organic compounds
Ethyl 3-ethoxycarbonylmethyl-7-methyl-5-phenyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylate
aDepartment of Studies in Chemistry, Bangalore University, Bangalore 560 001, India
*Correspondence e-mail: noorsb@rediffmail.com
In the title compound, C20H22N2O4S, the central pyrimidine ring incorporating a chiral C atom is significantly puckered and adopts a slight boat conformation with C atom bearing the phenyl ring and the N atom opposite displaced by 0.367 (2) and 0.107 (2) Å, respectively, from the plane formed by the remaining ring atoms. The benzene ring is positioned axially to the pyrimidine ring, making a dihedral angle of 88.99 (5)°. The thiazole ring is essentially planar (r.m.s. deviation = 0.0033 Å). In the crystal, pairs of C—H⋯O interactions result in centrosymmetric dimers with graph-set motifs R12(7) and R22(8). A weak C—H⋯π contact is also observed.
Related literature
For the therapeutic potential of thiazolopyrimidine derivatives, see: Zhi et al. (2008). For the synthesis of the title compound, see: Nagarajaiah et al. (2012). For a related structure, see: Nagarajaiah & Begum (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995). For carbonyl–π interactions, see: Gautrot et al. (2006).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 1998); cell SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
https://doi.org/10.1107/S1600536812037828/pv2584sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812037828/pv2584Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812037828/pv2584Isup3.cml
The synthesis of the title compound has already been reported (Nagarajaiah et al., 2012). The crystals suitable for X-ray crystallographic analysis were grown from a solution of ethylacetate.
The H atoms were placed at calculated positions in the riding model approximation with C—H = 0.93, 0.96, 0.97 and 0.98 Å for aryl, methyl, methylene and methyne H-atoms, respectively, with Uiso(H) = 1.5Ueq(C) for methyl H atoms and Uiso(H) = 1.2Ueq(C) for other H atoms.
Thiazolo[3,2-a]pyrimidine derivatives may be to generate enzyme inhibitors as novel therapeutical entities for severe neurodegenerative diseases (Zhi et al., 2008). In continuation to our research interests on thiazolo[3,2-a]pyrimidine derivatives (Nagarajaiah & Begum, 2011; Nagarajaiah et al. 2012), we report the
of the title compound.In the title molecule (Fig. 1), the benzene ring is positioned axially and lies almost perpendicular to the pyrimidine ring (N1/N2/C5/C6/C7/C9) with dihedral angle of 88.99 (5)°. The pyrimidine ring substituted with C5 chiral carbon atom is significantly puckered and adopts a slight boat conformation with N2 and C5 atoms displaced by 0.107 (2) and 0.367 (2) Å, respectively, from the plane formed by the remaining ring atoms. The thiazole ring (S1/N1/C2/C3/C9) is essentially planar with r.m.s.d 0.0033 Å for the fitted atoms. The ethyl carboxylate at C6 is almost co–planar with the thiazolopyrimidine ring with a dihedral angle of 13.40 (5)°, where as the other ethyl carboxylate group at C17 is inclined at an angle of 80.57 (4)° with the thiazolopyrimidine ring and is positioned almost parallel to the benzene ring. This is because of intramolecular carbonyl—π interaction of aryl ring with the ethyl carboxylate group (Gautrot et al., 2006). The exocyclic ester at C8 adopts a cis orientation with respect to C8═C9 double bond. The N1—C3 bond length (1.403 (2) Å) in the thiazole ring is longer than that of a typical C═N bond but shorter than a C—N single bond, indicating electron delocalization in the ring. The bond distances and angles in the title compound agree very well with the corresponding bond distances and angles reported in a closely related compound (Nagarajaiah & Begum, 2011).
The π–ring interaction of the type C—H···Cg (Cg being the centroid of the thiazolopyrimidine ring) is also observed in the (Table 1 and Fig. 2).
is stabilized by C—H···O intermolecular interactions involving carbonyl O2 atom, resulting in centrosymmetric dimers; the seven and eight membered rings thus resulting from these interaction can be described as R21(7) and R22(8) motifs in graph–set notations (Bernstein et al., 1995). In additionFor the therapeutical potential of thiazolopyrimidine derivatives, see: Zhi et al. (2008). For the synthesis of the title compound, see: Nagarajaiah et al. (2012). For a related structure, see: Nagarajaiah & Begum (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995). For carbonyl–π interactions, see: Gautrot et al. (2006).
Data collection: SMART (Bruker, 1998); cell
SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 1999).C20H22N2O4S | F(000) = 816 |
Mr = 386.46 | Dx = 1.400 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3102 reflections |
a = 10.0861 (4) Å | θ = 1.8–27.0° |
b = 7.7954 (3) Å | µ = 0.21 mm−1 |
c = 23.4088 (10) Å | T = 296 K |
β = 95.000 (3)° | Block, yellow |
V = 1833.52 (13) Å3 | 0.18 × 0.16 × 0.16 mm |
Z = 4 |
Bruker SMART APEX CCD detector diffractometer | 3982 independent reflections |
Radiation source: fine-focus sealed tube | 3102 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
ω scans | θmax = 27.0°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −12→12 |
Tmin = 0.964, Tmax = 0.968 | k = −6→9 |
11747 measured reflections | l = −29→29 |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0675P)2 + 0.5269P] where P = (Fo2 + 2Fc2)/3 |
3982 reflections | (Δ/σ)max < 0.001 |
247 parameters | Δρmax = 0.50 e Å−3 |
0 restraints | Δρmin = −0.29 e Å−3 |
C20H22N2O4S | V = 1833.52 (13) Å3 |
Mr = 386.46 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 10.0861 (4) Å | µ = 0.21 mm−1 |
b = 7.7954 (3) Å | T = 296 K |
c = 23.4088 (10) Å | 0.18 × 0.16 × 0.16 mm |
β = 95.000 (3)° |
Bruker SMART APEX CCD detector diffractometer | 3982 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 3102 reflections with I > 2σ(I) |
Tmin = 0.964, Tmax = 0.968 | Rint = 0.037 |
11747 measured reflections |
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.50 e Å−3 |
3982 reflections | Δρmin = −0.29 e Å−3 |
247 parameters |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 | ||
S1 | 0.18621 (4) | 0.21888 (6) | 0.308470 (19) | 0.01968 (14) | |
O1 | 0.64536 (12) | 0.10949 (17) | 0.36984 (5) | 0.0216 (3) | |
O2 | 0.67845 (13) | 0.00457 (18) | 0.45941 (6) | 0.0260 (3) | |
O3 | 0.31568 (12) | −0.40830 (18) | 0.48561 (5) | 0.0220 (3) | |
O4 | 0.12682 (12) | −0.51826 (17) | 0.44357 (5) | 0.0199 (3) | |
N1 | 0.30250 (14) | 0.0076 (2) | 0.37900 (6) | 0.0150 (3) | |
N2 | 0.11268 (14) | −0.1069 (2) | 0.32378 (6) | 0.0183 (3) | |
C1 | −0.00093 (18) | −0.3634 (3) | 0.34719 (8) | 0.0228 (4) | |
H1A | 0.0277 | −0.4809 | 0.3477 | 0.034* | |
H1B | −0.0437 | −0.3361 | 0.3100 | 0.034* | |
H1C | −0.0625 | −0.3465 | 0.3757 | 0.034* | |
C2 | 0.32329 (18) | 0.2865 (3) | 0.35279 (7) | 0.0189 (4) | |
H2 | 0.3582 | 0.3969 | 0.3524 | 0.023* | |
C3 | 0.37267 (17) | 0.1622 (2) | 0.38743 (7) | 0.0157 (4) | |
C4 | 0.0304 (2) | −0.7801 (3) | 0.47057 (10) | 0.0351 (5) | |
H4A | −0.0546 | −0.7244 | 0.4652 | 0.053* | |
