organic compounds
H-1,3-thiazolo[3,2-a]pyrimidine-6-carboxylate
of ethyl 2-cyano-3-[(1-ethoxyethylidene)amino]-5-(3-methoxyphenyl)-7-methyl-5aDepartment of Studies in Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, Karnataka, India
*Correspondence e-mail: noorsb@rediffmail.com
In the title compound, C22H24N4O4S, the central pyrimidine ring adopts a sofa conformation with the ring-junction N atom displaced by 0.2358 (6) Å from the mean plane of the remaining ring atoms. The 3-methoxyphenyl ring, at the chiral C atom opposite the other N atom, is positioned axially and is inclined to the thiazolopyrimidine ring with a dihedral angle of 83.88 (7)°. The thiazole ring is essentially planar (r.m.s. deviation = 0.0034 Å). In the crystal, pairs of weak C—H⋯O hydrogen bonds link molecules related by twofold rotation axes to form R22(8) rings, which in turn are linked by weak C—H⋯N interactions, forming ribbons along [-110]. In addition, π–π stacking interactions [centroid—centroid distance = 3.5744 (15) Å] connect the ribbons, forming slabs lying parallel to (001).
Keywords: crystal structure; pyrimidine; thiazolopyrimidine; thiazolo[3,2-a]pyrimidine; hydrogen bonding; π–π stacking interactions.
CCDC reference: 1054504
1. Related literature
For background and pharmacological properties of pyrimidine and thiazolopyrimidine derivatives, see: Singh et al. (2011); Ozair et al. (2010a,b); Sayed et al. (2010); Zhi et al. (2008); Mobinikhaledi et al. (2005). For related crystal structures, see: Krishnamurthy & Begum (2014); Krishnamurthy et al. (2014); Nagarajaiah & Begum (2011).
2. Experimental
2.1. Crystal data
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2.3. 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 for Windows (Farrugia, 2012) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 2012).
Supporting information
CCDC reference: 1054504
10.1107/S2056989015005241/su5092sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S2056989015005241/su5092Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989015005241/su5092Isup3.cml
A mixture of ethyl 3-amino-2-cyano-5-(3-methoxyphenyl)-7-methyl-5H- thiazolo[3,2 a] pyrimidine-6-carboxylate (1.85 g, 5 mmol) and triethylorthoacetate (2 ml) was heated under reflux in acetic anhydride for 6 h. Excess triethylorthoacetate and acetic anhydride was removed. The residue was treated with petroleum ether. The solid that separated was filtered, washed and recrystallized from petroleum ether by slow evaporation, yielding light-greenish yellow crystals suitable for X-ray diffraction studies (yield 83%; m.p.: 384 K).
The H atoms were placed at calculated positions in the riding model approximation: C—H = 0.95 - 1.00 Å with Uiso(H) = 1.5Ueq(C) for methyl H atoms and = 1.2Ueq(C) for other H atoms.
Pyrimidine has been subjected to a variety of structural modifications in order to synthesize derivatives (Singh et al., 2011) with different biological properties, among which, a thiazole ring fused to a pyrimidine ring, viz. a thiazolopyrimidine, has been found to be more active (Ozair et al., 2010a,b; Sayed et al., 2010). Thiazolo[3,2-a]pyrimidine derivatives act as potential enzyme inhibitors and are novel therapeutic entities for severe neurodegenerative diseases (Zhi et al., 2008). In continuation of our research interests on thiazolo[3,2-a]pyrimidine derivatives (Krishnamurthy & Begum, 2014; Krishnamurthy et al., 2014), we attempted to synthesize tricyclic thiazolopyrimidine derivatives (Mobinikhaledi et al., 2005). The title compound, an intermediate, was isolated and we report herein on its crystal structure.
