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The title compound, C18H19N3O2, was obtained by an azo-coupling reaction with en­amino­nes and is composed of a planar azoen­amine skeleton which forms a six-membered ring through a symmetrical intramolecular hydrogen bond. The compound was found to exist as an equilibrium mixture of major hydrazoimino and minor azoen­amine tautomers. Quantification of the relative contribution of the tautomeric forms is obscured by the existence of the hydrogen bond. Comparison of the results with those obtained for a similar structure revealed a substantial effect on the tautomeric equilibria of the nature of the substituent bonded to the amine nitro­gen.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101004851/gd1141sup1.cif
Contains datablocks default1, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101004851/gd1141IIsup2.hkl
Contains datablock II

CCDC reference: 166988

Comment top

N-substituted aminoethylene derivatives having carbonyl function(s) in the β-position - known as enaminones - have been extensively investigated in view of their interesting structural characteristics, such as distinct geometric forms and tautomerism (Eberlin et al., 1990). They can also be viewed as push-pull ethylenes, a class of reactive and versatile compounds presenting an unusually low rotational barrier around the CC double bond with an absorption in the near-ultraviolet and visible regions due to the delocalization of π electrons (Wennerbeck, 1973). Therefore, such compounds have found widespread applications in pharmaceutical and medicinal chemistry, e.g. as prodrugs of primary amines or intermediates in preparation of antiulcer and antibacterial drugs (Naringrekar & Stella, 1990; Vishnu, 1980) as well as in chemical industry (organic dyes, agrochemicals). The structural and hence the physicochemical variability of enaminones is even increased upon introduction of an azo group to the β-position of the ethylenic bond; such azo coupling products from enaminones and diazonium ions may in principle exist in tautomeric forms Ia-c. Previous studies have shown that the proportion of individual tautomers depends sensitively on the nature of substituents R1R4; recent results from 13C and 15N NMR spectroscopy have revealed that the title derivative (II; R1 = R2 = Me, R3 = Ph, R4 = 4-methoxyphenyl) exists in CDCl3 solution predominantly in the hydrazo form, (Ib), with a small amount of the azo form, (Ia) (Macháček et al., 2001). To confirm the NMR results and, at the same time, to establish the structural details, a single-crystal X-ray analysis of (II) was undertaken. \sch

The molecular structure together with the atom-numbering scheme is shown in Fig. 1. As can be seen, the azoenamine grouping (atoms N7, N8, C9, C13, N15) in the central part of the molecule adopts a planar [r.m.s. deviation 0.014 (2) Å] chelate-like form and is completed to a six-membered ring through an intramolecular hydrogen bond betweem atoms N7 and N15. The hydrogen bond is symmetrical: the proton H15 was found in the difference Fourier synthesis midway between N7 and N15 and freely refined during the least-squares refinement. The details of this hydrogen bond are: N7···H15 1.35 (3), N15···H15 1.45 (3), N7···N15 2.479 (3) Å, N7···H15···N15 125 (2)°. Of the substituents, the acetyl group and the phenyl ring at N7 are approximately coplanar with the plane of the central six-membered ring, the dihedral angles being 3.5 (2) and 7.3 (2)°, respectively. By contrast, the 4-methoxyphenyl group bonded to the aminic nitrogen (N15) is rotated by 67.7 (1)° from the central molecular plane. Thus, the planarity of the molecule as a whole is perturbed by the 4-methoxyphenyl group.

