ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, vol.73, pp.96-104, 2017 (ESCI)
The essential part (including all the non-hydrogen atoms except two methyl carbons) of the molecule of the title compound, C21H26N4O5, lies on a mirror plane, which bisects the t-butyl groups. The conformation of the C N bond of this Schiff base compound is E, and there is an intramolecular N-H center dot center dot center dot O hydrogen bond present, forming an S(6) ring motif. In the crystal, molecules are linked via O-H center dot center dot center dot O hydrogen bonds, forming zigzag chains propagating along the a-axis direction. There are no other significant intermolecular contacts present.