A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein: R 1 is O or S; R 2 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 17 of F; R 3 is halo or -C 1-8 alkyl; R 4 is -C 1-8 alkyl or C 3-6 cycloalkyl; R 5 is -H, halo, -CN, -C 1-8 alkyl, -C 2-8 alkenyl, -C(O)OC 1-8 alkyl, -C(O)C 1-8 alkyl or -C(O)NR 8 R 9 ; R 6 is -H or halo; R 7 is -H or halo; represents a 6-membered heterocyclic ring attached by a nitrogen atom in said ring to the carbon atom in -C(R 7 )-, wherein the 6-membered heterocyclic ring is selected from pyridinone, pyrimidinone, pyrimidin-dione, pyrazinone, pyrazin-dione and pyridazinone, wherein each ring is unsubstituted or substituted with one or more substituents up to the maximum number allowed by valence, independently selected at each occurrence from: (i) halo, (ii) -NR 8 R 9 , (iii) -CN, (iv) -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo, (v) -C 1-4 alkyl-O-C 1-4 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH or halo, and (vi) -C 3-6 cycloalkyl unsubstituted or substituted with 2 to 5 substituents independently selected at each occurrence from -OH or halo, and (vii) -OC 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo; R 8 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo; and R 9 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo. R 1 is O or S; R 2 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 17 of F; R 3 is halo or -C 1-8 alkyl; R 4 is -C 1-8 alkyl or C 3-6 cycloalkyl; R 5 is -H, halo, -CN, -C 1-8 alkyl, -C 2-8 alkenyl, -C(O)OC 1-8 alkyl, -C(O)C 1-8 alkyl or -C(O)NR 8 R 9 ; R 6 is -H or halo; R 7 is -H or halo; represents a 6-membered heterocyclic ring attached by a nitrogen atom in said ring to the carbon atom in -C(R 7 )-, wherein the 6-membered heterocyclic ring is selected from pyridinone, pyrimidinone, pyrimidin-dione, pyrazinone, pyrazin-dione and pyridazinone, wherein each ring is unsubstituted or substituted with one or more substituents up to the maximum number allowed by valence, independently selected at each occurrence from: (i) halo, (ii) -NR 8 R 9 , (iii) -CN, (iv) -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo, (v) -C 1-4 alkyl-O-C 1-4 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH or halo, and (vi) -C 3-6 cycloalkyl unsubstituted or substituted with 2 to 5 substituents independently selected at each occurrence from -OH or halo, and (vii) -OC 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo; (i) halo, (ii) -NR 8 R 9 , (iii) -CN, (iv) -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo, (v) -C 1-4 alkyl-O-C 1-4 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH or halo, and (vi) -C 3-6 cycloalkyl unsubstituted or substituted with 2 to 5 substituents independently selected at each occurrence from -OH or halo, and (vii) -OC 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo; R 8 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo; and R 9 is -H or -C 1-8 alkyl unsubstituted or substituted with 1 to 8 substituents independently selected at each occurrence from -OH and halo. <EOS>