(E)-5-[(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)iminomethyl]-2-methoxyphenyl 4-bromobenzenesulfonate

In the title compound, C25H22BrN3O5S, the central benzene ring makes dihedral angles of 32.02 (14), 37.49 (18) and 80.52 (13)°, respectively, with the pyrazolone ring, the bromobenzene ring and the terminal phenyl ring. This conformation features a short intramolecular C—H⋯O contact that generates an S(6) ring. In the crystal, inversion dimers linked by pairs of C—H⋯O=C hydrogen bonds occur.

In the title compound, C 25 H 22 BrN 3 O 5 S, the central benzene ring makes dihedral angles of 32.02 (14), 37.49 (18) and 80.52 (13) , respectively, with the pyrazolone ring, the bromobenzene ring and the terminal phenyl ring. This conformation features a short intramolecular C-HÁ Á ÁO contact that generates an S(6) ring. In the crystal, inversion dimers linked by pairs of C-HÁ Á ÁO C hydrogen bonds occur.

Experimental
An anhydrous ethanol solution (50 ml) of 5-formyl-2-methoxyphenyl 4-bromobenzenesulfonate (3.71 g, 10 mmol) was added to an anhydrous ethanol solution (50 ml) of 4-amino-1,5-dimethyl-2-phenylpyrazol-3-one (2.03 g, 10 mmol) and the mixture stirred at 350 K for 3 h under N 2 , giving a yellow precipitate. The product was isolated, recrystallized from acetonitrile, and then dried in a vacuum to give pure compound (I) in 83% yield. Yellow blocks of (I) were obtained by slow evaporation of an acetonitrile solution.

Refinement
The H atoms were included in calculated positions and refined using a riding model approximation. Constrained C-H bond lengths and isotropic U parameters: 0.93 Å and U iso (H) = 1.2U eq (C) for Csp 2 -H; 0.96 Å and U iso (H) = 1.5U eq (C) Fig. 1. The structure of (I), with displacement ellipsoids for non-H atoms drawn at the 50% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 Rfactors(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq