5-(2-Pyridyl)-1,3-di­thia­ne-2-thione

The title compound, C₉H₉NS₃, crystallizes with two mol­ecules in the asymmetric unit. In both mol­ecules, the di­thia­ne-2-thione rings adopt a symmetric half-boat conformation with the C atom opposite the C-S_thione bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half-boat by 82.7 (2) and 84.5 (2)° in the two mol­ecules, so that the N atom is trans to the axial C-H bond in both cases.

S1. Comment

We were unsuccessful in reproducing the synthesis of S,S'-[2-(2-pyridyl)trimethylene]bis(O-ethyl dithiocarbonate), (I) (Uneme et al., 1992). Instead, the previously unknown ring-closed product 5-(2-pyridyl)-1,3-dithiane-2-thione, (II), was recovered. The only important difference in the procedures was that we heated the heterogeneous reaction mixture for a short time.

The crystal structure of (II) has two almost identical molecules in the asymmetric unit (Fig. 1). Both the dithiane-2-thione rings adopt a symmetric half-boat conformation with the C atom opposite to the C—S_thione bond out of the plane determined by the other atoms; the largest deviations from the plane are 0.05 (4) Å for S3 and 0.04 (2) Å for S2A. This symmetric half-boat conformation is one of the intermediates postulated for the preferential mode of inversion for the chair form of the related molecule cyclohexanone (Bucourt & Hainaut, 1967). This conformation is also found for 1,3-dithiane-2-thione in a series of copper complexes (Bellito et al., 1994). The bond distances found here: S═C 1.658 (1) and 1.662 (1) Å, Csp²—S 1.714 (1)–1.719 (1) Å and S—Csp³ 1.811 (1)—1.815 (1) Å are very similar to those in the copper complexes, although there the ligand is mono-, di- or tridentate. For both molecules, the pyridine ring is in the equatorial position and twisted by 82.7 (2) and 84.5 (2)° out of the plane of the half-boat. In both molecules, the N atom is trans to the axial C—H bond so that the molecules have approximate mirror symmetry. The two molecules are not exactly identical; superimposing the non-H atoms gives a mean-square deviation of 0.42 Ų. The difference is mainly in the angle between the planes C2/C3/C4 and S1/S2/S3/C1/C2/C4, which is 124.8 (2)° for molecule 1 and 120.4 (2)° for molecule 2 (the molecule with suffix A on the labels). This, together with a difference in the angle between C5—C3 and the plane through C2/C3/C4 [55.5 (1)° for molecule 1 and 54.0 (1)° for molecule 2] means that the angles between C5—C3 and the plane through S1/S2/S3/C1/C2/C4 differ by 6.0 (2)° so that in molecule 2 the pyridine ring is bent out of plane.

The shortest intermolecular S···S contact is 3.570 (1) Å between S2 and S3A(x, -1/2 - y, 1/2 + z). The x and y coordinates of the two independent molecules are related approximately by 1.5 - x and -y, but there is no simple relation between the z coordinates.

S2. Experimental

Triethylamine (3.95 g, 39 mmol) was added dropwise to a solution of 2-(2-pyridyl)-1,3-propanediol (Guanti et al., 1997; 2.40 g, 16 mmol) and p-toluensulfonyl chloride (6.55 g, 34 mmol) in acetonitrile (32 ml) at 273 K over a period of ca 30 min. The mixture was kept at 279 K for 24 h and then poured into water (120 ml). An oil precipitated which crystallized after removal of the water and the addition of a little ethanol. The crude product was recrystallized from ethanol giving 3.10 g (43%) of 2-(pyridyl)trimethylene bis(p-toluenesulfonate). ¹H NMR (CDCl₃): δ 2.40 (6H, s), 3.46 (1H, quintet), 4.32 (4H, d), 7.0–7.4 (6H, m), 7.5–7.8 (5H, m), 8.3–8.4 (1H, m). ¹³C NMR (CDCl₃): δ 22(CH₃), 46 (CH), 68 (CH₂), 122.5 (py-C3), 124 (py-C5), 128 (Ar—C3,C5), 130 (Ar—C2,C6), 132 (Ar—C4), 137(py-C4), 134 (Ar—C1), 149.5 (py-C6), 155.5 (py-C2). A suspension of 2-(pyridyl)trimethylene bis(p-toluenesulfonate) (3.1 g, 6.9 mmol) and potassium O-ethyldithiocarbonate (3.18 g, 20 mmol) in acetonitrile (50 ml) was heated under reflux for 20 min and then poured into water (250 ml). The reaction product was extracted with 3 × 100 ml CHCl₃ and purified by column chromatography (CH₂Cl₂) to afford a crude product (ca 300 mg) and a yellow oil. The crude product was crystallized from ethanol. Yield: 200 mg (14%) of (II) as yellow crystals. The crystals used for the structure analysis were deposited from CDCl₃ (m.p. 393–394 K). Analysis calculated for C₉H₉NS₃: C 47.54, H 3.99, N 6.16, S 42.31%; found: C 47.59, H 4.10, N 6.17, S 32.30%. ¹H NMR (CDCl₃): δ 3.2–3.8 (5H, m), 7.2–7.4 (3H, m), 7.6–7.8 (1H, m), 8.5–8.6 (1H, m); ¹³C NMR (CDCl₃): δ 39.1 (CH2), 39.2 (CH), 122.2 (py-C3), 122.7 (py-C5), 137 (py-C4), 150 (py-C6), 160 (py-C2), 220 (C═S); IR: 1010 cm^-1, ν(C═ S); EIMZ: m/z 227 (M⁺, 58), 194 (23), 180 (17), 162 (11), 150 (10), 136 (26), 118 (32), 106 (100), 79 (25).

