(Z)-Methyl 3-(4-ethoxy­anilino)but-2-enoate

Li-Ping Zhang; Cai-Hua Ni; Zhi-Yong Li; Wei Zhang

doi:10.1107/S160053680800891X

. 2008 May 10;64(Pt 6):o1051. doi: 10.1107/S160053680800891X

(Z)-Methyl 3-(4-ethoxyanilino)but-2-enoate

Li-Ping Zhang ^a,^*, Cai-Hua Ni ^a, Zhi-Yong Li ^a, Wei Zhang ^a

PMCID: PMC2961375 PMID: 21202570

Abstract

The title compound, C₁₃H₁₇NO₃, was synthesized from methyl 3-oxobutanoate and 4-ethoxybenzenamine using a catalytic amount of InBr₃ under solvent-free conditions. The 3-aminobut-2-enoic acid methyl ester group is planar and forms a dihedral angle of 83.4 (1)° with the benzene ring. The ethoxy group is slightly twisted away from the benzene ring [dihedral angle = 13.8 (1)°]. An intramolecular N—H⋯O hydrogen bond generating an S(6) ring is observed. Molecules are linked into a chain along the b axis by intermolecular C—H⋯O hydrogen bonding.

Related literature

For general background on β-enamino esters, see: Bartoli et al. (1994 ▶); Cimarelli & Palmieri (1996 ▶); Cimarelli et al. (1994 ▶); Elassar & El-Khair (2003 ▶); Greenhill (1977 ▶); Lubell et al. (1991 ▶); Michael et al. (1999 ▶); Paola et al. (2000 ▶); Rybarczyk-Pirek & Grabowski (2002 ▶); Yunus et al. (2008 ▶).

Experimental

Crystal data

C₁₃H₁₇NO₃
M _r = 235.28
Monoclinic,
a = 12.421 (2) Å
b = 6.3372 (13) Å
c = 16.569 (3) Å
β = 96.519 (3)°
V = 1295.7 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 294 (2) K
0.30 × 0.26 × 0.20 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.942, T _max = 0.990
6917 measured reflections
2628 independent reflections
1629 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.136
S = 1.00
2628 reflections
158 parameters
H-atom parameters constrained
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.11 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1999 ▶); 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 datablocks global, I. DOI: 10.1107/S160053680800891X/ci2569sup1.cif

e-64-o1051-sup1.cif^{(17.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680800891X/ci2569Isup2.hkl

e-64-o1051-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
N1—H1⋯O2	0.86	2.08	2.741 (2)	133
C6—H6⋯O2ⁱ	0.93	2.57	3.362 (3)	143

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors acknowledge financial support from the Southern Yangtze University.

supplementary crystallographic information

Comment

β-Enamino esters are useful precursors for the preparation of biologically active compounds such as β-enamino acids, γ-enamino alcohols or β-enamino esters (Lubell et al., 1991; Bartoli et al., 1994; Cimarelli et al., 1994; Cimarelli & Palmieri, 1996). Therefore, many synthetic methods have been developed for the preparation of these compounds (Greenhill, 1977; Elassar et al., 2003; Michael et al., 1999). As part of our program on developing new environmental friendly methodologies for the preparation of β-enamino compounds, we have synthesized the title compound (Fig.1). We report here the crystal structure of it.

In the title molecule, the 3-amino-but-2-enoic acid methyl ester group is planar (r.m.s. deviation 0.045 Å) and it forms a dihedral angle of 83.4 (1)° with the benzene ring. The ethoxy group is slightly twisted away from the benzene ring [dihedral angle 13.8 (1)°]. An intramolecular N1—H1···O2 hydrogen bond generating an S(6) ring is observed. The N1—C9 bond length [1.341 (2) Å] is shorter than the N1—C1 [1.435 (2) Å] bond length, indicating electron delocalization.

The molecules are linked into a chain along the b axis by intermolecular C—H···O hydrogen bonds (Fig. 2).

Experimental

A mixture of the methyl-3-oxobutanoate (5 mmol), 4-ethoxybenzenamine (5 mmol) and InBr₃ (0.05 mmol) was stirred at room temperature for 1 h. After completion of the reaction, the reaction mixture was diluted with H₂O (10 ml) and extracted with EtOAc (210 ml). The combined organic layers were dried, concentrated, purified by column chromatography on SiO₂ with ethyl acetate-cyclohexane (2:8). Single crystals suitable for X-ray diffraction study were obtained from EtOAc-cyclohexane (1:10 v/v) by slow evaporation at room temperature.