Crystal structure and conformational analysis of 2-hy-droxy-3-(2-methyl-prop-1-en-1-yl)naphthalene-1,4-dione.

In the structure of the title compound, C14H12O3, the substituent side chain, in which the H atoms of both methyl groups are disordered over six equivalent sites, lies outside of the plane of the naphthalene-dione ring. The ring-to-chain C-C-C-C torsion angles are 50.7 (3), -176.6 (2) and 4.9 (4)°. An intra-molecular meth-yl-hy-droxy C-H⋯O hydrogen bond is present. In the crystal, mol-ecules are primarily connected by inter-molecular O-H⋯O hydrogen bonds, forming a centrosymmetric cyclic dimer motif [graph set R 2 (2)(10)]. Also present is a weak inter-molecular C-H⋯O hydrogen bond linking the dimers and a weak π-π ring inter-action [ring centroid separation = 3.7862 (13) Å], giving layers parallel to (10-3).

Chemical context

Naphtho­quinone compounds exhibit several biological activities, being utilized for the treatment of parasitic diseases (Salas et al., 2008 ▸) some types of cancer (Tonholo et al., 1998 ▸) and cardiovascular disease (Silva & Torres, 2013 ▸). The compound in this study, 2-hy­droxy-3-(2-metilprop-1-enol)naphthalene-1,4-dione, C14H12O3, is a naphthoquinone deriv­ative and the structure is reported herein.

Structural commentary

The mol­ecular structure of the title compound is shown in Fig. 1 ▸. In this structure the side chain is rotated out of the plane of the naphthalene­dione ring, with torsion angles C2—C3—C9—C10, C3—C9—C10—C12 and C3—C9—C10—C22 of 50.7 (3), −176.6 (2) and 4.9 (4)°, respectively. Present also in the mol­ecule is an intra­molecular methyl C22⋯O3 [2.959 (3) Å; see Table 1 ▸] and a short O3⋯O1 contact [2.665 (2) Å]. When compared with other analogous structures in the literature, e.g. 2-chloro-3-(4-chloro­benzamido)-1,4-naphtho­quinone (Brandy et al., 2009 ▸), it is observed that the title compound has similar conformational features with respect to the side chain, which lies out of the naphtho­quinone plane.

Figure 1

Mol­ecular conformation and atom-numbering scheme, with non-H atoms drawn at the 50% probability level. The H atoms of the rotationally disordered methyl groups are shown as six equivalent half-occupancy sites.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H1O3⋯O1i	0.97 (3)	1.93 (3)	2.770 (2)	143 (3)
C7—H7⋯O2ii	0.93	2.43	3.339 (3)	164
C22—H22C⋯O3	0.96	2.21	2.959 (3)	134

Symmetry codes: (i) ; (ii) .

Supra­molecular features

In the crystal, the mol­ecules are connected by classic inter­molecular O3—H⋯O1i hydrogen bonds (Table 1 ▸), forming a centrosymmetric cyclic dimer [graph set (10)] (Bernstein et al., 1995 ▸) (Fig. 2 ▸ a). Also present in the structure is a weak inter­molecular C7—H⋯O2ii hydrogen bond [3.339 (3) Å], linking the dimers and a weak π–π ring inter­action between the benzene and quinone ring moieties of the parent ring system [ring centroid separation Cg⋯ iii = 3.7862 (13) Å; symmetry code: (iii) x + 1, y, z], giving layers parallel to (10) (Figs. 2 ▸ b and 3 ▸).

Figure 2

The centrosymmetric dimers formed from the O3—H⋯O1i hydrogen bonds, viewed (a) along a and (b) along b. For symmetry code (i), see Table 1 ▸.

Figure 3

The crystal packing in the unit cell, showing intra- and inter­molecular inter­actions as dashed lines.

Database survey

A search of the Cambridge Structural Database (Groom & Allen, 2014 ▸) revealed the presence of 40 structures containing the 2-hy­droxy­naphthalene-1,4-dione core moiety. There were 787 structures which possess the naphthalene-1,4-dione moiety. There are structures similar to the title compound, whichvary depending on the oxidant used in the synthesis.

Synthesis and crystallization

The compound was obtained through to the lapachol oxidation product as can be seen in the scheme below (Hooker, 1936 ▸). The sample was subjected to an ethyl acetate solution at 301 K for crystallization.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. The O3-bound H atom was located in a difference Fourier map and was freely refined. The remaining H atoms were positioned geometrically with aromatic C—H = 0.93 Å and U iso(H) = 1.2U eq(C). Rotational disorder was identified in the hydrogen atoms of the methyl carbon atoms C12 and C22 and these were included in the refinement over six equivalent 60° sites with 50% occupation, with C—H = 0.96 Å and U iso(H) = 1.5U eq(C).

