Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103021000/fa1032sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103021000/fa1032Isup2.hkl | |
Portable Document Format (PDF) file https://doi.org/10.1107/S0108270103021000/fa1032sup3.pdf |
CCDC reference: 226120
A solution of N,N'-di(2-methylphenyl)dithiooxamide (1.2 g, 4.0 mmol) and potassium carbonate (1.1 g, 8.0 mmol) in anhydrous DMSO (8 ml) was stirred at ~303–313 K for 1 h. 1,2-Dibromoethane (4.3 g, 22.9 mmol) was added slowly, and the reaction mixture was kept at 333–338 K for 4 h, until all the N,N'-di(2-methylphenyl)dithiooxamide had disappeared (monitored by thin-layer chromatography). The mixture was cooled, ice water was added and the organic compound was extracted with petroleum ether. The solvent was removed in vacuo and the title compound was separated on a column of alumina with petroleum ether and ethyl acetate as eluants for stepwise elution. Yellow single crystals of (I) suitable for X-ray crystallographic analysis were obtained by recrystallization from a mixture of petroleum ether and ethyl acetate. **Cg1 is the center of gravity of the phenyl ring C1 - C6.
The structure was solved by direct methods. All H atoms were positioned geometrically and refined as riding atoms, with isotropic thermal parameters set to 1.2Ueq or 1.5Ueq of the parent atoms. The distances to H atoms were set by the program and are in the range 0.93–0.97 Å.
Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
C18H18N2S2 | F(000) = 688 |
Mr = 326.46 | Dx = 1.287 Mg m−3 |
Orthorhombic, Pbcn | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2n 2ab | Cell parameters from 2043 reflections |
a = 6.7333 (9) Å | θ = 3.2–24.4° |
b = 12.6195 (16) Å | µ = 0.31 mm−1 |
c = 19.827 (3) Å | T = 293 K |
V = 1684.7 (4) Å3 | Prism, yellow |
Z = 4 | 0.3 × 0.25 × 0.2 mm |
CCD area-detector diffractometer | 1941 independent reflections |
Radiation source: sealed tube | 1270 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
ϕ and ω scans | θmax = 27.5°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→8 |
Tmin = 0.91, Tmax = 0.93 | k = −10→16 |
9287 measured reflections | l = −22→25 |
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)] = 0.058 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.147 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.05P)2 + 1.3P] where P = (Fo2 + 2Fc2)/3 |
1941 reflections | (Δ/σ)max < 0.001 |
101 parameters | Δρmax = 0.68 e Å−3 |
0 restraints | Δρmin = −0.81 e Å−3 |
C18H18N2S2 | V = 1684.7 (4) Å3 |
Mr = 326.46 | Z = 4 |
Orthorhombic, Pbcn | Mo Kα radiation |
a = 6.7333 (9) Å | µ = 0.31 mm−1 |
b = 12.6195 (16) Å | T = 293 K |
c = 19.827 (3) Å | 0.3 × 0.25 × 0.2 mm |
CCD area-detector diffractometer | 1941 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1270 reflections with I > 2σ(I) |
Tmin = 0.91, Tmax = 0.93 | Rint = 0.044 |
9287 measured reflections |
R[F2 > 2σ(F2)] = 0.058 | 0 restraints |
wR(F2) = 0.147 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.68 e Å−3 |
1941 reflections | Δρmin = −0.81 e Å−3 |
101 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.02580 (13) | 0.11165 (6) | 0.16204 (4) | 0.0686 (3) | |
N1 | 0.1607 (4) | 0.29881 (16) | 0.20454 (11) | 0.0586 (6) | |
C1 | 0.2742 (4) | 0.30486 (19) | 0.14447 (12) | 0.0514 (7) | |
C2 | 0.4483 (5) | 0.2476 (2) | 0.13862 (15) | 0.0643 (8) | |
H2 | 0.4847 | 0.2007 | 0.1726 | 0.077* | |
C3 | 0.5676 (5) | 0.2594 (2) | 0.08328 (16) | 0.0705 (8) | |
H3 | 0.6834 | 0.2198 | 0.0793 | 0.085* | |
C4 | 0.5157 (5) | 0.3298 (3) | 0.03380 (15) | 0.0689 (8) | |
H4 | 0.5963 | 0.3382 | −0.0039 | 0.083* | |
C5 | 0.3457 (5) | 0.3877 (2) | 0.03998 (14) | 0.0621 (8) | |
