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Acta Cryst. (2008). E64, o2266    [ doi:10.1107/S1600536808035575 ]

3-(3-Fluorobenzyl)-1H-isochromen-1-one

T. M. Babar, G. Qadeer, O.-R. Abid, N. H. Rama and A. Ruzicka

Abstract top

The asymmetric unit of the title compound, C16H11FO2, contains two independent molecules. The isochromene ring systems are planar and are oriented with respect to the fluorobenzene rings at dihedral angles of 87.15 (3) and 87.85 (3)° in the two molecules.

Comment top

Isocoumarins are secondary metabolites derived from the acetate pathway and are structurally related to the coumarins, but with an inverted lactone ring (Hill, 1986). They are produced by microorganisms, insects and some higher plants, and have a wide range of biological activities, including antitumoral, antileucemic, antiviral and antimicrobial (Hill, 1986; Canedo et al., 1997; Whyte et al., 1996). Isocoumarins (Barry, 1964) are also useful intermediates in the synthesis of a variety of important compounds including some isoquinoline alkaloids. In view of their natural occurrence, biological activities and utility as synthetic intermediates, we have synthesized the title compound, and reported herein its crystal structure.

The asymmetric unit of the title compound contains two crystallographically independent molecules of similar geometry (Fig 1). The bond lengths (Allen et al., 1987) and angles are within normal ranges and comparable with 3-(2-chlorobenzyl)isocoumarin (Abid et al., 2006). Rings A (C1A-C4A/C9A/O2A), B (C4A-C9A), C (C11A-C16A) and D (C1B-C4B/C9B/O2B), E (C4B-C9B), F (C11B-C16B) are, of course, planar and dihedral angles between them are A/B = 1.44 (3)°, A/C = 87.50 (3)°, B/C = 86.91 (4)° and D/E = 0.46 (3)°, D/F = 88.10 (3)°, E/F = 87.65 (3)°.

Related literature top

For general background, see: Barry (1964); Hill (1986); Canedo et al. (1997); Whyte et al. (1996). For a related structure, see: Abid et al. (2006). For bond-length data, see: Allen et al. (1987).

Experimental top

A mixture of 3-fluorophenylacetic acid (5 g, 32 mmol) and thionyl chloride (2.94 ml, 34 mmol) was heated for 30 min in the presence of a few drops of DMF under reflux at 343 K to give 2-(3-fluorophenyl)acetyl chloride. Completion of reaction was indicated by the disappearance of gas evolution. Removal of excess thionyl chloride was carried out under reduced pressure to afford 2-(3-fluorophenyl)acetyl chloride. Homophthalic acid (1.3 g, 7.2 mmol) was then added and the solution was refluxed for 4 h at 473 K with stirring. The reaction mixture was extracted with ethyl acetate (3 × 100 ml), and an aqueous solution of sodium carbonate (5%, 200 ml) was added to remove the unreacted homophthalic acid. The organic layer was separated, concentrated and chromatographed on silica gel using petroleum ether (313-353 K fractions) as eluent to afford the title compound (yield; 72%, m.p. 447-448 K). Single crystals suitable for X-ray analysis were obtained by slow evaporation of an ethyl acetate solution.

