Propyl 2-(1H-indol-3-yl)acetate

Tang, G.-M.; Xu, W.

doi:10.1107/S1600536813027633

organic compounds

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ISSN: 2056-9890

Volume 69| Part 11| November 2013| Page o1686

doi:10.1107/S1600536813027633

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Propyl 2-(1H-indol-3-yl)acetate

Guo-Min Tang ^a ^* and Wei Xu ^a

^aDepartment of Chemical Engineering, Taizhou Institute of Science and Technology, NJUST, Meilan Dong Road No. 8 Taizhou, Taizhou 225300, People's Republic of China
^*Correspondence e-mail: tgm333@126.com

(Received 2 October 2013; accepted 9 October 2013; online 23 October 2013)

In the title compound, C₁₃H₁₅NO₂, the acetate group [C—C(=O)—O] makes a dihedral angle of 62.35 (13)° with the mean plane of the indole ring system [maximum deviation = 0.011 (3) Å]. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming helical chains propagating along [010].

CCDC reference: 965567

Related literature

For the use of the title compound as a starting material for the synthesis of platinum complexes with antitumor activity, see: Kim et al. (1994 ). For its use as an intermediate in organic synthesis, see: Pandey et al. (1997 ). For the synthesis of indole-3-acetic acid, see: Johnson & Donald (1973 ). For standard bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₁₃H₁₅NO₂
M_r = 217.26
Monoclinic, P 2₁ /c
a = 7.8230 (16) Å
b = 8.1740 (16) Å
c = 18.994 (4) Å
β = 97.18 (3)°
V = 1205.1 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 K
0.30 × 0.20 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.976, T_max = 0.992
2387 measured reflections
2210 independent reflections
1463 reflections with I > 2σ(I)
R_int = 0.083
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.063
wR(F²) = 0.183
S = 1.00
2210 reflections
145 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O2ⁱ	0.86	2.13	2.953 (3)	160
Symmetry code: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

CCDC reference: 965567

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813027633/su2653sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813027633/su2653Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813027633/su2653Isup3.cml

checkCIF report

Comment top

Indole derivatives are some of the most effective anticancer agents currently available. The title compound is a starting material for the synthesis of platinum complexes with antitumor activity (Kim et al., 1994) and is also an important intermediate in organic synthesis (Pandey et al., 1997). As part of our studies of the synthesis and characterization of such compounds, we herein report on the crystal structure of the title compound.

The molecular structure of the title compound is shown in Fig. 1. The bond lengths (Allen et al., 1987) and angles are within normal ranges. The acetate group [C5-C4(═O2)-O1] makes a dihedral angle of 62.35 (13) ° with the mean plane of the indole ring system [N1/C6-C13; maximum deviation = 0.011 (3) Å for atom C9].

In the crystal, molecules are linked by N—H···O hydrogen bonds forming helical chains propagating along the b axis direction (Table 1 and Fig 2).

Related literature top

For the use of the title compound as a starting material for the synthesis of platinum complexes with antitumor activity, see: Kim et al. (1994). For its use as an intermediate in organic synthesis, see: Pandey et al. (1997). For the synthesis of indole-3-acetic acid, see: Johnson & Donald (1973). For standard bond-length data, see: Allen et al. (1987).

Experimental top

Indole-3-acetic acid was synthesized following a literature procedure (Johnson & Donald, 1973). The title compound was synthesized by adding indole-3-acetic acid (10 g, 0.057 mol) and 100 mL of dichloromethane to a three-neck flask with stirring and cooled in an ice bath. 4.3 mL of thionyl chloride was added drop wise, after the solution was stirred for a further 10 min. 15 mL of 1-propanol was then added and the reaction was followed using TLC until completion. The title compound was obtained as a light yellow solid [Yield = 10.5 g, 0.048 mol]. Recrystallization with ethanol gave yellow block-like crystals, suitable for X-ray diffraction analysis.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title molecule, with atom labelling. The displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A view along the a axis of the crystal packing of the title compound. The hydrogen bonds are shown as dashed lines (see Table 1 for details).

