5-tert-But­yl-4-nitro-1H-pyrazol-3-ol

The structure of the title compound, C₇H₁₁N₃O₃, consists of mol­ecules that pack in a linear hydrogen-bonded ribbon motif. This hydrogen-bonding arrangement is constructed through two dimer formations, one that is atypical of pyrazoles (N—H...N) and the other via an inter­action from the hydr­oxy OH group to one of the nitro O atoms.

5-tert-But­yl-4-bromo-1,2-dihydro-1H-pyrazol-3(2H)-one monohydrate

The structure of the title compound, C₇H₁₁BrN₂O·H₂O, exhibits an elaborate hydrogen-bonding network involving pyrazole N—H...O dimers and two other hydrogen-bonding motifs, both including water mol­ecules. One motif is a distorted hexa­gonal R₃⁵(11) graph set, while the other is a distorted octa­gonal boat conformation R₆⁴(14) graph set.