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Acta Crystallogr Sect E Struct Rep Online. 2008 December 1; 64(Pt 12): o2290.
Published online 2008 November 8. doi:  10.1107/S1600536808035782
PMCID: PMC2959939

Dimethyl 3-acetyl-3-(1,3-benzothia­zol-2-yl)penta­nedioate

Abstract

The title compound, C16H17NO5S, was one of two condensation products from the reaction of 1-(1,3-benzothia­zol-2-yl)propan-2-one with methyl chloro­acetate. The non-H atoms in each of the four substituent groups on the central quaternary C atom are virtually coplanar. The maximum deviations from the least-squares planes are 0.015 (2) and 0.020 (2) Å for the methyl C atoms in the methyl acetate substituents and 0.033 (1) Å for the linked C atom of the benzothia­zole substituent. The S, C and N atoms in the thia­zole ring of the benzothia­zole substituent lie −0.037 (2), 0.046 (2) and −0.028 (2) Å, respectively, from the mean plane defined by the benzene ring atoms.

Related literature

For general background, see: Palmer et al. (1971 [triangle]); Bénéteau et al., 1999 [triangle]; El-Sherbeny (2000 [triangle]); Abayeh et al. (1994 [triangle]); Ivanov & Yuritsyn (1971 [triangle]); Monsanto (1968 [triangle]); Lee et al. (2001 [triangle]). For related structures, see: Chen (1994 [triangle]); Chu et al. (2003 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-o2290-scheme1.jpg

Experimental

Crystal data

  • C16H17NO5S
  • M r = 335.37
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o2290-efi1.jpg
  • a = 14.4075 (3) Å
  • b = 8.8089 (2) Å
  • c = 13.8968 (3) Å
  • β = 118.011 (1)°
  • V = 1557.10 (6) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.23 mm−1
  • T = 100 (2) K
  • 0.54 × 0.47 × 0.25 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2004 [triangle]) T min = 0.883, T max = 0.945
  • 94263 measured reflections
  • 3766 independent reflections
  • 3396 reflections with I > 2σ(I)
  • R int = 0.030

Refinement

  • R[F 2 > 2σ(F 2)] = 0.030
  • wR(F 2) = 0.083
  • S = 1.02
  • 3766 reflections
  • 211 parameters
  • H-atom parameters constrained
  • Δρmax = 0.40 e Å−3
  • Δρmin = −0.23 e Å−3

Data collection: SMART (Bruker, 2004 [triangle]); cell refinement: SAINT (Bruker, 2007 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: DIAMOND (Brandenburg, 1999 [triangle]); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 [triangle]).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808035782/fj2155sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808035782/fj2155Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

Benzothiazole compounds show interesting biological and pharmacological properties (see, e.g., Palmer et al., 1971; Bénéteau et al., 1999; El-Sherbeny, 2000; Abayeh et al., 1994). Besides some few papers with industrial background (see, e.g., Ivanov & Yuritsyn, 1971; Monsanto, 1968) many papers discuss the synthesis, structure-property relationship and complexation behaviour of these compounds. An important group among the different derivatives of benzothiazole are those substituted at C2 (see, e.g., Lee et al., 2001).

In the following we describe the synthesis and structural characterization of such a kind of benzothiazole derivative. This compound, dimethyl 3-acetyl-3-(1,3-benzothiazol-2-yl)pentanedioate, 3, was synthesized according to reaction scheme 1 through alkylation of 1-(1,3-benzothiazol-2-yl)propan-2-one, 1, with methyl chloroacetate under classical condensation conditions, giving methyl 2-(2-(2-oxopropylidene)1,3-benzothiazol-3(2H)-yl)acetate, 2, as second reaction product. The starting material 1 was obtained by condensing 2-aminothiophenol with ethyl acetoacetate in xylene at 160° C for 1 h 30 min.

