2-[(1H-Imidazol-1-yl)meth­yl]-1-[4-(trifluoro­meth­yl)phen­yl]-1H-indole

Wang, R.; Shi, H.; Du, L.; Zhao, J.; Liu, J.

doi:10.1107/S1600536812010471

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 4| April 2012| Page o1081

doi:10.1107/S1600536812010471

Open

access

2-[(1H-Imidazol-1-yl)methyl]-1-[4-(trifluoromethyl)phenyl]-1H-indole

Rui Wang,^a Hong-fan Shi,^a Lin Du,^a Jing-feng Zhao ^a and Jian-ping Liu ^a ^*

^aKey Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, People's Republic of China
^*Correspondence e-mail: jpliu@ynu.edu.cn

(Received 1 March 2012; accepted 9 March 2012; online 17 March 2012)

In the title compound, C₁₉H₁₄F₃N₃, the dihedral angles between the mean planes of the indole ring and the 4-CF₃-phenyl and imidazole rings are 54.95 (4) and 61.36 (7)°, respectively.

Related literature

For background to indole derivatives and their biological activity, see: Muftuoglua & Mustatab (2010 ); Jiao et al. (2010 ). For related structures, see: Borgne et al. (1999 ); Lézé et al. (2006 ); Marchand et al. (2003 ).

Experimental

Crystal data

C₁₉H₁₄F₃N₃
M_r = 341.33
Orthorhombic, P b c a
a = 10.3732 (17) Å
b = 7.9960 (13) Å
c = 37.665 (6) Å
V = 3124.0 (9) Å³
Z = 8
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 100 K
0.53 × 0.26 × 0.05 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ) T_min = 0.943, T_max = 0.994
30000 measured reflections
4505 independent reflections
3217 reflections with I > 2σ(I)
R_int = 0.093

Refinement

R[F² > 2σ(F²)] = 0.079
wR(F²) = 0.214
S = 0.99
4505 reflections
226 parameters
H-atom parameters constrained
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Data collection: APEX2 (Bruker, 1998 ); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812010471/jj2125sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812010471/jj2125Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812010471/jj2125Isup3.cml

checkCIF report

Comment top

Iodole derivatives are an important class of heterocycles in medicinal chemistry (Borgne et al., 1999; Marchand et al., 2003; Lézé et al., 2006; Jiao et al., 2010; Muftuoglua & Mustatab, 2010). In continuation of our studies on N-aromatization in the indole ring, we present here the the crystal structure of the title compound, C₁₉H₁₄F₃N₃, (I). With one molecule in the asymmetric unit, the dihedral angles between the mean planes of the indole ring and the 4-CF₃-phenyl and imidazole rings are 54.95 (4)° and 61.36 (7)°, respectively (Fig. 1). Bond lengths and angles are in normal ranges.

Related literature top

For background to indole derivatives and their biological activity, see: Muftuoglua & Mustatab (2010); Jiao et al. (2010). For related structures, see: Borgne et al. (1999); Lézé et al. (2006); Marchand et al. (2003).

Experimental top

The title compound, C₁₉H₁₄F₃N₃, was prepared in one step. (1-(4-(trifluoromethyl)phenyl)-1H-indol-2-yl)methanol (50 mg, 0.17 mmol) and N,N'-carbonyldiimidazole (83 mg, 3 equiv) in dry CH₃CN was stirred for 48 h at room temperature. The solvent was evaporated and the residue purified on silica gel to give the title compound,(I). Yield: 53% (33 mg). Recrystallization from absolute ethyl acetate gave colorless and clear single crystals for X-ray diffraction measurement.

Structure description top

For background to indole derivatives and their biological activity, see: Muftuoglua & Mustatab (2010); Jiao et al. (2010). For related structures, see: Borgne et al. (1999); Lézé et al. (2006); Marchand et al. (2003).

Computing details top

Data collection: APEX2 (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); 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

	Fig. 1. The molecular structure of (I) showing the atomic numbering and 50% probability displacement ellipsoids.
	Fig. 2. The crystal packing of (I) viewed along the b axis. H atoms have been removed for clarity.