H4B | 0.0287 | −0.8646 | 0.5003 | 0.053* | |
H4C | 0.0495 | −0.8349 | 0.4355 | 0.053* | |
C5 | 0.34164 (16) | −0.1592 (2) | 0.40446 (7) | 0.0149 (4) | |
H5 | 0.3749 | −0.1416 | 0.4446 | 0.018* | |
C6 | 0.21811 (16) | −0.2722 (2) | 0.40233 (7) | 0.0150 (4) | |
C7 | 0.11731 (18) | −0.2487 (2) | 0.35981 (7) | 0.0177 (4) | |
C8 | 0.1356 (2) | −0.6503 (3) | 0.48718 (8) | 0.0256 (4) | |
H8A | 0.1217 | −0.6011 | 0.5242 | 0.031* | |
H8B | 0.2228 | −0.7035 | 0.4896 | 0.031* | |
C9 | 0.19752 (17) | 0.0147 (2) | 0.33814 (7) | 0.0165 (4) | |
C10 | 0.22567 (17) | −0.4028 (2) | 0.44727 (7) | 0.0167 (4) | |
C11 | 0.44966 (17) | −0.2466 (2) | 0.37322 (7) | 0.0147 (4) | |
C12 | 0.54419 (17) | −0.3488 (2) | 0.40333 (7) | 0.0164 (4) | |
H12 | 0.5466 | −0.3548 | 0.4431 | 0.020* | |
C13 | 0.63526 (17) | −0.4424 (2) | 0.37482 (8) | 0.0190 (4) | |
H13 | 0.6978 | −0.5110 | 0.3955 | 0.023* | |
C14 | 0.63328 (18) | −0.4338 (2) | 0.31562 (8) | 0.0202 (4) | |
H14 | 0.6940 | −0.4968 | 0.2965 | 0.024* | |
C15 | 0.54006 (18) | −0.3308 (3) | 0.28515 (8) | 0.0210 (4) | |
H15 | 0.5385 | −0.3242 | 0.2454 | 0.025* | |
C16 | 0.44914 (18) | −0.2375 (2) | 0.31367 (7) | 0.0188 (4) | |
H16 | 0.3872 | −0.1682 | 0.2929 | 0.023* | |
C17 | 0.48437 (17) | 0.1764 (2) | 0.43372 (7) | 0.0181 (4) | |
H17A | 0.4536 | 0.1319 | 0.4689 | 0.022* | |
H17B | 0.5041 | 0.2971 | 0.4399 | 0.022* | |
C18 | 0.61252 (18) | 0.0854 (2) | 0.42323 (7) | 0.0190 (4) | |
C19 | 0.76628 (18) | 0.0231 (3) | 0.35511 (8) | 0.0237 (4) | |
H19A | 0.7534 | −0.1002 | 0.3551 | 0.028* | |
H19B | 0.8397 | 0.0508 | 0.3831 | 0.028* | |
C20 | 0.7966 (2) | 0.0815 (3) | 0.29736 (9) | 0.0362 (6) | |
H20A | 0.7213 | 0.0601 | 0.2703 | 0.054* | |
H20B | 0.8724 | 0.0201 | 0.2859 | 0.054* | |
H20C | 0.8156 | 0.2022 | 0.2984 | 0.054* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0253 (2) | 0.0184 (3) | 0.0147 (2) | 0.0029 (2) | −0.00124 (17) | 0.00322 (18) |
O1 | 0.0244 (6) | 0.0245 (8) | 0.0158 (6) | 0.0014 (6) | 0.0020 (5) | 0.0011 (5) |
O2 | 0.0318 (7) | 0.0281 (8) | 0.0173 (7) | 0.0032 (6) | −0.0033 (5) | 0.0032 (6) |
O3 | 0.0260 (7) | 0.0255 (8) | 0.0138 (6) | −0.0037 (6) | −0.0028 (5) | 0.0060 (5) |
O4 | 0.0233 (6) | 0.0185 (7) | 0.0180 (6) | −0.0037 (6) | 0.0021 (5) | 0.0045 (5) |
N1 | 0.0186 (7) | 0.0158 (8) | 0.0103 (7) | 0.0005 (6) | −0.0001 (5) | 0.0002 (6) |
N2 | 0.0208 (7) | 0.0194 (9) | 0.0141 (7) | 0.0005 (7) | −0.0015 (6) | 0.0011 (6) |
C1 | 0.0219 (9) | 0.0263 (11) | 0.0194 (9) | −0.0026 (8) | −0.0033 (7) | 0.0028 (8) |
