

S = 1.06

3865 reflections

257 parameters

H-atom parameters constrained

Δρmax = 0.17 e Å−3

Δρmin = −0.25 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2007 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033989/hk2546sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808033989/hk2546Isup2.hkl

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

C11H12N2O	Z = 4
Mr = 188.23	F(000) = 400
Triclinic, P1	Dx = 1.322 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.4101 (6) Å	Cell parameters from 4794 reflections
b = 9.1405 (8) Å	θ = 2.8–31.9°
c = 14.2960 (12) Å	µ = 0.09 mm−1
α = 84.976 (7)°	T = 180 K
β = 78.717 (7)°	Block, colorless
γ = 88.137 (7)°	0.18 × 0.13 × 0.07 mm
V = 945.82 (14) Å3

Oxford Diffraction Xcalibur diffractometer	3865 independent reflections
Radiation source: fine-focus sealed tube	2874 reflections with I > 2σ(I)
graphite	Rint = 0.021
φ and ω scans	θmax = 26.4°, θmin = 2.8°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	h = −9→8
Tmin = 0.988, Tmax = 0.991	k = −11→11
7441 measured reflections	l = −14→17

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.111	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0636P)2 + 0.0861P] where P = (Fo2 + 2Fc2)/3
3865 reflections	(Δ/σ)max < 0.001
257 parameters	Δρmax = 0.17 e Å−3
0 restraints	Δρmin = −0.25 e Å−3

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
O1	0.46438 (13)	0.21858 (11)	0.37756 (7)	0.0375 (3)
O2	0.28053 (14)	0.17912 (12)	−0.17004 (7)	0.0438 (3)
N1	0.33532 (14)	0.31106 (11)	0.51763 (7)	0.0244 (2)
N2	0.28293 (14)	0.57622 (11)	0.41274 (8)	0.0279 (3)
N3	0.30886 (13)	0.14773 (11)	−0.01436 (7)	0.0258 (2)
N4	0.19176 (14)	−0.14053 (12)	−0.01083 (8)	0.0274 (3)
C1	0.39293 (17)	0.32233 (14)	0.42044 (9)	0.0267 (3)
C2	0.36552 (17)	0.46723 (14)	0.37053 (9)	0.0274 (3)
C3	0.21391 (16)	0.55680 (13)	0.51001 (9)	0.0237 (3)
C4	0.11835 (18)	0.67263 (14)	0.55460 (10)	0.0300 (3)
H4	0.1021	0.7601	0.5186	0.036*
C5	0.04770 (19)	0.66048 (15)	0.65059 (10)	0.0342 (3)
H5	−0.0161	0.7388	0.6799	0.041*
C6	0.07254 (19)	0.52952 (16)	0.70377 (10)	0.0344 (3)
H6	0.0251	0.521	0.7692	0.041*
C7	0.16544 (18)	0.41247 (15)	0.66197 (9)	0.0296 (3)
H7	0.1795	0.3253	0.6987	0.036*
C8	0.23840 (16)	0.42472 (13)	0.56451 (9)	0.0228 (3)
C9	0.37008 (19)	0.16990 (14)	0.56915 (10)	0.0311 (3)
H9A	0.3822	0.1864	0.6337	0.037*
H9B	0.4852	0.1276	0.5373	0.037*
C10	0.2174 (2)	0.06358 (15)	0.57337 (11)	0.0386 (3)
H10A	0.1059	0.1005	0.6106	0.058*
H10B	0.2494	−0.0298	0.6025	0.058*
H10C	0.1995	0.0522	0.5097	0.058*
C11	0.4365 (2)	0.48358 (17)	0.26554 (10)	0.0396 (3)
H11A	0.3503	0.4428	0.2332	0.059*
H11B	0.5527	0.4326	0.251	0.059*
H11C	0.4525	0.5858	0.2446	0.059*
C12	0.26924 (17)	0.09898 (15)	−0.09593 (9)	0.0287 (3)
C13	0.21489 (17)	−0.05575 (15)	−0.08903 (9)	0.0279 (3)
C14	0.22409 (16)	−0.08415 (13)	0.07134 (9)	0.0236 (3)
C15	0.19919 (18)	−0.17617 (15)	0.15556 (9)	0.0306 (3)
H15	0.157	−0.2709	0.1556	0.037*
C16	0.23571 (19)	−0.12955 (17)	0.23841 (10)	0.0361 (3)
H16	0.2194	−0.1921	0.2942	0.043*
C17	0.29710 (19)	0.01175 (17)	0.23769 (10)	0.0358 (3)
H17	0.3223	0.044	0.2936	0.043*
C18	0.32169 (17)	0.10564 (15)	0.15571 (10)	0.0308 (3)
H18	0.3624	0.2006	0.1567	0.037*
C19	0.28562 (16)	0.05865 (13)	0.07122 (8)	0.0232 (3)
C20	0.37012 (19)	0.29997 (14)	−0.01979 (11)	0.0359 (3)
H20A	0.432	0.3291	−0.0847	0.043*
H20B	0.4577	0.3061	0.022	0.043*
C21	0.2105 (2)	0.40401 (17)	0.00908 (14)	0.0525 (4)
H21A	0.1243	0.399	−0.0326	0.079*
H21B	0.2549	0.5024	0.0044	0.079*
H21C	0.1508	0.3768	0.0739	0.079*
C22	0.1875 (2)	−0.11426 (18)	−0.17904 (10)	0.0399 (4)
H22A	0.1497	−0.2146	−0.166	0.06*
H22B	0.3009	−0.109	−0.2251	0.06*
H22C	0.0943	−0.0569	−0.2042	0.06*

