PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 January 1; 66(Pt 1): o137.
Published online 2009 December 16. doi:  10.1107/S1600536809052386
PMCID: PMC2980268

(Z)-Ethyl 2-hydroxy­imino-2-(4-nitro­benz­yl)ethanoate

Abstract

The title mol­ecule, C11H10N2O6, has a Z conformation about the C=N bond of the oxime unit. There are significant twists from planarity throughout the mol­ecule, the most significant being between the hydroxy­imino and ester groups which are effectively orthogonal with an N—C—C—Ocarbon­yl torsion angle of 91.4 (2)°. The crystal packing features oxime–benzoyl O—H(...)O contacts that lead to chains along [010] and C—H(...)O interactions also occur.

Related literature

For background to the synthesis of chiral hydroxy­amino­acids and hydroxy­amino­alcohols, see: Corrêa & Moran (1999 [triangle]); Kreutz et al. (1997 [triangle], 2000 [triangle]). For related structures, see: Ramos Silva et al. (2004 [triangle]); Forsyth et al. (2006 [triangle]). For the synthesis, see: Adkins & Reeve (1938 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0o137-scheme1.jpg

Experimental

Crystal data

  • C11H10N2O6
  • M r = 266.21
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o137-efi1.jpg
  • a = 23.2347 (7) Å
  • b = 12.0698 (6) Å
  • c = 8.9698 (4) Å
  • β = 106.100 (2)°
  • V = 2416.82 (18) Å3
  • Z = 8
  • Mo Kα radiation
  • μ = 0.12 mm−1
  • T = 290 K
  • 0.18 × 0.15 × 0.12 mm

Data collection

  • Nonius KappaCCD diffractometer
  • 8147 measured reflections
  • 2752 independent reflections
  • 2004 reflections with I > 2σ(I)
  • R int = 0.033

Refinement

  • R[F 2 > 2σ(F 2)] = 0.048
  • wR(F 2) = 0.128
  • S = 1.05
  • 2752 reflections
  • 189 parameters
  • H-atom parameters constrained
  • Δρmax = 0.20 e Å−3
  • Δρmin = −0.19 e Å−3

Data collection: COLLECT (Nonius, 1999 [triangle]); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 [triangle]); data reduction: DENZO (Otwinowski & Minor, 1997 [triangle]) and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: DIAMOND (Brandenburg, 2006 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]), PARST (Nardelli, 1995 [triangle]) and publCIF (Westrip, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809052386/hg2614sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809052386/hg2614Isup2.hkl

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

Acknowledgments

We thank FAPESP, CNPq and CAPES for financial support. Publication costs were met by FAPESP (Proc. 2008/02531–5).

supplementary crystallographic information

Comment

The title compound (I) was prepared as an intermediary during the synthesis of chiral hydroxyaminoacids and hydroxyaminoalcohols, as α-ketomethoxyimino compounds are reduced by sodium borohydride (Corrêa & Moran, 1999) and enantioselectively bio-reduced by whole cells of yeast (Kreutz et al., 1997; Kreutz et al., 2000).

The structure of (I) is non-planar as seen by the values of the C3–C4–C7–O3 and C4–C7–C8–N2 torsion angles within the central moiety of 8.8 (2) and 15.8 (2) °, respectively. The peripheral residues are twisted with respect to the inner atoms. Thus, the nitro ring is twisted out of the plane of the benzene ring to which it is connected: the C2–C1–N1–O1 torsion angle is -13.7 (3) °. Even more dramatic is the twist about the C8—C9 bond with the C7–C8–C9–O6 torsion angle being 94.77 (17)°, indicating the terminal ester group is orthogonal to the hydroxyimino residue. With respect to the C8═N2 bond, the conformation is Z. There are two other structures in the literature containing the basic C(═O)C(═NOH)C(═O)OC framework. In benzyl 2-(hydroxyimino)acetoacetate a Z conformation is found for the oxime group (Forsyth et al., 2006) whereas in each of the two independent molecules comprising the asymmetric unit in ethyl 2-(hydroxyimino)-3-oxo-3-phenylpropionate, an E conformation is found (Ramos Silva et al., 2004).

