To improve the drug-like properties of the YC-1 scaffold, we synthesized a final set of analogs as illustrated in Table . We incorporated the 4-nitrogen in the indazole core and an additional nitrogen in the southern benzyl ring in analogs 60-63: these compounds had aqueous solubilities of >30 g/mL and t1/2 >15 min in rat, mouse, and human liver microsomes (LM). Unfortunately, their primary RBE cytotoxic activity was dampened compared to YC-1. At this point, our mechanistic studies had provided evidence that the northern hydroxyl group, upon in-situ sulfonation by SULT1A1 and elimination, acted as an electrophilic alkylator to lysines on the surface of RNA binding proteins in cancer cells. (Figure ). 2 Thus, we were interested in exploring the additional possibility that a primary amine in this region could also function similarly as an alkylator. Encouraged by the activity of furfuryl amine 15 (RBE IC50 2.34 M) in Table , we prepared analogs 58, 59, and 63. In this set only compound 58, which was prepared by combining the southern 4-pyridyl group with the primary amine in the northern region, retained its potency.