	U11	U22	U33	U12	U13	U23
O1	0.0409 (6)	0.0364 (5)	0.0342 (5)	0.0068 (4)	−0.0026 (4)	−0.0111 (4)
O2	0.0460 (6)	0.0514 (6)	0.0287 (5)	0.0052 (5)	−0.0026 (4)	0.0131 (5)
N1	0.0263 (5)	0.0214 (5)	0.0260 (6)	0.0021 (4)	−0.0066 (4)	−0.0019 (4)
N2	0.0302 (6)	0.0253 (6)	0.0291 (6)	−0.0059 (4)	−0.0083 (5)	0.0009 (4)
N3	0.0222 (5)	0.0247 (5)	0.0273 (6)	0.0021 (4)	0.0011 (4)	0.0009 (4)
N4	0.0246 (6)	0.0304 (6)	0.0266 (6)	0.0030 (4)	−0.0023 (4)	−0.0061 (5)
C1	0.0221 (6)	0.0302 (7)	0.0285 (7)	−0.0015 (5)	−0.0051 (5)	−0.0058 (5)
C2	0.0257 (6)	0.0310 (7)	0.0263 (7)	−0.0063 (5)	−0.0065 (5)	−0.0013 (5)
C3	0.0219 (6)	0.0229 (6)	0.0283 (6)	−0.0039 (5)	−0.0086 (5)	−0.0024 (5)
C4	0.0321 (7)	0.0212 (6)	0.0396 (8)	−0.0005 (5)	−0.0136 (6)	−0.0036 (5)
C5	0.0326 (7)	0.0302 (7)	0.0419 (8)	0.0034 (6)	−0.0077 (6)	−0.0154 (6)
C6	0.0359 (8)	0.0396 (8)	0.0277 (7)	−0.0012 (6)	−0.0033 (6)	−0.0094 (6)
C7	0.0331 (7)	0.0295 (7)	0.0265 (7)	0.0001 (6)	−0.0071 (5)	−0.0006 (5)
C8	0.0212 (6)	0.0223 (6)	0.0268 (6)	−0.0013 (5)	−0.0075 (5)	−0.0046 (5)
C9	0.0369 (8)	0.0251 (7)	0.0312 (7)	0.0088 (6)	−0.0081 (6)	−0.0015 (5)
C10	0.0475 (9)	0.0257 (7)	0.0394 (8)	0.0006 (6)	−0.0026 (7)	0.0013 (6)
C11	0.0436 (8)	0.0447 (8)	0.0284 (7)	−0.0039 (7)	−0.0023 (6)	0.0003 (6)
C12	0.0216 (6)	0.0377 (7)	0.0234 (7)	0.0069 (5)	0.0010 (5)	0.0014 (6)
C13	0.0202 (6)	0.0381 (7)	0.0242 (7)	0.0066 (5)	−0.0014 (5)	−0.0060 (5)
C14	0.0193 (6)	0.0268 (6)	0.0235 (6)	0.0041 (5)	−0.0010 (5)	−0.0041 (5)
C15	0.0295 (7)	0.0287 (7)	0.0301 (7)	0.0041 (5)	−0.0002 (5)	0.0028 (5)
C16	0.0351 (8)	0.0462 (9)	0.0235 (7)	0.0105 (6)	−0.0019 (6)	0.0039 (6)
C17	0.0319 (7)	0.0518 (9)	0.0251 (7)	0.0110 (6)	−0.0078 (5)	−0.0102 (6)
C18	0.0263 (7)	0.0332 (7)	0.0341 (7)	0.0034 (5)	−0.0058 (5)	−0.0117 (6)
C19	0.0171 (6)	0.0265 (6)	0.0238 (6)	0.0054 (5)	0.0001 (5)	−0.0017 (5)
C20	0.0325 (7)	0.0263 (7)	0.0445 (8)	−0.0010 (6)	0.0015 (6)	0.0022 (6)
C21	0.0460 (9)	0.0285 (8)	0.0800 (13)	0.0068 (7)	−0.0047 (8)	−0.0070 (8)
C22	0.0340 (8)	0.0588 (10)	0.0284 (7)	0.0060 (7)	−0.0064 (6)	−0.0136 (7)

C1—O1	1.2238 (15)	C12—O2	1.2245 (15)
C1—N1	1.3671 (16)	C12—N3	1.3705 (17)
C1—C2	1.4759 (18)	C12—C13	1.473 (2)
C2—N2	1.2854 (16)	C13—N4	1.2891 (17)
C2—C11	1.4862 (18)	C13—C22	1.4876 (19)
C3—N2	1.3825 (17)	C14—N4	1.3882 (16)
C3—C4	1.3862 (17)	C14—C15	1.3918 (18)
C3—C8	1.4049 (17)	C14—C19	1.3963 (18)
C4—C5	1.366 (2)	C15—C16	1.371 (2)
C4—H4	0.93	C15—H15	0.93
C5—C6	1.388 (2)	C16—C17	1.382 (2)
C5—H5	0.93	C16—H16	0.93
C6—C7	1.3707 (19)	C17—C18	1.3761 (19)
C6—H6	0.93	C17—H17	0.93
C7—C8	1.3885 (18)	C18—C19	1.3926 (18)
C7—H7	0.93	C18—H18	0.93
C8—N1	1.3891 (15)	C19—N3	1.3934 (16)
C9—N1	1.4696 (15)	C20—N3	1.4687 (17)
C9—H9A	0.97	C20—H20A	0.97
C9—H9B	0.97	C20—H20B	0.97
C10—C9	1.5041 (19)	C21—C20	1.509 (2)
C10—H10A	0.96	C21—H21A	0.96
C10—H10B	0.96	C21—H21B	0.96
C10—H10C	0.96	C21—H21C	0.96
C11—H11A	0.96	C22—H22A	0.96
C11—H11B	0.96	C22—H22B	0.96
C11—H11C	0.96	C22—H22C	0.96
O1—C1—N1	121.88 (12)	N4—C13—C22	119.61 (13)
O1—C1—C2	122.05 (12)	C12—C13—C22	116.56 (12)
N1—C1—C2	116.07 (11)	N4—C14—C15	118.06 (12)
N2—C2—C1	123.59 (11)	N4—C14—C19	122.33 (11)
N2—C2—C11	119.68 (12)	C15—C14—C19	119.57 (12)
C1—C2—C11	116.73 (12)	C16—C15—C14	121.14 (13)
N2—C3—C4	118.34 (11)	C16—C15—H15	119.4
N2—C3—C8	122.24 (11)	C14—C15—H15	119.4
C4—C3—C8	119.42 (12)	C15—C16—C17	118.97 (13)
C5—C4—C3	121.10 (12)	C15—C16—H16	120.5
C5—C4—H4	119.5	C17—C16—H16	120.5
C3—C4—H4	119.5	C18—C17—C16	121.23 (13)
C4—C5—C6	119.04 (12)	C18—C17—H17	119.4
C4—C5—H5	120.5	C16—C17—H17	119.4
C6—C5—H5	120.5	C17—C18—C19	120.05 (13)
C7—C6—C5	121.44 (13)	C17—C18—H18	120
C7—C6—H6	119.3	C19—C18—H18	120
C5—C6—H6	119.3	C18—C19—N3	122.96 (12)
C6—C7—C8	119.68 (12)	C18—C19—C14	119.04 (12)
C6—C7—H7	120.2	N3—C19—C14	118.00 (11)
C8—C7—H7	120.2	N3—C20—C21	111.52 (11)
C7—C8—N1	122.76 (11)	N3—C20—H20A	109.3
C7—C8—C3	119.32 (11)	C21—C20—H20A	109.3
N1—C8—C3	117.92 (11)	N3—C20—H20B	109.3
N1—C9—C10	111.68 (11)	C21—C20—H20B	109.3
N1—C9—H9A	109.3	H20A—C20—H20B	108
C10—C9—H9A	109.3	C20—C21—H21A	109.5
N1—C9—H9B	109.3	C20—C21—H21B	109.5
C10—C9—H9B	109.3	H21A—C21—H21B	109.5
H9A—C9—H9B	107.9	C20—C21—H21C	109.5
C9—C10—H10A	109.5	H21A—C21—H21C	109.5
C9—C10—H10B	109.5	H21B—C21—H21C	109.5
H10A—C10—H10B	109.5	C13—C22—H22A	109.5
C9—C10—H10C	109.5	C13—C22—H22B	109.5
H10A—C10—H10C	109.5	H22A—C22—H22B	109.5
H10B—C10—H10C	109.5	C13—C22—H22C	109.5
C2—C11—H11A	109.5	H22A—C22—H22C	109.5
C2—C11—H11B	109.5	H22B—C22—H22C	109.5
H11A—C11—H11B	109.5	C1—N1—C8	121.35 (10)
C2—C11—H11C	109.5	C1—N1—C9	116.87 (10)
H11A—C11—H11C	109.5	C8—N1—C9	121.66 (10)
H11B—C11—H11C	109.5	C2—N2—C3	118.47 (11)
O2—C12—N3	121.81 (13)	C12—N3—C19	121.53 (11)
O2—C12—C13	122.35 (13)	C12—N3—C20	117.23 (11)
N3—C12—C13	115.83 (11)	C19—N3—C20	121.20 (11)
N4—C13—C12	123.82 (12)	C13—N4—C14	118.27 (11)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O2i	0.93	2.43	3.291 (3)	154
C17—H17···O1	0.93	2.46	3.301 (3)	151
C11—H11B···Cg3ii	0.96	3.34	3.893 (3)	119
C22—H22C···Cg4iii	0.96	2.71	3.516 (3)	142

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯O2i	0.93	2.43	3.291 (3)	154
C17—H17⋯O1	0.93	2.46	3.301 (3)	151
C22—H22C⋯Cg4ii	0.96	2.71	3.516 (3)	142

Symmetry codes: (i) ; (ii) . Cg4 is the centroid of the C14–C19 ring.