In light of our previous work on the synthesis of novel antitumor heterocycles [39,40,41,42,43,44,45,46] and with consideration of the aforementioned results, a new sort of VEGFR-2 inhibitors has been developed as prospective anti-breast cancer agents by hybridizing the coumarin and 1,3-thiazole moieties, which have been found to inhibit kinases and have antiproliferative properties. The gene discussed is KDR; the disease is breast cancer.