5-Acetyl-3-(5-phenyl-1H-pyrazol-3-yl)-1,3,4-thiadiazol-2(3H)-one monohydrate

In the title hydrate, C13H10N4O2S·H2O, the dihedral angles between the central pyrazole ring and its pendant phenyl and thiadiazole rings are 9.93 (8) and 4.56 (7)°, respectively. In the crystal, the components are linked by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, generating [100] chains incorporating R 4 4(10) loops. A weak C—H⋯O interaction helps to consolidate the packing.


Experimental
The title compound was synthesised according to literature (Abdelhamid et al., 2001 ) procedure and recrystalized from methanol solution under slow evaporation to yield brown plates.

Refinement
All the hydrogen atoms found from a Fourier difference map and allowed to refine freely with appropriate riding models.

Computing details
Data The molecular structure of title compound with 50% probability displacement ellipsoids.

Figure 2
The packing diagram showing inversion dimers through hydrogen bonds, drawn using dashed lines.

5-Acetyl-3-(5-phenyl-1H-pyrazol-3-yl)-1,3,4-thiadiazol-2(3H)-one monohydrate
where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.002 Δρ max = 0.23 e Å −3 Δρ min = −0.19 e Å −3 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 > 2sigma(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.