2-(2,4-Di­chloro­phenyl­methyl­ene)-1-tetralone

The title compound, C₁₇H₁₂Cl₂O, has a cyclo­hexenone ring in the half-chair conformation. The aryl ring in the side chain attached to the tetralone ring is twisted out of the plane of the α,β-unsaturated ketone plane as a result of non-bonded interactions.

Key indicators

• Single-crystal X-ray study
• T = 193 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.033
• wR factor = 0.082
• Data-to-parameter ratio = 14.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



ABSTM_02  Alert C The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
          Tmin and Tmax reported:      0.682     0.962
          Tmin' and Tmax expected:      0.852     0.956
          RR' =      0.795
          Please check that your absorption correction is appropriate.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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S1. Comment

Recently, the synthesis and cytotoxic properties of a series of 2-arylidenebenzocycloalkanones were reported (Dimmock et al., 1999), which revealed, inter alia, that the relative positions of the two aryl rings influenced bioactivity. In order to develop structure–activity relationships in this group of compounds, analogues with ortho substituents were required, including 2-(2,4-dichlorophenylmethylene)-1-tetralone, (I). During the synthesis of (I), a second product was isolated which was shown by X-ray crystallography to be 2-(2,4-dichlorophenyl-hydroxymethyl)-1-tetralone, (II) (Oloo et al., 2002).

The cyclohexenone (C1—C2—C3—C4—C5—C10) ring of (I) has one multiple bond shared with the phenyl moiety and two external double bonds (the carbonyl O and C11 attached to C2). The atoms in the cyclohexenone ring adopted a conformation, with C2 and C3 on the same side of the plane determined by the other four atoms. Conjugation of the dichlorophenyl group with the α,β-unsaturated ketone should favor coplanarity, but steric effects interfere. The torsion angle C2—C11—C12—C17 is -39.6 (3)°, indicating that the aryl ring (C12–C17) is twisted out of the plane of the α,β-unsaturated ketone. This effect may be due to the Cl1···H11 and O···H11 non-bonded repulsions, since these interatomic distances are 2.72 and 2.40 Å, respectively. In addition, the distance between H17 and the pseudo-equatorial H atom on atom C3 is 2.29 Å, which may also contribute to the torsion angle observed.

Compound (I) has no possibility of classical hydrogen bonding. In Table 1, a non-classical intramolecular hydrogen bond is shown between H11 and O. In addition, intermolecular hydrogen bonds are listed between H4 and O, between H11 and Cl2, and between H17 and O, which link the molecules into a three-dimensional network.

S2. Experimental

An ice-cold solution of sodium hydroxide (0.005 mol) in water (0.25 ml) and methanol (50 ml) was added to an ice-cold solution of 2,4-dichlorobenzaldehyde (0.01 mol) and 1-tetralone (0.01 mol) in methanol (75 ml). After stirring at room temperature for 2 d, the mixture was refrigerated (268 K) for 1 d and the precipitate collected and dried. Column chromatography using keiselgel 60 and an eluting solvent of toluene afforded (I) (m.p. 381–383 K) in 56% yield, while an eluting solvent of 1% methanol in toluene led to 2-(2,4-dichlorophenyl-hydroxymethyl)-1-tetralone, (II) (m.p. 444–446 K) in 13% yield. Elemental analysis, calculated for C₁₇H₁₂Cl₂O: C 67.35, H 3.99%; found: C 67.21, H 3.73%. The cytotoxicity of (I) was determined using murine P388 and L1210 cells, as well as human Molt 4/C8 and CEM T-lymphocytes. The IC₅₀ values of (I) were 17.2±0.5, 34.4±5.4, 28.4±7.6 and 8.73±1.24 µM, respectively.

S3. Refinement

All H atoms were placed in calculated positions on their parent C atoms (C—H = 0.99 Å on aliphatic C atoms and 0.95 Å on aromatic C atoms). The U_iso value of each H atom was assigned as equal to 1.2 times the U_eq of the attached C atom.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Xtal3.7 (Hall et al., 2000); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. The molecular structure of (I), with displacement ellipsoids drawn at the 50% probability level.

2-(2,4-dichlorophenylmethylene)-1-tetralone

Crystal data

C17H12Cl2O	F(000) = 624
Mr = 303.17	Dx = 1.435 Mg m^−3
Monoclinic, P21/c	Melting point = 381–383 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 12.3695 (9) Å	Cell parameters from 5425 reflections
b = 13.7644 (10) Å	θ = 2.5–25°
c = 8.2403 (6) Å	µ = 0.45 mm^−1
β = 90.01 (1)°	T = 193 K
V = 1402.98 (18) Å^3	Prism, colourless
Z = 4	0.35 × 0.10 × 0.10 mm

Data collection

Bruker SMART1000 CCD diffractometer	2668 independent reflections
Radiation source: fine-focus sealed tube	2022 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
Detector resolution: 17 pixels mm^-1	θmax = 25.8°, θmin = 1.7°
CCD scans	h = −15→15
Absorption correction: multi-scan (SADABS; Blessing, 1995)	k = −16→15
Tmin = 0.682, Tmax = 0.962	l = −10→9
8415 measured reflections

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.082	H-atom parameters constrained
S = 0.98	w = 1/[σ^2(Fo^2) + (0.0418P)^2] where P = (Fo^2 + 2Fc^2)/3
2668 reflections	(Δ/σ)max = 0.005
181 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.19 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 was by full-matrix least-squares methods. 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
Cl1	0.53090 (4)	0.24397 (4)	0.41220 (7)	0.04201 (16)
Cl2	0.64505 (4)	−0.04634 (4)	0.80642 (6)	0.03862 (15)
O	0.16014 (9)	0.36507 (9)	0.45961 (17)	0.0375 (3)
C1	0.12921 (13)	0.28081 (14)	0.4465 (2)	0.0282 (4)
C2	0.19817 (13)	0.19697 (13)	0.4989 (2)	0.0266 (4)
C3	0.14545 (13)	0.09859 (14)	0.5011 (2)	0.0306 (4)
H3A	0.1008	0.0922	0.6001	0.037*
H3B	0.2019	0.0477	0.5042	0.037*
C4	0.07426 (14)	0.08367 (14)	0.3512 (2)	0.0336 (5)
H4A	0.1205	0.0812	0.2532	0.040*
H4B	0.0360	0.0207	0.3605	0.040*
C5	−0.00700 (14)	0.16379 (15)	0.3329 (2)	0.0337 (5)
C6	−0.10931 (15)	0.14709 (17)	0.2676 (3)	0.0446 (6)
H6	−0.1293	0.0832	0.2358	0.053*
C7	−0.18195 (17)	0.2225 (2)	0.2486 (3)	0.0553 (7)
H7	−0.2512	0.2101	0.2032	0.066*
C8	−0.15467 (16)	0.3155 (2)	0.2951 (3)	0.0544 (7)
H8	−0.2053	0.3668	0.2827	0.065*
C9	−0.05385 (15)	0.33414 (16)	0.3597 (2)	0.0412 (5)
