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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Crystal structure of 4-chloro-2-[(5-eth­­oxy-1,3,4-thia­diazol-2-yl)meth­yl]-5-(piperidin-1-yl)pyridazin-3(2H)-one

aCollege of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, 333 Longteng Road, Shanghai, People's Republic of China
*Correspondence e-mail: lihongsen19@163.com

Edited by E. R. T. Tiekink, University of Malaya, Malaysia (Received 1 September 2014; accepted 15 September 2014; online 20 September 2014)

In the title mol­ecule, C14H18ClN5O2S, the six atoms of the 1,6-di­hydro­pyridazine ring are essentially coplanar (r.m.s. deviation = 0.008 Å), and the dihedral angle between this and the 1,3,4-thia­diazole ring is 62.06 (10)°. In the crystal, centrosymmetrically related mol­ecules are linked by inter­molecular C—H—O hydrogen bonding to form a supra­molecular dimer. The terminal ethyl group is statistically disordered over two positions.

1. Related literature

For the biological activity of pyridazinone derivatives, see: Abouzid et al. (2008[Abouzid, K., Hakeem, M. A., Khalil, O. & Maklad, Y. (2008). Bioorg. Med. Chem. 16, 382-389.]); Siddiqui et al. (2010[Siddiqui, A. A., Mishra, R. & Shaharyar, M. (2010). Eur. J. Med. Chem. 45, 2283-2290.]), and for their synthesis, see: Wang et al. (2010[Wang, T. T., Bing, G. F., Zhang, X. & Qin, Z. F. (2010). Chem. J. Chin. Univ. 31, 708-713.]); Zhang et al. (2002[Zhang, Y., Liu, D. & Dai, C. F. (2002). Chem. J. Chin. Univ. 23, 1882-1886.]).

[Scheme 1]

2. Experimental

2.1. Crystal data

  • C14H18ClN5O2S

  • Mr = 355.84

  • Triclinic, [P \overline 1]

  • a = 5.2840 (8) Å

  • b = 11.0323 (16) Å

  • c = 14.902 (2) Å

  • α = 107.318 (2)°

  • β = 91.590 (2)°

  • γ = 99.528 (2)°

  • V = 815.1 (2) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.38 mm−1

  • T = 296 K

  • 0.30 × 0.24 × 0.16 mm

2.2. Data collection

  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Gοttingen, Germany.]) Tmin = 0.895, Tmax = 0.942

  • 4244 measured reflections

  • 2828 independent reflections

  • 2490 reflections with I > 2σ(I)

  • Rint = 0.012

2.3. Refinement

  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.121

  • S = 1.58

  • 2828 reflections

  • 229 parameters

  • H-atom parameters constrained

  • Δρmax = 0.22 e Å−3

  • Δρmin = −0.23 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C14A—H14A⋯O1i 0.96 2.45 3.366 (11) 160
Symmetry code: (i) -x+2, -y, -z.

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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Experimental top

A mixture of 4,5-di­chloro-2-[(5-eth­oxy-1,3,4-thia­diazol-2-yl)methyl]-pyridazin-3(2H)-one (3.98 g, 1.3 mmol), piperidine (1.37 g, 19.5 mmol), potassium carbonate (3 g) and dry DMF (30mL) was stirred at 40oC for 8 h. The mixture was then poured into ice-water and a yellow precipitate -formed. The precipitate was washed with water, followed by vaccum drying, to give the pure title compound (3.38 g, yield: 73.2 %). The obtained compound was recrystallized from its ethyl acetate/petroleum ether (5:1) to give yellow crystals.

Refinement top

Carbon-bound H-atoms were placed in calculated positions (C—H = 0.93 to 0.97 Å) and were included in the refinement in the riding model approximation, with Uiso(H) = 1.2–1.5Ueq(C). The terminal ethyl group (C13 and C14) was statistically disordered over two positions.

Related literature top

For the biological activity of pyridazinone derivatives, see: Abouzid et al. (2008); Siddiqui et al. (2010), and for their synthesis, see: Wang et al. (2010); Zhang et al. (2002).

