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ISSN: 2056-9890

4-Nitro-N-phthalyl-L-tryptophan

aDepartment of Chemistry, University of Namur, 61, Rue de Bruxelles, B-5000 Namur, Belgium, and bLouvain Drug Research Institute (LDRI), UCL, 50, Avenue Mounier, B-1200 Woluwe-Saint-Lambert, Belgium
*Correspondence e-mail: johan.wouters@fundp.ac.be

(Received 1 July 2011; accepted 19 July 2011; online 23 July 2011)

The crystal structure of the title compound [systematic name: (2R)-3-(1H-indol-3-yl)-2-(4-nitro-1,3-dioxoisoindolin-2-yl)propanoic acid], C19H13N3O6, an analogue of epigenetic modulator RG108, is constrained by strong hydrogen bonds between the indole N—H group and a carbonyl O atom of the phthalimide ring of a symmetry-related mol­ecule, and between the protonated O atom of the carboxyl group and a carbonyl O atom of the phthalimide ring. ππ stacking inter­actions with centroid–centroid distances of 3.638 (1) and 3.610 (1) Å are also observed between indole and phthalimide rings.

Related literature

For crystallographic information and details of the RG108 analogue, see: Braun et al. (2010[Braun, J., Boittiaux, I., Tilborg, A., Lambert, D. & Wouters, J. (2010). Acta Cryst. E66, o3175-o3176.]) and for details of the biological evaluation, see: Brueckner et al. (2005[Brueckner, B., Boy, R. G., Siedlecki, P., Munsch, T., Kliem, H. C., Zielenkiewicz, P., Suhai, S., Wiessler, M. & Lyko, F. (2005). Cancer Res. 65, 6305-6311.]).

[Scheme 1]

Experimental

Crystal data
  • C19H13N3O6

  • Mr = 379.33

  • Monoclinic, P 21

  • a = 7.0569 (3) Å

  • b = 15.5302 (8) Å

  • c = 7.6947 (4) Å

  • β = 95.415 (4)°

  • V = 839.54 (7) Å3

  • Z = 2

  • Cu Kα radiation

  • μ = 0.97 mm−1

  • T = 293 K

  • 0.22 × 0.10 × 0.03 mm

Data collection
  • Oxford Diffraction Xcalibur Ruby Gemini ultra diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]) Tmin = 0.815, Tmax = 0.972

  • 9007 measured reflections

  • 2966 independent reflections

  • 2735 reflections with I > 2σ(I)

  • Rint = 0.029

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.091

  • S = 1.06

  • 2966 reflections

  • 262 parameters

  • 1 restraint

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

  • Δρmax = 0.15 e Å−3

  • Δρmin = −0.13 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 1371 Friedel pairs

  • Flack parameter: −0.1 (2)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2⋯O1i 0.86 (4) 2.28 (4) 3.002 (3) 142 (4)
O4—H1⋯O2ii 1.00 (4) 1.78 (4) 2.716 (2) 154 (3)
Symmetry codes: (i) [-x+1, y-{\script{1\over 2}}, -z]; (ii) x, y, z-1.

Data collection: CrysAlis PRO (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEPIII (Burnett & Johnson, 1996[Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

4-Nitro-N-phthalyl-L-tryptophan is an analog of RG108, a DNA methyltransferase (DNMT) inhibitor discovered by virtual screening (Brueckner et al. (2005)). Introduction of a nitro functional group on the phtalimide moiety is excepted to improve inhibition ability (unpublished results).

Isomer S (C9) of 4-nitro-N-phthalyl-tryptophan is obtained from L-tryptophan and nitrophthalic anhydride in DMF.

Two main types of H-bonding interactions are observed in the structure: one between N—H of the indole ring (N2) and O1 of the phtalimide ring, and the other between the protonated oxygen (O4) from the carboxylic moiety and O2 from the phtalimide ring (see Table 1).

In addition to H-bonds, crystal packing organization is further stabilized by ππ-stacking interactions involving symmetry-related molecules, in particularly between the 6-membered coupled rings of nitrophthalimide and indole moiety (see Table 2). No interactions of this type are present in the packing of the dicyclohexylamine salt of RG108 (Braun et al. (2010), because of the presence of the ammonium counter-cation and water molecules included in the crystalline network.

