(R)-(+)-Dimeth­yl[4-oxido-2-oxo-1-(1-phenyl­eth­yl)-1,2,5,6-tetra­hydro­pyridin-3-yl]sulfonium

Paola G Gordillo; Joel L Terán; Jorge R Juárez; Angel Mendoza

doi:10.1107/S1600536810052955

. 2011 Jan 8;67(Pt 2):o239. doi: 10.1107/S1600536810052955

(R)-(+)-Dimethyl[4-oxido-2-oxo-1-(1-phenylethyl)-1,2,5,6-tetrahydropyridin-3-yl]sulfonium

Paola G Gordillo ^a, Joel L Terán ^a, Jorge R Juárez ^a, Angel Mendoza ^a,^*

PMCID: PMC3051604 PMID: 21522933

Abstract

In the title zwitterionic compound, C₁₅H₁₉NO₂S, the six-membered heterocycle adopts a sofa conformation. The negative charge is delocalized along the carbonyl and enolate system on the ring and the positive charge is localized on the S atom. Two intermolecular C—H⋯O interactions help to establish the packing.

Related literature

For background to the synthesis of chiral non-racemic zwitterionic 4-alkoxy-3-sulfonium ylide pyridine-2-ones, see: Zang et al. (2008 ▶); Kappe et al. (1983 ▶); Palillero et al. (2009 ▶). For the biological activity of related structures, see: Basco et al. (1994 ▶); Koruzňjak et al., 2003 ▶). For ring conformation analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₅H₁₉NO₂S
M _r = 277.37
Orthorhombic,
a = 5.9860 (17) Å
b = 7.4050 (14) Å
c = 31.589 (5) Å
V = 1400.2 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 293 K
0.5 × 0.4 × 0.2 mm

Data collection

Siemens P4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.728, T _max = 0.846
3016 measured reflections
2683 independent reflections
1928 reflections with I > 2σ(I)
R _int = 0.045
3 standard reflections every 97 reflections intensity decay: 3%

Refinement

R[F ² > 2σ(F ²)] = 0.061
wR(F ²) = 0.153
S = 1.03
2683 reflections
172 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.39 e Å⁻³
Absolute structure: Flack (1983 ▶), 532 Friedel pairs
Flack parameter: −0.01 (16)

Data collection: XSCANS (Siemens, 1994 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810052955/bt5438sup1.cif

e-67-0o239-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052955/bt5438Isup2.hkl

e-67-0o239-Isup2.hkl^{(129.1KB, 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
C7—H7C⋯O2ⁱ	0.96	2.36	3.315 (6)	172
C15—H15A⋯O1ⁱⁱ	0.96	2.38	3.167 (5)	138

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

Acknowledgments

We are grateful to CONACyT (Project 83185) for financial support. PGG also thanks CONACyT for a scholarship (169011). Special thanks go to Dr Marcos Flores (USAI-FQ-UNAM) for useful comments.

supplementary crystallographic information

Comment

The synthesis of chiral non racemic zwitterionic 4-alkoxy-3-sulfonium ylide pyridine-2-ones is an original area of interest in organic chemistry (Zang et al., 2008; Kappe et al., 1983) because they are useful for the synthesis of piperidine-2,4-dione and pyridine-2-one (Palillero et al., 2009) compounds and because of their interesting biological properties (Basco et al., 1994; Koruzňjak et al., 2003).

The title compound I, features a zwitterionic molecule. The chiral centre shows an R configuration with [α]_D= +70.5. The six member ring N1/C1/C2/C3/C4/C5 shows an sofa conformation with puckering parameters (Cremer & Pople, 1975) Q = 0.465 (4) Å, θ₂ = 119.7 (5)°, φ₂ = 103.2 (6)°, q₂ = 0.404 (4) Å and q₃ = -0.231 (4) Å. The bond distances of N1—C1, N1—C5, C5—C4 and C4—C3 show typical values, so that C2—C3 distance shows a single double bond (1.415 (5) Å), while C1—C2 (1.455 (5) Å) distance is shorter than common sp³—sp³ bonds, furthermore C3—O2 (1.244 (5) Å) and C1—O1 (1.250 (4) Å) distances are longer than related enolates and amide groups respectively these values suggest that negative charge is delocalized over O1/C1/C2/C3/O2 system and in the sulfonium group is located the positive charge in the zwitterion. Crystal packing is stabilized by two weak intermolecular C —H···O interactions.

Experimental

The title compound, was obtained by an intramolecular cyclization reaction of (1'R)-(+)-{[(2-methoxycarbonyl-ethyl)-(1'-phenyl-ethyl)-carbamoyl]-methyl}-dimethyl-sulfonium; bromide (1 mmol), which was dissolved in CH₃CN (10 mL), treated with KOH (1.2 mmol) and stirred for two hours at room temperature. The resulting mixture was concentrated in vacuum and dissolved in ethyl acetate, filtered and concentrated giving the desired compound in 95%. Crystals were obtained from an ethyl acetate/diethylether solution; m.p. 139–140°C, [α]_D= +70.5 (c 1.1, MeOH). IR (KBr) 1656 cm^{-1. 1}H NMR (400 MHz, CDCl₃) δ (p.p.m., J Hz): 1.51 (d, J = 7.2, 3H, Me), 2.32 (m, 2H), 2.90 (m, 1H), 2.98 (s, 3H, SMe), 3.00 (s, 3H, SMe), 3.16 (m, 1H), 5.94 (q, J =7.2, 1H), 7.27–7.40 (m, 5H). ¹³C NMR (100 MHz, CDCl₃) δ p.p.m. 15.4, 26.0, 26.3, 36.3, 37.6, 48.9, 74.3, 126.5–141.0, 166.2, 187.5. HRMS (FAB): Calcd for C₁₅H₁₉NO₂S: 277.1124. Found: 277.1103.