| abstract |
A compound represented by formula (I): ** (See formula) ** wherein R1 is (1) a C1-6 alkyl group optionally substituted with 1 to 5 substituents selected from (a) a halogen atom, (b ) a C3-8 cycloalkyl group optionally substituted with 1 to 3 C1-6 alkyl groups, (c) a C1-6 alkoxycarbonyl group, and (d) a carbamoyl group, (2) an optionally C3-10 cycloalkyl group substituted with 1 to 3 C1-6 alkyl groups, or (3) a C6-14 aryl group optionally substituted with 1 to 3 substituents selected from (a) a halogen atom, (b) a C1-6 alkyl group optionally substituted with 1 to 3 halogen atoms, and (c) a cyano group; R2 is a hydrogen atom or a cyano group; R3 is a C1-3 alkyl group optionally substituted with 1 to 3 substituents selected from a halogen atom and a C1-6 alkoxy group; R4 is (1) a C1-6 alkyl group optionally substituted with 1 to 3 substituents selected from (a) a halogen atom, (b) a cyano group, (c) a hydroxy group, (d) an optionally mono amino group or disubstituted with C1-6 alkyl-carbonyl group (s), and (e) a carbamoyl group optionally mono or disubstituted with C1-6 alkyl group (s), and (2) a C3-10 cycloalkyl group, (3) a C6-14 aryl group optionally substituted with 1 to 3 substituents selected from a carbamoyl group optionally mono or disubstituted with C1-6 alkyl group (s), (4) a 5 or 6 membered non-aromatic heterocyclic group having an atom of oxygen, or ... |