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

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.


Experimental
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: YK2041). 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(Li et al., , 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.

Refinement
All H atoms were positioned geometrically with N-H = 0.86 Å and C-H = 0.93-0.98 Å, and constrained to ride on their parent atoms, with U iso (H) = xU eq (C,N), where x = 1.5 for methyl H and x = 1.2 for other H atoms.

Figure 2
The chain formed by the intermolecular C-H···O hydrogen bonds (shown by dashed lines).   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.