Acta Cryst. (2009). E65, o2328 [ doi:10.1107/S1600536809034321 ]
In the title compound, C8H6N2O3, the indol-2-one system is almost planar [maximum deviation = 0.010 (3) Å]. In the crystal structure, intermolecular N-H
O, O-HN and O-HO hydrogen bonds link the molecules into a three-dimensional network. ![[pi]](/logos/entities/pi_rmgif.gif)
- contacts between the indole ring systems [centroid-centroid distances = 3.494 (1), 3.731 (1) and 3.736 (1) Å] may further stabilize the structure.
For the preparation of the title compound, 2-(hydroxyimino)-N-(3-hydroxyphenyl)- acetamide (1 mmol), 1-n-butyl-3-methylimidazolium chloride (0.5 mmol) and 2,2,2-trifluoroacetic acid (0.05 mmol) were added into a sealed flask. The mixture was stirred for 90 min and the temperature maintained at 408 K. After the completion of reaction, ether was used to extract organic compounds from the ionic liquid phase, and the combined organic layers were concentrated under reduced pressure. Product purification was performed by column chromatography. Crystals suitable for X-ray analysis were obtained by dissolving the title compound (0.1 g) in ethyl acetate (10 ml) and evaporating the solvent slowly at room temperature for 2 d.
H atoms were positioned geometrically with N-H = 0.86 Å (for NH), O-H = 0.82 and 0.96 Å (for OH) and C-H = 0.93 Å for aromatic H atoms, respectively, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C,N,O), where x = 1.5 for OH H and x = 1.2 for all other 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: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
![[Figure 1]](./hk2760fig1thm.gif)
| Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. |
| C8H6N2O3 | F(000) = 368 |
| Mr = 178.15 | Dx = 1.594 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 25 reflections |
| a = 7.4160 (15) Å | θ = 9–13° |
| b = 7.1240 (14) Å | µ = 0.13 mm−1 |
| c = 14.111 (3) Å | T = 294 K |
| β = 95.21 (3)° | Block, yellow |
| V = 742.4 (3) Å3 | 0.30 × 0.30 × 0.10 mm |
| Z = 4 |
| Enraf–Nonius CAD-4 diffractometer | 994 reflections with I > 2σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.068 |
| graphite | θmax = 25.3°, θmin = 2.8° |
| ω/2θ scans | h = 0→8 |
| Absorption correction: ψ scan (North et al., 1968) | k = −8→8 |
| Tmin = 0.963, Tmax = 0.988 | l = −16→16 |
| 2787 measured reflections | 3 standard reflections every 120 min |
| 1350 independent reflections | intensity decay: 1% |
| 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)] = 0.061 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.172 | H-atom parameters constrained |
| S = 1.00 | w = 1/[σ2(Fo2) + (0.08P)2 + 0.6P] where P = (Fo2 + 2Fc2)/3 |
| 1350 reflections | (Δ/σ)max < 0.001 |
| 118 parameters | Δρmax = 0.44 e Å−3 |
| 0 restraints | Δρmin = −0.50 e Å−3 |
| C8H6N2O3 | V = 742.4 (3) Å3 |
| Mr = 178.15 | Z = 4 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 7.4160 (15) Å | µ = 0.13 mm−1 |
| b = 7.1240 (14) Å | T = 294 K |
| c = 14.111 (3) Å | 0.30 × 0.30 × 0.10 mm |
| β = 95.21 (3)° |
| Enraf–Nonius CAD-4 diffractometer | 994 reflections with I > 2σ(I) |
| Absorption correction: ψ scan (North et al., 1968) | Rint = 0.068 |
| Tmin = 0.963, Tmax = 0.988 | θmax = 25.3° |