As noted above, the main purpose of the present work was to identify the tautomer in which the title compound, (II), exists in the solid state (or the percentage of the possible forms Ia-c if it exists as an equilibrium mixture). This can be done crystallographically by determining the bond orders from the bond-length - bond-order curves proposed by Burke-Laing & Laing (1976). The C9—C13 and C13—N15 bond lengths of 1.473 (4) and 1.271 (3) Å (Table 2), respectively, are close to the values reported for a pure Csp2—Csp2 single bond [1.487 (5) Å; Shmueli et al., 1973] and a pure CN double bond (1.27 Å; Burke-Laing & Laing, 1976). These results are consistent with those obtained from the NMR spectroscopy (Macháček et al., 2000) which have indicated that (II) exists in CDCl3 solution as a 90:10 mixture of (Ib):(Ia) [with no contribution of (Ic)]. On the other hand, the N7—N8 and N8—C9 bond distances [1.316 (3) and 1.309 (3) Å, respectively] are both intermediate between single and double bonds (bond orders ca 1.4 and 1.7), assuming values of 1.41, 1.23, 1.45, and 1.27 Å for N—N, NN, C—N, and C N bonds, respectively (Burke-Laing & Laing, 1976). Obviously, if only forms (Ia) and (Ib) contribute to the electronic structure of the molecule, then there is a discrepancy in the indications concerning the position of the imine-enamine and azo-hydrazone tautomerisms. The discrepancy does not seem to be caused by some contribution of the enol form, (Ic), as indicated by a pure single-bond and a pure double-bond character of the C9—C10 and C10—O11 bonds, respectively (Table 2). Instead, the inconsistency most likely originates from the existence of the symmetrical hydrogen bond [i.e. the proton is not bonded to N7 as required by formula (Ib)] which should promote an accumulation of electron density on N7 and subsequently its transfer to the adjacent phenyl ring. Indeed, some degree of conjugation of the hydrazone moiety (atoms N7,N8, C9) with the phenyl ring (which should result in lowering and increasing of C9—N8 and N8—N7 bond orders, respectively) is clearly seen in (I) the coplanarity of the hydrazone group with the phenyl ring, (II) a partial double-bond character of C1—N7, and (II) a non-equivalency of the phenyl-ring C—C bonds (Table 2).

Another purpose of this work was to compare the present results with those of similar structures in order to explore the effects of substituents R1R4 bonded to the azoenamine skeleton on the position of the tautomeric equilibria in the solid state. However, a search of the Cambridge Structural Database (Allen & Kennard, 1993) for structures containing the azoenamine substructure revealed only one compound, ethyl 2-[(E)-5-chloro-2-hydroxy-4-nitrophenylazo]- 3-(E)-amino-2-butenoate (III; Rodrigues et al., 1996). The two compounds, (II) and (III), differ mainly in that (III) contains a primary amine (R4 = H) instead of the 4-methoxyphenylamine group. The principal characteristics of the two structures are the same with the exception that in (III) the proton remains bonded to the amine nitrogen, i.e. the compound exists predominantly as the azo-enamine tautomer, (Ia). Thus, based on the results obtained from (II) and (III) it may be concluded that the position of the tautomeric equilibria is a sensitive function of the substituents bonded to the terminal azo and amine N atoms (R3, R4).

As the only hydrogen bond donor of the molecule is involved in the intramolecular hydrogen bond, the intermolecular packing is governed by van der Waals interactions.

Related literature top

For related literature, see: Allen & Kennard (1993); Eberlin et al. (1990); Macháček et al. (2001); Naringrekar & Stella (1990); Rodrigues et al. (1996); Shmueli et al. (1973); Vishnu (1980); Wennerbeck (1973).

Experimental top

Compound (II) was prepared by the following procedure: aniline (0.93 g, 10 mmol) in tetrafluoroboric acid (10 ml of ca 30% HBF4) was diazotized by adding a solution of sodium nitrite (0.69 g, 10 mmol) in water (5 ml). After several minutes, sodium tetrafluoroborate (1 g, 9 mmol) was added, the suspension of benzenediazonium tetrafluoroborate formed was mixed, the precipitated solid collected by suction and thoroughly pressed on a small sintered-glass filter. The almost dry product was added portion-wise to a solution of 4-(4-methoxyphenylamino)pent-3-ene-2-one (2.26 g, 11 mmol) in diisopropyl ether (15 ml). The mixture was stirred at 273 K for 2 h, whereupon the solid was collected by suction, resuspended in ca 10 ml chloroform-ethyl acetate mixture (1:1) and transferred on a silica gel column. The product was eluted by the same solvent mixture. The fraction containing the product along with the unreacted enaminone was subjected to vacuum distillation to remove the solvent, and the residue was repeatedly triturated with hexane. The less hexane-soluble residue was again submitted to chromatography on a silica gel column with chloroform-ethyl acetate mixture (1:1). Finally, the product was recrystallized from cyclohexane (m.p. 411–413 K).

