Abstract
A series of rationally designed ROS1 tyrosine kinase inhibitors 6a-9b with bipyridinyl pyrazole scaffold was synthesized and screened. The scaffold itself has showed an exclusive selectivity profile over ROS1 closely related kinases, ALK and c-Met. The aim of this study was to further explore the structure-activity relationships (SAR) of the bipyridinyl pyrazole core structure, and to improve its ROS1 inhibitory potency. The rational of this study was to explore the nature of the proposed binding site for the pyrazole NH substituents. Careful selections of pyrazole NH substituent groups along with their regioisomers were considered. The compounds exhibited high degree of potency, IC50 values of 21-159 nM. A detailed SAR of bipyridinyl pyrazole scaffold has been finally well established and the virtual screening strategy, through molecular docking, has been performed for this type of ROS1 kinase inhibitors and the docked poses along with the activity data have gone in consistent with SAR specifications.