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The benzo­furan moiety of the title mol­ecule, C10H8O2, is planar and forms a dihedral angle of 6.69 (9)° with the attached acetyl group. In the crystal structure, symmetry-related mol­ecules are linked to form chains by C—H...O intermolecular hydrogen bonds involving the furan H atom and the O atom of the acetyl group. Adjacent chains are interlinked through weak C—H...π interactions involving the furan ring.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803004306/ci6204sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803004306/ci6204Isup2.hkl
Contains datablock I

CCDC reference: 209909

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.003 Å
  • R factor = 0.036
  • wR factor = 0.092
  • Data-to-parameter ratio = 13.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry








Comment top

A convenient method of preparing 2-acetylbenzofuran, (I), from 2-hydroxybenzaldehyde and chloroacetone in the presence of KOH has been reported (Elliot, 1951). We have obtained (I) using a phase-transfer catalytic method. The present X-ray diffraction study was undertaken to understand the geometry of the benzofuran ring system and the effect of acetyl group substitution at the second position of the furan ring.

In (I), the benzofuran moiety is planar and the acetyl group is slightly twisted about the C2—C21 bond, as seen from the torsion angles O1—C2—C21—O21 = 5.9 (3)° and C3—C2—C21—C22 = 6.7 (3)°. The geometry of the benzofuran ring is comparable to that found in ethyl 3-hydroxybenzo[b]furan-2-carboxylate (Gould et al., 1998). In the solid state, the symmetry-related molecules are linked by C3—H3···O21(3/2 − x, −y, −1/2 + z) hydrogen bonds to form chains along the c axis. The adjacent chains related by the symmetry operation (−1/2 + x, y, 3/2 − z) are linked by C—H···π hydrogen bonds involving the furan ring (Table 1), to form double chain structures.

Experimental top

The title compound was synthesized employing a phase-transfer catalytic technique. Salicylaldehyde (6.12 ml, 0.05 mol) and chloroacetone (4.0 ml, 0.05 mol) were taken in benzene (30 ml) and the reaction mixture was magnetically stirred for 3 h with 20% aqueous potassium carbonate (20 ml) solution in the presence of a catalytic amount of tetrabutylammonium hydrogen sulfate (200 mg) as a phase-transfer catalyst. The solid obtained was filtered off and dried in air. Recrystallization from 1,4-dioxane afforded the crystals. The yield of the isolated product was 86%.

Refinement top

The H atoms were fixed geometrically and were treated as riding on their parent C atoms, with isotropic displacement parameters. The methyl group was found to be disordered over two positions rotated from each other by 60°. It was refined as an idealized disordered methyl group.

