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ISSN: 2056-9890

2′-Methyl­pyrazolo[4′,3′:16,17]androst-5-en-3β-ol

aDepartment of Medicinal Chemistry, School of Pharmacy, Fudan University, 138 Yixueyuan Road Shanghai 200032, People's Republic of China
*Correspondence e-mail: yingchen71@fudan.edu.cn

(Received 15 May 2009; accepted 22 May 2009; online 29 May 2009)

In the title compound, C21H30N2O, there are five fused rings. The A and C rings adopt chair conformations, ring B adopts an 8β,9α-half-chair conformation and ring D adopts a 14α-envelope conformation. The pyrazole ring is planar. Inter­molecular O—H⋯N hydrogen bonds [H⋯N = 1.88 (5) Å] help to stabilize the crystal structure. The absolute structure was deduced from those of the starting materials.

Related literature

For general background, see: Kashiwada et al. (1996[Kashiwada, Y., Hashimoto, F. & Cosentino, L. M. (1996). J. Med. Chem. 39, 1016-1017.]); Spek (2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

[Scheme 1]

Experimental

Crystal data
  • C21H30N2O

  • Mr = 326.47

  • Orthorhombic, P 21 21 2

  • a = 11.779 (4) Å

  • b = 27.996 (10) Å

  • c = 6.361 (2) Å

  • V = 2097.6 (12) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.06 mm−1

  • T = 293 K

  • 0.20 × 0.10 × 0.08 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.988, Tmax = 0.995

  • 10038 measured reflections

  • 2633 independent reflections

  • 1670 reflections with I > 2σ(I)

  • Rint = 0.089

Refinement
  • R[F2 > 2σ(F2)] = 0.065

  • wR(F2) = 0.178

  • S = 0.99

  • 2633 reflections

  • 224 parameters

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

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.15 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯N2i 0.96 (5) 1.88 (6) 2.813 (5) 163 (5)
Symmetry code: (i) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z].

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The 3-O-(2',2'-dimethylsuccinyl)-betulinic acid, a derivative of natural product betulinic acid, was identified as a potent anti-HIV (human immunodificiency virus) agent with remarkable active value (Kashiwada et al., 1996). Based on the structure and bioactivity of 3-O-(2',2'-dimethylsuccinyl)-betulinic acid, we tried to synthesize some of its steroidal analogs with a heterocycle fused E ring. During synthesizing a target compound 3β-O-(2'',2''-dimethylsuccinyl)-4,4-dimethyl-androst-[17,16- c]-(2'-methyl)pyrazole, an important intermediate, 3β-hydroxy-androst-5-en-[17,16-c]-(2'-methyl)pyrazole, was obtained and its molecular structure was reported here.

Fig.1 shows the molecular structure of the title compound. This compound is a five-ring-fused compound. Ring A and ring C adopt chair conformations in each molecule. The C5–C6 distance of 1.340 (5) Å conform the localization of a double bond at this position. As a result of this double bond, the geometry around C5 is planar and hence ring B adopt 8β,9α-half-chair conformation. The ring D assumes 14α-envelope conformation. The pyrazole E ring is essentially planar. Intermolecular O1–H1···N2i hydrogen bond with parameters O1–H1 = 0.96 (5)Å, H1···N2i = 1.88 (6)Å, O1···N2i = 2.813 (5)Å and angle O1–H1···N2i = 163 (5)° (symmetry code: (i) -x+3/2, y+1/2, -z) help to stablize the crystal structure.

Related literature top

For general background, see: Kashiwada et al. (1996); Spek (2009).

Experimental top

3β-Hydroxy-16-hydroxymethylene-androst-5-en-17-one (500 mg, 1.58 mmol) was dissolved in 10 ml EtOH, and methylhydrazine (120 mg, 2.61 mmol) was added. The resulting mixture was stirred for 2 h at room temperature, and 100 ml H2O was added. After filtered, washed with water and dried, crude product of title compound (520 mg) was got. The crude product was purified by chromatography with petroleum ether/ EtOAc (10:3) as eluent and recrystallized from tetrahydrofuran to obtain its single-crystal for X-ray diffraction analysis.

