Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807032436/fl2139sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807032436/fl2139Isup2.hkl |
CCDC reference: 657695
To a refluxing solution of 2,3-dibromomethyl-1-(phenylsulfonyl)indole (415 mg, 0.937 mmol) (Mohanakrishnan & Srinivasan, 1995) and K2CO3 (397 mg, 2.80 mmol) in tetrahydrofuran (20 ml) was added a solution of 4-methoxybenzylamine (150 µL, 1.15 mmol) in tetrahydrofuran (20 ml) slowly via addition funnel. After 10 h, the opaque solution was filtered through a Celite pad with ethyl acetate rinses. The resulting yellow solution was concentrated in vacuo to yield a pale yellow solid which was purified by column chromatography (2:1 hexanes: ethyl acetate) to yield (I) as a white solid (290 mg, 74% yield): m.p. 391–391.5 K. As (I) was unstable toward oxidation, an elemental analysis was not attempted. Recrystallization from hexane–dichloromethane (3:1) yielded crystals that were suitable for X-ray crystallography.
The H atoms were included in the riding model approximation with C—H = 0.93–0.97 Å, and with Uiso(H) = 1.19–1.20Ueq(C).
The title compound, (I), was synthesized as a precursor to the corresponding pyrrolo[3,4-b]indole as a stable synthetic analogue of indole-2,3-quinodimethane and having a readily removable 4-methoxybenzyl protecting group. The X-ray crystallographic analysis confirms the molecular structure and atom connectivity for (I) that we had proposed for this compound based on NMR spectroscopy and chemical reactions (Kishbaugh & Gribble, 2002).
The pyrrolidine nitrogen N2 has bond angles totaling 337.8 (4)°, indicating slight flattening from a purely pyramidal nitrogen, which is 324° for ammonia with H—N—H bond angles of 108°, and is consistent with the inductive electron-withdrawing properties of a benzyl group.
For the synthesis of the title compound and related chemistry, see: Gribble (2003); Gribble et al. (2005); Roy, Kishbaugh et al. (2007); Roy, Pelkey et al. (2007); Kishbaugh & Gribble (2002); Mohanakrishnan & Srinivasan (1995). For a related structure, see: Kishbaugh et al. (2007).
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1994); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: CrystalStructure (Rigaku/MSC, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure.
Fig. 1. Molecular structure of (I) showing atom labelling and 50% probability displacement ellipsoids. |
C25H24N2O2S | F(000) = 880 |
Mr = 416.52 | Dx = 1.341 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71069 Å |
