Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807032357/sg2179sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807032357/sg2179Isup2.hkl |
CCDC reference: 659072
A mixture of N-(carboxyethyl)quinolinium bromide (1 mmol), methyl acrylate (3 mmol), TPCD (1.6 mmol) and sodium carbonate (2.5 mmol) in DMF (15 ml) was heated at 363 K for 4 h with magnetic stirring. The title compound (I) was isolated by column chromatography of the reaction mixture on silica gel in 60% yield. Single crystals of the title compound in colorless block shape were obtained by slow evaporation of a solution in petroleum ether/ethyl acetate (3:1, V/V), m.p. 404–406 K. Compound (I) has been reported before. [Basketter & Plunkett (1971); Tominaga et al., (1990)]. However there is no x-ray structure published yet. We prepared (I) with the same starting materials as in Tominaga et al., 1990, but under different reaction conditions and with the better yield. The spectroscopic and analytical data of (I) was found to be the same as the published data (Tominaga et al., 1990).
All H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å. The Uiso values were constrained to be 1.5Ueq of the carrier atom for methyl H atoms and 1.2Ueq for the remaining H atoms. A rotating group model was used for the methyl groups. 3573 Friedel pairs were merged as there is no significant anomalous dispersion to determine the absolute structure. The highest residual peak is located 0.68 Å from O2 and the deepest hole is located 0.67 Å from O2.
Indolizines are found in several naturally occurring alkaloids with important biological activities and are important synthetic targets (Saeva & Luss, 1988). As an extension of our research on the direct one-pot syntheses of indolizine derivatives (Liu et al., 2007), we have recently researched a general and versatile synthesis of indolizines and obtained the title compound, as one of the products. An x-ray crystallographic analysis was undertaken to elucidate its three-dimensional molecular and crystal structures.
The bond lengths and angles in the structure of the title compound (I) are within normal ranges (Allen et al., 1987), and comparable with those in related structures (Usman et al., 2002; Shen et al., 2006; Wang, 2006a; 2006b; Liu et al., 2007). In the title structure (Fig. 1), the pyrrolo[2,1-a]isoquinoline ring system [N1/C1–C12] is planar with the mean deviation of 0.006 (1) Å. The methoxycarbonyl group (O1/O2/C16/C17) is almost coplanar with the pyrrolo[2,1-a]isoquinoline ring. The plane of the methoxycarbonyl group is twisted about the C2—C16 bond by an angle of 8.00 (7)°. The ethoxycarbonyl group (O3/O4/C13–C15) is co-planarly attached at atom C12 of the pyrrole ring, as indicated by the torsion angles N1–C12–C13–O3 = -178.13 (10)° and C13–O3–C14–C15 = 179.39 (10)°. The planarity of the molecule is influenced by weak intramolecular C5—H5A···O2 and C11—H11A···O4 interactions (Fig. 1) which generate S(7) and S(6) ring motifs, respectively (Bernstein et al., 1995). The dihedral angle between the planes of two carboxylate groups is 8.33 (6)°.
In the crystal packing of (I) in Fig. 2, the molecules are arranged into molecular sheets parallel to the ac plane and these molecular sheets are stacked along the b axis. π···π interactions are also presented in the crystal with the distances of Cg1···Cg2 = 3.6683 (7) Å, Cg1···Cg3 = 3.5680 (7)Å and Cg2···Cg3 = 3.6514 (7)Å [symmetry codes; x, -1 + y, z and x, 1 + y, z for all π···π interactions]; Cg1, Cg2 and Cg3 are the centroids of N1/C1–C3/C12, N1/C3–C4/C9–C11 and C4–C9 rings, respectively. The crystal is stabilized by weak intramolecular and intermolecular C—H···O interactions (Table 1) and further stabilized by π···π interactions.
For reference values of bond lengths, see: Allen et al. (1987). For related literature on ring motifs, see: Bernstein et al. (1995). For examples of related structures, see: Usman et al. (2002); Shen et al. (2006); Wang (2006a,b); Liu et al. (2007). For related literature on indolizine derivatives and activities, see, for example: Basketter & Plunkett (1971); Saeva & Luss (1988); Tominaga et al. (1990); Gundersen et al. (2007).
Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
C17H15NO4 | F(000) = 624 |
Mr = 297.30 | Dx = 1.436 Mg m−3 |
Monoclinic, Cc | Melting point = 404–406 K |
Hall symbol: C -2yc | Mo Kα radiation, λ = 0.71073 Å |
a = 20.5388 (4) Å | Cell parameters from 3627 reflections |
b = 4.4550 (1) Å | θ = 2.2–37.5° |
c = 16.5764 (5) Å | µ = 0.10 mm−1 |
β = 114.955 (2)° | T = 100 K |
V = 1375.14 (6) Å3 | Block, colourless |
Z = 4 | 0.53 × 0.27 × 0.15 mm |
Bruker SMART APEXII CCD area-detector diffractometer | 3627 independent reflections |
Radiation source: fine-focus sealed tube | 3404 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
Detector resolution: 8.33 pixels mm-1 | θmax = 37.5°, θmin = 2.2° |
ω scans | h = −34→34 |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | k = −7→7 |
Tmin = 0.948, Tmax = 0.985 | l = −28→28 |
23077 measured reflections |
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)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0691P)2 + 0.0494P] where P = (Fo2 + 2Fc2)/3 |
3627 reflections | (Δ/σ)max < 0.001 |
201 parameters | Δρmax = 0.42 e Å−3 |
2 restraints | Δρmin = −0.28 e Å−3 |
C17H15NO4 | V = 1375.14 (6) Å3 |
Mr = 297.30 | Z = 4 |
Monoclinic, Cc | Mo Kα radiation |
a = 20.5388 (4) Å | µ = 0.10 mm−1 |
b = 4.4550 (1) Å | T = 100 K |
c = 16.5764 (5) Å | 0.53 × 0.27 × 0.15 mm |
β = 114.955 (2)° |
Bruker SMART APEXII CCD area-detector diffractometer | 3627 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 3404 reflections with I > 2σ(I) |
Tmin = 0.948, Tmax = 0.985 | Rint = 0.044 |
23077 measured reflections |
R[F2 > 2σ(F2)] = 0.038 | 2 restraints |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.42 e Å−3 |
3627 reflections | Δρmin = −0.28 e Å−3 |
201 parameters |
Experimental. The data was collected with the Oxford Cyrosystem Cobra low-temperature attachment. |
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 | 0.45336 (5) | −0.2384 (3) | 0.04828 (6) | 0.0244 (2) | |
O2 | 0.49888 (5) | 0.0351 (4) | 0.17187 (8) | 0.0383 (3) | |
O3 | 0.19014 (4) | −0.5425 (2) | −0.07101 (6) | 0.01815 (15) | |
O4 | 0.12973 (5) | −0.3018 (2) | −0.00418 (6) | 0.02089 (16) | |
N1 | 0.26700 (5) | −0.0079 (2) | 0.11014 (6) | 0.01466 (15) | |
C1 | 0.31898 (5) | −0.2445 (2) | 0.03391 (7) | 0.01531 (16) | |
H1A | 0.3262 | −0.3652 | −0.0074 | 0.018* | |
C2 | 0.37166 (5) | −0.0660 (3) | 0.09913 (7) | 0.01470 (16) | |
C3 | 0.33828 (5) | 0.0848 (2) | 0.14737 (7) | 0.01413 (16) | |
C4 | 0.36033 (5) | 0.2977 (3) | 0.21988 (7) | 0.01494 (16) | |
C5 | 0.43085 (6) | 0.4134 (3) | 0.26242 (7) | 0.01794 (18) | |
H5A | 0.4656 | 0.3528 | 0.2437 | 0.022* | |
C6 | 0.44863 (6) | 0.6159 (3) | 0.33164 (8) | 0.0202 (2) | |
H6A | 0.4953 | 0.6901 | 0.3588 | 0.024* | |
C7 | 0.39770 (7) | 0.7114 (3) | 0.36171 (8) | 0.0213 (2) | |
H7A | 0.4105 | 0.8472 | 0.4085 | 0.026* | |
C8 | 0.32840 (7) | 0.6021 (3) | 0.32128 (8) | 0.0201 (2) | |
H8A | 0.2944 | 0.6646 | 0.3411 | 0.024* | |
C9 | 0.30869 (6) | 0.3964 (3) | 0.25012 (7) | 0.01647 (17) | |
C10 | 0.23655 (6) | 0.2863 (3) | 0.20788 (8) | 0.01857 (18) | |
H10A | 0.2028 | 0.3514 | 0.2277 | 0.022* | |
C11 | 0.21679 (6) | 0.0901 (3) | 0.13991 (8) | 0.01766 (18) | |
H11A | 0.1697 | 0.0206 | 0.1130 | 0.021* | |
C12 | 0.25490 (5) | −0.2107 (2) | 0.04127 (7) | 0.01502 (17) | |
C13 | 0.18567 (5) | −0.3499 (3) | −0.01099 (7) | 0.01573 (17) | |
C14 | 0.12267 (6) | −0.6880 (3) | −0.12763 (8) | 0.01850 (18) | |
H14A | 0.0869 | −0.5390 | −0.1607 | 0.022* | |
H14B | 0.1047 | −0.8042 | −0.0918 | 0.022* | |
C15 | 0.13787 (7) | −0.8902 (3) | −0.19044 (8) | 0.0207 (2) | |
H15A | 0.0969 | −1.0153 | −0.2220 | 0.031* | |
H15B | 0.1788 | −1.0139 | −0.1572 | 0.031* | |
H15C | 0.1477 | −0.7704 | −0.2322 | 0.031* | |
C16 | 0.44691 (6) | −0.0746 (3) | 0.11232 (7) | 0.01717 (18) | |
C17 | 0.52569 (7) | −0.2785 (4) | 0.05696 (9) | 0.0269 (3) | |
H17A | 0.5248 | −0.3920 | 0.0073 | 0.040* | |
H17B | 0.5534 | −0.3843 | 0.1111 | 0.040* | |
H17C | 0.5471 | −0.0859 | 0.0583 | 0.040* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0118 (3) | 0.0404 (6) | 0.0210 (4) | −0.0009 (3) | 0.0068 (3) | −0.0103 (4) |
O2 | 0.0145 (4) | 0.0634 (9) | 0.0361 (6) | −0.0096 (4) | 0.0099 (4) | −0.0281 (6) |
O3 | 0.0124 (3) | 0.0199 (4) | 0.0192 (3) | −0.0015 (3) | 0.0037 (2) | −0.0022 (3) |
O4 | 0.0123 (3) | 0.0260 (4) | 0.0239 (4) | −0.0014 (3) | 0.0072 (3) | −0.0017 (3) |
N1 | 0.0110 (3) | 0.0175 (4) | 0.0152 (3) | 0.0005 (3) | 0.0052 (3) | 0.0006 (3) |
C1 | 0.0116 (3) | 0.0187 (4) | 0.0144 (4) | −0.0003 (3) | 0.0043 (3) | 0.0001 (3) |
C2 | 0.0111 (3) | 0.0183 (4) | 0.0137 (4) | −0.0006 (3) | 0.0043 (3) | −0.0002 (3) |
C3 | 0.0116 (3) | 0.0161 (4) | 0.0142 (4) | 0.0006 (3) | 0.0049 (3) | 0.0014 (3) |
C4 | 0.0136 (4) | 0.0162 (4) | 0.0138 (4) | 0.0006 (3) | 0.0047 (3) | 0.0005 (3) |
C5 | 0.0157 (4) | 0.0196 (5) | 0.0164 (4) | −0.0008 (3) | 0.0048 (3) | −0.0006 (3) |
C6 | 0.0186 (4) | 0.0216 (5) | 0.0162 (4) | −0.0012 (4) | 0.0034 (3) | −0.0018 (3) |
C7 | 0.0240 (5) | 0.0215 (5) | 0.0161 (4) | 0.0015 (4) | 0.0062 (4) | −0.0016 (4) |
C8 | 0.0223 (5) | 0.0204 (5) | 0.0173 (4) | 0.0028 (4) | 0.0081 (4) | 0.0001 (3) |
C9 | 0.0168 (4) | 0.0169 (4) | 0.0158 (4) | 0.0016 (3) | 0.0070 (3) | 0.0015 (3) |
C10 | 0.0162 (4) | 0.0202 (5) | 0.0209 (4) | 0.0016 (3) | 0.0094 (4) | −0.0004 (4) |
C11 | 0.0136 (4) | 0.0202 (5) | 0.0204 (5) | 0.0011 (3) | 0.0084 (3) | 0.0001 (3) |
C12 | 0.0111 (3) | 0.0175 (4) | 0.0149 (4) | −0.0004 (3) | 0.0040 (3) | 0.0003 (3) |
C13 | 0.0124 (4) | 0.0169 (4) | 0.0157 (4) | 0.0001 (3) | 0.0038 (3) | 0.0018 (3) |
C14 | 0.0133 (4) | 0.0192 (5) | 0.0194 (4) | −0.0029 (3) | 0.0033 (3) | −0.0013 (3) |
C15 | 0.0199 (4) | 0.0212 (5) | 0.0189 (5) | −0.0027 (4) | 0.0062 (4) | −0.0011 (4) |
C16 | 0.0120 (3) | 0.0241 (5) | 0.0152 (4) | −0.0010 (3) | 0.0056 (3) | −0.0017 (3) |
C17 | 0.0137 (4) | 0.0451 (8) | 0.0230 (5) | 0.0001 (4) | 0.0089 (4) | −0.0068 (5) |
O1—C16 | 1.3401 (14) | C6—H6A | 0.9300 |
O1—C17 | 1.4419 (14) | C7—C8 | 1.3810 (18) |
O2—C16 | 1.2097 (14) | C7—H7A | 0.9300 |
O3—C13 | 1.3458 (14) | C8—C9 | 1.4114 (16) |
O3—C14 | 1.4574 (13) | C8—H8A | 0.9300 |
O4—C13 | 1.2199 (13) | C9—C10 | 1.4322 (16) |
N1—C11 | 1.3882 (14) | C10—C11 | 1.3462 (17) |
N1—C3 | 1.3900 (13) | C10—H10A | 0.9300 |
N1—C12 | 1.3935 (14) | C11—H11A | 0.9300 |
C1—C12 | 1.3803 (14) | C12—C13 | 1.4551 (15) |
C1—C2 | 1.4088 (15) | C14—C15 | 1.5058 (17) |
C1—H1A | 0.9300 | C14—H14A | 0.9700 |
C2—C3 | 1.4224 (15) | C14—H14B | 0.9700 |
C2—C16 | 1.4673 (14) | C15—H15A | 0.9600 |
C3—C4 | 1.4457 (15) | C15—H15B | 0.9600 |
C4—C5 | 1.4137 (15) | C15—H15C | 0.9600 |
C4—C9 | 1.4207 (15) | C17—H17A | 0.9600 |
C5—C6 | 1.3819 (16) | C17—H17B | 0.9600 |
C5—H5A | 0.9300 | C17—H17C | 0.9600 |
C6—C7 | 1.4014 (18) | ||
C16—O1—C17 | 115.50 (9) | C11—C10—H10A | 119.5 |
C13—O3—C14 | 114.63 (9) | C9—C10—H10A | 119.5 |
C11—N1—C3 | 123.35 (9) | C10—C11—N1 | 119.67 (10) |
C11—N1—C12 | 126.35 (9) | C10—C11—H11A | 120.2 |
C3—N1—C12 | 110.29 (8) | N1—C11—H11A | 120.2 |
C12—C1—C2 | 108.84 (10) | C1—C12—N1 | 107.21 (9) |
C12—C1—H1A | 125.6 | C1—C12—C13 | 129.03 (10) |
C2—C1—H1A | 125.6 | N1—C12—C13 | 123.76 (9) |
C1—C2—C3 | 107.56 (9) | O4—C13—O3 | 122.75 (10) |
C1—C2—C16 | 121.27 (10) | O4—C13—C12 | 126.30 (11) |
C3—C2—C16 | 130.99 (10) | O3—C13—C12 | 110.94 (9) |
N1—C3—C2 | 106.09 (9) | O3—C14—C15 | 107.05 (9) |
N1—C3—C4 | 117.78 (9) | O3—C14—H14A | 110.3 |
C2—C3—C4 | 136.13 (9) | C15—C14—H14A | 110.3 |
C5—C4—C9 | 118.12 (10) | O3—C14—H14B | 110.3 |
C5—C4—C3 | 123.35 (10) | C15—C14—H14B | 110.3 |
C9—C4—C3 | 118.53 (9) | H14A—C14—H14B | 108.6 |
C6—C5—C4 | 120.56 (11) | C14—C15—H15A | 109.5 |
C6—C5—H5A | 119.7 | C14—C15—H15B | 109.5 |
C4—C5—H5A | 119.7 | H15A—C15—H15B | 109.5 |
C5—C6—C7 | 121.20 (11) | C14—C15—H15C | 109.5 |
C5—C6—H6A | 119.4 | H15A—C15—H15C | 109.5 |
C7—C6—H6A | 119.4 | H15B—C15—H15C | 109.5 |
C8—C7—C6 | 119.44 (11) | O2—C16—O1 | 121.21 (10) |
C8—C7—H7A | 120.3 | O2—C16—C2 | 128.49 (11) |
C6—C7—H7A | 120.3 | O1—C16—C2 | 110.26 (9) |
C7—C8—C9 | 120.53 (11) | O1—C17—H17A | 109.5 |
C7—C8—H8A | 119.7 | O1—C17—H17B | 109.5 |
C9—C8—H8A | 119.7 | H17A—C17—H17B | 109.5 |
C8—C9—C4 | 120.15 (10) | O1—C17—H17C | 109.5 |
C8—C9—C10 | 120.25 (10) | H17A—C17—H17C | 109.5 |
C4—C9—C10 | 119.60 (10) | H17B—C17—H17C | 109.5 |
C11—C10—C9 | 121.06 (10) | ||
C12—C1—C2—C3 | −0.68 (12) | C8—C9—C10—C11 | 179.98 (11) |
C12—C1—C2—C16 | 174.97 (10) | C4—C9—C10—C11 | 0.09 (17) |
C11—N1—C3—C2 | 179.63 (10) | C9—C10—C11—N1 | 0.08 (17) |
C12—N1—C3—C2 | 0.30 (11) | C3—N1—C11—C10 | 0.38 (17) |
C11—N1—C3—C4 | −0.95 (15) | C12—N1—C11—C10 | 179.60 (11) |
C12—N1—C3—C4 | 179.72 (9) | C2—C1—C12—N1 | 0.86 (12) |
C1—C2—C3—N1 | 0.23 (12) | C2—C1—C12—C13 | −179.75 (10) |
C16—C2—C3—N1 | −174.85 (11) | C11—N1—C12—C1 | 179.97 (10) |
C1—C2—C3—C4 | −179.03 (12) | C3—N1—C12—C1 | −0.72 (12) |
C16—C2—C3—C4 | 5.9 (2) | C11—N1—C12—C13 | 0.54 (17) |
N1—C3—C4—C5 | −178.91 (10) | C3—N1—C12—C13 | 179.84 (9) |
C2—C3—C4—C5 | 0.29 (19) | C14—O3—C13—O4 | 0.30 (15) |
N1—C3—C4—C9 | 1.06 (14) | C14—O3—C13—C12 | −178.83 (9) |
C2—C3—C4—C9 | −179.74 (11) | C1—C12—C13—O4 | −176.52 (12) |
C9—C4—C5—C6 | 0.23 (16) | N1—C12—C13—O4 | 2.79 (18) |
C3—C4—C5—C6 | −179.79 (11) | C1—C12—C13—O3 | 2.57 (16) |
C4—C5—C6—C7 | 0.17 (18) | N1—C12—C13—O3 | −178.13 (10) |
C5—C6—C7—C8 | −0.23 (19) | C13—O3—C14—C15 | 179.39 (10) |
C6—C7—C8—C9 | −0.12 (18) | C17—O1—C16—O2 | 1.39 (19) |
C7—C8—C9—C4 | 0.53 (17) | C17—O1—C16—C2 | −176.48 (12) |
C7—C8—C9—C10 | −179.36 (11) | C1—C2—C16—O2 | −169.91 (15) |
C5—C4—C9—C8 | −0.57 (15) | C3—C2—C16—O2 | 4.6 (2) |
C3—C4—C9—C8 | 179.45 (10) | C1—C2—C16—O1 | 7.77 (15) |
C5—C4—C9—C10 | 179.32 (10) | C3—C2—C16—O1 | −177.72 (11) |
C3—C4—C9—C10 | −0.66 (15) |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5A···O2 | 0.93 | 2.14 | 2.9691 (19) | 148 |
C11—H11A···O4 | 0.93 | 2.27 | 2.8891 (16) | 123 |
C14—H14A···O2i | 0.97 | 2.60 | 3.2930 (17) | 129 |
C14—H14B···O4ii | 0.97 | 2.58 | 3.3817 (16) | 140 |
Symmetry codes: (i) x−1/2, −y−1/2, z−1/2; (ii) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | C17H15NO4 |
Mr | 297.30 |
Crystal system, space group | Monoclinic, Cc |
Temperature (K) | 100 |
a, b, c (Å) | 20.5388 (4), 4.4550 (1), 16.5764 (5) |
β (°) | 114.955 (2) |
V (Å3) | 1375.14 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.53 × 0.27 × 0.15 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.948, 0.985 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 23077, 3627, 3404 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.857 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.101, 1.03 |
No. of reflections | 3627 |
No. of parameters | 201 |
No. of restraints | 2 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.42, −0.28 |
Computer programs: APEX2 (Bruker, 2005), APEX2, SAINT (Bruker, 2005), SHELXTL (Sheldrick, 1998), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5A···O2 | 0.93 | 2.1389 | 2.9691 (19) | 148 |
C11—H11A···O4 | 0.93 | 2.2725 | 2.8891 (16) | 123 |
C14—H14A···O2i | 0.97 | 2.5957 | 3.2930 (17) | 129 |
C14—H14B···O4ii | 0.97 | 2.5803 | 3.3817 (16) | 140 |
Symmetry codes: (i) x−1/2, −y−1/2, z−1/2; (ii) x, y−1, z. |
Indolizines are found in several naturally occurring alkaloids with important biological activities and are important synthetic targets (Saeva & Luss, 1988). As an extension of our research on the direct one-pot syntheses of indolizine derivatives (Liu et al., 2007), we have recently researched a general and versatile synthesis of indolizines and obtained the title compound, as one of the products. An x-ray crystallographic analysis was undertaken to elucidate its three-dimensional molecular and crystal structures.
The bond lengths and angles in the structure of the title compound (I) are within normal ranges (Allen et al., 1987), and comparable with those in related structures (Usman et al., 2002; Shen et al., 2006; Wang, 2006a; 2006b; Liu et al., 2007). In the title structure (Fig. 1), the pyrrolo[2,1-a]isoquinoline ring system [N1/C1–C12] is planar with the mean deviation of 0.006 (1) Å. The methoxycarbonyl group (O1/O2/C16/C17) is almost coplanar with the pyrrolo[2,1-a]isoquinoline ring. The plane of the methoxycarbonyl group is twisted about the C2—C16 bond by an angle of 8.00 (7)°. The ethoxycarbonyl group (O3/O4/C13–C15) is co-planarly attached at atom C12 of the pyrrole ring, as indicated by the torsion angles N1–C12–C13–O3 = -178.13 (10)° and C13–O3–C14–C15 = 179.39 (10)°. The planarity of the molecule is influenced by weak intramolecular C5—H5A···O2 and C11—H11A···O4 interactions (Fig. 1) which generate S(7) and S(6) ring motifs, respectively (Bernstein et al., 1995). The dihedral angle between the planes of two carboxylate groups is 8.33 (6)°.
In the crystal packing of (I) in Fig. 2, the molecules are arranged into molecular sheets parallel to the ac plane and these molecular sheets are stacked along the b axis. π···π interactions are also presented in the crystal with the distances of Cg1···Cg2 = 3.6683 (7) Å, Cg1···Cg3 = 3.5680 (7)Å and Cg2···Cg3 = 3.6514 (7)Å [symmetry codes; x, -1 + y, z and x, 1 + y, z for all π···π interactions]; Cg1, Cg2 and Cg3 are the centroids of N1/C1–C3/C12, N1/C3–C4/C9–C11 and C4–C9 rings, respectively. The crystal is stabilized by weak intramolecular and intermolecular C—H···O interactions (Table 1) and further stabilized by π···π interactions.