In contrast to the structure of the dicyclohexylamine salt of RG108 (Braun et al. (2010)), where the compound conformation is constrained by strong (charge-assisted) H-bonds with the dicyclohexylammonium ion and extra water molecules, the angle between the two fused rings is 14.23 (4)° in the present structure compared to 58.35 (4)° in the case of the RG108 salt. The torsion angle of the chain between the two aromatic moieties (N1—C9—C10—C11) is also distinct: -155.66 (17)° and -61.93 (17) ° for the title and RG108 salt structures, respectively.

Related literature top

For crystallographic information and details about the RG108 analogue, see: Braun et al. (2010) and for its biological evaluation, see: Brueckner et al. (2005).

Experimental top

Synthesis of the compound was accomplished by micro-wave heating of L-tryptophan (1 mmol, 204 mg) and 4-nitro phthalic anhydride (1 mmol, 193 mg) in 5 ml of DMF. The mixture was then poured in cold aqueous buffer solution (pH = 2) and extracted with ethyl acetate. After drying with Na2SO4, the organic phase is evaporated and the residue is purified by flash chromatography (dichloromethane and methanol: 9/1; yield = 60%, 230 mg).

Refinement top

H1 and H2, bound to O4 and N2 respectively and involved in hydrogen bonds, were located from ΔF Fourier difference maps and their position refined freely. All other remaining H-atoms were placed at idealized positions and allowed to ride on their parent atoms, with C—H distances of 0.93 – 0.98 Å and with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. ORTEP view and atom numbering of the title compound. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.
(2R)-3-(1H-indol-3-yl)-2-(4-nitro-1,3-dioxoisoindolin- 2-yl)propanoic acid top
Crystal data top
C19H13N3O6F(000) = 392
Mr = 379.33Dx = 1.501 Mg m3
Monoclinic, P21Cu Kα radiation, λ = 1.54184 Å
Hall symbol: P 2ybCell parameters from 4268 reflections
a = 7.0569 (3) Åθ = 2.8–67.9°
b = 15.5302 (8) ŵ = 0.97 mm1
c = 7.6947 (4) ÅT = 293 K
β = 95.415 (4)°Prism, yellow
V = 839.54 (7) Å30.22 × 0.10 × 0.03 mm
Z = 2
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini ultra
diffractometer
2966 independent reflections
Radiation source: fine-focus sealed tube2735 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
Detector resolution: 10.3712 pixels mm-1θmax = 68.0°, θmin = 5.7°
ω scansh = 88
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2009)
k = 1817
Tmin = 0.815, Tmax = 0.972l = 98
9007 measured reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.031 w = 1/[σ2(Fo2) + (0.0492P)2 + 0.1477P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.091(Δ/σ)max < 0.001
S = 1.06Δρmax = 0.15 e Å3
2966 reflectionsΔρmin = 0.13 e Å3