a = 11.929 (7) Å | Cell parameters from 20 reflections |
b = 9.397 (7) Å | θ = 6.2–7.8° |
c = 19.198 (4) Å | µ = 0.18 mm−1 |
β = 106.47 (3)° | T = 296 K |
V = 2063.6 (19) Å3 | Prism, colourless |
Z = 4 | 0.50 × 0.40 × 0.20 mm |
Rigaku AFC-6S diffractometer | 1590 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 27.5°, θmin = 1.8° |
ω/2θ scans | h = 0→15 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→12 |
Tmin = 0.915, Tmax = 0.965 | l = −24→23 |
4739 measured reflections | 3 standard reflections every 150 reflections |
4739 independent reflections | intensity decay: none |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.061 | H-atom parameters constrained |
wR(F2) = 0.284 | w = 1/[σ2(Fo2) + (0.1351P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max < 0.001 |
4739 reflections | Δρmax = 0.48 e Å−3 |
273 parameters | Δρmin = −0.38 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0052 (19) |
C25H24N2O2S | V = 2063.6 (19) Å3 |
Mr = 416.52 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.929 (7) Å | µ = 0.18 mm−1 |
b = 9.397 (7) Å | T = 296 K |
c = 19.198 (4) Å | 0.50 × 0.40 × 0.20 mm |
β = 106.47 (3)° |
Rigaku AFC-6S diffractometer | 1590 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.000 |
Tmin = 0.915, Tmax = 0.965 | 3 standard reflections every 150 reflections |
4739 measured reflections | intensity decay: none |
4739 independent reflections |
R[F2 > 2σ(F2)] = 0.061 | 0 restraints |
wR(F2) = 0.284 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.48 e Å−3 |
4739 reflections | Δρmin = −0.38 e Å−3 |
273 parameters |
Experimental. 1H (CD2Cl2) δ 8.04 (d, 1H, 8 Hz), 7.88 (m, 2H), 7.24-7.56 (m, 8H), 6.95 (m, 2H), 4.32 (m, 2H), 4.00 (s, 2H), 3.96 (m, 2H), 3.86 (s, 3H); 13C (CD2Cl2) δ 159.2, 140.3, 139.8, 138.4, 134.3, 131.4, 130.2, 129.7, 129.3, 129.0, 128.8, 126.9, 126.7, 126.3, 124.0, 123.7, 119.6, 114.5, 114.4, 114.1, 60.1, 55.5, 54.9, 53.1; IR (film) λmax 3056, 2933, 2832, 1611, 1511, 1447, 1369, 1247, 1177, 996, 750, 723, 685 cm-1; UV (EtOH) λmax 224, 260 nm. |
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 | ||
S1 | 0.29345 (13) | 0.16620 (16) | 0.82158 (8) | 0.0408 (4) | |
O1 | 0.3017 (3) | 0.0241 (4) | 0.7988 (2) | 0.0510 (11) | |
O2 | 0.3618 (3) | 0.2133 (5) | 0.8910 (2) | 0.0532 (12) | |
N1 | 0.3285 (4) | 0.2660 (5) | 0.7598 (2) | 0.0390 (11) | |
N2 | 0.3015 (4) | 0.1362 (5) | 0.5746 (2) | 0.0440 (13) | |
C1 | 0.3125 (6) | 0.0860 (6) | 0.6496 (3) | 0.0481 (15) | |
H1 | 0.2440 | 0.0332 | 0.6521 | 0.058* | |
