Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
In the mol­ecule of 4-(2-chloro­phenyl)­pyrrolo­[1,2-a]­quinoxa­line, C17H11ClN2, (I), the bond lengths are consistent with electron delocalization in the two outer rings of the fused tricyclic system, with a localized double bond in the central ring. The mol­ecules of (I) are linked into chains by a [pi]-[pi] stacking inter­action. In (4RS)-4-(1,3-benzo­dioxol-6-yl)-4,5-di­­hydro­pyrrolo­[1,2-a]­quinoxaline, C18H14N2O2, (II), the central ring of the fused tricyclic system adopts a conformation inter­mediate between screw-boat and half-chair forms. A combination of N-H...O and C-H...[pi](arene) hydrogen bonds links the mol­ecules of (II) into a sheet. Comparisons are made with related compounds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270113009098/yf3029sup1.cif
Contains datablocks global, I, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270113009098/yf3029Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270113009098/yf3029IIsup3.hkl
Contains datablock II

cml

Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270113009098/yf3029Isup4.cml
Supplementary material

cml

Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270113009098/yf3029IIsup5.cml
Supplementary material

CCDC references: 950373; 950374

Comment top

Pyrrolo[1,2-a]quinoxalines and their 4,5-dihydro-derivatives exhibit interesting pharmacological properties (Maeba et al., 1990; Lancelot et al., 1994; Grande et al., 2007). Some compounds containing this system have shown activity as potent IkappaB kinase (IKK) inhibitors (Beaulieu et al., 2007), as potent and selective serotonin-1B agonists (Neale et al., 1987), as antileishmanial agents (Guillon et al., 2007) and antiproliferative activity against human leukaemia and breast cancer (Desplat et al., 2010). Here, we report the molecular and supramolecular structures of the title compounds, (I) (Fig. 1) and (II) (Fig. 2), as representative examples of these classes of compound, prepared as part of our current programme related to the synthesis of novel quinoxaline derivatives of biological interest (Abonía et al., 2001; Castillo et al., 2010).

Compound (I) contains a formally aromatic six-membered heterocyclic ring, while (II) contains a reduced 4,5-dihydro-ring in the corresponding position. We also compare the structures of (I) and (II) with those of their analogues, (III) (Castillo et al., 2010) and (IV) (Castillo et al., 2013) (see scheme). Compounds (I) and (III) contain the same fused ring system but differ in the substituents carried by the pendent aryl ring; (II) and (IV) both contain the same reduced ring system, but (II) contains a benzodioxolyl substituent where (IV) contains a dimethoxyphenyl substituent.

The crystallization characteristics of (I)–(IV), despite their rather similar constitutions, are all different. Thus, (I), (II) and (IV) all crystallize with Z' = 1, but in three different space groups (P21/c, C2/c and Pbca, respectively), while (III) crystallizes with Z' = 2. Despite the absence in (III) of any crystallographic symmetry in addition to that of the space group P21/c, where it crystallizes as a pseudo-merohedral twin emulating a metrically orthorhombic cell, the two independent molecules are nonetheless related by an approximate, but non-crystallographic, pseudo-screw axis parallel to the [100] direction of the monoclinic unit cell (Castillo et al., 2010). The molecules of (II) contain a stereogenic centre at atom C4 and the reference molecule was selected as one having the R configuration at C4. Likewise, there is a stereogenic centre at atom C4 in (IV), but this compound exhibits configurational disorder, with a given molecular site occupied by a fraction 0.692 (5) of one enantiomer and 0.308 (5) of the other (Castillo et al., 2013).

The bond distances in (I) and (II) (Tables 1 and 2) show some interesting contrasts, consequent upon the difference in the oxidation level of their respective six-membered heterocyclic rings. In (I), the C—C distances in the five-membered ring span a range of less than 0.03 Å, despite the fact that the C1—C2 and C3—C3a bonds are formally double, while C2—C3 is formally a single bond. These distances thus indicate some degree of electron delocalization in this ring. By contrast, in (II) the C—C distances in the pyrrole ring show a much clearer distinction between single and double bonds. At the same time, the bond distances for the fused carbocyclic ring of (I), but not for that of (II), indicate some slight bond fixation in the C6—C7 and C8—C9 bonds, while in the central fused ring of (I) there is a clearly localized double bond at C4—N5. The overall pattern of the distances in (I) indicates the presence of 6π circuits in the two outer rings of the fused system and a localized double bond in the central ring, analogous to the electronic structure of phenanthrene (Glidewell & Lloyd, 1984, 1986). This pattern of distances in (I) is fairly similar to that found for (III) (Castillo et al., 2010).

In (II), the dioxolane ring is essentially planar, with a maximum deviation from the mean plane of the five ring atoms of only 0.034 (2) Å for atom O43. For the central ring of the fused tricyclic system, the ring-puckering parameters (Cremer & Pople, 1975) for the atom sequence N5/C4/C3a/N9b/C9a/C5a are Q = 0.345 (2) Å, θ = 118.2 (3)° and ϕ = 216.4 (3)°, indicative of a conformation intermediate between screw-boat and half-chair forms, for which the idealized values of θ are 112.5 and 129.2°, respectively, with both forms having an idealized value for ϕ of (60k + 30)°, where k represents an integer. For the major and minor disorder forms of (IV) (Castillo et al., 2013), the ring-puckering angles for the atom sequences corresponding to that of (II) are, respectively, θ = 121 (2) and 62 (4)°, and ϕ = 212 (2) and 29 (4)°, showing the close conformational similarity between (II) and the major form of (IV). It also confirms the enantiomeric nature of the two disorder components of (IV), since a change of absolute configuration transforms θ into (180 - θ) and ϕ into (180 + ϕ). Consequent upon the puckering of the central fused ring of (II), the dihedral angle between the planes of the two outer rings of the fused tricyclic system is 10.0 (2)°, whereas the corresponding dihedral angle in (I) is only 1.3 (2)°. In (I), the dihedral angle between the pendent aryl ring and the adjacent heterocyclic ring is 67.2 (2)°, and in (II) the corresponding angle is 87.1 (2)°.