C2 | 0.0241 (9) | 0.0169 (10) | 0.0158 (9) | −0.0006 (8) | 0.0018 (7) | −0.0022 (7) |
C3 | 0.0212 (8) | 0.0151 (10) | 0.0113 (8) | −0.0003 (7) | 0.0038 (6) | −0.0020 (7) |
C4 | 0.0472 (13) | 0.0245 (12) | 0.0348 (12) | −0.0122 (11) | 0.0094 (10) | 0.0019 (10) |
C5 | 0.0208 (8) | 0.0151 (10) | 0.0084 (8) | 0.0001 (7) | −0.0004 (6) | 0.0011 (6) |
C6 | 0.0182 (8) | 0.0152 (10) | 0.0118 (8) | −0.0012 (7) | 0.0021 (6) | −0.0012 (7) |
C7 | 0.0203 (9) | 0.0192 (10) | 0.0138 (8) | 0.0020 (8) | 0.0027 (6) | −0.0010 (7) |
C8 | 0.0347 (10) | 0.0195 (11) | 0.0230 (10) | −0.0028 (9) | 0.0043 (8) | 0.0070 (8) |
C9 | 0.0209 (8) | 0.0192 (10) | 0.0094 (8) | 0.0038 (8) | 0.0011 (6) | 0.0005 (7) |
C10 | 0.0198 (8) | 0.0172 (10) | 0.0133 (8) | 0.0008 (8) | 0.0035 (7) | −0.0012 (7) |
C11 | 0.0179 (8) | 0.0130 (10) | 0.0129 (8) | −0.0031 (7) | 0.0004 (6) | −0.0002 (7) |
C12 | 0.0209 (8) | 0.0159 (10) | 0.0122 (8) | −0.0033 (7) | −0.0006 (6) | 0.0017 (7) |
C13 | 0.0205 (8) | 0.0158 (10) | 0.0201 (9) | −0.0012 (8) | −0.0017 (7) | 0.0004 (7) |
C14 | 0.0216 (9) | 0.0187 (10) | 0.0209 (9) | −0.0013 (8) | 0.0054 (7) | −0.0043 (8) |
C15 | 0.0254 (9) | 0.0265 (11) | 0.0112 (8) | −0.0017 (8) | 0.0018 (7) | −0.0012 (7) |
C16 | 0.0211 (9) | 0.0224 (11) | 0.0125 (8) | −0.0010 (8) | −0.0008 (7) | 0.0028 (7) |
C17 | 0.0246 (9) | 0.0170 (10) | 0.0125 (8) | −0.0026 (8) | 0.0005 (7) | −0.0010 (7) |
C18 | 0.0259 (9) | 0.0160 (10) | 0.0146 (9) | −0.0043 (8) | −0.0013 (7) | −0.0017 (7) |
C19 | 0.0230 (9) | 0.0238 (11) | 0.0243 (10) | 0.0029 (8) | 0.0013 (7) | −0.0007 (8) |
C20 | 0.0342 (11) | 0.0451 (15) | 0.0307 (12) | 0.0145 (11) | 0.0109 (9) | 0.0093 (10) |
S1—C9 | 1.7363 (19) | C5—H5 | 0.9800 |
S1—C2 | 1.7367 (19) | C6—C7 | 1.372 (2) |
O1—C18 | 1.334 (2) | C6—C10 | 1.461 (2) |
O1—C19 | 1.460 (2) | C8—H8A | 0.9700 |
O2—C18 | 1.208 (2) | C8—H8B | 0.9700 |
O3—C10 | 1.220 (2) | C11—C12 | 1.387 (2) |
O4—C10 | 1.340 (2) | C11—C16 | 1.395 (2) |
O4—C8 | 1.447 (2) | C12—C13 | 1.388 (3) |
N1—C9 | 1.365 (2) | C12—H12 | 0.9300 |
N1—C3 | 1.403 (2) | C13—C14 | 1.386 (3) |
N1—C5 | 1.470 (2) | C13—H13 | 0.9300 |
N2—C9 | 1.302 (2) | C14—C15 | 1.386 (3) |
N2—C7 | 1.389 (2) | C14—H14 | 0.9300 |
C1—C7 | 1.499 (3) | C15—C16 | 1.386 (3) |
C1—H1A | 0.9600 | C15—H15 | 0.9300 |
C1—H1B | 0.9600 | C16—H16 | 0.9300 |
C1—H1C | 0.9600 | C17—C18 | 1.513 (3) |
C2—C3 | 1.332 (3) | C17—H17A | 0.9700 |
C2—H2 | 0.9300 | C17—H17B | 0.9700 |
C3—C17 | 1.498 (2) | C19—C20 | 1.483 (3) |
C4—C8 | 1.493 (3) | C19—H19A | 0.9700 |
C4—H4A | 0.9600 | C19—H19B | 0.9700 |
C4—H4B | 0.9600 | C20—H20A | 0.9600 |
C4—H4C | 0.9600 | C20—H20B | 0.9600 |
C5—C6 | 1.523 (2) | C20—H20C | 0.9600 |
C5—C11 | 1.525 (2) | ||
C9—S1—C2 | 91.05 (9) | N2—C9—S1 | 123.07 (13) |
C18—O1—C19 | 115.91 (14) | N1—C9—S1 | 109.73 (13) |
C10—O4—C8 | 115.64 (14) | O3—C10—O4 | 121.68 (16) |
C9—N1—C3 | 114.51 (15) | O3—C10—C6 | 122.88 (16) |
C9—N1—C5 | 118.99 (15) | O4—C10—C6 | 115.44 (15) |
C3—N1—C5 | 126.05 (14) | C12—C11—C16 | 118.65 (16) |
C9—N2—C7 | 115.87 (15) | C12—C11—C5 | 120.09 (15) |
C7—C1—H1A | 109.5 | C16—C11—C5 | 121.04 (15) |
C7—C1—H1B | 109.5 | C11—C12—C13 | 120.78 (16) |
H1A—C1—H1B | 109.5 | C11—C12—H12 | 119.6 |
C7—C1—H1C | 109.5 | C13—C12—H12 | 119.6 |
H1A—C1—H1C | 109.5 | C14—C13—C12 | 120.20 (17) |
H1B—C1—H1C | 109.5 | C14—C13—H13 | 119.9 |
C3—C2—S1 | 112.24 (15) | C12—C13—H13 | 119.9 |
C3—C2—H2 | 123.9 | C13—C14—C15 | 119.50 (17) |
S1—C2—H2 | 123.9 | C13—C14—H14 | 120.3 |
C2—C3—N1 | 112.47 (16) | C15—C14—H14 | 120.3 |
C2—C3—C17 | 127.16 (17) | C14—C15—C16 | 120.25 (17) |
N1—C3—C17 | 120.27 (16) | C14—C15—H15 | 119.9 |
C8—C4—H4A | 109.5 | C16—C15—H15 | 119.9 |
C8—C4—H4B | 109.5 | C15—C16—C11 | 120.62 (17) |
H4A—C4—H4B | 109.5 | C15—C16—H16 | 119.7 |
C8—C4—H4C | 109.5 | C11—C16—H16 | 119.7 |
H4A—C4—H4C | 109.5 | C3—C17—C18 | 116.57 (15) |
H4B—C4—H4C | 109.5 | C3—C17—H17A | 108.2 |
N1—C5—C6 | 107.96 (13) | C18—C17—H17A | 108.2 |
N1—C5—C11 | 112.26 (13) | C3—C17—H17B | 108.2 |
C6—C5—C11 | 110.02 (14) | C18—C17—H17B | 108.2 |
N1—C5—H5 | 108.8 | H17A—C17—H17B | 107.3 |
C6—C5—H5 | 108.8 | O2—C18—O1 | 124.34 (17) |
C11—C5—H5 | 108.8 | O2—C18—C17 | 123.84 (16) |
C7—C6—C10 | 127.18 (16) | O1—C18—C17 | 111.80 (15) |
C7—C6—C5 | 119.94 (16) | O1—C19—C20 | 108.42 (16) |
C10—C6—C5 | 112.84 (14) | O1—C19—H19A | 110.0 |
C6—C7—N2 | 122.04 (17) | C20—C19—H19A | 110.0 |
C6—C7—C1 | 126.17 (17) | O1—C19—H19B | 110.0 |
N2—C7—C1 | 111.77 (15) | C20—C19—H19B | 110.0 |
O4—C8—C4 | 107.47 (16) | H19A—C19—H19B | 108.4 |
O4—C8—H8A | 110.2 | C19—C20—H20A | 109.5 |
C4—C8—H8A | 110.2 | C19—C20—H20B | 109.5 |
O4—C8—H8B | 110.2 | H20A—C20—H20B | 109.5 |
C4—C8—H8B | 110.2 | C19—C20—H20C | 109.5 |
H8A—C8—H8B | 108.5 | H20A—C20—H20C | 109.5 |
N2—C9—N1 | 127.15 (17) | H20B—C20—H20C | 109.5 |
C9—S1—C2—C3 | −0.19 (14) | C2—S1—C9—N2 | 177.08 (15) |
S1—C2—C3—N1 | 0.62 (19) | C2—S1—C9—N1 | −0.30 (13) |
S1—C2—C3—C17 | −175.77 (14) | C8—O4—C10—O3 | −1.0 (2) |
C9—N1—C3—C2 | −0.9 (2) | C8—O4—C10—C6 | 178.56 (15) |
C5—N1—C3—C2 | 171.25 (15) | C7—C6—C10—O3 | −175.52 (17) |
C9—N1—C3—C17 | 175.79 (15) | C5—C6—C10—O3 | 6.9 (2) |
C5—N1—C3—C17 | −12.1 (2) | C7—C6—C10—O4 | 4.9 (3) |
C9—N1—C5—C6 | −28.50 (19) | C5—C6—C10—O4 | −172.68 (14) |
C3—N1—C5—C6 | 159.69 (15) | N1—C5—C11—C12 | 147.17 (16) |
C9—N1—C5—C11 | 92.94 (17) | C6—C5—C11—C12 | −92.58 (19) |
C3—N1—C5—C11 | −78.87 (19) | N1—C5—C11—C16 | −38.2 (2) |
N1—C5—C6—C7 | 28.9 (2) | C6—C5—C11—C16 | 82.0 (2) |
C11—C5—C6—C7 | −93.96 (19) | C16—C11—C12—C13 | −1.0 (3) |
N1—C5—C6—C10 | −153.39 (14) | C5—C11—C12—C13 | 173.77 (16) |
C11—C5—C6—C10 | 83.79 (17) | C11—C12—C13—C14 | 0.4 (3) |
C10—C6—C7—N2 | 171.60 (16) | C12—C13—C14—C15 | 0.2 (3) |
C5—C6—C7—N2 | −11.0 (3) | C13—C14—C15—C16 | −0.3 (3) |
C10—C6—C7—C1 | −6.2 (3) | C14—C15—C16—C11 | −0.3 (3) |
C5—C6—C7—C1 | 171.16 (16) | C12—C11—C16—C15 | 0.9 (3) |
C9—N2—C7—C6 | −10.1 (2) | C5—C11—C16—C15 | −173.75 (17) |
C9—N2—C7—C1 | 167.97 (15) | C2—C3—C17—C18 | −110.7 (2) |
C10—O4—C8—C4 | −171.20 (16) | N1—C3—C17—C18 | 73.2 (2) |
C7—N2—C9—N1 | 10.8 (3) | C19—O1—C18—O2 | 3.2 (3) |
C7—N2—C9—S1 | −166.12 (13) | C19—O1—C18—C17 | −178.60 (15) |
C3—N1—C9—N2 | −176.53 (16) | C3—C17—C18—O2 | −138.12 (19) |
C5—N1—C9—N2 | 10.7 (2) | C3—C17—C18—O1 | 43.6 (2) |
C3—N1—C9—S1 | 0.71 (17) | C18—O1—C19—C20 | −172.85 (17) |
C5—N1—C9—S1 | −172.02 (11) |
Cg is the centroid of the thiazolopyrimidine ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C17—H17A···O2i | 0.97 | 2.47 | 3.415 (3) | 164 |
C5—H5···O2i | 0.98 | 2.59 | 3.429 (2) | 144 |
C20—H20B···N2ii | 0.96 | 2.70 | 3.516 (3) | 144 |
C4—H4C···Cg1iii | 0.96 | 3.03 | 3.897 (4) | 151 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x+1, y, z; (iii) x, −y−3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C20H22N2O4S |
Mr | 386.46 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 296 |
a, b, c (Å) | 10.0861 (4), 7.7954 (3), 23.4088 (10) |
β (°) | 95.000 (3) |
V (Å3) | 1833.52 (13) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.21 |
Crystal size (mm) | 0.18 × 0.16 × 0.16 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD detector |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.964, 0.968 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11747, 3982, 3102 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.118, 1.00 |
No. of reflections | 3982 |
No. of parameters | 247 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.50, −0.29 |
Computer programs: SMART (Bruker, 1998), SAINT-Plus (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1996), WinGX (Farrugia, 1999).
