Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270113004344/sk3475sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270113004344/sk3475Isup2.hkl | |
Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270113004344/sk3475Isup5.cml | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270113004344/sk3475IIsup4.hkl | |
Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270113004344/sk3475IIsup6.cml | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270113004344/sk3475IIIsup3.hkl | |
Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270113004344/sk3475IIIsup7.cml |
CCDC references: 934579; 934580; 934581
The following is a general procedure for the synthesis of N-substituted 2-(methylsulfanyl)nicotinamides. A stirred solution of methyl 2-(methylsulfanyl)nicotinate (1 mmol), prepared from 2-mercaptonicotinic acid, methyl iodide and K2CO3, and an amine (20 mmol) was refluxed for 24 h. The reaction was concentrated under reduced pressure and the residue was diluted with ethyl acetate, washed with brine, dried over Na2SO4, filtered and evaporated. The crude product was purified by column chromatography on silica gel (0–50% ethyl acetate in hexane) affording the N-substituted 2-(methylsulfanyl)nicotinamide derivatives in 60–88% yield. Each of the derivatives was recrystallized from appropriate solvents for the structure determinations. For N-cyclohexyl-2-(methylsulfanyl)nicotinamide, (I) (yield: 60%), the crystals used in the structure determination were grown from an ethanol solution. For N-isopropyl-2-(methylsulfanyl)nicotinamide (II) (yield: 65%), the crystals used in the structure determination were grown from a methanol solution. For N-(2-hydroxyethyl)-2-(methylsulfanyl)nicotinamide, (III) (yield: 88%), the crystals used in the structure determination were grown from a moist ethyl acetate solution.
In (I)and (II), H atoms were treated as riding atoms, with aromatic C—H = 0.95 Å and N—H = 0.88 Å, with Uiso(H) = 1.2Ueq(C, N), and methyl C—H = 0.98 Å, with Uiso(H) = 1.5Ueq(C). In (III), H atoms were treated as riding atoms, with aromatic C—H = 0.95 Å and Uiso(H) = 1.2Ueq(C), and methyl C—H = 0.98 Å and Uiso(H) = 1.5Ueq(C). The positions of the H atoms attached to N, hydroxy O and the water O atoms were located in a difference map and allowed to ride at these positions, with Uiso(H) = 1.2Ueq(N) and 1.5Uwq(O).
The positions of the H atoms attached to N atoms, methyl groups, hydroxy groups and water molecules were checked on difference maps during and after the refinement was completed.
The crystals of (II) were very small (0.10 × 0.03 × 0.01 mm) and even though data were collected by synchrotron radiation it was not possible to collect a complete observable data set.
For all compounds, data collection: CrystalClear-SM Expert (Rigaku, 2011); cell refinement: CrystalClear-SM Expert (Rigaku, 2011); data reduction: CrystalClear-SM Expert (Rigaku, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008). Program(s) used to refine structure: OSCAIL (McArdle et al., 2004) and SHELXS97 (Sheldrick, 2008) for (I); OSCAIL (McArdle et al., 2004) and SHELXL97 (Sheldrick, 2008) for (II), (III). For all compounds, molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: OSCAIL (McArdle et al., 2004) and SHELXL97 (Sheldrick, 2008).
C13H18N2OS | F(000) = 536 |
Mr = 250.35 | Dx = 1.276 Mg m−3 |
Orthorhombic, Pca21 | Mo Kα radiation, λ = 0.71075 Å |
Hall symbol: P 2c -2ac | Cell parameters from 11307 reflections |
a = 11.5273 (9) Å | θ = 3.0–27.6° |
b = 13.4634 (10) Å | µ = 0.24 mm−1 |
c = 8.3956 (6) Å | T = 100 K |
V = 1302.97 (17) Å3 | Plate, colourless |
Z = 4 | 0.26 × 0.19 × 0.04 mm |
Rigaku Saturn724+ (2x2 bin mode) diffractometer | 2731 independent reflections |
Radiation source: Rotating Anode | 2657 reflections with I > 2σ(I) |
Confocal monochromator | Rint = 0.026 |
Detector resolution: 28.5714 pixels mm-1 | θmax = 27.5°, θmin = 3.0° |
profile data from ω–scans | h = −14→14 |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | k = −17→16 |
Tmin = 0.942, Tmax = 0.991 | l = −10→9 |
11531 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.024 | H-atom parameters constrained |
wR(F2) = 0.064 | w = 1/[σ2(Fo2) + (0.0369P)2 + 0.1954P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
2731 reflections | Δρmax = 0.25 e Å−3 |
156 parameters | Δρmin = −0.15 e Å−3 |
1 restraint | Absolute structure: Flack, (1983) |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.06 (5) |
C13H18N2OS | V = 1302.97 (17) Å3 |
Mr = 250.35 | Z = 4 |
Orthorhombic, Pca21 | Mo Kα radiation |
a = 11.5273 (9) Å | µ = 0.24 mm−1 |
b = 13.4634 (10) Å | T = 100 K |
c = 8.3956 (6) Å | 0.26 × 0.19 × 0.04 mm |
Rigaku Saturn724+ (2x2 bin mode) diffractometer | 2731 independent reflections |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | 2657 reflections with I > 2σ(I) |
Tmin = 0.942, Tmax = 0.991 | Rint = 0.026 |
11531 measured reflections |
R[F2 > 2σ(F2)] = 0.024 | H-atom parameters constrained |
wR(F2) = 0.064 | Δρmax = 0.25 e Å−3 |
S = 1.06 | Δρmin = −0.15 e Å−3 |
2731 reflections | Absolute structure: Flack, (1983) |
156 parameters | Absolute structure parameter: 0.06 (5) |
1 restraint |
Experimental. N-Cyclohexyl-2-(methylsulfanyl)nicotinamide (I). NMR1H (400MHz, DMSO-d6) δ (ppm): 8.50 (1H, dd; J = 4.8 and J = 1.7, H6), 8.27 (1H, d, J = 7.7 Hz, NH), 7.68 (1H, dd, J = 7.5 and J = 1.7 Hz, H4), 7.16 (1H, dd, J = 7.5 and J = 4.8Hz, H5), 3.70 (1H, m; CHNH), 2.43 (3H, s; (CH3)S), 1.8-1.2 (10H, m, Cy). NMR 13C (100MHz, DMSO-d6) δ (ppm): 165.2,157.2, 149.6, 134.8, 130.6, 118.6, 48.1, 32.2, 25.2, 24.6, 12.9. IR (cm-1; KBr): 3231 (NH), 1643 (CON) MS/ESI: [M+Na]: 273.1 |
