2-Amino-benzoic acid-4-(pyridin-4-yl-disulfan-yl)pyridine (1/1).

The title 1:1 co-crystal, C(7)H(7)NO(2)·C(10)H(8)N(2)S(2), features a highly twisted 4-(pyridin-4-yldisulfan-yl)pyridine mol-ecule [dihedral angle between the pyridine rings = 89.06 (10)°]. A small twist is evident in the 2-amino-benzoic acid mol-ecule, with the C-C-C-O torsion angle being -7.7 (3)°. An N-H⋯O hydrogen bond occurs in the 2-amino-benzoic acid mol-ecule. In the crystal, mol-ecules are linked by O-H⋯N and N-H⋯N hydrogen bonds into a supra-molecular chain along the b axis. These are connected into layers by π-π inter-actions occurring between pyridine rings [centroid-centroid distance = 3.8489 (15) Å]. The layers are connected along the a axis by C-H⋯O contacts. The crystal studied was a racemic twin.