Patent ID: 8466166

Claim:
A compound of the formula (I): or a pharmaceutically acceptable salt thereof, wherein; R 1 represents a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group, a hydroxy-substituted C 3 -C 7 cycloalkyl group, a hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group, an aryl group, a hydroxy-substituted aryl group, a heteroaryl group and a halogen-substituted heteroaryl group; R 2 represents a hydrogen atom or a C 1 -C 6 alkyl group being unsubstituted or substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group and a C 1 -C 6 alkoxy group; R 3 and R 4 independently represent a hydrogen atom, or a C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or heteroaryl group being unsubstituted or substituted with 1 to 3 substituents independently selected from the group consisting of a deuterium, a halogen atom, a hydroxy group, a C 1 -C 6 alkoxy group and a C 3 -C 7 cycloalkyl group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form a 4 to 6 membered heterocyclic group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group, and a hydroxy-C 1 -C 6 alkyl group; A represents an aryl or heteroaryl group being unsubstituted or substituted with 1 to 5 substituents independently selected from the group consisting of a halogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, —NR 5 SO 2 R 6 and —CONR 7 R 8 ; R 5 , R 7 and R 8 independently represent a hydrogen atom or a C 1 -C 6 alkyl group; R 6 represents a C 1 -C 6 alkyl group; and E represents an oxygen atom or NH.