Refinement top

H atoms were positioned geometrically, with C-H = 0.93 and 0.97 Å for aromatic and methylene H, respectively, and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); data reduction: COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
3-(3-Fluorobenzyl)-1H-isochromen-1-one top
Crystal data top
C16H11FO2Z = 4
Mr = 254.25F(000) = 528
Triclinic, P1Dx = 1.392 Mg m−3
Hall symbol: -P 1Melting point: 447(1) K
a = 7.0130 (7) ÅMo Kα radiation, λ = 0.71073 Å
b = 11.7570 (9) ÅCell parameters from 19831 reflections
c = 15.8070 (7) Åθ = 1–27.5°
α = 97.515 (6)°µ = 0.10 mm−1
β = 100.520 (4)°T = 150 K
γ = 105.397 (7)°Block, colorless
V = 1213.12 (16) Å30.38 × 0.24 × 0.22 mm
Data collection top
Bruker–Nonius KappaCCD area-detector
diffractometer		5458 independent reflections
Radiation source: fine-focus sealed tube3741 reflections with I > 2σ(I)
graphiteRint = 0.103
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 1.3°
φ and ω scansh = −9→9
Absorption correction: gaussian
(Coppens, 1970)		k = −15→15
Tmin = 0.925, Tmax = 0.961l = −20→20
19724 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.074Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.218H-atom parameters constrained
S = 1.15 w = 1/[σ2(Fo2) + (0.0736P)2 + 0.9938P]
where P = (Fo2 + 2Fc2)/3
5458 reflections(Δ/σ)max < 0.001
343 parametersΔρmax = 1.11 e Å−3
0 restraintsΔρmin = −0.33 e Å−3
Crystal data top
C16H11FO2γ = 105.397 (7)°
Mr = 254.25V = 1213.12 (16) Å3
Triclinic, P1Z = 4
a = 7.0130 (7) ÅMo Kα radiation
b = 11.7570 (9) ŵ = 0.10 mm−1
c = 15.8070 (7) ÅT = 150 K
α = 97.515 (6)°0.38 × 0.24 × 0.22 mm
β = 100.520 (4)°
Data collection top
Bruker–Nonius KappaCCD area-detector
diffractometer		5458 independent reflections
Absorption correction: gaussian
(Coppens, 1970)		3741 reflections with I > 2σ(I)
Tmin = 0.925, Tmax = 0.961Rint = 0.103
19724 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.074H-atom parameters constrained
wR(F2) = 0.218Δρmax = 1.11 e Å−3
S = 1.15Δρmin = −0.33 e Å−3
5458 reflectionsAbsolute structure: ?
343 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 (Å2) top
xyzUiso*/Ueq
F1A−0.3150 (4)−0.1110 (3)0.3167 (2)0.1171 (11)
O1A0.3057 (4)0.66409 (18)0.51835 (14)0.0554 (6)
O2A0.2277 (3)0.46688 (17)0.49561 (12)0.0445 (5)
C1A0.2626 (5)0.5733 (2)0.46489 (18)0.0396 (6)
C2A0.1748 (4)0.3568 (2)0.44071 (18)0.0366 (6)
C3A0.1539 (4)0.3464 (2)0.35504 (17)0.0327 (6)
H3A0.11650.27080.31960.039*
C4A0.1886 (4)0.4520 (2)0.31613 (16)0.0307 (5)
C5A0.1696 (4)0.4466 (3)0.22617 (17)0.0376 (6)
H5A0.13040.37270.18840.045*
C6A0.2087 (5)0.5508 (3)0.19368 (19)0.0448 (7)
H6A0.19470.54690.13360.054*
C7A0.2686 (5)0.6617 (3)0.2486 (2)0.0494 (8)