The crystal packing of (I) is dominated by O—H···O hydrogen bonding involving the oxime-O4—H and benzoyl-O3 atoms which leads to the formation of supramolecular chains along [0 1 0] with a flat topology, Fig. 2 and Table 1. The presence of C–H···O contacts provide stability to the chain. These C5–H···O5 contacts close 13-membered {···OC3O···HC4NOH} synthons, Fig. 3 and Table 1. The chains are linked into 2-D arrays in the [3 0 1] plane by further C–H···O contacts involving the nitro groups and centrosymmetric 10-membered {···ONC2H}2 synthons, Fig. 3 and Table 1. The resultant layer is essentially flat with the ethoxy groups lying above and below the layer. The methyl-H atoms of one of the disordered ethoxy groups form C–H···O contacts with the nitro-O1 atoms providing stability to the stacked layers, Fig. 4 and Table 1.

Experimental

The title compound, (I), was prepared following a modified literature method (Adkins and Reeve, 1938). A solution of sodium nitrite (5 mmol) and water (2 ml) was added drop-wise to a solution of ethyl 3-oxo-3-(4-nitrophenyl)propanoate (2 mmol) in glacial acetic acid (3 ml) at 273 K. The resulting solution was stirred for 1 h at 273 K. The temperature was then raised to 303 K and the reaction left for a further hour. The reaction mixture was quenched with water (2.5 ml) and treated with ether (4 x 5 ml). The organic layer was dried with Mg(SO4) and the solvent evaporated to afford a mixture of Z:E (40:60) isomers in 87% yield that were separated by dissolving in ethyl acetate and precipitating with hexane.

Refinement

The O– and C-bound H atoms were geometrically placed (O–H = 0.82 Å and C–H = 0.9–0.97 Å) and refined as riding with Uiso(H) = 1.2Ueq(C) and 1.5Ueq(O and methyl-C).

Disorder was modelled for the ethyl group with two positions resolved for each of the C10 and C11 atoms. Fractional refinement (anisotropic) showed that the site occupancy factors were equal within experimental error and thus these were fixed at 0.5 in the final cycles of refinement.

Figures

Fig. 1.
Molecular structure of (I) showing atom labelling scheme and displacement ellipsoids at the 50% probability level (arbitrary spheres for the H atoms). Only one component of the disordered ethyl group is shown for reasons of clarity.
Fig. 2.
Supramolecular chain aligned along [0 1 0] in (I) mediated by oxime-O—H···O-benzoyl hydrogen bonding (orange dashed lines). Colour code: O, red; N, blue; C, grey; and H, green.
Fig. 3.
2-D array in (I) whereby the chains shown in Fig. 2 are reinforced by and are connected by C–H···O contacts (blue dashed lines). Colour code as for Fig. 2.
Fig. 4.
A view of the crystal packing in (I) showing the stacking of layers. Colour code as for Fig. 2.

Crystal data

C11H10N2O6F(000) = 1104
Mr = 266.21Dx = 1.463 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 4194 reflections
a = 23.2347 (7) Åθ = 27.5–1.0°
b = 12.0698 (6) ŵ = 0.12 mm1
c = 8.9698 (4) ÅT = 290 K
β = 106.100 (2)°Irregular, colourless
V = 2416.82 (18) Å30.18 × 0.15 × 0.12 mm
Z = 8

Data collection

Nonius KappaCCD diffractometer2004 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.033
graphiteθmax = 27.5°, θmin = 1.9°
CCD rotation images, thick slices scansh = −30→28
8147 measured reflectionsk = −15→14
2752 independent reflectionsl = −8→11

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.128H-atom parameters constrained
S = 1.05w = 1/[σ2(Fo2) + (0.0493P)2 + 1.3639P] where P = (Fo2 + 2Fc2)/3
2752 reflections(Δ/σ)max < 0.001
189 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = −0.19 e Å3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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*/UeqOcc. (<1)
O10.50114 (9)0.16899 (16)1.0271 (2)0.1080 (7)
O20.47793 (8)0.32527 (15)0.9163 (2)0.0950 (6)
O30.29936 (6)−0.09600 (9)0.44259 (15)0.0585 (4)
O40.21512 (6)0.18581 (10)0.13275 (15)0.0581 (4)
H4O0.21680.25250.11690.087*
O50.21223 (6)−0.07843 (11)0.10633 (16)0.0652 (4)
O60.15870 (6)−0.01284 (12)0.25941 (16)0.0662 (4)
N10.47188 (8)0.22595 (16)0.9220 (2)0.0685 (5)
N20.26049 (6)0.15679 (11)0.26243 (16)0.0477 (3)
C10.42724 (8)0.17138 (15)0.7937 (2)0.0517 (4)
C20.42939 (8)0.05779 (16)0.7813 (2)0.0586 (5)
H20.45800.01650.85270.070*
C30.38815 (8)0.00701 (15)0.6605 (2)0.0539 (4)
H30.3893−0.06950.64890.065*
C40.34459 (7)0.06915 (13)0.55497 (18)0.0426 (4)
C50.34325 (8)0.18320 (13)0.5725 (2)0.0489 (4)
H50.31400.22490.50360.059*
C60.38527 (8)0.23516 (15)0.6919 (2)0.0537 (4)
H60.38510.31180.70300.064*
C70.30018 (7)0.00492 (13)0.43324 (19)0.0434 (4)
C80.25518 (7)0.05606 (13)0.29990 (18)0.0423 (4)
C90.20639 (7)−0.02027 (13)0.2087 (2)0.0460 (4)
C100.1039 (4)−0.0815 (6)0.1899 (9)0.066 (2)0.50
H10A0.0680−0.03940.18680.079*0.50
H10B0.1026−0.10310.08490.079*0.50
C110.1074 (2)−0.1772 (4)0.2855 (6)0.0772 (13)0.50
H11A0.0750−0.22640.23900.116*0.50
H11B0.1048−0.15520.38630.116*0.50
H11C0.1448−0.21430.29540.116*0.50
C10A0.1143 (2)−0.0975 (4)0.1926 (6)0.093 (5)0.50
H10C0.1335−0.16790.18580.112*0.50
H10D0.0907−0.07610.08950.112*0.50
C11A0.0755 (3)−0.1055 (8)0.3013 (8)0.127 (3)0.50
H11D0.0423−0.15400.25780.190*0.50
H11E0.0607−0.03330.31620.190*0.50
H11F0.0986−0.13440.39930.190*0.50

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.1132 (14)0.0968 (14)0.0788 (11)0.0063 (10)−0.0320 (10)−0.0089 (10)
O20.1013 (13)0.0768 (12)0.0881 (12)−0.0268 (9)−0.0050 (9)−0.0171 (9)
O30.0739 (8)0.0300 (6)0.0639 (8)−0.0020 (5)0.0064 (6)0.0004 (5)
O40.0661 (8)0.0380 (6)0.0606 (8)0.0033 (6)0.0019 (6)0.0087 (6)
O50.0750 (9)0.0528 (8)0.0690 (9)−0.0128 (6)0.0219 (7)−0.0214 (7)
O60.0567 (8)0.0706 (9)0.0725 (9)−0.0230 (6)0.0200 (7)−0.0229 (7)
N10.0640 (10)0.0740 (12)0.0597 (10)−0.0055 (9)0.0045 (8)−0.0137 (9)
N20.0525 (8)0.0343 (7)0.0530 (8)−0.0005 (6)0.0090 (6)0.0020 (6)
C10.0474 (9)0.0570 (11)0.0489 (9)−0.0046 (8)0.0102 (7)−0.0072 (8)
C20.0537 (10)0.0581 (11)0.0564 (11)0.0083 (8)0.0026 (8)0.0019 (9)
C30.0572 (10)0.0403 (9)0.0599 (11)0.0054 (8)0.0090 (8)0.0003 (8)
C40.0437 (8)0.0358 (8)0.0483 (9)−0.0003 (6)0.0127 (7)−0.0003 (6)
C50.0513 (9)0.0356 (8)0.0553 (10)0.0010 (7)0.0071 (7)−0.0010 (7)
C60.0604 (10)0.0399 (9)0.0581 (10)−0.0047 (8)0.0120 (8)−0.0070 (8)
C70.0482 (9)0.0328 (8)0.0496 (9)−0.0010 (7)0.0144 (7)−0.0007 (6)
C80.0463 (8)0.0328 (8)0.0474 (9)−0.0017 (6)0.0126 (7)−0.0028 (6)
C90.0515 (9)0.0344 (8)0.0492 (9)−0.0023 (7)0.0089 (7)0.0022 (7)
C100.043 (2)0.057 (3)0.087 (5)−0.016 (2)0.001 (3)−0.004 (3)
C110.068 (3)0.074 (3)0.081 (3)−0.027 (2)0.005 (2)0.007 (3)
C10A0.061 (5)0.139 (10)0.085 (6)−0.044 (5)0.031 (4)−0.056 (6)
C11A0.105 (5)0.187 (8)0.105 (4)−0.088 (5)0.057 (4)−0.057 (5)

Geometric parameters (Å, °)

O1—N11.212 (2)C4—C71.494 (2)
O2—N11.210 (2)C5—C61.384 (2)
O3—C71.2215 (19)C5—H50.9300
O4—N21.3809 (18)C6—H60.9300
O4—H4O0.8200C7—C81.487 (2)
O5—C91.193 (2)C8—C91.513 (2)
O6—C91.312 (2)C10—C111.427 (10)
O6—C10A1.458 (5)C10—H10A0.9700
O6—C101.502 (6)C10—H10B0.9700
N1—C11.474 (2)C11—H11A0.9600
N2—C81.276 (2)C11—H11B0.9600
C1—C61.372 (3)C11—H11C0.9600
C1—C21.378 (3)C10A—C11A1.503 (8)
C2—C31.376 (3)C10A—H10C0.9700
C2—H20.9300C10A—H10D0.9700
C3—C41.397 (2)C11A—H11D0.9600
C3—H30.9300C11A—H11E0.9600
C4—C51.387 (2)C11A—H11F0.9600
N2—O4—H4O109.5N2—C8—C9123.39 (14)
C9—O6—C10A112.3 (3)C7—C8—C9115.87 (13)
C9—O6—C10121.3 (4)O5—C9—O6126.44 (16)
O2—N1—O1123.25 (18)O5—C9—C8123.10 (16)
O2—N1—C1118.35 (18)O6—C9—C8110.45 (14)
O1—N1—C1118.39 (19)C11—C10—O6107.2 (6)
C8—N2—O4110.88 (13)C11—C10—H10A110.3
C6—C1—C2122.63 (16)O6—C10—H10A110.3
C6—C1—N1119.02 (17)C11—C10—H10B110.3
C2—C1—N1118.35 (17)O6—C10—H10B110.3
C3—C2—C1118.33 (17)H10A—C10—H10B108.5
C3—C2—H2120.8C10—C11—H11A109.5
C1—C2—H2120.8C10—C11—H11B109.5
C2—C3—C4120.66 (17)H11A—C11—H11B109.5
C2—C3—H3119.7C10—C11—H11C109.5
C4—C3—H3119.7H11A—C11—H11C109.5
C5—C4—C3119.42 (16)H11B—C11—H11C109.5
C5—C4—C7124.40 (15)O6—C10A—C11A105.2 (4)
C3—C4—C7116.12 (15)O6—C10A—H10C110.7
C6—C5—C4120.29 (16)C11A—C10A—H10C110.7
C6—C5—H5119.9O6—C10A—H10D110.7
C4—C5—H5119.9C11A—C10A—H10D110.7
C1—C6—C5118.66 (16)H10C—C10A—H10D108.8
C1—C6—H6120.7C10A—C11A—H11D109.5
C5—C6—H6120.7C10A—C11A—H11E109.5
O3—C7—C8116.64 (14)H11D—C11A—H11E109.5
O3—C7—C4119.20 (15)C10A—C11A—H11F109.5
C8—C7—C4124.15 (14)H11D—C11A—H11F109.5
N2—C8—C7120.63 (14)H11E—C11A—H11F109.5
O2—N1—C1—C6−14.5 (3)O4—N2—C8—C7177.96 (13)
O1—N1—C1—C6166.2 (2)O4—N2—C8—C91.9 (2)
O2—N1—C1—C2165.6 (2)O3—C7—C8—N2−165.30 (16)
O1—N1—C1—C2−13.7 (3)C4—C7—C8—N215.8 (2)
C6—C1—C2—C30.9 (3)O3—C7—C8—C911.0 (2)
N1—C1—C2—C3−179.25 (16)C4—C7—C8—C9−167.90 (14)
C1—C2—C3—C4−1.1 (3)C10A—O6—C9—O58.9 (3)
C2—C3—C4—C50.2 (3)C10—O6—C9—O50.4 (4)
C2—C3—C4—C7−176.95 (16)C10A—O6—C9—C8−170.7 (2)
C3—C4—C5—C61.0 (3)C10—O6—C9—C8−179.1 (3)
C7—C4—C5—C6177.94 (15)N2—C8—C9—O591.4 (2)
C2—C1—C6—C50.3 (3)C7—C8—C9—O5−84.8 (2)
N1—C1—C6—C5−179.55 (16)N2—C8—C9—O6−89.0 (2)
C4—C5—C6—C1−1.3 (3)C7—C8—C9—O694.77 (17)
C5—C4—C7—O3−168.26 (17)C9—O6—C10—C1196.0 (7)
C3—C4—C7—O38.8 (2)C10A—O6—C10—C1153.9 (18)
C5—C4—C7—C810.7 (2)C9—O6—C10A—C11A159.5 (4)
C3—C4—C7—C8−172.33 (15)C10—O6—C10A—C11A−59 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O4—H4o···O3i0.821.912.7165 (16)166
C5—H5···O5i0.932.583.371 (2)144
C2—H2···O1ii0.932.553.393 (3)151
C11—H11a···O1iii0.962.523.426 (5)158

Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) −x+1, −y, −z+2; (iii) x−1/2, y−1/2, z−1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2614).

References

  • Adkins, H. & Reeve, E. W. (1938). J. Am. Chem. Soc.60, 1328–1331.
  • Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst.32, 115–119.
  • Brandenburg, K. (2006). DIAMOND Crystal Impact GbR, Bonn, Germany.
  • Corrêa, I. R. & Moran, P. J. S. (1999). Tetrahedron, 55, 14221–14232.
  • Farrugia, L. J. (1999). J. Appl. Cryst.32, 837–838.
  • Forsyth, C. M., Langford, S. J. & Lee, K. A. (2006). Acta Cryst. E62, o5654–o5655.
  • Kreutz, O. C., Moran, P. J. S. & Rodrigues, J. A. R. (1997). Tetrahedron Asymmetry, 8, 2649–2653.
  • Kreutz, O. C., Segura, R. C. M., Rodrigues, J. A. R. & Moran, P. J. S. (2000). Tetrahedron Asymmetry, 11, 2107–2115.
  • Nardelli, M. (1995). J. Appl. Cryst.28, 659.
  • Nonius (1999). COLLECT Nonius BV, Delft, The Netherlands.
  • Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.
  • Ramos Silva, M., Matos Beja, A., Paixão, J. A., Lopes, S. H., Cabral, A. M. T. D. P. V., d’A. Rocha Gonsalves, A. M. & Sobral, A. J. F. N. (2004). Z. Kristallogr. New Cryst. Struct.219, 145–146.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Westrip, S. P. (2009). publCIF In preparation.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography