In the title mol-ecule, C(10)H(8)N(2)O(4), the imidazolidine ring adopts a twisted conformation. In the crystal, the mol-ecules are linked via a pair of bifurcated inter-molecular O-H⋯O hydrogen bonds, forming an inversion dimer. The dimers are further linked via N-H⋯O hydrogen bonds into a tape along the b axis.