Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104031713/sk1788sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270104031713/sk1788Isup2.hkl |
CCDC reference: 263035
A solution of (IV) (0.54 g, 2.53 mmol), phosphoryl oxychloride (20 ml) and phosphorus pentachloride (3.00 g, 14.38 mmol) was refluxed for 18 h under N2. The cooled resulting solution was poured onto ice-water (40 ml) and neutralized with NH4OH until the pH was 7. The precipitate was collected by filtration, washed with water, dried and purified by silica-gel chromatography with hexane/ethyl acetate (4:1). Single crystals of (I) suitable for X-ray data collection were obtained by slow evaporation from a hexane/ethyl acetate solution (4:1) (Yield 0.80 g, 85%). M.p. 493 K (yellow crystalline solid). 1H NMR (CDCl3): δ 7.65 (d, J=4.8 Hz, 1H), 8.63 (d, J=4.8 Hz, 1H); 13C NMR (CDCl3): δ 116.69, 119.10, 128.23, 131.05, 137.05, 143.31, 144.59, 148.35, 148.70, 153.17, 156.31. Analysis calculated for C11H2Cl5N3O: C 35.75, H 0.54, N 11.37; found: C 35.61, H 0.54, N 11.25%.
H atoms were placed in idealized positions and treated using a riding model, with C—H distances of 0.95 Å and with Ueq(H) fixed at 1.2Uiso of the parent atom.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: SET4 in CAD-4 EXPRESS; data reduction: HELENA (Spek, 1996); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
C11H2Cl5N3O | F(000) = 1456 |
Mr = 369.41 | Dx = 1.947 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 25 reflections |
a = 16.453 (3) Å | θ = 10.0–14.0° |
b = 7.173 (1) Å | µ = 1.15 mm−1 |
c = 22.368 (3) Å | T = 193 K |
β = 107.26 (2)° | Irregular block, yellow |
V = 2520.9 (7) Å3 | 0.50 × 0.30 × 0.23 mm |
Z = 8 |
Enraf–Nonius CAD-4 diffractometer | 3857 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.089 |
Graphite monochromator | θmax = 25.1°, θmin = 1.3° |
ω–2θ scans | h = −18→19 |
Absorption correction: ψ scan (North et al., 1968) | k = −8→0 |
Tmin = 0.597, Tmax = 0.777 | l = −26→0 |
4607 measured reflections | 3 standard reflections every 200 reflections |
4476 independent reflections | intensity decay: 1% |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.111 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0703P)2 + 2.546P] where P = (Fo2 + 2Fc2)/3 |
4476 reflections | (Δ/σ)max = 0.001 |
361 parameters | Δρmax = 0.50 e Å−3 |
0 restraints | Δρmin = −0.41 e Å−3 |
C11H2Cl5N3O | V = 2520.9 (7) Å3 |
Mr = 369.41 | Z = 8 |
Monoclinic, P21/c | Mo Kα radiation |
a = 16.453 (3) Å | µ = 1.15 mm−1 |
b = 7.173 (1) Å | T = 193 K |
c = 22.368 (3) Å | 0.50 × 0.30 × 0.23 mm |
β = 107.26 (2)° |
Enraf–Nonius CAD-4 diffractometer | 3857 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.089 |