2-[(1H-Imidazol-1-yl)methyl]-1-[4-(trifluoromethyl)phenyl]-1H- indole top

Crystal data top

C₁₉H₁₄F₃N₃	F(000) = 1408
M_r = 341.33	D_x = 1.451 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 5075 reflections
a = 10.3732 (17) Å	θ = 2.2–30.1°
b = 7.9960 (13) Å	µ = 0.11 mm⁻¹
c = 37.665 (6) Å	T = 100 K
V = 3124.0 (9) Å³	Laminiplantation, colourless
Z = 8	0.53 × 0.26 × 0.05 mm

Data collection top

Bruker APEXII CCD diffractometer	4505 independent reflections
Radiation source: fine-focus sealed tube	3217 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.093
Detector resolution: 0.71 pixels mm^-1	θ_max = 30.2°, θ_min = 1.1°
φ and ω scans	h = −14→14
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	k = −11→11
T_min = 0.943, T_max = 0.994	l = −52→52
30000 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.079	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.214	H-atom parameters constrained
S = 0.99	w = 1/[σ²(F_o²) + (0.0877P)² + 8.8995P] where P = (F_o² + 2F_c²)/3
4505 reflections	(Δ/σ)_max = 0.001
226 parameters	Δρ_max = 0.51 e Å⁻³
0 restraints	Δρ_min = −0.38 e Å⁻³

Crystal data top

C₁₉H₁₄F₃N₃	V = 3124.0 (9) Å³
M_r = 341.33	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 10.3732 (17) Å	µ = 0.11 mm⁻¹
b = 7.9960 (13) Å	T = 100 K
c = 37.665 (6) Å	0.53 × 0.26 × 0.05 mm

Data collection top

Bruker APEXII CCD diffractometer	4505 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	3217 reflections with I > 2σ(I)
T_min = 0.943, T_max = 0.994	R_int = 0.093
30000 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.079	0 restraints
wR(F²) = 0.214	H-atom parameters constrained
S = 0.99	Δρ_max = 0.51 e Å⁻³
4505 reflections	Δρ_min = −0.38 e Å⁻³
226 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.