Table 2

Experimental details

Crystal data
Chemical formula	C14H12O3
M r	228.24
Crystal system, space group	Monoclinic, P21/c
Temperature (K)	293
a, b, c (Å)	4.3564 (2), 16.4069 (8), 15.8598 (7)
β (°)	94.793 (2)
V (Å3)	1129.62 (9)
Z	4
Radiation type	Mo Kα
μ (mm−1)	0.09
Crystal size (mm)	0.14 × 0.11 × 0.10
Data collection
Diffractometer	Nonius KappaCCD
No. of measured, independent and observed [I > 2σ(I)] reflections	4661, 2585, 1802
R int	0.041
(sin θ/λ)max (Å−1)	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.061, 0.191, 1.03
No. of reflections	2585
No. of parameters	158
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.31, −0.30

Computer programs: COLLECT (Enraf–Nonius, 2001 ▸), DENZO and SCALEPACK (Otwinowski & Minor, 1997 ▸), SHELXS97 and SHELXL97 (Sheldrick, 2008 ▸), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ▸), Mercury (Macrae et al., 2008 ▸), publCIF (Westrip, 2010 ▸) and PLATON (Spek, 2009 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015024755/zs2357sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015024755/zs2357Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015024755/zs2357Isup3.cml

CCDC reference: 1444109

Additional supporting information: crystallographic information; 3D view; checkCIF report

C14H12O3	F(000) = 480
Mr = 228.24	Dx = 1.342 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2659 reflections
a = 4.3564 (2) Å	θ = 1.0–27.5°
b = 16.4069 (8) Å	µ = 0.09 mm−1
c = 15.8598 (7) Å	T = 293 K
β = 94.793 (2)°	Block, red
V = 1129.62 (9) Å3	0.14 × 0.11 × 0.10 mm
Z = 4

Nonius KappaCCD diffractometer	1802 reflections with I > 2σ(I)
Radiation source: Enraf-Nonius FR590	Rint = 0.041
Graphite monochromator	θmax = 27.5°, θmin = 2.6°
Detector resolution: 9 pixels mm-1	h = −5→5
CCD rotation images, thick slices scans	k = −19→21
4661 measured reflections	l = −20→20
2585 independent reflections

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)] = 0.061	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.191	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ2(Fo2) + (0.0946P)2 + 0.4119P] where P = (Fo2 + 2Fc2)/3
2585 reflections	(Δ/σ)max < 0.001
158 parameters	Δρmax = 0.31 e Å−3
0 restraints	Δρmin = −0.30 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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)
O3	0.3690 (4)	0.37038 (10)	0.48362 (10)	0.0407 (4)
O1	0.2205 (4)	0.52143 (9)	0.43377 (9)	0.0404 (4)
O2	−0.3406 (4)	0.27382 (9)	0.26721 (10)	0.0481 (5)
C10	0.0940 (5)	0.19603 (13)	0.47932 (13)	0.0395 (5)
C9	0.0749 (5)	0.23006 (12)	0.40272 (13)	0.0386 (5)
H9	0.1126	0.1961	0.3578	0.046*
H1O3	0.448 (7)	0.424 (2)	0.5005 (19)	0.073 (9)*
C4A	−0.3114 (5)	0.41650 (12)	0.28476 (13)	0.0349 (5)
C8A	−0.1689 (5)	0.48205 (13)	0.32860 (13)	0.0348 (5)
C2	0.1441 (5)	0.38047 (12)	0.42115 (13)	0.0351 (5)
C1	0.0733 (5)	0.46622 (12)	0.39675 (13)	0.0350 (5)
C5	−0.5333 (5)	0.43122 (14)	0.21845 (13)	0.0400 (5)
H5	−0.6268	0.3879	0.1885	0.048*
C3	0.0007 (5)	0.31557 (12)	0.38155 (12)	0.0358 (5)
C4	−0.2235 (5)	0.33077 (13)	0.30859 (13)	0.0369 (5)
C6	−0.6151 (5)	0.51093 (14)	0.19709 (14)	0.0426 (5)
H6	−0.7628	0.5207	0.1524	0.051*
C8	−0.2532 (5)	0.56203 (13)	0.30691 (14)	0.0386 (5)
H8	−0.1584	0.6056	0.3362	0.046*
C7	−0.4789 (5)	0.57607 (13)	0.24159 (14)	0.0413 (5)
H7	−0.5389	0.6291	0.2277	0.05*
C12	0.1899 (6)	0.10858 (13)	0.49043 (15)	0.0475 (6)
H12A	0.1919	0.0939	0.5491	0.071*	0.5
H12B	0.3923	0.1015	0.4718	0.071*	0.5
H12C	0.0468	0.0744	0.4575	0.071*	0.5
H12D	0.2288	0.086	0.4365	0.071*	0.5
H12E	0.0283	0.0784	0.5138	0.071*	0.5
H12F	0.3738	0.1055	0.5281	0.071*	0.5
C22	0.0189 (6)	0.23815 (14)	0.55869 (14)	0.0452 (6)
H22A	0.0507	0.2013	0.6056	0.068*	0.5
H22B	−0.1923	0.2554	0.553	0.068*	0.5
H22C	0.1503	0.2848	0.5684	0.068*	0.5
H22D	−0.0449	0.2931	0.5457	0.068*	0.5
H22E	0.1981	0.2389	0.5983	0.068*	0.5
H22F	−0.1445	0.2095	0.583	0.068*	0.5

	U11	U22	U33	U12	U13	U23
O3	0.0435 (9)	0.0323 (8)	0.0450 (9)	−0.0013 (6)	−0.0051 (6)	−0.0002 (7)
O1	0.0456 (9)	0.0318 (8)	0.0431 (8)	−0.0041 (6)	−0.0005 (6)	−0.0022 (6)
O2	0.0651 (11)	0.0308 (8)	0.0460 (9)	−0.0033 (7)	−0.0096 (7)	−0.0026 (7)
C10	0.0438 (12)	0.0302 (10)	0.0439 (12)	−0.0025 (8)	−0.0013 (9)	−0.0004 (9)
C9	0.0462 (12)	0.0282 (10)	0.0409 (11)	0.0009 (9)	0.0011 (9)	−0.0027 (9)
C4A	0.0422 (11)	0.0292 (10)	0.0340 (10)	−0.0011 (8)	0.0061 (8)	0.0012 (8)
C8A	0.0398 (11)	0.0305 (11)	0.0346 (10)	−0.0016 (8)	0.0057 (8)	−0.0001 (8)
C2	0.0384 (11)	0.0314 (11)	0.0355 (10)	0.0003 (8)	0.0035 (8)	0.0009 (8)
C1	0.0398 (11)	0.0288 (10)	0.0367 (10)	−0.0019 (8)	0.0055 (8)	−0.0034 (8)
C5	0.0486 (13)	0.0343 (11)	0.0368 (11)	−0.0025 (9)	0.0015 (9)	−0.0004 (9)
C3	0.0431 (11)	0.0292 (10)	0.0355 (10)	−0.0006 (8)	0.0064 (8)	−0.0006 (8)
C4	0.0453 (12)	0.0299 (10)	0.0357 (11)	−0.0025 (9)	0.0040 (9)	−0.0011 (8)
C6	0.0500 (13)	0.0383 (12)	0.0391 (11)	0.0013 (9)	0.0003 (9)	0.0039 (9)
C8	0.0460 (12)	0.0293 (10)	0.0410 (11)	−0.0005 (8)	0.0062 (9)	−0.0002 (8)
C7	0.0493 (12)	0.0312 (11)	0.0436 (11)	0.0027 (9)	0.0060 (9)	0.0055 (9)
C12	0.0651 (15)	0.0315 (11)	0.0447 (12)	0.0020 (10)	−0.0024 (10)	0.0011 (9)
C22	0.0587 (14)	0.0346 (11)	0.0420 (12)	0.0006 (10)	0.0033 (10)	0.0011 (9)

O3—C2	1.344 (3)	C3—C4	1.472 (3)
O3—H1O3	0.97 (4)	C6—C7	1.387 (3)
O1—C1	1.230 (2)	C6—H6	0.93
O2—C4	1.228 (2)	C8—C7	1.387 (3)
C10—C9	1.333 (3)	C8—H8	0.93
C10—C22	1.496 (3)	C7—H7	0.93
C10—C12	1.501 (3)	C12—H12A	0.96
C9—C3	1.472 (3)	C12—H12B	0.96
C9—H9	0.93	C12—H12C	0.96
C4A—C5	1.389 (3)	C12—H12D	0.96
C4A—C8A	1.398 (3)	C12—H12E	0.96
C4A—C4	1.498 (3)	C12—H12F	0.96
C8A—C8	1.398 (3)	C22—H22A	0.96
C8A—C1	1.469 (3)	C22—H22B	0.96
C2—C3	1.361 (3)	C22—H22C	0.96
C2—C1	1.485 (3)	C22—H22D	0.96
C5—C6	1.390 (3)	C22—H22E	0.96
C5—H5	0.93	C22—H22F	0.96
C2—O3—H1O3	108.3 (18)	C10—C12—H12C	109.5
C9—C10—C22	124.9 (2)	H12A—C12—H12C	109.5
C9—C10—C12	120.2 (2)	H12B—C12—H12C	109.5
C22—C10—C12	114.91 (19)	C10—C12—H12D	109.5
C10—C9—C3	127.1 (2)	H12A—C12—H12D	141.1
C10—C9—H9	116.5	H12B—C12—H12D	56.3
C3—C9—H9	116.5	H12C—C12—H12D	56.3
C5—C4A—C8A	119.67 (19)	C10—C12—H12E	109.5
C5—C4A—C4	120.09 (19)	H12A—C12—H12E	56.3
C8A—C4A—C4	120.23 (18)	H12B—C12—H12E	141.1
C4A—C8A—C8	120.21 (19)	H12C—C12—H12E	56.3
C4A—C8A—C1	119.46 (19)	H12D—C12—H12E	109.5
C8—C8A—C1	120.32 (19)	C10—C12—H12F	109.5
O3—C2—C3	121.45 (19)	H12A—C12—H12F	56.3
O3—C2—C1	115.56 (18)	H12B—C12—H12F	56.3
C3—C2—C1	122.95 (19)	H12C—C12—H12F	141.1
O1—C1—C8A	122.31 (19)	H12D—C12—H12F	109.5
O1—C1—C2	119.00 (18)	H12E—C12—H12F	109.5
C8A—C1—C2	118.68 (18)	C10—C22—H22A	109.5
C4A—C5—C6	119.8 (2)	C10—C22—H22B	109.5
C4A—C5—H5	120.1	H22A—C22—H22B	109.5
C6—C5—H5	120.1	C10—C22—H22C	109.5
C2—C3—C4	118.61 (19)	H22A—C22—H22C	109.5
C2—C3—C9	123.83 (19)	H22B—C22—H22C	109.5
C4—C3—C9	117.35 (18)	C10—C22—H22D	109.5
O2—C4—C3	120.66 (19)	H22A—C22—H22D	141.1
O2—C4—C4A	119.58 (18)	H22B—C22—H22D	56.3
C3—C4—C4A	119.76 (18)	H22C—C22—H22D	56.3
C7—C6—C5	120.7 (2)	C10—C22—H22E	109.5
C7—C6—H6	119.6	H22A—C22—H22E	56.3
C5—C6—H6	119.6	H22B—C22—H22E	141.1
C7—C8—C8A	119.7 (2)	H22C—C22—H22E	56.3
C7—C8—H8	120.2	H22D—C22—H22E	109.5
C8A—C8—H8	120.2	C10—C22—H22F	109.5
C6—C7—C8	119.9 (2)	H22A—C22—H22F	56.3
C6—C7—H7	120	H22B—C22—H22F	56.3
C8—C7—H7	120	H22C—C22—H22F	141.1
C10—C12—H12A	109.5	H22D—C22—H22F	109.5
C10—C12—H12B	109.5	H22E—C22—H22F	109.5
H12A—C12—H12B	109.5
O1—C1—C2—O3	0.2 (3)	O2—C4—C4A—C5	2.6 (3)
O1—C1—C2—C3	−177.5 (2)	O2—C4—C4A—C8A	−176.8 (2)
C8A—C1—C2—O3	179.69 (19)	C3—C4—C4A—C5	−177.0 (2)
C8A—C1—C2—C3	2.0 (3)	C3—C4—C4A—C8A	3.5 (3)
O1—C1—C8A—C4A	175.2 (2)	C4—C4A—C5—C6	179.6 (2)
O1—C1—C8A—C8	−3.9 (3)	C8A—C4A—C5—C6	−1.0 (3)
C2—C1—C8A—C4A	−4.3 (3)	C4—C4A—C8A—C1	1.6 (3)
C2—C1—C8A—C8	176.6 (2)	C4—C4A—C8A—C8	−179.4 (2)
O3—C2—C3—C4	−174.50 (19)	C5—C4A—C8A—C1	−177.9 (2)
O3—C2—C3—C9	0.2 (3)	C5—C4A—C8A—C8	1.2 (3)
C1—C2—C3—C4	3.1 (3)	C4A—C5—C6—C7	−0.4 (3)
C1—C2—C3—C9	177.8 (2)	C5—C6—C7—C8	1.5 (3)
C2—C3—C4—O2	174.5 (2)	C6—C7—C8—C8A	−1.3 (3)
C2—C3—C4—C4A	−5.9 (3)	C7—C8—C8A—C1	179.0 (2)
C9—C3—C4—O2	−0.5 (3)	C7—C8—C8A—C4A	−0.1 (3)
C9—C3—C4—C4A	179.15 (19)	C3—C9—C10—C12	−176.6 (2)
C2—C3—C9—C10	50.7 (3)	C3—C9—C10—C22	4.9 (4)
C4—C3—C9—C10	−134.6 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H1O3···O1i	0.97 (3)	1.93 (3)	2.770 (2)	143 (3)
C7—H7···O2ii	0.93	2.43	3.339 (3)	164
C22—H22C···O3	0.96	2.21	2.959 (3)	134