Refinement top

H atoms were treated as riding, with Uiso set to 1.2 (1.5 for the methyl H atoms) times Ueq of the parent atom, except for H15 which was fully refined with respect to positional and Uiso parameters.

Computing details top

Data collection: Syntex P21 diffractometer software (Pavelčík, 1987); cell refinement: Syntex P21 diffractometer software; data reduction: XP21 (Pavelčík, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. A view of the title molecule showing the labelling of the non-H atoms. Displacement ellipsoids are shown at the 35% probability level and H atoms are drawn as small circles of arbitrary radii. Dashed lines indicate symmetrical intramolecular hydrogen bonds.
3-Phenylazo-2-(4-methoxyphenylamino)-2-penten-4-one top
Crystal data top
C18H19N3O2Dx = 1.264 Mg m3
Dm = 1.27 (1) Mg m3
Dm measured by flotation in bromoform/cyclohexane
Mr = 309.36Melting point: 412 K
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 11.525 (5) ÅCell parameters from 15 reflections
b = 14.465 (6) Åθ = 7–18°
c = 9.761 (3) ŵ = 0.08 mm1
β = 92.82 (4)°T = 293 K
V = 1625.3 (11) Å3Plate, yellow
Z = 40.30 × 0.25 × 0.10 mm
F(000) = 656
Data collection top
Syntex P21
diffractometer
Rint = 0.049
Radiation source: fine-focus sealed tubeθmax = 25.1°, θmin = 1.8°
Graphite monochromatorh = 130
θ/2θ scansk = 017
3054 measured reflectionsl = 1111
2890 independent reflections2 standard reflections every 98 reflections
1319 reflections with I > 2σ(I) intensity decay: 4%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.070Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.139H atoms treated by a mixture of independent and constrained refinement
S = 0.93 w = 1/[σ2(Fo2) + (0.0433P)2]
where P = (Fo2 + 2Fc2)/3
2890 reflections(Δ/σ)max = 0.002
215 parametersΔρmax = 0.11 e Å3
0 restraintsΔρmin = 0.12 e Å3
Crystal data top
C18H19N3O2V = 1625.3 (11) Å3
Mr = 309.36Z = 4
Monoclinic, P21/cMo Kα radiation
a = 11.525 (5) ŵ = 0.08 mm1
b = 14.465 (6) ÅT = 293 K
c = 9.761 (3) Å0.30 × 0.25 × 0.10 mm
β = 92.82 (4)°
Data collection top
Syntex P21
diffractometer
Rint = 0.049
3054 measured reflections2 standard reflections every 98 reflections
2890 independent reflections intensity decay: 4%
1319 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0700 restraints
wR(F2) = 0.139H atoms treated by a mixture of independent and constrained refinement
S = 0.93Δρmax = 0.11 e Å3
2890 reflectionsΔρmin = 0.12 e Å3
215 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.6983 (3)0.97733 (19)0.1612 (3)0.0525 (9)
C20.7262 (3)1.0639 (2)0.2188 (3)0.0625 (10)
H20.66801.10190.25000.075*
C30.8417 (3)1.0922 (2)0.2287 (3)0.0607 (9)
H30.86111.14880.26880.073*
C40.9270 (3)1.0369 (2)0.1796 (3)0.0624 (9)
H41.00351.05760.18310.075*
C50.9009 (3)0.9522 (2)0.1258 (3)0.0603 (10)