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

	x	y	z	U_iso*/U_eq
F1	−0.1652 (2)	0.1525 (3)	0.97255 (6)	0.0444 (6)
F2	−0.1194 (2)	0.4118 (3)	0.97874 (6)	0.0422 (6)
F3	−0.0238 (2)	0.2278 (3)	1.01033 (5)	0.0430 (6)
N1	0.3126 (2)	0.1845 (3)	0.86957 (5)	0.0130 (4)
N2	0.0946 (2)	0.1498 (3)	0.80082 (6)	0.0141 (4)
N3	−0.0810 (2)	0.2676 (3)	0.77776 (7)	0.0229 (5)
C1	0.2961 (3)	0.1098 (3)	0.83609 (6)	0.0133 (5)
C2	0.4120 (3)	0.1060 (3)	0.81894 (6)	0.0143 (5)
H2	0.4275	0.0596	0.7961	0.017*
C3	0.6355 (3)	0.2300 (4)	0.83646 (7)	0.0192 (6)
H3	0.6802	0.1996	0.8154	0.023*
C4	0.6967 (3)	0.3203 (4)	0.86292 (8)	0.0228 (6)
H4	0.7839	0.3535	0.8598	0.027*
C5	0.6313 (3)	0.3638 (4)	0.89460 (7)	0.0215 (6)
H5	0.6758	0.4248	0.9124	0.026*
C6	0.5041 (3)	0.3194 (4)	0.90018 (7)	0.0167 (5)
H6	0.4604	0.3484	0.9215	0.020*
C7	0.4424 (2)	0.2299 (3)	0.87310 (7)	0.0147 (5)
C8	0.5063 (3)	0.1844 (3)	0.84135 (7)	0.0151 (5)
C9	0.2173 (3)	0.2037 (3)	0.89657 (7)	0.0140 (5)
C10	0.1007 (2)	0.2828 (3)	0.88912 (7)	0.0144 (5)
H10	0.0841	0.3242	0.8659	0.017*
C11	0.0090 (3)	0.3010 (4)	0.91571 (7)	0.0168 (5)
H11	−0.0712	0.3530	0.9106	0.020*
C12	0.0349 (3)	0.2429 (3)	0.94987 (7)	0.0160 (5)
C13	0.1510 (3)	0.1651 (3)	0.95761 (7)	0.0170 (5)
H13	0.1679	0.1257	0.9809	0.020*
C14	0.2428 (3)	0.1450 (3)	0.93089 (6)	0.0164 (5)
H14	0.3225	0.0916	0.9360	0.020*
C15	−0.0667 (3)	0.2588 (4)	0.97782 (7)	0.0205 (6)
C16	0.1706 (3)	0.0383 (3)	0.82356 (7)	0.0152 (5)
H16A	0.1884	−0.0661	0.8103	0.018*
H16B	0.1181	0.0083	0.8446	0.018*
C17	−0.0343 (3)	0.1775 (4)	0.80402 (7)	0.0189 (5)
H17	−0.0849	0.1364	0.8231	0.023*
C18	0.0239 (3)	0.2973 (4)	0.75601 (7)	0.0202 (6)
H18	0.0207	0.3596	0.7346	0.024*
C19	0.1328 (3)	0.2251 (3)	0.76948 (7)	0.0166 (5)
H19	0.2169	0.2264	0.7595	0.020*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
F1	0.0345 (11)	0.0602 (15)	0.0383 (12)	−0.0245 (11)	0.0181 (9)	−0.0139 (11)
F2	0.0478 (13)	0.0346 (11)	0.0444 (12)	0.0137 (10)	0.0285 (10)	0.0034 (10)
F3	0.0367 (11)	0.0788 (17)	0.0134 (9)	0.0105 (11)	0.0078 (8)	0.0042 (10)
N1	0.0148 (10)	0.0162 (10)	0.0081 (9)	0.0008 (8)	−0.0002 (8)	0.0005 (8)
N2	0.0169 (11)	0.0151 (10)	0.0105 (10)	−0.0008 (8)	−0.0006 (8)	−0.0022 (8)
N3	0.0195 (12)	0.0278 (13)	0.0215 (12)	0.0005 (10)	−0.0042 (10)	−0.0042 (10)
C1	0.0195 (12)	0.0123 (11)	0.0082 (10)	0.0026 (9)	0.0004 (9)	0.0018 (9)
C2	0.0207 (13)	0.0143 (11)	0.0079 (10)	0.0023 (10)	0.0011 (9)	−0.0015 (9)
C3	0.0161 (13)	0.0258 (14)	0.0157 (12)	0.0045 (11)	0.0025 (10)	0.0014 (11)
C4	0.0149 (12)	0.0335 (16)	0.0202 (13)	−0.0007 (11)	0.0004 (10)	−0.0006 (12)
C5	0.0167 (13)	0.0314 (15)	0.0165 (13)	−0.0001 (11)	−0.0042 (10)	−0.0047 (11)
C6	0.0173 (12)	0.0213 (13)	0.0114 (11)	0.0022 (10)	0.0001 (9)	−0.0021 (10)
C7	0.0145 (11)	0.0171 (12)	0.0123 (11)	0.0021 (9)	−0.0007 (9)	0.0008 (9)
C8	0.0172 (12)	0.0177 (12)	0.0104 (11)	0.0040 (10)	−0.0001 (9)	−0.0002 (9)
C9	0.0186 (12)	0.0132 (11)	0.0102 (11)	−0.0002 (9)	0.0027 (9)	−0.0011 (9)
C10	0.0177 (12)	0.0170 (12)	0.0085 (11)	−0.0010 (10)	−0.0009 (9)	0.0014 (9)
C11	0.0163 (12)	0.0216 (13)	0.0125 (12)	0.0004 (10)	−0.0007 (9)	−0.0006 (10)
C12	0.0188 (12)	0.0188 (12)	0.0104 (11)	−0.0032 (10)	0.0021 (10)	−0.0014 (9)
C13	0.0236 (13)	0.0197 (13)	0.0076 (11)	−0.0016 (10)	−0.0014 (10)	0.0015 (9)
C14	0.0190 (12)	0.0196 (13)	0.0106 (11)	0.0023 (10)	−0.0005 (10)	0.0009 (10)
C15	0.0214 (13)	0.0254 (15)	0.0148 (12)	−0.0026 (11)	0.0068 (10)	−0.0013 (10)
C16	0.0209 (13)	0.0144 (12)	0.0103 (11)	−0.0026 (10)	−0.0023 (10)	0.0006 (9)
C17	0.0148 (12)	0.0262 (14)	0.0157 (12)	−0.0012 (11)	0.0008 (10)	−0.0039 (11)
C18	0.0271 (14)	0.0198 (13)	0.0136 (12)	0.0003 (11)	−0.0043 (11)	−0.0019 (10)
C19	0.0208 (13)	0.0175 (12)	0.0115 (11)	−0.0012 (10)	−0.0006 (10)	−0.0003 (10)

