Oxazolo, thiazolo and selenazolo [4,5-c]-quinolin-4-amines and analogs thereof

A compound of formula I:

• wherein:
• R1 is selected from the group consisting of oxygen, sulfur and selenium;
• R2 is selected from the group consisting of
• -hydrogen;
• -alkyl;
• -alkyl-OH;
• -haloalkyl;
• -alkenyl;
• -alkyl-X-alkyl;
• -alkyl-X-alkenyl;
• -alkenyl-X-alkyl;
• -alkenyl-X-alkenyl;
• -alkyl-N(R5)2;
• -alkyl-N3;
• -alkyl-O—C(O)—N(R5)2;
• -aryl;
• -alkyl-X-aryl;
• and
• -alkenyl-X-aryl;
• R3 and R4 join to form a heteroaromatic or heterocyclic ring that contains one nitrogen as the only ring hetero atom;
• X is selected from the group consisting of —O—, —S—, —NR5—, —C(O)—, —C(O)O—, —OC(O)—, and a bond;
• and
• each R5 is independently H or C1-8alkyl;
• or a pharmaceutically acceptable salt thereof.