Regorafenib analogues and their ferrocenic counterparts: synthesis and biological evaluation

Approved by the FDA in 2012, regorafenib is one of the last chance treatments for colorectal cancer. While various analogues have already been prepared, ferrocenic derivatives have never been evaluated. In this study, we prepared various ferrocene-containing derivatives of regorafenib and recorded their biological activity in kinase and cellular assays. This led to the identification of a squaramide derivative which shows a good cellular activity and three ferrocene analogues with promising activity in both kinase and cellular assays.