Synthesis and biological evaluation of pyrrolo[2,1-c][1,4]benzodiazepine (PBD) C8 cyclic amine conjugates

We report examples of a series of novel pyrrolo[2,1-c][1,4]benzodiazepine (PBD) analogues 12–15 prepared from a common functionalized building block 11 that can be conveniently synthesized on a large scale and in optically pure form. Isoindoline analogue 15 is the most cytotoxic agent in this series, has the highest DNA-binding affinity, and shows significant activity in the in vivo hollow fibre assay.