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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

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

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, B. (2002). J. Invest. Dermatol. 118, 205-207.]); Kasraee et al. (2005[Kasraee, B., Handjani, F., Parhizgar, A., Omrani, G. R., Fallahi, M. R., Amini, M., Nikbakhsh, M., Tran, C., Hügin, A., Sorg, O. & Saurat, J.-H. (2005). Dermatology, 211, 360-362.]) and for inhibiting tyrosinase, see: Liao et al. (2012[Liao, W. C., Wu, W. H., Tsai, P.-C., Wang, H.-F., Liu, Y.-H. & Chan, C.-F. (2012). Appl. Biochem. Biotechnol. 166, 259-267.]). For related structures containing inter­molecular N—H⋯S hydrogen bonds, see: Krepps et al. (2001[Krepps, M. K., Parkin, S. & Atwood, D. A. (2001). Cryst. Growth Des. 1, 291-297.]).

[Scheme 1]

Experimental

Crystal data
  • C8H12N2O2S

  • Mr = 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[Agilent (2011). CrysAlis PRO. Agilent Technologies, Yarnton, England.]) Tmin = 0.859, Tmax = 1.000

  • 4722 measured reflections

  • 2472 independent reflections

  • 1808 reflections with I > 2σ(I)

  • Rint = 0.047

Refinement
  • R[F2 > 2σ(F2)] = 0.070

  • wR(F2) = 0.213

  • S = 1.09

  • 2472 reflections

  • 118 parameters

  • H-atom parameters constrained

  • Δρmax = 0.37 e Å−3

  • Δρmin = −0.67 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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[Agilent (2011). CrysAlis PRO. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


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.

Refinement top

All H atoms were placed in geometrically idealized positions and treated as riding on their parent atoms, with C—H = 0.93 - 0.96 Å, N—H = 0.86 Å and Uiso(H) > 1.2Ueq(C,N) or 1.5 Ueq(Cmethyl).

Structure description 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).

