(4-Chloro­benzoyl)(2-eth­oxy-7-methoxy­naphthalen-1-yl)methanone

In the title compound, C₂₀H₁₇ClO₃, the naphthalene and benzene rings form an inter­planar angle of 83.30 (8)°. The conformation around the central C=O group is such that the C=O bond vector forms a larger angle to the plane of the naphthalene ring than to the plane of the benzene ring, viz. 55.8 (2)° versus 15.8 (2)°. The 4-chloro­phenyl groups form a centrosymmetric π–π inter­action, with a centroid–centroid distance of 3.829 (1) Å and a lateral offset of 1.758 Å. An inter­molecular C—H...O inter­action is formed between the 4-chloro­phenyl group and the O atom of a neighbouring meth­oxy group, and two very weak C—H...π contacts are present.

Key indicators

• Single-crystal X-ray study
• T = 193 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.041
• wR factor = 0.120
• Data-to-parameter ratio = 14.2

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   193.000
            Value of melting point given =     0.000
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C4     --  C5      ..       6.54 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C6     --  C7      ..       6.40 su

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......         23

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

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

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S1. Comment

Recently, we have reported the crystal structures of 1-(4-chlorobenzoyl)-2,7-dimethoxynaphthalene and (4-chlorophenyl)(2-hydroxy-7-methoxynaphthalen-1-yl)methanone (Mitsui, Nakaema, Noguchi, Okamoto & Yonezawa, 2008; Mitsui, Nakaema, Noguchi & Yonezawa, 2008). As a part of our ongoing studies on the synthesis and crystal structure analyses of aroylated naphthalene derivatives, this paper reports the crystal structure of the title compound, prepared by ethylation of (4-chlorophenyl)(2-hydroxy-7-methoxynaphthalen-1-yl)methanone with ethyl iodide.

In the molecule (Fig. 1), the interplanar angle between the benzene ring [C12–C17] and the naphthalene ring [C1–C10] is 83.30 (8)°. The C=O bond vector lies close to the mean plane of the benzene ring (angle 15.8 (2)°), but forms an angle of 55.77 (15)° to the plane of the naphthalene ring. The conformation of these groups is similar to 1-(4-chlorobenzoyl)-2,7-dimethoxynaphthalene. On the other hand, the methoxy group is arranged toward the aroyl group [C20—O3—C8—C7 torsion angle = 177.7 (2)°] while that of the aforementioned related compound is arranged toward the naphthalene ring [-7.1 (3)°]. In both compounds, the C—O bond vector of the methoxy group lies approximately in the plane of the naphthalene ring [angle 4.2 (1)° in the title compound, 5.05 (9)° in the related compound].

In the crystal structure, the naphthalene rings interact with ethyl groups [C7···H18A = 2.87 Å, C7···H18B = 2.88 Å] and methyl groups [C5···H20B = 2.75 Å] of the adjacent molecule along the a axis (Fig. 2). The neighboring inversion-related ethyl groups interact with each other [H19C···H19C = 2.39 Å] along the c axis. The C=O groups interact with benzene rings [O1···H17 = 2.66 Å] along the b axis (Fig. 3). Adjacent 4-chlorophenyl groups related by crystallographic inversion centers are exactly antiparallel and the perpendicular distance between the mean planes of these groups is 3.402 (1) Å (Fig. 4). The centroid–centroid distance between the two antiparallel phenyl rings is 3.829 (1) Å and the lateral offset is 1.758 Å, indicating the presence of a π–π interaction. Moreover, molecules are linked by C—H···π interactions. The methyl group acts as a hydrogen-bond donor and the π system of the naphthalene ring [C1/C2/C3/C4/C5/C10 ring (with centroid Cg1)] of an adjacent molecule acts as an acceptor, viz. C20—H20B···π, C20—H20C···π (Fig. 2 and Table 1). Intermolecular C—H···O hydrogen bonds between the methoxy O and an H atom of the 4-chlorophenyl group of the adjacent molecule are also found along the c axis (C13—H13···O3ⁱ; Fig. 2 and Table 1).

Related literature

For structures of closely related compounds, see: Mitsui, Nakaema, Noguchi, Okamoto & Yonezawa (2008); Mitsui, Nakaema, Noguchi & Yonezawa (2008).

