We report herein the design and synthesis of a series of novel 5-halogenated-7-azaindolin-2-one derivatives containing a 2,4-dimethylpyrrole moiety. Nine target compounds with >= 70% inhibition against MCF-7 at 30 mu M were further evaluated for their in vitro antitumor activity against seven human cancer cell lines by SRB assay. Results reveal that some compounds have potent antitumor activity, and the most active 13c7 (IC(50)s: 4.49-15.39 mu M) was found to be more active than Sunitinib (IC(50)s: 4.70 -> 30 mu M) against all of the tested cancer cell lines. (C) 2015 Elsevier Ltd. All rights reserved.