Propyl 2-(1H-indol-3-yl)acetate top

Crystal data top

C₁₃H₁₅NO₂	F(000) = 464
M_r = 217.26	D_x = 1.198 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.8230 (16) Å	θ = 10–13°
b = 8.1740 (16) Å	µ = 0.08 mm⁻¹
c = 18.994 (4) Å	T = 293 K
β = 97.18 (3)°	Block, yellow
V = 1205.1 (4) Å³	0.30 × 0.20 × 0.10 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	1463 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.083
Graphite monochromator	θ_max = 25.4°, θ_min = 2.2°
ω/2θ scans	h = 0→9
Absorption correction: ψ scan (North et al., 1968)	k = 0→9
T_min = 0.976, T_max = 0.992	l = −22→22
2387 measured reflections	3 standard reflections every 200 reflections
2210 independent reflections	intensity decay: 1%

Refinement top

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)] = 0.063	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.183	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.1P)² + 0.3P] where P = (F_o² + 2F_c²)/3
2210 reflections	(Δ/σ)_max < 0.001
145 parameters	Δρ_max = 0.22 e Å⁻³
0 restraints	Δρ_min = −0.30 e Å⁻³

Crystal data top

C₁₃H₁₅NO₂	V = 1205.1 (4) Å³
M_r = 217.26	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.8230 (16) Å	µ = 0.08 mm⁻¹
b = 8.1740 (16) Å	T = 293 K
c = 18.994 (4) Å	0.30 × 0.20 × 0.10 mm
β = 97.18 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1463 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.083
T_min = 0.976, T_max = 0.992	3 standard reflections every 200 reflections
2387 measured reflections	intensity decay: 1%
2210 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.063	0 restraints
wR(F²) = 0.183	H-atom parameters constrained
S = 1.00	Δρ_max = 0.22 e Å⁻³
2210 reflections	Δρ_min = −0.30 e Å⁻³
145 parameters

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	U_iso*/U_eq
N1	0.4476 (3)	0.5291 (3)	0.76568 (11)	0.0551 (6)
H1N	0.4531	0.5727	0.8071	0.066*
O1	0.6827 (3)	0.2944 (2)	0.50091 (9)	0.0572 (6)
C1	0.9681 (5)	0.2675 (5)	0.4162 (2)	0.0913 (12)
H1A	1.0120	0.2982	0.3731	0.137*
H1B	1.0455	0.1909	0.4418	0.137*
H1C	0.9582	0.3630	0.4448	0.137*
O2	0.6241 (3)	0.1504 (2)	0.59452 (9)	0.0580 (6)
C2	0.7950 (5)	0.1904 (4)	0.39885 (15)	0.0677 (9)
H2A	0.8070	0.0929	0.3707	0.081*
H2B	0.7205	0.2658	0.3700	0.081*
C3	0.7106 (5)	0.1444 (4)	0.46239 (16)	0.0684 (9)
H3A	0.6015	0.0904	0.4478	0.082*
H3B	0.7838	0.0702	0.4925	0.082*
C4	0.6405 (3)	0.2803 (3)	0.56652 (12)	0.0417 (6)
C5	0.6233 (3)	0.4467 (3)	0.59888 (13)	0.0462 (6)
H5A	0.7379	0.4897	0.6132	0.055*
H5B	0.5672	0.5189	0.5626	0.055*
C6	0.5254 (3)	0.4523 (3)	0.66121 (12)	0.0408 (6)
C7	0.5740 (3)	0.5333 (3)	0.72294 (13)	0.0493 (7)
H7A	0.6799	0.5847	0.7344	0.059*
C8	0.3090 (3)	0.4439 (3)	0.73219 (13)	0.0461 (6)
C9	0.1503 (4)	0.4081 (4)	0.75382 (17)	0.0608 (8)
H9A	0.1222	0.4447	0.7973	0.073*
C10	0.0360 (4)	0.3173 (4)	0.7092 (2)	0.0685 (9)
H10A	−0.0707	0.2901	0.7228	0.082*
C11	0.0784 (4)	0.2654 (4)	0.64391 (18)	0.0637 (8)
H11A	−0.0011	0.2038	0.6145	0.076*
C12	0.2337 (3)	0.3022 (3)	0.62148 (15)	0.0516 (7)
H12A	0.2590	0.2669	0.5774	0.062*
C13	0.3536 (3)	0.3938 (3)	0.66602 (12)	0.0401 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0693 (15)	0.0572 (14)	0.0401 (11)	−0.0058 (12)	0.0115 (11)	−0.0130 (11)
O1	0.0821 (14)	0.0501 (11)	0.0442 (10)	0.0020 (9)	0.0262 (10)	−0.0014 (8)
C1	0.091 (3)	0.092 (3)	0.099 (3)	−0.007 (2)	0.044 (2)	−0.015 (2)
O2	0.0766 (14)	0.0506 (11)	0.0497 (11)	0.0029 (10)	0.0196 (10)	0.0071 (9)
C2	0.098 (3)	0.0577 (19)	0.0503 (17)	0.0110 (17)	0.0201 (17)	−0.0075 (14)
C3	0.093 (2)	0.0551 (18)	0.0615 (18)	−0.0074 (16)	0.0259 (17)	−0.0124 (15)
C4	0.0379 (13)	0.0513 (15)	0.0365 (12)	0.0005 (11)	0.0068 (10)	0.0026 (11)
C5	0.0498 (14)	0.0459 (14)	0.0435 (14)	−0.0043 (12)	0.0084 (12)	0.0024 (11)
C6	0.0408 (13)	0.0426 (13)	0.0385 (12)	0.0022 (11)	0.0028 (10)	−0.0013 (10)
C7	0.0488 (14)	0.0527 (16)	0.0461 (14)	−0.0088 (12)	0.0048 (12)	−0.0076 (12)
C8	0.0525 (15)	0.0414 (14)	0.0464 (14)	0.0074 (11)	0.0139 (12)	−0.0012 (11)
C9	0.0635 (18)	0.0532 (17)	0.072 (2)	0.0104 (15)	0.0338 (16)	0.0031 (15)
C10	0.0427 (16)	0.0605 (19)	0.105 (3)	0.0053 (14)	0.0206 (17)	0.0063 (18)
C11	0.0389 (15)	0.0631 (19)	0.086 (2)	0.0008 (13)	−0.0035 (14)	−0.0015 (16)
C12	0.0414 (14)	0.0563 (17)	0.0553 (15)	0.0044 (12)	−0.0010 (12)	−0.0069 (13)
C13	0.0388 (13)	0.0414 (13)	0.0390 (13)	0.0027 (10)	0.0012 (10)	0.0004 (11)

Geometric parameters (Å, º) top

N1—C7	1.356 (3)	C5—C6	1.489 (3)
N1—C8	1.375 (3)	C5—H5A	0.9700
N1—H1N	0.8600	C5—H5B	0.9700
O1—C4	1.333 (3)	C6—C7	1.359 (3)
O1—C3	1.458 (3)	C6—C13	1.440 (3)
C1—C2	1.493 (5)	C7—H7A	0.9300
C1—H1A	0.9600	C8—C9	1.387 (4)
C1—H1B	0.9600	C8—C13	1.407 (3)
C1—H1C	0.9600	C9—C10	1.371 (4)
O2—C4	1.201 (3)	C9—H9A	0.9300
C2—C3	1.495 (4)	C10—C11	1.390 (5)
C2—H2A	0.9700	C10—H10A	0.9300
C2—H2B	0.9700	C11—C12	1.370 (4)
C3—H3A	0.9700	C11—H11A	0.9300
C3—H3B	0.9700	C12—C13	1.399 (4)
C4—C5	1.506 (4)	C12—H12A	0.9300

