3-Methyl-1-phenyl­benzothieno[3,2-d]imidazo[1,2-a]pyrimidine-2,5(1H,3H)-dione

Cao, M.-H.

doi:10.1107/S1600536807017576

3-Methyl-1-phenylbenzothieno[3,2-d]imidazo[1,2-a]pyrimidine-2,5(1H,3H)-dione

In the molecule of the title compound, C₁₉H₁₃N₃O₂S, the pyrimidine ring is not planar and has a flattened-boat conformation; it also has a pseudo-mirror plane running through the bridgehead N atom and the opposite C atom. The dihedral angles between the planar fused benzene (A), thienyl (B), imidazole (D) and substituent phenyl (E) rings are A/B = 1.63 (3)°, A/D = 5.80 (2)°, B/D = 5.49 (3)° and D/E = 39.73 (3)°. In the crystal structure, intermolecular C—H

O hydrogen bonds and π–π stacking interactions may be effective in the stabilization of the structure [adjacent thiophene rings have a centroid–centroid distance of 3.79 (1) Å (symmetry code:

), while adjacent imidazole and benzene rings have a centroid–centroid distance of 3.48 (1) Å (symmetry codes: ${1 \over 2}-x, {1 \over 2}+y, z$ and ${3 \over 2}-x, -{1 \over 2}+y, z$ )].

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807017576/hk2230sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536807017576/hk2230Isup2.hkl Contains datablock I

CCDC reference: 647685

checkCIF report

Key indicators

Single-crystal X-ray study
T = 292 K
Mean (C-C) = 0.003 Å
R factor = 0.050
wR factor = 0.115
Data-to-parameter ratio = 16.9

checkCIF/PLATON results

No syntax errors found



Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.108
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.11
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N3     -   C10     ..       5.31 su

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

Comment top

Thienopyrimidine derivatives are of interest as possible antiviral agents, and because of their other biological properties, including antibacterial, antifungal, antiallergic and antiinflammatory activities (Chambhare et al., 2003). We have recently focused on the synthesis of the fused heterocyclic systems containing thienopyrimidine via aza-Wittig reactions at room temperature (Ding et al., 2004). We herein report the crystal structure of one such thienopyrimidine derivative, the title compound, (I).

In the molecule of (I), (Fig. 1) the bond lengths and angles are within normal ranges (Allen et al., 1987). The ring C (N1/N2/C7—C10) is not planar having a total puckering amplitude, Q_T of 0.228 (2) Å and a flattened-boat conformation [φ = 54.10 (2)° and θ = 63.62 (3)°] (Cremer & Pople, 1975). Ring C has a pseudo mirror plane running through atoms N2 and C7, as can be deduced from the torsion angles (Table 1). Rings A (C1—C6), B (S1/C1/C6—C8), D (N2/N3/C10—C12) and E (C14—C19) are, of course, planar and the dihedral angles between them are A/B = 1.63 (3)°, A/D = 5.80 (2)°, B/D = 5.49 (3)° and D/E = 39.73 (3)°.

In the crystal structure, the weak intermolecular C—H···O hydrogen bonds (Table 2) cause to the formation of a three dimensional network (Fig. 2), in which they may be effective in the stabilization of the structure. Further stability is provided by offset π-π stacking interactions (Janiak, 2000), involving the rings; B, D and E. The adjacent B rings have a centroid-centroid distance of 3.79 (1) %A [symmetry code: 1 - x, 2 - y, 1 - z], while rings D and E have a centroid-centroid distance of 3.48 (1) %A [symmetry codes: 3/2 - x, y + 1/2, z; 3/2 - x, y - 1/2, z].

Related literature top

For related literature, see: Cao (2007); Chambhare et al. (2003); Ding et al. (2004); Janiak (2000).

For related literature, see: Allen et al. (1987); Cremer & Pople (1975).

Experimental top

The title compound was synthesized according to the literature method (Cao, 2007). Crystals suitable for X-ray analysis were grown from acetone at 277 K.

Structure description top

For related literature, see: Cao (2007); Chambhare et al. (2003); Ding et al. (2004); Janiak (2000).

For related literature, see: Allen et al. (1987); Cremer & Pople (1975).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL (Bruker, 2001).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A packing diagram for (I). Hydrogen bonds are shown as dashed lines.

