(S)-4-Phenyl-2-(1,2,3,4-tetra­hydro­isoquinolin-3-yl)-1,3-thia­zole

Pawar, S.; Bhatt, P.; Govender, T.; Kruger, H.G.; Maguire, G.E.M.

doi:10.1107/S1600536811052585

organic compounds

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Volume 68| Part 1| January 2012| Page o176

doi:10.1107/S1600536811052585

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(S)-4-Phenyl-2-(1,2,3,4-tetrahydroisoquinolin-3-yl)-1,3-thiazole

Sunayna Pawar,^a Pralav Bhatt,^b Thavendran Govender,^a Hendrik G. Kruger ^b and Glenn E. M. Maguire ^b ^*

^aSchool of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4000, South Africa, and ^bSchool of Chemistry, University of KwaZulu-Natal, Durban 4000, South Africa
^*Correspondence e-mail: maguireg@ukzn.ac.za

(Received 7 September 2011; accepted 6 December 2011; online 21 December 2011)

In the title compound, C₁₈H₁₆N₂S, the N-containing ring adopts a half-chair configuration. The crystal packing features C—H⋯N contacts. There is no π–π stacking within the crystal structure.

Related literature

The title compound is a potential ligand for the asymmetric Henry reaction. For the application of these ligands as catalysts, see: Chakka et al. (2010 ); Kawthekar et al. (2010 ); Peters et al. (2010 ); Naicker et al. (2010 ). For related structures, see: Naicker et al. (2011a ,b ).

Experimental

Crystal data

C₁₈H₁₆N₂S
M_r = 292.39
Trigonal, P 3₂
a = 16.223 (1) Å
c = 4.8130 (3) Å
V = 1097.0 (1) Å³
Z = 3
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 173 K
0.20 × 0.10 × 0.09 mm

Data collection

Bruker Kappa DUO APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2008 ) T_min = 0.958, T_max = 0.981
14735 measured reflections
3676 independent reflections
3205 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.084
S = 1.03
3676 reflections
194 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.22 e Å⁻³
Absolute structure: Flack (1983 ), 1832 Friedel pairs
Flack parameter: −0.02 (6)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11⋯N1ⁱ	0.95	2.54	3.341 (3)	142
Symmetry code: (i) $[-y+1, x-y+2, z-{\script{1\over 3}}]$ .

Data collection: APEX2 (Bruker, 2006 ); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811052585/gw2110sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811052585/gw2110Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811052585/gw2110Isup3.cml

checkCIF report

Comment top

Tetrahydroisoquinoline is a core structure in various natural and pharmaceutically active compounds, displaying a broad spectrum of activity. Molecules with a C₁-symmetric tetrahydroisoquinoline backbone have been studied for various catalytic reactions such as allylic alkylation (Blanc et al.,2003), Henry reactions (Kawthekar et al., 2010), asymmetric hydrogenation reactions (Chakka et al.,2010; Peters et al., 2010) and Diels-Alder reactions (Naicker et al.,2010). The title compound is one of the ligands used for asymmetric Henry reaction, its' catalytic activity is currently under investigation. The chiral carbon (C9) has been assigned an S configuration from two-dimensional NMR measurements.

In the title compound, the piperidine ring of the tetrahydroisoquinolinone unit adopts a half chair (Fig 1). This hetrocyclic ring within similar structures displays either a half chair or half boat conformation (Naicker et al. 2011a; 2011b). From the crystal structure it is evident that the N-containing six membered ring assumes a half chair conformation [Q = 0.483 (2) Å, θ = 50.1 (2)° and ϕ = 321.8 (3)°]. The torsion angle for C1—N1—C9—C10 is -171.72 (14)°. From the plain formed by the atoms C1—C2—C7—C8—C9—N1 the maximum displacement from planarity for N1 is 0.297 Å and for C9 0.331 Å (Fig. 1). This is similar to our previously reported structures which also assume half chair conformations (Naicker et al., 2011a; 2011b). The crystal packing contains C—H···N contacts of distance 3.341 (3) Å (see Fig. 2) (Table 1). There is no π-π stacking within the crystal structure.

Related literature top

The title compound is a potential ligand for the assymetric Henry reaction. For the application of these ligands as catalysts, see: Chakka et al. (2010); Kawthekar et al. (2010); Peters et al. (2010); Naicker et al. (2010). For related structures, see: Naicker et al. (2011a,b).

