1-sec-Butyl-3-[hy-droxy(1-methyl-1H-indol-3-yl)methyl-idene]pyrrolidine-2,4-dione.

In the title compound, C(18)H(20)N(2)O(3), the dihedral angle between the indole ring system (r.m.s. deviation = 0.018 Å) and the hy-droxy-methyl-enepyrrolidine-2,4-dione plane (r.m.s. deviation = 0.036 Å) is 9.87 (7)°. The keto and enol groups are involved in an intra-molecular O-H⋯O hydrogen bond. An intra-molecular C-H⋯O inter-action also occurs. The sec-butyl group is disordered over two orientations corresponding to an approximate 180° rotation about the N-C bond, with occupancies of 0.670 (6) and 0.330 (6). In the crystal, mol-ecules are linked into chains along the c axis by C-H⋯O hydrogen bonds.

Related literature

For the anti­biotic activity of 3-acyl­pyrrolidine-2,4-dione compounds, see: Baan et al. (1978 ▶); Holzapfel et al. (1970 ▶); Mackellar et al. (1971 ▶); Matsuo et al. (1980 ▶); Rinehart et al. (1963 ▶); Sticking (1959 ▶); Wu et al. (2002 ▶). For a related structure, see: Ellis & Spek (2001 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C18H20N2O3

M = 312.36

Monoclinic,

a = 11.781 (2) Å

b = 10.529 (2) Å

c = 12.644 (3) Å

β = 97.18 (3)°

V = 1556.1 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 113 K

0.18 × 0.16 × 0.10 mm

Data collection

Rigaku Saturn diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.984, T max = 0.991

12618 measured reflections

3698 independent reflections

2687 reflections with I > 2σ(I)

R int = 0.034

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.168

S = 1.13

3698 reflections

218 parameters

10 restraints

H-atom parameters constrained

Δρmax = 0.66 e Å−3

Δρmin = −0.57 e Å−3

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810030679/ci5139sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810030679/ci5139Isup2.hkl

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

C18H20N2O3	F(000) = 664
Mr = 312.36	Dx = 1.333 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4289 reflections
a = 11.781 (2) Å	θ = 2.5–27.9°
b = 10.529 (2) Å	µ = 0.09 mm−1
c = 12.644 (3) Å	T = 113 K
β = 97.18 (3)°	Prism, yellow
V = 1556.1 (5) Å3	0.18 × 0.16 × 0.10 mm
Z = 4

Rigaku Saturn diffractometer	3698 independent reflections
Radiation source: fine-focus sealed tube	2687 reflections with I > 2σ(I)
graphite	Rint = 0.034
ω scans	θmax = 27.9°, θmin = 2.6°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	h = −9→15
Tmin = 0.984, Tmax = 0.991	k = −13→13
12618 measured reflections	l = −16→16