H2 | 0.3816 | 0.0274 | 0.6681 | 0.058* | |
C2 | 0.3454 (6) | 0.2842 (7) | 0.5768 (3) | 0.0505 (16) | |
H3 | 0.2956 | 0.3415 | 0.5383 | 0.061* | |
H4 | 0.4247 | 0.2866 | 0.5729 | 0.061* | |
C3 | 0.3404 (5) | 0.3338 (6) | 0.6499 (3) | 0.0403 (14) | |
C4 | 0.3571 (5) | 0.4598 (6) | 0.6937 (3) | 0.0410 (14) | |
C5 | 0.3785 (5) | 0.6024 (7) | 0.6835 (4) | 0.0495 (16) | |
H5 | 0.3885 | 0.6333 | 0.6396 | 0.059* | |
C6 | 0.3850 (5) | 0.6982 (7) | 0.7393 (4) | 0.0539 (17) | |
H6 | 0.3998 | 0.7938 | 0.7331 | 0.065* | |
C7 | 0.3693 (5) | 0.6521 (7) | 0.8044 (3) | 0.0482 (15) | |
H7 | 0.3722 | 0.7188 | 0.8407 | 0.058* | |
C8 | 0.3498 (5) | 0.5120 (7) | 0.8177 (3) | 0.0481 (16) | |
H8 | 0.3398 | 0.4831 | 0.8619 | 0.058* | |
C9 | 0.3456 (4) | 0.4154 (6) | 0.7622 (3) | 0.0369 (13) | |
C10 | 0.3227 (4) | 0.2224 (6) | 0.6887 (3) | 0.0342 (12) | |
C11 | 0.1462 (5) | 0.2100 (6) | 0.8114 (3) | 0.0393 (13) | |
C12 | 0.0626 (6) | 0.1670 (8) | 0.7498 (4) | 0.0645 (19) | |
H9 | 0.0837 | 0.1128 | 0.7150 | 0.077* | |
C13 | −0.0525 (6) | 0.2044 (9) | 0.7397 (4) | 0.078 (2) | |
H10 | −0.1095 | 0.1763 | 0.6979 | 0.093* | |
C14 | −0.0823 (6) | 0.2839 (9) | 0.7920 (4) | 0.074 (2) | |
H11 | −0.1601 | 0.3087 | 0.7856 | 0.088* | |
C15 | 0.0002 (6) | 0.3265 (8) | 0.8529 (4) | 0.074 (2) | |
H12 | −0.0209 | 0.3801 | 0.8879 | 0.089* | |
C16 | 0.1157 (6) | 0.2897 (7) | 0.8625 (4) | 0.0613 (18) | |
H13 | 0.1727 | 0.3194 | 0.9039 | 0.074* | |
C17 | 0.3508 (6) | 0.0386 (7) | 0.5328 (3) | 0.0546 (17) | |
H14 | 0.4272 | 0.0083 | 0.5624 | 0.066* | |
H15 | 0.3614 | 0.0883 | 0.4909 | 0.066* | |
C18 | 0.2758 (5) | −0.0919 (7) | 0.5071 (3) | 0.0451 (15) | |
C19 | 0.3262 (6) | −0.2176 (7) | 0.4941 (3) | 0.0519 (16) | |
H16 | 0.4069 | −0.2241 | 0.5039 | 0.062* | |
C20 | 0.2568 (7) | −0.3341 (7) | 0.4664 (4) | 0.0613 (18) | |
H17 | 0.2922 | −0.4179 | 0.4577 | 0.074* | |
C21 | 0.1367 (6) | −0.3297 (7) | 0.4512 (3) | 0.0574 (17) | |
C22 | 0.0872 (6) | −0.2050 (7) | 0.4657 (4) | 0.0569 (18) | |
H18 | 0.0066 | −0.1990 | 0.4572 | 0.068* | |
C23 | 0.1563 (6) | −0.0897 (7) | 0.4924 (4) | 0.0565 (17) | |
H19 | 0.1206 | −0.0062 | 0.5010 | 0.068* | |
C24 | 0.0782 (5) | −0.4476 (5) | 0.4251 (3) | 0.0391 (14) | |
H20 | 0.1015 | −0.5207 | 0.4621 | 0.047* | |
H21 | 0.1039 | −0.4784 | 0.3839 | 0.047* | |
C25 | −0.0396 (10) | −0.4433 (9) | 0.4036 (5) | 0.109 (3) | |
H22 | −0.0689 | −0.4663 | 0.4439 | 0.131* | |
H23 | −0.0687 | −0.5110 | 0.3653 | 0.131* | |
