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In the title compound, C17H22N2O6, the di­hydro­pyrimidine ring adopts a flattened boat conformation. The dihedral angle between the benzene ring and the mean plane of the di­hydro­pyrimidine ring is 75.25 (6)°. In the crystal, mol­ecules are linked via pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8) ring motif which are linked through N—H...O and weak C—H...O hydrogen bonds. These, together with π–π ring inter­actions [centroid–centroid distance = 3.7965 (10) Å], give an overall three-dimensional structure.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S2056989015003576/zs2327sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S2056989015003576/zs2327Isup2.hkl
Contains datablock I

cml

Chemical Markup Language (CML) file https://doi.org/10.1107/S2056989015003576/zs2327Isup3.cml
Supplementary material

CCDC reference: 1050728

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.003 Å
  • R factor = 0.050
  • wR factor = 0.154
  • Data-to-parameter ratio = 16.0

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 5 Report
Alert level G PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite 2 Note PLAT005_ALERT_5_G No _iucr_refine_instructions_details in the CIF Please Do ! PLAT007_ALERT_5_G Number of Unrefined Donor-H Atoms .............. 2 Report PLAT154_ALERT_1_G The su's on the Cell Angles are Equal .......... 0.00100 Degree PLAT199_ALERT_1_G Reported _cell_measurement_temperature ..... (K) 293 Check PLAT200_ALERT_1_G Reported _diffrn_ambient_temperature ..... (K) 293 Check PLAT793_ALERT_4_G The Model has Chirality at C13 (Centro SPGR) R Verify PLAT860_ALERT_3_G Number of Least-Squares Restraints ............. 1 Note PLAT899_ALERT_4_G SHELXL97 is Deprecated and Succeeded by SHELXL 2014 Note PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L= 0.600 27 Note
0 ALERT level A = Most likely a serious problem - resolve or explain 0 ALERT level B = A potentially serious problem, consider carefully 1 ALERT level C = Check. Ensure it is not caused by an omission or oversight 10 ALERT level G = General information/check it is not something unexpected 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 3 ALERT type 4 Improvement, methodology, query or suggestion 2 ALERT type 5 Informative message, check

Comment top

Dihydropyrimidinones (DHPMs) occupy a special place in the areas of natural and synthetic organic chemistry, because of their therapeutic and pharmacological properties. The dihydropyrimidinone scaffold has emerged as an integral backbone for several drugs used as calcium channel blockers as well as anti-hypertensive and anti-cancer agents. DHPMs also exhibit anti-diabetic activity (Jawale et al., 2011). Furthermore, the 2-oxodihydropyrimidine-5-carboxylate core unit is also found in many marine natural products, including the batzelladine alkaloids, which were found to be potent HIV gp-120-CD4 inhibitors (Karade et al., 2007; Beşoluk et al., 2010). Because of this background and in order to obtain detailed information on its molecular conformation, the X-ray structure of the title compound, C17H22N2O2 has been determined and is presented herein.

In the racemic title compound (Fig. 1) the dihydropyrimidone ring adopts a flattened boat conformation with the atom C13 and N2 deviating by -0.1218 (11) and 0.1432 (12) Å, respectively from the least squares plane defined by the remaining atoms N1/C11/C12/C14 in the ring. The puckering parameters are q2 = 0.207 Å, q3 = -0.074 Å, Q = 0.220 Å, Θ = 109.7° and Φ = 35.0°. The C1—C6 benzene ring is twisted with respect to the dihydropyrimidinone ring, with an inter-ring dihedral angle of 75.25 (9)°. The ethyl acetate group attached to the pyrimidine ring shows an extended conformation [torsion angle C12—C15—O2—C16 = -177.55 (20)°]. The methoxy two substituent groups at C3 and C5 are almost coplanar with the benzene ring [torsion angles C2—C3—O3—C7 = 7.7 (3)° and C6—C5—O5—C9 = -5.1 (3)°] whereas the central group at C4 deviates significantly from the benzene plane [C3—C4—O4—C8 = 102.7 (2)°].

In the crystal, molecules are linked via a pair of N—H···O hydrogen bonds (Table 1) forming a centrosymmetric cyclic dimer with an R22(8) ring motif. The inter-dimer N2—H···O3ii and N2—H···O4ii interactions constitute a bifurcated association generating an asymmetric R21(5) ring motif. The one-dimensional chain structures extend across [101] (Fig. 2) while the crystal structure is further stabilized by weak C—H···O hydrogen bonds and by ππ stacking interactions between inversion-related benzene rings [ring centroid–centroid distance = 3.7965 (10)Å] (Fig. 3), giving an overall three-dimensional structure.

Related literature top

For general background and the biological activity of dihydropyrimidinones, see: Jawale et al. (2011); Beşoluk et al. (2010); Karade et al. (2007).

Experimental top

A mixture of ethyl acetoacetate (0.13 ml, 1 mmol), 3,4,5-trimethoxybenzaldehyde (0.196 g, 1 mmol), and urea (0.18 g, 3 mmol) in ethanol (5 ml) was heated under reflux in the presence of cerium chloride heptahydrate (25%) for 1 h (monitored by TLC). After the completion of the reaction, the reaction mixture was cooled to room temperature and poured onto crushed ice and stirred for 5–10 min. The solid was separated and filtered under suction, washed with ice-cold water (50 ml) and then recrystallized from hot ethanol to afford the pure product [m.p. 445 K; yield 96%].

Refinement top

H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances fixed in the range 0.93–0.97 Å and N—H = 0.86 Å with Uiso(H) = 1.5Ueq(CH3) and 1.2Ueq(CH2, CH, NH).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: APEX2 and SAINT (Bruker, 2008); data reduction: SAINT and XPREP (Bruker, 2008); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Cystal packing of the title compound viewed along the a axis. Hydrogen bonds are shown as dashed lines (Table 1). For clarity only the H atoms participating in these interactions are shown.
[Figure 3] Fig. 3. A view showing the ππ interactions. The H atoms are omitted for the sake of clarity.
Ethyl 6-methyl-2-oxo-4-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydropyrimidine-5-carboxylate top
Crystal data top
C17H22N2O6Z = 2
Mr = 350.37F(000) = 372
Triclinic, P1Dx = 1.313 Mg m3
Hall symbol: -P 1Melting point: 445 K
a = 10.1447 (3) ÅMo Kα radiation, λ = 0.71073 Å
b = 10.1919 (2) ÅCell parameters from 3659 reflections
c = 10.8724 (2) Åθ = 1.0–26.5°
α = 117.882 (1)°µ = 0.10 mm1
β = 101.371 (1)°T = 293 K
γ = 105.498 (1)°Block, colourless
V = 886.40 (4) Å30.20 × 0.15 × 0.10 mm
Data collection top
Bruker Kappa APEXII CCD
diffractometer
3659 independent reflections
Radiation source: fine-focus sealed tube3009 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.020
ϕ and ω scansθmax = 26.5°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 1212
Tmin = 0.970, Tmax = 0.995k = 1212
13060 measured reflectionsl = 1313
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)] = 0.050H-atom parameters constrained
wR(F2) = 0.154 w = 1/[σ2(Fo2) + (0.0769P)2 + 0.2863P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
3659 reflectionsΔρmax = 0.60 e Å3
228 parametersΔρmin = 0.30 e Å3
1 restraintExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.023 (4)
Crystal data top
C17H22N2O6γ = 105.498 (1)°
Mr = 350.37V = 886.40 (4) Å3
Triclinic, P1Z = 2
a = 10.1447 (3) ÅMo Kα radiation
b = 10.1919 (2) ŵ = 0.10 mm1
c = 10.8724 (2) ÅT = 293 K
α = 117.882 (1)°0.20 × 0.15 × 0.10 mm
β = 101.371 (1)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
3659 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
3009 reflections with I > 2σ(I)
Tmin = 0.970, Tmax = 0.995Rint = 0.020
13060 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0501 restraint
wR(F2) = 0.154H-atom parameters constrained
S = 1.06Δρmax = 0.60 e Å3
3659 reflectionsΔρmin = 0.30 e Å3
228 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*/Ueq
C10.37112 (18)0.3299 (2)0.72474 (17)0.0394 (4)
C20.44867 (19)0.2873 (2)0.80886 (18)0.0410 (4)
H20.40090.19460.80730.049*
C30.59827 (19)0.3837 (2)0.89570 (18)0.0415 (4)
C40.66902 (18)0.5242 (2)0.90186 (18)0.0429 (4)
C50.5914 (2)0.5645 (2)0.8146 (2)0.0477 (4)
C60.4429 (2)0.4661 (2)0.7249 (2)0.0466 (4)
H60.39160.49180.66470.056*
C70.6280 (3)0.2077 (3)0.9753 (3)0.0698 (6)
H7A0.70160.20401.04270.105*
H7B0.59920.11740.87430.105*
H7C0.54330.20111.00280.105*
C80.9201 (2)0.6153 (3)0.9346 (2)0.0652 (6)
H8A1.01720.69071.01030.098*
H8B0.90110.64040.85990.098*
H8C0.91410.50620.88820.098*
C90.5979 (3)0.7486 (3)0.7382 (4)0.0828 (8)
H9A0.66400.85010.75910.124*
H9B0.51240.75960.75900.124*
H9C0.56790.66470.63430.124*
C100.0111 (2)0.1030 (3)0.2264 (2)0.0599 (5)
H10A0.07260.12540.20060.090*
H10B0.02030.01230.18060.090*
H10C0.08240.14080.19080.090*
C110.07976 (19)0.1893 (2)0.39399 (19)0.0445 (4)
C120.15090 (18)0.1416 (2)0.47179 (19)0.0425 (4)
C130.20307 (18)0.2357 (2)0.64192 (18)0.0410 (4)
H130.16990.15730.66940.049*
C140.0864 (2)0.4142 (2)0.62100 (19)0.0455 (4)
C150.1840 (2)0.0008 (2)0.3951 (2)0.0496 (4)
C160.2722 (3)0.1808 (3)0.4190 (3)0.0833 (8)
H16A0.34370.15720.37640.100*
H16B0.18550.27810.33880.100*
C170.3362 (5)0.2078 (4)0.5344 (4)0.1191 (13)
H17A0.36340.29770.48980.179*
H17B0.26470.23210.57540.179*
H17C0.42230.11130.61310.179*
N10.06044 (18)0.33131 (19)0.47041 (16)0.0507 (4)
H1N0.03040.36990.42050.061*
N20.13307 (16)0.34918 (19)0.69333 (16)0.0447 (4)
H2N0.12100.37610.77660.054*
O10.1753 (2)0.07004 (19)0.26618 (17)0.0744 (5)
O20.23206 (16)0.04531 (16)0.48721 (16)0.0609 (4)
O30.68614 (15)0.35473 (16)0.98399 (14)0.0559 (4)
O40.81300 (14)0.62806 (16)1.00213 (14)0.0542 (4)
O50.67016 (17)0.70646 (19)0.8294 (2)0.0717 (5)
O60.06186 (17)0.53697 (18)0.68139 (15)0.0598 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0405 (8)0.0409 (8)0.0349 (8)0.0214 (7)0.0128 (7)0.0178 (7)
C20.0455 (9)0.0391 (8)0.0371 (8)0.0222 (7)0.0126 (7)0.0189 (7)
C30.0465 (9)0.0450 (9)0.0316 (8)0.0272 (7)0.0116 (7)0.0170 (7)
C40.0390 (8)0.0457 (9)0.0338 (8)0.0192 (7)0.0105 (6)0.0153 (7)
C50.0468 (9)0.0465 (9)0.0505 (10)0.0197 (8)0.0179 (8)0.0273 (8)
C60.0450 (9)0.0532 (10)0.0487 (10)0.0246 (8)0.0138 (8)0.0324 (8)
C70.0782 (15)0.0662 (13)0.0680 (13)0.0347 (12)0.0081 (11)0.0440 (11)
C80.0440 (10)0.0744 (14)0.0590 (12)0.0240 (10)0.0159 (9)0.0256 (11)
C90.0771 (16)0.0827 (17)0.117 (2)0.0329 (14)0.0329 (15)0.0762 (17)
C100.0654 (12)0.0652 (12)0.0397 (10)0.0334 (10)0.0109 (9)0.0223 (9)
C110.0431 (9)0.0451 (9)0.0386 (9)0.0197 (7)0.0121 (7)0.0190 (7)
C120.0385 (8)0.0399 (8)0.0397 (9)0.0160 (7)0.0099 (7)0.0174 (7)
C130.0402 (8)0.0438 (9)0.0409 (9)0.0207 (7)0.0127 (7)0.0240 (7)
C140.0454 (9)0.0535 (10)0.0405 (9)0.0290 (8)0.0156 (7)0.0237 (8)
C150.0433 (9)0.0399 (9)0.0471 (10)0.0154 (7)0.0070 (7)0.0157 (8)
C160.0882 (17)0.0513 (12)0.0835 (17)0.0417 (12)0.0098 (13)0.0202 (12)
C170.142 (3)0.094 (2)0.107 (2)0.079 (2)0.012 (2)0.0433 (19)
N10.0662 (10)0.0574 (9)0.0382 (8)0.0390 (8)0.0178 (7)0.0269 (7)
N20.0461 (8)0.0586 (9)0.0364 (7)0.0312 (7)0.0170 (6)0.0257 (7)
O10.0979 (12)0.0630 (9)0.0499 (9)0.0456 (9)0.0243 (8)0.0172 (7)
O20.0668 (9)0.0449 (7)0.0571 (8)0.0302 (7)0.0086 (7)0.0203 (6)
O30.0544 (8)0.0581 (8)0.0487 (7)0.0271 (6)0.0034 (6)0.0289 (6)
O40.0419 (7)0.0570 (8)0.0397 (7)0.0149 (6)0.0088 (5)0.0152 (6)
O50.0554 (8)0.0653 (9)0.0974 (12)0.0163 (7)0.0160 (8)0.0564 (9)
O60.0778 (10)0.0686 (9)0.0446 (7)0.0525 (8)0.0231 (7)0.0277 (7)
Geometric parameters (Å, º) top
C1—C21.384 (2)C10—C111.501 (2)
C1—C61.384 (2)C10—H10A0.9600
C1—C131.533 (2)C10—H10B0.9600
C2—C31.389 (2)C10—H10C0.9600
C2—H20.9300C11—C121.344 (2)
C3—O31.368 (2)C11—N11.383 (2)
C3—C41.383 (3)C12—C151.468 (2)
C4—O41.382 (2)C12—C131.518 (2)
C4—C51.390 (3)C13—N21.464 (2)
C5—O51.368 (2)C13—H130.9800
C5—C61.387 (3)C14—O61.233 (2)
C6—H60.9300C14—N21.338 (2)
C7—O31.406 (3)C14—N11.371 (2)
C7—H7A0.9600C15—O11.210 (2)
C7—H7B0.9600C15—O21.340 (2)
C7—H7C0.9600C16—O21.444 (3)
C8—O41.428 (2)C16—C171.472 (3)
C8—H8A0.9600C16—H16A0.9700
C8—H8B0.9600C16—H16B0.9700
C8—H8C0.9600C17—H17A0.9600
C9—O51.410 (3)C17—H17B0.9600
C9—H9A0.9600C17—H17C0.9600
C9—H9B0.9600N1—H1N0.8600
C9—H9C0.9600N2—H2N0.8600
C2—C1—C6120.13 (15)H10B—C10—H10C109.5
C2—C1—C13120.26 (15)C12—C11—N1119.53 (15)
C6—C1—C13119.40 (15)C12—C11—C10127.51 (17)
C1—C2—C3119.70 (16)N1—C11—C10112.94 (15)
C1—C2—H2120.1C11—C12—C15120.97 (16)
C3—C2—H2120.2C11—C12—C13121.07 (15)
O3—C3—C4114.49 (15)C15—C12—C13117.94 (15)
O3—C3—C2125.05 (16)N2—C13—C12109.34 (13)
C4—C3—C2120.42 (15)N2—C13—C1109.29 (14)
O4—C4—C3119.43 (15)C12—C13—C1114.52 (14)
O4—C4—C5120.85 (16)N2—C13—H13107.8
C3—C4—C5119.58 (16)C12—C13—H13107.8
O5—C5—C6124.58 (17)C1—C13—H13107.8
O5—C5—C4115.35 (16)O6—C14—N2123.56 (16)
C6—C5—C4120.03 (17)O6—C14—N1120.72 (16)
C1—C6—C5120.03 (16)N2—C14—N1115.66 (15)
C1—C6—H6120.0O1—C15—O2122.09 (18)
C5—C6—H6120.0O1—C15—C12125.98 (18)
O3—C7—H7A109.5O2—C15—C12111.89 (16)
O3—C7—H7B109.5O2—C16—C17109.0 (2)
H7A—C7—H7B109.5O2—C16—H16A109.9
O3—C7—H7C109.5C17—C16—H16A109.9
H7A—C7—H7C109.5O2—C16—H16B109.9
H7B—C7—H7C109.5C17—C16—H16B109.9
O4—C8—H8A109.5H16A—C16—H16B108.3
O4—C8—H8B109.5C16—C17—H17A109.5
H8A—C8—H8B109.5C16—C17—H17B109.5
O4—C8—H8C109.5H17A—C17—H17B109.5
H8A—C8—H8C109.5C16—C17—H17C109.5
H8B—C8—H8C109.5H17A—C17—H17C109.5
O5—C9—H9A109.5H17B—C17—H17C109.5
O5—C9—H9B109.5C14—N1—C11123.90 (15)
H9A—C9—H9B109.5C14—N1—H1N118.1
O5—C9—H9C109.5C11—N1—H1N118.1
H9A—C9—H9C109.5C14—N2—C13125.19 (14)
H9B—C9—H9C109.5C14—N2—H2N117.4
C11—C10—H10A109.5C13—N2—H2N117.4
C11—C10—H10B109.5C15—O2—C16114.13 (17)
H10A—C10—H10B109.5C3—O3—C7118.70 (15)
C11—C10—H10C109.5C4—O4—C8113.93 (14)
H10A—C10—H10C109.5C5—O5—C9117.35 (17)
C6—C1—C2—C31.3 (2)C6—C1—C13—N252.6 (2)
C13—C1—C2—C3173.41 (15)C2—C1—C13—C12114.87 (17)
C1—C2—C3—O3179.57 (16)C6—C1—C13—C1270.4 (2)
C1—C2—C3—C41.8 (2)C11—C12—C15—O112.9 (3)
O3—C3—C4—O45.5 (2)C13—C12—C15—O1165.48 (19)
C2—C3—C4—O4172.46 (15)C11—C12—C15—O2169.40 (16)
O3—C3—C4—C5178.81 (15)C13—C12—C15—O212.2 (2)
C2—C3—C4—C53.2 (3)O6—C14—N1—C11177.32 (18)
O4—C4—C5—O53.7 (3)N2—C14—N1—C110.0 (3)
C3—C4—C5—O5179.34 (16)C12—C11—N1—C1411.8 (3)
O4—C4—C5—C6174.07 (16)C10—C11—N1—C14166.62 (18)
C3—C4—C5—C61.6 (3)O6—C14—N2—C13161.54 (18)
C2—C1—C6—C52.9 (3)N1—C14—N2—C1321.2 (3)
C13—C1—C6—C5171.79 (16)C12—C13—N2—C1427.1 (2)
O5—C5—C6—C1176.06 (17)C1—C13—N2—C1498.96 (19)
C4—C5—C6—C11.5 (3)O1—C15—O2—C160.3 (3)
N1—C11—C12—C15174.94 (16)C12—C15—O2—C16177.52 (18)
C10—C11—C12—C156.9 (3)C17—C16—O2—C15174.6 (2)
N1—C11—C12—C133.4 (3)C4—C3—O3—C7174.43 (18)
C10—C11—C12—C13174.76 (18)C2—C3—O3—C77.7 (3)
C11—C12—C13—N213.6 (2)C3—C4—O4—C8102.7 (2)
C15—C12—C13—N2167.97 (15)C5—C4—O4—C881.7 (2)
C11—C12—C13—C1109.38 (18)C6—C5—O5—C95.1 (3)
C15—C12—C13—C169.0 (2)C4—C5—O5—C9177.3 (2)
C2—C1—C13—N2122.09 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···O6i0.862.012.867 (2)171
N2—H2N···O3ii0.862.563.0629 (19)118
N2—H2N···O4ii0.862.393.1331 (19)145
C8—H8A···O1iii0.962.463.325 (3)149
C9—H9A···O1iv0.962.563.491 (3)163
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y+1, z+2; (iii) x+1, y+1, z+1; (iv) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···O6i0.862.012.867 (2)171
N2—H2N···O4ii0.862.393.1331 (19)145
C8—H8A···O1iii0.962.463.325 (3)149
C9—H9A···O1iv0.962.563.491 (3)163
Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y+1, z+2; (iii) x+1, y+1, z+1; (iv) x+1, y+1, z+1.
 

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