Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807019964/cf2100sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807019964/cf2100Isup2.hkl |
CCDC reference: 601660
Compound (I) (m.p. 447.6–448.6 K) was prepared according to a known procedure (Cunha et al., 2007). Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution in CHCl3 at room temperature.
All H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å, and with Uiso(H) = 1.5Ueq(C) for methyl H atoms and Uiso(H) = 1.2Ueq(C) for other atoms. The C18 methyl atom were modelled as a disordered group over two sites with refined occupancies 0.80 (2) and 0.20 (2), and refined with equal displacement parameter constraints. In consequence, the bond length C17–C18 was poorly determined. The whole carboxylate group is possibly disordered by a rotation around the C5–C14 σ-bond, but this could not be modelled reliably.
In continuation of our solid-state studies of bioactive thioxopyrimidine, we performed the crystallographic characterization of the title 4-thioxopyrimidine (I), which exhibited a lowered antifungal but enhanced trypanocidal activities compared to related compounds (Cunha et al., 2007).
The molecule of (I) is depicted in Fig. 1. This derivative differs from those of Parts 1 and 2 by a substituent on the ring atom N1, where (I) has a butyl group instead of a hydroxyethyl group. The conformation of compound (I) is defined by steric effects. The pyrimidine ring is planar with an r.m.s. deviation of 0.022 Å. With reference to this plane, the phenyl ring is rotated by 65.0 (1)°, approaching a gauche conformation. The torsion angles C4—C5—C14—O15 and C20—C19—N1—C6 are -99.3 (4)° and -92.9 (3)°, respectively. Bond lengths are within the expected ranges with the exception of the C2–C7 and C5–C14 bonds which are elongated by an average of 0.035 Å from the formal single bond distance.
It is interesting to note that the crystal packing of compound (I) is maintained by van der Waals forces only; it does not form dimers involving C═O···π-ring interactions as observed in the previous derivatives. It is supposed that the steric inaccessibility due to the long butyl substituent group prevents the pyrimidine ring stacking. The packing is shown in Fig. 2.
For the synthesis, see: Cunha et al. (2007). A butyl group on atom N1 in this structure replaces a hydroxyethyl group in the derivatives described in the preceding papers (Sabino, Lariucci et al., 2007; Sabino, Vencato et al., 2007). Owing to the different chemical nature of the butyl group, the title compound does not pack in the same manner and lacks the intermolecular hydrogen-bond contacts observed in the previous derivatives.