C7—N1—C8	109.1 (2)	C6—C5—H5B	108.4
C7—N1—H1N	125.4	C4—C5—H5B	108.4
C8—N1—H1N	125.4	H5A—C5—H5B	107.4
C4—O1—C3	117.8 (2)	C7—C6—C13	105.7 (2)
C2—C1—H1A	109.5	C7—C6—C5	125.8 (2)
C2—C1—H1B	109.5	C13—C6—C5	128.1 (2)
H1A—C1—H1B	109.5	N1—C7—C6	110.9 (2)
C2—C1—H1C	109.5	N1—C7—H7A	124.5
H1A—C1—H1C	109.5	C6—C7—H7A	124.5
H1B—C1—H1C	109.5	N1—C8—C9	130.8 (3)
C1—C2—C3	114.1 (3)	N1—C8—C13	107.0 (2)
C1—C2—H2A	108.7	C9—C8—C13	122.3 (3)
C3—C2—H2A	108.7	C10—C9—C8	118.1 (3)
C1—C2—H2B	108.7	C10—C9—H9A	121.0
C3—C2—H2B	108.7	C8—C9—H9A	121.0
H2A—C2—H2B	107.6	C9—C10—C11	120.4 (3)
O1—C3—C2	107.6 (2)	C9—C10—H10A	119.8
O1—C3—H3A	110.2	C11—C10—H10A	119.8
C2—C3—H3A	110.2	C12—C11—C10	122.0 (3)
O1—C3—H3B	110.2	C12—C11—H11A	119.0
C2—C3—H3B	110.2	C10—C11—H11A	119.0
H3A—C3—H3B	108.5	C11—C12—C13	118.9 (3)
O2—C4—O1	122.9 (2)	C11—C12—H12A	120.6
O2—C4—C5	126.7 (2)	C13—C12—H12A	120.6
O1—C4—C5	110.4 (2)	C12—C13—C8	118.3 (2)
C6—C5—C4	115.7 (2)	C12—C13—C6	134.4 (2)
C6—C5—H5A	108.4	C8—C13—C6	107.3 (2)
C4—C5—H5A	108.4

C4—O1—C3—C2	−166.9 (2)	C13—C8—C9—C10	1.6 (4)
C1—C2—C3—O1	62.5 (4)	C8—C9—C10—C11	−1.0 (4)
C3—O1—C4—O2	−0.4 (4)	C9—C10—C11—C12	0.0 (5)
C3—O1—C4—C5	177.9 (2)	C10—C11—C12—C13	0.5 (4)
O2—C4—C5—C6	−20.2 (4)	C11—C12—C13—C8	0.1 (4)
O1—C4—C5—C6	161.6 (2)	C11—C12—C13—C6	179.0 (3)
C4—C5—C6—C7	134.1 (3)	N1—C8—C13—C12	179.3 (2)
C4—C5—C6—C13	−54.7 (3)	C9—C8—C13—C12	−1.2 (4)
C8—N1—C7—C6	−0.3 (3)	N1—C8—C13—C6	0.1 (3)
C13—C6—C7—N1	0.3 (3)	C9—C8—C13—C6	179.6 (2)
C5—C6—C7—N1	173.2 (2)	C7—C6—C13—C12	−179.3 (3)
C7—N1—C8—C9	−179.4 (3)	C5—C6—C13—C12	8.2 (5)
C7—N1—C8—C13	0.1 (3)	C7—C6—C13—C8	−0.3 (3)
N1—C8—C9—C10	−179.0 (3)	C5—C6—C13—C8	−172.9 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.86	2.13	2.953 (3)	160

Symmetry code: (i) −x+1, y+1/2, −z+3/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.86	2.13	2.953 (3)	160

Symmetry code: (i) −x+1, y+1/2, −z+3/2.

Acknowledgements

The authors thank Liu Bo Nian from Nanjing University of Technology for useful discussions and the Center of Testing and Analysis, Nanjing University, for measuring the X-ray diffraction data.

References

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