3-Methyl-1-phenylbenzothieno[3,2-d]imidazo[1,2-a]pyrimidine-2,5(1H,3H)-dione top

Crystal data top

C₁₉H₁₃N₃O₂S	F(000) = 1440
M_r = 347.38	D_x = 1.431 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 3753 reflections
a = 12.6184 (18) Å	θ = 2.4–22.8°
b = 11.0787 (16) Å	µ = 0.22 mm⁻¹
c = 23.074 (3) Å	T = 292 K
V = 3225.7 (8) Å³	Block, colorless
Z = 8	0.20 × 0.20 × 0.10 mm

Data collection top

Bruker SMART 4K CCD area-detector diffractometer	2529 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.109
Graphite monochromator	θ_max = 28.0°, θ_min = 1.8°
φ and ω scans	h = −16→12
19405 measured reflections	k = −14→14
3847 independent reflections	l = −29→27

Refinement top

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.115	H-atom parameters constrained
S = 0.92	w = 1/[σ²(F_o²) + (0.0558P)²] where P = (F_o² + 2F_c²)/3
3847 reflections	(Δ/σ)_max = 0.002
227 parameters	Δρ_max = 0.30 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₁₉H₁₃N₃O₂S	V = 3225.7 (8) Å³
M_r = 347.38	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 12.6184 (18) Å	µ = 0.22 mm⁻¹
b = 11.0787 (16) Å	T = 292 K
c = 23.074 (3) Å	0.20 × 0.20 × 0.10 mm

