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

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ISSN: 2056-9890

2-(6-Bromo­benzo[d]thia­zol-2-yl)-5,5-di­methyl­thia­zol-4(5H)-one

aInstitut für Organische Chemie und Makromolekulare Chemie, Universität Jena, Humboldtstr. 10, 07743 Jena, Germany, and bInstitut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität, Jena, Humboldt-Str. 8, 07743 Jena, Germany
*Correspondence e-mail: c6bera@rz.uni-jena.de

(Received 4 November 2013; accepted 15 November 2013; online 23 November 2013)

The title compound, C12H9BrN2OS2, was obtained by reacting 6-bromo­benzo[d]thia­zole-2-carbo­nitrile in iso-propanol with ethyl 2-mercapto-2-methyl­propano­ate at reflux temperature for several hours. The resulting di­methyl­oxyluciferin derivative shows partial double-bond character of the carbon–carbon bond between the two heterocyclic moieties [C—C = 1.461 (3) Å]. This double bond restricts rotation around this C—C axis, therefore leading to an almost planar mol­ecular structure [N—C—C—S torsion angle = 9.7 (3)°]. The five-membered thiazoline ring is not completely planar as a result of the bulky S atom [C—S—C—C torsion angle = 5.17 (12)°].

Related literature

For the chemi- and bioluminescence of firefly luciferin and related compounds, see: Jung et al. (1975[Jung, J., Chin, C.-A. & Song, P.-S. (1975). J. Am. Chem. Soc. 97, 3949-3954.]); White et al. (1961[White, E. H., Capra, F. M., Field, G. F. & McElroy, W. D. (1961). J. Am. Chem. Soc. 83, 2402-2403.], 1979[White, E. H., Steinmetz, M. G., Miano, J. D., Wildes, P. D. & Morland, R. (1979). J. Am. Chem. Soc. 101, 3199-3208.]); Branchini et al. (2002[Branchini, B. R., Murtiashaw, M. H., Magyar, R. A., Portier, N. C., Ruggiero, M. C. & Stroh, J. G. (2002). J. Am. Chem. Soc. 124, 2112-2113.]). For structural modifications of firefly luciferin, see: Meroni et al. (2009[Meroni, G., Rajabi, M. & Santaniello, E. (2009). Arkivoc, pp. 265-288.]); McCutcheon et al. (2012[McCutcheon, D. C., Paley, M. A., Steinhardt, R. C. & Prescher, J. A. (2012). J. Am. Chem. Soc. 134, 7604-7607.]); Branchini et al. (2012[Branchini, B. R., Woodroofe, C. C., Meisenheimer, P. L., Klaubert, D. H., Kovic, Y., Rosenberg, J. C., Behney, C. E. & Southworth, T. L. (2012). Biochemistry, 51, 9807-9813.]); Würfel (2012[Würfel, H. (2012). PhD thesis, Friedrich-Schiller-University Jena, Germany.]). Luciferin and related structures are widely used in clinical and biochemical applications, see: Schäffer (1987a[Schäffer, J. M. (1987a). US patent US 4665022.],b[Schäffer, J. M. (1987b). Chem. Abstr.107, 55320.]); Kricka (1988[Kricka, L. J. (1988). Anal. Biochem. 175, 14-21.]); Josel et al. (1994a[Josel, H.-P., Herrmann, R., Klein, C. & Heindl, D. (1994a). German patent DE 4210759.],b[Josel, H.-P., Herrmann, R., Klein, C. & Heindl, D. (1994b). Chem. Abstr. 120, 164160.]); Shinde et al. (2006[Shinde, R., Perkins, J. & Contag, C. H. (2006). Biochemistry, 45, 11103-11112.]). For details of the synthetic procedure, see: Armarego & Chai (2009[Armarego, W. L. & Chai, C. L. (2009). Purification of Laboratory Chemicals, 6th ed. Amsterdam, Boston, Heidelberg, London, New York, Oxford, Paris, San Diego, San Francisco, Singapore, Sydney, Tokyo: Elsevier.]); Bardsley et al. (2009a[Bardsley, K., Agyemang, D. O. & Pei, T. (2009a). US patent US20090232747A1.],b[Bardsley, K., Agyemang, D. O. & Pei, T. (2009b). Chem. Abstr. 151, 366000.]); Würfel et al. (2012[Würfel, H., Weiss, D., Beckert, R. & Güther, A. (2012). J. Sulfur Chem. 33, 9-16.]).

