Substituted heterocycles for treating cancer

A compound, or a pharmaceutically salt thereof, the compound having a formula of

• wherein:
• Alk is (—CH2—)n, wherein n is 1-6;
• R1 is selected from hydrogen, hydroxyl, hydroxyalkyl, amino, alkylamino, dialkylamino, alkoxy, hydroxyalkoxy, or R1 is a 3-, 4-, 5-, or 6-membered ring comprising carbon atoms and optionally comprising one or more heteroatoms selected from N, O, and S, wherein the ring is unsaturated or saturated at one or more positions and the ring optionally is substituted at one or more positions with a substituent selected from oxo, dioxo, alkoxycarbonyl, amidinyl, alkyl, alkoxy, haloalkyl, alkylcarbonyl, aminocarbonyl, halogen, hydroxyl, hydroxyalkyl, and aryl optionally substituted with halo;
• R2 is methyl substituted with halo;
• R3 is selected from halo, hydrogen, methyl, and hydroxyl;
• and
• with the proviso that if R2 is trifluoromethyl, R3 is chloro, and n is 1, then R1 is not piperdine-4-yl or tert-butyl piperidine-1-carboxylate.