4-[2-(Benzyl­sulfan­yl)acet­yl]-3,4-dihydro­quinoxalin-2(1H)-one

Waqar Nasir; Munawar Ali Munawar; Sohail Nadeem; Rana Amjad; Ahmad Adnan

doi:10.1107/S1600536811008178

. 2011 Mar 12;67(Pt 4):o848. doi: 10.1107/S1600536811008178

4-[2-(Benzylsulfanyl)acetyl]-3,4-dihydroquinoxalin-2(1H)-one

Waqar Nasir ^a, Munawar Ali Munawar ^a,^*, Sohail Nadeem ^a, Rana Amjad ^a, Ahmad Adnan ^b

PMCID: PMC3099835 PMID: 21754130

Abstract

In the title compound, C₁₇H₁₆N₂O₂S, the pyrazinone ring is non-planar (r.m.s. deviation = 0.1595 Å), with maximum deviations for the 4-position N atom and the adjacent non-fused-ring C atom of 0.2557 (15) and −0.2118 (16) Å, respectively. The dihedral angle between the benzyl ring and pyrazinone rings is 30.45 (18)°. Intermolecular N—H⋯O hydrogen-bonding interactions forms inversion dimers which lead to eight-membered R ₂ ²(8) ring motifs. The dimers are further connected by C—H⋯O interactions.

Related literature

For the biological activity of quinoxalines, see: Ali et al. (2000 ▶); Moustafa & Yameda (2001 ▶). For related structures see: Nasir et al. (2009) ▶. For graph-set notation, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₇H₁₆N₂O₂S
M _r = 312.38
Orthorhombic,
a = 13.9502 (8) Å
b = 32.2588 (17) Å
c = 6.9728 (3) Å
V = 3137.9 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 296 K
0.47 × 0.23 × 0.07 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.906, T _max = 0.985
16363 measured reflections
3892 independent reflections
2412 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.183
S = 1.00
3889 reflections
203 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811008178/hg2799sup1.cif

e-67-0o848-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811008178/hg2799Isup2.hkl

e-67-0o848-Isup2.hkl^{(186.9KB, hkl)}

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
C5—H5⋯O4ⁱ	0.93	2.60	3.452 (3)	153
C10—H10B⋯O4ⁱ	0.97	2.45	3.202 (3)	134
N2—H1N⋯O3ⁱⁱ	0.85 (3)	2.02 (3)	2.875 (3)	175 (3)

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

Acknowledgments

The authors acknowledge the Higher Education Commission, Pakistan, for providing funding for this research.

supplementary crystallographic information

Comment

Annulated pyrazines like quinoxalinones represents an important class of nitrogen containing heterocyclic compounds possessing wide variety of biological and industrial applications. The synthetic and naturally occurring quinoxalines compounds have been reported to show antibacterial (Ali et al., 2000) and antitumor (Moustafa & Yameda, 2001). In the present project we aimed to synthesize novel quinoxalinone derivatives which may have enhanced biological and pharmaceutical application.

The title compound (I) is in continuation of previously published work on the analoguous structure, 4-[(2,5-dimethylanilino)acetyl]-3,4- dihydroquinoxalin-2(1H)-one (II) (Nasir, et al., 2009). The dihedral angle between the aromatic ring (C1/C2/C3/C4/C5/C6) and pyrazinone (C1/C6/N2/C8/C7/N1)is 14.01 (12)°. Unlike (II) no intramolecular hydrogen bonding have been observed in (I). The N—H···O type intermolecular hydrogen bonding developed from the cyclic amido functional group forms the inversion dimers and produce eight membered ring motif R₂²(8) (Bernstein et al., 1995). Another C—H···O type hydrogen bonding interaction connects these dimers to another molecule Fig. 2. The benzyl ring (C12/C13/C14/C15/C16/C17) is oriented at dihedral angle of 14.01 (12)° and 30.45 (18)° with respect to aromatic and pyrazinone rings.

Experimental

To a suspension of 4-(chloroacetyl)-3,4-dihydroquinoxalin-2(1H)-2-one (2.0 g, 8.9 mmoles) in absolute ethanol (60 mL) fine powdered sodium bicarbonate (1.5 g, 17.8 mmole) was added along with phenylmethanethiol (1.1 mL, 9.0 mmoles). The reaction mixture was heated under reflux for 8-10 h, the progress of the reaction was monitored by TLC (chloroform:ethyl acetate, 7:3 v/v). The reaction mixture was concentrated to half of the original volume under reduced pressure and the precipitate of the product which formed on cooling was filtered, washed with cold ethanol and recrystallized in ethanol.