2 Acetyl­benzo­[b]­furan

Acta Cryst.(2003). E59, o395±o396 DOI: 10.1107/S1600536803004306 A. Thiruvalluvaret al. C₁₀H₈O₂

o395

organic papers

Acta Crystallographica Section E Structure Reports

Online

ISSN 1600-5368

2-Acetylbenzo[

b

]furan

A. Thiruvalluvar,a_{* S. Silvarani,}a

A. Vadivelu,a_{K. Sithik Ali}b_and

V. R. Venkataramanb

a_{Department of Physics, Rajah Serfoji} Government College, Thanjavur 613 005, Tamilnadu, India, andb_{Post Graduate and} Research Department of Chemistry, Jamal Mohamed College, Tiruchirappalli 620 020, India

Correspondence e-mail: [email protected]

Key indicators Single-crystal X-ray study

T= 293 K

Mean(C±C) = 0.003 AÊ Disorder in main residue

Rfactor = 0.036

wRfactor = 0.092

Data-to-parameter ratio = 13.0

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2003 International Union of Crystallography Printed in Great Britain ± all rights reserved

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 CÐH O intermolecular hydrogen bonds involving the furan H atom and the O atom of the acetyl group. Adjacent chains are interlinked through weak CÐH interactions involving the furan ring.

Comment

A convenient method of preparing 2-acetylbenzofuran, (I), from 2-hydroxybenzaldehyde and chloroacetone in the presence of KOH has been reported (Elliott, 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 position 2 of the furan ring.

In (I), the benzofuran moiety is planar and the acetyl group is slightly twisted about the C2ÐC21 bond, as seen from the

torsion angles O1ÐC2ÐC21ÐO21 = 5.9 (3) _{and C3ÐC2Ð}

C21ÐC22 = 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 C3Ð

H3 O21(3

2ÿx, ÿy, ÿ12 +z) hydrogen bonds to form chains

along the c axis. Adjacent chains related by the symmetry operation (ÿ1

2 +x, y,32ÿz) are linked by CÐH hydrogen

bonds involving the furan ring (Table 1), to form double-chain structures.

Experimental

The title compound was synthesized employing a phase-transfer catalytic technique. Salicylaldehyde (6.12 ml, 0.05 mol) and chloro-acetone (4.0 ml, 0.05 mol) were added to 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 resulting solid was ®ltered off and dried in air. Recrystallization from 1,4-dioxane afforded the crystals. The yield of the isolated product was 86%.

Crystal data

C10H8O2 Mr= 160.16 Orthorhombic,Pbca a= 8.3865 (13) AÊ

b= 18.273 (4) AÊ

c= 10.652 (2) AÊ

V= 1632.4 (5) AÊ3 Z= 8

Dx= 1.303 Mg mÿ3

MoKradiation Cell parameters from 25

re¯ections

= 10±15 = 0.09 mmÿ1 T= 293 (2) K Block, light brown 0.30.30.3 mm

Data collection

Enraf±Nonius CAD-4 diffractometer

!±2scans

Absorption correction: none 1419 measured re¯ections 1419 independent re¯ections 907 re¯ections withI> 2(I)

max= 25.0 h= 0!9

k= 0!21

l= 0!12

2 standard re¯ections every 100 re¯ections intensity decay: none

Re®nement

Re®nement onF2 R[F2_{> 2(F}2_{)] = 0.036} wR(F2_{) = 0.092} S= 1.03 1419 re¯ections 109 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.0348P)2 + 0.2715P]

whereP= (Fo2+ 2Fc2)/3 (/)max< 0.001

max= 0.10 e AÊÿ3

min=ÿ0.12 e AÊÿ3

Table 1

Hydrogen-bonding geometry (AÊ,_).

DÐH A DÐH H A D A DÐH A

C3ÐH3 O21i _{0.93 2.42 3.190 (2) 140}

C7ÐH7 Cg1ii _{0.93 2.89 3.431 (2) 119} Symmetry codes: (i)3

2ÿx;ÿy;zÿ12; (ii)xÿ12;y;32ÿz.

The H atoms were ®xed 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 re®ned as an idealized disordered}

methyl group.

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

KS thanks the UGC, India, for partial ®nancial assistance.

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999).J. Appl. Cryst.32, 115±119.

Elliott, E. D. (1951).J. Am. Chem. Soc.73, 754.

Enraf±Nonius (1994). CAD-4 Software. Enraf±Nonius, Delft, The Nether-lands.

Fair, C. K. (1990).MolEN.Enraf±Nonius, Delft, The Netherlands. Farrugia, L. J. (1997).J. Appl. Cryst.30, 565.

Farrugia, L. J. (1999).J. Appl. Cryst.32, 837±838.

Gould, R. O., Guest, M. F., Joswig, J.-O., Palmer, M. H. & Parsons, S. (1998).

Acta Cryst.C54, 1951±1954.

Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany. Spek, A. L. (1990).Acta Cryst.A46, C-34.

Figure 1

The molecular structure of (I), showing 50% probability displacement ellipsoids (Farrugia, 1997).

Figure 2

supporting information

sup-1

supporting information

Acta Cryst. (2003). E59, o395–o396 [doi:10.1107/S1600536803004306]

2-Acetylbenzo[

b

]furan

A. Thiruvalluvar, S. Silvarani, A. Vadivelu, K. Sithik Ali and V. R. Venkataraman

S1. Comment

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.

S2. Experimental

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%.

S3. Refinement

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

Figure 1

The molecular structure of (I), showing 50% probability displacement ellipsoids (Farrugia, 1997).

Figure 2

The molecular packing of (I), viewed down the a axis (Spek, 1990).

(I)

Crystal data

C10H8O2 Mr = 160.16

Orthorhombic, Pbca Hall symbol: -P 2ac 2ab a = 8.3865 (13) Å b = 18.273 (4) Å

c = 10.652 (2) Å V = 1632.4 (5) Å3 Z = 8

F(000) = 672 Dx = 1.303 Mg m−3

supporting information

sup-3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 25 reflections θ = 10–15°

µ = 0.09 mm−1

T = 293 K

Block, light brown 0.3 × 0.3 × 0.3 mm

Data collection

Enraf-Nonius CAD-4 diffractometer ω–2θ scans

1419 measured reflections 1419 independent reflections 907 reflections with I > 2σ(I) Rint = 0

θmax = 25.0°, θmin = 2.2° h = 0→9

k = 0→21 l = 0→12

2 standard reflections every 100 reflections intensity decay: none

Refinement

Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.036} wR(F2_{) = 0.092} S = 1.03 1419 reflections 109 parameters

0 restraints

H-atom parameters constrained w = 1/[σ2_(F

o2) + (0.0348P)2 + 0.2715P] where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001 Δρmax = 0.10 e Å−3 Δρmin = −0.12 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

x y z Uiso*/Ueq Occ. (<1)

O1 0.58354 (15) 0.03542 (6) 0.72975 (11) 0.0612 (4) C2 0.6746 (2) 0.00551 (10) 0.63421 (15) 0.0547 (4) C3 0.6747 (2) 0.04877 (10) 0.53242 (16) 0.0575 (5)

H3 0.7277 0.0399 0.4572 0.069*

C4 0.5316 (2) 0.17426 (11) 0.4978 (2) 0.0713 (6)

H4 0.5641 0.1831 0.4157 0.086*

C5 0.4360 (3) 0.22329 (11) 0.5604 (2) 0.0797 (6)

H5 0.4031 0.2656 0.5193 0.096*

C6 0.3873 (2) 0.21127 (11) 0.6835 (2) 0.0774 (6)

H6 0.3236 0.2459 0.7232 0.093*

C7 0.4314 (2) 0.14917 (10) 0.7477 (2) 0.0695 (5)

H7 0.3991 0.1407 0.8299 0.083*

C8 0.5263 (2) 0.10015 (10) 0.68320 (16) 0.0555 (5) C9 0.5787 (2) 0.11078 (10) 0.56100 (16) 0.0555 (5) C21 0.7495 (2) −0.06530 (10) 0.66040 (17) 0.0616 (5) C22 0.8610 (2) −0.09450 (11) 0.56308 (19) 0.0772 (6)

H22A 0.9441 −0.1221 0.6031 0.116* 0.5

H22B 0.9071 −0.0545 0.5172 0.116* 0.5

H22C 0.8035 −0.1256 0.5064 0.116* 0.5

H22E 0.8627 −0.147 0.5673 0.116* 0.5

H22F 0.9663 −0.0759 0.5781 0.116* 0.5

O21 0.72146 (19) −0.09825 (7) 0.75714 (13) 0.0808 (4)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

O1 0.0704 (8) 0.0599 (7) 0.0533 (7) 0.0007 (6) 0.0086 (7) 0.0016 (6) C2 0.0540 (10) 0.0610 (11) 0.0491 (9) −0.0048 (9) 0.0013 (9) −0.0087 (9) C3 0.0522 (10) 0.0720 (11) 0.0482 (10) −0.0095 (10) −0.0001 (9) −0.0030 (10) C4 0.0660 (13) 0.0729 (12) 0.0751 (12) −0.0148 (11) −0.0053 (11) 0.0131 (12) C5 0.0771 (15) 0.0593 (12) 0.1028 (17) −0.0088 (11) −0.0156 (14) 0.0150 (12) C6 0.0656 (13) 0.0623 (13) 0.1043 (17) 0.0025 (10) −0.0035 (13) −0.0101 (12) C7 0.0693 (12) 0.0653 (11) 0.0738 (12) −0.0032 (11) 0.0079 (11) −0.0048 (11) C8 0.0530 (10) 0.0531 (10) 0.0604 (11) −0.0057 (9) −0.0014 (9) 0.0008 (9) C9 0.0507 (10) 0.0603 (11) 0.0553 (10) −0.0124 (9) −0.0058 (9) 0.0043 (9) C21 0.0647 (11) 0.0626 (11) 0.0575 (10) −0.0035 (10) −0.0091 (10) −0.0083 (10) C22 0.0728 (13) 0.0756 (13) 0.0833 (13) 0.0080 (11) 0.0005 (12) −0.0165 (11) O21 0.1054 (12) 0.0714 (8) 0.0657 (8) 0.0089 (8) −0.0034 (8) 0.0052 (8)

Geometric parameters (Å, º)

O1—C8 1.369 (2) C6—H6 0.93

O1—C2 1.3848 (19) C7—C8 1.381 (2)

C2—C3 1.342 (2) C7—H7 0.93

C2—C21 1.465 (3) C8—C9 1.388 (2)

C3—C9 1.423 (2) C21—O21 1.216 (2)

C3—H3 0.93 C21—C22 1.495 (3)

C4—C5 1.374 (3) C22—H22A 0.96

C4—C9 1.398 (2) C22—H22B 0.96

C4—H4 0.93 C22—H22C 0.96

C5—C6 1.391 (3) C22—H22D 0.96

C5—H5 0.93 C22—H22E 0.96

C6—C7 1.376 (3) C22—H22F 0.96

C8—O1—C2 105.55 (13) O21—C21—C2 121.04 (18) C3—C2—O1 111.21 (16) O21—C21—C22 122.12 (19) C3—C2—C21 132.36 (17) C2—C21—C22 116.84 (17)

O1—C2—C21 116.43 (15) C21—C22—H22A 109.5

C2—C3—C9 107.21 (16) C21—C22—H22B 109.5

C2—C3—H3 126.4 H22A—C22—H22B 109.5

C9—C3—H3 126.4 C21—C22—H22C 109.5

C5—C4—C9 118.18 (19) H22A—C22—H22C 109.5

C5—C4—H4 120.9 H22B—C22—H22C 109.5

C9—C4—H4 120.9 C21—C22—H22D 109.5

C4—C5—C6 121.7 (2) H22A—C22—H22D 141.1

C4—C5—H5 119.1 H22B—C22—H22D 56.3

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C7—C6—C5 121.3 (2) C21—C22—H22E 109.5

C7—C6—H6 119.3 H22A—C22—H22E 56.3

C5—C6—H6 119.3 H22B—C22—H22E 141.1

C6—C7—C8 116.3 (2) H22C—C22—H22E 56.3

C6—C7—H7 121.9 H22D—C22—H22E 109.5

C8—C7—H7 121.9 C21—C22—H22F 109.5

O1—C8—C7 125.59 (17) H22A—C22—H22F 56.3

O1—C8—C9 110.47 (16) H22B—C22—H22F 56.3

C7—C8—C9 123.94 (18) H22C—C22—H22F 141.1

C8—C9—C4 118.57 (18) H22D—C22—H22F 109.5

C8—C9—C3 105.57 (16) H22E—C22—H22F 109.5

C4—C9—C3 135.86 (18)

C8—O1—C2—C3 −0.20 (19) C7—C8—C9—C4 −0.9 (3) C8—O1—C2—C21 −179.59 (15) O1—C8—C9—C3 −0.49 (18) O1—C2—C3—C9 −0.1 (2) C7—C8—C9—C3 178.76 (17) C21—C2—C3—C9 179.16 (18) C5—C4—C9—C8 0.3 (3) C9—C4—C5—C6 0.5 (3) C5—C4—C9—C3 −179.22 (18) C4—C5—C6—C7 −0.7 (3) C2—C3—C9—C8 0.35 (18) C5—C6—C7—C8 0.2 (3) C2—C3—C9—C4 179.92 (19) C2—O1—C8—C7 −178.81 (17) C3—C2—C21—O21 −173.37 (19) C2—O1—C8—C9 0.43 (18) O1—C2—C21—O21 5.9 (3) C6—C7—C8—O1 179.79 (17) C3—C2—C21—C22 6.7 (3) C6—C7—C8—C9 0.6 (3) O1—C2—C21—C22 −174.04 (14) O1—C8—C9—C4 179.85 (15)

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

C3—H3···O21i _{0.93 2.42 3.190 (2) 140}

C7—H7···Cg1ii _{0.93 2.89 3.431 (2) 119}