The crystal structures of two isomers of 5-(phenyl-iso-thia-zol-yl)-1,3,4-oxa-thia-zol-2-one.

The syntheses and crystal structures of two isomers of phenyl iso-thia-zolyl oxa-thia-zolone, C11H6N2O2S2, are described [systematic names: 5-(3-phenyl-iso-thia-zol-5-yl)-1,3,4-oxa-thia-zol-2-one, (I), and 5-(3-phenyl-iso-thia-zol-4-yl)-1,3,4-oxa-thia-zol-2-one, (II)]. There are two almost planar (r.m.s. deviations = 0.032 and 0.063 Å) mol-ecules of isomer (I) in the asymmetric unit, which form centrosymmetric tetra-mers linked by strong S⋯N [3.072 (2) Å] and S⋯O contacts [3.089 (1) Å]. The tetra-mers are π-stacked parallel to the a-axis direction. The single mol-ecule in the asymmetric unit of isomer (II) is twisted into a non-planar conformation by steric repulsion [dihedral angles between the central iso-thia-zolyl ring and the pendant oxa-thia-zolone and phenyl rings are 13.27 (6) and 61.18 (7)°, respectively], which disrupts the π-conjugation between the heteroaromatic iso-thia-zoloyl ring and the non-aromatic oxa-thia-zolone heterocycle. In the crystal of isomer (II), the strong S⋯O [3.020 (1) Å] and S⋯C contacts [3.299 (2) Å] and the non-planar structure of the mol-ecule lead to a form of π-stacking not observed in isomer (I) or other oxa-thia-zolone derivatives.

Chemical context

Compounds containing the iso­thia­zolyl moiety are well known in organic and pharmacological research, with extensive reviews on the synthesis and chemistry of the ring (Abdel-Sattar & Elgazwy, 2003 ▸) and the medicinal and industrial uses of compounds containing the iso­thia­zolyl heterocycle (Kaberdin & Potkin 2002 ▸). The solid-state structural features of iso­thia­zole derivatives have been reviewed (Abdel-Sattar & Elgazwy, 2003 ▸). In general, the iso­thia­zolyl ring is recognised as a heteroaromatic ring with extensive π-delocalization (incorporating the empty sulfur 3d-orbitals) within the ring leading to almost planar heterocycles.

Derivatives of the oxa­thia­zolone heterocycle have been known since their first preparation fifty years ago (Muhlbauer & Weiss, 1967 ▸). The facile synthesis of the heterocycle from commercially available amides reacting with chloro­carbonyl sulfenyl chloride under a range of conditions has resulted in the publication of significant libraries of substituted oxa­thia­zolone compounds (Senning & Rasmussen, 1973 ▸; Howe et al., 1978 ▸; Lin et al., 2009 ▸; Fordyce et al., 2010 ▸; Russo et al., 2015 ▸) leading to hundreds of known oxa­thia­zolone derivatives. The predominant chemistry of the heterocycle has been the thermal cyclo­reversion to the short lived n class="Chemical">nitrile sulfide [R—C≡N(+)—S(−)] , a propargyl allenyl 1,3-dipole, which can be trapped by electron-deficient π bonds in reasonable yield to give families of new heterocycles (Paton, 1989 ▸), including iso­thia­zole derivatives. As a result of the electronic properties of the short-lived nitrile sulfide inter­mediates, optimal conditions for cyclization require trapping reactions with electron-deficient dipolariphiles. Industrially, various derivatives of the oxa­thia­zolone heterocycle have been reported as potential fungicides (Klaus et al., 1965 ▸), pesticides (Hölzl, 2004 ▸) and as polymer additives (Crosby 1978 ▸). More recently, the medicinal properties of the oxa­thia­zolone heterocycle have been explored as selective inhibitors for tuberculosis (Lin et al., 2009 ▸), inflammatory diseases (Fan et al., 2014 ▸) and as proteasome inhibitors (Russo et al., 2015 ▸).

In previous structural studies on oxa­thia­zolone compounds, the non-aromatic heterocyclic rings were found to be planar with largely localized C=n class="Chemical">N and C=O double bonds. The extent of π-delocalization within the oxa­thia­zolone ring and to the substituent group and the effect on the structure and chemical properties have been discussed spectroscopically (Markgraf et al., 2007 ▸) and structurally (Krayushkin et al., 2010a ▸,b ▸). Our inter­est in this system was prompted by the possibility that catenated systems of iso­thia­zolone heterocycles may have useful electronic properties as the number of π systems is increased.

Structural commentary

There are two independent mol­ecules in the asymmetric unit of (I) (Fig. 1 ▸). In general, the two mol­ecules are not significantly different with the exception of the C—S bonds in the oxa­thia­zolone rings. In one of the mol­ecules, the C1—S1 distance [1.762 (2) Å] is longer than the same bond in the second mol­ecule, C12—S3 [1.746 (2) Å]. The difference may arise from the nature of the inter­molecular contacts to the sulfur atoms, with a strong pair of co-planar S⋯n class="Chemical">N contacts [3.086 (2) Å] in the first mol­ecule but only one S⋯N contact [3.072 (2) Å] in the second mol­ecule (which is also twisted out of the plane of the mol­ecule). These differences are due to the position of the independent mol­ecules in the tetra­mer that will be described below. For the purposes of further structural analysis, we will restrict our discussion to the first mol­ecule in the asymmetric unit. The asymmetric unit of (II) is shown in Fig. 2 ▸.

