Hydrogen-bond motifs in N-monosubstituted derivatives of barbituric acid: 5-allyl-5-isopropyl-1-methyl­barbituric acid (enallyl­propymal) and 1,5-di(but-2-en­yl)-5-ethyl­barbituric acid

Both title structures exhibit essentially planar barbiturate rings. The crystal structure of enallyl­propymal (5-allyl-5-isopropyl-1-methyl­barbituric acid), C₁₁H₁₆N₂O₃, is composed of centrosymmetric N—H...O hydrogen-bonded dimers, while 1,5-di(but-2-en­yl)-5-ethyl­barbituric acid, C₁₄H₂₀N₂O₃, forms N—H...O hydrogen-bonded helical chains. Each of the ten known crystal structures of closely related N-monosubstituted derivatives of barbituric acid displays one of the fundamental N—H...O hydrogen-bonded motifs of the two title structures, i.e. either a dimer or a chain.

S1. Comment

Barbituric acid derivatives are sedative, anaesthetic, anxiolytic, hypnotic and anticonvulsant agents, which have largely been replaced in pharmaceutical use by other drugs of lower abuse liability. However, barbiturates remain a very interesting class of compounds because of their well known propensity to form multiple crystalline forms (Brandstätter-Kuhnert & Aepkers, 1962) and their hydrogen-bonding capabilities. The rigid barbiturate ring determines the geometric configuration of the potential hydrogen-bond donor and acceptor sites in the molecule (NH and carbonyl groups, see Scheme). This in turn limits the geometric diversity of the hydrogen-bond patterns that can be formed. Subsequently, the observed patterns in the subset of compounds with R¹ = H are all based on a small number of standard motifs (Gelbrich et al., 2007; Zencirci et al., 2009). The number of feasible motifs should be even smaller for the related N-monosubstituted derivatives (R¹ = alkyl), to which the two title compounds belong, simply because they have only one hydrogen-bond donor functionality.

Enallylpropymal, (I) [systematic name 1-methyl-5-(propan-2-yl)-5-(prop-2-en-1-yl)pyrimidine-2,4,6(1H, 3H,5H)-trione and also known as narconumal], was marketed as a potent sedative and hypnotic drug (Demole, 1937). Brandstätter-Kuhnert & Aepkers (1962) have studied its solid-state behaviour and found evidence for the existence of only one crystalline form. It has a melting point of 331–334 K, which is remarkably low in comparison to the other N-monosubstituted derivatives of barbituric acid listed in the same paper. The thermomicroscopic and DSC [differential scanning calorimetry?] data obtained for our crystals of (I) are consistent with the data reported by Brandstätter-Kuhnert & Aepkers (1962).

The asymmetric unit of (I) contains one formula unit (see Fig. 1a). The barbiturate ring is essentially planar so that the root mean square deviation of the six fitted atoms from the mean plane is just 0.02 Å. The analogous parameter is 0.05 Å for the C10—C8—C5—C11—C12 fragment, which involves adjacent sections of the isopropyl and allyl substituents. These two essentially planar molecular fragments lie almost perpendicular to one another and form an angle of 88.7 (1)°.

Two molecules of (I) are joined together by two N—H···O bonds to give a centrosymmetric dimer with a central R²₂(8) ring (Bernstein et al., 1995). This motif is present in many barbiturates with two NH hydrogen-bond donor groups (i.e. R¹ = H, Zencirci et al., 2009). Neighbouring hydrogen-bonded dimers in the crystal structure of (I) are related to one another by translational symmetry. They assemble in such a way that the isopropyl and allyl moieties of adjacent dimers align themselves in an approximately antiparallel fashion (see Fig. 2). Furthermore, an (allyl)C—H···O6 interaction links the dimers into double-stranded chains which propagate parallel to the a axis (see Fig. 2 and Table 1).

Crystals of (II) {systematic name 1,5-di[(2E)-but-2-en-1-yl]-5-ethylpyrimidine-2,4,6(1H,3H,5H)-trione} were identified as an unexpected byproduct in a commercial sample of 5-(but-2-enyl)-5-ethylbarbituric acid, kalypnon (Boehringer und Söhne), obtained by our laboratory some 40 years ago. Kalypnon (also known as kalipnon, crotylbarbital, crotarbital, mepertan, barotal) was used for the treatment of insomnia during the 1960s.

