4-Amino-6-benzyl­oxy-2-(methyl­sulfanyl)-5-nitro­so­pyrimidine: hydrogen-bonded dimers linked into π-stacked chains

The title compound, C₁₂H₁₂N₄O₂S, crystallizes with Z′ = 2 in space group P2₁/c. The intramolecular dimensions are consis­tent with a highly polarized electronic structure. Each of the independent mol­ecules forms a centrosymmetric dimer linked by paired N—H...N hydrogen bonds, and these dimers are linked into a single type of chain by aromatic π–π-stacking interactions.

S1. Comment

Alkoxy- and amino-substituted O⁶-benzyloxy-5-nitrosopyrimidines (Marchal et al., 2000, 2002; Quesada et al., 2000) are important as potential, or proven, in vitro inhibitors of the human DNA-repair protein O⁶-alkylguanine-DNA-transferase (Chae et al., 1995; Quesada et al., 2002). We report here the molecular and supramolecular structure of a closely-related analogue (I) containing a (methylthio) substituent.

The title compound, (I), crystallizes in space group P2₁/c with two independent molecules in the asymmetric unit, i.e. with Z' = 2 (Fig. 1), but no additional symmetry could be detected. The intramolecular dimensions of the two independent molecules are very similar (Table 1), and show a number of features typical of 5-nitrosopyrimidines (Low et al., 2000; Low, Cannon et al., 2001; Low, Moreno et al., 2001; Quesada et al., 2002); in particular, there is marked fixation of the C—C and C—N bonds, with bonds Cn2—Nn3, Cn4—Nn4 and Cn6—Nn1 (n = 1 or 2) being short, despite the Cn4—Nn4 bond being formally a single bond in the classical representation of (I); in addition, the C—N and N—O distances in each C-nitroso fragment differ by only ca 0.11 Å, whereas in simple neutral compounds, where there is no possibility of significant electronic delocalization, these distances normally differ by at least 0.20 Å (Talberg, 1977; Schlemper et al., 1986) and the NO distance rarely exceeds 1.25 Å (Davis et al., 1965; Bauer & Andreassen, 1972; Talberg, 1977; Schlemper et al., 1986). The dimensions all point to the importance of the charge-separated form (Ia) (see Scheme) as an important contributor. In this respect, the electronic structure of (I) resembles that of the 2-benzyloxy analogue (II) (Quesada et al., 2002). Although the Cn2—Sn2 (n = 1 or 2) distances are significantly shorter than typical C_ar—S distances (Allen et al., 1987), there is no other support for a significant contribution from form (Ib), although the atoms concerned in (Ib) are almost coplanar (Table 1); the methyl–S distances are entirely normal.

In each of the independent molecules of (I), there is an intramolecular N—H···O hydrogen bond (Table 2) generating S(6) motifs; it is this motif which emphasizes the close similarity in overall molecular shape between 4-amino-5-nitroso pyrimidines, (III), and purines, (IV), which may indeed influence the biochemical activity of compounds of type (III). In addition, the molecules of each type are linked by paired N—H···N hydrogen bonds into centrosymmetric dimers (Fig. 2), in which the ring atoms N13 and N23 act as the acceptors (Table 2); molecules of type 1 (containing atom S12) form a dimer centred at (1/2, 1/2, 1/2), while molecules of type 2 (containing atom S22) form a dimer centred at (0, 1/2, 1/2).

The formation of hydrogen-bonded dimers which themselves form no other hydrogen bonds is unusual in this type of pyrimidine (Quesada et al., 2002); however, there are aromatic π–π-stacking interactions between the dimer units formed by (I). Within the asymmetric unit, the two pyrimidine planes make an angle of 0.57 (6)°; the centroid separation is 3.4421 (8) Å and the interplanar spacing ca 3.35 Å. Thus, the hydrogen-bonded dimer centred at (1/2, 1/2, 1/2) and formed by molecules of type 1 forms π–π-stacking interactions with the type 2 dimers centred at (0, 1/2, 1/2) and (1, 1/2, 1/2), and propagation of these interactions generates a chain running parallel to the [100] direction in which type 1 and type 2 dimers alternate (Fig. 3).

