This paper is a case history of the early stage chemical development of CHIR-258 (4-amino- 5-fluoro-3-[6 (4-methyl-1-piperazinyl)-1H-benzimidazol-2-yl]-2 (1H)-quinolinone, DL-lactate salt), a vascular endothelial growth factor (VEGF) kinase inhibitor for treatment of solid and hematologic cancers. The article covers various aspects of work in chemical development. In particular we discuss evaluation of the medicinal chemistry route, scale-up, salt ...