The tetrahydrodiazepine ring in the title molecule, C H N O, adopts a twisted envelope conformation. In the crystal, inversion dimers are formed by N[sbnd]H⋯O hydrogen bonds which are connected into corrugated layers by N[sbnd]H⋯O hydrogen bonds and C[sbnd]H⋯π(ring) interactions. However, the Hirshfeld surface analysis indicated that the most important intermolecular interaction for the title compound is the H⋯H contact. Moreover, the DFT-B3LYP study showed that the title compound should have a slightly different geometry in the gas phase with respect to that in the solid phase. The antitumor activity of the novel tetrahydrodiazepine derivative is investigated by investigating its binding affinity into the active site of Checkpoint Kinase Chk1/SB218078. Docking outputs reveal moderate Checkpoint Kinase inhibition by tetrahydrodiazepine derivative. 11 12 2