Bis(4,6-diamino-pyrimidin-2-yl) disulfide dimethyl sufoxide disolvate.

The title compound, C(8)H(10)N(8)S(2)·2C(2)H(6)SO, was obtained unintentionally during an attempt to prepare a thiol-ate derivative of trimethyl-tin. The complete disulfide mol-ecule is generated by twofold rotation symmetry and the C-S-S-C torsion angle around the S-S bond is -85.70 (10)°. The mol-ecules are connected via N-H⋯N hydrogen bonds into strongly corrugated layers parallel to (001), generating an R(2) (2)(8) motif. The solvent mol-ecule, which exhibits minor disorder of its S atom [site occupancies = 0.9591 (18) and 0.0409 (18)], is linked to this layer via a pair of N-H⋯O inter-actions.