The barbiturate ring of (II) is essentially planar with the root mean square deviation of the six fitted atoms from the mean plane being just 0.04 Å (Fig. 1b). The analogous deviation computed for the C12—C11—C5—C15—C16 set of atoms involving the ring atom C5 and adjacent fragments of the crotyl and ethyl substituents, is 0.03 Å. Similar to the structure of (I), the barbiturate ring and the C₅-plane at C5 are almost perpendicular to one another and form an angle of 89.8 (2)°. The 1- and 5-substituted trans-crotyl groups lie on opposite sites [sides?] of the plane through the barbiturate ring, so that the associated anticlinal torsion angles N1—C7—C8—C9 and C5—C11—C12—C13 are of the opposite sign.

The molecules of (II) are linked to one another by one N—H···O bond (Table 2). The helical chains resulting from this interaction lie parallel to the b axis (see Fig. 3). Furthermore, chains that are adjacent to one another along the a axis are related by translational symmetry, while along the c axis there are centres of inversion between neighbouring chains. Two molecules belonging to neighbouring N—H···O-bonded chains are linked together via two (but-2-enyl)C—H···O4 contacts which are related by inversion symmetry (see Fig. 3 and Table 2). Altogether, N—H···O and C—H···O interactions result in a two-dimensional sheet of connected molecules that lies parallel to (101).

The crystal structures of eight N-monosubstituted barbituric acid derivatives with R¹ = alkyl (see Scheme) are currently known [Cambridge Structural Database (CSD) version 5.30, update September 2009; Allen, 2002], in addition to those of (I) and (II) (see Table 3). A common feature of all these structures is the formation of a single N—H···O bond in which the NH donor and one carbonyl acceptor site per molecule are employed. More precisely, only the carbonyl group in the 4-position (see Scheme) is ever engaged in this interaction, whereas the carbonyl groups in the 2- and 6-positions are avoided, presumably because of their close proximity to the alkyl substitutent at N1.

Four of these previous examples concern the dimer motif of (I) (Brunner et al., 2003; Dideberg et al., 1975; Lewis et al., 2005; Pyżalska et al., 1980). The dimer is always centrosymmetric, with the exception of one structure of an enantiomerically pure chiral compound (Brunner et al., 2003). The N—H···O-bonded chain motif is found in (II), where the chains exhibit a 2₁ symmetry, and in another four compounds (Gelbrich & Griesser, 2009; Nichol & Clegg, 2005; Wilhelm & Fischer, 1976; Wunderlich, 1973), where they show translational symmetry only. Consequently, the lattice vectors which correspond with the translation of these latter four hydrogen-bonded chains (see Table 3) are very similar in length (between 6.61 and 6.80 Å).

Related literature

For related literature, see: Allen (2002); Bernstein et al. (1995); Brandstätter-Kuhnert & Aepkers (1962); Brunner et al. (2003); Demole (1937); Dideberg et al. (1975); Gelbrich & Griesser (2009); Gelbrich et al. (2007); Lewis et al. (2005); Nichol & Clegg (2005); Pyżalska et al. (1980); Wilhelm & Fischer (1976); Wunderlich (1973); Zencirci et al. (2009).

S2. Experimental

Intergrown, irregular-shaped crystals of (I) were obtained from a commercial sample of narconumal (F. Hoffmann–La Roche). Additional crystallization experiments did not produce any crystals of better quality. The data collected for (I) were integrated for two separate, non-merohedrally twinned components. The final BASF parameter for the minor component was 0.356 (3).

A commercial sample of kalypnon (Boehringer und Söhne) was found to contain small, needle-shaped crystals of (II) which were clearly distinct from the rhombic crystals of the main product. The monoclinic lattice of (II) has a special geometry where the a and c axes are approximately equal in length, giving rise to imperfect pseudo-merohedral twinning. The data integration was performed out with a larger shoe box than usual in order to include the combined contributions from both twin components, and in the structure refinement the idealized pseudo-merohedral twin matrix (0 0 - 1 0 - 1 0 - 1 0 0) was applied. The final BASF parameter for the minor twin component was 0.272 (2). The data quality may also be affected by additional, small, non-merohedral twin components that could not be modelled adequately.

