Patent ID: 7977336

Claim:
A compound of Formula [I]: or a pharmaceutically acceptable salt or ester thereof wherein: R 1 is a substituent selected from <Substituent Group α>; a lower alkyl group which may be substituted with one or more substituents selected from <Substituent Group α>; or a cyclopropyl group, where the <Substituent Group α> is a halogen atom; and R 2 is a hydrogen atom; one of R 3 and R 4 is a hydrogen atom, while the other one of R 3 and R 4 is: a) a lower alkyl group substituted with NR a R b , where R a and R b , which may be the same or different, are each a hydrogen atom, a lower alkyl group, a benzyl group, or a cycloalkyl group having three to six carbon atoms, wherein the cycloalkyl group may be substituted with one or more substituents, which may be the same or different, selected from the following 1) to 3): 1) a lower alkyl group; 2) a substituent selected from <Substituent Group β>; and 3) a lower alkyl group substituted with one or more substituents selected from <Substituent Group β>; and the cycloalkyl group may include an unsaturated bond; b) a 4 -to 6-membered aliphatic heterocyclic group selected from an azetidinyl group, a pyrrolidinyl group, a piperidinyl group, and a piperazinyl group; or c) a lower alkyl group substituted with a 4- to 6-membered aliphatic heterocyclic group selected from an azetidinyl group, a pyrrolidinyl group, a piperidinyl group, and a piperazinyl group, wherein the aliphatic heterocyclic group may be substituted with one or more substituents, which may be the same or different, selected from the following 1) to 4): 1) a lower alkyl group; 2) a substituent selected from the <Substituent Group β>; 3) a lower alkyl group substituted with one or more substituents selected from the <Substituent Group β>; and 4) a cycloalkyl group having 3 to 6 carbon atoms, which may be substituted with one or more substituents selected from the <Substituent Group β>; R 5 is a hydrogen atom, a cyano group, a halogen atom, or a methyl group; and <Substituent Group α> and <Substituent Group β> are defined as below: <Substituent Group α>: a halogen atom, a hydroxy group, a nitro group, a cyano group, an amino group, a carbamoyl group, an aminosulfonyl group, an imino group, a lower alkylamino group, a di-lower alkylamino group, a lower alkylsulfonyl group, a lower alkylsulfonylamino group, a lower alkoxy group, a lower alkoxycarbonyl group, a lower alkoxycarbonylamino group, a lower alkanoyl group, a lower alkanoyloxy group, a lower alkylthio group, and a carboxyl group; and <Substituent Group β>: a halogen atom, a hydroxy group, a nitro group, a cyano group, an amino group, a carbamoyl group, an aminosulfonyl group, an imino group, a lower alkylsulfonyl group, a lower alkylsulfonylamino group, a lower alkoxy group, a lower alkoxycarbonyl group, a lower alkoxycarbonylamino group, a lower alkanoyl group, a lower alkanoyloxy group, a lower alkylthio group, a carboxyl group, and a benzyl group.