[Scheme 1]

Experimental

Crystal data
  • C12H9BrN2OS2

  • Mr = 341.24

  • Monoclinic, P 21 /c

  • a = 12.8246 (3) Å

  • b = 11.9115 (3) Å

  • c = 8.5375 (2) Å

  • β = 99.735 (1)°

  • V = 1285.41 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 3.51 mm−1

  • T = 133 K

  • 0.06 × 0.05 × 0.04 mm

Data collection
  • Nonius KappaCCD diffractometer

  • 7856 measured reflections

  • 2927 independent reflections

  • 2676 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.025

  • wR(F2) = 0.065

  • S = 1.02

  • 2927 reflections

  • 165 parameters

  • H-atom parameters constrained

  • Δρmax = 0.44 e Å−3

  • Δρmin = −0.40 e Å−3

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by Carter, C. W. Jr & Sweet, R. M., pp. 307-326. New York: Academic Press.]); data reduction: DENZO; 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: XP in SHELXTL/PC (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Heterocycles are widely used in nature for a great variety of purposes. One of the most interesting ones is bioluminescence which is defined as the chemically stimulated emission of light by living organisms. One prominent example of a bioluminescent organism is the firefly (Photinus pyralis), which employs the benzothiazole containing Luciferin for light emission (White et al., 1961). One known inhibitor for this Luciferin-Luciferase reaction is the structurally close related dimethyloxyluciferin (Meroni et al., 2009). This compound also shows a bright red fluorescence in the visible spectrum in the deprotonated state (Branchini et al., 2002). Therefore investigations where conducted in our group focusing on modifications of the benzo[d]thiazol moiety of dimethyloxyluciferin (Würfel, 2012).

The title compound was synthesized by condensation of 6-bromobenzo[d]thiazole-2-carbonitrile with 2-mercapto-2-methylpropanoate. The Br—C bond length of 1.898 (2) Å (Br1—C4) is typical for a bromine atom bonded to an aromatic ring. The substituted benzo[d]-thiazol moiety builds up a planar structure, whereas the thiazoline ring is not exactly planar because of one sp3 carbon atom (C10). Since sp3 carbon atoms prefer smaller bond angles than sp2 carbons, C10 is pushed out of the thiazoline plane. The C—C bond, connecting the heterocyclic moieties shows a partial double bond character (C1—C8, 1.461 (3) Å). The sulfur atoms S1 and S2 are arranged trans in the crystal, thus providing the maximal distance from each other (4.3686 (7) Å). Despite of the double bond character of C1—C8 the heterocyclic moieties are not exactly coplanar with respect to each other. The torsion angles N1—C1—C8—S2 show a deviation of -9.7 (3)°.

Related literature top

For the chemi- and bioluminescence of firefly luciferin and related compounds, see: Jung et al. (1975); White et al. (1961, 1979); Branchini et al. (2002). For structural modifications of firefly luciferin, see: Meroni et al. (2009); McCutcheon et al. (2012); Branchini et al. (2012); Würfel (2012). Luciferin and related structures are widely used in clinical and biochemical applications, see: Schäffer (1987a,b); Kricka (1988); Josel et al. (1994a,b); Shinde et al. (2006). For details of the synthetic procedure, see: Armarego & Chai (2009); Bardsley et al. (2009a,b); Würfel et al. (2012).

Experimental top

All chemicals were synthesized according to given literature or purchased from commercial sources. All solvents were purified and dried according to Armarego & Chai (2009). 3.46 g (14.5 mmol) 6-bromobenzo[d]thiazole-2-carbonitrile, 2.5 ml (approx. 17.4 mmol) ethyl 2-mercapto-2-methylpropanoate and 4.8 ml (34.8 mmol) triethylamine were refluxed in 20 ml of iso-propanol for 6 h. The product was recrystallized from ethanol yielding 70% (3.46 g, 10.1 mmol) pale yellow crystals. 6-Bromobenzo[d]thiazole-2-carbonitrile was prepared analog to Würfel et al. (2012). Ethyl 2-mercapto-2-methylpropanoate was prepared according to Bardsley et al. (2009a,b). Yellow single crystals of the title compound were obtained by dissolving the compound in ethanol at reflux temperature and after cooling to r. t. the closed vessel was left alone for several days. Elemental analysis calculated for C12H9BrN2OS2: C 42.24, H 2.66, Br 23.42, N 8.21, S 18.79; found: C 42.12, H 2.63, Br 23.51, N 8.11, S 19.00.

Refinement top

All hydrogen atoms were set to idealized positions and were refined with Uiso(H) = 1.2 Ueq(C) (1.5 for methyl groups). Methyl groups were allowed to rotate but not to tip.

Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO (Otwinowski & Minor 1997); data reduction: DENZO (Otwinowski & Minor 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL/PC (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure and numbering scheme of the title compound 1 showing displacement ellipsoids at the 40% probability level.
2-(6-Bromobenzo[d]thiazol-2-yl)-5,5-dimethylthiazol-4(5H)-one top
Crystal data top
C12H9BrN2OS2F(000) = 680
Mr = 341.24Dx = 1.763 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 7856 reflections
a = 12.8246 (3) Åθ = 2.4–27.5°
b = 11.9115 (3) ŵ = 3.51 mm1
c = 8.5375 (2) ÅT = 133 K
β = 99.735 (1)°Prism, colourless
V = 1285.41 (5) Å30.06 × 0.05 × 0.04 mm
Z = 4
Data collection top
Nonius KappaCCD
diffractometer
2676 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.033
Graphite monochromatorθmax = 27.5°, θmin = 2.4°
phi– + ω–scanh = 1616
7856 measured reflectionsk = 1515
2927 independent reflectionsl = 1111
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)] = 0.025Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.065H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0282P)2 + 1.1743P]
where P = (Fo2 + 2Fc2)/3
2927 reflections(Δ/σ)max = 0.001
165 parametersΔρmax = 0.44 e Å3
0 restraintsΔρmin = 0.40 e Å3
Crystal data top
C12H9BrN2OS2V = 1285.41 (5) Å3
Mr = 341.24Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.8246 (3) ŵ = 3.51 mm1
b = 11.9115 (3) ÅT = 133 K
c = 8.5375 (2) Å0.06 × 0.05 × 0.04 mm
β = 99.735 (1)°
Data collection top
Nonius KappaCCD
diffractometer
2676 reflections with I > 2σ(I)
7856 measured reflectionsRint = 0.033
2927 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0250 restraints
wR(F2) = 0.065H-atom parameters constrained
S = 1.02Δρmax = 0.44 e Å3
2927 reflectionsΔρmin = 0.40 e Å3
165 parameters
Special details top

