2-Amino-5-chloro­pyridine–fumaric acid (1/2)

The asymmetric unit of the title compound, C(5)H(5)ClN(2)·0.5C(4)H(4)O(4), comprises a neutral 2-amino-5-chloro­pyridine mol­ecule and one half of a fumaric acid mol­ecule which lies on an inversion center. The dihedral angle between the pyridine ring and the plane formed by the fumaric acid mol­ecule is 3.22 (8)°. The 2-amino-5-chloro­pyridine mol­ecule is planar, with a maximum deviation of 0.004 (1) Å for the pyridine N atom. In the crystal, the 2-amino-5-chloro­pyridine mol­ecules inter­act with the carboxyl groups of fumaric acid mol­ecules through N—H⋯O and O—H⋯N hydrogen bonds, forming centrosymmetric R (2) (2)(8) ring motifs and another N—H⋯O hydrogen bond links these motifs into a two-dimensional network parallel to (100).