In a cytotoxic compound of the general formula (I) R is H or methyl or methylene substituted by C1-C4 straight or branched alkyl, R1 is selected from the group consisting of H, C1-C4 straight or branched alkyl, methoxy, methoxy substituted by from one to three fluorine, halogen; R2 is H or C1-C4 straight or branched alkyl; X is CH or N; Y is CH or N.