Patent ID: 8178552

Claim:
A compound of formula (I); or a pharmaceutically acceptable salt thereof, wherein R 1 represents a 5-7 membered non-aromatic hydrocarbon cyclic group substituted with 1-4 substituent(s) selected from the group consisting of a halogen atom, a cyano group, a hydroxyl group, an oxo group, an ethylenedioxy group, a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 1-6 hydroxyalkyl group, —C(O)OH, —CONH 2 , a NHR 5 group, a NR 5 R 6 group and —R a —R b ; wherein R a represents a single bond or —CH 2 —; wherein R b represents a 4-8 membered non-aromatic heterocyclic group, a C 6-10 aryl group or a 5-7 membered heteroaryl group, substituted with 1-4 substituent(s) selected from the group consisting of a halogen atom and a C 1-6 alkyl group; wherein R 5 and R 6 are independently selected from a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 1-6 hydroxyalkyl group or a 6-membered non-aromatic heterocyclic group wherein two or more positions on R 1 are optionally bridged by a group —X— wherein X is O, CH 2 , CH 2 —CH 2 , NR 7 , CH 2 —CH 2 —CH 2 , CH 2 —CH(CH 2 —)—CH 2 or N(R 7 )—CH(CH 2 —)CH 2 to form a bicyclic or tricyclic ring system, wherein R 7 is selected from hydrogen or a C 1-6 alkyl group and wherein said bridge may be optionally and substituted with one or more of a C 1-6 alkyl group, a cyano group, CO 2 NH 2 , a C 1-6 hydroxyalkyl group, an oxo group, a hydroxy group, a C 1-6 alkylamino group or a 6-membered non-aromatic heterocyclic group wherein R 2 represents a hydrogen atom, a C 1-6 alkyl group optionally substituted with a 4-7 membered non-aromatic heterocyclic group or a C 1-6 haloalkyl group R 3 represents a hydrogen atom or a C 1-6 alkyl group and R 4 represents a hydrogen atom or a C 1-6 alkyl group.