(2E)-1-Phenyl-2-[1-(2-phenyl­prop-2-en-1-yl)pyrrolidin-2-yl­idene]ethanone

Madeley, L.G.; Morgans, G.L.; Lemmerer, A.; Michael, J.P.

doi:10.1107/S1600536812044443

organic compounds

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Volume 68| Part 12| December 2012| Page o3281

doi:10.1107/S1600536812044443

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(2E)-1-Phenyl-2-[1-(2-phenylprop-2-en-1-yl)pyrrolidin-2-ylidene]ethanone

Lee G. Madeley,^a Garreth L. Morgans,^a Andreas Lemmerer ^a and Joseph P. Michael ^a ^*

^aMolecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, PO WITS, 2050, Johannesburg, South Africa
^*Correspondence e-mail: joseph.michael@wits.ac.za

(Received 17 October 2012; accepted 26 October 2012; online 3 November 2012)

The title compound, C₂₁H₂₁NO, is a vinylogous amide (enaminone) produced by reaction of 1-(2-phenylprop-2-en-1-yl)pyrrolidine-2-thione with phenacyl bromide. In the molecule, the phenyl rings are twisted from the mean plane of the pyrrolidine ring by 11.2 (1) and 67.3 (1)°. In the crystal, weak C—H⋯O hydrogen bonds link the molecules related by translation along the b axis into chains.

Related literature

For details of the synthesis of enaminones, see: Roth et al. (1971 ). For applications of enaminones in alkaloid synthesis, see: Michael et al. (1999 ). For a related enaminone structure, see: Lemmerer et al. (2007 ).

Experimental

Crystal data

C₂₁H₂₁NO
M_r = 303.39
Triclinic, P 1
a = 5.7806 (6) Å
b = 7.9407 (7) Å
c = 9.6089 (9) Å
α = 82.579 (7)°
β = 76.793 (7)°
γ = 83.510 (7)°
V = 424.21 (7) Å³
Z = 1
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 K
0.4 × 0.2 × 0.19 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
5222 measured reflections
1563 independent reflections
970 reflections with I > 2σ(I)
R_int = 0.040

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.119
S = 0.98
1563 reflections
208 parameters
3 restraints
H-atom parameters constrained
Δρ_max = 0.11 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O1ⁱ	0.93	2.45	3.368 (5)	170
Symmetry code: (i) x, y+1, z.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT-Plus (Bruker, 2004 ); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and DIAMOND (Brandenburg, 1999 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812044443/cv5350sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812044443/cv5350Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812044443/cv5350Isup3.mol

Supporting information file. DOI: 10.1107/S1600536812044443/cv5350Isup4.cml

checkCIF report

Comment top

The title compound, (2E)-1-phenyl-2-[1-(2-phenylprop-2-en-1-yl)pyrrolidin-2-ylidene] ethanone, (I), was prepared as part of an ongoing project dealing with the use of enaminones as intermediates for alkaloid synthesis (Michael et al., 1999).

In (I) (Fig. 1), two phenyl rings are twisted from the mean plane of the central pyrrolidine ring by 11.2 (1) and 67.3 (1)°, respectively. The (E) configuration and s-cis conformation of the exocyclic C═C bond of the enaminone are similar to those found in a related enaminone (Lemmerer et al., 2007). In the crystal, weak intermolecular C—H···O hydrogen bonds (Table 1) link the molecules related by translation along the b axis into chains (Fig. 2).

Related literature top

For details of the synthesis of enaminones, see: Roth et al. (1971). For applications of enaminones in alkaloid synthesis, see: Michael et al. (1999). For a related enaminone structure, see: Lemmerer et al. (2007).

