Crystal structure of (2-methyl-4-phenyl-4H-benzo[4,5]thia­zolo[3,2-a]pyrimidin-3-yl)(phen­yl)methanone

T Sankar; S Naveen; N K Lokanath; K Gunasekaran

doi:10.1107/S2056989015006428

. 2015 Apr 2;71(Pt 5):o276–o277. doi: 10.1107/S2056989015006428

Crystal structure of (2-methyl-4-phenyl-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-3-yl)(phenyl)methanone

T Sankar ^a, S Naveen ^b, N K Lokanath ^c, K Gunasekaran ^a,^*

PMCID: PMC4420141 PMID: 25995902

Abstract

In the title compound, C₂₄H₁₈N₂OS, the pyrimidine ring has a flat envelope conformation with the methine C atom as the flap. The attached phenyl and benzoyl rings are inclined to the mean plane of the pyrimidine ring by 84.87 (8) and 75.33 (9)°, respectively. The benzothiazolo group is planar (r.m.s. deviation = 0.009 Å) and inclined to the mean plane of the pyrimidine ring by 3.27 (6)°. In the crystal, molecules are linked by pairs of C—H⋯N hydrogen bonds, forming inversion dimers.

Keywords: crystal structure, pyrimidine, benzo, thiazolo, C—H⋯N hydrogen bonding

Related literature

For general background to the biological activities of pyrimidine derivatives, see: Kumar et al. (2002 ▸); Baraldi et al. (2002 ▸); Nasr & Gineinah (2002 ▸). For literature on the synthesis of fused benzothiazolo derivatives, see: Nagarapu et al. (2013a ▸,b ▸). graphic file with name e-71-0o276-scheme1.jpg

Experimental

Crystal data

C₂₄H₁₈N₂OS
M _r = 382.46
Monoclinic,
a = 12.1894 (6) Å
b = 18.6119 (8) Å
c = 8.9370 (4) Å
β = 110.360 (1)°
V = 1900.85 (15) Å³
Z = 4
Cu Kα radiation
μ = 1.64 mm⁻¹
T = 296 K
0.25 × 0.20 × 0.18 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▸) T _min = 0.709, T _max = 0.745
11594 measured reflections
3090 independent reflections
3047 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.109
S = 1.08
3090 reflections
254 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▸); cell refinement: SAINT (Bruker, 2008 ▸); data reduction: SAINT; 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 ▸); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▸).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015006428/su5105sup1.cif

e-71-0o276-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015006428/su5105Isup2.hkl

e-71-0o276-Isup2.hkl^{(151.6KB, hkl)}

Click here for additional data file.^{(7.3KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015006428/su5105Isup3.cml

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015006428/su5105fig1.tif

The molecular structure of the title compound, with atom labelling. The displacement ellipsoids are drawn at the 30% probability level.

Click here for additional data file.^{(1.3MB, tif)}

a . DOI: 10.1107/S2056989015006428/su5105fig2.tif

The crystal packing of the title compound viewed along the a axis. The hydrogen bonds are shown as dashed lines (see Table 1 for details).

CCDC reference: 1056199

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C27H27N1ⁱ	0.93	2.56	3.472(2)	166

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are thankful to Institution of Excellence, University of Mysore, for providing the single-crystal X-ray diffraction facility.

supplementary crystallographic information

S1. Synthesis and crystallization

A mixture of benzaldehyde was treated with 1-phenyl butane 1-3-dione and 2-aminobenzothiazole in the presence of ammonium acetate in ethanol. The mixture was gently warmed in a water bath at 353 K until the colour changed to yellow. It was kept aside overnight at room temperature. On completion of reaction (monitored by TLC) the solid obtained was separated and purified by column chromatography using hexane and ethyl acetate as eluent. The solid obtained was recrystallized using a 1:1 mixture of ethanol and THF giving yellow block-like crystals.

S2. Structural commentary

Many pyrimidine derivatives show strong activity against bacteria, tumor and some viruses (Kumar et al., 2012; Baraldi et al., 2002; Nasr & Gineinah, 2002). Owing to the above said important properties of pyrimidine derivatives,the crystal structure determination of the title compound is carried out.

The molecular structure of the title compound is shown in Fig. 1. The pyrimidine ring [N1/C2/N19/C11—C13] has a envelope conformation with the maximum deviation of 0.1342 (17) Å shown by the flap atom C11. The attached phenyl ring [C15—C20] is twisted at an angle of 84.87 (8) ° with respect to pyrimidine ring mean plane. The thiazolo group [S3/C2/N10/C4/C9] is also planar and fused with a benzene ring [C4—C9]. The phenylmethanone ring [C23—C28] is almost perpendicular to the pyrimidine ring mean plane, with a dihedral angle between of 75.33 (9) Å.

In the crystal, molecules are linked via pairs of C—H···N hydrogen bonds forming inversion dimers (Table 1 and Fig. 2).

S3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. H atoms were positioned geometrically (C—H = 0.93-0.98 Å) and allowed to ride on their parent atoms, with U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for other H atoms.