The structure of the title compound can be best described in relation to the central quaternary carbon atom [C1] surrounded by a benzothiazole moiety, two methyl acetate residues and an acetyl group (Fig. 1). The corresponding bond lengths at C1 of 1.537 (2) Å [C30], 1.538 (2) Å [C20], 1.561 (2) Å [C10] and 1.521 (2) Å are in good agreement with carbon-carbon single bonds, as well as are the angles of 110.9 (1)° - 108.5 (1)° in the range for a tetrahedral coordination. Within the benzothiazole rest bond lengths and angles are very similar to those in comparable compounds like the 2-methyl benzothiazole molecule (Chen, 1994; Chu et al., 2003), which was found as non complexing agent in some crystal structures. Especially the bond angle at the sulfur [88.99 (6)°] and nitrogen [110.5 (1)°] atoms as well as the lengths of the sulfur carbon bonds [1.734 (1)/1.755 (1) A] and the carbon nitrogen double bond between C2 and N3 [129.2 (2) A] are very similar. In relation to the benzenic part [C4 - C9] of the benzothiazole rest which is almost planar [maximal deviation from the least squares plain: -0.0031 (8) Å] the remaining atoms [S1, C2, N3] of the thiazole ring lie -0.037 (2), 0.046 (2) and -0.028 (2) Å above/below this point of reference. This conformation is somewhat different to the 2-methyl benzothiazole molecule where the corresponding values are -0.028 (1), -0.004 (5), 0.017 (4) Å (Chen, 1994) and -0.024 (1), -0.030 (3), -0.017 (3) Å (Chu et al., 2003), respectively, indicating a conformational flexibility of the thiazole moitie. Bond angles and lengths of the two methyl acetate rests as well as those of the acetyl moietie are in the expected ranges [f.e. d(C=O) = 1.201 (2) - 1.206 (2) Å, d(Ccarbonyl—Omethoxy) = 1.341 (2)/1.332 (2) Å, d(Cmethyl—O) = 1.450 (2)/1.450 (2) Å].

Intermolecular forces are restricted mainly to van der Waals ones. No π-π interactions as well as classical hydrogen bonds are found although there are two short intramolecular contacts between the oxygen atoms of two carbonyl groups and adjacent hydrogen atoms [d(O21 - H301) = 2.49 Å, d(O31—H202) = 2.54 Å] and one short intermolecular contact between the sulfur atom of the benzothiazole group and the hydrogen atom of a methylene group [d(Sn1—H301) = 2.86 Å] of a neigbhouring molecule.

Experimental

All solvents and reagents were used as received from Aldrich and Fluka. IR data were recorded using a Bruker VERTEX 70 FTIR spectrometer with ATR device. Wavelengths (ν) are reported in cm-1. 1H and 13C NMR were obtained at ambient temperature using a Bruker AVANCE 300 A spectrometer. Chemical shifts (δ) are reported in parts per million (p.p.m.) relative to internal standards. Mass spectra were carried out using a LCQ Advantage MAX spectrometer employing Electro Spray Ionization (ESI).

2.84 g (2.61 mmol) methyl chloroacetate were added in one portion to a stirred solution of 100 ml acetone containing 1 g (5.23 mmol) 1-(benzothiazol-2-yl)propan-2-one, 1, and 7.22 g (52.3 mmol) K2CO3. The reaction mixture was refluxed for 12 h, filtered off and the solvent evaporated. After cooling a pale white precipitate of 2 appeared. These crystals were collected by filtration and recrystallized from ethanol (yield 0.5 g, 36.5%). The filtrate was leaved overnight at room temperature. Thereafter a second crystalline product was obtained which on recrystallization from ethanol gave white single crystals of 3 (yield 0.8 g, 45.6%).

Methyl 2-(2-(2-oxopropylidene)1,3-benzothiazol-3(2H)-yl)acetate, 2: mp. 208–210° C; IR (ATR), ν[cm-1]): 1608; 1739; 1H-NMR (300 MHz; CDCl3), δ (p.p.m.): 3.78 (s, 2H), 5.75 (s,1H), 6.9–7.6 (m, 4H); 13C-NMR (75 MHZ; CDCl3), δ (p.p.m.): 29.3; 46,9, 53,1; 90.9; 109.5; 122.7; 123.3; 127.2; 139.4; 160.5; 167.2, 191.5.

Dimethyl 3-acetyl-3-(1,3-benzothiazol-2-yl)pentandioate, 3: mp: 166–168° C; IR (ATR), ν[cm-1): 1617; 1718; 1H-NMR (30 MHz; CDCl3), δ (p.p.m.): 2.24 (s, 3H), 3.54–371 (m, 10H) 7.4–8.0 (m, 4H);13C-NMR (75 MHz; CDCl3), δ (p.p.m.): 25.7; 38.9; 51.9, 57.5, 121.6, 123.4, 125.5, 126.2, 135.4, 152.4, 152.6 169.8, 171.0, 203.6; MS(ESI): m/z 336 [M+1]+, 639 [2M+23]+.

A suitable single-crystal of 3 was selected under a polarization microsope and mounted on a 50 µm MicroMesh MiTeGen MicromountTM using FROMBLIN Y perfluoropolyether (LVAC 16/6, Aldrich).

Figures

Fig. 1.
Thermal ellipsoid plot of the title compound with the atomic numbering scheme used. With exception of the hydrogen atoms, which are represented as spheres of arbitrary radius, all other atoms are shown as thermal displacement ellipsoids (oxygen = white, ...
Fig. 2.
The formation of the title compound.

Crystal data

C16H17NO5SF000 = 704
Mr = 335.37Dx = 1.431 Mg m3
Monoclinic, P21/cMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9633 reflections
a = 14.4075 (3) Åθ = 2.8–32.7º
b = 8.8089 (2) ŵ = 0.23 mm1
c = 13.8968 (3) ÅT = 100 (2) K
β = 118.011 (1)ºIrregular, colourless
V = 1557.10 (6) Å30.54 × 0.47 × 0.25 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer3766 independent reflections
Radiation source: fine-focus sealed tube3396 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.030
T = 100(2) Kθmax = 28.0º
[var phi] and ω scansθmin = 1.6º
Absorption correction: multi-scan(SADABS; Bruker, 2004)h = −16→19
Tmin = 0.884, Tmax = 0.945k = −11→11
94263 measured reflectionsl = −18→17

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H-atom parameters constrained
wR(F2) = 0.083  w = 1/[σ2(Fo2) + (0.0379P)2 + 0.9909P] where P = (Fo2 + 2Fc2)/3
S = 1.02(Δ/σ)max = 0.001
3766 reflectionsΔρmax = 0.40 e Å3
211 parametersΔρmin = −0.23 e Å3
Primary atom site location: structure-invariant direct methodsExtinction correction: none

Special details

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)

