Crystal structure of 3,6,6-trimethyl-4-oxo-1-(pyridin-2-yl)-4,5,6,7-tetra­hydro-1H-indazol-7-aminium chloride and its monohydrate

The title compounds, C(15)H(19)N(4)O(+)·Cl(−) and C(15)H(19)N(4)O(+)·Cl(−)·H(2)O, obtained in attempts to synthesize metal complexes using tetra­hydro­indazole as a ligand, were characterized by NMR, IR and X-ray diffraction techniques. The partially saturated ring in the tetra­hydro­indazole core adopts a sofa conformation. An intra­molecular N—H⋯N hydrogen bond formed by the protonated amino group and the N atom of the pyridyl substituent is found in the first structure. In the hydro­chloride, the organic moieties are linked by two N—H⋯Cl(−) hydrogen bonds, forming a C(4) graph-set. In the hydrate crystal, a Cl(−) anion and a water mol­ecule assemble the moieties into infinite bands showing hydrogen-bond patterns with graph sets C(6), R (6) (4)(12) and R (4) (2)(8). Organic moieties form π–π stacked supra­molecular structures running along the b axis in both structures.