Figure 1

The mol­ecular structure of (I), showing 50% probability displacement ellipsoids.

Figure 2

The mol­ecular structure of (II), showing 50% probability displacement ellipsoids.

The bond distances and angles within the terminal phenyl rings in compounds (I) and (II) are not significantly different from the those reported for related compounds (Schriver & Zaworotko, 1995 ▸; Krayushkin et al., 2010a ▸,b ▸). The sum of the endocyclic bond angles in the iso­thia­zole moieties for both (I) and (II) (540.0°) is consistent with planar (ideal sum = 540°) π-delocalized five-membered rings, as expected. The bond lengths of the endocyclic bonds in the iso­thia­zolyl moieties in (I) and (II) are not significantly (δ > 3σ) different from the statistical averages from previous structural studies (Bridson et al., 1994 ▸, 1995 ▸). While the C=N bonds in the iso­thia­zolyl rings of (I) [1.327 (3) Å] and (II) [1.321 (2) Å] and the C=C bonds in (I) [1.361 (3) Å] and (II) [1.374 (2) Å] are mostly longer than the statistical averages for C=n class="Chemical">N [1.308 ± 0.016 Å] and C=C bonds [1.369 ± 0.002 Å], the differences are not sufficient to warrant an assessment of their cause or their effect on the structure.

The bond distances and angles within the oxa­thia­zolone rings in compounds (I) and (II) are not significantly different (δ ≥ 3σ) from the statistical averages for published crystal structures (Schriver & Zaworotko, 1995 ▸; Bridson et al. 1994 ▸, 1995 ▸; Vorontsova et al., 1996 ▸; McMillan et al., 2006 ▸; Krayushkin et al., 2010a ▸,b ▸; Nason et al., 2017 ▸). The sum of the endocyclic bond angles in the oxa­thia­zolone rings for both (I) and (II) (540.0°) is consistent with planar rings (ideal sum = 540°). The S—n class="Chemical">N bonds in the oxa­thia­zolone rings of (I) [1.685 (2) Å] and (II) [1.682 (1) Å], the Csub—O bonds in (I) [1.364 (2) Å] and (II) [1.375 (1) Å] and the inter-ring Csp 2—Csp 2 bonds in (I) [1.449 (3) Å] and (II) [1.451 (2) Å] are all consistently shorter than the statistical averages for S—N [1.696 ± 0.022 Å], Csub—O [1.392 ± 0.030 Å] and C=C bonds [1.461 ± 0.025 Å]. These differences, however, are not sufficient to warrant an assessment of their cause or their effect on the structure.

The three rings in the mol­ecules of (I) are nearly co-planar, with the dihedral angles between central iso­thia­zolyl ring and the pendant oxa­thia­zolone and phenyl rings being 3.06 (11) and 1.10 (12)°, respectively, for the S1 mol­ecule and 2.62 (9) and 6.84 (10)°, respectively, for the S3 mol­ecule. Overall r.m.s. deviations for the S1 and S3 mol­ecules are 0.032 and 0.063 Å, respectively. In contrast to the near planarity of both asymmetric mol­ecules of (I), the single mol­ecule of (II) features significant twists between the central iso­thia­zolyl ring and the pendant oxa­thia­zolone and phenyl rings [dihedral angles of 13.27 (6) and 61.18 (7)°, respectively], which may be ascribed to steric crowding. It has been argued, based on spectroscopic and structural evidence, that π-delocalization extends between the rings of oxa­thia­zolone heterocycles attached to aromatic rings, resulting in observable differences (Schriver & Zaworotko, 1995 ▸; Krayushkin et al., 2010a ▸,b ▸; Markgraf et al., 2007 ▸). In this work it can be seen that nearly identical mol­ecules result, even when torsion angles are present that would effectively disrupt any π conjugation between the rings, suggesting that the presence or absence of inter-ring π delocalization does not have a significant effect on the structure of the mol­ecules.

Supra­molecular features

In all previous reports on the solid-state structures of compounds containing the oxa­thia­zolone heterocycle, the inter­molecular inter­actions have been ignored or described as insignificant, with the exception of the recent observation of π-stacking in the styryl derivative (Nason et al., 2017 ▸). The strongest inter­molecular contacts in (I) are S3⋯n class="Chemical">N3 [3.086 (2) Å], S1⋯N4 [3.072 (2) Å] and S4⋯O1 [3.089 (1) Å] (Fig. 3 ▸). The S3⋯N3 contacts assist in the formation of a co-planar pair of identical mol­ecules within the asymmetric unit. The other mol­ecules in the asymmetric unit are connected via the S1⋯N4 [3.072 (2) Å] and S4⋯O1 [3.089 (1) Å] contacts. Taken together, the contacts between two pairs of identical mol­ecules in the asymmetric unit form a centrosymmetric tetra­mer that in turn form π-stacks parallel to the a axis. The inter­molecular contacts between sulfur and nitro­gen and oxygen have been observed in another oxa­thia­zolone ring that also resulted in π-stacking of the planar mol­ecules (Nason et al., 2017 ▸).