Data collection: CAD-4-PC (Enraf–Nonius, 1993); cell refinement: CAD-4-PC; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999).
C18H22N2O2S | F(000) = 352 |
Mr = 330.45 | Dx = 1.208 Mg m−3 |
Monoclinic, P21 | Cu Kα radiation, λ = 1.54180 Å |
Hall symbol: P 2yb | Cell parameters from 25 reflections |
a = 10.9870 (18) Å | θ = 12.9–40.6° |
b = 7.2840 (14) Å | µ = 1.66 mm−1 |
c = 12.5885 (13) Å | T = 297 K |
β = 115.591 (9)° | Prism, yellow |
V = 908.6 (3) Å3 | 0.35 × 0.25 × 0.05 mm |
Z = 2 |
Enraf–Nonius CAD-4 diffractometer | Rint = 0.047 |
ω/2θ scans | θmax = 67.1°, θmin = 3.9° |
Absorption correction: ψ scan (North et al., 1968) | h = −13→11 |
Tmin = 0.594, Tmax = 0.922 | k = −1→8 |
2129 measured reflections | l = 0→15 |
2034 independent reflections | 2 standard reflections every 120 min |
1907 reflections with I > 2σ(I) | intensity decay: 2% |
Refinement on F2 | w = 1/[σ2(Fo2) + (0.1111P)2 + 0.0314P] where P = (Fo2 + 2Fc2)/3 |
Least-squares matrix: full | (Δ/σ)max < 0.001 |
R[F2 > 2σ(F2)] = 0.052 | Δρmax = 0.28 e Å−3 |
wR(F2) = 0.136 | Δρmin = −0.44 e Å−3 |
S = 1.09 | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
2034 reflections | Extinction coefficient: 0.034 (3) |
214 parameters | Absolute structure: Flack (1983), 270 Friedel pairs |
1 restraint | Absolute structure parameter: 0.10 (3) |
H-atom parameters constrained |
C18H22N2O2S | V = 908.6 (3) Å3 |
Mr = 330.45 | Z = 2 |
Monoclinic, P21 | Cu Kα radiation |
a = 10.9870 (18) Å | µ = 1.66 mm−1 |
b = 7.2840 (14) Å | T = 297 K |
c = 12.5885 (13) Å | 0.35 × 0.25 × 0.05 mm |
β = 115.591 (9)° |
Enraf–Nonius CAD-4 diffractometer | 1907 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.047 |
Tmin = 0.594, Tmax = 0.922 | 2 standard reflections every 120 min |
2129 measured reflections | intensity decay: 2% |
2034 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.136 | Δρmax = 0.28 e Å−3 |
S = 1.09 | Δρmin = −0.44 e Å−3 |
2034 reflections | Absolute structure: Flack (1983), 270 Friedel pairs |
214 parameters | Absolute structure parameter: 0.10 (3) |
1 restraint |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
S | 0.77081 (9) | 0.15710 (13) | 0.75355 (7) | 0.0651 (3) | |
N1 | 0.7310 (2) | 0.5282 (3) | 0.46126 (19) | 0.0458 (5) | |
C2 | 0.7929 (2) | 0.3596 (4) | 0.4803 (2) | 0.0423 (6) | |
N3 | 0.8080 (2) | 0.2499 (4) | 0.5663 (2) | 0.0466 (5) | |
C4 | 0.7614 (3) | 0.3022 (4) | 0.6479 (2) | 0.0463 (6) | |
C5 | 0.7055 (2) | 0.4821 (4) | 0.6357 (2) | 0.0462 (6) | |
C6 | 0.6850 (3) | 0.5898 (4) | 0.5420 (2) | 0.0476 (6) | |
C7 | 0.8475 (2) | 0.2935 (4) | 0.3973 (2) | 0.0435 (6) | |
C8 | 0.7920 (3) | 0.1380 (5) | 0.3314 (2) | 0.0508 (7) | |
H8 | 0.7191 | 0.0806 | 0.3365 | 0.061* | |
C9 | 0.8442 (3) | 0.0673 (6) | 0.2581 (3) | 0.0632 (8) | |
H9 | 0.8066 | −0.0378 | 0.2142 | 0.076* | |
C10 | 0.9521 (3) | 0.1521 (7) | 0.2496 (3) | 0.0665 (9) | |
H10 | 0.9874 | 0.1041 | 0.2002 | 0.08* | |
C11 | 1.0069 (3) | 0.3070 (7) | 0.3139 (3) | 0.0681 (10) | |
H11 | 1.0784 | 0.3652 | 0.3069 | 0.082* | |
C12 | 0.9574 (3) | 0.3781 (5) | 0.3895 (3) | 0.0575 (8) | |
H12 | 0.997 | 0.4814 | 0.4346 | 0.069* | |
C13 | 0.6183 (4) | 0.7740 (6) | 0.5228 (3) | 0.0734 (10) | |
H13A | 0.542 | 0.7765 | 0.4471 | 0.11* | |
H13B | 0.6814 | 0.8674 | 0.5259 | 0.11* | |
H13C | 0.5888 | 0.7963 | 0.5832 | 0.11* | |
C14 | 0.6638 (3) | 0.5473 (5) | 0.7281 (3) | 0.0556 (7) | |
O15 | 0.5505 (2) | 0.5468 (6) | 0.7192 (2) | 0.0825 (9) | |
O16 | 0.7694 (2) | 0.6091 (5) | 0.82076 (18) | 0.0664 (7) | |
C17 | 0.7489 (5) | 0.6655 (11) | 0.9216 (4) | 0.1002 (18) | |
H17A | 0.6863 | 0.7678 | 0.9003 | 0.12* | |
H17B | 0.7103 | 0.565 | 0.9474 | 0.12* | |
C18A | 0.8742 (8) | 0.719 (3) | 1.0149 (7) | 0.154 (6) | 0.807 (19) |
H18A | 0.8707 | 0.7003 | 1.089 | 0.231* | 0.807 (19) |
H18B | 0.8908 | 0.8461 | 1.0063 | 0.231* | 0.807 (19) |
H18C | 0.9455 | 0.6458 | 1.0122 | 0.231* | 0.807 (19) |
C18B | 0.843 (4) | 0.569 (11) | 1.019 (3) | 0.154 (6) | 0.193 (19) |
H18D | 0.8499 | 0.625 | 1.0903 | 0.231* | 0.193 (19) |
H18E | 0.93 | 0.573 | 1.0174 | 0.231* | 0.193 (19) |
H18F | 0.815 | 0.4439 | 1.0157 | 0.231* | 0.193 (19) |
C19 | 0.7021 (3) | 0.6331 (5) | 0.3526 (2) | 0.0546 (7) | |
H19A | 0.778 | 0.6213 | 0.3329 | 0.066* | |
H19B | 0.6928 | 0.762 | 0.367 | 0.066* | |
C20 | 0.5751 (3) | 0.5694 (5) | 0.2488 (2) | 0.0565 (7) | |
H20A | 0.4982 | 0.5836 | 0.2668 | 0.068* | |
H20B | 0.5832 | 0.4404 | 0.2338 | 0.068* | |
C21 | 0.5532 (4) | 0.6817 (7) | 0.1401 (2) | 0.0729 (10) | |
H21A | 0.55 | 0.8108 | 0.1576 | 0.087* | |
H21B | 0.6297 | 0.6638 | 0.1219 | 0.087* | |
C22 | 0.4257 (5) | 0.6321 (9) | 0.0332 (3) | 0.0909 (13) | |
H22A | 0.4174 | 0.7079 | −0.032 | 0.136* | |
H22B | 0.3493 | 0.6514 | 0.0499 | 0.136* | |
H22C | 0.4293 | 0.5054 | 0.0137 | 0.136* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S | 0.0847 (5) | 0.0628 (5) | 0.0606 (4) | 0.0110 (4) | 0.0435 (4) | 0.0122 (4) |
N1 | 0.0506 (11) | 0.0397 (12) | 0.0433 (11) | 0.0013 (10) | 0.0166 (9) | −0.0012 (10) |
C2 | 0.0426 (11) | 0.0394 (14) | 0.0428 (12) | −0.0002 (10) | 0.0163 (10) | −0.0022 (11) |
N3 | 0.0534 (11) | 0.0428 (13) | 0.0476 (11) | 0.0064 (11) | 0.0255 (9) | 0.0035 (11) |
C4 | 0.0426 (12) | 0.0493 (15) | 0.0463 (13) | −0.0003 (12) | 0.0186 (10) | −0.0024 (13) |
C5 | 0.0388 (11) | 0.0492 (16) | 0.0475 (13) | −0.0005 (11) | 0.0157 (9) | −0.0088 (12) |
C6 | 0.0448 (12) | 0.0441 (14) | 0.0470 (13) | 0.0032 (11) | 0.0134 (10) | −0.0076 (12) |
C7 | 0.0437 (12) | 0.0437 (14) | 0.0441 (12) | 0.0013 (11) | 0.0200 (9) | 0.0026 (12) |
C8 | 0.0529 (13) | 0.0488 (17) | 0.0592 (14) | −0.0056 (13) | 0.0322 (11) | −0.0033 (14) |
C9 | 0.0650 (16) | 0.070 (2) | 0.0627 (17) | −0.0080 (16) | 0.0350 (14) | −0.0179 (18) |
C10 | 0.0630 (16) | 0.087 (3) | 0.0629 (16) | 0.008 (2) | 0.0401 (13) | 0.002 (2) |
C11 | 0.0493 (14) | 0.088 (3) | 0.078 (2) | −0.0044 (17) | 0.0380 (14) | 0.005 (2) |
C12 | 0.0467 (13) | 0.0606 (18) | 0.0642 (17) | −0.0108 (13) | 0.0230 (12) | −0.0040 (16) |
C13 | 0.086 (2) | 0.057 (2) | 0.068 (2) | 0.026 (2) | 0.0248 (17) | −0.0021 (18) |
C14 | 0.0483 (13) | 0.0607 (19) | 0.0589 (15) | 0.0017 (14) | 0.0243 (11) | −0.0098 (15) |
O15 | 0.0518 (11) | 0.118 (3) | 0.0857 (15) | 0.0043 (14) | 0.0368 (10) | −0.0215 (18) |
O16 | 0.0597 (11) | 0.0851 (18) | 0.0565 (11) | −0.0044 (12) | 0.0269 (9) | −0.0261 (12) |
C17 | 0.096 (3) | 0.136 (5) | 0.077 (2) | −0.001 (3) | 0.044 (2) | −0.045 (3) |
C18A | 0.100 (5) | 0.269 (19) | 0.080 (3) | −0.018 (7) | 0.027 (3) | −0.099 (8) |
C18B | 0.100 (5) | 0.269 (19) | 0.080 (3) | −0.018 (7) | 0.027 (3) | −0.099 (8) |
C19 | 0.0628 (15) | 0.0433 (16) | 0.0532 (14) | 0.0017 (13) | 0.0208 (12) | 0.0074 (14) |
C20 | 0.0618 (15) | 0.0568 (18) | 0.0475 (14) | 0.0066 (15) | 0.0204 (11) | 0.0068 (15) |
C21 | 0.085 (2) | 0.080 (3) | 0.0484 (15) | −0.003 (2) | 0.0241 (14) | 0.0064 (18) |
C22 | 0.109 (3) | 0.093 (3) | 0.0504 (16) | −0.009 (3) | 0.0157 (17) | 0.003 (2) |
S—C4 | 1.666 (3) | C14—O15 | 1.201 (3) |
N1—C2 | 1.374 (4) | C14—O16 | 1.319 (4) |
N1—C6 | 1.390 (4) | O16—C17 | 1.442 (4) |
N1—C19 | 1.477 (4) | C17—C18B | 1.40 (6) |
C2—N3 | 1.297 (4) | C17—C18A | 1.424 (10) |
C2—C7 | 1.492 (4) | C17—H17A | 0.97 |
N3—C4 | 1.385 (3) | C17—H17B | 0.97 |
C4—C5 | 1.427 (4) | C18A—H18A | 0.96 |
C5—C6 | 1.353 (4) | C18A—H18B | 0.96 |
C5—C14 | 1.499 (4) | C18A—H18C | 0.96 |
C6—C13 | 1.498 (5) | C18B—H18D | 0.96 |
C7—C8 | 1.381 (4) | C18B—H18E | 0.96 |
C7—C12 | 1.396 (4) | C18B—H18F | 0.96 |
C8—C9 | 1.380 (4) | C19—C20 | 1.515 (4) |
C8—H8 | 0.93 | C19—H19A | 0.97 |
C9—C10 | 1.382 (5) | C19—H19B | 0.97 |
C9—H9 | 0.93 | C20—C21 | 1.522 (4) |
C10—C11 | 1.367 (7) | C20—H20A | 0.97 |
C10—H10 | 0.93 | C20—H20B | 0.97 |
C11—C12 | 1.384 (5) | C21—C22 | 1.508 (5) |
C11—H11 | 0.93 | C21—H21A | 0.97 |
C12—H12 | 0.93 | C21—H21B | 0.97 |
C13—H13A | 0.96 | C22—H22A | 0.96 |
C13—H13B | 0.96 | C22—H22B | 0.96 |
C13—H13C | 0.96 | C22—H22C | 0.96 |
C2—N1—C6 | 118.0 (2) | C18B—C17—O16 | 106.8 (16) |
C2—N1—C19 | 121.1 (2) | C18A—C17—O16 | 109.9 (4) |
C6—N1—C19 | 120.6 (2) | C18B—C17—H17A | 142.5 |
N3—C2—N1 | 124.9 (2) | C18A—C17—H17A | 109.7 |