Tmin = 0.597, Tmax = 0.777 | 3 standard reflections every 200 reflections |
4607 measured reflections | intensity decay: 1% |
4476 independent reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.111 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.50 e Å−3 |
4476 reflections | Δρmin = −0.41 e Å−3 |
361 parameters |
x | y | z | Uiso*/Ueq | ||
C1A | 0.75977 (17) | 0.7134 (4) | 0.56516 (13) | 0.0176 (5) | |
C2 | 0.90251 (18) | 0.6646 (4) | 0.60516 (14) | 0.0245 (6) | |
H2 | 0.9524 | 0.6660 | 0.6400 | 0.029* | |
C3 | 0.91034 (18) | 0.6200 (4) | 0.54716 (14) | 0.0242 (6) | |
H3 | 0.9645 | 0.5924 | 0.5423 | 0.029* | |
C4 | 0.83810 (18) | 0.6160 (4) | 0.49616 (13) | 0.0211 (6) | |
C4A | 0.75803 (17) | 0.6707 (4) | 0.50275 (12) | 0.0179 (6) | |
C5 | 0.67701 (18) | 0.6784 (4) | 0.45435 (12) | 0.0205 (6) | |
C6 | 0.60410 (17) | 0.7005 (4) | 0.47013 (12) | 0.0196 (6) | |
C6A | 0.60449 (17) | 0.7389 (4) | 0.53376 (13) | 0.0196 (6) | |
C8 | 0.53175 (18) | 0.8082 (4) | 0.60275 (14) | 0.0234 (6) | |
C9 | 0.60317 (18) | 0.8618 (4) | 0.64815 (13) | 0.0218 (6) | |
C10 | 0.68507 (17) | 0.8530 (4) | 0.63736 (12) | 0.0197 (6) | |
N1 | 0.82829 (14) | 0.7057 (3) | 0.61462 (11) | 0.0215 (5) | |
N7 | 0.53147 (15) | 0.7565 (4) | 0.54511 (11) | 0.0240 (5) | |
N10A | 0.68302 (14) | 0.7648 (3) | 0.57859 (10) | 0.0179 (5) | |
O1 | 0.74979 (12) | 0.9158 (3) | 0.67339 (9) | 0.0258 (5) | |
Cl1 | 0.85216 (5) | 0.53137 (12) | 0.42775 (3) | 0.0303 (2) | |
Cl2 | 0.66924 (5) | 0.66533 (13) | 0.37632 (3) | 0.0329 (2) | |
Cl3 | 0.50657 (4) | 0.69676 (11) | 0.41527 (3) | 0.02813 (19) | |
Cl4 | 0.43414 (5) | 0.81213 (14) | 0.61592 (4) | 0.0369 (2) | |
Cl5 | 0.60123 (5) | 0.95300 (11) | 0.71853 (3) | 0.02978 (19) | |
C11A | 0.07727 (17) | 0.7403 (4) | 0.30104 (12) | 0.0177 (5) | |
C12 | −0.06641 (18) | 0.7132 (4) | 0.26181 (13) | 0.0230 (6) | |
H12 | −0.1150 | 0.6736 | 0.2293 | 0.028* | |
C13 | −0.07854 (17) | 0.7903 (4) | 0.31505 (13) | 0.0211 (6) | |
H13 | −0.1344 | 0.8114 | 0.3177 | 0.025* | |
C14 | −0.00813 (18) | 0.8365 (4) | 0.36449 (12) | 0.0193 (6) | |
C14A | 0.07479 (17) | 0.8033 (4) | 0.36041 (12) | 0.0177 (6) | |
C15 | 0.15543 (17) | 0.8095 (4) | 0.41023 (12) | 0.0198 (6) | |
C16 | 0.22768 (17) | 0.7500 (4) | 0.39953 (12) | 0.0191 (6) | |
C16A | 0.23084 (17) | 0.6974 (4) | 0.33785 (13) | 0.0179 (6) | |
C18 | 0.30526 (17) | 0.6132 (4) | 0.27137 (13) | 0.0208 (6) | |
C19 | 0.23984 (18) | 0.6529 (4) | 0.21984 (13) | 0.0207 (6) | |
C20 | 0.16181 (17) | 0.7304 (4) | 0.22555 (12) | 0.0198 (6) | |
N11 | 0.01005 (15) | 0.6918 (4) | 0.25380 (11) | 0.0209 (5) | |
N17 | 0.30359 (15) | 0.6425 (4) | 0.33061 (11) | 0.0223 (5) | |
N20A | 0.15679 (14) | 0.7166 (3) | 0.28922 (10) | 0.0181 (5) | |
O2 | 0.10672 (12) | 0.8050 (3) | 0.18439 (9) | 0.0271 (5) | |
Cl6 | −0.02940 (5) | 0.93633 (13) | 0.42822 (3) | 0.0336 (2) | |
Cl7 | 0.16148 (4) | 0.88150 (11) | 0.48464 (3) | 0.02616 (18) | |
Cl8 | 0.32331 (4) | 0.74718 (11) | 0.45735 (3) | 0.02521 (18) | |
Cl9 | 0.40059 (4) | 0.53309 (12) | 0.26428 (3) | 0.0308 (2) | |
Cl10 | 0.24718 (5) | 0.63364 (12) | 0.14515 (3) | 0.0305 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1A | 0.0154 (13) | 0.0173 (13) | 0.0194 (13) | 0.0000 (10) | 0.0042 (11) | 0.0017 (11) |
C2 | 0.0136 (13) | 0.0326 (17) | 0.0240 (15) | −0.0001 (12) | 0.0004 (11) | 0.0006 (12) |
C3 | 0.0152 (13) | 0.0316 (16) | 0.0262 (15) | −0.0012 (12) | 0.0070 (11) | −0.0007 (13) |
C4 | 0.0217 (14) | 0.0242 (14) | 0.0196 (14) | −0.0024 (12) | 0.0095 (11) | −0.0011 (12) |
C4A | 0.0171 (13) | 0.0186 (13) | 0.0170 (13) | −0.0025 (11) | 0.0034 (11) | 0.0010 (10) |
C5 | 0.0221 (14) | 0.0242 (14) | 0.0139 (13) | −0.0017 (12) | 0.0030 (11) | 0.0016 (11) |
C6 | 0.0170 (13) | 0.0235 (14) | 0.0150 (13) | −0.0015 (11) | −0.0004 (11) | 0.0015 (11) |
C6A | 0.0148 (13) | 0.0228 (14) | 0.0185 (14) | −0.0005 (11) | 0.0008 (11) | 0.0023 (11) |
C8 | 0.0165 (14) | 0.0300 (16) | 0.0239 (15) | 0.0005 (12) | 0.0063 (11) | −0.0002 (12) |
C9 | 0.0201 (14) | 0.0291 (15) | 0.0163 (13) | 0.0011 (12) | 0.0057 (11) | 0.0000 (12) |
C10 | 0.0196 (14) | 0.0223 (14) | 0.0160 (13) | 0.0011 (11) | 0.0035 (11) | 0.0025 (11) |
N1 | 0.0154 (11) | 0.0287 (13) | 0.0178 (12) | 0.0004 (10) | 0.0009 (9) | −0.0011 (10) |
N7 | 0.0150 (11) | 0.0344 (14) | 0.0205 (12) | −0.0005 (10) | 0.0023 (9) | −0.0009 (11) |
N10A | 0.0136 (11) | 0.0242 (12) | 0.0144 (11) | −0.0004 (9) | 0.0018 (9) | 0.0015 (9) |
O1 | 0.0171 (10) | 0.0345 (12) | 0.0230 (11) | −0.0005 (9) | 0.0015 (8) | −0.0074 (9) |
Cl1 | 0.0274 (4) | 0.0440 (5) | 0.0226 (4) | 0.0000 (3) | 0.0123 (3) | −0.0066 (3) |
Cl2 | 0.0282 (4) | 0.0561 (5) | 0.0136 (3) | −0.0004 (4) | 0.0050 (3) | −0.0004 (3) |
Cl3 | 0.0175 (3) | 0.0431 (4) | 0.0184 (3) | 0.0006 (3) | −0.0031 (3) | −0.0009 (3) |
Cl4 | 0.0181 (4) | 0.0617 (6) | 0.0335 (4) | −0.0039 (3) | 0.0118 (3) | −0.0096 (4) |
Cl5 | 0.0284 (4) | 0.0405 (4) | 0.0224 (4) | −0.0019 (3) | 0.0106 (3) | −0.0081 (3) |
C11A | 0.0160 (13) | 0.0226 (14) | 0.0141 (13) | −0.0005 (11) | 0.0038 (10) | 0.0009 (11) |
C12 | 0.0163 (13) | 0.0330 (16) | 0.0165 (13) | −0.0022 (12) | −0.0001 (11) | 0.0019 (12) |
C13 | 0.0147 (13) | 0.0266 (15) | 0.0220 (14) | 0.0005 (11) | 0.0056 (11) | 0.0025 (12) |
C14 | 0.0209 (14) | 0.0225 (14) | 0.0159 (13) | 0.0016 (11) | 0.0075 (11) | 0.0010 (11) |
C14A | 0.0153 (13) | 0.0212 (14) | 0.0156 (13) | −0.0015 (11) | 0.0033 (10) | 0.0013 (11) |
C15 | 0.0208 (14) | 0.0259 (15) | 0.0112 (13) | −0.0036 (11) | 0.0024 (11) | 0.0011 (11) |
C16 | 0.0151 (13) | 0.0242 (14) | 0.0144 (13) | −0.0011 (11) | −0.0011 (10) | 0.0026 (11) |
C16A | 0.0150 (13) | 0.0198 (13) | 0.0170 (13) | −0.0009 (11) | 0.0016 (10) | 0.0035 (11) |
C18 | 0.0152 (13) | 0.0258 (15) | 0.0218 (14) | 0.0016 (11) | 0.0059 (11) | 0.0000 (12) |
C19 | 0.0219 (14) | 0.0233 (15) | 0.0173 (14) | −0.0006 (11) | 0.0067 (11) | −0.0004 (11) |
C20 | 0.0175 (13) | 0.0257 (15) | 0.0160 (14) | −0.0023 (11) | 0.0046 (11) | 0.0012 (11) |
N11 | 0.0163 (11) | 0.0299 (13) | 0.0146 (11) | −0.0008 (10) | 0.0015 (9) | 0.0015 (10) |
N17 | 0.0157 (11) | 0.0309 (13) | 0.0190 (12) | 0.0009 (10) | 0.0031 (9) | 0.0017 (10) |
N20A | 0.0145 (11) | 0.0263 (12) | 0.0121 (11) | 0.0015 (9) | 0.0018 (9) | 0.0012 (9) |
O2 | 0.0179 (10) | 0.0468 (13) | 0.0154 (10) | 0.0059 (9) | 0.0031 (8) | 0.0083 (9) |
Cl6 | 0.0244 (4) | 0.0543 (5) | 0.0250 (4) | −0.0026 (3) | 0.0117 (3) | −0.0145 (3) |
Cl7 | 0.0270 (4) | 0.0366 (4) | 0.0130 (3) | −0.0005 (3) | 0.0031 (3) | −0.0047 (3) |
Cl8 | 0.0167 (3) | 0.0372 (4) | 0.0161 (3) | −0.0011 (3) | −0.0037 (3) | 0.0012 (3) |
Cl9 | 0.0207 (4) | 0.0441 (5) | 0.0282 (4) | 0.0090 (3) | 0.0083 (3) | 0.0023 (3) |
Cl10 | 0.0232 (4) | 0.0531 (5) | 0.0170 (3) | 0.0056 (3) | 0.0085 (3) | 0.0005 (3) |
C1A—N1 | 1.326 (4) | C11A—N11 | 1.329 (4) |
C1A—C4A | 1.421 (4) | C11A—C14A | 1.415 (4) |
C1A—N10A | 1.430 (4) | C11A—N20A | 1.420 (3) |
C2—N1 | 1.333 (4) | C12—N11 | 1.331 (4) |
C2—C3 | 1.379 (4) | C12—C13 | 1.380 (4) |
C2—H2 | 0.9500 | C12—H12 | 0.9500 |
C3—C4 | 1.382 (4) | C13—C14 | 1.384 (4) |
C3—H3 | 0.9500 | C13—H13 | 0.9500 |
C4—C4A | 1.423 (4) | C14—C14A | 1.414 (4) |
C4—Cl1 | 1.724 (3) | C14—Cl6 | 1.721 (3) |
C4A—C5 | 1.448 (4) | C14A—C15 | 1.458 (4) |
C5—C6 | 1.357 (4) | C15—C16 | 1.350 (4) |
C5—Cl2 | 1.714 (3) | C15—Cl7 | 1.717 (3) |
C6—C6A | 1.448 (4) | C16—C16A | 1.446 (4) |
C6—Cl3 | 1.707 (3) | C16—Cl8 | 1.715 (3) |
C6A—N7 | 1.306 (4) | C16A—N17 | 1.315 (4) |
C6A—N10A | 1.393 (3) | C16A—N20A | 1.378 (3) |
C8—N7 | 1.340 (4) | C18—N17 | 1.350 (4) |
C8—C9 | 1.361 (4) | C18—C19 | 1.354 (4) |
C8—Cl4 | 1.717 (3) | C18—Cl9 | 1.721 (3) |
C9—C10 | 1.439 (4) | C19—C20 | 1.439 (4) |
C9—Cl5 | 1.714 (3) | C19—Cl10 | 1.716 (3) |
C10—O1 | 1.215 (3) | C20—O2 | 1.209 (3) |
C10—N10A | 1.450 (4) | C20—N20A | 1.454 (3) |
N1—C1A—C4A | 125.1 (3) | N11—C11A—C14A | 125.5 (2) |
N1—C1A—N10A | 114.9 (2) | N11—C11A—N20A | 114.6 (2) |
C4A—C1A—N10A | 120.0 (2) | C14A—C11A—N20A | 119.9 (2) |
N1—C2—C3 | 123.1 (3) | N11—C12—C13 | 123.1 (3) |
N1—C2—H2 | 118.4 | N11—C12—H12 | 118.4 |
C3—C2—H2 | 118.4 | C13—C12—H12 | 118.4 |
C2—C3—C4 | 118.9 (3) | C12—C13—C14 | 119.0 (3) |
C2—C3—H3 | 120.5 | C12—C13—H13 | 120.5 |
C4—C3—H3 | 120.5 | C14—C13—H13 | 120.5 |
C3—C4—C4A | 120.3 (3) | C13—C14—C14A | 120.2 (2) |
C3—C4—Cl1 | 115.5 (2) | C13—C14—Cl6 | 115.7 (2) |
C4A—C4—Cl1 | 124.1 (2) | C14A—C14—Cl6 | 124.1 (2) |
C1A—C4A—C4 | 114.3 (2) | C14—C14A—C11A | 114.3 (2) |
C1A—C4A—C5 | 118.2 (2) | C14—C14A—C15 | 128.4 (2) |
C4—C4A—C5 | 127.5 (2) | C11A—C14A—C15 | 117.0 (2) |
C6—C5—C4A | 119.9 (2) | C16—C15—C14A | 120.3 (2) |
C6—C5—Cl2 | 117.8 (2) | C16—C15—Cl7 | 117.8 (2) |
C4A—C5—Cl2 | 122.2 (2) | C14A—C15—Cl7 | 121.9 (2) |
C5—C6—C6A | 122.1 (2) | C15—C16—C16A | 122.3 (2) |
C5—C6—Cl3 | 121.8 (2) | C15—C16—Cl8 | 122.0 (2) |
C6A—C6—Cl3 | 116.0 (2) | C16A—C16—Cl8 | 115.6 (2) |
N7—C6A—N10A | 123.9 (3) | N17—C16A—N20A | 123.8 (2) |
N7—C6A—C6 | 118.3 (2) | N17—C16A—C16 | 119.2 (2) |
N10A—C6A—C6 | 117.8 (2) | N20A—C16A—C16 | 117.0 (2) |
N7—C8—C9 | 123.5 (3) | N17—C18—C19 | 124.1 (3) |
N7—C8—Cl4 | 115.7 (2) | N17—C18—Cl9 | 115.3 (2) |
C9—C8—Cl4 | 120.8 (2) | C19—C18—Cl9 | 120.5 (2) |
C8—C9—C10 | 120.4 (3) | C18—C19—C20 | 120.7 (2) |
C8—C9—Cl5 | 123.1 (2) | C18—C19—Cl10 | 123.0 (2) |
C10—C9—Cl5 | 116.4 (2) | C20—C19—Cl10 | 116.1 (2) |
O1—C10—C9 | 123.5 (3) | O2—C20—C19 | 126.2 (2) |
O1—C10—N10A | 122.9 (2) | O2—C20—N20A | 121.9 (2) |
C9—C10—N10A | 113.6 (2) | C19—C20—N20A | 111.8 (2) |
C1A—N1—C2 | 118.0 (2) | C11A—N11—C12 | 117.4 (2) |
C6A—N7—C8 | 118.2 (2) | C16A—N17—C18 | 116.9 (2) |
C6A—N10A—C1A | 120.2 (2) | C16A—N20A—C11A | 120.8 (2) |
C6A—N10A—C10 | 118.5 (2) | C16A—N20A—C20 | 119.1 (2) |
C1A—N10A—C10 | 121.2 (2) | C11A—N20A—C20 | 119.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O2i | 0.95 | 2.45 | 3.308 (3) | 151 |
C12—H12···O1ii | 0.95 | 2.30 | 3.219 (3) | 164 |
Symmetry codes: (i) x+1, −y+3/2, z+1/2; (ii) x−1, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C11H2Cl5N3O |
Mr | 369.41 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 193 |
a, b, c (Å) | 16.453 (3), 7.173 (1), 22.368 (3) |
β (°) | 107.26 (2) |
V (Å3) | 2520.9 (7) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 1.15 |
Crystal size (mm) | 0.50 × 0.30 × 0.23 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.597, 0.777 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4607, 4476, 3857 |
Rint | 0.089 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.111, 1.05 |
No. of reflections | 4476 |
No. of parameters | 361 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.50, −0.41 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), SET4 in CAD-4 EXPRESS, HELENA (Spek, 1996), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.