The molecular structure of the title compound is shown in Fig. 1. The 3-methoxy phenyl ring at chiral carbon C5 is positioned axially and exactly bisects the thiazolopyrimidine ring with a dihedral angle of 83.88 (7)°. The pyrimidine ring adopts a flattened sofa conformation with atom N1 displaced by 0.2358 (6) Å from the mean plane of the other five atoms (C5/C6/C7/N2/C9). The carbonyl group of the exocyclic ester at C6 adopts a cis orientation with respect to C6—C7 double bond. The 3-methoxy phenyl ring adopts a syn periplanar conformation with respect to C5—H5 bond of the pyrimidine ring. The thiazole ring is essentially planar (r.m.s. deviation = 0.0034 Å).
In the crystal, pairs of weak C—H···O hydrogen bonds link molecules related by twofold rotation axes to form R22(8) rings, which are in turn linked by weak C—H···N interactions to form ribbons along [110]; Table 1 and Fig. 2. In addition, π–π stacking interactions with a centroid—centroid distance of 3.5744 (15) Å connect the ribbons to form slabs lying parallel to (001); [Cg1···.Cg1i where Cg1 is the centroid of ring S1/N1/C2/C3/C9; symmetry code: (i) -x, y, -z+1/2].
For background and pharmacological properties of pyrimidine and thiazolopyrimidine derivatives, see: Singh et al. (2011); Ozair et al. (2010a,b); Sayed et al. (2010); Zhi et al. (2008); Mobinikhaledi et al. (2005). For related crystal structures, see: Krishnamurthy & Begum (2014); Krishnamurthy et al. (2014); Nagarajaiah & Begum (2011).
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 for Windows (Farrugia, 2012) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Farrugia, 2012).C22H24N4O4S | F(000) = 1856 |
Mr = 440.51 | Dx = 1.356 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 3793 reflections |
a = 14.371 (3) Å | θ = 1.8–25.0° |
b = 13.368 (3) Å | µ = 0.19 mm−1 |
c = 22.771 (6) Å | T = 100 K |
β = 99.325 (5)° | Block, yellow |
V = 4316.9 (16) Å3 | 0.16 × 0.12 × 0.10 mm |
Z = 8 |
Bruker SMART APEX CCD detector diffractometer | 3793 independent reflections |
Radiation source: fine-focus sealed tube | 2882 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.052 |
ω scans | θmax = 25.0°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −17→17 |
Tmin = 0.967, Tmax = 0.971 | k = −15→15 |
11002 measured reflections | l = −27→19 |
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)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.149 | H-atom parameters constrained |
