1-Vinyl-4-imidazoline-2-thione

Lampl, M.; Laus, G.; Wurst, K.; Huppertz, H.; Schottenberger, H.

doi:10.1107/S241431461701207X

organic compounds

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ISSN: 2414-3146

Volume 2| Part 8| August 2017| x171207

https://doi.org/10.1107/S241431461701207X

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1-Vinyl-4-imidazoline-2-thione

Martin Lampl,^a Gerhard Laus,^a Klaus Wurst,^a Hubert Huppertz ^a and Herwig Schottenberger ^a ^*

^aUniversity of Innsbruck, Faculty of Chemistry and Pharmacy, Innrain 80-82, 6020 Innsbruck, Austria
^*Correspondence e-mail: herwig.schottenberger@uibk.ac.at

Edited by P. McArdle, National University of Ireland, Ireland (Received 12 July 2017; accepted 22 August 2017; online 25 August 2017)

The title compound, C₅H₆N₂S, was obtained by deprotonation of 1-vinylimidazole and subsequent reaction with elemental sulfur. In the crystal, the molecules are linked by N—H⋯S and C—H⋯S hydrogen bonds, and arranged in layers parallel to the ab plane.

Keywords: crystal structure; imidazole; thione; vinyl.

CCDC reference: 1570185

Structure description

Imidazoline-2-thiones (Laus et al., 2013 ) are versatile and easy-to-synthesize building blocks. The title compound is one of the small molecules whose structure, surprisingly, has not yet been described. Not only is the molecule itself interesting, it also allows further derivatization at the S and N atoms (Hummel et al., 2017 ; Oberparleiter et al., 2016 ), and gives access to a plethora of functionalized imidazolium salts. The primary alkylation takes place at the S atom; the resulting salt can then be deprotonated to yield a neutral 2-alkylsulfanyl-1-vinylimidazole, which can then be transformed into a quaternary salt. In addition, the vinyl substituent renders the molecule polymerizable and thus permits a path to imidazole-based polymers (Anderson & Long, 2010 ; Nakabayashi & Mori, 2013 ).

The synthesis of the title compound involves deprotonation of 1-vinylimidazole and subsequent reaction with elemental sulfur. Strong bases, such as isopropylmagnesium chloride or hexyllithium, are required. Other reaction conditions, such as sulfur in KOH/DMSO (Yuan et al., 2010 ), K₂CO₃/MeOH (Ansell et al., 1970 ) or Et₃N/pyridine (Becker et al., 1973 ), did not yield the desired product.

The C=S bond length of 1.688 (1) Å is in agreement with the accepted value of 1.68±0.02 Å for imidazoline-2-thiones (Laus et al., 2013), ruling out the possibility of a thiol tautomer. The molecular structure is depicted in Fig. 1. The imidazoline-2-thione molecules are linked by N—H⋯S and C—H⋯S hydrogen bonds (Table 1) to form layers, which are arranged parallel to the ab plane (Fig. 2).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯S1ⁱ	0.86 (1)	2.54 (1)	3.378 (1)	167 (1)
C2—H2⋯S1ⁱⁱ	0.95	2.82	3.728 (1)	160
Symmetry codes: (i) $[-x, y, -z+{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, y-{\script{1\over 2}}, z]$ .

Figure 1
The molecular structure of the title compound, showing the atom labels and 50% probability displacement ellipsoids for the non-H atoms.

Figure 2
The unit cell of the title compound, viewed in the direction of (a) the a axis, (b) the b axis and (c) the c axis.

Related structures, such as 3-(1H,1H,2H,2H-perfluorooctyl)-1-vinylimidazoline-2-thione (Partl, Laus, Gelbrich et al., 2017 ) and 3,3′-(hexane-1,6-diyl)bis(1-vinylimidazoline-2-thione) (Partl, Laus, Kahlenberg et al., 2017 ), have been reported recently. Polymorphs of the analogous 1-methylimidazoline-2-thione (`methimazole') have been described (Lodochnikova et al., 2013 ).

