The effects of some metal ions on the amination and arylation of 5,8-quinolinedione (1) and on the amine displacement of 6-piperidino-5,8-quinolinedione have been investigated. The reaction of 1 with various amines in chloroform or ethanol was specifically promoted by Ni(II) ions to give selectively the corresponding 6(substituted amino)-5,8-quinolinediones. With N,N-dialkylanilines in acetic acid