Hydrogen-bonded bilayers in 7-benzyl-3-tert-butyl-1-phenyl-4,5,6,7-tetrahydro-1H-spiro[pyrazolo[3,4-b]pyridine-5,2'-indan]-1',3'-dione.

In the title compound, C₃₁H₂₉N₃O₂, the reduced pyridine ring adopts a conformation intermediate between the envelope and half-chair forms. The aryl rings of the benzyl and phenyl substituents are nearly parallel and overlap, indicative of an intramolecular π-π stacking interaction. A combination of two C-H∙∙∙O hydrogen bonds and one C-H∙∙∙N hydrogen bond links the molecules into a bilayer having tert-butyl groups on both faces.