Novel benzoyl nitrogen mustard derivatives of pyrazole analogues of distamycin A: Synthesis and antileukemic activity

The design and synthesis of novel benzoic acid mustard (BAM) derivs. of distamycin A, e.g., I, bearing one or more pyrazole rings replacing the pyrrole rings of the latter are described. In vitro and in vivo activities against L1210 leukemia are reported and discussed. Some of these compds. show an activity profile comparable to tallimustine. All the compds. bearing the pyrazole ring close to the BAM moiety show reduced cytotoxicity in comparison to derivs. characterized by the BAM linked to a pyrrole: the same effect has not been obsd. when occurring at the amidine terminus of the oligopeptidic frame.