S2. Experimental

(4-Chlorophenyl)(2-hydroxy-7-methoxynaphthalen-1-yl)methanone (0.13 g, 0.40 mmol) was dissolved in acetone (1.0 ml) and aqueous 0.8M NaOH (1.0 ml). EtI (0.31 g, 2.0 mmol) was added and the reaction mixture was heated at reflux for 6 h. Upon cooling to ambient temperature, the mixture was poured into H₂O (5 ml) and CHCl₃ (5 ml), and the aqueous layer was extracted with CHCl₃ (3 × 5 ml). The combined organic layers were washed with brine (3 × 20 ml), and dried over MgSO₄ overnight. The solvent was removed in vacuo and the crude material was purified by recrystallization from hexanes to give the title compound as colorless blocks (m.p. 365.5–366.0 K, yield 95 mg, 70%).

Spectroscopic Data: ¹H NMR (300 MHz, CDCl₃) δ 7.83 (d, 1H), 7.77 (d, 2H), 7.70 (d, 1H), 7.38 (d, 2H), 7.11 (d, 1H), 7.02 (dd, 1H), 6.86 (d, 1H), 4.05 (q, 2H), 3.74 (s, 3H), 1.10 (s, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 196.8, 159.1, 154.8, 139.4, 137.1, 133.2, 131.3, 130.7, 129.7, 128.7, 124.5, 121.7, 117.2, 111.5, 102.3, 65.0, 55.2, 14.6; IR (KBr): 1671, 1624, 1582, 1511, 1464, 1249, 1227, 1046; HRMS (m/z): [M + H]⁺ calcd for C₂₀H₁₈ClO₃, 341.0945; found, 341.0903.

S3. Refinement

Rigid bond restraints were applied to the U_ij values of the naphthalene ring (C4—C7) (5 restraints with the DELU command in SHELXL97). Further restraints were used to generate similar U_ij values for the atoms of naphthalene ring (18 restraints with the SIMU command in SHELXL97). All H atoms were visible in difference maps but were subsequently placed in calculated positions and refined as riding, with C—H = 0.95 (aromatic), 0.98 (methyl) and 0.99 (methylene) Å, and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Molecular structure with displacement ellipsoids at 30% probability for non-H atoms.
	Fig. 2. Packing diagram viewed down the b axis. Van der Waals, C—H···π and C—H···O interactions are shown as black, red and green dashed lines, respectively.
	Fig. 3. Partial packing diagram viewed down the a axis. Van der Waals interactions are shown as dashed lines.
	Fig. 4. Side-on view of the π–π interaction.

(4-Chlorobenzoyl)(2-ethoxy-7-methoxynaphthalen-1-yl)methanone

Crystal data

C20H17ClO3	F(000) = 712
Mr = 340.79	Dx = 1.330 Mg m^−3
Monoclinic, P21/c	Melting point = 365.5–366.0 K
Hall symbol: -P 2ybc	Cu Kα radiation, λ = 1.54187 Å
a = 7.26434 (13) Å	Cell parameters from 26200 reflections
b = 20.8849 (4) Å	θ = 3.9–68.1°
c = 12.2094 (2) Å	µ = 2.11 mm^−1
β = 113.201 (1)°	T = 193 K
V = 1702.55 (5) Å^3	Block, colorless
Z = 4	0.40 × 0.30 × 0.20 mm

Data collection

Rigaku R-AXIS RAPID diffractometer	3104 independent reflections
Radiation source: rotating anode	2544 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Detector resolution: 10.00 pixels mm^-1	θmax = 68.1°, θmin = 4.2°
ω scans	h = −8→8
Absorption correction: numerical (NUMABS; Higashi, 1999)	k = −25→25
Tmin = 0.542, Tmax = 0.656	l = −14→14
30947 measured reflections

