Ethyl 5-oxo-4-phenyl-5,6-di­hydro-4H-1,3,4-oxadiazine-2-carboxyl­ate

K Shubakara; Chandra; N Srikantamurthy; M Mahendra; K B Umesha

doi:10.1107/S1600536814011106

. 2014 May 17;70(Pt 6):o661. doi: 10.1107/S1600536814011106

Ethyl 5-oxo-4-phenyl-5,6-dihydro-4H-1,3,4-oxadiazine-2-carboxylate

K Shubakara ^a, Chandra ^b, N Srikantamurthy ^a, M Mahendra ^b, K B Umesha ^a,^*

PMCID: PMC4051085 PMID: 24940244

Abstract

The asymmetric unit of title compound, C₁₂H₁₂N₂O₄, consists of two independent molecules. In each molecule, the oxadiazine ring has a flattened envelope conformation with the methylene C atom as the flap atom, and the ethoxycarbonyl unit is in a syn-periplanar conformation with respect to the oxadiazine ring as indicated by O—C—C=O torsion angles of 1.9 (4) and 2.5 (4)°. The dihedral angles between the mean plane of the oxadiazine ring and the phenyl ring are 80.07 (13) and 42.98 (14)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds and stacked in a double-column along the a-axis direction.

Related literature

For the biological activity of oxadiazine derivatives, see: Barbari et al. (2003 ▶); Gsell & Maientisch (1998 ▶). For a related structure, see: Chopra et al. (2004 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶). graphic file with name e-70-0o661-scheme1.jpg

Experimental

Crystal data

C₁₂H₁₂N₂O₄
M _r = 248.24
Triclinic,
a = 9.3499 (7) Å
b = 9.3601 (8) Å
c = 15.2707 (15) Å
α = 104.007 (8)°
β = 99.366 (7)°
γ = 107.862 (7)°
V = 1192.9 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 296 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
9756 measured reflections
4176 independent reflections
2173 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.054
wR(F ²) = 0.177
S = 1.03
4176 reflections
327 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814011106/is5362sup1.cif

e-70-0o661-sup1.cif^{(34.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814011106/is5362Isup2.hkl

e-70-0o661-Isup2.hkl^{(204.6KB, hkl)}

Click here for additional data file.^{(4.8KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814011106/is5362Isup3.cml

CCDC reference: 1003020

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2A—H2A2⋯O1A ⁱ	0.97	2.55	3.150 (3)	120
C14B—H14A⋯O3A ⁱⁱ	0.97	2.59	3.418 (4)	143
C14B—H14B⋯O5B ⁱⁱ	0.97	2.57	3.163 (3)	120

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

Acknowledgments

Chandra would like to thank the UGC, New Delhi, for the award of an RFSMS fellowship under the head DV5/Physics/389/RFSMS/2009–2010/10.07.2012.

supplementary crystallographic information

1. Comment

Heterocyclic compounds containing nitrogen and oxygen atoms are of great synthetic interest due to their versatile biological significance. Oxadiazine derivatives are one among those heterocyclic compounds exhibiting various biological activities, for instance 1,2,5-oxadiazine-3,6-diones are potent antiviral agents (Barbari et al., 2003). Also, as an important type of insecticides, oxadiazine derivatives are highly efficient and of low toxicity (Gsell & Maientisch, 1998). With this background on oxadiazine derivatives, we have synthesized the title compound to study its crystal structure.

The two independent molecules (A and B) of the title compound (Fig. 1) in the asymmetric unit exhibit highly planar conformation, with their maximum deviations on ring planes at N1A and N3B are 0.081 (2) Å and 0.055 (2) Å, respectively. The central oxadiazine moiety adopts a flattened envelope conformation with puckering parameters Q(2) = 0.281 (3) Å, Q(3) = 0.118 (3) Å and φ = 325.4 (6)° (Cremer & Pople, 1975). The bond lengths and angles are generally within normal ranges and are comparable to a related structure (Chopra et al., 2004). In the molecules A and B, the oxadiazine moiety makes a dihedral angle of 80.07 (13) and 42.98 (14)°, with the phenyl rings (C4A–C9A and C16B–C21B), respectively. The ethoxycarbonyl unit is in a syn-periplanar conformation with respect to the oxadiazine moiety, as indicated by the torsion angles of 1.9 (4)° (O1A—C1A—C10A—O3A) and 2.5 (4)° (O5B—C13B—C22B—O7B) for A and B, respectively. The crystal structure is stabilized by C—H···O hydrogen bonds and the molecules are stacked in a column along the a axis (Fig. 2).

2. Experimental

Ethyl 5-oxo-4-phenyl-5,6-dihydro-4H-1,3,4-oxadiazine-2-carboxylate were obtained from ethyl 2-oxo-2-(2-phenylhydrazinyl) acetate by one pot condensation-cyclization reaction with chloroacetylchloride using potassium carbonate in dry acetone as a solvent. Compounds were purified by column chromatography using petroleum ether and acetone in (2:8) as eluent.