The title compound, C38H36N2O2S, has a heterocyclic ring that assumes a half-chair conformation. The phenyl rings of neighbouring molecules align forming alternating chains parallel to [100] within the crystal packing. The absolute stereochemistry of the crystal was confirmed to be R,S at the 1- and 3-positions, respectively, by proton NMR spectroscopy. A single intramolecular N—H...N hydrogen bond is observed.