Experimental top

The synthesis employed followed the Eschenmoser procedure (Roth et al., 1971). A solution of phenacyl bromide (4.30 g, 21.6 mmol) and 1-(2-phenylprop-2-en-1-yl)pyrrolidine-2-thione (4.27 g, 19.6 mmol) in dry acetonitrile (20 ml) was stirred at room temperature under an argon atmosphere until precipitation of the adduct as a gum was complete. The mixture was briefly warmed to solubilize the precipitate, after which a solution of triphenylphosphine (5.66 g, 21.6 mmol) and triethylamine (3.31 ml, 23.6 mmol) in dry MeCN (20 ml) was added dropwise to induce extrusion of sulfur, and stirring was maintained for 18 h. The solvent was evaporated and the residue was taken up into ethyl acetate (200 ml) and washed with water (3 × 100 ml) and brine (50 ml). The organic phase was dried over MgSO₄, filtered and evaporated to give an orange gum. Column chromatography on silica gel with hexane:ethyl acetate (3:2 v/v) afforded the title compound (5.42 g, 91%) as very pale yellow needles, m.p. 325—326 K.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of (I) showing the atomic numbering scheme. Displacement ellipsoids are shown at the 50% probability level.
	Fig. 2. A portion of the crystal packing showing C—H···O hydrogen bonds as dashed red lines. H atoms not involved in hydrogen bonding are omitted for clarity.

(2E)-1-Phenyl-2-[1-(2-phenylprop-2-en-1-yl)pyrrolidin-2-ylidene]ethanone top

Crystal data top

C₂₁H₂₁NO	Z = 1
M_r = 303.39	F(000) = 162
Triclinic, P1	D_x = 1.188 Mg m⁻³
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.7806 (6) Å	Cell parameters from 1287 reflections
b = 7.9407 (7) Å	θ = 2.2–24.8°
c = 9.6089 (9) Å	µ = 0.07 mm⁻¹
α = 82.579 (7)°	T = 293 K
β = 76.793 (7)°	Prism, colourless
γ = 83.510 (7)°	0.4 × 0.2 × 0.19 mm
V = 424.21 (7) Å³

Data collection top

Bruker APEXII CCD area-detector diffractometer	R_int = 0.040
ω scans	θ_max = 25.5°, θ_min = 2.2°
5222 measured reflections	h = −6→6
1563 independent reflections	k = −9→9
970 reflections with I > 2σ(I)	l = −11→11

Refinement top

Refinement on F²	3 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.044	w = 1/[σ²(F_o²) + (0.0653P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.119	(Δ/σ)_max < 0.001
S = 0.98	Δρ_max = 0.11 e Å⁻³
1563 reflections	Δρ_min = −0.13 e Å⁻³
208 parameters

Crystal data top

C₂₁H₂₁NO	γ = 83.510 (7)°
M_r = 303.39	V = 424.21 (7) Å³
Triclinic, P1	Z = 1
a = 5.7806 (6) Å	Mo Kα radiation
b = 7.9407 (7) Å	µ = 0.07 mm⁻¹
c = 9.6089 (9) Å	T = 293 K
α = 82.579 (7)°	0.4 × 0.2 × 0.19 mm
β = 76.793 (7)°