H7A0.29610.73160.22550.059*
C8A0.2869 (5)0.6691 (3)0.3371 (2)0.0438 (7)
H8A0.32640.74360.37410.053*
C9A0.2464 (4)0.5642 (2)0.37126 (17)0.0336 (6)
C10A0.1492 (5)0.2591 (3)0.49354 (19)0.0477 (8)
H10AA0.03840.25970.52230.057*
H10AB0.27210.27540.53870.057*
C11A0.1064 (5)0.1367 (2)0.43876 (19)0.0415 (7)
C12A−0.0899 (5)0.0666 (3)0.4031 (2)0.0500 (8)
H12A−0.19860.09260.41420.060*
C13A−0.1233 (6)−0.0442 (3)0.3506 (2)0.0597 (9)
C14A0.0309 (6)−0.0860 (3)0.3330 (2)0.0605 (9)
H14A0.0045−0.16030.29720.073*
C15A0.2262 (6)−0.0157 (3)0.3690 (2)0.0582 (9)
H15A0.3335−0.04310.35760.070*
C16A0.2644 (5)0.0946 (3)0.4218 (2)0.0486 (8)
H16A0.39790.14100.44620.058*
F1B0.6734 (4)0.4452 (2)0.02309 (13)0.0755 (7)
O1B−0.0906 (3)0.1067 (2)0.15717 (17)0.0560 (6)
O2B0.2406 (3)0.14988 (17)0.19855 (12)0.0379 (5)
C1B0.0550 (4)0.0724 (3)0.15393 (19)0.0377 (6)
C2B0.4190 (4)0.1206 (2)0.20150 (17)0.0338 (6)
C3B0.4207 (4)0.0158 (2)0.15905 (17)0.0362 (6)
H3B0.5434−0.00130.16130.043*
C4B0.2357 (4)−0.0713 (2)0.10937 (16)0.0335 (6)
C5B0.2287 (5)−0.1833 (3)0.06398 (18)0.0414 (7)
H5B0.3484−0.20370.06510.050*
C6B0.0472 (5)−0.2627 (3)0.01779 (19)0.0479 (8)
H6B0.0445−0.3373−0.01150.057*
C7B−0.1311 (5)−0.2330 (3)0.0146 (2)0.0486 (8)
H7B−0.2535−0.2871−0.01740.058*
C8B−0.1287 (4)−0.1243 (3)0.0585 (2)0.0448 (7)
H8B−0.2490−0.10440.05640.054*
C9B0.0545 (4)−0.0429 (2)0.10674 (17)0.0346 (6)
C10B0.5958 (4)0.2185 (3)0.25670 (17)0.0385 (6)
H10BA0.71660.19250.26020.046*
H10BB0.57400.23280.31550.046*
C11B0.6324 (4)0.3355 (2)0.22315 (17)0.0341 (6)
C12B0.6343 (4)0.3367 (3)0.13607 (18)0.0393 (6)
H12B0.61210.26560.09710.047*
C13B0.6700 (5)0.4442 (3)0.10830 (19)0.0452 (7)
C14B0.7068 (5)0.5520 (3)0.1630 (2)0.0512 (8)
H14B0.73120.62380.14230.061*
C15B0.7077 (5)0.5502 (3)0.2497 (2)0.0507 (8)
H15B0.73250.62180.28860.061*
C16B0.6707 (4)0.4437 (3)0.28008 (19)0.0418 (7)
H16B0.67240.44420.33910.050*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
F1A0.0800 (19)0.0779 (18)0.155 (3)−0.0105 (14)−0.0160 (18)0.0182 (18)
O1A0.0836 (17)0.0300 (11)0.0420 (12)0.0070 (11)0.0081 (11)−0.0009 (9)
O2A0.0694 (14)0.0310 (10)0.0299 (10)0.0109 (9)0.0095 (9)0.0056 (8)
C1A0.0471 (17)0.0285 (14)0.0389 (15)0.0074 (12)0.0048 (12)0.0061 (11)
C2A0.0453 (16)0.0264 (13)0.0390 (14)0.0099 (11)0.0112 (12)0.0083 (11)
C3A0.0368 (14)0.0248 (12)0.0353 (13)0.0085 (10)0.0060 (11)0.0055 (10)
C4A0.0292 (13)0.0292 (13)0.0331 (13)0.0076 (10)0.0061 (10)0.0079 (10)
C5A0.0428 (16)0.0361 (15)0.0323 (13)0.0111 (12)0.0054 (11)0.0072 (11)
C6A0.0510 (18)0.0479 (17)0.0349 (14)0.0116 (14)0.0076 (12)0.0157 (13)
C7A0.0557 (19)0.0398 (16)0.0495 (17)0.0071 (14)0.0049 (14)0.0221 (14)
C8A0.0499 (17)0.0276 (14)0.0475 (16)0.0048 (12)0.0033 (13)0.0099 (12)