Data collection top

Bruker SMART 4K CCD area-detector diffractometer	2529 reflections with I > 2σ(I)
19405 measured reflections	R_int = 0.109
3847 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.115	H-atom parameters constrained
S = 0.92	Δρ_max = 0.30 e Å⁻³
3847 reflections	Δρ_min = −0.21 e Å⁻³
227 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.43864 (12)	0.97800 (15)	0.59301 (7)	0.0371 (4)
C2	0.37664 (13)	0.87999 (17)	0.60996 (8)	0.0438 (4)
H2	0.4039	0.8215	0.6347	0.053*
C3	0.27466 (14)	0.87107 (18)	0.58957 (8)	0.0518 (5)
H3	0.2330	0.8055	0.6003	0.062*
C4	0.23303 (15)	0.9589 (2)	0.55310 (8)	0.0549 (5)
H4	0.1637	0.9511	0.5400	0.066*
C5	0.29153 (15)	1.0568 (2)	0.53598 (8)	0.0535 (5)
H5	0.2628	1.1151	0.5116	0.064*
C6	0.39535 (14)	1.06644 (16)	0.55618 (7)	0.0422 (4)
C7	0.54732 (13)	1.00455 (15)	0.60685 (7)	0.0362 (4)
C8	0.58174 (14)	1.10884 (15)	0.58091 (7)	0.0409 (4)
C9	0.68825 (15)	1.15173 (16)	0.58730 (8)	0.0441 (4)
C10	0.70455 (13)	0.97290 (15)	0.64790 (7)	0.0371 (4)
C11	0.87532 (14)	0.98872 (18)	0.68008 (9)	0.0472 (5)
C12	0.85911 (13)	1.08834 (17)	0.63630 (8)	0.0470 (5)
H12	0.8682	1.1672	0.6549	0.056*
C13	0.93537 (16)	1.0761 (2)	0.58549 (10)	0.0740 (7)
H13A	0.9255	0.9990	0.5673	0.111*
H13B	1.0069	1.0827	0.5992	0.111*
H13C	0.9217	1.1390	0.5579	0.111*
C14	0.76691 (13)	0.82173 (14)	0.72199 (7)	0.0378 (4)
C15	0.84826 (14)	0.73933 (17)	0.72829 (9)	0.0472 (5)
H15	0.9104	0.7479	0.7070	0.057*
C16	0.83663 (16)	0.64405 (18)	0.76645 (10)	0.0560 (5)
H16	0.8919	0.5895	0.7715	0.067*
C17	0.74425 (18)	0.62940 (18)	0.79685 (9)	0.0576 (5)
H17	0.7363	0.5643	0.8219	0.069*
C18	0.66351 (16)	0.71136 (19)	0.79017 (9)	0.0535 (5)
H18	0.6008	0.7013	0.8108	0.064*
C19	0.67441 (13)	0.80874 (16)	0.75303 (8)	0.0432 (4)
H19	0.6199	0.8647	0.7491	0.052*
N1	0.60876 (10)	0.93359 (12)	0.64293 (6)	0.0368 (3)
N2	0.74802 (10)	1.07041 (12)	0.62043 (6)	0.0403 (4)
N3	0.78190 (10)	0.92229 (12)	0.68350 (6)	0.0393 (4)
O1	0.72739 (11)	1.24438 (12)	0.56814 (6)	0.0616 (4)
O2	0.95559 (11)	0.96797 (14)	0.70621 (7)	0.0704 (5)
S1	0.48557 (4)	1.18039 (5)	0.53977 (2)	0.05129 (17)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0397 (10)	0.0392 (10)	0.0324 (9)	0.0063 (8)	−0.0013 (7)	−0.0013 (7)
C2	0.0434 (10)	0.0456 (11)	0.0423 (10)	0.0043 (8)	−0.0025 (8)	0.0016 (8)
C3	0.0467 (11)	0.0583 (13)	0.0504 (12)	−0.0060 (10)	−0.0037 (9)	−0.0042 (10)
C4	0.0433 (11)	0.0738 (15)	0.0477 (12)	0.0029 (10)	−0.0129 (9)	−0.0055 (10)
C5	0.0558 (13)	0.0639 (14)	0.0407 (11)	0.0191 (11)	−0.0120 (9)	−0.0010 (9)
C6	0.0481 (11)	0.0449 (11)	0.0337 (10)	0.0081 (8)	−0.0039 (8)	−0.0015 (8)
C7	0.0408 (10)	0.0349 (10)	0.0329 (9)	0.0041 (7)	0.0004 (7)	0.0000 (7)
C8	0.0478 (11)	0.0387 (10)	0.0363 (10)	0.0037 (8)	0.0004 (8)	0.0038 (8)
C9	0.0546 (11)	0.0406 (11)	0.0369 (10)	−0.0025 (9)	0.0039 (9)	0.0036 (8)
C10	0.0380 (10)	0.0369 (10)	0.0365 (9)	0.0027 (8)	0.0029 (8)	−0.0006 (8)
C11	0.0369 (10)	0.0537 (12)	0.0509 (12)	−0.0030 (9)	−0.0025 (9)	−0.0032 (9)
C12	0.0411 (11)	0.0496 (12)	0.0502 (12)	−0.0097 (8)	0.0000 (8)	−0.0008 (9)
C13	0.0514 (13)	0.1027 (19)	0.0680 (15)	−0.0104 (12)	0.0124 (11)	0.0078 (14)
C14	0.0374 (10)	0.0348 (10)	0.0414 (10)	0.0019 (8)	−0.0076 (8)	−0.0007 (8)
C15	0.0403 (10)	0.0466 (12)	0.0546 (12)	0.0064 (8)	−0.0088 (9)	−0.0059 (9)
C16	0.0588 (13)	0.0429 (12)	0.0662 (14)	0.0134 (10)	−0.0237 (11)	−0.0006 (10)
C17	0.0705 (14)	0.0451 (12)	0.0572 (13)	−0.0027 (11)	−0.0145 (11)	0.0146 (10)
C18	0.0548 (12)	0.0558 (13)	0.0501 (12)	−0.0011 (10)	−0.0009 (9)	0.0097 (10)
C19	0.0417 (11)	0.0431 (11)	0.0448 (11)	0.0068 (8)	−0.0035 (8)	0.0035 (8)
N1	0.0325 (8)	0.0378 (8)	0.0402 (8)	0.0024 (6)	−0.0016 (6)	0.0051 (6)
N2	0.0391 (8)	0.0411 (9)	0.0406 (8)	−0.0046 (6)	0.0014 (6)	0.0048 (7)
N3	0.0326 (8)	0.0422 (9)	0.0432 (8)	0.0002 (6)	−0.0050 (6)	0.0043 (7)
O1	0.0727 (10)	0.0515 (9)	0.0606 (9)	−0.0163 (7)	−0.0034 (7)	0.0190 (7)
O2	0.0430 (8)	0.0753 (11)	0.0928 (12)	−0.0110 (7)	−0.0214 (8)	0.0140 (9)
S1	0.0614 (3)	0.0464 (3)	0.0461 (3)	0.0063 (2)	−0.0065 (2)	0.0134 (2)

Geometric parameters (Å, º) top

C1—C2	1.394 (2)	C11—O2	1.201 (2)
C1—C6	1.407 (2)	C11—N3	1.392 (2)
C1—C7	1.439 (2)	C11—C12	1.510 (3)
C2—C3	1.374 (2)	C12—N2	1.462 (2)
C2—H2	0.9300	C12—C13	1.523 (3)
C3—C4	1.390 (3)	C12—H12	0.9800
C3—H3	0.9300	C13—H13A	0.9600
C4—C5	1.370 (3)	C13—H13B	0.9600
C4—H4	0.9300	C13—H13C	0.9600
C5—C6	1.395 (2)	C14—C19	1.377 (2)
C5—H5	0.9300	C14—C15	1.381 (2)
C6—S1	1.7416 (19)	C14—N3	1.437 (2)
C7—C8	1.372 (2)	C15—C16	1.382 (3)
C7—N1	1.383 (2)	C15—H15	0.9300
C8—C9	1.433 (3)	C16—C17	1.370 (3)
C8—S1	1.7326 (17)	C16—H16	0.9300
C9—O1	1.222 (2)	C17—C18	1.373 (3)
C9—N2	1.402 (2)	C17—H17	0.9300
C10—N1	1.2898 (19)	C18—C19	1.385 (3)
C10—N2	1.367 (2)	C18—H18	0.9300
C10—N3	1.394 (2)	C19—H19	0.9300

C2—C1—C6	119.59 (15)	N2—C12—H12	110.0
C2—C1—C7	129.19 (16)	C11—C12—H12	110.0
C6—C1—C7	111.21 (15)	C13—C12—H12	110.0
C3—C2—C1	119.05 (17)	C12—C13—H13A	109.5
C3—C2—H2	120.5	C12—C13—H13B	109.5
C1—C2—H2	120.5	H13A—C13—H13B	109.5
C2—C3—C4	120.73 (18)	C12—C13—H13C	109.5
C2—C3—H3	119.6	H13A—C13—H13C	109.5
C4—C3—H3	119.6	H13B—C13—H13C	109.5
C5—C4—C3	121.69 (18)	C19—C14—C15	120.41 (17)
C5—C4—H4	119.2	C19—C14—N3	120.93 (15)
C3—C4—H4	119.2	C15—C14—N3	118.65 (16)
C4—C5—C6	118.05 (18)	C14—C15—C16	119.52 (19)
C4—C5—H5	121.0	C14—C15—H15	120.2
C6—C5—H5	121.0	C16—C15—H15	120.2
C5—C6—C1	120.88 (18)	C17—C16—C15	120.46 (18)
C5—C6—S1	126.64 (15)	C17—C16—H16	119.8
C1—C6—S1	112.47 (13)	C15—C16—H16	119.8
C8—C7—N1	124.34 (16)	C16—C17—C18	119.70 (18)
C8—C7—C1	112.15 (15)	C16—C17—H17	120.2
N1—C7—C1	123.50 (15)	C18—C17—H17	120.2
C7—C8—C9	122.08 (16)	C17—C18—C19	120.73 (19)
C7—C8—S1	113.75 (14)	C17—C18—H18	119.6
C9—C8—S1	124.16 (13)	C19—C18—H18	119.6
O1—C9—N2	121.32 (18)	C14—C19—C18	119.18 (17)
O1—C9—C8	128.33 (17)	C14—C19—H19	120.4
N2—C9—C8	110.34 (15)	C18—C19—H19	120.4
N1—C10—N2	126.98 (15)	C10—N1—C7	112.77 (14)
N1—C10—N3	124.95 (15)	C10—N2—C9	123.00 (15)
N2—C10—N3	108.07 (14)	C10—N2—C12	112.08 (14)
O2—C11—N3	125.77 (18)	C9—N2—C12	124.40 (14)
O2—C11—C12	126.16 (17)	C11—N3—C10	110.30 (14)
N3—C11—C12	108.04 (15)	C11—N3—C14	123.81 (14)
N2—C12—C11	101.42 (14)	C10—N3—C14	125.73 (14)
N2—C12—C13	113.64 (16)	C8—S1—C6	90.41 (9)
C11—C12—C13	111.38 (17)

C6—C1—C2—C3	0.9 (3)	C17—C18—C19—C14	1.0 (3)
C7—C1—C2—C3	−177.67 (17)	N2—C10—N1—C7	−2.4 (2)
C1—C2—C3—C4	−0.7 (3)	N3—C10—N1—C7	176.89 (15)
C2—C3—C4—C5	0.3 (3)	C8—C7—N1—C10	−2.8 (2)
C3—C4—C5—C6	0.1 (3)	C1—C7—N1—C10	178.25 (15)
C4—C5—C6—C1	0.1 (3)	N1—C10—N2—C9	8.1 (3)
C4—C5—C6—S1	178.95 (15)	N3—C10—N2—C9	−171.26 (15)
C2—C1—C6—C5	−0.6 (3)	N1—C10—N2—C12	−179.83 (16)
C7—C1—C6—C5	178.24 (15)	N3—C10—N2—C12	0.81 (19)
C2—C1—C6—S1	−179.58 (13)	O1—C9—N2—C10	172.59 (16)
C7—C1—C6—S1	−0.77 (18)	C8—C9—N2—C10	−7.4 (2)
C2—C1—C7—C8	178.66 (17)	O1—C9—N2—C12	1.5 (3)
C6—C1—C7—C8	0.0 (2)	C8—C9—N2—C12	−178.46 (15)
C2—C1—C7—N1	−2.3 (3)	C11—C12—N2—C10	−2.32 (18)
C6—C1—C7—N1	179.04 (15)	C13—C12—N2—C10	117.31 (18)
N1—C7—C8—C9	2.6 (3)	C11—C12—N2—C9	169.62 (16)
C1—C7—C8—C9	−178.41 (15)	C13—C12—N2—C9	−70.7 (2)
N1—C7—C8—S1	−178.25 (13)	O2—C11—N3—C10	179.24 (19)
C1—C7—C8—S1	0.78 (19)	C12—C11—N3—C10	−2.7 (2)
C7—C8—C9—O1	−177.43 (18)	O2—C11—N3—C14	3.6 (3)
S1—C8—C9—O1	3.5 (3)	C12—C11—N3—C14	−178.36 (15)
C7—C8—C9—N2	2.5 (2)	N1—C10—N3—C11	−178.10 (16)
S1—C8—C9—N2	−176.57 (13)	N2—C10—N3—C11	1.27 (19)
O2—C11—C12—N2	−179.01 (19)	N1—C10—N3—C14	−2.6 (3)
N3—C11—C12—N2	2.98 (18)	N2—C10—N3—C14	176.78 (14)
O2—C11—C12—C13	59.8 (3)	C19—C14—N3—C11	136.45 (18)
N3—C11—C12—C13	−118.24 (18)	C15—C14—N3—C11	−42.1 (2)
C19—C14—C15—C16	−0.6 (3)	C19—C14—N3—C10	−38.5 (2)
N3—C14—C15—C16	178.01 (16)	C15—C14—N3—C10	142.93 (17)
C14—C15—C16—C17	1.6 (3)	C7—C8—S1—C6	−1.03 (14)
C15—C16—C17—C18	−1.3 (3)	C9—C8—S1—C6	178.14 (16)
C16—C17—C18—C19	0.0 (3)	C5—C6—S1—C8	−177.92 (17)
C15—C14—C19—C18	−0.7 (3)	C1—C6—S1—C8	1.01 (14)
N3—C14—C19—C18	−179.25 (16)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C19—H19···O2ⁱ	0.93	2.58	3.409 (2)	148
C16—H16···O2ⁱⁱ	0.93	2.40	3.328 (2)	172
C5—H5···O1ⁱⁱⁱ	0.93	2.45	3.358 (2)	165

Symmetry codes: (i) x−1/2, y, −z+3/2; (ii) −x+2, y−1/2, −z+3/2; (iii) x−1/2, −y+5/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₉H₁₃N₃O₂S
M_r	347.38
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	292
a, b, c (Å)	12.6184 (18), 11.0787 (16), 23.074 (3)
V (Å³)	3225.7 (8)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.22
Crystal size (mm)	0.20 × 0.20 × 0.10

Data collection
Diffractometer	Bruker SMART 4K CCD area-detector
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	19405, 3847, 2529
R_int	0.109
(sin θ/λ)_max (Å⁻¹)	0.661

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.115, 0.92
No. of reflections	3847
No. of parameters	227
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.21

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXTL (Bruker, 2001).

Selected torsion angles (º) top

N1—C7—C8—C9	2.6 (3)	C8—C7—N1—C10	−2.8 (2)
C7—C8—C9—N2	2.5 (2)	N1—C10—N2—C9	8.1 (3)
N2—C10—N1—C7	−2.4 (2)	C8—C9—N2—C10	−7.4 (2)