Methyl 5-(4-hy­droxy-3-meth­oxy­phen­yl)-2-(4-meth­oxy­benzyl­idene)-7-methyl-3-oxo-2,3-dihydro-5H-thia­zolo[3,2-a]pyrimidine-6-carboxyl­ate

H Nagarajaiah; Noor Shahina Begum

doi:10.1107/S1600536811048987

. 2011 Nov 25;67(Pt 12):o3444. doi: 10.1107/S1600536811048987

Methyl 5-(4-hydroxy-3-methoxyphenyl)-2-(4-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-6-carboxylate

H Nagarajaiah ^a, Noor Shahina Begum ^a,^*

PMCID: PMC3239076 PMID: 22199924

Abstract

In the title compound, C₂₄H₂₂N₂O₆S, a pyrimidine ring substituted with 4-hydroxy-3-methoxyphenyl is fused with a thiazole ring. The 4-hydroxy-3-methoxyphenyl group is positioned axially to the pyrimidine ring, making a dihedral angle 85.36 (7)°. The pyrimidine ring adopts a twist boat conformation. In the crystal, O—H⋯N interactions result in a chain running along the b axis. The carbonyl O atom bonded to the thiazole ring is involved in two C—H⋯O hydrogen-bond interactions forming centrosymmetric dimers; the ten- and six-membered rings resulting from these interactions have R ₂ ²(10) and R ₁ ²(6) motifs, respectively.

Related literature

For pharmacological properties of pyrimidine derivatives, see: Alam et al. (2010 ▶). For related structures, see: Jotani et al. (2010 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₄H₂₂N₂O₆S
M _r = 466.50
Triclinic,
a = 6.8096 (12) Å
b = 9.9343 (18) Å
c = 16.246 (3) Å
α = 86.816 (3)°
β = 85.588 (3)°
γ = 81.318 (3)°
V = 1082.1 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 296 K
0.18 × 0.16 × 0.16 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.966, T _max = 0.969
6570 measured reflections
4581 independent reflections
3452 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.069
wR(F ²) = 0.279
S = 1.33
4581 reflections
303 parameters
H-atom parameters constrained
Δρ_max = 0.69 e Å⁻³
Δρ_min = −0.62 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: 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 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811048987/pv2473sup1.cif

e-67-o3444-sup1.cif^{(22.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811048987/pv2473Isup2.hkl

e-67-o3444-Isup2.hkl^{(219.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811048987/pv2473Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H6⋯N2ⁱ	0.82	2.01	2.783 (4)	156
C10—H10⋯O2ⁱⁱ	0.93	2.55	3.425 (4)	156
C12—H12⋯O2ⁱⁱ	0.93	2.67	3.499 (4)	149
C1—H1A⋯O6ⁱⁱⁱ	0.96	2.57	3.444 (5)	152
C17—H17C⋯O2^iv	0.96	2.47	3.429 (5)	179

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

NSB is thankful to the University Grants Commission (UGC), India, for financial assistance and the Department of Science and Technology, (DST), India, for the data-collection facility under the IRHPA–DST program.

supplementary crystallographic information

Comment

Pyrimidine derivatives are of interest because of their pharmacological properties (Alam et al., 2010).

The central pyrimidine ring with a chiral C5 atom is significantly puckered and adopts a conformation which is best described as an intermediate between a boat and a screw boat form as seen earlier (Jotani et al., 2010). The atoms C5 and N1 deviate from the mean plane C6/C7/N2/C8 by 0.1024 (3) and -0.0602 (3) Å, respectively, indicating that the conformation of the pyrimidine ring is that of a twisted boat. In the molecule, The fused thiazole-pyrimidine ring is coplanar with benzylidene ring with dihedral angle 5.19 (7)°. The dihedral angle between the thiazolopyrimidine ring and 4-hydroxy-3-methoxy-phenyl group is 85.36 (7)°. The crystal structure is stabilized by a strong intermolecular O—H···N hydrogen bond resulting in a one dimensional chain of molecules along the b axis. The structure is further consolidated by C—H···O type intermolecular interactions, involving carbonyl O2 atom, forming centrosymmetric dimers; the ten and 6 membered rings thus resulting from these interactions can be described as R²₂(10) and R²₁(6) motifs in graph-set notations (Bernstein et al., 1995).

Experimental

A mixture of 4-(4-hydroxy-3-methoxy-phenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydro -pyrimidine-5-carboxylic acid methyl ester (0.01 mol), chloroaceticacid (0.01 mol), 4-methoxy benzaldehyde (0.01 mol) and sodium acetate (1.5 g) in a mixture of glacial acetic acid and acetic anhydride (25 ml; 1:1) was refluxed for 8–10 h.The reaction mixture was concentrated and the solid thus obtained was filtered and recrystallized from ethyl acetate to get the title compound. (78% yield, mp 427 K). The compound was recrystallized by slow evaporation of an ethyl acetate-ethanol (3:2) solution, yielding pale yellow single crystals suitable for X-ray diffraction studies.