Data collection top

Bruker APEXII CCD area-detector diffractometer	970 reflections with I > 2σ(I)
5222 measured reflections	R_int = 0.040
1563 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	3 restraints
wR(F²) = 0.119	H-atom parameters constrained
S = 0.98	Δρ_max = 0.11 e Å⁻³
1563 reflections	Δρ_min = −0.13 e Å⁻³
208 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.6399 (6)	0.8328 (4)	1.0527 (4)	0.0522 (9)
C2	0.5691 (7)	1.0058 (4)	1.0341 (4)	0.0653 (11)
H2	0.446	1.0433	0.9869	0.078*
C3	0.6799 (8)	1.1226 (5)	1.0850 (5)	0.0752 (12)
H3	0.6316	1.2382	1.0718	0.09*
C4	0.8608 (8)	1.0687 (6)	1.1548 (5)	0.0785 (13)
H4	0.9371	1.1472	1.1881	0.094*
C5	0.9283 (7)	0.8981 (6)	1.1751 (5)	0.0789 (13)
H5	1.0501	0.8604	1.2233	0.095*
C6	0.8181 (7)	0.7835 (5)	1.1250 (4)	0.0659 (11)
H6	0.8656	0.668	1.1406	0.079*
C7	0.5255 (7)	0.6979 (4)	1.0017 (4)	0.0636 (11)
C8	0.3853 (7)	0.7440 (4)	0.8977 (4)	0.0585 (10)
H8	0.3737	0.8574	0.8591	0.07*
C9	0.2666 (7)	0.6322 (5)	0.8508 (4)	0.0636 (11)
C10	0.2782 (9)	0.4424 (5)	0.8878 (5)	0.0838 (13)
H10A	0.2124	0.4137	0.9893	0.101*
H10B	0.4419	0.3929	0.8653	0.101*
C11	0.1326 (11)	0.3781 (7)	0.7980 (7)	0.1127 (19)
H11A	0.2347	0.3109	0.7267	0.135*
H11B	0.0148	0.3068	0.8582	0.135*
C12	0.0139 (10)	0.5276 (7)	0.7269 (6)	0.1016 (17)
H12A	−0.1575	0.5333	0.7633	0.122*
H12B	0.0477	0.5234	0.6238	0.122*
C13	0.0360 (8)	0.8452 (6)	0.7109 (4)	0.0773 (12)
H13A	0.0421	0.9211	0.7811	0.093*
H13B	−0.1294	0.8469	0.7046	0.093*
C14	0.1767 (8)	0.9137 (6)	0.5674 (4)	0.0778 (12)
C15	0.0892 (8)	1.0875 (6)	0.5101 (4)	0.0751 (12)
C16	−0.1450 (9)	1.1520 (6)	0.5513 (6)	0.0909 (14)
H16	−0.2506	1.0866	0.6185	0.109*
C17	−0.2279 (11)	1.3117 (8)	0.4954 (7)	0.1099 (17)
H17	−0.3873	1.3518	0.5237	0.132*
C18	−0.0743 (16)	1.4078 (8)	0.3995 (7)	0.1170 (19)
H18	−0.1294	1.5144	0.3614	0.14*
C19	0.1563 (17)	1.3526 (10)	0.3579 (6)	0.121 (2)
H19	0.2612	1.422	0.2942	0.145*
C20	0.2381 (9)	1.1892 (8)	0.4114 (5)	0.1007 (17)
H20	0.3965	1.1492	0.3792	0.121*
C21	0.3663 (10)	0.8275 (8)	0.4994 (6)	0.1161 (19)
H21A	0.4527	0.8741	0.4117	0.139*
H21B	0.4147	0.7197	0.5389	0.139*
O1	0.5650 (7)	0.5495 (3)	1.0546 (4)	0.0998 (11)
N1	0.1148 (6)	0.6753 (4)	0.7626 (3)	0.0725 (10)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.067 (2)	0.0394 (18)	0.049 (2)	−0.0063 (17)	−0.0088 (18)	−0.0052 (16)
C2	0.081 (3)	0.041 (2)	0.076 (3)	−0.004 (2)	−0.019 (2)	−0.0123 (18)
C3	0.094 (3)	0.048 (2)	0.086 (3)	−0.011 (2)	−0.016 (3)	−0.018 (2)
C4	0.086 (3)	0.078 (3)	0.077 (3)	−0.024 (3)	−0.012 (3)	−0.027 (2)
C5	0.074 (3)	0.089 (3)	0.079 (3)	−0.004 (3)	−0.022 (2)	−0.019 (3)
C6	0.080 (3)	0.052 (2)	0.065 (3)	−0.003 (2)	−0.015 (2)	−0.0099 (19)
C7	0.089 (3)	0.044 (2)	0.058 (3)	−0.007 (2)	−0.012 (2)	−0.0082 (19)
C8	0.074 (2)	0.044 (2)	0.057 (2)	−0.0108 (19)	−0.009 (2)	−0.0080 (18)
C9	0.074 (3)	0.063 (2)	0.054 (2)	−0.017 (2)	−0.002 (2)	−0.017 (2)
C10	0.111 (3)	0.058 (2)	0.088 (3)	−0.024 (2)	−0.015 (3)	−0.023 (2)
C11	0.135 (5)	0.097 (4)	0.118 (5)	−0.047 (4)	−0.020 (4)	−0.034 (4)
C12	0.107 (4)	0.113 (4)	0.097 (4)	−0.035 (3)	−0.019 (3)	−0.043 (3)
C13	0.069 (3)	0.101 (3)	0.065 (3)	−0.009 (2)	−0.015 (2)	−0.017 (2)
C14	0.072 (3)	0.106 (3)	0.055 (2)	−0.022 (2)	−0.011 (2)	−0.001 (2)
C15	0.077 (3)	0.108 (3)	0.048 (2)	−0.032 (3)	−0.015 (2)	−0.014 (2)
C16	0.091 (4)	0.091 (3)	0.094 (3)	−0.023 (3)	−0.022 (3)	−0.004 (3)
C17	0.125 (5)	0.108 (4)	0.112 (5)	−0.010 (4)	−0.052 (4)	−0.021 (4)
C18	0.172 (7)	0.113 (5)	0.083 (4)	−0.042 (5)	−0.049 (4)	−0.009 (4)
C19	0.179 (7)	0.126 (5)	0.064 (4)	−0.078 (5)	−0.019 (4)	0.010 (3)
C20	0.107 (4)	0.145 (5)	0.055 (3)	−0.051 (4)	−0.005 (3)	−0.015 (3)
C21	0.108 (4)	0.129 (4)	0.085 (3)	0.000 (3)	0.025 (3)	−0.007 (3)
O1	0.165 (3)	0.0361 (15)	0.114 (3)	−0.0150 (15)	−0.065 (2)	0.0006 (14)
N1	0.082 (2)	0.075 (2)	0.067 (2)	−0.0187 (19)	−0.018 (2)	−0.0181 (18)