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. |
x | y | z | Uiso*/Ueq | ||
S12 | 0.57915 (2) | 0.73272 (2) | 0.50452 (5) | 0.01785 (8) | |
O1 | 0.35932 (8) | 0.73433 (7) | 0.35091 (12) | 0.0187 (2) | |
N2 | 0.21218 (8) | 0.75002 (7) | 0.52819 (14) | 0.0164 (2) | |
H2 | 0.1828 | 0.7291 | 0.6189 | 0.020* | |
N11 | 0.55072 (9) | 0.58148 (10) | 0.70269 (16) | 0.0249 (3) | |
C1 | 0.31404 (10) | 0.71397 (9) | 0.47992 (16) | 0.0144 (2) | |
C12 | 0.49487 (10) | 0.64461 (9) | 0.60905 (16) | 0.0162 (3) | |
C13 | 0.37295 (10) | 0.64360 (9) | 0.59140 (15) | 0.0152 (2) | |
C14 | 0.31125 (11) | 0.57267 (9) | 0.67571 (17) | 0.0200 (3) | |
H14 | 0.2292 | 0.5698 | 0.6669 | 0.024* | |
C15 | 0.36892 (13) | 0.50619 (11) | 0.7725 (2) | 0.0274 (3) | |
H15 | 0.3280 | 0.4570 | 0.8310 | 0.033* | |
C16 | 0.48803 (14) | 0.51356 (12) | 0.7814 (2) | 0.0314 (4) | |
H16 | 0.5281 | 0.4677 | 0.8474 | 0.038* | |
C121 | 0.71530 (12) | 0.72066 (11) | 0.6085 (2) | 0.0292 (3) | |
H12A | 0.7017 | 0.7247 | 0.7235 | 0.044* | |
H12B | 0.7676 | 0.7743 | 0.5757 | 0.044* | |
H12C | 0.7505 | 0.6564 | 0.5827 | 0.044* | |
C21 | 0.14793 (10) | 0.82314 (9) | 0.43501 (16) | 0.0149 (2) | |
H21 | 0.1579 | 0.8071 | 0.3195 | 0.018* | |
C22 | 0.19572 (10) | 0.92726 (9) | 0.46497 (18) | 0.0198 (3) | |
H22A | 0.1877 | 0.9440 | 0.5793 | 0.024* | |
H22B | 0.2792 | 0.9290 | 0.4376 | 0.024* | |
C23 | 0.13070 (11) | 1.00374 (10) | 0.36499 (19) | 0.0216 (3) | |
H23A | 0.1615 | 1.0709 | 0.3876 | 0.026* | |
H23B | 0.1429 | 0.9896 | 0.2505 | 0.026* | |
C24 | 0.00155 (11) | 1.00077 (10) | 0.40255 (17) | 0.0187 (3) | |
H24A | −0.0400 | 1.0478 | 0.3321 | 0.022* | |
H24B | −0.0112 | 1.0219 | 0.5141 | 0.022* | |
C25 | −0.04705 (10) | 0.89657 (10) | 0.37903 (18) | 0.0203 (3) | |
H25A | −0.0435 | 0.8793 | 0.2645 | 0.024* | |
H25B | −0.1296 | 0.8958 | 0.4117 | 0.024* | |
C26 | 0.01919 (10) | 0.81846 (9) | 0.47470 (17) | 0.0190 (3) | |
H26A | 0.0078 | 0.8304 | 0.5900 | 0.023* | |
H26B | −0.0112 | 0.7515 | 0.4493 | 0.023* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S12 | 0.01405 (13) | 0.01819 (14) | 0.02131 (17) | −0.00011 (9) | 0.00024 (15) | 0.00287 (15) |
O1 | 0.0153 (4) | 0.0281 (5) | 0.0128 (5) | 0.0022 (3) | 0.0006 (4) | 0.0030 (4) |
N2 | 0.0152 (5) | 0.0206 (5) | 0.0133 (6) | 0.0026 (3) | 0.0016 (4) | 0.0032 (4) |
N11 | 0.0199 (5) | 0.0276 (6) | 0.0272 (7) | 0.0055 (4) | −0.0005 (5) | 0.0090 (5) |
C1 | 0.0141 (5) | 0.0168 (5) | 0.0122 (7) | −0.0016 (4) | −0.0013 (4) | −0.0010 (5) |
C12 | 0.0163 (6) | 0.0163 (6) | 0.0161 (6) | 0.0019 (4) | 0.0018 (5) | −0.0005 (5) |
C13 | 0.0159 (5) | 0.0158 (6) | 0.0140 (7) | 0.0018 (4) | −0.0005 (5) | −0.0023 (5) |
C14 | 0.0194 (6) | 0.0203 (6) | 0.0203 (7) | 0.0004 (5) | 0.0026 (5) | 0.0006 (6) |
C15 | 0.0280 (7) | 0.0225 (7) | 0.0316 (9) | 0.0016 (5) | 0.0072 (6) | 0.0120 (6) |
C16 | 0.0279 (8) | 0.0319 (9) | 0.0344 (9) | 0.0081 (6) | 0.0007 (6) | 0.0189 (7) |
C121 | 0.0161 (6) | 0.0332 (8) | 0.0383 (10) | −0.0020 (5) | −0.0055 (6) | 0.0065 (7) |
C21 | 0.0129 (5) | 0.0185 (6) | 0.0131 (6) | 0.0018 (4) | 0.0002 (4) | −0.0001 (5) |
C22 | 0.0118 (5) | 0.0209 (6) | 0.0267 (8) | −0.0002 (4) | −0.0020 (5) | −0.0010 (5) |
C23 | 0.0143 (6) | 0.0198 (6) | 0.0306 (8) | 0.0001 (5) | 0.0028 (5) | 0.0021 (6) |
C24 | 0.0137 (5) | 0.0214 (6) | 0.0210 (7) | 0.0039 (4) | 0.0018 (5) | 0.0001 (5) |
C25 | 0.0121 (5) | 0.0244 (6) | 0.0243 (7) | 0.0009 (5) | −0.0023 (5) | 0.0002 (5) |
C26 | 0.0121 (5) | 0.0206 (6) | 0.0244 (8) | −0.0012 (4) | 0.0004 (5) | 0.0024 (5) |
S12—C12 | 1.7668 (13) | C121—H12C | 0.9800 |
S12—C121 | 1.8030 (15) | C21—C26 | 1.5222 (15) |
O1—C1 | 1.2332 (16) | C21—C22 | 1.5271 (17) |
N2—C1 | 1.3336 (15) | C21—H21 | 1.0000 |
N2—C21 | 1.4593 (16) | C22—C23 | 1.5253 (18) |
N2—H2 | 0.8800 | C22—H22A | 0.9900 |
N11—C12 | 1.3247 (17) | C22—H22B | 0.9900 |
N11—C16 | 1.340 (2) | C23—C24 | 1.5223 (17) |
C1—C13 | 1.4949 (17) | C23—H23A | 0.9900 |
C12—C13 | 1.4132 (16) | C23—H23B | 0.9900 |
C13—C14 | 1.3853 (18) | C24—C25 | 1.5234 (19) |
C14—C15 | 1.379 (2) | C24—H24A | 0.9900 |
C14—H14 | 0.9500 | C24—H24B | 0.9900 |
C15—C16 | 1.379 (2) | C25—C26 | 1.5278 (18) |
C15—H15 | 0.9500 | C25—H25A | 0.9900 |
C16—H16 | 0.9500 | C25—H25B | 0.9900 |
C121—H12A | 0.9800 | C26—H26A | 0.9900 |
C121—H12B | 0.9800 | C26—H26B | 0.9900 |
C12—S12—C121 | 100.24 (7) | C26—C21—H21 | 108.4 |
C1—N2—C21 | 121.97 (11) | C22—C21—H21 | 108.4 |
C1—N2—H2 | 119.0 | C23—C22—C21 | 110.60 (10) |
C21—N2—H2 | 119.0 | C23—C22—H22A | 109.5 |
C12—N11—C16 | 117.93 (12) | C21—C22—H22A | 109.5 |
O1—C1—N2 | 123.96 (12) | C23—C22—H22B | 109.5 |
O1—C1—C13 | 119.91 (11) | C21—C22—H22B | 109.5 |
N2—C1—C13 | 116.13 (11) | H22A—C22—H22B | 108.1 |
N11—C12—C13 | 122.64 (11) | C24—C23—C22 | 110.41 (11) |
N11—C12—S12 | 117.28 (9) | C24—C23—H23A | 109.6 |
C13—C12—S12 | 120.08 (9) | C22—C23—H23A | 109.6 |
C14—C13—C12 | 117.62 (11) | C24—C23—H23B | 109.6 |
C14—C13—C1 | 121.57 (11) | C22—C23—H23B | 109.6 |
C12—C13—C1 | 120.75 (11) | H23A—C23—H23B | 108.1 |
C15—C14—C13 | 120.05 (12) | C23—C24—C25 | 110.92 (10) |
C15—C14—H14 | 120.0 | C23—C24—H24A | 109.5 |
C13—C14—H14 | 120.0 | C25—C24—H24A | 109.5 |
C16—C15—C14 | 117.72 (13) | C23—C24—H24B | 109.5 |
C16—C15—H15 | 121.1 | C25—C24—H24B | 109.5 |
C14—C15—H15 | 121.1 | H24A—C24—H24B | 108.0 |
N11—C16—C15 | 124.03 (13) | C24—C25—C26 | 112.45 (11) |
N11—C16—H16 | 118.0 | C24—C25—H25A | 109.1 |
C15—C16—H16 | 118.0 | C26—C25—H25A | 109.1 |
S12—C121—H12A | 109.5 | C24—C25—H25B | 109.1 |
S12—C121—H12B | 109.5 | C26—C25—H25B | 109.1 |
H12A—C121—H12B | 109.5 | H25A—C25—H25B | 107.8 |
S12—C121—H12C | 109.5 | C21—C26—C25 | 110.10 (10) |
H12A—C121—H12C | 109.5 | C21—C26—H26A | 109.6 |
H12B—C121—H12C | 109.5 | C25—C26—H26A | 109.6 |
N2—C21—C26 | 110.46 (10) | C21—C26—H26B | 109.6 |
N2—C21—C22 | 110.36 (10) | C25—C26—H26B | 109.6 |
C26—C21—C22 | 110.71 (10) | H26A—C26—H26B | 108.2 |
N2—C21—H21 | 108.4 | ||
C21—N2—C1—O1 | −4.14 (18) | C1—C13—C14—C15 | 177.27 (13) |
C21—N2—C1—C13 | 176.90 (10) | C13—C14—C15—C16 | 0.1 (2) |
C16—N11—C12—C13 | 0.9 (2) | C12—N11—C16—C15 | −0.9 (3) |
C16—N11—C12—S12 | −179.30 (12) | C14—C15—C16—N11 | 0.4 (3) |
C121—S12—C12—N11 | −13.77 (13) | C1—N2—C21—C26 | 155.76 (11) |
C121—S12—C12—C13 | 166.03 (11) | C1—N2—C21—C22 | −81.49 (14) |
N11—C12—C13—C14 | −0.45 (19) | N2—C21—C22—C23 | 178.71 (10) |
S12—C12—C13—C14 | 179.76 (10) | C26—C21—C22—C23 | −58.69 (14) |
N11—C12—C13—C1 | −177.82 (12) | C21—C22—C23—C24 | 57.95 (15) |
S12—C12—C13—C1 | 2.39 (16) | C22—C23—C24—C25 | −55.64 (15) |
O1—C1—C13—C14 | −139.12 (13) | C23—C24—C25—C26 | 54.76 (16) |
N2—C1—C13—C14 | 39.88 (17) | N2—C21—C26—C25 | 178.91 (11) |
O1—C1—C13—C12 | 38.15 (17) | C22—C21—C26—C25 | 56.37 (14) |
N2—C1—C13—C12 | −142.85 (11) | C24—C25—C26—C21 | −54.86 (15) |
C12—C13—C14—C15 | −0.08 (19) |
Cg1 is the centroid of the pyridine ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1i | 0.88 | 2.01 | 2.8399 (15) | 157 |
C16—H16···Cg1ii | 0.95 | 2.97 | 3.7489 (18) | 141 |
Symmetry codes: (i) −x+1/2, y, z+1/2; (ii) −x+1, −y+1, z+1/2. |
C10H14N2OS | F(000) = 896 |
Mr = 210.29 | Dx = 1.211 Mg m−3 |
Monoclinic, P21/c | Synchrotron radiation, λ = 0.68890 Å |
Hall symbol: -P 2ybc | Cell parameters from 3067 reflections |
a = 11.42 (2) Å | θ = 1.7–26.9° |
b = 8.580 (19) Å | µ = 0.25 mm−1 |
c = 23.61 (5) Å | T = 100 K |
β = 94.15 (3)° | Plate, colourless |
V = 2307 (8) Å3 | 0.10 × 0.03 × 0.01 mm |
Z = 8 |
CrystalLogic diffractometer | 4493 independent reflections |
Radiation source: synchrotron, DLS beamline I19 | 2445 reflections with I > 2σ(I) |
Double crystal silicon monochromator | Rint = 0.150 |
Detector resolution: 28.5714 pixels mm-1 | θmax = 26.4°, θmin = 1.7° |
profile data from ω–scans | h = −14→7 |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | k = −9→11 |
Tmin = 0.975, Tmax = 0.998 | l = −30→24 |
10806 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.119 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.366 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.1896P)2 + 2.8333P] where P = (Fo2 + 2Fc2)/3 |
4493 reflections | (Δ/σ)max < 0.001 |
259 parameters | Δρmax = 0.67 e Å−3 |
0 restraints | Δρmin = −0.67 e Å−3 |
C10H14N2OS | V = 2307 (8) Å3 |
Mr = 210.29 | Z = 8 |
Monoclinic, P21/c | Synchrotron radiation, λ = 0.68890 Å |
a = 11.42 (2) Å | µ = 0.25 mm−1 |
b = 8.580 (19) Å | T = 100 K |
c = 23.61 (5) Å | 0.10 × 0.03 × 0.01 mm |
β = 94.15 (3)° |
CrystalLogic diffractometer | 4493 independent reflections |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | 2445 reflections with I > 2σ(I) |
Tmin = 0.975, Tmax = 0.998 | Rint = 0.150 |
10806 measured reflections |
R[F2 > 2σ(F2)] = 0.119 | 0 restraints |
wR(F2) = 0.366 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.67 e Å−3 |
4493 reflections | Δρmin = −0.67 e Å−3 |
259 parameters |
Experimental. N-iso-Propyl-2-(methylsulfanyl)nicotinamide (II). NMR 1H (400MHz, DMSO-d6) δ (ppm): 8.51 (1H, dd; J = 4.8 and J = 1.7 Hz, H6), 8.28 (1H, d, J = 7.5Hz, NH), 7.70 (1H, dd; J = 7.5 and J = 1.7 Hz, H4), 7.16 (1H, dd, J = 7.5 and J = 4.8 Hz, H5), 4.02 (1H, dq, J = 7.5 and J = 6.5 Hz, CH), 2.43 (3H, s, (CH3)S), 1.14 (6H, d, J= 6.5 Hz, (CH3)2C). (ppm): 165.2, 157.3, 149.6, 134.8, 130.5, 118.5, 40.9, 22.1, 12.9. IR (cm-1; KBr): 3234 (NH), 1628 (CON) MS/ESI: [M-H]: 209.2 |
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. |
x | y | z | Uiso*/Ueq | ||
S12A | 0.60559 (16) | 0.3799 (2) | 0.37711 (6) | 0.0381 (5) | |
O1A | 0.3807 (4) | 0.2214 (5) | 0.39115 (18) | 0.0376 (11) | |
N2A | 0.2371 (5) | 0.4063 (6) | 0.3933 (2) | 0.0327 (12) | |
H2A | 0.2086 | 0.4931 | 0.3780 | 0.039* | |
N11A | 0.5566 (5) | 0.5227 (6) | 0.2767 (2) | 0.0348 (13) | |
C1A | 0.3330 (6) | 0.3455 (7) | 0.3729 (2) | 0.0325 (15) | |
C3A | 0.1751 (6) | 0.3348 (8) | 0.4410 (3) | 0.0406 (16) | |
H3A | 0.1850 | 0.2191 | 0.4398 | 0.049* | |
C12A | 0.5072 (6) | 0.4513 (7) | 0.3210 (2) | 0.0358 (16) | |
C13A | 0.3849 (6) | 0.4327 (7) | 0.3244 (3) | 0.0333 (15) | |
C14A | 0.3125 (6) | 0.4980 (8) | 0.2806 (3) | 0.0367 (15) | |
H14A | 0.2296 | 0.4918 | 0.2816 | 0.044* | |
C15A | 0.3611 (6) | 0.5724 (8) | 0.2352 (3) | 0.0375 (16) | |
H15A | 0.3122 | 0.6172 | 0.2052 | 0.045* | |
C16A | 0.4819 (6) | 0.5794 (7) | 0.2350 (3) | 0.0362 (15) | |
H16A | 0.5143 | 0.6274 | 0.2034 | 0.043* | |
C21A | 0.7443 (7) | 0.4600 (10) | 0.3566 (3) | 0.0506 (19) | |
H21A | 0.7634 | 0.4142 | 0.3204 | 0.076* | |
H22A | 0.8067 | 0.4355 | 0.3859 | 0.076* | |
H23A | 0.7372 | 0.5733 | 0.3525 | 0.076* | |
C31A | 0.0452 (6) | 0.3729 (9) | 0.4337 (3) | 0.0462 (18) | |
H31A | 0.0343 | 0.4857 | 0.4370 | 0.069* | |
H32A | 0.0042 | 0.3197 | 0.4632 | 0.069* | |
H33A | 0.0133 | 0.3378 | 0.3962 | 0.069* | |
C32A | 0.2312 (7) | 0.3956 (9) | 0.4979 (3) | 0.0475 (18) | |
H34A | 0.3156 | 0.3735 | 0.5004 | 0.071* | |
H35A | 0.1950 | 0.3436 | 0.5292 | 0.071* | |
H36A | 0.2187 | 0.5083 | 0.5003 | 0.071* | |
S12B | −0.04296 (18) | 0.8929 (2) | 0.40668 (8) | 0.0484 (6) | |
O1B | 0.1648 (4) | 0.7202 (5) | 0.3693 (2) | 0.0451 (12) | |
N2B | 0.3119 (5) | 0.9004 (6) | 0.3819 (2) | 0.0339 (12) | |
H2B | 0.3328 | 0.9970 | 0.3751 | 0.041* | |
N11B | −0.0650 (5) | 1.0966 (7) | 0.3200 (2) | 0.0421 (14) | |
C1B | 0.2044 (6) | 0.8554 (7) | 0.3633 (3) | 0.0346 (15) | |
C3B | 0.3975 (6) | 0.7991 (7) | 0.4128 (3) | 0.0371 (16) | |
H3B | 0.3786 | 0.6885 | 0.4024 | 0.044* | |
C12B | 0.0103 (6) | 0.9958 (7) | 0.3477 (3) | 0.0376 (16) | |
C13B | 0.1274 (6) | 0.9771 (7) | 0.3327 (3) | 0.0328 (15) | |
C14B | 0.1687 (7) | 1.0629 (8) | 0.2883 (3) | 0.0391 (16) | |
H14B | 0.2475 | 1.0522 | 0.2784 | 0.047* | |
C15B | 0.0905 (7) | 1.1664 (8) | 0.2583 (3) | 0.0393 (16) | |
H15B | 0.1150 | 1.2278 | 0.2278 | 0.047* | |
C16B | −0.0235 (7) | 1.1754 (9) | 0.2749 (3) | 0.048 (2) | |
H16B | −0.0769 | 1.2411 | 0.2534 | 0.058* | |
C21B | −0.1738 (8) | 1.0040 (11) | 0.4210 (4) | 0.063 (2) | |
H21B | −0.2127 | 0.9546 | 0.4520 | 0.094* | |
H22B | −0.2278 | 1.0065 | 0.3867 | 0.094* | |
H23B | −0.1513 | 1.1107 | 0.4318 | 0.094* | |
C31B | 0.5220 (6) | 0.8371 (8) | 0.3944 (3) | 0.0443 (18) | |
H31B | 0.5404 | 0.9467 | 0.4026 | 0.066* | |
H32B | 0.5245 | 0.8182 | 0.3535 | 0.066* | |
H33B | 0.5798 | 0.7704 | 0.4153 | 0.066* | |
C32B | 0.3868 (7) | 0.8189 (9) | 0.4767 (3) | 0.0505 (19) | |
H34B | 0.3070 | 0.7916 | 0.4859 | 0.076* | |
H35B | 0.4032 | 0.9275 | 0.4875 | 0.076* | |
H36B | 0.4433 | 0.7503 | 0.4976 | 0.076* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S12A | 0.0347 (12) | 0.0414 (9) | 0.0374 (8) | 0.0036 (7) | −0.0040 (7) | 0.0016 (6) |
O1A | 0.036 (3) | 0.030 (2) | 0.046 (2) | 0.002 (2) | −0.0012 (19) | 0.0024 (18) |
N2A | 0.030 (4) | 0.026 (2) | 0.041 (3) | 0.004 (2) | 0.000 (2) | 0.002 (2) |
N11A | 0.031 (4) | 0.033 (3) | 0.041 (3) | −0.001 (2) | −0.002 (2) | −0.002 (2) |
C1A | 0.036 (4) | 0.022 (3) | 0.038 (3) | −0.002 (3) | −0.006 (3) | 0.002 (2) |
C3A | 0.040 (5) | 0.036 (3) | 0.046 (4) | −0.001 (3) | 0.007 (3) | 0.004 (3) |
C12A | 0.049 (5) | 0.027 (3) | 0.030 (3) | −0.002 (3) | −0.003 (3) | −0.003 (2) |
C13A | 0.029 (4) | 0.027 (3) | 0.043 (3) | 0.005 (3) | −0.005 (3) | −0.003 (2) |
C14A | 0.031 (4) | 0.037 (3) | 0.042 (3) | −0.001 (3) | 0.000 (3) | 0.001 (3) |
C15A | 0.038 (5) | 0.036 (3) | 0.037 (3) | 0.003 (3) | −0.003 (3) | 0.008 (3) |
C16A | 0.035 (5) | 0.032 (3) | 0.041 (3) | −0.002 (3) | 0.003 (3) | 0.005 (3) |
C21A | 0.049 (5) | 0.054 (4) | 0.047 (4) | 0.002 (4) | −0.005 (3) | 0.008 (3) |
C31A | 0.034 (5) | 0.054 (4) | 0.051 (4) | −0.009 (3) | 0.001 (3) | 0.002 (3) |
C32A | 0.046 (5) | 0.054 (4) | 0.041 (3) | 0.000 (4) | −0.004 (3) | 0.005 (3) |
S12B | 0.0406 (13) | 0.0465 (10) | 0.0590 (11) | 0.0049 (8) | 0.0088 (9) | 0.0150 (8) |
O1B | 0.040 (3) | 0.026 (2) | 0.069 (3) | 0.001 (2) | −0.006 (2) | 0.003 (2) |
N2B | 0.026 (3) | 0.027 (2) | 0.048 (3) | −0.001 (2) | −0.006 (2) | 0.003 (2) |
N11B | 0.024 (4) | 0.044 (3) | 0.057 (3) | 0.005 (3) | −0.007 (2) | 0.006 (3) |
C1B | 0.032 (4) | 0.033 (3) | 0.039 (3) | 0.006 (3) | 0.001 (3) | −0.001 (2) |
C3B | 0.039 (5) | 0.024 (3) | 0.046 (3) | 0.003 (3) | −0.009 (3) | 0.002 (2) |
C12B | 0.037 (5) | 0.025 (3) | 0.049 (4) | 0.001 (3) | −0.008 (3) | −0.001 (3) |
C13B | 0.027 (4) | 0.029 (3) | 0.040 (3) | 0.000 (3) | −0.008 (3) | −0.003 (2) |
C14B | 0.044 (5) | 0.034 (3) | 0.038 (3) | −0.002 (3) | −0.006 (3) | −0.001 (3) |
C15B | 0.039 (5) | 0.038 (3) | 0.040 (3) | 0.004 (3) | −0.001 (3) | 0.004 (3) |
C16B | 0.043 (5) | 0.046 (4) | 0.052 (4) | 0.005 (3) | −0.017 (3) | 0.006 (3) |
C21B | 0.046 (6) | 0.063 (5) | 0.083 (6) | 0.007 (4) | 0.027 (4) | 0.020 (4) |
C31B | 0.036 (5) | 0.043 (4) | 0.052 (4) | 0.011 (3) | −0.001 (3) | 0.006 (3) |
C32B | 0.048 (5) | 0.048 (4) | 0.054 (4) | 0.003 (4) | −0.009 (3) | 0.007 (3) |
S12A—C12A | 1.783 (7) | S12B—C12B | 1.791 (7) |
S12A—C21A | 1.823 (8) | S12B—C21B | 1.824 (9) |
O1A—C1A | 1.257 (7) | O1B—C1B | 1.257 (8) |
N2A—C1A | 1.333 (8) | N2B—C1B | 1.331 (8) |
N2A—C3A | 1.504 (8) | N2B—C3B | 1.464 (8) |
N2A—H2A | 0.8800 | N2B—H2B | 0.8800 |
N11A—C16A | 1.346 (8) | N11B—C12B | 1.354 (8) |
N11A—C12A | 1.369 (8) | N11B—C16B | 1.374 (10) |
C1A—C13A | 1.524 (9) | C1B—C13B | 1.514 (9) |
C3A—C31A | 1.516 (10) | C3B—C32B | 1.532 (10) |
C3A—C32A | 1.536 (9) | C3B—C31B | 1.552 (11) |
C3A—H3A | 1.0000 | C3B—H3B | 1.0000 |
C12A—C13A | 1.413 (10) | C12B—C13B | 1.417 (10) |
C13A—C14A | 1.395 (9) | C13B—C14B | 1.391 (10) |
C14A—C15A | 1.396 (9) | C14B—C15B | 1.413 (9) |
C14A—H14A | 0.9500 | C14B—H14B | 0.9500 |
C15A—C16A | 1.381 (10) | C15B—C16B | 1.389 (11) |
C15A—H15A | 0.9500 | C15B—H15B | 0.9500 |
C16A—H16A | 0.9500 | C16B—H16B | 0.9500 |
C21A—H21A | 0.9800 | C21B—H21B | 0.9800 |
C21A—H22A | 0.9800 | C21B—H22B | 0.9800 |
C21A—H23A | 0.9800 | C21B—H23B | 0.9800 |
C31A—H31A | 0.9800 | C31B—H31B | 0.9800 |
C31A—H32A | 0.9800 | C31B—H32B | 0.9800 |
C31A—H33A | 0.9800 | C31B—H33B | 0.9800 |
C32A—H34A | 0.9800 | C32B—H34B | 0.9800 |
C32A—H35A | 0.9800 | C32B—H35B | 0.9800 |
C32A—H36A | 0.9800 | C32B—H36B | 0.9800 |
C12A—S12A—C21A | 100.7 (3) | C12B—S12B—C21B | 102.4 (4) |
C1A—N2A—C3A | 123.6 (5) | C1B—N2B—C3B | 124.0 (5) |
C1A—N2A—H2A | 118.2 | C1B—N2B—H2B | 118.0 |
C3A—N2A—H2A | 118.2 | C3B—N2B—H2B | 118.0 |
C16A—N11A—C12A | 116.5 (6) | C12B—N11B—C16B | 116.5 (6) |
O1A—C1A—N2A | 123.7 (6) | O1B—C1B—N2B | 124.1 (6) |
O1A—C1A—C13A | 119.3 (6) | O1B—C1B—C13B | 119.3 (6) |
N2A—C1A—C13A | 117.0 (5) | N2B—C1B—C13B | 116.6 (6) |
N2A—C3A—C31A | 109.7 (5) | N2B—C3B—C32B | 109.1 (6) |
N2A—C3A—C32A | 109.1 (6) | N2B—C3B—C31B | 109.1 (5) |
C31A—C3A—C32A | 111.6 (6) | C32B—C3B—C31B | 113.1 (6) |
N2A—C3A—H3A | 108.8 | N2B—C3B—H3B | 108.4 |
C31A—C3A—H3A | 108.8 | C32B—C3B—H3B | 108.4 |
C32A—C3A—H3A | 108.8 | C31B—C3B—H3B | 108.4 |
N11A—C12A—C13A | 123.9 (6) | N11B—C12B—C13B | 121.9 (6) |
N11A—C12A—S12A | 116.7 (5) | N11B—C12B—S12B | 116.8 (6) |
C13A—C12A—S12A | 119.4 (5) | C13B—C12B—S12B | 121.2 (5) |
C14A—C13A—C12A | 116.6 (6) | C14B—C13B—C12B | 120.5 (6) |
C14A—C13A—C1A | 120.8 (6) | C14B—C13B—C1B | 120.5 (6) |
C12A—C13A—C1A | 122.6 (5) | C12B—C13B—C1B | 119.0 (6) |
C13A—C14A—C15A | 120.4 (7) | C13B—C14B—C15B | 118.2 (7) |
C13A—C14A—H14A | 119.8 | C13B—C14B—H14B | 120.9 |
C15A—C14A—H14A | 119.8 | C15B—C14B—H14B | 120.9 |
C16A—C15A—C14A | 118.4 (6) | C16B—C15B—C14B | 117.7 (6) |
C16A—C15A—H15A | 120.8 | C16B—C15B—H15B | 121.1 |
C14A—C15A—H15A | 120.8 | C14B—C15B—H15B | 121.1 |
N11A—C16A—C15A | 124.2 (6) | N11B—C16B—C15B | 125.0 (6) |
N11A—C16A—H16A | 117.9 | N11B—C16B—H16B | 117.5 |
C15A—C16A—H16A | 117.9 | C15B—C16B—H16B | 117.5 |
S12A—C21A—H21A | 109.5 | S12B—C21B—H21B | 109.5 |
S12A—C21A—H22A | 109.5 | S12B—C21B—H22B | 109.5 |
H21A—C21A—H22A | 109.5 | H21B—C21B—H22B | 109.5 |
S12A—C21A—H23A | 109.5 | S12B—C21B—H23B | 109.5 |
H21A—C21A—H23A | 109.5 | H21B—C21B—H23B | 109.5 |
H22A—C21A—H23A | 109.5 | H22B—C21B—H23B | 109.5 |
C3A—C31A—H31A | 109.5 | C3B—C31B—H31B | 109.5 |
C3A—C31A—H32A | 109.5 | C3B—C31B—H32B | 109.5 |
H31A—C31A—H32A | 109.5 | H31B—C31B—H32B | 109.5 |
C3A—C31A—H33A | 109.5 | C3B—C31B—H33B | 109.5 |
H31A—C31A—H33A | 109.5 | H31B—C31B—H33B | 109.5 |
H32A—C31A—H33A | 109.5 | H32B—C31B—H33B | 109.5 |
C3A—C32A—H34A | 109.5 | C3B—C32B—H34B | 109.5 |
C3A—C32A—H35A | 109.5 | C3B—C32B—H35B | 109.5 |
H34A—C32A—H35A | 109.5 | H34B—C32B—H35B | 109.5 |
C3A—C32A—H36A | 109.5 | C3B—C32B—H36B | 109.5 |
H34A—C32A—H36A | 109.5 | H34B—C32B—H36B | 109.5 |
H35A—C32A—H36A | 109.5 | H35B—C32B—H36B | 109.5 |
C3A—N2A—C1A—O1A | 0.6 (9) | C3B—N2B—C1B—O1B | −1.4 (10) |
C3A—N2A—C1A—C13A | 180.0 (5) | C3B—N2B—C1B—C13B | 179.2 (6) |
C1A—N2A—C3A—C31A | −149.9 (6) | C1B—N2B—C3B—C32B | −92.6 (7) |
C1A—N2A—C3A—C32A | 87.5 (7) | C1B—N2B—C3B—C31B | 143.3 (6) |
C16A—N11A—C12A—C13A | 1.0 (9) | C16B—N11B—C12B—C13B | 2.6 (9) |
C16A—N11A—C12A—S12A | −178.6 (4) | C16B—N11B—C12B—S12B | 179.8 (5) |
C21A—S12A—C12A—N11A | 8.1 (6) | C21B—S12B—C12B—N11B | −15.3 (6) |
C21A—S12A—C12A—C13A | −171.6 (5) | C21B—S12B—C12B—C13B | 162.0 (6) |
N11A—C12A—C13A—C14A | −2.8 (9) | N11B—C12B—C13B—C14B | −0.1 (9) |
S12A—C12A—C13A—C14A | 176.9 (5) | S12B—C12B—C13B—C14B | −177.2 (5) |
N11A—C12A—C13A—C1A | 176.9 (5) | N11B—C12B—C13B—C1B | −176.4 (6) |
S12A—C12A—C13A—C1A | −3.5 (8) | S12B—C12B—C13B—C1B | 6.4 (8) |
O1A—C1A—C13A—C14A | 138.7 (6) | O1B—C1B—C13B—C14B | −128.7 (7) |
N2A—C1A—C13A—C14A | −40.7 (8) | N2B—C1B—C13B—C14B | 50.7 (8) |
O1A—C1A—C13A—C12A | −40.9 (8) | O1B—C1B—C13B—C12B | 47.7 (8) |
N2A—C1A—C13A—C12A | 139.7 (6) | N2B—C1B—C13B—C12B | −132.9 (6) |
C12A—C13A—C14A—C15A | 2.1 (9) | C12B—C13B—C14B—C15B | −1.1 (9) |
C1A—C13A—C14A—C15A | −177.5 (6) | C1B—C13B—C14B—C15B | 175.2 (5) |
C13A—C14A—C15A—C16A | 0.0 (10) | C13B—C14B—C15B—C16B | −0.3 (9) |
C12A—N11A—C16A—C15A | 1.4 (9) | C12B—N11B—C16B—C15B | −4.2 (10) |
C14A—C15A—C16A—N11A | −2.0 (10) | C14B—C15B—C16B—N11B | 3.1 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2A—H2A···O1B | 0.88 | 2.02 | 2.862 (9) | 160 |
N2B—H2B···O1Ai | 0.88 | 2.03 | 2.869 (9) | 159 |
Symmetry code: (i) x, y+1, z. |
C9H12N2O2S·2H2O | F(000) = 528 |
Mr = 248.30 | Dx = 1.406 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71075 Å |
Hall symbol: -P 2yn | Cell parameters from 11307 reflections |
a = 7.194 (2) Å | θ = 3.0–27.6° |
b = 7.285 (3) Å | µ = 0.28 mm−1 |
c = 22.388 (8) Å | T = 100 K |
β = 90.341 (5)° | Plate, colourless |
V = 1173.3 (7) Å3 | 0.26 × 0.12 × 0.05 mm |
Z = 4 |
Rigaku Saturn724+ (2x2 bin mode) diffractometer | 2063 independent reflections |
Radiation source: Rotating Anode | 1977 reflections with I > 2σ(I) |
Confocal monochromator | Rint = 0.016 |
Detector resolution: 28.5714 pixels mm-1 | θmax = 25.0°, θmin = 2.9° |
profile data from ω–scans | h = −8→8 |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | k = −8→8 |
Tmin = 0.931, Tmax = 0.986 | l = −26→25 |
6865 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0367P)2 + 0.579P] where P = (Fo2 + 2Fc2)/3 |
2063 reflections | (Δ/σ)max < 0.001 |
146 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C9H12N2O2S·2H2O | V = 1173.3 (7) Å3 |
Mr = 248.30 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.194 (2) Å | µ = 0.28 mm−1 |
b = 7.285 (3) Å | T = 100 K |
c = 22.388 (8) Å | 0.26 × 0.12 × 0.05 mm |
β = 90.341 (5)° |
Rigaku Saturn724+ (2x2 bin mode) diffractometer | 2063 independent reflections |
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | 1977 reflections with I > 2σ(I) |
Tmin = 0.931, Tmax = 0.986 | Rint = 0.016 |
6865 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.25 e Å−3 |
2063 reflections | Δρmin = −0.24 e Å−3 |
146 parameters |
Experimental. N-(2-Hydroxyethyl)-2-(methylsulfanyl)nicotinamide (III)' NMR 1H (400MHz, DMSO-d6) δ (ppm): 8.51 (1H, dd, J = 4.8 and J = 1.6 Hz, H6), 8.37 (1H, s, NH), 7.77 (1H, dd, J = 7.6 and J = 1.6Hz, H4) 7.16 (1H, dd, J = 7.6 and J = 4.8 Hz, H5), 3.50 (2H, t, J = 6.2 Hz, CH2OH), 3.30 (2H, t, J = 6.2 Hz, CH2NH), 2.42 (3H, s, (CH3)S). NMR 13C (100MHz, DMSO-d6) δ (ppm): 166.1; 157.7; 149.8; 135.0; 129.8; 118.4; 59.6; 41.9; 12.9. IR (cm-1; KBr): 3258 (NH, OH); 1643 (CON) MS/ESI: [M+Na]: 235.1 |
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. |
x | y | z | Uiso*/Ueq | ||
S12 | 0.16008 (5) | 0.17288 (4) | 0.496490 (14) | 0.01456 (12) | |
O1 | 0.14465 (13) | 0.15851 (13) | 0.35800 (4) | 0.0178 (2) | |
O23 | 0.63288 (13) | 0.21703 (14) | 0.22908 (4) | 0.0189 (2) | |
H23 | 0.6034 | 0.3265 | 0.2359 | 0.028* | |
N2 | 0.45696 (15) | 0.17664 (14) | 0.34545 (5) | 0.0139 (2) | |
H2 | 0.5746 | 0.2354 | 0.3572 | 0.017* | |
N11 | 0.25158 (14) | 0.52793 (15) | 0.50671 (5) | 0.0126 (2) | |
C1 | 0.29727 (17) | 0.23204 (18) | 0.36899 (6) | 0.0125 (3) | |
C12 | 0.24506 (17) | 0.38431 (18) | 0.46972 (6) | 0.0115 (3) | |
C13 | 0.30932 (17) | 0.39415 (18) | 0.41033 (6) | 0.0120 (3) | |
C14 | 0.37886 (17) | 0.55973 (18) | 0.38990 (6) | 0.0140 (3) | |
H14 | 0.4243 | 0.5702 | 0.3503 | 0.017* | |
C15 | 0.38137 (18) | 0.71039 (18) | 0.42798 (6) | 0.0143 (3) | |
H15 | 0.4257 | 0.8262 | 0.4147 | 0.017* | |
C16 | 0.31791 (18) | 0.68745 (18) | 0.48552 (6) | 0.0135 (3) | |
H16 | 0.3213 | 0.7902 | 0.5116 | 0.016* | |
C21 | 0.46845 (19) | 0.02847 (18) | 0.30153 (6) | 0.0159 (3) | |
H21A | 0.3589 | −0.0527 | 0.3057 | 0.019* | |
H21B | 0.5811 | −0.0457 | 0.3096 | 0.019* | |
C22 | 0.47580 (19) | 0.10174 (19) | 0.23793 (6) | 0.0177 (3) | |
H22A | 0.4812 | −0.0026 | 0.2097 | 0.021* | |
H22B | 0.3609 | 0.1720 | 0.2293 | 0.021* | |
C121 | 0.11816 (19) | 0.2207 (2) | 0.57439 (6) | 0.0173 (3) | |
H12A | 0.2350 | 0.2567 | 0.5938 | 0.026* | |
H12B | 0.0689 | 0.1105 | 0.5938 | 0.026* | |
H12C | 0.0278 | 0.3208 | 0.5778 | 0.026* | |
O2 | 0.80120 (13) | 0.33454 (13) | 0.37567 (4) | 0.0185 (2) | |
H2A | 0.7959 | 0.3934 | 0.4074 | 0.028* | |
H2B | 0.8969 | 0.2784 | 0.3749 | 0.028* | |
O3 | 0.52737 (13) | 0.56527 (13) | 0.25016 (4) | 0.0185 (2) | |
H3A | 0.6327 | 0.6270 | 0.2546 | 0.028* | |
H3B | 0.4761 | 0.5936 | 0.2199 | 0.028* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S12 | 0.01866 (19) | 0.01151 (18) | 0.01353 (19) | −0.00259 (12) | 0.00296 (13) | −0.00031 (12) |
O1 | 0.0135 (5) | 0.0220 (5) | 0.0179 (5) | −0.0025 (4) | 0.0007 (4) | −0.0069 (4) |
O23 | 0.0196 (5) | 0.0173 (5) | 0.0198 (5) | 0.0005 (4) | 0.0046 (4) | 0.0003 (4) |
N2 | 0.0135 (5) | 0.0146 (6) | 0.0136 (6) | −0.0010 (4) | 0.0020 (4) | −0.0037 (4) |
N11 | 0.0117 (5) | 0.0133 (5) | 0.0126 (5) | 0.0017 (4) | −0.0003 (4) | −0.0010 (4) |
C1 | 0.0141 (6) | 0.0139 (6) | 0.0096 (6) | 0.0000 (5) | 0.0004 (5) | 0.0018 (5) |
C12 | 0.0087 (6) | 0.0125 (6) | 0.0132 (6) | 0.0007 (5) | −0.0006 (5) | 0.0004 (5) |
C13 | 0.0091 (6) | 0.0144 (6) | 0.0124 (6) | 0.0016 (5) | −0.0010 (5) | −0.0010 (5) |
C14 | 0.0119 (6) | 0.0181 (7) | 0.0120 (6) | 0.0015 (5) | 0.0002 (5) | 0.0019 (5) |
C15 | 0.0127 (6) | 0.0123 (6) | 0.0178 (7) | −0.0009 (5) | −0.0009 (5) | 0.0029 (5) |
C16 | 0.0119 (6) | 0.0121 (6) | 0.0165 (7) | 0.0015 (5) | −0.0016 (5) | −0.0024 (5) |
C21 | 0.0175 (7) | 0.0133 (6) | 0.0169 (7) | 0.0003 (5) | 0.0038 (5) | −0.0043 (5) |
C22 | 0.0183 (7) | 0.0181 (7) | 0.0166 (7) | 0.0002 (6) | 0.0001 (5) | −0.0041 (5) |
C121 | 0.0193 (7) | 0.0191 (7) | 0.0134 (7) | −0.0032 (6) | 0.0022 (5) | 0.0013 (5) |
O2 | 0.0152 (5) | 0.0243 (5) | 0.0161 (5) | 0.0004 (4) | 0.0013 (4) | −0.0070 (4) |
O3 | 0.0186 (5) | 0.0206 (5) | 0.0163 (5) | −0.0007 (4) | −0.0005 (4) | 0.0037 (4) |
S12—C12 | 1.7635 (14) | C15—C16 | 1.379 (2) |
S12—C121 | 1.8055 (15) | C15—H15 | 0.9500 |
O1—C1 | 1.2449 (16) | C16—H16 | 0.9500 |
O23—C22 | 1.4228 (17) | C21—C22 | 1.5219 (19) |
O23—H23 | 0.8397 | C21—H21A | 0.9900 |
N2—C1 | 1.3295 (17) | C21—H21B | 0.9900 |
N2—C21 | 1.4628 (17) | C22—H22A | 0.9900 |
N2—H2 | 0.9827 | C22—H22B | 0.9900 |
N11—C12 | 1.3351 (17) | C121—H12A | 0.9800 |
N11—C16 | 1.3439 (18) | C121—H12B | 0.9800 |
C1—C13 | 1.5026 (18) | C121—H12C | 0.9800 |
C12—C13 | 1.4121 (19) | O2—H2A | 0.8308 |
C13—C14 | 1.3846 (19) | O2—H2B | 0.8012 |
C14—C15 | 1.390 (2) | O3—H3A | 0.8865 |
C14—H14 | 0.9500 | O3—H3B | 0.7957 |
C12—S12—C121 | 102.71 (6) | N11—C16—H16 | 118.2 |
C22—O23—H23 | 109.5 | C15—C16—H16 | 118.2 |
C1—N2—C21 | 122.88 (11) | N2—C21—C22 | 111.87 (11) |
C1—N2—H2 | 120.4 | N2—C21—H21A | 109.2 |
C21—N2—H2 | 116.7 | C22—C21—H21A | 109.2 |
C12—N11—C16 | 118.03 (11) | N2—C21—H21B | 109.2 |
O1—C1—N2 | 123.66 (12) | C22—C21—H21B | 109.2 |
O1—C1—C13 | 120.49 (11) | H21A—C21—H21B | 107.9 |
N2—C1—C13 | 115.84 (11) | O23—C22—C21 | 111.68 (11) |
N11—C12—C13 | 122.27 (12) | O23—C22—H22A | 109.3 |
N11—C12—S12 | 118.99 (10) | C21—C22—H22A | 109.3 |
C13—C12—S12 | 118.72 (10) | O23—C22—H22B | 109.3 |
C14—C13—C12 | 118.44 (12) | C21—C22—H22B | 109.3 |
C14—C13—C1 | 120.06 (11) | H22A—C22—H22B | 107.9 |
C12—C13—C1 | 121.47 (12) | S12—C121—H12A | 109.5 |
C13—C14—C15 | 119.26 (12) | S12—C121—H12B | 109.5 |
C13—C14—H14 | 120.4 | H12A—C121—H12B | 109.5 |
C15—C14—H14 | 120.4 | S12—C121—H12C | 109.5 |
C16—C15—C14 | 118.29 (12) | H12A—C121—H12C | 109.5 |
C16—C15—H15 | 120.9 | H12B—C121—H12C | 109.5 |
C14—C15—H15 | 120.9 | H2A—O2—H2B | 109.0 |
N11—C16—C15 | 123.69 (12) | H3A—O3—H3B | 110.9 |
C21—N2—C1—O1 | 3.3 (2) | N2—C1—C13—C14 | 59.14 (16) |
C21—N2—C1—C13 | −176.08 (11) | O1—C1—C13—C12 | 57.58 (17) |
C16—N11—C12—C13 | 1.62 (18) | N2—C1—C13—C12 | −123.06 (13) |
C16—N11—C12—S12 | 179.59 (9) | C12—C13—C14—C15 | −0.68 (18) |
C121—S12—C12—N11 | −3.62 (12) | C1—C13—C14—C15 | 177.19 (11) |
C121—S12—C12—C13 | 174.42 (10) | C13—C14—C15—C16 | 1.50 (19) |
N11—C12—C13—C14 | −0.92 (18) | C12—N11—C16—C15 | −0.74 (19) |
S12—C12—C13—C14 | −178.90 (9) | C14—C15—C16—N11 | −0.8 (2) |
N11—C12—C13—C1 | −178.76 (11) | C1—N2—C21—C22 | 97.15 (14) |
S12—C12—C13—C1 | 3.27 (16) | N2—C21—C22—O23 | 59.98 (14) |
O1—C1—C13—C14 | −120.22 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2 | 0.98 | 1.83 | 2.8096 (16) | 176 |
O23—H23···O3 | 0.84 | 1.85 | 2.6906 (17) | 177 |
O3—H3B···O1i | 0.80 | 2.00 | 2.7966 (15) | 178 |
O3—H3A···O23ii | 0.89 | 1.84 | 2.7200 (15) | 170 |
O2—H2A···N11iii | 0.83 | 2.04 | 2.8449 (17) | 164 |
C14—H14···O3 | 0.95 | 2.37 | 3.3122 (19) | 174 |
C21—H21A···O1 | 0.99 | 2.48 | 2.8208 (17) | 100 |
Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) −x+3/2, y+1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
Experimental details
(I) | (II) | (III) | |
Crystal data | |||
Chemical formula | C13H18N2OS | C10H14N2OS | C9H12N2O2S·2H2O |
Mr | 250.35 | 210.29 | 248.30 |
Crystal system, space group | Orthorhombic, Pca21 | Monoclinic, P21/c | Monoclinic, P21/n |
Temperature (K) | 100 | 100 | 100 |
a, b, c (Å) | 11.5273 (9), 13.4634 (10), 8.3956 (6) | 11.42 (2), 8.580 (19), 23.61 (5) | 7.194 (2), 7.285 (3), 22.388 (8) |
α, β, γ (°) | 90, 90, 90 | 90, 94.15 (3), 90 | 90, 90.341 (5), 90 |
V (Å3) | 1302.97 (17) | 2307 (8) | 1173.3 (7) |
Z | 4 | 8 | 4 |
Radiation type | Mo Kα | Synchrotron, λ = 0.68890 Å | Mo Kα |
µ (mm−1) | 0.24 | 0.25 | 0.28 |
Crystal size (mm) | 0.26 × 0.19 × 0.04 | 0.10 × 0.03 × 0.01 | 0.26 × 0.12 × 0.05 |
Data collection | |||
Diffractometer | Rigaku Saturn724+ (2x2 bin mode) diffractometer | CrystalLogic diffractometer | Rigaku Saturn724+ (2x2 bin mode) diffractometer |
Absorption correction | Multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | Multi-scan (CrystalClear-SM Expert; Rigaku, 2011) | Multi-scan (CrystalClear-SM Expert; Rigaku, 2011) |
Tmin, Tmax | 0.942, 0.991 | 0.975, 0.998 | 0.931, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11531, 2731, 2657 | 10806, 4493, 2445 | 6865, 2063, 1977 |
Rint | 0.026 | 0.150 | 0.016 |
(sin θ/λ)max (Å−1) | 0.649 | 0.644 | 0.595 |
Refinement | |||
R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.064, 1.06 | 0.119, 0.366, 1.06 | 0.027, 0.071, 1.07 |
No. of reflections | 2731 | 4493 | 2063 |
No. of parameters | 156 | 259 | 146 |
No. of restraints | 1 | 0 | 0 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.25, −0.15 | 0.67, −0.67 | 0.25, −0.24 |
Absolute structure | Flack, (1983) | ? | ? |
Absolute structure parameter | 0.06 (5) | ? | ? |
Computer programs: CrystalClear-SM Expert (Rigaku, 2011), OSCAIL (McArdle et al., 2004) and SHELXS97 (Sheldrick, 2008), OSCAIL (McArdle et al., 2004) and SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).
Cg1 is the centroid of the pyridine ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1i | 0.88 | 2.01 | 2.8399 (15) | 157 |
C16—H16···Cg1ii | 0.95 | 2.97 | 3.7489 (18) | 141 |
Symmetry codes: (i) −x+1/2, y, z+1/2; (ii) −x+1, −y+1, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2A—H2A···O1B | 0.88 | 2.02 | 2.862 (9) | 160 |
N2B—H2B···O1Ai | 0.88 | 2.03 | 2.869 (9) | 159 |
Symmetry code: (i) x, y+1, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2 | 0.98 | 1.83 | 2.8096 (16) | 176 |
O23—H23···O3 | 0.84 | 1.85 | 2.6906 (17) | 177 |
O3—H3B···O1i | 0.80 | 2.00 | 2.7966 (15) | 178 |
O3—H3A···O23ii | 0.89 | 1.84 | 2.7200 (15) | 170 |
O2—H2A···N11iii | 0.83 | 2.04 | 2.8449 (17) | 164 |
C14—H14···O3 | 0.95 | 2.37 | 3.3122 (19) | 174 |
C21—H21A···O1 | 0.99 | 2.48 | 2.8208 (17) | 100 |
Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) −x+3/2, y+1/2, −z+1/2; (iii) −x+1, −y+1, −z+1. |
(I) | (IIA) | (IIB) | (III) | |
O1—C1—C13—C14 | -139.12 (13) | 138.7 (6) | -128.7 (7) | -120.22 (14) |
N2—C1—C13—C14 | 39.88 (17) | -40.7 (8) | 50.7 (8) | 59.14 (16) |
O1—C1—C13—C12 | 38.15 (17) | -40.9 (8) | 47.7 (8) | 57.58 (17) |
N2—C1—C13—C12 | -142.85 (11) | 139.7 (6) | -132.9 (6) | -123.06 (13) |
The angles are the equivalent torsion angles for each molecule. In (IIA) and (IIB), C21 is labelled as C3A and C3B, respectively. |
(IV) | (V) | (VI) | (VII) | |
O1—C1—C13—C14 | 22.27 (19) | 19.7 (2) | -30.87 | -148.37 (18) |
N2—C1—C13—C14 | -157.12 (12) | -158.21 (16) | 149.63' | 29.5 (3) |
O1—C1—C13—C12 | -156.49 (13) | -158.93 (18) | 146.37 | 26.6 (3) |
N2—C1—C13—C12 | -142.85 (18) | 23.2 (2) | -36.12' | -155.55 (18) |
The angles are the equivalent torsion angles for each molecule as for the current compounds. |
Tuberculosis (TB) is the second greatest contributor among infectious diseases to adult mortality, causing approximately 1.4 million deaths worldwide in 2010 (WHO, 2010). While heteroaromatic amides, such as nicotinamide (3-amidopyridine) and pyrazinamide (2-amidopyrazine) as well as heteroaromatic thioamides, such as thioisonicotinamide (3- thioamidopyridine), are well established anti-TB agents, there is a need for new drugs in particular to combat the emergence of resistant strains to current treatments (de Souza, 2006, 2012; Gonçalves et al., 2012). In continuation of our studies of amidopyridines and related compounds (de Souza et al., 2005; Cuffini et al., 2006; Wardell et al., 2007a,b, 2008), we now report the structures of the three N-alkyl-2-(methylsulfanyl)nicotinamide derivatives, namely N-cyclohexyl-2-(methylsulfanyl)nicotinamide, (I), N-isopropyl-2-(methylsulfanyl)nicotinamide, (II), and N-(2-hydroxyethyl)-2-(methylsulfanyl)nicotinamide dihydrate, (III), shown in Scheme 1. The Scheme also gives details of four related compounds, (IV)–(VII), and gives details of the dihedral angles between the amide group and the heterocyclic ring, as well as highlighting their conformation with respect to each other. Compounds (I)–(III) have been synthesized for an anti-TB activity study, the results of which will be published elsewhere.
In N-cyclohexyl-2-(methylsulfanyl)nicotinamide, (I) (Fig. 1), the cyclohexyl ring adopts a chair conformation. In N-isopropyl-2-(methylsulfanyl)nicotinamide, (II) (Fig. 2), there are two molecules (A and B) in the asymmetric unit which were chosen to form a hydrogen-bonded pair. The results of a quaternion fit of the non-H atoms with MOLFIT in PLATON (Mackay, 1984; Spek, 2009), indicates that B inverted on to A, with a fit rotation angle of -166.88°, and gives r.m.s. deviations of 0.142 (unweighted) and 0.180 (weighted) for 14 atoms. N-(2-Hydroxyethyl)-2-(methylsulfanyl)nicotinamide dihydrate, (III) (Fig. 3), crystallizes with two water molecules in the asymmetric unit.
The steric hindrance imposed by the methylsulfanyl substituent at the 2-position of the pyridine ring is reflected, as expected, by a relatively high torsion for this ring with respect to the amide group. Considering that methylsulfanyl is a soft acceptor it is reasonable to assume that conformational changes imposed by the group will be similar in solid and in aqueous environments.
The dihedral angles in compounds (I)–(III) between the mean plane of the heterocyclic ring and that of the amide group (defined by atoms C1, O1 and N2) can be compared with those of similar compounds without the methylsulfanyl substituent on C2, using data derived from the Cambridge Structural Database (CSD, Version 5.34; Allen, 2002). Relevant compounds are N-cyclohexylnicotinide, (IV) (Li, 2010), which is the nonsubstituted derivative of (I), N-ethylnicotinamide, (V) (Srikrishnan & Parthasarathy, 1990), and (S)-N-(α-methylbenzyl)nicotinamide, (VI) (Little & Morimoto, 1981), which are similar to (II), as well as N-(pyridin-3-ylcarbonyl)glycine, (VII) (Krishnaswamy et al., 1987). Such comparisons show that the methylsulfanyl group affects the degree of twist of the pyridine ring and thus the relative position of the heteroatom with respect to the amide. These are conformational aspects that may affect the docking to the receptor and thus the pharmacological activity of the substances described here. The values for the dihedral angles between the amide group and the pyridine rings are shown in the schematic. The dihedral angles, taken in conjunction with the values for the torsion angles about the C1—C11 bond in Tables 1 and 2, clearly indicate that the presence of the methylsulfanyl group results in changes in the orientation of the heterocyclic ring with respect to the amide group. The dihedral angles for the unsubstituted compounds are in the range 20–35°, which have lower angular values than the range of 40–60° for compounds with the methylsulfanyl substituent. The presence of an methylsulfanyl sustituent at the 2-position also conditions the direction of rotation of the ring. The magnitudes of the torsion angles for compounds (I)–(III), around the C1—C11 bond (Table 1), indicate that, in order for the methylsulfanyl group to avoid the proximity of the N—H of the amide group a clockwise rotation takes place such that the pyridine heteroatom sits in a cis position with respect to the O atom of the carbonyl group. This contrasts with the situation in compounds with unsubstituted 2-positions, in which the amide O atom is trans with respect to atom C2 of the pyridine ring, as a result of the anticlockwise rotation of the pyridine ring. These differences are highlighted in Scheme 1.
The S atom of the methylsulfanyl group is a very weak electron acceptor and is not expected to enter into an intramolecular interaction with the amino H atom of the amide group. Such intramolecular interactions can be observed with strong electron-acceptor substituents at 2-position of the pyridine ring. In N-(2,4-difluorophenyl)-2-[3-(trifluorophenyl)phenoxy]pyridine-3-carboxamide (CSD refcode; ZIKXEW; Pèpe, et al., 1995), there is an intramolecular hydrogen bond between the amide N atom and the phenoxy O atom [N—H = 0.93 (4) Å, H···O = 1.76 (4) Å, N···O = 2.649 (4) Å and N—H···O = 160 (3)°]; the dihedral angle between the mean planes of the pyrimidine ring and the amide group is 4.6 (4)°.
The main factor affecting the conformation of molecules containing the amide group is the presence of intra- and intermolecular hydrogen bonding. One common supramolecular structure found in compounds with amide groups is the formation of C4 chains (Bernstein et al., 1995) via intermolecular N—H···O═C—NH··· hydrogen bonds. Another common supramolecular structure, mentioned below, involves the formation of intermolecular amide–pyridine N—H···N hydrogen bonds. While these supramolecular structures are common, they may not occur in the presence of other strong acceptors, e.g. by the water molecules in (III). All the other structures discussed above do contain these C4 chains.
In (I), molecules are linked by N—H···O hydrogen bonds to form C(4) chains (Bernstein et al., 1995), generated by the glide-plane axis at x = 1/4 and with translations parallel to the c axis (Fig. 4 and Table 3). C16—H16···Cg1(-x+1, -y+1, z+1/2) interactions (Cg1 is the centroid of the pyridine ring) link these chains into a three-dimensional network (Fig. 5). There are no other intermolecular interactions.
In (II), molecules A and B are linked by N—H···O hydrogen bonds within the selected asymmetric unit (Table 4). These pairs are then linked to further pairs of molecules by unit-cell translation along the b axis to form a C(8) chain (Bernstein et al., 1995) (Fig. 6). There are no other intermolecular interactions.
In (III), the asymmetric unit was selected so that the N—H and O—H donors formed hydrogen bonds with the water molecules via N2—H2···O2 and O23—H23···O3 hydrogen bonds within that unit (Table 5). Having so many donors and acceptors available leads to a complex supramolecular structure which is best described by considering the several substructures.
In (III), nicotinamide molecules and hydrate atom O2 form two centrosymmetric R22(16) rings (Bernstein et al., 1995), one centred on the centre of symmetry at (1/2, 1/2, 1/2) and the other at (0, 1/2, 1/2). In the first of these, the O2—H2A···N11 hydrogen bond links the asymmetric unit and its centrosymmetric counterpart at (-x+1, -y+1, -z+1) to form the ring. In the second of these, the water molecules at (-x+1, -y+1, -z+1) and (x-1, y, z) act as hydrogen donors, via H2A, to atom N11 at (x, y, z) and (-x+1, -y+1, -z+1), respectively, and via H2B to atom O1 at (-x+1, -y+1, -z+1) and (x, y, z), respectively, to form the ring. These rings alternate within a ladder structure which runs parallel to the a axis (Fig. 7). There is a π–π interaction between the pyrimidine rings in the first of these rings, in which the centroid–centroid distance between these pyrimidine rings which lie across the centre of symmetry at (1/2, 1/2, 1/2) is 3.5839 (16) Å, the perpendicular distance between the rings is 3.3083 (5) Å and the slippage is 1.378 Å, so supplementing this substructure. Water molecule O3 is hydrogen bonded to atom O23 via atom H23 in the asymmetric unit, as mentioned above. The action of the screw axis at (3/4, y, 1/4) produces a zigzag C22(4) chain (Bernstein et al., 1995), which runs parallel to the b axis. Atom O3 acts as a donor via H3A to atom O23 at (-x+3/2, y+1/2, -z+1/2) and this links via H23 to atom O3 in the same asymmetric residue unit so forming the chain (Fig. 8). This water molecule also acts as a hydrogen-bond donors to atoms O1 and O23. C22(9) chains (Bernstein et al., 1995) are thus produced along the a axis linking molecules at (-x+1/2, y+1/2, -z+1/2), (-x+3/2, y+1/2, -z+1/2) etc. via water molecules at (x, y, z) and at unit-cell translations along the a axis (Fig. 9). These two interactions combine to form a sheet of R66(20) rings (Bernstein et al., 1995) (Fig. 10). A packing diagram involving all these substructures is shown in Fig. 11. All potential strong hydrogen-bond donors and acceptors are utilized in the building of the supramolecular structure.