Regensburg, Univ., Diss., 1995.

Universiẗat, Diss., 2001--Dortmund.

Universiẗat, Diss., 2003--Münster (Westfalen).

In the crystal structure of the title compound, C30H50N4O4, the two bis­(hy­droxy­eth­yl)amino moieties and the 2,4-di­methyl­pyridinyl­amino unit of the mol­ecule are located on one side of the central benzene ring, while the ethyl substituents are oriented in the opposite direction. The dihedral angle between the planes of the aromatic rings is 73.6 (1)°. The conformation of the mol­ecule is stabilized by intra­molecular O—H⋯O (1.86–2.12 Å) and C—H⋯N (2.40, 2.54 Å) hydrogen bonds. Dimers of inversion-related mol­ecules represent the basic supra­molecular entities of the crystal structure. They are further connected via O—H⋯O hydrogen bonding into undulating layers extending parallel to the crystallographic bc plane. Inter­layer inter­action is accomplished by weak C—H⋯π contacts.