Computing details top

Data collection: CAD-4 Software (Enraf-Nonius, 1994); cell refinement: MolEN (Fair, 1990); data reduction: MolEN; program(s) used to solve structure: SIR97 (Altomare et al. 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids (Farrugia, 1997).
[Figure 2] Fig. 2. The molecular packing of (I), viewed down the a axis (Spek, 1990).
(I) top
Crystal data top
C10H8O2Dx = 1.303 Mg m3
Mr = 160.16Melting point: 344–345 K K
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 25 reflections
a = 8.3865 (13) Åθ = 10–15°
b = 18.273 (4) ŵ = 0.09 mm1
c = 10.652 (2) ÅT = 293 K
V = 1632.4 (5) Å3Block, light brown
Z = 80.3 × 0.3 × 0.3 mm
F(000) = 672
Data collection top
Enraf-Nonius CAD-4
diffractometer
θmax = 25.0°, θmin = 2.2°
ω–2θ scansh = 09
1419 measured reflectionsk = 021
1419 independent reflectionsl = 012
907 reflections with I > 2σ(I)2 standard reflections every 100 reflections
Rint = 0 intensity decay: none
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.036 w = 1/[σ2(Fo2) + (0.0348P)2 + 0.2715P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.092(Δ/σ)max < 0.001
S = 1.03Δρmax = 0.10 e Å3
1419 reflectionsΔρmin = 0.12 e Å3
109 parameters
Crystal data top
C10H8O2V = 1632.4 (5) Å3
Mr = 160.16Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 8.3865 (13) ŵ = 0.09 mm1
b = 18.273 (4) ÅT = 293 K
c = 10.652 (2) Å0.3 × 0.3 × 0.3 mm
Data collection top
Enraf-Nonius CAD-4
diffractometer
Rint = 0
1419 measured reflections2 standard reflections every 100 reflections
1419 independent reflections intensity decay: none
907 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0360 restraints
wR(F2) = 0.092H-atom parameters constrained
S = 1.03Δρmax = 0.10 e Å3
1419 reflectionsΔρmin = 0.12 e Å3
109 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O10.58354 (15)0.03542 (6)0.72975 (11)0.0612 (4)
C20.6746 (2)0.00551 (10)0.63421 (15)0.0547 (4)
C30.6747 (2)0.04877 (10)0.53242 (16)0.0575 (5)
H30.72770.03990.45720.069*
C40.5316 (2)0.17426 (11)0.4978 (2)0.0713 (6)
H40.56410.18310.41570.086*
C50.4360 (3)0.22329 (11)0.5604 (2)0.0797 (6)
H50.40310.26560.51930.096*
C60.3873 (2)0.21127 (11)0.6835 (2)0.0774 (6)
H60.32360.24590.72320.093*
C70.4314 (2)0.14917 (10)0.7477 (2)0.0695 (5)
H70.39910.14070.82990.083*
C80.5263 (2)0.10015 (10)0.68320 (16)0.0555 (5)
C90.5787 (2)0.11078 (10)0.56100 (16)0.0555 (5)
C210.7495 (2)0.06530 (10)0.66040 (17)0.0616 (5)
C220.8610 (2)0.09450 (11)0.56308 (19)0.0772 (6)
H22A0.94410.12210.60310.116*0.5
H22B0.90710.05450.51720.116*0.5
H22C0.80350.12560.50640.116*0.5
H22D0.82570.07940.48130.116*0.5
H22E0.86270.1470.56730.116*0.5
H22F0.96630.07590.57810.116*0.5
O210.72146 (19)0.09825 (7)0.75714 (13)0.0808 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0704 (8)0.0599 (7)0.0533 (7)0.0007 (6)0.0086 (7)0.0016 (6)
C20.0540 (10)0.0610 (11)0.0491 (9)0.0048 (9)0.0013 (9)0.0087 (9)
C30.0522 (10)0.0720 (11)0.0482 (10)0.0095 (10)0.0001 (9)0.0030 (10)
C40.0660 (13)0.0729 (12)0.0751 (12)0.0148 (11)0.0053 (11)0.0131 (12)
C50.0771 (15)0.0593 (12)0.1028 (17)0.0088 (11)0.0156 (14)0.0150 (12)
C60.0656 (13)0.0623 (13)0.1043 (17)0.0025 (10)0.0035 (13)0.0101 (12)
C70.0693 (12)0.0653 (11)0.0738 (12)0.0032 (11)0.0079 (11)0.0048 (11)
C80.0530 (10)0.0531 (10)0.0604 (11)0.0057 (9)0.0014 (9)0.0008 (9)
C90.0507 (10)0.0603 (11)0.0553 (10)0.0124 (9)0.0058 (9)0.0043 (9)
C210.0647 (11)0.0626 (11)0.0575 (10)0.0035 (10)0.0091 (10)0.0083 (10)
C220.0728 (13)0.0756 (13)0.0833 (13)0.0080 (11)0.0005 (12)0.0165 (11)
O210.1054 (12)0.0714 (8)0.0657 (8)0.0089 (8)0.0034 (8)0.0052 (8)
Geometric parameters (Å, º) top
O1—C81.369 (2)C6—H60.93
O1—C21.3848 (19)C7—C81.381 (2)
C2—C31.342 (2)C7—H70.93
C2—C211.465 (3)C8—C91.388 (2)
C3—C91.423 (2)C21—O211.216 (2)
C3—H30.93C21—C221.495 (3)
C4—C51.374 (3)C22—H22A0.96
C4—C91.398 (2)C22—H22B0.96
C4—H40.93C22—H22C0.96
C5—C61.391 (3)C22—H22D0.96
C5—H50.93C22—H22E0.96
C6—C71.376 (3)C22—H22F0.96
C8—O1—C2105.55 (13)O21—C21—C2121.04 (18)
C3—C2—O1111.21 (16)O21—C21—C22122.12 (19)
C3—C2—C21132.36 (17)C2—C21—C22116.84 (17)
O1—C2—C21116.43 (15)C21—C22—H22A109.5
C2—C3—C9107.21 (16)C21—C22—H22B109.5
C2—C3—H3126.4H22A—C22—H22B109.5
C9—C3—H3126.4C21—C22—H22C109.5
C5—C4—C9118.18 (19)H22A—C22—H22C109.5
C5—C4—H4120.9H22B—C22—H22C109.5
C9—C4—H4120.9C21—C22—H22D109.5
C4—C5—C6121.7 (2)H22A—C22—H22D141.1
C4—C5—H5119.1H22B—C22—H22D56.3
C6—C5—H5119.1H22C—C22—H22D56.3
C7—C6—C5121.3 (2)C21—C22—H22E109.5
C7—C6—H6119.3H22A—C22—H22E56.3
C5—C6—H6119.3H22B—C22—H22E141.1
C6—C7—C8116.3 (2)H22C—C22—H22E56.3
C6—C7—H7121.9H22D—C22—H22E109.5
C8—C7—H7121.9C21—C22—H22F109.5
O1—C8—C7125.59 (17)H22A—C22—H22F56.3
O1—C8—C9110.47 (16)H22B—C22—H22F56.3
C7—C8—C9123.94 (18)H22C—C22—H22F141.1
C8—C9—C4118.57 (18)H22D—C22—H22F109.5
C8—C9—C3105.57 (16)H22E—C22—H22F109.5
C4—C9—C3135.86 (18)
C8—O1—C2—C30.20 (19)C7—C8—C9—C40.9 (3)
C8—O1—C2—C21179.59 (15)O1—C8—C9—C30.49 (18)
O1—C2—C3—C90.1 (2)C7—C8—C9—C3178.76 (17)
C21—C2—C3—C9179.16 (18)C5—C4—C9—C80.3 (3)
C9—C4—C5—C60.5 (3)C5—C4—C9—C3179.22 (18)
C4—C5—C6—C70.7 (3)C2—C3—C9—C80.35 (18)
C5—C6—C7—C80.2 (3)C2—C3—C9—C4179.92 (19)
C2—O1—C8—C7178.81 (17)C3—C2—C21—O21173.37 (19)
C2—O1—C8—C90.43 (18)O1—C2—C21—O215.9 (3)
C6—C7—C8—O1179.79 (17)C3—C2—C21—C226.7 (3)
C6—C7—C8—C90.6 (3)O1—C2—C21—C22174.04 (14)
O1—C8—C9—C4179.85 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O21i0.932.423.190 (2)140
C7—H7···Cg1ii0.932.893.431 (2)119
Symmetry codes: (i) x+3/2, y, z1/2; (ii) x1/2, y, z+3/2.

Experimental details

Crystal data
Chemical formulaC10H8O2
Mr160.16
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)293
a, b, c (Å)8.3865 (13), 18.273 (4), 10.652 (2)
V3)1632.4 (5)
Z8
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.3 × 0.3 × 0.3
Data collection
DiffractometerEnraf-Nonius CAD-4
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
1419, 1419, 907
Rint0
(sin θ/λ)max1)0.594
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.092, 1.03
No. of reflections1419
No. of parameters109
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.10, 0.12

Computer programs: CAD-4 Software (Enraf-Nonius, 1994), MolEN (Fair, 1990), MolEN, SIR97 (Altomare et al. 1999), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O21i0.932.423.190 (2)140
C7—H7···Cg1ii0.932.893.431 (2)119
Symmetry codes: (i) x+3/2, y, z1/2; (ii) x1/2, y, z+3/2.
 

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