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)] = 0.041	H-atom parameters constrained
wR(F^2) = 0.120	w = 1/[σ^2(Fo^2) + (0.0592P)^2 + 0.3688P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.001
3104 reflections	Δρmax = 0.27 e Å^−3
218 parameters	Δρmin = −0.28 e Å^−3
23 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0020 (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
Cl1	1.10278 (9)	0.57118 (2)	0.30495 (5)	0.0781 (2)
O1	0.4618 (2)	0.39338 (6)	0.45026 (12)	0.0659 (4)
O2	0.3297 (2)	0.37751 (7)	0.15066 (12)	0.0756 (4)
O3	0.9489 (2)	0.19765 (7)	0.67286 (15)	0.0765 (4)
C1	0.5171 (3)	0.31905 (9)	0.31945 (17)	0.0566 (4)
C2	0.4068 (3)	0.31950 (10)	0.19824 (18)	0.0656 (5)
C3	0.3762 (3)	0.26240 (12)	0.1314 (2)	0.0767 (6)
H3	0.3019	0.2628	0.0476	0.092*
C4	0.4553 (3)	0.20662 (11)	0.1892 (2)	0.0784 (7)
H4	0.4326	0.1681	0.1443	0.094*
C5	0.5692 (3)	0.20400 (9)	0.3128 (2)	0.0671 (5)
C6	0.6600 (4)	0.14645 (10)	0.3747 (3)	0.0794 (7)
H6	0.6349	0.1072	0.3321	0.095*
C7	0.7796 (4)	0.14653 (10)	0.4912 (3)	0.0785 (6)
H7	0.8367	0.1075	0.5296	0.094*
C8	0.8208 (3)	0.20409 (9)	0.5568 (2)	0.0665 (5)
C9	0.7332 (3)	0.26027 (8)	0.50295 (18)	0.0572 (4)
H9	0.7589	0.2987	0.5482	0.069*
C10	0.6044 (3)	0.26155 (8)	0.38026 (18)	0.0579 (5)
C11	0.5461 (3)	0.38232 (8)	0.38384 (15)	0.0536 (4)
C12	0.6830 (3)	0.42954 (8)	0.36347 (15)	0.0505 (4)
C13	0.8197 (3)	0.40999 (8)	0.31679 (16)	0.0547 (4)
H13	0.8235	0.3663	0.2963	0.066*
C14	0.9509 (3)	0.45307 (9)	0.29947 (16)	0.0587 (4)
H14	1.0453	0.4393	0.2684	0.070*
C15	0.9411 (3)	0.51637 (8)	0.32839 (15)	0.0569 (4)
C16	0.8073 (3)	0.53732 (9)	0.37524 (16)	0.0599 (5)
H16	0.8032	0.5812	0.3945	0.072*
C17	0.6795 (3)	0.49384 (8)	0.39383 (16)	0.0569 (4)
H17	0.5887	0.5077	0.4275	0.068*
C18	0.2883 (4)	0.38987 (15)	0.0278 (2)	0.0872 (7)
H18A	0.1616	0.3689	−0.0242	0.105*
H18B	0.3980	0.3735	0.0067	0.105*
C19	0.2714 (5)	0.46071 (17)	0.0136 (3)	0.1199 (11)
H19A	0.2428	0.4720	−0.0695	0.144*
H19B	0.3976	0.4806	0.0658	0.144*
H19C	0.1626	0.4761	0.0350	0.144*
C20	1.0050 (3)	0.25362 (11)	0.7447 (2)	0.0754 (6)
H20A	1.0970	0.2420	0.8256	0.090*
H20B	0.8853	0.2738	0.7476	0.090*
H20C	1.0715	0.2837	0.7105	0.090*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0934 (4)	0.0670 (3)	0.0780 (4)	−0.0205 (3)	0.0382 (3)	0.0047 (2)
O1	0.0784 (9)	0.0658 (8)	0.0721 (8)	0.0068 (7)	0.0496 (7)	0.0002 (6)
O2	0.0841 (10)	0.0855 (10)	0.0595 (8)	−0.0073 (8)	0.0306 (7)	0.0064 (7)
O3	0.0712 (9)	0.0656 (9)	0.1016 (11)	0.0101 (7)	0.0435 (9)	0.0261 (8)
C1	0.0633 (11)	0.0567 (10)	0.0629 (11)	−0.0068 (8)	0.0390 (9)	−0.0048 (8)
C2	0.0665 (12)	0.0731 (13)	0.0699 (12)	−0.0139 (10)	0.0406 (10)	−0.0083 (10)
C3	0.0749 (14)	0.0969 (17)	0.0735 (13)	−0.0280 (12)	0.0457 (11)	−0.0229 (12)
C4	0.0799 (14)	0.0744 (14)	0.1077 (17)	−0.0300 (12)	0.0658 (14)	−0.0359 (13)
C5	0.0698 (12)	0.0585 (11)	0.0970 (15)	−0.0162 (9)	0.0586 (12)	−0.0188 (10)
C6	0.0850 (15)	0.0482 (11)	0.138 (2)	−0.0128 (10)	0.0796 (16)	−0.0187 (12)
C7	0.0798 (15)	0.0507 (11)	0.128 (2)	0.0019 (10)	0.0655 (15)	0.0056 (12)
C8	0.0659 (12)	0.0546 (11)	0.1001 (16)	0.0007 (9)	0.0554 (12)	0.0089 (10)
C9	0.0637 (11)	0.0479 (9)	0.0766 (12)	0.0002 (8)	0.0453 (10)	0.0028 (8)
C10	0.0628 (11)	0.0496 (9)	0.0820 (12)	−0.0056 (8)	0.0507 (10)	−0.0057 (8)
C11	0.0607 (10)	0.0541 (10)	0.0527 (9)	0.0091 (8)	0.0295 (8)	0.0040 (7)
C12	0.0617 (10)	0.0464 (9)	0.0483 (9)	0.0066 (7)	0.0270 (8)	0.0026 (7)
C13	0.0677 (11)	0.0456 (9)	0.0600 (10)	0.0003 (8)	0.0351 (9)	−0.0031 (7)
C14	0.0658 (11)	0.0593 (10)	0.0589 (10)	−0.0008 (8)	0.0332 (9)	−0.0021 (8)
C15	0.0676 (11)	0.0525 (9)	0.0491 (9)	−0.0038 (8)	0.0213 (8)	0.0060 (7)
C16	0.0758 (12)	0.0439 (9)	0.0585 (10)	0.0067 (8)	0.0247 (9)	0.0043 (7)
C17	0.0691 (11)	0.0508 (9)	0.0550 (9)	0.0120 (8)	0.0290 (9)	0.0019 (7)
C18	0.0657 (13)	0.134 (2)	0.0608 (12)	−0.0117 (13)	0.0243 (10)	0.0111 (13)
C19	0.119 (2)	0.142 (3)	0.0847 (18)	−0.014 (2)	0.0247 (16)	0.0474 (18)
C20	0.0702 (13)	0.0782 (14)	0.0890 (15)	0.0106 (11)	0.0434 (12)	0.0189 (12)

