Ethyl 1-acetyl-1H-indole-3-carboxyl-ate.

The title compound, C(13)H(13)NO(3), was synthesized by acetyl-ation of ethyl 1H-indole-3-carboxyl-ate. The aromatic ring system of the mol-ecule is essentially planar, but the saturated ethyl group is also located within this plane and the overall r.m.s. deviation from planarity is only 0.034 Å. Pairs of C-H⋯O inter-actions connect mol-ecules into chains along the diagonal of the unit cell. Mol-ecules also form weakly connected dimers via π⋯π stacking inter-actions of the indole rings with centroid-centroid separations of 3.571 (1) Å. C-H⋯π inter-actions between methyl-ene and methyl groups and the indole and benzene ring complete the directional inter-molecular inter-actions found in the crystal structure.

Related literature

For the biological properties of tryptophan derivatives, see: Ma et al. (2001 ▶); Zhou et al. (2006 ▶); Zhao, Smith et al. (2002 ▶); Zhao, Liao & Cook (2002 ▶). For synthetic procedures towards tryptophan-like compounds, see: Ager & Laneman (2004 ▶); Amir-Heidari et al. (2007 ▶); Carlier et al. (2002 ▶); Hengartner et al. (1979 ▶); Moriya et al. (1980 ▶). For the synthesis of 2-acetamido-3-eth­oxy-3-oxopropanoic acid, see: Hellmann et al. (1958 ▶). For NMR data for the title compound, see: Reimann et al. (1990 ▶).

Experimental

Crystal data

C13H13NO3

M = 231.24

Triclinic,

a = 7.519 (1) Å

b = 8.479 (1) Å

c = 10.187 (2) Å

α = 97.38 (1)°

β = 95.78 (2)°

γ = 114.28 (1)°

V = 578.58 (15) Å3

Z = 2

Mo Kα radiation

μ = 0.10 mm−1

T = 296 K

0.51 × 0.41 × 0.20 mm

Data collection

Siemens P4 diffractometer

Absorption correction: multi-scan [XSCANS (Siemens, 1996 ▶) and XPREP (Siemens, 1994 ▶)] T min = 0.823, T max = 0.981

2536 measured reflections

2027 independent reflections

1696 reflections with I > 2σ(I)

R int = 0.019

3 standard reflections every 97 reflections intensity decay: <1%

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.120

S = 1.09

2027 reflections

155 parameters

H-atom parameters constrained

Δρmax = 0.17 e Å−3

Δρmin = −0.18 e Å−3

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: XPREP (Siemens 1994 ▶) and SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809025379/bh2233sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809025379/bh2233Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C13H13NO3	Z = 2
Mr = 231.24	F(000) = 244
Triclinic, P1	Dx = 1.327 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.519 (1) Å	Cell parameters from 23 reflections
b = 8.479 (1) Å	θ = 3.7–11.4°
c = 10.187 (2) Å	µ = 0.10 mm−1
α = 97.38 (1)°	T = 296 K
β = 95.78 (2)°	Block, colourless
γ = 114.28 (1)°	0.51 × 0.41 × 0.20 mm
V = 578.58 (15) Å3

Siemens P4 diffractometer	1696 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.019
graphite	θmax = 25.0°, θmin = 2.1°
2θ/ω scans	h = −8→1
Absorption correction: multi-scan [XSCANS (Siemens 1996) and XPREP (Siemens, 1994)]	k = −9→9
Tmin = 0.823, Tmax = 0.981	l = −12→12
2536 measured reflections	3 standard reflections every 97 reflections
2027 independent reflections	intensity decay: <1%

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)] = 0.042	H-atom parameters constrained
wR(F2) = 0.120	w = 1/[σ2(Fo2) + (0.0647P)2 + 0.0738P] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max = 0.001
2027 reflections	Δρmax = 0.17 e Å−3
155 parameters	Δρmin = −0.18 e Å−3
0 restraints	Extinction correction: SHELXTL (Bruker, 2003; Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 constraints	Extinction coefficient: 0.103 (12)
Primary atom site location: structure-invariant direct methods