262 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
1 restraintExtinction coefficient: 0.0080 (8)
0 constraintsAbsolute structure: Flack (1983), 1371 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.1 (2)
Secondary atom site location: difference Fourier map
Crystal data top
C19H13N3O6V = 839.54 (7) Å3
Mr = 379.33Z = 2
Monoclinic, P21Cu Kα radiation
a = 7.0569 (3) ŵ = 0.97 mm1
b = 15.5302 (8) ÅT = 293 K
c = 7.6947 (4) Å0.22 × 0.10 × 0.03 mm
β = 95.415 (4)°
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini ultra
diffractometer
2966 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2009)
2735 reflections with I > 2σ(I)
Tmin = 0.815, Tmax = 0.972Rint = 0.029
9007 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.031H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.091Δρmax = 0.15 e Å3
S = 1.06Δρmin = 0.13 e Å3
2966 reflectionsAbsolute structure: Flack (1983), 1371 Friedel pairs
262 parametersAbsolute structure parameter: 0.1 (2)
1 restraint
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
C10.7937 (3)0.58969 (13)0.3293 (3)0.0401 (4)
C20.8237 (3)0.64858 (13)0.4829 (3)0.0385 (4)
C30.7949 (3)0.73572 (14)0.5072 (3)0.0427 (5)
C40.8157 (3)0.77052 (15)0.6745 (3)0.0481 (5)
H40.78810.82830.69130.058*
C50.8772 (3)0.71950 (17)0.8159 (3)0.0533 (6)
H50.89430.74370.92690.064*
C60.9135 (3)0.63265 (16)0.7939 (3)0.0497 (5)
H60.95810.59840.88810.060*
C70.8815 (3)0.59866 (14)0.6286 (3)0.0410 (4)
C80.8976 (3)0.50848 (14)0.5709 (2)0.0402 (4)
C90.8329 (3)0.42945 (12)0.2879 (3)0.0391 (4)
H90.90700.38540.35570.047*
C100.6282 (3)0.39570 (14)0.2619 (3)0.0479 (5)
H10A0.56550.40770.36610.057*
H10B0.56010.42650.16560.057*
C110.6167 (3)0.30101 (14)0.2249 (3)0.0437 (5)
C120.5649 (3)0.26268 (17)0.0691 (3)0.0532 (6)
H120.53550.29170.03570.064*
C130.6095 (3)0.15405 (15)0.2600 (3)0.0488 (5)
C140.6192 (3)0.07499 (16)0.3441 (4)0.0607 (7)
H140.59200.02410.28300.073*
C150.6705 (3)0.07453 (17)0.5213 (4)0.0650 (7)
H150.67790.02240.58100.078*
C160.7115 (3)0.15063 (19)0.6124 (4)0.0590 (6)
H160.74680.14820.73180.071*
C170.7012 (3)0.22977 (16)0.5303 (3)0.0479 (5)
H170.72940.28010.59280.058*
C180.6472 (3)0.23231 (14)0.3505 (3)0.0413 (4)
C190.9328 (3)0.44380 (13)0.1227 (3)0.0433 (5)
N10.8488 (2)0.50773 (11)0.3922 (2)0.0397 (4)
N20.5622 (3)0.17470 (15)0.0885 (3)0.0591 (6)
N30.7496 (3)0.79406 (12)0.3599 (3)0.0518 (5)
O10.7311 (2)0.60263 (10)0.18047 (19)0.0526 (4)
O20.9409 (2)0.44385 (10)0.65541 (19)0.0518 (4)
O31.0857 (3)0.47711 (14)0.1246 (2)0.0659 (5)
O40.8377 (3)0.41420 (14)0.0186 (2)0.0709 (6)
O50.8221 (3)0.77922 (12)0.2254 (2)0.0683 (5)
O60.6475 (3)0.85593 (12)0.3807 (3)0.0768 (6)
H10.913 (5)0.425 (2)0.120 (5)0.093 (11)*
H20.525 (6)0.138 (3)0.008 (5)0.095 (12)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0449 (10)0.0354 (11)0.0400 (11)0.0023 (8)0.0046 (8)0.0025 (8)
