Potent inhibitor of the tyrosine kinases c-Src, fibroblast growth factor receptor 1 (FGFR1), and platelet-derived growth factor receptor β (PDGFRβ) (IC50 values are 8.4, 39.3 and 98.3 nM respectively). Also inhibits the checkpoint kinases Wee1 and Myt1; abolishes Cdc2 phosphorylation in numerous tumor cell lines and abrogates the G2 checkpoint.