In the structure of the title compound, C(13)H(15)NO(6)·0.5H(2)O, the water O atom lies on a twofold rotation axis. The methoxy-carbonyl-methyl and amino groups are essentially coplanar and the methoxy-carbonyl-methyl group makes a dihedral angle of 79.73 (10)° with the mean plane of the hydroxy-phenyl ring. The amino and methoxy-carbonyl-methyl groups are involved in an intra-molecular N-H⋯O hydrogen bond which generates an S(5) ring motif. In the crystal structure, mol-ecules are linked via N-H⋯O and O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions into a two-dimensional network parallel to the (01) plane. The crystal structure is further stabilized by C-H⋯π inter-actions.