The asymmetric unit of the title compound, C30H33N5O3, contains two independent molecules, A and B. In molecule A, the tert-butyl 4-methylpiperazine-1-carboxylate group was refined as disordered over two sets of sites with an occupancy ratio of 0.821 (4):0.179 (4). The piperazine ring adopts a chair conformation in both molecules. The dihedral angles between the pyrimidine ring and methoxyphenyl ring are 20.27 (14) and 8.72 (11)° for molecules A and B, respectively. The quinoline ring system makes dihedral angles of 30.68 (11) and 37.76 (10)° with the pyrimidine ring in molecules A and B, respectively. In the crystal, C—H...O hydrogen bonds link the molecules into chains along [100].
