(R)-2-Phen­oxy-1-(4-phenyl-2-sulfan­ylidene-1,3-oxazolidin-3-yl)ethanone

Ignez Caracelli; Daniel C S Coelho; Paulo R Olivato; Thiago C Correra; Alessandro Rodrigues; Edward R T Tiekink

doi:10.1107/S160053681103858X

. 2011 Sep 30;67(Pt 10):o2755–o2756. doi: 10.1107/S160053681103858X

(R)-2-Phenoxy-1-(4-phenyl-2-sulfanylidene-1,3-oxazolidin-3-yl)ethanone

Ignez Caracelli ^a,^*, Daniel C S Coelho ^b, Paulo R Olivato ^c, Thiago C Correra ^c, Alessandro Rodrigues ^d, Edward R T Tiekink ^e

PMCID: PMC3201535 PMID: 22065310

Abstract

The central 1,3-oxazolidine-2-thione ring in the title compound, C₁₇H₁₅NO₃S, is approximately planar with maximum deviations of 0.036 (4) and −0.041 (5) Å for the O and methylene-C atoms, respectively. The dihedral angles formed between this plane and the two benzene rings, which lie to the same side of the central plane, are 86.5 (2) [ring-bound benzene] and 50.6 (3)°. The ethan-1-one residue is also twisted out of the central plane, forming a O—C—N—C torsion angle of 151.5 (5)°. The dihedral angle formed by the benzene rings is 62.8 (2)° so that overall, the molecule has a twisted U-shape. In the crystal, molecules are linked into supramolecular arrays two molecules thick in the bc plane through C—H⋯O, C—H⋯S and C—H⋯π interactions.

Related literature

For background to oxazolidine-2-thiones, see: Evans et al. (1981 ▶); Crimmins & King (1998 ▶); Zhang et al. (2004) ▶; Shinisha & Sunoj (2010 ▶); Tamura et al. (2009 ▶). For related structures, see: Kitoh et al. (2002 ▶). For the synthesis, see: Wu et al. (2004 ▶); Rodrigues et al. (2005 ▶).

Experimental

Crystal data

C₁₇H₁₅NO₃S
M _r = 313.37
Monoclinic,
a = 33.514 (3) Å
b = 5.7514 (6) Å
c = 7.7172 (8) Å
β = 93.808 (7)°
V = 1484.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 126 K
0.30 × 0.25 × 0.16 mm

Data collection

Bruker APEXII CCD diffractometer
7408 measured reflections
2588 independent reflections
2166 reflections with I > 2σ(I)
R _int = 0.064

Refinement

R[F ² > 2σ(F ²)] = 0.066
wR(F ²) = 0.180
S = 1.08
2588 reflections
199 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.81 e Å⁻³
Δρ_min = −0.47 e Å⁻³
Absolute structure: Flack (1983 ▶), 1143 Friedel pairs
Flack parameter: 0.01 (18)

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); 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: MarvinSketch (Chemaxon, 2010 ▶) and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681103858X/hg5095sup1.cif

e-67-o2755-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681103858X/hg5095Isup2.hkl

e-67-o2755-Isup2.hkl^{(124.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681103858X/hg5095Isup3.cml

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

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

Cg1 and Cg2 are the centroids of the C4–C9 and C12–C17 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5⋯O2ⁱ	0.95	2.29	3.202 (6)	162
C9—H9⋯O3ⁱⁱ	0.95	2.56	3.350 (6)	140
C11—H11b⋯Sⁱⁱⁱ	0.99	2.87	3.814 (5)	160
C17—H17⋯Cg1^iv	0.95	2.99	3.703 (5)	133
C8—H8⋯Cg2ⁱⁱ	0.95	2.79	3.523 (6)	135

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

Acknowledgments

We thank the Brazilian agencies FAPESP, CNPq (fellowships to IC and PRO) and CAPES (808/2009 to IC) for financial support. We also thank Dr Charles H. Lake from Indiana University of Pennsylvania for the data collection during the American Crystallographic Association Summer Course in small molecule crystallography.

supplementary crystallographic information

Comment

Since the first report in 1981 (Evans et al. 1981) exploring oxazolidin-2-ones as chiral auxiliaries in enantioselective aldol condensations, a number of related oxazolidin-2-ones and their synthetic applications have been reported. Recently, studies have shown that sulfur oxazolidine-2-thione derivatives have some advantages in terms of the asymmetric induction over the original 2-oxo analogues (Crimmins et al., 1998; Zhang et al., 2004; Shinisha et al., 2010). For this reason, the use of oxazolidine-2-thiones as chiral auxiliaries is a widely employed strategy for the total synthesis of relevant biological compounds (Tamura et al., 2009). An interesting study reported by Kitoh and collaborators (Kitoh et al., 2002) showed an alternative route to chiral 4-phenyl-1,3-oxazolidine-2-thione by optical resolution of the racemate through preferential crystallization. In this study, the crystal structure and vibrational spectra analysis of chiral 4-phenyl-1,3-oxazolidine-2-thione, (I), are reported.

The molecular structure of (I), Fig. 1, features a planar 1,3-oxazolidine-2-thione ring with the maximum deviations from the least-squares plane being 0.036 (4) for atom O1 and -0.041 (5) for atom C2. With reference to this plane, the two benzene rings are orientated to the same side and form dihedral angles of 86.5 (2) [ring-bound benzene ring] and 50.6 (2) °, respectively, with it. The ethan-1-one group is not co-planar with the five-membered ring as seen in the value of the O2—C10—N—C1 torsion angle of 151.5 (5) °; the carbonyl-O2 atom lies to the opposide side of the central plane to the benzene rings. The dihedral angle formed between the two benzene rings of 62.8 (2) ° indicates a non-parallel alignment. Overall, the molecule of (I) adopts a twisted U-shape.

The presence of C—H···O and C—H···S contacts, Table 1, leads to the formation of supramolecular 2-D arrays in the bc-plane, Fig. 2. The layers are two molecules thick. Additional stability to the layers is afforded by C—H···π interactions, Table 1. The layers with a flat topology stack along the a-direction, Fig. 3.

Experimental

The starting (R)-4-phenyloxazolidine-2-thione was synthesized from (R)-phenylglycine in three steps as previously reported (Wu et al. 2004). The phenoxyacetyl-oxazolidine- 2-thione derivative was prepared by acylation of (R)-4- phenyloxazolidine-2-thione (Rodrigues et al. 2005). The title compound was then obtained by adding DCC (N,N'-dicyclohexylcarbodiimide) (690 mg, 3.35 mmol) in one portion to an ice-cooled solution of (R)-4-phenyloxazolidine-2-thione (500 mg, 2.79 mmol), N,N-dimethylpyridin-4-amine (34 mg, 0.28 mmol) and 2-phenoxyacetic acid (510 mg, 3.35 mmol) in methylene chloride (10 ml). The resulting suspension, kept under a nitrogen atmosphere during the reaction time, was then allowed to reach r.t. After 48 h under stirring, the dicyclohexylurea formed was filtered off and the precipitate washed with methylene chloride (10 ml). The organic layers were washed with a sat. aq. solution of NaHCO₃ (20 ml) and dried over Na₂SO₄. Filtration and evaporation of the solvent in vacuum gave the crude product which was purified by flash column chromatography on silica gel with 30% acetone in hexanes to give the pure product as a white solid (320 mg, 37%). Colourless crystals of the compound were obtained by vapour diffusion from hexane/acetone at 298 K: m.p. = 385–387 K;[α]_D²⁵ -66.7° (c 1.8, CHCl₃); ¹H NMR (300 MHz, CDCl₃/TMS), δ (p.p.m.): 7.40–7.29 (m, 5H), 7.26–7.21 (m, 2H), 6.98–6.92 (m, 1H), 6.85–6.82 (m, 2H), 5.71 (dd,³J = 8.65 Hz, ³J = 3.24 Hz, 1H), 5.55 (AB system,Δν = 56.0 Hz, ²J = 17.7 Hz, 1H). ³C NMR (75 MHz, CDCl₃/TMS); δ(p.p.m.): 184.93, 168.69, 157.60, 137.99, 129.52, 129.32, 129.14, 126.29, 121.70, 114.76, 75.26, 69.34, 62.07. Anal. calcd. for C₁₇H₁₅NO₃S: C,65.16%; H,4.82%, N, 4.47%. Found: C,64.48%; H,4.71%, N, 4.18%. Mass Spectra: M+ = 314.0836, Exact mass = 314.0845.