Ethyl (E)-3-hy­droxy-2-{N-[2-(thio­phen-2-yl)ethen­yl]carbamo­yl}but-2-enoate

Bao-Shuo Liu; Sheng-Yin Zhao

doi:10.1107/S1600536812028176

. 2012 Jun 30;68(Pt 7):o2284. doi: 10.1107/S1600536812028176

Ethyl (E)-3-hydroxy-2-{N-[2-(thiophen-2-yl)ethenyl]carbamoyl}but-2-enoate

Bao-Shuo Liu ^a, Sheng-Yin Zhao ^a,^*

PMCID: PMC3394063 PMID: 22798928

Abstract

In the title compound, C₁₃H₁₅NO₄S, there are two independent but conformationally similar molecules in the asymmetric unit, both having an E conformation of the side-chain C=C group. Intramolecular N—H⋯O and O—H⋯O hydrogen-bonding interactions are present in both molecules. In the crystal, one of the molecule types is linked through intermolecular hydroxy–ketone O—H⋯O interactions, forming one-dimensional chains extending along [010], whereas the other molecule type shows no associations.

Related literature

For applications of 4-hydroxy-2-pyridones, see: Buisson et al. (1996 ▶); Jessen & Gademann (2010 ▶). For general background to the synthesis, see: Rigby & Burkhardt (1986 ▶); Rigby & Qabar (1989 ▶). For the structure of a similar compound, see: Zhao & Huang (2012 ▶).

Experimental

Crystal data

C₁₃H₁₅NO₄S
M _r = 281.33
Monoclinic,
a = 14.0185 (15) Å
b = 13.1232 (14) Å
c = 15.0141 (16) Å
β = 96.853 (2)°
V = 2742.4 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 293 K
0.32 × 0.21 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T _min = 0.394, T _max = 1.000
15596 measured reflections
5099 independent reflections
3538 reflections with I > 2σ(I)
R _int = 0.061

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.179
S = 1.05
5099 reflections
357 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: SMART (Bruker, 2003 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812028176/zs2216sup1.cif

e-68-o2284-sup1.cif^{(24.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812028176/zs2216Isup2.hkl

e-68-o2284-Isup2.hkl^{(249.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812028176/zs2216Isup3.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
N1′—H1′A⋯O3′	0.77 (3)	1.98 (3)	2.615 (3)	139 (3)
N1—H1A⋯O3	0.68 (3)	2.10 (3)	2.637 (3)	137 (3)
O2′—H2′⋯O1′	0.82	1.65	2.399 (3)	152
O2—H2A⋯O1	0.82	1.67	2.419 (3)	151
O2—H2A⋯O3ⁱ	0.82	2.48	2.936 (3)	117

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors acknowledge financial support from the National Natural Science Foundation of China (grant No. 21072029) and the Shanghai Municipal Natural Science Foundation (grant No. 10ZR1400700).

supplementary crystallographic information

Comment

The derivatives of 4-hydroxy-2-pyridones exhibit a wide range of biological activities (Buisson et al., 1996; Jessen & Gademann, 2010). The title compound, C₁₃H₁₅NO₄S, is an important intermediate in the synthesis of 4-hydroxy-2-pyridone derivatives (Rigby & Burkhardt, 1986; Rigby & Qabar, 1989). In the title compound, there are two independent but conformationally similar molecules in the asymmetric unit (Figs. 1 and 2), both of which have an E configuration of the side chain C5═C6. The molecular conformation is stabilized by intramolecular N—H···O_ketone and hydroxyl O—H···O_ketone hydrogen bonds (Table 1, Figs. 1 and 2).

In the crystal, only one of the molecule types is linked through intermolecular hydroxyl O—H···O_ketone interactions forming one-dimensional chain structures extending along (010) (Fig. 3), whereas the other molecule type is unassociated. The thiophene rings have normal hydrophobic contacts without any stacking interactions. For the structure of a similar compound, see Zhao & Huang (2012).

Experimental

To an ice-cooled solution of 3-(2-thienyl)acrylic acid (5.0 g, 32.5 mmol) in 70 ml of ethyl acetate was added triethylamine (4.3 g, 42.2 mmol) and diphenyl phosphorazidate (DPPA, 11.6 g, 42.2 mmol). The solution was stirred at room temperature for 4 h. The acyl azide product was washed by dilution with cold water. The organic layers were dried over MgSO₄, and the solvent was removed under reduced pressure (< 318 K). The acyl azide was dissolved in 50 ml of benzene and heated under reflux until azide decomposition was complete. The reaction mixture was then cooled to 273 K and ethyl sodio-acetoacetate [prepared from ethyl acetoacetate (5.07 g, 39.0 mmol) and sodium hydride (1.1 g, 60% dispersion in oil, 45.5 mmol) in toluene (100 ml) at 273 K] was added. After warming to room temperature for 2 h, the mixture was quenched with saturated aqueous ammonium chloride solution, rinsed with brine, and dried over MgSO₄. The solvent was removed in vacuo to give green crystals: 5.57 g, yield, 61.0% (m.p. 366–368 K). 1H NMR (400 MHz, chloroform-d) 1.37 (t, J = 7.1 Hz, 3H, CH₃), 2.47 (s, 3H, CH₃), 4.29 (q, J = 7.1 Hz, 2H, CH₂), 6.41 (d, J = 14.5 Hz, 1H, =CH), 6.91 (s, 1H, Ar—H), 6.93 (d, J = 4.4 Hz, 1H, Ar—H), 7.10 (d, J = 4.9 Hz, 1H, Ar—H), 7.41 (dd, J = 14.3, 10.8 Hz, 1H, =CH), 11.06 (d, J = 10.0 Hz, 1H, NH), 18.04 (s, 1H, OH). Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation at room temperature from a solution in a mixture of hexane and ethyl acetate (10:1).