The supramolecular assembly in the crystal structure of (I) is very simple, as there are no hydrogen bonds of any type present. The principal direction-specific intermolecular interaction is a ππ stacking interaction between the five-membered ring of the molecule at (x, y, z) and the fused aryl ring of the molecule at (x, -y + 3/2, z - 1/2). The planes of these two rings make a dihedral angle of less than 1°, with a ring-centroid separation of 3.690 (2) Å. The shortest interplanar spacing is ca 3.45 Å, with a ring-centroid offset of ca 1.32 Å, and the shortest of the individual atom···atom distances associated with this contact is C1···C9ai = 3.282 (3) Å [symmetry code: (i) x, -y + 3/2, z - 1/2]. By this means, molecules related by the c-glide plane at y = 3/4 are linked into a chain running parallel to the [001] direction (Fig. 3). The only other direction-specific interaction between the molecules is a Cl···Cl contact of 3.213 (2) Å involving the molecules at (x, y, z) and (-x + 1, -y + 1, -z + 2). While this distance is certainly less than the van der Waals sum (Bondi, 1964), the expected partial negative charges on the two atoms involved, together with their rather low polarizability, makes it unclear whether this contact is attractive or repulsive.

The supramolecular assembly in (II) takes the form of a sheet built from a combination of N—H···O and C—H···π(arene) hydrogen bonds (Table 3). Inversion-related pairs of molecules are linked by paired N—H···O hydrogen bonds to form a cyclic centrosymmetric dimer characterized by an R22(16) motif (Bernstein et al., 1995) and centred at (1/2, 1/2, 1/2) (Fig. 4). This dimeric unit can conveniently be regarded as the key building block for the sheet formation. Within the reference dimer, the atoms of type C1 at (x, y, z) and (-x + 1, -y + 1, -z + 1) act as hydrogen-bond donors to, respectively, the fused aryl rings C5a/C6–C8/C9/C9a in the molecules at (-x + 1/2, y + 1/2, -z + 1/2) and (x + 1/2, -y + 1/2, z + 1/2), which themselves form part of the cyclic dimers centred at (0, 1, 0) and (1, 0, 1). Similarly, the fused aryl rings at (x, y, z) and (-x + 1, -y + 1, -z + 1) accept hydrogen bonds from the atoms of type C1 in the molecules at, respectively, (-x + 1/2, y - 1/2, -z + 1/2) and (x + 1/2, -y + 3/2, z + 1/2), which form part of the cyclic dimers centred at (0, 0, 0) and (1, 1, 1). In this manner, a single C—H···π(arene) hydrogen bond links the cyclic R22(16) dimers into a sheet lying parallel to (101) (Fig. 5).

A number of other C—H···π contacts can be identified in the structure of (II) (Table 3), all of which lie within the reference sheet described above, so that, even if they were regarded as structurally significant, they could not affect the dimensionality of the supramolecular aggregation but would merely increase its complexity. The contact involving atom C42 has a C—H···(ring centroid) angle of only 123° and the corresponding interaction energy is thus likely to be very small (Wood et al., 2009). The two contacts from atoms C8 and C46 both involve the pyrrole ring where, as noted above, there is a considerable degree of bond fixation, so that the delocalized aromatic character of this ring is likely to be rather modest.

It is of interest briefly to compare the supramolecular assembly in (I) and (II) with that in, respectively, (III) and (IV) (Castillo et al., 2010, 2013). The presence of both hydroxyl and methoxy substituents in the molecules of (III) naturally leads to a more complex mode of supramolecular assembly for (III) than was found for (I). In (III), where Z' = 2, a combination of two independent O—H···N hydrogen bonds and four independent C—H···O hydrogen bonds gives rise to a complex sheet structure. By contrast with the structure of (I), there are no ππ stacking interactions in the structure of (III). For both the major and minor disorder components of (IV), the molecules are linked by pairs of N—H···O hydrogen bonds to form cyclic centrosymmetric R22(14) dimers, somewhat similar to the dimer formed in (II), but reinforced in (IV) by a ππ interaction within the dimer involving the pendent phenyl rings. By contrast, there are no ππ stacking interactions in the structure of (II).

Related literature top

For related literature, see: Abonía et al. (2001); Beaulieu et al. (2007); Bernstein et al. (1995); Bondi (1964); Castillo et al. (2010, 2013); Cremer & Pople (1975); Desplat et al. (2010); Glidewell & Lloyd (1984, 1986); Grande et al. (2007); Guillon et al. (2007); Lancelot et al. (1994); Maeba et al. (1990); Neale et al. (1987); Wood et al. (2009).