Synthesis and crystallization

Method A: isopropylmagnesium chloride solution (10 ml, 2 M in Et₂O, 20.0 mmol) was added to a solution of 1-vinylimidazole (1.52 g, 16.1 mmol) in anhydrous tetrahydrofuran (THF; 15 ml), and the mixture was stirred for 17 h under an argon atmosphere. Elemental sulfur (573 mg, 17.9 mmol) was added to the clear solution and stirring was continued at room temperature. After 28 h, H₂O (20 ml) was added and acidified with HCl (30 ml, 1 M, 30.0 mmol). The mixture was extracted with chloroform (3 × 40 ml). The combined organic phases were washed with H₂O (2 × 60 ml). The solvent was removed under reduced pressure, yielding 1.43 g (70%) of 1-vinylimidazoline-2-thione as an off-white solid.

Method B: n-hexyllithium (16 ml, 2.3 M in hexanes, 36.8 mmol) was added to a cooled (193 K) solution of 1-vinylimidazole (3.07 g, 32.6 mmol) in anhydrous THF (40 ml) under an argon atmosphere. The mixture was stirred for 2 h at 195 K and then for 1 h at 263 K. Sulfur (1.1 g, 34.2 mmol) was added and stirring was continued for 68 h. The reaction was quenched with H₂O (20 ml) and acidified with HCl (51 ml, 1 M, 51.0 mmol). The THF was removed under reduced pressure, and the residue was extracted with CHCl₃ (3 × 100 ml) and with EtOAc (100 ml). The combined organic phases were washed with H₂O (100 ml). The solution was treated with activated charcoal, followed by filtration over celite. The solvent was removed under reduced pressure and the product dried overnight at high vacuum, yielding 2.2 g (54%) of 1-vinylimidazoline-2-thione as an off-white solid. Single crystals were obtained by slow evaporation of a solution in CHCl₃ (m.p. 416–418 K; sublimation above 396 K). The PXRD (Mo Kα radiation) of the bulk material was an excellent match to that calculated from the single-crystal diffraction data (Fig. 3), indicating phase purity.

Figure 3
Rietveld fit (R_wp = 0.126, R_exp = 0.121, R_p = 0.096, goodness-of-fit = 1.04) of the PXRD data with a model calculated from the structural data of the single-crystal structure determination. Black dots indicate raw data, while the red line indicates the calculated model. Tick marks (green) are the 2θ positions for the hkl reflections. The difference curve is shown in blue.

¹H NMR (300 MHz, DMSO-d₆): δ 12.35 (s, 1H), 7.52 (t, J = 2.1 Hz, 1H), 7.38 (dd, J = 16.1, 9.1 Hz, 1H), 7.04 (t, J = 2.6 Hz, 1H), 5.43 (dd, J = 16.2, 1.3 Hz, 1H), 4.92 (dd, J = 9.1, 1.4 Hz, 1H). ¹³C NMR (75 MHz, DMSO-d₆): δ 161.8, 129.0, 116.3, 113.8, 101.0. IR (neat): ν 3120, 3108, 3006, 1646, 1568, 1462, 1414, 1285, 1267, 1244, 1122, 1090, 1022, 960, 875, 772, 742, 682, 651, 545, 491 cm⁻¹.

Refinement

The H atom at N2 was found and refined isotropically with an N—H bond-length restraint of 0.87 (2) Å. Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₅H₆N₂S
M_r	126.18
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	173
a, b, c (Å)	10.7775 (3), 9.6848 (3), 12.1792 (4)
β (°)	108.139 (1)
V (Å³)	1208.06 (6)
Z	8
Radiation type	Mo Kα
μ (mm⁻¹)	0.42
Crystal size (mm)	0.17 × 0.12 × 0.07

Data collection
Diffractometer	Bruker D8 QUEST PHOTON 100
Absorption correction	Multi-scan (SADABS; Bruker, 2014 )
T_min, T_max	0.864, 0.911
No. of measured, independent and observed [I > 2σ(I)] reflections	16916, 1187, 1114
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.065, 1.08
No. of reflections	1187
No. of parameters	78
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.22
Computer programs: APEX2 (Bruker, 2014), SAINT (Bruker, 2014), XT in SHELXTL (Bruker, 2014), SHELXL2014 (Sheldrick, 2015 ), ORTEP-3 for Windows (Farrugia, 2012 ) and Mercury (Macrae et al., 2008 ).