Geometric parameters (Å, º) top

C1—C6	1.365 (5)	C11—H11B	0.97
C1—C2	1.389 (4)	C12—N1	1.478 (6)
C1—C7	1.507 (5)	C12—H12A	0.97
C2—C3	1.380 (5)	C12—H12B	0.97
C2—H2	0.93	C13—N1	1.437 (5)
C3—C4	1.368 (6)	C13—C14	1.501 (6)
C3—H3	0.93	C13—H13A	0.97
C4—C5	1.368 (6)	C13—H13B	0.97
C4—H4	0.93	C14—C21	1.309 (6)
C5—C6	1.360 (6)	C14—C15	1.495 (6)
C5—H5	0.93	C15—C20	1.371 (6)
C6—H6	0.93	C15—C16	1.379 (6)
C7—O1	1.239 (4)	C16—C17	1.390 (7)
C7—C8	1.413 (5)	C16—H16	0.93
C8—C9	1.358 (5)	C17—C18	1.348 (8)
C8—H8	0.93	C17—H17	0.93
C9—N1	1.342 (5)	C18—C19	1.341 (8)
C9—C10	1.500 (5)	C18—H18	0.93
C10—C11	1.503 (7)	C19—C20	1.404 (8)
C10—H10A	0.97	C19—H19	0.93
C10—H10B	0.97	C20—H20	0.93
C11—C12	1.472 (7)	C21—H21A	0.93
C11—H11A	0.97	C21—H21B	0.93

C6—C1—C2	117.7 (3)	C11—C12—N1	104.6 (4)
C6—C1—C7	118.8 (3)	C11—C12—H12A	110.8
C2—C1—C7	123.5 (3)	N1—C12—H12A	110.8
C3—C2—C1	120.5 (4)	C11—C12—H12B	110.8
C3—C2—H2	119.7	N1—C12—H12B	110.8
C1—C2—H2	119.7	H12A—C12—H12B	108.9
C4—C3—C2	120.2 (4)	N1—C13—C14	115.3 (4)
C4—C3—H3	119.9	N1—C13—H13A	108.5
C2—C3—H3	119.9	C14—C13—H13A	108.5
C3—C4—C5	119.4 (4)	N1—C13—H13B	108.5
C3—C4—H4	120.3	C14—C13—H13B	108.5
C5—C4—H4	120.3	H13A—C13—H13B	107.5
C6—C5—C4	120.2 (4)	C21—C14—C15	122.8 (4)
C6—C5—H5	119.9	C21—C14—C13	121.7 (5)
C4—C5—H5	119.9	C15—C14—C13	115.5 (4)
C5—C6—C1	122.0 (4)	C20—C15—C16	116.7 (5)
C5—C6—H6	119	C20—C15—C14	121.3 (4)
C1—C6—H6	119	C16—C15—C14	122.0 (4)
O1—C7—C8	123.9 (3)	C15—C16—C17	122.0 (5)
O1—C7—C1	116.2 (4)	C15—C16—H16	119
C8—C7—C1	119.9 (3)	C17—C16—H16	119
C9—C8—C7	123.8 (3)	C18—C17—C16	119.1 (6)
C9—C8—H8	118.1	C18—C17—H17	120.5
C7—C8—H8	118.1	C16—C17—H17	120.5
N1—C9—C8	124.8 (3)	C19—C18—C17	121.3 (6)
N1—C9—C10	108.2 (3)	C19—C18—H18	119.3
C8—C9—C10	127.0 (4)	C17—C18—H18	119.3
C9—C10—C11	105.7 (4)	C18—C19—C20	119.5 (6)
C9—C10—H10A	110.6	C18—C19—H19	120.3
C11—C10—H10A	110.6	C20—C19—H19	120.3
C9—C10—H10B	110.6	C15—C20—C19	121.3 (6)
C11—C10—H10B	110.6	C15—C20—H20	119.4
H10A—C10—H10B	108.7	C19—C20—H20	119.4
C12—C11—C10	107.5 (4)	C14—C21—H21A	120
C12—C11—H11A	110.2	C14—C21—H21B	120
C10—C11—H11A	110.2	H21A—C21—H21B	120
C12—C11—H11B	110.2	C9—N1—C13	126.6 (3)
C10—C11—H11B	110.2	C9—N1—C12	113.4 (4)
H11A—C11—H11B	108.5	C13—N1—C12	119.8 (4)

