3-(1-Phenyl­sulfonyl-2-methyl­indol-3-yl­carbonyl)­propanoic acid

In the title compound, C₁₉H₁₇NO₅S, the indole system is not strictly planar and the dihedral angle between the fused rings is 2.1 (1)°. The indole and phenyl rings are orthogonal to each other and the dihedral angle between them is 87.2 (1)°. The mol­ecules are joined into head-to-head dimers by hydrogen bonds involving the butyric acid groups. The centrosymmet­rically related C—H...O hydrogen bond pattern joins the head-to-head dimers into chains running parallel to the c axis. Neighbouring chains are held together by weak C—H...π and π–π interactions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.052
• wR factor = 0.149
• Data-to-parameter ratio = 17.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

---

S1. Comment

Indole is an important heterocyclic compounds. Its ring system is present in a large number of natural products. Many of these natural products, as well as the synthetic derivatives, show a variety of useful biological properties, such as antibacterial (Okabe & Adachi, 1998), antitumour (Schollmeyer et al., 1995), antidepressant (Grinev et al., 1984), antimicrobial (El-Sayed et al., 1986; Gadaginamath & Patil, 1999) and anti-inflammatory (Rodriguez et al., 1985) activities. 4-(3-Indolyl)butyric acid (IBA) is known to possess growth-regulating activity (Steward & Krikorian, 1971). IBA shows a root-promoting effect in all lemon and lime varieties (Sircar, 1971) and is also effective in bud inhibition in many plants. The interaction of phenylsulfonylindole with the calf-thymus DNA by spectroscopic methods has also been studied (Sivaraman et al., 1996). Indoles have been proved to display high aldose reductose inhibitory activity (Rajeswaran et al., 1999). The structure determination of the title compound, (I), was undertaken as part of our studies on indole derivatives.

The indole system is not strictly planar and the dihedral angle formed by the pyrrole and benzene planes is 2.1 (1)°. The dihedral angle between the indole system and the phenyl ring is 87.2 (1)°. The 4-oxobutyric acid group is characterized by two planes, viz. the 3-oxopropyl group and the acid group. The plane of the indole system makes angles of 36.3 (1) and 68.2 (1)° with the 3-oxopropyl group and the acid group, respectively. Atoms S1, C16 and C17 deviate from the weighted least-squares plane through the indole system by −0.392 (1), 0.072 (3) and −0.108 (2) Å, respectively. Atoms N1 deviates by 0.155 (2) Å from the mean plane passing through atoms C2, C5 and S1. This slight pyramidalization behaviour is also observed in related indole derivatives (Sankaranarayanan et al., 2000, 2001). The bond angles around S1 show distorted tetrahedral geometry. The widening of the O1—S1—O2 angle [120.1 (1)°] from the tetrahedral value is presumably the results of repulsive interactions between the short S═O bonds. Similar observations have been noted in the related structure (Sankaranarayanan et al., 2001). The S—C bond distance [1.757 (2) Å] agrees well with the literature value of 1.758 (13) Å (Allen et al., 1987) and S—N [1.698 (2) Å] bond distance is sligtly longer than the literature value of 1.642 (24) Å (Allen et al., 1987). The lengthening of the C—N distances in the pyrrole ring is due to the electron- withdrawing character of the phenylsulfonyl group. The 3-oxopropyl chain bond lengths and angles are in the expected ranges but its conformation is of interest. The torsion angles C2—C3—C17—O3, C4—C3—C17—C18, C3—C17—C18—C19, C17—C18—C19—C20, and C18—C19—C20—O4 are 24.3 (3), 24.7 (3), 171.8 (2), 79.6 (2) and 32.9 (3)°, respectively. C—H···O interactions have been recognized as important secondary interactions and, in many cases, play a dominant role in the molecular conformation (Steiner, 1997). Four such intramolecular interactions can be identified in the present structure. The conformation of the aliphatic chain is governed by two C—H···O intramolecular interactions. Evidence for steric strain is seen at the point where the phenylsulfonyl group joins the indole. The sulfonyl group comprising of atoms O1, O2 and S1, is prevented from lying in the plane of the indole ring by close approach of O1 and H atom bound to C6, while O2 is close to the methyl substituent at C2. Thus, the orientation of the indole subtituent is influenced by weak C6—H6···O1 and C16—H16B···O2 interactions, defined by the torsion angles C6—C5—N1—S1, C5—N1—S1—C10, C16—C2—N1—S1 and C2—N1—S1—C10.