S = 1.01 | w = 1/[σ2(Fo2) + (0.1696P)2] where P = (Fo2 + 2Fc2)/3 |
3793 reflections | (Δ/σ)max < 0.001 |
285 parameters | Δρmax = 0.49 e Å−3 |
0 restraints | Δρmin = −0.32 e Å−3 |
C22H24N4O4S | V = 4316.9 (16) Å3 |
Mr = 440.51 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 14.371 (3) Å | µ = 0.19 mm−1 |
b = 13.368 (3) Å | T = 100 K |
c = 22.771 (6) Å | 0.16 × 0.12 × 0.10 mm |
β = 99.325 (5)° |
Bruker SMART APEX CCD detector diffractometer | 3793 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 2882 reflections with I > 2σ(I) |
Tmin = 0.967, Tmax = 0.971 | Rint = 0.052 |
11002 measured reflections |
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.149 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.49 e Å−3 |
3793 reflections | Δρmin = −0.32 e Å−3 |
285 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 | 0.13934 (4) | 0.70794 (4) | 0.20570 (3) | 0.0237 (2) | |
O1 | 0.10595 (11) | 1.16153 (12) | 0.30234 (7) | 0.0258 (4) | |
O2 | 0.12547 (12) | 1.21281 (12) | 0.21099 (8) | 0.0309 (5) | |
O3 | 0.33654 (13) | 1.03011 (15) | 0.48409 (8) | 0.0406 (5) | |
O4 | 0.11827 (12) | 0.80604 (12) | 0.46167 (7) | 0.0277 (4) | |
N1 | 0.11799 (13) | 0.86522 (14) | 0.26730 (8) | 0.0204 (5) | |
N2 | 0.13810 (13) | 0.89673 (15) | 0.16753 (9) | 0.0240 (5) | |
N3 | 0.08826 (13) | 0.80714 (14) | 0.36078 (9) | 0.0219 (5) | |
N4 | 0.12362 (15) | 0.52819 (16) | 0.33506 (10) | 0.0319 (5) | |
C1 | 0.11149 (19) | 1.05852 (19) | 0.12197 (11) | 0.0336 (7) | |
H1A | 0.1037 | 1.1294 | 0.1311 | 0.050* | |
H1B | 0.0551 | 1.0346 | 0.0957 | 0.050* | |
H1C | 0.1667 | 1.0505 | 0.1021 | 0.050* | |
C2 | 0.12358 (16) | 0.69605 (17) | 0.28022 (11) | 0.0216 (5) | |
C3 | 0.11295 (15) | 0.78635 (17) | 0.30573 (10) | 0.0200 (5) | |
C4 | 0.0977 (2) | 1.2676 (2) | 0.38543 (12) | 0.0420 (7) | |
H4A | 0.0383 | 1.2355 | 0.3905 | 0.063* | |
H4B | 0.0978 | 1.3371 | 0.3992 | 0.063* | |
H4C | 0.1505 | 1.2315 | 0.4087 | 0.063* | |
C5 | 0.13384 (16) | 0.96962 (16) | 0.28873 (10) | 0.0197 (5) | |
H5 | 0.0840 | 0.9878 | 0.3128 | 0.024* | |
C6 | 0.12340 (16) | 1.03689 (17) | 0.23357 (10) | 0.0211 (5) | |
C7 | 0.12523 (15) | 0.99914 (18) | 0.17838 (10) | 0.0225 (6) | |
C8 | 0.10788 (18) | 1.26578 (17) | 0.32076 (11) | 0.0275 (6) | |
H8A | 0.0555 | 1.3031 | 0.2968 | 0.033* | |
H8B | 0.1682 | 1.2973 | 0.3151 | 0.033* | |
C9 | 0.13237 (15) | 0.83739 (18) | 0.21150 (10) | 0.0208 (5) | |
C10 | 0.11810 (16) | 1.14516 (19) | 0.24543 (11) | 0.0245 (6) | |
C11 | 0.23017 (16) | 0.97772 (17) | 0.32810 (10) | 0.0216 (5) | |
C12 | 0.31098 (16) | 0.95397 (16) | 0.30541 (11) | 0.0238 (6) | |
H12 | 0.3070 | 0.9350 | 0.2649 | 0.029* | |
C13 | 0.39864 (18) | 0.95799 (18) | 0.34235 (12) | 0.0299 (6) | |
H13 | 0.4543 | 0.9425 | 0.3267 | 0.036* | |
C14 | 0.40474 (18) | 0.98420 (19) | 0.40119 (12) | 0.0329 (7) | |
H14 | 0.4644 | 0.9862 | 0.4262 | 0.039* | |
C15 | 0.32356 (19) | 1.00781 (19) | 0.42400 (11) | 0.0301 (6) | |
C16 | 0.23615 (17) | 1.00501 (18) | 0.38753 (10) | 0.0256 (6) | |
H16 | 0.1807 | 1.0217 | 0.4031 | 0.031* | |
C17 | 0.2546 (2) | 1.0463 (2) | 0.51025 (12) | 0.0491 (8) | |
H17A | 0.2234 | 1.1080 | 0.4943 | 0.074* | |
H17B | 0.2726 | 1.0524 | 0.5535 | 0.074* | |
H17C | 0.2114 | 0.9897 | 0.5011 | 0.074* | |
C18 | 0.12295 (16) | 0.60302 (18) | 0.31003 (11) | 0.0227 (6) | |
C19 | 0.14560 (17) | 0.79047 (17) | 0.40873 (11) | 0.0239 (6) | |
C20 | 0.24524 (17) | 0.7560 (2) | 0.41573 (11) | 0.0318 (6) | |
H20A | 0.2485 | 0.6850 | 0.4267 | 0.048* | |
H20B | 0.2838 | 0.7951 | 0.4470 | 0.048* | |
H20C | 0.2690 | 0.7651 | 0.3781 | 0.048* | |
C21 | 0.01889 (18) | 0.8272 (2) | 0.46214 (12) | 0.0316 (6) | |
H21A | −0.0065 | 0.8681 | 0.4270 | 0.038* | |
H21B | 0.0122 | 0.8659 | 0.4983 | 0.038* | |
C22 | −0.0361 (2) | 0.7323 (2) | 0.46124 (13) | 0.0427 (7) | |
H22A | −0.0306 | 0.6946 | 0.4250 | 0.064* | |
H22B | −0.1025 | 0.7479 | 0.4619 | 0.064* | |
H22C | −0.0112 | 0.6920 | 0.4962 | 0.064* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0270 (4) | 0.0215 (3) | 0.0222 (4) | −0.0008 (2) | 0.0033 (3) | −0.0006 (2) |
O1 | 0.0300 (10) | 0.0192 (9) | 0.0288 (10) | 0.0005 (7) | 0.0063 (8) | −0.0008 (7) |
O2 | 0.0403 (11) | 0.0223 (10) | 0.0297 (11) | 0.0001 (8) | 0.0042 (8) | 0.0083 (8) |
O3 | 0.0430 (12) | 0.0532 (13) | 0.0230 (11) | −0.0142 (10) | −0.0023 (9) | −0.0023 (9) |
O4 | 0.0325 (10) | 0.0313 (10) | 0.0188 (10) | 0.0022 (8) | 0.0031 (8) | 0.0003 (7) |
N1 | 0.0228 (11) | 0.0190 (10) | 0.0192 (11) | −0.0003 (8) | 0.0026 (8) | 0.0009 (8) |
N2 | 0.0269 (11) | 0.0222 (11) | 0.0228 (12) | −0.0013 (9) | 0.0038 (9) | −0.0004 (9) |
N3 | 0.0249 (11) | 0.0218 (11) | 0.0195 (11) | 0.0000 (8) | 0.0049 (9) | 0.0013 (8) |
N4 | 0.0347 (13) | 0.0252 (12) | 0.0358 (14) | −0.0007 (10) | 0.0057 (10) | 0.0041 (10) |
C1 | 0.0477 (17) | 0.0295 (15) | 0.0225 (14) | −0.0074 (13) | 0.0017 (12) | 0.0030 (11) |
C2 | 0.0189 (12) | 0.0208 (13) | 0.0247 (14) | −0.0007 (10) | 0.0024 (10) | 0.0008 (10) |
C3 | 0.0145 (12) | 0.0232 (13) | 0.0213 (13) | −0.0011 (10) | 0.0006 (10) | 0.0044 (10) |
C4 | 0.061 (2) | 0.0289 (15) | 0.0363 (18) | −0.0040 (14) | 0.0081 (15) | −0.0063 (13) |
C5 | 0.0239 (13) | 0.0141 (12) | 0.0215 (13) | 0.0001 (9) | 0.0048 (10) | −0.0019 (9) |
C6 | 0.0206 (13) | 0.0182 (12) | 0.0240 (14) | −0.0013 (9) | 0.0020 (10) | 0.0040 (10) |
C7 | 0.0181 (12) | 0.0257 (13) | 0.0234 (14) | −0.0003 (10) | 0.0019 (10) | 0.0021 (10) |
C8 | 0.0292 (14) | 0.0169 (12) | 0.0362 (16) | 0.0005 (11) | 0.0042 (12) | −0.0046 (11) |
C9 | 0.0168 (12) | 0.0265 (13) | 0.0181 (13) | −0.0013 (10) | 0.0003 (10) | −0.0015 (10) |
C10 | 0.0169 (12) | 0.0290 (14) | 0.0270 (14) | 0.0028 (10) | 0.0017 (10) | 0.0032 (11) |
C11 | 0.0263 (13) | 0.0146 (12) | 0.0235 (14) | −0.0010 (10) | 0.0029 (10) | 0.0034 (10) |
C12 | 0.0269 (14) | 0.0185 (12) | 0.0252 (14) | 0.0000 (10) | 0.0020 (11) | −0.0014 (10) |
C13 | 0.0239 (14) | 0.0252 (14) | 0.0398 (17) | 0.0018 (11) | 0.0028 (12) | −0.0015 (11) |
C14 | 0.0306 (15) | 0.0237 (14) | 0.0401 (18) | −0.0022 (11) | −0.0070 (13) | 0.0011 (12) |
C15 | 0.0365 (16) | 0.0254 (14) | 0.0262 (15) | −0.0052 (12) | −0.0017 (12) | −0.0003 (11) |
C16 | 0.0268 (14) | 0.0257 (14) | 0.0235 (14) | −0.0032 (11) | 0.0015 (11) | 0.0014 (11) |
C17 | 0.057 (2) | 0.065 (2) | 0.0247 (16) | −0.0221 (17) | 0.0049 (14) | −0.0069 (14) |
C18 | 0.0241 (13) | 0.0210 (13) | 0.0231 (14) | −0.0013 (10) | 0.0041 (11) | −0.0016 (11) |
C19 | 0.0281 (13) | 0.0211 (13) | 0.0220 (14) | −0.0015 (10) | 0.0026 (11) | 0.0019 (10) |
C20 | 0.0316 (15) | 0.0353 (15) | 0.0269 (15) | 0.0035 (12) | −0.0005 (12) | 0.0032 (12) |
C21 | 0.0371 (16) | 0.0339 (15) | 0.0251 (15) | 0.0042 (12) | 0.0094 (12) | −0.0019 (11) |
C22 | 0.0474 (18) | 0.0475 (18) | 0.0355 (17) | −0.0082 (15) | 0.0139 (14) | −0.0015 (14) |
S1—C9 | 1.740 (2) | C5—H5 | 1.0000 |
S1—C2 | 1.755 (3) | C6—C7 | 1.359 (3) |
O1—C10 | 1.353 (3) | C6—C10 | 1.476 (3) |
O1—C8 | 1.454 (3) | C8—H8A | 0.9900 |
O2—C10 | 1.213 (3) | C8—H8B | 0.9900 |
O3—C15 | 1.383 (3) | C11—C12 | 1.382 (3) |
O3—C17 | 1.419 (3) | C11—C16 | 1.391 (3) |
O4—C19 | 1.343 (3) | C12—C13 | 1.398 (3) |
O4—C21 | 1.458 (3) | C12—H12 | 0.9500 |
N1—C9 | 1.371 (3) | C13—C14 | 1.374 (4) |
N1—C3 | 1.380 (3) | C13—H13 | 0.9500 |
N1—C5 | 1.484 (3) | C14—C15 | 1.388 (4) |
N2—C9 | 1.291 (3) | C14—H14 | 0.9500 |
N2—C7 | 1.409 (3) | C15—C16 | 1.390 (3) |
N3—C19 | 1.277 (3) | C16—H16 | 0.9500 |
N3—C3 | 1.385 (3) | C17—H17A | 0.9800 |
N4—C18 | 1.151 (3) | C17—H17B | 0.9800 |
C1—C7 | 1.496 (3) | C17—H17C | 0.9800 |
C1—H1A | 0.9800 | C19—C20 | 1.488 (3) |
C1—H1B | 0.9800 | C20—H20A | 0.9800 |
C1—H1C | 0.9800 | C20—H20B | 0.9800 |
C2—C3 | 1.359 (3) | C20—H20C | 0.9800 |
C2—C18 | 1.418 (3) | C21—C22 | 1.492 (4) |
C4—C8 | 1.503 (4) | C21—H21A | 0.9900 |
C4—H4A | 0.9800 | C21—H21B | 0.9900 |
C4—H4B | 0.9800 | C22—H22A | 0.9800 |
C4—H4C | 0.9800 | C22—H22B | 0.9800 |
C5—C11 | 1.526 (3) | C22—H22C | 0.9800 |
C5—C6 | 1.532 (3) | ||
C9—S1—C2 | 89.92 (11) | O2—C10—C6 | 126.9 (2) |
C10—O1—C8 | 115.58 (18) | O1—C10—C6 | 110.6 (2) |
C15—O3—C17 | 117.4 (2) | C12—C11—C16 | 120.0 (2) |
C19—O4—C21 | 117.78 (18) | C12—C11—C5 | 120.1 (2) |
C9—N1—C3 | 114.3 (2) | C16—C11—C5 | 119.8 (2) |
C9—N1—C5 | 121.45 (19) | C11—C12—C13 | 119.7 (2) |
C3—N1—C5 | 122.10 (19) | C11—C12—H12 | 120.1 |
C9—N2—C7 | 115.8 (2) | C13—C12—H12 | 120.1 |
C19—N3—C3 | 121.0 (2) | C14—C13—C12 | 120.4 (2) |
C7—C1—H1A | 109.5 | C14—C13—H13 | 119.8 |
C7—C1—H1B | 109.5 | C12—C13—H13 | 119.8 |
H1A—C1—H1B | 109.5 | C13—C14—C15 | 119.9 (2) |
C7—C1—H1C | 109.5 | C13—C14—H14 | 120.1 |
H1A—C1—H1C | 109.5 | C15—C14—H14 | 120.1 |
H1B—C1—H1C | 109.5 | O3—C15—C14 | 115.6 (2) |
C3—C2—C18 | 124.4 (2) | O3—C15—C16 | 124.1 (2) |
C3—C2—S1 | 111.95 (18) | C14—C15—C16 | 120.2 (2) |
C18—C2—S1 | 123.66 (18) | C15—C16—C11 | 119.7 (2) |
C2—C3—N1 | 112.8 (2) | C15—C16—H16 | 120.1 |
C2—C3—N3 | 128.9 (2) | C11—C16—H16 | 120.1 |
N1—C3—N3 | 117.9 (2) | O3—C17—H17A | 109.5 |
C8—C4—H4A | 109.5 | O3—C17—H17B | 109.5 |
C8—C4—H4B | 109.5 | H17A—C17—H17B | 109.5 |
H4A—C4—H4B | 109.5 | O3—C17—H17C | 109.5 |
C8—C4—H4C | 109.5 | H17A—C17—H17C | 109.5 |
H4A—C4—H4C | 109.5 | H17B—C17—H17C | 109.5 |
H4B—C4—H4C | 109.5 | N4—C18—C2 | 178.8 (3) |
N1—C5—C11 | 109.64 (18) | N3—C19—O4 | 119.9 (2) |
N1—C5—C6 | 107.05 (18) | N3—C19—C20 | 128.5 (2) |
C11—C5—C6 | 113.51 (19) | O4—C19—C20 | 111.6 (2) |
N1—C5—H5 | 108.8 | C19—C20—H20A | 109.5 |
C11—C5—H5 | 108.8 | C19—C20—H20B | 109.5 |
C6—C5—H5 | 108.8 | H20A—C20—H20B | 109.5 |
C7—C6—C10 | 122.9 (2) | C19—C20—H20C | 109.5 |
C7—C6—C5 | 121.8 (2) | H20A—C20—H20C | 109.5 |
C10—C6—C5 | 115.2 (2) | H20B—C20—H20C | 109.5 |
C6—C7—N2 | 123.1 (2) | O4—C21—C22 | 110.6 (2) |
C6—C7—C1 | 125.3 (2) | O4—C21—H21A | 109.5 |
N2—C7—C1 | 111.6 (2) | C22—C21—H21A | 109.5 |
O1—C8—C4 | 107.32 (19) | O4—C21—H21B | 109.5 |
O1—C8—H8A | 110.2 | C22—C21—H21B | 109.5 |
C4—C8—H8A | 110.3 | H21A—C21—H21B | 108.1 |
O1—C8—H8B | 110.3 | C21—C22—H22A | 109.5 |
C4—C8—H8B | 110.2 | C21—C22—H22B | 109.5 |
H8A—C8—H8B | 108.5 | H22A—C22—H22B | 109.5 |
N2—C9—N1 | 126.2 (2) | C21—C22—H22C | 109.5 |
N2—C9—S1 | 122.74 (18) | H22A—C22—H22C | 109.5 |
N1—C9—S1 | 111.07 (17) | H22B—C22—H22C | 109.5 |
O2—C10—O1 | 122.5 (2) | ||
C9—S1—C2—C3 | 0.67 (18) | C5—N1—C9—S1 | 164.04 (16) |
C9—S1—C2—C18 | −178.8 (2) | C2—S1—C9—N2 | −179.1 (2) |
C18—C2—C3—N1 | 178.9 (2) | C2—S1—C9—N1 | −0.59 (17) |
S1—C2—C3—N1 | −0.6 (3) | C8—O1—C10—O2 | −3.5 (3) |
C18—C2—C3—N3 | −8.9 (4) | C8—O1—C10—C6 | 174.89 (19) |
S1—C2—C3—N3 | 171.65 (19) | C7—C6—C10—O2 | −9.0 (4) |
C9—N1—C3—C2 | 0.1 (3) | C5—C6—C10—O2 | 166.8 (2) |
C5—N1—C3—C2 | −163.4 (2) | C7—C6—C10—O1 | 172.7 (2) |
C9—N1—C3—N3 | −173.04 (18) | C5—C6—C10—O1 | −11.5 (3) |
C5—N1—C3—N3 | 23.4 (3) | N1—C5—C11—C12 | 59.5 (3) |
C19—N3—C3—C2 | 71.3 (3) | C6—C5—C11—C12 | −60.2 (3) |
C19—N3—C3—N1 | −116.8 (2) | N1—C5—C11—C16 | −117.8 (2) |
C9—N1—C5—C11 | −99.3 (2) | C6—C5—C11—C16 | 122.5 (2) |
C3—N1—C5—C11 | 63.1 (3) | C16—C11—C12—C13 | −0.3 (3) |
C9—N1—C5—C6 | 24.2 (3) | C5—C11—C12—C13 | −177.6 (2) |
C3—N1—C5—C6 | −173.38 (19) | C11—C12—C13—C14 | 0.8 (4) |
N1—C5—C6—C7 | −15.6 (3) | C12—C13—C14—C15 | −0.6 (4) |
C11—C5—C6—C7 | 105.5 (2) | C17—O3—C15—C14 | −174.8 (2) |
N1—C5—C6—C10 | 168.50 (18) | C17—O3—C15—C16 | 3.1 (4) |
C11—C5—C6—C10 | −70.4 (3) | C13—C14—C15—O3 | 178.0 (2) |
C10—C6—C7—N2 | 174.6 (2) | C13—C14—C15—C16 | 0.0 (4) |
C5—C6—C7—N2 | −1.0 (3) | O3—C15—C16—C11 | −177.3 (2) |
C10—C6—C7—C1 | −7.2 (4) | C14—C15—C16—C11 | 0.5 (4) |
C5—C6—C7—C1 | 177.2 (2) | C12—C11—C16—C15 | −0.3 (3) |
C9—N2—C7—C6 | 11.2 (3) | C5—C11—C16—C15 | 177.0 (2) |
C9—N2—C7—C1 | −167.2 (2) | C3—C2—C18—N4 | −50 (14) |
C10—O1—C8—C4 | −177.4 (2) | S1—C2—C18—N4 | 130 (13) |
C7—N2—C9—N1 | −2.1 (3) | C3—N3—C19—O4 | −176.35 (19) |
C7—N2—C9—S1 | 176.16 (16) | C3—N3—C19—C20 | 5.0 (4) |
C3—N1—C9—N2 | 178.8 (2) | C21—O4—C19—N3 | 9.1 (3) |
C5—N1—C9—N2 | −17.5 (3) | C21—O4—C19—C20 | −172.0 (2) |
C3—N1—C9—S1 | 0.4 (2) | C19—O4—C21—C22 | 84.7 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13···N4i | 0.95 | 2.67 | 3.396 (4) | 134 |
C21—H21A···N2ii | 0.99 | 2.65 | 3.538 (2) | 149 |
C20—H20B···O4iii | 0.98 | 2.68 | 3.249 (5) | 117 |
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) −x, y, −z+1/2; (iii) −x+1/2, −y+3/2, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13···N4i | 0.95 | 2.668 | 3.396 (4) | 134 |
