The synthesis and crystal structure of the title compound, C13H24BNO2 [systematic name: 3,5-di-methyl-adamantanyl-amine-borane-carb-oxy-lic acid or N-(carb-oxy-boranyl-idene)-3,5-di-methyl-adamantan-1-amine], derived from the anti-Alzheimer's disease drug memantine is reported. The C-N-B-CO2 unit is almost planar (r.m.s. deviation = 0.095 Å). The extended structure shows typical carb-oxy-lic 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 mol-ecules 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.
Keywords: CORCB; adamantane; crystal structure; memantine; memantine-carboxyborane.