1,5-Dimethyl-2-phenyl-4-[(1 E)-(2-quinolyl)methylideneamino]-1 H-pyrazol-3(2 H)-one.

The title compound, C21H18N4O, was synthesized by condensation of quinoline-2-carbaldehyde and 4-aminoantipyrine. The mean planes of the pyrazole and phenyl rings make a dihedral angle of 55.7 (3)°. The crystal packing is stabilized by weak intermolecular C—H...O hydrogen bonds and π–π interactions. [ABSTRACT FROM AUTHOR]