Cg is the centroid of the thiazolopyrimidine ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C17—H17A···O2i | 0.970 | 2.471 | 3.415 (3) | 164 |
C5—H5···O2i | 0.980 | 2.586 | 3.429 (2) | 144 |
C20—H20B···N2ii | 0.960 | 2.695 | 3.516 (3) | 144 |
C4—H4C···Cg1iii | 0.960 | 3.032 | 3.897 (4) | 151 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x+1, y, z; (iii) x, −y−3/2, z−1/2. |
Acknowledgements
NSB is thankful to the University Grants Commission (UGC), India, for financial assistance and HN thanks for the fellowship.
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker. (1998). SMART, SAINT-Plus and SADABS. Bruker Axs Inc., Madison, Wisconcin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Gautrot, J. E., Hodge, P., Cupertino, D. & Helliwell, M. (2006). New J. Chem. 30, 1801–1807. Web of Science CSD CrossRef CAS Google Scholar
Nagarajaiah, H. & Begum, N. S. (2011). Acta Cryst. E67, o3444. Web of Science CSD CrossRef IUCr Journals Google Scholar
Nagarajaiah, H., Khazi, I. M. & Begum, N. S. (2012). J. Chem. Sci. 124, 847–855. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, University of Oxford, England. Google Scholar
Zhi, H., Lan-mei, C., Lin-lin, Z., Si-jie, L., David, C. C. W., Huang-quan, L. & Chun, H. (2008). ARKIVOC, xiii, 266–277. CrossRef Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Thiazolo[3,2-a]pyrimidine derivatives may be to generate enzyme inhibitors as novel therapeutical entities for severe neurodegenerative diseases (Zhi et al., 2008). In continuation to our research interests on thiazolo[3,2-a]pyrimidine derivatives (Nagarajaiah & Begum, 2011; Nagarajaiah et al. 2012), we report the crystal structure of the title compound.
In the title molecule (Fig. 1), the benzene ring is positioned axially and lies almost perpendicular to the pyrimidine ring (N1/N2/C5/C6/C7/C9) with dihedral angle of 88.99 (5)°. The pyrimidine ring substituted with C5 chiral carbon atom is significantly puckered and adopts a slight boat conformation with N2 and C5 atoms displaced by 0.107 (2) and 0.367 (2) Å, respectively, from the plane formed by the remaining ring atoms. The thiazole ring (S1/N1/C2/C3/C9) is essentially planar with r.m.s.d 0.0033 Å for the fitted atoms. The ethyl carboxylate at C6 is almost co–planar with the thiazolopyrimidine ring with a dihedral angle of 13.40 (5)°, where as the other ethyl carboxylate group at C17 is inclined at an angle of 80.57 (4)° with the thiazolopyrimidine ring and is positioned almost parallel to the benzene ring. This is because of intramolecular carbonyl—π interaction of aryl ring with the ethyl carboxylate group (Gautrot et al., 2006). The exocyclic ester at C8 adopts a cis orientation with respect to C8═C9 double bond. The N1—C3 bond length (1.403 (2) Å) in the thiazole ring is longer than that of a typical C═N bond but shorter than a C—N single bond, indicating electron delocalization in the ring. The bond distances and angles in the title compound agree very well with the corresponding bond distances and angles reported in a closely related compound (Nagarajaiah & Begum, 2011).
The crystal structure is stabilized by C—H···O intermolecular interactions involving carbonyl O2 atom, resulting in centrosymmetric dimers; the seven and eight membered rings thus resulting from these interaction can be described as R21(7) and R22(8) motifs in graph–set notations (Bernstein et al., 1995). In addition π–ring interaction of the type C—H···Cg (Cg being the centroid of the thiazolopyrimidine ring) is also observed in the crystal structure (Table 1 and Fig. 2).