title: N-Phenyl-maleamic acid.
abstract: The two independent mol-ecules in the title compound (systematic name: 4-amino-4-oxobut-2-enoic acid), C(10)H(9)NO(3), are both essentially planar (r.m.s. deviations = 0.05 and 0.06 Å). In both mol-ecules, the -OH group forms an intra-molecular hydrogen bond to the amide O atom. Adjacent mol-ecules are linked by N-H⋯O hydrogen bonds into a flat ribbon that runs along the a axis of the monoclinic unit cell.
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Kong Mun
authors.initials: KM
authors.lastname: Lo
authors.forename: Seik Weng
authors.initials: SW
authors.lastname: Ng