The synthesis and extraction properties of new 2-(phosphorylalkyl)-and 2-(phosphorylalkenyl)-substituted 1,8- and 1,6-naphthyridines

New 1,8- and 1,6-naphthyridines containing a phosphoryl group in the side chain were synthesized via Friedlӓnder reaction by combining the appropriate aminonicotinic aldehydes and phosphoryl ketones in alcohol medium in the presence of basic catalysts (pyrrolidine or KOH). A series of phosphoryl-substituted 1,8-naphthyridines effectively extracted uranium(VI) from neutral aqueous solutions containing lanthanide(III) into 1,2-dichloroethane.