xyzUiso*/Ueq
S10.07547 (2)0.86573 (3)0.43919 (2)0.01676 (8)
C20.19378 (9)0.80630 (13)0.54977 (9)0.0140 (2)
N30.20635 (8)0.66132 (11)0.56438 (8)0.01443 (19)
C40.11159 (9)0.42603 (14)0.47444 (10)0.0170 (2)
H40.16370.36220.52730.024 (2)*
C50.02392 (10)0.36495 (14)0.38745 (10)0.0190 (2)
H50.01630.25780.38020.024 (2)*
C6−0.05382 (10)0.45859 (15)0.30984 (10)0.0193 (2)
H6−0.11320.41350.25080.024 (2)*
C7−0.04607 (9)0.61526 (15)0.31719 (9)0.0179 (2)
H7−0.09910.67840.26460.024 (2)*
C80.04263 (9)0.67687 (14)0.40475 (9)0.0149 (2)
C90.12163 (9)0.58417 (13)0.48265 (9)0.0141 (2)
C10.27346 (9)0.92387 (13)0.62176 (9)0.0145 (2)
C100.22105 (9)1.00619 (14)0.68333 (9)0.0160 (2)
O100.18549 (8)1.13226 (10)0.65710 (8)0.0249 (2)
C110.20998 (10)0.91849 (15)0.77027 (10)0.0219 (3)
H1110.27940.90520.83350.0431 (14)*
H1120.17920.81880.74170.0431 (14)*
H1130.16410.97430.79220.0431 (14)*
C200.37450 (9)0.84101 (13)0.70162 (10)0.0173 (2)
H2010.35530.75320.73310.0431 (14)*
H2020.41020.80140.66080.0431 (14)*
C210.45015 (9)0.94072 (14)0.79307 (10)0.0170 (2)
O210.43873 (8)1.07423 (11)0.80278 (8)0.0304 (2)
O220.53173 (7)0.86031 (10)0.86465 (8)0.0229 (2)
C220.60859 (10)0.94308 (15)0.95845 (11)0.0232 (3)
H2210.66520.87421.00550.0431 (14)*
H2220.57470.98520.99930.0431 (14)*
H2230.63791.02580.93390.0431 (14)*
C300.29294 (10)1.04297 (13)0.55238 (10)0.0168 (2)
H3010.22801.10380.51290.0431 (14)*
H3020.34891.11260.60210.0431 (14)*
C310.32428 (9)0.98185 (14)0.47030 (10)0.0177 (2)
O310.34329 (8)0.85225 (11)0.45908 (8)0.0272 (2)
O320.32806 (9)1.09691 (11)0.40907 (8)0.0281 (2)
C320.36038 (13)1.05932 (17)0.32765 (12)0.0309 (3)
H3210.35871.15090.28690.0431 (14)*
H3220.31230.98330.27740.0431 (14)*
H3230.43201.01830.36360.0431 (14)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
S10.01835 (15)0.01332 (14)0.01468 (14)0.00202 (10)0.00450 (11)0.00100 (10)
C20.0143 (5)0.0144 (5)0.0137 (5)0.0014 (4)0.0071 (4)0.0008 (4)
N30.0153 (4)0.0135 (5)0.0152 (5)−0.0003 (4)0.0078 (4)−0.0001 (4)
C40.0197 (6)0.0144 (5)0.0205 (6)0.0007 (4)0.0124 (5)0.0000 (4)
C50.0231 (6)0.0159 (6)0.0229 (6)−0.0043 (5)0.0150 (5)−0.0047 (5)
C60.0201 (6)0.0236 (6)0.0165 (5)−0.0058 (5)0.0105 (5)−0.0067 (5)
C70.0184 (5)0.0222 (6)0.0134 (5)0.0001 (5)0.0077 (5)−0.0014 (4)
C80.0178 (5)0.0144 (5)0.0153 (5)0.0001 (4)0.0100 (5)−0.0011 (4)
C90.0155 (5)0.0150 (5)0.0146 (5)−0.0009 (4)0.0094 (4)−0.0010 (4)
C10.0161 (5)0.0113 (5)0.0160 (5)0.0002 (4)0.0074 (4)0.0002 (4)
C100.0153 (5)0.0164 (6)0.0149 (5)−0.0015 (4)0.0059 (4)−0.0022 (4)
O100.0319 (5)0.0192 (5)0.0284 (5)0.0088 (4)0.0181 (4)0.0030 (4)
C110.0260 (6)0.0235 (6)0.0189 (6)−0.0034 (5)0.0127 (5)−0.0007 (5)
C200.0157 (5)0.0131 (5)0.0193 (6)0.0001 (4)0.0050 (5)−0.0006 (4)
C210.0146 (5)0.0172 (6)0.0189 (6)−0.0013 (4)0.0077 (5)−0.0003 (4)
O210.0262 (5)0.0173 (5)0.0323 (5)0.0016 (4)0.0011 (4)−0.0066 (4)
O220.0195 (4)0.0179 (4)0.0214 (4)−0.0004 (3)0.0013 (4)−0.0009 (4)
C220.0160 (5)0.0240 (6)0.0220 (6)−0.0038 (5)0.0026 (5)−0.0027 (5)
C300.0211 (6)0.0121 (5)0.0191 (6)−0.0011 (4)0.0110 (5)−0.0004 (4)
C310.0172 (5)0.0173 (6)0.0187 (6)−0.0036 (4)0.0086 (5)−0.0019 (5)
O310.0409 (6)0.0178 (5)0.0324 (5)0.0027 (4)0.0250 (5)−0.0007 (4)
O320.0501 (6)0.0179 (5)0.0291 (5)−0.0045 (4)0.0290 (5)−0.0020 (4)
C320.0486 (9)0.0270 (7)0.0308 (7)−0.0086 (6)0.0300 (7)−0.0046 (6)

Geometric parameters (Å, °)