C1A—N10A | 1.430 (4) | C11A—N20A | 1.420 (3) |
C6A—N7 | 1.306 (4) | C16A—N17 | 1.315 (4) |
C6A—N10A | 1.393 (3) | C16A—N20A | 1.378 (3) |
C8—N7 | 1.340 (4) | C18—N17 | 1.350 (4) |
C10—N10A | 1.450 (4) | ||
C1A—C4A—C4 | 114.3 (2) | C6A—N10A—C1A | 120.2 (2) |
C1A—C4A—C5 | 118.2 (2) | C6A—N10A—C10 | 118.5 (2) |
C4—C4A—C5 | 127.5 (2) | C1A—N10A—C10 | 121.2 (2) |
N7—C6A—N10A | 123.9 (3) | C11A—N11—C12 | 117.4 (2) |
N7—C6A—C6 | 118.3 (2) | C16A—N17—C18 | 116.9 (2) |
N10A—C6A—C6 | 117.8 (2) | C16A—N20A—C11A | 120.8 (2) |
C1A—N1—C2 | 118.0 (2) | C16A—N20A—C20 | 119.1 (2) |
C6A—N7—C8 | 118.2 (2) | C11A—N20A—C20 | 119.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O2i | 0.95 | 2.45 | 3.308 (3) | 151 |
C12—H12···O1ii | 0.95 | 2.30 | 3.219 (3) | 164 |
Symmetry codes: (i) x+1, −y+3/2, z+1/2; (ii) x−1, −y+3/2, z−1/2. |
A variety of pyrimido[1,2-a]1,8-naphthyridines are of biological interest because of their antimicrobial (Harper & Wibberley, 1971) and antihypertensive activities (Ferrarini et al., 1990). Naphthyridines containing the pyrimide moiety, such as pyrimido[2,1-f]1,6-naphthyridines, have shown tracheal muscle relaxation activity (Sasaki et al., 1999). We have already investigated extensively the use of 5-arylaminomethylene Meldrum's acid derivatives as important key intermediates for the synthesis of azaheterocyclic compounds with potential biological activity (Silva et al., 2002). As an extension of this methodology, we have prepared naphthyridines by a thermal decarboxylation/cyclization process of the bis-adduct (III) in refluxing diphenyl ether according to the method reported by Cassis et al. (1985); this processs leads exclusively to 4,10-dioxo-1H-Pyrimido[1,2-a]-1,8-naphthyridine, (IV). Although two possible isomers could be formed, the preferential formation of the angular product (IV) was established from 1H and 13C NMR data.
Halonaphthyridines are prone to nucleophilic aromatic substitution; this makes them important precursors for the introduction of a wide variety of groups containing nucleophilic heteroatoms (OR, SR, NHR and others). Halonaphthyridines can be obtained? by several methods, including direct halogenation (Lowe, 1982) of naphthyridines, the Meisenheimer reaction of their N-oxides (Paudler & Pokorny, 1971) and the treatment of naphthyridinones with PCl5/POCl3 (Brown & Plasz, 1971).
As our methodology for the construction of naphthyridine derivatives is based on the preparation of halonaphthyridines, we allowed compound (IV) to react with phosphoryl chloride and phosphorus pentachoride under the reaction conditions used by Carboni (1970), in order to obtain the monochloro derivative. However, the product was found to be a pentachloro derivative, on the basis of the elemental analysis. The 1H NMR spectrum showed two doublet signals, at 8.63 and 7.65 p.p.m., with J of 4.8 Hz, indicating a vicinal relationship between two H atoms. We could not safely determine the structure from these data, but we were able to obtain crystals of the product suitable for X-ray analysis, which showed the product to be 4,5,6,8,9-pentachloro-10-oxo-pyrimido[1,2-a]1,8-naphthyridine, (I). According to the Cambridge Structural Database (CSD; Version 5.25; Allen, 2002), this type of heterocyclic system is the second example of a crystal structure of a pyrimido[1,2-a]1,8-naphthyridine (Ferrarini et al., 1990).
The asymmetric unit consists of two independent molecules of (I) (Fig. 1). The molecules are chemically identical but they have different structural parameters, as demonstrated by the different bond angles around atoms N10A [C6A—N10A—C10 = 118.5 (2)°, C6A—N10A—C1A = 120.2 (2)° and C1A—N10A—C10 = 121.2 (2)°] and N20A [C16A—N20A—C11A = 120.8 (2)°, C16A—N20A—C20 = 119.1 (2)° and C11A—N20A—C20 = 119.8 (2)°], and by the dihedral angles between the mean planes defined by the rings N1/C2/C3/C4/C4A/C1A and N7/C8/C9/C10/N10A/C6A [15.5 (1)°], and N11/C12/C13/C14/C14A/C11A and N17/C18/C19/C20/N20A/C16A [25.2 (1)°], in molecules 1 and 2, respectively. The torsion angle involving the N—C bond in the non-aromatic conjugated ring [C6—C6A—N10A—C10 = 163.2 (3)°] in molecule 1 is 4.8° greater than that in molecule 2 [C16—C16A—N20A—C20 = 158.5 (3)°]. In addition, the conformational analysis of the ten-membered rings N7/C8/C9/C10/N10A/C1A/C4A/C5/C6/C6A [Q = 0.385 (3) Å] in molecule 1 and N17/C18/C19/C20/N20A/C11A/C14A/C15/C16/C16A [Q = 0.464 (3) Å] in molecule 2 shows a significant difference in the total amplitude of the puckering parameter Q (Cremer & Pople, 1975).
Several forces govern the arrangement of the molecules in the crystal structure of (I). The non-covalent force π–π stacking acts between the aromatic rings N11/C12/C13/C14/C14A/C11A and N1/C2/C3/C4/C4A/C1A, resulting in a dimeric structure (Fig. 2). The geometric parameters are within the acceptable range (Janiak, 2000). The Cg1—Cg2 distance is 4.595 (2) Å (where Cg is the centroid of the ring), whereas the Cg1—H2 distance is 3.287 Å. The perpendicular distance between the planes is 3.727 (2) Å. The slipping angle γ (defined by the Cg1···Cg2 vector and the normal to plane from Cg1 and calculated geometrically) is 35.85° and the dihedral angle between the mean planes of the rings is 14.1 (1)°. These parameters demonstrate that the rings are almost coplanar and indicate that slipped π–π stacking governs the dimer formation. The dimeric structures are connected to one another by several halogen bonds, weak C—H···O interactions, and Cl···O and C···O short contacts, forming an intricate three-dimensional network. These intermolecular contacts have values in the range 3.20–3.45 Å for the Cl—Cl bond and 2.30–2.45 Å for C—H···O interactions. In the Cl···O contact, atoms Cl1 and O2i [symmetry code: (i) 1 − x, y − 0.5, 0.5 − z] are seperated by 3.224 (3) Å. Unexpected and very short C···O intermolecular contacts are also observed, with a C16···O1ii separation of 2.980 (4) Å, and a C16A···O1ii separation of 2.810 (4) Å [symmetry code: (ii) 1 − x, 2 − y, 1 − z], where C16 and C16A are Csp2 atoms. Atom O1 lies 0.252 (5) Å out of the mean plane of the N7/C8/C9/C10/N10A/C6A ring, towards the neighboring C atoms. A similar C···O intermolecular contact has been observed in other crystal structures (Vila et al., 2002). The geometric parameters of these interactions can be obtained from the archived CIF.