H50.95970.91400.09660.072*
C60.7841 (3)0.9225 (2)0.1145 (3)0.0541 (9)
H60.76560.86550.07520.065*
N70.58126 (19)0.95294 (17)0.1578 (2)0.0454 (7)
N80.55000 (19)0.87400 (16)0.1000 (2)0.0457 (7)
C90.4402 (2)0.8507 (2)0.1000 (3)0.0481 (8)
C100.4202 (3)0.7588 (2)0.0333 (3)0.0523 (9)
O110.3278 (2)0.71984 (16)0.0303 (3)0.1059 (10)
C120.5196 (3)0.7141 (2)0.0345 (4)0.0879 (12)
H12A0.58050.70050.03310.132*
H12B0.54840.75530.10200.132*
H12C0.49350.65780.07820.132*
C130.3489 (2)0.9028 (2)0.1669 (3)0.0461 (8)
C140.2265 (2)0.8675 (2)0.1566 (3)0.0638 (10)
H14A0.22190.81070.20720.096*
H14B0.20360.85650.06210.096*
H14C0.17570.91250.19410.096*
N150.37957 (19)0.97722 (16)0.2277 (2)0.0456 (7)
H150.503 (3)0.995 (2)0.235 (3)0.120 (12)*
C160.2957 (2)1.0332 (2)0.2927 (3)0.0454 (8)
C170.2460 (3)1.0090 (2)0.4108 (3)0.0636 (10)
H170.26310.95180.45060.076*
C180.1697 (2)1.0687 (2)0.4731 (3)0.0569 (9)
H180.13601.05210.55420.068*
C190.1452 (3)1.1529 (2)0.4119 (4)0.0590 (10)
C200.1978 (3)1.1773 (2)0.2932 (3)0.0644 (10)
H200.18071.23380.25150.077*
C210.2751 (2)1.1184 (2)0.2368 (3)0.0586 (9)
H210.31391.13660.15990.070*
O220.06806 (18)1.21518 (14)0.4597 (2)0.0770 (7)
C230.0094 (2)1.18568 (19)0.5605 (4)0.0714 (11)
H23A0.06451.23390.57620.107*
H23B0.03391.17210.64460.107*
H23C0.05001.13120.52870.107*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.056 (2)0.0324 (19)0.069 (2)0.0064 (16)0.0055 (18)0.0121 (17)
C20.039 (2)0.070 (2)0.079 (3)0.0056 (16)0.0113 (18)0.002 (2)
C30.064 (2)0.049 (2)0.070 (3)0.0104 (18)0.015 (2)0.0175 (19)
C40.063 (2)0.062 (2)0.062 (2)0.0142 (19)0.0026 (19)0.006 (2)
C50.066 (2)0.066 (2)0.049 (2)0.0209 (18)0.0157 (19)0.0100 (19)
C60.052 (2)0.058 (2)0.052 (2)0.0055 (17)0.0027 (18)0.0086 (17)
N70.0356 (14)0.0576 (16)0.0439 (17)0.0232 (12)0.0120 (12)0.0028 (13)
N80.0427 (15)0.0389 (14)0.0545 (18)0.0025 (12)0.0063 (13)0.0051 (13)
C90.0416 (19)0.053 (2)0.049 (2)0.0174 (16)0.0004 (16)0.0040 (16)
C100.0539 (19)0.0397 (19)0.063 (2)0.0066 (16)0.0007 (19)0.0003 (17)
O110.0709 (16)0.0846 (18)0.164 (3)0.0283 (14)0.0229 (18)0.0453 (19)
C120.065 (2)0.091 (3)0.109 (3)0.012 (2)0.007 (2)0.041 (3)
C130.0350 (17)0.0443 (19)0.059 (2)0.0272 (15)0.0005 (16)0.0094 (17)
C140.0419 (18)0.067 (2)0.082 (3)0.0021 (16)0.0025 (18)0.005 (2)
N150.0320 (14)0.0431 (16)0.0604 (19)0.0080 (12)0.0094 (13)0.0027 (14)
C160.056 (2)0.0377 (18)0.042 (2)0.0041 (15)0.0098 (17)0.0109 (16)
C170.067 (2)0.071 (2)0.053 (2)0.0060 (18)0.0068 (19)0.023 (2)
C180.059 (2)0.058 (2)0.056 (2)0.0032 (17)0.0255 (18)0.0011 (19)
C190.058 (2)0.0317 (18)0.089 (3)0.0066 (15)0.019 (2)0.021 (2)
C200.060 (2)0.071 (2)0.064 (3)0.0157 (18)0.016 (2)0.009 (2)
C210.059 (2)0.055 (2)0.064 (2)0.0007 (17)0.0183 (18)0.002 (2)
O220.0817 (16)0.0501 (14)0.1017 (19)0.0072 (13)0.0286 (15)0.0179 (14)
C230.053 (2)0.055 (2)0.107 (3)0.0091 (16)0.009 (2)0.001 (2)