Structural data

CCDC reference: 1570185

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S241431461701207X/qm4003sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S241431461701207X/qm4003Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S241431461701207X/qm4003Isup3.mol

Supporting information file. DOI: https://doi.org/10.1107/S241431461701207X/qm4003Isup4.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: XT in SHELXTL (Bruker, 2014); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: Mercury (Macrae et al., 2008).

1-Vinyl-4-imidazoline-2-thione top

Crystal data top

C₅H₆N₂S	D_x = 1.387 Mg m⁻³
M_r = 126.18	Melting point: 418 K
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.7775 (3) Å	Cell parameters from 9910 reflections
b = 9.6848 (3) Å	θ = 2.9–26.4°
c = 12.1792 (4) Å	µ = 0.42 mm⁻¹
β = 108.139 (1)°	T = 173 K
V = 1208.06 (6) Å³	Prism, colourless
Z = 8	0.17 × 0.12 × 0.07 mm
F(000) = 528

Data collection top

Bruker D8 QUEST PHOTON 100 diffractometer	1187 independent reflections
Radiation source: Incoatec Microfocus	1114 reflections with I > 2σ(I)
Multi layered optics monochromator	R_int = 0.026
Detector resolution: 10.4 pixels mm^-1	θ_max = 26.0°, θ_min = 2.9°
φ and ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Bruker, 2014)	k = −11→11
T_min = 0.864, T_max = 0.911	l = −15→15
16916 measured reflections

Refinement top

Refinement on F²	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.024	w = 1/[σ²(F_o²) + (0.0314P)² + 1.0869P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.065	(Δ/σ)_max < 0.001
S = 1.08	Δρ_max = 0.24 e Å⁻³
1187 reflections	Δρ_min = −0.22 e Å⁻³
78 parameters	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.0068 (9)

Special details top

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.

Refinement. Hydrogen atom at N2 were found and refined isotropically with bond restraint (d=87pm).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
S1	0.11344 (3)	0.54728 (4)	0.42718 (3)	0.02539 (14)
N1	0.31623 (10)	0.38500 (11)	0.41324 (9)	0.0200 (2)
N2	0.17797 (11)	0.43417 (12)	0.24678 (9)	0.0225 (2)
H2N	0.1110 (15)	0.4659 (17)	0.1942 (13)	0.034 (4)*
C1	0.20309 (12)	0.45566 (12)	0.36118 (11)	0.0192 (3)
C2	0.35897 (13)	0.32017 (14)	0.32890 (11)	0.0241 (3)
H2	0.4349	0.2647	0.3421	0.029*
C3	0.27288 (13)	0.35079 (14)	0.22622 (11)	0.0250 (3)
H3	0.2762	0.3209	0.1529	0.030*
C4	0.37875 (13)	0.38285 (14)	0.53361 (11)	0.0262 (3)
H4	0.3320	0.4176	0.5821	0.031*
C5	0.49716 (14)	0.33608 (16)	0.58291 (12)	0.0327 (3)
H5A	0.5466	0.3006	0.5369	0.039*
H5B	0.5335	0.3376	0.6647	0.039*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.01913 (19)	0.0318 (2)	0.0239 (2)	0.00659 (12)	0.00469 (13)	−0.00509 (12)
N1	0.0173 (5)	0.0214 (5)	0.0203 (5)	0.0030 (4)	0.0045 (4)	0.0000 (4)
N2	0.0179 (5)	0.0267 (6)	0.0197 (5)	0.0030 (4)	0.0014 (4)	−0.0020 (4)
C1	0.0159 (6)	0.0192 (6)	0.0213 (6)	−0.0016 (4)	0.0042 (5)	−0.0007 (4)
C2	0.0215 (6)	0.0253 (7)	0.0260 (7)	0.0045 (5)	0.0081 (5)	−0.0034 (5)
C3	0.0226 (6)	0.0280 (7)	0.0244 (7)	0.0015 (5)	0.0074 (5)	−0.0055 (5)
C4	0.0277 (7)	0.0303 (7)	0.0199 (6)	0.0060 (5)	0.0066 (5)	0.0020 (5)
C5	0.0319 (8)	0.0397 (8)	0.0227 (7)	0.0104 (6)	0.0028 (6)	0.0026 (6)