H5 | 0.3126 | 0.4358 | 0.0062 | 0.075* | |
C6 | 0.2204 (4) | 0.37701 (19) | 0.09524 (13) | 0.0529 (7) | |
C7 | 0.0352 (4) | 0.4414 (2) | 0.10194 (14) | 0.0598 (7) | |
H7A | −0.0779 | 0.3980 | 0.0915 | 0.090* | |
H7B | 0.0404 | 0.5002 | 0.0713 | 0.090* | |
H7C | 0.0239 | 0.4671 | 0.1473 | 0.090* | |
C8 | 0.0562 (4) | 0.21875 (19) | 0.21749 (12) | 0.0495 (6) | |
C9 | −0.0579 (5) | 0.0094 (2) | 0.21801 (14) | 0.0677 (8) | |
H9A | −0.1974 | 0.0200 | 0.2281 | 0.081* | |
H9B | −0.0440 | −0.0589 | 0.1961 | 0.081* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0913 (6) | 0.0540 (4) | 0.0606 (5) | −0.0039 (4) | 0.0056 (4) | −0.0159 (3) |
N1 | 0.0832 (17) | 0.0427 (12) | 0.0499 (12) | −0.0035 (11) | 0.0156 (12) | −0.0027 (9) |
C1 | 0.0680 (18) | 0.0400 (13) | 0.0462 (13) | −0.0082 (12) | 0.0075 (13) | −0.0061 (11) |
C2 | 0.083 (2) | 0.0516 (16) | 0.0584 (17) | 0.0045 (15) | 0.0060 (16) | 0.0005 (13) |
C3 | 0.070 (2) | 0.0679 (19) | 0.073 (2) | 0.0032 (16) | 0.0141 (17) | −0.0096 (16) |
C4 | 0.073 (2) | 0.081 (2) | 0.0530 (16) | −0.0179 (18) | 0.0134 (15) | −0.0064 (16) |
C5 | 0.074 (2) | 0.0633 (18) | 0.0488 (15) | −0.0184 (16) | −0.0047 (14) | 0.0075 (13) |
C6 | 0.0568 (16) | 0.0464 (14) | 0.0555 (15) | −0.0129 (12) | −0.0028 (13) | −0.0022 (12) |
C7 | 0.0652 (18) | 0.0520 (15) | 0.0622 (16) | −0.0111 (14) | −0.0037 (14) | 0.0004 (13) |
C8 | 0.0649 (17) | 0.0371 (12) | 0.0464 (13) | 0.0040 (12) | 0.0032 (12) | 0.0009 (10) |
C9 | 0.081 (2) | 0.0521 (16) | 0.0705 (18) | −0.0064 (15) | 0.0107 (16) | −0.0172 (14) |
S1—C8 | 1.754 (2) | C4—H4 | 0.9300 |
S1—C9 | 1.793 (3) | C5—C6 | 1.390 (4) |
N1—C8 | 1.258 (3) | C5—H5 | 0.9300 |
N1—C1 | 1.417 (3) | C6—C7 | 1.494 (4) |
C1—C2 | 1.382 (4) | C7—H7A | 0.9600 |
C1—C6 | 1.383 (4) | C7—H7B | 0.9600 |
C2—C3 | 1.368 (4) | C7—H7C | 0.9600 |
C2—H2 | 0.9300 | C8—C8i | 1.495 (5) |
C3—C4 | 1.369 (4) | C9—C9i | 1.489 (6) |
C3—H3 | 0.9300 | C9—H9A | 0.9700 |
C4—C5 | 1.364 (4) | C9—H9B | 0.9700 |
C8—S1—C9 | 101.73 (12) | C1—C6—C7 | 120.9 (2) |
C8—N1—C1 | 121.1 (2) | C5—C6—C7 | 121.6 (3) |
C2—C1—C6 | 120.5 (3) | C6—C7—H7A | 109.5 |
C2—C1—N1 | 120.0 (2) | C6—C7—H7B | 109.5 |
C6—C1—N1 | 119.2 (3) | H7A—C7—H7B | 109.5 |
C3—C2—C1 | 120.6 (3) | C6—C7—H7C | 109.5 |
C3—C2—H2 | 119.7 | H7A—C7—H7C | 109.5 |
C1—C2—H2 | 119.7 | H7B—C7—H7C | 109.5 |
C2—C3—C4 | 119.7 (3) | N1—C8—C8i | 117.34 (18) |
C2—C3—H3 | 120.1 | N1—C8—S1 | 123.79 (19) |
C4—C3—H3 | 120.1 | C8i—C8—S1 | 118.78 (15) |
C5—C4—C3 | 119.8 (3) | C9i—C9—S1 | 111.3 (2) |
C5—C4—H4 | 120.1 | C9i—C9—H9A | 109.4 |
C3—C4—H4 | 120.1 | S1—C9—H9A | 109.4 |
C4—C5—C6 | 121.9 (3) | C9i—C9—H9B | 109.4 |
C4—C5—H5 | 119.0 | S1—C9—H9B | 109.4 |
C6—C5—H5 | 119.0 | H9A—C9—H9B | 108.0 |
C1—C6—C5 | 117.5 (3) |
Symmetry code: (i) −x, y, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9B···Cg1ii | 0.97 | 2.81 | 3.683 (3) | 150 |
Symmetry code: (ii) −x+1/2, y−1/2, z. |
Experimental details
Crystal data | |
Chemical formula | C18H18N2S2 |
Mr | 326.46 |
Crystal system, space group | Orthorhombic, Pbcn |
Temperature (K) | 293 |
a, b, c (Å) | 6.7333 (9), 12.6195 (16), 19.827 (3) |
V (Å3) | 1684.7 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.31 |
Crystal size (mm) | 0.3 × 0.25 × 0.2 |
Data collection | |
Diffractometer | CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.91, 0.93 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9287, 1941, 1270 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.147, 1.00 |
No. of reflections | 1941 |
No. of parameters | 101 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.68, −0.81 |
Computer programs: SMART (Bruker, 2000), SMART, SAINT (Bruker, 2000), SHELXTL (Bruker, 2000), SHELXTL.