Geometric parameters (Å, º) top
C1—C61.362 (4)C13—N151.271 (3)
C1—N71.394 (3)C13—C141.499 (3)
C1—C21.403 (4)C14—H14A0.9600
C2—C31.392 (4)C14—H14B0.9600
C2—H20.9300C14—H14C0.9600
C3—C41.372 (4)N15—C161.433 (3)
C3—H30.9300N15—H151.45 (3)
C4—C51.362 (4)C16—C171.359 (4)
C4—H40.9300C16—C211.364 (3)
C5—C61.412 (4)C17—C181.393 (4)
C5—H50.9300C17—H170.9300
C6—H60.9300C18—C191.381 (4)
N7—N81.316 (3)C18—H180.9300
N7—H151.35 (3)C19—O221.364 (3)
N8—C91.309 (3)C19—C201.379 (4)
C9—C131.473 (4)C20—C211.367 (4)
C9—C101.493 (4)C20—H200.9300
C10—O111.204 (3)C21—H210.9300
C10—C121.498 (4)O22—C231.426 (3)
C12—H12A0.9600C23—H23A0.9600
C12—H12B0.9600C23—H23B0.9600
C12—H12C0.9600C23—H23C0.9600
C6—C1—N7124.2 (3)C9—C13—C14119.1 (3)
C6—C1—C2119.9 (3)C13—C14—H14A109.5
N7—C1—C2115.9 (3)C13—C14—H14B109.5
C3—C2—C1119.3 (3)H14A—C14—H14B109.5
C3—C2—H2120.4C13—C14—H14C109.5
C1—C2—H2120.4H14A—C14—H14C109.5
C4—C3—C2120.3 (3)H14B—C14—H14C109.5
C4—C3—H3119.9C13—N15—C16120.5 (2)
C2—C3—H3119.9C13—N15—H15115.3 (12)
C5—C4—C3120.7 (3)C16—N15—H15124.0 (13)
C5—C4—H4119.7C17—C16—C21120.0 (3)
C3—C4—H4119.7C17—C16—N15123.5 (3)
C4—C5—C6119.7 (3)C21—C16—N15116.2 (3)
C4—C5—H5120.2C16—C17—C18120.8 (3)
C6—C5—H5120.2C16—C17—H17119.6
C1—C6—C5120.1 (3)C18—C17—H17119.6
C1—C6—H6119.9C19—C18—C17118.6 (3)
C5—C6—H6119.9C19—C18—H18120.7
N8—N7—C1118.3 (2)C17—C18—H18120.7
N8—N7—H15117.3 (14)O22—C19—C20116.1 (3)
C1—N7—H15122.8 (14)O22—C19—C18123.9 (3)
C9—N8—N7117.8 (2)C20—C19—C18120.0 (3)
N8—C9—C13125.4 (3)C21—C20—C19120.1 (3)
N8—C9—C10110.9 (3)C21—C20—H20120.0
C13—C9—C10123.4 (3)C19—C20—H20120.0
O11—C10—C9123.0 (3)C16—C21—C20120.4 (3)
O11—C10—C12118.8 (3)C16—C21—H21119.8
C9—C10—C12118.2 (3)C20—C21—H21119.8
C10—C12—H12A109.5C19—O22—C23118.7 (2)
C10—C12—H12B109.5O22—C23—H23A109.5
H12A—C12—H12B109.5O22—C23—H23B109.5
C10—C12—H12C109.5H23A—C23—H23B109.5
H12A—C12—H12C109.5O22—C23—H23C109.5
H12B—C12—H12C109.5H23A—C23—H23C109.5
N15—C13—C9116.9 (2)H23B—C23—H23C109.5
N15—C13—C14124.0 (3)
C6—C1—C2—C30.7 (5)N8—C9—C13—C14179.5 (3)
N7—C1—C2—C3178.5 (3)C10—C9—C13—C146.2 (4)
C1—C2—C3—C41.6 (5)C9—C13—N15—C16178.6 (2)
C2—C3—C4—C52.8 (5)C14—C13—N15—C160.3 (4)
C3—C4—C5—C63.0 (5)C13—N15—C16—C1772.1 (4)
N7—C1—C6—C5178.2 (3)C13—N15—C16—C21114.1 (3)
C2—C1—C6—C50.9 (5)C21—C16—C17—C182.8 (5)
C4—C5—C6—C12.0 (5)N15—C16—C17—C18176.5 (3)
C6—C1—N7—N83.4 (4)C16—C17—C18—C190.3 (5)
C2—C1—N7—N8177.4 (3)C17—C18—C19—O22176.9 (3)
C1—N7—N8—C9178.5 (3)C17—C18—C19—C201.4 (5)
N7—N8—C9—C133.9 (4)O22—C19—C20—C21179.1 (3)
N7—N8—C9—C10178.8 (2)C18—C19—C20—C210.7 (5)
N8—C9—C10—O11174.3 (3)C17—C16—C21—C204.9 (5)
C13—C9—C10—O110.7 (5)N15—C16—C21—C20179.0 (3)
N8—C9—C10—C126.6 (4)C19—C20—C21—C163.8 (5)
C13—C9—C10—C12178.4 (3)C20—C19—O22—C23164.9 (3)
N8—C9—C13—N151.1 (4)C18—C19—O22—C2313.5 (5)
C10—C9—C13—N15175.4 (3)