The molecules are joined into head-to-head dimers with graph-set R²₂(8) (Bernstein et al., 1995) by hydrogen bonds involving the carboxylic acid groups. The O5···O4 distance is 2.715 (2) Å. Centrosymmetric hydrogen bonds between atom C15 of the phenyl ring and carbonyl atom O3 of 4-oxobutyric acid form another dimer with graph-set R²₂(18). This hydrogen bond pattern joins the head-to-head dimers into chains running parallel to c axis. The close edge-to-face interactions are observed between A and Bⁱⁱⁱ and the equivalent pair B and Aⁱⁱⁱ, with interplanar angle of 88° and centroid-centroid distance of 5.088 (2) Å [symmetry code: (iii) 2 − x, −y, −z]. Face-to-face ring interactions between P (pyrrole) ring and P^v, and ring A and Aⁱⁱⁱ, are observed which stack in the lattice along a, with centroid-centroid distances of 4.129 (2) and 3.986 (2) Å, respectively [symmetry code: (v) 1 − x, −y, −z].

S2. Experimental

The title compound was prepared by the Friedel–Crafts acylation of 1-phenylsulfonly-2-methylindole with succinic anhydride in the presence of anhydrous aluminium chloride in dry methylene chloride.

S3. Refinement

All H atoms were included in calculated positions and allowed to ride on their corresponding parent atoms.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1997) and PLATON (Spek, 1990); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).

Figures

	Fig. 1. The molecular structure of the title compound, showing 35% probability displacement elliposids and the atom-numbering scheme.
	Fig. 2. A view of the crystal strucutre of (I), viewed down the a axis.

3-(1-Phenylsulfonyl-2-methylindol-3-ylcarbonyl)propanoic acid

Crystal data

C19H17NO5S	Z = 2
Mr = 371.40	F(000) = 388
Triclinic, P1	Dx = 1.423 Mg m^−3
a = 8.1825 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.9758 (1) Å	Cell parameters from 3857 reflections
c = 12.3121 (1) Å	θ = 1.8–28.3°
α = 69.281 (1)°	µ = 0.22 mm^−1
β = 72.067 (1)°	T = 293 K
γ = 70.878 (1)°	Block, colourless
V = 866.92 (2) Å^3	0.46 × 0.42 × 0.24 mm

Data collection

Siemens SMART CCD area-detector diffractometer	3144 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.025
Graphite monochromator	θmax = 28.3°, θmin = 1.8°
ω scans	h = −10→8
6104 measured reflections	k = −13→12
4175 independent reflections	l = −16→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.149	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.091P)^2] where P = (Fo^2 + 2Fc^2)/3
4175 reflections	(Δ/σ)max < 0.001
236 parameters	Δρmax = 0.54 e Å^−3
0 restraints	Δρmin = −0.48 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
S1	0.50958 (6)	0.07847 (6)	0.31671 (4)	0.04313 (17)
O1	0.5320 (2)	−0.07044 (18)	0.38969 (12)	0.0594 (4)
O2	0.34092 (18)	0.1803 (2)	0.33014 (14)	0.0592 (4)
O3	0.5942 (3)	0.38243 (17)	−0.16717 (15)	0.0787 (6)
O4	0.9696 (2)	0.34093 (18)	−0.41035 (15)	0.0667 (5)
O5	0.7594 (2)	0.52339 (17)	−0.48807 (15)	0.0655 (5)
H5	0.8387	0.5671	−0.5141	0.098*
N1	0.5662 (2)	0.06819 (18)	0.17460 (13)	0.0405 (4)
C2	0.5299 (2)	0.1871 (2)	0.07346 (16)	0.0402 (4)
C3	0.6399 (2)	0.1493 (2)	−0.02604 (15)	0.0389 (4)
C4	0.7505 (2)	0.0013 (2)	0.01113 (16)	0.0379 (4)
C5	0.7065 (2)	−0.0455 (2)	0.13608 (16)	0.0390 (4)
C6	0.7942 (3)	−0.1812 (2)	0.20103 (19)	0.0515 (5)
H6	0.7638	−0.2105	0.2837	0.062*
C7	0.9275 (3)	−0.2708 (2)	0.1393 (2)	0.0549 (5)
H7	0.9889	−0.3613	0.1810	0.066*
C8	0.9716 (3)	−0.2284 (2)	0.0158 (2)	0.0550 (5)
H8	1.0607	−0.2915	−0.0239	0.066*
C9	0.8852 (3)	−0.0940 (2)	−0.04857 (19)	0.0497 (5)
H9	0.9160	−0.0665	−0.1313	0.060*
C10	0.6703 (2)	0.1553 (2)	0.32291 (15)	0.0354 (4)
C11	0.8229 (3)	0.0634 (2)	0.36120 (17)	0.0429 (4)
H11	0.8393	−0.0387	0.3870	0.051*
C12	0.9508 (2)	0.1286 (3)	0.35991 (19)	0.0490 (5)
H12	1.0545	0.0693	0.3847	0.059*
C13	0.9246 (3)	0.2797 (2)	0.32226 (19)	0.0499 (5)
H13	1.0116	0.3218	0.3208	0.060*
C14	0.7714 (3)	0.3693 (2)	0.2868 (2)	0.0553 (5)
H14	0.7544	0.4714	0.2625	0.066*
C15	0.6419 (3)	0.3071 (2)	0.2873 (2)	0.0481 (5)
H15	0.5375	0.3670	0.2640	0.058*
C16	0.3821 (3)	0.3227 (3)	0.0792 (2)	0.0580 (6)
H16A	0.4190	0.3896	0.1013	0.087*
H16B	0.2805	0.2955	0.1374	0.087*
H16C	0.3521	0.3700	0.0028	0.087*
C17	0.6432 (3)	0.2493 (2)	−0.14853 (17)	0.0438 (4)
C18	0.7129 (3)	0.1844 (2)	−0.25187 (16)	0.0450 (4)
H18A	0.6551	0.1068	−0.2368	0.054*
H18B	0.8389	0.1397	−0.2581	0.054*
C19	0.6834 (3)	0.2986 (2)	−0.36994 (17)	0.0485 (5)
H19A	0.6893	0.2480	−0.4259	0.058*
H19B	0.5657	0.3635	−0.3574	0.058*
C20	0.8174 (3)	0.3898 (2)	−0.42252 (16)	0.0453 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0373 (3)	0.0634 (3)	0.0339 (2)	−0.0278 (2)	0.00063 (18)	−0.0130 (2)
O1	0.0784 (11)	0.0707 (10)	0.0356 (7)	−0.0471 (9)	−0.0023 (7)	−0.0048 (7)
O2	0.0301 (7)	0.0998 (12)	0.0534 (9)	−0.0213 (7)	0.0010 (6)	−0.0317 (9)
O3	0.1296 (18)	0.0431 (9)	0.0502 (9)	−0.0043 (10)	−0.0254 (10)	−0.0082 (7)
O4	0.0577 (10)	0.0624 (10)	0.0679 (10)	−0.0298 (8)	−0.0220 (8)	0.0167 (8)
O5	0.0639 (10)	0.0526 (9)	0.0722 (11)	−0.0240 (8)	−0.0239 (8)	0.0080 (8)
N1	0.0403 (8)	0.0504 (9)	0.0327 (7)	−0.0188 (7)	−0.0043 (6)	−0.0099 (7)
C2	0.0381 (9)	0.0477 (10)	0.0391 (9)	−0.0165 (8)	−0.0090 (7)	−0.0112 (8)
C3	0.0432 (10)	0.0429 (10)	0.0341 (9)	−0.0177 (8)	−0.0082 (7)	−0.0085 (7)
C4	0.0410 (9)	0.0407 (9)	0.0359 (9)	−0.0187 (8)	−0.0079 (7)	−0.0078 (7)
C5	0.0407 (10)	0.0438 (10)	0.0371 (9)	−0.0217 (8)	−0.0078 (7)	−0.0071 (7)
C6	0.0611 (13)	0.0501 (11)	0.0420 (10)	−0.0216 (10)	−0.0144 (9)	−0.0013 (9)
C7	0.0590 (13)	0.0404 (10)	0.0622 (13)	−0.0115 (10)	−0.0226 (11)	−0.0036 (9)
C8	0.0558 (13)	0.0473 (12)	0.0588 (13)	−0.0093 (10)	−0.0094 (10)	−0.0171 (10)
C9	0.0561 (12)	0.0469 (11)	0.0430 (10)	−0.0157 (9)	−0.0028 (9)	−0.0131 (9)
C10	0.0293 (8)	0.0460 (10)	0.0314 (8)	−0.0141 (7)	−0.0017 (6)	−0.0111 (7)
C11	0.0379 (9)	0.0437 (10)	0.0444 (10)	−0.0073 (8)	−0.0100 (8)	−0.0109 (8)
C12	0.0302 (9)	0.0676 (14)	0.0510 (11)	−0.0071 (9)	−0.0103 (8)	−0.0220 (10)
C13	0.0354 (10)	0.0660 (13)	0.0576 (12)	−0.0212 (9)	−0.0037 (9)	−0.0257 (11)
C14	0.0534 (13)	0.0479 (11)	0.0699 (14)	−0.0197 (10)	−0.0155 (11)	−0.0143 (10)
C15	0.0405 (10)	0.0463 (11)	0.0587 (12)	−0.0095 (8)	−0.0191 (9)	−0.0100 (9)
C16	0.0540 (13)	0.0633 (14)	0.0521 (12)	−0.0041 (11)	−0.0121 (10)	−0.0196 (11)
C17	0.0499 (11)	0.0420 (10)	0.0391 (10)	−0.0142 (9)	−0.0111 (8)	−0.0069 (8)
C18	0.0560 (12)	0.0459 (10)	0.0350 (9)	−0.0259 (9)	−0.0043 (8)	−0.0063 (8)
C19	0.0554 (12)	0.0596 (12)	0.0349 (9)	−0.0288 (10)	−0.0079 (8)	−0.0067 (9)
C20	0.0535 (12)	0.0495 (11)	0.0322 (9)	−0.0223 (9)	−0.0095 (8)	−0.0019 (8)

