organic compounds
(+)-(S,S)-1,3-Bis[(tetrahydrofuran-2-yl)methyl]thiourea
aLaboratorio de Síntesis de Complejos, Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, AP 1067, 72001 Puebla, Pue., Mexico, and bDEP Facultad de Ciencias Químicas, UANL, Guerrero y Progreso S/N, Col. Treviño, 64570 Monterrey, NL, Mexico
*Correspondence e-mail: sylvain_bernes@Hotmail.com
The title compound, C11H20N2O2S, is an enantiomerically pure heterocycle-substituted thiourea synthesized under solvent-free conditions. The thiourea unit adopts a ZZ conformation, with the HN—(C=S)—NH core almost planar and the tetrahydrofurfuryl groups placed below and above this plane. The whole molecule thus approximates to noncrystallographic C2 symmetry. Unexpectedly, the C=S group is not involved in intermolecular hydrogen bonding, as generally observed in homodisubstituted thioureas. Instead, molecules form a one-dimensional network based on weak N—H⋯O(heterocycle) hydrogen bonding, resulting in a zigzag ribbon-like structure around the crystallographic 21 screw axis along [100].
Related literature
For general background about solvent-free synthesis, see: Tanaka & Toda (2000); Jeon et al. (2005). For C2 homosubstituted thioureas, see: Bailey et al. (1997); Lai & Tiekink (2002). For common hydrogen-bonding schemes in thioureas, see: Vázquez et al. (2004); Custelcean et al. (2005); Shashidhar et al. (2006); Sadiq-ur-Rehman et al. (2007); Saxena & Pike (2007).
Experimental
Crystal data
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Data collection: XSCANS (Siemens, 1996); cell XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536808040373/ci2734sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808040373/ci2734Isup2.hkl
Under solvent-free conditions, (S)-(+)-tetrahydrofurfurylamine (0.49 g, 4.88 mmol) and CS2 (0.19 g, 2.44 mmol) were mixed at 298 K, giving a white solid. The crude was recrystallized from EtOH, affording colourless crystals of the title compound. Yield 99%; m.p. 376–378 K; [α]25D=+28.7 (c=1, CHCl3). Anal. Calcd for C11H20N2O2S: C 54.07, H 8.25, N 11.46, O 13.10, S 13.12%; found: C 53.12, H 8.18, N 11.30, O 12.98, S 13.87%. Spectroscopic data are in agreement with the X-ray formula (see archived CIF).
Methylene and methine H atoms were placed in idealized positions and refined as riding to their carrier C atoms. Amine H atoms, H2 and H12, were found in a difference map and refined with N—H bond lengths restrained to 0.86 (1) Å. For all H atoms, isotropic displacement parameters were calculated as Uiso(H) = 1.2Ueq(carrier atom).
Data collection: XSCANS (Siemens, 1996); cell
XSCANS (Siemens, 1996); data reduction: XSCANS (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C11H20N2O2S | Dx = 1.221 Mg m−3 |
Mr = 244.35 | Melting point = 376–378 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 78 reflections |
a = 7.8588 (9) Å | θ = 4.6–13.7° |
b = 10.8265 (11) Å | µ = 0.23 mm−1 |
c = 15.6196 (16) Å | T = 298 K |
V = 1329.0 (2) Å3 | Block, colourless |
Z = 4 | 0.6 × 0.6 × 0.6 mm |
F(000) = 528 |
