6-Methyl-3-phenyl-2-sulfanyl­idene-1,2,3,4-tetra­hydro­quinazolin-4-one

Adel S El-Azab; Alaa A-M Abdel-Aziz; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812007301

. 2012 Feb 29;68(Pt 3):o862. doi: 10.1107/S1600536812007301

6-Methyl-3-phenyl-2-sulfanylidene-1,2,3,4-tetrahydroquinazolin-4-one

Adel S El-Azab ^a,^b,^‡, Alaa A-M Abdel-Aziz ^a,^c, Seik Weng Ng ^d,^e, Edward R T Tiekink ^d,^*

PMCID: PMC3297914 PMID: 22412717

Abstract

The title compound, C₁₅H₁₂N₂OS, exists as the thione tautomer in the solid state. The phenyl group is almost perpendicular [dihedral angle = 87.96 (5)°] to the fused ring system (r.m.s. deviation = 0.036 Å for 13 ring and exocyclic non-H atoms). In the crystal, centrosymmetric dimers, sustained by pairs of N—H⋯S hydrogen bonds, are connected into layers parallel to (-101) by C—H⋯O and C—H⋯S interactions.

Related literature

For recent studies on synthesis, drug discovery and crystal structures of quinazoline-4(3H)-one derivatives, see: El-Azab & El-Tahir (2012 ▶); El-Azab et al. (2011 ▶, 2010 ▶). For the antimicrobial activity of the title compound, see: Al-Omar et al. (2004 ▶). For the structures of related compounds, see: Bowman et al. (2007 ▶); Hashim et al. (2010 ▶).

Experimental

Crystal data

C₁₅H₁₂N₂OS
M _r = 268.33
Monoclinic,
a = 12.7770 (3) Å
b = 5.1384 (1) Å
c = 19.0973 (4) Å
β = 91.814 (2)°
V = 1253.17 (5) Å³
Z = 4
Cu Kα radiation
μ = 2.23 mm⁻¹
T = 100 K
0.35 × 0.15 × 0.05 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.967, T _max = 0.998
4636 measured reflections
2576 independent reflections
2348 reflections with I > 2σ(I)
R _int = 0.016

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.098
S = 1.06
2576 reflections
177 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812007301/qm2054sup1.cif

e-68-0o862-sup1.cif^{(18.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812007301/qm2054Isup2.hkl

e-68-0o862-Isup2.hkl^{(126.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812007301/qm2054Isup3.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
N2—H1n⋯S1ⁱ	0.91 (2)	2.49 (2)	3.3662 (12)	163.6 (17)
C3—H3⋯O1ⁱⁱ	0.95	2.33	3.2522 (17)	163
C11—H11⋯S1ⁱⁱⁱ	0.95	2.86	3.7333 (16)	154
C15—H15⋯O1^iv	0.95	2.32	3.1988 (18)	154

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

Acknowledgments

This work was supported by the Research Center of Pharmacy, King Saud University, Riyadh, Saudi Arabia. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

Quinazoline-4(3H)-one derivatives are known for their various biological activities (El-Azab & El-Tahir, 2012; El-Azab et al. (2011, 2010). The title compound (I) has been investigated previously for its anti-microbial activity (Al-Omar et al., 2004). Herein, its crystal and molecular structure is described.

The key result of the crystal structure determination of (I), Fig. 1, is the confirmation that the compound exists as the thione tautomer in the solid-state. The non-hydrogen atoms comprising the fused ring system, including the exocyclic atoms, are co-planar with a r.m.s. deviation = 0.036 Å. The maximum deviations from the least-squares plane through these atoms are 0.038 (1) Å for the S1 atom and -0.085 (1) Å for N1, consistent with some pyramidal character for the latter atom. The phenyl group is almost perpendicular to the aforementioned plane: the dihedral angle = 87.96 (5)°.

The presence of the thione tautomer confirms the results of previous structure determinations on related compounds (Bowman et al., 2007; Hashim et al., 2010).

The key feature of the crystal packing is the formation of N—H···S hydrogen bonds between centrosymmetrically related molecules, Table 1. The dimeric aggregates thus formed are connected into layers parallel to (1 0 1) by C—H···O interactions, involving the bifurcated carbonyl-O atom, and C—H···S interactions, Fig. 2 and Table 1. Layers stack with no specific intermolecular interactions between them, Fig. 3.

Experimental

A mixture of 2-amino-5-methylbenzoic acid (1.51 g m, 10 mmol) and phenyl isothiocyanate (1.35 g m, 10 mmol) in absolute ethanol (30 ml) containing triethylamine (1.1 mg, 10 mmol) was refluxed for 3 h. The reaction mixture was allowed to cool, the solvent was removed under reduced pressure, and the solid obtained was dried and recrystallized from EtOH. Yield 90%; M.pt: 340–342 K; ¹H NMR (500 MHz, DMSO-d6): δ 12.98 (s, 1H, exchangeable), 7.75 (s, 1H), 7.60 (d, 1H, J=8.0 Hz), 7.48 (t, 2H, J=7.0, 7.5 Hz), 7.41 (d, 1H, J=7.0 Hz), 7.36 (d, 1H, J=8.0 Hz), 7.26 (d, 2H, J=8.0 Hz), 2.37 (s, 3H). ¹³C NMR (DMSO-d6): δ 176.0, 160.2, 139.8, 138.1, 137.1, 134.4, 129.5, 129.3, 128.5, 127.2, 116.5, 116.2, 20.9.