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
[Figure 1] 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-
Mr = 200.26Dx = 1.248 Mg m3
Monoclinic, P21/cMelting point: 439 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 6.8316 (3) ÅCell parameters from 1507 reflections
b = 8.8893 (5) Åθ = 3.0–29.2°
c = 17.5458 (15) ŵ = 0.28 mm1
β = 90.789 (6)°T = 293 K
V = 1065.42 (12) Å3Parallelpiped, colourless
Z = 40.60 × 0.50 × 0.35 mm
F(000) = 424
Data collection top
Agilent Xcalibur Sapphire3 Gemini
diffractometer
2472 independent reflections
Radiation source: fine-focus sealed tube1808 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
Detector resolution: 16.0690 pixels mm-1θmax = 29.2°, θmin = 3.0°
ω scansh = 99
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2011)
k = 1111
Tmin = 0.859, Tmax = 1.000l = 2321
4722 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.070Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.213H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.120P)2]
where P = (Fo2 + 2Fc2)/3
2472 reflections(Δ/σ)max < 0.001
118 parametersΔρmax = 0.37 e Å3
0 restraintsΔρmin = 0.67 e Å3
Crystal data top
C8H12N2O2SV = 1065.42 (12) Å3
Mr = 200.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.8316 (3) ŵ = 0.28 mm1
b = 8.8893 (5) ÅT = 293 K
c = 17.5458 (15) Å0.60 × 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)
Tmin = 0.859, Tmax = 1.000Rint = 0.047
4722 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0700 restraints
wR(F2) = 0.213H-atom parameters constrained
S = 1.09Δρmax = 0.37 e Å3
2472 reflectionsΔρmin = 0.67 e Å3
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
xyzUiso*/Ueq
S0.27124 (9)0.62848 (7)0.03744 (6)0.0726 (4)
O10.3738 (3)0.9165 (2)0.12448 (15)0.0823 (8)
O20.1365 (3)1.08602 (18)0.14513 (10)0.0541 (5)
N10.1123 (3)0.6966 (2)0.03370 (11)0.0468 (5)
H1A0.14570.61260.01290.056*
N20.0567 (3)0.87696 (19)0.08377 (11)0.0389 (5)
C10.0732 (3)0.7337 (2)0.05224 (13)0.0415 (5)
C20.2421 (3)0.8086 (3)0.05181 (14)0.0508 (6)
H2A0.37700.80610.04400.061*
C30.1412 (3)0.9201 (3)0.08217 (13)0.0472 (6)
H3A0.19161.01090.09940.057*
C40.2096 (3)0.9595 (3)0.11969 (14)0.0469 (6)
C50.2572 (4)1.1899 (3)0.19323 (15)0.0587 (7)
C60.1128 (6)1.3169 (4)0.2072 (2)0.0962 (12)
H6A0.00461.27950.23600.144*
H6B0.06561.35530.15920.144*
H6C0.17691.39600.23520.144*
C70.4278 (5)1.2477 (4)0.1471 (2)0.0896 (11)
H7A0.51771.16690.13790.134*
H7B0.49351.32640.17480.134*
H7C0.38001.28650.09920.134*
C80.3180 (8)1.1119 (4)0.2653 (2)0.1084 (15)
H8A0.40831.03270.25380.163*
H8B0.20471.07020.28930.163*
H8C0.37981.18290.29920.163*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S0.0365 (4)0.0442 (5)0.1370 (8)0.0011 (3)0.0015 (4)0.0349 (4)
O10.0419 (11)0.0628 (12)0.142 (2)0.0071 (9)0.0166 (12)0.0510 (13)
O20.0475 (10)0.0450 (9)0.0696 (11)0.0052 (8)0.0040 (8)0.0234 (8)
N10.0350 (10)0.0458 (11)0.0598 (11)0.0064 (9)0.0021 (8)0.0122 (9)
N20.0304 (9)0.0365 (9)0.0501 (10)0.0008 (7)0.0051 (7)0.0070 (8)
C10.0348 (12)0.0363 (11)0.0535 (12)0.0065 (9)0.0045 (9)0.0055 (10)
C20.0310 (11)0.0640 (16)0.0574 (14)0.0018 (11)0.0019 (10)0.0141 (12)
C30.0346 (12)0.0546 (14)0.0525 (13)0.0079 (10)0.0028 (9)0.0103 (11)
C40.0383 (12)0.0404 (12)0.0622 (14)0.0022 (10)0.0011 (10)0.0125 (11)
C50.0710 (18)0.0431 (13)0.0619 (15)0.0010 (13)0.0053 (13)0.0206 (12)
C60.104 (3)0.0696 (19)0.115 (3)0.014 (2)0.003 (2)0.048 (2)
C70.090 (2)0.0680 (19)0.111 (3)0.0256 (19)0.000 (2)0.029 (2)
C80.167 (5)0.082 (3)0.075 (2)0.001 (2)0.038 (2)0.0115 (19)
Geometric parameters (Å, º) top
S—C11.668 (2)C5—C81.496 (5)
O1—C41.186 (3)C5—C71.518 (4)
O2—C41.312 (3)C5—C61.521 (4)
O2—C51.492 (3)C6—H6A0.9600
N1—C11.345 (3)C6—H6B0.9600
N1—C21.374 (3)C6—H6C0.9600
N1—H1A0.8600C7—H7A0.9600
N2—C11.394 (3)C7—H7B0.9600
N2—C31.405 (3)C7—H7C0.9600
N2—C41.417 (3)C8—H8A0.9600
C2—C31.316 (3)C8—H8B0.9600
C2—H2A0.9300C8—H8C0.9600
C3—H3A0.9300
C4—O2—C5120.9 (2)O2—C5—C6101.3 (2)
C1—N1—C2112.04 (19)C8—C5—C6112.4 (3)
C1—N1—H1A124.0C7—C5—C6109.8 (3)
C2—N1—H1A124.0C5—C6—H6A109.5
C1—N2—C3108.91 (18)C5—C6—H6B109.5
C1—N2—C4125.90 (19)H6A—C6—H6B109.5
C3—N2—C4124.82 (19)C5—C6—H6C109.5
N1—C1—N2103.84 (18)H6A—C6—H6C109.5
N1—C1—S126.03 (17)H6B—C6—H6C109.5
N2—C1—S130.11 (16)C5—C7—H7A109.5
C3—C2—N1107.6 (2)C5—C7—H7B109.5
C3—C2—H2A126.2H7A—C7—H7B109.5
N1—C2—H2A126.2C5—C7—H7C109.5
C2—C3—N2107.6 (2)H7A—C7—H7C109.5
C2—C3—H3A126.2H7B—C7—H7C109.5
N2—C3—H3A126.2C5—C8—H8A109.5
O1—C4—O2128.0 (2)C5—C8—H8B109.5
O1—C4—N2123.7 (2)H8A—C8—H8B109.5
O2—C4—N2108.25 (19)C5—C8—H8C109.5
O2—C5—C8109.7 (2)H8A—C8—H8C109.5
O2—C5—C7109.3 (2)H8B—C8—H8C109.5
C8—C5—C7113.7 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Si0.862.473.324 (2)174
Symmetry code: (i) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC8H12N2O2S
Mr200.26
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)6.8316 (3), 8.8893 (5), 17.5458 (15)
β (°) 90.789 (6)
V3)1065.42 (12)
Z4
Radiation typeMo Kα
µ (mm1)0.28
Crystal size (mm)0.60 × 0.50 × 0.35
Data collection
DiffractometerAgilent Xcalibur Sapphire3 Gemini
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2011)
Tmin, Tmax0.859, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
4722, 2472, 1808
Rint0.047
(sin θ/λ)max1)0.687
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.070, 0.213, 1.09
No. of reflections2472
No. of parameters118
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)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···AD—HH···AD···AD—H···A
N1—H1A···Si0.862.473.324 (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

First citationAgilent (2011). CrysAlis PRO. Agilent Technologies, Yarnton, England.  Google Scholar
First citationKasraee, B. (2002). J. Invest. Dermatol. 118, 205–207.  Web of Science CrossRef PubMed CAS Google Scholar
First citationKasraee, B., Handjani, F., Parhizgar, A., Omrani, G. R., Fallahi, M. R., Amini, M., Nikbakhsh, M., Tran, C., Hügin, A., Sorg, O. & Saurat, J.-H. (2005). Dermatology, 211, 360–362.  Web of Science CrossRef PubMed CAS Google Scholar
First citationKrepps, M. K., Parkin, S. & Atwood, D. A. (2001). Cryst. Growth Des. 1, 291–297.  Web of Science CSD CrossRef CAS Google Scholar
First citationLiao, W. C., Wu, W. H., Tsai, P.-C., Wang, H.-F., Liu, Y.-H. & Chan, C.-F. (2012). Appl. Biochem. Biotechnol. 166, 259–267.  Web of Science CrossRef CAS PubMed Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds