Crystal structure of ethyl 2-(3-amino-5-oxo-2-tosyl-2,5-di-hydro-1H-pyrazol-1-yl)acetate.

In the title compound, C14H17N3O5S, the five-membered ring is essentially planar. The substituents at the nitro-gen atoms subtend a C-N-N-S torsion angle of -95.52 (6)°. The amino group forms an intra-molecular hydrogen bond to a sulfonyl oxygen atom; two inter-molecular hydrogen bonds from the amino group, to the other S=O group and to the oxo substituent, form a layer structure parallel to the ab plane. The structure determination confirms that the title compound is N- rather than O-alkyl-ated. © Metwally et al. 2021.