Refinement top

All H atoms except H1 were positioned geometrically and refined using a riding model with C–H = 0.93Å for aromatic H atoms and C–H = 0.96Å for methyl H atoms, and refine in riding mode with Uiso(H) = 1.2Ueq(C) for aromatic H atoms and Uiso(H) = 1.5Ueq(C) for methyl H atoms. H1 had been found on the different Fourier map and refined without bond restrain. In the absence of significant anomalous scattering, 845 Friedel pairs were merged and all Δf" values to be set to zero.

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with the atom numbering scheme. The displacement ellipsoids are drawn at the 50% probability level. The H atoms are presented as a small spheres of arbitrary radius.
2'-Methylpyrazolo[4',3':16,17]androst-5-en-3β-ol top
Crystal data top
C21H30N2OF(000) = 712
Mr = 326.47Dx = 1.034 Mg m3
Orthorhombic, P21212Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2 2abCell parameters from 985 reflections
a = 11.779 (4) Åθ = 2.3–21.3°
b = 27.996 (10) ŵ = 0.06 mm1
c = 6.361 (2) ÅT = 293 K
V = 2097.6 (12) Å3Column, colourless
Z = 40.20 × 0.10 × 0.08 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
2633 independent reflections
Radiation source: fine-focus sealed tube1670 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.089
ϕ and ω scansθmax = 27.1°, θmin = 1.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1115
Tmin = 0.988, Tmax = 0.995k = 3527
10038 measured reflectionsl = 88
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.065H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.178 w = 1/[σ2(Fo2) + (0.097P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.99(Δ/σ)max < 0.001
2633 reflectionsΔρmax = 0.26 e Å3
224 parametersΔρmin = 0.15 e Å3
0 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0 (10)
Crystal data top
C21H30N2OV = 2097.6 (12) Å3
Mr = 326.47Z = 4
Orthorhombic, P21212Mo Kα radiation
a = 11.779 (4) ŵ = 0.06 mm1
b = 27.996 (10) ÅT = 293 K
c = 6.361 (2) Å0.20 × 0.10 × 0.08 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
2633 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1670 reflections with I > 2σ(I)
Tmin = 0.988, Tmax = 0.995Rint = 0.089
10038 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.065H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.178Δρmax = 0.26 e Å3
S = 0.99Δρmin = 0.15 e Å3
2633 reflectionsAbsolute structure: Flack (1983)
224 parametersAbsolute structure parameter: 0 (10)
0 restraints
Special details top