C6—C1—C2—C3	1.3 (5)	N1—C13—C14—C15	177.5 (3)
C7—C1—C2—C3	179.2 (4)	C21—C14—C15—C20	−21.8 (7)
C1—C2—C3—C4	−0.2 (6)	C13—C14—C15—C20	156.6 (4)
C2—C3—C4—C5	−0.8 (6)	C21—C14—C15—C16	156.8 (5)
C3—C4—C5—C6	0.6 (7)	C13—C14—C15—C16	−24.7 (5)
C4—C5—C6—C1	0.5 (6)	C20—C15—C16—C17	0.4 (6)
C2—C1—C6—C5	−1.5 (6)	C14—C15—C16—C17	−178.3 (4)
C7—C1—C6—C5	−179.5 (4)	C15—C16—C17—C18	−1.0 (7)
C6—C1—C7—O1	14.8 (5)	C16—C17—C18—C19	−0.4 (8)
C2—C1—C7—O1	−163.2 (4)	C17—C18—C19—C20	2.2 (8)
C6—C1—C7—C8	−164.4 (4)	C16—C15—C20—C19	1.5 (6)
C2—C1—C7—C8	17.7 (5)	C14—C15—C20—C19	−179.8 (4)
O1—C7—C8—C9	4.2 (6)	C18—C19—C20—C15	−2.8 (8)
C1—C7—C8—C9	−176.7 (3)	C8—C9—N1—C13	−5.1 (6)
C7—C8—C9—N1	173.4 (4)	C10—C9—N1—C13	174.4 (4)
C7—C8—C9—C10	−6.0 (6)	C8—C9—N1—C12	179.0 (4)
N1—C9—C10—C11	5.6 (5)	C10—C9—N1—C12	−1.5 (5)
C8—C9—C10—C11	−174.9 (4)	C14—C13—N1—C9	94.1 (4)
C9—C10—C11—C12	−7.5 (5)	C14—C13—N1—C12	−90.3 (5)
C10—C11—C12—N1	6.6 (5)	C11—C12—N1—C9	−3.3 (5)
N1—C13—C14—C21	−4.0 (6)	C11—C12—N1—C13	−179.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1ⁱ	0.93	2.45	3.368 (5)	170

Symmetry code: (i) x, y+1, z.

Experimental details

Crystal data
Chemical formula	C₂₁H₂₁NO
M_r	303.39
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	5.7806 (6), 7.9407 (7), 9.6089 (9)
α, β, γ (°)	82.579 (7), 76.793 (7), 83.510 (7)
V (Å³)	424.21 (7)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.4 × 0.2 × 0.19

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	5222, 1563, 970
R_int	0.040
(sin θ/λ)_max (Å⁻¹)	0.605

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.119, 0.98
No. of reflections	1563
No. of parameters	208
No. of restraints	3
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.11, −0.13

Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SAINT-Plus and XPREP (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1999), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1ⁱ	0.93	2.45	3.368 (5)	170

Symmetry code: (i) x, y+1, z.

Acknowledgements

This research was supported by the University of the Witwatersrand and the Molecular Sciences Institute, which are thanked for providing the infrastructure required to do this work.

References

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