Geometric parameters (Å, º)

S1—O2	1.422 (2)	C9—H9	0.9300
S1—O1	1.424 (2)	C10—C15	1.379 (3)
S1—N1	1.698 (2)	C10—C11	1.389 (3)
S1—C10	1.757 (2)	C11—C12	1.395 (3)
O3—C17	1.212 (2)	C11—H11	0.9300
O4—C20	1.215 (3)	C12—C13	1.375 (3)
O5—C20	1.309 (2)	C12—H12	0.9300
O5—H5	0.8200	C13—C14	1.374 (3)
N1—C2	1.414 (2)	C13—H13	0.9300
N1—C5	1.422 (2)	C14—C15	1.390 (3)
C2—C3	1.371 (3)	C14—H14	0.9300
C2—C16	1.497 (3)	C15—H15	0.9300
C3—C4	1.453 (3)	C16—H16A	0.9600
C3—C17	1.483 (2)	C16—H16B	0.9600
C4—C9	1.402 (3)	C16—H16C	0.9600
C4—C5	1.405 (2)	C17—C18	1.502 (3)
C5—C6	1.392 (3)	C18—C19	1.527 (3)
C6—C7	1.377 (3)	C18—H18A	0.9700
C6—H6	0.9300	C18—H18B	0.9700
C7—C8	1.388 (3)	C19—C20	1.499 (3)
C7—H7	0.9300	C19—H19A	0.9700
C8—C9	1.378 (3)	C19—H19B	0.9700
C8—H8	0.9300
O2—S1—O1	120.1 (1)	C10—C11—H11	120.9
O2—S1—N1	106.9 (1)	C12—C11—H11	120.9
O1—S1—N1	105.6 (1)	C13—C12—C11	120.4 (2)
O2—S1—C10	109.3 (1)	C13—C12—H12	119.8
O1—S1—C10	109.9 (1)	C11—C12—H12	119.8
N1—S1—C10	103.7 (1)	C14—C13—C12	120.7 (2)
C20—O5—H5	109.5	C14—C13—H13	119.7
C2—N1—C5	108.5 (1)	C12—C13—H13	119.7
C2—N1—S1	125.8 (1)	C13—C14—C15	120.0 (2)
C5—N1—S1	122.6 (1)	C13—C14—H14	120.0
C3—C2—N1	108.5 (2)	C15—C14—H14	120.0
C3—C2—C16	127.8 (2)	C10—C15—C14	119.1 (2)
N1—C2—C16	123.4 (2)	C10—C15—H15	120.4
C2—C3—C4	108.4 (2)	C14—C15—H15	120.4
C2—C3—C17	123.7 (2)	C2—C16—H16A	109.5
C4—C3—C17	127.9 (2)	C2—C16—H16B	109.5
C9—C4—C5	118.3 (2)	H16A—C16—H16B	109.5
C9—C4—C3	134.6 (2)	C2—C16—H16C	109.5
C5—C4—C3	107.1 (2)	H16A—C16—H16C	109.5
C6—C5—C4	122.0 (2)	H16B—C16—H16C	109.5
C6—C5—N1	130.6 (2)	O3—C17—C3	121.4 (2)
C4—C5—N1	107.4 (2)	O3—C17—C18	119.3 (2)
C7—C6—C5	118.1 (2)	C3—C17—C18	119.3 (2)
C7—C6—H6	121.0	C17—C18—C19	113.0 (2)
C5—C6—H6	121.0	C17—C18—H18A	109.0
C6—C7—C8	121.1 (2)	C19—C18—H18A	109.0
C6—C7—H7	119.4	C17—C18—H18B	109.0
C8—C7—H7	119.4	C19—C18—H18B	109.0
C9—C8—C7	120.9 (2)	H18A—C18—H18B	107.8
C9—C8—H8	119.6	C20—C19—C18	112.6 (2)
C7—C8—H8	119.6	C20—C19—H19A	109.1
C8—C9—C4	119.7 (2)	C18—C19—H19A	109.1
C8—C9—H9	120.1	C20—C19—H19B	109.1
C4—C9—H9	120.1	C18—C19—H19B	109.1
C15—C10—C11	121.6 (2)	H19A—C19—H19B	107.8
C15—C10—S1	118.5 (1)	O4—C20—O5	122.9 (2)
C11—C10—S1	119.9 (1)	O4—C20—C19	122.7 (2)
C10—C11—C12	118.2 (2)	O5—C20—C19	114.4 (2)
O2—S1—N1—C2	36.8 (2)	C5—C6—C7—C8	−0.9 (3)
O1—S1—N1—C2	165.8 (2)	C6—C7—C8—C9	1.1 (4)
C10—S1—N1—C2	−78.7 (2)	C7—C8—C9—C4	−0.2 (3)
O2—S1—N1—C5	−165.8 (1)	C5—C4—C9—C8	−0.9 (3)
O1—S1—N1—C5	−36.8 (2)	C3—C4—C9—C8	176.7 (2)
C10—S1—N1—C5	78.8 (2)	O2—S1—C10—C15	−27.9 (2)
C5—N1—C2—C3	1.3 (2)	O1—S1—C10—C15	−161.7 (2)
S1—N1—C2—C3	161.4 (1)	N1—S1—C10—C15	85.8 (2)
C5—N1—C2—C16	176.0 (2)	O2—S1—C10—C11	153.2 (2)
S1—N1—C2—C16	−23.9 (3)	O1—S1—C10—C11	19.3 (2)
N1—C2—C3—C4	0.3 (2)	N1—S1—C10—C11	−93.2 (2)
C16—C2—C3—C4	−174.1 (2)	C15—C10—C11—C12	−1.7 (3)
N1—C2—C3—C17	−178.0 (2)	S1—C10—C11—C12	177.2 (1)
C16—C2—C3—C17	7.6 (3)	C10—C11—C12—C13	0.4 (3)
C2—C3—C4—C9	−179.7 (2)	C11—C12—C13—C14	0.9 (3)
C17—C3—C4—C9	−1.5 (3)	C12—C13—C14—C15	−0.8 (3)
C2—C3—C4—C5	−1.9 (2)	C11—C10—C15—C14	1.7 (3)
C17—C3—C4—C5	176.4 (2)	S1—C10—C15—C14	−177.2 (2)
C9—C4—C5—C6	1.1 (3)	C13—C14—C15—C10	−0.5 (3)
C3—C4—C5—C6	−177.1 (2)	C2—C3—C17—O3	24.3 (3)
C9—C4—C5—N1	−179.1 (2)	C4—C3—C17—O3	−153.7 (2)
C3—C4—C5—N1	2.7 (2)	C2—C3—C17—C18	−157.3 (2)
C2—N1—C5—C6	177.3 (2)	C4—C3—C17—C18	24.7 (3)
S1—N1—C5—C6	16.4 (3)	O3—C17—C18—C19	−9.8 (3)
C2—N1—C5—C4	−2.5 (2)	C3—C17—C18—C19	171.8 (2)
S1—N1—C5—C4	−163.4 (1)	C17—C18—C19—C20	79.6 (2)
C4—C5—C6—C7	−0.2 (3)	C18—C19—C20—O4	32.9 (3)
N1—C5—C6—C7	−179.9 (2)	C18—C19—C20—O5	−150.8 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O1	0.93	2.30	2.901 (3)	122
C16—H16B···O2	0.96	2.37	2.871 (3)	112
C16—H16C···O3	0.96	2.40	2.954 (3)	117
C18—H18B···O4	0.97	2.49	2.851 (3)	102
O5—H5···O4^i	0.82	1.90	2.715 (2)	173
C15—H15···O3^ii	0.93	2.40	3.180 (3)	142
C8—H8···Cg^iii	0.93	3.39	3.997 (2)	125
C9—H9···Cg^iii	0.93	3.19	3.893 (2)	134
C19—H19A···Cg^iv	0.97	3.04	3.910 (3)	150

Symmetry codes: (i) −x+2, −y+1, −z−1; (ii) −x+1, −y+1, −z; (iii) −x+2, −y, −z; (iv) x, y, z−1.