In the title compound, C21H24N2O3, the diazepane ring adopts a chair conformation. The central diazepane ring forms dihedral angles 67.80 (7) and 72.29 (5)° with the two benzene rings. The ethoxycarbonyl group is disordered over two conformations with site-occupancy factors of 0.643 (5) and 0.357 (5). In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R
2
2(8) loops
