2-(4-Bromo­phen­yl)-1-(methyl­sulfan­yl)­naphtho[2,1-b]furan

The title compound, C₁₉H₁₃BrOS, was synthesized by the Lewis acid-catalyzed reaction of 2-naphthol with 4′-bromo-2-chloro-2-(methyl­sulfan­yl)acetophenone. The methyl group lies above the naphthofuran ring system and the benzene ring is rotated out of the naphthofuran plane with a dihedral angle of 42.29 (8)°. The crystal structure is stabilized by aromatic π–π stacking between the furan and benzene rings, C—H...O and C—H...Br hydrogen bonds, and a Br...Br inter­action.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.026
• wR factor = 0.071
• Data-to-parameter ratio = 14.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.09
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)        100 Ang.
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        200 Deg.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9     ..  O       ..       2.70 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H19A   ..  BR      ..       3.01 Ang.

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

   2 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
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Naphthofuran compounds have attracted widespread interest in view of their biological and pharmacological activities (Goel & Dixit, 2004; Hagiwara et al., 1999; Piloto et al., 2005). As part of our ongoing work on the synthesis and structures of naphthofuran derivatives, the crystal structures of 1-methylsulfinyl-2-phenylnaphtho[2,1-b]furan (Choi, Seo, Kang et al., 2006) and 7-bromo-1-methylsulfanyl-2-phenylnaphtho[2,1-b]furan (Choi, Seo, Son & Lee, 2006) have been described to the literature. Herein we report the molecular and crystal structure of the title compound (I) (Fig. 1).

The naphthofuran unit is essentially planar, with a mean deviation of 0.049 Å from the least-squares plane defined by the thirteen constituent atoms. The dihedral angle in (I) formed by the plane of the naphthofuran ring and the plane of phenyl ring is 42.29 (8)°. The molecular packing (Fig. 2) is stabilized by aromatic π–π stacking interactions between adjacent naphthofuran units. The Cg1···Cg2 ⁱ distance is 3.649 (3) Å (Cg1 and Cg2 are the centroids of the C1/C2/O/C3/C12 and C6—C11 rings; symmetry code as in Fig. 2). Further stability comes from weak C—H···O and C—H···Br hydrogen bonds in Table 1, and a Br···Br interaction at 3.6890 (6) Å.

Related literature

For the crystal structures of the isomers of the title compound, see: Choi, Seo, Kang et al. (2006) and Choi, Seo, Son & Lee (2006). For details of the biological and pharmacological activity of naphthofuran compounds, see: Goel & Dixit (2004); Hagiwara et al. (1999); Piloto et al. (2005).

S2. Experimental

Zinc chloride (273 mg, 2.0 mmol) was added at room temperature to a stirred solution of 2-naphthol (288 mg, 2.0 mmol) and 4'-bromo-2-chloro-2-(methylsulfanyl)acetophenone (559 mg, 2.0 mmol) in CH₂Cl₂ (30 ml), and stirred for 40 min. The mixture was quenched with water and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (CCl₄) to afford the title compound as white needles (450 mg, 61%). M.p. 411–412 K). Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a dilute solution of title compound (I) in benzene at room temperature.

S3. Refinement

All H atoms were geometrically located in ideal positions and refined using a riding model, with C—H = 0.95 Å for aromatic H atoms and C—H=0.98 Å for methyl H atoms, and with U_iso(H) = 1.2Ueq(C) for aromatic H atoms, and U_iso(H) = 1.5Ueq(C) for methyl H atoms. The highest peak in the difference map is 0.97 Å from Br and the largest hole is 1.00 Å from Br.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97-2 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97-2 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97-2.

Figures

	Fig. 1. The molecular structure of (I), showing displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. π—π interactions in (I). Cg denotes ring centroids. [Symmetry code: (i) 2 - x, 1 - y, 1 - z.]

2-(4-Bromophenyl)-1-(methylsulfanyl)naphtho[2,1-b]furan

Crystal data

C19H13BrOS	Z = 2
Mr = 369.26	F(000) = 372
Triclinic, P1	Dx = 1.645 Mg m^−3
Hall symbol: -P 1	Melting point = 411–412 K
a = 9.359 (1) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.487 (1) Å	Cell parameters from 4258 reflections
c = 9.860 (1) Å	θ = 2.3–28.2°
α = 94.352 (2)°	µ = 2.90 mm^−1
β = 115.271 (2)°	T = 173 K
γ = 105.312 (2)°	Block, colorless
V = 745.50 (14) Å^3	0.53 × 0.42 × 0.35 mm

Data collection

Bruker SMART CCD diffractometer	2878 independent reflections
Radiation source: fine-focus sealed tube	2644 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 10.00 pixels mm^-1	θmax = 26.0°, θmin = 2.3°
φ and ω scans	h = −11→11
Absorption correction: multi-scan SADABS (Sheldrick, 1999)	k = −11→11
Tmin = 0.239, Tmax = 0.371	l = −12→12
5896 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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.071	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0402P)^2 + 0.3452P] where P = (Fo^2 + 2Fc^2)/3
2878 reflections	(Δ/σ)max < 0.001
199 parameters	Δρmax = 0.72 e Å^−3
0 restraints	Δρmin = −0.35 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 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
Br	0.20442 (3)	0.97204 (2)	0.56099 (3)	0.03172 (10)
S	0.91609 (6)	0.70175 (5)	0.72850 (6)	0.02278 (13)
O	0.56320 (17)	0.44038 (16)	0.80420 (16)	0.0229 (3)
C1	0.7820 (2)	0.5608 (2)	0.7661 (2)	0.0201 (4)
C2	0.6367 (2)	0.5661 (2)	0.7640 (2)	0.0214 (4)
C3	0.6644 (2)	0.3531 (2)	0.8272 (2)	0.0216 (4)
C4	0.6264 (3)	0.2104 (2)	0.8593 (2)	0.0246 (4)
H4	0.5305	0.1687	0.8728	0.030*
C5	0.7350 (3)	0.1345 (2)	0.8700 (2)	0.0263 (5)
H5	0.7122	0.0363	0.8886	0.032*
C6	0.8815 (3)	0.1983 (2)	0.8540 (2)	0.0234 (4)
C7	0.9922 (3)	0.1173 (2)	0.8657 (2)	0.0282 (5)
H7	0.9652	0.0174	0.8796	0.034*
C8	1.1365 (3)	0.1793 (3)	0.8574 (2)	0.0304 (5)
H8	1.2099	0.1235	0.8676	0.037*
C9	1.1769 (3)	0.3259 (3)	0.8338 (2)	0.0278 (5)
H9	1.2783	0.3693	0.8295	0.033*
C10	1.0704 (3)	0.4066 (2)	0.8168 (2)	0.0241 (4)
H10	1.0981	0.5047	0.7988	0.029*
C11	0.9206 (2)	0.3460 (2)	0.8258 (2)	0.0202 (4)
C12	0.8019 (2)	0.4214 (2)	0.8082 (2)	0.0197 (4)
C13	0.5404 (2)	0.6688 (2)	0.7216 (2)	0.0218 (4)