Geometric parameters (Å, º) top

F1—C15	1.344 (4)	C5—H5	0.9500
F2—C15	1.340 (4)	C6—C7	1.401 (4)
F3—C15	1.326 (3)	C6—H6	0.9500
N1—C7	1.400 (3)	C7—C8	1.415 (4)
N1—C1	1.406 (3)	C9—C10	1.393 (4)
N1—C9	1.427 (3)	C9—C14	1.400 (3)
N2—C17	1.360 (3)	C10—C11	1.389 (4)
N2—C19	1.383 (3)	C10—H10	0.9500
N2—C16	1.466 (3)	C11—C12	1.394 (4)
N3—C17	1.316 (4)	C11—H11	0.9500
N3—C18	1.383 (4)	C12—C13	1.387 (4)
C1—C2	1.365 (4)	C12—C15	1.495 (4)
C1—C16	1.498 (4)	C13—C14	1.395 (4)
C2—C8	1.436 (4)	C13—H13	0.9500
C2—H2	0.9500	C14—H14	0.9500
C3—C4	1.385 (4)	C16—H16A	0.9900
C3—C8	1.401 (4)	C16—H16B	0.9900
C3—H3	0.9500	C17—H17	0.9500
C4—C5	1.416 (4)	C18—C19	1.366 (4)
C4—H4	0.9500	C18—H18	0.9500
C5—C6	1.382 (4)	C19—H19	0.9500

C7—N1—C1	108.2 (2)	C11—C10—H10	120.1
C7—N1—C9	124.8 (2)	C9—C10—H10	120.1
C1—N1—C9	126.9 (2)	C10—C11—C12	119.9 (3)
C17—N2—C19	106.6 (2)	C10—C11—H11	120.0
C17—N2—C16	125.1 (2)	C12—C11—H11	120.0
C19—N2—C16	127.5 (2)	C13—C12—C11	120.7 (2)
C17—N3—C18	104.4 (2)	C13—C12—C15	120.2 (2)
C2—C1—N1	109.0 (2)	C11—C12—C15	119.0 (3)
C2—C1—C16	127.4 (2)	C12—C13—C14	119.5 (2)
N1—C1—C16	123.4 (2)	C12—C13—H13	120.2
C1—C2—C8	108.2 (2)	C14—C13—H13	120.2
C1—C2—H2	125.9	C13—C14—C9	119.9 (2)
C8—C2—H2	125.9	C13—C14—H14	120.1
C4—C3—C8	118.7 (3)	C9—C14—H14	120.1
C4—C3—H3	120.7	F3—C15—F2	106.5 (2)
C8—C3—H3	120.7	F3—C15—F1	105.9 (2)
C3—C4—C5	121.0 (3)	F2—C15—F1	105.7 (3)
C3—C4—H4	119.5	F3—C15—C12	113.4 (2)
C5—C4—H4	119.5	F2—C15—C12	112.5 (2)
C6—C5—C4	121.5 (3)	F1—C15—C12	112.2 (2)
C6—C5—H5	119.3	N2—C16—C1	114.8 (2)
C4—C5—H5	119.3	N2—C16—H16A	108.6
C5—C6—C7	117.2 (2)	C1—C16—H16A	108.6
C5—C6—H6	121.4	N2—C16—H16B	108.6
C7—C6—H6	121.4	C1—C16—H16B	108.6
N1—C7—C6	129.9 (2)	H16A—C16—H16B	107.6
N1—C7—C8	107.7 (2)	N3—C17—N2	112.6 (3)
C6—C7—C8	122.1 (2)	N3—C17—H17	123.7
C3—C8—C7	119.5 (2)	N2—C17—H17	123.7
C3—C8—C2	133.5 (2)	C19—C18—N3	111.0 (2)
C7—C8—C2	106.8 (2)	C19—C18—H18	124.5
C10—C9—C14	120.2 (2)	N3—C18—H18	124.5
C10—C9—N1	120.5 (2)	C18—C19—N2	105.3 (2)
C14—C9—N1	119.4 (2)	C18—C19—H19	127.4
C11—C10—C9	119.8 (2)	N2—C19—H19	127.4

