2-Amino-5-bromo-pyridinium 3-carb-oxy-prop-2-enoate

In the title salt, C(5)H(6)BrN(2) (+)·C(4)H(3)O(4) (-), the 2-amino-5-bromo-pyridinium cation and hydrogen maleate anion are planar, with maximum deviations from their mean planes of 0.016 (1) and 0.039 (1) Å, respectively. An intra-molecular O-H⋯O hydrogen bond generates an S(7) ring motif in the anion. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen-bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. The motifs are linked into a two-dimensional network parallel to (011) by N-H⋯O and C-H⋯O hydrogen bonds.