Figure 3

A packing diagram of (I) showing π–π stacking parallel to the a-axis direction (top). Co-planar paired head-to-head mol­ecules [green lines, S⋯N distance of 3.086 (2) Å] and paired mol­ecules separated by out-of-plane contacts [blue lines, S⋯N distance of 3.072 (2) Å], violet lines S⋯O distance of 3.089 (1) Å].

The strongest inter­molecular contacts in (II) are S2⋯O2 [3.020 (1) Å], S1⋯C10 [3.299 (2) Å] and C4⋯O2 [3.100 (2) Å] (Fig. 4 ▸). The C4⋯O2 contact, while significantly shorter than the sum of van der Waals radii for the atoms, is to some extent, the result of the adjacent stronger S2⋯O2 contact. The geometry of the mol­ecule (II) reduces the opportunity for the formation of π-stacks but it is observed that the centroid of the terminal phenyl ring is 3.632 (2) Å above and parallel to the nearly planar portion of an adjacent mol­ecule formed by the two heterocyclic rings (Fig. 4 ▸).

Figure 4

A packing diagram of (II) within the unit cell showing mol­ecular pairs linked by S⋯O contacts of 3.020 (1) Å.

Database survey

A search of the Cambridge Structural Database (Version 5.38; Groom et al., 2016 ▸) revealed that eleven crystal structures of oxa­thia­zolone derivatives in peer-reviewed journals have been reported previously (Bridson et al., 1994 ▸, 1995 ▸; Schriver & Zaworotko, 1995 ▸; Vorontsova et al., 1996 ▸; McMillan et al., 2006 ▸; Krayushkin et al., 2010a ▸,b ▸; Nason et al., 2017 ▸), which have been partially reviewed (McMillan et al., 2006 ▸ and Krayushkin et al., 2010a ▸,b ▸). An additional five X-ray oxa­thia­zolone crystal structures have been reported in theses (Demas, 1982 ▸; Zhu, 1997 ▸). There are also two published gas-phase electron-diffraction structures of oxa­thia­zolone derivatives (n class="Chemical">Bak et al., 1978 ▸, 1982 ▸). The structures fall into two groups: those that feature a Csp 2—Csp 3 bond between the heterocycle and the saturated organic substituent and those that feature a Csp 2—Csp 2 bond between the heterocycle and the unsaturated organic substituent (either a phenyl group, heterocyclic ring or alkenyl moiety).

Synthesis and crystallization

Compound (I) was prepared following a local variation of literature methods (Howe et al., 1978 ▸). 3-Phenyl­iso­thia­zole-4-carbonamide (Zhu, 1997 ▸) (2.90 g, 14.2 mmol) was placed in 50 ml of toluene under nitro­gen and chloro­carbonyl sulfenyl chloride (4.20 g, 32.0 mmol, approximately 2 × molar excess) was added dropwise to the stirred solution. The resulting mixture was heated (363–373 K) under nitro­gen for 1.5 h and allowed to evaporate to a solid residue. The evaporate was recrystallized from n class="Chemical">toluene solution to give colourless needle-shaped crystals (Fig. 5 ▸) (3.20 g, 12.2 mmol, 86%). Elemental analysis: calculated % (Found %): 50.35 (50.2); H 2.3 (2.4); N 10.7 (10.7). IR (KBr): 3100 (w), 1812 (w), 1749 (s), 1735 (s), 1598 (s), 1182 (m), 1088 (m), 1014 (w), 959 (s), 884 (ms). 834 (ms), 765 (s), 734 (s), 692 (ms). 1H NMR (400 MHz, CDCl3, δ p.p.m.): 9.28 (5, 1H), 7.61 (m, 2H), 7.46 (m, 3H). 13C NMR (100 MHz, CDCl3, δ p.p.m.): 172.7,167.0, 154.1, 152.1, 134.0, 129.6, 129.0, 128.2, 123.3. MS (EI): C11H6N2O2S2 requires (M +), 262.301, found m/e (%, assign.): 262 (22, M+), 218 (2, M--CO2), 188 (78, M–CONS), 186 (100, C6H5[CCCNS)CN), 160 (1 3, M–COCONS), 135 (26, C6H5CNS), 103 (13, C6H5CN), 77 (29, C6H5). UV–visible spectroscopy (hexa­ne) λxax (log ∊) : 275–230 nm (4.11), 197 nm (4.72).

Figure 5

A photograph of crystals of (I) (5 × 5 mm background grid).