Experimental details

Crystal data
Chemical formulaC18H19N3O2
Mr309.36
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)11.525 (5), 14.465 (6), 9.761 (3)
β (°) 92.82 (4)
V3)1625.3 (11)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.30 × 0.25 × 0.10
Data collection
DiffractometerSyntex P21
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
3054, 2890, 1319
Rint0.049
(sin θ/λ)max1)0.596
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.070, 0.139, 0.93
No. of reflections2890
No. of parameters215
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.11, 0.12

Computer programs: Syntex P21 diffractometer software (Pavelčík, 1987), Syntex P21 diffractometer software, XP21 (Pavelčík, 1987), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXL97.

Selected geometric parameters (Å, º) top
C1—C61.362 (4)N7—N81.316 (3)
C1—N71.394 (3)N8—C91.309 (3)
C1—C21.403 (4)C9—C131.473 (4)
C2—C31.392 (4)C9—C101.493 (4)
C3—C41.372 (4)C10—O111.204 (3)
C4—C51.362 (4)C13—N151.271 (3)
C5—C61.412 (4)N15—C161.433 (3)
C6—C1—N7124.2 (3)C13—C9—C10123.4 (3)
C6—C1—C2119.9 (3)O11—C10—C9123.0 (3)
N7—C1—C2115.9 (3)N15—C13—C9116.9 (2)
N8—N7—C1118.3 (2)N15—C13—C14124.0 (3)
C9—N8—N7117.8 (2)C9—C13—C14119.1 (3)
N8—C9—C13125.4 (3)C13—N15—C16120.5 (2)
N8—C9—C10110.9 (3)
C6—C1—N7—N83.4 (4)N8—C9—C13—C14179.5 (3)
C1—N7—N8—C9178.5 (3)C10—C9—C13—C146.2 (4)
N7—N8—C9—C133.9 (4)C9—C13—N15—C16178.6 (2)
N7—N8—C9—C10178.8 (2)C13—N15—C16—C1772.1 (4)
N8—C9—C13—N151.1 (4)C20—C19—O22—C23164.9 (3)
 

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