Siemens P4 diffractometer | 2484 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.031 |
Graphite monochromator | θmax = 27.5°, θmin = 2.3° |
2θ/ω scans | h = −10→10 |
Absorption correction: ψ scan (XSCANS; Siemens, 1996) | k = −14→14 |
Tmin = 0.782, Tmax = 0.870 | l = −20→20 |
4611 measured reflections | 3 standard reflections every 97 reflections |
3026 independent reflections | intensity decay: 1% |
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)] = 0.054 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.165 | w = 1/[σ2(Fo2) + (0.0916P)2 + 0.2186P] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max = 0.001 |
3026 reflections | Δρmax = 0.22 e Å−3 |
151 parameters | Δρmin = −0.16 e Å−3 |
2 restraints | Absolute structure: Flack (1983), 1267 Friedel pairs |
0 constraints | Absolute structure parameter: −0.01 (14) |
Primary atom site location: structure-invariant direct methods |
C11H20N2O2S | V = 1329.0 (2) Å3 |
Mr = 244.35 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.8588 (9) Å | µ = 0.23 mm−1 |
b = 10.8265 (11) Å | T = 298 K |
c = 15.6196 (16) Å | 0.6 × 0.6 × 0.6 mm |
Siemens P4 diffractometer | 2484 reflections with I > 2σ(I) |
Absorption correction: ψ scan (XSCANS; Siemens, 1996) | Rint = 0.031 |
Tmin = 0.782, Tmax = 0.870 | 3 standard reflections every 97 reflections |
4611 measured reflections | intensity decay: 1% |
3026 independent reflections |
R[F2 > 2σ(F2)] = 0.054 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.165 | Δρmax = 0.22 e Å−3 |
S = 1.03 | Δρmin = −0.16 e Å−3 |
3026 reflections | Absolute structure: Flack (1983), 1267 Friedel pairs |
151 parameters | Absolute structure parameter: −0.01 (14) |
2 restraints |
x | y | z | Uiso*/Ueq | ||
S1 | 0.48959 (12) | 0.46401 (7) | 0.34087 (6) | 0.0889 (3) | |
C1 | 0.4852 (3) | 0.5875 (2) | 0.40545 (16) | 0.0582 (5) | |
N2 | 0.4051 (3) | 0.6930 (2) | 0.38410 (17) | 0.0688 (6) | |
H2 | 0.389 (5) | 0.752 (2) | 0.4186 (18) | 0.083* | |
C3 | 0.3199 (4) | 0.7142 (4) | 0.3037 (2) | 0.0845 (9) | |
H3A | 0.3768 | 0.6668 | 0.2594 | 0.101* | |
H3B | 0.3303 | 0.8009 | 0.2889 | 0.101* | |
C4 | 0.1361 (4) | 0.6803 (3) | 0.30448 (19) | 0.0750 (8) | |
H4A | 0.1225 | 0.5952 | 0.3248 | 0.090* | |
C5 | 0.0534 (7) | 0.6947 (6) | 0.2172 (3) | 0.1303 (19) | |
H5A | 0.1088 | 0.7591 | 0.1842 | 0.156* | |
H5B | 0.0582 | 0.6180 | 0.1852 | 0.156* | |
C6 | −0.1224 (7) | 0.7283 (7) | 0.2368 (3) | 0.146 (2) | |
H6A | −0.1636 | 0.7898 | 0.1967 | 0.175* | |
H6B | −0.1957 | 0.6563 | 0.2336 | 0.175* | |
C7 | −0.1204 (6) | 0.7774 (6) | 0.3230 (3) | 0.1225 (16) | |
H7A | −0.1498 | 0.8644 | 0.3220 | 0.147* | |
H7B | −0.2033 | 0.7344 | 0.3580 | 0.147* | |
O8 | 0.0435 (3) | 0.7618 (2) | 0.35753 (14) | 0.0872 (7) | |
N12 | 0.5602 (3) | 0.5888 (2) | 0.48261 (15) | 0.0677 (5) | |
H12 | 0.541 (4) | 0.651 (2) | 0.5153 (17) | 0.081* | |
C13 | 0.6525 (4) | 0.4849 (3) | 0.5184 (2) | 0.0796 (8) | |
H13A | 0.5944 | 0.4092 | 0.5026 | 0.096* | |
H13B | 0.6503 | 0.4911 | 0.5803 | 0.096* | |
C14 | 0.8356 (3) | 0.4768 (2) | 0.48913 (18) | 0.0647 (6) | |
H14A | 0.8394 | 0.4820 | 0.4265 | 0.078* | |
C15 | 0.9260 (6) | 0.3588 (3) | 0.5178 (4) | 0.1075 (14) | |
H15A | 0.8723 | 0.3243 | 0.5684 | 0.129* | |
H15B | 0.9252 | 0.2972 | 0.4727 | 0.129* | |
C16 | 1.0986 (6) | 0.3991 (4) | 0.5365 (4) | 0.1293 (18) | |
H16A | 1.1421 | 0.3569 | 0.5867 | 0.155* | |
H16B | 1.1731 | 0.3815 | 0.4885 | 0.155* | |
C17 | 1.0897 (5) | 0.5297 (5) | 0.5515 (4) | 0.132 (2) | |
H17A | 1.1046 | 0.5465 | 0.6121 | 0.158* | |
H17B | 1.1801 | 0.5711 | 0.5205 | 0.158* | |
O18 | 0.9296 (3) | 0.57528 (19) | 0.52400 (18) | 0.0850 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0894 (5) | 0.0744 (4) | 0.1029 (6) | 0.0133 (4) | −0.0215 (5) | −0.0363 (4) |
C1 | 0.0455 (10) | 0.0558 (11) | 0.0733 (14) | −0.0014 (10) | 0.0034 (11) | −0.0067 (10) |
N2 | 0.0585 (12) | 0.0615 (12) | 0.0864 (15) | 0.0100 (10) | −0.0053 (11) | −0.0065 (11) |
C3 | 0.0738 (18) | 0.098 (2) | 0.0813 (18) | 0.0236 (18) | 0.0124 (15) | 0.0169 (17) |
C4 | 0.0749 (18) | 0.0776 (17) | 0.0724 (16) | 0.0170 (15) | −0.0110 (14) | −0.0098 (14) |
C5 | 0.117 (3) | 0.194 (5) | 0.081 (2) | 0.061 (4) | −0.026 (2) | −0.034 (3) |
C6 | 0.114 (4) | 0.217 (6) | 0.107 (3) | 0.064 (4) | −0.045 (3) | −0.035 (4) |
C7 | 0.075 (2) | 0.160 (4) | 0.133 (4) | 0.036 (3) | −0.009 (2) | −0.030 (3) |
O8 | 0.0645 (11) | 0.1192 (17) | 0.0778 (12) | 0.0116 (11) | 0.0004 (10) | −0.0262 (11) |
N12 | 0.0551 (11) | 0.0755 (13) | 0.0725 (13) | −0.0009 (10) | −0.0071 (10) | −0.0105 (11) |
C13 | 0.0672 (15) | 0.0860 (19) | 0.0856 (18) | −0.0126 (14) | −0.0081 (14) | 0.0201 (16) |
C14 | 0.0654 (13) | 0.0590 (13) | 0.0698 (14) | 0.0061 (11) | −0.0113 (11) | −0.0025 (12) |
C15 | 0.107 (3) | 0.0628 (16) | 0.153 (4) | 0.0133 (17) | −0.039 (3) | 0.004 (2) |
C16 | 0.096 (3) | 0.104 (3) | 0.188 (5) | 0.032 (2) | −0.051 (3) | −0.006 (3) |
C17 | 0.0660 (19) | 0.128 (4) | 0.201 (5) | 0.005 (2) | −0.030 (3) | −0.052 (4) |
O18 | 0.0640 (11) | 0.0632 (10) | 0.1278 (18) | −0.0006 (9) | −0.0082 (12) | −0.0171 (11) |
S1—C1 | 1.675 (2) | C7—H7B | 0.97 |
C1—N12 | 1.342 (3) | N12—C13 | 1.450 (4) |
C1—N2 | 1.346 (3) | N12—H12 | 0.862 (10) |
N2—C3 | 1.442 (4) | C13—C14 | 1.513 (4) |
N2—H2 | 0.849 (10) | C13—H13A | 0.97 |
C3—C4 | 1.490 (5) | C13—H13B | 0.97 |
C3—H3A | 0.97 | C14—O18 | 1.407 (3) |
C3—H3B | 0.97 | C14—C15 | 1.529 (4) |
C4—O8 | 1.413 (4) | C14—H14A | 0.98 |
C4—C5 | 1.519 (5) | C15—C16 | 1.454 (7) |
C4—H4A | 0.98 | C15—H15A | 0.97 |
C5—C6 | 1.461 (7) | C15—H15B | 0.97 |
C5—H5A | 0.97 | C16—C17 | 1.436 (6) |
C5—H5B | 0.97 | C16—H16A | 0.97 |
C6—C7 | 1.447 (6) | C16—H16B | 0.97 |
C6—H6A | 0.97 | C17—O18 | 1.418 (5) |
C6—H6B | 0.97 | C17—H17A | 0.97 |
C7—O8 | 1.407 (5) | C17—H17B | 0.97 |
C7—H7A | 0.97 | ||
N12—C1—N2 | 114.8 (2) | C7—O8—C4 | 108.8 (3) |
N12—C1—S1 | 122.69 (19) | C1—N12—C13 | 123.9 (2) |
N2—C1—S1 | 122.5 (2) | C1—N12—H12 | 118 (2) |
C1—N2—C3 | 124.6 (3) | C13—N12—H12 | 118 (2) |
C1—N2—H2 | 124 (2) | N12—C13—C14 | 113.8 (2) |
C3—N2—H2 | 111 (3) | N12—C13—H13A | 108.8 |
N2—C3—C4 | 113.8 (3) | C14—C13—H13A | 108.8 |
N2—C3—H3A | 108.8 | N12—C13—H13B | 108.8 |
C4—C3—H3A | 108.8 | C14—C13—H13B | 108.8 |
N2—C3—H3B | 108.8 | H13A—C13—H13B | 107.7 |
C4—C3—H3B | 108.8 | O18—C14—C13 | 109.8 (2) |
H3A—C3—H3B | 107.7 | O18—C14—C15 | 106.0 (2) |
O8—C4—C3 | 110.5 (3) | C13—C14—C15 | 113.7 (3) |
O8—C4—C5 | 104.0 (3) | O18—C14—H14A | 109.1 |
C3—C4—C5 | 112.5 (4) | C13—C14—H14A | 109.1 |
O8—C4—H4A | 109.9 | C15—C14—H14A | 109.1 |
C3—C4—H4A | 109.9 | C16—C15—C14 | 104.0 (3) |
C5—C4—H4A | 109.9 | C16—C15—H15A | 111.0 |
C6—C5—C4 | 104.0 (4) | C14—C15—H15A | 111.0 |
C6—C5—H5A | 111.0 | C16—C15—H15B | 111.0 |
C4—C5—H5A | 111.0 | C14—C15—H15B | 111.0 |
C6—C5—H5B | 111.0 | H15A—C15—H15B | 109.0 |
C4—C5—H5B | 111.0 | C17—C16—C15 | 106.4 (4) |
H5A—C5—H5B | 109.0 | C17—C16—H16A | 110.4 |
C7—C6—C5 | 106.0 (4) | C15—C16—H16A | 110.4 |
C7—C6—H6A | 110.5 | C17—C16—H16B | 110.4 |
C5—C6—H6A | 110.5 | C15—C16—H16B | 110.4 |
C7—C6—H6B | 110.5 | H16A—C16—H16B | 108.6 |
C5—C6—H6B | 110.5 | O18—C17—C16 | 109.7 (4) |
H6A—C6—H6B | 108.7 | O18—C17—H17A | 109.7 |
O8—C7—C6 | 108.8 (3) | C16—C17—H17A | 109.7 |
O8—C7—H7A | 109.9 | O18—C17—H17B | 109.7 |
C6—C7—H7A | 109.9 | C16—C17—H17B | 109.7 |
O8—C7—H7B | 109.9 | H17A—C17—H17B | 108.2 |
C6—C7—H7B | 109.9 | C14—O18—C17 | 108.6 (3) |
H7A—C7—H7B | 108.3 | ||
N12—C1—N2—C3 | 178.2 (3) | N2—C1—N12—C13 | 179.6 (2) |
S1—C1—N2—C3 | −2.2 (4) | S1—C1—N12—C13 | 0.0 (4) |
C1—N2—C3—C4 | 91.0 (4) | C1—N12—C13—C14 | 84.0 (3) |
N2—C3—C4—O8 | 68.5 (4) | N12—C13—C14—O18 | 68.7 (3) |
N2—C3—C4—C5 | −175.7 (3) | N12—C13—C14—C15 | −172.8 (3) |
O8—C4—C5—C6 | −28.9 (6) | O18—C14—C15—C16 | −22.6 (5) |
C3—C4—C5—C6 | −148.5 (5) | C13—C14—C15—C16 | −143.3 (4) |
C4—C5—C6—C7 | 21.4 (7) | C14—C15—C16—C17 | 21.4 (7) |
C5—C6—C7—O8 | −6.3 (7) | C15—C16—C17—O18 | −13.3 (8) |
C6—C7—O8—C4 | −12.9 (6) | C13—C14—O18—C17 | 138.2 (4) |
C3—C4—O8—C7 | 146.8 (4) | C15—C14—O18—C17 | 15.0 (5) |
C5—C4—O8—C7 | 25.9 (5) | C16—C17—O18—C14 | −1.6 (7) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O18i | 0.85 (1) | 2.10 (2) | 2.897 (3) | 157 (3) |
N12—H12···O8ii | 0.86 (1) | 2.20 (2) | 2.978 (3) | 150 (3) |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) x+1/2, −y+3/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C11H20N2O2S |
Mr | 244.35 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 7.8588 (9), 10.8265 (11), 15.6196 (16) |
V (Å3) | 1329.0 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.23 |
Crystal size (mm) | 0.6 × 0.6 × 0.6 |
Data collection | |
Diffractometer | Siemens P4 diffractometer |
Absorption correction | ψ scan (XSCANS; Siemens, 1996) |
Tmin, Tmax | 0.782, 0.870 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4611, 3026, 2484 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.054, 0.165, 1.03 |
No. of reflections | 3026 |
No. of parameters | 151 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.22, −0.16 |
Absolute structure | Flack (1983), 1267 Friedel pairs |
Absolute structure parameter | −0.01 (14) |
Computer programs: XSCANS (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2006).
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O18i | 0.85 (1) | 2.095 (17) | 2.897 (3) | 157 (3) |
N12—H12···O8ii | 0.86 (1) | 2.197 (18) | 2.978 (3) | 150 (3) |
Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) x+1/2, −y+3/2, −z+1. |
Acknowledgements
Partial support from VIEP-UAP (grant No. GUPJ-NAT08-G) is acknowledged.
References
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The development of straightforward and eco-friendly synthetic procedures remains an important aim in organic synthesis. Many organic solvents, particularly chlorinated hydrocarbons, that are used in large quantities in organic reactions are potential threat to human health and environment. Thus, the design of chemical reactions under solvent-free conditions is getting a renewed interest. In this regard, solvent-free organic syntheses have great applied value and expansive prospects considering their advantages such as high efficiency and selectivity, easy separation and purification and environmental acceptability. All these merits are in accord with the green chemistry's requests of energy-saving, high efficiency and environmentally benign features (Tanaka & Toda, 2000; Jeon et al., 2005). On the other hand, N,N'-disubstituted thioureas have recently received much interest due to their diverse applications, such as, inter alia, antiviral, antituberculous, fungicidal, herbicidal activities, as well as tranquilizing and antidiabetic drugs, agrochemical properties, antioxidants in gasoline, corrosion inhibitors, etc. In view of these and in continuation of our earlier work on the synthesis of thioureas (Vázquez et al., 2004), we synthesized the title compound under solvent-free conditions (see experimental).
The asymmetric unit contains one molecule in general position (Fig. 1). As the amine used as starting material was enantiopure, the thiourea is found to be a pure (S,S) isomer. The central core HN—(C═S)—NH unit is close to be planar, the r.m.s. deviation from the mean plane S1/C1/N2/H2/N12/H12 being 0.039 Å. This core adopts a ZZ conformation (i.e. amine H atoms are arranged syn) and tetrahydrofurfuryl groups are placed below and above the central HN—(C═S)—NH plane. The whole molecule thus approximates a local C2 point symmetry. The observed conformation is identical to that found in other related homosubstituted thioureas (Lai & Tiekink, 2002; Bailey et al., 1997).
The ZZ conformation avoids the formation of intramolecular hydrogen bonds (Saxena & Pike, 2007). Regarding the packing structure, it is clear that the thioketone functionality does not participate in intermolecular contacts. Such a situation is unexpected, since for previously X-ray characterized chiral and non-chiral homosubstituted thioureas, one-dimensional supramolecular structures based on C═S···H—N hydrogen bonds are predominant, providing that the thiourea is in a ZZ conformation (e.g. Vázquez et al., 2004; Custelcean et al., 2005; Shashidhar et al., 2006; Sadiq-ur-Rehman et al., 2007). Instead, the crystal structure of the title compound is determined by weak N—H···O(heterocycle) hydrogen bonds, aggregating molecules in a backbone arrangement (Fig. 2), parallel to the crystallographic 21 screw axis along [100].