Protein tyrosine kinase inhibitors

A compound selected from the group consisting of a compound of Formula I, a pharmaceutically acceptable salt thereof and a stereoisomer thereof:

• wherein n is an integer;
• wherein R1 and R2 are independently selected from the group consisting of:
• wherein R3 is selected from the group consisting of H;
• alkyl;
• alkenyl;
• alkynyl;
• halogen;
• aryl;
• heteroaryl containing N, O, or S;
• NZ1Z2, wherein Z1 and Z2 are independently selected from the group consisting of H and alkyl;
• and (CO)Y wherein Y is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, heteroaryl containing N, O, or S;
• and
• wherein R4 is selected from the group consisting of H and alkyl