S1—C81.7343 (12)C11—H1120.9800
S1—C21.7552 (12)C11—H1130.9800
C2—N31.2924 (15)C20—C211.5078 (16)
C2—C11.5207 (16)C20—H2010.9900
N3—C91.3926 (15)C20—H2020.9900
C4—C51.3827 (18)C21—O211.2038 (16)
C4—C91.3997 (16)C21—O221.3320 (15)
C4—H40.9500O22—C221.4496 (15)
C5—C61.4012 (18)C22—H2210.9800
C5—H50.9500C22—H2220.9800
C6—C71.3845 (18)C22—H2230.9800
C6—H60.9500C30—C311.5095 (16)
C7—C81.3957 (17)C30—H3010.9900
C7—H70.9500C30—H3020.9900
C8—C91.4060 (16)C31—O311.2012 (15)
C1—C301.5373 (16)C31—O321.3409 (15)
C1—C201.5383 (16)O32—C321.4497 (16)
C1—C101.5605 (16)C32—H3210.9800
C10—O101.2055 (15)C32—H3220.9800
C10—C111.5043 (17)C32—H3230.9800
C11—H1110.9800
C8—S1—C288.99 (6)C10—C11—H113109.5
N3—C2—C1124.25 (10)H111—C11—H113109.5
N3—C2—S1116.04 (9)H112—C11—H113109.5
C1—C2—S1119.70 (8)C21—C20—C1113.34 (10)
C2—N3—C9110.46 (10)C21—C20—H201108.9
C5—C4—C9118.40 (11)C1—C20—H201108.9
C5—C4—H4120.8C21—C20—H202108.9
C9—C4—H4120.8C1—C20—H202108.9
C4—C5—C6121.04 (11)H201—C20—H202107.7
C4—C5—H5119.5O21—C21—O22123.70 (11)
C6—C5—H5119.5O21—C21—C20125.51 (11)
C7—C6—C5121.49 (11)O22—C21—C20110.77 (10)
C7—C6—H6119.3C21—O22—C22115.95 (10)
C5—C6—H6119.3O22—C22—H221109.5
C6—C7—C8117.45 (11)O22—C22—H222109.5
C6—C7—H7121.3H221—C22—H222109.5
C8—C7—H7121.3O22—C22—H223109.5
C7—C8—C9121.61 (11)H221—C22—H223109.5
C7—C8—S1129.28 (10)H222—C22—H223109.5
C9—C8—S1109.11 (9)C31—C30—C1115.97 (10)
N3—C9—C4124.73 (11)C31—C30—H301108.3
N3—C9—C8115.28 (10)C1—C30—H301108.3
C4—C9—C8120.00 (11)C31—C30—H302108.3
C2—C1—C30110.85 (9)C1—C30—H302108.3
C2—C1—C20108.53 (9)H301—C30—H302107.4
C30—C1—C20112.75 (10)O31—C31—O32123.80 (11)
C2—C1—C10105.49 (9)O31—C31—C30127.20 (11)
C30—C1—C10107.74 (9)O32—C31—C30109.00 (10)
C20—C1—C10111.26 (9)C31—O32—C32116.51 (11)
O10—C10—C11121.71 (11)O32—C32—H321109.5
O10—C10—C1120.57 (11)O32—C32—H322109.5
C11—C10—C1117.58 (10)H321—C32—H322109.5
C10—C11—H111109.5O32—C32—H323109.5
C10—C11—H112109.5H321—C32—H323109.5
H111—C11—H112109.5H322—C32—H323109.5
C8—S1—C2—N3−3.31 (9)N3—C2—C1—C10−111.43 (12)
C8—S1—C2—C1177.11 (9)S1—C2—C1—C1068.12 (11)
C1—C2—N3—C9−177.68 (10)C2—C1—C10—O10−104.69 (13)
S1—C2—N3—C92.75 (12)C30—C1—C10—O1013.77 (15)
C9—C4—C5—C6−0.72 (17)C20—C1—C10—O10137.83 (12)
C4—C5—C6—C7−0.08 (18)C2—C1—C10—C1171.08 (12)
C5—C6—C7—C80.34 (17)C30—C1—C10—C11−170.47 (10)
C6—C7—C8—C90.21 (17)C20—C1—C10—C11−46.41 (14)
C6—C7—C8—S1−178.77 (9)C2—C1—C20—C21−167.17 (9)
C2—S1—C8—C7−178.22 (11)C30—C1—C20—C2169.63 (13)
C2—S1—C8—C92.70 (8)C10—C1—C20—C21−51.54 (13)
C2—N3—C9—C4179.46 (11)C1—C20—C21—O21−3.89 (18)
C2—N3—C9—C8−0.50 (14)C1—C20—C21—O22174.63 (10)
C5—C4—C9—N3−178.70 (10)O21—C21—O22—C220.40 (18)
C5—C4—C9—C81.25 (17)C20—C21—O22—C22−178.16 (10)
C7—C8—C9—N3178.94 (10)C2—C1—C30—C31−53.93 (13)
S1—C8—C9—N3−1.90 (12)C20—C1—C30—C3167.97 (13)
C7—C8—C9—C4−1.02 (17)C10—C1—C30—C31−168.88 (10)
S1—C8—C9—C4178.15 (9)C1—C30—C31—O31−6.12 (19)
N3—C2—C1—C30132.23 (12)C1—C30—C31—O32173.84 (10)
S1—C2—C1—C30−48.22 (12)O31—C31—O32—C32−1.96 (19)
N3—C2—C1—C207.89 (15)C30—C31—O32—C32178.08 (11)
S1—C2—C1—C20−172.56 (8)

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FJ2155).

References

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