Experimental. Compound contains disordered unassigned solvent (tetrahydrofuran), which was SQEEZED with program PLATON (Spek, 2003). Solvent is not contained in chemical formula and quantities derived thereof. Informations on the SQUEEZE procedure are given subsequently.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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
xyzUiso*/Ueq
O10.8092 (3)0.49975 (10)0.3404 (5)0.0957 (11)
H10.809 (4)0.5288 (17)0.261 (10)0.114 (16)*
N10.7846 (3)0.11087 (10)0.1171 (5)0.0720 (9)
N20.7158 (4)0.07461 (12)0.0492 (6)0.0859 (11)
C10.8428 (4)0.38834 (12)0.0088 (6)0.0682 (10)
H1A0.89830.37970.09730.082*
H1B0.76860.38840.05730.082*
C20.8696 (4)0.43932 (13)0.0914 (7)0.0774 (12)
H2A0.94550.44000.15030.093*
H2B0.86670.46190.02410.093*
C30.7851 (4)0.45347 (13)0.2566 (7)0.0740 (11)
H30.70900.45370.19450.089*
C40.7871 (4)0.41834 (13)0.4390 (7)0.0746 (11)
H4A0.86020.42000.50890.090*
H4B0.72900.42710.54010.090*
C50.7665 (3)0.36782 (12)0.3634 (6)0.0583 (9)
C60.6856 (3)0.34023 (13)0.4488 (6)0.0674 (10)
H60.63890.35400.55000.081*
C70.6648 (3)0.28952 (13)0.3943 (6)0.0613 (9)
H7A0.59580.28730.31180.074*
H7B0.65360.27140.52250.074*
C80.7623 (3)0.26762 (10)0.2707 (5)0.0482 (8)
H80.82700.26270.36500.058*
C90.7973 (3)0.30251 (11)0.0934 (5)0.0496 (8)
H90.72690.31100.02040.060*
C100.8443 (3)0.35012 (11)0.1862 (5)0.0513 (8)
C110.8757 (3)0.28075 (12)0.0755 (6)0.0610 (9)
H11A0.87660.30190.19630.073*
H11B0.95230.27950.01990.073*
C120.8425 (3)0.23078 (12)0.1496 (5)0.0578 (9)
H12A0.90170.21810.23960.069*
H12B0.77300.23250.23090.069*
C130.8252 (3)0.19741 (12)0.0396 (5)0.0508 (8)
C140.7296 (3)0.22009 (12)0.1721 (5)0.0497 (8)
H140.66980.22790.07070.060*
C150.6785 (3)0.17936 (12)0.3103 (6)0.0609 (10)
H15A0.72040.17510.44030.073*
H15B0.59890.18480.34150.073*
C160.6951 (3)0.13810 (12)0.1623 (6)0.0619 (9)
C170.7721 (3)0.14936 (12)0.0079 (6)0.0598 (9)
C180.9367 (3)0.19017 (13)0.1615 (7)0.0654 (10)
H18A0.92130.17350.29040.098*
H18B0.96980.22070.19250.098*
H18C0.98850.17180.07770.098*
C190.9641 (3)0.34398 (13)0.2742 (7)0.0667 (10)
H19A0.96520.31750.37030.100*
H19B0.98620.37260.34660.100*
H19C1.01600.33790.16090.100*
C200.6632 (4)0.09124 (14)0.1184 (8)0.0744 (11)
H200.61130.07380.19750.089*
C210.8604 (5)0.10396 (15)0.2928 (8)0.0969 (16)
H21A0.91340.13000.29910.145*
H21B0.81730.10280.42070.145*
H21C0.90100.07450.27530.145*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.149 (3)0.0445 (15)0.094 (2)0.0112 (17)0.004 (2)0.0059 (15)
N10.106 (2)0.0424 (17)0.067 (2)0.0002 (17)0.002 (2)0.0005 (14)
N20.128 (3)0.0485 (19)0.081 (3)0.006 (2)0.010 (2)0.0001 (17)
C10.094 (3)0.053 (2)0.058 (2)0.0022 (19)0.001 (2)0.0149 (17)
C20.117 (3)0.051 (2)0.065 (3)0.000 (2)0.002 (2)0.0167 (18)
C30.103 (3)0.049 (2)0.070 (3)0.014 (2)0.002 (2)0.0118 (18)
C40.107 (3)0.051 (2)0.066 (3)0.007 (2)0.007 (2)0.0039 (18)
C50.077 (2)0.052 (2)0.0456 (19)0.0034 (18)0.0003 (18)0.0079 (15)
C60.079 (2)0.063 (2)0.061 (2)0.0153 (19)0.0104 (19)0.0022 (18)
C70.0549 (18)0.062 (2)0.067 (2)0.0033 (16)0.0072 (17)0.0038 (17)
C80.0528 (17)0.0477 (18)0.0443 (18)0.0005 (13)0.0003 (15)0.0059 (13)
C90.0541 (17)0.0499 (18)0.0448 (19)0.0011 (14)0.0031 (14)0.0082 (14)
C100.0623 (19)0.0460 (18)0.046 (2)0.0007 (15)0.0033 (15)0.0095 (14)
C110.075 (2)0.059 (2)0.049 (2)0.0049 (18)0.0132 (17)0.0069 (16)
C120.068 (2)0.062 (2)0.043 (2)0.0023 (16)0.0073 (17)0.0037 (15)
C130.0562 (17)0.0490 (19)0.0472 (19)0.0049 (15)0.0012 (14)0.0024 (14)
C140.0499 (17)0.0526 (18)0.0466 (19)0.0060 (15)0.0022 (14)0.0063 (14)
C150.066 (2)0.056 (2)0.060 (2)0.0136 (16)0.0087 (17)0.0066 (17)
C160.068 (2)0.047 (2)0.071 (3)0.0079 (16)0.0052 (19)0.0035 (17)
C170.070 (2)0.052 (2)0.057 (2)0.0006 (17)0.0049 (19)0.0013 (16)
C180.0574 (19)0.066 (2)0.073 (3)0.0055 (17)0.0036 (18)0.008 (2)
C190.063 (2)0.065 (2)0.072 (3)0.0086 (18)0.0060 (19)0.0068 (19)
C200.086 (3)0.058 (2)0.079 (3)0.013 (2)0.008 (2)0.013 (2)
C210.159 (4)0.061 (3)0.071 (3)0.004 (3)0.025 (3)0.004 (2)
Geometric parameters (Å, º) top
O1—C31.429 (5)C9—C101.559 (5)
O1—H10.96 (5)C9—H90.9800
N1—C171.347 (5)C10—C191.527 (5)
N1—N21.369 (5)C11—C121.527 (5)
N1—C211.443 (6)C11—H11A0.9700
N2—C201.317 (6)C11—H11B0.9700
C1—C21.553 (5)C12—C131.537 (5)
C1—C101.555 (4)C12—H12A0.9700
C1—H1A0.9700C12—H12B0.9700
C1—H1B0.9700C13—C171.497 (5)
C2—C31.501 (6)C13—C181.538 (5)
C2—H2A0.9700C13—C141.543 (4)
C2—H2B0.9700C14—C151.560 (4)
C3—C41.521 (6)C14—H140.9800
C3—H30.9800C15—C161.503 (5)
C4—C51.513 (5)C15—H15A0.9700
C4—H4A0.9700C15—H15B0.9700
C4—H4B0.9700C16—C171.374 (5)
C5—C61.341 (5)C16—C201.393 (5)
C5—C101.535 (5)C18—H18A0.9600
C6—C71.482 (5)C18—H18B0.9600
C6—H60.9300C18—H18C0.9600
C7—C81.520 (5)C19—H19A0.9600
C7—H7A0.9700C19—H19B0.9600
C7—H7B0.9700C19—H19C0.9600
C8—C141.521 (4)C20—H200.9300
C8—C91.548 (4)C21—H21A0.9600
C8—H80.9800C21—H21B0.9600
C9—C111.542 (5)C21—H21C0.9600
C3—O1—H1125 (3)C1—C10—C9108.0 (3)
C17—N1—N2110.0 (3)C12—C11—C9115.1 (3)
C17—N1—C21129.2 (3)C12—C11—H11A108.5
N2—N1—C21120.7 (3)C9—C11—H11A108.5
C20—N2—N1105.8 (3)C12—C11—H11B108.5
C2—C1—C10112.6 (3)C9—C11—H11B108.5
C2—C1—H1A109.1H11A—C11—H11B107.5
C10—C1—H1A109.1C11—C12—C13110.4 (3)
C2—C1—H1B109.1C11—C12—H12A109.6
C10—C1—H1B109.1C13—C12—H12A109.6
H1A—C1—H1B107.8C11—C12—H12B109.6
C3—C2—C1110.2 (3)C13—C12—H12B109.6
C3—C2—H2A109.6H12A—C12—H12B108.1
C1—C2—H2A109.6C17—C13—C12119.7 (3)
C3—C2—H2B109.6C17—C13—C18107.8 (3)
C1—C2—H2B109.6C12—C13—C18111.2 (3)
H2A—C2—H2B108.1C17—C13—C1497.9 (3)
O1—C3—C2111.6 (3)C12—C13—C14105.9 (3)
O1—C3—C4107.4 (4)C18—C13—C14113.7 (3)
C2—C3—C4110.7 (3)C8—C14—C13113.6 (2)
O1—C3—H3109.0C8—C14—C15120.3 (3)
C2—C3—H3109.0C13—C14—C15106.8 (3)
C4—C3—H3109.0C8—C14—H14104.9
C5—C4—C3111.1 (3)C13—C14—H14104.9
C5—C4—H4A109.4C15—C14—H14104.9
C3—C4—H4A109.4C16—C15—C1499.1 (3)
C5—C4—H4B109.4C16—C15—H15A111.9
C3—C4—H4B109.4C14—C15—H15A111.9
H4A—C4—H4B108.0C16—C15—H15B111.9
C6—C5—C4121.6 (3)C14—C15—H15B111.9
C6—C5—C10122.4 (3)H15A—C15—H15B109.6
C4—C5—C10116.0 (3)C17—C16—C20104.5 (4)
C5—C6—C7125.1 (3)C17—C16—C15110.9 (3)
C5—C6—H6117.5C20—C16—C15144.6 (4)
C7—C6—H6117.5N1—C17—C16108.1 (3)
C6—C7—C8112.5 (3)N1—C17—C13138.8 (4)
C6—C7—H7A109.1C16—C17—C13112.7 (3)
C8—C7—H7A109.1C13—C18—H18A109.5
C6—C7—H7B109.1C13—C18—H18B109.5
C8—C7—H7B109.1H18A—C18—H18B109.5
H7A—C7—H7B107.8C13—C18—H18C109.5
C7—C8—C14112.0 (3)H18A—C18—H18C109.5
C7—C8—C9108.9 (3)H18B—C18—H18C109.5
C14—C8—C9108.6 (3)C10—C19—H19A109.5
C7—C8—H8109.1C10—C19—H19B109.5
C14—C8—H8109.1H19A—C19—H19B109.5
C9—C8—H8109.1C10—C19—H19C109.5
C11—C9—C8114.7 (3)H19A—C19—H19C109.5
C11—C9—C10112.9 (3)H19B—C19—H19C109.5
C8—C9—C10111.0 (3)N2—C20—C16111.6 (4)
C11—C9—H9105.8N2—C20—H20124.2
C8—C9—H9105.8C16—C20—H20124.2
C10—C9—H9105.8N1—C21—H21A109.5
C19—C10—C5108.6 (3)N1—C21—H21B109.5
C19—C10—C1110.7 (3)H21A—C21—H21B109.5
C5—C10—C1107.7 (3)N1—C21—H21C109.5
C19—C10—C9111.7 (3)H21A—C21—H21C109.5
C5—C10—C9110.0 (3)H21B—C21—H21C109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N2i0.96 (5)1.88 (6)2.813 (5)163 (5)
Symmetry code: (i) x+3/2, y+1/2, z.

Experimental details

Crystal data
Chemical formulaC21H30N2O
Mr326.47
Crystal system, space groupOrthorhombic, P21212
Temperature (K)293
a, b, c (Å)11.779 (4), 27.996 (10), 6.361 (2)
V3)2097.6 (12)
Z4
Radiation typeMo Kα
µ (mm1)0.06
Crystal size (mm)0.20 × 0.10 × 0.08
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.988, 0.995
No. of measured, independent and
observed [I > 2σ(I)] reflections
10038, 2633, 1670
Rint0.089
(sin θ/λ)max1)0.640
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.065, 0.178, 0.99
No. of reflections2633
No. of parameters224
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.26, 0.15
Absolute structureFlack (1983)
Absolute structure parameter0 (10)

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N2i0.96 (5)1.88 (6)2.813 (5)163 (5)
Symmetry code: (i) x+3/2, y+1/2, z.
 

Acknowledgements

The authors acknowledge Miss Wang Jingmei, Center of Analysis and Measurement, Fudan University, for her help with the crystal structure analysis.

References

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First citationKashiwada, Y., Hashimoto, F. & Cosentino, L. M. (1996). J. Med. Chem. 39, 1016–1017.  CrossRef CAS PubMed Web of Science Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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