tert-Butyl 2-sulfanylidene-2,3-dihydro-1H-imidazole-1-carboxyl­ate

Lee, P.-C.; Guo, Y.-C.; Huang, B.-H.; Chen, M.-J.

doi:10.1107/S1600536812027924

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 7| July 2012| Page o2208

https://doi.org/10.1107/S1600536812027924

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tert-Butyl 2-sulfanylidene-2,3-dihydro-1H-imidazole-1-carboxylate

Pei-Chi Lee,^a Yi-Cin Guo,^a Bor-Hunn Huang ^b and Ming-Jen Chen ^a ^*

^aDepartment of Applied Cosmetology and Graduate Institute of Cosmetic Science, Hungkuang University, Taichung 433, Taiwan, and ^bDepartment of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
^*Correspondence e-mail: mjchen@sunrise.hk.edu.tw

(Received 11 June 2012; accepted 20 June 2012; online 27 June 2012)

In the title molecule, C₈H₁₂N₂O₂S, the imidazole ring forms a dihedral angle of 5.9 (2)° with the mean plane of the carboxylate group. In the crystal, molecules are linked by pairs of N—H⋯S hydrogen bonds, forming inversion dimers.

Related literature

The title compound is a mercaptoimidazole derivative. For applications of mercaptoimidazole derivatives in the treatment of hyperpigmentation, see: Kasraee (2002 ); Kasraee et al. (2005 ) and for inhibiting tyrosinase, see: Liao et al. (2012 ). For related structures containing intermolecular N—H⋯S hydrogen bonds, see: Krepps et al. (2001 ).

Experimental

Crystal data

C₈H₁₂N₂O₂S
M_r = 200.26
Monoclinic, P 2₁ /c
a = 6.8316 (3) Å
b = 8.8893 (5) Å
c = 17.5458 (15) Å
β = 90.789 (6)°
V = 1065.42 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 293 K
0.60 × 0.50 × 0.35 mm

Data collection

Agilent Xcalibur Sapphire3 Gemini diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ) T_min = 0.859, T_max = 1.000
4722 measured reflections
2472 independent reflections
1808 reflections with I > 2σ(I)
R_int = 0.047

Refinement

R[F² > 2σ(F²)] = 0.070
wR(F²) = 0.213
S = 1.09
2472 reflections
118 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.67 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯Sⁱ	0.86	2.47	3.324 (2)	174
Symmetry code: (i) -x, -y+1, -z.

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536812027924/lh5490sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812027924/lh5490Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536812027924/lh5490Isup3.cml

checkCIF report

Comment top

1-methyl-2-mercaptoimidazole causes hypopigmentation by inhibiting tyrosinase in the clinical oral antithyroid medication (Kasraee (2002); Kasraee et al., 2005). Ergothioneine has a significant effect on inhibiting tyrosinase enzyme activity, resulting from the presence of the sulfur substituent in the imidazole ring (Liao et al., 2012). It shows that molecules with a 2-mercaptoimidazole group have potential as skin whitening agents. In this regard, we report here the synthesis and crystal structure of the title compound. The molecular structure of the title compound is shown in Fig. 1. The essentially planar imidazoline ring (C1/C2/C3/N1/N2) forms a dihedral angle of 5.9 (2)° with the mean plane of the carboxylate group (N2/C4/O1/O2). In the crystal, pairs of molecules are linked by N—H···S hydrogen bonds to form inversion dimers. Intermolecular N—H···S hydrogen bonds are highlighted in the literature by Krepps et al. (2001).

Related literature top

The title compound is a mercaptoimidazole derivative. For applications of mercaptoimidazole derivatives in the treatment of hyperpigmentation, see: Kasraee (2002); Kasraee et al. (2005) and for inhibiting tyrosinase, see: Liao et al. (2012). For related structures containing intermolecular N—H···S hydrogen bonds, see: Krepps et al. (2001).

Experimental top

To a mixture of 2-mercaptoimidazole (351 mg, 3.5 mmole) and potassium carbonate (968 mg, 7 mmole) in 7 ml of N,N-dimethylformamide was added di-tert-butyl dicarbonate (1.1 ml, 5.2 mmol). The reaction mixture was stirred at 298 K for 24 h under N₂ atmosphere. The resulting mixture was partitioned between ethyl acetate (40 ml) and H₂O (20 ml). The organic layer was dried over MgSO₄ and concentrated in vacuo. The residue was separated by chromatography over silica gel and eluted with hexane/ethyl acetate (3/7) to afford 297 mg of the title compound (I) in 42% yield. Single crystals suitable for X-ray measurements were obtained by recrystallization from a dichloromethane/hexane solution of the title compound at room temperature. Anal. Calcd for C₈H₁₂N₂O₂S: C, 47.98; H, 6.04; N, 13.99; Found: C, 47.86; H, 6.14; N, 13.92.