H24 | −0.0650 | −0.3495 | 0.3863 | 0.131* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0453 (9) | 0.0433 (9) | 0.0367 (8) | 0.0029 (7) | 0.0163 (6) | 0.0038 (7) |
O1 | 0.062 (3) | 0.039 (3) | 0.057 (3) | 0.007 (2) | 0.025 (2) | 0.007 (2) |
O2 | 0.051 (3) | 0.070 (3) | 0.036 (2) | 0.008 (2) | 0.0096 (19) | 0.002 (2) |
N1 | 0.045 (3) | 0.035 (3) | 0.040 (3) | −0.001 (2) | 0.018 (2) | −0.001 (2) |
N2 | 0.056 (3) | 0.045 (3) | 0.035 (3) | −0.006 (2) | 0.020 (2) | −0.004 (2) |
C1 | 0.058 (4) | 0.047 (4) | 0.044 (4) | −0.007 (3) | 0.022 (3) | −0.005 (3) |
C2 | 0.065 (4) | 0.047 (4) | 0.044 (3) | 0.003 (3) | 0.022 (3) | 0.005 (3) |
C3 | 0.045 (3) | 0.043 (3) | 0.036 (3) | −0.003 (3) | 0.017 (3) | −0.004 (3) |
C4 | 0.033 (3) | 0.043 (4) | 0.050 (4) | −0.002 (3) | 0.015 (3) | −0.002 (3) |
C5 | 0.042 (3) | 0.047 (4) | 0.060 (4) | 0.000 (3) | 0.016 (3) | 0.010 (3) |
C6 | 0.046 (4) | 0.039 (4) | 0.074 (5) | −0.006 (3) | 0.011 (3) | −0.005 (3) |
C7 | 0.047 (4) | 0.043 (4) | 0.053 (4) | 0.002 (3) | 0.011 (3) | −0.012 (3) |
C8 | 0.051 (4) | 0.056 (4) | 0.038 (3) | 0.000 (3) | 0.012 (3) | −0.005 (3) |
C9 | 0.029 (3) | 0.046 (4) | 0.033 (3) | 0.002 (3) | 0.006 (2) | 0.001 (3) |
C10 | 0.036 (3) | 0.039 (3) | 0.030 (3) | −0.002 (2) | 0.012 (2) | 0.000 (3) |
C11 | 0.041 (3) | 0.041 (3) | 0.039 (3) | −0.001 (3) | 0.016 (3) | 0.001 (3) |
C12 | 0.050 (4) | 0.088 (5) | 0.056 (4) | −0.006 (4) | 0.016 (3) | −0.017 (4) |
C13 | 0.048 (5) | 0.108 (7) | 0.071 (5) | −0.010 (4) | 0.006 (4) | −0.009 (5) |
C14 | 0.040 (4) | 0.091 (6) | 0.090 (6) | 0.000 (4) | 0.018 (4) | −0.005 (5) |
C15 | 0.055 (4) | 0.087 (6) | 0.090 (5) | 0.006 (4) | 0.036 (4) | −0.028 (5) |
C16 | 0.055 (4) | 0.073 (5) | 0.057 (4) | 0.003 (4) | 0.017 (3) | −0.008 (4) |
C17 | 0.068 (4) | 0.062 (4) | 0.038 (3) | −0.004 (4) | 0.022 (3) | −0.003 (3) |
C18 | 0.052 (4) | 0.052 (4) | 0.035 (3) | 0.001 (3) | 0.018 (3) | −0.002 (3) |
C19 | 0.054 (4) | 0.055 (4) | 0.051 (4) | 0.000 (3) | 0.021 (3) | −0.010 (3) |
C20 | 0.081 (5) | 0.048 (4) | 0.058 (4) | 0.010 (4) | 0.025 (4) | −0.010 (4) |
C21 | 0.069 (5) | 0.052 (4) | 0.051 (4) | 0.009 (4) | 0.017 (3) | −0.003 (3) |
C22 | 0.049 (4) | 0.063 (5) | 0.060 (4) | −0.007 (3) | 0.017 (3) | −0.012 (4) |
C23 | 0.064 (5) | 0.046 (4) | 0.062 (4) | −0.001 (3) | 0.022 (3) | −0.011 (3) |
C24 | 0.042 (3) | 0.019 (3) | 0.052 (4) | −0.006 (3) | 0.006 (3) | −0.012 (3) |
C25 | 0.168 (11) | 0.062 (6) | 0.087 (7) | −0.036 (6) | 0.018 (6) | −0.014 (5) |
S1—O1 | 1.416 (4) | C12—C13 | 1.376 (9) |
S1—O2 | 1.421 (4) | C12—H9 | 0.9300 |
S1—N1 | 1.656 (5) | C13—C14 | 1.377 (10) |
