Phosphatidylinositol 3-kinase inhibitors

A compound having the structure of formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, or unsubstituted or substituted alkyl;
• n is 0, 1, 2, or 3;
• each R2 is independently halo or unsubstituted or substituted alkyl;
• R3 is unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted cycloalkyl, or unsubstituted or substituted heterocycloalkyl;
• R4 is hydrogen, alkyl, or NH2;
• R5 is alkyl;
• and
• R6 is hydrogen, or R5 together with the carbon to which it is attached and R6 together with the nitrogen to which it is attached are taken together to form a, four-, five- or six-membered heterocycle.