S2. Experimental

Isoamyl nitrite (1.65 ml, 12 mmol) was added to a solution of 4-amino-6-benzyloxy-2-(methylthio)pyrimidine (2.47 g, 10 mmol) in dimethyl sulfoxide (DMSO, 25 ml). The reaction mixture was stirred at room temperature and monitored by thin-layer chromatography (eluent CH₂Cl₂/MeOH, 9:1 v/v) until the starting pyrimidine was no longer detected (24 h). Addition of water (50 ml) precipitated product (I). The product was filtered, washed with water and dried, and then recrystallized from acetonitrile–dimethyl sulfoxide (5:1, v/v) [yield 2.10 g, 76%; m.p. 420 K]. ¹H NMR (DMSO-d₆) δ: 10.02 (bs, 1H, NH₂), 8.80 (bs, 1H, NH₂), 7.55–7.58 (m, 2H), 7.40–7.46 (m, 5H), 5.70 (s, 2H, CH₂O), 2.57 (s, 3H, CH ₃S); ¹³C NMR (DMSO-d₆) δ: 177.8, 168.5, 145.7, 140.2, 135.9, 128.6, 128.5, 128.4, 69.1, 14.1. Crystals of (I) suitable for single-crystal X-ray diffraction analysis were selected directly from the analytical sample.

S3. Refinement

H atoms were treated as riding, with C—H distances in the range 0.95–0.99 Å and N—H distances of 0.88 Å.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures

	Fig. 1. The two independent molecules of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Part of the crystal structure of (I), showing the formation of hydrogen-bonded dimers (a) by molecules of type 1 and (b) by molecules of type 2. Atoms marked with an asterisk (*) or hash (#) are at the symmetry positions (1 - x, 1 - y, 1 - z) and (-x, -y, 1 - z), respectively.
	Fig. 3. Stereoview of part of the structure of (I), showing a [100] chain formed by the linking of hydrogen-bonded dimers by means of π–π stacking. For the sake of clarity, the benzyl groups have been omitted.

(I)

Crystal data

C12H12N4O2S	F(000) = 1152
Mr = 276.32	Dx = 1.439 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6223 reflections
a = 15.6152 (10) Å	θ = 1.3–29.0°
b = 9.1842 (6) Å	µ = 0.26 mm^−1
c = 17.7920 (11) Å	T = 120 K
β = 90.830 (2)°	Block, colourless
V = 2551.3 (3) Å^3	0.50 × 0.35 × 0.20 mm
Z = 8

Data collection

Bruker-SMART-1000 CCD diffractometer	6223 independent reflections
Radiation source: fine-focus sealed X-ray tube	4840 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ϕ scans, and ω scans with κ offsets	θmax = 29.0°, θmin = 1.3°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −20→20
Tmin = 0.882, Tmax = 0.950	k = −12→12
24010 measured reflections	l = −23→23

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.101	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.058P)^2 + 0.327P] where P = (Fo^2 + 2Fc^2)/3
6223 reflections	(Δ/σ)max = 0.001
345 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

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

	x	y	z	Uiso*/Ueq
N11	0.26619 (7)	0.57631 (12)	0.38289 (6)	0.0256 (2)
C12	0.34204 (8)	0.50920 (15)	0.39377 (7)	0.0251 (3)
S12	0.37614 (2)	0.38279 (4)	0.32777 (2)	0.03292 (10)
C121	0.29268 (10)	0.3893 (2)	0.25706 (9)	0.0404 (4)
N13	0.39803 (7)	0.52625 (12)	0.45058 (6)	0.0253 (2)
C14	0.37771 (8)	0.62629 (15)	0.50305 (7)	0.0250 (3)
N14	0.43291 (7)	0.64343 (14)	0.55976 (7)	0.0315 (3)
C15	0.29961 (8)	0.70870 (15)	0.49700 (8)	0.0261 (3)
N15	0.27135 (8)	0.81465 (14)	0.54536 (7)	0.0363 (3)
O15	0.31865 (7)	0.84115 (13)	0.60181 (6)	0.0432 (3)
C16	0.24639 (8)	0.67458 (15)	0.43399 (8)	0.0255 (3)
O16	0.17207 (6)	0.74563 (11)	0.42737 (6)	0.0298 (2)
C167	0.11727 (9)	0.70483 (16)	0.36374 (8)	0.0312 (3)
C161	0.04088 (9)	0.80449 (16)	0.36150 (8)	0.0288 (3)
C162	0.00075 (10)	0.85356 (16)	0.42541 (8)	0.0330 (3)
C163	−0.07137 (10)	0.94235 (17)	0.42015 (9)	0.0355 (3)
C164	−0.10439 (10)	0.98162 (19)	0.35154 (9)	0.0410 (4)
C165	−0.06544 (12)	0.9315 (2)	0.28700 (10)	0.0558 (5)
C166	0.00637 (11)	0.8434 (2)	0.29205 (9)	0.0479 (5)
N21	0.23421 (7)	0.27186 (13)	0.50043 (6)	0.0264 (2)
C22	0.15755 (8)	0.30913 (15)	0.46994 (7)	0.0261 (3)
S22	0.12166 (2)	0.21882 (4)	0.38943 (2)	0.03311 (10)
C221	0.20532 (10)	0.09006 (17)	0.37297 (10)	0.0390 (4)
N23	0.10250 (7)	0.40863 (13)	0.49387 (6)	0.0273 (3)
C24	0.12322 (8)	0.47877 (16)	0.55858 (8)	0.0281 (3)
N24	0.06825 (8)	0.57627 (15)	0.58339 (7)	0.0383 (3)
C25	0.20171 (9)	0.44616 (16)	0.59792 (8)	0.0293 (3)
N25	0.22988 (8)	0.50434 (16)	0.66500 (7)	0.0407 (3)
O25	0.18349 (8)	0.60084 (15)	0.69388 (7)	0.0528 (3)
C26	0.25442 (8)	0.34040 (15)	0.56363 (8)	0.0270 (3)
O26	0.32842 (6)	0.31138 (11)	0.59831 (5)	0.0303 (2)
C267	0.38374 (9)	0.20328 (17)	0.56463 (9)	0.0335 (3)
C261	0.45856 (9)	0.18088 (17)	0.61798 (9)	0.0337 (3)
C262	0.50491 (11)	0.0520 (2)	0.61235 (12)	0.0511 (5)
C263	0.57526 (12)	0.0281 (2)	0.65882 (14)	0.0668 (6)