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
Br10.858415 (15)0.276647 (17)0.06700 (2)0.02385 (8)
S10.46626 (4)0.21606 (4)0.14052 (6)0.01968 (11)
S20.26944 (4)0.47143 (4)0.31410 (6)0.02169 (12)
O10.11449 (13)0.20363 (13)0.3753 (2)0.0295 (4)
N10.48242 (12)0.42814 (14)0.21789 (19)0.0197 (3)
N20.26810 (13)0.25109 (15)0.2854 (2)0.0206 (3)
C10.42214 (15)0.34012 (16)0.2154 (2)0.0190 (4)
C20.57634 (15)0.28879 (16)0.1035 (2)0.0180 (4)
C30.66043 (15)0.24949 (16)0.0334 (2)0.0188 (4)
H3A0.66230.17480.00490.023*
C40.74046 (15)0.32508 (17)0.0230 (2)0.0188 (4)
C50.73963 (15)0.43642 (17)0.0770 (2)0.0202 (4)
H5A0.79730.48500.06910.024*
C60.65474 (15)0.47491 (17)0.1416 (2)0.0208 (4)
H6A0.65250.55050.17650.025*
C70.57210 (15)0.40109 (16)0.1549 (2)0.0188 (4)
C80.32045 (15)0.34245 (16)0.2709 (2)0.0189 (4)
C90.17367 (16)0.27547 (16)0.3418 (2)0.0211 (4)
C100.14997 (15)0.40174 (16)0.3551 (2)0.0195 (4)
C110.05518 (16)0.43242 (19)0.2281 (2)0.0250 (4)
H11B0.00720.39040.24710.037*
H11C0.07080.41340.12280.037*
H11D0.04120.51310.23300.037*
C120.13018 (16)0.42953 (18)0.5223 (2)0.0231 (4)
H12B0.06770.38860.54330.035*
H12C0.11830.51040.53070.035*
H12D0.19190.40730.60020.035*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.02181 (11)0.02233 (12)0.02884 (12)0.00282 (7)0.00841 (8)0.00194 (8)
S10.0206 (2)0.0135 (2)0.0256 (2)0.00276 (17)0.00599 (19)0.00213 (18)
S20.0223 (2)0.0131 (2)0.0311 (3)0.00125 (17)0.00843 (19)0.00089 (19)
O10.0320 (8)0.0187 (7)0.0420 (9)0.0057 (6)0.0182 (7)0.0017 (7)
N10.0204 (8)0.0157 (8)0.0237 (8)0.0015 (6)0.0059 (6)0.0001 (6)
N20.0204 (8)0.0160 (8)0.0263 (8)0.0018 (6)0.0062 (7)0.0031 (7)
C10.0208 (9)0.0163 (9)0.0196 (9)0.0010 (7)0.0024 (7)0.0003 (7)
C20.0200 (9)0.0158 (9)0.0177 (9)0.0029 (7)0.0019 (7)0.0015 (7)
C30.0218 (9)0.0138 (9)0.0204 (9)0.0018 (7)0.0023 (7)0.0015 (8)
C40.0183 (8)0.0198 (9)0.0187 (9)0.0023 (7)0.0043 (7)0.0016 (8)
C50.0212 (9)0.0175 (9)0.0220 (9)0.0030 (7)0.0035 (7)0.0009 (7)
C60.0224 (9)0.0152 (9)0.0258 (10)0.0004 (7)0.0064 (8)0.0014 (8)
C70.0203 (9)0.0157 (9)0.0202 (9)0.0006 (7)0.0026 (7)0.0007 (7)
C80.0216 (9)0.0139 (9)0.0209 (9)0.0001 (7)0.0024 (7)0.0003 (7)
C90.0231 (9)0.0180 (10)0.0229 (10)0.0001 (7)0.0058 (8)0.0019 (8)
C100.0204 (9)0.0158 (9)0.0235 (9)0.0007 (7)0.0067 (7)0.0001 (7)
C110.0232 (9)0.0288 (11)0.0226 (10)0.0006 (8)0.0031 (8)0.0017 (8)
C120.0255 (10)0.0225 (10)0.0221 (10)0.0031 (8)0.0064 (8)0.0012 (8)
Geometric parameters (Å, º) top
Br1—C41.8985 (19)C3—H3A0.9500
S1—C21.730 (2)C4—C51.405 (3)
S1—C11.742 (2)C5—C61.379 (3)
S1—S24.3686 (7)C5—H5A0.9500
S2—C81.734 (2)C6—C71.396 (3)
S2—C101.8276 (19)C6—H6A0.9500
O1—C91.210 (3)C9—C101.542 (3)
N1—C11.301 (3)C10—C121.528 (3)
N1—C71.387 (2)C10—C111.530 (3)
N2—C81.296 (3)C11—H11B0.9800
N2—C91.407 (3)C11—H11C0.9800
C1—C81.461 (3)C11—H11D0.9800
C2—C31.399 (3)C12—H12B0.9800
C2—C71.412 (3)C12—H12C0.9800
C3—C41.379 (3)C12—H12D0.9800
C2—S1—C188.17 (9)N1—C7—C2114.75 (17)
C2—S1—S2104.45 (7)C6—C7—C2120.10 (18)
C1—S1—S216.82 (6)N2—C8—C1121.36 (18)
C8—S2—C1089.82 (9)N2—C8—S2120.25 (15)
C8—S2—S118.27 (7)C1—C8—S2118.38 (15)
C10—S2—S1107.45 (6)O1—C9—N2123.07 (18)
C1—N1—C7109.63 (17)O1—C9—C10122.21 (19)
C8—N2—C9110.44 (17)N2—C9—C10114.71 (17)
N1—C1—C8122.68 (18)C12—C10—C11111.89 (16)
N1—C1—S1117.44 (15)C12—C10—C9110.22 (17)
C8—C1—S1119.88 (15)C11—C10—C9108.90 (17)
C3—C2—C7121.53 (17)C12—C10—S2110.94 (14)
C3—C2—S1128.47 (15)C11—C10—S2110.32 (14)
C7—C2—S1109.99 (15)C9—C10—S2104.29 (13)
C4—C3—C2116.41 (18)C10—C11—H11B109.5
C4—C3—H3A121.8C10—C11—H11C109.5
C2—C3—H3A121.8H11B—C11—H11C109.5
C3—C4—C5123.22 (18)C10—C11—H11D109.5
C3—C4—Br1118.70 (15)H11B—C11—H11D109.5
C5—C4—Br1118.07 (15)H11C—C11—H11D109.5
C6—C5—C4119.70 (18)C10—C12—H12B109.5
C6—C5—H5A120.2C10—C12—H12C109.5
C4—C5—H5A120.2H12B—C12—H12C109.5
C5—C6—C7118.98 (18)C10—C12—H12D109.5
C5—C6—H6A120.5H12B—C12—H12D109.5
C7—C6—H6A120.5H12C—C12—H12D109.5
N1—C7—C6125.15 (18)
C2—S1—S2—C8164.7 (2)C3—C2—C7—C62.3 (3)
C1—S1—S2—C8149.8 (3)S1—C2—C7—C6177.93 (15)
C2—S1—S2—C10179.56 (9)C9—N2—C8—C1179.51 (17)
C1—S1—S2—C10165.6 (2)C9—N2—C8—S21.7 (2)
C7—N1—C1—C8178.67 (17)N1—C1—C8—N2171.43 (19)
C7—N1—C1—S10.8 (2)S1—C1—C8—N29.2 (3)
C2—S1—C1—N11.39 (16)N1—C1—C8—S29.7 (3)
S2—S1—C1—N1167.0 (3)S1—C1—C8—S2169.70 (11)
C2—S1—C1—C8178.06 (16)C10—S2—C8—N22.53 (17)
S2—S1—C1—C812.46 (13)S1—S2—C8—N2167.5 (3)
C1—S1—C2—C3178.28 (19)C10—S2—C8—C1176.35 (16)
S2—S1—C2—C3174.01 (16)S1—S2—C8—C111.38 (12)
C1—S1—C2—C71.52 (15)C8—N2—C9—O1174.9 (2)
S2—S1—C2—C75.78 (14)C8—N2—C9—C106.1 (2)
C7—C2—C3—C42.4 (3)O1—C9—C10—C1254.4 (3)
S1—C2—C3—C4177.87 (15)N2—C9—C10—C12126.62 (18)
C2—C3—C4—C50.7 (3)O1—C9—C10—C1168.7 (3)
C2—C3—C4—Br1178.80 (14)N2—C9—C10—C11110.29 (19)
C3—C4—C5—C61.2 (3)O1—C9—C10—S2173.56 (18)
Br1—C4—C5—C6179.35 (15)N2—C9—C10—S27.5 (2)
C4—C5—C6—C71.3 (3)C8—S2—C10—C12123.84 (15)
C1—N1—C7—C6178.89 (19)S1—S2—C10—C12128.72 (12)
C1—N1—C7—C20.5 (2)C8—S2—C10—C11111.60 (15)
C5—C6—C7—N1179.72 (18)S1—S2—C10—C11106.71 (13)
C5—C6—C7—C20.3 (3)C8—S2—C10—C95.19 (14)
C3—C2—C7—N1178.30 (17)S1—S2—C10—C910.08 (14)
S1—C2—C7—N11.5 (2)

Experimental details

Crystal data
Chemical formulaC12H9BrN2OS2
Mr341.24
Crystal system, space groupMonoclinic, P21/c
Temperature (K)133
a, b, c (Å)12.8246 (3), 11.9115 (3), 8.5375 (2)
β (°) 99.735 (1)
V3)1285.41 (5)
Z4
Radiation typeMo Kα
µ (mm1)3.51
Crystal size (mm)0.06 × 0.05 × 0.04
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
7856, 2927, 2676
Rint0.033
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.025, 0.065, 1.02
No. of reflections2927
No. of parameters165
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.44, 0.40

Computer programs: COLLECT (Nonius, 1998), DENZO (Otwinowski & Minor 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL/PC (Sheldrick, 2008).

 

Acknowledgements

The authors thank Roche Diagnostics GmbH, Penzberg, for financial support.

References

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