Abstract
In the title compound, C18H21F3N4O4, the piperazine ring adopts a chair conformation and the dihedral angle between the oxa-diazole and benzene rings is 6.45 (14)°. The C atoms and their attached H atoms in the piperazine ring are disordered, with site-occupation factors of 0.576 (12) and 0.424 (12). In the crystal, mol-ecules are linked through weak C-H⋯O inter-actions, generating an R 2 (2)(12) motif. Further, secondary C-H⋯O inter-molecular inter-actions link the mol-ecules into C(6) chains along [100].