C7—N1—C1—C2	0.6 (3)	C14—C9—C10—C11	−1.0 (4)
C9—N1—C1—C2	−176.1 (2)	N1—C9—C10—C11	−179.8 (2)
C7—N1—C1—C16	177.2 (2)	C9—C10—C11—C12	1.2 (4)
C9—N1—C1—C16	0.4 (4)	C10—C11—C12—C13	−0.8 (4)
N1—C1—C2—C8	−1.6 (3)	C10—C11—C12—C15	−178.1 (3)
C16—C1—C2—C8	−178.0 (2)	C11—C12—C13—C14	0.1 (4)
C8—C3—C4—C5	1.0 (5)	C15—C12—C13—C14	177.4 (3)
C3—C4—C5—C6	−0.6 (5)	C12—C13—C14—C9	0.1 (4)
C4—C5—C6—C7	−0.2 (4)	C10—C9—C14—C13	0.4 (4)
C1—N1—C7—C6	174.3 (3)	N1—C9—C14—C13	179.1 (2)
C9—N1—C7—C6	−8.9 (4)	C13—C12—C15—F3	14.2 (4)
C1—N1—C7—C8	0.6 (3)	C11—C12—C15—F3	−168.5 (3)
C9—N1—C7—C8	177.4 (2)	C13—C12—C15—F2	135.1 (3)
C5—C6—C7—N1	−172.3 (3)	C11—C12—C15—F2	−47.5 (4)
C5—C6—C7—C8	0.6 (4)	C13—C12—C15—F1	−105.8 (3)
C4—C3—C8—C7	−0.6 (4)	C11—C12—C15—F1	71.6 (4)
C4—C3—C8—C2	173.6 (3)	C17—N2—C16—C1	−134.7 (3)
N1—C7—C8—C3	174.1 (2)	C19—N2—C16—C1	56.1 (3)
C6—C7—C8—C3	−0.2 (4)	C2—C1—C16—N2	−86.5 (3)
N1—C7—C8—C2	−1.5 (3)	N1—C1—C16—N2	97.6 (3)
C6—C7—C8—C2	−175.8 (2)	C18—N3—C17—N2	1.0 (3)
C1—C2—C8—C3	−172.8 (3)	C19—N2—C17—N3	−1.5 (3)
C1—C2—C8—C7	1.9 (3)	C16—N2—C17—N3	−172.5 (2)
C7—N1—C9—C10	129.0 (3)	C17—N3—C18—C19	−0.2 (3)
C1—N1—C9—C10	−54.7 (4)	N3—C18—C19—N2	−0.7 (3)
C7—N1—C9—C14	−49.7 (4)	C17—N2—C19—C18	1.2 (3)
C1—N1—C9—C14	126.5 (3)	C16—N2—C19—C18	172.0 (2)

Experimental details

Crystal data
Chemical formula	C₁₉H₁₄F₃N₃
M_r	341.33
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	100
a, b, c (Å)	10.3732 (17), 7.9960 (13), 37.665 (6)
V (Å³)	3124.0 (9)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.53 × 0.26 × 0.05

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Sheldrick, 2004)
T_min, T_max	0.943, 0.994
No. of measured, independent and observed [I > 2σ(I)] reflections	30000, 4505, 3217
R_int	0.093
(sin θ/λ)_max (Å⁻¹)	0.708

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.079, 0.214, 0.99
No. of reflections	4505
No. of parameters	226
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.51, −0.38

Computer programs: APEX2 (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

This work was supported by the Natural Science Foundation of P. R. China (20562012).

References

Borgne, M. L., Marchand, P., Delevoye-Seiller, B., Robert, J.-M., Baut, G. L., Hartmann, R. W. & Palzer, M. (1999). Bioorg. Med. Chem. Lett. 9, 333–336. Web of Science PubMed Google Scholar
Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Jiao, J., Xiang, H. & Liao, Q. (2010). Curr. Med. Chem. 17, 3476–3487. CrossRef CAS PubMed Google Scholar
Lézé, M.-P., Borgne, M. L., Pinson, P., Palusczak, A., Duflos, M., Baut, G. L. & Hartmann, R. W. (2006). Bioorg. Med. Chem. Lett. 16, 1134–1137. Web of Science PubMed Google Scholar
Marchand, P., Borgne, M. L., Palzer, M., Baut, G. L. & Hartmann, R. W. (2003). Bioorg. Med. Chem. Lett. 13, 1553–1555. Web of Science CrossRef PubMed CAS Google Scholar
Muftuoglua, Y. & Mustatab, G. (2010). Bioorg. Med. Chem. Lett. 20, 3050–3064. Web of Science PubMed Google Scholar
Sheldrick, G. M. (2004). SADBAS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar