Amination of quinolones with morpholine derivatives

The aromatic nucleophilic substitution reaction of 7-chloroquinolone carboxylic acid and its ethyl ester with cyclic amines under microwave irradiation conditions was investigated. 1H NMR spectroscopy was used to monitor the progress of the substitution reaction. The reaction proceeded in high yield with simple cyclic amines and was less efficient for sterically more demanding bimorpholine derivatives. A Pd-catalyzed amination of quinolone carboxylic acid ethyl ester with bimorpholine derivatives provided new C-7 bimorpholino-substituted quinolone derivatives.