C264	0.60074 (11)	0.1306 (2)	0.71148 (13)	0.0611 (6)
C265	0.55452 (10)	0.2569 (2)	0.71799 (10)	0.0480 (5)
C266	0.48365 (9)	0.28248 (19)	0.67110 (9)	0.0389 (4)
H12A	0.2367	0.3832	0.2812	0.061*
H12B	0.2992	0.3072	0.2224	0.061*
H12C	0.2966	0.4809	0.2291	0.061*
H14A	0.4800	0.5909	0.5618	0.038*
H14B	0.4224	0.7073	0.5953	0.038*
H16A	0.0983	0.6026	0.3692	0.037*
H16B	0.1494	0.7133	0.3164	0.037*
H162	0.0226	0.8264	0.4735	0.040*
H163	−0.0979	0.9759	0.4647	0.043*
H164	−0.1534	1.0426	0.3481	0.049*
H165	−0.0881	0.9576	0.2391	0.067*
H166	0.0323	0.8092	0.2474	0.058*
H22A	0.2597	0.1417	0.3671	0.059*
H22B	0.1922	0.0349	0.3271	0.059*
H22C	0.2099	0.0230	0.4157	0.059*
H24A	0.0205	0.5933	0.5581	0.046*
H24B	0.0794	0.6242	0.6252	0.046*
H26A	0.4040	0.2378	0.5153	0.040*
H26B	0.3523	0.1107	0.5570	0.040*
H262	0.4882	−0.0197	0.5765	0.061*
H263	0.6066	−0.0601	0.6545	0.080*
H264	0.6496	0.1137	0.7427	0.073*
H265	0.5708	0.3273	0.7546	0.058*
H266	0.4524	0.3707	0.6758	0.047*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N11	0.0202 (5)	0.0290 (6)	0.0275 (6)	−0.0012 (4)	−0.0042 (4)	0.0013 (5)
C12	0.0214 (6)	0.0269 (7)	0.0270 (6)	−0.0037 (5)	−0.0007 (5)	0.0006 (5)
S12	0.02645 (18)	0.0395 (2)	0.03268 (19)	0.00186 (15)	−0.00430 (14)	−0.01012 (15)
C121	0.0306 (8)	0.0596 (11)	0.0308 (8)	−0.0036 (7)	−0.0061 (6)	−0.0118 (7)
N13	0.0195 (5)	0.0288 (6)	0.0276 (6)	0.0006 (5)	−0.0034 (4)	−0.0007 (5)
C14	0.0203 (6)	0.0276 (7)	0.0269 (6)	−0.0028 (5)	−0.0033 (5)	0.0012 (5)
N14	0.0239 (6)	0.0381 (7)	0.0324 (6)	0.0051 (5)	−0.0090 (5)	−0.0083 (5)
C15	0.0212 (6)	0.0265 (7)	0.0306 (7)	0.0000 (5)	−0.0036 (5)	−0.0001 (5)
N15	0.0306 (7)	0.0371 (7)	0.0409 (7)	0.0034 (5)	−0.0065 (5)	−0.0090 (6)
O15	0.0353 (6)	0.0503 (7)	0.0437 (6)	0.0053 (5)	−0.0125 (5)	−0.0178 (5)
C16	0.0193 (6)	0.0267 (7)	0.0305 (7)	−0.0018 (5)	−0.0033 (5)	0.0050 (5)
O16	0.0218 (5)	0.0331 (5)	0.0343 (5)	0.0042 (4)	−0.0099 (4)	−0.0013 (4)
C167	0.0249 (7)	0.0363 (8)	0.0320 (7)	0.0017 (6)	−0.0106 (6)	0.0006 (6)
C161	0.0205 (6)	0.0345 (8)	0.0314 (7)	−0.0026 (6)	−0.0053 (5)	0.0046 (6)
C162	0.0348 (8)	0.0348 (8)	0.0293 (7)	−0.0004 (6)	−0.0072 (6)	0.0022 (6)
C163	0.0311 (8)	0.0387 (8)	0.0367 (8)	−0.0016 (6)	0.0002 (6)	−0.0033 (6)
C164	0.0260 (8)	0.0500 (10)	0.0467 (9)	0.0080 (7)	−0.0078 (7)	−0.0018 (7)
C165	0.0461 (10)	0.0865 (15)	0.0344 (9)	0.0268 (10)	−0.0097 (8)	0.0083 (9)
C166	0.0390 (9)	0.0765 (13)	0.0283 (8)	0.0208 (9)	0.0005 (7)	0.0071 (8)
N21	0.0193 (5)	0.0307 (6)	0.0293 (6)	0.0015 (5)	−0.0019 (4)	0.0056 (5)
C22	0.0218 (6)	0.0307 (7)	0.0257 (6)	−0.0005 (5)	−0.0009 (5)	0.0060 (5)
S22	0.02616 (18)	0.0416 (2)	0.03141 (19)	0.00181 (15)	−0.00467 (14)	−0.00393 (15)
C221	0.0344 (8)	0.0364 (8)	0.0463 (9)	0.0017 (7)	0.0016 (7)	−0.0075 (7)
N23	0.0205 (5)	0.0354 (6)	0.0259 (6)	0.0033 (5)	−0.0050 (4)	0.0024 (5)
C24	0.0199 (6)	0.0362 (8)	0.0281 (7)	0.0027 (6)	−0.0042 (5)	0.0029 (6)
N24	0.0266 (6)	0.0523 (8)	0.0358 (7)	0.0138 (6)	−0.0112 (5)	−0.0106 (6)
C25	0.0197 (6)	0.0397 (8)	0.0282 (7)	0.0034 (6)	−0.0057 (5)	0.0027 (6)
N25	0.0291 (7)	0.0567 (9)	0.0361 (7)	0.0086 (6)	−0.0080 (5)	−0.0073 (6)
O25	0.0370 (6)	0.0748 (9)	0.0460 (7)	0.0187 (6)	−0.0140 (5)	−0.0226 (6)
C26	0.0192 (6)	0.0328 (7)	0.0287 (7)	0.0000 (5)	−0.0025 (5)	0.0102 (6)
O26	0.0196 (5)	0.0387 (6)	0.0324 (5)	0.0063 (4)	−0.0053 (4)	0.0053 (4)
C267	0.0231 (7)	0.0353 (8)	0.0420 (8)	0.0065 (6)	−0.0030 (6)	0.0043 (6)
C261	0.0173 (6)	0.0391 (8)	0.0447 (8)	0.0025 (6)	0.0001 (6)	0.0159 (7)
C262	0.0294 (8)	0.0452 (10)	0.0787 (13)	0.0099 (7)	−0.0015 (8)	0.0112 (9)
C263	0.0315 (9)	0.0584 (13)	0.1103 (18)	0.0178 (9)	−0.0063 (11)	0.0271 (12)
C264	0.0215 (8)	0.0762 (14)	0.0852 (15)	−0.0004 (9)	−0.0142 (9)	0.0438 (12)
C265	0.0275 (8)	0.0641 (12)	0.0520 (10)	−0.0124 (8)	−0.0118 (7)	0.0252 (9)
C266	0.0242 (7)	0.0445 (9)	0.0476 (9)	−0.0001 (6)	−0.0066 (6)	0.0177 (7)

Geometric parameters (Å, º)

N11—C12	1.347 (2)	N21—C22	1.351 (2)
C12—N13	1.336 (2)	C22—N23	1.329 (2)
N13—C14	1.351 (2)	N23—C24	1.354 (2)
C14—C15	1.438 (2)	C24—C25	1.434 (2)
C15—C16	1.421 (2)	C25—C26	1.417 (2)
C16—N11	1.321 (2)	C26—N21	1.323 (2)
C12—S12	1.740 (2)	C22—S22	1.741 (2)
S12—C121	1.799 (2)	S22—C221	1.789 (2)
C121—H12A	0.9800	C221—H22A	0.9800
C121—H12B	0.9800	C221—H22B	0.9800
C121—H12C	0.9800	C221—H22C	0.9800
C14—N14	1.327 (2)	C24—N24	1.321 (2)
N14—H14A	0.8800	N24—H24A	0.8800
N14—H14B	0.8800	N24—H24B	0.8800
C15—N15	1.376 (2)	C25—N25	1.374 (2)
N15—O15	1.262 (2)	N25—O25	1.259 (2)
C16—O16	1.335 (2)	C26—O26	1.329 (2)
O16—C167	1.458 (2)	O26—C267	1.451 (2)
C167—C161	1.504 (2)	C267—C261	1.509 (2)
C167—H16A	0.9900	C267—H26A	0.9900
C167—H16B	0.9900	C267—H26B	0.9900
C161—C162	1.382 (2)	C261—C266	1.381 (2)
C161—C166	1.388 (2)	C261—C262	1.392 (2)
C162—C163	1.392 (2)	C262—C263	1.383 (3)
C162—H162	0.9500	C262—H262	0.9500
C163—C164	1.367 (2)	C263—C264	1.382 (3)
C163—H163	0.9500	C263—H263	0.9500
C164—C165	1.386 (2)	C264—C265	1.372 (3)
C164—H164	0.9500	C264—H264	0.9500
C165—C166	1.384 (2)	C265—C266	1.396 (2)
C165—H165	0.9500	C265—H265	0.9500
C166—H166	0.9500	C266—H266	0.9500
C16—N11—C12	115.3 (2)	C26—N21—C22	114.8 (2)
N13—C12—N11	128.3 (2)	N23—C22—N21	128.3 (2)
N13—C12—S12	112.67 (9)	N23—C22—S22	112.91 (9)
N11—C12—S12	119.04 (9)	N21—C22—S22	118.9 (2)
C12—S12—C121	102.95 (7)	C22—S22—C221	102.85 (7)
S12—C121—H12A	109.5	S22—C221—H22A	109.5
S12—C121—H12B	109.5	S22—C221—H22B	109.5
H12A—C121—H12B	109.5	H22A—C221—H22B	109.5
S12—C121—H12C	109.5	S22—C221—H22C	109.5
H12A—C121—H12C	109.5	H22A—C221—H22C	109.5
H12B—C121—H12C	109.5	H22B—C221—H22C	109.5
C12—N13—C14	116.4 (2)	C22—N23—C24	116.9 (2)
N14—C14—N13	116.7 (2)	N24—C24—N23	117.3 (2)
N14—C14—C15	122.4 (2)	N24—C24—C25	122.2 (2)
N13—C14—C15	120.9 (2)	N23—C24—C25	120.5 (2)
C14—N14—H14A	120.0	C24—N24—H24A	120.0
C14—N14—H14B	120.0	C24—N24—H24B	120.0
H14A—N14—H14B	120.0	H24A—N24—H24B	120.0
N15—C15—C16	117.4 (2)	N25—C25—C26	117.4 (2)
N15—C15—C14	127.2 (2)	N25—C25—C24	127.1 (2)
C16—C15—C14	115.4 (2)	C26—C25—C24	115.5 (2)
O15—N15—C15	116.4 (2)	O25—N25—C25	116.7 (2)
N11—C16—O16	119.0 (2)	N21—C26—O26	119.6 (2)
N11—C16—C15	123.6 (2)	N21—C26—C25	124.0 (2)
O16—C16—C15	117.4 (2)	O26—C26—C25	116.4 (2)
C16—O16—C167	116.3 (2)	C26—O26—C267	117.7 (2)
O16—C167—C161	108.7 (2)	O26—C267—C261	107.1 (2)
O16—C167—H16A	110.0	O26—C267—H26A	110.3
C161—C167—H16A	110.0	C261—C267—H26A	110.3
O16—C167—H16B	110.0	O26—C267—H26B	110.3
C161—C167—H16B	110.0	C261—C267—H26B	110.3
H16A—C167—H16B	108.3	H26A—C267—H26B	108.6
C162—C161—C166	118.3 (2)	C266—C261—C262	118.8 (2)
C162—C161—C167	123.1 (2)	C266—C261—C267	123.2 (2)
C166—C161—C167	118.6 (2)	C262—C261—C267	118.0 (2)
C161—C162—C163	120.8 (2)	C263—C262—C261	120.1 (2)
C161—C162—H162	119.6	C263—C262—H262	120.0
C163—C162—H162	119.6	C261—C262—H262	120.0
C164—C163—C162	120.6 (2)	C264—C263—C262	121.1 (2)
C164—C163—H163	119.7	C264—C263—H263	119.5
C162—C163—H163	119.7	C262—C263—H263	119.5
C163—C164—C165	119.2 (2)	C265—C264—C263	119.1 (2)
C163—C164—H164	120.4	C265—C264—H264	120.5
C165—C164—H164	120.4	C263—C264—H264	120.5
C166—C165—C164	120.3 (2)	C264—C265—C266	120.3 (2)
C166—C165—H165	119.8	C264—C265—H265	119.8
C164—C165—H165	119.8	C266—C265—H265	119.8
C165—C166—C161	120.8 (2)	C261—C266—C265	120.7 (2)
C165—C166—H166	119.6	C261—C266—H266	119.7
C161—C166—H166	119.6	C265—C266—H266	119.7
C121—S12—C12—N13	−177.1 (1)	C221—S22—C22—N23	−178.0 (1)
O15—N15—C15—C16	178.5 (1)	O25—N25—C25—C26	178.3 (1)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N14—H14A···N13^i	0.88	2.20	3.073 (2)	171
N14—H14B···O15	0.88	2.04	2.661 (2)	127
N24—H24A···N23^ii	0.88	2.12	2.985 (2)	168
N24—H24B···O25	0.88	2.03	2.655 (2)	127

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