| 2787 measured reflections | 3 standard reflections every 120 min |
| 1350 independent reflections | intensity decay: 1% |
| R[F2 > 2σ(F2)] = 0.061 | H-atom parameters constrained |
| wR(F2) = 0.172 | Δρmax = 0.44 e Å−3 |
| S = 1.00 | Δρmin = −0.50 e Å−3 |
| 1350 reflections | Absolute structure: ? |
| 118 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | 0.9722 (3) | 0.3850 (3) | 0.61373 (16) | 0.0540 (7) | |
| H1C | 0.8846 | 0.4824 | 0.5992 | 0.081* | |
| O2 | 0.5104 (3) | −0.3981 (3) | 0.38450 (15) | 0.0518 (6) | |
| O3 | 0.6534 (3) | 0.1382 (3) | 0.29758 (15) | 0.0573 (7) | |
| H3A | 0.6170 | 0.1652 | 0.2427 | 0.086* | |
| N1 | 0.6497 (4) | −0.2911 (4) | 0.52693 (17) | 0.0446 (7) | |
| H1A | 0.6331 | −0.3880 | 0.5615 | 0.054* | |
| N2 | 0.6071 (3) | −0.0423 (4) | 0.31580 (17) | 0.0443 (7) | |
| C1 | 0.8929 (4) | 0.2147 (5) | 0.5948 (2) | 0.0489 (8) | |
| C2 | 0.8858 (4) | 0.0912 (5) | 0.6684 (2) | 0.0504 (9) | |
| H2B | 0.9338 | 0.1245 | 0.7292 | 0.060* | |
| C3 | 0.8071 (4) | −0.0837 (5) | 0.6524 (2) | 0.0458 (8) | |
| H3B | 0.8021 | −0.1699 | 0.7015 | 0.055* | |
| C4 | 0.7367 (4) | −0.1255 (4) | 0.5612 (2) | 0.0381 (7) | |
| C5 | 0.7418 (4) | 0.0035 (4) | 0.48642 (18) | 0.0369 (7) | |
| C6 | 0.8213 (4) | 0.1782 (4) | 0.5024 (2) | 0.0424 (7) | |
| H6A | 0.8263 | 0.2660 | 0.4539 | 0.051* | |
| C7 | 0.5958 (4) | −0.2790 (4) | 0.4338 (2) | 0.0387 (7) | |
| C8 | 0.6537 (4) | −0.0880 (4) | 0.40277 (19) | 0.0352 (7) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0682 (15) | 0.0357 (12) | 0.0553 (14) | −0.0148 (11) | −0.0103 (11) | −0.0125 (10) |
| O2 | 0.0762 (15) | 0.0374 (13) | 0.0403 (12) | −0.0061 (11) | −0.0038 (11) | −0.0018 (10) |
| O3 | 0.0793 (16) | 0.0455 (14) | 0.0451 (13) | −0.0082 (12) | −0.0054 (11) | 0.0099 (10) |
| N1 | 0.0608 (16) | 0.0344 (14) | 0.0371 (13) | 0.0006 (12) | −0.0042 (11) | 0.0031 (11) |
| N2 | 0.0558 (16) | 0.0358 (14) | 0.0411 (14) | 0.0023 (12) | 0.0034 (12) | 0.0048 (11) |
| C1 | 0.0478 (18) | 0.0425 (18) | 0.0549 (19) | 0.0001 (15) | −0.0036 (15) | −0.0128 (15) |
| C2 | 0.0521 (18) | 0.058 (2) | 0.0383 (16) | 0.0025 (16) | −0.0081 (13) | −0.0096 (16) |
| C3 | 0.0490 (18) | 0.051 (2) | 0.0354 (16) | 0.0054 (15) | −0.0063 (13) | 0.0016 (14) |
| C4 | 0.0381 (15) | 0.0380 (16) | 0.0370 (15) | 0.0066 (13) | −0.0027 (12) | −0.0006 (12) |
| C5 | 0.0402 (15) | 0.0362 (16) | 0.0335 (15) | 0.0065 (13) | 0.0001 (11) | −0.0005 (12) |
| C6 | 0.0487 (17) | 0.0354 (16) | 0.0428 (16) | 0.0011 (14) | 0.0022 (13) | −0.0016 (13) |
| C7 | 0.0478 (16) | 0.0317 (15) | 0.0353 (15) | 0.0039 (13) | −0.0028 (12) | −0.0034 (12) |
| C8 | 0.0395 (15) | 0.0333 (15) | 0.0321 (14) | 0.0050 (12) | 0.0000 (11) | 0.0010 (12) |
| O1—C1 | 1.364 (4) | C1—C6 | 1.387 (4) |
| O1—H1C | 0.9600 | C2—C3 | 1.386 (5) |
| O2—C7 | 1.234 (3) | C2—H2B | 0.9300 |
| O3—H3A | 0.8200 | C3—C4 | 1.376 (4) |
| N1—C4 | 1.409 (4) | C3—H3B | 0.9300 |
| N1—C7 | 1.342 (4) | C4—C5 | 1.402 (4) |
| N1—H1A | 0.8600 | C5—C6 | 1.387 (4) |
| N2—O3 | 1.361 (3) | C5—C8 | 1.451 (4) |
| N2—C8 | 1.286 (4) | C6—H6A | 0.9300 |
| C1—C2 | 1.365 (5) | C7—C8 | 1.504 (4) |
| C1—O1—H1C | 109.2 | C3—C4—C5 | 121.9 (3) |
| N2—O3—H3A | 109.5 | C3—C4—N1 | 128.7 (3) |
| C4—N1—H1A | 124.2 | C5—C4—N1 | 109.4 (2) |
| C7—N1—C4 | 111.6 (2) | C6—C5—C4 | 120.4 (3) |
| C7—N1—H1A | 124.2 | C6—C5—C8 | 133.5 (3) |
| C8—N2—O3 | 111.6 (3) | C4—C5—C8 | 106.1 (3) |
| O1—C1—C2 | 118.0 (3) | C5—C6—C1 | 116.2 (3) |
| O1—C1—C6 | 118.2 (3) | C5—C6—H6A | 121.9 |
| C2—C1—C6 | 123.8 (3) | C1—C6—H6A | 121.9 |
| C1—C2—C3 | 120.0 (3) | O2—C7—N1 | 126.8 (3) |
| C1—C2—H2B | 120.0 | O2—C7—C8 | 127.1 (3) |
| C3—C2—H2B | 120.0 | N1—C7—C8 | 106.0 (2) |
| C4—C3—C2 | 117.7 (3) | N2—C8—C5 | 136.4 (3) |
| C4—C3—H3B | 121.1 | N2—C8—C7 | 116.6 (3) |
| C2—C3—H3B | 121.1 | C5—C8—C7 | 106.8 (2) |
| O1—C1—C2—C3 | −179.7 (3) | C2—C1—C6—C5 | −1.1 (5) |
| C6—C1—C2—C3 | 1.4 (5) | C4—N1—C7—O2 | −177.1 (3) |
| C1—C2—C3—C4 | −0.5 (5) | C4—N1—C7—C8 | 0.5 (3) |
| C2—C3—C4—C5 | −0.6 (4) | O3—N2—C8—C5 | 0.5 (5) |
| C2—C3—C4—N1 | −179.6 (3) | O3—N2—C8—C7 | 175.0 (2) |
| C7—N1—C4—C3 | 178.8 (3) | C6—C5—C8—N2 | −4.9 (6) |
| C7—N1—C4—C5 | −0.3 (3) | C4—C5—C8—N2 | 175.2 (3) |
| C3—C4—C5—C6 | 0.9 (4) | C6—C5—C8—C7 | −179.7 (3) |
| N1—C4—C5—C6 | −180.0 (3) | C4—C5—C8—C7 | 0.3 (3) |
| C3—C4—C5—C8 | −179.2 (3) | O2—C7—C8—N2 | 1.1 (5) |
| N1—C4—C5—C8 | 0.0 (3) | N1—C7—C8—N2 | −176.6 (3) |
| C4—C5—C6—C1 | 0.0 (4) | O2—C7—C8—C5 | 177.2 (3) |
| C8—C5—C6—C1 | −180.0 (3) | N1—C7—C8—C5 | −0.5 (3) |
| O1—C1—C6—C5 | −180.0 (3) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N1—H1A···O2i | 0.86 | 2.05 | 2.854 (4) | 156 |
| O1—H1C···N1ii | 0.96 | 2.52 | 3.466 (4) | 168 |
| O3—H3A···O2iii | 0.82 | 2.00 | 2.753 (3) | 152 |
| Symmetry codes: (i) −x+1, −y−1, −z+1; (ii) x, y+1, z; (iii) −x+1, y+1/2, −z+1/2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N1—H1A···O2i | 0.86 | 2.05 | 2.854 (4) | 156 |
| O1—H1C···N1ii | 0.96 | 2.52 | 3.466 (4) | 168 |
| O3—H3A···O2iii | 0.82 | 2.00 | 2.753 (3) | 152 |
| Symmetry codes: (i) −x+1, −y−1, −z+1; (ii) x, y+1, z; (iii) −x+1, y+1/2, −z+1/2. |
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.
Pinto, A. C., Lapis, A. A. M., da Silva, B. V., Bastos, R. S., Dupont, J. & Neto, B. A. D. (2008). Tetrahedron Lett. 49, 5639–5641.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
The title compound is one kind of important isatin-3-oxime derivatives, which displays diverse biological and pharmacological properties (Pinto et al., 2008). We report herein its crystal structure.
In the molecule of the title compound, (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges. The indole ring system is planar with a maximum deviation of -0.010 (3) Å for atom C2. Atoms O1, O2, O3 and N2 are 0.005 (3), -0.059 (3), -0.184 (3) and -0.085 (3) Å away from the plane of the indole ring system, respectively.
In the crystal structure, intermolecular N-H···O, O-H···N and O-H···O hydrogen bonds (Table 1) link the molecules into a three-dimensional network, in which they may be effective in the stabilization of the structure. The π–π contacts between the indole rings, Cg1—Cg1i, Cg2—Cg2ii and Cg1—Cg2i [symmetry codes: (i) 1 - x, 1 - y, -z, (ii) 2 - x, 1 - y, -z, where Cg1 and Cg2 are centroids of the rings (N1/C4/C5/C7/C8) and (C1-C6), respectively] may further stabilize the structure, with centroid-centroid distances of 3.494 (1), 3.731 (1) and 3.736 (1) Å, respectively.