	x	y	z	Uiso*/Ueq
C1	0.3179 (2)	0.9158 (2)	0.76860 (15)	0.0474 (4)
C2	0.3276 (2)	0.8319 (2)	0.64495 (16)	0.0560 (4)
H2	0.3926	0.8952	0.5826	0.067*
C3	0.2364 (3)	0.6502 (2)	0.61896 (18)	0.0641 (5)
H3	0.2402	0.5898	0.5371	0.077*
C4	0.1394 (3)	0.5554 (2)	0.71141 (19)	0.0658 (5)
H4	0.0804	0.4330	0.6907	0.079*
C5	0.1286 (3)	0.6392 (2)	0.83389 (17)	0.0572 (4)
H5	0.0629	0.5747	0.8955	0.069*
C6	0.2186 (2)	0.8227 (2)	0.86285 (15)	0.0477 (4)
C7	0.2359 (2)	0.9517 (2)	0.97738 (15)	0.0477 (4)
C8	0.3421 (2)	1.1130 (2)	0.95024 (15)	0.0491 (4)
H8	0.3747	1.2189	1.0077	0.059*
C9	0.1539 (2)	0.9133 (2)	1.10037 (16)	0.0526 (4)
C10	0.5038 (3)	1.2371 (2)	0.76197 (16)	0.0563 (4)
C11	0.5648 (3)	1.4194 (3)	0.8383 (2)	0.0756 (6)
H11A	0.6392	1.4336	0.9248	0.113*
H11B	0.4491	1.4377	0.8497	0.113*
H11C	0.6452	1.5037	0.7894	0.113*
C12	0.1351 (3)	1.0333 (3)	1.31867 (17)	0.0613 (5)
H12A	0.1950	0.9683	1.3634	0.074*
H12B	−0.0076	0.9667	1.3045	0.074*
C13	0.1950 (3)	1.2107 (3)	1.40273 (18)	0.0724 (5)
H13A	0.1508	1.1970	1.4875	0.109*
H13B	0.1361	1.2743	1.3572	0.109*
H13C	0.3366	1.2747	1.4175	0.109*
N1	0.39555 (19)	1.09788 (17)	0.82406 (12)	0.0489 (4)
O1	0.0559 (3)	0.76795 (18)	1.11828 (14)	0.0845 (5)
O2	0.20161 (17)	1.05915 (15)	1.19112 (11)	0.0559 (3)
O3	0.5434 (2)	1.20764 (19)	0.65295 (13)	0.0814 (5)

	U11	U22	U33	U12	U13	U23
C1	0.0485 (8)	0.0506 (9)	0.0420 (8)	0.0226 (7)	0.0046 (6)	0.0028 (6)
C2	0.0594 (10)	0.0612 (10)	0.0452 (9)	0.0262 (8)	0.0100 (7)	0.0006 (7)
C3	0.0707 (11)	0.0617 (11)	0.0531 (10)	0.0282 (9)	0.0083 (8)	−0.0092 (8)
C4	0.0744 (11)	0.0493 (10)	0.0660 (11)	0.0245 (9)	0.0072 (9)	−0.0049 (8)
C5	0.0631 (10)	0.0494 (9)	0.0552 (10)	0.0216 (8)	0.0084 (8)	0.0070 (7)
C6	0.0492 (8)	0.0497 (8)	0.0437 (8)	0.0231 (7)	0.0043 (6)	0.0036 (7)
C7	0.0521 (8)	0.0502 (9)	0.0419 (8)	0.0239 (7)	0.0077 (6)	0.0062 (7)
C8	0.0569 (9)	0.0503 (9)	0.0405 (8)	0.0245 (7)	0.0102 (6)	0.0032 (6)
C9	0.0617 (9)	0.0541 (10)	0.0467 (9)	0.0283 (8)	0.0122 (7)	0.0108 (7)
C10	0.0656 (10)	0.0570 (10)	0.0478 (9)	0.0254 (8)	0.0155 (7)	0.0131 (7)
C11	0.0980 (15)	0.0525 (11)	0.0726 (12)	0.0247 (10)	0.0284 (11)	0.0146 (9)
C12	0.0718 (11)	0.0789 (12)	0.0442 (9)	0.0395 (10)	0.0208 (8)	0.0160 (8)
C13	0.0812 (13)	0.0925 (14)	0.0491 (10)	0.0451 (11)	0.0156 (9)	0.0023 (9)
N1	0.0562 (8)	0.0484 (7)	0.0406 (7)	0.0215 (6)	0.0105 (5)	0.0044 (5)
O1	0.1286 (12)	0.0546 (8)	0.0692 (9)	0.0304 (8)	0.0424 (8)	0.0197 (6)
O2	0.0660 (7)	0.0586 (7)	0.0430 (6)	0.0256 (6)	0.0172 (5)	0.0069 (5)
O3	0.1158 (11)	0.0731 (9)	0.0556 (8)	0.0346 (8)	0.0377 (7)	0.0162 (7)

C1—C2	1.389 (2)	C9—O1	1.197 (2)
C1—C6	1.399 (2)	C9—O2	1.3367 (19)
C1—N1	1.4186 (19)	C10—O3	1.201 (2)
C2—C3	1.379 (2)	C10—N1	1.400 (2)
C2—H2	0.9300	C10—C11	1.497 (3)
C3—C4	1.384 (3)	C11—H11A	0.9600
C3—H3	0.9300	C11—H11B	0.9600
C4—C5	1.381 (2)	C11—H11C	0.9600
C4—H4	0.9300	C12—O2	1.449 (2)
C5—C6	1.393 (2)	C12—C13	1.494 (3)
C5—H5	0.9300	C12—H12A	0.9700
C6—C7	1.449 (2)	C12—H12B	0.9700
C7—C8	1.352 (2)	C13—H13A	0.9600
C7—C9	1.467 (2)	C13—H13B	0.9600
C8—N1	1.391 (2)	C13—H13C	0.9600
C8—H8	0.9300
C2—C1—C6	122.32 (15)	O2—C9—C7	112.43 (14)
C2—C1—N1	130.20 (15)	O3—C10—N1	120.26 (16)
C6—C1—N1	107.48 (13)	O3—C10—C11	123.11 (16)
C3—C2—C1	116.89 (17)	N1—C10—C11	116.63 (15)
C3—C2—H2	121.6	C10—C11—H11A	109.5
C1—C2—H2	121.6	C10—C11—H11B	109.5
C2—C3—C4	121.75 (17)	H11A—C11—H11B	109.5
C2—C3—H3	119.1	C10—C11—H11C	109.5
C4—C3—H3	119.1	H11A—C11—H11C	109.5
C5—C4—C3	121.27 (17)	H11B—C11—H11C	109.5
C5—C4—H4	119.4	O2—C12—C13	107.88 (15)
C3—C4—H4	119.4	O2—C12—H12A	110.1
C4—C5—C6	118.33 (17)	C13—C12—H12A	110.1
C4—C5—H5	120.8	O2—C12—H12B	110.1
C6—C5—H5	120.8	C13—C12—H12B	110.1
C5—C6—C1	119.44 (14)	H12A—C12—H12B	108.4
C5—C6—C7	133.47 (15)	C12—C13—H13A	109.5
C1—C6—C7	107.10 (14)	C12—C13—H13B	109.5
C8—C7—C6	107.50 (14)	H13A—C13—H13B	109.5
C8—C7—C9	126.52 (15)	C12—C13—H13C	109.5
C6—C7—C9	125.98 (15)	H13A—C13—H13C	109.5
C7—C8—N1	110.33 (14)	H13B—C13—H13C	109.5
C7—C8—H8	124.8	C8—N1—C10	126.27 (14)
N1—C8—H8	124.8	C8—N1—C1	107.60 (13)
O1—C9—O2	123.51 (15)	C10—N1—C1	126.12 (13)
O1—C9—C7	124.06 (16)	C9—O2—C12	116.25 (13)
C6—C1—C2—C3	−0.9 (2)	C8—C7—C9—O1	177.82 (17)
N1—C1—C2—C3	−179.95 (15)	C6—C7—C9—O1	−2.6 (3)
C1—C2—C3—C4	0.1 (3)	C8—C7—C9—O2	−2.5 (2)
C2—C3—C4—C5	0.5 (3)	C6—C7—C9—O2	177.09 (13)
C3—C4—C5—C6	−0.2 (3)	C7—C8—N1—C10	179.14 (15)
C4—C5—C6—C1	−0.6 (2)	C7—C8—N1—C1	0.04 (17)
C4—C5—C6—C7	179.54 (17)	O3—C10—N1—C8	179.02 (16)
C2—C1—C6—C5	1.2 (2)	C11—C10—N1—C8	−1.0 (3)
N1—C1—C6—C5	−179.57 (13)	O3—C10—N1—C1	−2.1 (3)
C2—C1—C6—C7	−178.95 (14)	C11—C10—N1—C1	177.96 (15)
N1—C1—C6—C7	0.31 (16)	C2—C1—N1—C8	178.95 (16)
C5—C6—C7—C8	179.58 (17)	C6—C1—N1—C8	−0.23 (16)
C1—C6—C7—C8	−0.29 (17)	C2—C1—N1—C10	−0.1 (3)
C5—C6—C7—C9	0.0 (3)	C6—C1—N1—C10	−179.32 (15)
C1—C6—C7—C9	−179.90 (14)	O1—C9—O2—C12	2.7 (2)
C6—C7—C8—N1	0.15 (18)	C7—C9—O2—C12	−177.03 (13)
C9—C7—C8—N1	179.76 (14)	C13—C12—O2—C9	−177.54 (14)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O3i	0.93	2.61	3.296 (2)	131
C5—H5···O1ii	0.93	2.64	3.273 (2)	125
C12—H12B···Cg1iii	0.96	2.95	3.618 (3)	127
C13—H13B···Cg2iii	0.96	2.78	3.587 (3)	142

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O3i	0.93	2.61	3.296 (2)	131
C5—H5⋯O1ii	0.93	2.64	3.273 (2)	125
C12—H12B⋯Cg1iii	0.96	2.95	3.618 (3)	127
C13—H13B⋯Cg2iii	0.96	2.78	3.587 (3)	142

Symmetry codes: (i) ; (ii) ; (iii) . Cg1 is the centroid of the N1,C1,C6–C8 pyrrole ring and Cg2 is the centroid of the C1–C6 phenyl ring.