Di-n-butyl 4,4'-dihy-droxy-3,3'-{[(3aRS,7aRS)-2,3,3a,4,5,6,7,7a-octa-hydro-1H-1,3-benzimidazole-1,3-di-yl]bis-(methyl-ene)}dibenzoate.

The complete molecule of the title compound, C(31)H(42)N(2)O(6), is generated by crystallographic twofold symmetry, with one C atom lying on the axis. The dihedral angle between the aromatic rings is 57.03†(6)°. The central heterocyclic ring adopts a half-chair conformation. The mol-ecular conformation is stabilized by two intra-molecular O-H⋯N hydrogen bonds with the N atoms of the heterocyclic ring as the acceptors. In the crystal, mol-ecules are linked into chains along the c axis by non-classical C-H⋯O hydrogen bonds.