Structure description top

The title compound is a mercaptoimidazole derivative. For applications of mercaptoimidazole derivatives in the treatment of hyperpigmentation, see: Kasraee (2002); Kasraee et al. (2005) and for inhibiting tyrosinase, see: Liao et al. (2012). For related structures containing intermolecular N—H···S hydrogen bonds, see: Krepps et al. (2001).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of (I), with ellipsoids for non-H atoms shown at the 50% probability level.

tert-Butyl 2-sulfanylidene-2,3-dihydro-1H-imidazole-1-carboxylate top

Crystal data top

C₈H₁₂N₂O₂S	-
M_r = 200.26	D_x = 1.248 Mg m⁻³
Monoclinic, P2₁/c	Melting point: 439 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 6.8316 (3) Å	Cell parameters from 1507 reflections
b = 8.8893 (5) Å	θ = 3.0–29.2°
c = 17.5458 (15) Å	µ = 0.28 mm⁻¹
β = 90.789 (6)°	T = 293 K
V = 1065.42 (12) Å³	Parallelpiped, colourless
Z = 4	0.60 × 0.50 × 0.35 mm
F(000) = 424

Data collection top

Agilent Xcalibur Sapphire3 Gemini diffractometer	2472 independent reflections
Radiation source: fine-focus sealed tube	1808 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.047
Detector resolution: 16.0690 pixels mm^-1	θ_max = 29.2°, θ_min = 3.0°
ω scans	h = −9→9
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −11→11
T_min = 0.859, T_max = 1.000	l = −23→21
4722 measured reflections

Refinement top

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)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.213	H-atom parameters constrained
S = 1.09	w = 1/[σ²(F_o²) + (0.120P)²] where P = (F_o² + 2F_c²)/3
2472 reflections	(Δ/σ)_max < 0.001
118 parameters	Δρ_max = 0.37 e Å⁻³
0 restraints	Δρ_min = −0.67 e Å⁻³

Crystal data top

C₈H₁₂N₂O₂S	V = 1065.42 (12) Å³
M_r = 200.26	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 6.8316 (3) Å	µ = 0.28 mm⁻¹
b = 8.8893 (5) Å	T = 293 K
c = 17.5458 (15) Å	0.60 × 0.50 × 0.35 mm
β = 90.789 (6)°

Data collection top

Agilent Xcalibur Sapphire3 Gemini diffractometer	2472 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	1808 reflections with I > 2σ(I)
T_min = 0.859, T_max = 1.000	R_int = 0.047
4722 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.070	0 restraints
wR(F²) = 0.213	H-atom parameters constrained
S = 1.09	Δρ_max = 0.37 e Å⁻³
2472 reflections	Δρ_min = −0.67 e Å⁻³
118 parameters

Special details top

Experimental. Absorption correction: CrysAlisPro, Agilent Technologies, Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET) (compiled Oct 27 2011,15:02:11) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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 (Å²) top

	x	y	z	U_iso*/U_eq
S	0.27124 (9)	0.62848 (7)	0.03744 (6)	0.0726 (4)
O1	0.3738 (3)	0.9165 (2)	0.12448 (15)	0.0823 (8)
O2	0.1365 (3)	1.08602 (18)	0.14513 (10)	0.0541 (5)
N1	−0.1123 (3)	0.6966 (2)	0.03370 (11)	0.0468 (5)
H1A	−0.1457	0.6126	0.0129	0.056*
N2	0.0567 (3)	0.87696 (19)	0.08377 (11)	0.0389 (5)
C1	0.0732 (3)	0.7337 (2)	0.05224 (13)	0.0415 (5)
C2	−0.2421 (3)	0.8086 (3)	0.05181 (14)	0.0508 (6)
H2A	−0.3770	0.8061	0.0440	0.061*
C3	−0.1412 (3)	0.9201 (3)	0.08217 (13)	0.0472 (6)
H3A	−0.1916	1.0109	0.0994	0.057*
C4	0.2096 (3)	0.9595 (3)	0.11969 (14)	0.0469 (6)
C5	0.2572 (4)	1.1899 (3)	0.19323 (15)	0.0587 (7)
C6	0.1128 (6)	1.3169 (4)	0.2072 (2)	0.0962 (12)
H6A	0.0046	1.2795	0.2360	0.144*
H6B	0.0656	1.3553	0.1592	0.144*
H6C	0.1769	1.3960	0.2352	0.144*
C7	0.4278 (5)	1.2477 (4)	0.1471 (2)	0.0896 (11)
H7A	0.5177	1.1669	0.1379	0.134*
H7B	0.4935	1.3264	0.1748	0.134*
H7C	0.3800	1.2865	0.0992	0.134*
C8	0.3180 (8)	1.1119 (4)	0.2653 (2)	0.1084 (15)
H8A	0.4083	1.0327	0.2538	0.163*
H8B	0.2047	1.0702	0.2893	0.163*
H8C	0.3798	1.1829	0.2992	0.163*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S	0.0365 (4)	0.0442 (5)	0.1370 (8)	−0.0011 (3)	0.0015 (4)	−0.0349 (4)
O1	0.0419 (11)	0.0628 (12)	0.142 (2)	0.0071 (9)	−0.0166 (12)	−0.0510 (13)
O2	0.0475 (10)	0.0450 (9)	0.0696 (11)	0.0052 (8)	−0.0040 (8)	−0.0234 (8)
N1	0.0350 (10)	0.0458 (11)	0.0598 (11)	−0.0064 (9)	0.0021 (8)	−0.0122 (9)
N2	0.0304 (9)	0.0365 (9)	0.0501 (10)	0.0008 (7)	0.0051 (7)	−0.0070 (8)
C1	0.0348 (12)	0.0363 (11)	0.0535 (12)	−0.0065 (9)	0.0045 (9)	−0.0055 (10)
C2	0.0310 (11)	0.0640 (16)	0.0574 (14)	0.0018 (11)	0.0019 (10)	−0.0141 (12)
C3	0.0346 (12)	0.0546 (14)	0.0525 (13)	0.0079 (10)	0.0028 (9)	−0.0103 (11)
C4	0.0383 (12)	0.0404 (12)	0.0622 (14)	0.0022 (10)	0.0011 (10)	−0.0125 (11)
C5	0.0710 (18)	0.0431 (13)	0.0619 (15)	−0.0010 (13)	−0.0053 (13)	−0.0206 (12)
C6	0.104 (3)	0.0696 (19)	0.115 (3)	0.014 (2)	−0.003 (2)	−0.048 (2)
C7	0.090 (2)	0.0680 (19)	0.111 (3)	−0.0256 (19)	0.000 (2)	−0.029 (2)
C8	0.167 (5)	0.082 (3)	0.075 (2)	0.001 (2)	−0.038 (2)	−0.0115 (19)

