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ISSN: 2056-9890

Ethyl 2-[4-(1,3-benzo­thiazol-2-yl)­anilino]acetate

aSchool of Chemical and Materials Engineering, Huangshi Institute of Technology, Huangshi 435003, People's Republic of China
*Correspondence e-mail: zy0340907@yahoo.com.cn

(Received 13 July 2010; accepted 23 July 2010; online 31 July 2010)

In the title compound, C17H16N2O2S, the dihedral angle between the benzothia­zole ring system and the benzene ring is 1.20 (2)°. The substituted amino substituent is in an extended conformation with an N—C—C—O torsion angle of 179.4 (3)°. In the crystal structure, pairs of mol­ecules are connected by inter­molecular N—H⋯O and weak C—H⋯O hydrogen bonds, forming centrosymmetric dimers.

Related literature

For background to thio­flavin T (ThT), a benzothia­zole dye that exhibits enhanced fluorescence upon binding to amyloid fibrils, and its derivatives, see: Kung et al. (2001[Kung, H. F., Lee, C.-W., Zhuang, Z.-P., Kung, M.-P., Hou, C. & Plssl, K. (2001). J. Am. Chem. Soc. 123, 12740-12741.]); Qu et al. (2007[Qu, W., Kung, M.-P., Hou, C., Oya, S. & Kung, H. F. (2007). J. Med. Chem. 50, 3380-3387.]); Zhang & Zhao (2009[Zhang, Y. & Zhao, B. (2009). Acta Cryst. E65, o2762.]). For the synthesis, see: Stephenson et al. (2007[Stephenson, K. A., Chandra, R., Zhuang, Z.-P., Hou, C., Oya, S., Kung, M.-P. & Kung, H. F. (2007). Bioconjugate Chem. 18, 238-246.]).

[Scheme 1]

Experimental

Crystal data
  • C17H16N2O2S

  • Mr = 312.38

  • Monoclinic, P 21 /n

  • a = 5.6303 (1) Å

  • b = 26.1604 (5) Å

  • c = 10.5989 (2) Å

  • β = 98.294 (1)°

  • V = 1544.79 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.22 mm−1

  • T = 298 K

  • 0.36 × 0.24 × 0.21 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.926, Tmax = 0.956

  • 11631 measured reflections

  • 3808 independent reflections

  • 3015 reflections with I > 2σ(I)

  • Rint = 0.076

Refinement
  • R[F2 > 2σ(F2)] = 0.058

  • wR(F2) = 0.145

  • S = 1.07

  • 3808 reflections

  • 203 parameters

  • 1 restraint

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.39 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C12—H12⋯O2i 0.93 2.60 3.390 (2) 144
N2—H2A⋯O2i 0.85 (1) 2.40 (1) 3.188 (2) 154 (2)
Symmetry code: (i) -x-1, -y, -z+1.

Data collection: SMART (Bruker, 2007[Bruker (2007). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 2007[Bruker (2007). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; 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: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Supporting information


Comment top

Thioflavin T (ThT) is a benzothiazole dye that exhibits enhanced fluorescence upon binding to amyloid fibrils and is commonly used to diagnose amyloid fibrils, both ex vivo and in vitro. Many derivatives of thioflavin T have been synthesized and evaluated recently (Kung et al., 2001; Qu et al., 2007; Zhang, et al., 2009). We are interested in developing fluorescent probes that are expected to bind to hydrophobic sites in proteins. With this in mind, the title compound, (I), was synthesized and we reported the crystal structure herein.

In the molecular structure (Fig. 1), the dihedral angle between the benzothiazole ring system and the benzene ring is 1.20 (2)°. The substituted amino substituent is in an extended conformation with an N—C—C—O torsion angle of 179.4 (3)°. In the crystal structure, pairs of molecules are connected by intermolecular N—H···O and weak C-H···O hydrogen bonds to form centrosymmetric dimers (Fig. 2).

Related literature top

For background to thioflavin T (ThT), a benzothiazole dye that exhibits enhanced fluorescence upon binding to amyloid fibrils, see: Kung et al. (2001); Qu et al. (2007); Zhang & Zhao (2009).

Experimental top

Compound (I) was synthesized according to the method described by Stephenson et al. (2007). Pale yellow single crystals suitable for an X-ray diffraction study were obtained by slow evaporation of an methanol solution.

Refinement top

All H atoms were placed in idealized positions [CH(methyl)=0.96 Å, 0.97Å (methylene) and 0.93 Å (aromatic),with Uiso(H)= 1.5Ueq(methyl C) 1.2Ueq(other C). N-bounded hydrogen atom was found from the difference map and refined with the restraint of N—H = 0.86 (1)Å and Uiso(H) = 1.2 Ueq(N).

