Experimental

R factor = 0.065; wR factor = 0.168; data-to-parameter ratio = 13.1. In the title compound, C12H15NO5, the dihedral angle between the benzene ring and the C atoms of the terminal isopropyl group is 83.48 (16). Intramolecular N—H O and O— H O hydrogen bonds generate S(5) and S(6) rings, respectively. In the crystal, molecules are linked by O— H O hydrogen bonds, generating C(7) chains propagating in [001]. Weak aromatic – stacking [centroid–centroid separa-tion = 3.604 (3) Å] is also observed. Related literature For related structures, see: Chen et al. (2011); Naz et al. (2013)