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: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound showing atom labelling and displacement ellipsoids at 50%.
4-Chloro-2-[(5-ethoxy-1,3,4-thiadiazol-2-yl)methyl]-5-(piperidin-1-yl)pyridazin-3(2H)-one top
Crystal data top
C14H18ClN5O2SZ = 2
Mr = 355.84F(000) = 372
Triclinic, P1Dx = 1.450 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.2840 (8) ÅCell parameters from 2456 reflections
b = 11.0323 (16) Åθ = 2.8–27.3°
c = 14.902 (2) ŵ = 0.38 mm1
α = 107.318 (2)°T = 296 K
β = 91.590 (2)°Block, yellow
γ = 99.528 (2)°0.30 × 0.24 × 0.16 mm
V = 815.1 (2) Å3
Data collection top
Bruker APEXII CCD
diffractometer
2828 independent reflections
Radiation source: fine-focus sealed tube2490 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.012
ϕ and ω scansθmax = 25.1°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 66
Tmin = 0.895, Tmax = 0.942k = 1313
4244 measured reflectionsl = 1317
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)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.121H-atom parameters constrained
S = 1.58 w = 1/[σ2(Fo2) + (0.0546P)2]
where P = (Fo2 + 2Fc2)/3
2828 reflections(Δ/σ)max = 0.050
229 parametersΔρmax = 0.22 e Å3
0 restraintsΔρmin = 0.23 e Å3
Crystal data top
C14H18ClN5O2Sγ = 99.528 (2)°
Mr = 355.84V = 815.1 (2) Å3
Triclinic, P1Z = 2
a = 5.2840 (8) ÅMo Kα radiation
b = 11.0323 (16) ŵ = 0.38 mm1
c = 14.902 (2) ÅT = 296 K
α = 107.318 (2)°0.30 × 0.24 × 0.16 mm
β = 91.590 (2)°
Data collection top
Bruker APEXII CCD
diffractometer
2828 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2490 reflections with I > 2σ(I)
Tmin = 0.895, Tmax = 0.942Rint = 0.012
4244 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.121H-atom parameters constrained
S = 1.58Δρmax = 0.22 e Å3
2828 reflectionsΔρmin = 0.23 e Å3
229 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.

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*/UeqOcc. (<1)
C11.1293 (4)0.40442 (18)0.64144 (14)0.0529 (5)
H1A0.99630.43620.68070.064*
H1B1.16200.45500.59840.064*
C21.3686 (5)0.4198 (2)0.70167 (19)0.0710 (7)
H2A1.42360.51000.73760.085*
H2B1.50430.39280.66210.085*
C31.3239 (5)0.3396 (2)0.76876 (18)0.0726 (7)
H3A1.48500.34480.80380.087*
H3B1.20370.37330.81350.087*
C41.2172 (5)0.2004 (2)0.71378 (17)0.0623 (6)
H4A1.34940.16330.67680.075*
H4B1.17190.15210.75760.075*
C50.9873 (5)0.1870 (2)0.65010 (17)0.0654 (6)
H5A0.93580.09730.61220.079*
H5B0.84610.21200.68730.079*
C60.8041 (4)0.24108 (16)0.34196 (13)0.0418 (4)
C70.9639 (3)0.28093 (16)0.42889 (13)0.0390 (4)
C80.8999 (4)0.23463 (16)0.50280 (13)0.0426 (4)
C90.6649 (4)0.14118 (19)0.48425 (14)0.0513 (5)
H90.61670.10650.53230.062*
C100.3987 (4)0.1095 (2)0.25530 (14)0.0517 (5)
H10A0.38530.18330.23400.062*
H10B0.23070.07830.27290.062*
C110.4730 (4)0.00539 (18)0.17587 (13)0.0452 (5)
C120.6399 (5)0.1324 (2)0.05014 (15)0.0605 (6)
C13A0.6909 (17)0.3381 (7)0.0461 (7)0.074 (2)0.503 (13)
H13A0.67440.36540.00990.089*0.503 (13)
H13B0.52820.36680.08450.089*0.503 (13)
C14A0.9045 (12)0.3878 (6)0.1004 (7)0.083 (3)0.503 (13)
H14A0.93870.34610.14800.125*0.503 (13)
H14B0.85610.47940.12980.125*0.503 (13)
H14C1.05650.37010.05840.125*0.503 (13)
C13B0.7259 (16)0.3012 (8)0.0838 (6)0.071 (2)0.497 (13)
H13C0.80750.30140.14130.085*0.497 (13)
H13D0.54140.32830.09870.085*0.497 (13)
C14B0.8311 (17)0.3870 (7)0.0377 (8)0.086 (3)0.497 (13)
H14D1.00400.34830.01140.129*0.497 (13)
H14E0.83120.46920.08360.129*0.497 (13)
H14F0.72600.39870.01160.129*0.497 (13)
Cl11.24862 (9)0.38323 (4)0.42952 (4)0.0529 (2)
N11.0406 (3)0.26824 (15)0.58761 (11)0.0507 (4)
N20.5837 (3)0.15084 (14)0.33835 (11)0.0437 (4)
N30.5152 (3)0.10080 (16)0.40812 (12)0.0519 (4)
N40.3405 (4)0.10968 (17)0.14941 (13)0.0585 (5)
N50.4391 (4)0.19254 (17)0.07519 (14)0.0630 (5)
O10.8484 (3)0.27791 (13)0.27325 (10)0.0585 (4)
O20.7819 (4)0.1833 (2)0.01905 (13)0.0901 (6)
S10.73552 (11)0.02873 (5)0.11291 (4)0.0556 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0616 (13)0.0406 (11)0.0504 (12)0.0058 (9)0.0067 (10)0.0075 (9)
C20.0735 (16)0.0530 (13)0.0755 (16)0.0080 (11)0.0252 (13)0.0164 (12)
C30.0772 (17)0.0714 (15)0.0639 (15)0.0039 (12)0.0229 (13)0.0205 (13)
C40.0673 (15)0.0634 (14)0.0622 (14)0.0080 (11)0.0004 (11)0.0307 (12)
C50.0680 (15)0.0626 (14)0.0651 (14)0.0112 (11)0.0107 (12)0.0326 (12)
C60.0471 (11)0.0336 (9)0.0436 (11)0.0097 (8)0.0044 (8)0.0091 (8)
C70.0404 (10)0.0292 (8)0.0459 (10)0.0035 (7)0.0023 (8)0.0109 (7)
C80.0475 (11)0.0324 (9)0.0443 (11)0.0013 (7)0.0012 (8)0.0102 (8)
C90.0562 (13)0.0474 (11)0.0436 (11)0.0099 (9)0.0005 (9)0.0145 (9)
C100.0438 (11)0.0568 (12)0.0496 (12)0.0116 (9)0.0059 (9)0.0085 (9)