S3. Refinement

All H atoms were identified in a difference map. Methyl H atoms were idealized and included as rigid groups that were allowed to rotate but not tip (C—H = 0.98 Å) and refined with 1.5U_eq(C). H atoms bonded to secondary CH₂ (C—H = 0.99 Å) and aromatic C atoms (C—H = 0.95 Å) were positioned geometrically and refined with U_iso = 1.2 U_eq(C)_. H atoms attached to N were refined with restrained distances [N—H = 0.88 (2) Å], and their U_iso parameters were refined freely.

Computing details

For both compounds, data collection: COLLECT (Hooft, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997). Data reduction: EVALCCD (Duisenberg et al., 2003) for (I); HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997) for (II). For both compounds, program(s) used to solve structure: SHELXL97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP/SHELXTL (Sheldrick, 2008) and Mercury (Bruno et al., 2002); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures

	Fig. 1. The molecular structures of (I) (a) and (II) (b) with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary size.
	Fig. 2. N—H···O-bonded dimers and C—H···O contacts in the crystal structure of (I). H and O atoms directly involved in these interactions are drawn as balls.
	Fig. 3. The packing of N—H···O-bonded chains and C—H···O contacts in the crystal structure of (II) viewed parallel to the a axis. H and O atoms directly involved in these interactions are drawn as balls.

(I) 5-allyl-5-isopropyl-1-methylbarbituric acid

Crystal data

C11H16N2O3	Z = 2
Mr = 224.26	F(000) = 240
Triclinic, P1	Dx = 1.298 Mg m^−3
Hall symbol: -P 1	Melting point: 332(1) K
a = 6.4160 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.9559 (8) Å	Cell parameters from 2190 reflections
c = 11.9569 (12) Å	θ = 0.4–26.4°
α = 77.574 (7)°	µ = 0.10 mm^−1
β = 80.837 (7)°	T = 120 K
γ = 75.518 (6)°	Block, colourless
V = 573.51 (10) Å^3	0.25 × 0.2 × 0.2 mm

Data collection

KappaCCD diffractometer	2000 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	1386 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0
Detector resolution: 9.091 pixels mm^-1	θmax = 25°, θmin = 3.3°
ϕ and ω scans	h = −7→7
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −9→9
Tmin = 0.977, Tmax = 0.981	l = 0→14
2000 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.071	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.114	w = 1/[σ^2(Fo^2) + (0.0042P)^2 + 0.6197P] where P = (Fo^2 + 2Fc^2)/3
S = 1.18	(Δ/σ)max < 0.001
2000 reflections	Δρmax = 0.32 e Å^−3
154 parameters	Δρmin = −0.33 e Å^−3
1 restraint	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.027 (4)

Special details

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
N1	0.0431 (4)	0.9439 (4)	0.1859 (2)	0.0178 (7)
O2	0.2302 (4)	1.0928 (3)	0.0345 (2)	0.0241 (6)
C2	0.2261 (5)	0.9609 (4)	0.1091 (3)	0.0180 (8)
N3	0.4043 (5)	0.8231 (4)	0.1193 (2)	0.0195 (7)
H3	0.522 (4)	0.841 (5)	0.074 (3)	0.041 (13)*
O4	0.5950 (4)	0.5603 (3)	0.2026 (2)	0.0283 (6)
C4	0.4222 (5)	0.6678 (4)	0.2010 (3)	0.0200 (8)
C5	0.2236 (5)	0.6386 (4)	0.2817 (3)	0.0165 (7)
O6	−0.1331 (4)	0.7966 (3)	0.3374 (2)	0.0236 (6)
C6	0.0318 (5)	0.7967 (4)	0.2716 (3)	0.0180 (8)
C7	−0.1499 (5)	1.0909 (4)	0.1761 (3)	0.0229 (8)
H7A	−0.279	1.0438	0.1808	0.034*
H7B	−0.1333	1.1708	0.1021	0.034*
H7C	−0.1657	1.1558	0.2391	0.034*
C8	0.1419 (6)	0.4828 (4)	0.2531 (3)	0.0213 (8)
H8	−0.0056	0.4842	0.2959	0.026*
C9	0.2853 (6)	0.3000 (5)	0.2918 (3)	0.0321 (10)
H9A	0.2257	0.2093	0.2723	0.048*
H9B	0.2896	0.279	0.3753	0.048*
H9C	0.4324	0.2949	0.2525	0.048*
C10	0.1185 (6)	0.5130 (5)	0.1245 (3)	0.0274 (9)
H10A	0.2621	0.5023	0.0803	0.041*
H10B	0.0299	0.6315	0.1006	0.041*
H10C	0.0485	0.4246	0.1101	0.041*
C11	0.2828 (6)	0.6007 (5)	0.4062 (3)	0.0252 (9)
H11A	0.1569	0.5737	0.4605	0.03*
H11B	0.404	0.4955	0.4161	0.03*
C12	0.3475 (6)	0.7548 (5)	0.4349 (3)	0.0244 (8)
H12	0.4767	0.7857	0.3947	0.029*
C13	0.2382 (6)	0.8492 (5)	0.5113 (3)	0.0313 (9)
H13A	0.1082	0.8221	0.5531	0.038*
H13B	0.289	0.9447	0.5248	0.038*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0161 (15)	0.0174 (15)	0.0181 (16)	−0.0012 (12)	−0.0021 (12)	−0.0025 (12)
O2	0.0266 (14)	0.0190 (14)	0.0223 (14)	−0.0047 (11)	0.0016 (11)	0.0019 (12)
C2	0.0196 (19)	0.0180 (19)	0.0181 (19)	−0.0037 (15)	−0.0027 (15)	−0.0072 (16)
N3	0.0162 (17)	0.0202 (16)	0.0184 (16)	−0.0030 (13)	0.0026 (13)	−0.0003 (13)
O4	0.0163 (14)	0.0284 (15)	0.0333 (16)	0.0009 (12)	−0.0016 (11)	0.0014 (12)
C4	0.017 (2)	0.0208 (19)	0.022 (2)	−0.0028 (16)	−0.0037 (15)	−0.0047 (15)
C5	0.0149 (18)	0.0167 (18)	0.0166 (18)	−0.0022 (14)	−0.0024 (14)	−0.0015 (14)
O6	0.0191 (14)	0.0255 (14)	0.0227 (14)	−0.0051 (10)	0.0022 (11)	−0.0002 (11)
C6	0.0167 (19)	0.023 (2)	0.0170 (19)	−0.0087 (15)	−0.0009 (16)	−0.0047 (16)
C7	0.020 (2)	0.0159 (19)	0.030 (2)	0.0015 (15)	−0.0028 (16)	−0.0045 (16)
C8	0.0185 (19)	0.0178 (18)	0.027 (2)	−0.0047 (15)	−0.0002 (15)	−0.0041 (15)
C9	0.030 (2)	0.024 (2)	0.044 (2)	−0.0058 (17)	−0.0137 (19)	−0.0035 (18)
C10	0.031 (2)	0.028 (2)	0.026 (2)	−0.0085 (17)	−0.0047 (17)	−0.0067 (17)
C11	0.024 (2)	0.026 (2)	0.024 (2)	−0.0032 (16)	−0.0040 (16)	−0.0027 (16)
C12	0.0159 (19)	0.035 (2)	0.022 (2)	−0.0077 (16)	−0.0044 (15)	−0.0018 (17)
C13	0.036 (2)	0.034 (2)	0.026 (2)	−0.0091 (18)	−0.0041 (18)	−0.0083 (18)

Geometric parameters (Å, º)