Experimental top

For the synthesis of (I), a mixture of 1-(2-aminophenyl)pyrrole (0.63 mmol), 2-chlorobenzaldehyde (0.63 mmol) and palladium/charcoal (10%, 0.63 mmol) was dissolved in acetonitrile (2 ml). The solution was stirred at ambient temperature for 48 h until the starting materials were no longer detected by thin-layer chromatography. The palladium/charcoal was then removed by filtration, the solvent was removed under reduced pressure and the crude product was purified by column chromatography on silica gel using a 3:1 v/v chloroform–hexane mixture as eluent. Colourless crystals of (I) suitable for single-crystal X-ray diffraction were grown by slow evaporation, at ambient temperature and in air, of a solution in ethanol (yield 91%, m.p. 453 K). MS (70 eV) m/z (%): 280/278 (34/100) [M+], 254/252 (8/25), 121 (41); analysis, found: C 73.3, H 3.9, N 10.1%; C17H11ClN2 requires: C 73.3, H 4.0, N 10.1%. For the synthesis of (II), a mixture of 1-(2-aminophenyl)pyrrole (0.63 mmol) and piperonal (0.63 mmol) was dissolved in a mixture of acetonitrile and water (2:1 v/v; 1.5 ml). The mixture was left at ambient temperature without stirring for 6 d; the resulting solid product was collected by filtration and washed with hexane. Yellow crystals of (II) suitable for single-crystal X-ray diffraction were grown by slow evaporation, at ambient temperature and in air, of a solution in ethanol (yield 86%, m.p. 434 K). MS (70 eV) m/z (%): 290 (42) [M+], 229 (7), 169 (100), 157 (9), 115 (8); analysis, found: C 74.3, H 4.9, N 9.4%; C18H14N2O2 requires: C 74.5, H 4.9, N 9.7%.

Refinement top

All H atoms were located in difference maps. C-bound H atoms were then treated as riding in geometrically idealized positions, with C—H = 0.95 (aromatic and pyrrole), 0.99 (CH2) or 1.00 Å (aliphatic), and with Uiso(H) = 1.2Ueq(C). The N-bound H atom in (II) was permitted to ride at the position found in a difference map, with Uiso(H) = 1.2Ueq(N), giving N—H = 0.88 Å.

