CDC7, a serine-threonine kinase, plays conserved and important roles in regulation of DNA replication and has been recognized as a potential anticancer target. We report here the optimization of a series of furanone analogues starting from compound 1 with a focus on ADME properties suitable for clinical development. By replacing the 2-chlorobenzene moiety in 1 with various aliphatic groups, we identified compound 24 as a potent CDC7 inhibitor with excellent kinase selectivity and favorable oral bioavailability in multiple species. Oral administration of 24 demonstrated robust in vivo antitumor efficacy in a colorectal cancer xenograft model. Compound 24 (AS-0141) is currently in phase I clinical trials for the treatment of solid cancers.