N1—C2	1.386 (4)	C8—C10	1.531 (5)
N1—C6	1.389 (4)	C8—C9	1.534 (5)
N1—C7	1.476 (4)	C8—H8	1
O2—C2	1.225 (4)	C9—H9A	0.98
C2—N3	1.372 (4)	C9—H9B	0.98
N3—C4	1.392 (4)	C9—H9C	0.98
N3—H3	0.881 (19)	C10—H10A	0.98
O4—C4	1.219 (4)	C10—H10B	0.98
C4—C5	1.506 (5)	C10—H10C	0.98
C5—C6	1.523 (5)	C11—C12	1.508 (5)
C5—C11	1.543 (5)	C11—H11A	0.99
C5—C8	1.579 (5)	C11—H11B	0.99
O6—C6	1.214 (4)	C12—C13	1.311 (5)
C7—H7A	0.98	C12—H12	0.95
C7—H7B	0.98	C13—H13A	0.95
C7—H7C	0.98	C13—H13B	0.95
C2—N1—C6	123.6 (3)	C9—C8—C5	113.4 (3)
C2—N1—C7	118.1 (3)	C10—C8—H8	107.4
C6—N1—C7	118.3 (3)	C9—C8—H8	107.4
O2—C2—N3	120.8 (3)	C5—C8—H8	107.4
O2—C2—N1	121.8 (3)	C8—C9—H9A	109.5
N3—C2—N1	117.4 (3)	C8—C9—H9B	109.5
C2—N3—C4	126.5 (3)	H9A—C9—H9B	109.5
C2—N3—H3	116 (3)	C8—C9—H9C	109.5
C4—N3—H3	117 (3)	H9A—C9—H9C	109.5
O4—C4—N3	119.0 (3)	H9B—C9—H9C	109.5
O4—C4—C5	123.0 (3)	C8—C10—H10A	109.5
N3—C4—C5	118.0 (3)	C8—C10—H10B	109.5
C4—C5—C6	114.0 (3)	H10A—C10—H10B	109.5
C4—C5—C11	108.0 (3)	C8—C10—H10C	109.5
C6—C5—C11	107.4 (3)	H10A—C10—H10C	109.5
C4—C5—C8	109.6 (3)	H10B—C10—H10C	109.5
C6—C5—C8	105.4 (3)	C12—C11—C5	112.0 (3)
C11—C5—C8	112.5 (3)	C12—C11—H11A	109.2
O6—C6—N1	118.9 (3)	C5—C11—H11A	109.2
O6—C6—C5	121.0 (3)	C12—C11—H11B	109.2
N1—C6—C5	120.1 (3)	C5—C11—H11B	109.2
N1—C7—H7A	109.5	H11A—C11—H11B	107.9
N1—C7—H7B	109.5	C13—C12—C11	124.7 (3)
H7A—C7—H7B	109.5	C13—C12—H12	117.7
N1—C7—H7C	109.5	C11—C12—H12	117.7
H7A—C7—H7C	109.5	C12—C13—H13A	120
H7B—C7—H7C	109.5	C12—C13—H13B	120
C10—C8—C9	110.4 (3)	H13A—C13—H13B	120
C10—C8—C5	110.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···O2^i	0.88 (2)	1.99 (2)	2.866 (4)	174 (4)
C12—H12···O6^ii	0.95	2.51	3.424 (4)	163

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

(II) 1,5-di(but-2-enyl)-5-ethylbarbituric acid

Crystal data

C14H20N2O3	F(000) = 568
Mr = 264.32	Dx = 1.237 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2756 reflections
a = 10.2825 (11) Å	θ = 0.4–26.7°
b = 13.2972 (16) Å	µ = 0.09 mm^−1
c = 10.3959 (10) Å	T = 120 K
β = 92.999 (7)°	Needle, colourless
V = 1419.5 (3) Å^3	0.1 × 0.03 × 0.02 mm
Z = 4

Data collection

KappaCCD diffractometer	2440 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode	1367 reflections with I > 2σ(I)
10cm confocal mirrors monochromator	Rint = 0.147
Detector resolution: 4096x4096pixels / 62x62mm pixels mm^-1	θmax = 25°, θmin = 3.1°
ϕ and ω scans	h = −12→12
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −13→15
Tmin = 0.991, Tmax = 1.000	l = −11→12
11137 measured reflections

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)] = 0.080	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.21	w = 1/[σ^2(Fo^2) + (0.0057P)^2 + 0.6664P] where P = (Fo^2 + 2Fc^2)/3
2440 reflections	(Δ/σ)max < 0.001
180 parameters	Δρmax = 0.33 e Å^−3
1 restraint	Δρmin = −0.29 e Å^−3

