organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Ethyl 1,3-di­methyl-1H-indole-2-carboxyl­ate

aDepartment of Physics, Presidency College, Chennai 600 005, India, bDepartment of Physics, CPCL Polytechnic College, Chennai 600 068, India, and cDepartment of Organic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, India
*Correspondence e-mail: manivan_1999@yahoo.com

(Received 9 October 2008; accepted 19 October 2008; online 25 October 2008)

In the title compound, C13H15NO2, the plane of the indole ring forms a dihedral angle of 5.26 (6)° with the ester group and the ethyl side-chain C atoms. The crystal packing is stabilized by weak inter­molecular C—H⋯O and C—H⋯π inter­actions.

Related literature

For biological activities of indole derivatives, see: Okabe & Adachi (1998[Okabe, N. & Adachi, Y. (1998). Acta Cryst. C54, 386-387.]); Schollmeyer et al. (1995[Schollmeyer, D., Fischer, G. & Pindur, U. (1995). Acta Cryst. C51, 2572-2575.]). For related structures, see: Chakkaravarthi et al. (2007[Chakkaravarthi, G., Dhayalan, V., Mohanakrishnan, A. K. & Manivannan, V. (2007). Acta Cryst. E63, o3673.], 2008[Chakkaravarthi, G., Dhayalan, V., Mohanakrishnan, A. K. & Manivannan, V. (2008). Acta Cryst. E64, o542.]).

[Scheme 1]

Experimental

Crystal data
  • C13H15NO2

  • Mr = 217.26

  • Monoclinic, P 21 /c

  • a = 7.5511 (3) Å

  • b = 12.2476 (6) Å

  • c = 12.9449 (5) Å

  • β = 105.488 (2)°

  • V = 1153.71 (9) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 295 (2) K

  • 0.25 × 0.20 × 0.20 mm

Data collection
  • Bruker Kappa APEXII diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.979, Tmax = 0.983

  • 15440 measured reflections

  • 3620 independent reflections

  • 2068 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.056

  • wR(F2) = 0.184

  • S = 1.03

  • 3620 reflections

  • 148 parameters

  • H-atom parameters constrained

  • Δρmax = 0.21 e Å−3

  • Δρmin = −0.17 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C2—H2⋯O1i 0.93 2.53 3.401 (2) 156
C12—H12ACg1ii 0.97 2.76 3.646 (2) 152
Symmetry codes: (i) [-x+2, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) -x+2, -y, -z+1. Cg1 is the centroid of the C1–C6 ring.

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT; data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The indole derivatives are found to possess antibacterial (Okabe and Adachi, 1998) and antitumour activities (Schollmeyer et al., 1995). In continuation to our studies in indole derivatives, we determine the crystal structure of the title compound (I). The geometric parameters of the molecule of (I) (Fig. 1) agree well with the reported structures (Chakkaravarthi et al., 2007; Chakkaravarthi et al., 2008).

The five- (N1/C1/C6/C7/C8) and six- (C1—C6) membered rings in the indane group are almost planar, with a dihedral angle of 1.67 (6)° between these rings. The plane of indole ring forms a dihedral angle of 5.26 (6)° with the ester group. The molecular packing is stabilized by weak intramolecular C—H···O interaction and the crystal packing of (I) is stabilized by weak intermolecular C—H···O and C—H···π interactions (Table 1) (Fig. 2).

Related literature top

For biological activities of indole derivatives, see: Okabe & Adachi (1998); Schollmeyer et al. (1995). For related structures, see: Chakkaravarthi et al. (2007, 2008). Cg1 is the centroid of the C1–C6 ring.

Experimental top

To a stirred suspension of NaH (0.6 mmol, hexane washed) in THF (2 ml), a solution of 2-carbethoxy-3-methyl indole (0.5 mmol) in THF (2 ml) was added and stirred for 30 minutes at room temperature. To the reaction mixture, a solution of Iodomethane (0.6 mmol) was added and stirring was continued for further 6 hr. After the indole was consumed (monitored by TLC), the reaction mixture was quenched with cold dil HCl (25 ml), extracted with ethyl acetate (2 x 10 ml) and dried (Na2SO4). Removal of solvent followed by crystalization (hexane) afforded as yellow crystal.