H9	−0.0350	0.3983	0.3913	0.049*
C10	0.02048 (14)	0.25846 (14)	0.3787 (2)	0.0316 (5)
C11	0.30183 (14)	0.21563 (13)	0.5357 (2)	0.0271 (4)
H11	0.3252	0.2807	0.5199	0.033*
C12	0.38339 (13)	0.14768 (12)	0.5974 (2)	0.0255 (4)
C13	0.49238 (13)	0.15561 (13)	0.5509 (2)	0.0257 (4)
C14	0.57174 (13)	0.09564 (13)	0.6111 (2)	0.0271 (4)
H14	0.6444	0.1018	0.5751	0.032*
C15	0.54406 (14)	0.02651 (13)	0.7244 (2)	0.0276 (4)
C16	0.43831 (14)	0.01589 (14)	0.7764 (2)	0.0301 (4)
H16	0.4200	−0.0321	0.8546	0.036*
C17	0.35992 (14)	0.07620 (13)	0.7127 (2)	0.0285 (4)
H17	0.2874	0.0689	0.7484	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0294 (2)	0.0449 (3)	0.0518 (4)	0.0006 (2)	0.0041 (2)	0.0214 (3)
Cl2	0.0382 (3)	0.0394 (3)	0.0383 (3)	0.0128 (2)	−0.0011 (2)	0.0065 (2)
O	0.0330 (7)	0.0261 (8)	0.0534 (10)	0.0024 (6)	0.0024 (6)	0.0010 (6)
C1	0.0251 (8)	0.0312 (11)	0.0282 (11)	0.0016 (8)	0.0081 (8)	0.0006 (8)
C2	0.0261 (9)	0.0270 (10)	0.0268 (10)	−0.0001 (8)	0.0044 (8)	−0.0009 (8)
C3	0.0267 (9)	0.0286 (10)	0.0365 (11)	−0.0023 (8)	0.0018 (8)	0.0017 (9)
C4	0.0293 (9)	0.0325 (11)	0.0388 (12)	−0.0070 (8)	0.0011 (8)	−0.0014 (9)
C5	0.0266 (9)	0.0444 (12)	0.0300 (11)	−0.0033 (8)	0.0035 (8)	0.0040 (9)
C6	0.0315 (10)	0.0576 (15)	0.0445 (14)	−0.0066 (10)	−0.0024 (9)	0.0030 (11)
C7	0.0284 (11)	0.084 (2)	0.0530 (16)	−0.0002 (12)	−0.0090 (10)	0.0073 (14)
C8	0.0330 (11)	0.0735 (18)	0.0566 (16)	0.0166 (11)	−0.0033 (10)	0.0107 (14)
C9	0.0331 (10)	0.0475 (13)	0.0429 (13)	0.0084 (9)	0.0030 (9)	0.0056 (11)
C10	0.0241 (9)	0.0402 (12)	0.0306 (11)	0.0008 (8)	0.0055 (8)	0.0075 (9)
C11	0.0286 (9)	0.0220 (9)	0.0309 (11)	0.0002 (8)	0.0024 (8)	−0.0028 (8)
C12	0.0250 (8)	0.0246 (10)	0.0271 (10)	−0.0010 (7)	−0.0014 (7)	−0.0049 (8)
C13	0.0281 (9)	0.0253 (10)	0.0237 (10)	−0.0034 (7)	−0.0003 (7)	0.0012 (8)
C14	0.0237 (8)	0.0313 (10)	0.0262 (10)	0.0011 (8)	0.0012 (7)	−0.0030 (8)
C15	0.0316 (9)	0.0265 (10)	0.0247 (10)	0.0063 (8)	−0.0027 (8)	−0.0043 (8)
C16	0.0354 (10)	0.0277 (10)	0.0272 (11)	−0.0001 (8)	0.0019 (8)	−0.0008 (8)
C17	0.0256 (8)	0.0295 (10)	0.0304 (11)	−0.0019 (8)	0.0031 (8)	−0.0038 (8)

Geometric parameters (Å, º)

Cl1—C13	1.7357 (18)	C7—C8	1.378 (3)
Cl2—C15	1.7386 (17)	C7—H7	0.9500
O—C1	1.226 (2)	C8—C9	1.380 (3)
C1—C10	1.488 (2)	C8—H8	0.9500
C1—C2	1.499 (3)	C9—C10	1.398 (3)
C2—C11	1.342 (2)	C9—H9	0.9500
C2—C3	1.503 (2)	C11—C12	1.467 (2)
C3—C4	1.530 (2)	C11—H11	0.9500
C3—H3A	0.9900	C12—C17	1.398 (2)
C3—H3B	0.9900	C12—C13	1.406 (2)
C4—C5	1.500 (3)	C13—C14	1.375 (2)
C4—H4A	0.9900	C14—C15	1.376 (3)
C4—H4B	0.9900	C14—H14	0.9500
C5—C6	1.394 (3)	C15—C16	1.384 (2)
C5—C10	1.398 (3)	C16—C17	1.380 (2)
C6—C7	1.382 (3)	C16—H16	0.9500
C6—H6	0.9500	C17—H17	0.9500
O—C1—C10	120.71 (16)	C9—C8—H8	120.0
O—C1—C2	121.69 (16)	C8—C9—C10	119.9 (2)
C10—C1—C2	117.60 (16)	C8—C9—H9	120.0
C11—C2—C1	117.48 (16)	C10—C9—H9	120.0
C11—C2—C3	125.74 (16)	C9—C10—C5	120.29 (17)
C1—C2—C3	116.76 (15)	C9—C10—C1	118.82 (18)
C2—C3—C4	111.16 (16)	C5—C10—C1	120.89 (16)
C2—C3—H3A	109.4	C2—C11—C12	127.83 (17)
C4—C3—H3A	109.4	C2—C11—H11	116.1
C2—C3—H3B	109.4	C12—C11—H11	116.1
C4—C3—H3B	109.4	C17—C12—C13	116.05 (15)
H3A—C3—H3B	108.0	C17—C12—C11	122.77 (15)
C5—C4—C3	111.60 (16)	C13—C12—C11	121.04 (16)
C5—C4—H4A	109.3	C14—C13—C12	122.65 (16)
C3—C4—H4A	109.3	C14—C13—Cl1	117.53 (13)
C5—C4—H4B	109.3	C12—C13—Cl1	119.82 (13)
C3—C4—H4B	109.3	C13—C14—C15	118.82 (16)
H4A—C4—H4B	108.0	C13—C14—H14	120.6
C6—C5—C10	118.57 (18)	C15—C14—H14	120.6
C6—C5—C4	121.73 (19)	C14—C15—C16	121.22 (16)
C10—C5—C4	119.68 (16)	C14—C15—Cl2	118.92 (13)
C7—C6—C5	120.7 (2)	C16—C15—Cl2	119.84 (15)
C7—C6—H6	119.7	C17—C16—C15	118.84 (17)
C5—C6—H6	119.7	C17—C16—H16	120.6
C8—C7—C6	120.5 (2)	C15—C16—H16	120.6
C8—C7—H7	119.8	C16—C17—C12	122.40 (16)
C6—C7—H7	119.8	C16—C17—H17	118.8
C7—C8—C9	120.1 (2)	C12—C17—H17	118.8
C7—C8—H8	120.0
O—C1—C2—C11	−10.8 (3)	C2—C1—C10—C9	167.10 (17)
C10—C1—C2—C11	169.74 (17)	O—C1—C10—C5	167.00 (18)
O—C1—C2—C3	170.81 (18)	C2—C1—C10—C5	−13.6 (3)
C10—C1—C2—C3	−8.6 (2)	C1—C2—C11—C12	176.61 (17)
C11—C2—C3—C4	−136.25 (19)	C3—C2—C11—C12	−5.2 (3)
C1—C2—C3—C4	42.0 (2)	C2—C11—C12—C17	−39.6 (3)
C2—C3—C4—C5	−54.3 (2)	C2—C11—C12—C13	144.8 (2)
C3—C4—C5—C6	−146.85 (18)	C17—C12—C13—C14	1.5 (3)
C3—C4—C5—C10	34.6 (2)	C11—C12—C13—C14	177.41 (16)
C10—C5—C6—C7	0.0 (3)	C17—C12—C13—Cl1	−178.44 (13)
C4—C5—C6—C7	−178.6 (2)	C11—C12—C13—Cl1	−2.6 (2)
C5—C6—C7—C8	−0.5 (4)	C12—C13—C14—C15	−1.6 (3)
C6—C7—C8—C9	0.6 (4)	Cl1—C13—C14—C15	178.36 (14)
C7—C8—C9—C10	−0.3 (3)	C13—C14—C15—C16	0.8 (3)
C8—C9—C10—C5	−0.2 (3)	C13—C14—C15—Cl2	−177.58 (13)
C8—C9—C10—C1	179.13 (19)	C14—C15—C16—C17	0.0 (3)
C6—C5—C10—C9	0.4 (3)	Cl2—C15—C16—C17	178.35 (13)
C4—C5—C10—C9	178.93 (18)	C15—C16—C17—C12	0.0 (3)
C6—C5—C10—C1	−178.96 (18)	C13—C12—C17—C16	−0.7 (3)
C4—C5—C10—C1	−0.4 (3)	C11—C12—C17—C16	−176.51 (16)
O—C1—C10—C9	−12.3 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···O	0.95	2.40	2.774 (2)	103
C4—H4A···O^i	0.99	2.58	3.470 (2)	150
C11—H11···Cl2^ii	0.95	2.80	3.5858 (18)	140
C17—H17···O^iii	0.95	2.52	3.302 (2)	140

Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x+1, y+1/2, −z+3/2; (iii) x, −y+1/2, z+1/2.