Experimental top

The N-protected thiazole (3 mmol) was dissolved in THF (15 ml), to this 12 M HCl (15 ml) was added slowly and the reaction mixture was stirred at room temperature for 2 h. THF was evaporated under vacuum. The reaction was monitored by TLC using EtOAc/Hexane (20:80, R_f = 0.5). The reaction mixture was slowly poured into aqueous saturated NaHCO₃ solution, the mixture was then extracted with CH₂Cl₂ (3 x 30 ml). The combined organic layer was dried over MgSO₄. The solvent was evaporated under reduced pressure, the residue was purified by column chromatography on silica gel (deactivated with 5% Et₃N) with Et₃N/EtOAc/Hexane (5/8/100) as the eluent to afford the thiazole as a yellow solid (0.27 g, yield 95%). M.p. = 357–360 K.

Recrystallization from tetrahydrofuran at room temperature afforded colourless crystals suitable for X-ray analysis.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 40% probability level. The hydrogen atoms have been omitted for clarity.
	Fig. 2. CH···N interactions along the b axis.

(S)-4-Phenyl-2-(1,2,3,4-tetrahydroisoquinolin-3-yl)-1,3-thiazole top

Crystal data top

C₁₈H₁₆N₂S	D_x = 1.328 Mg m⁻³
M_r = 292.39	Mo Kα radiation, λ = 0.71073 Å
Trigonal, P3₂	Cell parameters from 14735 reflections
Hall symbol: P 32	θ = 2.5–28.4°
a = 16.223 (1) Å	µ = 0.22 mm⁻¹
c = 4.8130 (3) Å	T = 173 K
V = 1097.0 (1) Å³	Needle, yellow
Z = 3	0.20 × 0.10 × 0.09 mm
F(000) = 462

Data collection top

Bruker Kappa DUO APEXII diffractometer	3676 independent reflections
Radiation source: fine-focus sealed tube	3205 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
0.5° ϕ scans and ω scans	θ_max = 28.4°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	h = −21→21
T_min = 0.958, T_max = 0.981	k = −21→21
14735 measured reflections	l = −6→6

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.035	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.084	w = 1/[σ²(F_o²) + (0.0433P)² + 0.1159P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
3676 reflections	Δρ_max = 0.23 e Å⁻³
194 parameters	Δρ_min = −0.22 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 1832 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.02 (6)

Crystal data top

C₁₈H₁₆N₂S	Z = 3
M_r = 292.39	Mo Kα radiation
Trigonal, P3₂	µ = 0.22 mm⁻¹
a = 16.223 (1) Å	T = 173 K
c = 4.8130 (3) Å	0.20 × 0.10 × 0.09 mm
V = 1097.0 (1) Å³

Data collection top

Bruker Kappa DUO APEXII diffractometer	3676 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	3205 reflections with I > 2σ(I)
T_min = 0.958, T_max = 0.981	R_int = 0.030
14735 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.084	Δρ_max = 0.23 e Å⁻³
S = 1.03	Δρ_min = −0.22 e Å⁻³
3676 reflections	Absolute structure: Flack (1983), 1832 Friedel pairs
194 parameters	Absolute structure parameter: −0.02 (6)
1 restraint

Special details top

Experimental. Half sphere of data collected using the Bruker SAINT software package. Crystal to detector distance = 30 mm; combination of ϕ and ω scans of 0.5°, 60 s per °, 2 iterations.

