organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

5-Methyl-3-phenyl­isoxazole-4-carb­­oxy­lic acid

aDepartment of Studies in Physics, Manasagangotri, University of Mysore, Mysore 570 006, India, bDepartment of Chemistry, Yuvaraja's College, University of Mysore, Mysore 570 005, India, and cDepartment of Physics, St Philomena's College, Mysore, India
*Correspondence e-mail: mahendra@physics.uni-mysore.ac.in

(Received 3 April 2013; accepted 26 April 2013; online 15 May 2013)

In the title compound, C11H9NO3, the phenyl and isoxazole rings form a dihedral angle of 56.64 (8)°. The carb­oxy group is almost in the same plane as the isoxazole ring with a C—C—C—O torsion angle of −3.3 (2)°. In the crystal, pairs of O—H⋯O hydrogen bonds link the mol­ecules into head-to-head dimers. C—H⋯N hydrogen bonds and ππ stacking inter­actions between phenyl rings [centroid–centroid distance = 3.9614 (17)Å] link the dimers into a three-dimensional network.

Related literature

For the biological and pharmaceutical importance of isoxazoles, see: Basappa et al., (2003[Basappa, M. P., Sadashiva, K., Mantelingu, S., Nanjunda, S. & Rangappa, K. S. (2003). Bioorg. Med. Chem. Lett. 11, 4539-4544.]); Conti et al. (1998[Conti, P., Dallanoce, C., Amici, M. D., Micheli, C. D. & Klotz, K. N. (1998). Bioorg. Med. Chem. 6, 401-408.]); Kang et al. (2000[Kang, Y. Y., Shin, K. L., Yoo, K. H., Seo, K. J., Hong, C. Y., Lee, C. S., Park, S. Y., Kim, D. J. & Park, S. W. (2000). Bioorg. Med. Chem. Lett. 10, 95-99.]); Lee et al. (2009[Lee, Y., Park, S. M. & Kim, B. H. (2009). Bioorg. Med. Chem. Lett. 19, 1126-1128.]); Shin et al. (2005[Shin, K. D., Lee, M. Y., Shin, D. S., Lee, S., Son, K. H., Koh, S., Paik, Y. K., Kwon, B. M. & Han, D. C. (2005). J. Biol. Chem. 280, 41439-41448.]); Stevens & Albizati (1984[Stevens, R. V. & Albizati, K. F. (1984). Tetrahedron Lett. 25, 4587-4591.]). For bond-length and angle data in related structures, see: Wolf et al. (1995[Wolf, R., Wong, M. W., Kennard, C. H. L. & Wentrup, C. (1995). J. Am. Chem. Soc. 117, 6789-6790.]); Chandra et al., (2013[Chandra, Raghu, K., Srikantamurthy, N., Umesha, K. B., Palani, K. & Mahendra, M. (2013). Acta Cryst. E69, o388.]).

[Scheme 1]

Experimental

Crystal data
  • C11H9NO3

  • Mr = 203.19

  • Monoclinic, P 21 /n

  • a = 11.953 (4) Å

  • b = 5.981 (2) Å

  • c = 14.142 (5) Å

  • β = 105.548 (6)°

  • V = 974.0 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 273 K

  • 0.30 × 0.25 × 0.20 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • 8619 measured reflections

  • 1712 independent reflections

  • 1558 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.111

  • S = 1.05

  • 1712 reflections

  • 138 parameters

  • H-atom parameters constrained

  • Δρmax = 0.19 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O14—H14⋯O15i 0.82 1.81 2.6252 (18) 172
C11—H11A⋯N8ii 0.96 2.51 3.427 (2) 159
Symmetry codes: (i) -x+2, -y, -z; (ii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z-{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Isoxazole derivatives bearing various substituents are known to have diverse biological and pharmaceutical activities; such as anti-tumor (Kang et al., 2000), antiviral (Lee et al., 2009), hypoglycemic (Conti et al., 1998), antifungal (Basappa et al., 2003) and anti-HIV activities (Shin et al., 2005). In addition, isoxazoles and related compounds have attracted much interest because of their fungicidal, plant-growth regulating and antibacterial activities (Stevens & Albizati, 1984). As part of our interest in these compounds and our extensive background on isoxazole derivatives, we have synthesized the title compound to study its crystal structure.

Fig. 1 presents an ellipsoid plot of the title compound (I). The (C7/N8/O9/C10/C12) isoxazole ring is in Syn-Clinal conformation with respect to the (C1-C2-C3-C4-C5-C6) phenyl ring, as indicated by the (C1-C6-C7-N8) torsion angle of -54.40 (19)°. The carboxylic acid group at C12 is almost in the same plane as the isoxazole ring (C7-C12-C13-O15 torsion angle = -3.3 (2)°). The bond lengths and angles are within normal ranges and are comparable to related structure (Wolf et al., 1995 & Chandra et al., 2013). The crystal structure is stabilized by O—H···O bonds (Table 1), which define head to head dimers, and weaker C-H···N bonds (Table 1), thus defining planes parallel to (101) (Fig 2). Finally, there are π···π stacking interacions between phenyl rings with Cg···Cg[1-x,1-y,-z] and slippage displacement distances of 3.9614 (17)Å and 1.284Å respectively (Fig 3) which link planes into a 3D structure.

Related literature top

For the biological and pharmaceutical importance of isoxazoles, see: Basappa et al., (2003); Conti et al. (1998); Kang et al. (2000); Lee et al. (2009); Shin et al. (2005); Stevens & Albizati (1984). For bond-length and angle data in related structures, see: Wolf et al. (1995); Chandra et al., (2013).

Experimental top

A mixture of benzaldehyde oxime (1 mmol), ethyl acetoacetate (2 mmol) and anhydrous zinc chloride (0.1 mmol) were taken in a 10 ml round bottomed flask and the contents were gradually heated to 60°C without any solvent for about one hour. After completion of the reaction (as indicated by TLC), the mixture was cooled to room temperature and ethanol was added with stirring for about 30 min. The solid ethyl 5-methyl-3-phenylisoxazole-4-carboxylate thus obtained was treated with 5% NaOH (10 ml) at room temperature for about 4hr. After completion of the reaction (as indicated by TLC), the reaction mixture was acidified with 2 N HCl. The solids thus obtained were filtered and recrystalized from hot ethanol to get crystals of the title compound.