Compound (II) prepared following a local variation of literature methods (Howe et al., 1978 ▸). 3-Phenyl­iso­thia­zole-5-carbonamide (Zhu, 1997 ▸) (4.08 g, 20.0 mmol) was placed in 50 ml of toluene under nitro­gen and chloro­carbonyl sulfenyl chloride (6.50 g, 50.0 mmol, approximately 2.5 × molar excess) was added dropwise to the stirred solution. The resulting mixture was heated (363–373 K) under nitro­gen for 8.5 h and allowed to evaporate to a solid residue (6.093 g). The evaporate was recrystallized from n class="Chemical">toluene solution to give colourless block-shaped crystals (Fig. 6 ▸) (4.20 g, 20.6 mmol, 83%), Elemental analysis: calculated % (found%) 50.35 (50.0); H 2.3 (2.35); N 10.7 (10.5). IR (KBr): 3097 (w), 3066 (w), 3032 (w), 1813 (ms), 1759 (s), 1738 (s), 1600 (ms), 1590 (ms), 1517 (s), 1496 (s), 1055 (ms), 973 (s), 902 (s), 776 (s), 695 (s) cm−1. 1H NMR (400 MHz, CDCl3, δ p.p.m.): 7.425–7.487 (m, 3H), 7.906–7.937 (m, 2H), 7.976 (5, 1H). 13C NMR (100MHz, CDCl3, δ p.p.m.): 171.5, 167.9, 150.7, 150.5, 133.4, 129.9, 128.9, 126.8, 122.5. MS (EI): C11H6N2O2S2 requires (M +), 262.301, found m/e (%, assign.): 262 (52, M+), 218 (3, M-CO2), 188 (100, M–CONS), 160 (9, M–COCONS), 135 (2, M–HC–C­COCONS). UV–visible spectroscopy (hexa­ne) λxax (log ∊) : 283 nm (4.25), 248 nm (4.36), 203 nm (94.49).

Figure 6

A photograph of crystals of (II) (5 × 5 mm background grid).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1 ▸. H atoms were positioned geometrically (C—H = 0.93 Å) and refined as riding with U iso(H) = 1.2U eq(C).

Table 1

Experimental details

	(I)	(II)
Crystal data
Chemical formula	C11H6N2O2S2	C11H6N2O2S2
M r	262.30	262.30
Crystal system, space group	Triclinic, P	Monoclinic, P21/c
Temperature (K)	296	296
a, b, c (Å)	7.2739 (7), 11.2713 (11), 14.6909 (15)	9.7202 (6), 9.9723 (6), 11.2165 (7)
α, β, γ (°)	87.562 (1), 78.341 (1), 71.624 (1)	90, 90.399 (1), 90
V (Å3)	1119.16 (19)	1087.22 (12)
Z	4	4
Radiation type	Mo Kα	Mo Kα
μ (mm−1)	0.46	0.48
Crystal size (mm)	0.49 × 0.25 × 0.14	0.48 × 0.43 × 0.37
Data collection
Diffractometer	Bruker APEXII CCD	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2008 ▸)	Multi-scan (SADABS; Bruker, 2008 ▸)
T min, T max	0.804, 0.936	0.719, 0.837
No. of measured, independent and observed [I > 2σ(I)] reflections	7476, 3862, 3485	8041, 2362, 2228
R int	0.015	0.017
(sin θ/λ)max (Å−1)	0.595	0.639
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.031, 0.106, 1.04	0.030, 0.083, 1.02
No. of reflections	3862	2362
No. of parameters	308	155
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.33, −0.23	0.37, −0.28

Computer programs: APEX2 and SAINT (Bruker, 2008 ▸), SHELXS97 (Sheldrick, 2008 ▸) and SHELXL2014 (Sheldrick, 2015 ▸).

Crystal structure: contains datablock(s) I, II, ms003_0m. DOI: 10.1107/S2056989017015067/hb7705sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989017015067/hb7705Isup2.hkl

Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989017015067/hb7705IIsup3.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989017015067/hb7705Isup4.cml

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989017015067/hb7705IIsup5.cml

CCDC references: 1580338, 1580337

Additional supporting information: crystallographic information; 3D view; checkCIF report

C11H6N2O2S2	Z = 4
Mr = 262.30	F(000) = 536
Triclinic, P1	Dx = 1.557 Mg m−3
a = 7.2739 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.2713 (11) Å	Cell parameters from 5699 reflections
c = 14.6909 (15) Å	θ = 2.4–28.6°
α = 87.562 (1)°	µ = 0.46 mm−1
β = 78.341 (1)°	T = 296 K
γ = 71.624 (1)°	Needle, colourless
V = 1119.16 (19) Å3	0.49 × 0.25 × 0.14 mm

Bruker APEXII CCD diffractometer	3485 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.015
φ and ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −5→8
Tmin = 0.804, Tmax = 0.936	k = −13→13
7476 measured reflections	l = −17→17
3862 independent reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.031	w = 1/[σ2(Fo2) + (0.0697P)2 + 0.2729P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.106	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.33 e Å−3
3862 reflections	Δρmin = −0.23 e Å−3
308 parameters	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.031 (3)
Primary atom site location: structure-invariant direct methods

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
S1	0.85294 (8)	0.03895 (4)	0.15683 (4)	0.05223 (17)
O1	0.8238 (2)	0.18576 (13)	0.30252 (9)	0.0593 (4)
N1	0.8263 (3)	0.12000 (15)	0.05875 (12)	0.0510 (4)
C1	0.8229 (3)	0.17293 (17)	0.22295 (13)	0.0446 (4)
S2	0.77918 (10)	0.29901 (5)	−0.10629 (4)	0.05823 (18)
O2	0.7971 (2)	0.27252 (11)	0.16249 (8)	0.0443 (3)
N2	0.7537 (3)	0.44255 (17)	−0.14107 (11)	0.0541 (4)
C2	0.8016 (3)	0.23440 (17)	0.07498 (12)	0.0415 (4)
S3	0.59888 (8)	0.83750 (5)	0.55508 (4)	0.05152 (17)
O3	0.6679 (3)	0.59670 (16)	0.59752 (14)	0.0797 (5)
N3	0.4193 (2)	0.89051 (14)	0.49359 (11)	0.0454 (4)
C3	0.7806 (3)	0.33109 (18)	0.00604 (12)	0.0415 (4)
S4	0.09624 (8)	0.94818 (4)	0.37616 (4)	0.05119 (17)
O4	0.4345 (2)	0.68529 (12)	0.51338 (9)	0.0472 (3)
N4	−0.0487 (3)	0.89146 (15)	0.33086 (11)	0.0479 (4)
C4	0.7628 (3)	0.45417 (17)	0.01441 (12)	0.0419 (4)
H4B	0.7607	0.4931	0.0693	0.050*
C5	0.7479 (3)	0.51552 (18)	−0.07130 (12)	0.0410 (4)
C6	0.7266 (3)	0.64887 (18)	−0.08776 (13)	0.0425 (4)
C7	0.7228 (3)	0.72818 (19)	−0.01704 (14)	0.0503 (5)
H7A	0.7348	0.6969	0.0418	0.060*
C8	0.7015 (3)	0.8528 (2)	−0.03326 (18)	0.0604 (6)
H8A	0.6980	0.9050	0.0149	0.073*
C9	0.6854 (3)	0.9007 (2)	−0.12035 (19)	0.0652 (6)
H9A	0.6719	0.9847	−0.1312	0.078*
C10	0.6895 (4)	0.8231 (2)	−0.19106 (17)	0.0658 (6)
H10A	0.6784	0.8551	−0.2498	0.079*
C11	0.7101 (3)	0.6982 (2)	−0.17573 (15)	0.0553 (5)
H11A	0.7129	0.6467	−0.2242	0.066*
C12	0.5796 (3)	0.68671 (19)	0.56116 (15)	0.0526 (5)
C13	0.3557 (3)	0.80060 (16)	0.47969 (12)	0.0396 (4)
C14	0.2024 (3)	0.81178 (16)	0.42756 (12)	0.0399 (4)
C15	0.1224 (3)	0.72317 (17)	0.40912 (12)	0.0411 (4)
H15A	0.1576	0.6415	0.4299	0.049*
C16	−0.0219 (3)	0.77277 (16)	0.35387 (12)	0.0400 (4)
C17	−0.1434 (3)	0.70474 (18)	0.32326 (12)	0.0430 (4)
C18	−0.2967 (3)	0.7675 (2)	0.27896 (14)	0.0523 (5)
H18A	−0.3229	0.8525	0.2681	0.063*
C19	−0.4109 (3)	0.7038 (2)	0.25083 (15)	0.0595 (6)
H19A	−0.5127	0.7462	0.2207	0.071*
C20	−0.3750 (3)	0.5778 (2)	0.26715 (16)	0.0622 (6)
H20A	−0.4528	0.5355	0.2485	0.075*
C21	−0.2239 (4)	0.5153 (2)	0.31101 (18)	0.0665 (6)
H21A	−0.1988	0.4303	0.3219	0.080*
C22	−0.1083 (3)	0.5782 (2)	0.33915 (16)	0.0551 (5)
H22A	−0.0063	0.5351	0.3690	0.066*

	U11	U22	U33	U12	U13	U23
S1	0.0666 (4)	0.0408 (3)	0.0557 (3)	−0.0208 (2)	−0.0206 (2)	0.0026 (2)
O1	0.0852 (11)	0.0496 (8)	0.0412 (8)	−0.0173 (7)	−0.0144 (7)	0.0018 (6)
N1	0.0606 (11)	0.0476 (9)	0.0501 (9)	−0.0188 (8)	−0.0199 (8)	−0.0004 (7)
C1	0.0459 (10)	0.0403 (9)	0.0471 (11)	−0.0130 (8)	−0.0093 (8)	0.0029 (8)
S2	0.0818 (4)	0.0563 (3)	0.0435 (3)	−0.0271 (3)	−0.0187 (3)	−0.0022 (2)
O2	0.0543 (8)	0.0386 (7)	0.0404 (7)	−0.0131 (6)	−0.0127 (6)	0.0008 (5)
N2	0.0673 (11)	0.0586 (10)	0.0407 (9)	−0.0234 (9)	−0.0148 (8)	0.0033 (7)
C2	0.0387 (9)	0.0452 (10)	0.0420 (9)	−0.0133 (8)	−0.0108 (7)	−0.0007 (7)
S3	0.0545 (3)	0.0546 (3)	0.0554 (3)	−0.0224 (2)	−0.0255 (2)	0.0045 (2)
O3	0.0906 (13)	0.0567 (10)	0.1022 (14)	−0.0145 (9)	−0.0602 (11)	0.0188 (9)
N3	0.0500 (9)	0.0432 (8)	0.0505 (9)	−0.0191 (7)	−0.0202 (7)	0.0050 (7)
C3	0.0358 (9)	0.0496 (10)	0.0399 (9)	−0.0125 (8)	−0.0105 (7)	0.0008 (7)
S4	0.0666 (3)	0.0398 (3)	0.0594 (3)	−0.0221 (2)	−0.0330 (3)	0.0094 (2)
O4	0.0534 (8)	0.0396 (7)	0.0538 (8)	−0.0150 (6)	−0.0225 (6)	0.0052 (6)
N4	0.0575 (10)	0.0443 (9)	0.0500 (9)	−0.0191 (7)	−0.0244 (7)	0.0048 (7)
C4	0.0408 (10)	0.0469 (10)	0.0387 (9)	−0.0130 (8)	−0.0099 (7)	−0.0016 (7)
C5	0.0322 (9)	0.0530 (10)	0.0381 (9)	−0.0136 (7)	−0.0070 (7)	−0.0002 (8)
C6	0.0329 (9)	0.0512 (10)	0.0434 (9)	−0.0129 (7)	−0.0084 (7)	0.0039 (8)
C7	0.0424 (10)	0.0569 (12)	0.0515 (11)	−0.0151 (9)	−0.0098 (8)	0.0013 (9)
C8	0.0518 (12)	0.0536 (12)	0.0756 (15)	−0.0155 (10)	−0.0120 (11)	−0.0060 (10)
C9	0.0525 (13)	0.0535 (12)	0.0885 (17)	−0.0163 (10)	−0.0142 (11)	0.0128 (12)
C10	0.0649 (15)	0.0684 (14)	0.0657 (14)	−0.0224 (11)	−0.0186 (11)	0.0252 (12)
C11	0.0554 (12)	0.0638 (13)	0.0487 (11)	−0.0201 (10)	−0.0139 (9)	0.0073 (9)
C12	0.0551 (12)	0.0499 (11)	0.0563 (12)	−0.0133 (9)	−0.0248 (9)	0.0056 (9)
C13	0.0423 (10)	0.0378 (9)	0.0394 (9)	−0.0129 (7)	−0.0094 (7)	0.0012 (7)
C14	0.0419 (10)	0.0391 (9)	0.0399 (9)	−0.0125 (7)	−0.0115 (7)	0.0016 (7)
C15	0.0418 (10)	0.0377 (9)	0.0456 (10)	−0.0134 (7)	−0.0119 (8)	0.0033 (7)
C16	0.0411 (10)	0.0416 (9)	0.0380 (9)	−0.0139 (7)	−0.0081 (7)	0.0002 (7)
C17	0.0419 (10)	0.0496 (10)	0.0391 (9)	−0.0179 (8)	−0.0046 (7)	−0.0051 (7)
C18	0.0532 (12)	0.0622 (12)	0.0491 (11)	−0.0252 (10)	−0.0164 (9)	0.0030 (9)
C19	0.0531 (12)	0.0857 (16)	0.0502 (11)	−0.0313 (11)	−0.0171 (9)	−0.0032 (11)
C20	0.0600 (14)	0.0822 (16)	0.0566 (12)	−0.0385 (12)	−0.0090 (10)	−0.0175 (11)
C21	0.0719 (16)	0.0575 (13)	0.0790 (16)	−0.0310 (11)	−0.0153 (12)	−0.0107 (11)
C22	0.0540 (12)	0.0494 (11)	0.0671 (13)	−0.0195 (9)	−0.0170 (10)	−0.0051 (9)

