(2Z)-4-[(2-Hy­droxy­phen­yl)carbamo­yl]prop-2-enoic acid

In the title compound, C(10)H(9)NO(4), the 2-hy­droxy­anilinic and the 4-oxobut-2-enoic acid groups are almost planar, with r.m.s. deviations of 0.0086 and 0.0262 Å, respectively. The dihedral angle between the two groups is 6.65 (1)°. Intra­molecular N—H⋯O, C—H⋯O and O—H⋯O hydrogen bonds form S(5), S(6) and S(7) ring motifs. In the crystal, the mol­ecules are dimerized due to C—H⋯O and O—H⋯O inter­molecular hydrogen bonds, with R (2) (2)(8) ring motifs. The dimers are inter­linked into polymeric chains along [010] with R (4) (3)(13) ring motifs by C—H⋯O, N—H⋯O and O—H⋯O hydrogen bonds.