Pyrimethaminium 2-{[4-(tri­fluoro­meth­yl)phen­yl]sulfan­yl}benzoate dimethyl sulfoxide monosolvate

In the cation of the title solvated mol­ecular salt, C(12)H(14)ClN(4) (+)·C(14)H(8)F(3)O(2)S(−)·C(2)H(6)OS [systematic name of the cation: 2,4-di­amino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidin-1-ium], the dihedral angle between the planes of the pyrimidinium and 4-chloro­phenyl rings is 77.2 (5)°. In the anion, the planes of the benzene rings are twisted with respect to each other by 71.5 (5)°. Disorder was modelled for the dimethyl sulfoxide solvent mol­ecule over two set of sites in a 0.7487 (13):0.2513 (13) ratio. In the crystal, the cations are linked by inversion-generated pairs of N—H⋯N hydrogen bonds, with an R (2) (2)(8) graph-set motif. The cation donates two N—H⋯O hydrogen bonds to the anion, also generating an R (2) (2)(8) loop. These inter­actions, along with cation–solvent N—H⋯O hydrogen bonds, and cation–anion C—H⋯F, solvent–anion C—H⋯O and C—H⋯F inter­actions, result in a three-dimensional network.