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
S1	0.00297 (4)	0.88075 (3)	0.01223 (14)	0.04813 (15)
N1	−0.22129 (10)	0.70793 (10)	0.1094 (3)	0.0316 (3)
H1N	−0.2357 (14)	0.6647 (15)	−0.032 (4)	0.036 (5)*
N2	−0.01656 (9)	0.71580 (9)	−0.0576 (3)	0.0287 (3)
C1	−0.30267 (13)	0.67560 (13)	0.2960 (4)	0.0359 (4)
H1A	−0.3603	0.6569	0.1825	0.043*
H1B	−0.2926	0.7298	0.4142	0.043*
C2	−0.32126 (11)	0.59286 (11)	0.4831 (4)	0.0287 (3)
C3	−0.40599 (13)	0.54595 (12)	0.6353 (4)	0.0359 (4)
H3	−0.4520	0.5655	0.6174	0.043*
C4	−0.42359 (13)	0.47165 (13)	0.8110 (4)	0.0393 (4)
H4	−0.4816	0.4402	0.9122	0.047*
C5	−0.35671 (14)	0.44283 (12)	0.8399 (4)	0.0385 (4)
H5	−0.3688	0.3915	0.9599	0.046*
C6	−0.27209 (13)	0.48947 (12)	0.6927 (4)	0.0323 (4)
H6	−0.2260	0.4702	0.7145	0.039*
C7	−0.25347 (12)	0.56434 (11)	0.5129 (3)	0.0272 (3)
C8	−0.16028 (11)	0.61485 (12)	0.3565 (4)	0.0290 (3)
H8A	−0.1630	0.5759	0.1945	0.035*
H8B	−0.1080	0.6222	0.4791	0.035*
C9	−0.13971 (12)	0.71258 (12)	0.2570 (4)	0.0307 (4)
H9	−0.1268	0.7538	0.4244	0.037*
C10	−0.05355 (12)	0.75944 (11)	0.0730 (4)	0.0300 (3)
C11	0.08088 (13)	0.87065 (13)	−0.2040 (4)	0.0388 (4)
H11	0.1314	0.9222	−0.3007	0.047*
C12	0.06065 (11)	0.77863 (11)	−0.2186 (4)	0.0297 (3)
C13	0.11195 (12)	0.74191 (12)	−0.3839 (4)	0.0304 (4)
C14	0.08499 (13)	0.64602 (13)	−0.3768 (4)	0.0362 (4)
H14	0.0336	0.6036	−0.2616	0.043*
C15	0.13257 (14)	0.61174 (14)	−0.5369 (5)	0.0433 (4)
H15	0.1135	0.5460	−0.5304	0.052*
C16	0.20739 (14)	0.67241 (16)	−0.7052 (5)	0.0468 (5)
H16	0.2398	0.6489	−0.8150	0.056*
C17	0.23454 (16)	0.76791 (16)	−0.7122 (5)	0.0506 (5)
H17	0.2860	0.8102	−0.8275	0.061*
C18	0.18785 (15)	0.80224 (15)	−0.5542 (4)	0.0435 (5)
H18	0.2076	0.8681	−0.5611	0.052*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0455 (3)	0.0274 (2)	0.0703 (3)	0.0174 (2)	0.0198 (3)	0.0061 (2)
N1	0.0336 (7)	0.0316 (7)	0.0329 (8)	0.0188 (6)	0.0027 (6)	−0.0008 (6)
N2	0.0263 (7)	0.0257 (7)	0.0299 (7)	0.0099 (6)	0.0002 (6)	0.0010 (6)
C1	0.0344 (9)	0.0346 (9)	0.0433 (10)	0.0208 (8)	0.0042 (8)	0.0016 (8)
C2	0.0280 (8)	0.0268 (8)	0.0284 (8)	0.0116 (7)	−0.0020 (7)	−0.0058 (7)
C3	0.0294 (8)	0.0337 (9)	0.0423 (10)	0.0141 (7)	0.0030 (8)	−0.0054 (8)
C4	0.0344 (9)	0.0319 (9)	0.0413 (10)	0.0088 (7)	0.0103 (8)	−0.0014 (8)
C5	0.0463 (11)	0.0280 (8)	0.0348 (10)	0.0138 (8)	0.0055 (8)	0.0025 (7)
C6	0.0372 (9)	0.0299 (8)	0.0300 (9)	0.0169 (7)	−0.0014 (7)	−0.0031 (7)
C7	0.0291 (8)	0.0255 (7)	0.0243 (8)	0.0117 (6)	−0.0010 (6)	−0.0058 (6)
C8	0.0303 (8)	0.0295 (8)	0.0290 (8)	0.0163 (7)	0.0008 (7)	−0.0004 (7)
C9	0.0321 (8)	0.0278 (8)	0.0314 (9)	0.0143 (7)	0.0012 (7)	−0.0026 (7)
C10	0.0293 (8)	0.0241 (8)	0.0332 (9)	0.0106 (6)	−0.0004 (7)	0.0027 (7)
C11	0.0307 (9)	0.0323 (9)	0.0492 (11)	0.0127 (7)	0.0090 (8)	0.0062 (8)
C12	0.0246 (7)	0.0282 (8)	0.0324 (9)	0.0102 (6)	−0.0018 (7)	0.0026 (7)
C13	0.0259 (7)	0.0331 (8)	0.0292 (9)	0.0126 (7)	−0.0028 (7)	0.0006 (7)
C14	0.0316 (9)	0.0334 (9)	0.0422 (10)	0.0152 (7)	0.0045 (8)	0.0038 (8)
C15	0.0432 (10)	0.0385 (10)	0.0516 (12)	0.0230 (9)	0.0000 (9)	−0.0032 (9)
C16	0.0408 (10)	0.0552 (12)	0.0475 (12)	0.0263 (10)	0.0019 (9)	−0.0101 (10)
C17	0.0432 (11)	0.0513 (12)	0.0493 (13)	0.0177 (10)	0.0186 (10)	0.0060 (10)
C18	0.0424 (10)	0.0369 (10)	0.0456 (11)	0.0157 (8)	0.0133 (9)	0.0078 (9)

Geometric parameters (Å, º) top

S1—C11	1.707 (2)	C7—C8	1.512 (2)
S1—C10	1.7306 (17)	C8—C9	1.525 (2)
N1—C1	1.460 (2)	C8—H8A	0.9900
N1—C9	1.470 (2)	C8—H8B	0.9900
N1—H1N	0.92 (2)	C9—C10	1.501 (2)
N2—C10	1.297 (2)	C9—H9	1.0000
N2—C12	1.390 (2)	C11—C12	1.361 (2)
C1—C2	1.516 (2)	C11—H11	0.9500
C1—H1A	0.9900	C12—C13	1.475 (2)
C1—H1B	0.9900	C13—C14	1.390 (2)
C2—C7	1.397 (2)	C13—C18	1.393 (3)
C2—C3	1.400 (2)	C14—C15	1.389 (3)
C3—C4	1.380 (3)	C14—H14	0.9500
C3—H3	0.9500	C15—C16	1.380 (3)
C4—C5	1.387 (3)	C15—H15	0.9500
C4—H4	0.9500	C16—C17	1.383 (3)
C5—C6	1.386 (3)	C16—H16	0.9500
C5—H5	0.9500	C17—C18	1.372 (3)
C6—C7	1.396 (2)	C17—H17	0.9500
C6—H6	0.9500	C18—H18	0.9500

C11—S1—C10	89.46 (9)	H8A—C8—H8B	108.0
C1—N1—C9	110.51 (13)	N1—C9—C10	109.12 (13)
C1—N1—H1N	110.0 (13)	N1—C9—C8	112.02 (13)
C9—N1—H1N	106.0 (13)	C10—C9—C8	112.09 (13)
C10—N2—C12	111.30 (14)	N1—C9—H9	107.8
N1—C1—C2	115.29 (14)	C10—C9—H9	107.8
N1—C1—H1A	108.5	C8—C9—H9	107.8
C2—C1—H1A	108.5	N2—C10—C9	125.27 (15)
N1—C1—H1B	108.5	N2—C10—S1	114.34 (13)
C2—C1—H1B	108.5	C9—C10—S1	120.36 (12)
H1A—C1—H1B	107.5	C12—C11—S1	110.66 (14)
C7—C2—C3	119.19 (16)	C12—C11—H11	124.7
C7—C2—C1	120.86 (14)	S1—C11—H11	124.7
C3—C2—C1	119.92 (15)	C11—C12—N2	114.22 (16)
C4—C3—C2	120.90 (17)	C11—C12—C13	126.56 (16)
C4—C3—H3	119.5	N2—C12—C13	119.21 (14)
C2—C3—H3	119.5	C14—C13—C18	118.28 (17)
C3—C4—C5	120.06 (17)	C14—C13—C12	120.88 (16)
C3—C4—H4	120.0	C18—C13—C12	120.83 (16)
C5—C4—H4	120.0	C15—C14—C13	120.51 (17)
C6—C5—C4	119.54 (17)	C15—C14—H14	119.7
C6—C5—H5	120.2	C13—C14—H14	119.7
C4—C5—H5	120.2	C16—C15—C14	120.46 (19)
C5—C6—C7	121.10 (17)	C16—C15—H15	119.8
C5—C6—H6	119.5	C14—C15—H15	119.8
C7—C6—H6	119.5	C15—C16—C17	119.16 (19)
C6—C7—C2	119.21 (15)	C15—C16—H16	120.4
C6—C7—C8	120.20 (15)	C17—C16—H16	120.4
C2—C7—C8	120.58 (15)	C18—C17—C16	120.65 (19)
C7—C8—C9	111.08 (13)	C18—C17—H17	119.7
C7—C8—H8A	109.4	C16—C17—H17	119.7
C9—C8—H8A	109.4	C17—C18—C13	120.93 (19)
C7—C8—H8B	109.4	C17—C18—H18	119.5
C9—C8—H8B	109.4	C13—C18—H18	119.5

C9—N1—C1—C2	−43.4 (2)	C8—C9—C10—N2	19.7 (2)
N1—C1—C2—C7	12.8 (2)	N1—C9—C10—S1	73.07 (17)
N1—C1—C2—C3	−169.22 (16)	C8—C9—C10—S1	−162.25 (13)
C7—C2—C3—C4	−0.7 (3)	C11—S1—C10—N2	0.18 (15)
C1—C2—C3—C4	−178.73 (16)	C11—S1—C10—C9	−178.05 (15)
C2—C3—C4—C5	0.3 (3)	C10—S1—C11—C12	0.02 (16)
C3—C4—C5—C6	0.4 (3)	S1—C11—C12—N2	−0.2 (2)
C4—C5—C6—C7	−0.8 (3)	S1—C11—C12—C13	179.92 (14)
C5—C6—C7—C2	0.4 (3)	C10—N2—C12—C11	0.3 (2)
C5—C6—C7—C8	179.40 (16)	C10—N2—C12—C13	−179.78 (15)
C3—C2—C7—C6	0.3 (2)	C11—C12—C13—C14	178.82 (19)
C1—C2—C7—C6	178.32 (16)	N2—C12—C13—C14	−1.0 (2)
C3—C2—C7—C8	−178.67 (15)	C11—C12—C13—C18	−2.1 (3)
C1—C2—C7—C8	−0.6 (2)	N2—C12—C13—C18	178.05 (16)
C6—C7—C8—C9	−160.07 (15)	C18—C13—C14—C15	−0.3 (3)
C2—C7—C8—C9	18.9 (2)	C12—C13—C14—C15	178.84 (17)
C1—N1—C9—C10	−171.71 (14)	C13—C14—C15—C16	0.0 (3)
C1—N1—C9—C8	63.57 (18)	C14—C15—C16—C17	0.1 (3)
C7—C8—C9—N1	−50.29 (18)	C15—C16—C17—C18	0.0 (3)
C7—C8—C9—C10	−173.34 (13)	C16—C17—C18—C13	−0.2 (3)
C12—N2—C10—C9	177.80 (16)	C14—C13—C18—C17	0.4 (3)
C12—N2—C10—S1	−0.32 (18)	C12—C13—C18—C17	−178.8 (2)
N1—C9—C10—N2	−104.95 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···N1ⁱ	0.95	2.54	3.341 (3)	142

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

Experimental details

Crystal data
Chemical formula	C₁₈H₁₆N₂S
M_r	292.39
Crystal system, space group	Trigonal, P3₂
Temperature (K)	173
a, c (Å)	16.223 (1), 4.8130 (3)
V (Å³)	1097.0 (1)
Z	3
Radiation type	Mo Kα
µ (mm⁻¹)	0.22
Crystal size (mm)	0.20 × 0.10 × 0.09

Data collection
Diffractometer	Bruker Kappa DUO APEXII diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2008)
T_min, T_max	0.958, 0.981
No. of measured, independent and observed [I > 2σ(I)] reflections	14735, 3676, 3205
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.669

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.084, 1.03
No. of reflections	3676
No. of parameters	194
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.22
Absolute structure	Flack (1983), 1832 Friedel pairs
Absolute structure parameter	−0.02 (6)

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···N1ⁱ	0.95	2.54	3.341 (3)	142

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

Acknowledgements

The authors thank Dr Hong Su of the University of Capetown for the data collection and structure refinement.

References

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