Methyl 2-{[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl­idene)(4-nitro­phen­yl)meth­yl]amino}-3-phenyl­propano­ate

Xin Zhang; Chen Sun; Fei-ran Li; Hua Zhang

doi:10.1107/S1600536812010343

. 2012 Mar 14;68(Pt 4):o1062. doi: 10.1107/S1600536812010343

Methyl 2-{[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylidene)(4-nitrophenyl)methyl]amino}-3-phenylpropanoate

Xin Zhang ^a,^*, Chen Sun ^a, Fei-ran Li ^a, Hua Zhang ^a

PMCID: PMC3344020 PMID: 22589929

Abstract

The molecule of the title compound, C₂₇H₂₄N₄O₅, exists in the keto–enamine tautomeric form, stabilized by an intramolecular N—H⋯O hydrogen bond. An intramolecular C—H⋯·O hydrogen bond also occurs. In the crystal, C—H⋯O hydrogen bonds link the molecules into chains.

Related literature

For general background to Schiff bases in coordination chemistry, see: Wu et al. (1993 ▶); Harrop et al. (2003 ▶); Habibi et al. (2007 ▶). For antibacterial properties of Schiff bases derived from 4-acyl-5-pyrazolone and their metal complexes, see: Li et al. (1997 ▶, 2004 ▶). For the antibacterial and biological activity of amino acid esters, see: Xiong et al. (1993 ▶). For related structures, see: Wang et al. (2003 ▶); Zhang et al. (2005 ▶). For synthetic details, see: Remya et al. (2005 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₂₇H₂₄N₄O₅
M _r = 484.50
Monoclinic,
a = 6.7713 (16) Å
b = 8.917 (2) Å
c = 20.339 (5) Å
β = 92.489 (4)°
V = 1226.9 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.20 × 0.16 × 0.12 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.980, T _max = 0.989
6305 measured reflections
2315 independent reflections
1855 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.106
S = 1.07
2315 reflections
327 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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/S1600536812010343/yk2041sup1.cif

e-68-o1062-sup1.cif^{(23.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812010343/yk2041Isup2.hkl

e-68-o1062-Isup2.hkl^{(113.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812010343/yk2041Isup3.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
N4—H4⋯O1	0.86	2.04	2.738 (4)	138
C1—H1⋯O1	0.93	2.41	3.001 (4)	121
C20—H20A⋯O1ⁱ	0.96	2.55	3.385 (5)	145

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

In recent years, Schiff bases play an important role in the development of coordination chemistry related to catalysis and enzymatic reactions, magnetism, and molecular architectures (Wu et al., 1993; Harrop et al., 2003; Habibi et al., 2007). In recent years, the Schiff bases derived from 4–acyl–5–pyrazolone and their metal complexes have been studied widely for their high antibacterial activity (Li et al., 1997, 2004). Both 1–phenyl–3–methyl–4–(p–nitro–benzyl)–5–pyrazolone and its metal complexes are widely used and well known for their analgetic activity (Remya et al., 2005). Amino acid esters also demonstrate high antibacterial and biological activity (Xiong et al., 1993). Structure of Schiff base derived from 4–acyl–5–pyrazolone and amino acid ester, closely related to the title compound, has been reported (Zhang et al., 2005).

The molecular structure of the title compound is presented in Fig. 1, and the numerical results are given in tables below. Atoms O1, C9, C8, C11 and N4 form a plane, the largest deviation being 0.021 (4) Å for atom C11. The dihedral angle between this mean plane and the pyrazolone ring is 1.2 (1)°, indicating that they are essentially coplanar, as seen in 4–{[3,4–dihydro–5–methyl–3–oxo–2–phenyl–2H–pyrazol–4–ylidene]–(phenyl)methyl]amino}–1,5–dimethyl–2–phenyl–1H–pyrazol–3(2H)–one [3.56 (3)°; Wang et al., 2003]. The bond lengths within central part of the molecule lie between typical single- and double- bond lengths, indicating extensive conjugation. A strong intramolecular N—H···O hydrogen bond is observed, stabilizing the enamine-keto tautomeric form. In the crystal structure, intermolecular C1—H1···O4 hydrogen bonds link the molecules into chains, shown in Fig. 2.

Experimental

The title compound was synthesized by refluxing a mixture of 1–phenyl–3—methyl–4–(p–nitro–benzyl)–5–pyrazolone (15 mmol) (Remya et al., 2005) and phenylalanine methyl ester (15 mmol) in ethanol (100 ml) for about 5 h. The product was recrystallized from ethanol, affording pale yellow crystals suitable for X–ray analysis.