Abstract: Methods for the treatment of a proliferative disorder are provided in which a subject in need of such treatment is administered an effective amount of a compound selected from: compounds of formula (I) or a pharmaceutically acceptable salt thereof, wherein X1 and X2 are independently H, Cl, F, Br, I, CN, CF3 or NO2, and Ar1 is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl; and compounds of formula (II) wherein X3 and X4 are each independently H, Cl, F, Br, I, CN, CF3 or NO2; Y is (C2–C6)alkylene or (C2–C6)heteroalkylene; and Z is Cl, F, Br, I, CN, CF3 or NO2.