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with displacement ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. Part of the crystal structure of (I) showing hydrogen bonds as dashed lines.
Ethyl 2-[4-(1,3-benzothiazol-2-yl)anilino]acetate top
Crystal data top
C17H16N2O2SF(000) = 656
Mr = 312.38Dx = 1.343 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3368 reflections
a = 5.6303 (1) Åθ = 2.5–26.1°
b = 26.1604 (5) ŵ = 0.22 mm1
c = 10.5989 (2) ÅT = 298 K
β = 98.294 (1)°Block, pale-yellow
V = 1544.79 (5) Å30.36 × 0.24 × 0.21 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
3808 independent reflections
Radiation source: fine-focus sealed tube3015 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.076
ϕ and ω scansθmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 76
Tmin = 0.926, Tmax = 0.956k = 3434
11631 measured reflectionsl = 1014
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)] = 0.058Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.145H atoms treated by a mixture of independent and constrained refinement
S = 1.07 w = 1/[σ2(Fo2) + (0.0584P)2 + 0.2785P]
where P = (Fo2 + 2Fc2)/3
3808 reflections(Δ/σ)max < 0.001
203 parametersΔρmax = 0.39 e Å3
1 restraintΔρmin = 0.30 e Å3
Crystal data top
C17H16N2O2SV = 1544.79 (5) Å3
Mr = 312.38Z = 4
Monoclinic, P21/nMo Kα radiation
a = 5.6303 (1) ŵ = 0.22 mm1
b = 26.1604 (5) ÅT = 298 K
c = 10.5989 (2) Å0.36 × 0.24 × 0.21 mm
β = 98.294 (1)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
3808 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
3015 reflections with I > 2σ(I)
Tmin = 0.926, Tmax = 0.956Rint = 0.076
11631 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0581 restraint
wR(F2) = 0.145H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.39 e Å3
3808 reflectionsΔρmin = 0.30 e Å3
203 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
C10.4095 (4)0.16282 (7)1.27189 (19)0.0459 (4)
C20.5567 (4)0.18305 (9)1.3771 (2)0.0584 (6)
H20.70500.16851.40670.070*
C30.4757 (5)0.22514 (9)1.4357 (2)0.0624 (6)
H30.57120.23971.50540.075*
C40.2521 (5)0.24629 (8)1.3919 (2)0.0614 (6)
H40.20070.27481.43300.074*
C50.1066 (4)0.22608 (8)1.2896 (2)0.0552 (5)
H50.04260.24061.26180.066*
C60.1840 (3)0.18348 (7)1.22724 (19)0.0429 (4)
C70.1778 (3)0.12057 (7)1.08723 (18)0.0388 (4)
C80.0933 (3)0.08695 (7)0.98019 (17)0.0383 (4)
C90.2312 (3)0.04687 (7)0.94479 (19)0.0459 (5)
H90.38150.04080.99150.055*
C100.1514 (3)0.01576 (7)0.84224 (19)0.0461 (5)
H100.24720.01100.82140.055*
C110.0722 (3)0.02423 (7)0.76967 (18)0.0404 (4)
C120.2144 (3)0.06424 (7)0.80651 (19)0.0444 (4)
H120.36570.07010.76080.053*
C130.1326 (3)0.09459 (7)0.90894 (19)0.0440 (4)
H130.22950.12090.93150.053*
C140.0362 (3)0.04854 (7)0.62537 (19)0.0448 (4)
H14A0.01750.07340.69410.054*
H14B0.12220.03940.60680.054*
C150.1818 (3)0.07146 (7)0.50852 (19)0.0439 (4)
C160.1958 (4)0.13779 (8)0.3566 (2)0.0503 (5)
H16A0.21570.11380.28600.060*
H16B0.35300.15020.36940.060*
C170.0407 (4)0.18121 (8)0.3288 (2)0.0621 (6)
H17A0.11780.16880.32280.093*
H17B0.10700.19680.24950.093*
H17C0.03290.20600.39610.093*
N10.0567 (3)0.15892 (6)1.12304 (15)0.0441 (4)
N20.1552 (3)0.00386 (7)0.66362 (18)0.0538 (5)
H2A0.294 (2)0.0014 (8)0.622 (2)0.065*
O10.0780 (3)0.11295 (5)0.47181 (14)0.0506 (4)
O20.3671 (3)0.05410 (6)0.45639 (16)0.0655 (5)
S10.46125 (9)0.11103 (2)1.17793 (6)0.05496 (19)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0511 (11)0.0454 (10)0.0419 (11)0.0041 (8)0.0096 (9)0.0032 (8)
C20.0616 (13)0.0634 (13)0.0489 (13)0.0079 (10)0.0030 (10)0.0080 (10)
C30.0821 (16)0.0581 (13)0.0474 (13)0.0199 (12)0.0104 (11)0.0098 (10)
C40.0927 (17)0.0426 (11)0.0531 (13)0.0085 (11)0.0250 (13)0.0090 (10)
C50.0695 (13)0.0426 (11)0.0554 (13)0.0028 (9)0.0160 (11)0.0009 (10)
C60.0519 (11)0.0375 (9)0.0409 (10)0.0028 (8)0.0121 (8)0.0019 (8)
C70.0396 (9)0.0392 (9)0.0374 (10)0.0001 (7)0.0049 (7)0.0034 (7)
C80.0394 (9)0.0394 (9)0.0362 (10)0.0009 (7)0.0056 (7)0.0017 (7)
C90.0423 (10)0.0463 (10)0.0463 (11)0.0070 (8)0.0032 (8)0.0016 (9)
C100.0485 (10)0.0402 (10)0.0476 (12)0.0084 (8)0.0004 (9)0.0051 (8)
C110.0428 (9)0.0380 (9)0.0399 (10)0.0026 (7)0.0038 (8)0.0003 (8)
C120.0364 (9)0.0493 (10)0.0459 (11)0.0039 (7)0.0011 (8)0.0025 (9)
C130.0422 (10)0.0439 (10)0.0463 (11)0.0056 (8)0.0073 (8)0.0023 (8)
C140.0470 (10)0.0422 (10)0.0432 (11)0.0000 (8)0.0001 (8)0.0022 (8)
C150.0479 (10)0.0413 (10)0.0421 (11)0.0022 (8)0.0051 (8)0.0011 (8)
C160.0563 (12)0.0487 (11)0.0455 (12)0.0081 (9)0.0052 (9)0.0084 (9)
C170.0786 (15)0.0489 (12)0.0609 (15)0.0035 (11)0.0173 (12)0.0134 (11)
N10.0489 (9)0.0400 (8)0.0430 (9)0.0032 (7)0.0056 (7)0.0004 (7)
N20.0507 (10)0.0511 (10)0.0544 (11)0.0084 (8)0.0106 (8)0.0151 (8)
O10.0578 (8)0.0440 (7)0.0478 (9)0.0042 (6)0.0004 (6)0.0084 (6)
O20.0596 (9)0.0661 (10)0.0640 (11)0.0166 (7)0.0141 (8)0.0198 (8)
S10.0455 (3)0.0623 (3)0.0537 (4)0.0105 (2)0.0047 (2)0.0168 (3)
Geometric parameters (Å, º) top
C1—C21.394 (3)C10—H100.9300
C1—C61.398 (3)C11—N21.367 (2)
C1—S11.731 (2)C11—C121.407 (3)
C2—C31.374 (3)C12—C131.370 (3)
C2—H20.9300C12—H120.9300
C3—C41.392 (4)C13—H130.9300
C3—H30.9300C14—N21.434 (2)
C4—C51.367 (3)C14—C151.507 (3)
C4—H40.9300C14—H14A0.9700
C5—C61.397 (3)C14—H14B0.9700
C5—H50.9300C15—O21.197 (2)
C6—N11.385 (2)C15—O11.318 (2)
C7—N11.300 (2)C16—O11.456 (2)
C7—C81.460 (3)C16—C171.488 (3)
C7—S11.7579 (18)C16—H16A0.9700
C8—C91.388 (3)C16—H16B0.9700
C8—C131.397 (3)C17—H17A0.9600
C9—C101.380 (3)C17—H17B0.9600
C9—H90.9300C17—H17C0.9600
C10—C111.395 (3)N2—H2A0.853 (9)
C2—C1—C6122.01 (19)C13—C12—C11120.77 (17)
C2—C1—S1128.85 (17)C13—C12—H12119.6
C6—C1—S1109.13 (14)C11—C12—H12119.6
C3—C2—C1117.9 (2)C12—C13—C8121.42 (17)
C3—C2—H2121.1C12—C13—H13119.3
C1—C2—H2121.1C8—C13—H13119.3
C2—C3—C4120.7 (2)N2—C14—C15109.62 (15)
C2—C3—H3119.6N2—C14—H14A109.7
C4—C3—H3119.6C15—C14—H14A109.7
C5—C4—C3121.4 (2)N2—C14—H14B109.7
C5—C4—H4119.3C15—C14—H14B109.7
C3—C4—H4119.3H14A—C14—H14B108.2
C4—C5—C6119.4 (2)O2—C15—O1124.76 (18)
C4—C5—H5120.3O2—C15—C14124.23 (18)
C6—C5—H5120.3O1—C15—C14111.01 (16)
N1—C6—C5125.91 (19)O1—C16—C17107.31 (17)
N1—C6—C1115.52 (16)O1—C16—H16A110.3
C5—C6—C1118.57 (19)C17—C16—H16A110.3
N1—C7—C8124.46 (16)O1—C16—H16B110.3
N1—C7—S1115.02 (14)C17—C16—H16B110.3
C8—C7—S1120.52 (13)H16A—C16—H16B108.5
C9—C8—C13117.59 (17)C16—C17—H17A109.5
C9—C8—C7122.20 (16)C16—C17—H17B109.5
C13—C8—C7120.21 (16)H17A—C17—H17B109.5
C10—C9—C8121.81 (17)C16—C17—H17C109.5
C10—C9—H9119.1H17A—C17—H17C109.5
C8—C9—H9119.1H17B—C17—H17C109.5
C9—C10—C11120.39 (17)C7—N1—C6110.97 (16)
C9—C10—H10119.8C11—N2—C14123.52 (16)
C11—C10—H10119.8C11—N2—H2A121.2 (16)
N2—C11—C10122.80 (17)C14—N2—H2A114.6 (16)
N2—C11—C12119.18 (16)C15—O1—C16116.58 (16)
C10—C11—C12118.00 (17)C1—S1—C789.35 (9)
C6—C1—C2—C31.2 (3)C10—C11—C12—C131.5 (3)
S1—C1—C2—C3179.40 (17)C11—C12—C13—C80.1 (3)
C1—C2—C3—C40.8 (3)C9—C8—C13—C121.0 (3)
C2—C3—C4—C50.1 (4)C7—C8—C13—C12178.72 (17)
C3—C4—C5—C60.3 (3)N2—C14—C15—O20.6 (3)
C4—C5—C6—N1179.89 (19)N2—C14—C15—O1179.36 (16)
C4—C5—C6—C10.0 (3)C8—C7—N1—C6180.00 (16)
C2—C1—C6—N1179.10 (18)S1—C7—N1—C60.2 (2)
S1—C1—C6—N10.4 (2)C5—C6—N1—C7179.97 (18)
C2—C1—C6—C50.8 (3)C1—C6—N1—C70.1 (2)
S1—C1—C6—C5179.68 (15)C10—C11—N2—C148.1 (3)
N1—C7—C8—C9179.13 (18)C12—C11—N2—C14173.43 (19)
S1—C7—C8—C90.6 (3)C15—C14—N2—C11177.26 (18)
N1—C7—C8—C130.6 (3)O2—C15—O1—C162.3 (3)
S1—C7—C8—C13179.68 (14)C14—C15—O1—C16177.66 (16)
C13—C8—C9—C100.7 (3)C17—C16—O1—C15176.34 (17)
C7—C8—C9—C10178.98 (18)C2—C1—S1—C7179.0 (2)
C8—C9—C10—C110.6 (3)C6—C1—S1—C70.41 (15)
C9—C10—C11—N2176.82 (19)N1—C7—S1—C10.39 (15)
C9—C10—C11—C121.7 (3)C8—C7—S1—C1179.83 (16)
N2—C11—C12—C13177.13 (19)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C12—H12···O2i0.932.603.390 (2)144
N2—H2A···O2i0.85 (1)2.40 (1)3.188 (2)154 (2)
Symmetry code: (i) x1, y, z+1.

