2-Phenyl-4H-thia­zolo[3,2-a][1,3,5]­triazine-4-thione

The title compound, C₁₁H₇N₃S₂, was synthesized from benzoyl chloride, ammonium thio­cyanate and 2-amino­thia­zole in dry acetone. The whole molecule is essentially planar. The structure was determined using data from a non-merohedrally twinned crystal with a refined twin fraction of 0.523 (1). The structure is stabilized by short inter­molecular S...S [3.491 (1) Å] and π–π stacking inter­actions, as well as weak C—H...N and C—H...S hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.031
• wR factor = 0.088
• Data-to-parameter ratio = 19.0

checkCIF/PLATON results

No syntax errors found



Alert level A
TYPE059_ALERT_1_A  _diffrn_reflns_av_R_equivalents is not of type numb.

Author Response: The value output was 0.0, i.e. not defined due to twin pairing errors.

REFLT03_ALERT_3_A  Reflection count > 15% excess reflns - sys abs data present?
           From the CIF: _diffrn_reflns_theta_max           26.46
           From the CIF: _diffrn_reflns_theta_full          26.46
           From the CIF: _reflns_number_total               2777
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         2117
           Completeness (_total/calc)            131.18%

Author Response: The crystal under investigation was non-merohedrally twinned (see _exptl_special_details for details). The data were integrated using TWINSAINT, equivalent reflections were merged in TWINABS, and all reflections having at least one contribution from the major component were used for the hklf 5 refinement. Due to "twin pairing errors" (equivalent reflections being counted as overlapping for one reflection, but as not overlapped for an equivalent one) the merging in TWINABS is incomplete, thus resulting in too many independent reflections.

Alert level B
PLAT021_ALERT_1_B Ratio Unique / Expected Reflections too High ...       1.31

Author Response: The data were integrated using TWINSAINT, equivalent reflections were merged in TWINABS, and all reflections having at least one contribution from the major component were used for the hklf 5 refinement. Due to "twin pairing errors" (equivalent reflections being counted as overlapping for one reflection, but as not overlapped for an equivalent one) the merging in TWINABS is incomplete, thus resulting in too many independent reflections.

   2 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Fused heterocyclic 1,3,5-triazines possess a wide array of biological activities such as herbicidal activity (Vicentini et al., 2004), antitumor activity (Lakomska et al., 2005), and inhibitory activity against the enzymes phosphodiesterase (PED) (Senga et al., 1982; Leroux et al., 1999), which is expected to be the target for the treatment of diseases like asthma, diabetes mellitus, and thrombosis. They are also able to block dihydrofolate reductase (DHFR), the inhibition of which leads to cell death (Lee & Chui, 1999). The title compound (I) is an example of a such a fused heterocyclic 1,3,5-triazine.

The whole of molecule (I) is essentially planar. The CN bond distances of the triazine ring are in the range of 1.310 (2)–1.417 (2) Å, in which the N1—C5 bond length is slightly longer than that of N3—C5. These values are intermediate between those expected for single and double C—N bonds (1.47 and 1.27 Å, respectively). The C=S bond length of 1.661 (2) Å is slightly longer than the pure double bond distance (1.61 Å) (Pauling 1960). The bond angles and bond lengths in the thiazole ring attached to the triazine ring are within the normal ranges. The crystal structure is stabilized by intermolecular S···S interactions with atom S1 of the thiazole ring linking to S2 of of the 1,3,5-triazine ring] (with a distance of 3.491 (1) Å; symmetry code x - 1/2, -y + 3/2, +z - 1/2). There are also weak C—H···N and C—H···S hydrogen bonding interactions (Table 1). Finally, the molecules are stacked one above the other in a head-to-tail fashion, linked by π-π stacking interactions (see Table 1 and Figure 2).

Related literature

For related literature, see: Lakomska et al. (2005); Lee & Chui (1999); Leroux et al. (1999); Senga et al. (1982); Vicentini et al. (2004).

For related literature, see: Pauling (1960).

S2. Experimental

A mixture of ammonium thiocyanate (26 mmol) and benzoyl chloride (26 mmol) in dry acetone (60 ml) was stirred for 30 min. Then 2-aminothiazole (26 mmol) was added and the reaction mixture was heated to reflux for 2 h. After cooling, the reaction mixture was poured in acidified cold water. The resulting yellow solid was filtered and washed with cold acetone. The title compound (I) was obtained as single crystals suitable for X-ray analysis after recrystallization of the yellow solid from an ethanol-dichloromethane mixture.

S3. Refinement

H atoms were included in calculated positions using the riding method with C—H distances of 0.95 Å and U_iso(H) being equal to 1.2 times U_eq of their respective parent atoms.

The crystal under investigation was found to be non-merohedrally twinned. The orientation matrices for the two components were identified using the program Cell_Now (Sheldrick, 2005), and the data were processed using both orientation matrices with SAINT (Bruker 2002), resulting in a total of 10242 reflections. 2489 reflections (983 unique ones) involved component 1 only (mean I/sigma = 14.8), 2468 reflections (976 unique ones) involved component 2 only (mean I/sigma = 15.3), and 5285 reflections (1891 unique ones) involved both components (mean I/sigma = 18.2). The exact twin matrix identified by the integration program was found to be (-1.000 - 0.001 - 0.001 / 0.003 - 1.000 - 0.001 / 0.838 0.003 1.000). The second domain is rotated from first domain by 180 ° about the reciprocal lattice c axis. The absorption correction was carried out using TWINABS (Sheldrick 2007) to create an hklf5 file which was used in all refinements; the structure was solved using direct methods with only the non-overlapping reflections of component 1. The twin fraction refined to a value of 0.523 (1). When the twinning was not accounted for, the conventional R1 value was around 18%.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: CELL_NOW (Sheldrick, 2005); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001) and PLATON (Spek 2003); software used to prepare material for publication: SHELXTL and PLATON.

Figures

	Fig. 1. The molecular structure of (I) with ellipsoids drawn at the 50% probability level.
	Fig. 2. showing S1···S2, π-π stacking and hydrogen bonding interactions with dashed lines; the symmetry code a is -1/2 + x,3/2 - y,-1/2 + z.

2-phenyl-4H-thiazolo[3,2-a][1,3,5]triazine-4-thione

Crystal data

C11H7N3S2	F(000) = 504
Mr = 245.32	Dx = 1.589 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2yn	Cell parameters from 4033 reflections
a = 6.847 (3) Å	θ = 2.4–26.8°
b = 10.839 (4) Å	µ = 0.49 mm^−1
c = 14.110 (6) Å	T = 100 K
β = 101.622 (6)°	Plate, yellow
V = 1025.6 (7) Å^3	0.40 × 0.25 × 0.08 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2777 independent reflections
Radiation source: fine-focus sealed tube	2486 reflections with I > 2σ(I)
Graphite monochromator	Rint = not defined due to twin pairing errors
φ and ω scans	θmax = 26.5°, θmin = 2.4°
Absorption correction: multi-scan (TWINABS; Sheldrick, 2007)	h = −8→8
Tmin = 0.814, Tmax = 0.96	k = 0→13
10242 measured reflections	l = 0→17

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.088	H-atom parameters constrained
S = 1.15	w = 1/[σ^2(Fo^2) + (0.0527P)^2 + 0.056P] where P = (Fo^2 + 2Fc^2)/3
2777 reflections	(Δ/σ)max = 0.001
146 parameters	Δρmax = 0.49 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
S1	0.08047 (7)	0.93115 (4)	0.21369 (3)	0.01678 (13)
S2	0.25020 (9)	0.61499 (4)	0.49345 (3)	0.02268 (15)
N1	0.1783 (2)	0.79541 (14)	0.36309 (10)	0.0135 (3)
N2	0.1877 (2)	1.00925 (14)	0.39873 (11)	0.0147 (3)
N3	0.2645 (2)	0.85785 (14)	0.52456 (11)	0.0151 (3)
C1	0.0830 (3)	0.77317 (18)	0.20055 (14)	0.0177 (4)
H1	0.0498	0.7322	0.1399	0.021*
C2	0.1368 (3)	0.71478 (18)	0.28516 (14)	0.0172 (4)
H2	0.1457	0.6276	0.2913	0.021*
C3	0.1563 (3)	0.91697 (17)	0.33755 (14)	0.0142 (4)
C4	0.2431 (3)	0.97366 (16)	0.49194 (13)	0.0129 (4)
C5	0.2320 (3)	0.76289 (17)	0.46220 (13)	0.0146 (4)
C6	0.2830 (3)	1.07262 (17)	0.56603 (13)	0.0146 (4)
C7	0.2579 (3)	1.19652 (18)	0.53972 (14)	0.0182 (4)
H7	0.2133	1.2184	0.4737	0.022*
C8	0.2981 (3)	1.28779 (19)	0.60983 (15)	0.0221 (4)
H8	0.2813	1.3721	0.5915	0.027*
C9	0.3625 (3)	1.25680 (19)	0.70655 (15)	0.0211 (4)
H9	0.3906	1.3198	0.7542	0.025*
C10	0.3858 (3)	1.13343 (18)	0.73370 (14)	0.0194 (4)
H10	0.4288	1.1117	0.7999	0.023*
C11	0.3459 (3)	1.04248 (18)	0.66347 (14)	0.0173 (4)
H11	0.3616	0.9582	0.6820	0.021*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0206 (2)	0.0167 (2)	0.0122 (2)	−0.0003 (2)	0.0012 (2)	0.00127 (18)
S2	0.0368 (3)	0.0119 (2)	0.0165 (2)	0.0001 (2)	−0.0015 (2)	0.00132 (18)
N1	0.0147 (8)	0.0124 (7)	0.0128 (8)	0.0006 (6)	0.0013 (6)	−0.0007 (6)
N2	0.0143 (8)	0.0134 (8)	0.0160 (8)	−0.0012 (7)	0.0026 (7)	−0.0009 (6)
N3	0.0155 (8)	0.0150 (8)	0.0140 (8)	−0.0003 (7)	0.0012 (6)	−0.0016 (6)
C1	0.0176 (10)	0.0185 (10)	0.0167 (10)	0.0002 (8)	0.0026 (8)	−0.0036 (7)
C2	0.0179 (10)	0.0163 (9)	0.0164 (10)	−0.0006 (8)	0.0008 (8)	−0.0059 (7)
C3	0.0121 (9)	0.0162 (9)	0.0144 (9)	−0.0004 (8)	0.0028 (7)	0.0013 (7)
C4	0.0103 (9)	0.0134 (10)	0.0154 (9)	−0.0002 (7)	0.0031 (7)	0.0000 (7)
C5	0.0137 (10)	0.0151 (10)	0.0142 (9)	−0.0003 (8)	0.0007 (7)	0.0026 (7)
C6	0.0115 (9)	0.0158 (9)	0.0172 (9)	−0.0017 (8)	0.0049 (7)	−0.0016 (7)
C7	0.0171 (10)	0.0177 (10)	0.0197 (10)	−0.0006 (8)	0.0037 (8)	−0.0001 (8)
C8	0.0222 (11)	0.0146 (10)	0.0301 (11)	−0.0006 (9)	0.0062 (9)	−0.0035 (8)
C9	0.0193 (10)	0.0193 (10)	0.0258 (11)	−0.0034 (8)	0.0068 (9)	−0.0090 (8)
C10	0.0173 (10)	0.0250 (11)	0.0162 (9)	−0.0014 (8)	0.0037 (8)	−0.0043 (8)
C11	0.0148 (10)	0.0177 (10)	0.0194 (10)	−0.0009 (8)	0.0034 (8)	−0.0002 (8)

Geometric parameters (Å, º)

S1—C1	1.723 (2)	C4—C6	1.484 (3)
S1—C3	1.727 (2)	C6—C11	1.394 (3)
S2—C5	1.661 (2)	C6—C7	1.395 (3)
N1—C3	1.366 (2)	C7—C8	1.387 (3)
N1—C2	1.388 (2)	C7—H7	0.9500
N1—C5	1.417 (2)	C8—C9	1.388 (3)
N2—C3	1.310 (2)	C8—H8	0.9500
N2—C4	1.350 (2)	C9—C10	1.391 (3)
N3—C4	1.335 (2)	C9—H9	0.9500
N3—C5	1.343 (2)	C10—C11	1.385 (3)
C1—C2	1.336 (3)	C10—H10	0.9500
C1—H1	0.9500	C11—H11	0.9500
C2—H2	0.9500
C1—S1—C3	90.74 (9)	N1—C5—S2	119.53 (14)
C3—N1—C2	113.83 (15)	C11—C6—C7	119.02 (18)
C3—N1—C5	119.54 (15)	C11—C6—C4	120.11 (17)
C2—N1—C5	126.58 (16)	C7—C6—C4	120.87 (17)
C3—N2—C4	113.60 (16)	C8—C7—C6	120.06 (19)
C4—N3—C5	120.16 (16)	C8—C7—H7	120.0
C2—C1—S1	112.43 (15)	C6—C7—H7	120.0
C2—C1—H1	123.8	C7—C8—C9	120.45 (19)
S1—C1—H1	123.8	C7—C8—H8	119.8
C1—C2—N1	112.65 (17)	C9—C8—H8	119.8
C1—C2—H2	123.7	C8—C9—C10	119.96 (19)
N1—C2—H2	123.7	C8—C9—H9	120.0
N2—C3—N1	124.59 (17)	C10—C9—H9	120.0
N2—C3—S1	125.08 (15)	C11—C10—C9	119.45 (19)
N1—C3—S1	110.33 (13)	C11—C10—H10	120.3
N3—C4—N2	126.49 (17)	C9—C10—H10	120.3
N3—C4—C6	116.41 (17)	C10—C11—C6	121.06 (18)
N2—C4—C6	117.10 (15)	C10—C11—H11	119.5
N3—C5—N1	115.57 (16)	C6—C11—H11	119.5
N3—C5—S2	124.90 (15)
C3—S1—C1—C2	0.37 (16)	C4—N3—C5—S2	−179.04 (15)
S1—C1—C2—N1	−0.2 (2)	C3—N1—C5—N3	−2.3 (3)
C3—N1—C2—C1	−0.2 (2)	C2—N1—C5—N3	−179.84 (18)
C5—N1—C2—C1	177.56 (18)	C3—N1—C5—S2	177.64 (14)
C4—N2—C3—N1	−0.7 (3)	C2—N1—C5—S2	0.1 (3)
C4—N2—C3—S1	179.01 (14)	N3—C4—C6—C11	2.1 (3)
C2—N1—C3—N2	−179.82 (18)	N2—C4—C6—C11	−178.31 (17)
C5—N1—C3—N2	2.3 (3)	N3—C4—C6—C7	−177.70 (17)
C2—N1—C3—S1	0.4 (2)	N2—C4—C6—C7	1.9 (3)
C5—N1—C3—S1	−177.46 (13)	C11—C6—C7—C8	0.9 (3)
C1—S1—C3—N2	179.80 (18)	C4—C6—C7—C8	−179.29 (18)
C1—S1—C3—N1	−0.44 (15)	C6—C7—C8—C9	−0.3 (3)
C5—N3—C4—N2	0.8 (3)	C7—C8—C9—C10	−0.5 (3)
C5—N3—C4—C6	−179.72 (16)	C8—C9—C10—C11	0.5 (3)
C3—N2—C4—N3	−0.9 (3)	C9—C10—C11—C6	0.1 (3)
C3—N2—C4—C6	179.61 (16)	C7—C6—C11—C10	−0.8 (3)
C4—N3—C5—N1	0.9 (3)	C4—C6—C11—C10	179.37 (18)