C20.0382 (9)0.0391 (11)0.0391 (10)0.0004 (8)0.0080 (8)0.0029 (8)
C30.0408 (10)0.0409 (11)0.0475 (11)0.0011 (8)0.0092 (8)0.0035 (9)
C40.0440 (11)0.0449 (12)0.0576 (13)0.0067 (9)0.0161 (9)0.0150 (10)
C50.0539 (12)0.0625 (14)0.0451 (12)0.0119 (11)0.0133 (10)0.0138 (11)
C60.0527 (12)0.0579 (15)0.0397 (11)0.0068 (10)0.0100 (9)0.0027 (10)
C70.0434 (10)0.0442 (11)0.0363 (10)0.0038 (8)0.0083 (8)0.0055 (8)
C80.0414 (10)0.0436 (11)0.0362 (10)0.0003 (8)0.0078 (8)0.0037 (9)
C90.0482 (10)0.0314 (10)0.0381 (10)0.0020 (8)0.0068 (8)0.0011 (8)
C100.0477 (12)0.0417 (12)0.0549 (13)0.0001 (9)0.0085 (9)0.0007 (10)
C110.0409 (10)0.0400 (11)0.0511 (12)0.0037 (8)0.0087 (9)0.0006 (9)
C120.0575 (13)0.0598 (15)0.0422 (11)0.0117 (11)0.0034 (10)0.0017 (10)
C130.0442 (11)0.0413 (11)0.0618 (14)0.0044 (9)0.0104 (10)0.0042 (10)
C140.0490 (12)0.0396 (12)0.095 (2)0.0061 (9)0.0157 (13)0.0023 (12)
C150.0497 (12)0.0517 (15)0.095 (2)0.0012 (11)0.0143 (13)0.0218 (14)
C160.0486 (12)0.0678 (16)0.0610 (15)0.0017 (11)0.0068 (10)0.0146 (12)
C170.0430 (10)0.0505 (12)0.0506 (12)0.0002 (9)0.0060 (9)0.0034 (10)
C180.0371 (9)0.0404 (11)0.0474 (11)0.0035 (8)0.0088 (8)0.0003 (9)
C190.0553 (12)0.0359 (10)0.0388 (10)0.0026 (9)0.0053 (9)0.0012 (8)
N10.0527 (10)0.0349 (9)0.0315 (8)0.0015 (7)0.0053 (7)0.0001 (7)
N20.0653 (13)0.0558 (14)0.0568 (13)0.0161 (10)0.0081 (10)0.0152 (10)
N30.0536 (10)0.0382 (10)0.0639 (13)0.0008 (8)0.0069 (9)0.0001 (8)
O10.0717 (10)0.0440 (8)0.0401 (8)0.0082 (7)0.0046 (7)0.0003 (7)
O20.0694 (10)0.0456 (9)0.0406 (8)0.0043 (7)0.0057 (7)0.0065 (7)
O30.0628 (11)0.0857 (13)0.0511 (9)0.0194 (9)0.0148 (8)0.0044 (8)
O40.0945 (13)0.0828 (13)0.0363 (8)0.0362 (11)0.0113 (9)0.0052 (8)
O50.1017 (14)0.0533 (10)0.0511 (10)0.0083 (9)0.0135 (9)0.0002 (8)
O60.0812 (12)0.0447 (10)0.1084 (16)0.0170 (9)0.0289 (11)0.0126 (10)
Geometric parameters (Å, º) top
C1—O11.205 (3)C10—H10B0.9700
C1—N11.403 (3)C11—C121.358 (3)
C1—C21.493 (3)C11—C181.442 (3)
C2—C31.384 (3)C12—N21.375 (3)
C2—C71.392 (3)C12—H120.9300
C3—C41.391 (3)C13—N21.369 (3)
C3—N31.463 (3)C13—C141.386 (4)
C4—C51.382 (4)C13—C181.413 (3)
C4—H40.9300C14—C151.377 (4)
C5—C61.386 (4)C14—H140.9300
C5—H50.9300C15—C161.391 (4)
C6—C71.376 (3)C15—H150.9300
C6—H60.9300C16—C171.381 (4)
C7—C81.477 (3)C16—H160.9300
C8—O21.219 (2)C17—C181.401 (3)
C8—N11.386 (3)C17—H170.9300
C9—N11.455 (2)C19—O31.195 (3)
C9—C191.527 (3)C19—O41.306 (3)
C9—C101.532 (3)N2—H20.86 (4)
C9—H90.9800N3—O51.219 (3)
C10—C111.499 (3)N3—O61.221 (3)
C10—H10A0.9700O4—H11.00 (4)
O1—C1—N1122.92 (18)C12—C11—C10127.1 (2)
O1—C1—C2131.44 (18)C18—C11—C10126.7 (2)
N1—C1—C2105.61 (16)C11—C12—N2110.2 (2)
C3—C2—C7118.11 (19)C11—C12—H12124.9
C3—C2—C1133.98 (19)N2—C12—H12124.9