Refinement top

H atoms were placed at idealized positions and allowed to ride on their parent atoms with C–H distances in the range of 0.93 to 0.96 Å; Uiso(H) = 1.2Ueq(carrier atom) for all H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Perspective diagram of the molecule with 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. Packing diagram of the molecule viewed down the 'b' axis, showing the H-bonded dimers.
[Figure 3] Fig. 3. Packing diagram of the molecule viewed down the 'b' axis, showing the ππ interactions.
5-Methyl-3-phenylisoxazole-4-carboxylic acid top
Crystal data top
C11H9NO3F(000) = 424
Mr = 203.19Dx = 1.386 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1712 reflections
a = 11.953 (4) Åθ = 2.0–25.0°
b = 5.981 (2) ŵ = 0.10 mm1
c = 14.142 (5) ÅT = 273 K
β = 105.548 (6)°Block, yellow
V = 974.0 (6) Å30.30 × 0.25 × 0.20 mm
Z = 4
Data collection top
Bruker APEXII CCD area-detector
diffractometer
Rint = 0.026
ω and ϕ scansθmax = 25.0°, θmin = 2.0°
8619 measured reflectionsh = 1414
1712 independent reflectionsk = 77
1558 reflections with I > 2σ(I)l = 1616
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.039H-atom parameters constrained
wR(F2) = 0.111 w = 1/[σ2(Fo2) + (0.0647P)2 + 0.1799P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
1712 reflectionsΔρmax = 0.19 e Å3
138 parametersΔρmin = 0.14 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), FC*=KFC[1+0.001XFC2Λ3/SIN(2Θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.078 (6)
Crystal data top
C11H9NO3V = 974.0 (6) Å3
Mr = 203.19Z = 4
Monoclinic, P21/nMo Kα radiation
a = 11.953 (4) ŵ = 0.10 mm1
b = 5.981 (2) ÅT = 273 K
c = 14.142 (5) Å0.30 × 0.25 × 0.20 mm
β = 105.548 (6)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1558 reflections with I > 2σ(I)
8619 measured reflectionsRint = 0.026
1712 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.111H-atom parameters constrained
S = 1.05Δρmax = 0.19 e Å3
1712 reflectionsΔρmin = 0.14 e Å3
138 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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
O90.78858 (10)0.77608 (19)0.16618 (8)0.0644 (4)
O140.98209 (9)0.19333 (19)0.09796 (8)0.0626 (4)
O150.89662 (9)0.16156 (18)0.02382 (7)0.0583 (4)
N80.72219 (12)0.7544 (2)0.09692 (10)0.0627 (5)
C10.70696 (13)0.6540 (3)0.10434 (12)0.0577 (5)
C20.65298 (14)0.6027 (3)0.17680 (13)0.0667 (6)
C30.59319 (14)0.4050 (3)0.17315 (12)0.0646 (6)
C40.58949 (14)0.2546 (3)0.09855 (13)0.0634 (5)
C50.64525 (13)0.3017 (3)0.02718 (11)0.0556 (5)
C60.70323 (11)0.5035 (2)0.02904 (9)0.0458 (4)
C70.75633 (11)0.5675 (2)0.05041 (10)0.0465 (4)
C100.85935 (12)0.6006 (2)0.15866 (10)0.0503 (4)
C110.93670 (14)0.6030 (3)0.22477 (11)0.0643 (6)
C120.84386 (10)0.4605 (2)0.08704 (9)0.0445 (4)
C130.90974 (11)0.2583 (2)0.05073 (10)0.0454 (4)
H10.745700.789400.106200.0690*
H20.657100.702300.228100.0800*
H30.555300.372800.221000.0780*
H40.549200.120800.096300.0760*
H50.644000.198200.022200.0670*
H11A0.911800.490900.274600.0960*
H11B1.014900.572400.187500.0960*
H11C0.933500.747400.255100.0960*
H141.014900.079300.072600.0940*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O90.0729 (7)0.0625 (7)0.0640 (7)0.0040 (5)0.0289 (6)0.0164 (5)
O140.0661 (7)0.0664 (7)0.0657 (7)0.0140 (5)0.0357 (5)0.0054 (5)
O150.0618 (6)0.0630 (7)0.0569 (6)0.0092 (5)0.0275 (5)0.0080 (5)
N80.0654 (8)0.0622 (8)0.0683 (8)0.0096 (6)0.0312 (7)0.0138 (6)
C10.0544 (8)0.0569 (9)0.0676 (9)0.0019 (7)0.0264 (7)0.0099 (7)
C20.0636 (9)0.0795 (11)0.0660 (10)0.0025 (8)0.0328 (8)0.0163 (8)
C30.0604 (9)0.0801 (11)0.0630 (9)0.0064 (8)0.0332 (7)0.0068 (8)
C40.0634 (9)0.0615 (9)0.0722 (10)0.0058 (7)0.0304 (8)0.0056 (8)
C50.0597 (9)0.0553 (9)0.0559 (8)0.0029 (7)0.0226 (7)0.0044 (7)
C60.0397 (7)0.0511 (8)0.0488 (7)0.0059 (5)0.0155 (5)0.0022 (6)
C70.0442 (7)0.0481 (7)0.0483 (7)0.0006 (6)0.0142 (6)0.0001 (6)
C100.0513 (7)0.0547 (8)0.0459 (7)0.0069 (6)0.0147 (6)0.0019 (6)
C110.0708 (10)0.0761 (11)0.0535 (9)0.0162 (8)0.0297 (8)0.0023 (7)