Geometric parameters (Å, º)

Cl1—C15	1.7426 (19)	C9—H9	0.950
O1—C11	1.215 (2)	C11—C12	1.490 (3)
O2—C2	1.365 (3)	C12—C13	1.387 (2)
O2—C18	1.432 (3)	C12—C17	1.396 (2)
O3—C8	1.361 (3)	C13—C14	1.386 (3)
O3—C20	1.421 (3)	C13—H13	0.950
C1—C2	1.378 (3)	C14—C15	1.377 (3)
C1—C10	1.423 (3)	C14—H14	0.950
C1—C11	1.509 (2)	C15—C16	1.379 (3)
C2—C3	1.413 (3)	C16—C17	1.380 (3)
C3—C4	1.366 (4)	C16—H16	0.950
C3—H3	0.950	C17—H17	0.950
C4—C5	1.408 (3)	C18—C19	1.489 (4)
C4—H4	0.950	C18—H18A	0.990
C5—C10	1.422 (3)	C18—H18B	0.990
C5—C6	1.435 (3)	C19—H19A	0.980
C6—C7	1.343 (3)	C19—H19B	0.980
C6—H6	0.950	C19—H19C	0.980
C7—C8	1.410 (3)	C20—H20A	0.980
C7—H7	0.950	C20—H20B	0.980
C8—C9	1.373 (3)	C20—H20C	0.980
C9—C10	1.420 (3)
C2—O2—C18	119.19 (18)	C13—C12—C11	120.47 (15)
C8—O3—C20	118.27 (16)	C17—C12—C11	120.62 (16)
C2—C1—C10	121.15 (17)	C14—C13—C12	121.21 (16)
C2—C1—C11	117.15 (17)	C14—C13—H13	119.4
C10—C1—C11	121.68 (16)	C12—C13—H13	119.4
O2—C2—C1	115.52 (17)	C15—C14—C13	118.40 (17)
O2—C2—C3	124.0 (2)	C15—C14—H14	120.8
C1—C2—C3	120.5 (2)	C13—C14—H14	120.8
C4—C3—C2	118.9 (2)	C14—C15—C16	121.81 (17)
C4—C3—H3	120.6	C14—C15—Cl1	118.81 (15)
C2—C3—H3	120.6	C16—C15—Cl1	119.38 (14)
C3—C4—C5	122.49 (19)	C15—C16—C17	119.29 (17)
C3—C4—H4	118.8	C15—C16—H16	120.4
C5—C4—H4	118.8	C17—C16—H16	120.4
C4—C5—C10	118.9 (2)	C16—C17—C12	120.37 (17)
C4—C5—C6	123.5 (2)	C16—C17—H17	119.8
C10—C5—C6	117.6 (2)	C12—C17—H17	119.8
C7—C6—C5	121.9 (2)	O2—C18—C19	106.0 (2)
C7—C6—H6	119.1	O2—C18—H18A	110.5
C5—C6—H6	119.1	C19—C18—H18A	110.5
C6—C7—C8	120.4 (2)	O2—C18—H18B	110.5
C6—C7—H7	119.8	C19—C18—H18B	110.5
C8—C7—H7	119.8	H18A—C18—H18B	108.7
O3—C8—C9	125.51 (19)	C18—C19—H19A	109.5
O3—C8—C7	114.35 (19)	C18—C19—H19B	109.5
C9—C8—C7	120.1 (2)	H19A—C19—H19B	109.5
C8—C9—C10	120.65 (18)	C18—C19—H19C	109.5
C8—C9—H9	119.7	H19A—C19—H19C	109.5
C10—C9—H9	119.7	H19B—C19—H19C	109.5
C9—C10—C5	119.24 (18)	O3—C20—H20A	109.5
C9—C10—C1	122.64 (16)	O3—C20—H20B	109.5
C5—C10—C1	118.02 (19)	H20A—C20—H20B	109.5
O1—C11—C12	122.05 (16)	O3—C20—H20C	109.5
O1—C11—C1	120.71 (16)	H20A—C20—H20C	109.5
C12—C11—C1	117.24 (14)	H20B—C20—H20C	109.5
C13—C12—C17	118.90 (16)
C18—O2—C2—C1	154.21 (17)	C6—C5—C10—C1	179.21 (16)
C18—O2—C2—C3	−26.8 (3)	C2—C1—C10—C9	174.41 (16)
C10—C1—C2—O2	179.52 (15)	C11—C1—C10—C9	−3.8 (3)
C11—C1—C2—O2	−2.2 (2)	C2—C1—C10—C5	−2.0 (3)
C10—C1—C2—C3	0.5 (3)	C11—C1—C10—C5	179.83 (16)
C11—C1—C2—C3	178.82 (16)	C2—C1—C11—O1	109.0 (2)
O2—C2—C3—C4	−177.90 (18)	C10—C1—C11—O1	−72.7 (2)
C1—C2—C3—C4	1.0 (3)	C2—C1—C11—C12	−71.7 (2)
C2—C3—C4—C5	−1.1 (3)	C10—C1—C11—C12	106.57 (18)
C3—C4—C5—C10	−0.4 (3)	O1—C11—C12—C13	161.18 (18)
C3—C4—C5—C6	−177.56 (19)	C1—C11—C12—C13	−18.1 (2)
C4—C5—C6—C7	175.11 (19)	O1—C11—C12—C17	−17.2 (3)
C10—C5—C6—C7	−2.1 (3)	C1—C11—C12—C17	163.60 (16)
C5—C6—C7—C8	−0.4 (3)	C17—C12—C13—C14	−0.3 (3)
C20—O3—C8—C9	−2.8 (3)	C11—C12—C13—C14	−178.72 (16)
C20—O3—C8—C7	177.68 (16)	C12—C13—C14—C15	−0.8 (3)
C6—C7—C8—O3	−178.08 (17)	C13—C14—C15—C16	1.0 (3)
C6—C7—C8—C9	2.3 (3)	C13—C14—C15—Cl1	−179.07 (14)
O3—C8—C9—C10	178.81 (16)	C14—C15—C16—C17	0.0 (3)
C7—C8—C9—C10	−1.7 (3)	Cl1—C15—C16—C17	−179.94 (14)
C8—C9—C10—C5	−0.9 (3)	C15—C16—C17—C12	−1.2 (3)
C8—C9—C10—C1	−177.22 (16)	C13—C12—C17—C16	1.4 (3)
C4—C5—C10—C9	−174.63 (16)	C11—C12—C17—C16	179.72 (16)
C6—C5—C10—C9	2.7 (2)	C2—O2—C18—C19	−162.1 (2)
C4—C5—C10—C1	1.9 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C20—H20B···Cg1^i	0.98	3.02	3.821 (3)	140
C20—H20C···Cg1^ii	0.98	3.01	3.477 (3)	110
C13—H13···O3^iii	0.95	2.44	3.213 (2)	138

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