3-Hydr­oxy-3-[(2-methyl­propano­yl)meth­yl]indolin-2-one

The title compound, C₁₃H₁₅NO₃, was synthesized by the Aldol reaction of isatin and 3-methyl­butan-2-one refluxing in methanol catalyzed by dimethyl­amine. The packing of the mol­ecules in the crystal structure features inter­molecular N—H...O and O—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.045
• wR factor = 0.161
• Data-to-parameter ratio = 16.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.05 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.32 Ratio
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K
PLAT793_ALERT_4_G The Model has Chirality at C2      (Verify) ....          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Isatin, an endogenous compound in mammalian tissues and body fluids (Glover, et al., 1988), has caught great attention of many researchers as a versatile lead molecule for designing of potential drugs (Pandeya, et al., 2000; Sun, et al., 1998; Teitz, et al., 1994). In our previous study, 3-hydroxy-3-(2-oxo-propyl)-1,3-dihydro-indol-2-one, yielded from the Aldol reaction of isatin with acetone, was found to be a new chemical activator against tobacco mosaic virus (TMV) infection (Li, 2008). In tobacco plant, external application of 3-hydroxy-3-(2-oxo-propyl)-1,3-dihydro-indol-2-one results in restriction of TMV multiplication and spread, accumulation of salicylic acid level expression of PR-1 gene, and activation and increase of phenylalanine ammonia-lyase (PAL) activity. With these findings, some analogs need to be synthesized for structure activity relationship research to find more potent molecules.

One of these analogs, 3-hydroxy-3-(3-methyl-2-oxo-butyl)-1,3-dihydro-indol-2-one (compound I), was synthesized by the Aldol reaction of isatin with 3-methyl-butan-2-one. In order to provide the structural information of compound I, we studied its crystal structure. The title compound was synthesized in a one step Aldol reaction of isatin (0.01 mmol) with 3-methyl-butan-2-one, according to the reported method (Garden et al., 2002). The molar ratio of isatin: 3-methyl-butan-2-one = 1:3 refluxed in methanol gave compound I in 72% yield, and colorless crystals of compound I were obtained in ethanol by recrystallization. The values of the geometric parameters of compound I are within normal ranges and experimental errors.

The molecular structure of compound I is illustrated in Fig. 1. In the molecule, the 2-oxo-indole ring is planar, and the angle between hydroxyl group and 3-methyl-2-oxo-butyl group is 105.10 (12)°. The intermolecular interactions are primarily responsible for the formation of the crystal structure of compound I. Each molecule is fixed by four hydrogen bond of other three molecules. N1–H1 acts as a hydrogen bond donor, and O1 is a hydrogen bond accepter. To O2–H2, it acts as both a hydrogen bond donor and a hydrogen bond accepter, which connects with two molecules by O–H···O and O···H–N with the angle of 119.21 (9)°. There is no anticipated intramolecular hydrogen bond between O2–H2 and O3, and O3 is not involved in any hydrogen bond (Fig. 2).

Related literature

For related structures, see: Garden et al. (2002); Li, et al. (2008). For the bioactivity of derivatives, see: Glover et al. (1988); Marti & Carreira (2003); Pandeya et al. (2000); Sun et al. (1998); Teitz et al. (1994).

For related literature, see: Brandenburg (1999).

S2. Experimental

A mixture of isatin (0.01 mmol) and 3-methyl-butan-2-one (0.03 mmol) was refluxed in methanol (60 ml), catalyzed by a drop of dimethylamine, until the disappearance of the starting material, as evidenced by thin-layer chromatography. The solvent was removed in vacuo and the residue was separated by column chromatography (silica gel, petroleum ether/ethyl acetate = 5:1), giving the title compound I 0.168 g, yield 72%. ¹H-NMR (CDCl₃, 400 MHz): 8.5 (1H,s), 7.32 (1H, d, J = 7.2 Hz), 7.24 (1H, t, J = 7.6 Hz), 7.03 (1H, t, J = 7.2 Hz), 6.88 (1H, d, J = 16.8 Hz), 4.81 (1H, s), 3.25 (1H, d, J = 16.8 Hz), 3.17 (1H, d, J = 16.8 Hz), 2.56 (1H, q, J = 6.8 Hz), 1.05 (6H, dd, J = 29.2, 6.8 Hz); ¹³C-NMR (CDCl₃, 100 MHz): 213.9, 178.5, 140.6, 130.3, 129.9, 124.1, 123.1, 110.5, 74.7, 45.6, 41.9, 17.6; MS (EI) m/z: 219 (M⁺). 30 mg of compound I was dissolved in 30 ml methanol and the solution was kept at room temperature for 4 d, natural evaporation gave colorless single crystals of compound I suitable for X-ray analysis.

S3. Refinement

All H atoms were positioned geometrically, with C–H = 0.93–0.98 Å, and refined using riding model, with U_iso(H) = 1.2U_eq(carrier).

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. An ORTEP-3 drawing of compound I, with the atom-numbering scheme and 30% probability displacement ellipsoids.
	Fig. 2. Packing diagram of the title compound. Dashed lines indicate hydrogen bonds.

3-Hydroxy-3-[(2-methylpropanoyl)methyl]indolin-2-one

Crystal data

C13H15NO3	F(000) = 496
Mr = 233.26	Dx = 1.333 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3113 reflections
a = 11.885 (2) Å	θ = 1.9–27.4°
b = 5.9244 (12) Å	µ = 0.10 mm^−1
c = 16.695 (3) Å	T = 293 K
β = 98.60 (3)°	Block, colorless
V = 1162.3 (5) Å^3	0.23 × 0.18 × 0.15 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2577 independent reflections
Radiation source: fine-focus sealed tube	1902 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ϕ and ω scans	θmax = 27.5°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2005)	h = −15→14
Tmin = 0.945, Tmax = 0.985	k = −7→7
8623 measured reflections	l = −21→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.045	H-atom parameters constrained
wR(F^2) = 0.161	w = 1/[σ^2(Fo^2) + (0.0562P)^2 + 0.2707P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
2577 reflections	Δρmax = 0.24 e Å^−3
155 parameters	Δρmin = −0.22 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4'
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.018 (4)

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
O2	0.57929 (9)	0.14669 (16)	0.55228 (6)	0.0335 (3)
H2A	0.5183	0.2128	0.5411	0.050*
O1	0.62325 (9)	0.59992 (19)	0.48205 (6)	0.0368 (3)
N1	0.60709 (11)	0.6720 (2)	0.61556 (8)	0.0324 (3)
H1A	0.5830	0.8088	0.6103	0.039*
O3	0.87069 (11)	0.5445 (2)	0.61665 (9)	0.0542 (4)
C1	0.63221 (12)	0.5435 (2)	0.55343 (9)	0.0292 (4)
C8	0.66420 (12)	0.3373 (2)	0.67659 (9)	0.0278 (4)
C9	0.77543 (13)	0.2149 (3)	0.56337 (10)	0.0320 (4)
H9A	0.7868	0.0611	0.5829	0.038*
H9B	0.7679	0.2105	0.5047	0.038*
C10	0.87990 (14)	0.3519 (3)	0.59554 (10)	0.0347 (4)
C7	0.62536 (13)	0.5539 (2)	0.69000 (9)	0.0289 (4)
C2	0.66509 (12)	0.3034 (2)	0.58702 (9)	0.0276 (4)
C3	0.69101 (13)	0.1899 (3)	0.74041 (9)	0.0322 (4)
H3A	0.7185	0.0462	0.7320	0.039*
C6	0.61006 (14)	0.6260 (3)	0.76617 (10)	0.0351 (4)
H6A	0.5832	0.7702	0.7746	0.042*
C4	0.67614 (14)	0.2602 (3)	0.81790 (10)	0.0383 (4)
H4A	0.6931	0.1621	0.8615	0.046*
C5	0.63660 (14)	0.4736 (3)	0.83018 (10)	0.0381 (4)
H5A	0.6273	0.5176	0.8823	0.046*
C11	0.99369 (15)	0.2365 (3)	0.59805 (12)	0.0500 (5)
H11A	0.9932	0.1539	0.5471	0.060*
C12	1.0100 (2)	0.0663 (4)	0.66754 (18)	0.0843 (9)
H12A	0.9472	−0.0375	0.6614	0.126*
H12B	1.0133	0.1446	0.7182	0.126*
H12C	1.0796	−0.0153	0.6667	0.126*
C13	1.09104 (19)	0.4058 (5)	0.60623 (16)	0.0752 (7)
H13A	1.0797	0.5089	0.5614	0.113*
H13B	1.1617	0.3271	0.6065	0.113*
H13C	1.0931	0.4880	0.6560	0.113*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O2	0.0286 (6)	0.0262 (6)	0.0431 (7)	−0.0024 (4)	−0.0035 (5)	−0.0012 (4)
O1	0.0390 (7)	0.0385 (7)	0.0323 (6)	0.0007 (5)	0.0031 (5)	0.0073 (5)
N1	0.0381 (8)	0.0242 (6)	0.0349 (8)	0.0044 (5)	0.0053 (6)	0.0016 (5)
O3	0.0401 (8)	0.0400 (8)	0.0817 (10)	−0.0055 (5)	0.0068 (7)	−0.0124 (7)
C1	0.0247 (8)	0.0269 (8)	0.0353 (9)	−0.0018 (6)	0.0021 (6)	0.0021 (6)
C8	0.0247 (8)	0.0271 (8)	0.0317 (8)	−0.0010 (6)	0.0044 (6)	0.0004 (6)
C9	0.0290 (8)	0.0312 (8)	0.0352 (8)	0.0019 (6)	0.0025 (6)	−0.0032 (6)
C10	0.0325 (9)	0.0390 (9)	0.0334 (9)	−0.0020 (7)	0.0074 (7)	−0.0007 (7)
C7	0.0252 (8)	0.0283 (8)	0.0332 (8)	−0.0003 (6)	0.0041 (6)	0.0025 (6)
C2	0.0263 (8)	0.0253 (8)	0.0300 (8)	−0.0016 (6)	0.0002 (6)	−0.0015 (6)
C3	0.0324 (9)	0.0277 (8)	0.0360 (9)	0.0022 (6)	0.0034 (7)	0.0036 (6)
C6	0.0346 (9)	0.0301 (9)	0.0415 (9)	0.0009 (6)	0.0085 (7)	−0.0054 (7)
C4	0.0377 (10)	0.0429 (10)	0.0333 (9)	−0.0001 (7)	0.0022 (7)	0.0066 (7)
C5	0.0340 (9)	0.0512 (11)	0.0298 (8)	−0.0023 (7)	0.0071 (6)	−0.0045 (7)
C11	0.0313 (10)	0.0610 (12)	0.0566 (12)	0.0022 (8)	0.0033 (8)	−0.0117 (10)
C12	0.0569 (15)	0.0593 (14)	0.127 (2)	0.0053 (11)	−0.0164 (14)	0.0254 (15)
C13	0.0335 (12)	0.1033 (19)	0.0886 (18)	−0.0095 (12)	0.0084 (11)	0.0082 (15)

Geometric parameters (Å, º)

O2—C2	1.4356 (16)	C3—C4	1.395 (2)
O2—H2A	0.8200	C3—H3A	0.9300
O1—C1	1.2270 (18)	C6—C5	1.399 (2)
N1—C1	1.355 (2)	C6—H6A	0.9300
N1—C7	1.4144 (19)	C4—C5	1.375 (3)
N1—H1A	0.8600	C4—H4A	0.9300
O3—C10	1.204 (2)	C5—H5A	0.9300
C1—C2	1.557 (2)	C11—C13	1.522 (3)
C8—C3	1.378 (2)	C11—C12	1.527 (3)
C8—C7	1.393 (2)	C11—H11A	0.9800
C8—C2	1.510 (2)	C12—H12A	0.9600
C9—C10	1.513 (2)	C12—H12B	0.9600
C9—C2	1.518 (2)	C12—H12C	0.9600
C9—H9A	0.9700	C13—H13A	0.9600
C9—H9B	0.9700	C13—H13B	0.9600
C10—C11	1.511 (2)	C13—H13C	0.9600
C7—C6	1.379 (2)
C2—O2—H2A	109.5	C8—C3—H3A	120.6
C1—N1—C7	111.85 (12)	C4—C3—H3A	120.6
C1—N1—H1A	124.1	C7—C6—C5	117.29 (15)
C7—N1—H1A	124.1	C7—C6—H6A	121.4
O1—C1—N1	126.39 (14)	C5—C6—H6A	121.4
O1—C1—C2	125.40 (14)	C5—C4—C3	120.42 (15)
N1—C1—C2	108.04 (13)	C5—C4—H4A	119.8
C3—C8—C7	120.23 (14)	C3—C4—H4A	119.8
C3—C8—C2	130.26 (14)	C4—C5—C6	121.53 (15)
C7—C8—C2	109.47 (12)	C4—C5—H5A	119.2
C10—C9—C2	114.65 (13)	C6—C5—H5A	119.2
C10—C9—H9A	108.6	C13—C11—C10	111.69 (16)
C2—C9—H9A	108.6	C13—C11—C12	111.02 (18)
C10—C9—H9B	108.6	C10—C11—C12	109.35 (17)
C2—C9—H9B	108.6	C13—C11—H11A	108.2
H9A—C9—H9B	107.6	C10—C11—H11A	108.2
O3—C10—C11	122.77 (15)	C12—C11—H11A	108.2
O3—C10—C9	120.45 (15)	C11—C12—H12A	109.5
C11—C10—C9	116.77 (14)	C11—C12—H12B	109.5
C6—C7—C8	121.75 (14)	H12A—C12—H12B	109.5
C6—C7—N1	129.26 (14)	C11—C12—H12C	109.5
C8—C7—N1	108.99 (13)	H12A—C12—H12C	109.5
O2—C2—C8	112.10 (12)	H12B—C12—H12C	109.5
O2—C2—C9	105.10 (11)	C11—C13—H13A	109.5
C8—C2—C9	115.95 (12)	C11—C13—H13B	109.5
O2—C2—C1	108.68 (11)	H13A—C13—H13B	109.5
C8—C2—C1	101.33 (11)	C11—C13—H13C	109.5
C9—C2—C1	113.69 (13)	H13A—C13—H13C	109.5
C8—C3—C4	118.76 (15)	H13B—C13—H13C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^i	0.86	2.22	3.0049 (18)	151
O2—H2A···O1^ii	0.82	2.00	2.8220 (17)	175

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