Special details

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
N1	0.6312 (4)	0.1080 (2)	0.7806 (4)	0.0229 (9)
C2	0.6267 (5)	0.0031 (3)	0.7883 (5)	0.0274 (11)
O2	0.5460 (3)	−0.0410 (2)	0.8480 (3)	0.0355 (9)
N3	0.7246 (4)	−0.0472 (3)	0.7292 (4)	0.0310 (10)
H3	0.743 (5)	−0.1094 (18)	0.752 (4)	0.055 (16)*
O4	0.9001 (3)	−0.0615 (2)	0.6108 (3)	0.0472 (10)
C4	0.8190 (5)	−0.0071 (4)	0.6561 (5)	0.0327 (12)
C5	0.8148 (4)	0.1050 (3)	0.6316 (4)	0.0284 (12)
O6	0.7160 (3)	0.2525 (2)	0.7095 (3)	0.0356 (8)
C6	0.7185 (5)	0.1609 (3)	0.7114 (5)	0.0267 (11)
C7	0.5246 (4)	0.1651 (3)	0.8424 (4)	0.0306 (12)
H7A	0.4971	0.1278	0.9187	0.037*
H7B	0.5579	0.2316	0.8717	0.037*
C8	0.4100 (5)	0.1793 (4)	0.7490 (5)	0.0357 (13)
H8	0.3583	0.1221	0.7263	0.043*
C9	0.3764 (5)	0.2670 (4)	0.6962 (5)	0.0391 (13)
H9	0.4278	0.324	0.7204	0.047*
C10	0.2651 (5)	0.2826 (4)	0.6023 (5)	0.0511 (15)
H10A	0.1977	0.322	0.6426	0.077*
H10B	0.2292	0.2172	0.5751	0.077*
H10C	0.2946	0.3188	0.5271	0.077*
C11	0.9511 (4)	0.1496 (4)	0.6548 (5)	0.0382 (13)
H11A	1.0117	0.1136	0.5999	0.046*
H11B	0.9491	0.2209	0.6274	0.046*
C12	1.0030 (5)	0.1443 (4)	0.7910 (5)	0.0437 (14)
H12	0.9696	0.1897	0.8516	0.052*
C13	1.0944 (5)	0.0786 (4)	0.8320 (5)	0.0498 (15)
H13	1.1266	0.0335	0.7703	0.06*
C14	1.1495 (6)	0.0707 (5)	0.9662 (5)	0.0635 (18)
H14A	1.2444	0.078	0.9672	0.095*
H14B	1.1276	0.0049	1.0016	0.095*
H14C	1.113	0.1239	1.0187	0.095*
C15	0.7702 (5)	0.1215 (3)	0.4879 (4)	0.0363 (13)
H15A	0.7752	0.1943	0.4687	0.044*
H15B	0.8325	0.0868	0.4336	0.044*
C16	0.6338 (5)	0.0850 (4)	0.4487 (5)	0.0437 (14)
H16A	0.6152	0.0984	0.3569	0.065*
H16B	0.5704	0.1206	0.4993	0.065*
H16C	0.6278	0.0126	0.4648	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.028 (2)	0.018 (2)	0.024 (2)	−0.0022 (17)	0.0106 (16)	−0.0004 (18)
C2	0.028 (3)	0.027 (3)	0.027 (3)	−0.005 (2)	0.003 (2)	−0.004 (3)
O2	0.034 (2)	0.035 (2)	0.038 (2)	−0.0033 (16)	0.0133 (16)	0.0074 (17)
N3	0.035 (3)	0.018 (2)	0.041 (3)	0.003 (2)	0.017 (2)	0.003 (2)
O4	0.050 (2)	0.0272 (19)	0.067 (3)	0.0081 (19)	0.0345 (19)	0.006 (2)
C4	0.038 (3)	0.025 (3)	0.036 (3)	0.003 (2)	0.007 (2)	0.007 (3)
C5	0.024 (3)	0.027 (3)	0.036 (3)	−0.004 (2)	0.013 (2)	−0.003 (2)
O6	0.040 (2)	0.0183 (16)	0.050 (2)	−0.0016 (16)	0.0135 (15)	−0.0018 (18)
C6	0.035 (3)	0.018 (2)	0.028 (3)	−0.003 (2)	0.001 (2)	−0.003 (2)
C7	0.024 (3)	0.032 (3)	0.037 (3)	0.003 (2)	0.018 (2)	−0.007 (2)
C8	0.029 (3)	0.035 (3)	0.044 (3)	−0.003 (2)	0.014 (2)	−0.005 (3)
C9	0.035 (3)	0.046 (3)	0.037 (3)	−0.001 (3)	0.009 (2)	−0.007 (3)
C10	0.040 (3)	0.067 (4)	0.048 (4)	0.005 (3)	0.010 (3)	0.007 (3)
C11	0.033 (3)	0.039 (3)	0.044 (3)	0.000 (3)	0.016 (2)	0.002 (3)
C12	0.030 (3)	0.039 (3)	0.062 (4)	−0.006 (3)	0.002 (3)	0.009 (3)
C13	0.044 (4)	0.056 (4)	0.050 (4)	−0.011 (3)	0.011 (3)	0.005 (3)
C14	0.058 (4)	0.074 (5)	0.058 (4)	−0.019 (3)	−0.004 (3)	0.016 (4)
C15	0.049 (3)	0.027 (3)	0.034 (3)	0.004 (3)	0.012 (2)	0.003 (3)
C16	0.056 (4)	0.038 (3)	0.038 (3)	−0.014 (3)	0.007 (3)	−0.002 (3)