C21—H21A···N2ii | 0.99 | 2.652 | 3.538 (2) | 149 |
C20—H20B···O4iii | 0.98 | 2.680 | 3.249 (5) | 117 |
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) −x, y, −z+1/2; (iii) −x+1/2, −y+3/2, −z+1. |
Acknowledgements
MSK is thankful to the University Grants Commission (UGC), India, for a UGC–BSR meritorious fellowship.
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Pyrimidine has been subjected to a variety of structural modifications in order to synthesize derivatives (Singh et al., 2011) with different biological properties, among which, a thiazole ring fused to a pyrimidine ring, viz. a thiazolopyrimidine, has been found to be more active (Ozair et al., 2010a,b; Sayed et al., 2010). Thiazolo[3,2-a]pyrimidine derivatives act as potential enzyme inhibitors and are novel therapeutic entities for severe neurodegenerative diseases (Zhi et al., 2008). In continuation of our research interests on thiazolo[3,2-a]pyrimidine derivatives (Krishnamurthy & Begum, 2014; Krishnamurthy et al., 2014), we attempted to synthesize tricyclic thiazolopyrimidine derivatives (Mobinikhaledi et al., 2005). The title compound, an intermediate, was isolated and we report herein on its crystal structure.
The molecular structure of the title compound is shown in Fig. 1. The 3-methoxy phenyl ring at chiral carbon C5 is positioned axially and exactly bisects the thiazolopyrimidine ring with a dihedral angle of 83.88 (7)°. The pyrimidine ring adopts a flattened sofa conformation with atom N1 displaced by 0.2358 (6) Å from the mean plane of the other five atoms (C5/C6/C7/N2/C9). The carbonyl group of the exocyclic ester at C6 adopts a cis orientation with respect to C6—C7 double bond. The 3-methoxy phenyl ring adopts a syn periplanar conformation with respect to C5—H5 bond of the pyrimidine ring. The thiazole ring is essentially planar (r.m.s. deviation = 0.0034 Å).
In the crystal, pairs of weak C—H···O hydrogen bonds link molecules related by twofold rotation axes to form R22(8) rings, which are in turn linked by weak C—H···N interactions to form ribbons along [110]; Table 1 and Fig. 2. In addition, π–π stacking interactions with a centroid—centroid distance of 3.5744 (15) Å connect the ribbons to form slabs lying parallel to (001); [Cg1···.Cg1i where Cg1 is the centroid of ring S1/N1/C2/C3/C9; symmetry code: (i) -x, y, -z+1/2].