An Oxidative SNH Alkylamination of 5(6,7,8)-Nitroquinoline N-Oxides in Aqueous Dioxane Medium

A novel and efficient method for the synthesis of 2-alkylamino and 2-dialkylamino derivatives of N-oxides of 5-, 6-, 7- and 8-nitroquinolines, which can potentially exhibit biological activity, as containing a pharmacophoric quinoline fragment, is described herein. The reactions of 5(6,7,8)-nitroquinoline N-oxides with various primary or secondary amines in the presence of potassium ferricyanide at in aqueous dioxane medium afforded the corresponding secondary and tertiary amines in moderate to excellent yields. This reaction is the first example of a Chichibabin reaction leading to the formation of 2-alkylaminoquinoline derivatives at position 2 under mild conditions. A study of the antibacterial activity of some products was carried out.