Geometric parameters (Å, º)

N1—C6	1.374 (5)	C10—H10A	0.98
N1—C2	1.398 (5)	C10—H10B	0.98
N1—C7	1.505 (5)	C10—H10C	0.98
C2—O2	1.213 (5)	C11—C12	1.489 (7)
C2—N3	1.379 (6)	C11—H11A	0.99
N3—C4	1.371 (6)	C11—H11B	0.99
N3—H3	0.881 (19)	C12—C13	1.336 (7)
O4—C4	1.217 (5)	C12—H12	0.95
C4—C5	1.513 (6)	C13—C14	1.482 (7)
C5—C6	1.518 (6)	C13—H13	0.95
C5—C11	1.530 (6)	C14—H14A	0.98
C5—C15	1.555 (6)	C14—H14B	0.98
O6—C6	1.219 (4)	C14—H14C	0.98
C7—C8	1.499 (6)	C15—C16	1.519 (6)
C7—H7A	0.99	C15—H15A	0.99
C7—H7B	0.99	C15—H15B	0.99
C8—C9	1.327 (6)	C16—H16A	0.98
C8—H8	0.95	C16—H16B	0.98
C9—C10	1.480 (7)	C16—H16C	0.98
C9—H9	0.95
C6—N1—C2	124.4 (4)	H10A—C10—H10B	109.5
C6—N1—C7	118.4 (4)	C9—C10—H10C	109.5
C2—N1—C7	116.9 (4)	H10A—C10—H10C	109.5
O2—C2—N3	121.9 (4)	H10B—C10—H10C	109.5
O2—C2—N1	122.5 (4)	C12—C11—C5	114.3 (4)
N3—C2—N1	115.6 (4)	C12—C11—H11A	108.7
C4—N3—C2	127.8 (4)	C5—C11—H11A	108.7
C4—N3—H3	111 (3)	C12—C11—H11B	108.7
C2—N3—H3	119 (3)	C5—C11—H11B	108.7
O4—C4—N3	120.2 (4)	H11A—C11—H11B	107.6
O4—C4—C5	122.3 (5)	C13—C12—C11	123.1 (5)
N3—C4—C5	117.5 (4)	C13—C12—H12	118.5
C4—C5—C6	113.8 (4)	C11—C12—H12	118.5
C4—C5—C11	109.7 (4)	C12—C13—C14	125.1 (6)
C6—C5—C11	110.0 (4)	C12—C13—H13	117.5
C4—C5—C15	107.8 (4)	C14—C13—H13	117.5
C6—C5—C15	106.8 (4)	C13—C14—H14A	109.5
C11—C5—C15	108.6 (3)	C13—C14—H14B	109.5
O6—C6—N1	120.4 (4)	H14A—C14—H14B	109.5
O6—C6—C5	119.6 (4)	C13—C14—H14C	109.5
N1—C6—C5	119.9 (4)	H14A—C14—H14C	109.5
C8—C7—N1	110.6 (4)	H14B—C14—H14C	109.5
C8—C7—H7A	109.5	C16—C15—C5	115.7 (4)
N1—C7—H7A	109.5	C16—C15—H15A	108.4
C8—C7—H7B	109.5	C5—C15—H15A	108.4
N1—C7—H7B	109.5	C16—C15—H15B	108.4
H7A—C7—H7B	108.1	C5—C15—H15B	108.4
C9—C8—C7	123.8 (5)	H15A—C15—H15B	107.4
C9—C8—H8	118.1	C15—C16—H16A	109.5
C7—C8—H8	118.1	C15—C16—H16B	109.5
C8—C9—C10	124.9 (5)	H16A—C16—H16B	109.5
C8—C9—H9	117.6	C15—C16—H16C	109.5
C10—C9—H9	117.6	H16A—C16—H16C	109.5
C9—C10—H10A	109.5	H16B—C16—H16C	109.5
C9—C10—H10B	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···O6^i	0.88 (2)	1.92 (2)	2.798 (5)	176 (5)
C11—H11A···O4^ii	0.99	2.51	3.432 (6)	155

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