2-(3-Oxo-1,3-dihydro­isobenzofuran-1-ylamino)benzoic acid

In the mol­ecule of the title compound, C(15)H(11)NO(4), the essentially planar phthalide group is oriented at a dihedral angle of 56.78 (5)° with respect to the substituted aromatic ring. An intra­molecular N—H⋯O hydrogen bond results in the formation of a non-planar six-membered ring, which adopts a nearly flattened-boat conformation. In the crystal structure, inter­molecular C—H⋯O, O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules, generating centrosymmetric R (2) (2)(8) and R (2) (2)(11) ring motifs and forming a three-dimensional network.