S1—N1	1.6845 (17)	C7—C8	1.380 (3)
S1—C1	1.7616 (19)	C7—H7A	0.9300
O1—C1	1.185 (2)	C8—C9	1.380 (3)
N1—C2	1.271 (2)	C8—H8A	0.9300
C1—O2	1.391 (2)	C9—C10	1.376 (4)
S2—N2	1.6406 (18)	C9—H9A	0.9300
S2—C3	1.7071 (18)	C10—C11	1.382 (3)
O2—C2	1.364 (2)	C10—H10A	0.9300
N2—C5	1.327 (2)	C11—H11A	0.9300
C2—C3	1.449 (3)	C13—C14	1.447 (3)
S3—N3	1.6790 (16)	C14—C15	1.365 (3)
S3—C12	1.746 (2)	C15—C16	1.417 (3)
O3—C12	1.187 (3)	C15—H15A	0.9300
N3—C13	1.278 (2)	C16—C17	1.479 (3)
C3—C4	1.361 (3)	C17—C22	1.386 (3)
S4—N4	1.6457 (17)	C17—C18	1.387 (3)
S4—C14	1.7084 (18)	C18—C19	1.384 (3)
O4—C13	1.361 (2)	C18—H18A	0.9300
O4—C12	1.385 (2)	C19—C20	1.380 (4)
N4—C16	1.329 (2)	C19—H19A	0.9300
C4—C5	1.417 (3)	C20—C21	1.371 (4)
C4—H4B	0.9300	C20—H20A	0.9300
C5—C6	1.476 (3)	C21—C22	1.386 (3)
C6—C7	1.390 (3)	C21—H21A	0.9300
C6—C11	1.398 (3)	C22—H22A	0.9300
N1—S1—C1	93.13 (8)	C9—C10—H10A	119.6
C2—N1—S1	109.43 (14)	C11—C10—H10A	119.6
O1—C1—O2	122.21 (17)	C10—C11—C6	120.3 (2)
O1—C1—S1	131.23 (16)	C10—C11—H11A	119.9
O2—C1—S1	106.56 (13)	C6—C11—H11A	119.9
N2—S2—C3	94.78 (9)	O3—C12—O4	122.3 (2)
C2—O2—C1	111.28 (14)	O3—C12—S3	130.15 (18)
C5—N2—S2	110.54 (13)	O4—C12—S3	107.58 (13)
N1—C2—O2	119.58 (17)	N3—C13—O4	120.27 (17)
N1—C2—C3	124.86 (17)	N3—C13—C14	123.90 (17)
O2—C2—C3	115.55 (16)	O4—C13—C14	115.82 (16)
N3—S3—C12	93.31 (9)	C15—C14—C13	128.92 (17)
C13—N3—S3	108.63 (13)	C15—C14—S4	109.41 (14)
C4—C3—C2	129.89 (17)	C13—C14—S4	121.66 (14)
C4—C3—S2	108.82 (14)	C14—C15—C16	110.62 (16)
C2—C3—S2	121.28 (14)	C14—C15—H15A	124.7
N4—S4—C14	94.50 (9)	C16—C15—H15A	124.7
C13—O4—C12	110.20 (15)	N4—C16—C15	115.12 (16)
C16—N4—S4	110.35 (13)	N4—C16—C17	119.36 (16)
C3—C4—C5	111.36 (16)	C15—C16—C17	125.51 (16)
C3—C4—H4B	124.3	C22—C17—C18	118.80 (18)
C5—C4—H4B	124.3	C22—C17—C16	120.93 (18)
N2—C5—C4	114.50 (17)	C18—C17—C16	120.26 (17)
N2—C5—C6	119.40 (16)	C19—C18—C17	120.2 (2)
C4—C5—C6	126.10 (16)	C19—C18—H18A	119.9
C7—C6—C11	118.40 (19)	C17—C18—H18A	119.9
C7—C6—C5	121.30 (17)	C20—C19—C18	120.6 (2)
C11—C6—C5	120.29 (18)	C20—C19—H19A	119.7
C8—C7—C6	120.7 (2)	C18—C19—H19A	119.7
C8—C7—H7A	119.7	C21—C20—C19	119.5 (2)
C6—C7—H7A	119.7	C21—C20—H20A	120.2
C7—C8—C9	120.5 (2)	C19—C20—H20A	120.2
C7—C8—H8A	119.7	C20—C21—C22	120.3 (2)
C9—C8—H8A	119.7	C20—C21—H21A	119.8
C10—C9—C8	119.4 (2)	C22—C21—H21A	119.8
C10—C9—H9A	120.3	C17—C22—C21	120.6 (2)
C8—C9—H9A	120.3	C17—C22—H22A	119.7
C9—C10—C11	120.7 (2)	C21—C22—H22A	119.7

C11H6N2O2S2	F(000) = 536
Mr = 262.30	Dx = 1.602 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.7202 (6) Å	Cell parameters from 6714 reflections
b = 9.9723 (6) Å	θ = 2.7–28.3°
c = 11.2165 (7) Å	µ = 0.48 mm−1
β = 90.399 (1)°	T = 296 K
V = 1087.22 (12) Å3	Block, colorless
Z = 4	0.48 × 0.43 × 0.37 mm

Bruker APEXII CCD diffractometer	2228 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.017
Absorption correction: multi-scan (SADABS; Bruker, 2008)	θmax = 27.0°, θmin = 2.9°
Tmin = 0.719, Tmax = 0.837	h = −12→12
8041 measured reflections	k = −12→9
2362 independent reflections	l = −14→14

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.030	w = 1/[σ2(Fo2) + (0.0465P)2 + 0.4061P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.083	(Δ/σ)max = 0.001
S = 1.02	Δρmax = 0.37 e Å−3
2362 reflections	Δρmin = −0.28 e Å−3
155 parameters	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.018 (2)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
S2	0.45224 (4)	0.17168 (4)	0.50567 (3)	0.04262 (13)
S1	0.88687 (4)	0.63218 (4)	0.59213 (4)	0.04650 (14)
O1	0.65815 (9)	0.53305 (10)	0.65111 (8)	0.0330 (2)
C1	0.74809 (14)	0.63165 (15)	0.69017 (12)	0.0365 (3)
C3	0.62185 (13)	0.35992 (13)	0.50912 (11)	0.0288 (3)
O2	0.72696 (12)	0.69783 (14)	0.77664 (11)	0.0542 (3)
C2	0.70630 (13)	0.47087 (13)	0.55025 (10)	0.0288 (3)
N2	0.55493 (14)	0.18187 (13)	0.38899 (11)	0.0427 (3)
N1	0.82008 (12)	0.51010 (13)	0.50596 (10)	0.0395 (3)
C4	0.51836 (13)	0.30589 (14)	0.57667 (12)	0.0330 (3)
H4	0.4894	0.3384	0.6501	0.040*
C5	0.63936 (13)	0.28477 (14)	0.40146 (11)	0.0325 (3)
C6	0.74116 (14)	0.31005 (14)	0.30578 (11)	0.0337 (3)
C11	0.83741 (15)	0.21201 (15)	0.27851 (13)	0.0386 (3)
H11A	0.8384	0.1317	0.3206	0.046*
C7	0.73957 (18)	0.42883 (17)	0.24153 (14)	0.0472 (4)
H7A	0.6757	0.4951	0.2595	0.057*
C10	0.93225 (15)	0.23383 (18)	0.18830 (14)	0.0465 (4)
H10A	0.9976	0.1687	0.1710	0.056*
C9	0.92952 (19)	0.3518 (2)	0.12467 (15)	0.0530 (4)
H9A	0.9927	0.3662	0.0641	0.064*
C8	0.8330 (2)	0.4488 (2)	0.15076 (15)	0.0560 (4)
H8A	0.8307	0.5280	0.1070	0.067*

	U11	U22	U33	U12	U13	U23
S2	0.0448 (2)	0.0372 (2)	0.0460 (2)	−0.01130 (15)	0.00795 (16)	−0.00051 (15)
S1	0.0414 (2)	0.0518 (3)	0.0465 (2)	−0.01591 (16)	0.01521 (16)	−0.01786 (17)
O1	0.0314 (4)	0.0366 (5)	0.0311 (4)	−0.0004 (4)	0.0070 (3)	−0.0061 (4)
C1	0.0343 (6)	0.0385 (7)	0.0368 (7)	0.0007 (5)	0.0045 (5)	−0.0079 (6)
C3	0.0290 (6)	0.0297 (6)	0.0277 (6)	0.0022 (5)	0.0018 (4)	0.0015 (5)
O2	0.0487 (6)	0.0632 (7)	0.0508 (6)	−0.0034 (5)	0.0123 (5)	−0.0286 (6)
C2	0.0309 (6)	0.0307 (6)	0.0248 (5)	0.0034 (5)	0.0032 (4)	−0.0011 (5)
N2	0.0485 (7)	0.0387 (7)	0.0409 (6)	−0.0091 (5)	0.0072 (5)	−0.0070 (5)
N1	0.0380 (6)	0.0447 (7)	0.0359 (6)	−0.0089 (5)	0.0103 (5)	−0.0122 (5)
C4	0.0341 (6)	0.0325 (6)	0.0325 (6)	0.0005 (5)	0.0038 (5)	0.0025 (5)
C5	0.0345 (6)	0.0321 (6)	0.0310 (6)	0.0003 (5)	0.0017 (5)	−0.0014 (5)
C6	0.0359 (7)	0.0375 (7)	0.0277 (6)	−0.0039 (5)	0.0018 (5)	−0.0069 (5)
C11	0.0390 (7)	0.0394 (7)	0.0375 (7)	−0.0018 (6)	−0.0013 (5)	−0.0091 (6)
C7	0.0556 (9)	0.0439 (9)	0.0422 (8)	0.0062 (7)	0.0132 (7)	0.0012 (7)
C10	0.0381 (7)	0.0568 (10)	0.0448 (8)	−0.0001 (7)	0.0056 (6)	−0.0179 (7)
C9	0.0525 (9)	0.0679 (11)	0.0389 (8)	−0.0095 (8)	0.0164 (7)	−0.0097 (8)
C8	0.0709 (11)	0.0543 (10)	0.0432 (8)	−0.0021 (8)	0.0166 (8)	0.0065 (7)

S2—N2	1.6546 (13)	C5—C6	1.4864 (18)
S2—C4	1.6827 (14)	C6—C7	1.386 (2)
S1—N1	1.6820 (12)	C6—C11	1.389 (2)
S1—C1	1.7463 (14)	C11—C10	1.391 (2)
O1—C2	1.3750 (14)	C11—H11A	0.9300
O1—C1	1.3849 (17)	C7—C8	1.383 (2)
C1—O2	1.1921 (17)	C7—H7A	0.9300
C3—C4	1.3737 (18)	C10—C9	1.376 (3)
C3—C5	1.4324 (17)	C10—H10A	0.9300
C3—C2	1.4511 (18)	C9—C8	1.380 (3)
C2—N1	1.2770 (17)	C9—H9A	0.9300
N2—C5	1.3208 (18)	C8—H8A	0.9300
C4—H4	0.9300
N2—S2—C4	95.45 (6)	C3—C5—C6	127.12 (12)
N1—S1—C1	93.61 (6)	C7—C6—C11	119.48 (13)
C2—O1—C1	111.27 (10)	C7—C6—C5	121.01 (13)
O2—C1—O1	122.58 (13)	C11—C6—C5	119.50 (13)
O2—C1—S1	130.46 (12)	C6—C11—C10	120.07 (15)
O1—C1—S1	106.96 (9)	C6—C11—H11A	120.0
C4—C3—C5	110.58 (12)	C10—C11—H11A	120.0
C4—C3—C2	122.58 (12)	C8—C7—C6	120.03 (15)
C5—C3—C2	126.64 (11)	C8—C7—H7A	120.0
N1—C2—O1	118.86 (12)	C6—C7—H7A	120.0
N1—C2—C3	126.82 (12)	C9—C10—C11	120.04 (15)
O1—C2—C3	114.23 (11)	C9—C10—H10A	120.0
C5—N2—S2	109.98 (10)	C11—C10—H10A	120.0
C2—N1—S1	109.27 (9)	C10—C9—C8	119.98 (15)
C3—C4—S2	109.25 (10)	C10—C9—H9A	120.0
C3—C4—H4	125.4	C8—C9—H9A	120.0
S2—C4—H4	125.4	C9—C8—C7	120.40 (17)
N2—C5—C3	114.74 (12)	C9—C8—H8A	119.8
N2—C5—C6	118.14 (12)	C7—C8—H8A	119.8