Patent ID: 8822453

Claim:
A compound of Formula (1) or a pharmaceutically acceptable salt thereof, wherein R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, lower alkyl, cyclo lower alkyl or lower alkoxy lower alkyl; R 2 and R 3 may be linked to form lower alkylene; A 1 is lower alkylene optionally substituted with one or more hydroxyls; Y 1 and Y 2 are each independently —N═ or —CH═; R 5 is a group represented by wherein R 6 and R 7 are each independently hydrogen, lower alkyl, cyclo lower alkyl, aryl or saturated or unsaturated monocyclic or polycyclic heterocyclic group containing at least one hetero atom selected from the group consisting of oxygen, sulfur and nitrogen, each of which is optionally substituted; R 6 and R 7 may be linked to form a ring together with the neighboring group —X A —N—X B —; X A and X B are each independently a bond, alkylene, alkenylene, —CO—, —SO 2 —, or —CONH—, wherein each of the alkylene and alkenylene chains can optionally contain one or more substituents selected from the group consisting of —S—, —C(═S)—, —SO 2 —, —CO—, —O—, —NH—, —CONH— and —SO 2 NH—, and the hydrogen atom (H) bonded to the nitrogen atom (N) in X A and X B is optionally substituted with a substituent selected from the group consisting of lower alkyl, phenyl lower alkyl and phenyl.