N3—C2—C7 | 116.1 (2) | O16—C17—H17A | 109.7 |
N1—C2—C7 | 119.0 (2) | C18B—C17—H17B | 66.2 |
C2—N3—C4 | 119.7 (2) | C18A—C17—H17B | 109.7 |
N3—C4—C5 | 116.9 (3) | O16—C17—H17B | 109.7 |
N3—C4—S | 120.2 (2) | H17A—C17—H17B | 108.2 |
C5—C4—S | 122.9 (2) | C17—C18A—H18A | 109.5 |
C6—C5—C4 | 121.9 (2) | C17—C18A—H18B | 109.5 |
C6—C5—C14 | 120.1 (3) | H18A—C18A—H18B | 109.5 |
C4—C5—C14 | 118.0 (3) | C17—C18A—H18C | 109.5 |
C5—C6—N1 | 118.3 (3) | H18A—C18A—H18C | 109.5 |
C5—C6—C13 | 123.1 (3) | H18B—C18A—H18C | 109.5 |
N1—C6—C13 | 118.6 (3) | C17—C18B—H18D | 109.5 |
C8—C7—C12 | 119.4 (3) | C17—C18B—H18E | 109.5 |
C8—C7—C2 | 118.6 (2) | H18D—C18B—H18E | 109.5 |
C12—C7—C2 | 121.9 (3) | C17—C18B—H18F | 109.5 |
C9—C8—C7 | 120.3 (3) | H18D—C18B—H18F | 109.5 |
C9—C8—H8 | 119.8 | H18E—C18B—H18F | 109.5 |
C7—C8—H8 | 119.8 | N1—C19—C20 | 112.9 (3) |
C8—C9—C10 | 120.2 (4) | N1—C19—H19A | 109 |
C8—C9—H9 | 119.9 | C20—C19—H19A | 109 |
C10—C9—H9 | 119.9 | N1—C19—H19B | 109 |
C11—C10—C9 | 119.7 (3) | C20—C19—H19B | 109 |
C11—C10—H10 | 120.1 | H19A—C19—H19B | 107.8 |
C9—C10—H10 | 120.1 | C19—C20—C21 | 109.8 (3) |
C10—C11—C12 | 120.9 (3) | C19—C20—H20A | 109.7 |
C10—C11—H11 | 119.6 | C21—C20—H20A | 109.7 |
C12—C11—H11 | 119.6 | C19—C20—H20B | 109.7 |
C11—C12—C7 | 119.4 (3) | C21—C20—H20B | 109.7 |
C11—C12—H12 | 120.3 | H20A—C20—H20B | 108.2 |
C7—C12—H12 | 120.3 | C22—C21—C20 | 113.5 (4) |
C6—C13—H13A | 109.5 | C22—C21—H21A | 108.9 |
C6—C13—H13B | 109.5 | C20—C21—H21A | 108.9 |
H13A—C13—H13B | 109.5 | C22—C21—H21B | 108.9 |
C6—C13—H13C | 109.5 | C20—C21—H21B | 108.9 |
H13A—C13—H13C | 109.5 | H21A—C21—H21B | 107.7 |
H13B—C13—H13C | 109.5 | C21—C22—H22A | 109.5 |
O15—C14—O16 | 124.3 (3) | C21—C22—H22B | 109.5 |
O15—C14—C5 | 125.3 (3) | H22A—C22—H22B | 109.5 |
O16—C14—C5 | 110.3 (2) | C21—C22—H22C | 109.5 |
C14—O16—C17 | 117.6 (3) | H22A—C22—H22C | 109.5 |
C18B—C17—C18A | 48 (3) | H22B—C22—H22C | 109.5 |
C6—N1—C2—N3 | 2.4 (4) | N3—C2—C7—C12 | −112.8 (3) |
C19—N1—C2—N3 | −171.8 (3) | N1—C2—C7—C12 | 67.4 (4) |
C6—N1—C2—C7 | −177.8 (2) | C12—C7—C8—C9 | −0.3 (5) |
C19—N1—C2—C7 | 8.0 (3) | C2—C7—C8—C9 | −176.8 (3) |
N1—C2—N3—C4 | −0.9 (4) | C7—C8—C9—C10 | −0.3 (5) |
C7—C2—N3—C4 | 179.3 (2) | C8—C9—C10—C11 | −0.2 (6) |
C2—N3—C4—C5 | −3.6 (3) | C9—C10—C11—C12 | 1.3 (6) |
C2—N3—C4—S | 175.89 (19) | C10—C11—C12—C7 | −1.9 (6) |
N3—C4—C5—C6 | 7.1 (4) | C8—C7—C12—C11 | 1.4 (5) |
S—C4—C5—C6 | −172.4 (2) | C2—C7—C12—C11 | 177.7 (3) |
N3—C4—C5—C14 | −175.5 (2) | C6—C5—C14—O15 | 78.1 (5) |
S—C4—C5—C14 | 5.0 (3) | C4—C5—C14—O15 | −99.3 (4) |
C4—C5—C6—N1 | −5.7 (4) | C6—C5—C14—O16 | −100.7 (3) |
C14—C5—C6—N1 | 176.9 (2) | C4—C5—C14—O16 | 81.8 (4) |
C4—C5—C6—C13 | 175.9 (3) | O15—C14—O16—C17 | 5.4 (7) |
C14—C5—C6—C13 | −1.5 (4) | C5—C14—O16—C17 | −175.8 (4) |
C2—N1—C6—C5 | 1.0 (4) | C14—O16—C17—C18B | 126 (3) |
C19—N1—C6—C5 | 175.2 (2) | C14—O16—C17—C18A | 177.0 (9) |
C2—N1—C6—C13 | 179.5 (3) | C2—N1—C19—C20 | 81.1 (3) |
C19—N1—C6—C13 | −6.3 (4) | C6—N1—C19—C20 | −92.9 (3) |
N3—C2—C7—C8 | 63.6 (3) | N1—C19—C20—C21 | −179.2 (3) |
N1—C2—C7—C8 | −116.2 (3) | C19—C20—C21—C22 | −177.8 (4) |
Experimental details
Crystal data | |
Chemical formula | C18H22N2O2S |
Mr | 330.45 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 297 |
a, b, c (Å) | 10.9870 (18), 7.2840 (14), 12.5885 (13) |
β (°) | 115.591 (9) |
V (Å3) | 908.6 (3) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 1.66 |
Crystal size (mm) | 0.35 × 0.25 × 0.05 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.594, 0.922 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2129, 2034, 1907 |
Rint | 0.047 |
(sin θ/λ)max (Å−1) | 0.598 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.136, 1.09 |
No. of reflections | 2034 |
No. of parameters | 214 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.28, −0.44 |
Absolute structure | Flack (1983), 270 Friedel pairs |
Absolute structure parameter | 0.10 (3) |
Computer programs: CAD-4-PC (Enraf–Nonius, 1993), CAD-4-PC, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), WinGX (Farrugia, 1999).
In continuation of our solid-state studies of bioactive thioxopyrimidine, we performed the crystallographic characterization of the title 4-thioxopyrimidine (I), which exhibited a lowered antifungal but enhanced trypanocidal activities compared to related compounds (Cunha et al., 2007).
The molecule of (I) is depicted in Fig. 1. This derivative differs from those of Parts 1 and 2 by a substituent on the ring atom N1, where (I) has a butyl group instead of a hydroxyethyl group. The conformation of compound (I) is defined by steric effects. The pyrimidine ring is planar with an r.m.s. deviation of 0.022 Å. With reference to this plane, the phenyl ring is rotated by 65.0 (1)°, approaching a gauche conformation. The torsion angles C4—C5—C14—O15 and C20—C19—N1—C6 are -99.3 (4)° and -92.9 (3)°, respectively. Bond lengths are within the expected ranges with the exception of the C2–C7 and C5–C14 bonds which are elongated by an average of 0.035 Å from the formal single bond distance.
It is interesting to note that the crystal packing of compound (I) is maintained by van der Waals forces only; it does not form dimers involving C═O···π-ring interactions as observed in the previous derivatives. It is supposed that the steric inaccessibility due to the long butyl substituent group prevents the pyrimidine ring stacking. The packing is shown in Fig. 2.