Geometric parameters (Å, º) top

S1—C1	1.6884 (13)	C2—C3	1.3380 (19)
N1—C1	1.3695 (16)	C2—H2	0.9500
N1—C2	1.3986 (16)	C3—H3	0.9500
N1—C4	1.4102 (16)	C4—C5	1.3104 (19)
N2—C1	1.3502 (16)	C4—H4	0.9500
N2—C3	1.3858 (17)	C5—H5A	0.9500
N2—H2N	0.859 (14)	C5—H5B	0.9500

C1—N1—C2	109.49 (10)	N1—C2—H2	126.4
C1—N1—C4	123.85 (11)	C2—C3—N2	107.24 (11)
C2—N1—C4	126.64 (11)	C2—C3—H3	126.4
C1—N2—C3	110.74 (11)	N2—C3—H3	126.4
C1—N2—H2N	124.5 (11)	C5—C4—N1	124.29 (13)
C3—N2—H2N	124.7 (11)	C5—C4—H4	117.9
N2—C1—N1	105.33 (11)	N1—C4—H4	117.9
N2—C1—S1	127.71 (10)	C4—C5—H5A	120.0
N1—C1—S1	126.95 (10)	C4—C5—H5B	120.0
C3—C2—N1	107.21 (11)	H5A—C5—H5B	120.0
C3—C2—H2	126.4

C3—N2—C1—N1	0.31 (14)	C1—N1—C2—C3	−0.01 (15)
C3—N2—C1—S1	−178.63 (10)	C4—N1—C2—C3	−178.69 (12)
C2—N1—C1—N2	−0.18 (14)	N1—C2—C3—N2	0.19 (15)
C4—N1—C1—N2	178.55 (11)	C1—N2—C3—C2	−0.32 (15)
C2—N1—C1—S1	178.77 (10)	C1—N1—C4—C5	−167.81 (14)
C4—N1—C1—S1	−2.51 (18)	C2—N1—C4—C5	10.7 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···S1ⁱ	0.86 (1)	2.54 (1)	3.378 (1)	167 (1)
C2—H2···S1ⁱⁱ	0.95	2.82	3.728 (1)	160

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

Acknowledgements

We are grateful to Barbara Schmidt for technical assistance.

References

Anderson, E. B. & Long, T. E. (2010). Polymer, 51, 2447–2454. Web of Science CrossRef CAS Google Scholar
Ansell, G. B., Forkey, D. M. & Moore, D. W. (1970). Chem. Commun. pp. 56–57. CrossRef Google Scholar
Becker, H. G. O., Nagel, D. & Timpe, H. J. (1973). J. Prakt. Chem. 315, 97–105. CrossRef CAS Google Scholar
Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hummel, M., Markiewicz, M., Stolte, S., Noisternig, M., Braun, D. E., Gelbrich, T., Griesser, U. J., Partl, G., Naier, B., Wurst, K., Krüger, B., Kopacka, H., Laus, G., Huppertz, H. & Schottenberger, H. (2017). Green Chem. 19, 3225–3237. CrossRef CAS Google Scholar
Laus, G., Kahlenberg, V., Wurst, K., Müller, T., Kopacka, H. & Schottenberger, H. (2013). Z. Naturforsch. Teil B, 68, 1239–1252. CAS Google Scholar
Lodochnikova, O. A., Bodrov, A. V., Saifina, A. F., Nikitina, L. E. & Litvinov, I. A. (2013). J. Struct. Chem. 54, 140–147. CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Nakabayashi, K. & Mori, H. (2013). Eur. Polym. J. 49, 2808–2838. CrossRef CAS Google Scholar
Oberparleiter, S., Laus, G., Wurst, K. & Schottenberger, H. (2016). IUCrData, 1, x161499. Google Scholar
Partl, G., Laus, G., Gelbrich, T., Wurst, K., Huppertz, H. & Schottenberger, H. (2017). IUCrData, 2, x170648. Google Scholar
Partl, G., Laus, G., Kahlenberg, V., Huppertz, H. & Schottenberger, H. (2017). IUCrData, 2, x170599. Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Yuan, Y., Thom, I., Kim, S. H., Chen, D., Beyer, A., Bonnamour, J., Zuidema, E., Chang, S. & Bolm, C. (2010). Adv. Synth. Catal. 352, 2892–2898. CrossRef CAS Google Scholar

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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

1-Vinyl-4-imidazoline-2-thione

Structure description

Synthesis and crystallization

Refinement

Structural data

Acknowledgements

References

organic compounds