Abstract. The 2-[bis-(alkylthio)-methyliden]-indan-l, 3-diones 3 and especially the niethylcompound 3a react with nucleophiles by substitution of the CH,-S-group. The reaction with amines are yields the S, N-or N, N-acetales 7 and S, respectively. Diamines, aniino hydroxy-or aminomercapto compounds as dinucleophiles give the cyclic cornpounds 9 or the condensed heterocycles 12 and 16, where the carbonyl group has been integrated in ...