(R*,S*)-(±)-1-(2-{[2,8-Bis(trifluoromethyl)quinolin-4-yl](hydroxy)methyl}piperidin-1-yl)ethanone methanol monosolvate.

The title mefloquine derivative has been crystallized as its 1:1 methanol solvate, C(19)H(18)F(6)N(2)O(2)·CH(3)OH. Each of the meth-ine-hydroxyl residue [the C-C-C-O torsion angle is -16.35 (17) °] and the piperidinyl group [distorted chair conformation] lies to one side of the quinolinyl ring system. The hydroxyl and carbonyl groups lie to either side of the mol-ecule, enabling their participation in inter-molecular inter-actions. Thus, the hydroxyl and carbonyl groups of two centrosymmetrically related mol-ecules are bridged by two methanol mol-ecules via O-H⋯O hydrogen bonds, leading to a four-mol-ecule aggregate. These are linked into a supra-molecular chain along the a axis via C-H⋯O inter-actions involving the hydroxyl-O atom. The chains assemble into layers that inter-digitate along the c axis being connected by C-H⋯F inter-actions.