N-(3-Chloro-phen-yl)maleamic acid.

In the title compound, C(10)H(8)ClNO(3), the molecular conformation is stabilized by two intra-molecular hydrogen bonds. The first is a short O-H⋯O hydrogen bond within the maleamic acid unit and the second is a C-H⋯O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1)° with the phenyl ring. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into C(7) chains running [010].