Acta Cryst. (2009). E65, o403 [ doi:10.1107/S1600536809002980 ]
The title compound, C12H14O6, was prepared by the Williamson reaction of 1,4-dihydroxybenzene and methyl chloroacetate with phase-transfer catalysis. The compound lies on an inversion center. The structure is stabilized by weak C-H
![[pi]](/logos/entities/pi_rmgif.gif)
interactions.
5.5 g (0.05 mole) hydroquinone was dissolved in 50 ml acetone, 6.9 g (0.05 mole) potassium carbonate, potassium iodide 0.8 g and tetrabutyl ammonium bromide 1.0 g were added. Then 8.8 ml L (0.10 mole) of methyl chloroacetate was dropped into the mixture. The mixture was boiled for 5 h with intensive stirring, cooled to room temperature, and filtered. The organic solution was evaporated under vacuum to dryness and the dry residue was recrystallized from methanol to obtain title compound. Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of ethyl acetate. 1H NMR (CDCl3, δ, p.p.m.) 6.85 (m, 4H), 4.58 (s, 4H), 3.79 (s,6H).
All H atoms were positioned geometrically and treated as riding on their parent C atoms with C—H = 0.93 Å (aromatic), 0.97Å (methylene) and 0.96Å (methyl) with Uiso(H) = xUeq(C), where x= 1.5 for methyl H and 1.2 for aromatic and methylene H atoms.
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./dn2426fig1thm.gif)
| Fig. 1. A view of the molecular structure of (I) showing the atom-numbering scheme. Ellipsoids are drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radii. [symmetry code: (A) 1/2-x, 1/2+y, 1/2-z]. |
| C12H14O6 | F(000) = 268 |
| Mr = 254.23 | Dx = 1.367 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 27 reflections |
| a = 7.4190 (15) Å | θ = 1–25° |
| b = 7.0990 (14) Å | µ = 0.11 mm−1 |
| c = 11.785 (2) Å | T = 293 K |
| β = 95.49 (3)° | Block, yellow |
| V = 617.8 (2) Å3 | 0.30 × 0.20 × 0.10 mm |
| Z = 2 |
| Enraf–Nonius CAD-4 diffractometer | 769 reflections with I > 2σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.0000 |
| graphite | θmax = 25.3°, θmin = 3.1° |
| ω/2θ scans | h = −8→8 |
| Absorption correction: ψ scan (North et al., 1968) | k = 0→8 |
| Tmin = 0.954, Tmax = 0.977 | l = 0→14 |
| 1123 measured reflections | 3 standard reflections every 200 reflections |
| 1123 independent reflections | intensity decay: 9% |
| 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)] = 0.058 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.173 | H-atom parameters constrained |
| S = 1.00 | w = 1/[σ2(Fo2) + (0.1P)2 + 0.23P] where P = (Fo2 + 2Fc2)/3 |
| 1123 reflections | (Δ/σ)max = 0.001 |
| 82 parameters | Δρmax = 0.26 e Å−3 |
| 0 restraints | Δρmin = −0.24 e Å−3 |
| C12H14O6 | V = 617.8 (2) Å3 |
| Mr = 254.23 | Z = 2 |
| Monoclinic, P21/n | Mo Kα radiation |
| a = 7.4190 (15) Å | µ = 0.11 mm−1 |
| b = 7.0990 (14) Å | T = 293 K |
| c = 11.785 (2) Å | 0.30 × 0.20 × 0.10 mm |
| β = 95.49 (3)° |
| Enraf–Nonius CAD-4 diffractometer | 769 reflections with I > 2σ(I) |
| Absorption correction: ψ scan (North et al., 1968) | Rint = 0.0000 |
| Tmin = 0.954, Tmax = 0.977 | θmax = 25.3° |
| 1123 measured reflections | 3 standard reflections every 200 reflections |
| 1123 independent reflections | intensity decay: 9% |
| R[F2 > 2σ(F2)] = 0.058 | H-atom parameters constrained |
| wR(F2) = 0.173 | Δρmax = 0.26 e Å−3 |
| S = 1.00 | Δρmin = −0.24 e Å−3 |
| 1123 reflections | Absolute structure: ? |
| 82 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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. |
| x | y | z | Uiso*/Ueq | ||
| O1 | 1.1983 (3) | 0.2968 (2) | −0.07350 (16) | 0.0520 (6) | |
| O2 | 1.3969 (3) | 0.5931 (3) | −0.13385 (19) | 0.0636 (7) | |
| O3 | 1.6159 (2) | 0.3997 (3) | −0.17937 (17) | 0.0531 (6) | |
| C1 | 0.8429 (3) | 0.0447 (3) | 0.0519 (2) | 0.0431 (7) | |
| H1A | 0.7382 | 0.0734 | 0.0859 | 0.052* | |
| C2 | 0.9507 (3) | 0.1863 (4) | 0.0139 (2) | 0.0444 (7) | |
| H2A | 0.9186 | 0.3114 | 0.0235 | 0.053* | |
| C3 | 1.1039 (3) | 0.1452 (4) | −0.0376 (2) | 0.0425 (7) | |
| C4 | 1.3668 (3) | 0.2569 (4) | −0.1199 (2) | 0.0460 (7) | |
| H4A | 1.3449 | 0.1844 | −0.1896 | 0.055* | |
| H4B | 1.4456 | 0.1845 | −0.0658 | 0.055* | |
| C5 | 1.4535 (3) | 0.4417 (4) | −0.1439 (2) | 0.0441 (7) | |
| C6 | 1.7243 (4) | 0.5536 (4) | −0.2101 (3) | 0.0617 (8) | |
| H6A | 1.8350 | 0.5067 | −0.2354 | 0.093* | |
| H6B | 1.7513 | 0.6340 | −0.1452 | 0.093* | |
| H6C | 1.6595 | 0.6240 | −0.2705 | 0.093* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0553 (11) | 0.0450 (11) | 0.0577 (12) | 0.0023 (9) | 0.0163 (9) | 0.0020 (9) |
| O2 | 0.0667 (14) | 0.0491 (12) | 0.0760 (16) | 0.0059 (10) | 0.0130 (11) | −0.0036 (11) |
| O3 | 0.0517 (11) | 0.0536 (12) | 0.0555 (12) | −0.0040 (9) | 0.0125 (9) | −0.0034 (9) |
| C1 | 0.0441 (14) | 0.0464 (14) | 0.0381 (14) | 0.0046 (11) | −0.0002 (10) | −0.0050 (11) |
| C2 | 0.0433 (14) | 0.0448 (14) | 0.0444 (16) | 0.0021 (11) | 0.0006 (11) | −0.0049 (12) |
| C3 | 0.0451 (14) | 0.0459 (14) | 0.0356 (14) | 0.0001 (11) | −0.0011 (11) | 0.0007 (11) |
| C4 | 0.0395 (13) | 0.0500 (15) | 0.0473 (15) | −0.0007 (11) | −0.0018 (11) | 0.0007 (12) |
| C5 | 0.0519 (15) | 0.0476 (15) | 0.0314 (13) | 0.0028 (12) | −0.0031 (11) | −0.0023 (11) |
| C6 | 0.0703 (19) | 0.0603 (18) | 0.0553 (18) | −0.0192 (15) | 0.0100 (14) | 0.0034 (15) |
| O1—C3 | 1.372 (3) | C2—C3 | 1.370 (4) |
| O1—C4 | 1.440 (3) | C2—H2A | 0.9300 |
| O2—C5 | 1.164 (3) | C4—C5 | 1.499 (4) |
| O3—C5 | 1.347 (3) | C4—H4A | 0.9700 |
| O3—C6 | 1.424 (3) | C4—H4B | 0.9700 |
| C1—C2 | 1.385 (4) | C6—H6A | 0.9600 |
| C1—C3i | 1.419 (3) | C6—H6B | 0.9600 |
| C1—H1A | 0.9300 | C6—H6C | 0.9600 |
| C3—O1—C4 | 116.7 (2) | C5—C4—H4A | 110.2 |
| C5—O3—C6 | 116.9 (2) | O1—C4—H4B | 110.2 |
| C2—C1—C3i | 118.4 (2) | C5—C4—H4B | 110.2 |
| C2—C1—H1A | 120.8 | H4A—C4—H4B | 108.5 |
| C3i—C1—H1A | 120.8 | O2—C5—O3 | 125.3 (3) |
| C3—C2—C1 | 121.2 (2) | O2—C5—C4 | 128.6 (3) |
| C3—C2—H2A | 119.4 | O3—C5—C4 | 106.1 (2) |
| C1—C2—H2A | 119.4 | O3—C6—H6A | 109.5 |
| C2—C3—O1 | 116.0 (2) | O3—C6—H6B | 109.5 |
| C2—C3—C1i | 120.4 (2) | H6A—C6—H6B | 109.5 |
| O1—C3—C1i | 123.5 (2) | O3—C6—H6C | 109.5 |
| O1—C4—C5 | 107.6 (2) | H6A—C6—H6C | 109.5 |
| O1—C4—H4A | 110.2 | H6B—C6—H6C | 109.5 |
| C3i—C1—C2—C3 | 0.9 (4) | C3—O1—C4—C5 | −175.2 (2) |
| C1—C2—C3—O1 | 178.9 (2) | C6—O3—C5—O2 | −1.9 (4) |
| C1—C2—C3—C1i | −0.9 (4) | C6—O3—C5—C4 | 178.7 (2) |
| C4—O1—C3—C2 | 175.4 (2) | O1—C4—C5—O2 | −3.6 (4) |
| C4—O1—C3—C1i | −4.8 (4) | O1—C4—C5—O3 | 175.74 (19) |
| Symmetry codes: (i) −x+2, −y, −z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C6—H6C···Cg1ii | 0.97 | 2.98 | 3.674 (2) | 130 |
| Symmetry codes: (ii) −x+3/2, y−1/2, −z+1/2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C6—H6C···Cg1i | 0.97 | 2.98 | 3.674 (2) | 130 |
| Symmetry codes: (i) −x+3/2, y−1/2, −z+1/2. |
The authors thank the Center of Testing and Analysis, Nanjing University, for support.
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The derivatives of aryloxyacetic acids and their derivatives constitute a class of compounds for both biological activity and plant growth regulators (Nagy et al., 1997; Wei et al.,2005). The phase-transfer catalysis, with the advantages of simple experimental operations, mild reaction conditions, and inexpensive and environmentally benign reagents, has established its significance in organic synthesis as one of the most useful methods for the acceleration of heterogeneous reactions (Perreux & Loupy, 2001).
Benzothiazole are remarkable heterocyclic ring systems. They have been found to exhibit a wide spectrum of biological activities. Many kinds of 2-substituted benzothiazoles are utilized as vulcanization accelators in the manufacture of rubber,as fluorescent brightening agents in textile dyeing,and in the leather industry (Chakraborti et al.,2004; Seijas et al.,2007; Wang et al.,2009). There are numerous synthetic methods to produce 2-arylbenzothiazoles. The most important ones include the reaction of o-aminothiophenols with benzoic acids or their derivatives (Chakraborti et al.,2004; Seijas et al.,2007; Wang et al.,2009). We are focusing on the synthesis of new products of bisbenzothiazole. We here report the crystal structure of the title compound (I).
The compound (I) lies on an inversion center(Fig.1). All bond lengths are within normal ranges (Allen et al., 1987). There are no typical hydrogen bonds, while weak intermolecular C—H···π interactions involving benzene ring (C1/C3/C2/C1a/C3a/C2a) (Table 1) may help in stabilizing the structure.