Oxazolo, thiazolo and selenazolo- (4,5-c) quinolin-4 amines and their analogs.

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; -I rent; -alkyl-OH; I -haloalkyl; I -alkenyl; -alkyl-X-alkyl; -alkyl-X-alkenyl; -alkenyl-X-alkyl; -alkenyl-X-alkenyl; -alkyl-N (R5) 2; N3 -alkyl-; -alkyl-OC (O) -N (R5) 2; I -heterocyclyl; -alkyl-X-heterocyclyl; -alkenyl-X-heterocicli-aryl; -alkyl-X-aryl; -alkenyl-X-aryl; -heteroaryl; -alkyl-X-heteroaryl; and -alkenyl-X-heteroaryl; wherein said heteroaryl is selected from the group consisting of furyl, thienyl, pyridyl, quinolinyl, tetrazolyl, imidazo; R3 and R4 taken together form a fused benzene ring which may be unsubstituted or substituted with one or more substituents selected from C1-4alkyl, C1-4alkoxy, halo, amino, alkylamino, dialkylamino, hydroxy, C1 -4-methyl and trifluoromethyl; 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.