Computing details top

For both compounds, data collection: COLLECT (Nonius, 1998); cell refinement: DIRAX/LSQ (Duisenberg et al., 2000); data reduction: EVALCCD (Duisenberg et al., 2003). Program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) for (I); SIR2004 (Burla et al., 2005) for (II). For both compounds, program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. The molecular structure of (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 3] Fig. 3. Part of the crystal structure of (I), showing the formation of a chain of π-stacked molecules along [001]. For the sake of clarity, all H atoms have been omitted. Atoms marked with an asterisk (*), a hash (#), a dollar sign ($) or an ampersand (&) are at the symmetry positions (x, -y + 3/2, z - 1/2), (x, -y + 3/2, z + 1/2), (x, y, z - 1) and (x, y, z + 1), respectively.
[Figure 4] Fig. 4. Part of the crystal structure of (II), showing the formation of a centrosymmetric hydrogen-bonded dimer centred at (1/2, 1/2, 1/2). For the sake of clarity, H atoms bonded to C atoms have been omitted. Atoms marked with an asterisk (*) are at the symmetry position (-x + 1, -y + 1, -z + 1).
[Figure 5] Fig. 5. A stereoview of part of the crystal structure of (II), showing the formation of a hydrogen-bonded sheet lying parallel to (101). For the sake of clarity, H atoms not involved in the motifs shown have been omitted.
(I) 4-(2-Chlorophenyl)pyrrolo[1,2-a]quinoxaline top
Crystal data top
C17H11ClN2F(000) = 576
Mr = 278.73Dx = 1.433 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2984 reflections
a = 13.5649 (13) Åθ = 3.0–27.5°
b = 11.8142 (11) ŵ = 0.29 mm1
c = 8.1678 (12) ÅT = 120 K
β = 99.281 (10)°Block, colourless
V = 1291.8 (3) Å30.42 × 0.25 × 0.22 mm
Z = 4
Data collection top
Bruker Nonius KappaCCD area-detector
diffractometer
2984 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode2187 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.0°
ϕ and ω scansh = 1717
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
k = 1415
Tmin = 0.890, Tmax = 0.940l = 1010
18171 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.043Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.116H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0544P)2 + 0.6625P]
where P = (Fo2 + 2Fc2)/3
2984 reflections(Δ/σ)max = 0.001
181 parametersΔρmax = 0.31 e Å3
0 restraintsΔρmin = 0.33 e Å3
Crystal data top
C17H11ClN2V = 1291.8 (3) Å3
Mr = 278.73Z = 4
Monoclinic, P21/cMo Kα radiation
a = 13.5649 (13) ŵ = 0.29 mm1
b = 11.8142 (11) ÅT = 120 K
c = 8.1678 (12) Å0.42 × 0.25 × 0.22 mm
β = 99.281 (10)°
Data collection top
Bruker Nonius KappaCCD area-detector
diffractometer
2984 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
2187 reflections with I > 2σ(I)
Tmin = 0.890, Tmax = 0.940Rint = 0.047
18171 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0430 restraints
wR(F2) = 0.116H-atom parameters constrained
S = 1.06Δρmax = 0.31 e Å3
2984 reflectionsΔρmin = 0.33 e Å3
181 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.34705 (14)0.75957 (17)0.4570 (2)0.0252 (4)
H10.35270.83820.43570.030*
C20.40865 (14)0.67575 (17)0.4147 (2)0.0270 (4)
H20.46420.68680.35910.032*
C30.37595 (14)0.57131 (17)0.4673 (2)0.0247 (4)
H30.40480.49930.45380.030*
C3a0.29317 (13)0.59319 (16)0.5431 (2)0.0210 (4)
C40.22842 (13)0.52535 (16)0.6229 (2)0.0216 (4)
N50.15083 (11)0.56487 (13)0.68203 (19)0.0219 (3)
C5a0.13447 (13)0.68197 (16)0.6709 (2)0.0213 (4)
C60.05335 (14)0.72742 (17)0.7364 (2)0.0251 (4)
H60.01030.67820.78400.030*
C70.03527 (15)0.84232 (18)0.7328 (2)0.0277 (4)
H70.01970.87180.77800.033*
C80.09805 (15)0.91530 (17)0.6624 (2)0.0276 (4)
H80.08540.99440.66010.033*
C90.17847 (15)0.87330 (16)0.5960 (2)0.0256 (4)
H90.22080.92310.54800.031*
C9a0.19646 (13)0.75749 (16)0.6006 (2)0.0210 (4)
N9b0.27628 (11)0.70985 (13)0.53517 (18)0.0209 (3)
C410.24779 (14)0.40080 (16)0.6382 (2)0.0217 (4)
C420.33173 (14)0.35660 (16)0.7397 (2)0.0230 (4)
Cl420.41717 (4)0.44616 (4)0.85870 (6)0.03018 (16)
C430.34865 (15)0.24091 (16)0.7547 (2)0.0262 (4)
H430.40600.21260.82510.031*
C440.28068 (15)0.16737 (17)0.6655 (2)0.0287 (4)
H440.29170.08800.67410.034*
C450.19673 (15)0.20885 (17)0.5637 (2)0.0275 (4)
H450.15020.15800.50330.033*
C460.18072 (14)0.32427 (17)0.5504 (2)0.0247 (4)
H460.12310.35200.48020.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0244 (10)0.0283 (10)0.0233 (9)0.0063 (8)0.0048 (8)0.0025 (8)
C20.0226 (10)0.0330 (11)0.0262 (10)0.0027 (8)0.0068 (8)0.0011 (8)
C30.0215 (9)0.0282 (11)0.0249 (9)0.0015 (8)0.0048 (8)0.0016 (8)
C3a0.0219 (9)0.0202 (9)0.0204 (9)0.0003 (7)0.0019 (7)0.0010 (7)
C40.0191 (9)0.0266 (10)0.0177 (9)0.0005 (8)0.0006 (7)0.0018 (7)
N50.0196 (8)0.0240 (8)0.0217 (8)0.0024 (6)0.0023 (6)0.0002 (6)
C5a0.0202 (9)0.0241 (10)0.0187 (9)0.0003 (8)0.0003 (7)0.0008 (7)
C60.0207 (9)0.0308 (11)0.0237 (10)0.0011 (8)0.0029 (8)0.0004 (8)
C70.0243 (10)0.0338 (11)0.0244 (10)0.0054 (9)0.0019 (8)0.0026 (8)
C80.0313 (11)0.0229 (10)0.0281 (10)0.0034 (8)0.0030 (8)0.0014 (8)
C90.0289 (10)0.0235 (10)0.0241 (10)0.0021 (8)0.0034 (8)0.0006 (8)
C9a0.0191 (9)0.0253 (10)0.0181 (9)0.0002 (7)0.0009 (7)0.0019 (7)
N9b0.0212 (8)0.0206 (8)0.0206 (7)0.0012 (6)0.0027 (6)0.0003 (6)
C410.0217 (9)0.0236 (9)0.0210 (9)0.0022 (8)0.0073 (7)0.0006 (7)
C420.0242 (9)0.0225 (9)0.0225 (9)0.0022 (8)0.0044 (7)0.0032 (7)
Cl420.0299 (3)0.0247 (3)0.0324 (3)0.0005 (2)0.00563 (19)0.0037 (2)
C430.0283 (10)0.0253 (10)0.0255 (10)0.0009 (8)0.0057 (8)0.0002 (8)
C440.0365 (11)0.0211 (10)0.0299 (10)0.0019 (9)0.0093 (9)0.0003 (8)
C450.0322 (11)0.0244 (10)0.0260 (10)0.0086 (8)0.0046 (8)0.0044 (8)
C460.0218 (9)0.0290 (10)0.0234 (9)0.0029 (8)0.0044 (7)0.0000 (8)
Geometric parameters (Å, º) top
C1—C21.375 (3)C9—H90.9500
C1—H10.9500C9a—N9b1.401 (2)
C2—C31.402 (3)N9b—C11.368 (2)
C2—H20.9500C3a—N9b1.397 (2)
C3—C3a1.391 (3)C5a—C9a1.410 (3)
C3—H30.9500C4—C411.497 (3)
C3a—C41.422 (3)C41—C461.396 (3)
C4—N51.313 (2)C41—C421.397 (3)
N5—C5a1.402 (2)C42—C431.388 (3)
C5a—C61.405 (3)C42—Cl421.7448 (19)
C6—C71.379 (3)C43—C441.385 (3)
C6—H60.9500C43—H430.9500
C7—C81.399 (3)C44—C451.386 (3)
C7—H70.9500C44—H440.9500
C8—C91.386 (3)C45—C461.382 (3)
C8—H80.9500C45—H450.9500
C9—C9a1.389 (3)C46—H460.9500
N9b—C1—C2107.96 (17)C8—C9—C9a119.21 (18)
N9b—C1—H1126.0C8—C9—H9120.4
C2—C1—H1126.0C9a—C9—H9120.4
C1—C2—C3108.77 (17)C9—C9a—N9b121.92 (17)
C1—C2—H2125.6C9—C9a—C5a121.36 (17)
C3—C2—H2125.6N9b—C9a—C5a116.73 (16)
C3a—C3—C2106.91 (17)C1—N9b—C3a108.85 (15)
C3a—C3—H3126.5C1—N9b—C9a130.49 (16)
C2—C3—H3126.5C3a—N9b—C9a120.65 (15)
C3—C3a—N9b107.51 (16)C46—C41—C42117.65 (17)
C3—C3a—C4134.56 (18)C46—C41—C4120.19 (17)
N9b—C3a—C4117.93 (16)C42—C41—C4122.16 (16)
N5—C4—C3a124.00 (17)C43—C42—C41121.85 (17)
N5—C4—C41117.36 (16)C43—C42—Cl42117.54 (15)
C3a—C4—C41118.63 (16)C41—C42—Cl42120.57 (14)
C4—N5—C5a117.08 (16)C44—C43—C42118.98 (19)
N5—C5a—C6118.55 (17)C44—C43—H43120.5
N5—C5a—C9a123.51 (17)C42—C43—H43120.5
C6—C5a—C9a117.92 (17)C43—C44—C45120.41 (18)
C7—C6—C5a121.02 (18)C43—C44—H44119.8
C7—C6—H6119.5C45—C44—H44119.8
C5a—C6—H6119.5C46—C45—C44119.96 (18)
C6—C7—C8119.85 (19)C46—C45—H45120.0
C6—C7—H7120.1C44—C45—H45120.0
C8—C7—H7120.1C45—C46—C41121.14 (18)
C9—C8—C7120.65 (19)C45—C46—H46119.4
C9—C8—H8119.7C41—C46—H46119.4
C7—C8—H8119.7
N9b—C1—C2—C30.0 (2)C2—C1—N9b—C9a179.42 (17)
C1—C2—C3—C3a0.2 (2)C3—C3a—N9b—C10.2 (2)
C2—C3—C3a—N9b0.2 (2)C4—C3a—N9b—C1178.91 (16)
C2—C3—C3a—C4178.7 (2)C3—C3a—N9b—C9a179.37 (15)
C3—C3a—C4—N5177.53 (19)C4—C3a—N9b—C9a1.5 (2)
N9b—C3a—C4—N53.6 (3)C9—C9a—N9b—C11.2 (3)
C3—C3a—C4—C411.1 (3)C5a—C9a—N9b—C1178.48 (18)
N9b—C3a—C4—C41177.72 (15)C9—C9a—N9b—C3a179.32 (17)
C3a—C4—N5—C5a2.8 (3)C5a—C9a—N9b—C3a1.0 (2)
C41—C4—N5—C5a178.51 (15)N5—C4—C41—C4666.5 (2)
C4—N5—C5a—C6178.58 (16)C3a—C4—C41—C46112.3 (2)
C4—N5—C5a—C9a0.0 (3)C3a—C4—C41—C4268.1 (2)
N5—C5a—C6—C7178.30 (17)N5—C4—C41—C42113.1 (2)
C9a—C5a—C6—C70.3 (3)C46—C41—C42—C430.3 (3)
C5a—C6—C7—C80.3 (3)C4—C41—C42—C43179.27 (17)
C6—C7—C8—C90.0 (3)C46—C41—C42—Cl42177.96 (13)
C7—C8—C9—C9a0.2 (3)C4—C41—C42—Cl421.6 (2)
C8—C9—C9a—N9b179.79 (17)C41—C42—C43—C440.5 (3)
C8—C9—C9a—C5a0.2 (3)Cl42—C42—C43—C44178.18 (14)
N5—C5a—C9a—C9178.45 (17)C42—C43—C44—C450.4 (3)
C6—C5a—C9a—C90.1 (3)C43—C44—C45—C460.3 (3)
N5—C5a—C9a—N9b1.9 (3)C44—C45—C46—C410.1 (3)
C6—C5a—C9a—N9b179.53 (16)C42—C41—C46—C450.1 (3)
C2—C1—N9b—C3a0.1 (2)C4—C41—C46—C45179.45 (17)
(II) (RS)-4-(1,3-Benzodioxol-6-yl)-4,5-dihydropyrrolo[1,2-a]quinoxaline top
Crystal data top
C18H14N2O2F(000) = 1216
Mr = 290.31Dx = 1.377 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 3225 reflections
a = 26.590 (3) Åθ = 2.6–27.5°
b = 6.2890 (9) ŵ = 0.09 mm1
c = 17.2655 (19) ÅT = 120 K
β = 104.017 (11)°Block, yellow
V = 2801.3 (6) Å30.45 × 0.24 × 0.16 mm
Z = 8
Data collection top
Bruker Nonius KappaCCD area-detector
diffractometer
3225 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode2350 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 2.6°
ϕ and ω scansh = 3434
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
k = 87
Tmin = 0.960, Tmax = 0.986l = 2222
23085 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.114H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.0376P)2 + 3.2029P]
where P = (Fo2 + 2Fc2)/3
3225 reflections(Δ/σ)max = 0.001
199 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = 0.24 e Å3
Crystal data top
C18H14N2O2V = 2801.3 (6) Å3
Mr = 290.31Z = 8
Monoclinic, C2/cMo Kα radiation
a = 26.590 (3) ŵ = 0.09 mm1
b = 6.2890 (9) ÅT = 120 K
c = 17.2655 (19) Å0.45 × 0.24 × 0.16 mm
β = 104.017 (11)°
Data collection top
Bruker Nonius KappaCCD area-detector
diffractometer
3225 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
2350 reflections with I > 2σ(I)
Tmin = 0.960, Tmax = 0.986Rint = 0.046
23085 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.114H-atom parameters constrained
S = 1.08Δρmax = 0.32 e Å3
3225 reflectionsΔρmin = 0.24 e Å3
199 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.33788 (7)1.1611 (3)0.20621 (10)0.0301 (4)
H10.31431.27450.18880.036*
C20.37700 (7)1.0999 (3)0.17223 (11)0.0326 (4)
H20.38531.16320.12700.039*
C30.40297 (7)0.9250 (3)0.21654 (10)0.0324 (4)
H30.43180.85050.20660.039*
C3a0.37859 (6)0.8837 (3)0.27650 (10)0.0275 (4)
C40.38528 (6)0.7100 (3)0.33813 (10)0.0269 (4)
H40.36370.58460.31480.032*
N50.36709 (5)0.7916 (2)0.40552 (8)0.0265 (3)
H50.37520.71090.44840.032*
C5a0.32160 (6)0.9076 (3)0.39337 (10)0.0231 (4)
C60.29136 (6)0.9131 (3)0.44910 (10)0.0255 (4)
H60.30060.82710.49560.031*
C70.24801 (7)1.0424 (3)0.43741 (10)0.0293 (4)
H70.22811.04550.47620.035*
C80.23350 (7)1.1672 (3)0.36950 (11)0.0332 (4)
H80.20371.25540.36160.040*
C90.26298 (7)1.1623 (3)0.31302 (10)0.0297 (4)
H90.25311.24670.26620.036*
C9a0.30662 (6)1.0348 (3)0.32491 (10)0.0235 (4)
N9b0.33884 (5)1.0288 (2)0.27039 (8)0.0246 (3)
O410.59642 (4)0.5001 (2)0.45054 (7)0.0287 (3)
C420.61376 (7)0.7065 (3)0.48326 (11)0.0334 (4)
H42A0.63220.69260.54020.040*
H42B0.63790.76910.45400.040*
O430.56956 (5)0.8395 (2)0.47560 (8)0.0386 (3)
C43a0.52790 (6)0.7248 (3)0.43325 (10)0.0269 (4)
C440.47709 (6)0.7900 (3)0.40861 (10)0.0281 (4)
H440.46660.92870.41980.034*
C450.44164 (6)0.6418 (3)0.36624 (10)0.0269 (4)
C460.45736 (7)0.4415 (3)0.35024 (11)0.0317 (4)
H460.43250.34380.32140.038*
C470.50945 (7)0.3788 (3)0.37585 (11)0.0327 (4)
H470.52050.24090.36470.039*
C47a0.54357 (6)0.5245 (3)0.41741 (10)0.0244 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0308 (9)0.0288 (10)0.0271 (9)0.0022 (8)0.0002 (7)0.0066 (8)
C20.0302 (9)0.0386 (11)0.0275 (9)0.0077 (8)0.0039 (7)0.0040 (8)
C30.0257 (9)0.0447 (12)0.0263 (9)0.0008 (8)0.0057 (7)0.0009 (8)
C3a0.0250 (8)0.0323 (10)0.0231 (8)0.0022 (7)0.0020 (7)0.0011 (7)
C40.0241 (8)0.0280 (10)0.0273 (9)0.0003 (7)0.0038 (7)0.0007 (7)
N50.0241 (7)0.0306 (8)0.0246 (7)0.0050 (6)0.0053 (6)0.0063 (6)
C5a0.0202 (8)0.0210 (9)0.0255 (8)0.0016 (7)0.0007 (6)0.0023 (7)
C60.0257 (8)0.0251 (9)0.0248 (8)0.0035 (7)0.0041 (7)0.0008 (7)
C70.0287 (9)0.0298 (10)0.0306 (9)0.0021 (8)0.0097 (7)0.0049 (8)
C80.0298 (9)0.0299 (10)0.0392 (10)0.0070 (8)0.0070 (8)0.0033 (8)
C90.0310 (9)0.0267 (10)0.0289 (9)0.0061 (8)0.0027 (7)0.0025 (8)
C9a0.0231 (8)0.0235 (9)0.0220 (8)0.0019 (7)0.0018 (6)0.0031 (7)
N9b0.0238 (7)0.0269 (8)0.0214 (7)0.0007 (6)0.0021 (5)0.0017 (6)
O410.0215 (6)0.0298 (7)0.0329 (6)0.0005 (5)0.0028 (5)0.0024 (5)
C420.0278 (9)0.0323 (11)0.0360 (10)0.0047 (8)0.0005 (7)0.0005 (8)
O430.0252 (6)0.0343 (8)0.0547 (8)0.0017 (6)0.0065 (6)0.0162 (7)
C43a0.0271 (8)0.0286 (10)0.0254 (8)0.0036 (7)0.0070 (7)0.0028 (7)
C440.0284 (9)0.0234 (9)0.0340 (9)0.0036 (7)0.0107 (7)0.0001 (7)
C450.0252 (8)0.0305 (10)0.0243 (8)0.0004 (7)0.0048 (7)0.0023 (7)
C460.0279 (9)0.0315 (10)0.0338 (10)0.0007 (8)0.0036 (7)0.0054 (8)
C470.0282 (9)0.0293 (10)0.0385 (10)0.0042 (8)0.0042 (8)0.0058 (8)
C47a0.0216 (8)0.0267 (9)0.0243 (8)0.0031 (7)0.0042 (6)0.0028 (7)
Geometric parameters (Å, º) top
C1—C21.367 (3)C9a—N9b1.418 (2)
C1—H10.9500N9b—C11.381 (2)
C2—C31.420 (3)C3a—N9b1.381 (2)
C2—H20.9500C5a—C9a1.403 (2)
C3—C3a1.373 (2)C4—C451.521 (2)
C3—H30.9500O41—C47a1.3917 (19)
C3a—C41.505 (2)O41—C421.446 (2)
C4—N51.457 (2)C42—O431.423 (2)
C4—H41.0000C42—H42A0.9900
N5—C5a1.384 (2)C42—H42B0.9900
N5—H50.8801O43—C43a1.375 (2)
C5a—C61.396 (2)C43a—C47a1.375 (3)
C6—C71.385 (2)C43a—C441.377 (2)
C6—H60.9500C44—C451.399 (2)
C7—C81.386 (3)C44—H440.9500
C7—H70.9500C45—C461.377 (3)
C8—C91.392 (3)C46—C471.404 (2)
C8—H80.9500C46—H460.9500
C9—C9a1.384 (2)C47—C47a1.364 (2)
C9—H90.9500C47—H470.9500
C2—C1—N9b107.85 (16)C9a—C9—H9119.9
C2—C1—H1126.1C8—C9—H9119.9
N9b—C1—H1126.1C9—C9a—C5a120.79 (16)
C1—C2—C3107.96 (16)C9—C9a—N9b122.44 (15)
C1—C2—H2126.0C5a—C9a—N9b116.76 (14)
C3—C2—H2126.0C1—N9b—C3a108.94 (15)
C3a—C3—C2107.21 (16)C1—N9b—C9a128.30 (15)
C3a—C3—H3126.4C3a—N9b—C9a122.74 (14)
C2—C3—H3126.4C47a—O41—C42104.85 (13)
C3—C3a—N9b108.04 (15)O43—C42—O41108.29 (13)
C3—C3a—C4132.36 (16)O43—C42—H42A110.0
N9b—C3a—C4119.41 (15)O41—C42—H42A110.0
N5—C4—C3a107.66 (14)O43—C42—H42B110.0
N5—C4—C45109.66 (13)O41—C42—H42B110.0
C3a—C4—C45111.65 (14)H42A—C42—H42B108.4
N5—C4—H4109.3C43a—O43—C42106.37 (14)
C3a—C4—H4109.3O43—C43a—C47a110.04 (15)
C45—C4—H4109.3O43—C43a—C44127.75 (17)
C5a—N5—C4120.77 (13)C47a—C43a—C44122.21 (16)
C5a—N5—H5117.3C43a—C44—C45116.73 (16)
C4—N5—H5114.0C43a—C44—H44121.6
N5—C5a—C6122.45 (15)C45—C44—H44121.6
N5—C5a—C9a119.18 (15)C46—C45—C44121.03 (16)
C6—C5a—C9a118.26 (15)C46—C45—C4121.18 (16)
C7—C6—C5a120.81 (16)C44—C45—C4117.79 (16)
C7—C6—H6119.6C45—C46—C47121.19 (17)
C5a—C6—H6119.6C45—C46—H46119.4
C6—C7—C8120.48 (17)C47—C46—H46119.4
C6—C7—H7119.8C47a—C47—C46117.17 (17)
C8—C7—H7119.8C47a—C47—H47121.4
C7—C8—C9119.44 (17)C46—C47—H47121.4
C7—C8—H8120.3C47—C47a—C43a121.66 (16)
C9—C8—H8120.3C47—C47a—O41128.22 (16)
C9a—C9—C8120.21 (16)C43a—C47a—O41110.11 (15)
N9b—C1—C2—C30.1 (2)C4—C3a—N9b—C9a6.3 (2)
C1—C2—C3—C3a0.3 (2)C9—C9a—N9b—C110.1 (3)
C2—C3—C3a—N9b0.4 (2)C5a—C9a—N9b—C1168.62 (16)
C2—C3—C3a—C4174.46 (18)C9—C9a—N9b—C3a171.77 (16)
C3—C3a—C4—N5155.30 (18)C5a—C9a—N9b—C3a9.5 (2)
N9b—C3a—C4—N530.3 (2)C47a—O41—C42—O435.94 (18)
C3—C3a—C4—C4534.9 (3)O41—C42—O43—C43a5.37 (19)
N9b—C3a—C4—C45150.72 (15)C42—O43—C43a—C47a2.70 (19)
C3a—C4—N5—C5a43.5 (2)C42—O43—C43a—C44177.50 (18)
C45—C4—N5—C5a165.13 (15)O43—C43a—C44—C45179.76 (16)
C4—N5—C5a—C6152.41 (16)C47a—C43a—C44—C450.0 (3)
C4—N5—C5a—C9a31.5 (2)C43a—C44—C45—C460.2 (3)
N5—C5a—C6—C7175.53 (16)C43a—C44—C45—C4179.83 (15)
C9a—C5a—C6—C70.6 (2)C3a—C4—C45—C4465.8 (2)
C5a—C6—C7—C80.7 (3)C3a—C4—C45—C46113.83 (19)
C6—C7—C8—C90.2 (3)N5—C4—C45—C4453.4 (2)
C7—C8—C9—C9a0.4 (3)N5—C4—C45—C46126.93 (17)
C8—C9—C9a—C5a0.5 (3)C44—C45—C46—C470.0 (3)
C8—C9—C9a—N9b178.08 (16)C4—C45—C46—C47179.67 (16)
N5—C5a—C9a—C9176.30 (15)C45—C46—C47—C47a0.3 (3)
C6—C5a—C9a—C90.0 (2)C46—C47—C47a—C43a0.4 (3)
N5—C5a—C9a—N9b2.4 (2)C46—C47—C47a—O41178.36 (16)
C6—C5a—C9a—N9b178.68 (14)O43—C43a—C47a—C47179.89 (16)
C2—C1—N9b—C3a0.20 (19)C44—C43a—C47a—C470.3 (3)
C2—C1—N9b—C9a178.18 (16)O43—C43a—C47a—O411.11 (19)
C3—C3a—N9b—C10.38 (19)C44—C43a—C47a—O41178.70 (15)
C4—C3a—N9b—C1175.26 (14)C42—O41—C47a—C47176.75 (18)
C3—C3a—N9b—C9a178.11 (15)C42—O41—C47a—C43a4.34 (18)
Hydrogen-bond geometry (Å, º) top
Cg1 represents the centroid of the C5a/C6–C9/C9a ring and Cg2 represents the centroid of the C1–C3/C3a/N9b ring.
D—H···AD—HH···AD···AD—H···A
N5—H5···O41i0.882.183.052 (2)173
C1—H1···Cg1ii0.952.953.878 (2)165
C8—H8···Cg2ii0.952.703.568 (2)152
C42—H42A···Cg1iii0.992.993.628 (2)123
C46—H46···Cg2iv0.952.903.845 (2)173
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1, y+2, z+1; (iv) x, y1, z.

Experimental details

(I)(II)
Crystal data
Chemical formulaC17H11ClN2C18H14N2O2
Mr278.73290.31
Crystal system, space groupMonoclinic, P21/cMonoclinic, C2/c
Temperature (K)120120
a, b, c (Å)13.5649 (13), 11.8142 (11), 8.1678 (12)26.590 (3), 6.2890 (9), 17.2655 (19)
β (°) 99.281 (10) 104.017 (11)
V3)1291.8 (3)2801.3 (6)
Z48
Radiation typeMo KαMo Kα
µ (mm1)0.290.09
Crystal size (mm)0.42 × 0.25 × 0.220.45 × 0.24 × 0.16
Data collection
DiffractometerBruker Nonius KappaCCD area-detector
diffractometer
Bruker Nonius KappaCCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Multi-scan
(SADABS; Sheldrick, 2003)
Tmin, Tmax0.890, 0.9400.960, 0.986
No. of measured, independent and
observed [I > 2σ(I)] reflections
18171, 2984, 2187 23085, 3225, 2350
Rint0.0470.046
(sin θ/λ)max1)0.6500.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.116, 1.06 0.049, 0.114, 1.08
No. of reflections29843225
No. of parameters181199
H-atom treatmentH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.31, 0.330.32, 0.24

Computer programs: COLLECT (Nonius, 1998), DIRAX/LSQ (Duisenberg et al., 2000), EVALCCD (Duisenberg et al., 2003), SHELXS97 (Sheldrick, 2008), SIR2004 (Burla et al., 2005), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Selected geometric parameters (Å, º) for (I) top
C1—C21.375 (3)C7—C81.399 (3)
C2—C31.402 (3)C8—C91.386 (3)
C3—C3a1.391 (3)C9—C9a1.389 (3)
C3a—C41.422 (3)C9a—N9b1.401 (2)
C4—N51.313 (2)N9b—C11.368 (2)
N5—C5a1.402 (2)C3a—N9b1.397 (2)
C5a—C61.405 (3)C5a—C9a1.410 (3)
C6—C71.379 (3)
C3a—C4—C41—C4268.1 (2)N5—C4—C41—C42113.1 (2)
Selected geometric parameters (Å, º) for (II) top
C1—C21.367 (3)C7—C81.386 (3)
C2—C31.420 (3)C8—C91.392 (3)
C3—C3a1.373 (2)C9—C9a1.384 (2)
C3a—C41.505 (2)C9a—N9b1.418 (2)
C4—N51.457 (2)N9b—C11.381 (2)
N5—C5a1.384 (2)C3a—N9b1.381 (2)
C5a—C61.396 (2)C5a—C9a1.403 (2)
C6—C71.385 (2)
C3a—C4—C45—C4465.8 (2)N5—C4—C45—C4453.4 (2)
C3a—C4—C45—C46113.83 (19)N5—C4—C45—C46126.93 (17)
Hydrogen-bond geometry (Å, º) for (II) top
Cg1 represents the centroid of the C5a/C6–C9/C9a ring and Cg2 represents the centroid of the C1–C3/C3a/N9b ring.
D—H···AD—HH···AD···AD—H···A
N5—H5···O41i0.882.183.052 (2)173
C1—H1···Cg1ii0.952.953.878 (2)165
C8—H8···Cg2ii0.952.703.568 (2)152
C42—H42A···Cg1iii0.992.993.628 (2)123
C46—H46···Cg2iv0.952.903.845 (2)173
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1, y+2, z+1; (iv) x, y1, z.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds