1,2,3,4-Tetra­hydro­phenazine 5,10-dioxide

The complete mol­ecule of the title compound, C₁₂H₁₂N₂O₂, lies on two crystallographic symmetry elements: a twofold axis and a mirror plane. In the mol­ecular structure, the quinoxaline ring and two methyl­ene substituents lie on the mirror plane while the other two methyl­ene groups are disordered about the plane. The crystal packing is stabilized by weak inter­molecular π–π stacking inter­actions with centroid–centroid distances of 3.6803 (7) Å.

Related literature

For the synthetic preparation, see: Haddadin & Issidorides (1965); Issidorides & Haddadin (1966). For background to quinoxaline di-N-oxide compounds, see: Edwards et al. (1975) and for their biological activity, see: Urquiola et al. (2008). For a related structure, see: Wang et al. (2010).

Experimental

Crystal data

• C₁₂H₁₂N₂O₂

• M_r = 216.24

• Orthorhombic, C m c m

• a = 11.7780 (2) Å

• b = 13.1938 (3) Å

• c = 6.5561 (1) Å

• V = 1018.80 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 296 K

• 0.31 × 0.29 × 0.26 mm

Data collection

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.67, T_max = 0.74

• 3311 measured reflections

• 620 independent reflections

• 534 reflections with I > 2σ(I)

• R_int = 0.016

Refinement

• R[F² > 2σ(F²)] = 0.040

• wR(F²) = 0.127

• S = 1.10

• 620 reflections

• 61 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.23 e Å⁻³

• Δρ_min = −0.29 e Å⁻³

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL; software used to prepare material for publication: WinGX (Farrugia, 1999).

Supporting information

S1. Comment

Quinoxaline di-N-oxide compounds are widely used in sterilization and growth-promoting of animals, pharmacological properties usable as intermediates for producing plant protection agents (Edwards et al.,1975). There has been a growing interest in the syntheses of quinoxaline di-N-oxide compounds that have both biological and commercial importance (Urquiola et al., 2008). Now, we report herein the crystal structure of the title benzotriazole derivative.

The complete molecule of the title compound, C₁₂H₁₂N₂O₂, is generated by a crystallographic symmetry operation along a twofold axis. In the moleclcular structure of the crystal, the quinoxaline ring and two methylene substituents of the quinoxaline ring locate at a mirror plane of the Cmcm group. The other two methylenes of the cyclohexane ring are disordered over two positions with half occupancy. The crystal packing is stabilized by weak intermolecular π-π aromatic stacking interactions with centroid-centroid distances of 3.6803 (7) Å.

Related literature

For the synthetic preparation, see: Haddadin & Issidorides (1965); Issidorides & Haddadin (1966). For background to quinoxaline di-N-oxide compounds, see: Edwards et al. (1975) and for their biological activity, see: Urquiola et al. (2008). For a related structure, see: Wang et al. (2010).

S2. Experimental

The compound was synthesized as described previously by Haddadin & Issidorides (1965) and Issidorides & Haddadin (1966). Yellow crystals were obtained by slow evaporation of a methanolic solution.

S3. Refinement

H atoms in the benzene were placed in geometrically calculated positions and refined using a riding model. H atoms in CH₂ groups were located in geometrically calculated positions also but their positions were refined independently and their isotropic displacement parameters were fixed to 0.08 in the refinement. Two CH₂ groups were disordered over symmetry elements and refined with half occupancy.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. Figure 1. A view of the title compound with displacement ellipsoids are drawn at the 30% probability level. Unlabelled atoms are related to labelled atoms by a twofold rotation. The second disorder component is omitted.

1,2,3,4-Tetrahydrophenazine 5,10-dioxide

Crystal data

C12H12N2O2	F(000) = 456
Mr = 216.24	Dx = 1.410 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2	Cell parameters from 1577 reflections
a = 11.7780 (2) Å	θ = 2.3–26.8°
b = 13.1938 (3) Å	µ = 0.10 mm^−1
c = 6.5561 (1) Å	T = 296 K
V = 1018.80 (3) Å^3	Prism, yellow
Z = 4	0.31 × 0.29 × 0.26 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	620 independent reflections
Radiation source: fine-focus sealed tube	534 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 26.9°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −14→14
Tmin = 0.67, Tmax = 0.74	k = −16→12
3311 measured reflections	l = −8→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0854P)^2 + 0.1004P] where P = (Fo^2 + 2Fc^2)/3
620 reflections	(Δ/σ)max < 0.001
61 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.29 e Å^−3

Special details

Experimental. 1H NMR (400?MHz, DMSO-d6): δ 8.67 (2H, d, J = 3.5?Hz, Ar—H), 7.89 (2H, d, J = 3.2?Hz, Ar—H), 3.77 (1H, s, CH), 2.66 (3H, s, CH3), 2.51 (2H, m, CH2), 1.45 (6H, s, CH3); Calcd for C13H16N2O2: C, 67.22; H, 6.94; N, 12.06. Found: C, 67.18; H, 6.99; N, 11.95; ESIMS calcd for C13H16N2O2H+ m/z 232.38, found m/z 232.19.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.44078 (13)	−0.14330 (10)	0.2500	0.0434 (4)
H1	0.4017	−0.2045	0.2500	0.052*
C2	0.38142 (12)	−0.05388 (9)	0.2500	0.0399 (4)
H2	0.3025	−0.0544	0.2500	0.048*
C3	0.44062 (11)	0.03818 (9)	0.2500	0.0311 (4)
C4	0.44068 (10)	0.21722 (9)	0.2500	0.0326 (4)
C5	0.37292 (12)	0.31337 (10)	0.2500	0.0470 (4)
H5	0.3247 (10)	0.3113 (9)	0.131 (2)	0.070*
C6	0.44666 (19)	0.40485 (17)	0.1867 (4)	0.0618 (9)	0.50
H6	0.407 (2)	0.4669 (19)	0.199 (5)	0.090*	0.50
H7	0.468 (3)	0.3993 (19)	0.040 (4)	0.090*	0.50
N1	0.38161 (10)	0.12976 (7)	0.2500	0.0336 (4)
O1	0.27161 (9)	0.12938 (6)	0.2500	0.0508 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0608 (9)	0.0288 (7)	0.0407 (7)	−0.0082 (5)	0.000	0.000
C2	0.0426 (8)	0.0339 (7)	0.0432 (7)	−0.0078 (5)	0.000	0.000
C3	0.0339 (8)	0.0281 (7)	0.0314 (6)	−0.0008 (4)	0.000	0.000
C4	0.0318 (7)	0.0277 (7)	0.0384 (7)	0.0008 (4)	0.000	0.000
C5	0.0372 (8)	0.0320 (8)	0.0719 (10)	0.0056 (5)	0.000	0.000
C6	0.0516 (11)	0.0289 (10)	0.105 (3)	0.0038 (7)	0.0002 (10)	0.0110 (10)
N1	0.0282 (6)	0.0313 (6)	0.0412 (6)	−0.0005 (3)	0.000	0.000
O1	0.0269 (6)	0.0447 (7)	0.0807 (8)	−0.0011 (3)	0.000	0.000

Geometric parameters (Å, º)

C1—C2	1.3714 (19)	C5—C6^ii	1.544 (3)
C1—C1^i	1.395 (3)	C5—C6	1.544 (3)
C1—H1	0.9300	C5—H5	0.965 (13)
C2—C3	1.4005 (17)	C6—C6^ii	0.831 (5)
C2—H2	0.9300	C6—C6^iii	1.256 (5)
C3—N1	1.3939 (15)	C6—C6^i	1.506 (4)
C3—C3^i	1.399 (2)	C6—H6	0.95 (2)
C4—N1	1.3474 (15)	C6—H7	1.00 (3)
C4—C4^i	1.397 (2)	N1—O1	1.2956 (16)
C4—C5	1.4987 (16)
C2—C1—C1^i	120.65 (9)	C6^ii—C6—C6^iii	90.000 (2)
C2—C1—H1	119.7	C6^ii—C6—C6^i	56.5 (2)
C1^i—C1—H1	119.7	C6^iii—C6—C6^i	33.5 (2)
C1—C2—C3	119.49 (15)	C6^ii—C6—C5	74.39 (10)
C1—C2—H2	120.3	C6^iii—C6—C5	124.23 (10)
C3—C2—H2	120.3	C6^i—C6—C5	108.72 (16)
N1—C3—C3^i	119.90 (7)	C6^ii—C6—H6	85.1 (18)
N1—C3—C2	120.24 (14)	C6^iii—C6—H6	119.6 (16)
C3^i—C3—C2	119.86 (8)	C6^i—C6—H6	111.4 (17)
N1—C4—C4^i	121.08 (7)	C5—C6—H6	112.1 (16)
N1—C4—C5	116.74 (12)	C6^ii—C6—H7	164.4 (18)
C4^i—C4—C5	122.17 (7)	C6^iii—C6—H7	75.0 (18)
C4—C5—C6^ii	111.23 (14)	C6^i—C6—H7	108.4 (18)
C4—C5—C6	111.23 (14)	C5—C6—H7	110.3 (16)
C6^ii—C5—C6	31.2 (2)	H6—C6—H7	106 (2)
C4—C5—H5	106.8 (7)	O1—N1—C4	121.31 (9)
C6^ii—C5—H5	124.8 (8)	O1—N1—C3	119.68 (9)
C6—C5—H5	97.8 (7)	C4—N1—C3	119.01 (13)
C1^i—C1—C2—C3	0.0	C4—C5—C6—C6^i	−50.6 (2)
C1—C2—C3—N1	180.0	C6^ii—C5—C6—C6^i	45.6 (2)
C1—C2—C3—C3^i	0.0	C4^i—C4—N1—O1	180.0
N1—C4—C5—C6^ii	163.23 (11)	C5—C4—N1—O1	0.0
C4^i—C4—C5—C6^ii	−16.77 (11)	C4^i—C4—N1—C3	0.0
N1—C4—C5—C6	−163.23 (11)	C5—C4—N1—C3	180.0
C4^i—C4—C5—C6	16.77 (11)	C3^i—C3—N1—O1	180.0
C4—C5—C6—C6^ii	−96.23 (6)	C2—C3—N1—O1	0.0
C4—C5—C6—C6^iii	−17.19 (11)	C3^i—C3—N1—C4	0.0
C6^ii—C5—C6—C6^iii	79.04 (8)	C2—C3—N1—C4	180.0

Symmetry codes: (i) −x+1, y, −z+1/2; (ii) x, y, −z+1/2; (iii) −x+1, y, z.