C120.0430 (7)0.0496 (7)0.0425 (7)0.0052 (5)0.0145 (5)0.0040 (5)
C130.0432 (7)0.0510 (8)0.0449 (7)0.0037 (5)0.0169 (5)0.0059 (6)
Geometric parameters (Å, º) top
O9—N81.4222 (19)C7—C121.4363 (19)
O9—C101.3342 (18)C10—C121.3649 (19)
O14—C131.2863 (18)C10—C111.481 (2)
O15—C131.2488 (17)C12—C131.4593 (18)
O14—H140.8200C1—H10.9300
N8—C71.3057 (18)C2—H20.9300
C1—C21.384 (2)C3—H30.9300
C1—C61.386 (2)C4—H40.9300
C2—C31.375 (3)C5—H50.9300
C3—C41.378 (3)C11—H11A0.9600
C4—C51.380 (2)C11—H11B0.9600
C5—C61.389 (2)C11—H11C0.9600
C6—C71.4813 (19)
O9···C10i3.268 (2)C10···O15iii3.345 (2)
O9···C11i3.351 (2)C10···C13iii3.566 (2)
O14···O15ii2.6252 (18)C11···O142.999 (2)
O14···C112.999 (2)C11···O9iv3.351 (2)
O15···C11iii3.316 (2)C11···N8iv3.427 (2)
O15···O14ii2.6252 (18)C11···O15iii3.316 (2)
O15···C13ii3.367 (2)C12···C13iii3.496 (2)
O15···C53.132 (2)C13···O15ii3.367 (2)
O15···C63.102 (2)C13···C10iii3.566 (2)
O15···C10iii3.345 (2)C13···C12iii3.496 (2)
O9···H11Ai2.6500C13···H14ii2.6600
O14···H11B2.6800H1···N82.8200
O14···H14ii2.9000H11A···O9iv2.6500
O15···H11Biii2.7700H11A···N8iv2.5100
O15···H14ii1.8100H11B···O142.6800
N8···C11i3.427 (2)H11B···O15iii2.7700
N8···H12.8200H14···O14ii2.9000
N8···H11Ai2.5100H14···O15ii1.8100
C5···O153.132 (2)H14···C13ii2.6600
C6···O153.102 (2)H14···H14ii2.3700
C10···O9iv3.268 (2)
N8—O9—C10109.41 (11)O14—C13—C12116.24 (12)
C13—O14—H14109.00O15—C13—C12120.20 (12)
O9—N8—C7105.56 (12)O14—C13—O15123.54 (12)
C2—C1—C6119.97 (16)C2—C1—H1120.00
C1—C2—C3120.23 (16)C6—C1—H1120.00
C2—C3—C4119.98 (16)C1—C2—H2120.00
C3—C4—C5120.28 (16)C3—C2—H2120.00
C4—C5—C6120.02 (15)C2—C3—H3120.00
C1—C6—C7118.88 (12)C4—C3—H3120.00
C5—C6—C7121.56 (12)C3—C4—H4120.00
C1—C6—C5119.49 (13)C5—C4—H4120.00
N8—C7—C6117.63 (12)C4—C5—H5120.00
N8—C7—C12111.06 (12)C6—C5—H5120.00
C6—C7—C12131.31 (11)C10—C11—H11A109.00
O9—C10—C11115.59 (12)C10—C11—H11B109.00
O9—C10—C12109.44 (12)C10—C11—H11C110.00
C11—C10—C12134.94 (13)H11A—C11—H11B110.00
C7—C12—C13128.23 (11)H11A—C11—H11C109.00
C10—C12—C13127.03 (12)H11B—C11—H11C109.00
C7—C12—C10104.53 (11)
C10—O9—N8—C70.33 (15)C1—C6—C7—C12124.36 (16)
N8—O9—C10—C11178.39 (12)C5—C6—C7—N8122.44 (15)
N8—O9—C10—C120.04 (15)N8—C7—C12—C100.45 (16)
O9—N8—C7—C120.47 (15)N8—C7—C12—C13175.43 (13)
O9—N8—C7—C6178.53 (11)C6—C7—C12—C10178.37 (14)
C2—C1—C6—C50.1 (2)C6—C7—C12—C133.4 (2)
C6—C1—C2—C31.6 (3)O9—C10—C12—C70.23 (15)
C2—C1—C6—C7176.80 (14)O9—C10—C12—C13175.28 (12)
C1—C2—C3—C41.7 (3)C11—C10—C12—C7177.67 (16)
C2—C3—C4—C50.2 (3)C11—C10—C12—C132.6 (3)
C3—C4—C5—C61.5 (3)C7—C12—C13—O14178.55 (13)
C4—C5—C6—C7175.22 (14)C7—C12—C13—O153.3 (2)
C4—C5—C6—C11.6 (2)C10—C12—C13—O147.5 (2)
C1—C6—C7—N854.40 (19)C10—C12—C13—O15170.61 (13)
C5—C6—C7—C1258.8 (2)
Symmetry codes: (i) x+3/2, y+1/2, z1/2; (ii) x+2, y, z; (iii) x+2, y+1, z; (iv) x+3/2, y1/2, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O14—H14···O15ii0.821.812.6252 (18)172
C11—H11A···N8iv0.962.513.427 (2)159
Symmetry codes: (ii) x+2, y, z; (iv) x+3/2, y1/2, z1/2.

Experimental details

Crystal data
Chemical formulaC11H9NO3
Mr203.19
Crystal system, space groupMonoclinic, P21/n
Temperature (K)273
a, b, c (Å)11.953 (4), 5.981 (2), 14.142 (5)
β (°) 105.548 (6)
V3)974.0 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.30 × 0.25 × 0.20
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
8619, 1712, 1558
Rint0.026
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.111, 1.05
No. of reflections1712
No. of parameters138
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.19, 0.14

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O14—H14···O15i0.82001.81002.6252 (18)172.00
C11—H11A···N8ii0.96002.51003.427 (2)159.00
Symmetry codes: (i) x+2, y, z; (ii) x+3/2, y1/2, z1/2.
 

Acknowledgements

The authors would like to thank the UGC, New Delhi, Government of India, for awarding a project under the head F·No.41–920/2012(SR) dated: 25–07-2012.

References

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