S1—C11 | 1.760 (6) | C13—H10 | 0.9300 |
N1—C10 | 1.407 (7) | C14—C15 | 1.357 (10) |
N1—C9 | 1.417 (7) | C14—H11 | 0.9300 |
N2—C17 | 1.448 (7) | C15—C16 | 1.380 (9) |
N2—C2 | 1.482 (7) | C15—H12 | 0.9300 |
N2—C1 | 1.485 (7) | C16—H13 | 0.9300 |
C1—C10 | 1.474 (8) | C17—C18 | 1.516 (8) |
C1—H1 | 0.9700 | C17—H14 | 0.9700 |
C1—H2 | 0.9700 | C17—H15 | 0.9700 |
C2—C3 | 1.495 (8) | C18—C23 | 1.373 (8) |
C2—H3 | 0.9700 | C18—C19 | 1.380 (8) |
C2—H4 | 0.9700 | C19—C20 | 1.384 (9) |
C3—C10 | 1.336 (7) | C19—H16 | 0.9300 |
C3—C4 | 1.433 (8) | C20—C21 | 1.379 (9) |
C4—C5 | 1.389 (8) | C20—H17 | 0.9300 |
C4—C9 | 1.423 (7) | C21—C24 | 1.330 (8) |
C5—C6 | 1.385 (9) | C21—C22 | 1.375 (9) |
C5—H5 | 0.9300 | C22—C23 | 1.370 (8) |
C6—C7 | 1.384 (9) | C22—H18 | 0.9300 |
C6—H6 | 0.9300 | C23—H19 | 0.9300 |
C7—C8 | 1.373 (9) | C24—C25 | 1.348 (11) |
C7—H7 | 0.9300 | C24—H20 | 0.9700 |
C8—C9 | 1.390 (8) | C24—H21 | 0.9700 |
C8—H8 | 0.9300 | C25—H22 | 0.9600 |
C11—C16 | 1.365 (8) | C25—H23 | 0.9600 |
C11—C12 | 1.374 (8) | C25—H24 | 0.9600 |
O1—S1—O2 | 120.7 (3) | C11—C12—C13 | 119.9 (6) |
O1—S1—N1 | 105.0 (2) | C11—C12—H9 | 120.1 |
O2—S1—N1 | 107.5 (3) | C13—C12—H9 | 120.1 |
O1—S1—C11 | 109.9 (3) | C12—C13—C14 | 119.3 (7) |
O2—S1—C11 | 108.7 (3) | C12—C13—H10 | 120.4 |
N1—S1—C11 | 103.5 (2) | C14—C13—H10 | 120.4 |
C10—N1—C9 | 106.7 (4) | C15—C14—C13 | 120.9 (7) |
C10—N1—S1 | 125.2 (4) | C15—C14—H11 | 119.5 |
C9—N1—S1 | 126.9 (4) | C13—C14—H11 | 119.5 |
C17—N2—C2 | 114.5 (5) | C14—C15—C16 | 119.7 (7) |
C17—N2—C1 | 113.4 (5) | C14—C15—H12 | 120.2 |
C2—N2—C1 | 109.7 (4) | C16—C15—H12 | 120.2 |
C10—C1—N2 | 100.9 (4) | C11—C16—C15 | 120.0 (6) |
C10—C1—H1 | 111.6 | C11—C16—H13 | 120.0 |
N2—C1—H1 | 111.6 | C15—C16—H13 | 120.0 |
C10—C1—H2 | 111.6 | N2—C17—C18 | 113.5 (5) |
N2—C1—H2 | 111.6 | N2—C17—H14 | 108.9 |
H1—C1—H2 | 109.4 | C18—C17—H14 | 108.9 |
N2—C2—C3 | 102.2 (5) | N2—C17—H15 | 108.9 |
N2—C2—H3 | 111.3 | C18—C17—H15 | 108.9 |
C3—C2—H3 | 111.3 | H14—C17—H15 | 107.7 |
N2—C2—H4 | 111.3 | C23—C18—C19 | 117.1 (6) |
C3—C2—H4 | 111.3 | C23—C18—C17 | 122.5 (6) |
H3—C2—H4 | 109.2 | C19—C18—C17 | 120.3 (5) |
C10—C3—C4 | 109.7 (5) | C18—C19—C20 | 120.2 (6) |
C10—C3—C2 | 109.5 (5) | C18—C19—H16 | 119.9 |
C4—C3—C2 | 140.6 (5) | C20—C19—H16 | 119.9 |
C5—C4—C9 | 118.9 (5) | C21—C20—C19 | 121.9 (6) |
C5—C4—C3 | 135.6 (6) | C21—C20—H17 | 119.0 |
C9—C4—C3 | 105.5 (5) | C19—C20—H17 | 119.0 |
C6—C5—C4 | 119.3 (6) | C24—C21—C22 | 125.2 (6) |
C6—C5—H5 | 120.3 | C24—C21—C20 | 117.2 (6) |
C4—C5—H5 | 120.3 | C22—C21—C20 | 117.6 (6) |
