A microwave-assisted nucleophilic substitution reaction on a quinoline system: the synthesis of amino analogues of nitroxoline

A reliable protocol for the synthesis of a series of 8-amino analogues of pharmacologically interesting nitroxoline (5-nitro-8-hydroxyquinoline) is described. The unprecedented displacement of the cyanomethoxy group of an O-cyanomethylated quinoline derivative by various primary and secondary amines selectively affords 5-nitroquinolin-8-ylamines in moderate-to-high yields. The reactions were accelerated significantly under microwave conditions in comparison with conventional heating.