S3. Refinement

The H atoms were included using a riding model and were constrained to have C—H = 0.95 Å and U_iso = 1.2U_eq of the their parent atom.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1997) and KRYSTAL (Hazell, 1995); program(s) used to refine structure: modified ORFLS (Bussing et al., 1962) and KRYSTAL; molecular graphics: ORTEP-III (Burnett & Johnson, 1996) and KRYSTAL; software used to prepare material for publication: KRYSTAL.

Figures

Fig. 1. View of the two molecules showing the labelling of the non-H atoms. Displacement ellipsoids are shown at 50% probability levels and H atoms are drawn as small circles of arbitrary radii. The short S···S interaction is shown by a dashed line.

5-(2-Pyridyl)-1,3-dithiane-2-thione

Crystal data

C9H9NS3	F(000) = 944.0
Mr = 227.38	Dx = 1.511 Mg m^−3
Monoclinic, P21/c	Melting point = 393–394 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 17.444 (2) Å	Cell parameters from 7124 reflections
b = 9.6329 (9) Å	θ = 2.5–30.5°
c = 12.680 (1) Å	µ = 0.69 mm^−1
β = 110.245 (2)°	T = 120 K
V = 1999.1 (3) Å^3	Plate, yellow
Z = 8	0.58 × 0.40 × 0.16 mm

Data collection

Siemens SMART CCD diffractometer	6191 independent reflections
Radiation source: x-ray tube	4802 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.047
ω rotation scans with narrow frames	θmax = 30.5°, θmin = 2.5°
Absorption correction: integration (XPREP; Siemens, 1995)	h = −24→24
Tmin = 0.687, Tmax = 0.894	k = −13→13
25069 measured reflections	l = −17→17

Refinement

Refinement on F	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.024	H-atom parameters constrained
wR(F^2) = 0.034	w = 1/{[σcs(F^2) + 1.03F^2]^1/2 - |F|}^2
S = 1.27	(Δ/σ)max = 0.001
4802 reflections	Δρmax = 0.48 (5) e Å^−3
235 parameters	Δρmin = −0.39 (5) e Å^−3

Special details

Refinement. Sfls: F calc weight full matrix

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.81410 (2)	−0.25035 (3)	0.39418 (3)	0.0266 (2)
S2	0.73950 (2)	−0.36895 (3)	0.54275 (3)	0.0243 (2)
S3	0.67796 (2)	−0.09741 (3)	0.41607 (3)	0.0215 (2)
N1	0.50040 (7)	−0.25240 (11)	0.60051 (9)	0.0240 (6)
C1	0.74142 (8)	−0.23950 (12)	0.45032 (10)	0.0201 (6)
C2	0.65608 (8)	−0.33603 (13)	0.59400 (11)	0.0231 (7)
C3	0.63387 (7)	−0.18392 (13)	0.59996 (10)	0.0192 (6)
C4	0.60245 (8)	−0.11704 (12)	0.48356 (11)	0.0213 (7)
C5	0.56700 (7)	−0.17484 (12)	0.65053 (10)	0.0194 (6)
C6	0.57467 (8)	−0.08970 (13)	0.74182 (11)	0.0238 (7)
C7	0.51165 (9)	−0.08622 (14)	0.78511 (12)	0.0279 (8)
C8	0.44298 (8)	−0.16706 (14)	0.73474 (12)	0.0274 (8)
C9	0.44015 (8)	−0.24654 (14)	0.64331 (12)	0.0271 (7)
S1A	0.70389 (2)	0.26815 (4)	0.12007 (3)	0.0247 (2)
S2A	0.77025 (2)	0.35898 (3)	0.35036 (3)	0.0210 (2)
S3A	0.83719 (2)	0.10558 (3)	0.26554 (3)	0.0232 (2)
N1A	0.99364 (6)	0.19444 (11)	0.64777 (8)	0.0206 (6)
C1A	0.77255 (7)	0.24448 (12)	0.24767 (10)	0.0186 (6)
C2A	0.85181 (7)	0.31130 (12)	0.47850 (9)	0.0189 (6)
C3A	0.86637 (7)	0.15540 (12)	0.49398 (9)	0.0168 (6)
C4A	0.90488 (8)	0.10043 (12)	0.41110 (10)	0.0199 (6)
C5A	0.92188 (7)	0.12700 (12)	0.61309 (10)	0.0167 (6)
C6A	0.89795 (8)	0.03788 (12)	0.68229 (10)	0.0202 (6)
C7A	0.94923 (8)	0.02037 (13)	0.79311 (10)	0.0234 (7)
C8A	1.02229 (8)	0.09199 (13)	0.83027 (10)	0.0237 (7)
C9A	1.04193 (8)	0.17599 (13)	0.75501 (10)	0.0227 (7)
H2a	0.67077	−0.37386	0.66753	0.0277*
H2b	0.60901	−0.38245	0.54555	0.0277*
H3	0.68061	−0.13476	0.64627	0.0230*
H4a	0.55927	−0.17292	0.43645	0.0256*
H4b	0.58202	−0.02749	0.49087	0.0256*
H6	0.62224	−0.03467	0.77420	0.0285*
H7	0.51555	−0.02950	0.84805	0.0335*
H8	0.39897	−0.16760	0.76262	0.0329*
H9	0.39255	−0.30061	0.60834	0.0325*
H2Aa	0.83865	0.34562	0.54038	0.0226*
H2Ab	0.90084	0.35363	0.47785	0.0226*
H3A	0.81557	0.11001	0.48094	0.0201*
H4Aa	0.95176	0.15493	0.41801	0.0239*
H4Ab	0.92088	0.00683	0.43015	0.0239*
H6A	0.84738	−0.01026	0.65429	0.0242*
H7A	0.93431	−0.03963	0.84225	0.0280*
H8A	1.05824	0.08369	0.90587	0.0284*
H9A	1.09276	0.22357	0.78082	0.0272*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0256 (2)	0.0283 (2)	0.0310 (2)	0.0036 (1)	0.0164 (1)	0.0038 (1)
S2	0.0246 (2)	0.0248 (2)	0.0263 (2)	0.0091 (1)	0.0124 (1)	0.0095 (1)
S3	0.0225 (2)	0.0194 (1)	0.0249 (2)	0.0031 (1)	0.0113 (1)	0.0057 (1)
N1	0.0175 (5)	0.0289 (6)	0.0235 (5)	−0.0032 (4)	0.0044 (4)	0.0031 (4)
C1	0.0198 (6)	0.0206 (6)	0.0188 (6)	−0.0009 (5)	0.0052 (5)	−0.0001 (4)
C2	0.0226 (6)	0.0242 (6)	0.0245 (6)	0.0025 (5)	0.0108 (5)	0.0051 (5)
C3	0.0152 (6)	0.0220 (6)	0.0194 (6)	−0.0011 (5)	0.0047 (5)	0.0004 (4)
C4	0.0187 (6)	0.0225 (6)	0.0227 (6)	0.0005 (5)	0.0071 (5)	0.0023 (5)
C5	0.0155 (6)	0.0214 (6)	0.0201 (6)	0.0009 (4)	0.0046 (5)	0.0042 (5)
C6	0.0208 (6)	0.0243 (6)	0.0264 (6)	−0.0020 (5)	0.0085 (5)	−0.0002 (5)
C7	0.0307 (7)	0.0288 (7)	0.0281 (7)	0.0049 (6)	0.0151 (6)	0.0023 (5)
C8	0.0210 (6)	0.0316 (7)	0.0332 (7)	0.0059 (5)	0.0141 (6)	0.0131 (6)
C9	0.0161 (6)	0.0331 (7)	0.0293 (7)	−0.0025 (5)	0.0044 (5)	0.0096 (5)
S1A	0.0187 (2)	0.0367 (2)	0.0164 (1)	0.0014 (1)	0.0031 (1)	0.0023 (1)
S2A	0.0180 (2)	0.0242 (2)	0.0191 (1)	0.0071 (1)	0.0042 (1)	−0.0013 (1)
S3A	0.0311 (2)	0.0220 (2)	0.0148 (1)	0.0070 (1)	0.0058 (1)	−0.0019 (1)
N1A	0.0178 (5)	0.0225 (5)	0.0200 (5)	−0.0011 (4)	0.0046 (4)	−0.0006 (4)
C1A	0.0168 (6)	0.0220 (6)	0.0179 (5)	−0.0025 (4)	0.0073 (5)	0.0006 (4)
C2A	0.0198 (6)	0.0200 (5)	0.0158 (5)	0.0022 (5)	0.0048 (5)	−0.0018 (4)
C3A	0.0152 (5)	0.0187 (5)	0.0163 (5)	−0.0008 (4)	0.0054 (4)	−0.0005 (4)
C4A	0.0210 (6)	0.0205 (6)	0.0173 (5)	0.0031 (5)	0.0053 (5)	−0.0015 (4)
C5A	0.0174 (6)	0.0166 (5)	0.0166 (5)	0.0017 (4)	0.0063 (5)	−0.0016 (4)
C6A	0.0201 (6)	0.0187 (5)	0.0226 (6)	0.0006 (5)	0.0085 (5)	0.0012 (5)
C7A	0.0288 (7)	0.0210 (6)	0.0220 (6)	0.0058 (5)	0.0108 (5)	0.0045 (5)
C8A	0.0263 (7)	0.0225 (6)	0.0186 (6)	0.0064 (5)	0.0031 (5)	0.0002 (5)
C9A	0.0192 (6)	0.0220 (6)	0.0230 (6)	0.0008 (5)	0.0023 (5)	−0.0017 (5)

Geometric parameters (Å, º)

S1—C1	1.658 (1)	C3A—C4A	1.525 (2)
S2—C1	1.719 (1)	C5A—C6A	1.391 (2)
S2—C2	1.815 (1)	C6A—C7A	1.390 (2)
S3—C1	1.719 (1)	C7A—C8A	1.381 (2)
S3—C4	1.812 (1)	C8A—C9A	1.382 (2)
N1—C9	1.340 (2)	C2—H2a	0.950
N1—C5	1.342 (2)	C2—H2b	0.950
C2—C3	1.524 (2)	C3—H3	0.950
C3—C5	1.516 (2)	C4—H4a	0.950
C3—C4	1.528 (2)	C4—H4b	0.950
C5—C6	1.387 (2)	C6—H6	0.950
C6—C7	1.389 (2)	C7—H7	0.950
C7—C8	1.386 (2)	C8—H8	0.950
C8—C9	1.376 (2)	C9—H9	0.950
S1A—C1A	1.662 (1)	C2A—H2Aa	0.950
S2A—C1A	1.717 (1)	C2A—H2Ab	0.950
S2A—C2A	1.810 (1)	C3A—H3A	0.950
S3A—C1A	1.714 (1)	C4A—H4Aa	0.950
S3A—C4A	1.815 (1)	C4A—H4Ab	0.950
N1A—C9A	1.341 (2)	C6A—H6A	0.950
N1A—C5A	1.342 (2)	C7A—H7A	0.950
C2A—C3A	1.524 (2)	C8A—H8A	0.950
C3A—C5A	1.510 (2)	C9A—H9A	0.950
S2···S3A^i	3.570 (1)	S1···S2A^ii	3.842 (1)
S2···S2A^ii	3.743 (1)
C1—S2—C2	108.93 (6)	C3—C2—H2b	107.9
C1—S3—C4	107.90 (6)	S2—C2—H2b	107.9
C5—N1—C9	117.2 (1)	C5—C3—H3	109.3
S1—C1—S3	117.58 (7)	C2—C3—H3	109.3
S1—C1—S2	116.42 (7)	C4—C3—H3	109.3
S2—C1—S3	125.94 (7)	H4a—C4—H4b	109.5
S2—C2—C3	115.77 (8)	C3—C4—H4a	108.1
C2—C3—C5	108.8 (1)	S3—C4—H4a	108.1
C4—C3—C5	108.2 (1)	C3—C4—H4b	108.1
C2—C3—C4	111.7 (1)	S3—C4—H4b	108.1
S3—C4—C3	115.08 (9)	C5—C6—H6	120.5
N1—C5—C6	122.8 (1)	C7—C6—H6	120.5
N1—C5—C3	115.8 (1)	C8—C7—H7	120.6
C3—C5—C6	121.4 (1)	C6—C7—H7	120.6
C5—C6—C7	118.9 (1)	C9—C8—H8	120.8
C6—C7—C8	118.7 (1)	C7—C8—H8	120.8
C7—C8—C9	118.3 (1)	N1—C9—H9	118.0
N1—C9—C8	124.1 (1)	C8—C9—H9	118.0
C1A—S2A—C2A	107.48 (6)	H2Aa—C2A—H2Ab	109.5
C1A—S3A—C4A	108.81 (6)	C3A—C2A—H2Aa	108.3
C5A—N1A—C9A	117.1 (1)	S2A—C2A—H2Aa	108.3
S1A—C1A—S3A	117.09 (7)	C3A—C2A—H2Ab	108.3
S1A—C1A—S2A	116.86 (7)	S2A—C2A—H2Ab	108.3
S2A—C1A—S3A	126.03 (7)	C5A—C3A—H3A	109.1
S2A—C2A—C3A	114.19 (8)	C2A—C3A—H3A	109.1
C2A—C3A—C5A	109.14 (9)	C4A—C3A—H3A	109.1
C4A—C3A—C5A	110.1 (1)	H4Aa—C4A—H4Ab	109.5
C2A—C3A—C4A	110.29 (9)	C3A—C4A—H4Aa	108.4
S3A—C4A—C3A	113.87 (9)	S3A—C4A—H4Aa	108.4
N1A—C5A—C6A	122.8 (1)	C3A—C4A—H4Ab	108.4
N1A—C5A—C3A	116.3 (1)	S3A—C4A—H4Ab	108.4
C3A—C5A—C6A	120.9 (1)	C7A—C6A—H6A	120.5
C5A—C6A—C7A	118.9 (1)	C5A—C6A—H6A	120.5
C6A—C7A—C8A	118.6 (1)	C8A—C7A—H7A	120.7
C7A—C8A—C9A	118.5 (1)	C6A—C7A—H7A	120.7
N1A—C9A—C8A	124.0 (1)	C7A—C8A—H8A	120.8
H2a—C2—H2b	109.5	C9A—C8A—H8A	120.8
C3—C2—H2a	107.9	N1A—C9A—H9A	118.0
S2—C2—H2a	107.9	C8A—C9A—H9A	118.0
C2—C3—C5—N1	−53.6 (1)	S3A—C4A—C3A—C2A	−68.2 (1)
C4—C3—C5—N1	68.0 (1)	C4A—C3A—C2A—S2A	71.2 (1)
C2A—C3A—C5A—N1A	−55.1 (1)	C3A—C2A—S2A—C1A	−35.9 (1)
C4A—C3A—C5A—N1A	66.1 (1)	C2A—S2A—C1A—S3A	2.9 (1)
S2—C1—S3—C4	−5.6 (1)	C2—S2—C1—S1	179.7 (1)
C1—S3—C4—C3	36.3 (1)	C4—S3—C1—S1	177.4 (1)
S3—C4—C3—C2	−67.7 (1)	C2A—S2A—C1A—S1A	−179.0 (1)
C4—C3—C2—S2	63.8 (1)	C4A—S3A—C1A—S1A	−179.2 (1)
C3—C2—S2—C1	−29.8 (1)	S2—C2—C3—C5	−176.7 (1)
C2—S2—C1—S3	2.7 (1)	S3—C4—C3—C5	172.5 (1)
S2A—C1A—S3A—C4A	−1.1 (1)	S2A—C2A—C3A—C5A	−167.8 (1)
C1A—S3A—C4A—C3A	31.6 (1)	S3A—C4A—C3A—C5A	171.3 (1)

Symmetry codes: (i) x, −y−1/2, z+1/2; (ii) x, y−1, z.