C7—C2—C1107.76 (18)N2—C13—C14130.9 (2)
C2—C3—C4120.1 (2)N2—C13—C18106.9 (2)
C2—C3—N3121.67 (19)C14—C13—C18122.2 (2)
C4—C3—N3118.2 (2)C15—C14—C13117.6 (2)
C5—C4—C3120.2 (2)C15—C14—H14121.2
C5—C4—H4119.9C13—C14—H14121.2
C3—C4—H4119.9C14—C15—C16121.2 (2)
C4—C5—C6120.6 (2)C14—C15—H15119.4
C4—C5—H5119.7C16—C15—H15119.4
C6—C5—H5119.7C17—C16—C15121.8 (2)
C7—C6—C5118.1 (2)C17—C16—H16119.1
C7—C6—H6121.0C15—C16—H16119.1
C5—C6—H6121.0C16—C17—C18118.3 (2)
C6—C7—C2122.7 (2)C16—C17—H17120.8
C6—C7—C8129.2 (2)C18—C17—H17120.8
C2—C7—C8108.11 (17)C17—C18—C13118.9 (2)
O2—C8—N1123.29 (19)C17—C18—C11133.8 (2)
O2—C8—C7129.99 (18)C13—C18—C11107.29 (19)
N1—C8—C7106.71 (17)O3—C19—O4123.7 (2)
N1—C9—C19108.63 (16)O3—C19—C9122.70 (19)
N1—C9—C10112.37 (17)O4—C19—C9113.59 (18)
C19—C9—C10116.40 (17)C8—N1—C1111.65 (16)
N1—C9—H9106.3C8—N1—C9123.58 (16)
C19—C9—H9106.3C1—N1—C9124.30 (16)
C10—C9—H9106.3C13—N2—C12109.5 (2)
C11—C10—C9113.22 (18)C13—N2—H2125 (3)
C11—C10—H10A108.9C12—N2—H2125 (3)
C9—C10—H10A108.9O5—N3—O6124.1 (2)
C11—C10—H10B108.9O5—N3—C3117.55 (18)
C9—C10—H10B108.9O6—N3—C3118.3 (2)
H10A—C10—H10B107.7C19—O4—H1109 (2)
C12—C11—C18106.1 (2)
O1—C1—C2—C31.5 (4)C16—C17—C18—C131.3 (3)
N1—C1—C2—C3179.2 (2)C16—C17—C18—C11178.1 (2)
O1—C1—C2—C7173.8 (2)N2—C13—C18—C17179.45 (18)
N1—C1—C2—C73.9 (2)C14—C13—C18—C171.8 (3)
C7—C2—C3—C42.8 (3)N2—C13—C18—C111.0 (2)
C1—C2—C3—C4172.1 (2)C14—C13—C18—C11177.7 (2)
C7—C2—C3—N3174.80 (18)C12—C11—C18—C17179.8 (2)
C1—C2—C3—N310.3 (3)C10—C11—C18—C173.3 (4)
C2—C3—C4—C54.2 (3)C12—C11—C18—C130.4 (2)
N3—C3—C4—C5173.46 (19)C10—C11—C18—C13176.2 (2)
C3—C4—C5—C61.9 (3)N1—C9—C19—O345.1 (3)
C4—C5—C6—C71.7 (3)C10—C9—C19—O3173.1 (2)
C5—C6—C7—C23.2 (3)N1—C9—C19—O4136.7 (2)
C5—C6—C7—C8176.1 (2)C10—C9—C19—O48.7 (3)
C3—C2—C7—C60.9 (3)O2—C8—N1—C1176.27 (19)
C1—C2—C7—C6177.10 (18)C7—C8—N1—C12.7 (2)
C3—C2—C7—C8178.52 (17)O2—C8—N1—C93.8 (3)
C1—C2—C7—C82.4 (2)C7—C8—N1—C9175.13 (18)
C6—C7—C8—O20.6 (4)O1—C1—N1—C8173.90 (19)
C2—C7—C8—O2178.8 (2)C2—C1—N1—C84.1 (2)
C6—C7—C8—N1179.5 (2)O1—C1—N1—C91.5 (3)
C2—C7—C8—N10.1 (2)C2—C1—N1—C9176.45 (17)
N1—C9—C10—C11155.69 (18)C19—C9—N1—C8134.89 (18)
C19—C9—C10—C1178.1 (2)C10—C9—N1—C894.9 (2)
C9—C10—C11—C12105.8 (3)C19—C9—N1—C153.6 (2)
C9—C10—C11—C1878.3 (3)C10—C9—N1—C176.7 (2)
C18—C11—C12—N20.4 (3)C14—C13—N2—C12177.3 (2)
C10—C11—C12—N2176.9 (2)C18—C13—N2—C121.3 (3)
N2—C13—C14—C15179.5 (2)C11—C12—N2—C131.1 (3)
C18—C13—C14—C151.1 (3)C2—C3—N3—O534.6 (3)
C13—C14—C15—C160.1 (4)C4—C3—N3—O5143.1 (2)
C14—C15—C16—C170.5 (4)C2—C3—N3—O6147.9 (2)
C15—C16—C17—C180.2 (3)C4—C3—N3—O634.5 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···O1i0.86 (4)2.28 (4)3.002 (3)142 (4)
O4—H1···O2ii1.00 (4)1.78 (4)2.716 (2)154 (3)
Symmetry codes: (i) x+1, y1/2, z; (ii) x, y, z1.

Experimental details

Crystal data
Chemical formulaC19H13N3O6
Mr379.33
Crystal system, space groupMonoclinic, P21
Temperature (K)293
a, b, c (Å)7.0569 (3), 15.5302 (8), 7.6947 (4)
β (°) 95.415 (4)
V3)839.54 (7)
Z2
Radiation typeCu Kα
µ (mm1)0.97
Crystal size (mm)0.22 × 0.10 × 0.03
Data collection
DiffractometerOxford Diffraction Xcalibur Ruby Gemini ultra
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Oxford Diffraction, 2009)
Tmin, Tmax0.815, 0.972
No. of measured, independent and
observed [I > 2σ(I)] reflections
9007, 2966, 2735
Rint0.029
(sin θ/λ)max1)0.601
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.091, 1.06
No. of reflections2966
No. of parameters262
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.15, 0.13
Absolute structureFlack (1983), 1371 Friedel pairs
Absolute structure parameter0.1 (2)

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008), ORTEPIII (Burnett & Johnson, 1996) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···O1i0.86 (4)2.28 (4)3.002 (3)142 (4)
O4—H1···O2ii1.00 (4)1.78 (4)2.716 (2)154 (3)
Symmetry codes: (i) x+1, y1/2, z; (ii) x, y, z1.
ππ stacking interactions between six-membered rings from indole (C13—C18; ring centroid Cg(1)) and nitrophthalimide (C2—C7; ring centroid Cg(2)). top
Cg-Cg : distance (Å) between ring centroids; α : dihedral angle(°) between ring planes 1 and 2 ; β : angle (°) between Cg(1)-->Cg(2) vector and normal to ring plane 1 ; γ : angle (°) between Cg(1)-->Cg(2) vector and normal to ring plane 2 ; Cg1_Perp : perpendicular distance (Å) of Cg(1) on ring plane 2 ; Cg2_Perp : perpendicular distance (Å) of Cg(2) on ring plane 1.
Cg(I)-Cg(J)sym (J)Cg-CgαβγCg1_PerpCg2_Perp
Cg(1)-Cg(2)(i)3.638 (1)7.2418.6920.72-3.403 (1)3.446 (1)
Cg(1)-Cg(2)(ii)3.610 (1)7.2419.4112.263.528 (1)3.405 (1)
Symmetry codes : (i) 1 - x, 1/2 + y, 1 - z, (ii) 2 - x, 1/2 + y, 1 - z
 

Acknowledgements

This work was supported in part by the Fonds National de la Recherche Scientifique (FRS – FNRS, Belgium) by a Télévie grant (IB). AT acknowledges the FRIA (Fonds pour la formation à la Recherche dans l'Industrie et dans l'Agriculture) for financial support.

References

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