What is claimed is a compound of Formula I: wherein A is R 1 is phenyl, which is optionally substituted with halo, R 5, (C=O)OR 5, (C=O)NR 5 R 6 or C 1-3 alkyl(C=O)OR 5; or heteroaryl, which is optionally substituted with one or two substituents independently selected from the group consisting of halo, oxo, R 5, OR 5, NR 5 R 6 and C 1-3 alkyl-NR 5 R 6; R 2 is hydrogen or C 1-6 alkyl; R 3 is heteroaryl, which is optionally substituted with one or two substituents independently selected from the group consisting of halo, oxo, cyclopropyl, R 5, OR 5, (C=O)OR 5 and CH 2 SO 2 CH 3; each R 4 is independently selected from halo, R 5 or OR 5, each R 5 is hydrogen or C 1-6 alkyl, which is optionally substituted with one to three substituents independently selected from the group consisting of halo and hydroxy; R 6 is hydrogen, cyclopropyl or C 1-6 alkyl, which is optionally substituted with one to three substituents independently selected from the group consisting of halo and hydroxy; R a is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R b is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R c is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R d is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); n is an integer between zero and two; wherein heteroaryl represents a stable monocyclic, bicyclic or tricyclic ring of up to 10 atoms in each ring, wherein at least one ring is aromatic, and at least one ring contains from 1 to 4 heteroatoms selected from the group consisting of O, N and S, and wherein the heteroaryl may optionally contain an N-oxide when a nitrogen atom is present; or a pharmaceutically acceptable salt thereof. wherein A is R 1 is phenyl, which is optionally substituted with halo, R 5, (C=O)OR 5, (C=O)NR 5 R 6 or C 1-3 alkyl(C=O)OR 5; or heteroaryl, which is optionally substituted with one or two substituents independently selected from the group consisting of halo, oxo, R 5, OR 5, NR 5 R 6 and C 1-3 alkyl-NR 5 R 6; R 2 is hydrogen or C 1-6 alkyl; R 3 is heteroaryl, which is optionally substituted with one or two substituents independently selected from the group consisting of halo, oxo, cyclopropyl, R 5, OR 5, (C=O)OR 5 and CH 2 SO 2 CH 3; each R 4 is independently selected from halo, R 5 or OR 5, each R 5 is hydrogen or C 1-6 alkyl, which is optionally substituted with one to three substituents independently selected from the group consisting of halo and hydroxy; R 6 is hydrogen, cyclopropyl or C 1-6 alkyl, which is optionally substituted with one to three substituents independently selected from the group consisting of halo and hydroxy; R a is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R b is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R c is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); R d is hydrogen, halo, C 1-6 alkyl or O(C 1-6 alkyl); n is an integer between zero and two; wherein heteroaryl represents a stable monocyclic, bicyclic or tricyclic ring of up to 10 atoms in each ring, wherein at least one ring is aromatic, and at least one ring contains from 1 to 4 heteroatoms selected from the group consisting of O, N and S, and wherein the heteroaryl may optionally contain an N-oxide when a nitrogen atom is present; or a pharmaceutically acceptable salt thereof.