Experimental details

Crystal data
Chemical formulaC17H16N2O2S
Mr312.38
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)5.6303 (1), 26.1604 (5), 10.5989 (2)
β (°) 98.294 (1)
V3)1544.79 (5)
Z4
Radiation typeMo Kα
µ (mm1)0.22
Crystal size (mm)0.36 × 0.24 × 0.21
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.926, 0.956
No. of measured, independent and
observed [I > 2σ(I)] reflections
11631, 3808, 3015
Rint0.076
(sin θ/λ)max1)0.668
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.058, 0.145, 1.07
No. of reflections3808
No. of parameters203
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.39, 0.30

Computer programs: SMART (Bruker, 2007), SAINT-Plus (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C12—H12···O2i0.932.603.390 (2)143.6
N2—H2A···O2i0.853 (9)2.402 (13)3.188 (2)154 (2)
Symmetry code: (i) x1, y, z+1.
 

References

First citationBruker (2007). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationKung, H. F., Lee, C.-W., Zhuang, Z.-P., Kung, M.-P., Hou, C. & Plssl, K. (2001). J. Am. Chem. Soc. 123, 12740–12741.  Web of Science CrossRef PubMed CAS
First citationQu, W., Kung, M.-P., Hou, C., Oya, S. & Kung, H. F. (2007). J. Med. Chem. 50, 3380–3387.  Web of Science CrossRef PubMed CAS
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals
First citationStephenson, K. A., Chandra, R., Zhuang, Z.-P., Hou, C., Oya, S., Kung, M.-P. & Kung, H. F. (2007). Bioconjugate Chem. 18, 238–246.  Web of Science CrossRef CAS
First citationZhang, Y. & Zhao, B. (2009). Acta Cryst. E65, o2762.  Web of Science CrossRef IUCr Journals

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COMMUNICATIONS
ISSN: 2056-9890
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