The crystal structure of the title compound, C20H18N2O3, was determined in the course of our studies of the synthesis of 3-acylindole derivatives. We obtained it as an unexpected racemic side product. The crystal structure contains chains of dimers along the a axis.
Supporting information
CCDC reference: 640295
Key indicators
- Single-crystal X-ray study
- T = 193 K
- Mean (C-C) = 0.002 Å
- R factor = 0.050
- wR factor = 0.147
- Data-to-parameter ratio = 13.1
checkCIF/PLATON results
No syntax errors found
Alert level C
ABSTM02_ALERT_3_C The ratio of Tmax/Tmin expected RT(exp) is > 1.10
Absorption corrections should be applied.
Tmin and Tmax expected: 0.678 0.773
RT(exp) = 1.140
PLAT057_ALERT_3_C Correction for Absorption Required RT(exp) ... 1.14
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent ..... ?
PLAT222_ALERT_3_C Large Non-Solvent H Ueq(max)/Ueq(min) ... 3.32 Ratio
PLAT369_ALERT_2_C Long C(sp2)-C(sp2) Bond C19 - C21 ... 1.53 Ang.
PLAT751_ALERT_4_C Bond Calc 0.88000, Rep 0.88(2) ...... Senseless su
N12 -H12 1.555 1.555
PLAT752_ALERT_4_C Angle Calc 125.00, Rep 124.9(9) ...... Senseless su
C11 -N12 -H12 1.555 1.555 1.555
PLAT752_ALERT_4_C Angle Calc 125.00, Rep 124.7(10) ...... Senseless su
C13 -N12 -H12 1.555 1.555 1.555
PLAT755_ALERT_4_C D-H Calc 0.88000, Rep 0.88(2) ...... Senseless su
N12 -H12 1.555 1.555
PLAT755_ALERT_4_C D-H Calc 0.88000, Rep 0.88(2) ...... Senseless su
N12 -H12 1.555 1.555
PLAT756_ALERT_4_C H...A Calc 2.29000, Rep 2.286(12) ...... Senseless su
H12 -O20 1.555 2.657
PLAT756_ALERT_4_C H...A Calc 2.41000, Rep 2.41(3) ...... Senseless su
H12 -O20 1.555 1.455
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
12 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
3 ALERT type 3 Indicator that the structure quality may be low
7 ALERT type 4 Improvement, methodology, query or suggestion
0 ALERT type 5 Informative message, check
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CORINC (Dräger & Gattow, 1971); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.
Ethyl (2,3-dihydro-1H,1'H-2,3'-biindol-1-yl)glyoxylate
top
Crystal data top
C20H18N2O3 | Z = 2 |
Mr = 334.37 | F(000) = 352 |
Triclinic, P1 | Dx = 1.329 Mg m−3 |
Hall symbol: -P 1 | Melting point: 168.2 K |
a = 8.441 (3) Å | Cu Kα radiation, λ = 1.54178 Å |
b = 9.596 (3) Å | Cell parameters from 25 reflections |
c = 10.925 (4) Å | θ = 65–70° |
α = 96.11 (2)° | µ = 0.73 mm−1 |
β = 96.49 (3)° | T = 193 K |
γ = 106.13 (2)° | Block, colourless |
V = 835.8 (4) Å3 | 0.60 × 0.50 × 0.35 mm |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.026 |
Radiation source: rotating anode | θmax = 69.8°, θmin = 4.1° |
Graphite monochromator | h = −10→0 |
ω/2θ scans | k = −11→11 |
3396 measured reflections | l = −13→13 |
3163 independent reflections | 3 standard reflections every 60 min |
3075 reflections with I > 2σ(I) | intensity decay: 5% |
Refinement top
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)] = 0.050 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.147 | w = 1/[σ2(Fo2) + (0.093P)2 + 0.3021P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
3163 reflections | Δρmax = 0.28 e Å−3 |
242 parameters | Δρmin = −0.32 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: 0.036 (3) |
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 | x | y | z | Uiso*/Ueq | |
C1 | 0.7233 (2) | 0.46349 (18) | 1.05023 (16) | 0.0356 (4) | |
H1A | 0.7529 | 0.5656 | 1.0318 | 0.039 (4)* | |
H1B | 0.6241 | 0.4457 | 1.0934 | 0.039 (4)* | |
C2 | 0.68925 (18) | 0.35349 (16) | 0.92911 (14) | 0.0276 (3) | |
H2 | 0.7298 | 0.4083 | 0.8604 | 0.025 (4)* | |
N3 | 0.79869 (15) | 0.25693 (13) | 0.95875 (11) | 0.0267 (3) | |
C4 | 0.90499 (18) | 0.31466 (16) | 1.07411 (13) | 0.0267 (3) | |
C5 | 1.02942 (19) | 0.26304 (17) | 1.13120 (15) | 0.0319 (4) | |
H5 | 1.0560 | 0.1806 | 1.0926 | 0.036 (5)* | |
C6 | 1.1131 (2) | 0.33723 (19) | 1.24710 (16) | 0.0385 (4) | |
H6 | 1.1974 | 0.3038 | 1.2890 | 0.050 (6)* | |
C7 | 1.0763 (2) | 0.4588 (2) | 1.30280 (16) | 0.0407 (4) | |
H7 | 1.1353 | 0.5076 | 1.3820 | 0.058 (6)* | |
C8 | 0.9532 (2) | 0.50981 (18) | 1.24335 (16) | 0.0371 (4) | |
H8 | 0.9286 | 0.5937 | 1.2810 | 0.039 (5)* | |
C9 | 0.86708 (19) | 0.43651 (16) | 1.12847 (14) | 0.0297 (4) | |
C10 | 0.51018 (19) | 0.26691 (16) | 0.88940 (14) | 0.0276 (3) | |
C11 | 0.4103 (2) | 0.17663 (18) | 0.95615 (15) | 0.0340 (4) | |
H11 | 0.4432 | 0.1596 | 1.0379 | 0.036 (5)* | |
N12 | 0.25563 (18) | 0.11426 (16) | 0.88776 (14) | 0.0385 (4) | |
H12 | 0.168 (3) | 0.0630 (16) | 0.9166 (9) | 0.060 (7)* | |
C13 | 0.2511 (2) | 0.16454 (18) | 0.77499 (16) | 0.0344 (4) | |
C14 | 0.1237 (2) | 0.1301 (2) | 0.67309 (18) | 0.0438 (5) | |
H14 | 0.0182 | 0.0621 | 0.6747 | 0.041 (5)* | |
C15 | 0.1569 (2) | 0.1985 (2) | 0.57054 (17) | 0.0486 (5) | |
H15 | 0.0728 | 0.1772 | 0.5000 | 0.056 (6)* | |
C16 | 0.3118 (2) | 0.2985 (2) | 0.56809 (17) | 0.0462 (5) | |
H16 | 0.3302 | 0.3451 | 0.4963 | 0.061 (7)* | |
C17 | 0.4388 (2) | 0.33135 (19) | 0.66736 (15) | 0.0368 (4) | |
H17 | 0.5438 | 0.3992 | 0.6642 | 0.045 (5)* | |
C18 | 0.40991 (19) | 0.26274 (17) | 0.77294 (14) | 0.0294 (4) | |
C19 | 0.79481 (18) | 0.13371 (16) | 0.88648 (13) | 0.0263 (3) | |
O20 | 0.87899 (14) | 0.05151 (12) | 0.91221 (10) | 0.0331 (3) | |
C21 | 0.68430 (18) | 0.09435 (16) | 0.75941 (14) | 0.0274 (3) | |
O22 | 0.71349 (14) | 0.16421 (12) | 0.67524 (10) | 0.0343 (3) | |
O23 | 0.56690 (14) | −0.03203 (12) | 0.75343 (10) | 0.0345 (3) | |
C24 | 0.4610 (2) | −0.08704 (19) | 0.63301 (15) | 0.0375 (4) | |
H24A | 0.5286 | −0.1064 | 0.5685 | 0.045 (4)* | |
H24B | 0.4055 | −0.0140 | 0.6079 | 0.045 (4)* | |
C25 | 0.3338 (3) | −0.2257 (3) | 0.6473 (2) | 0.0636 (7) | |
H25A | 0.2603 | −0.2659 | 0.5679 | 0.083 (5)* | |
H25B | 0.2675 | −0.2051 | 0.7112 | 0.083 (5)* | |
H25C | 0.3902 | −0.2970 | 0.6722 | 0.083 (5)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0374 (9) | 0.0317 (8) | 0.0381 (9) | 0.0146 (7) | 0.0018 (7) | −0.0017 (6) |
C2 | 0.0294 (8) | 0.0274 (7) | 0.0291 (7) | 0.0129 (6) | 0.0036 (6) | 0.0059 (6) |
N3 | 0.0265 (6) | 0.0294 (6) | 0.0255 (6) | 0.0120 (5) | 0.0002 (5) | 0.0033 (5) |
C4 | 0.0264 (7) | 0.0272 (7) | 0.0250 (7) | 0.0055 (6) | 0.0022 (6) | 0.0050 (6) |
C5 | 0.0309 (8) | 0.0319 (8) | 0.0320 (8) | 0.0098 (6) | −0.0012 (6) | 0.0049 (6) |
C6 | 0.0357 (9) | 0.0412 (9) | 0.0344 (9) | 0.0081 (7) | −0.0057 (7) | 0.0079 (7) |
C7 | 0.0399 (9) | 0.0436 (9) | 0.0291 (8) | 0.0025 (7) | −0.0033 (7) | −0.0014 (7) |
C8 | 0.0406 (9) | 0.0325 (8) | 0.0336 (8) | 0.0063 (7) | 0.0048 (7) | −0.0031 (6) |
C9 | 0.0301 (8) | 0.0275 (7) | 0.0306 (8) | 0.0068 (6) | 0.0049 (6) | 0.0036 (6) |
C10 | 0.0287 (7) | 0.0298 (7) | 0.0277 (7) | 0.0138 (6) | 0.0046 (6) | 0.0045 (6) |
C11 | 0.0328 (8) | 0.0386 (9) | 0.0338 (8) | 0.0139 (7) | 0.0070 (6) | 0.0077 (6) |
N12 | 0.0308 (7) | 0.0407 (8) | 0.0429 (8) | 0.0071 (6) | 0.0104 (6) | 0.0054 (6) |
C13 | 0.0294 (8) | 0.0375 (8) | 0.0368 (9) | 0.0139 (7) | 0.0046 (6) | −0.0028 (7) |
C14 | 0.0302 (8) | 0.0497 (10) | 0.0469 (10) | 0.0151 (7) | −0.0023 (7) | −0.0133 (8) |
C15 | 0.0433 (10) | 0.0643 (12) | 0.0363 (9) | 0.0260 (9) | −0.0104 (7) | −0.0116 (8) |
C16 | 0.0519 (11) | 0.0613 (12) | 0.0303 (9) | 0.0282 (9) | −0.0016 (8) | 0.0044 (8) |
C17 | 0.0386 (9) | 0.0433 (9) | 0.0310 (8) | 0.0165 (7) | 0.0033 (7) | 0.0059 (7) |
C18 | 0.0284 (7) | 0.0329 (8) | 0.0293 (8) | 0.0149 (6) | 0.0030 (6) | 0.0008 (6) |
C19 | 0.0251 (7) | 0.0279 (7) | 0.0269 (7) | 0.0089 (6) | 0.0034 (6) | 0.0048 (6) |
O20 | 0.0348 (6) | 0.0325 (6) | 0.0345 (6) | 0.0172 (5) | −0.0008 (4) | 0.0014 (4) |
C21 | 0.0283 (7) | 0.0287 (7) | 0.0268 (7) | 0.0115 (6) | 0.0040 (6) | 0.0026 (6) |
O22 | 0.0368 (6) | 0.0379 (6) | 0.0283 (6) | 0.0098 (5) | 0.0053 (4) | 0.0081 (5) |
O23 | 0.0388 (6) | 0.0333 (6) | 0.0256 (6) | 0.0034 (5) | 0.0001 (5) | 0.0032 (4) |
C24 | 0.0403 (9) | 0.0404 (9) | 0.0243 (8) | 0.0035 (7) | 0.0002 (6) | −0.0010 (6) |
C25 | 0.0646 (14) | 0.0592 (13) | 0.0416 (11) | −0.0171 (11) | −0.0019 (9) | 0.0011 (9) |
Geometric parameters (Å, º) top
C1—C9 | 1.502 (2) | C19—C21 | 1.530 (2) |
C1—C2 | 1.548 (2) | C21—O22 | 1.2026 (19) |
C2—C10 | 1.497 (2) | C21—O23 | 1.3259 (19) |
C2—N3 | 1.5129 (18) | O23—C24 | 1.4606 (19) |
N3—C19 | 1.340 (2) | C24—C25 | 1.495 (3) |
N3—C4 | 1.4213 (19) | C1—H1A | 0.990 |
C4—C9 | 1.388 (2) | C1—H1B | 0.990 |
C4—C5 | 1.394 (2) | C2—H2 | 1.000 |
C5—C6 | 1.391 (2) | C5—H5 | 0.950 |
C6—C7 | 1.386 (3) | C6—H6 | 0.950 |
C7—C8 | 1.392 (3) | C7—H7 | 0.950 |
C8—C9 | 1.386 (2) | C8—H8 | 0.950 |
C10—C11 | 1.364 (2) | C11—H11 | 0.950 |
C10—C18 | 1.437 (2) | N12—H12 | 0.88 (2) |
C11—N12 | 1.368 (2) | C14—H14 | 0.950 |
N12—C13 | 1.370 (2) | C15—H15 | 0.950 |
C13—C14 | 1.400 (2) | C16—H16 | 0.950 |
C13—C18 | 1.413 (2) | C17—H17 | 0.950 |
C14—C15 | 1.375 (3) | C24—H24A | 0.990 |
C15—C16 | 1.396 (3) | C24—H24B | 0.990 |
C16—C17 | 1.379 (2) | C25—H25A | 0.980 |
C17—C18 | 1.400 (2) | C25—H25B | 0.980 |
C19—O20 | 1.2329 (18) | C25—H25C | 0.980 |
| | | |
C9—C1—C2 | 105.03 (12) | C11—N12—H12 | 124.9 (9) |
C10—C2—N3 | 112.22 (12) | C13—N12—H12 | 124.7 (10) |
C10—C2—C1 | 114.77 (13) | C2—C1—H1A | 111.0 |
N3—C2—C1 | 103.21 (12) | C2—C1—H1B | 111.0 |
C19—N3—C4 | 124.90 (12) | C9—C1—H1A | 111.0 |
C19—N3—C2 | 124.59 (12) | C9—C1—H1B | 111.0 |
C4—N3—C2 | 110.51 (12) | H1A—C1—H1B | 109.0 |
C9—C4—C5 | 121.97 (14) | N3—C2—H2 | 109.0 |
C9—C4—N3 | 109.57 (13) | C1—C2—H2 | 109.0 |
C5—C4—N3 | 128.47 (14) | C10—C2—H2 | 109.0 |
C6—C5—C4 | 117.24 (15) | C4—C5—H5 | 121.0 |
C7—C6—C5 | 121.46 (16) | C6—C5—H5 | 121.0 |
C6—C7—C8 | 120.36 (15) | C5—C6—H6 | 119.0 |
C9—C8—C7 | 119.09 (16) | C7—C6—H6 | 119.0 |
C8—C9—C4 | 119.87 (15) | C6—C7—H7 | 120.0 |
C8—C9—C1 | 129.22 (15) | C8—C7—H7 | 120.0 |
C4—C9—C1 | 110.82 (13) | C7—C8—H8 | 120.0 |
C11—C10—C18 | 106.55 (14) | C9—C8—H8 | 120.0 |
C11—C10—C2 | 126.94 (14) | N12—C11—H11 | 125.0 |
C18—C10—C2 | 126.51 (14) | C10—C11—H11 | 125.0 |
C10—C11—N12 | 109.86 (15) | C13—C14—H14 | 121.0 |
C11—N12—C13 | 109.49 (14) | C15—C14—H14 | 121.0 |
N12—C13—C14 | 130.80 (17) | C14—C15—H15 | 119.0 |
N12—C13—C18 | 107.19 (14) | C16—C15—H15 | 119.0 |
C14—C13—C18 | 121.98 (17) | C15—C16—H16 | 119.0 |
C15—C14—C13 | 117.49 (17) | C17—C16—H16 | 119.0 |
C14—C15—C16 | 121.28 (16) | C16—C17—H17 | 121.0 |
C17—C16—C15 | 121.58 (18) | C18—C17—H17 | 121.0 |
C16—C17—C18 | 118.72 (17) | O23—C24—H24A | 110.0 |
C17—C18—C13 | 118.92 (15) | O23—C24—H24B | 110.0 |
C17—C18—C10 | 134.19 (15) | C25—C24—H24A | 110.0 |
C13—C18—C10 | 106.89 (14) | C25—C24—H24B | 110.0 |
O20—C19—N3 | 124.97 (14) | H24A—C24—H24B | 109.0 |
O20—C19—C21 | 116.76 (13) | C24—C25—H25A | 109.0 |
N3—C19—C21 | 118.20 (12) | C24—C25—H25B | 109.0 |
O22—C21—O23 | 126.33 (14) | C24—C25—H25C | 109.0 |
O22—C21—C19 | 122.81 (14) | H25A—C25—H25B | 109.0 |
O23—C21—C19 | 110.52 (12) | H25A—C25—H25C | 109.0 |
C21—O23—C24 | 115.65 (12) | H25B—C25—H25C | 109.0 |
O23—C24—C25 | 107.25 (14) | | |
| | | |
C9—C1—C2—C10 | 131.43 (14) | C10—C11—N12—C13 | −0.79 (19) |
C9—C1—C2—N3 | 9.01 (15) | C11—N12—C13—C14 | 178.03 (17) |
C10—C2—N3—C19 | 47.13 (19) | C11—N12—C13—C18 | −0.05 (18) |
C1—C2—N3—C19 | 171.23 (14) | N12—C13—C14—C15 | −179.41 (16) |
C10—C2—N3—C4 | −132.47 (13) | C18—C13—C14—C15 | −1.6 (2) |
C1—C2—N3—C4 | −8.36 (15) | C13—C14—C15—C16 | 0.0 (3) |
C19—N3—C4—C9 | −175.34 (13) | C14—C15—C16—C17 | 1.0 (3) |
C2—N3—C4—C9 | 4.26 (16) | C15—C16—C17—C18 | −0.4 (3) |
C19—N3—C4—C5 | 4.0 (2) | C16—C17—C18—C13 | −1.2 (2) |
C2—N3—C4—C5 | −176.44 (14) | C16—C17—C18—C10 | 178.40 (16) |
C9—C4—C5—C6 | 1.2 (2) | N12—C13—C18—C17 | −179.52 (14) |
N3—C4—C5—C6 | −178.01 (15) | C14—C13—C18—C17 | 2.2 (2) |
C4—C5—C6—C7 | −1.0 (2) | N12—C13—C18—C10 | 0.81 (17) |
C5—C6—C7—C8 | 0.1 (3) | C14—C13—C18—C10 | −177.47 (14) |
C6—C7—C8—C9 | 0.6 (3) | C11—C10—C18—C17 | 179.13 (17) |
C7—C8—C9—C4 | −0.4 (2) | C2—C10—C18—C17 | −0.9 (3) |
C7—C8—C9—C1 | 175.70 (16) | C11—C10—C18—C13 | −1.27 (17) |
C5—C4—C9—C8 | −0.5 (2) | C2—C10—C18—C13 | 178.66 (13) |
N3—C4—C9—C8 | 178.82 (13) | C4—N3—C19—O20 | 2.4 (2) |
C5—C4—C9—C1 | −177.32 (14) | C2—N3—C19—O20 | −177.09 (13) |
N3—C4—C9—C1 | 2.04 (18) | C4—N3—C19—C21 | −174.51 (12) |
C2—C1—C9—C8 | 176.41 (16) | C2—N3—C19—C21 | 6.0 (2) |
C2—C1—C9—C4 | −7.20 (18) | O20—C19—C21—O22 | −108.88 (17) |
N3—C2—C10—C11 | 58.8 (2) | N3—C19—C21—O22 | 68.3 (2) |
C1—C2—C10—C11 | −58.6 (2) | O20—C19—C21—O23 | 64.81 (17) |
N3—C2—C10—C18 | −121.11 (15) | N3—C19—C21—O23 | −117.99 (15) |
C1—C2—C10—C18 | 121.48 (16) | O22—C21—O23—C24 | −2.1 (2) |
C18—C10—C11—N12 | 1.27 (18) | C19—C21—O23—C24 | −175.53 (12) |
C2—C10—C11—N12 | −178.66 (14) | C21—O23—C24—C25 | −177.69 (16) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N12—H12···O20i | 0.88 (2) | 2.29 (1) | 2.982 (2) | 136 (2) |
N12—H12···O20ii | 0.88 (2) | 2.41 (3) | 3.115 (2) | 138 (2) |
Symmetry codes: (i) −x+1, −y, −z+2; (ii) x−1, y, z. |