3-Aminorhodanine 2 was reacted with cyclic anhydrides yielding 3-(2,5-dioxopyrrolidin-1-yl), 3-(2,6-dioxopiperidin-1-yl), and 3-(1,3-dioxoisoindolin-2-yl)rhodanine 6-8, which in turn were condensated in 5 position with several aldehydes yielding the new rhodaninederivatives 9-11.