r-2,c-6-Bis(2-methoxy-phen-yl)-t-3,t-5-dimethyl-piperidin-4-one acetic acid solvate.

In the title compound, C(21)H(25)NO(3)·C(2)H(4)O(2), the piperidone ring adopts a chair conformation. The two meth-oxy groups are nearly coplanar with the aromatic rings to which they are attached. The dihedral angle between the two aromatic rings is 60.9 (2)°. There are two short intra-molecular N-H⋯O contacts. The crystal packing is stabilized by inter-molecular O-H⋯N and C-H⋯O inter-actions.