C9A0.0333 (14)0.0295 (13)0.0348 (13)0.0070 (11)0.0029 (10)0.0066 (10)
C10A0.071 (2)0.0397 (16)0.0385 (15)0.0171 (15)0.0179 (14)0.0174 (13)
C11A0.0545 (18)0.0313 (14)0.0437 (15)0.0119 (13)0.0152 (13)0.0207 (12)
C12A0.0550 (19)0.0431 (17)0.0571 (19)0.0150 (15)0.0140 (15)0.0250 (15)
C13A0.059 (2)0.0387 (18)0.067 (2)−0.0041 (16)−0.0014 (17)0.0204 (16)
C14A0.087 (3)0.0299 (16)0.062 (2)0.0090 (17)0.0189 (19)0.0120 (15)
C15A0.073 (2)0.0362 (17)0.075 (2)0.0171 (16)0.0324 (19)0.0210 (16)
C16A0.0538 (19)0.0339 (15)0.0593 (19)0.0079 (14)0.0165 (15)0.0185 (14)
F1B0.1003 (18)0.0857 (16)0.0531 (12)0.0332 (14)0.0296 (11)0.0283 (11)
O1B0.0363 (12)0.0522 (13)0.0832 (17)0.0170 (10)0.0194 (11)0.0088 (12)
O2B0.0337 (10)0.0353 (10)0.0443 (11)0.0099 (8)0.0113 (8)0.0032 (8)
C1B0.0322 (14)0.0369 (15)0.0462 (15)0.0080 (12)0.0138 (12)0.0133 (12)
C2B0.0331 (14)0.0374 (14)0.0325 (13)0.0106 (11)0.0095 (10)0.0089 (11)
C3B0.0317 (14)0.0392 (15)0.0389 (14)0.0117 (11)0.0104 (11)0.0060 (11)
C4B0.0355 (14)0.0353 (14)0.0306 (12)0.0092 (11)0.0100 (10)0.0091 (11)
C5B0.0475 (17)0.0401 (16)0.0363 (14)0.0137 (13)0.0092 (12)0.0051 (12)
C6B0.060 (2)0.0355 (15)0.0403 (16)0.0058 (14)0.0082 (14)0.0019 (12)
C7B0.0432 (17)0.0437 (17)0.0461 (17)−0.0032 (13)0.0020 (13)0.0082 (14)
C8B0.0328 (15)0.0486 (18)0.0495 (17)0.0044 (13)0.0084 (12)0.0148 (14)
C9B0.0343 (14)0.0355 (14)0.0347 (13)0.0070 (11)0.0105 (11)0.0126 (11)
C10B0.0385 (15)0.0399 (15)0.0317 (13)0.0077 (12)0.0032 (11)0.0035 (11)
C11B0.0252 (13)0.0374 (14)0.0348 (13)0.0043 (11)0.0050 (10)0.0032 (11)
C12B0.0385 (15)0.0423 (16)0.0335 (14)0.0083 (12)0.0087 (11)0.0012 (12)
C13B0.0427 (16)0.0563 (19)0.0384 (15)0.0133 (14)0.0125 (12)0.0137 (14)
C14B0.0471 (18)0.0441 (18)0.065 (2)0.0102 (14)0.0188 (15)0.0183 (15)
C15B0.0509 (18)0.0377 (16)0.0570 (19)0.0054 (14)0.0142 (15)0.0003 (14)
C16B0.0384 (15)0.0439 (16)0.0353 (14)0.0045 (12)0.0060 (11)0.0000 (12)
Geometric parameters (Å, °) top
O1A—C1A1.202 (3)O2B—C1B1.374 (3)
O2A—C1A1.378 (3)O2B—C2B1.378 (3)
O2A—C2A1.378 (3)C2B—C3B1.328 (4)
C2A—C3A1.321 (4)C2B—C10B1.486 (4)
C2A—C10A1.498 (4)C3B—H3B0.9299
C3A—H3A0.9301C4B—C5B1.398 (4)
C4A—C3A1.440 (4)C4B—C3B1.436 (4)
C4A—C9A1.397 (4)C5B—C6B1.370 (4)
C5A—C4A1.395 (4)C5B—H5B0.9300
C5A—C6A1.370 (4)C6B—H6B0.9300
C5A—H5A0.9300C7B—C6B1.379 (5)
C6A—C7A1.382 (4)C7B—H7B0.9300
C6A—H6A0.9300C8B—C7B1.367 (4)
C7A—H7A0.9300C8B—H8B0.9300
C8A—C7A1.370 (4)C9B—C1B1.458 (4)
C8A—H8A0.9300C9B—C4B1.393 (4)
C9A—C1A1.451 (4)C9B—C8B1.395 (4)
C9A—C8A1.391 (4)C10B—H10BA0.9700
C10A—H10AA0.9701C10B—H10BB0.9701
C10A—H10AB0.9700C11B—C12B1.381 (4)
C11A—C10A1.504 (4)C11B—C16B1.390 (4)
C11A—C12A1.373 (5)C11B—C10B1.513 (4)
C11A—C16A1.383 (4)C12B—H12B0.9300
C12A—C13A1.386 (5)C13B—C12B1.368 (4)
C12A—H12A0.9300C13B—C14B1.370 (4)
C13A—F1A1.333 (4)C14B—H14B0.9301
C14A—C13A1.359 (5)C15B—C14B1.373 (5)
C14A—C15A1.368 (5)C15B—C16B1.377 (4)
C14A—H14A0.9300C15B—H15B0.9299
C15A—H15A0.9300C16A—C15A1.379 (4)
F1B—C13B1.353 (3)C16A—H16A0.9300
O1B—C1B1.200 (3)C16B—H16B0.9300
C2A—O2A—C1A122.3 (2)C1B—O2B—C2B122.5 (2)
O1A—C1A—O2A116.8 (3)O1B—C1B—O2B116.7 (3)
O1A—C1A—C9A126.6 (3)O1B—C1B—C9B126.4 (3)
O2A—C1A—C9A116.6 (2)O2B—C1B—C9B116.9 (2)
C3A—C2A—O2A122.1 (2)C3B—C2B—O2B121.2 (2)
C3A—C2A—C10A128.3 (2)C3B—C2B—C10B127.3 (3)
O2A—C2A—C10A109.6 (2)O2B—C2B—C10B111.4 (2)
C2A—C3A—C4A120.2 (2)C2B—C3B—C4B120.9 (2)
C2A—C3A—H3A120.1C2B—C3B—H3B119.6
C4A—C3A—H3A119.8C4B—C3B—H3B119.5
C5A—C4A—C9A119.0 (2)C9B—C4B—C5B118.5 (3)
C5A—C4A—C3A122.7 (2)C9B—C4B—C3B118.2 (2)
C9A—C4A—C3A118.3 (2)C5B—C4B—C3B123.2 (2)
C6A—C5A—C4A119.7 (3)C6B—C5B—C4B120.5 (3)
C6A—C5A—H5A120.1C6B—C5B—H5B119.9
C4A—C5A—H5A120.2C4B—C5B—H5B119.6
C5A—C6A—C7A121.1 (3)C5B—C6B—C7B120.5 (3)
C5A—C6A—H6A119.4C5B—C6B—H6B119.6
C7A—C6A—H6A119.4C7B—C6B—H6B119.9
C8A—C7A—C6A120.1 (3)C8B—C7B—C6B120.2 (3)
C8A—C7A—H7A119.9C8B—C7B—H7B119.8
C6A—C7A—H7A120.0C6B—C7B—H7B120.0
C7A—C8A—C9A119.6 (3)C7B—C8B—C9B120.1 (3)
C7A—C8A—H8A120.2C7B—C8B—H8B120.2
C9A—C8A—H8A120.2C9B—C8B—H8B119.8
C8A—C9A—C4A120.5 (2)C4B—C9B—C8B120.2 (3)
C8A—C9A—C1A119.0 (2)C4B—C9B—C1B120.2 (2)
C4A—C9A—C1A120.5 (2)C8B—C9B—C1B119.6 (3)
C2A—C10A—C11A112.7 (2)C2B—C10B—C11B113.9 (2)
C2A—C10A—H10AA109.2C2B—C10B—H10BA108.9
C11A—C10A—H10AA109.1C11B—C10B—H10BA108.8
C2A—C10A—H10AB108.9C2B—C10B—H10BB108.7
C11A—C10A—H10AB109.0C11B—C10B—H10BB108.7
H10AA—C10A—H10AB107.8H10BA—C10B—H10BB107.6
C12A—C11A—C16A119.1 (3)C12B—C11B—C16B119.0 (3)
C12A—C11A—C10A120.5 (3)C12B—C11B—C10B120.5 (2)
C16A—C11A—C10A120.4 (3)C16B—C11B—C10B120.5 (2)
C11A—C12A—C13A118.9 (3)C13B—C12B—C11B118.9 (3)
C11A—C12A—H12A120.6C13B—C12B—H12B120.6
C13A—C12A—H12A120.5C11B—C12B—H12B120.4
F1A—C13A—C14A119.6 (4)F1B—C13B—C12B118.7 (3)
F1A—C13A—C12A117.9 (4)F1B—C13B—C14B118.0 (3)
C14A—C13A—C12A122.5 (3)C12B—C13B—C14B123.2 (3)
C13A—C14A—C15A118.3 (3)C13B—C14B—C15B117.5 (3)
C13A—C14A—H14A120.8C13B—C14B—H14B121.3
C15A—C14A—H14A120.8C15B—C14B—H14B121.2
C14A—C15A—C16A120.6 (3)C14B—C15B—C16B121.0 (3)
C14A—C15A—H15A119.4C14B—C15B—H15B119.7
C16A—C15A—H15A120.0C16B—C15B—H15B119.3
C15A—C16A—C11A120.6 (3)C15B—C16B—C11B120.4 (3)
C15A—C16A—H16A119.6C15B—C16B—H16B119.9
C11A—C16A—H16A119.7C11B—C16B—H16B119.8
Acknowledgements top

TMB is grateful to The Higher Education Commission of Pakistan for financial support under the national support initiative program for pre-doctoral fellowships in Quaid-i-Azam University.

references
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