C14	0.4509 (3)	0.6956 (2)	0.7985 (2)	0.0240 (4)
H14	0.4585	0.6515	0.8836	0.029*
C15	0.3515 (3)	0.7858 (2)	0.7518 (2)	0.0253 (4)
H15	0.2918	0.8042	0.8048	0.030*
C16	0.3406 (2)	0.8483 (2)	0.6275 (2)	0.0236 (4)
C17	0.4267 (3)	0.8236 (2)	0.5482 (2)	0.0239 (4)
H17	0.4173	0.8673	0.4625	0.029*
C18	0.5266 (3)	0.7343 (2)	0.5961 (2)	0.0239 (4)
H18	0.5866	0.7172	0.5430	0.029*
C19	0.8666 (3)	0.6152 (3)	0.5368 (3)	0.0325 (5)
H19A	0.9338	0.6829	0.4998	0.049*
H19B	0.7475	0.5947	0.4679	0.049*
H19C	0.8916	0.5211	0.5390	0.049*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.02759 (14)	0.03285 (15)	0.03671 (15)	0.01813 (10)	0.01196 (10)	0.00744 (10)
S	0.0213 (3)	0.0187 (3)	0.0288 (3)	0.0045 (2)	0.0135 (2)	0.0039 (2)
O	0.0213 (7)	0.0222 (7)	0.0292 (8)	0.0080 (6)	0.0147 (6)	0.0064 (6)
C1	0.0203 (10)	0.0186 (10)	0.0220 (10)	0.0057 (8)	0.0110 (8)	0.0027 (8)
C2	0.0223 (10)	0.0193 (10)	0.0228 (10)	0.0057 (8)	0.0116 (8)	0.0029 (8)
C3	0.0219 (10)	0.0214 (10)	0.0211 (10)	0.0078 (8)	0.0095 (8)	0.0027 (8)
C4	0.0240 (10)	0.0236 (11)	0.0233 (10)	0.0032 (8)	0.0112 (9)	0.0039 (8)
C5	0.0317 (11)	0.0193 (10)	0.0240 (11)	0.0055 (9)	0.0111 (9)	0.0053 (8)
C6	0.0267 (10)	0.0227 (10)	0.0182 (9)	0.0092 (8)	0.0078 (8)	0.0026 (8)
C7	0.0394 (12)	0.0236 (11)	0.0227 (10)	0.0162 (10)	0.0116 (9)	0.0061 (9)
C8	0.0356 (12)	0.0365 (13)	0.0268 (11)	0.0238 (10)	0.0140 (10)	0.0079 (10)
C9	0.0251 (11)	0.0377 (13)	0.0259 (11)	0.0154 (9)	0.0135 (9)	0.0071 (9)
C10	0.0256 (10)	0.0247 (11)	0.0241 (10)	0.0107 (9)	0.0118 (9)	0.0060 (8)
C11	0.0219 (10)	0.0196 (10)	0.0182 (9)	0.0079 (8)	0.0083 (8)	0.0012 (8)
C12	0.0227 (10)	0.0173 (10)	0.0184 (9)	0.0057 (8)	0.0098 (8)	0.0014 (7)
C13	0.0188 (9)	0.0201 (10)	0.0257 (10)	0.0065 (8)	0.0101 (8)	0.0020 (8)
C14	0.0229 (10)	0.0258 (11)	0.0256 (10)	0.0082 (8)	0.0133 (9)	0.0048 (8)
C15	0.0211 (10)	0.0287 (11)	0.0285 (11)	0.0092 (9)	0.0134 (9)	0.0028 (9)
C16	0.0180 (10)	0.0203 (10)	0.0283 (11)	0.0062 (8)	0.0079 (8)	0.0004 (8)
C17	0.0229 (10)	0.0229 (10)	0.0241 (10)	0.0071 (8)	0.0100 (9)	0.0034 (8)
C18	0.0233 (10)	0.0243 (11)	0.0264 (10)	0.0084 (8)	0.0135 (9)	0.0028 (8)
C19	0.0343 (12)	0.0369 (13)	0.0283 (12)	0.0069 (10)	0.0196 (10)	0.0039 (10)

Geometric parameters (Å, º)

Br—C16	1.904 (2)	C8—H8	0.9500
S—C1	1.757 (2)	C9—C10	1.374 (3)
S—C19	1.810 (2)	C9—H9	0.9500
O—C3	1.376 (2)	C10—C11	1.412 (3)
O—C2	1.387 (2)	C10—H10	0.9500
C1—C2	1.365 (3)	C11—C12	1.431 (3)
C1—C12	1.449 (3)	C13—C18	1.399 (3)
C2—C13	1.463 (3)	C13—C14	1.402 (3)
C3—C12	1.377 (3)	C14—C15	1.387 (3)
C3—C4	1.402 (3)	C14—H14	0.9500
C4—C5	1.367 (3)	C15—C16	1.378 (3)
C4—H4	0.9500	C15—H15	0.9500
C5—C6	1.425 (3)	C16—C17	1.388 (3)
C5—H5	0.9500	C17—C18	1.385 (3)
C6—C7	1.419 (3)	C17—H17	0.9500
C6—C11	1.432 (3)	C18—H18	0.9500
C7—C8	1.363 (3)	C19—H19A	0.9800
C7—H7	0.9500	C19—H19B	0.9800
C8—C9	1.406 (3)	C19—H19C	0.9800
C1—S—C19	100.23 (10)	C11—C10—H10	119.5
C3—O—C2	105.97 (15)	C10—C11—C12	124.79 (19)
C2—C1—C12	106.68 (17)	C10—C11—C6	118.69 (19)
C2—C1—S	124.75 (16)	C12—C11—C6	116.51 (18)
C12—C1—S	128.55 (15)	C3—C12—C11	119.16 (18)
C1—C2—O	110.67 (17)	C3—C12—C1	105.39 (17)
C1—C2—C13	134.46 (19)	C11—C12—C1	135.40 (18)
O—C2—C13	114.78 (17)	C18—C13—C14	118.57 (19)
O—C3—C12	111.26 (18)	C18—C13—C2	120.25 (18)
O—C3—C4	123.56 (18)	C14—C13—C2	121.04 (19)
C12—C3—C4	125.13 (19)	C15—C14—C13	120.83 (19)
C5—C4—C3	116.29 (19)	C15—C14—H14	119.6
C5—C4—H4	121.9	C13—C14—H14	119.6
C3—C4—H4	121.9	C16—C15—C14	119.06 (19)
C4—C5—C6	122.0 (2)	C16—C15—H15	120.5
C4—C5—H5	119.0	C14—C15—H15	120.5
C6—C5—H5	119.0	C15—C16—C17	121.69 (19)
C7—C6—C5	120.9 (2)	C15—C16—Br	119.84 (16)
C7—C6—C11	118.3 (2)	C17—C16—Br	118.46 (16)
C5—C6—C11	120.81 (19)	C18—C17—C16	118.9 (2)
C8—C7—C6	121.5 (2)	C18—C17—H17	120.5
C8—C7—H7	119.2	C16—C17—H17	120.5
C6—C7—H7	119.2	C17—C18—C13	120.94 (19)
C7—C8—C9	120.0 (2)	C17—C18—H18	119.5
C7—C8—H8	120.0	C13—C18—H18	119.5
C9—C8—H8	120.0	S—C19—H19A	109.5
C10—C9—C8	120.3 (2)	S—C19—H19B	109.5
C10—C9—H9	119.8	H19A—C19—H19B	109.5
C8—C9—H9	119.8	S—C19—H19C	109.5
C9—C10—C11	121.0 (2)	H19A—C19—H19C	109.5
C9—C10—H10	119.5	H19B—C19—H19C	109.5
C19—S—C1—C2	−104.63 (19)	O—C3—C12—C11	−179.22 (16)
C19—S—C1—C12	77.0 (2)	C4—C3—C12—C11	−1.8 (3)
C12—C1—C2—O	0.9 (2)	O—C3—C12—C1	−1.5 (2)
S—C1—C2—O	−177.72 (14)	C4—C3—C12—C1	175.89 (19)
C12—C1—C2—C13	−175.2 (2)	C10—C11—C12—C3	−176.75 (19)
S—C1—C2—C13	6.1 (3)	C6—C11—C12—C3	3.4 (3)
C3—O—C2—C1	−1.8 (2)	C10—C11—C12—C1	6.5 (4)
C3—O—C2—C13	175.11 (16)	C6—C11—C12—C1	−173.4 (2)
C2—O—C3—C12	2.1 (2)	C2—C1—C12—C3	0.4 (2)
C2—O—C3—C4	−175.38 (19)	S—C1—C12—C3	178.95 (15)
O—C3—C4—C5	176.22 (18)	C2—C1—C12—C11	177.5 (2)
C12—C3—C4—C5	−0.9 (3)	S—C1—C12—C11	−3.9 (3)
C3—C4—C5—C6	1.8 (3)	C1—C2—C13—C18	37.9 (3)
C4—C5—C6—C7	180.0 (2)	O—C2—C13—C18	−138.13 (19)
C4—C5—C6—C11	0.0 (3)	C1—C2—C13—C14	−146.5 (2)
C5—C6—C7—C8	−177.0 (2)	O—C2—C13—C14	37.4 (3)
C11—C6—C7—C8	2.9 (3)	C18—C13—C14—C15	−0.3 (3)
C6—C7—C8—C9	−1.3 (3)	C2—C13—C14—C15	−175.99 (19)
C7—C8—C9—C10	−0.9 (3)	C13—C14—C15—C16	0.5 (3)
C8—C9—C10—C11	1.3 (3)	C14—C15—C16—C17	−0.1 (3)
C9—C10—C11—C12	−179.43 (19)	C14—C15—C16—Br	179.83 (15)
C9—C10—C11—C6	0.4 (3)	C15—C16—C17—C18	−0.3 (3)
C7—C6—C11—C10	−2.4 (3)	Br—C16—C17—C18	179.75 (15)
C5—C6—C11—C10	177.53 (19)	C16—C17—C18—C13	0.4 (3)
C7—C6—C11—C12	177.40 (18)	C14—C13—C18—C17	−0.1 (3)
C5—C6—C11—C12	−2.6 (3)	C2—C13—C18—C17	175.60 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9···O^i	0.95	2.70	3.635 (3)	170
C19—H19A···Br^i	0.98	3.01	3.885 (3)	149

Symmetry code: (i) x+1, y, z.