Crystal structure of memantine–carb­oxy­borane

The synthesis and crystal structure of the title compound, C(13)H(24)BNO(2) [systematic name: 3,5-di­methyl­adamantanyl­amine–borane­carb­oxy­lic acid or N-(carb­oxy­boranyl­idene)-3,5-di­methyl­adamantan-1-amine], derived from the anti-Alzheimer’s disease drug memantine is reported. The C—N—B—CO(2) unit is almost planar (r.m.s. deviation = 0.095 Å). The extended structure shows typical carb­oxy­lic acid inversion dimers linked by pairwise O—H⋯O hydrogen bonds [O⋯O = 2.662 (3) Å]. The amino group forms a weak N—H⋯O hydrogen bond [N⋯O = 3.011 (3) Å], linking the dimers into [001] chains in the crystal. Highly disordered solvent mol­ecules were treated using the SQUEEZE routine of PLATON [Spek (2015 ▸). Acta Cryst. C71, 9–18], which treats the electron density as a diffuse contribution without assignment of specific atom locations. A scattering contribution of 255 electrons was removed. The crystal studied was refined as a two-component twin.