C7—C6—C5 | 120.2 (6) | C23—C22—C21 | 120.1 (6) |
C7—C6—H6 | 119.9 | C23—C22—H18 | 119.9 |
C5—C6—H6 | 119.9 | C21—C22—H18 | 119.9 |
C8—C7—C6 | 122.7 (6) | C22—C23—C18 | 123.0 (6) |
C8—C7—H7 | 118.6 | C22—C23—H19 | 118.5 |
C6—C7—H7 | 118.6 | C18—C23—H19 | 118.5 |
C7—C8—C9 | 117.0 (6) | C21—C24—C25 | 118.7 (6) |
C7—C8—H8 | 121.5 | C21—C24—H20 | 107.6 |
C9—C8—H8 | 121.5 | C25—C24—H20 | 107.6 |
C8—C9—N1 | 130.2 (5) | C21—C24—H21 | 107.6 |
C8—C9—C4 | 121.7 (6) | C25—C24—H21 | 107.6 |
N1—C9—C4 | 108.1 (5) | H20—C24—H21 | 107.1 |
C3—C10—N1 | 110.0 (5) | C24—C25—H22 | 109.5 |
C3—C10—C1 | 113.6 (5) | C24—C25—H23 | 109.5 |
N1—C10—C1 | 136.2 (5) | H22—C25—H23 | 109.5 |
C16—C11—C12 | 120.3 (6) | C24—C25—H24 | 109.5 |
C16—C11—S1 | 120.6 (5) | H22—C25—H24 | 109.5 |
C12—C11—S1 | 119.0 (5) | H23—C25—H24 | 109.5 |
Experimental details
Crystal data | |
Chemical formula | C25H24N2O2S |
Mr | 416.52 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 296 |
a, b, c (Å) | 11.929 (7), 9.397 (7), 19.198 (4) |
β (°) | 106.47 (3) |
V (Å3) | 2063.6 (19) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.18 |
Crystal size (mm) | 0.50 × 0.40 × 0.20 |
Data collection | |
Diffractometer | Rigaku AFC-6S |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.915, 0.965 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4739, 4739, 1590 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.651 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.284, 1.03 |
No. of reflections | 4739 |
No. of parameters | 273 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.48, −0.38 |
Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1994), MSC/AFC Diffractometer Control Software, CrystalStructure (Rigaku/MSC, 2005), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), CrystalStructure.
The title compound, (I), was synthesized as a precursor to the corresponding pyrrolo[3,4-b]indole as a stable synthetic analogue of indole-2,3-quinodimethane and having a readily removable 4-methoxybenzyl protecting group. The X-ray crystallographic analysis confirms the molecular structure and atom connectivity for (I) that we had proposed for this compound based on NMR spectroscopy and chemical reactions (Kishbaugh & Gribble, 2002).
The pyrrolidine nitrogen N2 has bond angles totaling 337.8 (4)°, indicating slight flattening from a purely pyramidal nitrogen, which is 324° for ammonia with H—N—H bond angles of 108°, and is consistent with the inductive electron-withdrawing properties of a benzyl group.