S1—C8 | 1.754 (2) | N1—C1 | 1.417 (3) |
S1—C9 | 1.793 (3) | C8—C8i | 1.495 (5) |
N1—C8 | 1.258 (3) | C9—C9i | 1.489 (6) |
C8—S1—C9 | 101.73 (12) | N1—C8—S1 | 123.79 (19) |
C8—N1—C1 | 121.1 (2) | C8i—C8—S1 | 118.78 (15) |
N1—C8—C8i | 117.34 (18) |
Symmetry code: (i) −x, y, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9B···Cg1ii | 0.97 | 2.813 | 3.683 (3) | 150 |
Symmetry code: (ii) −x+1/2, y−1/2, z. |
The chemistry of sulfur compounds has been the subject of intensive research in organic chemistry. As versatile intermediates and precursors, sulfur compounds have been employed to achieve the syntheses of many target compounds that are otherwise difficult to access, and thus sulfur has played an increasingly important role in organic synthesis. Organic sulfur compounds have also found important applications as? organic conductors and superconductors, and in the life sciences (Page, 1999).
Thioamides are important organic sulfur compounds. The electronegativity of the S atom and the special electronic structure of these compounds make them more reactive than the corresponding amides, and thioamides take part in diverse chemical reactions. These compounds are of both academic and industrial interest because of their high stability and lack of odour, and because they can be synthesized and refined easily (Sosnicki et al., 2001). More recently, some thioamides have shown wide? bioactivities and have been used as anti-inflammatory and fungistatic reagents (Matysiak et al., 2000) and as antituberculins. Thioamides have also served as special reagents used as chain terminators in Sanger-DNA sequencing (Schwarzer et al., 2001) and as versatile intermediates in the syntheses of antitumor agents.
We have investigated the reaction of N,N'-di(2-methylphenyl)dithiooxamide with 1,2-dibromoethane in the presence of potassium carbonate and have found that the product, (I), is a 1,4-dithiacyclohexane with a double Schiff base (see scheme). Such compounds are versatile intermediates in the synthesis of organic compounds because of their exceptional structures, and they have special utility in the synthesis of bioactive compounds (Jorgensen, 2000).
The crystal data show that the bond lengths and angles in (I) have unexceptional values and that there is a twofold axis in the molecule. The S—Csp3, S—Csp2 and Csp2═Nsp bond lengths are 1.793 (3), 1.754 (2) and 1.258 (3) Å, respectively, and are similar to those found for the compound reported by Ozarowski et al. (1988), in which the S—Csp3, S—Csp2 and Csp2═Nsp bond lengths are 1.796 (3), 1.751 (2) and 1.263 (4) Å, respectively.
Recently, there has been increased interest in non-covalent hydrogen-bridged interactions involving π acceptors (Ni et al., 2003). Jeffrey (1997) mentions this possibility and classifies these interactions as weak hydrogen bonds. In (I), weak C—H···π interactions play an important role; indeed, every molecule makes such contacts to two neighbors [C9—H9b···Cg1i; symmetry code: (i) 0.5 − x,-0.5 + y,z; Cg1i is the center of gravity of the aromatic ring]. The molecule is packed into a layer structure, with aromatic rings acting as weak proton acceptors (see Fig. 2 and Table 2). The layers lie parallel to the ab plane and are stacked along the c axis, with molecules in ?adjacent layers having alternate orientations (adjacent layers are related by a c-glide perpendicular to the b axis; Fig. 3).