Refinement top

H atoms were positioned geometrically and refined using riding model with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C) for aromatic H atoms, C—H = 0.97 Å and Uiso(H) = 1.2Ueq(C) for CH2 and C—H = 0.96 Å and Uiso(H) = 1.5Ueq(C) for methyl H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 (Bruker, 2004); data reduction: APEX2 (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with atom labeling scheme. Displacement ellipsoids are drawn at 50% probability level.
[Figure 2] Fig. 2. The crystal structure of (I), viewed down the a face. For the sake of clarity, H atoms not involved in interaction have been omitted.
Ethyl 1,3-dimethyl-1H-indole-2-carboxylate top
Crystal data top
C13H15NO2F(000) = 464
Mr = 217.26Dx = 1.251 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 4312 reflections
a = 7.5511 (3) Åθ = 2.3–24.1°
b = 12.2476 (6) ŵ = 0.08 mm1
c = 12.9449 (5) ÅT = 295 K
β = 105.488 (2)°Block, yellow
V = 1153.71 (9) Å30.25 × 0.20 × 0.20 mm
Z = 4
Data collection top
Bruker Kappa APEXII
diffractometer
3620 independent reflections
Radiation source: fine-focus sealed tube2068 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
ω and ϕ scansθmax = 31.0°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1010
Tmin = 0.979, Tmax = 0.983k = 1717
15440 measured reflectionsl = 1818
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)] = 0.056Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.184H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0844P)2 + 0.1542P]
where P = (Fo2 + 2Fc2)/3
3620 reflections(Δ/σ)max < 0.001
148 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C13H15NO2V = 1153.71 (9) Å3
Mr = 217.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.5511 (3) ŵ = 0.08 mm1
b = 12.2476 (6) ÅT = 295 K
c = 12.9449 (5) Å0.25 × 0.20 × 0.20 mm
β = 105.488 (2)°
Data collection top
Bruker Kappa APEXII
diffractometer
3620 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2068 reflections with I > 2σ(I)
Tmin = 0.979, Tmax = 0.983Rint = 0.026
15440 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0560 restraints
wR(F2) = 0.184H-atom parameters constrained
S = 1.03Δρmax = 0.21 e Å3
3620 reflectionsΔρmin = 0.17 e Å3
148 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.7616 (2)0.19859 (13)0.57067 (13)0.0527 (4)
C20.7747 (2)0.30504 (16)0.61130 (15)0.0653 (5)
H20.83240.31940.68290.078*
C30.7003 (3)0.38637 (16)0.54252 (18)0.0750 (5)
H30.70750.45770.56790.090*
C40.6132 (3)0.36648 (16)0.43493 (18)0.0738 (5)
H40.56460.42460.39010.089*
C50.5983 (2)0.26368 (16)0.39465 (14)0.0655 (4)
H50.53860.25100.32300.079*
C60.67448 (19)0.17669 (13)0.46276 (12)0.0525 (4)
C70.68784 (19)0.06336 (13)0.44615 (11)0.0501 (4)
C80.78272 (19)0.01966 (13)0.54312 (11)0.0512 (4)
C90.9305 (3)0.09425 (17)0.73226 (14)0.0757 (5)
H9A0.93840.16510.76500.114*
H9B0.86890.04490.76870.114*
H9C1.05190.06750.73710.114*
C100.6076 (2)0.00822 (15)0.34166 (13)0.0670 (5)
H10A0.54640.05750.35340.100*
H10B0.52090.05610.29550.100*
H10C0.70380.00950.30880.100*
C110.8333 (2)0.09395 (14)0.57069 (13)0.0559 (4)
C120.8335 (2)0.27250 (13)0.50367 (14)0.0644 (4)
H12A0.96520.28370.52860.077*
H12B0.77710.30070.55730.077*
C130.7583 (3)0.32875 (18)0.40024 (17)0.0805 (6)
H13A0.80790.29620.34650.121*
H13B0.79130.40460.40770.121*
H13C0.62690.32190.37930.121*
N10.82742 (18)0.10221 (11)0.61980 (10)0.0568 (4)
O10.9033 (2)0.12730 (12)0.65918 (10)0.0943 (5)
O20.79272 (16)0.15785 (9)0.48555 (9)0.0632 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0489 (7)0.0561 (9)0.0535 (9)0.0029 (6)0.0146 (6)0.0022 (7)
C20.0636 (9)0.0662 (11)0.0666 (11)0.0026 (8)0.0182 (8)0.0136 (9)
C30.0774 (12)0.0564 (11)0.0939 (15)0.0017 (9)0.0278 (11)0.0091 (10)
C40.0742 (11)0.0606 (11)0.0849 (14)0.0079 (9)0.0183 (10)0.0079 (10)
C50.0627 (9)0.0696 (11)0.0595 (10)0.0025 (8)0.0081 (7)0.0072 (9)
C60.0476 (7)0.0574 (9)0.0519 (8)0.0043 (6)0.0122 (6)0.0002 (7)
C70.0499 (7)0.0552 (9)0.0439 (8)0.0047 (6)0.0104 (6)0.0002 (6)
C80.0529 (8)0.0556 (9)0.0459 (8)0.0041 (6)0.0144 (6)0.0012 (7)
C90.0883 (13)0.0815 (13)0.0488 (9)0.0011 (10)0.0035 (9)0.0088 (9)
C100.0770 (11)0.0675 (11)0.0492 (9)0.0038 (9)0.0043 (8)0.0050 (8)
C110.0624 (9)0.0597 (10)0.0462 (8)0.0004 (7)0.0155 (7)0.0025 (7)
C120.0722 (10)0.0549 (10)0.0682 (11)0.0016 (8)0.0226 (8)0.0044 (8)
C130.0902 (13)0.0688 (12)0.0804 (13)0.0093 (10)0.0189 (11)0.0097 (10)
N10.0588 (7)0.0631 (9)0.0467 (7)0.0022 (6)0.0109 (6)0.0036 (6)
O10.1481 (14)0.0728 (9)0.0498 (7)0.0162 (9)0.0050 (8)0.0092 (6)
O20.0805 (8)0.0518 (7)0.0536 (7)0.0007 (5)0.0113 (6)0.0014 (5)
Geometric parameters (Å, º) top
C1—N11.370 (2)C9—N11.459 (2)
C1—C21.400 (2)C9—H9A0.9600
C1—C61.402 (2)C9—H9B0.9600
C2—C31.354 (3)C9—H9C0.9600
C2—H20.9300C10—H10A0.9600
C3—C41.394 (3)C10—H10B0.9600
C3—H30.9300C10—H10C0.9600
C4—C51.356 (3)C11—O11.198 (2)
C4—H40.9300C11—O21.319 (2)
C5—C61.404 (2)C12—O21.443 (2)
C5—H50.9300C12—C131.478 (3)
C6—C71.412 (2)C12—H12A0.9700
C7—C81.377 (2)C12—H12B0.9700
C7—C101.488 (2)C13—H13A0.9600
C8—N11.394 (2)C13—H13B0.9600
C8—C111.462 (2)C13—H13C0.9600
N1—C1—C2130.38 (16)H9A—C9—H9C109.5
N1—C1—C6108.26 (14)H9B—C9—H9C109.5
C2—C1—C6121.33 (16)C7—C10—H10A109.5
C3—C2—C1117.57 (17)C7—C10—H10B109.5
C3—C2—H2121.2H10A—C10—H10B109.5
C1—C2—H2121.2C7—C10—H10C109.5
C2—C3—C4122.06 (18)H10A—C10—H10C109.5
C2—C3—H3119.0H10B—C10—H10C109.5
C4—C3—H3119.0O1—C11—O2122.77 (16)
C5—C4—C3121.00 (18)O1—C11—C8125.30 (16)
C5—C4—H4119.5O2—C11—C8111.93 (14)
C3—C4—H4119.5O2—C12—C13107.02 (15)
C4—C5—C6119.02 (17)O2—C12—H12A110.3
C4—C5—H5120.5C13—C12—H12A110.3
C6—C5—H5120.5O2—C12—H12B110.3
C1—C6—C5119.01 (15)C13—C12—H12B110.3
C1—C6—C7107.83 (14)H12A—C12—H12B108.6
C5—C6—C7133.16 (15)C12—C13—H13A109.5
C8—C7—C6106.51 (13)C12—C13—H13B109.5
C8—C7—C10129.70 (16)H13A—C13—H13B109.5
C6—C7—C10123.78 (14)C12—C13—H13C109.5
C7—C8—N1109.60 (14)H13A—C13—H13C109.5
C7—C8—C11129.14 (14)H13B—C13—H13C109.5
N1—C8—C11121.25 (14)C1—N1—C8107.79 (13)
N1—C9—H9A109.5C1—N1—C9123.47 (14)
N1—C9—H9B109.5C8—N1—C9128.70 (15)
H9A—C9—H9B109.5C11—O2—C12116.72 (13)
N1—C9—H9C109.5
N1—C1—C2—C3177.99 (16)C6—C7—C8—C11179.58 (14)
C6—C1—C2—C30.1 (2)C10—C7—C8—C110.7 (3)
C1—C2—C3—C40.0 (3)C7—C8—C11—O1173.58 (17)
C2—C3—C4—C50.5 (3)N1—C8—C11—O15.4 (3)
C3—C4—C5—C60.9 (3)C7—C8—C11—O26.4 (2)
N1—C1—C6—C5178.77 (13)N1—C8—C11—O2174.65 (12)
C2—C1—C6—C50.3 (2)C2—C1—N1—C8178.04 (15)
N1—C1—C6—C70.08 (16)C6—C1—N1—C80.24 (16)
C2—C1—C6—C7178.54 (14)C2—C1—N1—C90.1 (3)
C4—C5—C6—C10.8 (2)C6—C1—N1—C9178.40 (14)
C4—C5—C6—C7177.72 (16)C7—C8—N1—C10.48 (16)
C1—C6—C7—C80.37 (16)C11—C8—N1—C1179.62 (13)
C5—C6—C7—C8178.25 (16)C7—C8—N1—C9178.52 (15)
C1—C6—C7—C10178.61 (14)C11—C8—N1—C92.3 (2)
C5—C6—C7—C102.8 (3)O1—C11—O2—C121.2 (2)
C6—C7—C8—N10.52 (15)C8—C11—O2—C12178.80 (13)
C10—C7—C8—N1178.38 (15)C13—C12—O2—C11173.84 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C10—H10A···O20.962.492.858 (2)103
C2—H2···O1i0.932.533.401 (2)156
C12—H12A···Cg1ii0.972.763.646 (2)152
Symmetry codes: (i) x+2, y1/2, z+3/2; (ii) x+2, y, z+1.

Experimental details

Crystal data
Chemical formulaC13H15NO2
Mr217.26
Crystal system, space groupMonoclinic, P21/c
Temperature (K)295
a, b, c (Å)7.5511 (3), 12.2476 (6), 12.9449 (5)
β (°) 105.488 (2)
V3)1153.71 (9)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.25 × 0.20 × 0.20
Data collection
DiffractometerBruker Kappa APEXII
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.979, 0.983
No. of measured, independent and
observed [I > 2σ(I)] reflections
15440, 3620, 2068
Rint0.026
(sin θ/λ)max1)0.724
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.056, 0.184, 1.03
No. of reflections3620
No. of parameters148
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.21, 0.17

Computer programs: APEX2 (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C10—H10A···O20.962.492.858 (2)103
C2—H2···O1i0.932.533.401 (2)156
C12—H12A···Cg1ii0.972.763.646 (2)152
Symmetry codes: (i) x+2, y1/2, z+3/2; (ii) x+2, y, z+1.
 

Acknowledgements

The authors acknowledge the Sophisticated Analytical Instrument Facility, Indian Institute of Technology, Madras, for the data collection.

References

First citationBruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChakkaravarthi, G., Dhayalan, V., Mohanakrishnan, A. K. & Manivannan, V. (2007). Acta Cryst. E63, o3673.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationChakkaravarthi, G., Dhayalan, V., Mohanakrishnan, A. K. & Manivannan, V. (2008). Acta Cryst. E64, o542.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationOkabe, N. & Adachi, Y. (1998). Acta Cryst. C54, 386–387.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSchollmeyer, D., Fischer, G. & Pindur, U. (1995). Acta Cryst. C51, 2572–2575.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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