Geometric parameters (Å, º) top

S—C1	1.668 (2)	C5—C8	1.496 (5)
O1—C4	1.186 (3)	C5—C7	1.518 (4)
O2—C4	1.312 (3)	C5—C6	1.521 (4)
O2—C5	1.492 (3)	C6—H6A	0.9600
N1—C1	1.345 (3)	C6—H6B	0.9600
N1—C2	1.374 (3)	C6—H6C	0.9600
N1—H1A	0.8600	C7—H7A	0.9600
N2—C1	1.394 (3)	C7—H7B	0.9600
N2—C3	1.405 (3)	C7—H7C	0.9600
N2—C4	1.417 (3)	C8—H8A	0.9600
C2—C3	1.316 (3)	C8—H8B	0.9600
C2—H2A	0.9300	C8—H8C	0.9600
C3—H3A	0.9300

C4—O2—C5	120.9 (2)	O2—C5—C6	101.3 (2)
C1—N1—C2	112.04 (19)	C8—C5—C6	112.4 (3)
C1—N1—H1A	124.0	C7—C5—C6	109.8 (3)
C2—N1—H1A	124.0	C5—C6—H6A	109.5
C1—N2—C3	108.91 (18)	C5—C6—H6B	109.5
C1—N2—C4	125.90 (19)	H6A—C6—H6B	109.5
C3—N2—C4	124.82 (19)	C5—C6—H6C	109.5
N1—C1—N2	103.84 (18)	H6A—C6—H6C	109.5
N1—C1—S	126.03 (17)	H6B—C6—H6C	109.5
N2—C1—S	130.11 (16)	C5—C7—H7A	109.5
C3—C2—N1	107.6 (2)	C5—C7—H7B	109.5
C3—C2—H2A	126.2	H7A—C7—H7B	109.5
N1—C2—H2A	126.2	C5—C7—H7C	109.5
C2—C3—N2	107.6 (2)	H7A—C7—H7C	109.5
C2—C3—H3A	126.2	H7B—C7—H7C	109.5
N2—C3—H3A	126.2	C5—C8—H8A	109.5
O1—C4—O2	128.0 (2)	C5—C8—H8B	109.5
O1—C4—N2	123.7 (2)	H8A—C8—H8B	109.5
O2—C4—N2	108.25 (19)	C5—C8—H8C	109.5
O2—C5—C8	109.7 (2)	H8A—C8—H8C	109.5
O2—C5—C7	109.3 (2)	H8B—C8—H8C	109.5
C8—C5—C7	113.7 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Sⁱ	0.86	2.47	3.324 (2)	174

Symmetry code: (i) −x, −y+1, −z.

Experimental details

Crystal data
Chemical formula	C₈H₁₂N₂O₂S
M_r	200.26
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	6.8316 (3), 8.8893 (5), 17.5458 (15)
β (°)	90.789 (6)
V (Å³)	1065.42 (12)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.28
Crystal size (mm)	0.60 × 0.50 × 0.35

Data collection
Diffractometer	Agilent Xcalibur Sapphire3 Gemini
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2011)
T_min, T_max	0.859, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	4722, 2472, 1808
R_int	0.047
(sin θ/λ)_max (Å⁻¹)	0.687

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.070, 0.213, 1.09
No. of reflections	2472
No. of parameters	118
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.67

Computer programs: CrysAlis PRO (Agilent, 2011), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Sⁱ	0.86	2.47	3.324 (2)	173.9

Symmetry code: (i) −x, −y+1, −z.

Acknowledgements

We gratefully acknowledge financial support in part from the National Science Council, Taiwan (NSC 99-2119-M-241-001-MY2). Helpful comments from the reviewers are also greatly appreciated.

References

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