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.168	H-atom parameters constrained
S = 1.13	w = 1/[σ2(Fo2) + (0.0947P)2 + 0.1812P] where P = (Fo2 + 2Fc2)/3
3698 reflections	(Δ/σ)max = 0.001
218 parameters	Δρmax = 0.66 e Å−3
10 restraints	Δρmin = −0.57 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.66886 (10)	1.07272 (11)	0.42060 (10)	0.0232 (3)
H1	0.6268	1.0643	0.4691	0.035*
O2	0.93397 (11)	0.78344 (12)	0.54741 (11)	0.0297 (3)
O3	0.59380 (11)	1.00771 (11)	0.58894 (10)	0.0258 (3)
N1	0.98265 (12)	0.96858 (14)	0.26733 (12)	0.0224 (3)
N2	0.69798 (14)	0.85187 (15)	0.68474 (13)	0.0282 (4)
C1	0.83455 (14)	1.00283 (15)	0.35989 (13)	0.0194 (4)
C2	0.81236 (14)	1.06960 (15)	0.25917 (13)	0.0202 (4)
C3	0.72166 (16)	1.14252 (16)	0.20819 (15)	0.0253 (4)
H3	0.6560	1.1595	0.2425	0.030*
C4	0.72960 (18)	1.18928 (18)	0.10697 (15)	0.0306 (4)
H4	0.6677	1.2368	0.0714	0.037*
C5	0.82620 (19)	1.16822 (18)	0.05608 (16)	0.0319 (5)
H5	0.8299	1.2041	−0.0123	0.038*
C6	0.91688 (17)	1.09601 (17)	0.10329 (15)	0.0278 (4)
H6	0.9827	1.0810	0.0687	0.033*
C7	0.90694 (15)	1.04631 (16)	0.20424 (14)	0.0216 (4)
C8	0.93954 (14)	0.94263 (16)	0.35943 (14)	0.0211 (4)
H8	0.9757	0.8910	0.4154	0.025*
C9	1.08481 (15)	0.91093 (18)	0.23351 (16)	0.0285 (4)
H9A	1.1285	0.8681	0.2943	0.043*
H9B	1.1322	0.9770	0.2065	0.043*
H9C	1.0623	0.8489	0.1770	0.043*
C10	0.75981 (14)	0.99897 (15)	0.44100 (13)	0.0186 (4)
C11	0.76929 (14)	0.92599 (15)	0.53493 (14)	0.0201 (4)
C12	0.84678 (15)	0.82736 (17)	0.57785 (14)	0.0236 (4)
C13	0.80043 (16)	0.77699 (18)	0.67725 (16)	0.0298 (4)
H13A	0.7816	0.6855	0.6696	0.036*
H13B	0.8569	0.7890	0.7413	0.036*
C14	0.67860 (15)	0.93502 (16)	0.60328 (14)	0.0220 (4)
C15	0.61807 (18)	0.8307 (2)	0.76310 (17)	0.0412 (6)
H15	0.5520	0.8898	0.7455	0.049*
C16	0.6765 (2)	0.8655 (4)	0.87609 (19)	0.0717 (10)
H16A	0.7046	0.9511	0.8762	0.108*	0.670 (6)
H16B	0.6218	0.8582	0.9260	0.108*	0.670 (6)
H16C	0.7391	0.8085	0.8962	0.108*	0.670 (6)
H16D	0.7043	0.9511	0.8756	0.086*	0.330 (6)
H16E	0.7411	0.8106	0.8945	0.086*	0.330 (6)
C17	0.5719 (2)	0.6974 (2)	0.7563 (2)	0.0582 (8)
H17A	0.5187	0.6874	0.8073	0.070*	0.670 (6)
H17B	0.6336	0.6388	0.7749	0.070*	0.670 (6)
H17C	0.5373	0.6820	0.6846	0.087*	0.330 (6)
H17D	0.6328	0.6378	0.7745	0.087*	0.330 (6)
H17E	0.5155	0.6875	0.8043	0.087*	0.330 (6)
C18	0.5146 (3)	0.6638 (3)	0.6507 (3)	0.0524 (13)	0.670 (6)
H18A	0.4453	0.7153	0.6346	0.079*	0.670 (6)
H18B	0.4939	0.5736	0.6495	0.079*	0.670 (6)
H18C	0.5662	0.6800	0.5971	0.079*	0.670 (6)
C18'	0.5954 (8)	0.8519 (12)	0.9604 (7)	0.087 (4)	0.330 (6)
H18D	0.5255	0.9007	0.9387	0.130*	0.330 (6)
H18E	0.6326	0.8840	1.0287	0.130*	0.330 (6)
H18F	0.5758	0.7621	0.9678	0.130*	0.330 (6)

	U11	U22	U33	U12	U13	U23
O1	0.0214 (6)	0.0279 (7)	0.0218 (7)	0.0049 (5)	0.0084 (5)	0.0028 (5)
O2	0.0252 (7)	0.0340 (7)	0.0313 (8)	0.0094 (6)	0.0096 (6)	0.0056 (6)
O3	0.0230 (6)	0.0314 (7)	0.0240 (7)	0.0073 (5)	0.0073 (5)	0.0040 (5)
N1	0.0202 (7)	0.0254 (7)	0.0229 (8)	−0.0016 (6)	0.0077 (6)	−0.0021 (6)
N2	0.0258 (8)	0.0336 (8)	0.0275 (8)	0.0063 (7)	0.0119 (7)	0.0098 (6)
C1	0.0201 (8)	0.0194 (8)	0.0193 (8)	−0.0042 (6)	0.0051 (7)	−0.0015 (6)
C2	0.0228 (8)	0.0190 (8)	0.0198 (8)	−0.0036 (6)	0.0063 (7)	−0.0012 (6)
C3	0.0251 (9)	0.0254 (9)	0.0268 (10)	−0.0003 (7)	0.0085 (8)	0.0016 (7)
C4	0.0356 (10)	0.0301 (9)	0.0265 (10)	0.0024 (8)	0.0062 (8)	0.0053 (8)
C5	0.0441 (12)	0.0315 (10)	0.0222 (9)	0.0004 (9)	0.0123 (9)	0.0059 (8)
C6	0.0333 (10)	0.0275 (9)	0.0248 (9)	−0.0033 (8)	0.0124 (8)	−0.0010 (7)
C7	0.0235 (8)	0.0198 (8)	0.0227 (9)	−0.0035 (7)	0.0072 (7)	−0.0025 (6)
C8	0.0203 (8)	0.0242 (8)	0.0194 (9)	−0.0030 (7)	0.0049 (7)	−0.0021 (6)
C9	0.0219 (9)	0.0339 (10)	0.0318 (10)	0.0016 (8)	0.0120 (8)	−0.0040 (8)
C10	0.0181 (8)	0.0182 (8)	0.0200 (9)	−0.0017 (6)	0.0039 (6)	−0.0027 (6)
C11	0.0196 (8)	0.0207 (8)	0.0205 (9)	−0.0002 (6)	0.0051 (7)	0.0003 (6)
C12	0.0233 (9)	0.0260 (9)	0.0222 (9)	−0.0014 (7)	0.0058 (7)	0.0010 (7)
C13	0.0282 (9)	0.0324 (10)	0.0304 (10)	0.0071 (8)	0.0103 (8)	0.0106 (8)
C14	0.0219 (8)	0.0247 (8)	0.0198 (9)	−0.0015 (7)	0.0046 (7)	0.0006 (7)
C15	0.0355 (11)	0.0539 (13)	0.0387 (12)	0.0133 (10)	0.0218 (10)	0.0209 (10)
C16	0.0500 (16)	0.129 (3)	0.0391 (15)	0.0170 (17)	0.0182 (13)	0.0283 (16)
C17	0.0434 (13)	0.0516 (14)	0.086 (2)	0.0139 (11)	0.0349 (15)	0.0354 (14)
C18	0.042 (2)	0.0387 (19)	0.080 (3)	−0.0026 (16)	0.020 (2)	0.0083 (18)
C18'	0.079 (6)	0.126 (8)	0.058 (6)	0.012 (6)	0.021 (5)	0.010 (5)

O1—C10	1.322 (2)	C10—C11	1.407 (2)
O1—H1	0.84	C11—C12	1.443 (2)
O2—C12	1.231 (2)	C11—C14	1.459 (2)
O3—C14	1.254 (2)	C12—C13	1.527 (2)
N1—C8	1.355 (2)	C13—H13A	0.99
N1—C7	1.387 (2)	C13—H13B	0.99
N1—C9	1.459 (2)	C15—C17	1.504 (3)
N2—C14	1.349 (2)	C15—C16	1.550 (3)
N2—C13	1.455 (2)	C15—H15	1.00
N2—C15	1.467 (2)	C16—C18'	1.525 (5)
C1—C8	1.390 (2)	C16—H16A	0.96
C1—C10	1.433 (2)	C16—H16B	0.96
C1—C2	1.450 (2)	C16—H16C	0.96
C2—C3	1.405 (2)	C16—H16D	0.96
C2—C7	1.406 (2)	C16—H16E	0.96
C3—C4	1.385 (3)	C17—C18	1.462 (4)
C3—H3	0.95	C17—H17A	0.96
C4—C5	1.393 (3)	C17—H17B	0.96
C4—H4	0.95	C17—H17C	0.96
C5—C6	1.384 (3)	C17—H17D	0.96
C5—H5	0.95	C17—H17E	0.96
C6—C7	1.398 (3)	C18—H18A	0.98
C6—H6	0.95	C18—H18B	0.98
C8—H8	0.95	C18—H18C	0.98
C9—H9A	0.98	C18'—H18D	0.98
C9—H9B	0.98	C18'—H18E	0.98
C9—H9C	0.98	C18'—H18F	0.98
C10—O1—H1	109.5	N2—C15—H15	107.6
C8—N1—C7	109.27 (14)	C17—C15—H15	107.6
C8—N1—C9	125.41 (16)	C16—C15—H15	107.6
C7—N1—C9	124.87 (15)	C18'—C16—C15	112.1 (5)
C14—N2—C13	111.38 (14)	C18'—C16—H16A	109.5
C14—N2—C15	123.56 (16)	C15—C16—H16A	109.6
C13—N2—C15	124.71 (15)	C15—C16—H16B	109.2
C8—C1—C10	128.05 (16)	H16A—C16—H16B	109.5
C8—C1—C2	106.28 (14)	C18'—C16—H16C	106.5
C10—C1—C2	125.66 (15)	C15—C16—H16C	109.6
C3—C2—C7	118.22 (15)	H16A—C16—H16C	109.5
C3—C2—C1	135.34 (15)	H16B—C16—H16C	109.5
C7—C2—C1	106.40 (15)	C18'—C16—H16D	109.7
C4—C3—C2	118.86 (17)	C15—C16—H16D	109.2
C4—C3—H3	120.6	H16B—C16—H16D	109.7
C2—C3—H3	120.6	H16C—C16—H16D	109.7
C3—C4—C5	121.56 (19)	C18'—C16—H16E	108.7
C3—C4—H4	119.2	C15—C16—H16E	109.2
C5—C4—H4	119.2	H16A—C16—H16E	107.6
C6—C5—C4	121.27 (17)	H16B—C16—H16E	111.7
C6—C5—H5	119.4	H16D—C16—H16E	107.8
C4—C5—H5	119.4	C18—C17—C15	113.6 (2)
C5—C6—C7	116.82 (17)	C18—C17—H17A	108.8
C5—C6—H6	121.6	C15—C17—H17A	109.0
C7—C6—H6	121.6	C18—C17—H17B	108.5
N1—C7—C6	128.67 (16)	C15—C17—H17B	109.1
N1—C7—C2	108.13 (14)	H17A—C17—H17B	107.6
C6—C7—C2	123.20 (17)	C15—C17—H17C	108.7
N1—C8—C1	109.93 (16)	H17A—C17—H17C	112.4
N1—C8—H8	125.0	H17B—C17—H17C	110.0
C1—C8—H8	125.0	C18—C17—H17D	107.9
N1—C9—H9A	109.5	C15—C17—H17D	110.0
N1—C9—H9B	109.5	H17A—C17—H17D	107.3
H9A—C9—H9B	109.5	H17C—C17—H17D	109.5
N1—C9—H9C	109.5	C18—C17—H17E	105.9
H9A—C9—H9C	109.5	C15—C17—H17E	109.8
H9B—C9—H9C	109.5	H17B—C17—H17E	109.7
O1—C10—C11	117.53 (14)	H17C—C17—H17E	109.5
O1—C10—C1	113.52 (15)	H17D—C17—H17E	109.5
C11—C10—C1	128.93 (15)	C17—C18—H18A	109.5
C10—C11—C12	133.64 (15)	H17C—C18—H18A	107.5
C10—C11—C14	118.53 (15)	C17—C18—H18B	109.5
C12—C11—C14	107.45 (14)	H17C—C18—H18B	118.4
O2—C12—C11	131.76 (16)	H18A—C18—H18B	109.5
O2—C12—C13	121.67 (16)	C17—C18—H18C	109.5
C11—C12—C13	106.56 (14)	H17C—C18—H18C	102.1
N2—C13—C12	104.50 (14)	H18A—C18—H18C	109.5
N2—C13—H13A	110.9	H18B—C18—H18C	109.5
C12—C13—H13A	110.9	C16—C18'—H18D	109.5
N2—C13—H13B	110.9	H16B—C18'—H18D	104.2
C12—C13—H13B	110.9	C16—C18'—H18E	109.5
H13A—C13—H13B	108.9	H16B—C18'—H18E	113.9
O3—C14—N2	124.21 (16)	H18D—C18'—H18E	109.5
O3—C14—C11	125.70 (16)	C16—C18'—H18F	109.5
N2—C14—C11	110.08 (15)	H16B—C18'—H18F	110.2
N2—C15—C17	111.19 (18)	H18D—C18'—H18F	109.5
N2—C15—C16	109.75 (18)	H18E—C18'—H18F	109.5
C17—C15—C16	112.9 (2)
C8—C1—C2—C3	176.72 (18)	C1—C10—C11—C12	−5.6 (3)
C10—C1—C2—C3	−1.9 (3)	O1—C10—C11—C14	0.5 (2)
C8—C1—C2—C7	−0.62 (18)	C1—C10—C11—C14	−177.42 (16)
C10—C1—C2—C7	−179.19 (15)	C10—C11—C12—O2	5.9 (3)
C7—C2—C3—C4	−0.7 (3)	C14—C11—C12—O2	178.41 (19)
C1—C2—C3—C4	−177.76 (18)	C10—C11—C12—C13	−173.30 (18)
C2—C3—C4—C5	−1.6 (3)	C14—C11—C12—C13	−0.80 (19)
C3—C4—C5—C6	2.1 (3)	C14—N2—C13—C12	1.2 (2)
C4—C5—C6—C7	−0.4 (3)	C15—N2—C13—C12	174.59 (18)
C8—N1—C7—C6	180.00 (18)	O2—C12—C13—N2	−179.49 (17)
C9—N1—C7—C6	−7.3 (3)	C11—C12—C13—N2	−0.2 (2)
C8—N1—C7—C2	−0.17 (19)	C13—N2—C14—O3	177.45 (17)
C9—N1—C7—C2	172.49 (15)	C15—N2—C14—O3	4.0 (3)
C5—C6—C7—N1	177.90 (17)	C13—N2—C14—C11	−1.8 (2)
C5—C6—C7—C2	−1.9 (3)	C15—N2—C14—C11	−175.24 (17)
C3—C2—C7—N1	−177.39 (15)	C10—C11—C14—O3	−3.8 (3)
C1—C2—C7—N1	0.49 (18)	C12—C11—C14—O3	−177.61 (17)
C3—C2—C7—C6	2.5 (3)	C10—C11—C14—N2	175.43 (15)
C1—C2—C7—C6	−179.67 (16)	C12—C11—C14—N2	1.6 (2)
C7—N1—C8—C1	−0.24 (19)	C14—N2—C15—C17	115.6 (2)
C9—N1—C8—C1	−172.85 (15)	C13—N2—C15—C17	−57.0 (3)
C10—C1—C8—N1	179.06 (16)	C14—N2—C15—C16	−118.7 (2)
C2—C1—C8—N1	0.53 (18)	C13—N2—C15—C16	68.7 (3)
C8—C1—C10—O1	176.19 (15)	N2—C15—C16—C18'	177.0 (5)
C2—C1—C10—O1	−5.5 (2)	C17—C15—C16—C18'	−58.3 (6)
C8—C1—C10—C11	−5.8 (3)	N2—C15—C17—C18	−57.2 (3)
C2—C1—C10—C11	172.44 (16)	C16—C15—C17—C18	178.9 (2)
O1—C10—C11—C12	172.36 (17)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O3	0.84	1.72	2.5003 (19)	154
C8—H8···O2	0.95	2.12	2.916 (2)	140
C9—H9C···O2i	0.98	2.51	3.441 (3)	159

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O3	0.84	1.72	2.5003 (19)	154
C8—H8⋯O2	0.95	2.12	2.916 (2)	140
C9—H9C⋯O2i	0.98	2.51	3.441 (3)	159

Symmetry code: (i) .