(Z)-Ethyl 2-(4-chloro­phen­yl)-3-[(2,4-difluoro­phen­yl)amino]­prop-2-enoate

Zhu-Ping Xiao; Xu-Dong Wang; Tian Liu; Jian Zhu; Zhi-Ping Li

doi:10.1107/S1600536810043801

. 2010 Oct 31;66(Pt 11):o3016. doi: 10.1107/S1600536810043801

(Z)-Ethyl 2-(4-chlorophenyl)-3-[(2,4-difluorophenyl)amino]prop-2-enoate

Zhu-Ping Xiao ^a,^*, Xu-Dong Wang ^a, Tian Liu ^a, Jian Zhu ^a, Zhi-Ping Li ^a

PMCID: PMC3009196 PMID: 21589175

Abstract

In the title compound, C₁₇H₁₄ClF₂NO₂, the aminoacryloyloxy group makes dihedral angles of 47.55 (11)° with the 4-chlorophenyl group and 8.74 (12)° with the difluorophenyl group; the dihedral angle between the rings is 52.32 (11)°. The structure of the title compound reveals a Z configuration with respect to the C=C double bond in the aminoacrylate fragment. A bifurcated intramolecular N—H⋯(O,F) hydrogen bond occurs. In the crystal, molecules are linked into chains by C—H⋯O hydrogen bonds.

Related literature

For background to Schiff bases, see: You & Zhu, 2006 ▶. For applications of enamines, see: Xiao et al. (2007 ▶, 2008a ▶,b ▶,c ▶).

Experimental

Crystal data

C₁₇H₁₄ClF₂NO₂
M _r = 337.74
Monoclinic,
a = 16.276 (3) Å
b = 7.5030 (15) Å
c = 13.812 (3) Å
β = 111.11 (3)°
V = 1573.5 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.27 mm⁻¹
T = 298 K
0.30 × 0.10 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.923, T _max = 0.973
2957 measured reflections
2824 independent reflections
1566 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.065
wR(F ²) = 0.170
S = 0.99
2824 reflections
213 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SMART; data reduction: SAINT (Bruker, 2007 ▶); 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810043801/bq2244sup1.cif

e-66-o3016-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810043801/bq2244Isup2.hkl

e-66-o3016-Isup2.hkl^{(138.6KB, 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—H18⋯F1	0.83 (3)	2.29 (3)	2.674 (3)	108 (3)
N1—H18⋯O1	0.83 (3)	2.07 (3)	2.675 (4)	129 (3)
C6—H6⋯O1ⁱ	0.93	2.51	3.321 (4)	146

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was financed by the Scientific Research Fund of Hunan Provincial Education Department (Project No. 09B083) and by a grant from Jishou University for talent introduction (project No. JSDXKYZZ0801).

supplementary crystallographic information

Comment

A 2-aryl-3-arylaminoacrylate contains characteristic N—C═C bond and is therefore identified as enamine. It is well known that Schiff base harbors an N═C—C bond, which indicates that an enamine is the tautomeric isomer of the correspond Schiff base. Enamines, like Schiff bases (You & Zhu, 2006), show good antimicrobial activities (Xiao et al., 2007; Xiao et al., 2008a), especially against bacterium. On the other hand, an enamine is the key intermediate for anticancer agents, 3-arylquinolone (Xiao et al., 2008b) and 3-arylquinoline (Xiao et al., 2008c). In a continuation of our work on the structural characterization of enamine derivatives, we report herein the crystal structure of the title compound, (I).

The bond length of C13—N1 (1.344 (4) Å) is shorter than standard C—N single bond (1.48 Å) but longer than C—N double bond (1.28 Å), indicating that the p orbital of N1 is conjugated with the π molecular orbital of C13—C14 double bond. For the same reason, C1—N1 (1.394 (4) Å) is single bond with some double-bond character. The stereochemistry of the double bond in aminoacrylate moiety was assigned as (E)-configuration based on X-ray crystallography (Fig. 1) of the title compound.

Aminoacryloyloxy moiety, O2—C15—O1—C14—C13, forms a plane with the mean deviation of 0.0249 Å, which makes a dihedral angle of 47.55 (11) ° with the 4-chlorophenyl group and 8.74 (12) ° with the difluorophenyl group. The molecules are linked through intermolecular C—H···O hydrogen bonds, forming an infinite one-dimensional ribbons (Table 1, Fig. 2).

Experimental

Equimolar quantities (6 mmol) of ethyl 2-(4-chlorophenyl)-3-oxopropanoate (1.36 g) and 2,4-difluorobenzenamine (0.77 g) in absolute alcohol (18 ml) were heated at 344–354 K for 2 h. The excess solvent was removed under reduced pressure. The residue was purified by a flash chromatography with EtOAc–petrolum ether (1:6, v/v) to afford two fractions. The second fraction gave a E-isomer, and the first fraction, after partial solvent evaporated, furnished colorless blocks of (I) suitable for single-crystal structure determination.