C110.0427 (11)0.0483 (11)0.0413 (10)0.0047 (8)0.0079 (8)0.0117 (8)
C120.0638 (15)0.0613 (13)0.0476 (12)0.0168 (11)0.0100 (11)0.0022 (10)
C13A0.088 (5)0.058 (4)0.058 (5)0.008 (3)0.015 (4)0.006 (3)
C14A0.073 (4)0.068 (4)0.088 (6)0.010 (3)0.024 (4)0.007 (3)
C13B0.080 (4)0.073 (5)0.045 (4)0.009 (3)0.002 (3)0.000 (3)
C14B0.090 (6)0.075 (4)0.085 (6)0.010 (4)0.001 (5)0.017 (4)
Cl10.0456 (3)0.0449 (3)0.0658 (4)0.0037 (2)0.0049 (2)0.0198 (2)
N10.0600 (11)0.0404 (9)0.0476 (10)0.0061 (7)0.0102 (8)0.0170 (7)
N20.0423 (9)0.0424 (8)0.0409 (9)0.0042 (7)0.0018 (7)0.0069 (7)
N30.0518 (10)0.0487 (9)0.0467 (10)0.0064 (7)0.0007 (8)0.0107 (8)
N40.0539 (11)0.0553 (11)0.0567 (11)0.0004 (8)0.0072 (9)0.0092 (9)
N50.0615 (12)0.0521 (11)0.0610 (12)0.0042 (9)0.0115 (10)0.0007 (9)
O10.0772 (10)0.0514 (8)0.0479 (8)0.0030 (7)0.0008 (7)0.0220 (7)
O20.0843 (13)0.0960 (14)0.0663 (11)0.0270 (11)0.0062 (10)0.0163 (10)
S10.0575 (4)0.0545 (3)0.0502 (3)0.0046 (2)0.0026 (3)0.0120 (2)
Geometric parameters (Å, º) top
C1—N11.466 (2)C10—N21.464 (2)
C1—C21.486 (3)C10—C111.496 (3)
C1—H1A0.9700C10—H10A0.9700
C1—H1B0.9700C10—H10B0.9700
C2—C31.520 (3)C11—N41.284 (3)
C2—H2A0.9700C11—S11.723 (2)
C2—H2B0.9700C12—N51.282 (3)
C3—C41.512 (3)C12—O21.334 (3)
C3—H3A0.9700C12—S11.725 (2)
C3—H3B0.9700C13A—C14A1.491 (13)
C4—C51.480 (3)C13A—O21.619 (8)
C4—H4A0.9700C13A—H13A0.9700
C4—H4B0.9700C13A—H13B0.9700
C5—N11.476 (2)C14A—H14A0.9600
C5—H5A0.9700C14A—H14B0.9600
C5—H5B0.9700C14A—H14C0.9600
C6—O11.224 (2)C13B—O21.349 (7)
C6—N21.390 (2)C13B—C14B1.489 (14)
C6—C71.436 (3)C13B—H13C0.9700
C7—C81.374 (3)C13B—H13D0.9700
C7—Cl11.7228 (18)C14B—H14D0.9600
C8—N11.366 (2)C14B—H14E0.9600
C8—C91.438 (3)C14B—H14F0.9600
C9—N31.282 (3)N2—N31.347 (2)
C9—H90.9300N4—N51.385 (3)
N1—C1—C2110.36 (17)N2—C10—H10A109.0
N1—C1—H1A109.6C11—C10—H10A109.0
C2—C1—H1A109.6N2—C10—H10B109.0
N1—C1—H1B109.6C11—C10—H10B109.0
C2—C1—H1B109.6H10A—C10—H10B107.8
H1A—C1—H1B108.1N4—C11—C10121.30 (19)
C1—C2—C3110.7 (2)N4—C11—S1114.96 (16)
C1—C2—H2A109.5C10—C11—S1123.74 (14)
C3—C2—H2A109.5N5—C12—O2126.0 (2)
C1—C2—H2B109.5N5—C12—S1116.59 (17)
C3—C2—H2B109.5O2—C12—S1117.4 (2)
H2A—C2—H2B108.1C14A—C13A—O2102.4 (7)
C4—C3—C2109.89 (19)C14A—C13A—H13A111.3
C4—C3—H3A109.7O2—C13A—H13A111.3
C2—C3—H3A109.7C14A—C13A—H13B111.3
C4—C3—H3B109.7O2—C13A—H13B111.3
C2—C3—H3B109.7H13A—C13A—H13B109.2
H3A—C3—H3B108.2O2—C13B—C14B104.2 (7)
C5—C4—C3112.46 (19)O2—C13B—H13C110.9
C5—C4—H4A109.1C14B—C13B—H13C110.9
C3—C4—H4A109.1O2—C13B—H13D110.9
C5—C4—H4B109.1C14B—C13B—H13D110.9
C3—C4—H4B109.1H13C—C13B—H13D108.9
H4A—C4—H4B107.8C13B—C14B—H14D109.5
N1—C5—C4111.07 (17)C13B—C14B—H14E109.5
N1—C5—H5A109.4H14D—C14B—H14E109.5
C4—C5—H5A109.4C13B—C14B—H14F109.5
N1—C5—H5B109.4H14D—C14B—H14F109.5
C4—C5—H5B109.4H14E—C14B—H14F109.5
H5A—C5—H5B108.0C8—N1—C1120.60 (15)
O1—C6—N2119.39 (17)C8—N1—C5119.35 (15)
O1—C6—C7125.93 (18)C1—N1—C5111.72 (16)
N2—C6—C7114.67 (16)N3—N2—C6125.32 (15)
C8—C7—C6122.23 (17)N3—N2—C10115.33 (15)
C8—C7—Cl1123.29 (14)C6—N2—C10119.26 (16)
C6—C7—Cl1114.37 (14)C9—N3—N2116.97 (16)
N1—C8—C7125.69 (17)C11—N4—N5113.00 (19)
N1—C8—C9120.06 (17)C12—N5—N4110.34 (17)
C7—C8—C9114.23 (17)C12—O2—C13B127.2 (5)
N3—C9—C8126.57 (19)C12—O2—C13A105.7 (4)
N3—C9—H9116.7C13B—O2—C13A29.3 (3)
C8—C9—H9116.7C11—S1—C1285.12 (11)
N2—C10—C11112.73 (15)
N1—C1—C2—C358.3 (3)C7—C6—N2—N30.2 (3)
C1—C2—C3—C454.5 (3)O1—C6—N2—C104.9 (3)
C2—C3—C4—C552.6 (3)C7—C6—N2—C10176.21 (15)
C3—C4—C5—N153.7 (3)C11—C10—N2—N3100.33 (19)
O1—C6—C7—C8179.95 (18)C11—C10—N2—C682.9 (2)
N2—C6—C7—C81.1 (3)C8—C9—N3—N20.1 (3)
O1—C6—C7—Cl13.6 (2)C6—N2—N3—C90.8 (3)
N2—C6—C7—Cl1175.26 (12)C10—N2—N3—C9175.75 (18)
C6—C7—C8—N1179.63 (17)C10—C11—N4—N5179.86 (16)
Cl1—C7—C8—N14.3 (3)S1—C11—N4—N50.5 (2)
C6—C7—C8—C91.6 (3)O2—C12—N5—N4180.0 (2)
Cl1—C7—C8—C9174.41 (14)S1—C12—N5—N40.7 (2)
N1—C8—C9—N3179.9 (2)C11—N4—N5—C120.8 (3)
C7—C8—C9—N31.0 (3)N5—C12—O2—C13B9.5 (7)
N2—C10—C11—N4112.2 (2)S1—C12—O2—C13B171.2 (5)
N2—C10—C11—S168.2 (2)N5—C12—O2—C13A13.1 (5)
C7—C8—N1—C150.6 (3)S1—C12—O2—C13A166.2 (4)
C9—C8—N1—C1130.8 (2)C14B—C13B—O2—C1287.8 (7)
C7—C8—N1—C5163.8 (2)C14B—C13B—O2—C13A38.9 (11)
C9—C8—N1—C514.9 (3)C14A—C13A—O2—C12163.5 (7)
C2—C1—N1—C8152.6 (2)C14A—C13A—O2—C13B55.1 (11)
C2—C1—N1—C559.4 (2)N4—C11—S1—C120.12 (17)
C4—C5—N1—C8154.6 (2)C10—C11—S1—C12179.72 (17)
C4—C5—N1—C156.8 (3)N5—C12—S1—C110.36 (18)
O1—C6—N2—N3178.74 (16)O2—C12—S1—C11179.71 (19)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C14A—H14A···O1i0.962.453.366 (11)160
Symmetry code: (i) x+2, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C14A—H14A···O1i0.962.453.366 (11)160
Symmetry code: (i) x+2, y, z.
 

Acknowledgements

Financial support from the Development Program of the Shanghai University of Engineering Science is gratefully acknowledged.

References

First citationAbouzid, K., Hakeem, M. A., Khalil, O. & Maklad, Y. (2008). Bioorg. Med. Chem. 16, 382–389.  Web of Science CrossRef PubMed CAS Google Scholar
First citationBruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Gοttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSiddiqui, A. A., Mishra, R. & Shaharyar, M. (2010). Eur. J. Med. Chem. 45, 2283–2290.  Web of Science CrossRef CAS PubMed Google Scholar
First citationWang, T. T., Bing, G. F., Zhang, X. & Qin, Z. F. (2010). Chem. J. Chin. Univ. 31, 708–713.  Google Scholar
First citationZhang, Y., Liu, D. & Dai, C. F. (2002). Chem. J. Chin. Univ. 23, 1882–1886.  CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds